WorldWideScience

Sample records for mev pri obluchenii

  1. USVAJANJE JEZIKA PRI OTROCIH

    OpenAIRE

    Kurmanšek, Urška

    2010-01-01

    Namen diplomske naloge je predstaviti usvajanje jezika pri otrocih, osnovne pogoje in stopnje le-tega in razložiti Chomskyijev pogled na jezikovno prirojenost in njegovo prepričanje, da učenje jezika ni nekaj, kar bi se otrok naučil, ampak da se mu enostavno zgodi na poti v razvoju v za to primernem socialnem okolju. Temu sledi razlaga Chomskyijeve in Skinnerjeve teorije o usvajanju jezika z namenom, da se poudarijo njuna različna pogleda na ta proces. Diplomska naloga je tako osredotočena na...

  2. Remotely sensing the photochemical reflectance index, PRI

    Science.gov (United States)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2015-09-01

    In remote sensing, the Photochemical Reflectance Index (PRI) provides insight into physiological processes occurring inside leaves in a plant stand. Developed by1,2, PRI evolved from laboratory reflectance measurements of individual leaves. Yet in a remotely sensed image, a pixel measurement may include light from both reflecting and transmitting leaves. We compared values of PRI based upon polarized reflectance and transmittance measurements of water and nutrient stressed leaves. Our results show the polarized leaf surface reflection should be removed when calculating PRI and that the leaf physiology information is in leaf interior reflectance, not leaf transmittance.

  3. Procesi pri transportu kohezivnih sedimentov

    OpenAIRE

    Pečovnik, Urška

    2015-01-01

    Pri procesih transporta, kot sta usedanje in privzdigovanje, obstajajo med kohezivnimi in nekohezivnimi sedimenti bistvene razlike. Obstoječi model PCFLOW3D ima v sedimentacijskem modulu vgrajene enačbe za nekohezivne sedimente, zato smo predpostavili, da na območjih kjer so sedimenti kohezivni, ne daje pravilnih rezultatov. Poiskali smo enačbe za račun usedanja, privzdigovanja in transporta kohezivnih sedimentov in jih primerjali z že vgrajenimi enačbami v modelu. Poiskali smo parametre, ki ...

  4. STRES IN IZGOREVANJE PRI DELU

    OpenAIRE

    Prašnikar, Maja

    2016-01-01

    Danes stres in izgorevanje predstavljata eno največjih težav, s katerimi se soočajo ljudje. Med mnogimi možnimi viri stresa so začetek šolanja, nova zaposlitev, nezaupanje vase, odnosi med sodelavci in nadrejenimi, pomembna odločanja in reševanje nujnih nalog pri delu, premeščanja itd. Ne moremo se ukvarjati z nečim, česar ne razumemo, zato je poznavanje mehanizmov stresa in izgorevanja, njihovih vzrokov in posledic ključnega pomena. Le na ta način lahko bolje razumemo in obvladujemo stre...

  5. Linking Knowledge and Action: PRI's Community Consultant.

    Science.gov (United States)

    Spencer, Gregory P.

    Within the Partnership for Rural Improvement (PRI), community consultants operate within three complex sets of relationships: client groups, the organizational structure of PRI, and the local operational base. Community consultants are responsible for developing and facilitating rural development and for providing assistance in community and…

  6. Linking Knowledge and Action: PRI's Community Consultant.

    Science.gov (United States)

    Spencer, Gregory P.

    Within the Partnership for Rural Improvement (PRI), community consultants operate within three complex sets of relationships: client groups, the organizational structure of PRI, and the local operational base. Community consultants are responsible for developing and facilitating rural development and for providing assistance in community and…

  7. DnaT is a PriC-binding protein.

    Science.gov (United States)

    Huang, Chien-Chih; Huang, Cheng-Yang

    2016-09-01

    DnaT and PriC are replication restart primosomal proteins required for re-initiating chromosomal DNA replication. DnaT is a component of the PriA-dependent primosome, while PriC belongs to the PriC-dependent primosome. Whether DnaT can interact with PriC is still unknown. In this study, we define a direct interaction between PriC, a key initiator protein in PriC-mediated DNA replication restart, and DnaT, a DnaB/C complex loader protein, from Klebsiella pneumoniae. In fluorescence titrations, PriC bound to single-stranded DNA with a binding-site size of approximately 9 nt. Gold nanoparticle assay showed that the solution of DnaT-PriC changed from red to purple, which indicated the protein-protein interactions due to gold nanoparticle aggregate. In addition, this DnaT-PriC complex could be co-purified by the heparin HP column. Surface plasmon resonance analysis showed that the Kd value of DnaT bound to PriC was 2.9 × 10(-8) M. These results constitute a pioneering study of the DnaT-PriC interaction and present a putative link between the two independent replication restart pathways, namely, PriA- and PriC-dependent primosome assemblies. Further research can directly focus on determining how DnaT binds to the PriC-SSB-DNA tricomplex and regulates the PriC-dependent replication restart.

  8. Presence of pRI1:

    DEFF Research Database (Denmark)

    Migura, Lourdes Garcia; Hasman, Henrik; Jensen, Lars Bogø

    2009-01-01

    This study focused on the molecular characterization of a small cryptic, mobilizable plasmid (6038 bp) sequenced from an E. faecium 9631160-1 of poultry origin. Sequence analysis of pRI1 revealed seven open reading frames. pRI1 contained an IS 100% identical to ISEfa4. This insertion element...... disrupted a putative mobilization gene (mobA) which presented 99% similarity to the one described in plasmid pJS42 (NC_010291). pRI1 harbored a cluster of four coding sequences which exhibited a homology to those described in contig 658 (from nucleotide 8940 to nt 10515) of E. faecium DO. In addition, a rep...... almost identical to the repA from the pEFNP1 and pKQ10 plasmids from E. faecium was also identified. Presence of the pRI1 replication initiation gene (rep) was analyzed in a panel of 159 E. faecium isolates of human and animal origin from different European countries, of which 60 tested positive...

  9. Remotely Sensing the Photochemical Reflectance Index (PRI)

    Science.gov (United States)

    Vanderbilt, Vern

    2015-01-01

    In remote sensing, the Photochemical Reflectance Index (PRI) provides insight into physiological processes occurring inside the leaves in a stand of plants. Developed by Gamon et al., (1990 and 1992), PRI evolved from laboratory measurements of the reflectance of individual leaves (Bilger et al.,1989). Yet in a remotely sensed image, a pixel measurement may include light from both reflecting and transmitting leaves. We conducted laboratory experiments comparing values of PRI based upon polarized reflectance and transmittance measurements of water and nutrient stressed leaves. We illuminated single detached leaves using a current controlled light source (Oriel model 66881) and measured the leaf weight using an analytical balance (Mettler model AE 260) and the light reflected and transmitted by the leaf during dry down using two Analytical Spectral Devices spectroradiometers. Polarizers on the incident and reflected light beams allowed us to divide the leaf reflectance into two parts: a polarized surface reflectance and a non-polarized 'leaf interior' reflectance. Our results underscore the importance when calculating PRI of removing the leaf surface reflection, which contains no information about physiological processes ongoing in the leaf interior. The results show that the leaf physiology information is in the leaf interior reflectance, not the leaf transmittance. Applied to a plant stand, these results suggest use of polarization measurements in sun-view directions that minimize the number of sunlit transmitting leaves in the sensor field of view.

  10. Improved method for pulse sorting based on PRI transform

    Science.gov (United States)

    Ren, Chunhui; Cao, Junqing; Fu, Yusheng; Barner, Kenneth E.

    2014-06-01

    To solve the problem of pulse sorting in complex electromagnetic environment, we propose an improved method for pulse sorting through in-depth analysis of the PRI transform algorithm principle and the advantages and disadvantages in this paper. The method is based on the traditional PRI transform algorithm, using spectral analysis of PRI transform spectrum to estimate the PRI centre value of jitter signal. Simulation results indicate that, the improved sorting method overcome the shortcomings of the traditional PRI jitter separation algorithm which cannot effectively sort jitter pulse sequence, in addition to the advantages of simple and accurate.

  11. Differential interference of vitamin D analogs PRI-1906, PRI-2191, and PRI-2205 with the renewal of human colon cancer cells refractory to treatment with 5-fluorouracil.

    Science.gov (United States)

    Kotlarz, Agnieszka; Przybyszewska, Małgorzata; Swoboda, Paweł; Miłoszewska, Joanna; Grygorowicz, Monika Anna; Kutner, Andrzej; Markowicz, Sergiusz

    2016-04-01

    This study was aimed to determine whether hypocalcemic analogs of active forms of vitamins D modulate expression of genes related to stem-like phenotype in colon cancer cell lines HT-29 and HCT-116 undergoing renewal after the treatment with 5-fluorouracil (5-FU). Both lines express vitamin D receptor, but differ in differentiation stage and vitamin D sensitivity. Cells that resisted the 5-FU exposure were treated with synthetic analog of 1,25-dihydroxyvitamin D2 (PRI-1906) and analogs of 1,25-dihydroxyvitamin D3 (PRI-2191 and PRI-2205). Proliferative activity was more profoundly affected by vitamin D analogs in HT-29/5-FU than in HCT-116/5-FU cells. In HT-29/5-FU cells, analogs PRI-1906 and PRI-2191 downregulated the expression of genes related to survival, re-growth, and invasiveness during renewal, while PRI-2205 increased expression of genes related to differentiation only. In HCT-116/5-FU cells, PRI-2191 decreased the expression of stemness- and angiogenesis-related genes, whereas PRI-1906 augmented their expression. The effects in HCT-116/5-FU cells were observed at higher concentrations of the analogs than those used for HT-29/5-FU cells. Out of the series of analogs studied, PRI-2191 might be used to counteract the renewal of both moderately and poorly differentiated cancer cells following conventional treatment.

  12. In situ measurement of Scots pine needle PRI.

    Science.gov (United States)

    Mõttus, Matti; Hernández-Clemente, Rocío; Perheentupa, Viljami; Markiet, Vincent

    2017-01-01

    The Photochemical Reflectance Index (PRI) calculated from narrow-band spectral reflectance data is a vegetation index which is increasingly used as an indicator of photosynthetic activity. The leaf-level link between the status of photosynthetic apparatus and PRI has been robustly established under controlled light conditions. However, when a whole canopy is measured instantaneously, the PRI signal is heavily modified by vegetation structure and local variations in incident light conditions. To apply PRI for monitoring the photosynthesis of whole canopies under natural conditions, these large-scale measurements need to be validated against simultaneous leaf PRI. Unfortunately, PRI changes dynamically with incident light and has a large natural variation. No generally accepted procedure exists today for determining the PRI of canopy elements in situ. We present a successful procedure for in situ measurements of needle PRI. We describe, characterize and test an optical measurement protocol and demonstrate its applicability in field conditions. The measurement apparatus consisted of a light source, needle clip, spectroradiometer and a controlling computer. The light level inside the clip was approximately two-thirds of that on sunlit needle surfaces at midday. During each measurement the needle was inserted into the clip for approximately 5 s. We found no near-instantaneous changes (sub-second scale jumps) in PRI during the measurements. The time constants for PRI variation in light to full shade acclimations were approximately 10 s. The procedure was successfully applied to monitor the greening-up of Scots pine trees. We detected both facultative (diurnal) PRI changes of 0.02 (unitless) and constitutive (seasonal) variations of 0.1. In order to reliably detect the facultative PRI change of 0.02, 20 needles need to be sampled from both sunlit and shaded locations. We established a robust procedure for irradiance-dependent leaf (needle) PRI measurements, facilitating

  13. [Sensitivity study of a revised leaf photochemical reflectance index (PRI)].

    Science.gov (United States)

    Wu, Chao-yang; Niu, Zheng; Tang, Quan

    2008-09-01

    Photochemical reflectance index (PRI) defined as a normalized difference index using two narrow reflectance bands at 531 and 570 nm that are closely related to xanthophyll cycle pigment content has been successfully used to estimate leaf photosynthetic light use efficiency (LUE) across species which vary in water content and nitrogen concentration. Previous research demonstrated that a consistent relationship could be established between PRI and LUE calculated from gas exchange measurements at the leaf, small canopy, and full forest or crop canopy scales. However, a number of problems, such as the saturation of PRI when LUE exceeds 0.03 mol CO2 mol(-1) PPED (photosynthetic photon flux density) and disjunctive relationships of PRI and LUE in seasonal changes, still existed and need to be handled in order to evaluate LUE more accurately. A sensitivity study of a revised PRI with four leaf parameters was performed based on PROSPECT model in the present article to study the effects of different biochemical concentrations on leaf SR-PRI (simple ratio PRI). Sensitivity study proved that leaf SR-PRI is more sensitive to leaf mesophyll structure parameter (N) and chlorophyll a + b content (c(ab)) than parameters of dry matter content (c(m)) and equivalent water thickness (c(w)), indicating that leaf mesophyll structure parameter (N) and chlorophyll a + b content (c(ab)) should be especially considered when acquiring leaf SR-PRI. And changes in the two parameters would cause large variation in SR-PRI which would reduce the precision for estimating light use efficiency. Validation study of SR-PRI was carried out in the analysis and the results proved that SR-PRI can also be a feasible index of estimating LUE for four species of plants with correlation coefficients better than that of PRI and LUE. The advantage of SR-PRI compared to PRI is its much clearer physical meaning and its sensitivity to the changes in reflectance at 531 nm which serves as a core parameter to evaluate

  14. A double-blind, clinical evaluation of facial augmentation treatments: a comparison of PRI 1, PRI 2, Zyplast and Perlane.

    Science.gov (United States)

    Downie, Jeff; Mao, Zhili; Rachel Lo, Tsz-Wai; Barry, Sarah; Bock, Mitchum; Siebert, J Paul; Bowman, Adrian; Ayoub, Ashraf

    2009-12-01

    Facial wrinkles are caused by weakening of the sub-dermal collagen support layer. Dermal fillers can be used to treat wrinkles, and this double-blind, randomised, single-centre study compared four fillers: PRI 1, PRI 2 (both porcine collagen), Zyplast (purified bovine collagen) and Perlane (cross-linked hyaluronic acid gel). 79 females (aged 25-55 years) with wrinkles in the upper lip line border were randomised to PRI 1 (19 patients), PRI 2 (19 patients), Perlane (23 patients), Zyplast (18 patients). Patients were assessed at 1 week and 1, 3, 6, 9 and 12 months using 2D images and by mathematically derived facial volume changes using 3D stereophotogrammetry. All treatments produced larger, less wrinkled, more prominent lips. PRI 1, PRI 2 and Zyplast showed similar lip volume gains, with Perlane showing the greatest upper lip volume increase. All treatments were comparable for rates of decrease in upper lip volume post-treatment, however, Perlane maintained higher lip volume gains at each time point. Investigators indicated PRI 1 was significantly easier to deliver than Zyplast. Patient satisfaction scores were similar, though there was a trend towards greater dissatisfaction for PRI 1 and PRI 2 at month 9 (p=0.052). Treatment was well-tolerated, with 'cold sore' being the most common adverse event. Results showed that PRI 1 and PRI 2 were comparable to Perlane and Zyplast as dermal fillers. Further rigorous studies are required to establish the performance of dermal fillers and patient acceptability. We propose the utilisation of stereophotogrammetry for assessment of volume changes.

  15. Synthesis and Biological Activity of Diastereomeric and Geometric Analogs of Calcipotriol, PRI-2202 and PRI-2205, Against Human HL-60 Leukemia and MCF-7 Breast Cancer Cells.

    Science.gov (United States)

    Milczarek, Magdalena; Chodyński, Michał; Filip-Psurska, Beata; Martowicz, Agnieszka; Krupa, Małgorzata; Krajewski, Krzysztof; Kutner, Andrzej; Wietrzyk, Joanna

    2013-10-31

    Diastereomeric and geometric analogs of calcipotriol, PRI-2202 and PRI-2205, were synthesized as advanced intermediates from vitamin D C-22 benzothiazoyl sulfones and side-chain aldehydes using our convergent strategy. Calcitriol, calcipotriol (PRI-2201) and tacalcitol (PRI-2191) were used as the reference compounds. Among a series of tested analogs the diastereomeric analog PRI-2202 showed the strongest antiproliferative activity on the human breast cancer cell line MCF-7, whereas the geometric analog PRI-2205 was the weakest. Both analogs were less potent in antiproliferative activity against HL-60 cells compared to the reference compounds. The ability to potentiate antiproliferative effect of cisplatin or doxorubicin against HL-60 cells or that of tamoxifen against the MCF-7 cell line was observed at higher doses of PRI-2202 or PRI-2205 than those of the reference compounds. The proapoptotic activity of tamoxifen, expressed as the diminished mitochondrial membrane potential, as well as the increased phosphatidylserine expression, was partially attenuated by calcitriol, PRI-2191, PRI-2201 and PRI-2205. The treatment of the MCF-7 cells with tamoxifen alone resulted in an increase in VDR expression. Moreover, a further increase in VDR expression was observed when the analogs PRI-2201 or PRI-2205, but not PRI-2191, were used in combination with tamoxifen. This observation could partially explain the potentiation of the antiproliferative effect of tamoxifen by vitamin D analogs.

  16. VPLIV IZVORA NADZOROVANJA NA NEKATERE DEJAVNIKE PRI DELU REVIZORJEV

    OpenAIRE

    Voje, Melita

    2012-01-01

    Izvor nadzorovanja (angl. Locus of Control) je psihološki pojem, ki ločuje posameznike na tiste s poudarjenim notranjim izvorom nadzorovanja – internaliste, in tiste s poudarjenim zunanjim izvorom nadzorovanja – eksternaliste. Razlika med njimi je v prepričanju, da kar se jim v življenju dogaja, je pri enih posledica njihovega lastnega napora, vloženega znanja, truda, pri drugih pa posledica sreče, usode. V drugem delu naloge smo opredelili pojem izvora nadzorovanja ter način ugotavljanja...

  17. PRI: An Periodically Receiver-Initiated Task Scheduling Algorithm

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Task scheduling is a key problem for the distributed computation. This thesis analyzes receiver-initiated(RI) task scheduling algorithm, finds its weakness and presents an improved algorithm-PRI algorithm. This algorithm schedules the concurrent tasks onto network of workstation dynamically at runtime, and initiates task scheduling by the node of low load. The threshold on each node can be modified according to the system information which is periodically detected. Meanwhile, the detecting period can be adjusted in terms of the change of the system state. The result of the experiments shows that the PRI algorithm is superior to the RI algorithm.

  18. Carlos A. Madrazo y la reforma imposible del PRI

    OpenAIRE

    Pedro Castro

    2007-01-01

    Este trabajo estudia el paso de Carlos A. Madrazo por la presidencia del Partido Revolucionario Institucional (pri) del 17 de diciembre de 1964 al 17 de noviembre de 1965, durante la administración de Gustavo Díaz Ordaz. Se apuntan antecedentes de su carrera política, las claves de su actividad en favor de la reforma partidaria, así como las razones plausibles de su salida. Su fracaso en cambiar las estructuras del pri evidenció las inercias provenientes de los sectores del aparato, los gober...

  19. Geology of Planina pri Jezeru and its environs (Slovenia

    Directory of Open Access Journals (Sweden)

    Mihael Brenčič

    2008-06-01

    Full Text Available The article describes the results of detailed geological mapping of the wider environs of Planina pri Jezeru north of Bohinj. In the literature the Upper Triassic massive and bedded limestone, Jurassic limestone, Cretaceous clastic rocks and Pleistocene sediments have been reported in this area up to now. The article supplements existing lithostratigraphic information by defining exact locations of the Pleistocene sediments at Planina pri Jezeru and Planina v Lazu, and of Jurassic rocks. In Poljane a Neptunian dyke and bioclastic limestone, while north of Mizčna glava a flat-bedded microsparitic limestone were described for the first time.Correlation to the Triglav Lakes Valley Jurassic beds indicates equivalent facieses. Allochthon Cretaceous biocalcarenite and jasper situated east of Planina pri Jezeru are also described due to their importance for further glaciological studies. The results show that the recent lake Jezero na Planini pri Jezeru is formed due to the accumulation of Pleistocene glacial-lacustrine fine-grained sediment in till,deposited on the Dachstein limestone.

  20. PRiME: integrating professional responsibility into the engineering curriculum.

    Science.gov (United States)

    Moore, Christy; Hart, Hillary; Randall, D'Arcy; Nichols, Steven P

    2006-04-01

    Engineering educators have long discussed the need to teach professional responsibility and the social context of engineering without adding to overcrowded curricula. One difficulty we face is the lack of appropriate teaching materials that can fit into existing courses. The PRiME (Professional Responsibility Modules for Engineering) Project (http://www.engr.utexas.edu/ethics/primeModules.cfm) described in this paper was initiated at the University of Texas, Austin to provide web-based modules that could be integrated into any undergraduate engineering class. Using HPL (How People Learn) theory, PRiME developed and piloted four modules during the academic year 2004-2005. This article introduces the modules and the pilot, outlines the assessment process, analyzes the results, and describes how the modules are being revised in light of the initial assessment. In its first year of development and testing, PRiME made significant progress towards meeting its objectives. The PRiME Project can strengthen engineering education by providing faculty with an effective system for engaging students in learning about professional responsibility.

  1. Toxicity and antitumor activity of the vitamin D analogs PRI-1906 and PRI-1907 in combined treatment with cyclophosphamide in a mouse mammary cancer model.

    Science.gov (United States)

    Wietrzyk, Joanna; Nevozhay, Dmitry; Milczarek, Magdalena; Filip, Beata; Kutner, Andrzej

    2008-10-01

    Active and less toxic vitamin D analogs could be useful for clinical applications. In the present study, we evaluated the toxicity and antitumor effect of two new synthetic analogs of vitamin D, namely PRI-1906 [(24E)-24a-Homo-(1S)-1,25-dihydroxyergocalciferol] and its side-chain unsaturated homo analog PRI-1907. The toxicity and calcemic activity, as well as antitumor effect of calcitriol analogs was investigated in vivo. The studies were performed in a mouse mammary 16/C cancer model. Since calcitriol and its analogs inhibited 16/C tumor growth only slightly, we applied them in the combined therapy with cyclophosphamide (CY). Moreover, cell cycle analysis and VDR and p27 expression were investigated. The LD50 values after five daily subcutaneous (s.c.) injections were 7.8, 10.0 and 2.4 microg/kg per day for calcitriol, PRI-1906 and PRI-1907, respectively. The serum calcium level increased to 40, 23 and 63% over the control for these compounds. We also compare the antitumor activity of the PRI-1906 with the calcitriol and previously studied PRI-2191 (1,24-dihydroxyvitamin D3, tacalcitol). Statistically significant inhibition of tumor growth by calcitriol up to the eighth day was observed in all schedules applied. PRI-1906 inhibited the tumor growth at doses 1 and 5 microg/kg per day, and PRI-2191 only at the dose 5 microg/kg per day. Addition of vitamin D analogs increased the antitumor effect of CY. PRI-1906 exhibited toxicity higher than PRI-2191 but lower than calcitriol and antitumor activity similar to both PRI-2191 and calcitriol. This new analog seems to be a good candidate for the combined treatment of mammary cancer.

  2. Canopy Level Chlorophyll Fluorescence and the PRI in a Cornfield

    Science.gov (United States)

    Middleton, Elizabeth M.; Cheng, Yen-Ben; Corp, Lawrence A.; Campbell, Petya K. E.; Huemmrich, K. Fred; Zhang, Qingyuan; Kustas, William P.

    2012-01-01

    Two bio-indicators, the Photochemical Reflectance Index (PRI) and solar-induced red and far-red Chlorophyll Fluorescence (SIF), were derived from directional hyperspectral observations and studied in a cornfield on two contrasting days in the growing season. Both red and far-red SIF exhibited higher values on the day when the canopy in the early senescent stage, but only the far-red SIF showed sensitivity to viewing geometry. Consequently, the red/far-red SIF ratio varied greatly among azimuth positions while the largest values were obtained for the "hotspot" at both growth stages. This ratio was lower (approx.0.88 +/- 0.4) in early July than in August when the ratio approached equivalence (near approx.1). In concert, the PRI exhibited stronger responses to both zenith and azimuth angles and different values on the two growth stages. The potential of using these indices to monitor photosynthetic activities needs further investigation

  3. The Primitive Material Explorer (PriME) Mission

    Science.gov (United States)

    Cochran, Anita L.; Weaver, H. A.; Science, PriME; Engineering Teams

    2010-10-01

    The Primitive Material Explorer (PriME) Mission is a proposed Discovery mission that will rendezvous with comet 46P/Wirtanen in 2021 in order to 1) clarify the roles played by comets in the formation and evolution of the Solar System and the origin of life; 2) ascertain the bulk physical properties, the surface geology, and the sources of activity in a fresh comet nucleus; and 3) investigate the compositional diversity of primitive material in the Solar System. PriME teams an experienced group of comet scientists (led by PI Anita Cochran and by DPI Harold Weaver) with university and industrial partners. The PriME payload accomplishes the mission objectives with only three instruments. MASPEX (MAss Spectrometer for Planetary EXploration) has higher mass resolution and is more sensitive than any mass spectrometer ever flown. MASPEX will measure D/H in H2O, noble gases, isotopes of many species, and complex molecular compounds to test solar nebula models and the role comets played in delivering water and other biologically important materials throughout the Solar System. The VIS (Visible Imaging System), consisting of a Narrow Angle Camera (NAC) and Wide-Angle Camera (WAC), will constrain the conditions under which the building blocks of the outer Solar System were assembled by measuring key physical properties of the nucleus of 46P/Wirtanen. Using the radio antenna and close flybys of the nucleus, PriME will determine the mass of the nucleus to an accuracy of 1% and the bulk density and average porosity of the nucleus to better than 5%. All spacecraft subsystems have significant planetary flight heritage. The spacecraft is a high-heritage derivative of the Kepler and Deep Impact spacecrafts, compatible with the three launch vehicle families specified in the Discovery Announcement of Opportunity.

  4. Prodifferentiation Activity of Novel Vitamin D2 Analogs PRI-1916 and PRI-1917 and Their Combinations with a Plant Polyphenol in Acute Myeloid Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Matan Nachliely

    2016-07-01

    Full Text Available 1α,25-dihydroxyvitamin D3 (1,25D3 is a powerful differentiation inducer for acute myeloid leukemia (AML cells. However, 1,25D3 doses required for differentiation of AML cells may cause lethal hypercalcemia in vivo. There is evidence that vitamin D2 is less toxic than vitamin D3 in animals. Here, we determined the differentiation effects of novel analogs of 1α,25-dihydroxyvitamin D2 (1,25D2, PRI-1916 and PRI-1917, in which the extended side chains of their previously reported precursors (PRI-1906 and PRI-1907, respectively underwent further 24Z (24-cis modification. Using four human AML cell lines representing different stages of myeloid maturation (KG-1a, HL60, U937, and MOLM-13, we found that the potency of PRI-1916 was slightly higher or equal to that of PRI-1906 while PRI-1917 was significantly less potent than PRI-1907. We also demonstrated that 1,25D2 was a less effective differentiation agent than 1,25D3 in these cell lines. Irrespective of their differentiation potency, all the vitamin D2 derivatives tested were less potent than 1,25D3 in transactivating the DR3-type vitamin D response elements. However, similar to 1,25D3, both 1,25D2 and its analogs could strongly cooperate with the plant polyphenol carnosic acid in inducing cell differentiation and inhibition of G1–S cell cycle transition. These results indicate that the 24Z modification has contrasting effects on the differentiation ability of PRI-1906 and PRI-1907 and that the addition of a plant polyphenol could result in a similar extent of cell differentiation induced by different vitamin D compounds. The enhanced antileukemic effects of the tested combinations may constitute the basis for the development of novel approaches for differentiation therapy of AML.

  5. Prodifferentiation Activity of Novel Vitamin D₂ Analogs PRI-1916 and PRI-1917 and Their Combinations with a Plant Polyphenol in Acute Myeloid Leukemia Cells.

    Science.gov (United States)

    Nachliely, Matan; Sharony, Ehud; Bolla, Narasimha Rao; Kutner, Andrzej; Danilenko, Michael

    2016-07-05

    1α,25-dihydroxyvitamin D₃ (1,25D3) is a powerful differentiation inducer for acute myeloid leukemia (AML) cells. However, 1,25D3 doses required for differentiation of AML cells may cause lethal hypercalcemia in vivo. There is evidence that vitamin D₂ is less toxic than vitamin D₃ in animals. Here, we determined the differentiation effects of novel analogs of 1α,25-dihydroxyvitamin D₂ (1,25D2), PRI-1916 and PRI-1917, in which the extended side chains of their previously reported precursors (PRI-1906 and PRI-1907, respectively) underwent further 24Z (24-cis) modification. Using four human AML cell lines representing different stages of myeloid maturation (KG-1a, HL60, U937, and MOLM-13), we found that the potency of PRI-1916 was slightly higher or equal to that of PRI-1906 while PRI-1917 was significantly less potent than PRI-1907. We also demonstrated that 1,25D2 was a less effective differentiation agent than 1,25D3 in these cell lines. Irrespective of their differentiation potency, all the vitamin D₂ derivatives tested were less potent than 1,25D3 in transactivating the DR3-type vitamin D response elements. However, similar to 1,25D3, both 1,25D2 and its analogs could strongly cooperate with the plant polyphenol carnosic acid in inducing cell differentiation and inhibition of G1-S cell cycle transition. These results indicate that the 24Z modification has contrasting effects on the differentiation ability of PRI-1906 and PRI-1907 and that the addition of a plant polyphenol could result in a similar extent of cell differentiation induced by different vitamin D compounds. The enhanced antileukemic effects of the tested combinations may constitute the basis for the development of novel approaches for differentiation therapy of AML.

  6. Relationships between the photochemical reflectance index (PRI) and chlorophyll fluorescence parameters and plant pigment indices at different leaf growth stages.

    Science.gov (United States)

    Rahimzadeh-Bajgiran, Parinaz; Munehiro, Masashi; Omasa, Kenji

    2012-09-01

    This study aimed to evaluate the photochemical reflectance index (PRI) for assessing plant photosynthetic performance throughout the plant life cycle. The relationships between PRI, chlorophyll fluorescence parameters, and leaf pigment indices in Solanum melongena L. (aubergine; eggplant) were studied using photosynthetic induction curves both in short-term (diurnal) and long-term (seasonal) periods under different light intensities. We found good correlations between PRI/non-photochemical quenching (NPQ) and PRI/electron transport rate (ETR) in the short term at the same site of a single leaf but these relationships did not hold throughout the life of the plant. In general, changes in PRI owing to NPQ or ETR variations in the short term were PRI was highly correlated to plant pigments, especially chlorophyll indices measured by spectral reflectance. Moreover, relationships of steady-state PRI/ETR and steady-state PRI/photochemical yield of photosystem II (Φ(PSII)) measured at uniform light intensity at different life stages proved that overall photosynthesis capacity and steady-state PRI were better correlated through chlorophyll content than NPQ and xanthophylls. The calibrated PRI index accommodated these pigments effects and gave better correlation with NPQ and ETR than PRI. Further studies of PRI indices based on pigments other than xanthophylls, and studies on PRI mechanisms in different species are recommended.

  7. Analiza toplotnih izgub pri različnih okenskih sistemih

    OpenAIRE

    Movrin, Miran

    2014-01-01

    Ob vseobsegajočih razvojnih trendih tudi okna niso bila izvzeta, njihov razvoj je med drugim šel tudi v smeri zmanjševanja toplotnih izgub. Raziskovali smo, kolikšne so toplotne izgube pri okenskih sistemih z različno okvirno konstrukcijo, s steklom in z distančno letvijo. Ugotovili smo, da imajo lesena, aluminijasta in PVC-okna z novimi PVC-distančniki manjše toplotne izgube od dosedanjih izdelanih s klasičnimi, aluminijastimi distančniki. Ugotovitev pa je tudi razultat primerjave velikosti ...

  8. Ustvarjalni proces gestualnega akta pri dijakih pod vplivom glasbe

    OpenAIRE

    Jerman, Rebeka

    2017-01-01

    V magistrskem delu smo raziskovali ustvarjalni proces gestualnega akta pri dijakih in vpliv glasbe nanj. Poskusi opredelitve ustvarjalnosti imajo korenine že v starih kulturah, nekateri od poznejših raziskovalcev pa so Helmholtz, Poincar, Wallas, Wertheimer (1945), Guilford (1967, v Pečjak in Štrukelj, 2013), Torrance, Cox idr. (Oblak, 1987). Read (1943, v Oblak, 1987) že na začetku 20. stoletja poudari njeno pomembnost v pedagoški sferi s svojo reformno pedagogiko in pobudo gibanja za učink...

  9. Pomen čustvene inteligentnosti pri vodenju v zdravstveni negi

    OpenAIRE

    Meško, Janja

    2011-01-01

    Diplomsko delo z naslovom pomen čustvene inteligentnosti pri vodenju v zdravstveni negi je teoretično. S pomočjo deskriptivne metode dela in študija različne literature smo predstavili pomen čustvene inteligentnosti, vodenja in predvsem povezavo obeh pojmov v zdravstveni negi. Dandanes je čustvena inteligentnost vedno bolj v ospredju ter vedno bolj središče zanimanja, saj so časi, v katerem so bila čustva označena kot nekaj, kar za posel ni pomembno, minili. Pregledali smo domačo in tujo lite...

  10. VEDENJE SLOVENSKIH POTROŠNIKOV PRI SPLETNEM NAKUPOVANJU

    OpenAIRE

    Kos, Jasmina

    2015-01-01

    Težko bi rekli, da bo spletno nakupovanje izpodrinilo klasično nakupovanje v fizičnih trgovinah in trgovskih centrih, vendar pa kljub temu lahko rečemo, da pričakujemo v naslednjih letih na spletu še več trgovin in povečano rast spletnih potrošnikov. Spletne trgovine imajo namreč mnogo prednosti, saj lahko udobno iz naslonjača kadarkoli in kjerkoli (dokler imamo internetno povezavo) kupimo izdelek, ki ga želimo, brez vsiljevanja prodajalčevega mnenja, čakanja na blagajni, iskanja parkirnega p...

  11. POMEN VAROVANJA INTELEKTUALNE LASTNINE PRI SNOVANJU POLITIKE PODJETJA

    OpenAIRE

    Budja, Matej

    2014-01-01

    V diplomskem seminarju sem ugotavljal medsebojno soodvisnost politike podjetja in pomena varovanja intelektualne lastnine. Osredotočil sem se na inovativno slovensko podjetje Eurel d.o.o., katerega vodi Štefan Kuzma, teoretični in praktični strokovnjak tako pri vodenju podjetja, kot tudi v zvezi z varovanjem IL. Ugotovil sem sledeče: • Eurel proizvaja izdelke skladno z zahtevanimi specifikacijami naročnikov in v dogovorjenih rokih • Zadovoljnost odjemalcev je njihova prioriteta • ...

  12. Three causes of variation in the photochemical reflectance index (PRI) in evergreen conifers.

    Science.gov (United States)

    Wong, Christopher Y S; Gamon, John A

    2015-04-01

    The photochemical reflectance index (PRI) reflects diurnal xanthophyll cycle activity and is also influenced by seasonally changing carotenoid : Chl pigment ratios. Both changing pigment pools and xanthophyll cycle activity contribute to photoprotection in evergreen conifers exposed to boreal winters, but they operate over different timescales, and their relative contribution to the PRI signal has often been unclear. To clarify these responses and their contribution to the PRI signal, leaf PRI, pigment composition, temperature and irradiance were monitored over 2 yr for two evergreen conifers (Pinus contorta and Pinus ponderosa) in a boreal climate. PRI was affected by three distinct processes operating over different timescales and exhibiting contrasting spectral responses. Over the 2 yr study period, the greatest change in PRI resulted from seasonally changing carotenoid : Chl pigment ratios, followed by a previously unreported shifting leaf albedo during periods of deep cold. Remarkably, the smallest change was attributable to the xanthophyll cycle. To properly distinguish these three effects, interpretation of PRI must consider temporal context, physiological responses to evolving environmental conditions, and spectral response. Consideration of the separate mechanisms affecting PRI over different timescales could greatly improve efforts to monitor changing photosynthetic activity using optical remote sensing.

  13. Draft genome sequence of the antagonistic rhizosphere bacterium Serratia plymuthica strain PRI-2C.

    Science.gov (United States)

    Garbeva, P; van Elsas, J D; de Boer, W

    2012-08-01

    Serratia plymuthica strain PRI-2C is a rhizosphere bacterial strain with antagonistic activity against different plant pathogens. Here we present the 5.39-Mb (G+C content, 55.67%) draft genome sequence of S. plymuthica strain PRI-2C with the aim of providing insight into the genomic basis of its antagonistic activity.

  14. PRI Play Important Role in West-East Project · Interview with PIR Director Xue Zhenkui

    Institute of Scientific and Technical Information of China (English)

    Xiao Lu

    2002-01-01

    @@ Pipeline Research Institute of CNPC (PRI) is playing a more and more important role in the oil and natural gas pipeline industrial development in the present-day China. The pipeline technology and equipment developed by PRI have proven costeffective and extremely useful in the country's WestEast gas transmission pipeline project

  15. Partnership for Rural Improvement: PRI in Transition. Annual Report 1979-80.

    Science.gov (United States)

    Hagood, Richard A.; And Others

    Covering 1979-80, which was the final year of the initial four year grant period for the Partnership for Rural Improvement (PRI), this report details the major assessments and program adjustments made during that year. Several program developments of critical importance to understanding the transition occurring in PRI are highlighted in the…

  16. Diffuse sky radiation influences the relationship between canopy PRI and shadow fraction

    Science.gov (United States)

    Mõttus, Matti; Takala, Tuure L. H.; Stenberg, Pauline; Knyazikhin, Yuri; Yang, Bin; Nilson, Tiit

    2015-07-01

    The Photochemical Reflectance Index (PRI) of green leaves is an indicator of photosynthetic downregulation: when the photosynthetic apparatus is close to the saturation limit, PRI becomes dependent on light conditions. Therefore, by measuring the PRI of leaves under different local irradiance conditions, it should be possible to determine the saturation level of the leaves and obtain information on the light use efficiency (LUE) of a vegetation canopy. The dependence of PRI on the ratio of sunlit to shaded foliage (quantified by the canopy shadow fraction) in the field of view of an instrument has been used to remotely measure canopy LUE on clear days. However, besides photosynthetic downregulation, the dependence of canopy PRI on shadow fraction is affected by the blue sky radiation caused by scattering in the atmosphere. To quantify this effect on remotely sensed PRI, we present the underlying definitions relating leaf and canopy PRI and perform the required calculations for typical midsummer conditions in Central Finland. We demonstrate that the effect of blue sky radiation on the variation of PRI with canopy shadow fraction is similar in shape and magnitude to that of LUE variations reported in literature.

  17. PriC-mediated DNA replication restart requires PriC complex formation with the single-stranded DNA-binding protein.

    Science.gov (United States)

    Wessel, Sarah R; Marceau, Aimee H; Massoni, Shawn C; Zhou, Ruobo; Ha, Taekjip; Sandler, Steven J; Keck, James L

    2013-06-14

    Frequent collisions between cellular DNA replication complexes (replisomes) and obstacles such as damaged DNA or frozen protein complexes make DNA replication fork progression surprisingly sporadic. These collisions can lead to the ejection of replisomes prior to completion of replication, which, if left unrepaired, results in bacterial cell death. As such, bacteria have evolved DNA replication restart mechanisms that function to reload replisomes onto abandoned DNA replication forks. Here, we define a direct interaction between PriC, a key Escherichia coli DNA replication restart protein, and the single-stranded DNA-binding protein (SSB), a protein that is ubiquitously associated with DNA replication forks. PriC/SSB complex formation requires evolutionarily conserved residues from both proteins, including a pair of Arg residues from PriC and the C terminus of SSB. In vitro, disruption of the PriC/SSB interface by sequence changes in either protein blocks the first step of DNA replication restart, reloading of the replicative DnaB helicase onto an abandoned replication fork. Consistent with the critical role of PriC/SSB complex formation in DNA replication restart, PriC variants that cannot bind SSB are non-functional in vivo. Single-molecule experiments demonstrate that PriC binding to SSB alters SSB/DNA complexes, exposing single-stranded DNA and creating a platform for other proteins to bind. These data lead to a model in which PriC interaction with SSB remodels SSB/DNA structures at abandoned DNA replication forks to create a DNA structure that is competent for DnaB loading.

  18. New insights into pri-miRNA processing and accumulation in plants.

    Science.gov (United States)

    Zhang, Shuxin; Liu, Yuhui; Yu, Bin

    2015-01-01

    MicroRNAs (miRNAs) regulate many biological processes such as development, metabolism, and others. They are processed from their primary transcripts called primary miRNA transcripts (pri-miRNAs) by the processor complex containing the RNAse III enzyme, DICER-LIKE1 (DCL1), in plants. Consequently, miRNA biogenesis is controlled through altering pri-miRNA accumulation and processing, which is crucial for plant development and adaptation to environmental changes. Plant pri-miRNAs are transcribed by DNA-dependent RNA polymerase II (Pol II) and their levels are determined through transcription and degradation, whereas pri-miRNA processing is affected by its structure, splicing, alternative splicing, loading to the processor and the processor activity, which involve in many accessory proteins. Here, we summarize recent progresses related to pri-miRNA transcription, stability, and processing in plants.

  19. Evidence for a cytoplasmic microprocessor of pri-miRNAs.

    Science.gov (United States)

    Shapiro, Jillian S; Langlois, Ryan A; Pham, Alissa M; Tenoever, Benjamin R

    2012-07-01

    microRNAs (miRNAs) represent a class of noncoding RNAs that fine-tune gene expression through post-transcriptional silencing. While miRNA biogenesis occurs in a stepwise fashion, initiated by the nuclear microprocessor, rare noncanonical miRNAs have also been identified. Here we characterize the molecular components and unique attributes associated with the processing of virus-derived cytoplasmic primary miRNAs (c-pri-miRNAs). RNA in situ hybridization and inhibition of cellular division demonstrated a complete lack of nuclear involvement in c-pri-miRNA cleavage while genetic studies revealed that maturation still relied on the canonical nuclear RNase III enzyme, Drosha. The involvement of Drosha was mediated by a dramatic relocalization to the cytoplasm following virus infection. Deep sequencing analyses revealed that the cytoplasmic localization of Drosha does not impact the endogenous miRNA landscape during infection, despite allowing for robust synthesis of virus-derived miRNAs in the cytoplasm. Taken together, this research describes a unique function for Drosha in the processing of highly structured cytoplasmic RNAs in the context of virus infection.

  20. Correcting the relationship between PRI and shadow fraction for the blue sky effect

    Science.gov (United States)

    Mõttus, Matti

    2016-04-01

    The Photochemical Reflectance Index (PRI) is defined as the normalized difference ratio of leaf reflectance at two specific wavelengths in the green spectral region. Its value depends on the status of leaf carotenoid content, and especially that of the xanthophyll cycle pigments. Due to the dependence on the xanthophyll cycle, when the photosynthetic apparatus of green leaves is close to the saturation limit, their PRI becomes dependent on light conditions. Therefore, by measuring the PRI of leaves in the same canopy under different local irradiance conditions on a sunny day, it should be possible to determine the saturation level of the leaves. In turn, this gives information on the light use efficiency (LUE) of the vegetation canopy. The average light conditions of visible foliage elements are often quantified with the shadow fraction -- the fraction of visible foliage not lit by direct sunlight. The dependence of PRI on the shadow fraction has been used to remotely measure canopy LUE on clear days. Variations in shadow fraction have been achieved with multiangular measurement. However, besides photosynthetic downregulation, the dependence of canopy PRI on shadow fraction is affected by the blue sky radiation caused by scattering in the atmosphere. To quantify this effect on remotely sensed PRI, we present the underlying definitions relating leaf and canopy PRI and perform the required calculations for typical midsummer conditions in Central Finland. We demonstrate that the effect of blue sky radiation on the variation of PRI with canopy shadow fraction is similar in shape and magnitude to that of LUE variations reported in literature. Next, we propose a new method to assess these PRI variations in structured vegetation. We investiagate this blue sky effect on the PRI -- shadow fraction relationship with high spatial (60 cm) and spectral (9.8 nm) resolution airborne imaging spectroscopy data from Hyytiälä, Finland. We evaluate the spectral irradiance in

  1. Beyond secondary structure: primary-sequence determinants license pri-miRNA hairpins for processing.

    Science.gov (United States)

    Auyeung, Vincent C; Ulitsky, Igor; McGeary, Sean E; Bartel, David P

    2013-02-14

    To use microRNAs to downregulate mRNA targets, cells must first process these ~22 nt RNAs from primary transcripts (pri-miRNAs). These transcripts form RNA hairpins important for processing, but additional determinants must distinguish pri-miRNAs from the many other hairpin-containing transcripts expressed in each cell. Illustrating the complexity of this recognition, we show that most Caenorhabditis elegans pri-miRNAs lack determinants required for processing in human cells. To find these determinants, we generated many variants of four human pri-miRNAs, sequenced millions that retained function, and compared them with the starting variants. Our results confirmed the importance of pairing in the stem and revealed three primary-sequence determinants, including an SRp20-binding motif (CNNC) found downstream of most pri-miRNA hairpins in bilaterian animals, but not in nematodes. Adding this and other determinants to C. elegans pri-miRNAs imparted efficient processing in human cells, thereby confirming the importance of primary-sequence determinants for distinguishing pri-miRNAs from other hairpin-containing transcripts.

  2. Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

    Science.gov (United States)

    Gamon, J. A.; Kovalchuck, O.; Wong, C. Y. S.; Harris, A.; Garrity, S. R.

    2015-07-01

    The vegetation indices normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI) provide indicators of pigmentation and photosynthetic activity that can be used to model photosynthesis from remote sensing with the light-use-efficiency model. To help develop and validate this approach, reliable proximal NDVI and PRI sensors have been needed. We tested new NDVI and PRI sensors, "spectral reflectance sensors" (SRS sensors; recently developed by Decagon Devices, during spring activation of photosynthetic activity in evergreen and deciduous stands. We also evaluated two methods of sensor cross-calibration - one that considered sky conditions (cloud cover) at midday only, and another that also considered diurnal sun angle effects. Cross-calibration clearly affected sensor agreement with independent measurements, with the best method dependent upon the study aim and time frame (seasonal vs. diurnal). The seasonal patterns of NDVI and PRI differed for evergreen and deciduous species, demonstrating the complementary nature of these two indices. Over the spring season, PRI was most strongly influenced by changing chlorophyll : carotenoid pool sizes, while over the diurnal timescale, PRI was most affected by the xanthophyll cycle epoxidation state. This finding demonstrates that the SRS PRI sensors can resolve different processes affecting PRI over different timescales. The advent of small, inexpensive, automated PRI and NDVI sensors offers new ways to explore environmental and physiological constraints on photosynthesis, and may be particularly well suited for use at flux tower sites. Wider application of automated sensors could lead to improved integration of flux and remote sensing approaches for studying photosynthetic carbon uptake, and could help define the concept of contrasting vegetation optical types.

  3. Prying Force Calculation and Design Method for T-shaped Tensile Connector with High Strength Bolt

    Institute of Scientific and Technical Information of China (English)

    Zhaoxin Hou; Guohong Huang; Chao Gong

    2015-01-01

    In order to establish the design method for T⁃shaped tensile connector with high strength bolt, the theoretical analysis is carried out. Firstly, it analyzes the performance of the connector and establishes prying force calculation model. Based on the model, prying force equation and function between bolt prying force and flange thickness is derived, and the min and max thickness requirement of flange plate under a certain tension load is then obtained. Finally, two simplified design methods of the connector are proposed, which are bolt pulling capacity method and flange plate bending capacity method.

  4. RAČUNOVODSKE INFORMACIJE PRI UPRAVLJANJU ČLOVEŠKIH VIROV V PODJETJU X

    OpenAIRE

    2012-01-01

    V diplomski nalogi je predstavljeno upravljanje človeških virov in računovodske informacije o le teh. Opredelili smo informacije nasploh in računovodske informacije, ki jih potrebujemo pri odločitvah o človeških virih. Od vsakega podjetja je odvisno ali bo pri različnih nalogah upravljanja človeških virov uporabil računovodske informacije. Pri vseh nalogah upravljanja človeških virov so uporabne računovodske informacije, odvisno od velikosti in razširjenosti upravljanja človeških virov v...

  5. Regulation of pri-miRNA processing by the hnRNP-like protein AtGRP7 in Arabidopsis.

    Science.gov (United States)

    Köster, Tino; Meyer, Katja; Weinholdt, Claus; Smith, Lisa M; Lummer, Martina; Speth, Corinna; Grosse, Ivo; Weigel, Detlef; Staiger, Dorothee

    2014-09-01

    The hnRNP-like glycine-rich RNA-binding protein AtGRP7 regulates pre-mRNA splicing in Arabidopsis. Here we used small RNA-seq to show that AtGRP7 also affects the miRNA inventory. AtGRP7 overexpression caused a significant reduction in the level of 30 miRNAs and an increase for 14 miRNAs with a minimum log2 fold change of ± 0.5. Overaccumulation of several pri-miRNAs including pri-miR398b, pri-miR398c, pri-miR172b, pri-miR159a and pri-miR390 at the expense of the mature miRNAs suggested that AtGRP7 affects pri-miRNA processing. Indeed, RNA immunoprecipitation revealed that AtGRP7 interacts with these pri-miRNAs in vivo. Mutation of an arginine in the RNA recognition motif abrogated in vivo binding and the effect on miRNA and pri-miRNA levels, indicating that AtGRP7 inhibits processing of these pri-miRNAs by direct binding. In contrast, pri-miRNAs of selected miRNAs that were elevated or not changed in response to high AtGRP7 levels were not bound in vivo. Reduced accumulation of miR390, an initiator of trans-acting small interfering RNA (ta-siRNA) formation, also led to lower TAS3 ta-siRNA levels and increased mRNA expression of the target AUXIN RESPONSE FACTOR4. Furthermore, AtGRP7 affected splicing of pri-miR172b and pri-miR162a. Thus, AtGRP7 is an hnRNP-like protein with a role in processing of pri-miRNAs in addition to its role in pre-mRNA splicing.

  6. Odzivi učencev na didaktične igre pri obravnavi gibanja pri predmetu Spoznavanje okolja

    OpenAIRE

    Novak, Ines

    2016-01-01

    Igra pri pouku je priporočljiva dejavnost predvsem z vidika učencev, saj spodbuja zanimanje in vse vrste motivacije. Učenci skozi igro projicirajo svoje primanjkljaje in jih na ta način lažje premagujejo. Ni dovolj, da se učenci v šoli zgolj učijo, ampak naj bi se tam tudi dobro počutili, kar pripomore k boljšemu spremljanju pouka in trajnejšemu znanju. V teoretičnem delu magistrskega dela predstavimo kognitivni, čustveni in socialni razvoj otroka, razvoj otroške igre ter vlogo didaktične igr...

  7. Pri peptides are mediators of ecdysone for the temporal control of development.

    Science.gov (United States)

    Chanut-Delalande, Hélène; Hashimoto, Yoshiko; Pelissier-Monier, Anne; Spokony, Rebecca; Dib, Azza; Kondo, Takefumi; Bohère, Jérôme; Niimi, Kaori; Latapie, Yvan; Inagaki, Sachi; Dubois, Laurence; Valenti, Philippe; Polesello, Cédric; Kobayashi, Satoru; Moussian, Bernard; White, Kevin P; Plaza, Serge; Kageyama, Yuji; Payre, François

    2014-11-01

    Animal development fundamentally relies on the precise control, in space and time, of genome expression. Whereas we have a wealth of information about spatial patterning, the mechanisms underlying temporal control remain poorly understood. Here we show that Pri peptides, encoded by small open reading frames, are direct mediators of the steroid hormone ecdysone for the timing of developmental programs in Drosophila. We identify a previously uncharacterized enzyme of ecdysone biosynthesis, GstE14, and find that ecdysone triggers pri expression to define the onset of epidermal trichome development, through post-translational control of the Shavenbaby transcription factor. We show that manipulating pri expression is sufficient to either put on hold or induce premature differentiation of trichomes. Furthermore, we find that ecdysone-dependent regulation of pri is not restricted to epidermis and occurs over various tissues and times. Together, these findings provide a molecular framework to explain how systemic hormonal control coordinates specific programs of differentiation with developmental timing.

  8. Pri sORF peptides induce selective proteasome-mediated protein processing.

    Science.gov (United States)

    Zanet, J; Benrabah, E; Li, T; Pélissier-Monier, A; Chanut-Delalande, H; Ronsin, B; Bellen, H J; Payre, F; Plaza, S

    2015-09-18

    A wide variety of RNAs encode small open-reading-frame (smORF/sORF) peptides, but their functions are largely unknown. Here, we show that Drosophila polished-rice (pri) sORF peptides trigger proteasome-mediated protein processing, converting the Shavenbaby (Svb) transcription repressor into a shorter activator. A genome-wide RNA interference screen identifies an E2-E3 ubiquitin-conjugating complex, UbcD6-Ubr3, which targets Svb to the proteasome in a pri-dependent manner. Upon interaction with Ubr3, Pri peptides promote the binding of Ubr3 to Svb. Ubr3 can then ubiquitinate the Svb N terminus, which is degraded by the proteasome. The C-terminal domains protect Svb from complete degradation and ensure appropriate processing. Our data show that Pri peptides control selectivity of Ubr3 binding, which suggests that the family of sORF peptides may contain an extended repertoire of protein regulators.

  9. Effect of nitrogen stress on relationship of PRI and LUE during winter wheat growth period

    Science.gov (United States)

    Guo, Jianmao; Gao, Yanghua; Wang, Qian; Fei, Dunyue; Liu, Junwei

    2014-11-01

    Light use efficiency (LUE ) is an important parameter for GPP and and NPP estimation model, cause by the existing model method to estimate the actual LUE is always simple and rough, which may lead to serious bias by GPP and NPP. The photochemical reflectance index ( PRI ) has great potential for direct estimation the actual LUE. In this paper, wheat in different nitrogen treatments was designed in field trial during Wheat growing period, for obtain photosynthesis and reflective hyperspectral data, and then LUE and PRI was calculated in critical period of wheat growth. The results show that, at different growth stages under three different nitrogen conditions, LUE and PRI value were significantly increased with increasing nitrogen absorption; Last longer, more capable of absorbing nitrogen amount, the correlation between LUE and PRI was better - for example, the correlation coefficient is obviously larger in heading stage than elongation stage for same nitrogen treatment.

  10. Microprocessor dynamics shows co- and post-transcriptional processing of pri-miRNAs.

    Science.gov (United States)

    Louloupi, Annita; Ntini, Evgenia; Liz, Julia; Ørom, Ulf Andersson

    2017-06-01

    miRNAs are small regulatory RNAs involved in the regulation of translation of target transcripts. miRNA biogenesis is a multistep process starting with the cleavage of the primary miRNA transcript in the nucleus by the Microprocessor complex. Endogenous processing of pri-miRNAs is challenging to study and the in vivo kinetics of this process is not known. Here, we present a method for determining the processing kinetics of pri-miRNAs within intact cells over time, using a pulse-chase approach to label transcribed RNA during 15 min, and follow the processing within a 1-hour window after labeling with bromouridine. We show that pri-miRNAs exhibit different processing kinetics ranging from fast over intermediate to slow processing, and we provide evidence that pri-miRNA processing can occur both cotranscriptionally and post-transcriptionally. © 2017 Louloupi et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  11. Affecting Factors and Recent Improvements of the Photochemical Reflectance Index (PRI for Remotely Sensing Foliar, Canopy and Ecosystemic Radiation-Use Efficiencies

    Directory of Open Access Journals (Sweden)

    Chao Zhang

    2016-08-01

    Full Text Available Accurately assessing terrestrial gross primary productivity (GPP is crucial for characterizing the climate-carbon cycle. Remotely sensing the photochemical reflectance index (PRI across vegetation functional types and spatiotemporal scales has received increasing attention for monitoring photosynthetic performance and simulating GPP over the last two decades. The factors confounding PRI variation, especially on long timescales, however, require the improvement of PRI understanding to generalize its use for estimating carbon uptake. In this review, we summarize the most recent publications that have reported the factors affecting PRI variation across diurnal and seasonal scales at foliar, canopy and ecosystemic levels; synthesize the reported correlations between PRI and ecophysiological variables, particularly with radiation-use efficiency (RUE and net carbon uptake; and analyze the improvements in PRI implementation. Long-term variation of PRI could be attributed to changes in the size of constitutive pigment pools instead of xanthophyll de-epoxidation, which controls the facultative short-term changes in PRI. Structural changes at canopy and ecosystemic levels can also affect PRI variation. Our review of the scientific literature on PRI suggests that PRI is a good proxy of photosynthetic efficiency at different spatial and temporal scales. Correcting PRI by decreasing the influence of physical or physiological factors on PRI greatly strengthens the relationships between PRI and RUE and GPP. Combining PRI with solar-induced fluorescence (SIF and optical indices for green biomass offers additional prospects.

  12. Generating time series of PRI across the Amazon basin using hyperspectral Hyperion data

    Science.gov (United States)

    Toh Yuan Kun, L.; Yang, X.; Silva, C. E.; Cushman, K.; Kellner, J. R.

    2016-12-01

    Models of carbon cycling in tropical forests rely on estimates of fAPAR and LUE that are based on field experiments or remote sensing. However, much uncertainty surrounds such models on a regional scale because of unresolved questions over ecosystem response to climate variability. The photochemical reflectance index (PRI) is a normalized difference index that is sensitive to short-term changes in photosynthetic activity, unlike other more commonly used indices like NDVI. This is because PRI is indicative of the epoxidation state of xanthophyll pigments involved in non-photochemical quenching. Hence, an understanding of how PRI varies spatially and temporally would be a useful benchmark against which to evaluate model output and measurements of solar-induced fluorescence (SIF). Computing PRI requires two narrow spectral bands at 531 and 570 nm, and therefore cannot be quantified using broad-band optical sensors. The Hyperion instrument has generated Earth observations since 2000 and provides a unique opportunity to quantify PRI over large spatial and temporal scales. Here we describe a quantitative framework to correct striping, spectral keystone, and spectral smile inherent in the Hyperion data record. We show how these data can be used to generate time series of PRI to facilitate deeper understanding of photosynthetic activity in the Amazon basin.

  13. Remote sensing of ecosystem light use efficiency with MODIS-based PRI

    Science.gov (United States)

    Goerner, A.; Reichstein, M.; Tomelleri, E.; Hanan, N.; Rambal, S.; Papale, D.; Dragoni, D.; Schmullius, C.

    2011-01-01

    Several studies sustained the possibility that a photochemical reflectance index (PRI) directly obtained from satellite data can be used as a proxy for ecosystem light use efficiency (LUE) in diagnostic models of gross primary productivity. This modelling approach would avoid the complications that are involved in using meteorological data as constraints for a fixed maximum LUE. However, no unifying model predicting LUE across climate zones and time based on MODIS PRI has been published to date. In this study, we evaluate the effectiveness with which MODIS-based PRI can be used to estimate ecosystem light use efficiency at study sites of different plant functional types and vegetation densities. Our objective is to examine if known limitations such as dependence on viewing and illumination geometry can be overcome and a single PRI-based model of LUE (i.e. based on the same reference band) can be applied under a wide range of conditions. Furthermore, we were interested in the effect of using different faPAR (fraction of absorbed photosynthetically active radiation) products on the in-situ LUE used as ground truth and thus on the whole evaluation exercise. We found that estimating LUE at site-level based on PRI reduces uncertainty compared to the approaches relying on a maximum LUE reduced by minimum temperature and vapour pressure deficit. Despite the advantages of using PRI to estimate LUE at site-level, we could not establish an universally applicable light use efficiency model based on MODIS PRI. Models that were optimised for a pool of data from several sites did not perform well.

  14. Bi-directional processing of pri-miRNAs with branched terminal loops by Arabidopsis Dicer-like1

    Science.gov (United States)

    Zhu, Hongliang; Zhou, Yuyi; Castillo-González, Claudia; Lu, Amber; Ge, Chunxiao; Zhao, Ying-Tao; Duan, Liusheng; Li, Zhaohu; Axtell, Michael J.; Wang, Xiu-Jie; Zhang, Xiuren

    2013-01-01

    miRNAs originate from primary transcripts (pri-miRNAs) with characteristic stem-loop structures. Accurate processing of pri-miRNAs is required for functional miRNAs. Here, using pri-miR166 family as a paradigm, we report the decisive role of pri-miRNA terminal loops in miRNA biogenesis. We found that multi-branched terminal loops in pri-miR166s substantially suppressed miR166 expression in vivo. Unlike canonical processing of pri-miRNAs, terminal-loop-branched (TLBed) pri-miRNAs can be processed by Dicer-like1 (DCL1) complexes bi-directionally: from base to loop and from loop to base, resulting in productive and abortive processing of miRNAs, respectively. In either case, DCL1 complexes canonically cut pri-miRNAs at a distance of 16-17 base pairs (bp) from a reference single-stranded loop region. DCL1 also adjusts processing sites toward an internal loop through its helicase domain. Thus, these results provide new insight into the poorly understood processing mechanism of pri-miRNAs with complicated secondary structures. PMID:23934148

  15. 新体制雷达信号 PRI 样本子图周期搜索提取方法%A New System Radar Signal Extraction Method by Searching PRI Pulse Sequence Subpattern Cycle

    Institute of Scientific and Technical Information of China (English)

    孟祥豪; 罗景青; 马贤同

    2015-01-01

    alming at the problem of radar signal extraction of interleaved pulse sequences intercepted by reconnalssance receiver,according to the description technique of pulse recurrence interval(PRI),a pulse extraction algorithm is proposed based on the searching of PRI pulse sequence subpattern(PSS)cycle.In this algorithm,the idea of searching adjacent pul-ses intervals in traditional PRI searching algorithm is replaced by that of searching the PRI-PSS cycle.A two-dimensional extraction function consisting of time of arrival and paracycle of PRI PSS is constructed to store the number of matching pul-ses which conform to a certaln assumed PRI-PSS cycle during the searching process.Then the PRI-PSS cycle is determined according to the maximum value of the function,thus the equivalent pulses can be extracted,realizing the signal extraction of complex type of PRI radar signals.The validity of this method has been verified by simulation experiments.%针对侦察接收机截获的交错脉冲序列中雷达信号的提取问题,在脉冲重复周期(PRI)样本子图描述技术的基础上,提出一种基于 PRI 样本子图周期搜索的脉冲提取算法。算法改传统 PRI 搜索法中的相邻脉冲间隔搜索思想为 PRI 样本子图周期搜索思想,通过构造由脉冲到达时间和准 PRI 样本子图周期构成的二维提取函数,将搜索过程中符合某一假定 PRI 样本子图周期的匹配脉冲数存储于二维提取函数中,然后根据二维提取函数的最大值确定 PRI 样本子图周期,提取对应的脉冲,实现复杂 PRI 类型的雷达信号提取。仿真结果验证了该方法的有效性。

  16. Diurnal and Directional Responses of Chlorophyll Fluorescence and the PRI in a Cornfield

    Science.gov (United States)

    Middleton, Elizabeth; Cheng, Y. B.; Corp, L.; Campbell, P.; Kustas, W.

    2010-01-01

    Determining the health and vigor of vegetation using high spectral resolution remote sensing is an important goal which has application to monitoring agriculture and ecosystem productivity and carbon exchange. Two spectral indices used to assess whether vegetation is performing near-optimally or exhibiting symptoms of environmental stress (e.g., drought or nutrient deficiency, non-optimal temperatures, etc.) are the Photochemical Reflectance Index (PRI) and solar-induced red and far-red Chlorophyll Fluorescence (Fs). Both the PRI and Fs capture the dynamics of photoprotection mechanisms within green foliage: the PRI is based on the association of the reflected radiation in the green spectrum with the xanthophyll cycle, whereas Fs measures the emitted radiation in the red and far-red spectrum. Fs was determined from retrievals in the atmospheric oxygen absorption features centered at 688 and 760 nm using a modified Fraunhofer Line Depth (FLD) method. We previously demonstrated diurnal and seasonal PRI differences for sunlit vs. shaded foliage in a conifer forest canopy, as expressed in the hotspot and darkspot of the Bidirectional Reflectance Function (BRF). In a USDA-ARS experimental field site located in Beltsville, MD, USA, measurements were acquired over a corn crop from a nadir view in 2008 with an ASD FieldSpec Pro (Analytical Spectral Devices, Inc., Boulder, CO, USA) to study the behavior of the PRI for sunlit and shaded foliage as captured in reflectance variations associated with the BRF, in a I m tall canopy in the vegetative growth stage. Those observations were compared to simulations obtained from two radiative transfer models. Measurements were then acquired to examine whether the PRI and Fs were influenced by view zenith and azimuth geometries at different times of day. Those measurements were made in 2010 with the Ocean Optics USB4000 Miniature Fiber Optic Spectrometer (Ocean Optics Inc., Dunedin, Florida, USA) at several times during the day on

  17. Gene structures and processing of Arabidopsis thaliana HYL1-dependent pri-miRNAs.

    Science.gov (United States)

    Szarzynska, Bogna; Sobkowiak, Lukasz; Pant, Bikram Datt; Balazadeh, Salma; Scheible, Wolf-Rüdiger; Mueller-Roeber, Bernd; Jarmolowski, Artur; Szweykowska-Kulinska, Zofia

    2009-05-01

    Arabidopsis thaliana HYL1 is a nuclear double-stranded RNA-binding protein involved in the maturation of pri-miRNAs. A quantitative real-time PCR platform for parallel quantification of 176 pri-miRNAs was used to reveal strong accumulation of 57 miRNA precursors in the hyl1 mutant that completely lacks HYL1 protein. This approach enabled us for the first time to pinpoint particular members of MIRNA family genes that require HYL1 activity for efficient maturation of their precursors. Moreover, the accumulation of miRNA precursors in the hyl1 mutant gave us the opportunity to carry out 3' and 5' RACE experiments which revealed that some of these precursors are of unexpected length. The alignment of HYL1-dependent miRNA precursors to A. thaliana genomic sequences indicated the presence of introns in 12 out of 20 genes studied. Some of the characterized intron-containing pri-miRNAs undergo alternative splicing such as exon skipping or usage of alternative 5' splice sites suggesting that this process plays a role in the regulation of miRNA biogenesis. In the hyl1 mutant intron-containing pri-miRNAs accumulate alongside spliced pri-miRNAs suggesting the recruitment of HYL1 into the miRNA precursor maturation pathway before their splicing occurs.

  18. PRI-Modeler: extracting RNA structural elements from PDB files of protein-RNA complexes.

    Science.gov (United States)

    Han, Kyungsook; Nepal, Chirag

    2007-05-01

    A complete understanding of protein and RNA structures and their interactions is important for determining the binding sites in protein-RNA complexes. Computational approaches exist for identifying secondary structural elements in proteins from atomic coordinates. However, similar methods have not been developed for RNA, due in part to the very limited structural data so far available. We have developed a set of algorithms for extracting and visualizing secondary and tertiary structures of RNA and for analyzing protein-RNA complexes. These algorithms have been implemented in a web-based program called PRI-Modeler (protein-RNA interaction modeler). Given one or more protein data bank files of protein-RNA complexes, PRI-Modeler analyzes the conformation of the RNA, calculates the hydrogen bond (H bond) and van der Waals interactions between amino acids and nucleotides, extracts secondary and tertiary RNA structure elements, and identifies the patterns of interactions between the proteins and RNAs. This paper presents PRI-Modeler and its application to the hydrogen bond and van der Waals interactions in the most representative set of protein-RNA complexes. The analysis reveals several interesting interaction patterns at various levels. The information provided by PRI-Modeler should prove useful for determining the binding sites in protein-RNA complexes. PRI-Modeler is accessible at http://wilab.inha.ac.kr/primodeler/, and supplementary materials are available in the analysis results section at http://wilab.inha.ac.kr/primodeler/.

  19. Subnuclear compartmentalization of transiently expressed polyadenylated pri-microRNAs: processing at transcription sites or accumulation in SC35 foci.

    Science.gov (United States)

    Pawlicki, Jan M; Steitz, Joan A

    2009-02-01

    MicroRNAs (miRNAs) are small, noncoding RNAs that post-transcriptionally regulate expression of their target messenger RNAs. We recently demonstrated that primary miRNA transcripts (pri-miRNAs) retained at transcription sites are processed with enhanced efficiency, suggesting that pri-miRNA processing is coupled to transcription in mammalian cells. We also observed that transiently expressed pri-miRNAs accumulate in nuclear foci with splicing factor SC35 and Microprocessor components, Drosha and DGCR8. Here, we show that pri-miRNAs containing a self-cleaving hepatitis delta ribozyme accumulate in the nucleoplasm after release from their transcription sites, but are not efficiently processed. Pri-miRNAs with ribozyme-generated 3' ends do not localize to SC35-containing foci, whereas cleaved and polyadenylated pri-miRNA transcripts with or without the pre-miRNA hairpin do. Pri-miRNA/SC35 foci contain a number of proteins normally associated with SC35 domains, including ASF/SF2, PABII, and the prolyl isomerase, Pin1. In contrast, RNA polymerase II and PM/Scl-100 do not strongly colocalize with pri-miRNAs in SC35-containing foci. These data argue that pri-miRNA/SC35-containing foci are not major sites of pri-miRNA processing and that pri-miRNA processing is coupled to transcription. We discuss the implications of our findings relative to recent insights into miRNA biogenesis, mRNA metabolism, and the nuclear organization of gene expression.

  20. Fluorescence, PRI and canopy temperature for water stress detection in cereal crops

    Science.gov (United States)

    Panigada, C.; Rossini, M.; Meroni, M.; Cilia, C.; Busetto, L.; Amaducci, S.; Boschetti, M.; Cogliati, S.; Picchi, V.; Pinto, F.; Marchesi, A.; Colombo, R.

    2014-08-01

    Narrow-band multispectral remote sensing techniques and thermal imagery were investigated for water stress detection in cereal crops. Visible and near infrared AISA Eagle (Specim, Finland) and thermal AHS-160 (Sensytech Inc., USA) imageries were acquired with an airborne survey on a farm-level experimental site where maize (Zea mays L.) and sorghum (Sorghum bicolor L.) were grown with three different irrigation treatments. Vegetation biophysical and eco-physiological measurements were collected concurrently with the airborne campaign. Leaf fluorescence yield (ΔF/Fm‧) resulted to be a good indirect measure of water stress. Therefore, ΔF/Fm‧ measurements were compared against remotely sensed indicators: (i) the Photochemical Reflectance Index (PRI), (ii) the sun-induced chlorophyll fluorescence at 760 nm (F760), retrieved by the Fraunhofer line depth method and (iii) the canopy temperature (TC) calculated decoupling soil and vegetation contributions. TC was related to ΔF/Fm‧ with the highest determination coefficient (R2 = 0.65), followed by PRI586 (reference band at 586 nm) (R2 = 0.51). The relationship with F760 was significant but weaker (R2 = 0.36). The coefficient of determination increased up to 0.54 when pigment concentration was considered by multiplying ΔF/Fm‧ and chlorophyll content, confirming the close relationship between passive fluorescence signal, pigment content and light photosystem efficiency. PRI586, F760 and TC maps were produced in maize and sorghum plots. The differences in the average values of PRI586, F760 and TC extracted from the plots with different water treatments showed that water treatments were well discriminated in maize plots by the three remotely sensed indicators. This was confirmed by the visual observation of the PRI586, F760 and TC maps, while in sorghum plots, F760 and TC appeared more sensitive to water stress compared to PRI586.

  1. 7 CFR 14.6 - Criteria for determining the pri- mary purpose of payments with respect to potential exclusion...

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Criteria for determining the pri- mary purpose of payments with respect to potential exclusion from gross income. 14.6 Section 14.6 Agriculture Office of the... Criteria for determining the pri- mary purpose of payments with respect to potential exclusion from...

  2. Bidirectional processing of pri-miRNAs with branched terminal loops by Arabidopsis Dicer-like1.

    Science.gov (United States)

    Zhu, Hongliang; Zhou, Yuyi; Castillo-González, Claudia; Lu, Amber; Ge, Chunxiao; Zhao, Ying-Tao; Duan, Liusheng; Li, Zhaohu; Axtell, Michael J; Wang, Xiu-Jie; Zhang, Xiuren

    2013-09-01

    MicroRNAs (miRNAs) originate from primary transcripts (pri-miRNAs) with characteristic stem-loop structures, and their accurate processing is required for the production of functional miRNAs. Here, using the pri-miR-166 family in Arabidopsis thaliana as a paradigm, we report the crucial role of pri-miRNA terminal loops in miRNA biogenesis. We found that multibranched terminal loops in pri-miR-166s substantially suppress miR-166 expression in vivo. Unlike canonical processing of pri-miRNAs, terminal loop-branched pri-miRNAs can be processed by Dicer-like 1 (DCL1) complexes bidirectionally from base to loop and from loop to base, resulting in productive and abortive processing of miRNAs, respectively. In both cases, DCL1 complexes canonically cut pri-miRNAs at a distance of 16-17 bp from a reference single-stranded loop region. DCL1 also adjusts processing sites toward an internal loop through its helicase domain. These results provide new insight into the poorly understood processing mechanism of pri-miRNAs with complex secondary structures.

  3. PriFi - Using a Multiple Alignment of Related Sequences to Find Primers for  Amplification of Homologs

    DEFF Research Database (Denmark)

    Fredslund, Jakob; Schauser, Leif; Madsen, Lene Heegaard

    2005-01-01

    Using a comparative approach, the web program PriFi (http://cgi-www.daimi.au.dk/cgi-chili/PriFi/main) designs pairs of primers useful for PCR amplification of genomic DNA in species where prior sequence information is not available. The program works with an alignment of DNA sequences from phylog...

  4. Functional interactions between polypyrimidine tract binding protein and PRI peptide ligand containing proteins.

    Science.gov (United States)

    Coelho, Miguel B; Ascher, David B; Gooding, Clare; Lang, Emma; Maude, Hannah; Turner, David; Llorian, Miriam; Pires, Douglas E V; Attig, Jan; Smith, Christopher W J

    2016-08-15

    Polypyrimidine tract binding protein (PTBP1) is a heterogeneous nuclear ribonucleoprotein (hnRNP) that plays roles in most stages of the life-cycle of pre-mRNA and mRNAs in the nucleus and cytoplasm. PTBP1 has four RNA binding domains of the RNA recognition motif (RRM) family, each of which can bind to pyrimidine motifs. In addition, RRM2 can interact via its dorsal surface with proteins containing short peptide ligands known as PTB RRM2 interacting (PRI) motifs, originally found in the protein Raver1. Here we review our recent progress in understanding the interactions of PTB with RNA and with various proteins containing PRI ligands.

  5. Drevesno preiskovanje Monte Carlo s Thompsonovim vzorčenjem pri igri Prebivalci otoka Catan

    OpenAIRE

    2016-01-01

    Drevesno preiskovanje Monte Carlo (MCTS) je ena izmed najbolj uporabljenih metod pri implementaciji močnega računalniškega igralca iger v umetni inteligenci, brez uporabe predhodnega znanja o domeni. Najmočnejši in najbolj popularni algoritmi, ki se pogosto uporabljajo za rešitev t.i. dileme raziskovanja (engl. exploration) proti izkoriščanju znanja (engl. exploitation) pri problemu več-rokih banditov, so raziskani in predstavljeni s pomočjo pregleda literature. Na podlagi empiričnih študij T...

  6. Pri-miR-124 rs531564 and pri-miR-34b/c rs4938723 polymorphisms are associated with decreased risk of esophageal squamous cell carcinoma in Chinese populations.

    Science.gov (United States)

    Zhang, Junjie; Huang, Xuewen; Xiao, Juanjuan; Yang, Yajun; Zhou, Yinghui; Wang, Xiaofeng; Liu, Qingmei; Yang, Jingmin; Wang, Mengyun; Qiu, Lixin; Zheng, Yabiao; Zhang, Ping; Li, Jin; Wang, Ya'nong; Wei, Qingyi; Jin, Li; Wang, Jiucun; Wang, Minghua

    2014-01-01

    MicroRNAs are a new class of small non-protein-coding RNAs that sometimes function as tumor suppressors or oncogenes. Aberrant expression and structural alteration of microRNAs have been reported to be involved in tumorigenesis and cancer development. Recently, rs531564/pri-miR-124-1, rs4938723/pri-miR-34b/c, rs7372209/pri-miR-26a-1, rs895819/pre-miR-27a, and rs11134527/pri-miR-218 were reported to be associated with risks of various cancers. In order to evaluate the relationship of these SNPs and esophageal squamous cell carcinoma (ESCC) risk, we conducted a case-control study with 1109 ESCC patients and 1275 control subjects to examine the potential association of these pri/pre-miRNA polymorphisms with ESCC susceptibility. As a result, two SNPs were associated with a significant risk of ESCC. We found that the GG genotype of pri-miR-124-1 rs531564 was associated to a significantly decreased risk of ESCC comparing with the CC/CG genotypes (p = 0.005; OR = 0.61, 95% CI = 0.43-0.86). In addition, the CC genotype of pri-miR-34b/c rs4938723 was associated with a significant decreased risk of ESCC (CC VS. p = 0.007, OR = 0.82, 95% CI = 0.71-0.95) in Chinese population. The present study provides the first evidence that pri-miR-124-1 rs531564 and pri-miR-34 rs4938723 were associated with the risk of ESCC in Chinese population.

  7. Association of a peptoid ligand with the apical loop of pri-miR-21 inhibits cleavage by Drosha.

    Science.gov (United States)

    Diaz, Jason P; Chirayil, Rachel; Chirayil, Sara; Tom, Martin; Head, Katie J; Luebke, Kevin J

    2014-04-01

    We have found a small molecule that specifically inhibits cleavage of a precursor to the oncogenic miRNA, miR-21, by the microprocessor complex of Drosha and DGCR8. We identified novel ligands for the apical loop of this precursor from a screen of 14,024 N-substituted oligoglycines (peptoids) in a microarray format. Eight distinct compounds with specific affinity were obtained, three having affinities for the targeted loop in the low micromolar range and greater than 15-fold discrimination against a closely related hairpin. One of these compounds completely inhibits microprocessor cleavage of a miR-21 primary transcript at concentrations at which cleavage of another miRNA primary transcript, pri-miR-16, is little affected. The apical loop of pri-miR-21, placed in the context of pri-miR-16, is sufficient for inhibition of microprocessor cleavage by the peptoid. This compound also inhibits cleavage of pri-miR-21 containing the pri-miR-16 apical loop, suggesting an additional site of association within pri-miR-21. The reported peptoid is the first example of a small molecule that inhibits microprocessor cleavage by binding to the apical loop of a pri-miRNA.

  8. Tertiary structure mapping of the pri-miRNA miR-17~92.

    Science.gov (United States)

    Chaulk, Steven G; Fahlman, Richard P

    2014-01-01

    The understanding of RNA in regulating gene expression has exploded over the past 15 years. MicroRNAs (miRNAs) have vastly expanded the role of RNA in gene regulation beyond spliceosomal, ribosomal, and messenger RNAs. Approximately one half of miRNAs are polycistronic, where two or more miRNAs are encoded on a single pri-miRNA transcript, termed a miRNA cluster. The six miRNAs of the miR-17~92 cluster are contained within a ~800 nucleotide region within intron 3 of the cl13orf25 ~7 kb pri-miRNA transcript. We recently reported on the tertiary structured domain of miR-17~92 and its role in modulating miRNA biogenesis. The key finding was that the cluster structure explained the differential processing of the miRNA hairpins by Drosha. This work demonstrated the need to consider pri-miRNA tertiary structure in miRNA biogenesis. Since biochemical structure probing is typically performed on relatively short RNAs (≤200 nucleotides), we had to adapt these methodologies for application on large RNAs (~800 nucleotide miR-17~92 pri-miRNA). We present here our adaptation of a protection footprinting method using ribonucleases to probe the structure of the ~800 nucleotide miR-17~92 pri-miRNA. We outline the technical difficulties involved in probing large RNAs and data visualization using denaturing polyacrylamide gel electrophoresis and how we adapted the existing approaches to probe large RNAs. The methodology outlined here is generally applicable to large RNAs including long noncoding RNAs (lncRNA).

  9. Regulation of pri-miRNA processing by a long noncoding RNA transcribed from an ultraconserved region.

    Science.gov (United States)

    Liz, Julia; Portela, Anna; Soler, Marta; Gómez, Antonio; Ling, Hui; Michlewski, Gracjan; Calin, George A; Guil, Sònia; Esteller, Manel

    2014-07-03

    Noncoding RNAs (ncRNAs) control cellular programs by affecting protein-coding genes, but evidence increasingly points to their involvement in a network of ncRNA-ncRNA interactions. Here, we show that a long ncRNA, Uc.283+A, controls pri-miRNA processing. Regulation requires complementarity between the lower stem region of the pri-miR-195 transcript and an ultraconserved sequence in Uc.283+A, which prevents pri-miRNA cleavage by Drosha. Mutation of the site in either RNA molecule uncouples regulation in vivo and in vitro. We propose a model in which lower-stem strand invasion by Uc.283+A impairs microprocessor recognition and efficient pri-miRNA cropping. In addition to identifying a case of RNA-directed regulation of miRNA biogenesis, our study reveals regulatory networks involving different ncRNA classes of importance in cancer.

  10. Construction of Pri-miR-20a Lentiviral Expression Vector%携带pri-mir-20a的慢病毒表达载体的构建

    Institute of Scientific and Technical Information of China (English)

    马清华; 徐艳敏; 武佳; 李伟; 钱程; 刘立

    2010-01-01

    采用PCR扩增获得的pri-mir-20a,过渡质粒pcDNA3.0-H1经BamH Ⅰ与Hin dⅢ双酶切后将两者连接产生pcDNA3.0-H1-pri-mir-20a重组质粒,再将PCR获得的H1-pri-mir-20a克隆到慢病毒载体pdc-SEW上获得重组慢病毒载体pdcH1-pri-mir-20a-SEW.将pCMV 8.91、pMD2.VSV.G、pdcH1-pri-mir-20a-SEW三质粒共转染293FT细胞,结果显示48 h后绿色荧光蛋白的表达达到80%,表明已成功构建出携带pri-mir-20a的慢病毒表达载体.该载体的成功构建为深入开展对miR-20a的生物学功能和靶标验证提供了有效的工具.

  11. Remote detection of water stress conditions via a diurnal photochemical reflectance index (PRI) improves yield prediction in rainfed wheat

    Science.gov (United States)

    Magney, T. S.; Vierling, L. A.; Eitel, J.

    2014-12-01

    Employing remotely sensed techniques to quantify the existence and magnitude of midday photosynthetic downregulation using the photochemical reflectance index (PRI) may reveal new information about plant responses to abiotic stressors in space and time. However, the interpretation and application of the PRI can be confounded because of its sensitivity to several variables changing at the diurnal (e.g., irradiation, shadow fraction) and seasonal (e.g., leaf area, chlorophyll and carotene pigment concentrations, irradiation) time scales. We explored different techniques to correct the PRI for variations in canopy structure and relative chlorophyll content (ChlR) using highly temporally resolved (frequency = five minutes) in-situ radiometric measurements of PRI and the Normalized Difference Vegetation Index (NDVI) over eight soft white spring wheat (Triticum aestivum L.)field plots under varying nitrogen and soil water conditions over two seasons. Our results suggest that the influence of seasonal variation in canopy ChlR and LAI on the diurnally measured PRI (PRIdiurnal) can be minimized using simple correction techniques, therefore improving the strength of PRI as a tool to quantify abiotic stressors such as daily changes in soil volumetric water content (SVWC), and vapor pressure deficit (VPD). PRIdiurnal responded strongly to available nitrogen, and linearly tracked seasonal changes in SVWC, VPD, and stomatal conductance (gc). Utilizing the PRI as an indicator of stress, yield predictions significantly over greenness indices such as the NDVI. This study provides insight towards the future interpretation and scaling of PRI to quantify rapid changes in photosynthesis, and as an indicator of plant stress.

  12. A central role for the primary microRNA stem in guiding the position and efficiency of Drosha processing of a viral pri-miRNA.

    Science.gov (United States)

    Burke, James M; Kelenis, Demetra P; Kincaid, Rodney P; Sullivan, Christopher S

    2014-07-01

    Processing of primary microRNA (pri-miRNA) stem-loops by the Drosha-DGCR8 complex is the initial step in miRNA maturation and crucial for miRNA function. Nonetheless, the underlying mechanism that determines the Drosha cleavage site of pri-miRNAs has remained unclear. Two prevalent but seemingly conflicting models propose that Drosha-DGCR8 anchors to and directs cleavage a fixed distance from either the basal single-stranded (ssRNA) or the terminal loop. However, recent studies suggest that the basal ssRNA and/or the terminal loop may influence the Drosha cleavage site dependent upon the sequence/structure of individual pri-miRNAs. Here, using a panel of closely related pri-miRNA variants, we further examine the role of pri-miRNA structures on Drosha cleavage site selection in cells. Our data reveal that both the basal ssRNA and terminal loop influence the Drosha cleavage site within three pri-miRNAs, the Simian Virus 40 (SV40) pri-miRNA, pri-miR-30a, and pri-miR-16. In addition to the flanking ssRNA regions, we show that an internal loop within the SV40 pri-miRNA stem strongly influences Drosha cleavage position and efficiency. We further demonstrate that the positions of the internal loop, basal ssRNA, and the terminal loop of the SV40 pri-miRNA cooperatively coordinate Drosha cleavage position and efficiency. Based on these observations, we propose that the pri-miRNA stem, defined by internal and flanking structural elements, guides the binding position of Drosha-DGCR8, which consequently determines the cleavage site. This study provides mechanistic insight into pri-miRNA processing in cells that has numerous biological implications and will assist in refining Drosha-dependent shRNA design.

  13. Potential use of the PRI and active fluorescence for the diagnosis of the physiological state of plants under ozone exposure and high atmospheric vapor pressure deficit.

    Science.gov (United States)

    Merlier, Elodie; Hmimina, Gabriel; Bagard, Matthieu; Dufrêne, Eric; Soudani, Kamel

    2017-08-09

    Assessing photosynthesis rates with remote sensing is important for tracking the physiological state of plants. The photochemical reflectance index (PRI) is a good estimator of short-term light-use efficiency (LUE) at the leaf scale but its responses to environmental factors are poorly understood. In this study, we assessed changes in the responses of the PRI to ozone exposure and to an increase in atmospheric drought (separately and combined) in oak (Quercus robur) and holm oak (Quercus ilex) that were planted in climatic cells under controlled conditions. The aim was to evaluate the ability of the PRI as a relevant indicator to assess the impact of abiotic factors on photosynthesis. Leaf-scale measurements of biochemical, physiological and spectral properties, including the PRI in dim light on dark-adapted leaves (PRI0), kinetics of PRI responses to PAR variations (photosynthetically active radiation), and leaf chlorophyll fluorescence parameters were performed. The results show that PRI0 is a good proxy of the leaf chlorophyll content, and is correlated to chlorophyll fluorescence parameters on dark adapted leaves (Fo, Fm). The correction of the PRI from the leaf chlorophyll content variations (PRIc) significantly improves correlations between the PRI and NPQ (non-photochemical quenching). The variability of PARsat (estimated PAR value at PRI saturation using PRI vs. PAR relationships) depends on ozone exposure and on the increase in atmospheric vapor pressure deficit. For Quercus robur, results highlight that PARsat is linked to abiotic stress indicating that the PRI may be used as a relevant indicator of abiotic factors limiting the photosynthesis. Quercus ilex did not show significant variability in PRI0 and PARsat, which suggest that it is a more drought resistant species than Q. robur.

  14. Photochemical Reflectance Index (PRI) as a proxy of Light Use Efficiency (LUE) and transpiration in Mediterranean crop sites

    Science.gov (United States)

    LE Dantec, V.; Chebbi, W.; Boulet, G.; Merlin, O.; Lili-Chabaane, Z.; Er Raki, S.; Ceschia, E.; Khabba, S.; Fanise, P.; Zawilski, B.; Simonneaux, V.; Jarlan, L.

    2016-12-01

    The Photochemical Reflectance Index (PRI) is based on the short term reversible xanthophyll pigment changes accompanying plant stress and therefore of the associated photosynthetic activities. Strong relationships between PRI and Light Use Efficiency (LUE) were shown at leaf and canopy scales and over a wide range of species (Garbulsky et al., 2011). But very few previous works have explored the potential link with plant water status. In this study, we have first analyzed the link between PRI and LUE at canopy scale on two different crops in terms of canopy structure and crop management: olive grove (Tunisia) and wheat grown under different water regimes (irrigated or rainfed) and climate zones (France, Morocco). We have investigated the daily and seasonal dynamics of PRI; linking its variations to meteorological factors (global radiation and sun angle effects, soil water content, relative air humidity …) and plant processes. The highest correlations were mainly observed in clear skies conditions. We have found, whatever site, linear negative relationships between PRI and LUE using data acquired in midday (i.e. in solar zenithal angle condition). Linear link between PRI and sapflow measurements was also revealed. This correlation was obtained over periods characterized by a moderate soil water deficit, i.e. by when transpiration rate was mainly control by Vapor Pressure Deficit. We will then briefly presented alternative and complementary approaches to this index, to detect different level of water stress using thermal infrared emissions.

  15. SOCIAL PRACTICE PERFORMED BY BALINESE SCULPTORS IN DISTRICTS OF UBUD AND SUKAWATI TO PRY INTO THE LAW OF PHORNOGRAPHY

    Directory of Open Access Journals (Sweden)

    I Ketut Sudita

    2013-02-01

    Full Text Available Balinese sculptors in districts of Ubud and Sukawati, Gianyar, Bali pry into the Law of Pornography. Those who agree state that the law is needed to maintain the morality which has been getting worse, and those who disagree state that it may emasculate their freedom and creativities. This study gives answers to (1 what social practices were performed by the Balinese sculptors to pry into the Law of Pornography?, (2 why did they pry into the application of the law?, and (3 what was the meaning of their prying? Several relevant critical theories such as the theory of structuration, the theory of hegemony, and the theory of aesthetics were eclectically used in this study. The data needed were collected through observation, in-depth interview, documentation study, and library research. The result of the study showed that the Balinese sculptors showed their resistance to the application of the law by making adaptation, changing profession, and still producing pornographic works. The sanction which might be imposed upon them, the consumers of pornographic works decreased, and they were eliminated from exhibitions scared them when they pried into the law. What they did could not be separated from economic, political, ideological, moral, and ethic factors. The meaning of their prying was that it caused them to lose their idealism, their consumers went down, and the number of pornographic works dropped as well.

  16. Ustvarjalni potencial pri prepoznanih nadarjenih učencih v drugem triletju osnovne šole

    OpenAIRE

    Kavčič, Manca

    2017-01-01

    Namen magistrskega dela je preizkus uporabe EPoC testa za oceno ustvarjalnega potenciala v slovenski osnovni šoli in ugotavljanje morebitnega doprinosa EPoC testa k nadaljnjemu ugotavljanju ustvarjalnega potenciala in prepoznavanju nadarjenih učencev pri vsakodnevnem delu učiteljev v slovenskem vzgojno-izobraževalnem prostoru. V teoretičnem delu je skozi spoznanja različnih avtorjev predstavljen pojem ustvarjalnosti, merjenje ustvarjalnosti, odnos med ustvarjalnostjo in nadarjenostjo in vpliv...

  17. Pri-miR-124 rs531564 polymorphism and colorectal cancer risk.

    Science.gov (United States)

    Gao, Xue-Ren; Wang, Hui-Ping; Zhang, Shu-Long; Wang, Ming-Xi; Zhu, Zhan-Sheng

    2015-10-01

    MiR-124 functions as a tumor suppressor and plays an important role in tumorigenesis. A common polymorphism (rs531564, C>G) in the pri-miR-124 has been recently studied in connection with cancer risk. The aim of the present study was to investigate the association between pri-miR-124 rs531564 polymorphism and the risk and clinicopathological characteristics of colorectal cancer (CRC). Two case-control studies involving 900 CRC patients and 1110 cancer-free controls showed that pri-miR-124 rs531564 polymorphism was significantly associated with the decreased risk of CRC in Xuzhou population [GG vs. CC: OR = 0.25, 95%CI = 0.09-0.67, P = 0.003; (CG+GG) vs. CC: OR = 0.73, 95%CI = 0.56-0.94, P = 0.01; GG vs. (CC+CG): OR = 0.27, 95%CI = 0.10-0.70, P = 0.004; G vs. C: OR = 0.70, 95%CI = 0.56-0.89, P = 0.003], Bengbu population [GG vs. CC: OR = 0.20, 95%CI = 0.04-0.90, P = 0.02; GG vs. (CC+CG): OR = 0.21, 95%CI = 0.05-0.95, P = 0.03; G vs. C: OR = 0.72, 95%CI = 0.54-0.98, P = 0.03] and pooled population [GG vs. CC: OR = 0.26, 95%CI = 0.11-0.59, Ppri-miR-124 rs531564 polymorphism was significantly associated with the decreased risk of poor differentiation and lymph node metastasis of CRC. Our results suggest that pri-miR-124 rs531564 polymorphism may be a genetic modifier for developing CRC. However, further studies are needed to validate our findings.

  18. [Effects of pri ming different low-dose rocurium on pharmacodynamics of mivacurium].

    Science.gov (United States)

    Xin, Yan; Guo, Ying; Jiang, Yuge; Zhang, Hong

    2014-06-03

    To explore the effects of pri ming rocuronium on neuromuscular blockade produced by mivacurium. Ethical approval was granted by the medical ethics committee of our hospital with a reference number of C-2013-018-01. A total of 120 ASA physical status I and II patients undergoing selective otorhinolaryngologic surgery under general anesthesia signed the form of informed consent. And they were randomly divided by a random number table into 4 groups. After a standardized imidazole-propofol-fentanyl induction, they received a saline placebo injection (GroupI) and a pri ming dose of rocuronium 0.06 mg/kg (GroupII) , rocuronium 0.075 mg/kg (Group III) and rocuronium 0.1 mg/kg (Group IV). An intubating dose of mivacurium 0.15 mg/kg was offered 3 minutes later. Anesthesia was maintained with propofol and remifentanyl continuous infusion. Neuromuscular block was monitored with train of four (TOF) stimulation. The onset time, reappearance of T1 (DUR TOFc 1), times of T1 25% and 75% recovery, recovery index and times of TOF25%, 75% and 90% recovery were recorded. The onset time of mivacurium was significantly shorter and the times of T1 25% and 75% recovery were significantly longer in groups of II, III and IV than those in groupI. No significant difference existed in recovery index among 4 groups. The onset time of mivacurium became progressively shorter with the growing pri ming dose of rocurium among three experiment groups. And it was not statistically significant. Pri ming rocuronium decreases the onset and intubating times of mivacurium without effect on recovery index. No significant difference exists in drug effect among 3 experiment groups.

  19. VARNOSTNA TVEGANJA PRI RAZVOJU INFORMACIJSKIH REŠITEV S POMOČJO SISTEMOV ZA UPRAVLJANJE VSEBIN

    OpenAIRE

    Leskovar, Uroš

    2015-01-01

    V diplomskem delu je obravnavana problematika varnostnih tveganj pri razvoju in uporabi informacijskih rešitev kadar uporabljamo sisteme za upravljanje vsebin. Varnost v informacijskih sistemih je pogosto ogrožena, kljub vedno novejšim tehnologijam. Diplomsko delo zajema splošen opis treh najpogostejših sistemov za upravljanje vsebin, primerjavo preteklih testiranj sistemov, varnostno testiranje s pomočjo navodil drugih organizacij in pregled najpogostejših nevarnosti. Ugotovljeno je bilo, da...

  20. Stimulation of pri-miR-18a Processing by hnRNP A1.

    Science.gov (United States)

    Michlewski, Gracjan; Guil, Sonia; Cáceres, Javier F

    2011-01-01

    Recent evidence suggests that the canonical miRNA processing pathway can be regulated by a number of positive and negative trans-acting factors. This chapter provides an overview of hnRNP Al-mediated regulation of miR-18a biogenesis. Our laboratory has recently established that the multifunctional RNA-binding protein hnRNP Al is required for the processing of miR-18a at the nuclear step of Drosha-mediated processing. By combining structural and functional analysis of RNA, we showed that hnRNP Al regulates the processing of pri-miR-18a by binding to its terminal loop and reshaping its stem-loop structure, thus allowing for a more effective Drosha cleavage. Furthermore, we linked the event of hnRNP A1-binding to the pri-miR-18a with an unusual phylogenetic sequence conservation of its terminal loop. Bioinformatic and mutational analysis revealed that a number of pri-miRNAs have highly conserved terminal loops, which are predicted to act as landing pads for trans-acting factors influencing miRNA processing. These results underscore a previously uncharacterized role for general RNA-binding proteins as factors that facilitate the processing of specific miRNAs, revealing an additional level of complexity for the regulation of miRNA production and function.

  1. Remote sensing of ecosystem light use efficiency with MODIS-based PRI – the DOs and DON'Ts

    Directory of Open Access Journals (Sweden)

    A. Goerner

    2010-09-01

    Full Text Available Several studies sustained the possibility that a photochemical reflectance index (PRI directly obtained from satellite data can be used as a proxy for ecosystem light use efficiency (LUE in diagnostic models of gross primary productivity. This modelling approach would avoid the complications that are involved in using meteorological data as constraints for a fixed maximum LUE. However, no unifying model predicting LUE across climate zones and time based on MODIS PRI has been published to date. In this study, we evaluate the efficiency with which MODIS-based PRI can be used to estimate ecosystem light use efficiency at study sites of different plant functional types and vegetation densities. Our objective is to examine if known limitations such as dependance on viewing and illumination geometry can be overcome and a single PRI-based model of LUE (i.e. based on the same reference band can be applied under a wide range of conditions. Furthermore, we were interested in the effect of using different faPAR (fraction of absorbed photosynthetically active radiation products on the in-situ LUE used as ground truth and thus on the whole evaluation exercise. We found that estimating LUE at site-level based on PRI reduces uncertainty compared to the approaches relying on a maximum LUE reduced by minimum temperature and vapour pressure deficit. Despite the advantages of using PRI to estimate LUE at site-level, we could not establish an universally applicable light use efficiency model based on MODIS PRI. Models that were optimised for a pool of data from several sites did not perform well.

  2. Remote sensing of ecosystem light use efficiency with MODIS-based PRI - the DOs and DON'Ts

    Science.gov (United States)

    Goerner, A.; Reichstein, M.; Tomelleri, E.; Hanan, N.; Rambal, S.; Papale, D.; Dragoni, D.; Schmullius, C.

    2010-09-01

    Several studies sustained the possibility that a photochemical reflectance index (PRI) directly obtained from satellite data can be used as a proxy for ecosystem light use efficiency (LUE) in diagnostic models of gross primary productivity. This modelling approach would avoid the complications that are involved in using meteorological data as constraints for a fixed maximum LUE. However, no unifying model predicting LUE across climate zones and time based on MODIS PRI has been published to date. In this study, we evaluate the efficiency with which MODIS-based PRI can be used to estimate ecosystem light use efficiency at study sites of different plant functional types and vegetation densities. Our objective is to examine if known limitations such as dependance on viewing and illumination geometry can be overcome and a single PRI-based model of LUE (i.e. based on the same reference band) can be applied under a wide range of conditions. Furthermore, we were interested in the effect of using different faPAR (fraction of absorbed photosynthetically active radiation) products on the in-situ LUE used as ground truth and thus on the whole evaluation exercise. We found that estimating LUE at site-level based on PRI reduces uncertainty compared to the approaches relying on a maximum LUE reduced by minimum temperature and vapour pressure deficit. Despite the advantages of using PRI to estimate LUE at site-level, we could not establish an universally applicable light use efficiency model based on MODIS PRI. Models that were optimised for a pool of data from several sites did not perform well.

  3. Prion-like nanofibrils of small molecules (PriSM): A new frontier at the intersection of supramolecular chemistry and cell biology.

    Science.gov (United States)

    Zhou, Jie; Du, Xuewen; Xu, Bing

    2015-01-01

    Formed by non-covalent interactions and not defined at genetic level, the assemblies of small molecules in biology are complicated and less explored. A common morphology of the supramolecular assemblies of small molecules is nanofibrils, which coincidentally resembles the nanofibrils formed by proteins such as prions. So these supramolecular assemblies are termed as prion-like nanofibrils of small molecules (PriSM). Emerging evidence from several unrelated fields over the past decade implies the significance of PriSM in biology and medicine. This perspective aims to highlight some recent advances of the research on PriSM. This paper starts with description of the intriguing similarities between PriSM and prions, discusses the paradoxical features of PriSM, introduces the methods for elucidating the biological functions of PriSM, illustrates several examples of beneficial aspects of PriSM, and finishes with the promises and current challenges in the research of PriSM. We anticipate that the research of PriSM will contribute to the fundamental understanding at the intersection of supramolecular chemistry and cell biology and ultimately lead to a new paradigm of molecular (or supramolecular) therapeutics for biomedicine.

  4. PRI-CAT: a web-tool for the analysis, storage and visualization of plant ChIP-seq experiments.

    Science.gov (United States)

    Muiño, Jose M; Hoogstraat, Marlous; van Ham, Roeland C H J; van Dijk, Aalt D J

    2011-07-01

    Although several tools for the analysis of ChIP-seq data have been published recently, there is a growing demand, in particular in the plant research community, for computational resources with which such data can be processed, analyzed, stored, visualized and integrated within a single, user-friendly environment. To accommodate this demand, we have developed PRI-CAT (Plant Research International ChIP-seq analysis tool), a web-based workflow tool for the management and analysis of ChIP-seq experiments. PRI-CAT is currently focused on Arabidopsis, but will be extended with other plant species in the near future. Users can directly submit their sequencing data to PRI-CAT for automated analysis. A QuickLoad server compatible with genome browsers is implemented for the storage and visualization of DNA-binding maps. Submitted datasets and results can be made publicly available through PRI-CAT, a feature that will enable community-based integrative analysis and visualization of ChIP-seq experiments. Secondary analysis of data can be performed with the aid of GALAXY, an external framework for tool and data integration. PRI-CAT is freely available at http://www.ab.wur.nl/pricat. No login is required.

  5. [Effects of N, K fertilization on the relationship between photosynthetic light use efficiency and photochemical reflectance index (PRI)].

    Science.gov (United States)

    Wu, Chao-Yang; Niu, Zheng; Tang, Quan; Huang, Wen-Jiang

    2009-02-01

    PRI (Photochemical reflectance index) has provided a fast and reliable method for estimating photosynthetic light use efficiency across species. Increasing efforts have been paid to explore the effects of such disturbances as water content and CO2 concentration on the relationship between PRI and LUE. In the present paper, five types of wheat with different nitrogen and kalium fertilization were selected to study the influence of varied fertilization levels on the relationship between PRI and LUE. The results proved that leaf chlorophyll contents as well as canopy PRI increased with the increase in nitrogen and kalium fertilization. For all the nitrogen and kalium fertilization of wheat, the regression coefficients R2 are 0.710 4 and 0.853 4 respectively. When considering different levels of fertilization, the regression coefficients R2 are 0.602 0, 0.640 4 and 0.801 4 for three types of nitrogen fertilization, and 0.379 1, 0.640 4 and 0.676 9 for kalium fertilization. Therefore, PRI not only can be a reliable indicator of LUE but also can reflect the fertilization situation of wheat with different precisions of LUE assessment which can provide important reference for management and precision agriculture.

  6. POZNAVANJE PLANETOV PRI UČENCIH NA RAZREDNI STOPNJI IZOBRAŽEVANJA

    OpenAIRE

    Makovec, Julijana

    2009-01-01

    Namen raziskave je ugotoviti poznavanje planetov med učenci nižjih razredov osnovne šole. Zanimalo nas je, koliko učenci poznajo planete po imenu in kako jih prepoznajo na podlagi slikovnega gradiva. V nadaljevanju smo želeli raziskati predstave učencev o planetih in njihovih lastnostih. Pri tem nas je zanimalo, ali učenci poznajo velikosti planetov in razmere na njih in ali ločijo planete od zvezd in naravnih satelitov. Na koncu pa smo preverili še, kaj učenci vedo o opazovanju planetov. Ugo...

  7. BALETNE VSEBINE PRI POUKU GLASBENE VZGOJE NA RAZREDNI STOPNJI DEVETLETNE OSNOVNE ŠOLE

    OpenAIRE

    Stergulec, Tjaša

    2011-01-01

    Diplomska naloga obravnava vključitev baletnih vsebin v pouk glasbene vzgoje na razredni stopnji devetletne osnovne šole. V osnovnih šolah imamo veliko plesnih in baletnih vsebin, ki so v učnem načrtu zapisane, vendar premalo podrobno opisane, da bi jih lahko učitelji uporabili. Namen je predstaviti balet kot pomembno dejavnost pri pouku glasbene vzgoje, saj danes otroci odraščajo v družbi, ki se vse premalo zaveda pomembnosti klasičnega baleta kot umetnosti. V diplomskem delu je predstavljen...

  8. Enfermedades priónicas: riesgos y medidas preventivas en Odontología

    OpenAIRE

    2015-01-01

    El objetivo del presente trabajo es hacer una revisión de los últimos trabajos de investigación sobre las enfermedades priónicas para poder actualizar y transmitir información sobre las medidas de prevención y bioseguridad de estos agentes infecciosos no convencionales. Los priones son glucoproteínas situadas en las superficies celulares. Las versiones modificadas de los priones normales ocasionan enfermedades de progresión lenta, a menudo mortales del sistema nervioso central, una de las más...

  9. Mobing kot motnja v komunikaciji pri delu in dejavnik duševnega zdravja dostojanstva posameznika

    OpenAIRE

    Tičar, Luka

    2012-01-01

    Avtor opozarja na vsebinsko kompleksnost pojma mobing, pri čemer pa se v njegovo vsebino ne spušča, četudi je tesno in pomembno povezan s temeljno človekovo pravico do dostojanstva. Izhaja iz predpostavke, da mobing pomeni motnjo v komunikaciji med ljudmi in da je kot tak prej predmet socioloških in psiholoških znanstvenih razprav kot poglobljene pravne analize. Zato izpostavi zgolj eno opredelitev mobinga, z namenom, da bi seznanile bralca z njegovo osnovno vsebino. Pravno razpravo pa omeji ...

  10. ZDRAVSTVENA NEGA IN PREHRANA BOLNIKA PRI KIRURŠKEM ZDRAVLJENJU TREBUŠNE SLINAVKE

    OpenAIRE

    Lulik, Mateja

    2014-01-01

    Diplomsko delo je sestavljeno iz dveh delov. V medicinskem delu je opisana anatomija, fiziologija ter bolezni trebušne slinavke. Drugi del diplomskega dela predstavlja zdravstveno nego bolnika pri kirurškem zdravljenju trebušne slinavke ter najpogostejše negovalne diagnoze po operaciji. Opisana je tudi prehrana bolnika po operaciji, najpogostejša priporočila za prehrano bolnika na domu po odpustu iz bolnišnice ter po operaciji. Diplomsko delo s pomočjo domače, tuje literature in razpoložlj...

  11. Vías de señalización en enfermedades priónicas

    OpenAIRE

    2007-01-01

    Las enfermedades priónicas, también conocidas como EETs (Encefalopatías Espongiformes Transmisibles), son un grupo de enfermedades neurodegenerativas fatales que, debido a su transmisibilidad potencial han tenido un gran impacto social, político y económico en las últimas décadas. Las EETs afectan a los humanos y a algunos grupos de animales, presentan largos períodos de incubación y producen la muerte pocos meses después de la aparición de la sintomatología clínica. Su origen se atribuye a ...

  12. Explaining the variability of Photochemical Reflectance Index (PRI): deconvolution of variability related to Light Use Efficiency and Canopy attributes.

    Science.gov (United States)

    Merlier, Elodie; Hmimina, Gabriel; Dufrêne, Eric; Soudani, Kamel

    2014-05-01

    The Photochemical Reflectance Index (PRI) was designed as a proxy of the state of xanthophyll cycle which is used as a response of plants to excess of light (Gamon et al., 1990; 1992). Strong relationships between PRI and LUE were shown at leaf and canopy scales and over a wide range of species (Garbulsky et al., 2011). However, its use at canopy scale was shown to be significantly hampered by effects of confounding factors such as the PRI sensitivity to leaf pigment content (Gamon et al. 2001; Nakaji et al. 2006) and to canopy structure (Hilker et al. 2008). Several approaches aimed at correcting such effects and recent works focused on the deconvolution of LUE related and LUE unrelated PRI variability (Rahimzadeh-Bajgiran et al. 2012).In this study, the PRI variability at canopy scale is investigated over two years on three species (Fagus sylvatica, Quercus robur and Pinus sylvestris) growing under two water regimes. At daily scale, PRI variability is mainly explained by radiation conditions. As already reported at leaf scale in Hmimina et al. (2014), analysis of PRI responses to incoming photosynthetically active radiation over seasonal scale allowed to separate two sources of variability : a constitutive variability mainly related to canopy structure and leaf chlorophyll content and a facultative variability mainly related to LUE and soil moisture content. These results highlight the composite nature of PRI signal measured at canopy scale and the importance of disentangling its sources of variability in order to accurately assess ecosystem light use efficiency. Gamon JA, Field CB, Bilger W, Björkman O, Fredeen AL, Peñuelas J. 1990. Remote sensing of the xanthophyll cycle and chlorophyll fluorescence in sunflower leaves and canopies. Oecologia 85, 1-7. Gamon JA, Field CB, Fredeen A AL, Thayer S. 2001. Assessing photosynthetic downregulation in sunflower stands with an optically-based model. Photosynthesis Research 67, 113-125. Gamon JA, Peñuelas J, Field CB

  13. <600> MeV synchro-cyclotron

    CERN Multimedia

    1971-01-01

    One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.

  14. MeV fullerene impacts on mica

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

  15. Oleic Acid Induces MiR-7 Processing through Remodeling of Pri-MiR-7/Protein Complex.

    Science.gov (United States)

    Kumar, Santosh; Downie Ruiz Velasco, Angela; Michlewski, Gracjan

    2017-06-02

    MicroRNAs (miRs) play a vital role in governing cell function, with their levels tightly controlled at transcriptional and post-transcriptional levels. Different sets of RNA-binding proteins interact with primary miRs (pri-miRs) and precursor-miR transcripts (pre-miRs), controlling their biogenesis post-transcriptionally. The Hu antigen R (HuR)-mediated binding of Musashi homolog2 (MSI2) to the conserved terminal loop of pri-miR-7 regulates the levels of brain-enriched miR-7 formation in a tissue-specific manner. Here, we show that oleic acid (OA) inhibits the binding of proteins containing RNA recognition motifs (RRM) to the conserved terminal loop of pri-miR-7. Using electrophoretic mobility shift assays in HeLa cell extracts, we show that OA treatment disrupts pre-miR/protein complexes. Furthermore, OA rescues in vitro processing of pri-miR-7, which is otherwise blocked by HuR and MSI2 proteins. On the contrary, pri-miR-16 shows reduced processing in the presence of OA. This indicates that OA may inhibit the binding of other RRM-containing protein/s necessary for miR-16 processing. Finally, we demonstrate that OA induces mature miR-7 production in HeLa cells. Together, our results demonstrate that OA can regulate the processing of pri-miRs by remodeling their protein complexes. This provides a new tool to study RNA processing and a potential lead for small molecules that target the miR-7 biogenesis pathway. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Attachment to Caregivers and Type 1 Diabetes in Children / Navezanost Na Starše in Sladkorna Bolezen Tipa 1 Pri Otrocih

    Directory of Open Access Journals (Sweden)

    Drobnič Radobuljac Maja

    2015-03-01

    Full Text Available Navezanost je vedenjski in fiziološki sistem, ki posamezniku omogoča dinamično prilagajanje na okolje. Navezanost se razvija pri sovplivu med dojenčkom in materjo, igra pomembno vlogo pri razvoju otrokovih možgan in vpliva na kvaliteto posameznikovih socialnih odnosov vse življenje.

  17. Assessing canopy PRI from airborne imagery to map water stress in maize

    Science.gov (United States)

    Rossini, M.; Fava, F.; Cogliati, S.; Meroni, M.; Marchesi, A.; Panigada, C.; Giardino, C.; Busetto, L.; Migliavacca, M.; Amaducci, S.; Colombo, R.

    2013-12-01

    This paper presents a method for mapping water stress in a maize field using hyperspectral remote sensing imagery. An airborne survey using AISA (Specim, Finland) was performed in July 2008 over an experimental farm in Italy. Hyperspectral data were acquired over a maize field with three different irrigation regimes. An intensive field campaign was also conducted concurrently with imagery acquisition to measure relative leaf water content (RWC), active chlorophyll fluorescence (ΔF/Fm‧), leaf temperature (Tl) and Leaf Area Index (LAI). The analysis of the field data showed that at the time of the airborne overpass the maize plots with irrigation deficits were experiencing a moderate water stress, affecting the plant physiological status (ΔF/Fm‧, difference between Tl and air temperature (Tair), and RWC) but not the canopy structure (LAI). Among the different Vegetation Indices (VIs) computed from the airborne imagery the Photochemical Reflectance Index computed using the reflectance at 570 nm as the reference band (PRI570) showed the strongest relationships with ΔF/Fm‧ (r2 = 0.76), Tl - Tair (r2 = 0.82) and RWC (r2 = 0.64) and the red-edge Chlorophyll Index (CIred-edge) with LAI (r2 = 0.64). Thus PRI has been proven to be related to water stress at early stages, before structural changes occurred.

  18. Recomposiciones: el PRI de la primera década del milenio

    Directory of Open Access Journals (Sweden)

    Rosa María Mirón-Lince

    2012-01-01

    Full Text Available Al priísmo del nacionalismo revolucionario, de los consensos forzados y la fundación institucional del México moderno, hoy le prosigue un partido de prácticas arraigadas al control, en el que sin el viejo referente de un jefe máximo encarnado por la figura presidencial, nuevos liderazgos han tenido que tomar la batuta. La recomposición de los flancos de orden y la obligada dispersión del poder al interior y al exterior del partido tricolor, ahora se suma indudablemente a la multiplicación de los epicentros y plataformas desde donde se ejerce el poder. De tal manera, este texto tiene el propósito de situar algunos de los cambios torales del PRI centrándose de forma particular en: 1 el tránsito institucional hacia el fortalecimiento de un marco partidista de mayor apertura y transversalidad; 2 el ascenso de los mandatarios locales como bastiones de la toma de decisiones al interior del partido; y 3 los reacomodos vinculados directamente con el uso táctico de los espacios parlamentarios.

  19. A pri-miR-218 variant and risk of cervical carcinoma in Chinese women

    Directory of Open Access Journals (Sweden)

    Shi Ting-Yan

    2013-01-01

    Full Text Available Abstract Background MicroRNA (miRNA-related single nucleotide polymorphisms (SNPs may compromise miRNA binding affinity and modify mRNA expression levels of the target genes, thus leading to cancer susceptibility. However, few studies have investigated roles of miRNA-related SNPs in the etiology of cervical carcinoma. Methods In this case–control study of 1,584 cervical cancer cases and 1,394 cancer-free female controls, we investigated associations between two miR-218-related SNPs involved in the LAMB3-miR-218 pathway and the risk of cervical carcinoma in Eastern Chinese women. Results We found that the pri-miR-218 rs11134527 variant GG genotype was significantly associated with a decreased risk of cervical carcinoma compared with AA/AG genotypes (adjusted OR=0.77, 95% CI=0.63-0.95, P=0.015. However, this association was not observed for the miR-218 binding site SNP (rs2566 on LAMB3. Using the multifactor dimensionality reduction analysis, we observed some evidence of interactions of these two SNPs with other risk factors, especially age at primiparity and menopausal status, in the risk of cervical carcinoma. Conclusions The pri-miR-218 rs11134527 SNP was significantly associated with the risk of cervical carcinoma in Eastern Chinese women. Larger, independent studies are warranted to validate our findings.

  20. A pri-miR-218 variant and risk of cervical carcinoma in Chinese women.

    Science.gov (United States)

    Shi, Ting-Yan; Chen, Xiao-Jun; Zhu, Mei-Ling; Wang, Meng-Yun; He, Jing; Yu, Ke-Da; Shao, Zhi-Ming; Sun, Meng-Hong; Zhou, Xiao-Yan; Cheng, Xi; Wu, Xiaohua; Wei, Qingyi

    2013-01-15

    MicroRNA (miRNA)-related single nucleotide polymorphisms (SNPs) may compromise miRNA binding affinity and modify mRNA expression levels of the target genes, thus leading to cancer susceptibility. However, few studies have investigated roles of miRNA-related SNPs in the etiology of cervical carcinoma. In this case-control study of 1,584 cervical cancer cases and 1,394 cancer-free female controls, we investigated associations between two miR-218-related SNPs involved in the LAMB3-miR-218 pathway and the risk of cervical carcinoma in Eastern Chinese women. We found that the pri-miR-218 rs11134527 variant GG genotype was significantly associated with a decreased risk of cervical carcinoma compared with AA/AG genotypes (adjusted OR=0.77, 95% CI=0.63-0.95, P=0.015). However, this association was not observed for the miR-218 binding site SNP (rs2566) on LAMB3. Using the multifactor dimensionality reduction analysis, we observed some evidence of interactions of these two SNPs with other risk factors, especially age at primiparity and menopausal status, in the risk of cervical carcinoma. The pri-miR-218 rs11134527 SNP was significantly associated with the risk of cervical carcinoma in Eastern Chinese women. Larger, independent studies are warranted to validate our findings.

  1. La democracia fallida: la batalla de Carlos A. Madrazo por cambiar al PRI

    Directory of Open Access Journals (Sweden)

    Ricardo Pozas-Horcasitas

    2008-03-01

    Full Text Available El artículo analiza la llegada de Carlos Alberto Madrazo al Comité Ejecutivo Nacional del Partido Revolucionario Institucional (PRI, y su intento por reformar al partido, introduciendo prácticas de selección a través de la elección directa de los representantes en el partido, así como en las candidaturas a los cargos de elección popular, reforma que confrontó la tradición de la autoridad política vertical y la designación de candidatos a cargos de elección en México.The article analyzes Carlos Alberto Madrazo's arrival at the National Executive Committee of the Institutional Revolutionary Party (PRI, the political environment of his arrival, his attempt to reform the party by introducing selection practices through the direct election of representatives in the party and candidacies for popularly-elected posts, a reform that challenged the tradition of vertical political authority and the designation of candidates toelected positions in Mexico.

  2. Explaining the variability of the photochemical reflectance index (PRI) at the canopy-scale: Disentangling the effects of phenological and physiological changes.

    Science.gov (United States)

    Merlier, Elodie; Hmimina, Gabriel; Dufrêne, Eric; Soudani, Kamel

    2015-10-01

    Assessing photosynthesis rates at the ecosystem scale and over large regions is important for tracking the global carbon cycle and remote sensing has provided new and useful approaches for performing this assessment. The photochemical reflectance index (PRI) is a good estimator of short-term light-use efficiency (LUE) at the leaf scale; however, confounding factors appear at larger temporal and spatial scales. In this study, canopy-scale PRI variability was investigated for three species (Fagus sylvatica L., Quercus robur L. and Pinus sylvestris L.) growing under contrasting soil moisture conditions. Throughout the growing season, no significant differences in chlorophyll content and in violaxanthin, antheraxanthin and zeaxanthin were found between species or treatments. The daily PRI vs PAR (photosynthetically active radiation) relationships were determined using continuous measurements obtained at high frequency throughout the entire growing season, from early spring budburst to later autumn senescence, and were used to deconvolute the physiological PRI variability related to LUE variations due to phenological variability and related to temporal changes in the biochemical and structural canopy attributes. The PRI vs PAR relationship is used to show that the canopy-scale PRI measured at low radiation depends on the chlorophyll content of the canopy. The range of PRI variations at an intra-daily scale and the dynamics of the xanthophyll pool do not vary between days, which suggests that the PRI responds to a xanthophyll ratio. The PAR values at PRI saturation are mainly related to the canopy chlorophyll content during budburst and senescence and to the soil moisture content when the chlorophyll content is no longer a limiting factor. This parameter is significantly lower in the oak species that experience less stress from variations in soil moisture and is species dependant. These results provide new insights regarding the analysis and the meaning of PRI

  3. Involvement of PI3-K in neuroprotective effects of the 1,25-dihydroxyvitamin D3 analogue - PRI-2191.

    Science.gov (United States)

    Regulska, Magdalena; Leśkiewicz, Monika; Budziszewska, Bogusława; Kutner, Andrzej; Basta-Kaim, Agnieszka; Kubera, Marta; Jaworska-Feil, Lucylla; Lasoń, Władysław

    2006-01-01

    The active form of 1,25-dihydroxyvitamin D(3) prevents neuronal damage in vitro and in vivo , however, it induces also hypercalcemia and hyperphosphatemia. Side-chain-modified analogues of 1,25-dihydroxyvitamin D(3), which show low calcemic activity, may be potentially useful in the treatment of some neurodegenerative diseases. Previously, we have found that PRI-2191 more potently than 1,25-dihydroxyvitamin D(3) protects human neuroblastoma (SH-SY5Y) cells against hydrogen-peroxide-induced toxicity. In the present study, we evaluated effects of two other 1,25-dihydroxyvitamin D(3) analogues - PRI-1890 and PRI-1901 on the neuronal degeneration in the same cell model. In line with the previous study, 24-h incubation with hydrogen peroxide (0.5 mM) was toxic to cells, as evidenced by an enhanced efflux of lactate dehydrogenase into the culture medium, and these effects were prevented by PRI-1890 and PRI-1901 at concentration of 5, 50 and 500 nM. Comparing the neuroprotective effects of secosteroids, we found that all three analogues were efficient at lower concentration than 1,25-dihydroxyvitamin D(3) and among them the PRI-2191 showed the most evident concentration-dependent effect. In the second part of this study, an involvement of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3-K), kinases which play a crucial role in neurodegenerative processes, in neuroprotective action of 1,25 dihydroxyvitamin D(3) and its the most potent analogue PRI-2191 has been investigated. The inhibitor of c-Jun N-terminal kinase (JNK)-MAPK (SP600125, 1 microM), inhibitor of p38-MAPK (SB-203580, 1 and 10 microM) and inhibitor of extracellular signal-regulated kinase (ERK)-MAPK (PD-98059, 15 and 30 microM) attenuated the hydrogen peroxide-induced toxicity. Moreover, PD-98059 (30 microM) enhanced neuroprotective effects of 1,25 dihydroxyvitamin D(3) but not that of PRI-2191. In contrast, the inhibitor of PI3-K (wortmannin, 10, 100 nM) did not affect hydrogen

  4. Association between pri-miR-218 polymorphism and risk of hepatocellular carcinoma in a Han Chinese population.

    Science.gov (United States)

    Zhang, Lu-Shun; Liang, Wei-Bo; Gao, Lin-Bo; Li, Hong-Yu; Li, Li-Juan; Chen, Peng-Yu; Liu, Yun; Chen, Tian-Yi; Han, Jun-Ge; Wei, Yong-Gang; Zhang, Lin

    2012-05-01

    MicroRNAs are noncoding RNA molecules of 18-25 nucleotides that regulate gene expression at the post-transcriptional level. The aim of this study was to investigate whether pri-miR-218 rs11134527 A/G polymorphism influences the risk of hepatocellular carcinoma (HCC) or not. pri-miR-218 rs11134527 A/G was genotyped in 302 HCC patients and 513 control subjects using the polymerase chain reaction-restriction fragment length polymorphism assay. The AG genotype of pri-miR-218 rs11134527 A/G was associated with family history (p=0.018, odds ratio [OR]=2.96, 95% confidence interval [CI]: 1.16-7.56) and elevated serum α-fetoprotein (serum alpha-fetoprotein [AFP]) levels (≥20 ng/mL; p=0.009, OR=1.92, 95% CI: 1.17-3.14) in HCC patients. These findings suggested that the AG genotype of pri-miR-218 rs11134527 might relate to genetic predisposition and be involved in regulating the expression of AFP in Chinese HCC patients.

  5. Interactions of Pri-miRNA-34b/c and TP53 Polymorphisms on the Risk of Osteoporosis.

    Science.gov (United States)

    Jia, Fu; Sun, Ruifen; Li, Jian; Li, Qi; Chen, Gang; Fu, Weili

    2016-07-01

    Osteoporosis (OP) is a common, multifactorial disorder. Here, we investigated the association between polymorphisms in pri-miR-34b/c (rs4938723) and TP53 (Arg72Pro) and the prevalence of OP. A total of 681 individuals were assessed in a case-control study, including 310 patients with OP and 371 controls. Variants in pri-miR-34b/c and TP53 were identified using a polymerase chain reaction-restriction fragment length polymorphism method. The presence of the CC and CT/CC pri-miR-34b/c genotypes were associated with a significantly reduced risk of OP compared with the TT genotype (CC vs. TT: odds ratio [OR] = 0.32, 95% confidence intervals [CI] = 0.17-0.59; p pri-miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms may contribute to the risk of OP.

  6. NEAT1 scaffolds RNA-binding proteins and the Microprocessor to globally enhance pri-miRNA processing.

    Science.gov (United States)

    Jiang, Li; Shao, Changwei; Wu, Qi-Jia; Chen, Geng; Zhou, Jie; Yang, Bo; Li, Hairi; Gou, Lan-Tao; Zhang, Yi; Wang, Yangming; Yeo, Gene W; Zhou, Yu; Fu, Xiang-Dong

    2017-08-28

    MicroRNA (miRNA) biogenesis is known to be modulated by a variety of RNA-binding proteins (RBPs), but in most cases, individual RBPs appear to influence the processing of a small subset of target miRNAs. Here, we report that the RNA-binding NONO-PSF heterodimer binds a large number of expressed pri-miRNAs in HeLa cells to globally enhance pri-miRNA processing by the Drosha-DGCR8 Microprocessor. NONO and PSF are key components of paraspeckles organized by the long noncoding RNA (lncRNA) NEAT1. We further demonstrate that NEAT1 also has a profound effect on global pri-miRNA processing. Mechanistic dissection reveals that NEAT1 broadly interacts with the NONO-PSF heterodimer as well as many other RBPs and that multiple RNA segments in NEAT1, including a 'pseudo pri-miRNA' near its 3' end, help attract the Microprocessor. These findings suggest a 'bird nest' model in which an lncRNA orchestrates efficient processing of potentially an entire class of small noncoding RNAs in the nucleus.

  7. Demonstrating FLAVOUR: Friendly Location-aware conference Assistant with priVacy Observant architectURe (Demo Paper)

    NARCIS (Netherlands)

    Muthukrishnan, Kavitha; Meratnia, Nirvana; Koprinkov, Georgi; Lijding, Maria; Havinga, Paul

    2005-01-01

    In this paper, we describe an implementation of FLAVOUR (Friendly Location-aware conference Assistant with priVacy Observant architectURe), in which people/infrastructure resources act as individual service providers offering their location as a service. By subscribing to this service, in the one ha

  8. PriFi - Using a Multiple Alignment of Related Sequences to Find Primers for  Amplification of Homologs

    DEFF Research Database (Denmark)

    Fredslund, Jakob; Schauser, Leif; Madsen, Lene Heegaard

    2005-01-01

    phylogenetically related species and outputs a list of possibly degenerate primer pairs fulfilling a number of criteria, such that the primers have a maximal probability of amplifying orthologous sequences in other phylogenetically related species. Operating on a genome-wide scale, PriFi automates the first steps...

  9. Remote sensing of plant emissions of volatile isoprenoids with PRI. Prospects for upscaling (Invited)

    Science.gov (United States)

    Penuelas, J.

    2013-12-01

    Josep Peñuelas*1,2, Giovanni Marino1,2,3,4, Joan LLusia1,2, Catherine Morfopoulos1,2,5, Gerard Farre-Armengol1,2, Shawn Kefauver, Alex Guenther6 , Francesca Rapparini7 , Roger Seco1,2,6, Marc Estiarte1,2, Mónica Mejia-Chang1,2, Romà Ogaya1,2, Jordi Sardans1,2 , Andrew Turnipseed6, Peter Harley6, Osvaldo Facini7, Rita Baraldi7, Jim Greenberg6 , Iolanda Filella1,2 1 CSIC, Global Ecology Unit CREAF-CEAB-UAB, Cerdanyola del Vallés 08193, Catalonia, Spain 2 CREAF, Cerdanyola del Vallés 08193, Catalonia, Spain 3 Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Contrada Fonte Lappone, 86090 Pesche (IS), Italy 4 Institute for Plant Protection, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy 5 Division of Ecology and Evolution, Imperial College, Silwood Park, Ascot, SL5 7PY, UK 6 Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000, USA 7 Biometeorology Institute, IBIMET-CNR, Via P. Gobetti 101, Bologna, Italy Abstract Terrestrial plants re-emit around 1-2% of the carbon they fix as isoprene and monoterpenes. These emissions play major roles in the ecological relationships among living organisms and in atmospheric chemistry and climate, and yet their actual quantification at the ecosystem level in different regions is far from being resolved. Phenomenological models are used to estimate the emission rates, but the limited understanding of the function and regulation of these emissions leads to large uncertainties in such estimations. Many measurements have been made at the foliar but few at the ecosystem level, and those that do exist are limited in space and time. We here provide evidence that a simple remote sensing index, the photochemical reflectance index (PRI), which is indicative of light use efficiency (LUE), is a good indirect estimator of foliar isoprenoid emissions and therefore can be used to sense them remotely. These results open

  10. The promoter of the pri-miR-375 gene directs expression selectively to the endocrine pancreas.

    Science.gov (United States)

    Avnit-Sagi, Tali; Kantorovich, Lia; Kredo-Russo, Sharon; Hornstein, Eran; Walker, Michael D

    2009-01-01

    microRNAs (miRNAs) are known to play an essential role in controlling a broad range of biological processes including animal development. Accordingly, many miRNAs are expressed preferentially in one or a small number of cell types. Yet the mechanisms responsible for this selectivity are not well understood. The aim of this study was to elucidate the molecular basis of cell-specific expression of the pri-miR-375 gene, which is selectively expressed in pancreatic islets, and has been implicated both in the development of islets, and the function of mature pancreatic beta cells. An evolutionarily conserved 768 bp region of DNA upstream of the pri-miR-375 gene was linked to GFP and luciferase reporter genes, and expression monitored in transgenic mice and transfected cultured cells. Deletion and targeted mutagenesis analysis was used to evaluate the functional significance of sequence blocks within the upstream fragment. 5'-RACE analysis was used for mapping the pri-miR-375 gene transcription start site. The conserved 768 bp region was able to direct preferential expression of a GFP reporter gene to pancreatic islets in transgenic mice. Deletion analysis using a luciferase reporter gene in transfected cultured cell lines confirmed the cell specificity of the putative promoter region, and identified several key cis-elements essential for optimal activity, including E-boxes and a TATA sequence. Consistent with this, 5'-RACE analysis identified a transcription start site within this DNA region, 24 bp downstream of the TATA sequence. These studies define the promoter of the pri-miR-375 gene, and show that islet-specific expression of the pri-miR-375 gene is controlled at the transcriptional level. Detailed analysis of the transcriptional mechanisms controlling expression of miRNA genes will be essential to permit a comprehensive understanding of the complex role of miRNAs such as miR-375 in developmental processes.

  11. Fungal volatile compounds induce production of the secondary metabolite Sodorifen in Serratia plymuthica PRI-2C.

    Science.gov (United States)

    Schmidt, Ruth; Jager, Victor de; Zühlke, Daniela; Wolff, Christian; Bernhardt, Jörg; Cankar, Katarina; Beekwilder, Jules; Ijcken, Wilfred van; Sleutels, Frank; Boer, Wietse de; Riedel, Katharina; Garbeva, Paolina

    2017-04-13

    The ability of bacteria and fungi to communicate with each other is a remarkable aspect of the microbial world. It is recognized that volatile organic compounds (VOCs) act as communication signals, however the molecular responses by bacteria to fungal VOCs remain unknown. Here we perform transcriptomics and proteomics analyses of Serratia plymuthica PRI-2C exposed to VOCs emitted by the fungal pathogen Fusarium culmorum. We find that the bacterium responds to fungal VOCs with changes in gene and protein expression related to motility, signal transduction, energy metabolism, cell envelope biogenesis, and secondary metabolite production. Metabolomic analysis of the bacterium exposed to the fungal VOCs, gene cluster comparison, and heterologous co-expression of a terpene synthase and a methyltransferase revealed the production of the unusual terpene sodorifen in response to fungal VOCs. These results strongly suggest that VOCs are not only a metabolic waste but important compounds in the long-distance communication between fungi and bacteria.

  12. Razvoj odklanjala za rastrsko vodenje žarka pri laserskem označevanju

    OpenAIRE

    Diaci, Janez; Babnik, Aleš; Bizjak, Aleš

    2015-01-01

    Prispevek predstavlja razvoj optomehatronskega sistema, ki omogoča izdelavo rastrskih vzorcev pri laserskem označevanju. Sistem deluje tako, da v eni osi odklanjamo obdelovalni laserski žarek s pomočjo poligonskega zrcala v obliki šesterokotne prizme, ki se vrti s konstantno kotno hitrostjo. Vsak laserski blisk povzroči na površini obdelovanca označbo v obliki točke. Z odklanjanjem žarka dosežemo, da so točkaste označbe razvrščene enakomerno v ravni črti - vrstici. Pomična miza, ki je pod odk...

  13. DIDAKTIČNE IGRE PRI POUKU SPOZNAVANJA OKOLJA ZUNAJ UČILNICE

    OpenAIRE

    Majcen, Doroteja

    2014-01-01

    Didaktična igra se uporablja kot učna metoda, imeti mora vse lastnosti igre in dosegati določene (učne) cilje. Didaktična igra zunaj učilnice nudi učencu izkušnje in ob njej razvija pozitiven odnos do okolja in narave, kar je pri pouku spoznavanja okolja še posebej poudarjeno. V teoretičnem delu smo opredelili predmet spoznavanja okolja ter navedli didaktična priporočila za uresničevanje ciljev predmeta in vpeljevanje pouka spoznavanja okolja v naravo. Našteli in opisali smo didaktične strate...

  14. Patología del sueño en las enfermedades priónicas Sleep disorders in prion diseases

    OpenAIRE

    2007-01-01

    Las enfermedades priónicas son un grupo de encefalopatías con cambios neurodegenerativos causados por una proteína alterada denominada prión cuyo dato característico es la transmisibilidad. Ocurren la mayoría de las veces de forma esporádica aunque un grupo de ellas son familiares asociadas a mutaciones en el gen de la proteína priónica. El polimorfismo genético parece determinar las diferentes variantes familiares. Una de las más enigmáticas e inhabituales es el Insomnio Letal Familiar (ILF)...

  15. Responses of the reflectance indices PRI and NDVI to experimental warming and drought in European shrublands along a north–south climatic gradient

    DEFF Research Database (Denmark)

    Mänd, Pille; Hallik, Lea; Peñuelas, Josep;

    2010-01-01

    canopy reflectance, effective green leaf area index (green LAIe) and chlorophyll fluorescence of dominant species. The treatment effects on green LAIe varied among sites. We calculated three reflectance indices: photochemical reflectance index PRI [531 nm; 570 nm], normalized difference vegetation index...... NDVI680 [780 nm; 680 nm] using red spectral region, and NDVI570 [780 nm; 570 nm] using the same green spectral region as PRI. All three reflectance indices were significantly related to green LAIe and were able to detect changes in shrubland vegetation among treatments. In general warming treatment...... in vegetation areas with low green LAIe. As both soil reflectance and LAI varied between northern and southern sites it is problematic to draw universal conclusions of climate-derived changes in all vegetation types based merely on PRI measurements. We propose that canopy level PRI measurements can be more...

  16. 一种 PRI 变化的雷达信号无源定位方法%A Passive Location Method of The Radar Signal with Variational PRI

    Institute of Scientific and Technical Information of China (English)

    陈晓威; 李彦志; 张国毅

    2016-01-01

    目前脉冲重复间隔(PRI)恒定的雷达信号已经越来越少,取而代之的是PRI变化的雷达信号。传统的相位差变化率定位法均假设PRI恒定,没有考虑因PRI变化引起的相位差变化率测量误差和定位误差。提出了一种利用插值法重新构造相位差数据的方法,提取了相位差变化率并进行了定位解算。仿真结果表明采用该相位差数据重构方法能够实现快速高精度的无源定位。%Currently ,radar signal with constant pulse repetition interval (PRI) is less and less ,in-stead of this is radar signal with variational PRI .Traditional location method of phase difference change rate almost supposes that PRI is constant ,hasn't considered the measuring error of phase difference rate and position error due to the change of PRI .This paper puts forward a kind of meth-od to reconstruct phase difference data by means of interpolation method ,abstracts the phase difference rate and performs location calculation .T he simulation results show that the method to reconstruct phase difference data can quickly achieve passive location with high accuracy .

  17. PRI 3.1: Electrolyte membrane fuel cells (Co-PACEM), final report (july 2002 to june 2004); PRI 3.1: Coeurs de piles a combustible a electrolyte membrane (Co-PACEM), rapport final (juillet 2002 a juin 2004)

    Energy Technology Data Exchange (ETDEWEB)

    Lamy, C.

    2004-07-01

    The researches realized in the PRI Co-PACEM aim to improve the operating of the core of the electrolyte membrane fuel cells, at low temperature in order to minimize the high voltage of the electro-chemical reactions, to decrease the cost of the membrane, to improve the properties (conductivity, mechanical and thermal stability...) and to optimize the transport of heat and reactive. The document presents the research programs. (A.L.B.)

  18. The pathogen-related yeast protein Pry1, a member of the CAP protein superfamily, is a fatty acid-binding protein.

    Science.gov (United States)

    Darwiche, Rabih; Mène-Saffrané, Laurent; Gfeller, David; Asojo, Oluwatoyin A; Schneiter, Roger

    2017-05-19

    Members of the CAP superfamily (cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins), also known as SCP superfamily (sperm-coating proteins), have been implicated in many physiological processes, including immune defenses, venom toxicity, and sperm maturation. Their mode of action, however, remains poorly understood. Three proteins of the CAP superfamily, Pry1, -2, and -3 (pathogen related in yeast), are encoded in the Saccharomyces cerevisiae genome. We have shown previously that Pry1 binds cholesterol in vitro and that Pry function is required for sterol secretion in yeast cells, indicating that members of this superfamily may generally bind sterols or related small hydrophobic compounds. On the other hand, tablysin-15, a CAP protein from the horsefly Tabanus yao, has been shown to bind leukotrienes and free fatty acids in vitro Therefore, here we assessed whether the yeast Pry1 protein binds fatty acids. Computational modeling and site-directed mutagenesis indicated that the mode of fatty acid binding is conserved between tablysin-15 and Pry1. Pry1 bound fatty acids with micromolar affinity in vitro, and its function was essential for fatty acid export in cells lacking the acyl-CoA synthetases Faa1 and Faa4. Fatty acid binding of Pry1 is independent of its capacity to bind sterols, and the two sterol- and fatty acid-binding sites are nonoverlapping. These results indicate that some CAP family members, such as Pry1, can bind different lipids, particularly sterols and fatty acids, at distinct binding sites, suggesting that the CAP domain may serve as a stable, secreted protein domain that can accommodate multiple ligand-binding sites. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. ¿Por qué perdió el PRI en Yucatán? Las transiciones de este año en bastiones priístas, caída de una imagen distorsionada

    Directory of Open Access Journals (Sweden)

    Lic. Fernando Pacheco Bailón

    2001-01-01

    Full Text Available El pasado domingo 27 de mayo, a eso de las 5:30 de la tarde, los mexicanos nos enteramos a través de los medios de comunicación de televisión abierta y pagada de la ventaja que tenía el candidato a la gubernatura de Yucatán, a través de la coalición PAN, PRD, PVEM, PT, Patricio Patrón Laviada, con respecto al candidato del PRI, Orlando Paredes Lara. Más tarde, de aquella llamada telefónica que hiciera el presidente Vicente Fox para felicitar al candidato que aventajaba al del tricolor, al hacer referencia a las encuestas de salida llevadas a cabo por empresas como Consulta Mitovsky, Garo y otras más. Hay muchas metodologías para poder analizar procesos electorales, así como distintas formas de abordar el problema del por qué perdió el PRI en Yucatán. Para efectos de estudio se planteará las condiciones preelectorales que se dieron, el propio momento electoral del pasado 27 de mayo, así como la visión futura de PRI como organización política en tiempos transitorios.

  20. Neki problemi pri prevođenju moderne poezije promatrani kroz teoriju konceptualne integracije

    Directory of Open Access Journals (Sweden)

    Sanja Cimer

    2011-12-01

    Full Text Available Straußeneimondaber ich finde nichts mehrnichts mehr an Buchstaben im Wortmache so ähnlichwie Luftgang ohne Seiles fällt nichts mehraber nichts ist eben auchZaungrenzeund LebenMittelstelzengangder Strauß legt seine Eier in den Himmelfast Massenproduktionkugelrunde Stundenmit Haut auf wirren ÜberzugHände greifen leerwenn nicht duaber das kann nicht –Angsttauchen mit Höhengangund die Hand als Schalewer fängt, – verliert!Mjesec od nojevog jajetaali nema ničeg višeničeg više u slovima riječičinim sličnokao hod po zraku bez konopcaništa više ne padaali i ništa jestgranica od ogradei životsredinom na štulamanoj liježe svoja jaja u nebogotovo masovna proizvodnjasati okrugli poput loptes kožom na neurednoj presvlaciruke posežu u praznoako nisi tiali to ne može –uron u strah s letom u visinei ruka poput ljusketko ulovi, – izgubi!Prevođenje poezije oduvijek se smatralo osobitom temom unutar ionako složenog područja književnog prevođenja. Budući da poezija predstavlja književni oblik u kojem su sadržaj i forma nerazdvojno povezani, jasno je zašto ona predstavlja najzahtjevniji oblik prevoditeljske aktivnosti. Problematičnu točku pri prevođenju poezije predstavlja činjenica da ona daje izrazito “zgusnutu” i kompaktnu formu te da jezik poezije uglavnom počiva na konotacijama, a ne na denotacijama. Noviji pristupi prevođenju prepoznaju da su nekadašnja protivljenja prevođenju poezije, to jest isticanja njezine neprevodivosti, zapravo bila usmjerena na nemogućnost potpunog prenošenja svih aspekata izvornog poetskog djela u ciljni jezik i njegovu kulturu i tradiciju (neprevodivost poezije isticali su, primjerice, T. S. Eliott: “[poezija je] stalni podsjetnik na sve ono što se može reći samo na jednom jeziku”, Roman Jakobson: “poezija je po definiciji neprevodiva” ili Nabokov: “pjesma ne može biti prevedena, reproducirana ni iznova oblikovana na ciljnom jeziku” (svi navedeni citati te citati

  1. Developmentally regulated expression and complex processing of barley pri-microRNAs.

    Science.gov (United States)

    Kruszka, Katarzyna; Pacak, Andrzej; Swida-Barteczka, Aleksandra; Stefaniak, Agnieszka K; Kaja, Elzbieta; Sierocka, Izabela; Karlowski, Wojciech; Jarmolowski, Artur; Szweykowska-Kulinska, Zofia

    2013-01-16

    MicroRNAs (miRNAs) regulate gene expression via mRNA cleavage or translation inhibition. In spite of barley being a cereal of great economic importance, very little data is available concerning its miRNA biogenesis. There are 69 barley miRNA and 67 pre-miRNA sequences available in the miRBase (release 19). However, no barley pri-miRNA and MIR gene structures have been shown experimentally. In the present paper, we examine the biogenesis of selected barley miRNAs and the developmental regulation of their pri-miRNA processing to learn more about miRNA maturation in barely. To investigate the organization of barley microRNA genes, nine microRNAs - 156g, 159b, 166n, 168a-5p/168a-3p, 171e, 397b-3p, 1120, and 1126 - were selected. Two of the studied miRNAs originate from one MIR168a-5p/168a-3p gene. The presence of all miRNAs was confirmed using a Northern blot approach. The miRNAs are encoded by genes with diverse organizations, representing mostly independent transcription units with or without introns. The intron-containing miRNA transcripts undergo complex splicing events to generate various spliced isoforms. We identified miRNAs that were encoded within introns of the noncoding genes MIR156g and MIR1126. Interestingly, the intron that encodes miR156g is spliced less efficiently than the intron encoding miR1126 from their specific precursors. miR397b-3p was detected in barley as a most probable functional miRNA, in contrast to rice where it has been identified as a complementary partner miRNA*. In the case of miR168a-5p/168a-3p, we found the generation of stable, mature molecules from both pre-miRNA arms, confirming evolutionary conservation of the stability of both species, as shown in rice and maize. We suggest that miR1120, located within the 3' UTR of a protein-coding gene and described as a functional miRNA in wheat, may represent a siRNA generated from a mariner-like transposable element. Seven of the eight barley miRNA genes characterized in this study contain

  2. Pri I J K(介绍国际青年世界语者大会)

    Institute of Scientific and Technical Information of China (English)

    王瑞祥

    1994-01-01

    ■irkaǔ160 esperantistoj el 33 landoj kun granda entuziasmo partoprenis en la 49-a Interna-cia Junulara Kongreso(IJK) de la 7-a ■is la 14-a de aǔgusto 1993 en la urbo Vraca, Bulgario.La inaǔguro okazis en la Urba Artgalerio. Aliaj kunvenoj estis aran■itaj en apudurba univer-sitata kvartalo, kie la ■eestantoj ankaǔ lo■is. Tage,LKK organizis interesajn programerojn laǔ lagustoj de la junuloj. Estis diskuto pri la modernaj tendencoj en Esperanto-Komunumo, prelegoj dela"kongresa universitato", renkonti■oj de redaktoroj de junularaj gazetoj kaj de partopernantoj deIJK en la jaro 1963, kiu okazis ankaǔ en Vraca, diversaj kursoj, forumo pri Bulgario, internaci-aj ekzamenoj de UEA/ILEI kaj pluraj Esperant-lingvaj videofilm-prezentoj. Interalie, la revuo

  3. The archaeo-eukaryotic GINS proteins and the archaeal primase catalytic subunit PriS share a common domain

    Directory of Open Access Journals (Sweden)

    Swiatek Agnieszka

    2010-04-01

    Full Text Available Abstract Primase and GINS are essential factors for chromosomal DNA replication in eukaryotic and archaeal cells. Here we describe a previously undetected relationship between the C-terminal domain of the catalytic subunit (PriS of archaeal primase and the B-domains of the archaeo-eukaryotic GINS proteins in the form of a conserved structural domain comprising a three-stranded antiparallel β-sheet adjacent to an α-helix and a two-stranded β-sheet or hairpin. The presence of a shared domain in archaeal PriS and GINS proteins, the genes for which are often found adjacent on the chromosome, suggests simple mechanisms for the evolution of these proteins. Reviewers This article was reviewed by Zvi Kelman (nominated by Michael Galperin and Kira Makarova.

  4. PRI变换法用于信号分选的性能研究%Research on performance of PRI transform in signal sorting

    Institute of Scientific and Technical Information of China (English)

    张什永; 张海黎; 徐龙; 胡泽宾

    2012-01-01

    Since it can suppress PRI harmonics efficiently,PRI transform,a DTOA-based algorithm,is widely researched in radar signal sorting.Phase factor is firstly discussed,and its effect in PRI spectrum accumulating is revealed;then both the limitations of PRI transform and its adapted PRI types are analyzed theoretically.Finally,the performance of PRI transform to real signal environment is given by computer simulations.Both theoretical analysis and simulation results can be used as engineering reference.%PRI变换是一种基于脉冲到达时间的信号分选方法,由于该算法能够有效抑制真实PRI的谐波,近年来受到越来越多的关注。首先讨论了相位因子的作用,揭示了相位因子是进行变换谱峰值累积的关键;接着通过理论分析指出了PRI变换法的局限和适用的PRI类型;最后仿真分析了该方法对分选过程所面临的信号环境的适应性。理论及仿真分析结果可作为工程应用的参考依据,具有一定的实用价值。

  5. No association of functional variant in pri-miR-218 and risk of congenital heart disease in a Chinese population.

    Science.gov (United States)

    Gao, Xiaobo; Yang, Liping; Ma, Yan; Yang, Juhua; Zhang, Guican; Huang, Guoying; Huang, Qiuyu; Chen, Liangwan; Fu, Fangmeng; Chen, Yandan; Su, Dongmei; Dong, Yi; Ma, Xu; Lu, Cailing; Peng, Xiaozhong

    2013-07-10

    MiR-218 plays an important role in heart development in zebrafish. pri-miR-218 rs11134527 variant is associated with cervical cancer carcinogenesis. Therefore, we hypothesized that single nucleotide polymorphism (SNPs) in pri-miR-218 might influence susceptibility to sporadic congenital heart disease (CHD). We conducted a case-control study of CHD in a Chinese population to test our hypothesis by sequencing and genotyping pri-miR-218 in 1116 CHD cases and 1219 non-CHD controls. We identified one SNP rs11134527 located in pri-miR-218 sequence. Logistic regression analyses showed that there was no significant association in genotype and allele frequencies of pri-miR-218 rs11134527 A/G polymorphism between CHD cases in overall or various subtypes and the control group. However, real-time PCR analysis showed that rs11134527 allele G significantly increased mature miR-218 expression. In vitro binding assays further revealed that the rs11134527 variant affects miR-218-mediated regulation of Robo1. This is the first study to investigate the relationship between miR-218 and CHD cases. Our results demonstrate that the functional variant rs11134527 in pri-miR-218 has no major role in genetic susceptibility to sporadic CHD, at least in the population studied here. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Promotion of cortico-cerebral precursors expansion by artificial pri-miRNAs targeted against the Emx2 locus.

    Science.gov (United States)

    Diodato, Assunta; Pinzan, Moira; Granzotto, Marilena; Mallamaci, Antonello

    2013-04-01

    Emx2 encodes for a transcription factor controlling several aspects of cerebral cortex development. Its overexpression promotes self-renewal of young cortico-cerebral precursors, it promotes neuronal rather than gliogenic fates and it protects neuronal progenitors from cell death. These are all key activities for purposes of gene-promoted brain repair. Artificial pri-miRNAs targeting non-coding cis-active modules and/or conserved sequences of the Emx2 locus were delivered to embryonic cortico-cerebral precursors, by lentiviral vectors. A subset of these pri-miRNAs upregulated Emx2, possibly stimulating its transcription. That led to enhanced self-renewal, delayed differentiation and reduced death of neuronally committed precursors, resulting in an appreciable expansion of the neuronogenic precursors pool. This method makes Emx2 overexpression for purposes of brain repair a more feasible goal, avoiding the drawbacks of exogenous gene copies introduction. Interestingly, the two genomic enhancers targeted by these pri-miRNAs were discovered to be naturally transcribed. Their expression profile suggests their possible involvement in regulation of Emx2 transcription.

  7. Blocking the maturation of OncomiRNAs using pri-miRNA-17∼92 aptamer in retinoblastoma.

    Science.gov (United States)

    Subramanian, Nithya; Kanwar, Jagat R; Kanwar, Rupinder K; Krishnakumar, Subramanian

    2015-02-01

    The miR-17∼92. or oncomiR-1, cluster encodes oncogenic microRNAs (miRNAs), and it also promotes retinoblastoma (RB) tumor formation. Antagomir and miRNA mimics based approaches are widely tried against oncogenic and tumor suppressive miRNAs. Other methods for targeting cancer related miRNAs are still under development. In the current study, we focused on the pri-miRNA-17∼92 aptamer (pri-apt), which can potentially replace the mix of five antagomirs by one aptamer that function to abrogate the maturation of miR-17, miR-18a, and miR-19b (Ppri-apt led to S-phase arrest in WERI-Rb1 cells and onset of apoptosis in both Y79 and WERI-Rb1 cell lines. There was increased cytotoxicity as measured by lactate dehydrogenase activity in pri-apt treated Y79 cells (Ppri-apt in RB cell lines, which can be readily modified by developing appropriate vectors for the delivery of the aptamer specifically to cancer cells.

  8. Role of pri-miRNA tertiary structure in miR-17~92 miRNA biogenesis.

    Science.gov (United States)

    Chaulk, Steven G; Thede, Gina L; Kent, Oliver A; Xu, Zhizhong; Gesner, Emily M; Veldhoen, Richard A; Khanna, Suneil K; Goping, Ing Swie; MacMillan, Andrew M; Mendell, Joshua T; Young, Howard S; Fahlman, Richard P; Glover, J N Mark

    2011-01-01

    MicroRNAs (miRNAs) regulate gene expression in a variety of biological pathways such as development and tumourigenesis. miRNAs are initially expressed as long primary transcripts (pri-miRNAs) that undergo sequential processing by Drosha and then Dicer to yield mature miRNAs. miR-17~92 is a miRNA cluster that encodes 6 miRNAs and while it is essential for development it also has reported oncogenic activity. To date, the role of RNA structure in miRNA biogenesis has only been considered in terms of the secondary structural elements required for processing of pri-miRNAs by Drosha. Here we report that the miR-17~92 cluster has a compact globular tertiary structure where miRNAs internalized within the core of the folded structure are processed less efficiently than miRNAs on the surface of the structure. Increased miR-92 expression resulting from disruption of the compact miR-17~92 structure results in increased repression of integrin α5 mRNA, a known target of miR-92a. In summary, we describe the first example of pri-miRNA structure modulating differential expression of constituent miRNAs.

  9. Pri-miR-17-92a transcript folds into a tertiary structure and autoregulates its processing.

    Science.gov (United States)

    Chakraborty, Saikat; Mehtab, Shabana; Patwardhan, Anand; Krishnan, Yamuna

    2012-05-01

    MicroRNAs control gene expression either by RNA transcript degradation or translational repression. Expressions of miRNAs are highly regulated in tissues, disruption of which leads to disease. How this regulation is achieved and maintained is still largely unknown. MiRNAs that reside on clustered or polycistronic transcripts represent a more complex case where individual miRNAs from a cluster are processed with different efficiencies despite being cotranscribed. To shed light on the regulatory mechanisms that might be operating in these cases, we considered the long polycistronic primary miRNA transcript pri-miR-17-92a that contains six miRNAs with diverse functions. The six miRNA domains on this cluster are differentially processed to produce varying amounts of resultant mature miRNAs in different tissues. How this is achieved is not known. We show, using various biochemical and biophysical methods coupled with mutational studies, that pri-miR-17-92a adopts a specific three-dimensional architecture that poses a kinetic barrier to its own processing. This tertiary structure could create suboptimal protein recognition sites on the pri-miRNA cluster due to higher-order structure formation.

  10. siRNA release from pri-miRNA scaffolds is controlled by the sequence and structure of RNA.

    Science.gov (United States)

    Galka-Marciniak, Paulina; Olejniczak, Marta; Starega-Roslan, Julia; Szczesniak, Michal W; Makalowska, Izabela; Krzyzosiak, Wlodzimierz J

    2016-04-01

    shmiRs are pri-miRNA-based RNA interference triggers from which exogenous siRNAs are expressed in cells to silence target genes. These reagents are very promising tools in RNAi in vivo applications due to their good activity profile and lower toxicity than observed for other vector-based reagents such as shRNAs. In this study, using high-resolution northern blotting and small RNA sequencing, we investigated the precision with which RNases Drosha and Dicer process shmiRs. The fidelity of siRNA release from the commonly used pri-miRNA shuttles was found to depend on both the siRNA insert and the pri-miR scaffold. Then, we searched for specific factors that may affect the precision of siRNA release and found that both the structural features of shmiR hairpins and the nucleotide sequence at Drosha and Dicer processing sites contribute to cleavage site selection and cleavage precision. An analysis of multiple shRNA intermediates generated from several reagents revealed the complexity of shmiR processing by Drosha and demonstrated that Dicer selects substrates for further processing. Aside from providing new basic knowledge regarding the specificity of nucleases involved in miRNA biogenesis, our results facilitate the rational design of more efficient genetic reagents for RNAi technology.

  11. Pri-miR-34b/c rs4938723 polymorphism increased the risk of prostate cancer.

    Science.gov (United States)

    Hashemi, Mohammad; Danesh, Hiva; Bizhani, Fatemeh; Narouie, Behzad; Sotoudeh, Mehdi; Nouralizadeh, Akbar; Sharifiaghdas, Farzaneh; Bahari, Gholamreza; Taheri, Mohsen

    2017-01-01

    The association studies between miR-34b/c rs4938723 polymorphism and cancer risk showed conflicting results. This study aimed to assess the impact of rs4938723 polymorphism on prostate cancer risk. This case-control study was done on 151 prostate cancer (PCa) patients and 152 benign prostate hyperplasia to examine whether rs4938723 polymorphism in the promoter of pri-miR-34b/c was linked to the carcinogenesis of PCa in a sample of Iranian population. Genotyping of Pri-miR-34 b/c rs4938723 polymorphism was performed by using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The results showed that rs4938723 variant significantly increased the risk of PCa in codominant (OR = 1.92, 95% CI = 1.15 - 3.18, p= 0.012, TC vs TT), dominant (OR = 1.99, 95% CI = 1.23 - 3.24, p= 0.005, TC + CC vs TT), and allelic (OR = 1.79, 95% CI = 1.20 - 2.68, p= 0.005, C vs T) inheritance model. Our findings propose that Pri-miR-34 b/c rs4938723 variant may be a risk factor for the development of PCa in a sample of Iranian population. Larger sample sizes with different ethnicities are required to validate our findings.

  12. 14 MeV neutrons physics and applications

    CERN Document Server

    Valkovic, Vladivoj

    2015-01-01

    Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the environment, and security.Drawing on his more than 50 years of experience working with 14 MeV neutrons, the author focuses on:Sources of 14 MeV neutrons, including laboratory size accelerators, small and sealed tube generators, well logging sealed tube ac

  13. Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R. [Univ. of New Mexico, Albuquerque, NM (United States); Hong-Nian Jow [Sandia National Laboratories, Albuquerque, NM (United States)

    1996-07-01

    The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm{sup 3} thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm{sup 3} active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response.

  14. A competitive regulatory mechanism discriminates between juxtaposed splice sites and pri-miRNA structures.

    Science.gov (United States)

    Mattioli, Chiara; Pianigiani, Giulia; Pagani, Franco

    2013-10-01

    We have explored the functional relationships between spliceosome and Microprocessor complex activities in a novel class of microRNAs (miRNAs), named Splice site Overlapping (SO) miRNAs, whose pri-miRNA hairpins overlap splice sites. We focused on the evolutionarily conserved SO miR-34b, and we identified two indispensable elements for recognition of its 3' splice site: a branch point located in the hairpin and a downstream purine-rich exonic splicing enhancer. In minigene systems, splicing inhibition owing to exonic splicing enhancer deletion or AG 3'ss mutation increases miR-34b levels. Moreover, small interfering-mediated silencing of Drosha and/or DGCR8 improves splicing efficiency and abolishes miR-34b production. Thus, the processing of this 3' SO miRNA is regulated in an antagonistic manner by the Microprocessor and the spliceosome owing to competition between these two machineries for the nascent transcript. We propose that this novel mechanism is commonly used to regulate the relative amount of SO miRNA and messenger RNA produced from primary transcripts.

  15. mirEX: a platform for comparative exploration of plant pri-miRNA expression data.

    Science.gov (United States)

    Bielewicz, Dawid; Dolata, Jakub; Zielezinski, Andrzej; Alaba, Sylwia; Szarzynska, Bogna; Szczesniak, Michal W; Jarmolowski, Artur; Szweykowska-Kulinska, Zofia; Karlowski, Wojciech M

    2012-01-01

    mirEX is a comprehensive platform for comparative analysis of primary microRNA expression data. RT-qPCR-based gene expression profiles are stored in a universal and expandable database scheme and wrapped by an intuitive user-friendly interface. A new way of accessing gene expression data in mirEX includes a simple mouse operated querying system and dynamic graphs for data mining analyses. In contrast to other publicly available databases, the mirEX interface allows a simultaneous comparison of expression levels between various microRNA genes in diverse organs and developmental stages. Currently, mirEX integrates information about the expression profile of 190 Arabidopsis thaliana pri-miRNAs in seven different developmental stages: seeds, seedlings and various organs of mature plants. Additionally, by providing RNA structural models, publicly available deep sequencing results, experimental procedure details and careful selection of auxiliary data in the form of web links, mirEX can function as a one-stop solution for Arabidopsis microRNA information. A web-based mirEX interface can be accessed at http://bioinfo.amu.edu.pl/mirex.

  16. Effect of long-term adherence to clopidogrel on the VASP-PRI after elective coronary stent implantation: a randomized controlled study.

    Science.gov (United States)

    Forni Ogna, Valentina; Menetrey, Isabelle; Muller, Olivier; Tousset, Eric; Guihard, Linda; Fontana, Pierre; Eeckhout, Eric; Eap, Chin B; Vrijens, Bernard; Burnier, Michel; Wuerzner, Grégoire

    2016-12-01

    The biological response to clopidogrel is highly variable and a poor responsiveness is associated with major adverse cardiac events. Adherence to therapy is a major cause of poor responsiveness but its impact on long-term platelet inhibition is unknown. The objective of the present study was to evaluate the effect of different programmes monitoring adherence to clopidogrel on platelet reactivity. The study took the form of a monocentric, parallel group, randomized controlled trial. Adults treated with clopidogrel 75 mg after elective coronary stenting were randomized into one of three groups: (i) a standard of care group; (ii) a standard of care + adherence electronic monitoring group, in which drug intake was recorded but kept blinded until the study end; or (iii) an integrated care group, with regular feedback on recorded adherence. Clopidogrel response was assessed with the vasodilator-stimulated phosphoprotein-platelet reactivity index (VASP-PRI) at randomization, 3 months and 6 months. A total of 123 adults were enrolled and randomized. Baseline VASP-PRI was highly variable, with a mean of 48 ± 18.8%. No difference between groups in VASP-PRI was found at 6 months (P = 0.761), despite better adherence to clopidogrel in the integrated care group. However, adherence (P = 0.035) and baseline VASP-PRI (P = 0.015) were associated with VASP-PRI at 3 months and 6 months. The association between adherence and VASP-PRI was lost in patients with baseline VASP-PRI > 50%. Diabetes, CYP2C19*2 carrier status and body mass index were significant predictors of VASP-PRI. The platelet response to clopidogrel during chronic therapy remained highly variable, despite high adherence. Different adherence monitoring programmes did not affect VASP-PRI at 6 months. Poor adherence is associated with lower VASP-PRI only in initial good responders to clopidogrel. © 2016 The British Pharmacological Society.

  17. Valine radiolysis by MeV ions

    Science.gov (United States)

    Da Silveira, Enio

    2016-07-01

    Valine, (CH3)2 CHCH (NH2) COOH, is a protein amino acid that has been identified in extraterrestrial environments and in the Murchison meteorite [1]. The knowledge of half-lives of small organic molecules under ionizing radiation is important for the setup of models describing the spread out of prebiotics across the Solar System or the Galaxy. We have investigated typical effects of MeV cosmic ray ions on prebiotic molecules in laboratory by impinging ions produced by the PUC-Rio Van de Graaff accelerator. Pure valine films, deposited by evaporation on KBr substrates, were irradiated by H ^{+}, He ^{+} and N ^{+} ion beams, from 0.5 to 1.5 MeV and up to a fluence of 10 ^{15} projectiles/cm ^{2}. The sample temperature was varied from 10 K to 300 K. The irradiation was interrupted several times for Mid-FTIR analysis of the sample. The main findings are: 1- The column density of the valine decreases exponentially with fluence. 2- In some cases, a second exponential appears in the beginning of irradiation; this feature has been attributed to sample compaction by the ion beam [2]. 3- Destruction cross sections of valine are in the 10 ^{-15} cm ^{2} range, while compaction cross sections are in the 10 ^{-14} cm ^{2} range. 4- Destruction cross section increases with the stopping power of the beam and also with the sample temperature. 5- Surprisingly, during the radiolysis of valine, just CO _{2} is seen by as a daughter molecule formed in the bulk. 6- After long beam fluence, also a CO peak appears in the infrared spectrum; this species is however interpreted as a fragment of the formed CO2 molecules. 7- Considering the flux ratio between laboratory experiments and actual galactic cosmic rays, half-life of valine is predicted for ISM conditions [3]. This work on pure valine is the first measurement of a series. New experiments are planned for determining cross sections of valine dissolved in H _{2}O or CO _{2}, inspired by the study performed for glycine [4]. [1] P

  18. Reverse transcriptase-PCR differential display analysis of meningococcal transcripts during infection of human cells: Up-regulation of priA and its role in intracellular replication

    Directory of Open Access Journals (Sweden)

    Alifano Pietro

    2008-07-01

    Full Text Available Abstract Background In vitro studies with cell line infection models are beginning to disclose the strategies that Neisseria meningitidis uses to survive and multiply inside the environment of the infected host cell. The goal of this study was to identify novel virulence determinants that are involved in this process using an in vitro infection system. Results By using reverse transcriptase-PCR differential display we have identified a set of meningococcal genes significantly up-regulated during residence of the bacteria in infected HeLa cells including genes involved in L-glutamate transport (gltT operon, citrate metabolism (gltA, disulfide bond formation (dsbC, two-partner secretion (hrpA-hrpB, capsulation (lipA, and DNA replication/repair (priA. The role of PriA, a protein that in Escherichia coli plays a central role in replication restart of collapsed or arrested DNA replication forks, has been investigated. priA inactivation resulted in a number of growth phenotypes that were fully complemented by supplying a functional copy of priA. The priA-defective mutant exhibited reduced viability during late logarithmic growth phase. This defect was more severe when it was incubated under oxygen-limiting conditions using nitrite as terminal electron acceptors in anaerobic respiration. When compared to wild type it was more sensitive to hydrogen peroxide and the nitric oxide generator sodium nitroprusside. The priA-defective strain was not affected in its ability to invade HeLa cells, but, noticeably, exhibited severely impaired intracellular replication and, at variance with wild type and complemented strains, it co-localized with lysosomal associated membrane protein 1. Conclusion In conclusion, our study i. demonstrates the efficacy of the experimental strategy that we describe for discovering novel virulence determinants of N. meningitidis and ii. provides evidence for a role of priA in preventing both oxidative and nitrosative injury, and in

  19. 150 MeV fixed field alternating gradient (FFAG) accelerator

    CERN Document Server

    Nakano, J

    2002-01-01

    150 MeV FFAG accelerator is prototype for practical use. Fundamental development of FFAG, research of FFAG accelerator and its application for therapy are investigated. 150 MeV ring consists of 12 sector magnets. The distribution of magnetic field of 12 sector magnets is almost same. 12 MeV proton beam is generated by cyclotron and injection to 150 MeV FFAG. The injection system consists of 2 bump magnets, kicker magnet and septum electrode. RF accelerating cavity system using high-permeability magnetic substance with high magnetic permeability accelerates proton beam to 150 MeV, then the first operation aims at 250 Hz. Return Yoke Free magnet was developed for adjustment. 150 MeV FFAG magnet is constructed and 12 MeV proton beam acceleration is conformed. The final state of 150 MeV FFAG magnet is explained by calculation results. On cancer therapy by proton beam, the three dimensions spot scan method is proposed. (S.Y.)

  20. 耐辐射球菌中priA类似基因突变对DNA修复和DNA转化的影响%EFFECT OF priA like GENE MUTATION ON DNA REPAIR AND DNA TRANSFORMATION OF Deinococcus radiodurans

    Institute of Scientific and Technical Information of China (English)

    王媛; 华跃进

    2012-01-01

    Replication fork progression can be blocked easily by DNA damage. Damaged DNA repair and the subsequent restart of the stalled or collapsed replication forks are critical for cell survival. The PriA-dependent pathway is the major replication restart mechanism in bacteria. To understand the roles of a priA-like gene (Dr2606) in Deinococcus radiodurans and DNA repair, a Dr2606 null mutant was constructed by replacing Dr2606 open reading frame with a kanamycin-resistanee gene and treated the Dr2606 mutant with UV and mitomycin C (MMC), and the DNA transformation efficiency of the Dr2606 mutant was also tested. Successively, the Dr2606 mutant showed a delayed growth and a dramatic decrease of cell viability. Unexpectedly, the DNA repair capability of D. radiodurans was not impaired by the inactivation of Dr2606. However, the DNA transformation efficiency was largely compromised in the mutant. These results indicate that the priA-like gene (Dr2606) is dispensable for stalled DNA replication forks restart in D. radiodurans and origin-independent replication restart in D. radiodurans may be different from other bacteria.%DNA损伤很易阻断复制叉的前进。损伤DNA的修复以及接下来停止复制叉的重启动过程对细胞生存极为重要。依赖于PriA的复制重启动机制是细菌复制重启动的主要途径。为了解priA类似基因Dr2606在耐辐射球菌中的作用,并检测Dr2606在DNA修复中的作用,本研究用卡那霉素抗性基因代替Dr2606阅读框,构建了Dr2606缺失突变株,并对突变株进行UV和丝裂霉素处理,测定了Dr2606突变株的转化效率。Dr2606的突变导致菌体生长缓慢,细胞生存率急剧下降。意外的是,耐辐射球菌的DNA修复能力没有削弱。但突变株的转化效率大大削弱。这说明在耐辐射球菌中priA类似基因Dr2606对停止复制叉的重启动过程并不是必需的;耐辐射球菌不依赖于原点的复制重启动过程可能与其他细菌不同。

  1. RF Operation for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung Tae; Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Song, Young Gi; Jang, Ji Ho; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The RF systems for the 100MeV linac were constructed. The HPRF system including klystrons, circulators, high power dummy loads, and waveguide components was installed at the klystron gallery, and the LLRF control systems including a commercial FPGA module and a LLRF analog chassis were also installed. The phase stability of the RF reference line was measured with S11 phase under temperature control. The RF systems for 100MeV linac have been operated for a beam commissioning, and the 100MeV proton beam has been supplied to users currently. The RF systems of the 100MeV proton linac for the KOMAC (KOrea Multi-purpose Accelerator Complex) were installed at the Gyeong-ju site. The 100MeV linac consists of a 3MeV RFQ, a 20MeV DTL with four tanks, two MEBT tanks, and seven 100MeV DTL tanks. For the 100MeV linac, nine sets of LLRF control systems and the HPRF systems including 1MW klystrons, circulators and waveguide components have been installed at the klystron gallery, and four high voltage converter modulators to drive nine klystrons have been installed at the modulator room. A RF reference system distributing 300MHz LO signal to each RF control system has also been installed with a temperature control system at the klystron gallery. The requirement of RF field control is within +/- 1% in RF amplitude and +/- 1 degree in RF phase. The RF systems have been operated for the beam commissioning. The installation and operation of the RF system for the 100MeV proton linac are presented in this paper.

  2. 基于PRI变换法的脉冲信号分选算法%Pulse Signals De-interleaving Algorithm Based on PRI Transform

    Institute of Scientific and Technical Information of China (English)

    乔宏乐; 王超; 王鹏

    2012-01-01

    脉冲重复间隔是电子对抗中信号分选的关键参数,本文研究的基于PRI变换法的信号分选算法克服了传统直方图统计法的子谐波问题,对脉冲重复间隔具有很高的估计精度,且具有很好的抗抖动性能。仿真分析表明,PRI变换法对固定PRI,抖动PRI具有很好的估计效果。%The pulse repetition interval (PRI) is a key parameter of radar signal de-interleaving in the field of elec-tronic countermeasures. The signal de-interleaving algorithm based on PRI transform overcomes the sub-harmonic problem produced in the histogram statistical method and can estimate the PRI with high precision, and possesses perfect anti - dithering capability. The simulated results indicate that PRI transform algorithm can estimate effect on fixed PRI and dithering PRI.

  3. The in-vitro antiproliferative effect of PRI-2191 and imatinib applied in combined treatment with cisplatin, idarubicin, or docetaxel on human leukemia cells.

    Science.gov (United States)

    Switalska, Marta; Nasulewicz-Goldeman, Anna; Opolska, Aleksandra; Maciejewska, Magdalena; Kutner, Andrzej; Wietrzyk, Joanna

    2012-01-01

    Imatinib mesylate (Gleevec, STI571) is a specific inhibitor of the Bcr/Abl fusion tyrosine kinase that exhibits potent antileukemic effects in chronic myelogenous leukemia. Bcr/Abl-positive K562 and Bcr/Abl-negative HL-60 human leukemia cells were used to investigate the effect of PRI-2191, a calcitriol analog, on the biological effects of imatinib combined with other anticancer drugs. The results show that PRI-2191 enhances the antiproliferative effect of imatinib on HL-60 cells. When these two agents together are applied with either docetaxel or cisplatin, but not with idarubicin, the antiproliferative effect could still be enhanced. Moreover, when the interaction between the chemotherapy agents was antagonistic or additive, PRI-2191 could even shift it to synergism. This effect correlated with an accumulation of HL-60 cells in the G0/G1 phase of the cell cycle and a decrease in the percentage of cells in the G2/M and S stage in the ternary combinations used. PRI-2191 did not influence apoptosis induced by imatinib alone or in ternary combinations with all the chemotherapy agents used. These results may suggest that the stronger antiproliferative effect of the combined treatment with PRI-2191 on HL-60 cells is related to cell cycle arrest rather than to the induction of apoptosis.

  4. No association of pri-miR-143 rs41291957 polymorphism with the risk of congenital heart disease in a Chinese population.

    Science.gov (United States)

    Yang, Liping; Gao, Xiaobo; Luo, Haiyan; Huang, Qiuyu; Wei, Ying; Zhang, Guican; Huang, Guoying; Su, Dongmei; Chen, Liangwan; Lu, Cailing; Yang, Juhua; Ma, Xu

    2014-08-01

    MiR-143 plays an important role in the heart development of zebra fish. The rs41291957 variant located in the pri-miR-143 sequence is associated with colorectal carcinogenesis. Therefore, the authors hypothesized that rs41291957 in pri-miR-143 might be involved in the risk of sporadic congenital heart disease (CHD). The authors conducted a case-control study of CHD in a Chinese population to test their hypothesis by genotyping pri-miR-143 rs41291957 in 1,109 CHD cases and 915 non-CHD control subjects. Logistic regression analyses showed no significant association of genotype or allele frequencies of pri-miR-143 rs41291957 A/G polymorphism with the CHD cases in overall or various subtypes compared with the control group. To the authors' knowledge, this is the first study to investigate the relationship between miR-143 and CHD cases. The results demonstrated that rs41291957 in pri-miR-143 has no major role in genetic susceptibility to sporadic CHD, at least in the current study population.

  5. Transcriptional, post-transcriptional and chromatin-associated regulation of pri-miRNAs, pre-miRNAs and moRNAs

    DEFF Research Database (Denmark)

    Nepal, Chirag; Coolen, Marion; Hadzhiev, Yavor;

    2015-01-01

    MicroRNAs (miRNAs) play a major role in the post-transcriptional regulation of target genes, especially in development and differentiation. Our understanding about the transcriptional regulation of miRNA genes is limited by inadequate annotation of primary miRNA (pri-miRNA) transcripts. Here, we...... used CAGE-seq and RNA-seq to provide genome-wide identification of the pri-miRNA core promoter repertoire and its dynamic usage during zebrafish embryogenesis. We assigned pri-miRNA promoters to 152 precursor-miRNAs (pre-miRNAs), the majority of which were supported by promoter associated post....... Developmental profiling revealed a subset of pri-miRNAs that are maternally inherited. Moreover, we show that promoter-associated H3K4me3, H2A.Z and RNAPII marks are not only present at pri-miRNA promoters but are also specifically enriched at pre-miRNAs, suggesting chromatin level regulation of pre...

  6. The pri-let-7a-2 rs1143770C>T is associated with prognosis of surgically resected non-small cell lung cancer.

    Science.gov (United States)

    Shin, Kyung Min; Jung, Deuk Kju; Hong, Mi Jeong; Kang, Hyo Jung; Lee, Won Kee; Yoo, Seung Soo; Lee, Shin Yup; Cha, Seung Ick; Lee, Jaehee; Kim, Chang Ho; Seok, Yangki; Cho, Sukki; Son, Ji Woong; Lee, Eung Bae; Jheon, Sanghoon; Kim, Young Tae; Park, Jae Yong

    2016-02-15

    Evidence indicates that let-7 of microRNA may be a prognostic factor in lung cancer. Genetic variation in microRNA precursors could influence the processing and expression of microRNAs, which could affect the prognosis of lung cancer. We aimed to investigate the impact of single nucleotide polymorphisms (SNPs) of pri-let-7 on the prognosis of non-small cell lung cancer (NSCLC). A total of 761 patients with surgically resected NSCLC were included. Four SNPs (pri-let-7a-2 rs1143770 and rs629367, pri-let-7a-1 rs10739971, and pri-let-7f-2 rs17276588) were genotyped using sequenom mass spectrometry-based genotyping assay. Overall survival (OS) and disease-free survival (DFS) were evaluated using Kaplan-Meier method and Cox proportional hazards model. Of the 4 SNPs evaluated, the rs1143770C>T was found to be significantly associated with OS and DFS. The rs1143770 CT or TT genotype exhibited a significantly better OS and DFS compared with the rs1143770 CC genotype (adjusted hazard ratio for OS=0.67, confidence interval, 0.49-0.91, P=0.01 and adjusted hazard ratio for DFS=0.74, confidence interval, 0.58-0.95, P=0.02). This observation indicates that pri-let-7a-2 rs1143770C>T may have a prognostic impact on surgically resected NSCLC. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Accuracy of Venous Filling Index on Standing (VFIst) and Pure Regurgitation Index (PRI), a Novel Index Obtained by Air Plethysmography, for Detecting Venous Reflux.

    Science.gov (United States)

    Shiraishi, Yasushi

    2015-01-01

    To evaluate the accuracy of venous filling index on standing (VFIst) and a new index named pure regurgitation index (PRI), obtained by air plethysmography, for detecting venous reflux. One hundred and sixty-one healthy subjects (161 limbs) and 180 varicose vein patients (180 limbs) were investigated. All subjects underwent duplex ultrasonography for verifying venous reflux and air plethysmography to obtain hemodynamic parameters such as VFIst, VFI in the supine position (VFIsu), and the maximum arterial inflow rate. To evaluate the accuracy of VFIst and PRI (= (VFIst - VFIsu)/body mass index), receiver operating characteristics curves were created. The optimal cut-off value, sensitivity, specificity, and area under the curve, obtained from analyzing the receiver operating characteristics curves, of VFIst vs. PRI were 2.058 mL/s vs. 0.059 mL · m(2)/s · kg, 93.3% vs. 90.3%, 88.8% vs. 91.3%, and 0.954 vs. 0.964, respectively. This study indicates that while both VFIst and PRI are highly accurate indicators of venous reflux, PRI, which is not affected by the arterial inflow rate and body mass index, is slightly superior to VFIst, especially in subjects with greater body mass index.

  8. PRI-CAT: a web-tool for the analysis, storage and visualization of plant ChIP-seq experiments.

    OpenAIRE

    2011-01-01

    Although several tools for the analysis of ChIP-seq data have been published recently, there is a growing demand, in particular in the plant research community, for computational resources with which such data can be processed, analyzed, stored, visualized and integrated within a single, user-friendly environment. To accommodate this demand, we have developed PRI-CAT (Plant Research International ChIP-seq analysis tool), a web-based workflow tool for the management and analysis of ChIP-seq ex...

  9. Approach to Radar Signal Clustering Based on PRI Entropy%基于PRI熵的雷达信号聚类方法研究

    Institute of Scientific and Technical Information of China (English)

    孙盼杰; 刘刚; 王杰

    2008-01-01

    针对脉冲分选聚类中存在的问题,引入熵的概念,定义了 PRI(脉冲重复间隔)熵,给出了雷达脉冲序列之间合并的 PRI 熵判据.并在此基础上提出了新的雷达信号聚类方法.采用先分选后合并的思路,通过计算合并前后 PRI 熵是否减小来判断是否对序列合并.通过仿真验证该方法解决增批问题的有效性.

  10. Transcriptional, post-transcriptional and chromatin-associated regulation of pri-miRNAs, pre-miRNAs and moRNAs.

    Science.gov (United States)

    Nepal, Chirag; Coolen, Marion; Hadzhiev, Yavor; Cussigh, Delphine; Mydel, Piotr; Steen, Vidar M; Carninci, Piero; Andersen, Jesper B; Bally-Cuif, Laure; Müller, Ferenc; Lenhard, Boris

    2016-04-20

    MicroRNAs (miRNAs) play a major role in the post-transcriptional regulation of target genes, especially in development and differentiation. Our understanding about the transcriptional regulation of miRNA genes is limited by inadequate annotation of primary miRNA (pri-miRNA) transcripts. Here, we used CAGE-seq and RNA-seq to provide genome-wide identification of the pri-miRNA core promoter repertoire and its dynamic usage during zebrafish embryogenesis. We assigned pri-miRNA promoters to 152 precursor-miRNAs (pre-miRNAs), the majority of which were supported by promoter associated post-translational histone modifications (H3K4me3, H2A.Z) and RNA polymerase II (RNAPII) occupancy. We validated seven miR-9 pri-miRNAs by in situ hybridization and showed similar expression patterns as mature miR-9. In addition, processing of an alternative intronic promoter of miR-9-5 was validated by 5' RACE PCR. Developmental profiling revealed a subset of pri-miRNAs that are maternally inherited. Moreover, we show that promoter-associated H3K4me3, H2A.Z and RNAPII marks are not only present at pri-miRNA promoters but are also specifically enriched at pre-miRNAs, suggesting chromatin level regulation of pre-miRNAs. Furthermore, we demonstrated that CAGE-seq also detects 3'-end processing of pre-miRNAs on Drosha cleavage site that correlates with miRNA-offset RNAs (moRNAs) production and provides a new tool for detecting Drosha processing events and predicting pre-miRNA processing by a genome-wide assay.

  11. Pri-let-7a-1 rs10739971 polymorphism is associated with gastric cancer prognosis and might affect mature let-7a expression.

    Science.gov (United States)

    Li, Ying; Xu, Qian; Liu, Jingwei; He, Caiyun; Yuan, Quan; Xing, Chengzhong; Yuan, Yuan

    2016-01-01

    The relationship between the pri-let-7a-1 rs10739971 polymorphism and gastric cancer (GC) risk has been reported. However, the role of this polymorphism in the prognosis of GC remains largely elusive. Sequenom MassARRAY platform method and the polymerase chain reaction (PCR)-restriction fragment length polymorphism were used to investigate pri-let-7a-1 rs10739971 G→A in 334 GC patients. Real-time PCR detected expression of mature let-7a in serum and tissue. Patients with AA or GA+AA genotypes of the pri-let-7a-1 rs10739971 polymorphism demonstrated significantly longer survival time than those with the wild GG genotype. Stratified analysis indicated that survival time was significantly longer in women with AA or GA+AA genotypes and in Borrmann type I/II patients with GA heterozygote or GA+AA genotypes. AA genotype was more frequent in the lymphatic-metastasis-negative subgroup. Serum mature let-7a expression in healthy people with the GA heterozygote and the GA+AA genotype was higher than in those with the GG genotype, and the difference remained significant in the female healthy subgroup. Pri-let-7a-1 rs10739971 polymorphism might be a biomarker for GC prognosis, especially for female and Borrmann type I/II patients. The pri-let-7a-1 rs10739971 polymorphism might affect serum mature let-7a expression, and partly explain the mechanism of the relationship between the pri-let-7a-1 rs10739971 polymorphism and GC survival.

  12. A novel method for the modulation type recognition of radar PRI%雷达PRI调制样式识别新方法

    Institute of Scientific and Technical Information of China (English)

    陈晟; 姜秋喜; 潘继飞

    2012-01-01

    Aiming at the shortcoming of the modulation type recognition of radar PRI,five classsified parameters which can effectively describe the modulation characteristics of radar PRI are given based on the analysis of radar PRI types,and the management methods for the missing and spurious pulsesv are analyzed.On these grounds,the recognition arithmetic and realized process for the modulation types of radar PRI are put forword and be used to effectively recognize five representative PRI modulation types.Theoretic analysis and computer simulation indicate that this method is robust in the presence of a low PRI measurement precision and a high rate of missing and spuriou pulses.%针对雷达PRI调制样式识别难题,在分析雷达PRI类型的基础上,提出了能够有效描述雷达PRI调制特征的五种分类特征参数,分析了对存在丢失和虚假脉冲的处理方法,并据此提出了PRI调制样式的识别算法与实现流程,实现了五种典型PRI调制样式的有效识别。理论分析与计算机仿真结果表明,该方法在PRI测量精度较低和丢失虚假脉冲比例较高的情况下具有稳健的识别性能。

  13. Visible Light Excited Catalysis and Reusability Performances of TiO2@Pr:Y2SiO5 Upconversion Materials

    Directory of Open Access Journals (Sweden)

    Yan Jiao

    2017-01-01

    Full Text Available To get high efficiency photodegradation on pollutants under visible light, Pr(III doped Y2SiO5 upconversion materials and anatase TiO2 nanofilm coated Pr:Y2SiO5 composite have been prepared by using a sol-gel method. XRD and SEM test results indicated that TiO2 nanofilm was well coated on Pr:Y2SiO5 to form TiO2@Pr:Y2SiO5 composite particles with the sizes of 0.5–1.0 μm. To avoid secondary pollution resulting from incomplete recovery of catalyst particles, TiO2@Pr:Y2SiO5 was loaded on the glass fiber filters by using a dip-coating method. It is found that the catalyst particles were embedded into the carrier firmly, even after having been reused for 6 times. The luminescence intensities of TiO2@Pr:Y2SiO5 were getting down sharply with the coating contents of TiO2 increased, which was attributed to the adsorption of the luminescence by the TiO2 film in situ. As a result, TiO2@Pr:Y2SiO5 with 4% TiO2, which presented lowest luminescence intensity, showed the highest efficiency on the photodegradation of nitrobenzene wastewater. The catalysts loaded on glass fiber filters showed excellent reusability on the photodegradation of nitrobenzene and presented a photodegradation rate of 95% at the first time and up to 75.9% even after 6 times of reusing by the treatment time of 12 h.

  14. Proximal disruption of base pairing of the second stem in the upper stem of pri-miR156a caused ambient temperature-sensitive flowering in Arabidopsis.

    Science.gov (United States)

    Kim, Wanhui; Jun, A Rim; Ahn, Ji Hoon

    2016-10-02

    MicroRNAs are generated from primary transcripts (pri-miRNAs) that form hairpin structures. Plant miRNAs play an important role in regulating flowering; however, little is known about the role of their structures in ambient temperature-responsive flowering. We recently showed that disruption of base pairing in the second stem (S2) in the upper stem of pri-miR156a caused hypersensitive flowering in response to ambient temperature changes. To further substantiate our findings on the role of S2 of pri-miR156a, we analyzed the effects of serial disruption (from the proximal or distal sides) of base-pairing in S2 of pri-miR156a on temperature-dependent flowering. We found that flowering time was gradually delayed with increasing size of the proximal disruption of S2 at 16°C. Particularly, disrupting base pairing of 5 nucleotides from the proximal side caused flowering to be hypersensitive to ambient temperature changes, which is similar to the phenotype of plants overexpressing pri-miR156a with a disruption of S2 (156-DBP-S2). However, disrupting base pairing from the distal side did not cause late flowering at 16°C and thus did not cause temperature-sensitive flowering. These results supported our notion that the second stem (S2) in the upper stem of pri-miR156a plays a role in the regulation of ambient temperature-responsive flowering.

  15. Dosimetric comparison of 4 MeV and 6 MeV electron beams for total skin irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung In; Park, So Yeon; Park, Jong Min; Ye, Sung Joon; Kim, Il Han [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-11-15

    Total skin electron irradiation (TSEI) was developed by Stanford University in the 1950s and introduced for the treatment of mycosis fungoides, the most common form of cutaneous T-cell lymphoma which generally affects the skin. In this study, dosimetric aspects of TSEI consisting of a 4 MeV beam with no spoiler were investigated in comparison to a nominal 6 MeV beam applications was evaluated. The suggested 4 MeV beam for TSEI could be applied to shallow depth skin diseases and to electron boost as second treatment course.

  16. Idejne rešitve odvajanja in čiščenja odpadnih voda v naseljih Cundrovec, Bukošek, Sela pri Dobovi in Dobova

    OpenAIRE

    Ljubić, Anamarina

    2015-01-01

    Kanalizacijski sistemi je hidravlična infrastruktura, sestavljena iz elementov, kot so cevi, jaški, rezervoarji, črpalke, ventili itd., in je ključnega pomena za zagotavljanje zdravja končnih potrošnikov. Učinkovitost, je bistvenega pomena pri oblikovanju novega kanalizacijskega omrežja ali razširitvi obstoječega. Potrebno je ustvariti zanesljivo omrežje, ki zagotavlja ustrezne hidrotehnične pogoje. Predmet naloge so naselja Dobova, Sela pri Dobovi, Cundrovec in Bukošek v občini Brežice. Za o...

  17. Improved RT-PCR Assay to Quantitate the Pri-, Pre-, and Mature microRNAs with Higher Efficiency and Accuracy.

    Science.gov (United States)

    Tong, Li; Xue, Huihui; Xiong, Li; Xiao, Junhua; Zhou, Yuxun

    2015-10-01

    Understanding of the functional significance of microRNAs (miRNAs) requires efficient and accurate detection method. In this study, we developed an improved miRNAs quantification system based on quantitative real-time polymerase chain reaction (qRT-PCR). This method showed higher efficiency and accuracy to survey the expression of primary miRNAs (pri-miRNAs), precursor miRNAs (pre-miRNAs), and mature miRNAs. Instead of relative quantification method, we quantified the pri-miRNAs and pre-miRNAs with absolute qRT-PCR based on SYBR Green I fluorescence. This improvement corrected for the inaccuracy caused by the differences in amplicon length and PCR efficiency. We also used SYBR Green method to quantify mature miRNAs based on the stem-loop qRT-PCR method. We extended the pairing part of the stem-loop reverse transcript (RT) primer from 6 to 11 bp, which greatly increased the efficiency of reverse transcription PCR (RT-PCR). The performance of the improved RT primer was tested using synthetic mature miRNAs and tissue RNA samples. Results showed that the improved RT primer demonstrated dynamic range of seven orders of magnitude and sensitivity of detection of hundreds of copies of miRNA molecules.

  18. Diurnal and Seasonal Responses of High Frequency Chlorophyll Fluorescence and PRI Measurements to Abiotic Stress in Almonds

    Science.gov (United States)

    Bambach-Ortiz, N. E.; Paw U, K. T.

    2016-12-01

    Plants have evolved to efficiently utilize light to synthesize energy-rich carbon compounds, and at the same time, dissipate absorbed but excessive photon that would otherwise transfer excitation energy to potentially toxic reactive oxygen species (ROS). Nevertheless, even the most rapidly growing plants with the highest rates of photosynthesis only utilize about half of the light their leaves absorb during the hours of peak irradiance in sun-exposed habitats. Usually, that daily peak of irradiance coincides with high temperature and a high vapor pressure deficit, which are conditions related to plant stomata closure. Consequently, specially in water stressed environments, plants need to have mechanisms to dissipate most of absorbed photons. Plants avoid photo-oxidative damage of the photosynthetic apparatus due to the formation of ROS under excess light using different mechanisms in order to either lower the amount of ROS formation or detoxify already formed ROS. Photoinhibition is defined as a reduction in photosynthetic activity due largely to a sustained reduction in the photochemical efficiency of Photosystem II (PSII), which can be assessed by monitoring Chlorophyll a fluorescence (ChlF). Alternatively, monitoring abiotic stress effects upon photosynthetic activity and photoinhibition may be possible using high frequency spectral reflectance sensors. We aim to find the potential relationships between high frequency PRI and ChlF as indicators of photoinhibition and permanent photodamage at a seasonal scale. Preliminary results show that PRI responses are sensitive to photoinhibition, but provide a poor representation of permanent photodamage observed at a seasonal scale.

  19. Association of the pri-miR-124-1 rs531564 polymorphism with cancer risk: A meta-analysis.

    Science.gov (United States)

    Fang, Cheng; Zeng, Hui; Li, Anling; Xu, Xianqun; Long, Xinghua

    2015-07-01

    Recently, several studies regarding the association between the pri-miR-124-1 rs531564 polymorphism and cancer susceptibility were explored. Owing to inconsistent results of these studies, a meta-analysis was conducted to determine the association of this polymorphism with cancer risk. Relevant studies were identified by a systematic search of PubMed, EMBASE, Web of Science and CNKI on-line databases. Odds ratios (ORs) and 95% confidence intervals (CIs) from eligible studies were pooled, and heterogeneity and publication bias were also evaluated. A total of five studies with 2,253 cases and 2,510 controls were included in the meta-analysis. Overall, the results showed that the pri-miR-124-1 rs531564 polymorphism was significantly associated with a reduced cancer risk (G vs. C: OR, 0.86; 95% CI, 0.77-0.96; GG vs. CC: OR, 0.52; 95% CI, 0.34-0.79; GG vs. OR, 0.54; 95% CI, 0.36-0.81). Furthermore, in the subgroup analysis by cancer sites, a statistical association was identified between the rs531564 polymorphism and a decreased esophageal squamous cell carcinoma (ESCC) risk (G vs. C: OR, 0.87; 95% CI, 0.77-0.98; GG vs. CC: OR, 0.54; 95% CI, 0.34-0.84). These findings suggested that the genetic variant of rs531564 may have a potential value in decreasing cancer risk, particularly in ESCC patients.

  20. Prediction of moment-rotation characteristic of top- and seat-angle bolted connection incorporating prying action

    Science.gov (United States)

    Ahmed, Ali

    2017-02-01

    Finite element (FE) analyses were performed to explore the prying influence on moment-rotation behaviour and to locate yielding zones of top- and seat-angle connections in author's past research studies. The results of those FE analyses with experimental failure strategies of the connections were used to develop failure mechanisms of top- and seat-angle connections in the present study. Then a formulation was developed based on three simple failure mechanisms considering bending and shear deformations, effects of prying action on the top angle and stiffness of the tension bolts to estimate rationally the ultimate moment M u of the connection, which is a vital parameter of the proposed four-parameter power model. Applicability of the proposed formulation is assessed by comparing moment-rotation (M-θ r ) curves and ultimate moment capacities with those measured by experiments and estimated by FE analyses and three-parameter power model. This study shows that proposed formulation and Kishi-Chen's method both achieved close approximation driving M-θ r curves of all given connections except a few cases of Kishi-Chen model, and M u estimated by the proposed formulation is more rational than that predicted by Kishi-Chen's method.

  1. 叶片光化学植被指数(PRI)的修正及其敏感性分析%Sensitivity Study of a Revised Leaf Photochemical Reflectance Index(PRI)

    Institute of Scientific and Technical Information of China (English)

    吴朝阳; 牛铮; 汤泉

    2008-01-01

    光化学植被指数(PRI)被成功的应用于估算不同叶片生化组分的光能利用率(LUE),这些生化组分包括叶片含水量、氮元素浓度等.以往的研究中已经成功建立了叶片、冠层和景观尺度PRI和LUE的相关关系.但是,为了利用PRI更加准确地估算叶片LUE,很多问题仍然亟需解决,比如当LUE高于0.03 molCO2 mol-1PPFD(photosynthetic photon flux density),PRI会出现一个明显的饱和区域以及PRI和LUE关系会随季节发生较大变化.文章对PRI进行了修正,并基于PROSPECT模型对这一修正形式进行了4个参数的敏感性分析.分析结果表明,叶片SR-PRI(Simple ratio PRI)对叶肉结构参数(N)、叶绿素浓度(Cab)敏感性要高于叶片的等效水厚(Cw)和干物质浓度(Cm).因此叶肉结构参数(N)和叶绿素浓度(Cab)的微小变化都会造成SR-PRI的较大变化,进而影响到LUE的估算精度.对SR-PRI的实证实验表明,这一指数也能够很好地用来估算叶片的光能利用率并且结果要优于PRI和LUE之间的相关关系.SR-PRI最重要的一方面在于其更清晰的物理意义和对531 nm处反射率变化的敏感性,因为这一波段位置的反射率变化是评价光能利用率的核心参数.

  2. MeV Pulsars: Modeling Spectra and Polarization

    Science.gov (United States)

    Kust Harding, Alice; Kalapotharakos, Constantinos

    2017-08-01

    A sub-population of energetic rotation-powered pulsars show high fluxes of pulsed non-thermal hard X-ray emission. While this ‘MeV pulsar’ population includes some radio-loud pulsars like the Crab and PSR B1509-58, a significant number have no detected radio or GeV emission, a mystery since gamma-ray emission is a common characteristic of pulsars with high spin-down power. Their steeply rising hard X-ray spectral energy distributions (SEDs) suggest peaks at 0.1 - 1 MeV but they have not been detected above 200 keV. Several upcoming and planned telescopes may shed light on the MeV pulsars. The Neutron star Interior Composition ExploreR (NICER) will observe pulsars in the 0.2 - 12 keV band and may discover additional MeV pulsars. The All-Sky Medium-Energy Gamma-Ray Observatory (AMEGO), in a study phase, can detect emission above 0.2 MeV and polarization in the 0.2 - 10 MeV band. We present a model for the spectrum and polarization of MeV pulsars where the X-ray emission comes from electron-positron pairs radiating in the outer magnetosphere and current sheet. This model predicts that the peak of the SED increases with surface magnetic field strength if the pairs are produced in polar cap cascades. For small inclination angles, viewing at large angles to the rotation axis can miss both the radio pulse and the GeV pulse from particles accelerating near the current sheet. Characterizing the emission and geometry of MeV pulsars can thus provide clues to the source of pairs and acceleration in the magnetosphere.

  3. The Effects of Utilization of PRI/RS on Reading Achievement in the Oklahoma City Public Schools. Evaluation of 1981-82.

    Science.gov (United States)

    Kimball, George H.

    1982-01-01

    A study was conducted to determine (1) the extent to which the degree of use of PRI/RS (the Prescriptive Reading Inventory Reading Systems, a criterion referenced management system developed by CTB/McGraw Hill) affected comparable groups of students on standardized achievement measures; (2) whether the degree of use differentially influenced…

  4. Inhibition of hepatitis B virus replication by helper dependent adenoviral vectors expressing artificial anti-HBV pri-miRs from a liver-specific promoter.

    Science.gov (United States)

    Mowa, Mohube Betty; Crowther, Carol; Ely, Abdullah; Arbuthnot, Patrick

    2014-01-01

    Research on applying RNA interference (RNAi) to counter HBV replication has led to identification of potential therapeutic sequences. However, before clinical application liver-specific expression and efficient delivery of these sequences remain an important objective. We recently reported short-term inhibition of HBV replication in vivo by using helper dependent adenoviral vectors (HD Ads) expressing anti-HBV sequences from a constitutively active cytomegalovirus (CMV) promoter. To develop the use of liver-specific transcription regulatory elements we investigated the utility of the murine transthyretin (MTTR) promoter for expression of anti-HBV primary microRNAs (pri-miRs). HD Ads containing MTTR promoter effected superior expression of anti-HBV pri-miRs in mice compared to HD Ads containing the CMV promoter. MTTR-containing HD Ads resulted in HBV replication knockdown of up to 94% in mice. HD Ads expressing trimeric anti-HBV pri-miRs silenced HBV replication for 5 weeks. We previously showed that the product of the codelivered lacZ gene induces an immune response, and the duration of HBV silencing in vivo is likely to be attenuated by this effect. Nevertheless, expression of anti-HBV pri-miRs from MTTR promoter is well suited to countering HBV replication and development of HD Ads through attenuation of their immunostimulatory effects should advance their clinical utility.

  5. Association between polymorphisms in the promoter region of pri-miR-34b/c and risk of hepatocellular carcinoma.

    Science.gov (United States)

    Chen, L L; Shen, Y; Zhang, J B; Wang, S; Jiang, T; Zheng, M Q; Zheng, Z J; Chen, C X

    2016-10-05

    Hepatocellular carcinoma (HCC) is a major cause of cancer-related deaths worldwide. MicroRNA-34 (miR-34) gene plays a key role in altering the apoptotic cycle and pathways of downstream cells, and therefore influences carcinogenesis. In this case-control study, we assessed the role of the pri-miR-34b/c rs4938723 polymorphism in HCC risk. The pri-miR-34b/c polymorphic genotype was determined in 286 patients with HCC and 572 controls using polymerase chain reaction-restriction fragment length polymorphism. The male gender (X(2) = 12.95, P pri-miR-34b/c rs4938723 were correlated with a higher risk of HCC compared to the TT genotype. Moreover, the TC+CC genotype was correlated with an increased risk of HCC compared to the TT genotype (adjusted OR = 1.64, 95%CI = 1.21-2.22). In the recessive model, the CC genotype of pri-miR-34b/c rs4938723 was significantly correlated with an elevated risk of HCC compared to the TT+TC genotype (adjusted OR = 2.50, 95%CI = 1.49-4.22). Further large-scale and multi-center studies are required to confirm these results.

  6. [Construction of a recombined adenovirus vector carrying pri-miR-21 gene and research on it's target gene TLR4].

    Science.gov (United States)

    Zhao, Jing; Xu, Guang-xian; Jia, Wei; Dong, Hui; Zhang, Yi-lin; Zhao, Zhi-jun; Wei, Jun

    2012-02-01

    To construct the recombined adenovirus vector carrying pri-miR-21 gene, which can express mature miR-21 efficiently, and to study the interaction of miR- 21 with its target gene TLR4. Using healthy mouse's gDNA as template, the primary miR-21 coding sequence was amplified by PCR and cloned into a shuttle vector pAdTrack-CMV. Constructed plasmid was sequenced and linearized for homologous recombination with pAdEasy-1 vector in BJ5183 bacteria. The recombined adenovirus vector carrying pri-miR-21 gene was used to challenge HeLa cell. The candidate target gene of miR-21 was determined by miRNA analysis databases. The expression level of TLR4 protein was detected by western blotting. Through the PCR, restriction enzyme digestion, DNA sequencing and expression of GFP, recombinant adenoviral vector pri-miR-21 gene was constructed successfully. Bioinformatic analysis suggested a few possible binding sites between miR-21 and TLR4. Results showed that miR-21 down-regulated TLR4 at protein levels. The recombinant adenoviral vector containing pri- miR-21 was successfully constructed. miR-21 gene interfered with the expression of TLR4 target gene.

  7. Construction and validation of the chronic acquired polyneuropathy patient-reported index (CAP-PRI): A disease-specific, health-related quality-of-life instrument.

    Science.gov (United States)

    Gwathmey, Kelly G; Conaway, Mark R; Sadjadi, Reza; Joshi, Amruta; Barnett, Carolina; Bril, Vera; Ng, Eduardo; David, William; Gable, Karissa; Guptill, Jeffrey T; Hobson-Webb, Lisa D; Dineen, Jennifer; Hehir, Michael; Brannagan, Thomas H; Byun, Esther; Adler, Margaret; Burns, Ted M

    2016-06-01

    Generic health-related quality-of-life (HRQOL) patient-reported outcome measures have been used in patients with chronic immune-mediated polyneuropathies. We have created a disease-specific HRQOL instrument. The chronic acquired polyneuropathy patient-reported index (CAP-PRI) was developed and validated in multiple steps. Items were initially generated through patient and specialist input. The performance of the preliminary 20 items was analyzed via a prospective, 5-center study involving chronic immune-mediated polyneuropathy patients. Data analysis suggested modification to a 15-item scale with 3 response categories rather than 5. The final CAP-PRI was validated in another prospective, 5-center study. The CAP-PRI appeared to be a unidimensional outcome measure that fit the Rasch model in our multicenter cohort. It correlated appropriately with outcome measures commonly used in this patient population. The CAP-PRI is a simple disease-specific HRQOL measure that appears to be useful for clinical care and possibly also for clinical trials. Muscle Nerve 54: 9-17, 2016. © 2015 Wiley Periodicals, Inc.

  8. Inhibition of Hepatitis B Virus Replication by Helper Dependent Adenoviral Vectors Expressing Artificial Anti-HBV Pri-miRs from a Liver-Specific Promoter

    Directory of Open Access Journals (Sweden)

    Mohube Betty Mowa

    2014-01-01

    Full Text Available Research on applying RNA interference (RNAi to counter HBV replication has led to identification of potential therapeutic sequences. However, before clinical application liver-specific expression and efficient delivery of these sequences remain an important objective. We recently reported short-term inhibition of HBV replication in vivo by using helper dependent adenoviral vectors (HD Ads expressing anti-HBV sequences from a constitutively active cytomegalovirus (CMV promoter. To develop the use of liver-specific transcription regulatory elements we investigated the utility of the murine transthyretin (MTTR promoter for expression of anti-HBV primary microRNAs (pri-miRs. HD Ads containing MTTR promoter effected superior expression of anti-HBV pri-miRs in mice compared to HD Ads containing the CMV promoter. MTTR-containing HD Ads resulted in HBV replication knockdown of up to 94% in mice. HD Ads expressing trimeric anti-HBV pri-miRs silenced HBV replication for 5 weeks. We previously showed that the product of the codelivered lacZ gene induces an immune response, and the duration of HBV silencing in vivo is likely to be attenuated by this effect. Nevertheless, expression of anti-HBV pri-miRs from MTTR promoter is well suited to countering HBV replication and development of HD Ads through attenuation of their immunostimulatory effects should advance their clinical utility.

  9. Field Flatness Tuning for PEFP 100 MeV DTL

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han-Sung; Kwon, Hyeok-Jung; Seol, Kyung-Tae; Kim, Dae-Il; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    A conventional 100 MeV drift tube linac is under development for Proton Engineering Frontier Project. Currently the proton linac up to 20 MeV, which consists of injector, 3 MeV RFQ and 20 MeV DTL is completed. To accelerate the proton beam up to 100 MeV additional 7 DTL tanks are required. The DTL should be tuned after fabrication and alignment of the drift tube inside the tank to meet the requirements from the beam dynamics. Tuning process includes the resonant frequency tuning, field flatness tuning and tilt sensitivity tuning. The tuning goal for the field flatness tuning is less than {+-}2% in field uniformity throughout the DTL tank with less than {+-}% standard deviation. A non-uniform field profile caused by the machining errors and alignment errors can be made uniform through the slug tuner adjustment. This procedure requires the field profile measurements and several iterations between the field profile measurements and adjustment. The methods and the results of the DTL field flatness tuning will be reported in this presentation.

  10. Temporal Structure of MeV Electron Precipitation

    Science.gov (United States)

    Millan, R. M.; Lorentzen, K. R.; Lin, R. P.; Smith, D. M.

    2001-12-01

    On January 12, 2000, the MAXIS (MeV Auroral X-ray Imaging and Spectroscopy) long duration balloon experiment was launched from McMurdo, Antarctica carrying x-ray instrumentation designed to search for MeV electron precipitation similar to the event observed in 1996 over Kiruna, Sweden (L=5.8). MAXIS detected seven x-ray bursts with significant flux extending above 0.8 MeV during the 18 day flight in addition to extended periods of softer X-ray activity. These seven events are characterized by an extremely flat spectrum ( ~E-1.7) indicating that the bulk of precipitating electrons producing the x-rays is at relativistic energies. The bursts were detected between magnetic latitudes 58o-67o (corresponding to L-values between 3.8-6.7) with durations varying from several minutes to several hours. The MeV bursts were found to occur preferentially in the late afternoon/dusk sectors (14:30-00:00 MLT) while softer precipitation was detected at all magnetic local times. Two of the strongest MeV events detected by MAXIS show strong modulation of the x-ray count rate at ULF timescales ( ~150 s) similar to modulations observed during the Kiruna event at 100-200 s. We present results from temporal analysis of the MAXIS germanium spectrometer data and examine ground-based and spacecraft observations for evidence of coincident ULF wave activity.

  11. 基于PRI谱的双门限雷达信号分选算法及其硬件平台设计%Double-Threshold PRI Sorting Algorithm Based on PRI Spectrum and Its Sorting Platform Design

    Institute of Scientific and Technical Information of China (English)

    柴娟芳; 司锡才; 马晓东

    2009-01-01

    针对修正的PRI变换法无法分选重频参差雷达信号的缺点,提出了一种基于PRI谱的双门限雷达信号分选算法.该算法先对PRI谱设定双门限检测各个准PRI,再结合组合查看及序列搜索提取各个PRI.同时,构建了一种预分选、主分选结合的新型分选平台.预分选利用带有PowerPC的FPGA构架片上系统,完成对脉冲雷达信号的实时测量、AOA分类及数据存储;主分选采用DSP专职完成其他维参数的分选算法.谊分选新算法在保留抑制PRI子谐波优点的同时,对重频固定、抖动和参差的雷达脉冲信号都有较好的检测结果.视频信号源的大量测试表明,谊分选平台对普通雷达、PRI抖动和参差雷达、频率捷变雷达及一些特殊雷达均具有较好的分选能力.

  12. Functional study of one nucleotide mutation in pri-miR-125a coding region which related to recurrent pregnancy loss.

    Science.gov (United States)

    Hu, Yi; Huo, Zheng-Hao; Liu, Chun-Mei; Liu, Shi-Guo; Zhang, Ning; Yin, Kun-Lun; Qi, Lu; Ma, Xu; Xia, Hong-Fei

    2014-01-01

    MicroRNAs (miRNAs) are short non-coding RNAs which modulate gene expression by binding to complementary segments present in the 3'UTR of the mRNAs of protein coding genes. MiRNAs play very important roles in maintaining normal human body physiology conditions, meanwhile, abnormal miRNA expressions have been found related to many human diseases spanning from psychiatric disorders to malignant cancers. Recently, emerging reports have indicated that disturbed miRNAs expression contributed to the pathogenesis of recurrent pregnancy loss (RPL). In this study, we identified a new mutation site (+29A>G, position relative to pre-miR-125a) by scanning pri-miR-125a coding region in 389 Chinese Han RPL patients. This site was co-existed with two polymorphisms (rs12976445 and rs41275794) in patients heterogeneously and changed the predicted secondary structures of pri-miR-125a. Subsequent in vitro analysis indicated that the A>G mutation reduced mature miR-125a expression, and further led to less efficient inhibition of verified target genes. Functional analysis showed that mutant pri-mir-125a can enhance endometrial stromal cells (ESCs) invasive capacity and increase the sensitivity of ESCs cells to mifepristone. Moreover, we further analyzed the possible molecular mechanism by RIP-chip assay and found that mutant pri-mir-125a disturbed the expression of miR-125a targetome, the functions of which includes embryonic development, cell proliferation, migration and invasion. These data suggest that A>G mutation in pri-miR-125a coding region contributes to the genetic predisposition to RPL by disordering the production of miR-125a, which consequently meddled in gene regulatory network between mir-125a and mRNA.

  13. Method of deinterleaving radar signal based on PRI transform algorithm%一种基于PRI变换的雷达信号分选方法

    Institute of Scientific and Technical Information of China (English)

    王海滨; 马琦

    2013-01-01

    With the signal environment of information warfare increasingly complicated, the radar signal sorting technology, as one of development directions of modern radar, is of great importance to radar reconnaissance. Several radar signal deinterleav-ing methods are proposed based on PRI parameter. The traditional PRI transform can overcome the subharmonic problem pro-duced in the histogram statistic methods, but has a poor performance on anti-jitter. The paper begins with a discussion of the im-proved PRI transform which overcomes the disadvantages of traditional PRI method effectively, followed by the description of the algorithm simulation. Finally, a method for sorting pulse repetition intervals of staggered PRI is discussed.%信息作战环境日益复杂,而雷达信号分选技术是作为现代信息对抗领域的重要发展方向之一,对于雷达侦察非常重要.对于雷达信号分选,基于PRI参数提出了很多分选方法.传统的PRI变换能克服直方图统计法中的子谐波问题,但抗抖动性差.讨论了修正的PRI变换分选算法,有效地克服了传统PRI变换的缺点,并对算法进行了计算机仿真.最后还讨论了重频参差抖动脉冲序列的分选方法.

  14. The interaction effects of pri-let-7a-1 rs10739971 with PGC and ERCC6 gene polymorphisms in gastric cancer and atrophic gastritis.

    Directory of Open Access Journals (Sweden)

    Qian Xu

    Full Text Available BACKGROUND: The aim of this study was to investigate the interaction effects of pri-let-7a-1 rs10739971 with pepsinogen C (PGC and excision repair cross complementing group 6 (ERCC6 gene polymorphisms and its association with the risks of gastric cancer and atrophic gastritis. We hoped to identify miRNA polymorphism or a combination of several polymorphisms that could serve as biomarkers for predicting the risk of gastric cancer and its precancerous diseases. METHODS: Sequenom MassARRAY platform method was used to detect polymorphisms of pri-let-7a-1 rs10739971 G → A, PGC rs4711690 C → G, PGC rs6458238 G → A, PGC rs9471643 G → C, and ERCC6 rs1917799 in 471 gastric cancer patients, 645 atrophic gastritis patients and 717 controls. RESULTS: An interaction effect of pri-let-7a-1 rs10739971 polymorphism with ERCC6 rs1917799 polymorphism was observed for the risk of gastric cancer (P interaction = 0.026; and interaction effects of pri-let-7a-1 rs10739971 polymorphism with PGC rs6458238 polymorphism (P interaction = 0.012 and PGC rs9471643 polymorphism (P interaction = 0.039 were observed for the risk of atrophic gastritis. CONCLUSION: The combination of pri-let-7a-1 rs10739971 polymorphism and ERCC6 and PGC polymorphisms could provide a greater prediction potential than a single polymorphism on its own. Large-scale studies and molecular mechanism research are needed to confirm our findings.

  15. The interaction effects of pri-let-7a-1 rs10739971 with PGC and ERCC6 gene polymorphisms in gastric cancer and atrophic gastritis.

    Science.gov (United States)

    Xu, Qian; Liu, Jing-wei; He, Cai-yun; Sun, Li-ping; Gong, Yue-hua; Jing, Jing-Jing; Xing, Cheng-zhong; Yuan, Yuan

    2014-01-01

    The aim of this study was to investigate the interaction effects of pri-let-7a-1 rs10739971 with pepsinogen C (PGC) and excision repair cross complementing group 6 (ERCC6) gene polymorphisms and its association with the risks of gastric cancer and atrophic gastritis. We hoped to identify miRNA polymorphism or a combination of several polymorphisms that could serve as biomarkers for predicting the risk of gastric cancer and its precancerous diseases. Sequenom MassARRAY platform method was used to detect polymorphisms of pri-let-7a-1 rs10739971 G → A, PGC rs4711690 C → G, PGC rs6458238 G → A, PGC rs9471643 G → C, and ERCC6 rs1917799 in 471 gastric cancer patients, 645 atrophic gastritis patients and 717 controls. An interaction effect of pri-let-7a-1 rs10739971 polymorphism with ERCC6 rs1917799 polymorphism was observed for the risk of gastric cancer (P interaction = 0.026); and interaction effects of pri-let-7a-1 rs10739971 polymorphism with PGC rs6458238 polymorphism (P interaction = 0.012) and PGC rs9471643 polymorphism (P interaction = 0.039) were observed for the risk of atrophic gastritis. The combination of pri-let-7a-1 rs10739971 polymorphism and ERCC6 and PGC polymorphisms could provide a greater prediction potential than a single polymorphism on its own. Large-scale studies and molecular mechanism research are needed to confirm our findings.

  16. Evaluation of the pri-miR-34b/c rs4938723 polymorphism and its association with breast cancer risk.

    Science.gov (United States)

    Sanaei, Sara; Hashemi, Mohammad; Rezaei, Maryam; Hashemi, Seyed Mehdi; Bahari, Gholamreza; Ghavami, Saeid

    2016-07-01

    MicroRNAs (miRNAs or miRs) are a family of small non-coding RNAs that function as oncogenes or tumor suppressor genes. Recent evidence suggests that the pri-miR-34b/c rs4938723 variant is associated with the development of cancer. At present, there is an inconsistent association between the single-nucleotide polymorphism in pri-miR-34b/c and cancer in the limited studies. The present study is a case-control investigation, with 263 breast cancer (BC) patients and 221 control women, which examined the potential association of the pri-miR-34b/c rs4938723 polymorphisms with BC susceptibility. The polymorphisms were genotyped by the polymerase chain reaction restriction fragment length polymorphism method. No significant association between the pri-miR-34b/c rs4938723 variant and BC was identified [TC vs. TT: Odds ratio (OR), 0.87; 95% confidence interval (CI), 0.60-1.26; P=0.506; CC vs. TT: OR, 1.22; 95% CI, 0.61-2.47; P=0.600; TC+CC vs. TT: OR, 0.91; 95% CI, 0.64-1.31; P=0.648; CC vs. TT+TC: OR, 1.32; 95% CI, 0.67-2.59; P=0.498; C vs. T: OR, 0.99; 95% CI, 0.75-1.31; P=0.986]. However, a significant association was observed between the pri-miR-34b/c rs4938723 genotypes and clinicopathological characteristics, such a grade, progesterone receptor and human epidermal growth factor receptor 2 status were observed (Ppri-miR-34b/c rs4938723 variant may not be a risk factor for the development of BC.

  17. 400-MeV upgrade for the Fermilab linac

    Energy Technology Data Exchange (ETDEWEB)

    Young, D.E.; Noble, R.J.

    1989-09-01

    Fermilab plans to upgrade the Tevatron to expand the physics research program in both the fixed target and the collider operating modes. The first phase of this program is to increase the energy of the H{sup -} linac from 200 to 400 MeV in order to reduce the incoherent space change tuneshift at injection into the Booster which can limit either the brightness or the total intensity of the beam. The linac upgrade will be achieved by replacing the last four 201 MeV, with seven 805 MHz side-coupled cavity modules operating at an average axial field of about 8 MV/m. This will allow acceleration to 400 MeV in the existing Linac enclosure. 4 refs., 3 figs., 1 tab.

  18. 3 MeV Test Stand commissioning report

    CERN Document Server

    Bellodi, Guilia; Andreassen, O; Comblin, J-F; Dimov, V; Lallement, J-B; Martin, C; Midttun, O; Ovalle, E; Raich, U; Roncarolo, F; Rossi, C; Scrivens, R; Vollaire, J; Yarmohammadi Satri, M; Zocca, Z

    2013-01-01

    Linac4 is a normal-conducting 160 MeV H- linear accelerator, presently under construction, that will replace the present 50 MeV Linac2 as injector of the CERN proton accelerator complex with the goal of increasing the LHC luminosity. The Linac4 front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, was commissioned at the 3 MeV test stand area during the first half of 2013. This report gives details of the installation and operational systems used, describes the commissioning phases and measurements performed and summarizes the results that were finally achieved and the lessons learnt in the process.

  19. NON-GENICULATE CORALLINE ALGAE (CORALLINALES, RHODOPHYTA FROM THE LOWER OLIGOCENE OF POLJŠICA PRI PODNARTU (NORTHERN SLOVENIA

    Directory of Open Access Journals (Sweden)

    LUKA GALE

    2009-03-01

    Full Text Available Despite their increasing importance in sedimentology and palaeoecology, non-geniculate coralline algae remain virtually overlooked in Slovenia. Though these plants are present or even abundant in the Cretaceous and Cainozoic strata, they have never been studied in detail with notable exception of corallines from the Lower Oligocene beds in the area of Gornji Grad. Poljšica pri Podnartu is another locality where Lower Oligocene beds are exposed, considered as equivalent to the former. The studied profile consists of pebbly limestone, mudstone, sandstone and limestone. Limestones contain abundant non-geniculate coralline algae. Nine species from six genera of these corallines have been identified: Lithoporella melobesioides (Foslie Foslie, 1909, Neogoniolithon contii (Mastrorilli Quaranta et al., 2007, Spongites sp., Lithothamnion sp. 1, Lithothamnion sp. 2, Mesophyllum sp. 1, Mesophyllum sp. 2, Mesophyllum sp. 3 and Sporolithon sp. Some of these species are described from Slovenia for the first time. 

  20. Protein kinase C α regulates nuclear pri-microRNA 15a release as part of endothelin signaling.

    Science.gov (United States)

    von Brandenstein, Melanie; Depping, Reinhard; Schäfer, Ekaterine; Dienes, Hans-Peter; Fries, Jochen W U

    2011-10-01

    Endothelin-1 induced signaling is characterized by an early induction of a nuclear factor-kappa B p65/mitogen-activated phosphokinase p38 transcription complex via its A-receptor versus a late induction via diacylglycerol, and protein kinase C. A possible interaction between these two pathways and a potential function for protein kinase C in this context has not previously been elucidated. Here we report that in Caki-1 tumor cells, protein kinase C α is a part of the transcription complex. With importin α4 and α5 as chaperones, the transcription complex transmigrates into the nucleus. Protein kinase C α blocks the nuclear release of pri-microRNA 15a by direct binding shown by electrophoretic mobility shift assay and Duolink immune histology. The expression levels of miRNA 15a can be further manipulated by transfection of si-protein kinase C α, or an expression vector containing protein kinase C α or miRNA 15. The miRNA 15a regulation by protein kinase C α is detectable in different malignant human tumor cell lines (renal cell carcinoma, breast carcinoma, and melanoma). Furthermore, all three cell lines harbor both endothelin receptors (ETAR/ETBR). Specific blockage of each receptor leads to major reduction of miRNA 15a expression due to increased nuclear protein kinase C α translocation. We conclude that the nuclear binding of pri-microRNA 15a is a novel function of protein kinase C α, which plays an important role in endothelin-1 mediated signaling. Since several endothelin-sensitive, malignant tumor cell lines harbor this regulation, it could indicate a more general role in tumor biology.

  1. Persistent organic pollutants, heavy metals and radioactivity in the urban soil of Priština City, Kosovo and Metohija.

    Science.gov (United States)

    Gulan, Ljiljana; Milenkovic, Biljana; Zeremski, Tijana; Milic, Gordana; Vuckovic, Biljana

    2017-03-01

    Polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), heavy metals content and radioactivity levels were measured in 27 soil samples collected from Priština, the capital of Kosovo and Metohija. The sixteen PAHs, twelve OCPs and six PCBs congeners were determined by gas chromatography system with mass spectrometry detection. Although the use of PCBs and OCPs was prohibited decades ago residues of those compounds still existed in measurable concentrations in soils of Priština. PAHs were also present in analyzed samples but their mean concentration was significantly lower than mean concentrations of PAHs previously reported in urban areas in the world. The concentrations of heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) were determined by the EDTA extraction protocols, along with their extractable concentrations. The activity concentrations of natural radionuclides ((226)Ra, (232)Th and (40)K) were determined by gamma spectrometry method. The Shapiro-Wilk normality test found that activity concentrations of natural radionuclides were normally distributed. Radiological risk was estimated through the annual effective dose, gonadal dose equivalent, excess lifetime cancer risk, radium equivalent activity, external and internal hazard indexes. Spearman correlation coefficient was used for analysis of correlations between physicochemical properties, heavy metal contents and radionuclide activity concentrations. Strong positive correlation between (226)Ra and (232)Th was found, as well as among pairs of As-Cd and Co-Mn. Very strong positive correlation (0.838) at the 0.01 significance level was noted for Pb-Zn pair. Strong correlations indicate common occurrence of these elements in the nature, as well as geogenic association. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Lifetime of 19Ne*(4.03 MeV)

    CERN Document Server

    Kanungo, R; Andreyev, A N; Ball, G C; Chakravarthy, R S; Chicoine, M; Churchman, R; Davids, B; Forster, J S; Gujrathi, S; Hackman, G; Howell, D; Leslie, J R; Morton, A C; Mythili, S; Pearson, C J; Ressler, J J; Ruiz, C; Savajols, H; Schumaker, M A; Tanihata, I; Walden, P L; Yen, S

    2006-01-01

    The Doppler-shift attenuation method was applied to measure the lifetime of the 4.03 MeV state in 19Ne. Utilizing a 3He-implanted Au foil as a target, the state was populated using the 20Ne(3He,alpha)19Ne reaction in inverse kinematics at a 20Ne beam energy of 34 MeV. De-excitation gamma rays were detected in coincidence with alpha particles. At the 1 sigma level, the lifetime was determined to be 11 +4, -3 fs and at the 95.45% confidence level the lifetime is 11 +8, -7 fs.

  3. Resolution considerations in MeV ion microscopy and lithography

    Energy Technology Data Exchange (ETDEWEB)

    Norarat, Rattanaporn, E-mail: rattanaporn@rmutl.ac.th [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Faculty of Sciences and Agricultural Technology, Rajamangala University of Technology Lanna, Chiang Rai, 57120 Chiang Rai (Thailand); Whitlow, Harry J. [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland)

    2015-04-01

    There a disparity between the way the resolution is specified in microscopy and lithography using light compared to MeV ion microscopy and lithography. In this work we explore the implications of the way the resolution is defined with a view to answering the questions; how are the resolving powers in MeV ion microscopy and lithography relate to their optical counterparts? and how do different forms of point spread function affect the modulation transfer function and the sharpness of the edge profile?.

  4. Linac4 crosses the 100 MeV threshold

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    The new linear accelerator, which from 2020 will be the first link in the accelerator chain, has entered a new stage of its commissioning.   Members of the team in charge of the commissioning of Linac4 in the accelerator’s control room. A few hours earlier, Linac4 accelerated a beam to 107 MeV for the first time. We couldn’t have imagined a more appropriate date: on 1 July (1.07), Linac4 reached an energy of 107 MeV. Having crossed the 100 MeV barrier, the linear accelerator is now on the home straight of its commissioning. “This stage was very quick – it took less than two weeks,” says Alessandra Lombardi, deputy project leader of Linac4, in charge of the commissioning. In 2020, Linac4 will replace the existing Linac2 as the first link in the accelerator chain. It will accelerate beams of H- ions (protons surrounded by two electrons) to 160 MeV, compared to 50 MeV with Linac2. The new machine is particularly sophisticated as it comprises...

  5. History of the ZGS 500 MeV booster.

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.; Martin; R.; Kustom, R.

    2006-05-09

    The history of the design and construction of the Argonne 500 MeV booster proton synchrotron from 1969 to 1982 is described. This accelerator has since been in steady use for the past 25 years to power the Argonne Intense Pulsed Neutron Source (IPNS).

  6. Association of polymorphism in pri-microRNAs-371-372-373 with the occurrence of hepatocellular carcinoma in hepatitis B virus infected patients.

    Science.gov (United States)

    Kwak, Min-Sun; Lee, Dong Hyeon; Cho, Yuri; Cho, Eun-Ju; Lee, Jeong-Hoon; Yu, Su Jong; Yoon, Jung-Hwan; Lee, Hyo-Suk; Kim, Chung Yong; Cheong, Jae Youn; Cho, Sung Won; Shin, Hyoung Doo; Kim, Yoon Jun

    2012-01-01

    Micro RNAs-371-372-373 (miRNAs-371-373), originating from the same pri-miRNA transcript, are reported to be upregulated in hepatocellular carcinoma (HCC) and to be related to the regulation of hepatitis B virus (HBV) infection. Our study investigated whether pri-miRNAs-371-373 polymorphisms are associated with the risk of HCC occurrence and HBV clearance. Genetic variations were identified through direct DNA sequencing using TaqMan assay. Three sequence variants of pri-miRNAs-371-373 were identified. Genetic associations of those with HCC occurrence and HBV clearance among patients with HBV infection were analyzed using logistic regression analyses with adjustment for age and gender (n = 1439). For the occurrence of HCC, polymorphism rs3859501C>A acted as a protective factor both in chronic carriers (OR = 0.75, P = 0.005 in a codominant model; OR = 0.71, P = 0.02 in a dominant model; OR = 0.66, P = 0.03 in recessive model) and liver cirrhosis patients (OR = 0.69, P = 0.001 in a codominant model; OR = 0.60, P = 0.003 in a dominant model; OR = 0.63, P = 0.03 in a recessive model). The pri-miRNAs-371-373_ht2 [C-A-C] also showed a protective effect on HCC occurrence both in the chronic carrier and liver cirrhosis groups (Ppri-miRNAs-371-373 polymorphisms and HBV clearance. In conclusion, among chronic carriers and liver cirrhosis patients, the A allele of rs3859501 and the haplotype pri-miRNAs-371-373_ht2 were more protective to HCC than other genotypes and haplotypes. Further studies into the roles of rs3859501 and pri-miRNAs-371-373_ht2 haplotype in hepatocarcinogenesis are needed.

  7. Genetic polymorphisms of IL17A and pri-microRNA-938, targeting IL17A 3'-UTR, influence susceptibility to gastric cancer.

    Science.gov (United States)

    Arisawa, Tomiyasu; Tahara, Tomomitsu; Shiroeda, Hisakazu; Matsue, Yasuhito; Minato, Takahiro; Nomura, Tomoe; Yamada, Hideto; Hayashi, Ranji; Saito, Takashi; Matsunaga, Kazuhiro; Fukuyama, Tomoki; Hayashi, Nobuhiko; Otsuka, Toshimi; Fukumura, Atsushi; Nakamura, Masakatsu; Shibata, Tomoyuki

    2012-07-01

    We report an association between gastric cancer (GC) and polymorphisms in IL17A, rs2275913 (-197 G > A), rs3748067 (*1249 C > T), and pri-miR-938, rs2505901 (T > C). We employed the multiplex PCR-SSCP method to detect gene polymorphisms in 337 GC cases and 587 controls. The minor allele frequency of rs2275913 was significantly higher, and those of rs3748067 and rs2505901 significantly lower, in GC cases than controls. The rs2275913 AA homozygote was associated with an increased risk (OR, 2.38; 95%CI, 1.63-3.46; p pri-miR-938 contribute to cancer risk susceptibility and therefore can affect the development of gastric cancer.

  8. Vartotojų elgsenos modeliai sprendimo priėmimo procese (remiantis UAB „Verbūnų duona“ pavyzdžiu)

    OpenAIRE

    Petrauskienė, Lina

    2009-01-01

    Magistro darbe išanalizuota vartotojų elgsenos samprata, esmė bei vartotojų elgsenos reikšmė organizacijai; įvertinta vartotojų elgsenos modelių įvairovė; atskleisti vartotojų elgseną lemiantys veiksniai, kurie daro įtaką sprendimo pirkti priėmimo procesui. Darbe atskleistos vartotojų elgsenos veiksnių, turinčių įtakos sprendimo pirkti priėmimo procesui, tyrimo projektavimo ir organizavimo procedūros, kurios nulėmė tyrimo imties bei metodų pasirinkimą. Praktinėje darbo dalyje apibendrinti UAB...

  9. Single-nucleotide polymorphism of the pri-miR-34b/c gene is not associated with susceptibility to congenital heart disease in the Han Chinese population.

    Science.gov (United States)

    Liu, Y-M; Wang, Y; Peng, W; Wu, Z; Wang, X-H; Wang, M-L; Wang, W; Sun, J; Zhang, Z-D; Mo, X-M

    2013-08-12

    Recent evidence has shown that the microRNA polymorphism may play an important role in the susceptibility to congenital heart disease (CHD). A potentially functional SNP rs4938723 (T>C) in the promoter region of pri-miR-34b/c might affect transcription factor GATA binding and therefore pri-miR-34b/c expression. We genotyped the pri-miR-34b/c polymorphism in a case-control study of 590 patients and 672 controls in a Han Chinese population and assessed the effects of the pri-miR-34b/c polymorphism on CHD susceptibility by TaqMan SNP genotyping assay. There was no association between the pri-miR-34b/c polymorphism and the risk of CHD in both genotype and allelic frequency. In a subsequent analysis of the association between this polymorphism and CHD classification, there was still no significant difference in both genotype and allelic frequency. Our results suggest that the pri-miR-34b/c polymorphism rs4938723 is not associated with susceptibility to sporadic CHD in the Han Chinese population.

  10. Zeaxanthin-independent energy quenching and alternative electron sinks cause a decoupling of the relationship between the photochemical reflectance index (PRI) and photosynthesis in an evergreen conifer during spring.

    Science.gov (United States)

    Fréchette, Emmanuelle; Wong, Christopher Y S; Junker, Laura Verena; Chang, Christine Yao-Yun; Ensminger, Ingo

    2015-12-01

    In evergreen conifers, the winter down-regulation of photosynthesis and its recovery during spring are the result of a reorganization of the chloroplast and adjustments of energy-quenching mechanisms. These phenological changes may remain undetected by remote sensing, as conifers retain green foliage during periods of photosynthetic down-regulation. The aim was to assess if the timing of the spring recovery of photosynthesis and energy-quenching characteristics are accurately monitored by the photochemical reflectance index (PRI) in the evergreen conifer Pinus strobus. The recovery of photosynthesis was studied using chlorophyll fluorescence, leaf gas exchange, leaf spectral reflectance, and photosynthetic pigment measurements. To assess if climate change might affect the recovery of photosynthesis, seedlings were exposed to cold spring conditions or warm spring conditions with elevated temperature. An early spring decoupling of the relationship between photosynthesis and PRI in both treatments was observed. This was caused by differences between the timing of the recovery of photosynthesis and the timing of carotenoid and chlorophyll pool size adjustments which are the main factors controlling PRI during spring. It was also demonstrated that zeaxanthin-independent NPQ mechanisms undetected by PRI further contributed to the early spring decoupling of the PRI-LUE relationship. An important mechanism undetected by PRI seems to involve increased electron transport around photosystem I, which was a significant energy sink during the entire spring transition, particularly in needles exposed to a combination of high light and cold temperatures.

  11. 基于PRI的脉冲序列去交错方法%PRI-Based Algorithms for Deinterleaving of Radar Pulses

    Institute of Scientific and Technical Information of China (English)

    周斌

    2002-01-01

    论述使用脉冲重复间隔(PRI)对雷达脉冲去交错的算法,分析PRI变换算法并对算法进行计算机仿真.对PRI变换算法进行改进,并对改进算法进行了计算机仿真和分析.

  12. Pri-miR-34b/c rs4938723 TC heterozygote is associated with increased cancer risks: evidence from published data.

    Science.gov (United States)

    Yi, De-Hui; Wang, Ben-Gang; Zhong, Xin-Ping; Liu, Hao; Liu, Yong-Feng

    2014-12-01

    The promoter region of the microRNA pri-miR-34b/c has a potentially functional polymorphism, rs4938723, located in a typical CpG island. Studies of the association between pri-miR-34b/c rs4938723 polymorphism and risks of various cancers have had inconsistent results. We therefore conducted a meta-analysis of nine studies that included 6,036 cancer patients and 7,490 controls to address this association. Overall, this meta-analysis showed the pri-miR-34b/c rs4938723 TC heterozygote to be significantly associated with increased risk of overall cancers compared with the wild-type TT genotype (P = 0.010, odds ratio (OR) = 1.10, 95 % confidence interval (CI) 1.02-1.18). In stratified analysis, the TC heterozygote was significantly associated with increased cancers risks in digestive tract cancers, in hepatocellular cancer, in Asian population and in the large-sample subgroup. The CC genotypes of rs4938723 were also associated with increased hepatocellular cancer risk but associated with decreased colorectal cancer risk in the stratification analysis by a single cancer type. Thus our meta-analysis suggests that the pri-miR-34b/c rs4938723 TC heterozygote contributes to increased overall cancer risks, as well as shown in digestive tract cancers, in hepatocellular cancer, in Asian population and in the large-sample subgroup. This rs4938723 SNP showed an opposite tendency orientation between the hepatocellular cancer and colorectal cancer risks. Large-sample studies are needed to verify our findings.

  13. Identification and analysis of genetic variations in pri-miRNAs expressed specifically or at a high level in sheep skeletal muscle.

    Science.gov (United States)

    Zhang, Wei; Wang, Limin; Zhou, Ping; Song, Guangchao; Shen, Min; Gan, Shangquan; Shi, Guoqing

    2015-01-01

    MicroRNAs (miRNAs) are key regulators in miRNA-mediated gene regulatory networks and play important roles in many biological processes, such as growth and development of mammals. In this study, we used microarrays to detect 261 miRNAs that are expressed in sheep skeletal muscle. We found 22 miRNAs that showed high levels of expression and equated to 89% of the total miRNA. Genetic variations in these 22 pri-miRNAs were further investigated using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing. A total of 49 genetic variations, which included 41 single nucleotide polymorphisms (SNPs) and 8 deletions/insertions, were identified in four sheep breeds. Three variations were further researched in a larger sample set, including five sheep breeds with different meat production performances. We found that the genotype and allele frequencies of the CCC deletion/insertion in pri-miR-133a were significantly related to the sheep meat production trait. Finally, cell assays and quantitative reverse transcription PCR (qRT-PCR) were employed to investigate the effect of pri-miRNA genetic variation on the miRNA biogenesis process. The results confirmed that genetic variations can influence miRNA biogenesis and increase or decrease the levels of mature miRNAs, in accordance with the energy and stability change of hair-pin secondary structures. Our findings will help to further the understanding of the functions of genetic variations in sheep pri-miRNAs in skeletal muscle growth and development.

  14. Identification and analysis of genetic variations in pri-miRNAs expressed specifically or at a high level in sheep skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available MicroRNAs (miRNAs are key regulators in miRNA-mediated gene regulatory networks and play important roles in many biological processes, such as growth and development of mammals. In this study, we used microarrays to detect 261 miRNAs that are expressed in sheep skeletal muscle. We found 22 miRNAs that showed high levels of expression and equated to 89% of the total miRNA. Genetic variations in these 22 pri-miRNAs were further investigated using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP and sequencing. A total of 49 genetic variations, which included 41 single nucleotide polymorphisms (SNPs and 8 deletions/insertions, were identified in four sheep breeds. Three variations were further researched in a larger sample set, including five sheep breeds with different meat production performances. We found that the genotype and allele frequencies of the CCC deletion/insertion in pri-miR-133a were significantly related to the sheep meat production trait. Finally, cell assays and quantitative reverse transcription PCR (qRT-PCR were employed to investigate the effect of pri-miRNA genetic variation on the miRNA biogenesis process. The results confirmed that genetic variations can influence miRNA biogenesis and increase or decrease the levels of mature miRNAs, in accordance with the energy and stability change of hair-pin secondary structures. Our findings will help to further the understanding of the functions of genetic variations in sheep pri-miRNAs in skeletal muscle growth and development.

  15. pri-miR-34b/c rs4938723 polymorphism is associated with hepatocellular carcinoma risk: a case-control study in a Chinese population.

    Science.gov (United States)

    Liu, Chun-Jia; Ma, Xue-Wei; Zhang, Xue-Jun; Shen, Shi-Qiang

    2017-01-01

    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. miR-34 induces changes of its downstream genes, and plays a key role in altering the apoptotic cycle and pathways of downstream cells, and finally influences the development of cancer. We assessed the relationship of the pri-miR-34b/c rs4938723 polymorphism with hepatocellular carcinoma risk in a Chinese population. During the period of January 2014 and December 2015, a total of 164 HCC patients and 305 healthy controls were recruited from the Inner Mongolia People's Hospital. Genotyping of the pri-miR-34b/c rs4938723 was determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Using χ(2) test, we observed that HCC patients were likely to have a habit of alcohol consumption (χ(2) = 10.24, P = 0.001) and infect with HBV or HCV (χ(2) = 128.17, P pri-miR-34b/c rs4938723 had a significant higher risk of HCC as compared with the TT genotype, and the corresponding adjusted OR (95% CI) was 4.14 (1.91-9.75). In dominant model, we observed that the TC+CC genotype were associated with an increased risk of HCC in comparison to the TT genotype (OR = 1.67, 95% CI = 1.17-2.55). In recessive model, the CC genotype was correlated with an elevated risk of HCC when compared with the TT+TC genotype (OR = 3.46, 95% CI = 1.62-8.54). The pri-miR-34b/c rs4938723 polymorphism was associated with a higher risk of HCC in the Chinese population examined. Further large-scale and multi-center studies are required to confirm these results.

  16. Prion-like nanofibrils of small molecules (PriSM): A new frontier at the intersection of supramolecular chemistry and cell biology

    OpenAIRE

    Zhou, Jie; Du, Xuewen; Xu, Bing

    2015-01-01

    Formed by non-covalent interactions and not defined at genetic level, the assemblies of small molecules in biology are complicated and less explored. A common morphology of the supramolecular assemblies of small molecules is nanofibrils, which coincidentally resembles the nanofibrils formed by proteins such as prions. So these supramolecular assemblies are termed as prion-like nanofibrils of small molecules (PriSM). Emerging evidence from several unrelated fields over the past decade implies ...

  17. Endocrine and Metabolic Effects of Adipose Tissue in Children and Adolescents / Endokrina in Presnovna Funkcija Maščobnega Tkiva Pri Otrocih in Mladostnikih

    Directory of Open Access Journals (Sweden)

    Kotnik Primož

    2015-03-01

    Full Text Available Maščobno tkivo ima vlogo pri številnih endokrinih in presnovnih procesih. Lepin je bil med prvimi odkritimi dejavniki iz maščobnega tkiva, ki delujejo avto-, para- in endokrino. Od opredelitve leptina so odkrili še številne druge dejavnike, od katerih se nekateri izločajo iz maščobnih celic, nekateri pa iz drugih celic maščobnega tkiva.

  18. The impact of pri-miR-218 rs11134527 on the risk and prognosis of patients with esophageal squamous cell carcinoma.

    Science.gov (United States)

    Jiang, Lin; Wang, Chaofu; Sun, Canlin; Xu, Yumin; Ding, Zhongqi; Zhang, Xueling; Huang, Junxing; Yu, Hong

    2014-01-01

    MicroRNA-218 (miR-218) acts as a tumor suppressor in numerous types of cancer by regulation of the expression of target genes. The aim of this study was to investigate whether polymorphisms in miR-218 LAMB3 pathway were associated with the risk and prognosis of esophageal squamous cell carcinoma (ESCC). Pri-mir-218 rs11134527 and LAMB3 rs2566 were genotyped in ESCC patients and 745 controls to assess their associations with cancer risk and overall survival. Pri-mir-218 rs11134527 was significantly associated with a decreased risk of ESCC under codominant, recessive and additive models. Although there was a significant association between rs11134527 and better survival of ESCC patients under codominant, recessive and additive models, the association disappeared after adjustment for TNM and LNM. However, further stratified analysis revealed that the association remained significant in patients with TNM stages I and II or non-LNM. Our data suggest that pri-miR-218 rs11134527 may contribute to the genetic susceptibility and prognosis for ESCC in Chinese Han population.

  19. The variant of pri-mir-26a-1 polymorphism is associated with decreased risk of betel quid-related oral premalignant lesions and oral squamous cell carcinoma.

    Science.gov (United States)

    Yang, Cheng-Mei; Chen, Chien-Chou; Tseng, Yu-Kai; Huang, Sin-Jhih; Liou, Huei-Han; Lee, Yi-Cheng; Lee, Jang-Hwa; Wang, Jyh-Seng; Chen, Hung-Chih; Chi, Chao-Chuan; Kang, Bor-Hwang; Lin, Yun-Chung; Tsai, Kuo-Wang; Ger, Luo-Ping

    2017-06-08

    This case-control study evaluated the association of the single nucleotide polymorphism rs7372209 (T>C) in pri-mir-26a-1 with the risk and progression of betel quid (BQ)-related oral premalignant lesions (OPLs) and oral squamous cell carcinoma (OSCC). In total, 597 BQ chewers were recruited: 196 healthy controls, 241 patients with OPLs, and 160 patients with OSCC. Genotypes were determined using the TaqMan real-time assay. The C/T + T/T genotypes and T allele in pri-mir-26a-1 were correlated with a decreased risk of BQ-related OPLs (P = .038 and .005, respectively), oral leukoplakia (P = .01 and .001, respectively), and advanced-stage OSCC (P = .021 and .004, respectively). The effects of the C/T + T/T genotypes and T allele on the decreased risk of OPLs were potent in the older age group (both Pinteraction pri-mir-26a-1 may have a decreased risk of oral leukoplakia, OPLs, and advanced-stage OSCC. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Application of carbon nanosorbent for PRiME pass-through cleanup of 10 selected local anesthetic drugs in human plasma samples.

    Science.gov (United States)

    Ma, Jian-Bo; Zhao, Li-Ming; Rui, Qiu-Hong; Liao, Yu-Feng; Chen, Yan-Min; Xu, Jin; Zhu, Yan; Zhao, Yong-Gang

    2017-04-01

    A novel PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure has been developed to improve the existing commercially available designs. Carbon nanosorbents, i.e., magnetic modified carboxyl-graphene (Mag-CG) and magnetic modified carboxyl-carbon nanotubes (Mag-CCNTs), have been synthesised and evaluated in PRiME pass-through cleanup procedure for human plasma prior to analysis of 10 selected local anesthetic drugs by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The matrix effect, an interesting phenomenon of ion suppression for local anesthetic drugs containing ester group and ion enhancement for other drugs containing acylamino group, has been minimized using carbon nanosorbents PRiME pass-through cleanup procedure. Under the optimal conditions, the obtained results show higher cleanup efficiency of the carbon nanosorbents with recoveries between 70.2% and 126%. Furthermore, the carbon nanosorbents are also evaluated for reuse up to 80-100 times. The limits of quantification (LOQs) for local anesthetic drugs are in the range of 0.024-0.15 μg/L. Validation results on linearity, specificity, accuracy, and precision, as well as the application to the analysis of lidocaine in five patients recruited from the lung cancer demonstrate the applicability to clinical studies.

  1. Magnifying lens for 800 MeV proton radiography.

    Science.gov (United States)

    Merrill, F E; Campos, E; Espinoza, C; Hogan, G; Hollander, B; Lopez, J; Mariam, F G; Morley, D; Morris, C L; Murray, M; Saunders, A; Schwartz, C; Thompson, T N

    2011-10-01

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  2. First Light: MeV Astrophysics from the Moon

    Science.gov (United States)

    Miller, Richard S.; Lawrence, David J.

    2016-06-01

    We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5-9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.

  3. Evolution of the 400 MeV linac design

    Energy Technology Data Exchange (ETDEWEB)

    MacLachlan, J.A.

    1987-11-09

    The basic premises of the conceptual design for the linac upgrade are pursued to establish lengths, gradients, power dissipation, etc., for the 400 MeV linac and matching section. The discussion is limited to accelerating and focusing components. Wherever values depend on the choice of the accelerating structure, the disk-and-washer structure is emphasized; the results are generally relevant to the side coupled cavity choice also.

  4. Construction of a pulsed MeV positron beam line

    Energy Technology Data Exchange (ETDEWEB)

    Masuno, Shin-ichi; Okada, Sohei; Kawasuso, Atsuo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    To develop a fast (1 MeV) and short pulsed (100 ps) positron beam which enables defect behavior analysis of bulk states of materials even at high temperatures where a usual positron source would melt, we have been performing design study and construction of the beam line in a three-year program since 1994. This report describes the components, design study results and experimental results of the completed parts until now. (author)

  5. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, A.F.; Ronningen, R.M.; Godeke, A.; Heilbronn, L.H.; McMahan-Norris, P.; Gupta, R.

    2007-11-27

    The use of HTS materials in high radiation environmentsrequires that the superconducting properties remain constant up to aradiation high dose. BSCCO-2223 samples from two manufacturers wereirradiated with 50 MeV protons at fluences of up to 5 x 1017 protons/cm2.The samples lost approximately 75 percent of their pre-irradiation Ic.This compares with Nb3Sn, which loses about 50 percent at the samedisplacements per atom.

  6. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, A.F.; Ronningen, R.M.; Godeke, Arno; Heibronn, L.H; McMahan-Norris, P.; Gupta, R.

    2007-11-01

    The use of HTS materials in high radiation environments requires that the superconducting properties remain constant up to a radiation high dose. BSCCO-2223 samples from two manufacturers were irradiated with 50 MeV protons at fluences of up to 5 x 10{sup 17} protons/cm{sup 2}. The samples lost approximately 75% of their pre-irradiation I{sub c}. This compares with Nb{sub 3}Sn, which loses about 50% at the same displacements per atom.

  7. Pri-miR-34b/c rs4938723 polymorphism contributes to acute lymphoblastic leukemia susceptibility in Chinese children.

    Science.gov (United States)

    Tong, Na; Chu, Haiyan; Wang, Meilin; Xue, Yao; Du, Mulong; Lu, Lingling; Zhang, Heng; Wang, Feng; Fang, Yongjun; Li, Jie; Wu, Dongmei; Zhang, Zhengdong; Sheng, Xiaojing

    2016-01-01

    A polymorphism rs4938723 (T > C) within the promoter region of pri-miR-34b/c has been found to not only affect the expression of mature miR-34b/c but also contribute to the susceptibility to several cancer types. We designed a case-control study to evaluate the role of rs4938723 in childhood acute lymphoblastic leukemia (ALL). The rs4938723 CC genotype was significantly associated with reduced ALL risk (p = 0.003, ORadjusted = 0.51, 95% CI = 0.33-0.80 for CC vs. TT). Stratification analyses showed the differences were pronounced in older (> 6 years), male subjects, as well as in patients in low risk and T-ALL subtypes. The in vitro luciferase assays in Jurkat and K-562 cell lines showed that the transcription activity of miR-34b/c was increased when T allele transited to C allele (p < 0.05). In conclusion, rs4938723 genetic variant contributed to the susceptibility to Chinese childhood ALL by influencing the transcription activity of miR-34b/c promoter.

  8. Magnetic and electric behavior of praseodymium substituted CuPryFe2-yO4 ferrites

    Science.gov (United States)

    Farid, Muhammad Tahir; Ahmad, Ishtiaq; Kanwal, Muddassara; Murtaza, Ghulam; Ali, Irshad; Ashiq, Muhammad Naeem; Khan, Sajjad Ahmad

    2017-01-01

    Spinel ferrites with chemical formula CuPryFe2-yO4(y=0.0,0.02,0.04,0.06,0.08,0.10) were synthesized using sol-gel technique. The sintered powder characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and vibrating sample magnetometer (VSM). X-ray Diffraction analysis showed that the samples with concentration (y=0.0-0.06) have single spinel phase and the samples with concentration at y=0.08-0.10 have secondary phase (ortho ferrite phase) along spinel phase. The Lattice constant a increased with the substitution of Praseodymium (Pr) ions. The crystallite size calculated from Scherre's formula is found in the range of 53-37 nm. It is observed that DC resistivity and activation energy enhances with the substitution of Pr. The dc resistivity decreased with the increase in temperature. The conduction below Curie temperature (Tc) is due to hopping of electrons and holes, whereas, above Curie temperature it is due to polaron hopping. The decrease in Tc with increasing Pr constant may be due to the fact that Pr-Fe interactions on the B sites are weaker than Fe-Fe interaction. The saturation magnetization (Ms) and remanence (Mr) decreased where as coercivity (Hc) has been increased with the increase of Pr content. The measured parameters suggest that these materials are potential candidates for high frequency applications.

  9. Neutron-induced fission cross section of 242Pu from 15 MeV to 20 MeV

    Directory of Open Access Journals (Sweden)

    Jovančević N.

    2017-01-01

    Full Text Available Accurate nuclear-data needs in the fast-neutron-energy region have been recently addressed for the development of next generation nuclear power plants (GEN-IV by the OECD Nuclear Energy Agency (NEA. This sensitivity study has shown that of particular interest is the 242Pu(n,f cross section for fast reactor systems. Measurements have been performed with quasi-monoenergetic neutrons in the energy range from 15 MeV to 20 MeV produced by the Van de Graaff accelerator of the JRC-Geel. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission fragment detector. The 242Pu(n,f cross section has been normalized to 238U(n,f cross section data. The results were compared with existing literature data and show acceptable agreement within 5%.

  10. A dynamic programming approach for quickly estimating large network-based MEV models

    DEFF Research Database (Denmark)

    Mai, Tien; Frejinger, Emma; Fosgerau, Mogens

    2017-01-01

    by a rooted, directed graph where each node without successor is an alternative. We formulate a family of MEV models as dynamic discrete choice models on graphs of correlation structures and show that the dynamic models are consistent with MEV theory and generalize the network MEV model (Daly and Bierlaire...

  11. First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

    CERN Multimedia

    Linac4 Project Team

    2013-01-01

    On 14 November, the first H- (one proton surrounded by two electrons) beam was accelerated to the energy of 3 MeV in the Linac4 - the new linear accelerator that will replace Linac2 as low-energy injector in the LHC accelerator chain.      A view of the Linac4 taken during the recent tests (top image) and the current measured by the instruments at the end of the acceleration line on 14 November (bottom image). Images: Linac4 collaboration. Using the recently installed Radio Frequency Quadrupole (RFQ) accelerator, 13 mA of current were accelerated to the energy of 3 MeV. After the successful commissioning of the Linac4 RFQ at the 3 MeV test stand completed during the first months of 2013, the whole equipment (composed of the RFQ itself, the following Medium Energy Beam Transport line and its diagnostic line) were moved to the Linac4 tunnel during summer and installed in their final position. In the meantime, a new ion source was assembled, installed and successfu...

  12. Annealing behaviour of MeV erbium implanted lithium niobate

    Energy Technology Data Exchange (ETDEWEB)

    Gortmaker, P.; McCallum, J.C. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1993-12-31

    Lithium niobate (LiNbO{sub 3}) is a crystalline ceramic commonly used in the fabrication of optoelectronic devices. Recently, rare earth doping of LiNbO{sub 3} has become a topic of particular interest. The electronic configuration of rare earth elements such as Erbium (Er) and Neodymium (Nd) allows them to lase in nearly any host matrix making fabrication of a whole range of new optoelectronic devices possible. At present, the doping technique, for LiNbO{sub 3} are centred upon diffusion technology, but the diffusion profiles for the rare earths are not generally well-matched to the optical modes of the device. The aim of this research is to develop MeV implantation and annealing conditions of rare earth doped LiNbO{sub 3} that would be compatible with optoelectronic device fabrication. To determine the characteristics of the rare earth elements in the LiNbO{sub 3} host material over the depth range of interest in optoelectronic device applications, high energy Rutherford backscattering spectrometry and ion channeling (RBS-C) must be used. Presented here are the Er depth profile and lattice damage results obtained from 5 MeV RBS-C measurements on samples of LiNbO{sub 3} implanted with various doses of MeV Erbium and subsequently thermally annealed at a temperature of 1000 deg C. It was found that there is a peak implant concentration (2 x 10{sup 16} Er/cm{sup 2}) for which erbium no longer goes substitutional in the lattice, and the implantation damage is not fully removed by annealing. 8 refs., 3 figs.

  13. An intense 14 MeV neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Su Tongling; Sun Biehe; Yang Baotai; Piao Yubo; Shui Yongqing; Chen Kefan; Wang Xuezhi; Yang Cheng; Niu Zhanqi; Liu Yanton; Pan Minshen; Hong Zhongti; Chen Qin (Lanzhou Univ., GS (China). Inst. of Nuclear Research)

    1990-02-15

    A 3x10{sup 12} n/s source of 14 MeV neutrons is described in this paper. The neutrons are produced by the T(d,n){sup 4}He reaction under a 30 mA, 300 keV deuteron beam bombarding a water-cooled, rotating titanium-tritide target. The size of the beam spot on the target is 1.8 cm, and at the distance of closest approach to the source a neutron flux of 5x10{sup 11} n/cm{sup 2} s is obtained. (orig.).

  14. Polarization Observables in Deuteron Photodisintegration below 360 MeV

    CERN Document Server

    Glister, J; Lee, B W; Gilman, R; Sarty, A J; Strauch, S; Higinbotham, D W; Piasetzky, E; Allada, K; Armstrong, W; Arrington, J; Beck, A; Benmokhtar, F; Berman, B L; Boeglin, W; Brash, E; Camsonne, A; Calarco, J; Chen, J P; Choi, Seonho; Chudakov, E; Coman, L; Craver, B; Cusanno, F; Dumas, J; Dutta, C; Feuerbach, R; Freyberger, A; Frullani, S; Garibaldi, F; Hansen, J -0; Holmstrom, T; Hyde, C E; Ibrahim, H; Ilieva, Y; de Jager, C W; Jiang, X; Jones, M K; Kang, H; Kelleher, A; Khrosinkova, E; Kuchina, E; Kumbartzki, G; LeRose, J J; Lindgren, R; Markowitz, P; Beck, S May-Tal; McCullough, E; Meekins, D; Meziane, M; Meziani, Z -E; Michaels, R; Moffit, B; Norum, B E; Oh, Y; Olson, M; Paolone, M; Paschke, K; Perdrisat, C F; Potokar, M; Pomatsalyuk, R; Pomerantz, I; Puckett, A; Punjabi, V; Qian, X; Qiang, Y; Ransome, R; Reyhan, M; Roche, J; Rousseau, Y; Saha, A; Sawatzky, B; Schulte, E; Shabestari, M; Shahinyan, A; Shneor, R; Sirca, S; Slifer, K; Solvignon, P; Song, J; Sparks, R; Subedi, R; Urciuoli, G M; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Zhan, X; Zhu, X

    2010-01-01

    High precision measurements of induced and transferred recoil proton polarization in d(polarized gamma, polarized p})n have been performed for photon energies of 277--357 MeV and theta_cm = 20 degrees -- 120 degrees. The measurements were motivated by a longstanding discrepancy between meson-baryon model calculations and data at higher energies. At the low energies of this experiment, theory continues to fail to reproduce the data, indicating that either something is missing in the calculations and/or there is a problem with the accuracy of the nucleon-nucleon potential being used.

  15. Radiation Monitoring System of 30 MeV Cyclotron

    Science.gov (United States)

    Lee, Jin-Woo; Hur, Min-Goo; Jeong, Gyosung; Kim, Jongil

    2017-09-01

    A state-of-the-art radiation monitoring system was implemented at KAERI for a 30-MeV cyclotron. This system consists of several types of radiation measuring systems for ambient dose equivalent rate measurements of outside photon and neutron areas as well as inside the cyclotron, and monitors the alpha and beta particulates released from a stack, as well as the results of worker contamination at the portal of the cyclotron. In addition, an automatic alarm system is also mounted if there are alarms in the measuring systems.

  16. Characterization of Staphylococcus aureus Primosomal DnaD Protein: Highly Conserved C-Terminal Region Is Crucial for ssDNA and PriA Helicase Binding but Not for DnaA Protein-Binding and Self-Tetramerization.

    Directory of Open Access Journals (Sweden)

    Yen-Hua Huang

    Full Text Available The role of DnaD in the recruitment of replicative helicase has been identified. However, knowledge of the DNA, PriA, and DnaA binding mechanism of this protein for the DnaA- and PriA-directed replication primosome assemblies is limited. We characterized the DNA-binding properties of DnaD from Staphylococcus aureus (SaDnaD and analyzed its interactions with SaPriA and SaDnaA. The gel filtration chromatography analysis of purified SaDnaD and its deletion mutant proteins (SaDnaD1-195, SaDnaD1-200 and SaDnaD1-204 showed a stable tetramer in solution. This finding indicates that the C-terminal region aa 196-228 is not crucial for SaDnaD oligomerization. SaDnaD forms distinct complexes with ssDNA of different lengths. In fluorescence titrations, SaDnaD bound to ssDNA with a binding-site size of approximately 32 nt. A stable complex of SaDnaD1-195, SaDnaD1-200, and SaDnaD1-204 with ssDNA dT40 was undetectable, indicating that the C-terminal region of SaDnaD (particularly aa 205-228 is crucial for ssDNA binding. The SPR results revealed that SaDnaD1-195 can interact with SaDnaA but not with SaPriA, which may indicate that DnaD has different binding sites for PriA and DnaA. Both SaDnaD and SaDnaDY176A mutant proteins, but not SaDnaD1-195, can significantly stimulate the ATPase activity of SaPriA. Hence, the stimulation effect mainly resulted from direct contact within the protein-protein interaction, not via the DNA-protein interaction. Kinetic studies revealed that the SaDnaD-SaPriA interaction increases the Vmax of the SaPriA ATPase fivefold without significantly affecting the Km. These results indicate that the conserved C-terminal region is crucial for ssDNA and PriA helicase binding, but not for DnaA protein-binding and self-tetramerization.

  17. A New Algorithm of PRI Transform%一种新的PRI变换分选算法

    Institute of Scientific and Technical Information of China (English)

    李英达; 肖立志; 于洋; 康一丁; 王宇

    2014-01-01

    脉冲重复间隔(pulse repetition interval,PRI)变换及其改进算法是雷达信号分选领域的经典算法之一.在早期的信号环境中,各部雷达信号的PRI值相对接近,传统的改进PRI变换算法能够有效地分选PRI抖动雷达信号,因而得到了广泛的应用.随着信号环境的日益复杂,不同雷达发射的信号其PRI值分布在一个较大的范围内,此时传统算法的分选能力大大减弱.针对上述问题,对传统算法中可变时间起点的改变、PRI箱的选择以及门限的确定三个方面进行改进,提出一种新的PRI变换分选算法.新算法中采用了可变的移动因子、固定的箱分辨率以及合理的门限,在保留原算法优点的同时,能够适应PRI值分布在较大范围内的抖动雷达信号分选问题,并通过模拟仿真验证了算法的有效性.

  18. Monitoring phenology of photosynthesis in temperate evergreen and mixed deciduous forests using the normalized difference vegetation index (NDVI) and the photochemical reflectance index (PRI) at leaf and canopy scales

    Science.gov (United States)

    Wong, C. Y.; Arain, M. A.; Ensminger, I.

    2016-12-01

    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which determines their phenology of high photosynthetic activity in the growing season and downregulation during the winter. Monitoring the timing of the transition between summer activity and winter downregulation in evergreens is difficult since this is a largely invisible process, unlike in deciduous trees that have a visible budding and a sequence of leaf unfolding in the spring and leaf abscission in the fall. The light-use efficiency (LUE) model estimates gross primary productivity (GPP) and may be parameterized using remotely sensed vegetation indices. Using spectral reflectance data, we derived the normalized difference vegetation index (NDVI), a measure of leaf "greenness", and the photochemical reflectance index (PRI), a proxy for chlorophyll:carotenoid ratios which is related to photosynthetic activity. To better understand the relationship between these vegetation indices and photosynthetic activity and to contrast this relationship between plant functional types, the phenology of NDVI, PRI and photosynthesis was monitored in an evergreen forest and a mixed deciduous forest at the leaf and canopy scale. Our data indicates that the LUE model can be parameterized by NDVI and PRI to track forest phenology. Differences in the sensitivity of PRI and NDVI will be discussed. These findings have implications to address the phenology of evergreen conifers by using PRI to complement NDVI in the LUE model, potentially improving model productivity estimates in northern hemisphere forests, that are dominated by conifers.

  19. Angular spreading measurements using MeV ion microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Whitlow, Harry J., E-mail: harry.whitlow@he-arc.ch [Institut des Microtechnologies Appliquées, Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Department of Physics, P.O. Box 35 (YFL), FI-40014 University of Jyväskylä (Finland); Ren, Minqin; Chen, Xiao; Osipowicz, Thomas; Kan, Jeroen A. van; Watt, Frank [Centre for Ion Beam Applications, National University of Singapore (Singapore)

    2013-07-01

    The sharpness of MeV ion microscope images is governed by small-angle scattering and associated lateral spreading of the ion beam in the sample. We have investigated measurement of the half-angle of the angular spreading distribution by characterising the image blurring in direct-Scanning Transmission Ion Microscopy (direct-STIM). In these tests Mylar™ foils of 0.5–6 μm were used to induce angular spreading. Images were taken of an electron microscope grid using 2 MeV protons with, and without, the foils in the beam path. The blurring was measured by fitting the width of a circular Gaussian point spread function to the images with and without the foil in position. The results show the half-angle width of the spreading has a square root dependence on foil thickness that lies intermediate between SRIM predictions and the theoretical estimates (Bird and Williams fits to the Sigmund and Winterbon data and Amsel et al.)

  20. Limitations of 14 MeV neutron simulation techniques

    Science.gov (United States)

    Kley, W.; Bishop, G. R.; Sinha, A.

    1988-07-01

    A D-T fusion cycle produces five times more neutrons per unit of energy released than a fission cycle, with about twice the damage energy and the capability to produce ten times more hydrogen, helium and transmutation products than fission neutrons. They determine, together with other parameters, the lifetime of the construction materials for the low plasma-density fusion reactors (tokamak, tandem-mirror, etc.), which require a first wall. For the economie feasibility of fusion power reactors the first wall and blanket materials must withstand a dose approaching 300 to 400 dpa. Arguments are presented that demonstrate that today's simulation techniques using existing fission reactors and charged particle beams are excellent tools to study the underlying basic physical phenomena of the evolving damage structures but are not sufficient to provide a valid technological data base for the design of economie fusion power reactors. It is shown than an optimized spallation neutron source based on a continuous beam of 600 MeV, 6 mA protons is suitable to simulate first wall conditions. Comparing it with FMIT the 35 MeV, 100 mA D + -Li neutron source, we arrive at the following figure of merit: FM = {(dpa·volume) EURAC}/{(dpa·volume) FMIT} = {} = 111 reflecting the fact that the proton beam generates about 100 times more neutrons than the deuteron beam in FMIT for the same beam power.

  1. (π+/-,π+/-p) reaction at 245 MeV

    Science.gov (United States)

    Piasetzky, E.; Ashery, D.; Altman, A.; Yavin, A. I.; Schlepütz, F. W.; Powers, R. J.; Bertl, W.; Felawka, L.; Walter, H. K.; Winter, R. G.; Pluym, J. V. D.

    1982-05-01

    The inclusive (π+/-,π+/-p) reactions on C, Fe, and Bi were studied at 245 MeV in a broad kinematic range by means of coincidence measurement of the outgoing particles. The π-p angular correlations and proton-energy spectra show features consistent with those expected from quasifree scattering. It is observed that about 80% of the inclusive inelastic scattering cross section at backward pion angles may be attributed to nucleon knockout mechanisms. The results allow identification of the direct quasifree process, unperturbed by higher order effects, which accounts for 30%, 20%, and 15% of the C, Fe, and Bi inclusive (π+,π+) differential cross sections, respectively. The ratio of positive to negative pion cross sections for quasifree scattering, integrated over the proton energy and angle, are in agreement with the ratio for free π-p scattering. Such is not the case for various proton angles. The deviation of the positive to negative ratio at the peak of the proton angular correlation from the free scattering ratio is most pronounced for more forward pion angles. NUCLEAR REACTIONS (π+/-,π+/-p) coin. measurements on C, Fe, Bi, E=245 MeV; deduced σknockout decomposition of σinelastic.

  2. Characteristic parameters of 6--21 MeV electron beams from a 21 MeV linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghazi, M.S.A.L. (Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada) Department of Physics, Lakehead University, Thunder Bay, Ontario P7B 5E1, (Canada) Lingman, D. Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada) Department of Computer Science, Lakehead University, Thunder Bay, Ontario P7B 5E1, (Canada)); Gilbert, L.D. (Thekkumthala, J. Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada))

    1991-07-01

    Dosimetry measurements have been carried out for the electron beams produced by a linear accelerator at energies 6, 8, 10, 14, 18, and 21 MeV. Characteristic parameters of the central axis dose distributions were derived and compared to corresponding values of electron beams from other accelerators in clinical use where such a comparison is appropriate. A comprehensive set of dosimetric parameters is provided for electron beam treatment planning. The data include central axis depth dose, range--energy parameters, beam penumbra and uniformity.

  3. pri-miR-21重组腺病毒载体构建及其对TLR4基因调控的研究%Construction of a recombined adenovirus vector carrying pri-miR-21 gene and research on it's target gene TLR4

    Institute of Scientific and Technical Information of China (English)

    赵婧; 徐广贤; 贾伟; 董辉; 张一琳; 赵志军; 魏军

    2012-01-01

    目的:构建能高效表达成熟miR-21小分子的腺病毒载体,探讨其对TLR4基因的靶向调控关系.方法:以正常小鼠基因组DNA为模板,PCR扩增pri-miR-21基因,克隆至穿梭载体pAdTrack-CMV中经PCR、酶切及基因测序分析正确无误后,与pAdEasy-1腺病毒骨架质粒进行同源重组,并利用293A细胞,包装成pri-miR-21重组腺病毒感染HeLa细胞,通过Westem blot检测TLR4的蛋白表达水平,验证miR-21与TLR4靶向调控的关系.结果:经PCR、酶切、测序及GFP表达证实,成功构建携带pri-miR-21基因的重组腺病毒载体并制备出高滴度重组病毒.Western blot证实,miR-21可抑制TLR4蛋白的表达.结论:所制备的小鼠pri- miR-21重组腺病毒,可以高效表达成熟miR-21小分子,能够抑制靶基因TLR4的表达.%AIM: To construct the recombined adenovi-rus vector carrying pri-miR-21 gene, which can express mature miR-21 efficiently, and to study the interaction of miR-21 with its target gene TLR4. METHODS: Using healthy mouse's gDNA as template, the primary miR-21 coding sequence was amplified by PCR and cloned into a shuttle vector pAdTrack-CMV. Constructed plasmid was sequenced and linearized for homologous recombination with pAdEasy-1 vector in BJ5183 bacteria. The recombined adenovirus vector carrying pri-miR-21 gene was used to challenge HeLa cell. The candidate target gene of miR-21 was determined by miRNA analysis databases. The expression level of TLR4 protein was detected by western blotting. RESULTS; Through the PCR, restriction enzyme digestion, DNA sequencing and expression of GFP, recombinant adenoviral vector pri-miR-21 gene was constructed successfully. Bioin-formatic analysis suggested a few possible binding sites between miR-21 and TLR4. Results showed that miR-21 down-regulated TLR4 at protein levels. CONCLUSION-. The recombinant adenoviral vector containing pri- miR-21 was successfully constructed. miR-21 gene interfered with the expression of TLR4 target gene.

  4. Pri-miR-34b/c rs4938723 polymorphism is associated with the risk of childhood acute lymphoblastic leukemia.

    Science.gov (United States)

    Hashemi, Mohammad; Bahari, Gholamreza; Naderi, Majid; Sadeghi-Bojd, Simin; Taheri, Mohsen

    2016-11-01

    MicroRNAs (miRNAs), small noncoding regulatory RNAs, are key regulators of gene expression. The impact of Pri-miR-34b/c rs4938723 variant on development of various cancers is still controversial. In the present study, we examined whether a rs4938723 variant located at the promoter region of Pri-miR-34b/c is associated with childhood ALL. A total of 110 children with acute lymphoblastic leukemia (ALL) and 120 healthy children were recruited to participate in this study. The rs4938723 variant was genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The rs4938723 variant decreased the risk of ALL in heterozygous (TC vs OR = 0.48, 95% CI = 0.28-0.84, p = 0.012, TC vs TT) and overdominant (OR = 0.51, 95% CI = 0.30-0.89, p = 0.0.020, TC vs TT + CC): OR = 1.32, 95% CI = 0.67-2.59, p = 0.498; C vs T: OR = 0.99, 95% CI = 0.75-1.31, p = 0.986) inheritance models tested. The C allele significantly decreased the risk of childhood ALL compared to T allele (OR = 0.52, 95% CI = 0.33-0.83, p = 0.006). Our findings proposed an association between Pri-miR-34 b/c rs4938723 variant and risk of childhood ALL development in a sample of Iranian population. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Improvement of the design and generation of highly specific plant knockdown lines using primary synthetic microRNAs (pri-smiRNAs

    Directory of Open Access Journals (Sweden)

    Alves Leonardo

    2010-03-01

    Full Text Available Abstract Background microRNAs (miRNAs are endogenous small non-coding RNAs that post-transcriptionally regulate gene expression. In plants, they typically show high complementarity to a single sequence motif within their target mRNAs and act by catalyzing specific mRNA cleavage and degradation. miRNAs are processed from much longer primary transcripts via precursor miRNAs containing fold-back structures. Leaving these secondary structures intact, miRNAs can be re-designed experimentally to target mRNAs of choice. Results We designed primary synthetic miRNAs (pri-smiRNAs on the basis of the primary transcript of the Arabidopsis MIR159A gene by replacing the original miR159a and the corresponding miR159a* with novel sequences, keeping the overall secondary structure as predicted by the program RNAfold. We used the program RNAhybrid to optimize smiRNA design and to screen the complete Arabidopsis transcriptome for potential off-targets. To improve the molecular cloning of the pri-smiRNA we inserted restriction sites in the original MIR159A primary transcript to easily accommodate the smiRNA/smiRNA* DNA fragment. As a proof-of-concept, we targeted the single gene encoding chalcone synthase (CHS in Arabidopsis. We demonstrate smiRNA(CHS expression and CHS mRNA cleavage in different transgenic lines. Phenotypic changes in these lines were observed for seed color and flavonol derivatives, and quantified with respect to anthocyanin content. We also tested the effect of mismatches and excess G:U base pairs on knockdown efficiency. Conclusions RNAhybrid-assisted design of smiRNAs and generation of pri-smiRNAs using a novel vector containing restriction sites greatly improves specificity and speed of the generation of stable knockdown lines for functional analyses in plants.

  6. Thermochemical cycles for the heat and cold long-range transport. Final report of the PRI 9.2 Cold transport. Annual report of the PR 2-8; Cycles thermochimiques pour le transport de chaleur et de froid a longue distance. Rapport final du PRI 9.2. Transport de froid. Rapport annuel du PR 2-8

    Energy Technology Data Exchange (ETDEWEB)

    Luo, L.; Tondeur, D. [Laboratoire des Sciences du Genie Chimique (LSGC), 54 - Nancy (France); Mazet, N.; Neveu, P.; Stitou, D.; Spinner, B. [Institut de Science et de Genie des Materiaux et Procedes (IMP), 66 - Perpignan (France)

    2004-07-01

    This PRI deals with the use of thermochemical processes, based on solid-gas reversible transformation, to transfer heat of cold at long-range distance (> 10 km), in order to enhance the energy efficiency. Four main aspects have been studied to confirm the process feasibility: the process identification and the operating conditions, the selection of compatible reagents, the design of an auto-thermal reactor and the gas transport impact on the global performances. (A.L.B.)

  7. The genetic association between pri-miR-34b/c polymorphism (rs4938723 T > C) and susceptibility to cancers: evidence from published studies.

    Science.gov (United States)

    Li, Xiaowei; Wang, Liguang; Yu, Jianyu; Xu, Jun; Du, Jiajun

    2014-12-01

    Recently, several molecular epidemiological studies have focused on the association between pri-miR-34b/c rs4938723 SNP and the susceptibility to different cancers. Due to the controversial rather than conclusive results, we performed this meta-analysis to assess more precise and comprehensive conclusion about the association. Data published until July 2014 were collected from PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure, Wanfang Data, Chinese BioMedical Literature Database, and VIP database of Chinese Journal. Ultimately, 13 articles with a total of 7,753 cases and 8,014 controls were considered eligible for inclusion. The odds ratio (OR) and its 95 % confidence interval (95%CI) were used to assess the strength of association. In the overall analysis, a significant association between pri-miR-34b/c rs4938723 polymorphism and increased cancer susceptibility was found in heterozygous model (TC vs. TT: OR = 1.148, 95%CI 1.034-1.275, P = 0.010) and dominant model (CC + TC vs. TT: OR =1.166, 95%CI 1.028-1.322, P = 0.017). In subgroup analysis of ethnicity, pri-miR-34b/c rs4938723 polymorphism was significantly associated with an increased cancer susceptibility for Asian population in heterozygous model (TC vs. TT: OR = 1.169, 95%CI 1.031-1.326, P = 0.015) and dominant model (CC + TC vs. TT: OR = 1.185, 95%CI 1.017-1.382, P = 0.030), whereas no significant association for Caucasian population was observed in any genetic models. Intriguingly, stratified analysis revealed opposite results that pri-miR-34b/c polymorphism contributed to susceptibility to hepatocellular carcinoma while reduced susceptibility to colorectal cancer and esophageal squamous cell cancer in Asians. Considering some limitation of our meta-analysis, future well-designed case-control studies with larger sample sizes are required to confirm our findings.

  8. Deinterleaving of Radar Signals Based on Modified PRI Transform Algorithm%一种改进型PRI变换雷达信号分选技术

    Institute of Scientific and Technical Information of China (English)

    赵永胜

    2007-01-01

    在对传统的脉冲重复间隔(PRI)变换法进行介绍的基础上,提出了一种改进型的PRI变换法来估计脉冲重复间隔,并给出了相应的门限设定方法,另外,文中还提出了一种适用的快速脉冲抽取算法.仿真表明,该方法对固定PRI、抖动PRI和参差PRI脉冲序列都有较好的估计效果.

  9. Conductivity of single-crystal Y1-yPryBa2Cu3O7-δ over a wide range of temperatures and Pr concentrations

    Science.gov (United States)

    Khadzhai, G. Ya.; Vovk, N. R.; Vovk, R. V.

    2014-06-01

    The in-plane electrical resistance of Y1-yPryBa2Cu3O7-δ single crystals with a high degree of perfection is studied for temperatures in the range TC-300 K, where TC ranges from 92 to 52 K, with varying praseodymium content. The experimental data are approximated by an expression that takes electron scattering on phonons and defects into account, as well as fluctuation conductivity in a 3D Aslamazov-Larkin model. According to the approximation data the Debye temperature ranges from 350-370 K, depending on the praseodymium content. The transverse coherence length is ˜1 Å.

  10. UČINAK KALIJEVOG I NATRIJEVOG LAKTATA NA ODRŽIVOST JUNEĆEG MLJEVENOG MESA PRI RAZLIČITIM UVJETIMA SKLADIŠTENJA

    OpenAIRE

    Šmidt, Gordana; Kovačić, Mirela; Grgurić, Ivana; Bertinovec, Ines

    2009-01-01

    Svježe mljeveno juneće meso tretirano kalijevim laktatom (KL) i natrijevim laktatom (NaL) u količini od 4% dodanima pojedinačno, odnosno svaki po 2% kada su kombinirani, upakirano je u modificiranu atmosferu sačinjenu od O2 i CO2 u omjeru 80%:20%, i skladišteno pri 2ºC i 8ºC kroz 7 dana. Uzorci su analizirani prvi, četvrti, šesti i sedmi dan. Rezultati ispitivanja pokazali su da je utjecaj KL i NaL na broj aerobnih mezofilnih bakterija podjednak, te su tretirani uzorci...

  11. Optimizacija svojstava samoorganiziranja graft kopolimera metoksi poli(etilen glikola) i masnih kiselina pri pripravi nanonosača s uklopljenim etopozidom

    OpenAIRE

    Varshosaz, Jaleh; HASANZADEH, FARSHID; ESLAMDOOST, MOJTABA

    2012-01-01

    Cilj je rada bio ispitati svojstva samoorganiziranja micela pripravljenih od graft kopolimera metoksipolietilenglikola (mPEG) i masnih kiselina različite duljine lanca za uklapanje etopozida. Sintetizirana su tri amfifilna kopolimera povezivanjem miristinske, stearinske i behenične kiseline esterskom vezom s mPEG. Veličina i zeta-potencijal micela određeni su metodom dinamičkog raspršivanja svjetlosti. Micele s uklopljenim etopozidom pripravljene su film-metodom pri različitim omjerima lijeka...

  12. Combined analysis of pri-miR-34b/c rs4938723 and TP53 Arg72Pro with cervical cancer risk.

    Science.gov (United States)

    Yuan, Fang; Sun, Ruifen; Chen, Peng; Liang, Yundan; Ni, Shanshan; Quan, Yi; Huang, Juan; Zhang, Lin; Gao, Linbo

    2016-05-01

    miR-34 family members can form a p53-miR-34 positive feedback loop and induce apoptosis, DNA repair, angiogenesis, and cell cycle arrest. We conducted a case-control study to examine whether two polymorphisms (i.e., rs4938723 in the promoter of pri-miR-34b/c and TP53 Arg72Pro) were linked to the carcinogenesis of cervical cancer among Chinese Han women. Genotypes of the two polymorphisms in 328 cervical cancer patients and 568 control subjects were determined by using a polymerase chain reaction-restriction fragment length polymorphism assay. We found a significantly increased cervical cancer risk in the pri-miR-34b/c rs4938723 under dominant and overdominant model (CT/CC vs. TT: adjusted OR = 1.34, 95 % CI = 1.01-1.77; CT vs. TT/CC: adjusted OR = 1.37, 95 % CI = 1.05-1.80, respectively). Increased cervical cancer risks were also found in the TP53 Arg72Pro under a heterozygous comparison and overdominant model (CG vs. GG: adjusted OR = 1.44, 95 % CI = 1.06-1.95; CG vs. GG/CC: adjusted OR = 1.47, 95 % CI = 1.12-1.94, respectively). Stratification analysis showed that patients carrying the pri-miR-34b/c rs4938723 CT genotype had a significantly increased risk for developing poorly differential status and clinical stage I. Moreover, increased cancer risks were observed for the TP53 Arg72Pro polymorphism in patients with poorly differential status, clinical stage II, and without lymph node metastasis. Combined analysis revealed that the genotypes of rs4938723 CT/CC and TP53 Arg72Pro CG/CC had an increased cervical cancer risk (OR = 2.21, 95 % CI = 1.38-3.53). These findings suggest that the pri-miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms may contribute to the genesis of cervical cancer.

  13. Multilevel hierarchy of phase separation processes in La5/8-yPryCa3/8MnO3

    Science.gov (United States)

    García-Muñoz, J. L.; Collado, A.; Aranda, M. A. G.; Ritter, C.

    2011-07-01

    We investigate two successive hierarchized phase segregations in La5/8-yPryCa3/8MnO3, which generate ferromagnetic metallic volumes (V1FM and V2FM) having different physical origins, stabilities, and parent electronic phases. The singular percolative transition around TC2 ≈ 100 K is due to a second electronic phase separation (PS), which is specific to the charge-order insulating regions segregated at the first PS process. These findings shed new light on the metastability, atypical dynamics, the nonvolatile magnetoresistance, or the supercooling glass transition in this complex magnetic system.

  14. Pregled aplikacij za operacijski sistem Android in njihova možnost uporabe pri pouku vsebin s področja elektronike in robotike

    OpenAIRE

    Černe, Klemen

    2017-01-01

    Razvoj znanosti nam omogoča uporabo najrazličnejših novih tehnologij. Velik napredek so v zadnjem času dosegli mobilni telefoni in tablični računalniki. S popularnostjo le teh pa se je začel množični razvoj aplikacij, ki so uporabljene na njih. Moderne tehnologije pa so prodrle tudi na področje poučevanja. Čedalje več institucij za pomoč pri izobraževanju uporablja različne vrste informacijsko komunikacijskih sredstev (IKT). V tem diplomskem delu smo pregledali nekaj aplikacij za operacijs...

  15. Quantitative analysis of histidine decarboxylase gene (hdcA) transcription and histamine production by Streptococcus thermophilus PRI60 under conditions relevant to cheese making.

    Science.gov (United States)

    Rossi, Franca; Gardini, Fausto; Rizzotti, Lucia; La Gioia, Federica; Tabanelli, Giulia; Torriani, Sandra

    2011-04-01

    This study evaluated the influence of parameters relevant for cheese making on histamine formation by Streptococcus thermophilus. Strains possessing a histidine decarboxylase (hdcA) gene represented 6% of the dairy isolates screened. The most histaminogenic, S. thermophilus PRI60, exhibited in skim milk a high basal level of expression of hdcA, upregulation in the presence of free histidine and salt, and repression after thermization. HdcA activity persisted in cell extracts, indicating that histamine might accumulate after cell lysis in cheese.

  16. Quantitative Analysis of Histidine Decarboxylase Gene (hdcA) Transcription and Histamine Production by Streptococcus thermophilus PRI60 under Conditions Relevant to Cheese Making▿†

    Science.gov (United States)

    Rossi, Franca; Gardini, Fausto; Rizzotti, Lucia; La Gioia, Federica; Tabanelli, Giulia; Torriani, Sandra

    2011-01-01

    This study evaluated the influence of parameters relevant for cheese making on histamine formation by Streptococcus thermophilus. Strains possessing a histidine decarboxylase (hdcA) gene represented 6% of the dairy isolates screened. The most histaminogenic, S. thermophilus PRI60, exhibited in skim milk a high basal level of expression of hdcA, upregulation in the presence of free histidine and salt, and repression after thermization. HdcA activity persisted in cell extracts, indicating that histamine might accumulate after cell lysis in cheese. PMID:21378060

  17. La declinación de la hegemonía del PRI en los gobiernos estatales de México, 1989-2014

    Directory of Open Access Journals (Sweden)

    Luis Carlos Rodríguez Montaño

    2017-04-01

    Full Text Available En este trabajo se indagó sobre la transición política mexicana en los gobiernos estatales, para lo que se planteó la pregunta: ¿qué tanto ha declinado la hegemonía del Partido Revolucionario Institucional en ellos? Para contestarla se revisaron tres indicadores: el partido de los gobernadores, el tamaño de la fracción del Partido Revolucionario Institucional en los congresos locales y la incidencia de los gobiernos hegemónicos priistas en los estados, de 1989 a 2014. El pluralismo político ha tenido avances sustantivos, y los regímenes de hegemonía priista se han reducido significativamente. Pero, mientras que en la mayoría de los estados hay gobiernos divididos, cinco mantienen la hegemonía priista sin alternancia, y hay 17 con dominio de otros partidos. A pesar de las limitaciones propias en los análisis sobre la evolución de la democracia, aquí se pretendió tener un punto de referencia sobre la pérdida del poder político de un partido que dominó la mayoría de los congresos locales durante gran parte del siglo XX. ______ This paper inquiries about Mexican political transition among state governments and it asks the question: how much the hegemony of the Institutional Revolutionary Party (PRI has declined among state governments? To answer this question, three indicators are revised: the party of governors, the size of PRI fraction within local congresses, and the count of hegemonic state governments during the approximate 1989-2014 period. The study finds out that political pluralism has made substantive progress and that hegemonic PRI state governments have significantly declined. There is however a broad variability; while the majority of states are divided governments, five maintain hegemonic PRI governments with no alternation, and also 17 states have governments where other party is dominant. Despite of limitations in the analysis of the evolution of democracy, it was intended here to have a reference point on the

  18. La democracia interna en los partidos políticos: el caso del PRI de México entre 1965-1984

    OpenAIRE

    Contreras Romero, Valente Alberto

    2015-01-01

    El presente trabajo de investigación pretende analizar los procesos de selección interna de candidatos a puestos de elección popular dentro de los partidos políticos especialmente aquellos donde se apliquen métodos de selección incluyentes y democraticos. El trabajo se enfocara principalmente en los partidos políticos hegemónicos en regímenes poco democraticos como fue el caso de México, para este efecto se realizará un estudio de caso aplicado al Partido Revolucionario Institucional (PRI) ...

  19. Proton Polarimeter Calibration between 82 and 217 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Glister, J; Lee, B; Beck, A; Brash, E; Camsonne, A; Choi, S; Dumas, J; Feuerbach, R; Gilman, R; Higinbotham, D W; Jiang, X; Jones, M K; May-Tal Beck, S; McCullough, E; Paolone, M; Piasetzky, E; Roche, J; Rousseau, Y; Sarty, A J; Sawatzky, B; Strauch, S

    2009-07-01

    The proton analyzing power in carbon has been measured for energies of 82 to 217 MeV and proton scattering angles of 5 to 41 degrees. The measurements were carried out using polarized protons from the elastic scattering H(pol. e, pol. p) reaction and the Focal Plane Polarimeter (FPP) in Hall A of Jefferson Lab. A new parameterization of the FPP p-C analyzing power was fit to the data, which is in good agreement with previous parameterizations and provides an extension to lower energies and larger angles. The main conclusions are that all polarimeters to date give consistent measurements of the carbon analyzing power, independently of the details of their construction and that measuring on a larger angular range significantly improves the polarimeter figure of merit at low energies.

  20. The 5 MeV bump - a nuclear whodunit mystery

    CERN Document Server

    Huber, Patrick

    2016-01-01

    We perform a combined analysis of recent NEOS and Daya Bay data on the reactor antineutrino spectrum. This analysis includes approximately 1.5 million antineutrino events, which is the largest neutrino event sample analyzed to date. We use a double ratio which cancels flux model dependence and related uncertainties as well as the effects of the detector response model. We find at 3-4 standard deviation significance level, that plutonium-239 and plutonium-241 are disfavored as the single source for the the so-called 5 MeV bump. This analysis method has general applicability and in particular with higher statistics data sets will be able to shed significant light on the issue of the bump. With some caveat this also should allow to improve the sensitivity for sterile neutrino searches in NEOS.

  1. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  2. Two charmoniumlike charged axial resonances near 3885 MeV

    CERN Document Server

    Voloshin, M B

    2016-01-01

    It is argued that the charged $Z^+_c(3885)$ resonance, treated as a `molecular' state of charmed $D$ and $D^*$ mesons, is likely to consist of two peaks unequally coupled to the $D^{*+} \\bar D^0$ and $D^+ \\bar D^{*0}$ channels. The peaks should be split in mass by at least approximately 1.5 MeV. This behavior arises from an enhancement of the effect of isospin violation in the masses of the $D$ and $D^*$ mesons due to apparent suppression of forces between the mesons depending on the spins of the heavy as well as of the light quarks. The suggested double-peak structure can be studied either by direct shape measurement in the channels with heavy mesons, or by isospin-violating transitions from $Z_c^\\pm(3885)$ to the states of charmonium plus a light meson.

  3. Focussed MeV ion beam implanted waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Von Bibra, M.L.; Roberts, A.; Nugent, K.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Single mode buried optical waveguides have been fabricated in fused silica by MeV proton implantation using a focussed hydrogen ion beam. The technique has the potential to direct write waveguide devices and produce multi-layered structures, without the need for intermediate steps such as mask fabrication or layered depositions. A micron resolution Confocal Raman Spectrometer has been used to map the distribution of atomic vacancies that forms the waveguiding region. The results are compared with theoretical calculations. Losses of 3 dB cm{sup -1} have been measured in unannealed samples, which decreases to less than 0.5 dB cm{sup -1} after annealing at 500 degrees Celsius. We describe methods for determining the refractive index distribution of single mode buried waveguides from their output intensity distributions via an inversion of the scalar wave equation. (authors). 5 figs.

  4. Design of 10 MeV cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    R Solhju

    2015-09-01

    Full Text Available Design and construction of 10MeV cyclotron has been started at Amirkabir University of Technology since 2012. So far, the conceptual and detail engineering design phases have been finalized. The main purpose of this baby cyclotron is to generate proton beam for the production of PET radioisotopes. The cyclotron consists of magnet, cavity, ion source, RF and LLRF system, vacuum system, cooling system, power amplifiers and power supplies system. In this paper, a brief of design principles for all the parts of cyclotron and their final simulation results is presented. It should be noted that these simulations have been performed and optimized by the most accurate softwares such as TOSCA, ANSYS, HFSS, SolidWorks and CST. Also, the manufacturing feasibility of all the parts is performed and their dimensions and parameters are synchronized with manufacturing standards

  5. Shielding measurements for a 230 MeV proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Siebers, J.V.

    1990-01-01

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0{degree}, 22{degree}, 45{degree}, and 90{degree} in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm{sup 3} to 1000 cm{sup 3} were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0{degree}, 22{degree}, and 45{degree}, yet correctly predicted the attenuation length at 90{degree}. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations.

  6. Conceptual Design Study of 13 MeV Proton Cyclotron

    Directory of Open Access Journals (Sweden)

    Silakhuddin

    2012-04-01

    Full Text Available A study to determine the conceptual design of a 13 MeV proton cyclotron for PET (Positron Emission Tomography facility has been carried out. Based on studies on reactions of PET radioisotopes production, reaction cross-sections and some design references, a design of the proton cyclotron is proposed. The design criteria for the main components are decided using empirical and semitheoretical methods, as well as by referring to data regarding cyclotrons for PET production. The empirical method was carried out by using some data from operational experiences of BATAN cyclotron at Serpong, while the semitheoretical method was carried out by using the commonly used equations of cyclotron basic theory. The general layout of components and the main components, namely the ion source, the RF dees, the magnet, and the extractor are discussed. Based on the calculations and on the data used, the cyclotron is designed as a negative ion acceleration cyclotron with internal ion source. The designated proton energy and beam currents are 13 MeV and 50 µA. Its magnetic field is in the relativistic mode with sectors on the pole. The magnetic field intensity at the extraction radius is 12.745 kG and in the innermost radius is 12.571 kG. The magnetic poles consist of four sectors to make adequate space for components placement such as dees, ion source, extractor and beam probe. The dee angle is 430. The dee operates at 78 MHz on the fourth harmonic. A multifoil extractor is chosen to obtain an efficient operation

  7. Pri-miR-34b/c rs4938723 polymorphism is associated with a decreased risk of gastric cancer.

    Science.gov (United States)

    Pan, Xin-Min; Sun, Rui-Fen; Li, Zhao-Hui; Guo, Xiao-Min; Qin, Hao-Jie; Gao, Lin-Bo

    2015-04-01

    Previous studies have demonstrated that miR-34 family members are abnormally expressed in gastric cancer. Overexpression of the miR-34 family suppresses gastric carcinogenesis, whereas downregulation of the miR-34 family promotes tumorigenesis. p53 can bind to the promoter region of miR-34b/c, leading to an increase of miR-34b/c expression. Recently, a variant in the promoter region of pri-miR-34b/c (rs4938723) has been discovered, with the function of altering the binding efficiency of transcription factor GATA. The purpose of this study was to examine the role of the miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms in the susceptibility of gastric cancer. We analyzed the distribution of the two polymorphisms in 197 patients with gastric cancer and 289 age-, gender-, ethnicity-, and living area-matched controls using polymerase chain reaction-restriction fragment length polymorphism and DNA direct sequencing. We found that the CT and CT/CC genotypes of the miR-34b/c rs4938723 were associated with a significantly decreased risk of gastric cancer compared with the TT genotype (CT vs. TT: odds ratio [OR]=0.66; 95% confidence interval [95% CI], 0.45-0.97; and CT/CC vs. TT: OR=0.67; 95% CI, 0.47-0.97, respectively). Combined analysis showed that subjects carrying the miR-34b/c rs4938723 CT/CC and TP53 CG/CC genotypes had a 0.62-fold decreased risk to develop gastric cancer compared with subjects carrying the miR-34b/c rs4938723 TT and TP53 CG/CC genotypes (OR=0.62; 95% CI, 0.40-0.96). These findings suggest that the miR-34b/c rs4938723 may individually and jointly have a protective effect on the risk of gastric risk.

  8. Congés… pour « prières » Prayers and days off

    Directory of Open Access Journals (Sweden)

    Claudine Viard

    2009-04-01

    Full Text Available Les premiers combats de la classe ouvrière se sont portés sur la demande d’une journée de repos, qui par tradition chrétienne a été fixée le dimanche en 1906. Quatre journées de congé à caractère chrétien ont en outre été retenues par le législateur. L’exercice du culte est donc concrètement garanti pour les chrétiens. Avec l’arrivée sur le territoire de la République  de populations de confessions variées, cette organisation du travail apparaît inégalitaire, voire de nature à porter atteinte à la liberté religieuse. Il a été proposé de reconnaître les jours de prières d’autres confessions. Pour l’instant, le législateur n’a pas adopté ces propositions. Mais la question reste posée. Or, la jurisprudence des tribunaux judiciaires et administratifs admet le droit de prier des fidèles des cultes minoritaires, ils peuvent prétendre à un congé lors des fêtes de leur religion dans la mesure où cela n’occasionne pas de perturbation. La consécration de cette jurisprudence souple par le législateur serait de nature à calmer le débat.At the turn of the century, the working classes fought for a day off in the week, which was granted on Sundays by the legislator in 1906. Four additional christian holidays are also legal. So the right to pray is garanteed for christians. As different populations with various faiths settled in France, this organisation has seemed to violate the principle of equality, and religious freedom. There has been a debate on the question whether some of the days of minority religions should also be observed by all the population. But so far, the legislator has not voted any of these proposals. It remains an issue. The French judge has consistently decided that the people of non christian faiths had the right to be granted a day off to pray on these special days, provided it would not cause prejudice to the organisation they work for. It might help to calm the debate if this

  9. PRI变换在脉冲列去交错中的适用性分析%Applicability Analysis of PRI Transform in Pulse Train Destagger

    Institute of Scientific and Technical Information of China (English)

    安振; 李运祯

    2007-01-01

    传统雷达脉冲列去交错方法中的脉冲重复间隔(PRI)估计算法,是以接收到的脉冲串的自相关函数为基础,很容易出现信号的PRI及其整数倍(即子谐波)同时存在的现象,给雷达脉冲串的去交错造成了困难.为克服上述缺点,提出了PRI变换的估计方法,几乎完全抑制了出现在自相关函数中的子谐波.研究了这种算法对于各种不同PRI信号的适用性.计算机仿真结果表明,这种算法适用于检测不同信号的PRI.

  10. PAZ, PRI, AND PROGRESS: OCTAVIO PAZ’S POLITICAL, ECONOMIC AND LITERARY STRUGGLE TO INSPIRE REFORM IN TWENTIETH-CENTURY MEXICO

    Directory of Open Access Journals (Sweden)

    D. Gene Pace

    2003-01-01

    Full Text Available Throughout most of the twentieth century; Mexico’s political and economic policies were heavily influenced by the Partido Revolucionario Institutional (PRI. The landmark 1998 victory by Vicente Fox, the first presidential candidate in seven decades to win without the official sanction of the PRI,marked an important milestone in Mexican history; Octavio Paz, an eloquent proponent of political, economic, and social reform, sought for decades to inspire change. This paper seeks to illuminate Paz’s economic philosophy, and to demonstrate how the acclaimed writer, through courageous symbolic action coupled with an inimitable and potent pen, challenged the PRI’s hegemony in Mexico and contributed to the historic election he almost lived to celebrate (an elderly Paz died shortly before the historic 1998 election.“The Aztec ritual of 2 October [1968] in the Plaza de Tlatelolco. . . convinced me to abandon the Mexican Foreign Service.”“October 2, 1968 ended the student movement. It also ended an era in thehistory of Mexico.”

  11. Neutron-induced fission cross sections of uraniums up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus); Hasegawa, A.

    1998-11-01

    Statistical theory of nuclear reactions, well-proved below 20 MeV, is applied for {sup 235}U and {sup 238}U fission data analysis up to {approx}40 MeV. It is shown that measured data could be reproduced. Chance structure of measured fission cross section is provided, it`s validity is supported by description of data for competing (n,xn)-reactions. Role of fissility of target nucleus is addressed. It seems that gap in incident neutron energy interval of 20 MeV - 50 MeV, below which evaluation approaches are well-developed, and above which simplified statistical approaches are valid, could be covered. (author)

  12. Backward Secondary Electron Emission Yield of Thick Targets Induced by MeV Ions

    Institute of Scientific and Technical Information of China (English)

    JIANG Lei; ZHAO Guo-Qing; ZHOU Zhu-Ying

    2000-01-01

    The backward secondary electron emission yields of MeV ions (H+, He+, He++, Cl, Si, and Cu ) impinging on thick carbon and gold targets are studied. The measured results for H+ (1MeV ≤ E ≤ 5MeV) on carbon are proportional to the electronic stopping power. Our experimental data and fitting formula of yields for H+ (1 MeV≤ E≤ 4.5MeV) impacting Au are compared with the theoretical expectation. The influence of the collective field and the charge state of ions on the secondary electron emission yield is discussed.

  13. Patología del sueño en las enfermedades priónicas Sleep disorders in prion diseases

    Directory of Open Access Journals (Sweden)

    T. Ayuso

    2007-01-01

    Full Text Available Las enfermedades priónicas son un grupo de encefalopatías con cambios neurodegenerativos causados por una proteína alterada denominada prión cuyo dato característico es la transmisibilidad. Ocurren la mayoría de las veces de forma esporádica aunque un grupo de ellas son familiares asociadas a mutaciones en el gen de la proteína priónica. El polimorfismo genético parece determinar las diferentes variantes familiares. Una de las más enigmáticas e inhabituales es el Insomnio Letal Familiar (ILF, trastorno hereditario caracterizado por pérdida del sueño fisiológico con estupor onírico, hiperactividad autonómica y motora, y anomalías motoras. La polisomnografía de esta entidad refleja la incapacidad para producir un patrón fisiológico del sueño NREM y REM, así como de las fluctuaciones circadianas hormonales y vegetativas; la transición de vigilia a sueño está marcadamente alterada con desaparición precoz de los husos de sueño. La hipótesis del origen de estos trastornos es la pérdida neuronal talámica, especialmente en los núcleos anterior y dorsomedial, descrita en la neuropatología de estos pacientes; además la PET revela hipofunción de núcleos talámicos, centros responsables del control vigilia-sueño. En la enfermedad de Creutzfeldt-Jakob las alteraciones de sueño-vigilia no se han considerado características, no obstante, se han encontrado frecuentes alteraciones en los registros electroencefalográficos de sueño. Además de la neurodegeneración talámica puede haber mecanismos etiopatogénicos comunes en las enfermedades priónicas en relación con la función biológica de la proteína priónica.Prion diseases are a group of encephalopathies with neurodegenerative changes caused by an altered protein named prion whose characteristic datum is transmissibility. In most cases they occur in a sporadic form although a group of them are familial associated with mutations in the gene of the prion protein

  14. A comparative study of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiated Si NPN BJTs

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Vinay, E-mail: Vkm288@gmail.com; Krishnaveni, S. [Department of studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Yashoda, T. [Deparment of Physics, AVK College for women, Hassan-573201 (India); Dinesh, C. M. [Department of Physics, Govt. First grade college for women, Chintamani-563125 (India); Krishnakumar, K. S. [Department of Physics, APS College of Engineering (India); Jayashree, B. [Department of Physics, Maharanis Science College for Women, Bangalore-560001 (India); Ramani [Department of Physics, Bangalore University, Jnanabharathi, Bangalore-560056 (India)

    2015-06-24

    The impact of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  15. A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

    Science.gov (United States)

    Kumar, M. Vinay; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani, Krishnaveni, S.

    2015-06-01

    The impact of 30MeV boron4+ and 60MeV oxygen8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  16. Nova libro pri interlingvistiko

    Index Scriptorium Estoniae

    2006-01-01

    Rets rmt.: Blanke, Detlev. Interlinguistische Beiträge : zum Wesen und zur Plansprachen / herausgegeben von Sabine Fiedler. Frankfurt/Main, Berlin ; Bern ; Bruxelles ; New York ; Oxford ; Wien : Europäischer Verlag der Wissenschaften Peter Lang

  17. Nova libro pri interlingvistiko

    Index Scriptorium Estoniae

    2006-01-01

    Rets rmt.: Blanke, Detlev. Interlinguistische Beiträge : zum Wesen und zur Plansprachen / herausgegeben von Sabine Fiedler. Frankfurt/Main, Berlin ; Bern ; Bruxelles ; New York ; Oxford ; Wien : Europäischer Verlag der Wissenschaften Peter Lang

  18. M-C simulation of shielding effects of PE, LiH and graphite fibers under 1 MeV electrons and 20 MeV protons

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Shielding effects of different materials under 1 MeV electron and 20 MeV proton beams were simulated with Geant4 code. It was found that shielding effects of polyethylene and graphite fibers are much better than aluminum. Energy depositions in the phantom shielded by the materials are calculated, with the least energy deposition by graphite fiber shielding. The results show that graphite fibers are good radiation shielding material in space programs.

  19. Measurements of 1.9 MeV electron Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Pino, Neivy; Cabal, Fatima Padilla; D' Alessandro, Katia [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Maidana, Nora Lia; Vanin, Vito Roberto; Martins, Marcos Nogueira; Malafronte, Alexandre; Bonini, Alfredo L. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica. Lab. do Acelerador Linear; Sempau, Josep [Universitat Politecnica de Catalunya, Barcelona (Spain)

    2011-07-01

    Full text: Bremsstrahlung Cross section of 1.9 MeV electrons in Ti, Ag, and Au were measured at the Microtron accelerator of the IFUSP. Target mass surface density was in the range 0.1 to 1 mg/cm{sup 2} and the electron current varied from 3 to 30 nA, measured by a Faraday cup. The spectra were measured at three angles (30 deg; 90 deg and 60 deg) using a shielded p-type HPGe detector with an spectroscopy amplifier with pile-up rejection and a fast ADC. A 20 cm in length and 1.2 cm in diameter Pb collimator was placed in front of the detector to reduce the contribution of radiation scattered in the irradiation chamber or other background sources. With the goal of increasing the peak to total gamma-ray efficiency, the collimator hole was placed with its axis parallel to the coaxial detector symmetry axis, but displaced 1.4 cm to the right of the detector crystal axis. Hence, the Ge thickness exposed directly to the Bremsstrahlung beam was about 5 times bigger than that in the crystal axis, where the n-contact hole is located. The detector response functions were obtained by Monte Carlo simulations based on experimentally determined detector dimensions, in a procedure described in a companion paper submitted to this conference (Response function of a p-type Ge detector). Two energy bins: 50 keV and 1 keV were used in the Bremsstrahlung spectrum deconvolution. The first one was employed to determine the energy differential cross section from 0.1 to 1.9 MeV, and the second one for a more specific spectra study, in the high frequency limit or 'tip region'. The experimental spectrum was corrected for pile-up, with a simple model that assumes that the amplifier pile-up rejection resolving time is the same for all measured energies, and the photon background, measured with the target retracted from the beam. The Bremsstrahlung spectra B were obtained as: B = R{sup -}1 X E, where R is the matrix of the detector response function and E the recorded spectrum vector

  20. Collective motion in selected central collisions of Au on Au at 150A MeV

    Science.gov (United States)

    Jeong, S. C.; Herrmann, N.; Fan, Z. G.; Freifelder, R.; Gobbi, A.; Hildenbrand, K. D.; Krämer, M.; Randrup, J.; Reisdorf, W.; Schüll, D.; Sodan, U.; Teh, K.; Wessels, J. P.; Pelte, D.; Trzaska, M.; Wienold, T.; Alard, J. P.; Amouroux, V.; Basrak, Z.; Bastid, N.; Belayev, I. M.; Berger, L.; Bini, M.; Blaich, Th.; Boussange, S.; Buta, A.; Čaplar, R.; Cerruti, C.; Cindro, N.; Coffin, J. P.; Dona, R.; Dupieux, P.; Erö, J.; Fintz, P.; Fodor, Z.; Fraysse, L.; Frolov, S.; Grigorian, Y.; Guillaume, G.; Hölbling, S.; Houari, A.; Jundt, F.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Kuhn, C.; Ibnouzahir, M.; Legrand, I.; Lebedev, A.; Maguire, C.; Manko, V.; Maurenzig, P.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Morel, P.; Neubert, W.; Olmi, A.; Pasquali, G.; Petrovici, M.; Poggi, G.; Rami, F.; Ramillien, V.; Sadchikov, A.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Tezkratt, R.; Vasiliev, M. A.; Wagner, P.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.

    1994-05-01

    Using the FOPI facility at GSI Darmstadt complete data of Au on Au collisions at 150A MeV were collected for charged products (Z=1-15) at laboratory angles 1°=3) are used to determine the collective energy which is found to be at least 10A MeV.

  1. Buncher Power Source Monitoring System of 100 MeV Cyclotron

    Institute of Scientific and Technical Information of China (English)

    WEI; Jun-yi; FU; Xiao-liang; GUO; Juan-juan; ZHANG; Yi-wang; CAO; Xue-long; YIN; Zhi-guo; JI; Bin

    2015-01-01

    The 100MeV cyclotron provides 70-100MeV and 200μA proton beam,which can be used in astrophysics,medical,defense,energy and other fields.Buncher system can enhance the beam intensity and expand the scope of application of the accelerator.Buncher system is one part of the

  2. Performance Results of the Modulator for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Il; Kwon, Hyeok Jung; Kim, Han Sung; Seol, Kyung Tae; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The modulator for the 100MeV proton linac has been installed at KOMAC (Korea of Multi-purpose Accelerator Complex) site. The specification of modulator is 5.8MW peak power with 1.5ms pulse width, 60Hz repetition rate. There are total 4 sets of modulator for 100-MeV proton linac including 3-MeV RFQ, 20-MeV DTL and 100-MeV DTL. A modulator drives two or three sets of the klystrons simultaneously. After installation and du mmy test of 4 modulators, it has been operated for 100MeV proton linac. In this paper, the performance results of modulators for the 100MeV proton linac are presented. 4 modulators were installed and tested for the 100MeV proton linac. The modulator was measured to have about less than 1% droops at flat top for 500 us pulse by using pulse frequency modulation droop compensation method. The long term voltage variation measurement showed that the voltage increased up to 0.05% for 8 hours. In future, the voltage droop and variation of modulator should be continuously checked in the high repetition rate.

  3. Klystron High Power Operation for KOMAC 100-MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung-Tae; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. Nine sets of 1MW klystrons have been operated for the 100-MeV proton linac. The klystron filament heating time was approximately 5700 hours in 2014, and RF operation time was 2863.4 hours. During the high power operation of the klystron, unstable RF waveforms appeared at the klystron output, and we have checked and performed cavity frequency adjustments, magnet and heater current, reflection from a circulator, klystron test without a circulator, and the frequency spectrum measurement. Nine sets of the klystrons have been operated for the KOMAC 100-MeV proton linac. The klystron filament heating time was 5700 hours and RF operation time was 2863.4 hours during the operation in 2014. Some klystrons have unstable RF waveforms at specific power level. We have checked and tested the cavity frequency adjustment, reflection from a circulator, high power test without a circulator, and frequency spectrum at the unstable RF.

  4. Initial Operation Results of the KOMAC 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyungtae; Kwon, Hyeokjung; Kim, Hansung; Kim, Daeil; Song, Younggi; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. The KOMAC started to provide a proton beam to users on July 2013. A 20-MeV beam line and a 100-MeV beam line have been operated for beam service during the first year. In 2013, the proton linac had been operated for more than 2200 hours and beam service time was 432 hours approximately. The accumulated downtime during the first year in 2013 is 94.7 hours and there were some faults at utilities, high voltage modulators, and RF components. The KOMAC started to provide a proton beam to users on July 2013. The proton linac had been operated for more than 2200 hours and beam service time was 432 hours approximately. Accumulated downtime was 94.7 hours and availability was 82 %. The plan for beam power and operation time in 2014 is 10 kW and 2500 hours respectively.

  5. Design of Cavity for 10 MeV Electron Irradiation Accelerator

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This article describes the 10 MeV high-power electron irradiation accelerator. This accelerator can output varied energy electron beam which the highest energy is 10 MeV or shooting target produce X-rays for industrial radiation processing.

  6. Multipurpose 5-MeV linear induction accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.L.; Hawkins, S.A.; Poor, S.E.; Reginato, L.L. Smith, M.W.

    1984-06-11

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, the researchers used new technology to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The paper describes the scheme. The magnetic drive system can be tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  7. Multipurpose 5-MeV linear induction accelerator

    Science.gov (United States)

    Birx, D. L.; Hawkins, S. A.; Poor, S. E.; Reginato, L. L.; Smith, M. W.

    1984-06-01

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, new technology was used to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The magnetic drive system are tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  8. CESAR, 2 MeV electron storage ring.

    CERN Multimedia

    1967-01-01

    CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

  9. CESAR, 2 MeV electron storage ring; general view.

    CERN Multimedia

    1964-01-01

    CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

  10. Automated Startup of the CEBAF 45 MeV Injector

    Science.gov (United States)

    Kehne, D.; Letta, P.; Dunham, B.; Kazimi, R.

    1997-05-01

    In order to improve the speed and reproducibility of restoring the beam in the CEBAF 45 MeV injector after a full or partial shutdown of the accelerator, a program has been written using the Tcl/Tk scripting language to automate most of the required steps. The procedure is separated into three main parts. The first consists of preliminary checks that verify that the hardware is set correctly and that systems are ready to be activated. The second part turns on the main interlocked systems including high power magnets and RF. The final step turns on the beam and verifies that the beam quality is satisfactory by measuring the transmission, orbit, bunch length, transverse emittance and match, energy spread, and dispersion. Minor corrections for phasing are also performed in the program. In order to identify inefficiencies in the startup, each step is timed and parameter changes are logged so that system drifts can be tracked. This paper describes the software implementation, the logic to achieve a successful startup, and efficiency results.

  11. 一种基于PRI谱特征的复杂雷达信号分选方法%A method of complex radar signal sorting based on PRI spectrum signatures

    Institute of Scientific and Technical Information of China (English)

    王亚莉; 胡进

    2011-01-01

    通过分析雷达截获机所处的复杂雷达信号环境,提出了一种基于PR I谱特征的复杂雷达信号分选方法。该方法利用PR I变换获取雷达信号PR I谱,并根据各种复杂雷达信号PR I谱特征实现复杂雷达信号的分选工作。仿真结果表明,该方法能够较好地实现复杂信号环境下雷达信号的分选工作。%In view of the complex radar signal environment for radar interceptors,a method of the complex radar signal sorting based on the PRI spectrum signatures is presented.The PRI spectrum is obtained through the PRI transform,and the complex radar signal sorting is realized based on the PRI spectrum signatures of various complex radar signals.The simulation results show that the method can better realize radar signal sorting in the complex signal environment.

  12. Survey and Alignment of the 100MeV Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Bumsik; Kwon, Hyeokjung; Jang, Jiho; Kim, Hansung; Kim, Daeil; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The 100MeV linear accelerator was installed and under commissioning at the Gyeongju site. The 100MeV proton linac was developed by the KOMAC according to the survey work and the alignment process. 100MeV proton beam will be supplied to the users after the beam commissioning. KOMAC is developing a 100MeV high-duty-factor proton linac. Linac is composed with a 50keV proton injector, a 3MeV RFQ, DTL tanks and a beam dump. In this paper, the survey and alignment scheme are described. To install the accelerator, the align network was built and the survey work was accomplished. On the basis of the survey result, all of the accelerator components were installed in the tunnel with two laser trackers.

  13. Sun-induced Chlorophyll fluorescence and PRI improve remote sensing GPP estimates under varying nutrient availability in a typical Mediterranean savanna ecosystem

    Science.gov (United States)

    Perez-Priego, O.; Guan, J.; Rossini, M.; Fava, F.; Wutzler, T.; Moreno, G.; Carvalhais, N.; Carrara, A.; Kolle, O.; Julitta, T.; Schrumpf, M.; Reichstein, M.; Migliavacca, M.

    2015-07-01

    This study investigates the performances of different optical indices to estimate gross primary production (GPP) of herbaceous stratum in a Mediterranean savanna with different Nitrogen (N) and Phosphorous (P) availability. Sun-induced chlorophyll Fluorescence yield computed at 760 nm (Fy760), scaled-photochemical reflectance index (sPRI), MERIS terrestrial-chlorophyll index (MTCI) and Normalized difference vegetation index (NDVI) were computed from near-surface field spectroscopy measurements collected using high spectral resolution spectrometers covering the visible near-infrared regions. GPP was measured using canopy-chambers on the same locations sampled by the spectrometers. We hypothesized that light-use efficiency (LUE) models driven by remote sensing quantities (RSM) can better track changes in GPP caused by nutrient supplies compared to those driven exclusively by meteorological data (MM). Particularly, we compared the performances of different RSM formulations - relying on the use of Fy760 or sPRI as proxy for LUE and NDVI or MTCI as fraction of absorbed photosynthetically active radiation (fAPAR) - with those of classical MM. Results showed significantly higher GPP in the N fertilized experimental plots during the growing period. These differences in GPP disappeared in the drying period when senescence effects masked out potential differences due to plant N content. Consequently, although MTCI was tightly related to plant N content (r2 = 0.86, p < 0.01), it was poorly related to GPP (r2 = 0.45, p < 0.05). On the contrary sPRI and Fy760 correlated well with GPP during the whole measurement period. Results revealed that the relationship between GPP and Fy760 is not unique across treatments but it is affected by N availability. Results from a cross validation analysis showed that MM (AICcv = 127, MEcv = 0.879) outperformed RSM (AICcv = 140, MEcv = 0.8737) when soil moisture was used to constrain the seasonal dynamic of LUE. However, residual analyses

  14. Base-pair opening dynamics of the microRNA precursor pri-miR156a affect temperature-responsive flowering in Arabidopsis.

    Science.gov (United States)

    Kim, Hee-Eun; Kim, Wanhui; Lee, Ae-Ree; Jin, Suhyun; Jun, A Rim; Kim, Nak-Kyoon; Lee, Joon-Hwa; Ahn, Ji Hoon

    2017-03-18

    Internal and environmental cues, including ambient temperature changes, regulate the timing of flowering in plants. Arabidopsis miR156 represses flowering and plays an important role in the regulation of temperature-responsive flowering. However, the molecular basis of miR156 processing at lower temperatures remains largely unknown. Here, we performed nuclear magnetic resonance studies to investigate the base-pair opening dynamics of model RNAs at 16 °C and investigated the in vivo effects of the mutant RNAs on temperature-responsive flowering. The A9C and A10CG mutations in the B5 bulge of the lower stem of pri-miR156a stabilized the C15∙G98 and U16∙A97 base-pairs at the cleavage site of pri-miR156a at 16 °C. Consistent with this, production of mature miR156 was severely affected in plants overexpressing the A9C and A10CG constructs and these plants exhibited almost no delay in flowering at 16 °C. The A10G and A9AC mutations did not strongly affect C15∙G98 and U16∙A97 base-pairs at 16 °C, and plants overexpressing A10G and A9AC mutants of miR156 produced more mature miR156 than plants overexpressing the A9C and A10CG mutants and showed a strong delay in flowering at 16 °C. Interestingly, the A9AC mutation had distinct effects on the opening dynamics of the C15∙G98 and U16∙A97 base-pairs between 16 °C and 23 °C, and plants expressing the A9AC mutant miR156 showed only a moderate delay in flowering at 16 °C. Based on these results, we propose that fine-tuning of the base-pair stability at the cleavage site is essential for efficient processing of pri-miR156a at a low temperature and for reduced flowering sensitivity to ambient temperature changes. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Genetic polymorphism of pri-microRNA 325, targeting SLC6A4 3'-UTR, is closely associated with the risk of functional dyspepsia in Japan.

    Science.gov (United States)

    Arisawa, Tomiyasu; Tahara, Tomomitsu; Fukuyama, Tomoki; Hayashi, Ranji; Matsunaga, Kazuhiro; Hayashi, Nobuhiko; Nakamura, Masakatsu; Toshikuni, Nobuyuki; Shiroeda, Hisakazu; Shibata, Tomoyuki

    2012-10-01

    The role of genetics in the susceptibility to functional dyspepsia (FD) remains unclear. We attempted to clarify the association between FD and polymorphisms in SLC6A4. In addition, rs5981521 (C>T) in the pri-microRNA 325 (pri-miR-325) coding region was also investigated. The study was performed in 395 subjects (172 with no upper abdominal symptoms and 223 with FD, including medication-resistant FD). We employed a polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) method to detect gene polymorphisms. Neither SLC6A4 -185 A>C nor *463 G>T was associated with susceptibility to FD. The number of rs5981521 T alleles was significantly correlated with an increased risk for FD (odds ratio [OR] 1.45, 95 % confidence interval [CI] 1.05-1.98; p = 0.022) and the TT homozygote was more closely associated with the risk for FD (OR 3.01, 95 % CI 1.41-6.42; p = 0.0043). The TT homozygote also had significantly increased risks for both the epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS) subtypes of FD (OR 3.04, 95 % CI 1.25-7.42; p = 0.014 and OR 3.05, 95 % CI 1.14-8.13; p = 0.026, respectively). In addition, Helicobacter pylori-negative TT homozygotes had a greater risk for FD (OR 8.37, 95 % CI 1.78-39.5; p = 0.0072). In subjects with the SLC6A4 5'-untranslated region (UTR) wild homozygote, the number of rs5981521 T alleles was significantly correlated to an increased risk for FD (OR 1.45, 95 % CI 1.03-2.04, p = 0.033). Of note, in subjects who were SLC6A4 3'-UTR mutant carriers, the number of rs5981521 T alleles was also significantly correlated with an increased risk for FD (OR 2.07, 95 % CI 1.08-3.98; p = 0.029). Our results suggest that the genetic polymorphism pri-miR-325 is associated with FD and interacts with SLC6A4 polymorphisms in increasing susceptibility to FD in Japanese.

  16. A Recognition Algorithm for Radar PRI Modulation Mode Based on Extremum Sequence Features Set%基于极值序列特征集的雷达PRI调制模式识别算法

    Institute of Scientific and Technical Information of China (English)

    周一鹏; 王星; 田元荣; 周东青; 程嗣怡

    2016-01-01

    识别雷达信号的脉冲重复间隔( PRI)调制模式是分析雷达工作状态和工作任务的重要手段。针对复杂体制雷达的PRI调制模式可实时切换并改变调制参数因而难于识别的问题,提出一种基于极值序列特征集的雷达PRI调制模式识别算法。该算法首先提取PRI序列的极值特征,构建极值序列特征集;然后,基于PRI序列及其特征集建立恒参、类正弦、正弦和抖动判定准则,实现雷达PRI调制模式的分层识别。仿真分析表明:该算法对复杂体制雷达PRI调制模式的识别正确率达95.3%,同时具有较高的实时性,在电子对抗应用领域具有良好的前景。%The recognition of pulse repetition interval ( PRI) modulation mode is meaningful for analyzing the condition and task of radar.In order to recognize advanced radar which could change its PRI modulation mode and parameters quickly , a recognition al-gorithm based on extremum sequence features set is proposed .Firstly, by extracting the extremum sequence features from PRI se-quence , the PRI extremum features set is constructed .Then the judge criterions of five PRI modulation modes based on PRI se-quence and its extremum features set is proposed .Finally, a multi-layer recognition algorithm is presented .The result shows that the recognition algorithm has preferable recognition correct rate (95.3%), and could classify the PRI modulation modes quickly , so the resae rch has a good application prospect in electronic support measures.

  17. 一种抗 SDIF 分选的脉冲重复间隔参差设计方法%A Design Method of PRI Stagger Countering the SDIF Sorting Algorithm

    Institute of Scientific and Technical Information of China (English)

    张保群

    2016-01-01

    To improve the anti-sorting and anti-recognition ability of radars against electronic reconnaissance systems,a design method of PRI stagger for radar signals was proposed based on the idea of destroying the performance of sorting with the pulse repetition interval (PRI).The working process of a typical PRI sorting algorithm,the sequential difference histogram (SDIF)was analyzed,and some critical steps were discussed.It is revealed that,when the staggered PRI values are chosen properly under some contracts,the correct sorting processing can be destroyed,as a result,more than one targets appear in the sorting results.Simulation results show that,the presented design is effective during countering the signal sorting based on the SDIF,therefore it provides a preliminary theoretical guidance for the radio frequency stealth design of radar signals.%为提高雷达对电子侦察系统抗分选识别能力,从破坏脉冲重复间隔(PRI)分选性能的角度出发,提出了一种雷达信号 PRI 参差设计方法。根据典型的序列差值直方图(SDIF)算法的工作流程,分析了 SDIF 实现 PRI 参差信号分选的关键步骤。合理设计参差 PRI 取值,使其满足一定约束条件,可以破坏正确分选流程,达到分选结果中目标增批的目的。仿真结果表明,该设计方法能有效对抗基于 SDIF 的信号分选策略,可以为雷达信号射频隐身设计提供初步的理论指导。

  18. PRI Detection of Segment Pulse Trains Based on Transform Spectrum Coherent Accumulation%基于变换谱相干积累的片段信号PRI检测

    Institute of Scientific and Technical Information of China (English)

    张什永; 胡泽宾; 王俊文

    2012-01-01

    Due to the effects of search modes and targets' beam scheduling, the reconnaissance systems can only intercept segment pulse trains from emitters, which is a big challenge for signal sorting. For this problem, a new method based on PRI transform spectrum coherent accumulation is proposed. PRI transform algorithm is introduced. The relationship between PRI spectrum peak value and pulse number included is given and its coherent accumulation feature is then revealed. Simulation results show that the new method can efficiently enhance PRI spectrum and is favourable to improve the detection propability.%受自身搜索方式和目标辐射源波束调度的影响,侦察系统往往只能截获辐射源的部分信号,这为后续分选处理带来了很大挑战.针对该问题,提出了通过时PRI变换谱进行相干积累以提高真实PRI检测概率的方法.首先介绍了PRI变换法,对算法原理进行了说明;接着从理论上推导了PRI变换谱峰值与脉冲个数的关系,指出了PRI变换谱的相干积累特性,并分析了其对虚假脉冲的适应能力;最后通过仿真试验对理论分析进行了验证.仿真结果表明,文中提出的方法能够有效提高片段信号的PRI 谱峰,从而有利于提高检测概率.

  19. An accurate estimation algorithm for PRI based on remainder of the cycle%一种基于余数周期的 PRI精确估计算法

    Institute of Scientific and Technical Information of China (English)

    苏焕程; 张君; 程良平; 程亦涵; 冷魁

    2016-01-01

    针对传统脉冲重复间隔(PRI)分选算法在估计PRI方面存在的不足,提出了一种对PRI周期信号的周期进行精确估计的算法。该算法首先从待分选脉冲序列中提取出属于一部雷达的脉冲样本,然后利用同余方程的余数周期性质对该雷达脉冲序列的PRI进行精确的估计。相对于传统的PRI估计算法,该算法有效地消除了TOA量化误差对PRI估计造成的影响,可以精确地估计出雷达脉冲序列的准确 PRI数值,从而能够更好地满足信号分选算法的处理需求。理论推导及仿真实验均表明了该算法的有效性。%For the defects in estimating pulse repetition interval (PRI) of traditional PRI de‐interleaving al‐gorithms ,a new algorithm of estimating the period of PRI periodic signals is put forward .The algorithm firstly extracts the pulse sample sequence of certain radar from the raw pulse sequence ,and then executes precise period estimation process based on the remainder of the cycle .Compared with the traditional PRI estimating algorithms ,this algorithm accurately estimates the PRI with TOA quantization error removing , which satisfies the requirement of the de‐interleaving process . Both theoretical derivation and simulation results verify the validity of the proposed algorithm .

  20. PRI 2.1: Basic researches on the photovoltaic: new materials (july 2002 - july 2004). Final report of the integrated research project; PRI 2.1: Recherches de base en photovoltaique: nouveaux materiaux (Juillet 2002 - Juin 2004). Rapport final du projet de recherche integre

    Energy Technology Data Exchange (ETDEWEB)

    Marfaing, Y.

    2004-07-01

    The main material of the photovoltaic cells is the massive crystalline silicon. For a large scale development of the photovoltaic industry, it is necessary to use thin layers. Many materials are possible to reach this objective: different types of silicon (amorphous, mono-crystal, poly-crystal), poly-crystal of CIS type (CuInSe{sub 2}) and organic molecules and polymers. The last two types are innovative and need some researches. These research axis are presented in this PRI. (A.L.B.)

  1. La proteína priónica celular: Análisis de su función neuroprotectora y reguladora del ciclo Celular

    OpenAIRE

    Carulla Martí, Patricia

    2013-01-01

    [spa] Las encefalopatías espongiformes transmisibles (EETs) son un conjunto de enfermedades neurodegenerativas letales que afectan tanto animales como humanos. Están causadas por unas partículas proteicas denominadas “priones”, resultantes de la transformación de la proteína priónica celular (PrP(C)) a una forma patogénica denominada PrP(SC), que se acumula en el cerebro en forma de agregados e induce la transformación de más moléculas a expensas de la reducción de los niveles de PrP(C)...

  2. 基于PRI的雷达脉冲序列分选方法%Algorithms for Sorting of Radar Pulses Based on PRI

    Institute of Scientific and Technical Information of China (English)

    杨文华; 高梅国

    2005-01-01

    高密度复杂信号环境下的信号分选处理技术是新一代雷达截获接收机信号处理的关键技术,也是雷达截获领域一个亟待解决的问题.文中讨论基于脉冲重复间隔(PRI)的脉冲分选算法,深入分析了基于直方图统计算法和PRI变换算法的优缺点,并对算法进行计算机仿真.最后针对这两种算法的优缺点提出一种综合的分选算法.

  3. 基于PRI变换和小波变换的雷达信号分选%Sorting of Radar Signal Based on PRI transfer and wavelet transfer

    Institute of Scientific and Technical Information of China (English)

    韩俊; 何明浩; 翟卫俊; 陈昌孝

    2007-01-01

    分析了脉冲重复间隔(PRI)变换算法和小波变换算法的基本原理,针对两种算法在雷达信号分选中的优缺点,提出了一种基于PRI变换和小波变换相结合的雷达信号综合分选方法.该方法首先利用PRI变换对雷达信号粗分选,然后应用小波变换进行细分选.仿真结果表明,在信噪比不低于10dB的条件下,该方法准确可行.

  4. Izobraževalna debata kot metoda makro-didaktične komponente preverjanje z ocenjevanjem pri pouku KEMIJE in NARAVOSLOVJA v osnovni šoli

    OpenAIRE

    Horvat, Davorin

    2014-01-01

    Hiter napredek znanosti in informacijske tehnologije ter dostopnosti do informacij preko medmrežja silijo k drugačnemu, alternativnemu načinu poučevanja (Pisar, 2006). Učence je potrebno uvajati v interdisciplinarno povezovanje aktualnih predmetnih področij. Aktivno učenje s pomočjo različnih metod dela ima pri vzgojno–izobraževalnem procesu čedalje večji pomen. Z metodo izobraževalne debate pridobijo učenci nekatere veščine, potrebne za uspešno soočanje z izzivi današnjega časa. Ta metod...

  5. Lower Oligocene non-geniculate coralline red algal (Corallinales, Rhodophyta assemblage from Poljšica pri Podnartu (Upper Carniola, Slovenia

    Directory of Open Access Journals (Sweden)

    Luka Gale

    2008-12-01

    Full Text Available The Lower Oligocene Gornji Grad beds from Polj{ica pri Podnartu consist of marly limestone, mudstone, several layers of limestones and two layers of sandstones, and were deposited on a mixed carbonate-siliciclastic ramp.Especially the limestones contain rich fossil fauna and non-geniculate coralline red algae. These were systematicallycollected from four horizons and researched in thin sections under an optical microscope. Genera Lithoporella,Neogoniolithon, Spongites, Lithothamnion, Mesophyllum and Spongites were recognized. Surface area for each genus was calculated and the differences in the coralline assemblages in the four horizons were analysed. Thecorallines originate from two source areas: sandy-muddy bottom of a shallow marine environment, and small coral bioherms with its encrusters.

  6. Odpadna embalaža in problem pri odpadni embalaži s pretisnimi omoti v farmacevtskem podjetju Krka d.d.

    OpenAIRE

    Krajnc, Urška

    2015-01-01

    Diplomska naloga obsega problem, ki nastane zaradi čedalje večjega in obsežnejšega nastajanja odpadne embalaže, in konkreten problem, s katerim se srečujejo v farmacevtskem podjetju Krka, d. d., iz Novega mesta. Kot nam je znano, je z odpadki vse več težav. S prostorskega vidika je to kopičenje odpadkov, z okoljskega vidika pa onesnaževanje okolja. Embalaža, ki predstavlja odpadek, ki ga ne potrebujemo več, nam predstavlja predmet, ki ga odvržemo. Pri tem je smiselno premisliti, če je embalaž...

  7. Fazna ravnoteža u sustavu NaNO3/KNO3 + glicerol + voda pri 288.15 K i 298.15 K

    OpenAIRE

    Zhang, H.-Y.; Zhu, W.-W.; Qin, G.-L.; Wei, Z.

    2014-01-01

    U ternarnom sustav NaNO3/KNO3 + glicerol + voda određeni su topljivost, gustoća i indeks loma pri 288,15 K i 298,15 K. Topljivost je izračunata na temelju gustoće i indeksa loma. U svim se slučajevima topljivost smanjuje s povećanjem udjela glicerola. Za indeks loma uočen je suprotan trend. Dodatkom glicerola smanjuje se gustoća otopine NaNO3, a povećava gustoća otopine KNO3. Eksperimentalni podatci za zasićene i podzasićene otopine korelirani su empirijskom jednadžbom s četiri i sedam parame...

  8. Extracción de una Proteasa Anti-Priónica de Líquenes (Orden: LECANORALES) en Fluido Gástrico e Intestinal Artificial -resumen-

    OpenAIRE

    Ricardo Millán-González; J Ducett; Johnson, C.

    2014-01-01

    La proteína priónica anormal (PrPTSE) es el agente etiológico de las encefalopatías espongiformes trasmisibles. Esta proteína posee una alta resistencia a ser inactivada por agentes químicos y ambientales‚ como la radiación y el calor‚ lo cual le da la capacidad de persistir en la tierra durante un periodo mayor a tres años después de haber sido enterrado‚ generando así una reserva de infectividad. Los líquenes son organismos simbióticos conformados por un hongo y un agente fotosintético que ...

  9. Bralno razumevanje angleščine pri učencih 6. razreda z disleksijo in brez disleksije s slušnim medijem vnosa

    OpenAIRE

    Deželan, Tadeja

    2017-01-01

    Ugotovitve znanstvenih raziskav so v zadnjih letih začele poudarjati pomembnost zgodnjega odkrivanja splošnih in specifičnih učnih težav učencev v šoli. Med specifičnimi učnimi težavami je najbolj prepoznavna in preučevana disleksija. Le-ta učencem povzroča velike težave pri osnovnem opismenjevanju in usvajanju jezikovnih spretnosti. Ker imajo učenci z disleksijo med drugim tudi težave z branjem in posledično tudi z razumevanjem prebranega, potrebujejo določene prilagoditve in podpore. V tej ...

  10. A SNP site in pri-miR-124 changes mature miR-124 expression but no contribution to Alzheimer's disease in a Mongolian population.

    Science.gov (United States)

    Qi, Lu; Hu, Yi; Zhan, Ying; Wang, Jing; Wang, Bing-Bing; Xia, Hong-Fei; Ma, Xu

    2012-04-25

    Increasing evidence shows that single nucleotide polymorphisms (SNPs) or mutations in microRNAs (miRNAs) sequence may affect the processing and function of miRNAs and participate in the occurrence of diseases. Although many SNPs of miRNAs were found, their functions in the pathological process of nerve cells were only just emerging. In the present study, the effect of the SNP of one neuronal miRNA, miR-124, on miRNA biogenesis and human genetic disease was investigated using in vitro cell line model and Alzheimer's disease (AD) in the Mongolian population. Bioinformatics prediction showed that a common G/C polymorphism designated rs531564 was found in the pri-miR-124 and the G allele changed the formation of a ring-shaped structure in the predicted secondary structure of the pri-miRNA for miR-124-1. Northern blot and real-time PCR analysis showed that the amount of mature miR-124 from the C/G heterozygosity of rs531564 was increased compared with the CC or GG homozygosity of rs531564. The expression of mature miR-124 from GG homozygosity was also higher than that from CC homozygosity. But in an association study of AD patients and controls, neither genotype nor allele distribution difference was found in AD patients compared with controls. Collectively, the present study is the first to evaluate the relationship between miR-124 and AD in the Mongolian population. SNP rs531564 of miR-124 may not represent a risk factor in the development of AD among Mongolian population.

  11. Two body photodisintegration of the deuteron from 100 to 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, R.; Annand, J.R.M.; Anthony, I. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Ahrens, J.; Beck, R. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Braghieri, A.; Pedroni, P. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy)]|[Pavia Univ. (Italy). Ist. di Fisica Nucleare; Audit, G.; D`Hose, N. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others

    1996-01-01

    The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author). Submitted to Nuclear Physics, B (NL); 23 refs.

  12. On the Origin of the MeV $\\gamma$-Ray Background

    CERN Document Server

    Stecker, F W; Done, C

    1999-01-01

    In this paper, we suggest a new hypothesis for explaining the spectrum of the extragalactic MeV gamma-ray background as observed by COMPTEL and SMM. We propose that both the flux level and spectrum can be accounted for as a superposition of non-thermal MeV tails in the spectra of Seyfert galaxies and other AGN. Although present detectors are not sensitive enough to obtain MeV data from individual extragalactic sources, indirect evidence in support of our hypothesis is found in OSSE and COMPTEL observations of the galactic black hole candidate Cygnus X-1.

  13. Pion absorption processes. [32 to 74 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Doss, K G.R.

    1980-04-01

    Proton and deuteron production from low-energy pion absorption in light nuclei leading to discrete and continuum states were measured. The LEP beam line at LAMPF was used with a stack of 8 intrinsic germanium crystals. The proton energy spectra are in general characterized by a broad bump at an energy approximately corresponding to ..pi../sup +/d ..-->.. pp reaction kinematics, suggestive of pion absorption on 2 nucleons. The energy-integrated cross-section for production of deuterons has an angular distribution similar to that for production of protons. The dependence of the total pion absorption cross-section on A is explained using a semi-classical model for pion transport in nuclei. The (..pi../sup +/,p) as well as (..pi../sup +/,d) reactions generally favor transitions involving larger angular momentum transfer to the residual nucleus when states of similar nuclear structure are considered. The low-energy excitation spectra from the (..pi../sup +/,p) reaction are similar to the spectra from (p,d) reaction on /sup 12/C and /sup 13/C. However, a calculation of the (..pi.. = ,p) cross-section using the measured (p,d) reaction with the formulation of Wilkin to relate the two reactions is in moderate disagreement with the measured (..pi../sup +/,p) cross-sections. The excitation spectra from the (..pi../sup +/,p) reaction indicte the importance of two-step processes for the reaction. The (..pi../sup +/,d) reaction leading to the ground state of -- residual nucleus has been seen for /sup 7/Li, /sup 12/C, and /sup 13/C targets. The measured cross section for the /sup 12/C(..pi../sup +/,d)/sup 10/C reaction to the 2/sup +/ state is much higher than that for the ground state. For the case of /sup 18/O, no counts were seen for excitation energy of < 10 MeV, at a sensitivity of approx. 100 nb/sr count. These features indicate a possible failure of the model of Betz and Kerman for the (..pi../sup +/,d) reaction.

  14. Comparison of bactericidal efficiency of 7.5 MeV X-rays, gamma-rays, and 10 MeV e-beams

    Science.gov (United States)

    Song, Beom-Seok; Lee, Yunjong; Moon, Byeong-Geum; Go, Seon-Min; Park, Jong-Heum; Kim, Jae-Kyung; Jung, Koo; Kim, Dong-Ho; Ryu, Sang-Ryeol

    2016-08-01

    This study was performed to verify the feasibility of 7.5 MeV X-rays for food pasteurization through a comparison of the bactericidal efficiency with those of other sources for selected bacterial pathogens. No significant differences were observed between the overall bactericidal efficiency for beef-inoculated pathogens based on the uncertainty of the absorbed dose and variations in bacterial counts. This result supported that all three irradiation sources were effective for inactivation of food-borne bacteria and that 7.5 MeV X-rays may be used for food pasteurization.

  15. An improved time of flight gamma-ray telescope to monitor diffuse gamma-ray in the energy range 5 MeV - 50 MeV

    Science.gov (United States)

    Dacostafereiraneri, A.; Bui-Van, A.; Lavigne, J. M.; Sabaud, C.; Vedrenne, G.; Agrinier, B.; Gouiffes, C.

    1985-01-01

    A time of flight measuring device is the basic triggering system of most of medium and high energy gamma-ray telescopes. A simple gamma-ray telescope has been built in order to check in flight conditions the functioning of an advanced time of flight system. The technical ratings of the system are described. This telescope has been flown twice with stratospheric balloons, its axis being oriented at various Zenital directions. Flight results are presented for diffuse gamma-rays, atmospheric secondaries, and various causes of noise in the 5 MeV-50 MeV energy range.

  16. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    Science.gov (United States)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  17. Performance of the 6 MeV injector for the Moscow racetrack microtron

    Science.gov (United States)

    Alimov, A. S.; Chepurnov, A. S.; Chubarov, O. V.; Gribov, I. V.; Ishkhanov, B. S.; Piskarev, I. M.; Rzhanov, A. G.; Sotnikov, M. A.; Surma, I. V.; Shumakov, A. V.; Shvedunov, V. I.; Tiunov, A. V.; Ushkanov, V. A.

    1993-03-01

    The 6 MeV injector for the Moscow racetrack microtron is described. The work presents the accelerator description, the rf power supply system and results of the computer simulation. The method of injector tuning and experimental results are discussed.

  18. Induced photonuclear interaction by Rhodotron-TT200 10 MeV electron beam

    Indian Academy of Sciences (India)

    Farshid Tabbakh; Mojtaba Mostajab Aldaavati; Mahdieh Hoseyni; Khadijeh Rezaee Ebrahim Saraee

    2012-02-01

    In this paper the photonuclear interaction induced by 10 MeV electron beam generating high-intensity neutrons is studied. Since the results depend on the target material, the calculations are performed for Pb, Ta and W targets which have high , in a simple geometry. MCNPX code has been used to simulate the whole process. Also, the results of photon generation has been compared with the experimental results to evaluate the reliability of the calculation. The results show that the obtained neutron flux can reach up to 1012 n/cm2 /s with average energies of 0.9 MeV, 0.4 MeV and 0.9 MeV for these three elements respectively with the maximum heat deposited as 3000 W/c3,4500 W/c3 and 6000 W/c3.

  19. Beam diagnostics measurements at 3 MeV of the LINAC4 H- beam at CERN

    CERN Document Server

    Zocca, F; Duraffourg, M; Focker, G J; Gerard, D; Kolad, B; Lenardon, F; Ludwig, M; Raich, U; Roncarolo, F; Sordet, M; Tan, J; Tassan-Viol, J; Vuitton, C; Feshenko, A

    2014-01-01

    As part of the CERN LHC injector chain upgrade, LINAC4 [1, 2] will accelerate H- ions to 160 MeV, replacing the old 50 MeV proton linac. The ion source, the Low Energy Beam Transfer (LEBT) line, the 3 MeV Radio Frequency Quadrupole and the Medium Energy Beam Transfer (MEBT) line hosting a chopper, have been commissioned in the LINAC4 tunnel. Diagnostic devices are installed in the LEBT and MEBT line and in a movable diagnostics test bench which is temporarily added to the MEBT exit. The paper gives an overview of all the instruments used, including beam current transformers, beam position monitors, wire scanners and wire grids for transverse profile measurements, a longitudinal bunch shape monitor and a slit-and-grid emittance meter. The instrumentation performance is discussed and the measurement results that allowed characterizing the 3 MeV beam in the LINAC4 tunnel are summarized.

  20. Coulomb dissociation of {sup 8}B at 254 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Suemmerer, K.; Boue, F.; Baumann, T.; Geissel, H.; Hellstroem, M.; Koczon, P.; Schwab, E.; Schwab, W.; Senger, P.; Surowiecz, A. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Iwasa, N.; Ozawa, A. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)]|[RIKEN Institute of Physical and Chemical Research, Saitama (Japan); Surowka, G. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)]|[Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Blank, B.; Czajkowski, S.; Marchand, C.; Pravikoff, M.S. [Centre d`Etudes Nucleaires de Bordeaux-Gradignan, 33 (France); Foerster, A.; Lauer, F.; Oeschler, H.; Speer, J.; Sturm, C.; Uhlig, F.; Wagner, A. [Technische Univ. Darmstadt (Germany); Gai, M. [Connecticut Univ., Storrs, CT (United States). Dept. of Physics; Grosse, E. [Inst. fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, Dresden (Germany); Kohlmeyer, B. [Philipps Univ., Marburg (Germany). Fachbereich Physik; Kulessa, R.; Walus, W. [Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Motobayashi, T. [Rikkyo Univ., Tokyo (Japan). Dept. of Physics; Teranishi, T. [RIKEN Institute of Physical and Chemical Research, Saitama (Japan)

    1998-06-01

    As an alternative method for determining the astrophysical S-factor for the {sup 7}Be(p,{gamma}){sup 8}B reaction we have measured the Coulomb dissociation of {sup 8}B at 254 A MeV. From our preliminary results, we obtain good agreement with both the accepted direct-reaction measurements and the low-energy Coulomb dissociation study of Iwasa et al. performed at about 50 A MeV. (orig.)

  1. Measurement of Prompt Fission Neutron Spectrum of 238U at 2.8 MeV

    Institute of Scientific and Technical Information of China (English)

    HUANG; Han-xiong; RUAN; Xi-chao; REN; Jie; LI; Guang-wu; LUAN; Guang-yuan

    2015-01-01

    The prompt fission neutron spectrum(PFNS,Fig.1)of 238U was measured at 2.8MeV incident neutron energy by using the Cockcroft&Walton accelerator in China Institute of Atomic Energy(CIAE).The effect-to-background ratio was improved by increasing the amount of sample mass and adding an appropriate shielding.The final uncertainty of neutron energy spectrum is less than 20%below 10MeV region at an bin size

  2. (n,Xn) measurements at 100 MeV. Recent developments and first results

    Energy Technology Data Exchange (ETDEWEB)

    Blideanu, V. [Lab. de Physique Corpusculaire, Caen (France); Blomgren, J.; Eudes, P.; Fontbonne, J.M.; Foucher, Y.; Guertin, A.; Hadad, F.; Hay, L.; Hildebrand, A.; Iltis, G.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Lefort, T.; Louvel, M.; Mermod, P.; Marie, N.; Olsson, N.; Pomp, S.; Osterlund, M.; Prokoviev, A.V.

    2003-07-01

    In the framework of the HINDAS project, we have studied the feasibility of (n,Xn) measurements at intermediate energy (20-200 MeV). To achieve this goal, we have developed a new set-up and performed several experiments using the monoenergetic neutron beam facility at the Svedberg laboratory (Sweden). The performance of this set-up is illustrated by first results obtained in 100 MeV neutron-induced reactions on a lead target. (orig.)

  3. High energy resolution characteristics on 14MeV neutron spectrometer for fusion experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Takada, Eiji; Nakazawa, Masaharu

    1996-10-01

    A 14MeV neutron spectrometer suitable for an ITER-like fusion experimental reactor is now under development on the basis of a recoil proton counter telescope principle in oblique scattering geometry. To verify its high energy resolution characteristics, preliminary experiments are made for a prototypical detector system. The comparison results show reasonably good agreement and demonstrate the possibility of energy resolution of 2.5% in full width at half maximum for 14MeV neutron spectrometry. (author)

  4. The cosmic monster quest: hunting MeV blazars with AMEGO

    Science.gov (United States)

    Buson, Sara; Ajello, Marco; Sharan Paliya, Vaidehi; Hartmann, Dieter; Venters, Tonia M.

    2017-08-01

    The All-Sky Medium Energy Gamma-ray Observatory (AMEGO) will explore the energy regime from 200 keV and 10 GeV with unprecedented sensitivity. Its wide field of view will allow us to observe the entire sky every three hours, making AMEGO a prime mission to study the long-term and short-term behavior of Active Galactic Nuclei (AGN) in the MeV band. This relatively unexplored energy range is particularly important since it enables us to investigate the emission mechanisms and environments of the MeV blazars, i.e. AGN whose peak power output lies in the MeV range. These distant MeV blazars host monster black holes, i.e., >1 billion solar mass, and are some of the most luminous and most distant gamma-ray AGN. Beside helping us in studying the evolution of supermassive black holes in the early Universe, MeV blazars play a key role in the context of extragalactic gamma ray background studies, especially in the challenging MeV regime.

  5. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV.

    Science.gov (United States)

    Sakata, S; Arikawa, Y; Kojima, S; Ikenouchi, T; Nagai, T; Abe, Y; Inoue, H; Morace, A; Utsugi, M; Kato, R; Nishimura, H; Nakai, M; Shiraga, H; Fujioka, S; Azechi, H

    2014-11-01

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (Ne = 1.0 × 10(-6) C, Ee = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%-70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10(-7), 10(-4), 10(-5), respectively, for 2-10, 11-15, and 15-25 MeV of photon energy ranges.

  6. Measurement of the Am241(n,2n) reaction cross section from 7.6 MeV to 14.5 MeV

    Science.gov (United States)

    Tonchev, A. P.; Angell, C. T.; Boswell, M.; Crowell, A. S.; Fallin, B.; Hammond, S.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Pedroni, R. S.; Tornow, W.; Becker, J. A.; Dashdorj, D.; Kenneally, J.; Macri, R. A.; Stoyer, M. A.; Wu, C. Y.; Bond, E.; Chadwick, M. B.; Fitzpatrick, J.; Kawano, T.; Rundberg, R. S.; Slemmons, A.; Vieira, D. J.; Wilhelmy, J. B.

    2008-05-01

    The (n,2n) cross section of the radioactive isotope Am241 (T1/2=432.6 y) has been measured in the incident neutron energy range from 7.6 to 14.5 MeV in steps of a few MeV using the activation technique. Monoenergetic neutron beams were produced via the H2(d,n)He3 reaction by bombarding a pressurized deuterium gas cell with an energetic deuteron beam at the TUNL 10-MV Van de Graaff accelerator facility. The induced γ-ray activity of Am240 was measured with high-resolution HPGe detectors. The cross section was determined relative to Al, Ni, and Au neutron activation monitor foils, measured in the same geometry. Good agreement is obtained with previous measurements at around 9 and 14 MeV, whereas for a large discrepancy is observed when our data are compared to those reported by Perdikakis near 11 MeV. Very good agreement is found with the END-B/VII evaluation, whereas the JENDL-3.3 evaluation is in fair agreement with our data.

  7. Measurement of (n,Xn) reaction cross sections at 96 MeV; Measure des sections efficaces (n,Xn) a 96 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)

    2006-10-15

    Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)

  8. A novel marsupial pri-miRNA transcript has a putative role in gamete maintenance and defines a vertebrate miRNA cluster paralogous to the miR-15a/miR-16-1 cluster.

    Science.gov (United States)

    Au, Phil Chi Khang; Frankenberg, Stephen; Selwood, Lynne; Familari, Mary

    2011-10-01

    Successful maintenance, survival and maturation of gametes rely on bidirectional communication between the gamete and its supporting cells. Before puberty, factors from the gamete and its supporting cells are necessary for spermatogonial stem cell and primordial follicle oocyte maintenance. Following gametogenesis, gametes rely on factors and nutrients secreted by cells of the reproductive tracts, the epididymis and/or oviduct, to complete maturation. Despite extensive studies on female and male reproduction, many of the molecular mechanisms of germ cell maintenance remain relatively unknown, particularly in marsupial species. We present the first study and characterisation of a novel primary miRNA transcript, pri-miR-16c, in the marsupial, the stripe-faced dunnart. Bioinformatic analysis showed that its predicted processed miRNA - miR-16c - is present in a wide range of vertebrates, but not eutherians. In situ hybridisation revealed dunnart pri-miR-16c expression in day 4 (primordial germ cells) and day 7 (oogonia) pouch young, in primary oocytes and follicle cells of primordial follicles but then only in follicle cells of primary, secondary and antral follicles in adult ovaries. In the adult testis, pri-miR-16c transcripts were present in the cytoplasm of spermatogonial cells. The oviduct and the epididymis both showed expression, but not any other somatic tissues examined or conceptuses during early embryonic development. This pattern of expression suggests that pri-miR-16c function may be associated with gamete maintenance, possibly through mechanisms involving RNA transfer, until the zygote enters the uterus at the pronuclear stage.

  9. 利用光化学反射植被指数估算光能利用率研究的进展%The Review of Estimating Light Use Efficiency through Photochemical Reflectance Index(PRI)

    Institute of Scientific and Technical Information of China (English)

    陈晋; 唐艳鸿; 陈学泓; 杨伟

    2008-01-01

    植被光能利用率(LUE)是估计植被初级生产力(GPP)和净初级生产力(NPP)模型的一个重要输入,准确地估计LUE对于生态学研究有重要的意义.由于LUE随环境的变化关系十分复杂,现有的LUE估算模型过于粗糙简单,而通过遥感直接估计LUE将会更加可靠.研究表明,光化学反射植被指数(PRI)与LUE有很好的相关性,故PRI在利用遥感估计LUE方面具有极大的潜力.但是很多研究也发现了PRI-LUE的关系不够稳健,受许多因素的干扰,比如物种构成、冠层结构及大气等.因此,PRI的广泛应用还需要更多的研究.本文首先介绍了PRI的定义及PRI随LUE变化的生理机制,再综述了一些利用遥感手段建立PRI-LUE关系的例子,然后分析了影响PRI-LUE关系的各种干扰因素,最后对PRI研究取得的成果、存在的问题以及发展前景作了总结.

  10. A study on signal sorting algorithm based on PRI spectrum signatures for staggered radars%基于PRI谱内特征的参差雷达信号分选算法研究

    Institute of Scientific and Technical Information of China (English)

    韩卫国; 胡进; 倪静静

    2011-01-01

    In view of the basic signatures of radar signals and some deficiencies of the PRI transform algorithm in the signal sorting,a signal sorting algorithm based on the PRI spectrum signatures for staggered radars is presented.The time-domain PRI spectrum of t%通过分析参差雷达信号的基本特征,针对PRI变换算法在参差雷达信号分选中存在的不足,提出了一种基于PRI谱内特征的参差雷达信号分选算法。该算法利用PRI变换获取信号的时域PRI谱,进而根据PRI谱内脉冲对数特征完成参差信号帧周期的分选工作。仿真结果表明,该方法能够较好地实现参差雷达信号的分选工作。

  11. Complete identification of states in 208Pb below Ex=6.2 MeV

    Science.gov (United States)

    Heusler, A.; Jolos, R. V.; Faestermann, T.; Hertenberger, R.; Wirth, H.-F.; von Brentano, P.

    2016-05-01

    The Q3D magnetic spectrograph at the Maier-Leibnitz-Laboratorium of the Ludwig-Maximilians-Universität München and the Technische Universität München (Garching, Germany), was used to study the 208Pb(p ,p' ) , 206,207,208Pb (d,p), and 208Pb(d ,d' ) reactions. One hundred fifty-one states at Ex<6.20 MeV in 208Pb are identified and spin and parity assigned. Four states are newly identified and new spins and/or parities are assigned to 25 states. Tentative spin assignments are done to five states at 5.90 MeV . Nearly 50 levels below Ex=6.20 MeV listed by the Nuclear Data Sheets as of 2007 are recognized to be nonexistent or doubly placed. The schematic shell model describing one-particle-one-hole configurations without residual interaction is extended by including two-particle-two-hole configurations. The number of configurations thus predicted at Ex<6.20 MeV nearly agrees with the number of states identified. Several states with dominant two-particle-two-hole configurations are identified. New isobaric analog resonances in 209Bi with two-particle-one-hole structure are discovered at Eres=17.6 MeV . The excitation energies of 70 states with unnatural parity at Ex<6.20 MeV are found to agree within about 200 keV with one-particle-one-hole configurations predicted by the extended schematic shell model. In contrast, the excitation energies of about 20 natural parity states are more than 0.5 MeV lower than predicted, demonstrating the residual interaction among the configurations to be much larger for natural parity than for unnatural parity.

  12. Neutron-induced fission cross sections of 242Pu from 0.3 MeV to 3 MeV

    Science.gov (United States)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-10-01

    The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the 242Pu(n ,f ) cross section. Within the same project both the 240Pu(n ,f ) cross section and the 242Pu(n ,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission-fragment detector. The 242Pu(n ,f ) cross section has been normalized to three different isotopes: 237Np(n ,f ) , 235U(n ,f ) , and 238U(n ,f ) . A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.

  13. Shielding calculations for industrial 5/7.5MeV electron accelerators using the MCNP Monte Carlo Code

    Science.gov (United States)

    Peri, Eyal; Orion, Itzhak

    2017-09-01

    High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, and by that extend the shelf life of the products. The production of X-rays is done by accelerating 5 MeV electrons and bombarding them into a heavy target (high Z). Since 2004, the FDA has approved using 7.5 MeV energy, providing higher production rates with lower treatments costs. In this study we calculated all the essential data needed for a straightforward concrete shielding design of typical food accelerator rooms. The following evaluation is done using the MCNP Monte Carlo code system: (1) Angular dependence (0-180°) of photon dose rate for 5 MeV and 7.5 MeV electron beams bombarding iron, aluminum, gold, tantalum, and tungsten targets. (2) Angular dependence (0-180°) spectral distribution simulations of bremsstrahlung for gold, tantalum, and tungsten bombarded by 5 MeV and 7.5 MeV electron beams. (3) Concrete attenuation calculations in several photon emission angles for the 5 MeV and 7.5 MeV electron beams bombarding a tantalum target. Based on the simulation, we calculated the expected increase in dose rate for facilities intending to increase the energy from 5 MeV to 7.5 MeV, and the concrete width needed to be added in order to keep the existing dose rate unchanged.

  14. Highly Stripped Ion Sources for MeV Ion Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hershcovitch, Ady

    2009-06-30

    Original technical objectives of CRADA number PVI C-03-09 between BNL and Poole Ventura, Inc. (PVI) were to develop an intense, high charge state, ion source for MeV ion implanters. Present day high-energy ion implanters utilize low charge state (usually single charge) ion sources in combination with rf accelerators. Usually, a MV LINAC is used for acceleration of a few rnA. It is desirable to have instead an intense, high charge state ion source on a relatively low energy platform (de acceleration) to generate high-energy ion beams for implantation. This de acceleration of ions will be far more efficient (in energy utilization). The resultant implanter will be smaller in size. It will generate higher quality ion beams (with lower emittance) for fabrication of superior semiconductor products. In addition to energy and cost savings, the implanter will operate at a lower level of health risks associated with ion implantation. An additional aim of the project was to producing a product that can lead to long­ term job creation in Russia and/or in the US. R&D was conducted in two Russian Centers (one in Tomsk and Seversk, the other in Moscow) under the guidance ofPVI personnel and the BNL PI. Multiple approaches were pursued, developed, and tested at various locations with the best candidate for commercialization delivered and tested at on an implanter at the PVI client Axcelis. Technical developments were exciting: record output currents of high charge state phosphorus and antimony were achieved; a Calutron-Bemas ion source with a 70% output of boron ion current (compared to 25% in present state-of-the-art). Record steady state output currents of higher charge state phosphorous and antimony and P ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb {sup 4 +}, Sb{sup 5+}, and Sb{sup 6+} respectively. Ultimate commercialization goals did not succeed (even though a number of the products like high

  15. Damage kinetics in MeV gold ion - Irradiated crystalline quartz

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, S.M.M. E-mail: ramos@dpm.univ-lyon1.fr; Clerc, C.; Canut, B.; Chaumont, J.; Toulemonde, M.; Bernas, H

    2000-05-02

    Damage creation in crystalline {alpha}-quartz under gold irradiation was studied at 1.0 and 5.5 MeV using the ARAMIS accelerator at CSNSM (Orsay). Although at these energies the total stopping powers are nearly equal (respectively, 4.20 and 4.46 keV nm{sup -1}), the electronic stopping power is only 1.23 keV nm{sup -1} (25% of the total) at 1 MeV while it reaches 2.75 keV nm{sup -1} (62% of the total) at 5.5 MeV. The electronic stopping power threshold for damage creation in {alpha}-quartz is about 1.8 keV/nm . The experiment thus allows us to follow the damage production kinetics due to nuclear collisions (at 1 MeV) versus electronic collisions (at 5.5 MeV). The damage was determined by channeling Rutherford backscattering (RBS-C) using the 2 MV Van de Graaff at DPM (Villeurbanne). Single ion impacts create damage when electronic stopping dominates, while several impacts are necessary to achieve complete damage when nuclear stopping dominates. Differences in damage efficiencies will be discussed.

  16. Elastic Neutron Scattering at 96 MeV from {sup 12}C and {sup 208}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Klug, J.; Blomgren, J.; Atac, A. [and others

    2003-04-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20-180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from {sup 12}C and {sup 208}Pb has been studied at 96 MeV in the 10-70 deg interval. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated uncertainty, 3 %, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic nuclear theory.

  17. Modification of semiconductor or metal nanoparticle lattices in amorphous alumina by MeV heavy ions

    Science.gov (United States)

    Bogdanović Radović, I.; Buljan, M.; Karlušić, M.; Jerčinović, M.; Dražič, G.; Bernstorff, S.; Boettger, R.

    2016-09-01

    In the present work we investigate effects of MeV heavy ions (from 0.4 MeV Xe to 15 MeV Si) on regularly ordered nanoparticle (NP) lattices embedded in amorphous alumina matrix. These nanostructures were produced by self-assembling growth using magnetron-sputtering deposition. From grazing incidence small-angle x-ray scattering measurements we have found that the used MeV heavy ions do not change the NP sizes, shapes or distances among them. However, ions cause a tilt of the entire NP lattice in the direction parallel to the surface. The tilt angle depends on the incident ion energy, type and the applied fluence and a nearly linear increase of the tilt angle with the ion fluence and irradiation angle was found. This way, MeV heavy ion irradiation can be used to design custom-made NP lattices. In addition, grazing incidence small-angle x-ray scattering can be effectively used as a method for the determination of material redistribution/shift caused by the ion hammering effect. For the first time, the deformation yield in amorphous alumina was determined for irradiation performed at the room temperature.

  18. A SNP in pri-miR-10a is associated with recurrent spontaneous abortion in a Han-Chinese population.

    Science.gov (United States)

    Li, Ying; Wang, Xue-Qin; Zhang, Lu; Lv, Xiao-Dan; Su, Xing; Tian, Shi; Liu, Chun-Mei; Ma, Xu; Xia, Hong-Fei

    2016-02-16

    MicroRNA-10a (miR-10a) has a wide range of functions in nearly all mammalian tissues and is involved in the occurrence of many diseases. However, it remains unknown whether miR-10a is associated with human recurrent spontaneous abortion (RSA). In this study, we found that rs3809783 A > T in miR-10a coding region was significantly associated with the increase of the risk of human unexplained RSA (URSA) acquisition in a Han-Chinese population. The T allele of rs3809783 hindered the production of mature miR-10a. A to T substitution in miR-10a rs3809783 repressed cell proliferation and migratory capacity. Further investigation discovered that Bcl-2-interacting mediator (Bim) was the functional target of miR-10a and inversely regulated Bim expression. Dual-luciferase assay indicated that A allele in miR-10a rs3809783 could more effectively suppress Bim expression than T allele. In addition, A to T substitution in miR-10a rs3809783 attenuated the sensibility of cells to progesterone and its antagonist mifepristone. Collectively, our data suggest that rs3809783 A > T in pri-miR-10a may be conductive to the genetic predisposition to RSA by disrupting the production of mature miR-10a and reinforcing the expression of Bim.

  19. microTSS: accurate microRNA transcription start site identification reveals a significant number of divergent pri-miRNAs.

    Science.gov (United States)

    Georgakilas, Georgios; Vlachos, Ioannis S; Paraskevopoulou, Maria D; Yang, Peter; Zhang, Yuhong; Economides, Aris N; Hatzigeorgiou, Artemis G

    2014-12-10

    A large fraction of microRNAs (miRNAs) are derived from intergenic non-coding loci and the identification of their promoters remains 'elusive'. Here, we present microTSS, a machine-learning algorithm that provides highly accurate, single-nucleotide resolution predictions for intergenic miRNA transcription start sites (TSSs). MicroTSS integrates high-resolution RNA-sequencing data with active transcription marks derived from chromatin immunoprecipitation and DNase-sequencing to enable the characterization of tissue-specific promoters. MicroTSS is validated with a specifically designed Drosha-null/conditional-null mouse model, generated using the conditional by inversion (COIN) methodology. Analyses of global run-on sequencing data revealed numerous pri-miRNAs in human and mouse either originating from divergent transcription at promoters of active genes or partially overlapping with annotated long non-coding RNAs. MicroTSS is readily applicable to any cell or tissue samples and constitutes the missing part towards integrating the regulation of miRNA transcription into the modelling of tissue-specific regulatory networks.

  20. 基于PRI变换的雷达信号分选%De-interleaving of Radar Signals Based on PRI Transform Algorithm

    Institute of Scientific and Technical Information of China (English)

    邹顺; 张群飞; 靳学明

    2006-01-01

    雷达信号分选是电子对抗的关键技术,而脉冲重复间隔是雷达信号分选的关键参数.目前基于PRI参数提出了很多分选方法.传统的PRI变换法对脉冲重复间隔具有很高的估计精度,它克服了直方图统计法中的子谐波问题,但是它的抗抖动能力很差.该文引入的修正的PRI变换法针对传统PRI变换法的缺点,利用可变的时间起点避免了相位因子的相位差,利用重叠的PRI箱增加PRI箱宽度,有效地克服了传统PRI变换中的缺点.此外,文中还给出了相应的门限设定方法和快速的脉冲抽取算法.仿真表明,该修正的PRI变换算法对固定PRI、抖动PRI和参差PRI脉冲序列都有较好的估计效果,它是精度较高的雷达信号分选方法.

  1. Comparison of the architectural and urban design workshop: in the town of Križevci pri Ljutomeru and the Jelovica architectural workshop

    Directory of Open Access Journals (Sweden)

    Tomaž Krušec

    2013-07-01

    Full Text Available The aim of the paper is to draw attention to the key advantages and potential disadvantages of the different types of architectural workshops and architectural/urban design workshops, i.e. based on an analysis and comparison of two workshops: architectural and urban design workshop in the town of Križevci pri Ljutomeru and the architectural workshop organised by the Jelovica Hiše d.o.o. company. The first workshop tried to find practical solutions to certain spatial problems of the town that the workshop addressed, while the client of the second workshop expected from the students to develop innovative solutions in using a specific building system for designing contemporary residential typologies. The differences in expectations meant that the workshops were carried out differently. In the first workshop, it was essential that the students stayed in the town that was the subject of the workshop, while in the second one, it was important that the students grasped the characteristics of the technological process and the special features of the building. To achieve this, the students made several visits to the company’s production plants and, as an end product of the workshop, the students had to produce a part of their designed structure. This was a most direct way of familiarising themselves with the way of building

  2. The exploitation of micromorphological parameters for identification in the section / Mentha Využitie mikromorfologických parametrov pri identifikácii v sekcii Mentha

    Directory of Open Access Journals (Sweden)

    Fialová S.

    2015-06-01

    Full Text Available Identifikacia druhov v rode Mentha L. je obzvlašť naročna. Je to sposobene ľahkym križenim podporenym gynodioeciou, ktora je ďalej skomplikovana polymorfizmom, pestovanim, polyploiditou a vegetativnym rozmnožovanim, čo vysvetľuje genetickopopulačne a mikroevolučne pozadie premenlivosti v rode Mentha. V tejto praci sme študovali využitie mikromorfologickych a fytochemickych parametrov pri identifikacii a charakterizacii vybranych druhov rodu Mentha. Na spodnej pokožke listov 20 populacii Mentha sme stanovili veľkosť a počet „žliazok typu Lamiaceae“. Silicu sme analyzovali pomocou GC MS. Identifikovali a charakterizovali sme populacie druhov M. × piperita, M. spicata, M. spicata subsp. condensata, M. spicata var. crispa, M. spicata var. citrata, M. × gentilis, M. aquatic, M. arvensis a M. longifolia. Sledovanie veľkosti a počtu „žliazok typu Lamiaceae prispievaju k charakterizacii niektorych druhov Mentha (najma M. longifolia a M. × piperita.

  3. Experimental and Calculated Effectiveness of a Radiochromic Dye Film to Stopping 21 MeV 7Li- and 64 MeV 16O Ions

    DEFF Research Database (Denmark)

    Olsen, Kjeld J; Hansen, Johnny

    1984-01-01

    particles developed by Katz et al. The experiment was designed to test calculations particularly in the Bragg-peak region of the slowing down particles where significant deviation between theory and experiment was found. Fitting of the characteristic D37 dose and the size of the radiation sensitive element......Relative radiation effectiveness, RE, of 21 MeV 7Li and 64 MeV 16O ions being completely stopped in a tissue equivalent film dose meter has been measured as a function of penetration depth and energy, and the results have been compared with calculations based on a δ-ray theory for heavy charged...... in the detector, which are important parameters in the theoretical model, does not improve the overall correlation between theory and experiment. It is concluded that disagreement between theoretical and experimental RE-values below 1.5 MeV/amu is partly due to lack of equivalence between the δ-ray spectrum...

  4. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of {sup nat}U

    Energy Technology Data Exchange (ETDEWEB)

    Penttilae, H.; Gorelov, D.; Elomaa, V.V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I.D.; Parkkonen, J.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Aeystoe, J. [Department of Physics, University of Jyvaskylae (Finland); Peraejaervi, K. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland); Rubchenya, V.A. [Department of Physics, University of Jyvaskylae (Finland); V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    2016-04-15

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {sup nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {sup nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution. (orig.)

  5. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, S., E-mail: sakata-s@ile.osaka-u.ac.jp; Arikawa, Y.; Kojima, S.; Ikenouchi, T.; Nagai, T.; Abe, Y.; Inoue, H.; Morace, A.; Utsugi, M.; Nishimura, H.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H. [Institute of Laser Engineering, Osaka University, Suita 565-0871 (Japan); Kato, R. [Institute of Scientific and Industrial Research, Osaka University, Ibaraki 565-0047 (Japan)

    2014-11-15

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (N{sub e} = 1.0 × 10{sup −6} C, E{sub e} = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%–70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10{sup −7}, 10{sup −4}, 10{sup −5}, respectively, for 2–10, 11–15, and 15–25 MeV of photon energy ranges.

  6. Digital neutron/gamma discrimination with an organic scintillator at energies between 1 MeV and 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Comrie, A.C. [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Buffler, A., E-mail: andy.buffler@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Smit, F.D. [iThemba LABS, Somerset West 7129 (South Africa); Wörtche, H.J. [INCAS" 3, Dr. Nassaulaan 9. 9400 AT Assen (Netherlands)

    2015-02-01

    Three different digital implementations of pulse shape discrimination for pulses from an EJ301 liquid scintillator detector are presented, and illustrated with neutrons and gamma-rays produced by an Am–Be radioisotopic source, a D–T generator and beams produced by cyclotron-accelerated protons of energies 42, 62 and 100 MeV on a Li target. A critical comparison between the three methods is provided.

  7. Calculating Rayleigh scattering amplitudes from 100 eV to 10 MeV. [100 eV to 10 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Parker, J.C.; Reynaud, G.W.; Botto, D.J.; Pratt, R.H.

    1979-05-01

    An attempt is made to explain how to calculate the contribution to elastic photon-atom scattering due to Rayleigh scattering (the scattering off bound electrons) in the photon energy range 100 eV less than or equal to W less than or equal to 10 MeV. All intermediate calculations are described, including the calculation of the potential, bound state wave functions, matrix elements, and final cross sections. 12 references. (JFP)

  8. Scalability of the LEU-Modified Cintichem Process: 3-MeV Van de Graaff and 35-MeV Electron Linear Accelerator Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brossard, Tom [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Roussin, Ethan [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jonah, Charles [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hafenrichter, Lohman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krebs, John [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-10-31

    Molybdenum-99, the mother of Tc-99m, can be produced from fission of U-235 in nuclear reactors and purified from fission products by the Cintichem process, later modified for low-enriched uranium (LEU) targets. The key step in this process is the precipitation of Mo with α-benzoin oxime (ABO). The stability of this complex to radiation has been examined. Molybdenum-ABO was irradiated with 3 MeV electrons produced by a Van de Graaff generator and 35 MeV electrons produced by a 50 MeV/25 kW electron linear accelerator. Dose equivalents of 1.7–31.2 kCi of Mo-99 were administered to freshly prepared Mo-ABO. Irradiated samples of Mo-ABO were processed according to the LEU Modified-Cintichem process. The Van de Graaff data indicated good radiation stability of the Mo-ABO complex up to ~15 kCi dose equivalents of Mo-99 and nearly complete destruction at doses >24 kCi Mo-99. The linear accelerator data indicate that even at 6.2 kCi of Mo-99 equivalence of dose, the sample lost ~20% of Mo-99. The 20% loss of Mo-99 at this low dose may be attributed to thermal decomposition of the product from the heat deposited in the sample during irradiation.

  9. 25 MeV Solar Proton Events in Cycle 24 and Previous Cycles

    Science.gov (United States)

    Richardson, I. G.; Cane, H. V.; von Rosenvinge, T. T.

    2014-12-01

    We summarize observations of nearly 1000 solar energetic particle events that include 25 MeV protons made by Goddard instruments on various spacecraft (IMPs IV, V, 7, 8, ISEE-3) and by other instruments on SOHO, since 1967, encompassing solar cycles 20 to 24. We also include recent observations of such events from the STEREO spacecraft. These extended observations place studies focusing on Cycles 23 and 24 in a broader context. For example, the time distribution of 25 MeV proton events varies from cycle to cycle such that each cycle is unique. In the current cycle, ~25 MeV proton events were absent during the preceding solar minimum, whereas earlier minima showed occasional, often reasonably intense events, and there have been, so far, fewer exceptionally intense events compared to Cycles 22 and 23, though Cycle 21 also apparently lacked such events.

  10. The photoresponse of stable N=82 nuclei below 10 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Volz, S. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany)]. E-mail: volz@ikp.tu-darmstadt.de; Tsoneva, N. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Institute for Nuclear Research and Nuclear Energy, 1784 Sofia (Bulgaria); Babilon, M. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Elvers, M. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Hasper, J. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Herzberg, R.-D. [Department of Physics, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lenske, H. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Lindenberg, K. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Savran, D. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Zilges, A. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany)

    2006-11-27

    High resolution photon scattering experiments were performed at the 10 MeV bremsstrahlung facility of the electron accelerator S-DALINAC at TU Darmstadt to investigate the semi-magic N=82 nuclei {sup 138}Ba, {sup 140}Ce, {sup 142}Nd and {sup 144}Sm. Energies and absolute strengths of dipole transitions below 10 MeV were determined in a model independent way. A concentration of electric dipole excitations exhausting up to 1% of the isovector E1 energy weighted sum rule is observed in all four nuclei around 6.5 MeV. Calculations in the framework of the Quasiparticle-Phonon Model (QPM) reproduce the gross experimental features.

  11. A possible approach to 14MeV neutron moderation: A preliminary study case.

    Science.gov (United States)

    Flammini, D; Pilotti, R; Pietropaolo, A

    2017-07-01

    Deuterium-Tritium (D-T) interactions produce almost monochromatic neutrons with about 14MeV energy. These neutrons are used in benchmark experiments as well as for neutron cross sections assessment in fusion reactors technology. The possibility to moderate 14MeV neutrons for purposes beyond fusion is worth to be studied in relation to projects of intense D-T sources. In this preliminary study, carried out using the MCNP Monte Carlo code, the moderation of 14MeV neutrons is approached foreseeing the use of combination of metallic materials as pre-moderator and reflectors coupled to standard water moderators. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis,modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC).The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000- 30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.

  13. Relativistic analysis of nuclear ground state densities at 135 to 200 MeV

    Indian Academy of Sciences (India)

    M A Suhail; N Neeloffer; Z A Khan

    2005-12-01

    A relativistic analysis of p + 40Ca elastic scattering with different nuclear ground state target densities at 135 to 200 MeV is presented in this paper. It is found that the IGO densities are more consistent in reproducing the data over the energy range considered here. The reproduction of spin-rotation-function data with the simultaneous fitting of differential cross-section and analyzing power, and the appearance of wine-bottle-bottom shaped Re eff() in the transition energy region, sensitively depends on the input nuclear ground state densities and are not solely the relativistic characteristic signatures. We also found that the wine-bottle-bottom shaped Re eff() is preferred by the spin observables in the transition energy region (i.e. 181 MeV to 200 MeV).

  14. 50 MeV Run of the IOTA / FAST Electron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Edstrom Jr., D.; et al.

    2017-02-02

    The low-energy section of the photoinjector-based electron linear accelerator at the Fermilab Accelerator Science & Technology (FAST) facility was recently commissioned to an energy of 50 MeV. This linear accelerator relies primarily upon pulsed SRF acceleration and an optional bunch compressor to produce a stable beam within a large operational regime in terms of bunch charge, total average charge, bunch length, and beam energy. Various instrumentation was used to characterize fundamental properties of the electron beam including the intensity, stability, emittance, and bunch length. While much of this instrumentation was commissioned in a 20 MeV running period prior, some (including a new Martin- Puplett interferometer) was in development or pending installation at that time. All instrumentation has since been recommissioned over the wide operational range of beam energies up to 50 MeV, intensities up to 4 nC/pulse, and bunch structures from ~1 ps to more than 50 ps in length.

  15. Neutron-proton analyzing power measurements from 375 to 775 MeV

    Science.gov (United States)

    Newsom, C. R.; Hollas, C. L.; Ransome, R. D.; Riley, P. J.; Bonner, B. E.; Boissevain, J. G. J.; Jarmer, J. J.; McNaughton, M. W.; Simmons, J. E.; Bhatia, T. S.; Glass, G.; Hiebert, J. C.; Northcliffe, L. C.; Tippens, W. B.

    1989-03-01

    As part of an experimental study of the nucleon-nucleon interaction at medium energy, the free neutron-proton analyzing power An(θ*n,Tn) has been measured at nine incident neutron energies in the range 375<=Tn<=775 MeV and for neutron c.m. angles in the range 57°<=θ*n<=159°. Unpolarized neutrons with a broad continuum of energies, produced by interaction of an 800 MeV proton beam with a beryllium target, were scattered from a polarized proton target. At each angle, for the whole energy region, the scattered neutron and conjugate recoil proton were detected in coincidence. A previously unseen minimum is observed in the energy dependence of An(θ*~100°) near 625 MeV.

  16. A proposed diagnostic for time-resolved 14 MeV neutron measurements on TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Ku, L.P.; Nazikian, R.; Prorvitch, V.

    1990-06-01

    A novel method for time resolved measurements of the 14 MeV neutron flux in an intense 2.5 MeV neutron and {gamma}-ray background has been developed. Discrimination against the background 2.5 MeV neutron and {gamma}-ray flux is achieved by the use of polyethylene and lead shielding. A high detection efficiency of DT neutrons is obtained by the use of large volume plastic scintillators and photomultiplier tube designed for operating in high magnetic field environments. Design computations for a such a detector system on TFTR show that an absolute detection efficiency of {approximately}10{sup {minus}8} counts per DT neutron may be obtained. A source strength of 10{sup 13} DT n/s may readily be detected by this method using both count mode and current mode operation with a resolution of {approximately}10 ms within a statistical accuracy of {approximately}5%. 12 refs., 8 figs., 2 tabs.

  17. Nuclear spin response of sup 40 Ca to 800 MeV polarized protons

    Energy Technology Data Exchange (ETDEWEB)

    Bimbot, L.; Fergerson, R.W.; Glashausser, C.; Jones, K.W.; Baker, F.T.; Beatty, D.; Cupps, V.; Green, A.; Nanda, S. (Institut de Physique Nucleaire, F-91406 Orsay, France (FR) Rutgers University, New Brunswick, NJ 08903 Los Alamos National Laboratory, Los Alamos, New Mexico 87545 University of Georgia, Athens, Georgia 30602 Continuous Electron Beam Accelerator Facility, Newport News, Virginia 23606)

    1990-12-01

    Doubly differential cross sections and spin-flip probabilities have been measured for 800-MeV proton scattering on {sup 40}Ca at 3.2{degree}, 4{degree}, 5{degree}, and 7{degree} in the laboratory, for excitation energies up to 45 MeV. The features of these observables in the continuum are discussed. The data indicate that nuclear spin excitations are enhanced at high excitation energy for angles corresponding to momentum transfers around 100 MeV/{ital c}, as previously observed for incident energies around 300 MeV. The relative nuclear spin response derived from these data is roughly independent of energy. This suggests that the dominance of spin-transfer excitation at high excitation energies for momentum transfers around 100 MeV/{ital c} is an intrinsic feature of the nuclear structure of {sup 40}Ca.

  18. A direct electron detector for time-resolved MeV electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

    2017-03-01

    The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.

  19. Depth profiling of fingerprint and ink signals by SIMS and MeV SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, M.J., E-mail: m.bailey@surrey.ac.u [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom); Jones, B.N. [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom); Hinder, S.; Watts, J. [Surface Analysis Laboratory, University of Surrey, GU2 7XH (United Kingdom); Bleay, S. [Home Office Scientific Development Branch, St. Albans (United Kingdom); Webb, R.P. [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom)

    2010-06-15

    Police institutions currently have no analytical method of knowing whether a fingerprint was deposited before or after the document was written or printed. The suitability of using MeV secondary ion mass spectrometry (i.e. SIMS with an MeV ion beam) to determine the order in which a fingerprint and written text were deposited on paper was therefore investigated. A 10 MeV O{sup 4+} beam was used to generate secondary ions from the surface of the samples and to map the molecular fragments from doped fingerprints and inks on paper. The images obtained and the sputtering behaviour of the samples was found to be indicative of the sequence of ink and fingerprint deposits.

  20. Resonance frequency control for the KOMAC 100-MeV drift tube linac

    Science.gov (United States)

    Kwon, Hyeok-Jung

    2015-02-01

    A 100-MeV proton accelerator has been developed, and the operation and beam service started at the Korea Multi-purpose Accelerator Complex (KOMAC) in July 2013. The accelerator consists of a 50-keV proton injector, a 3-MeV radio-frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The resonance frequencies of the DTL tanks are controlled by using the resonance frequency control cooling system (RCCS), installed at every DTL tank. Until now, the RCCS has been operating in the constant temperature mode. If the system is to be stabilized better, the RCCS must be operated in the frequency control mode. For this purpose, studies, including the relation between the resonance frequency and RCCS operation temperature, were done under various conditions. In this paper, the preparations for the frequency control loop of the RCCS are described.

  1. Splitting Behaviour of Implanted MeV Au+ Ions in LiB3O5

    Institute of Scientific and Technical Information of China (English)

    WANG Ke-ming; SHI Bo-rong; Nelson Cue; LU Fei; WANG Feng-xiang; XIE Zhao-xia; SHEN Ding-yu; LIU Yao-gang

    2000-01-01

    The diffusion behaviour of 1.0 and 2.0 MeV Au+ implanted into LiB3O5 single crystal has been studied by the Rutherford backscattering of 2.1 MeV He ions. Annealing was performed at temperatures of 600, 700, and 800℃each for 30min. The results show that the diffusion behaviour is quite different in two cases. In LiB3O5, the depth distribution of the 1.0 Me V Au is nearly Gaussian and becomes bimodal after annealing at 800℃ for 30 min.But in the case of 2.0 MeV, the depth distribution of as implanted Au+ in LiBsO5 has splitting behaviour. After 800C for 30 min annealing, there is no obvious diffusion observed. The precise interpretation is needed.

  2. First commissioning experience with the LINAC4 3 MeV front-end at CERN

    CERN Document Server

    Lallement, J B; Bellodi, G; Comblin, J F; Dimov, V A; Granemann Souza, E; Lettry, J; Lombardi, A M; Midttun, O; Ovalle, E; Raich, U; Roncarolo, F; Rossi, C; Sanchez Alvarez, R; Scrivens, C A; Valerio-Lizarraga, C A; Vretenar, M; Yarmohammadi Satri, M

    2013-01-01

    Linac4 is a normal-conducting 160 MeV H- linear accelerator presently under construction at CERN. It will replace the present 50 MeV Linac2 as injector of the proton accelerator complex as part of a project to increase the LHC luminosity. The Linac front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, have been commissioned at the 3 MeV test stand during the first half of 2013. The status of the installation and the results of the first commissioning stage are presented in this paper.

  3. Dispersive spherical optical model of neutron scattering from Al27 up to 250 MeV

    CERN Document Server

    Molina, A; Quesada, J M; Lozano, M

    2002-01-01

    A spherical optical model potential (OMP) containing a dispersive term is used to fit the available experimental database of angular distribution and total cross section data for n + Al27 covering the energy range 0.1- 250 MeV using relativistic kinematics and a relativistic extension of the Schroedinger equation. A dispersive OMP with parameters that show a smooth energy dependence and energy independent geometry are determined from fits to the entire data set. A very good overall agreement between experimental data and predictions is achieved up to 150 MeV. Inclusion of nonlocality effects in the absorptive volume potential allows to achieve an excellent agreement up to 250 MeV.

  4. Attenuation of 10 MeV electron beam energy to achieve low doses does not affect Salmonella spp. inactivation kinetics

    Science.gov (United States)

    Hieke, Anne-Sophie Charlotte; Pillai, Suresh D.

    2015-05-01

    The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation.

  5. RF phase stability in the 100-MeV proton linac operation

    Science.gov (United States)

    Seol, Kyung-Tae

    2015-02-01

    The 100-MeV proton linac of the Korea multi-purpose accelerator complex (KOMAC) has been operated to provide a proton beam to users. The 100-MeV linac consists of a 3-MeV radio-frequency quadrupole accelerator (RFQ), four 20-MeV drift-tube linac (DTL) tanks, two medium-energy beam-transmitter (MEBT) tanks, and seven 100-MeV DTL tanks. The requirements of the field stability are within ±1% in RF amplitude and ±1 degree in RF phase. The RF phase stability is influenced by a RF reference line, RF transmission lines, and a RF control system. The RF reference signal is chosen to be a 300-MHz local oscillator (LO) signal, and a rigid copper coaxial line with temperature control was installed for an RF reference distribution. A phase stability of ±0.1 degrees was measured under a temperature change of ±0.1 °C. A digital feedback control system with a field-programmable gate-array (FPGA) module was adopted for a high RF stability. The RF phase was maintained within ±0.1 degrees with a dummy cavity and was within ±0.3 degrees at RFQ operation. In the case of the 20-MeV DTL tanks, one klystron drives 4 tanks, and the input phases of 4 tanks were designed to be in phase. The input phases of 4 tanks were fixed within ±1 degree by adjusting a phase shifter in each waveguide.

  6. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani [Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, APS College, Bengaluru (India); Department of Physics, DCE, Govt. First Grade College, Mangalore (India); Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, Bangalore University, Bengaluru (India)

    2012-06-05

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O{sup 7+} ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O{sup 7+} ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  7. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    Science.gov (United States)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani

    2012-06-01

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O7+ ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O7+ ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  8. Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies

    Science.gov (United States)

    Abbott, D.; Adderley, P.; Adeyemi, A.; Aguilera, P.; Ali, M.; Areti, H.; Baylac, M.; Benesch, J.; Bosson, G.; Cade, B.; Camsonne, A.; Cardman, L. S.; Clark, J.; Cole, P.; Covert, S.; Cuevas, C.; Dadoun, O.; Dale, D.; Dong, H.; Dumas, J.; Fanchini, E.; Forest, T.; Forman, E.; Freyberger, A.; Froidefond, E.; Golge, S.; Grames, J.; Guèye, P.; Hansknecht, J.; Harrell, P.; Hoskins, J.; Hyde, C.; Josey, B.; Kazimi, R.; Kim, Y.; Machie, D.; Mahoney, K.; Mammei, R.; Marton, M.; McCarter, J.; McCaughan, M.; McHugh, M.; McNulty, D.; Mesick, K. E.; Michaelides, T.; Michaels, R.; Moffit, B.; Moser, D.; Muñoz Camacho, C.; Muraz, J.-F.; Opper, A.; Poelker, M.; Réal, J.-S.; Richardson, L.; Setiniyaz, S.; Stutzman, M.; Suleiman, R.; Tennant, C.; Tsai, C.; Turner, D.; Ungaro, M.; Variola, A.; Voutier, E.; Wang, Y.; Zhang, Y.; PEPPo Collaboration

    2016-05-01

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-Z target. Positron polarization up to 82% have been measured for an initial electron beam momentum of 8.19 MeV /c , limited only by the electron beam polarization. This technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community.

  9. The KAERI 10 MeV Electron Linac - Description and Operational Manual

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

    2005-06-15

    The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting.

  10. Design of the MYRRHA 17-600 MeV Superconducting Linac

    CERN Document Server

    Biarrotte, J-L; Bouly, F; Carneiro, J-P; Vandeplassche, D

    2013-01-01

    The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100MWth Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. This paper will briefly describe the beam dynamics design of the main superconducting linac section which covers the 17 to 600 MeV energy range and requires enhanced fault-tolerance capabilities.

  11. The physics design of magnet in 14 MeV cyclotron

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The 14 MeV, 400 μA compact cyclotron is under construction at China Institute of Atomic Energy (CIAE). The design of main magnet and the result of beam dynamics in the cyclotron will be described in this paper, including the choice of main parameters of magnet, the method of shimming isochronous field in the compact cyclotron and optimization of the magnetic field in central region. The beam will be accelerated to 14.6 MeV by optimizing the magnet structure.

  12. Design and experiment of insulation support of 2 MeV injector

    CERN Document Server

    Wang Meng; Dai Guang Sen; Wang Jing Sheng; Xia Lian Sheng; Huang Hai Bo

    2002-01-01

    Aiming at the technical request of high power injector, the authors designed two Nylon radial graded insulation supports on the heads of cathode and anode of the existing 2 MeV injector. The experiment results showed that, on the basis of credible insulation, the supports improved the quality of coaxiality between the cathode and the anode, ameliorated the identity of the three axes of beams, magnetic field and mechanism, and settled the groundwork for advancing each technical performances of the 2 MeV injector

  13. Design of an MeV ultra-fast electron diffraction experiment at Tsinghua university

    Institute of Scientific and Technical Information of China (English)

    LI Ren-Kai; TANG Chuan-Xiang; HUANG Wen-Hui; DU Ying-Chao; SHI Jia-Ru; YAN Li-Xin

    2009-01-01

    Time-resolved MeV ultra-fast electron difiraction(UED)is a powerful tool for structure dynamics studies.In this paper.we present a design of a MeV UED facility based on a photocathode RF gun at Tsinghua University.Electron beam qualities are optimized with numerical simulations,indicating that resolutions of 250 fs and 0.01 A.and bunch charge exceeding 105 electrons are expected with technically achievable machine parameters.Status of experiment preparation is also presented.

  14. Radiation hardness of a single crystal CVD diamond detector for MeV energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yuki, E-mail: y.sato@riken.jp [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Shimaoka, Takehiro; Kaneko, Junichi H. [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Murakami, Hiroyuki [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Isobe, Mitsutaka; Osakabe, Masaki [National Institute for Fusion Science, 322-6, Oroshi-cho Toki-city, Gifu 509-5292 (Japan); Tsubota, Masakatsu [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Ochiai, Kentaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shinichi [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2015-06-01

    We have fabricated a particle detector using single crystal diamond grown by chemical vapor deposition. The irradiation dose dependence of the output pulse height from the diamond detector was measured using 3 MeV protons. The pulse height of the output signals from the diamond detector decreases as the amount of irradiation increases at count rates of 1.6–8.9 kcps because of polarization effects inside the diamond crystal. The polarization effect can be cancelled by applying a reverse bias voltage, which restores the pulse heights. Additionally, the radiation hardness performance for MeV energy protons was compared with that of a silicon surface barrier detector.

  15. Beam Loss by Lorentz Stripping in a 100 MeV Compact H~- Cyclotron

    Institute of Scientific and Technical Information of China (English)

    Larry; Root

    2002-01-01

    The success of TRIUMF’s ISAC facility demonstrates that a 500 MeV 100 μ A H cyclotron is agood choice for the driver stage of an ISOL type RIB facility. As a result, China Institute of AtomicEnergy is proposing the construction of a 75~100 MeV 200~500μA H~- cyclotron as an upgrade to theBeijing Tandem Laboratory. This would be a multiple user facility, which would include a RIB target

  16. Effects of 3 MeV proton irradiation on the mechanical properties of polyimide films

    Science.gov (United States)

    Hill, David J. T.; Hopewell, Jefferson L.

    1996-11-01

    The effects of 3 MeV proton irradiation on the elongation to break, fracture energy and Young's Modulus have been investigated for films of Kapton and Ultem over the dose range 0-75 MGy at ambient temperature. The results have been compared with those reported by other workers for irradiation by 60Co gamma rays and 2 MeV electron beams under similar conditions, and little difference was found between the damage to the mechanical properties of the films induced by these three beam types.

  17. (π+/-,2N) reactions at 165 and 245 MeV

    Science.gov (United States)

    Altman, A.; Ashery, D.; Piasetzky, E.; Lichtenstadt, J.; Yavin, A. I.; Bertl, W.; Felawka, L.; Walter, H. K.; Powers, R. J.; Winter, R. G.; Pluym, J. V. D.

    1986-11-01

    The (π+,2p) and (π+/-, pn) reactions were studied by coincidence detection of the outgoing nucleons on C, Fe, and Bi at 165 and 245 MeV and on 16O and 18O at 165 MeV. The quasideuteron component is identified and found to account for only about 10% of the absorption cross section for carbon down to about 2% for bismuth. With corrections for the final-state interaction of outgoing nucleons it amounts to at most 40%. The data indicate that quasideuteron absorption following pion scattering is not likely. The absorption on T=1 nucleon pairs is about 4% of that on quasideuterons.

  18. Properties of the {sup 12}C 10 MeV state determined through {beta}-decay

    Energy Technology Data Exchange (ETDEWEB)

    Diget, C.A. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Barker, F.C. [Department of Theoretical Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia); Borge, M.J.G. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Cederkaell, J. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Fedosseev, V.N. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Fraile, L.M. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Fulton, B.R. [Department of Physics, University of York, Heslington, YO10 5DD (United Kingdom); Fynbo, H.O.U. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)]. E-mail: fynbo@phys.au.dk; Jeppesen, H.B. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Jonson, B. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Koester, U. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Meister, M. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Nilsson, T. [ISOLDE-CERN, CH-1211 Geneva 23 (Switzerland); Nyman, G. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Prezado, Y. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Riisager, K. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Rinta-Antila, S. [Department of Physics, University of Jyvaeskylae, FIN-40351 Jyvaeskylae (Finland); Tengblad, O. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Turrion, M. [Instituto Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Wilhelmsen, K. [Fundamental Fysik, Chalmers Tekniska Hoegskola, S-412 96 Goeteborg (Sweden); Aeystoe, J. [Department of Physics, University of Jyvaeskylae, FIN-40351 Jyvaeskylae (Finland); Helsinki Institute of Physics, University of Helsinki, FIN-00014 Helsinki (Finland)

    2005-10-03

    The {beta}-delayed triple-{alpha} particle decay of {sup 12}B has been measured with a setup that favours coincidence detection. A broad state in {sup 12}C, previously reported around 10 MeV, has been seen and its properties determined through R-matrix analysis of the excitation spectrum. The spin and parity are 0{sup +}. Interference between this state and the Hoyle state at 7.654 MeV has a marked influence on the spectrum. The coupling between the two states makes it difficult to determine the resonance energy.

  19. Pionic charge exchange on the proton from 40 to 250 MeV

    Science.gov (United States)

    Breitschopf, J.; Bauer, M.; Clement, H.; Cröni, M.; Denz, H.; Friedman, E.; Gibson, E. F.; Meier, R.; Wagner, G. J.

    2006-08-01

    The total cross sections for pionic charge exchange on hydrogen were measured using a transmission technique on thin CH2 and C targets. Data were taken for π- lab energies from 39 to 247 MeV with total errors of typically 2% over the Δ-resonance and up to 10% at the lowest energies. Deviations from the predictions of the SAID phase shift analysis in the 60-80 MeV region are interpreted as evidence for isospin-symmetry breaking in the s-wave amplitudes. The charge dependence of the Δ-resonance properties appears to be smaller than previously reported.

  20. Neutron field measurements at the 590 MeV ring cyclotron of the Paul Scherrer Institute

    CERN Document Server

    Grecescu, M; Boschung, M; Fiechtner, A; Gmuer, K; Laedermann, J P; Valley, J F; Wernli, C

    2002-01-01

    A complete characterization of the neutron field was performed at 3 representative areas around the 590 MeV Ring cyclotron of the Paul Scherrer Institute. The neutron spectra were measured with a Bonner spheres system, sup 2 sup 0 sup 9 Bi and sup 2 sup 3 sup 2 Th fission track detectors. Their shapes are very different according to the location; neutron energies up to about 200 MeV were recorded. The dosimetry was performed with various active instruments: 2202D, LB 6411, LINUS, nm 500, nm 500X, HANDI, REM 500. The comparison between the H*(10) values determined by different systems is presented and discussed.

  1. The response of the Sievert instrument in neutron beams up to 180 MeV

    CERN Document Server

    Kylionen, J E; Samuelson, G

    2001-01-01

    Measurements with a tissue-equivalent proportional counter (TEPC) using the variance-covariance method have been performed in neutron beams between 71 keV and 180 MeV and in the cosmic radiation reference field (CERF) at CERN. The results show that with appropriate linear Q/sub D/(y/sub D/) relations, the ambient dose equivalent can be determined within about 55% in these beams. Build- up measurements show that wall thickness is not crucial for H* determinations at 60 and 180 MeV. (26 refs).

  2. Thin Object Radiography with a 2.2 MeV Pulsed Power Machine

    Science.gov (United States)

    Haines, Todd; Danielson, Jeremy; Wood, W. Monty

    2015-06-01

    An experimental series was performed at a pulsed-power 2.2 MeV flash radiography machine to determine the lower limits of its mass sensitivity. This machine uses a rod-pinch diode with accelerating potential of 2.2 MeV and 50 ns pulse duration. Tungsten, aluminum, and titanium rod anodes were used to tune the emitted bremsstrahlung spectrum; as well as aluminum and beryllium filter materials. Analysis of thin tantalum foils shows a mass sensitivity as low as 300 μg/cm2. This is a factor of 5 better than previous measurements.

  3. Reactions sup 58,64 Ni( p ,. pi. sup + ) at 201 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Badala, A.; Barbera, R.; Palmeri, A.; Pappalardo, G.S.; Bonasera, A. (Istituto Nazionale di Fisica Nucleare, Corso Italia 57, 95129 Catania (Italy)); Riggi, F.; Adorno, A. (Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica dell' Universita di Catania, Corso Italia 57, 95129 Catania (Italy)); Bimbot, L. (Institut de Physique Nucleaire, Boite Postale 1, 91406 Orsay CEDEX (France))

    1992-08-01

    The production of positive and negative pions induced by 201 MeV protons on {sup 58}Ni and {sup 64}Ni isotopes has been studied. The double differential cross sections have been measured at the laboratory angles 22{degree}, 35{degree}, 55{degree}, 72{degree}, 90{degree}, 105{degree}, 120{degree}, 138{degree}, 155{degree} and from 20 MeV kinetic energy up to the kinematical limit. Features of the double differential cross sections relative to the two targets are discussed and compared to results obtained at higher incident energies.

  4. 16O+12C resonances within the strong absorption region for Ec.m.>23 MeV

    Science.gov (United States)

    Jachcinski, C. M.; Braun-Munzinger, P.; Berkowitz, G. M.; Freifelder, R. H.; Gai, M.; Renner, T. R.; Uhlhorn, C. D.

    1980-07-01

    Excitation functions for 12C(16O, 16O)12C elastic and inelastic scattering have been measured in the energy range 23<=Ec.m.<=32 MeV. Two strong structures at Ec.m.=25.5 and 29.6 MeV are observed in the 12C + 16O(3-,6.13 MeV) exit channel; angular correlation measurements at these energies suggest spin assignments of 15- and 16+, respectively. NUCLEAR REACTIONS 12C(16O, 16O*)12C*; Ec.m.=23-32 MeV, θc.m.(16O)=130°-155° measured σ(E) angular correlations.

  5. The design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    CERN Document Server

    Huang, Liang-Sheng; Ji, Hong-Fei

    2016-01-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary application, such as biology, material and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design was worked out, and all the important beam dynamics issues were investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, the achromatic structure is proposed and slow extraction method with RF knock-out is adopted and optimized.

  6. Measurement of thick target neutron yields for protons and deuterons in Ten's of MeV region

    Energy Technology Data Exchange (ETDEWEB)

    Baba, M.; Aoki, T.; Kawata, N.; Hagiwara, M.; Miura, T.; Yamadera, A.; Yonai, S.; Nakamura, T. [Tohoku Univ., Sendai (Japan)

    2002-07-01

    We have measured energy-angular differential thick target neutron yields (TTY) for C, Al, Ta, W(p,n) reactions at 50 MeV, and Li, Be (d,n) reactions for 25 MeV deuterons with the TOF method using Tohoku University K=110 MeV cyclotron equipped with a beam swinger system and a well collimated TOF line. Neutron spectrum data have been obtained down to {approx} 0.8 MeV from the highest energy at several laboratory angles from 0-deg to 90-deg. The results are compared with other experiments and a recent data library LA-150.

  7. Polymorphisms of the pri-miR-34b/c promoter and TP53 codon 72 are associated with risk of colorectal cancer.

    Science.gov (United States)

    Oh, Jisu; Kim, Jong Woo; Lee, Bo Eun; Jang, Moon Ju; Chong, So Young; Park, Pil Won; Hwang, Seong Gyu; Oh, Doyeun; Kim, Nam Keun

    2014-02-01

    The microRNA (miR)-34 family is a direct transcriptional target of tumor-suppressor TP53 and loss of miR-34 function may impair TP53-mediated cell cycle arrest and apoptosis. In the present study, we investigated whether the single nucleotide polymorphisms (SNPs) rs4938723 (T>C) in the promoter region of miR-34b/c and Arg72Pro (G>C) in codon 72 of TP53 are independently or complementarily associated with the risks and clinical outcomes of colorectal cancer (CRC) and whether the combined effect of these SNPs and metabolic risk factors are related to CRC. We evaluated the SNPs in 545 CRC patients and 428 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequence analysis. We found that the GC and GC/CC genotypes of TP53 Arg72Pro were associated with decreased risk of CRC (adjusted OR = 0.727 for GC; OR = 0.735 for GC/CC). The combined genotypes of TT-GC and CC-GG were significantly associated with reduced CRC risk (adjusted OR = 0.628 for TT-GC; OR = 0.381 for CC-GG, respectively). The SNP rs4938723 and diabetes mellitus (DM) together were associated with an increased CRC risk, but the SNP TP53 Arg72Pro CC with DM showed a protective effect against CRC. These findings indicate that rs4938723 in the promoter region of pri-miR-34b/c and the SNP in TP53 codon 72 were related to decreased risk of CRC in the population studied and those metabolic diseases and genetic variants influence each other with regard to CRC susceptibility.

  8. Li tter Fall i n A Pri mary an d Two Logged -over Lowland Tropical Rainfore sts in Pasirmayang, Jam bi.

    Directory of Open Access Journals (Sweden)

    UPIK ROSALI NA WAS R IN

    1999-01-01

    Full Text Available Litte r accu mulatio n in a prim ary and a log g ed-ove r lo wland dipterocarp fore st at Pa si rmayang, Ja mbi wa s measu red u sin g the litte r trap met hod . In the p rimary fore st , tra p s were placed in fou r d istinc t areas, reflectin g th e su ccess ion stages of the fo rest fr om building t o mat u ration. In the logged-over fo re st , litter p roduc tion w a s measured at two differe nt si tes, one cut in 197 9/1980 a nd t h e second i n 1 983/1984. In the prim ary fore st , ave rage litter production during the ob serv ation period wa s 925 g m"2yr '. In the lo gged -over f o r e st , ave rage l itte r production wa s 721 g m '2 yr1 for t h e sit e cut in 1979 /198 0 and 70 6 g m '2 yr1 f o r the site cut in 19 83/1 984 . Leave s com p ri sed the major con tri butor of litter wit h 67% of tota l litter produced in t h e pri m ary forest, 67% of total litter i n the 1979/ 1980 cut log g ed-o ver fore st, and 65 % of total li tter in the 1983/1984 cut logged-over fore st . The pu rp ose of the stu dy wa s to use litte r fa ll a s a measure of forest pro ductivi ty to a ssess the recovery of log g ed -over forests and , t o pro v ide a basi s for co mpariso n o f forest-de rived land practices for app ropriate fo re st manage ment stra tegies .

  9. Optimal Design of Proposed 800 MeV Proton Cyclotron Beam Dynamics

    Institute of Scientific and Technical Information of China (English)

    YANG; Jian-jun; LI; Ming; ZHANG; Tian-jue; SONG; Guo-fang; AN; Shi-zhong

    2015-01-01

    The high intensity beam dynamic simulation shows that the theoretic beam current limit of the original design version of the 800 MeV proton cyclotron CYCIEA-800is 1mA.In order to further improve the current limit and reduce beam losses in the cyclotron,the layout of the cyclotron

  10. Voltage holding study of 1 MeV accelerator for ITER neutral beam injector.

    Science.gov (United States)

    Taniguchi, M; Kashiwagi, M; Umeda, N; Dairaku, M; Takemoto, J; Tobari, H; Tsuchida, K; Yamanaka, H; Watanabe, K; Kojima, A; Hanada, M; Sakamoto, K; Inoue, T

    2012-02-01

    Voltage holding test on MeV accelerator indicated that sustainable voltage was a half of that of ideal quasi-Rogowski electrode. It was suggested that the emission of the clumps is enhanced by a local electric field concentration, which leads to discharge initiation at lower voltage. To reduce the electric field concentration in the MeV accelerator, gaps between the grid supports were expanded and curvature radii at the support corners were increased. After the modifications, the accelerator succeeded in sustaining -1 MV in vacuum without beam acceleration. However, the beam energy was still limited at a level of 900 keV with a beam current density of 150 A∕m(2) (346 mA) where the 3 × 5 apertures were used. Measurement of the beam profile revealed that deflection of the H(-) ions was large and a part of the H(-) ions was intercepted at the acceleration grid. This causes high heat load on the grids and the breakdowns during beam acceleration. To suppress the direct interception, new grid system was designed with proper aperture displacement based on a 3D beam trajectory analysis. As the result, the beam deflection was compensated and the voltage holding during the beam acceleration was improved. Beam parameter of the MeV accelerator was increased to 980 keV, 185 A∕m(2) (427 mA), which is close to the requirement of ITER accelerator (1 MeV, 200 A∕m(2)).

  11. Experimental bremsstrahlung yields for MeV proton bombardment of beryllium and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, David D. [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234 (Australia)], E-mail: dcz@ansto.gov.au; Stelcer, Eduard; Siegele, Rainer; Ionescu, Mihail; Prior, Michael [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234 (Australia)

    2008-04-15

    Experimental bremsstrahlung yields for 2, 3 and 4 MeV protons on thin beryllium and carbon targets have been measured. The yields have been corrected for detector efficiency, self-absorption in the target and fitted to 9th order polynomials over the X-ray energy range 1-10 keV for easy comparison with theoretical calculations.

  12. 10MeV/20kW Electron Linac for Irradiation Microwave System

    Institute of Scientific and Technical Information of China (English)

    WU; Qing-feng; ZHU; Zhi-bin; WANG; Xiu-long; LIU; Bao-jie; HU; Tao

    2015-01-01

    Microwave system is one of main subsystems of 10 MeV/20kW electron irradiating linac.It provides accelerating tube with microwave power,and accelerates electron beam to design energy,high-energy electron beam is ultimately used for irradiation processing.In order to meet the requirements of the

  13. Praseodymium activation detector for measuring bursts of 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Tim, E-mail: meehanbt@nv.doe.go [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Hagen, E.C. [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Ruiz, C.L.; Cooper, G.W. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185 (United States)

    2010-08-21

    A new, accurate, neutron activation detection scheme for measuring pulsed neutrons has been designed and tested. The detection system is sensitive to neutrons with energies above 10 MeV; importantly, it is insensitive to gamma radiation <10 MeV and to lower-energy (e.g., fission and thermal) neutrons. It is based upon the use of {sup 141}Pr, an element that has a single, naturally occurring isotope, a significant n,2n cross-section, and decays by positron emission that result in two coincident 511 keV photons. Neutron fluences are thus inferred by relating measured reaction product decay activity to fluence. Specific sample activity is measured using the sum-peak method to count gamma-ray coincidences from the annihilation of the positron decay products. The system was tested using 14 and 2.45 MeV neutron bursts produced by NSTec Dense Plasma Focus Laboratory fusion sources. Lead, copper, beryllium, and silver activation detectors were compared. The detection method allows measurement of 14 MeV neutron yield with a total error of {approx}18%.

  14. The pilot experimental study of 14 MeV fast neutron digital radiography

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    14 MeV Fast neutrons has good penetrability and the 14 MeV fast neutron radiography can meet the need of Non-Destructive Test of the structure and lacuna of heavy-massive sample, whose shell is made of heavy metal and in which there are some hydrogen materials, and the study of fast neutron digital radiography just begins in China. By the use of a D-T accelerator, a digital imaging system made up of a fast neutron scintillation screen made of ZnS(Ag) and polypropylene, lens and a scientific grade CCD, the experimental study of fast neutron radiography has been done between 4.3×1010-6.8×1010 n/s of neutron yield. Some 14 MeV fast neutron digital radiographs have been gotten. According to experimental radiographs and their data, the performance of the fast neutron scintillation screen and the basic characters of 14 MeV fast neutron radiography are analyzed, and it is helpful for the further research.

  15. Multi-turn injection of 50 MeV protons into the CERN Proton Synchrotron booster

    CERN Document Server

    Raginel, V; Carli, C; Mikulec, B

    2013-01-01

    Since 1978, Linac2 produces beams of 50 MeV protons with a current around 160 mA, which are injected into the CERN Proton Synchrotron Booster (PSB) with conventional multi-turn injection using a horizontal septum. It is planned to replace Linac2 during a future long stop with a new H- linac, Linac4, injecting at higher energy (160 MeV) and making use of the modern chargeexchange injection principle. Due to the age of Linac2 and to a delicate vacuum situation the risk of a serious Linac2 breakdown has to be considered. Therefore it is necessary to study if the PSB could produce beams useful for the LHC and other experiments injecting a Linac4 proton beam at 50 MeV with much lower average current compared to Linac2 and without the need for a long installation of the 160 MeV H- injection hardware. Benchmarking of the PSB injection model with the existing injection system with Linac2 using the ORBIT code has been done for a LHC-type beam and then the injection model was used to estimate the brightness for LHC-typ...

  16. Multi-turn injection of 50 MeV protons into the CERN Proton Synchrotron Booster

    CERN Document Server

    Raginel, V; Carli, C; Mikulec, B

    2013-01-01

    Since 1978, Linac2 produces beams of 50 MeV protons with a current around 160 mA, which are injected into the CERN Proton Synchrotron Booster (PSB) with conventional multi-turn injection using a horizontal septum. It is planned to replace Linac2 during a future long stop with a new H- linac, Linac4, injecting at higher energy (160 MeV) and making use of the modern chargeexchange injection principle. Due to the age of Linac2 and to a delicate vacuum situation the risk of a serious Linac2 breakdown has to be considered. Therefore it is necessary to study if the PSB could produce beams useful for the LHC and other experiments injecting a Linac4 proton beam at 50 MeV with much lower average current compared to Linac2 and without the need for a long installation of the 160 MeV H- injection hardware. Benchmarking of the PSB injection model with the existing injection system with Linac2 using the ORBIT code has been done for a LHC-type beam and then the injection model was used to estimate the brightness for LHC-typ...

  17. NUSTAR, SWIFT, and GROND Observations of the Flaring MEV Blazar PMN J0641-0320

    DEFF Research Database (Denmark)

    Ajello, M.; Ghisellini, G.; Paliya, V. S.;

    2016-01-01

    Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641-0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power...

  18. Positronium formation in helium bubbles in 600 MeV proton-irradiated aluminium

    DEFF Research Database (Denmark)

    Jensen, K. O.; Eldrup, Morten Mostgaard; Singh, Bachu Narain

    1985-01-01

    Aluminium samples containing helium bubbles produced by 600 MeV proton irradiation at 430°C were investigated by positron annihilation; both lifetime and angular correlation measurements were made. The angular correlation curves contain an unusually narrow component. This component is associated...

  19. Production of positive pions by 800 MeV protons on carbon

    Science.gov (United States)

    Denes, Peter; Dieterle, B. D.; Wolfe, D. M.; Bowles, T.; Dombeck, T.; Simmons, J. E.; Bhatia, T. S.; Glass, G.; Tippens, W. B.

    1983-03-01

    The double differential cross section for the reaction p+C-->π++X has been measured at laboratory angles of 7°, 15°, 20°, and 30°. NUCLEAR REACTIONS E=800 MeV, p+12C-->π++X measured dσdEπ for θπ=7°, 15°, 20°, 30°.

  20. The neutron-deuteron elastic scattering angular distribution at 95 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Mermod, Philippe

    2004-04-01

    The neutron-deuteron elastic scattering differential cross section has been measured at 95 MeV incident neutron energy, with the Medley setup at TSL in Uppsala. The neutron-proton differential cross section has also been measured for normalization purposes. The data are compared with theoretical calculations to investigate the role of three-nucleon force effects.

  1. Measurements of the analyzing power of elastic pd-scattering at 190 MeV

    NARCIS (Netherlands)

    Seip, M; Bieber, R; Drentje, AG; van Goethem, MJ; Harakeh, MN; Hoefman, M; Huisman, H; Kalantar-Nayestanaki, N; Kremers, HR; Messchendorp, JG; Volkerts, M; van der Werf, SY; Wilschut, HW; Desplanques, B; Protasov, K; SilvestreBrac, B; Carbonell, J

    1999-01-01

    A beam-polarimeter for medium energy protons and deuterons (E=100-200 MeV) has been constructed. Its operation is based on the p + d, p + p and d + p elastic scattering with coincident detection of both particles in 4 independent planes. The 16 detectors of the polarimeter have a phoswich constructi

  2. Scale size of magnetic turbulence in tokamaks probed with 30-MeV electrons

    NARCIS (Netherlands)

    Entrop, I.; Cardozo, N. J. L.; R. Jaspers,; Finken, K.H.

    2000-01-01

    Measurements of synchrotron radiation emitted by 30-MeV runaway electrons in the TEXTOR-94 tokamak show that the runaway population decays after switching on neutral beam injection (NBI). The decay starts only with a significant delay, which decreases with increasing NBI heating power. This delay pr

  3. Response of LaBr{sub 3}(Ce) scintillators to 14 MeV fusion neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cazzaniga, C., E-mail: carlo.cazzaniga@mib.infn.it [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy); Nocente, M. [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy); Tardocchi, M. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy); Rebai, M. [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Pillon, M. [Associazione EURATOM-ENEA sulla Fusione ENEA C.R. Frascati, Via E. Fermi, 45, 00044 Frascati, Roma (Italy); Camera, F.; Giaz, A.; Pellegri, L. [University of Milano, Departement of Physics, Via Celoria 16, Milano 1-20133 (Italy); Gorini, G. [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy)

    2015-04-01

    The response of a 3″×3″ LaBr{sub 3}(Ce) scintillator to 14 MeV neutron irradiation has been measured at the Frascati Neutron Generator and simulated by means of a dedicated MCNP model. Several reactions are found to contribute to the measured response, with a key role played by neutron inelastic scattering and (n,2n) reactions on {sup 79}Br, {sup 81}Br and {sup 139}La isotopes. An overall 43% efficiency to 14 MeV neutron detection above an experimental threshold of 0.35 MeV is calculated and confirmed by measurements. Post irradiation activation of the crystal has been also observed and is explained in terms of nuclear decays from the short lived {sup 78}Br and {sup 80}Br isotopes produced in (n,2n) reactions. The results presented in this paper are of relevance for the design of γ-ray detectors in burning plasma fusion experiments of the next generation, such as ITER, where capability to perform measurements in an intense 14 MeV neutron flux is required.

  4. Lead 207, 208 (n, xn gamma) reactions for neutron energies up to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Pavlik, A.; Vonach, H. [Univ. Wien (Austria). Inst. fuer Radiumforschung und Kernphysik; Chadwick, M.B.; Haight, R.C.; Nelson, R.O.; Wender, S.A.; Young, P.G. [Los Alamos National Lab., NM (United States)

    1994-07-01

    High-resolution {gamma}-ray spectra from the interaction of neutrons in the energy range from 3 to 200 MeV with {sup 207,208}Pb were measured with the white neutron source at the WNR facility at Los Alamos National Laboratory. From these data, excitation functions for prominent {gamma} transitions in {sup 200,202,204,206,207,208}Pb were derived from threshold to 200 MeV incident neutron energy. These {gamma}-production cross sections represent formation cross sections for excited states of the residual nuclei. The results are compared with the predictions of nuclear reaction calculations based on the exciton model for precompound emission, the Hauser-Feshbach theory for compound nuclear decay, and coupled channels calculations to account for direct excitation of collective levels. Good agreement was obtained over the entire energy range covered in the experiment with reasonable model parameters. The results demonstrate that multiple preequilibrium emission has to be taken into account above about 40 MeV, and that the level density model of Ignatyuk should be used instead of the Gilbert-Cameron and back-shifted Fermi-gas models if excitation energies exceed about 30 MeV.

  5. Stopping power of aluminium for 5-12 MeV protons and deuterons

    DEFF Research Database (Denmark)

    Andersen, H.H.; Garfinkel, A.F.; Hanke, C.C.;

    1966-01-01

    The stopping power of aluminium for 5-12 MeV protons and deuterons has been measured by a thermometric compensation technique working at liquid helium temperature. The experimental method is described and the standard deviation of the results is found to be 0.3%. In order to obtain this accuracy...

  6. Response of MEDEA BaF 2 detectors to 20-280 MeV photons

    Science.gov (United States)

    Bellia, G.; Alba, R.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Maiolino, C.; Migneco, E.; Piattelli, P.; Sapienza, P.; Frascaria, N.; Lhenry, I.; Roynette, J. C.; Suomijärvi, T.; Alamanos, N.; Auger, F.; Gillibert, A.; Pierroutsakou, D.; Sida, J. L.; Silveira Gomes, P. R.

    1993-05-01

    The response function of MEDEA BaF 2 crystals to high energy photons, up to 280 MeV, has been studied using monochromatic γ-rays from the in flight annihilation of positron beams. The experimental response functions are compared to the results of Monte Carlo simulations based on the EGS3 code and parametrized over the whole investigated energy range.

  7. POSITRON-ELECTRON DECAY OF SI-28, AT AN EXCITATION-ENERGY OF 50-MEV

    NARCIS (Netherlands)

    BUDA, A; BACELAR, JC; BALANDA, A; VANDERPLOEG, H; SUJKOWSKI, Z; VANDERWOUDE, A

    1993-01-01

    The electron-positron pair decay of Si-28 at 50 MeV excitation produced by the isospin T=0 (alpha + Mg-24) and the mixed isospin T=0,1 (He-3 + Mg-25) reactions has been studied using a special designed Positron-Electron pair spectrometer PEPSI.

  8. A study of proton-induced reactions at 190 MeV

    NARCIS (Netherlands)

    Mukherjee, B.; Bacelar, J.C.S; Beijers, J.P.M.; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Kis, M.; Löhner, H.; Mahjour Shafiei, M.

    2004-01-01

    Differential cross-sections and proton multiplicities, resulting from the bombardment of Fe-56, Pb-208, and U-238 targets by a 190 MeV proton beam were measured for the first time. Data were taken over two different angular ranges 5degrees-30degrees and 91degrees-160degrees with two different detect

  9. Nuclear data measurements for 40-90 MeV neutrons at TIARA

    Energy Technology Data Exchange (ETDEWEB)

    Baba, M. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center

    2000-03-01

    Experimental activities at the {sup 7}Li neutron source of TIARA, Japan Atomic Energy Research Institute, Takasaki Establishment are reviewed briefly. Experiments on (1) double-differential charged particle production cross sections for 40-90 MeV neutrons and protons, and (2) neutron elastic scattering and non-elastic cross sections are described as well as the frame of the research. (author)

  10. Design of a 10 MeV, 352.2 MHz drift tube Linac

    Indian Academy of Sciences (India)

    Nita S Kulkarni

    2012-08-01

    A conventional 10 MeV drift tube Linac is designed as a part of the - front end accelerator system for the future Indian Spallation Neutron Source. The front end Linac consists of a 50 keV H- ion source, low energy beam transport (LEBT), a 3 MeV radio frequency quadrupole (RFQ), and a 10 MeV drift tube Linac (DTL), which will be operated at 1.25% duty factor. Cell geometry of the DTL is optimized to house quadrupole magnets and to get maximum effective shunt impedance. Transmission efficiency and various other output parameters depend on the input design parameters. Beam dynamic studies are done to maximize the transmission efficiency with minimum emittance growth. Errors in the alignment of the quadrupoles inside the drift tubes or the DTL tank alignment with respect to transport line will degrade the beam quality and may reduce the transmission efficiency. Error study is performed to assess the acceptable tolerances on various parameters. This paper describes the 2D and 3D electromagnetic and beam dynamics simulations of the 352.2 MHz, 10 MeV drift tube Linac. Details of the DTL design are reported in this paper.

  11. Design of 7 MeV electron beams for breast radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jon In; Kim, Jung In; Kwon, Hyuck Jun [Interdisplinary Program in Radiation Applied Life Science, Seoul National University Graduate School, Seoul (Korea, Republic of); Ha, Sung Whan; Kim, Il Han [Dept. of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Hyun Suk; Ye, Sung Joon [Program in Biomedical Radiation Sciences, Dept. of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of)

    2013-04-15

    For treating early stage breast cancer, breast conserving therapy with lumpectomy followed by radiation therapy has been preferred as the standard method Irradiation technique consists of whole breast irradiation of 50.0 Gy and supplemental boost of 10 Gy to the tumor bed. The 'boost' to supplement the dose to the highest risk breast tissue around the lumpectomy following whole breast irradiation (WBI) improves in-breast local control. Electron beams have been favored radiation as boost irradiation. Because of limited depth in electron beams, it is possible to reduce the dose for unwished organ such as lung and heart in located in deeper region. Traditionally, electron beams can be modified using a bolus. The use of bolus conforms 90% isodose curve of a single energy electron beam to the distal edge of the target volume. However, it often increases the skin dose with electron beams of energy below 10 MeV. Therefore, with an aim to simultaneously control the penetration depth of the electron beams and the skin dose, we produced the new 7 MeV electron beam by modulating 9 MeV electron beams available in clinical linear accelerators. In this study, we show that the 7 MeV electron beam is appropriate for treatment of patient with a tumor bed located in clinical depth (R90 – R80)

  12. DPA damage analysis for 14-MeV neutrons on PFC materials

    Science.gov (United States)

    Kim, Dong-woo; Lee, Bo-young; Ko, Seung-kook; Kim, Hee-soo; Noh, Seung-jung

    2015-06-01

    The dpa (displacement per atom) damage for 14-MeV neutron in a pfc materials was simulated using MCNPX/SPECTER code. The dpa values in the main components of the structural material SS316L, Fe, Cr and Ni, were calculated to analyze the effect of nuclear damage. According to the neutron wall load for ITER design base, a neutron flux of 3.5 × 1013 neutrons/cm2·sec was applied. The simulated dpa values were found to be as 3.0 dpa/fpy for Fe, 2.9 dpa/fpy for Cr and 3.1 dpa/fpy for Ni. For practical experiments, the simulated dpa values due to the irradiation damage of 17-MeV protons were found to be as 0.67 dpa at the peak and 0.05 at the surface for SS316L using by SRIM code at the same fluence. For the 17-MeV proton irradiation, the Bragg peak appears at a 0.64-mm depth. Also, SS316L specimens irradiated by a 17-MeV proton beam with a fluence of 1016 protons/cm2 were analyzed by using transmission electron microscopy.

  13. The 270 MeV deuteron beam polarimeter at the Nuclotron Internal Target Station

    Energy Technology Data Exchange (ETDEWEB)

    Kurilkin, P.K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow State Institute of Radio-engineering Electronics and Automation (Technical University), Moscow (Russian Federation); Ladygin, V.P., E-mail: vladygin@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow State Institute of Radio-engineering Electronics and Automation (Technical University), Moscow (Russian Federation); Uesaka, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Suda, K. [RIKEN Nishina Center, Saitama (Japan); Gurchin, Yu.V.; Isupov, A.Yu. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Itoh, K. [Department of Physics, Saitama University, Saitama (Japan); Janek, M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Physics Department, University of Zilina, 010 26 Zilina (Slovakia); Karachuk, J.-T. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Advanced Research Institute for Electrical Engineering, Bucharest (Romania); Kawabata, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Khrenov, A.N.; Kiselev, A.S.; Kizka, V.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kliman, J. [Institute of Physics of Slovak Academy of Sciences, Bratislava (Slovakia); Krasnov, V.A.; Livanov, A.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Nuclear Research, Moscow (Russian Federation); Maeda, Y. [Kyushi University, Hakozaki (Japan); Malakhov, A.I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Matousek, V.; Morhach, M. [Institute of Physics of Slovak Academy of Sciences, Bratislava (Slovakia)

    2011-06-21

    A deuteron beam polarimeter has been constructed at the Internal Target Station at the Nuclotron of JINR. The polarimeter is based on spin-asymmetry measurements in the d-p elastic scattering at large angles and the deuteron kinetic energy of 270 MeV. It allows to measure vector and tensor components of the deuteron beam polarization simultaneously.

  14. Simulation and Field Measurement of Quadrupole Magnets for KOMAC 20MeV Beam line

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. H.; Kim, H. S.; Song, Y. G.; Kwon, H. J.; Cho, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, quadrupole magnets the same as installed at the beam line simulated and analyzed for magnetic fields. Also quadrupole magnets will be measured field stability and evaluated reliability on long time operation. Control system consisted of Labview program and communication method consisted of Ethernet and Rs-232 with optical fiber for devices safety from high voltage and/or high current. As a results the DC power supply is controlled, magnetic fields data is acquired and coil temperature is measured. Magnetic field with hall sensor and temperature with K-type thermo-couple are measured with conversion factor using by voltmeter. Korea Multi-purpose Accelerator Complex (KOMAC) was developed at Gyeongju in Korea in 2012. KOMAC including a 50-keV ion source, a 3-MeV RFQ, and a 100-MeV DTL. And beam line consists of 20-MeV and 100-MeV for user. Proton beam transferred from the linac to the beam line using by dipole magnets and transferred proton beam focused and decreased beam loss and by quadrupole magnets.

  15. The pilot experimental study of 14 MeV fast neutron digital radiography

    Institute of Scientific and Technical Information of China (English)

    TANG Bin; ZHOU ChangGen; HUO HeYong; WU Yang; LIU Bin; LOU BenChao; SUN Yong

    2009-01-01

    14 MeV Fast neutrons has good penetrability and the 14 MeV fast neutron radiography can meet the need of Non-Destructive Test of the structure and lacuna of heavy-massive sample,whose shell is made of heavy metal and in which there are some hydrogen materials,and the study of fast neutron digital radiography just begins in China.By the use of a D-T accelerator,a digital imaging system made up of a fast neutron scintillation screen made of ZnS(Ag) and polypropylene,lens and a scientific grade CCD,the experimental study of fast neutron radiography has been done between 4.3×1010-6.8×1010 n/s of neutron yield.Some 14 MeV fast neutron digital radiographs have been gotten.According to ex-perimental radiographs and their data,the performance of the fast neutron scintillation screen and the basic characters of 14 MeV fast neutron radiography are analyzed,and it is helpful for the further re-search.

  16. Integral cross sections for π+p scattering between 52 and 126 MeV

    Science.gov (United States)

    Friedman, E.; Goldring, A.; Wagner, G. J.; Altman, A.; Johnson, R. R.; Meirav, O.; Hanna, M.; Jennings, B. K.

    1989-11-01

    Integral cross sections for the elastic scattering of π+ on p from 20° and 30° to 180° were measured at seven energies between 52 and 126 MeV. These integrals are found to be in good agreement with predictions made with currently accepted phase shifts.

  17. Vector and tensor analyzing powers in deuteron-proton breakup at 130 MeV

    NARCIS (Netherlands)

    Stephan, E.; Kistryn, St.; Sworst, R.; Biegun, A.; Bodek, K.; Ciepal, I.; Deltuva, A.; Epelbaum, E.; Fonseca, A. C.; Golak, J.; Kalantar-Nayestanaki, N.; Kamada, H.; Kis, M.; Klos, B.; Kozela, A.; Mahjour-Shafiei, M.; Micherdzinska, A.; Nogga, A.; Skibinski, R.; Witala, H.; Wronska, A.; Zejma, J.; Zipper, W.

    2010-01-01

    High-precision data for vector and tensor analyzing powers for the (1)H((d) over right arrow, pp)n reaction at a 130-MeV deuteron beam energy have been measured over a large part of the phase space. Theoretical predictions based on various approaches to describe the three nucleon (3N) system reprodu

  18. Model independent optical potential for protons at 155 MeV

    Science.gov (United States)

    Brissaud, I.

    1981-06-01

    Using the model independent procedure, 155 MeV proton optical potentials are deduced from the elastic scattering data. The nuclear interior of these potentials are less attractative than predicted by a phenomenological potentials. A comparison is done with a self consistent meson model.

  19. I = 0 C = +1 mesons from 1920 to 2410 MeV

    CERN Document Server

    Anisovich, A V; Batty, C J; Bugg, D V; Hodd, C; Lu, H C; Nikonov, V A; Sarantsev, A V; Sarantsev, V V; Zou, B S; 10.1016/S0370-2693(00)01018-2

    2011-01-01

    A combined fit is presented to data on pbar-p annihilation in flight to final states eta-pizero-pizero, pizero-pizero, eta-eta, eta-etaprime and piminus-piplus. The emphasis lies in improving an earlier study of eta-pizero-pizero by fitting data at nine pbar momenta simultaneously and with parameters consistent with the two-body channels. There is evidence for all of the I=0, C=+ q-qbar states expected in this mass range. New resonances are reported with masses and widths M,Gamma as follows: JPC = 4^{-+} (2328+-38, Gamma=240+-90) MeV, 1^{++} (1971+-15, 240+-45) MeV, 0^{-+} (2285+-20, 325+-30) MeV, and 0^{-+} (2010 ^{+35}_{-60}, 270+-60) MeV. Errors on the masses and widths of other resonances are also reduced substantially. All states lie close to parallel straight line trajectories of excitation number v. mass squared.

  20. POSITRON-ELECTRON DECAY OF SI-28, AT AN EXCITATION-ENERGY OF 50-MEV

    NARCIS (Netherlands)

    BUDA, A; BACELAR, JC; BALANDA, A; VANDERPLOEG, H; SUJKOWSKI, Z; VANDERWOUDE, A

    1993-01-01

    The electron-positron pair decay of Si-28 at 50 MeV excitation produced by the isospin T=0 (alpha + Mg-24) and the mixed isospin T=0,1 (He-3 + Mg-25) reactions has been studied using a special designed Positron-Electron pair spectrometer PEPSI.

  1. Stopping powers for MeV Ge ions in Al foil

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Stopping powers for Ge ions (3.5MeV~8.0MeV) in Al foil were measured with RBS (Rutherford backscattering) technique and determined with a new method. Our results are much smaller than the values predicted by the TRIM code and LSS theory.

  2. Design of a 120 MeV $H^{-}$ Linac for CERN High-Intensity Applications

    CERN Document Server

    Gerigk, F

    2002-01-01

    The SPL (Superconducting Proton Linac) study at CERN foresees the construction of a 2.2 GeV linac as a high beam-power driver for applications such as a second-generation radioactive ion beam facility or a neutrino superbeam. At the same time such a high-performance injector would both modernize and improve the LHC injection chain. The 120 MeV normal-conducting section of the SPL could be used directly in a preliminary stage for H- charge-exchange injection into the PS Booster. This would increase the proton flux to the CERN experiments while also improving the quality and reliability of the beams for the LHC. The 120 MeV linac consists of a front-end, a conventional Drift Tube Linac (DTL) to 40 MeV and a Cell Coupled Drift Tube Linac (CCDTL) to the full energy. All the RF structures will operate at 352 MHz, using klystrons and RF equipment recovered from the LEP collider. This paper concentrates on the design of the 3 to 120 MeV section. It introduces the design criteria for high-stability beam optics and th...

  3. 22 MeV polarized proton scattering from 40Ca and effective NN interactions

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Analyzing powers and differential cross sections have been measured for elastic scattering of 22 MeV polarized protons from 40Ca, 16O and 12C, and diferential cross sections for inelastic scattering of 22 MeV protons from 3- (3.736 MeV)and 5-(4.491 MeV) states of 40Ca have also been measured. The experimental data for polarized proton elastic scattering have been analyzed with a phenomenological optical potential parameters, the experimental data and theoretical values are in good agreement. In the theoretical frame of microscopic single scattering model, transition densities extracted from electron inelastic scattering and M3Y and Halderson’s effective interactions have been utilized to analyze the experimental data of 22 MeV proton inelastic scattering from 40Ca. Overall, it seems that Halderson’s effective interaction can better describe the experimental data than M3Y although the degree of agreement between experimental and theoretical values needs to be improved.

  4. Defect microstructure in copper alloys irradiated with 750 MeV protons

    DEFF Research Database (Denmark)

    Zinkle, S.J.; Horsewell, A.; Singh, B.N.

    1994-01-01

    Transmission electron microscopy (TEM) disks of pure copper and solid solution copper alloys containing 5 at% of Al, Mn, or Ni were irradiated with 750 MeV protons to damage levels between 0.4 and 2 displacements per atom (dpa) at irradiation temperatures between 60 and 200 degrees C. The defect ...

  5. SPIN-ISOSPIN EXCITATIONS IN NUCLEI VIA (HE-3,T) REACTIONS AT 450 MEV

    NARCIS (Netherlands)

    FUJIWARA, M; AKIMUNE, H; DAITO, [No Value; EJIRI, H; FUJITA, Y; GREENFIELD, MB; HARAKEH, MN; HAZAMA, R; INOMATA, T; JANECKE, J; KUDOMI, N; KUME, K; NAKAYAMA, S; SHINMYO, K; TAMII, A; TANAKA, M; TOYOKAWA, H; YOSOI, M

    1994-01-01

    Spin-isospin excitations in nuclei havee been studied by means of the (He-3, t) reactions at 450 MeV. The Gamow-Teller (GT) resonances are found to be strongly excited. A fine structure of the giant Gamow Teller resonances in medium-heavy nuclei is observed with an energy resolution of 130 keV. The

  6. Measurement of 181 MeV H- ions stripping cross-sections by carbon stripper foil

    Science.gov (United States)

    Saha, P. K.; Yoshimoto, M.; Yamazaki, Y.; Hotchi, H.; Harada, H.; Okabe, K.; Kinsho, M.; Irie, Y.

    2015-03-01

    The stripping cross-sections of 181 MeV H- (negative hydrogen) ions by the carbon stripper foil are measured with good accuracy. The present experiment was carried out at the 3-GeV RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex). The stripping cross-sections for different charge states, also known as electron loss cross-sections of H- ion, are denoted as σ-11, σ-10 and σ01, for both electrons stripping (H- →H+), one-electron stripping (H- →H0) and the 2nd-electron stripping (H0 →H+) proceeding σ-10, respectively. We have established very unique and precise techniques for such measurements so as also to determine a foil stripping efficiency very accurately. The cross-sections σ-11, σ-10 and σ01 are obtained to be (0.002 ± 0.001) ×10-18cm2, (1.580 ± 0.034) ×10-18cm2 and (0.648 ± 0.014) ×10-18cm2, respectively. The presently given cross-sections are newly available experimental results for an incident H- energy below 200 MeV and they are also shown to be consistent with recently proposed energy (1 /β2) scaled cross-sections calculated from the previously measured data at 200 and 800 MeV. The present results have a great importance not only at J-PARC for the upgraded H- beam energy of 400 MeV but also for many new and upgrading similar accelerators, where H- beam energies in most cases are considered to be lower than 200 MeV.

  7. Total and differential cross sections of the reaction p + d -> 3He + eta at 48.8 MeV and 59.8MeV excess energy

    CERN Document Server

    Adlarson, P; Bardan, W; Bashkanov, M; Bergmann, F S; Berłowski, M; Bhatt, H; Büscher, M; Calén, H; Ciepał, I; Clement, H; Coderre, D; Czerwiński, E; Demmich, K; Doroshkevich, E; Engels, R; Erven, A; Erven, W; Eyrich, W; Fedorets, P; Föhl, K; Fransson, K; Goldenbaum, F; Goslawski, P; Goswami, A; Grigoryev, K; Gullström, C --O; Hauenstein, F; Heijkenskjöld, L; Hejny, V; Hodana, M; Höistad, B; Hüsken, N; Jany, A; Jany, B R; Jarczyk, L; Johansson, T; Kamys, B; Kemmerling, G; Khan, F A; Khoukaz, A; Kirillov, D A; Kistryn, S; Kłos, B; Kleines, H; Krapp, M; Krzemień, W; Kulessa, P; Kupść, A; Lalwani, K; Lersch, D; Lorentz, B; Magiera, A; Maier, R; Marciniewski, P; Mariański, B; Mikirtychiants, M; Morsch, H --P; Moskal, P; Ohm, H; Ozerianska, I; Passfeld, A; del Rio, E Perez; Piskunov, N M; Podkopał, P; Prasuhn, D; Pricking, A; Pszczel, D; Pysz, K; Pyszniak, A; Redmer, C F; Ritman, J; Roy, A; Rudy, Z; Sawant, S; Schadmand, S; Sefzick, T; Serdyuk, V; Siudak, R; Skorodko, T; Skurzok, M; Smyrski, J; Sopov, V; Stassen, R; Stepaniak, J; Stephan, E; Sterzenbach, G; Stockhorst, H; Ströher, H; Szczurek, A; Täschner, A; Trzciński, A; Varma, R; Wagner, G J; Węglorz, W; Wolke, M; Wrońska, A; Wüstner, P; Wurm, P; Yamamoto, A; Yurev, L; Zabierowski, J; Zieliński, M J; Zink, A; Złomańczuk, J; Żuprański, P; Żurek, M

    2014-01-01

    We present new data for the cross section ratio of the p + d -> 3He + eta reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum J\\"ulich) using a proton beam and a deuterium pellet target. By using an ANKE data point at 59.4 MeV excess energy, an absolute normalization was performed and total and differential cross sections have been determined. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.

  8. Neutron-induced fission cross sections of 233U and 243Am in the energy range 0.5 Mev En 20 MeV @ n_TOF

    CERN Document Server

    Belloni, F; Milazzo, P M; Calviani, M; Colonna, N; Mastinu, P; Abbondanno, U; Aerts, G; Álvarez, H; Álvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvár, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Koehler, P; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vazl, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross-sections of actinides have been recently measured at the neutron time of flight facility n_TOF at CERN in the frame of a research project involving isotopes relevant for nuclear astrophysics and nuclear technologies. Fission fragments are detected by a gas counter with good discrimination between nuclear fission products and background events. Neutron-induced fission cross-sections of 233U and 243Am were determined relative to 235U. The present paper reports the results obtained at neutron energies between 0.5 and 20 MeV.

  9. 10. 23 MeV M1 transition in the /sup 48/Ca(p,p ') /sup 48/Ca/sup / reaction at 319 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nanda, S.K.; Glashausser, C.; Jones, K.W.; McGill, J.A.; Carey, T.A.; McClelland, J.B.; Moss, J.M.; Seestrom-Morris, S.J.; Comfort, J.R.; Levenson, S.

    1984-02-01

    The cross section, analyzing power, and spin-flip probability have been measured for the M1 transition at 10.23 MeV excitation energy in the /sup 48/Ca(p,p') /sup 48/Ca /sup 48/Ca(p,p') /sup 48/Ca agreement with distorted-wave impulse approximation calculations; about 28% of the pure single particle (..nu..f/sub 7/2/ /sup -1/,f/sub 5/2/)M1 strength is observed. The results serve as a good calibration of results expected in heavy nuclei.

  10. Newly developed semi-empirical formulas for (, ) at 17.9 MeV and (, ) at 22.3 MeV reaction cross-sections

    Indian Academy of Sciences (India)

    Eyyup Tel; Abdullah Aydin; E Gamze Aydin; Abdullah Kaplan; Ömer Yavaş; İskender A Reyhancan

    2010-06-01

    In this study, we have investigated the asymmetry term effect for the (, ) and (, ) reaction cross-sections and obtained new coefficients for the (, ) and (, ) reaction cross-sections at 17.9 and 22.3 MeV energies. We have suggested semi-empirical formulas including the non-elastic effects of optical model found by fitting two parameters for proton-induced reactions. The coefficients were determined by least-square fitting method. The obtained cross-section formulas with new coefficients have been discussed and compared with the available experimental data.

  11. Fissility of actinide nuclei induced by 60-130 MeV photons; Fissionabilidade de nucleos actnideos induzida por fotons de energia 60-130 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Morcelle, Viviane; Tavares, Odilon A.P

    2004-06-15

    Nuclear fissilities obtained from recent photofission reaction cross section measurements carried out at Saskatchewan Accelerator Laboratory (Saskatoon, Canada) in the energy range 60-130 MeV for {sup 232} Th, {sup 233} U, {sup 235} U, {sup 238} U, and {sup 237} Np nuclei have been analysed in a systematic way. To this aim, a semiempirical approach has been developed based on the quasi-deuteron nuclear photoabsorption model followed by the process of competition between neutron evaporation and fission for the excited nucleus. The study reproduces satisfactorily well the increasing trend of nuclear fissility with parameter Z{sup 2}=A. (author)

  12. Stopping Power of Al, Cu, Ag, Au, Pb, and U for 5-18-MeV Protons and Deuterons

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, Hans Henrik

    1973-01-01

    High energy protons and deuterons of energies between 9 and 18 MeV have been used to extend earlier measurements of the stopping power of Al, Cu, Ag and Au and the stopping powers of Pb and U in the range 5-18 MeV have been determined for the first time. Mean excitation potentials have been...

  13. THE FE-54,FE-56)(N, P) MN-54,MN-56 REACTIONS AT E(N)=97 MEV

    NARCIS (Netherlands)

    RONNQVIST, T; CONDE, H; OLSSON, N; RAMSTROM, E; ZORRO, R; BLOMGREN, J; HAKANSSON, A; RINGBOM, A; TIBELL, G; JONSSON, O; NILSSON, L; RENBERG, PU; VANDERWERF, SY; UNKELBACH, W; BRADY, FP

    1993-01-01

    Double-differential cross sections of the Fe-54,Fe-56(n, p) reactions have been measured at 97 MeV in the angular range 0-30-degrees for excitation energies up to 40 MeV. The spectra have been decomposed into different multipolarities by a technique based on the use of sample angular distributions

  14. Total reaction cross sections for 20-30 MeV pions and the anomaly of pionic atoms

    Science.gov (United States)

    Friedman, E.; Goldring, A.; Johnson, R. R.; Meirav, O.; Vetterli, D.; Weber, P.; Altman, A.

    1991-03-01

    Total reaction cross sections of 20 MeV π- and 30 MeV π+ and π- have been measured for carbon and nickel targets. The experimental results are in very good agreement with calculations based on commonly accepted pion-nucleus potentials but disagree with calculations based on the potentials associated with the so-called pionic atom anomaly.

  15. Single Particle Strengths and Mirror States in $^{15}$N$-^{15}$O below 12.0 MeV

    CERN Document Server

    Mertin, C E; Crisp, A M; Keeley, N; Kemper, K W; Momtyuk, O; Roeder, B T; Volya, A

    2014-01-01

    New $^{14}$N(d,p) angular distribution data were taken at a deuteron bombarding energy of 16 MeV to locate all narrow single particle neutron states up to 15 MeV in excitation. A new shell model calculation is able to reproduce all levels in $^{15}$N up to 11.5 MeV and is used to characterize a narrow single particle level at 11.236 MeV and to provide a map of the single particle strengths. The known levels in $^{15}$N are then used to determine their mirrors in the lesser known nucleus $^{15}$O. The 2s$_{1/2}$ and 1d$_{5/2}$ single particle centroid energies are determined for the $^{15}$N$-^{15}$O mirror pair as: $^{15}$N $(\\text{2s}_{1/2}) = 8.08$ MeV, $^{15}$O $(\\text{2s}_{1/2}) = 7.43$ MeV, $^{15}$N $(\\text{1d}_{5/2}) = 7.97$ MeV, and $^{15}$O $(\\text{1d}_{5/2}) = 7.47$ MeV. These results confirm the degeneracy of these orbits and that the $^{15}$N$-^{15}$O nuclei are where the transition between the $\\text{2s}_{1/2}$ lying below the $\\text{1d}_{5/2}$ to lying above it, takes place. The $\\text{1d}_{3/2}$...

  16. A Radar Emitter Recognition Method Based on the PRI Switching Rules%一种基于PRI变化规律的雷达辐射源识别方法

    Institute of Scientific and Technical Information of China (English)

    关一夫; 张国毅; 王晓峰

    2015-01-01

    针对相控阵雷达中某些具有复杂PRI调制样式的工作模式难以准确识别的问题,提出一种通过提取PRI序列变化规律来进行辐射源识别的方法。该方法借鉴了脉冲样本图的模型以及生物信息学中基因序列比对的动态规划思想,较好地解决了某些复杂PRI调制样式不好描述,以及相控阵雷达中一个完整工作模式包含脉冲序列长度太短,以致很难通过统计的方法对其进行准确识别的问题。仿真结果表明该算法的有效性,而且在存在脉冲丢失和干扰脉冲的情况下具有稳健性。%Focusing on the problem that phased-array radar has some modes with complex PRI modulation patterns are difficult to accurately identify,this paper proposes a recognition method by extracting the switching rules of the PRI sequence. This method draws on the pulse template model and the dynamic programming theory of bioinformatics in gene sequence alignment,having solved the difficulty in describing some complex PRI modulation pattern and those for statistical methods in recognizing phased-array radars with mode includes a complete sequence of pulses with very short length. Simulation results show the effectiveness of the algorithm and its robustness even in the presence of interference pulses and missing pulses.

  17. Response of AGATA Segmented HPGe Detectors to Gamma Rays up to 15.1 MeV

    CERN Document Server

    Crespi, F C L; Camera, F; Akkoyun, S; Atac, A; Bazzacco, D; Bellato, M; Benzoni, G; Blasi, N; Bortolato, D; Bottoni, S; Bracco, A; Brambilla, S; Bruyneel, B; Cerutia, S; Ciemala, M; Coelli, S; Eberth, J; Fanin, C; Farnea, E; Gadea, A; Giaz, A; Gottardo, A; Hess, H; Kmiecik, M; Leoni, S; Maj, A; Mengoni, D; Michelagnoli, C; Million, B; Montanari, D; Pellegri, L; Recchia, F; Reiter, P; Riboldi, S; Ur, C A; Vandone, V; Valiente-Dobon, J J; Wieland, O; Wiens, A

    2012-01-01

    The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(11B,ng)12C at Ebeam = 19.1 MeV, while gamma-rays between 2 to 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%. Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation following neutron capture by Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape Analysis, is discussed.

  18. Support Group for Parents Coping with Children with Type 1 Diabetes / Skupina Za Starše Kot Podpora Družinam Pri Soočanju Z Otrokovo Sladkorno Boleznijo Tipa 1

    Directory of Open Access Journals (Sweden)

    Pate Tanja

    2015-03-01

    Full Text Available Izhodišče. Sladkorna bolezen tipa 1 je ena izmed pogostejših kroničnih bolezni v otroštvu. Optimalno vodenje in presnovna urejenost otrokove sladkorne bolezni sta povezana z aktivno vključenostjo staršev/ skrbnikov, podporo otroku pri nadzoru nad boleznijo in funkcionalnostjo družine. Raziskava predstavlja oceno zadovoljstva staršev s programom skupine za starše in njihovo doživljanje vpliva omenjenega programa na življenje otroka in spoprijemanje z njegovo SBT1.

  19. Displacement cross sections and PKA spectra: tables and applications. [Neutron damage energy cross sections to 20 MeV, primary knockon atom spectra to 15 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Doran, D G; Graves, N J

    1976-12-01

    Damage energy cross sections to 20 MeV are given for aluminum, vanadium, chromium, iron, nickel, copper, zirconium, niobium, molybdenum, tantalum, tungsten, lead, and 18Cr10Ni stainless steel. They are based on ENDF/B-IV nuclear data and the Lindhard energy partition model. Primary knockon atom (PKA) spectra are given for aluminum, iron, niobium, tantalum, and lead for neutron energies up to 15 MeV at approximately one-quarter lethargy intervals. The contributions of various reactions to both the displacement cross sections (taken to be proportional to the damage energy cross sections) and the PKA spectra are presented graphically. Spectral-averaged values of the displacement cross sections are given for several spectra, including approximate maps for the Experimental Breeder Reactor-II (EBR-II) and several positions in the Fast Test Reactor (FTR). Flux values are included to permit estimation of displacement rates. Graphs show integral PKA spectra for the five metals listed above for neutron spectra corresponding to locations in the EBR-II, the High Flux Isotope Reactor (HFIR), and a conceptual fusion reactor (UWMAK-I). Detailed calculations are given only for cases not previously documented. Uncertainty estimates are included.

  20. An analysis of 100 MeV F 8+ ion and 50 MeV Li 3+ ion irradiation effects on silicon NPN rf power transistors

    Science.gov (United States)

    Pushpa, N.; Praveen, K. C.; Gnana Prakash, A. P.; Prabhakara Rao, Y. P.; Tripati, Ambuj; Revannasiddaiah, D.

    2010-08-01

    The dc characteristics exhibited by NPN power transistors are studied systematically before and after irradiation by 100 MeV F 8+ ions and 50 MeV Li 3+ ions in the dose range of 100 krad to 100 Mrad. The transistor parameters such as excess base current (Δ IB= IBpost- IBpre), dc current gain ( hFE), transconductance ( gm), and collector-saturation current ( ICsat) were studied before and after irradiation. The damage factors ( k) for hFE were calculated for ion irradiated transistors using Messenger-Spratt relation. The base current ( IB) was found to increase significantly after ion irradiation and this in turn decreases the hFE of the transistors. The gm decreases significantly after ion irradiation. Moreover, the output characteristics of irradiated devices also show that the collector current ( IC) in the saturation region ( ICsat) decrease with increase in ion dose. The observed change in these characteristics may be due to the ion induced generation-recombination (G-R) centers in emitter-base (E-B) spacer oxide and the ion induced point defects and their complexes in the transistor structure.

  1. Radiation effects on silicon bipolar transistors caused by 3-10 MeV protons and 20-60 MeV bromine ions

    Science.gov (United States)

    Li, Xingji; Geng, Hongbin; Lan, Mujie; Liu, Chaoming; Yang, Dezhuang; He, Shiyu

    2010-03-01

    The current gain degradation in silicon NPN bipolar junction transistors (BJTs) was examined under irradiation with 3-10 MeV protons and 20-60 MeV bromine (Br) ions with various dose levels. To characterize the radiation damage of the NPN BJTs, the ionizing dose D i and displacement dose D d as a function of chip depth in the NPN BJTs were calculated for both the protons and Br ions with different energies. Based on the irradiation testing and calculated results, it is shown that the current gain degradation of NPN BJTs is sensitive to the ratio of D d/( D d+ D i) in the sensitive region given by protons and Br ions. The irradiation particles (protons and Br ions), which give larger D d/( D d+ D i) at a given total dose, would generate more severe damage to the NPN BJTs. The reciprocal of the gain variation as a function of the displacement dose was compared, showing that the Messenger-Spratt equation becomes relevant to describe the experimental data, when the ratio of the D d/( D d+ D i) are larger and the displacement dose are higher than a certain value.

  2. Elastic and inelastic scattering of {sup 14}N ions by {sup 7}Li at 80 MeV (c.m. 26.7 MeV)

    Energy Technology Data Exchange (ETDEWEB)

    Rudchik, A.T.; Herashchenko, O.V.; Rudchik, A.A.; Mezhevych, S.Yu.; Mokhnach, A.V.; Pirnak, V.M.; Ponkratenko, O.A.; Ilyin, A.P.; Uleshchenko, V.V. [Institute for Nuclear Research, Kyiv (Ukraine); Kemper, K.W. [Florida State University, Physics Department, Tallahassee, Florida (United States); Rusek, K. [National Institute for Nuclear Research, Warsaw (Poland); Heavy Ion Laboratory of Warsaw University, Warsaw (Poland); Koshchy, E.I. [Kharkiv National University, Kharkiv (Ukraine); Kliczewski, S.; Siudak, R.; Szczurek, A. [H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland); Plujko, V.A. [Taras Shevchenko Kyiv National University, Kyiv (Ukraine); Choinski, J. [Heavy Ion Laboratory of Warsaw University, Warsaw (Poland); Stolarz, A. [National Institute for Nuclear Research, Warsaw (Poland)

    2014-10-15

    New angular distribution data for {sup 7}Li + {sup 14}N elastic and inelastic scattering at the energy E{sub lab} ({sup 14}N) = 80 MeV (c.m. 26.7MeV) are presented. The data were analyzed within the optical model and the coupled-reaction-channels method using a channels-coupling scheme that included the {sup 7}Li and {sup 14}N inelastic scattering channels, spin reorientations of {sup 7}Li and {sup 14}N as well as most important transfer reactions. The low-energy excited states of {sup 7}Li and {sup 14}N were assumed to be collective in nature. The {sup 7}Li + {sup 14}N potential parameters as well as deformation parameters of {sup 7}Li and {sup 14}N were deduced. The {sup 7}Li + {sup 14}N potential and the data were compared with those of {sup 6}Li + {sup 14}N to observe isotopic differences. The enhanced large-angle elastic and inelastic scattering data are shown to have a large contribution from the ground-state reorientation of {sup 7}Li. (orig.)

  3. The 13C(n,α0)10Be cross section at 14.3 MeV and 17 MeV neutron energy

    Science.gov (United States)

    Kavrigin, P.; Belloni, F.; Frais-Koelbl, H.; Griesmayer, E.; Plompen, A. J. M.; Schillebeeckx, P.; Weiss, C.

    2017-09-01

    At nuclear fusion reactors, CVD diamond detectors are considered an advantageous solution for neutron flux monitoring. For such applications the knowledge of the cross section of neutron-induced nuclear reactions on natural carbon are of high importance. Especially the (n,α0) reactions, yielding the highest energy reaction products, are of relevance as they can be clearly distinguished in the spectrum. The 13C(n,α0)10Be cross section was measured relative to 12C(n,α0)9Be at the Van de Graaff facility of EC-JRC Geel, Belgium, at 14.3 MeV and 17.0 MeV neutron energies. The measurement was performed with an sCVD (single-crystal Chemical Vapor Deposition) diamond detector, where the detector material acted simultaneously as sample and as sensor. A novel data analysis technique, based on pulse-shape discrimination, allowed an efficient reduction of background events. The results of the measurement are presented and compared to previously published values for this cross-section.

  4. Simulation study of neutron production in thick beryllium targets by 35 MeV and 50.5 MeV proton beams

    Science.gov (United States)

    Shin, Jae Won; Park, Tae-Sun

    2017-09-01

    A data-driven nuclear model dedicated to an accurate description of neutron productions in beryllium targets bombarded by proton beams is developed as a custom development that can be used as an add-on to GEANT4 code. The developed model, G4Data(Endf7.1), takes as inputs the total and differential cross section data of ENDF/B-VII.1 for not only the charge-exchange 9Be(p,n)9B reaction which produces discrete neutrons but also the nuclear reactions relevant for the production of continuum neutrons such as 9Be(p,pn)8Be and 9Be(p,n α) 5Li . In our benchmarking simulations for two experiments with 35 MeV and 50.5 MeV proton beams impinged on 1.16 and 1.05 cm thick beryllium targets, respectively, we find that the G4Data(Endf7.1) model can reproduce both the total amounts and the spectral shapes of the measured neutron yield data in a satisfactory manner, while all the considered hadronic models of GEANT4 cannot.

  5. M-shell electron capture and direct ionization of gold by 25-MeV carbon and 32-MeV oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, M.C.; McDaniel, F.D.; Duggan, J.L.; Miller, P.D.; Pepmiller, P.L.; Krause, H.; Rosseel, T.; Rayburn, L.A.; Mehta, R.; Lapicki, G.

    1984-01-01

    M-shell x-ray production cross sections have been measured for thin solid targets of Au for 25 MeV /sup 12/C/sup q+/ (q = 4, 5, 6) and for 32 MeV /sup 16/O/sup q+/ (q = 5, 7, 8). The microscopic cross sections were determined from measurements made with targets ranging in thickness from 0.5 to 100 ..mu..g/cm/sup 2/. For projectiles with one or two K-shell vacancies, the M-shell x-ray production cross sections are found to be enhanced over those by projectiles without a K-shell vacancy. The sum of direct ionization to the continuum (DI) and electron capture (EC) to the L, M, N ... shells and EC to the K-shell of the projectile have been extracted from the data. The results are compared to the predictions of first Born theories i.e. PWBA for DI and OBK of Nikolaev for EC and the ECPSSR approach that accounts for energy loss, Coulomb deflection and relativistic effects in the perturbed stationary state theory. 25 references, 3 figures, 1 table.

  6. Isolation and Identification of Pathogenic Mink Enteritis Virus MEV-ZJ1 Strain%致病性水貂肠炎病毒MEV-ZJ1株的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    谭斌; 陈微晶; 武华

    2011-01-01

    自临床疑似水貂病毒性肠炎发病貂的粪便中分离出1株病毒,经病毒形态观察、理化特性检测、血清学、聚合酶链式反应(PCR)和动物试验鉴定表明,该分离毒为水貂肠炎病毒(mink enteritis virus,MEV),命名为MEV-ZJ1株.用分离毒接种水貂,试验动物均表现出典型水貂病毒性肠炎临床症状.研究表明,MEV-ZJ1分离株对水貂具有致病性,是1株强毒,为进一步开展该病毒流行病学、致病机理、疫苗免疫与诊断检测的研究奠定了基础.%A virus strain was isolated from feces of a mink suspected MEV infection. It was demonstrated to be MEV by morphology, physical and chemical properties, serum test, PCR and animal test,and it was named MEV-ZJ1. Minks were artificially infected by MEV-ZJ1 developed obvious symptoms of enteritis post-inoculation. The MEV-ZJ1 strain was virulent for minks. The successful isolation of MEV-ZJ1 provided a basis for further search on epidemiology, pathogenesis, vaccination and diagnostic.

  7. Pri-Mir-34b/C and Tp-53 Polymorphisms are Associated With The Susceptibility of Papillary Thyroid Carcinoma: A Case-Control Study.

    Science.gov (United States)

    Chen, Peng; Sun, Ruifen; Pu, Yan; Bai, Peng; Yuan, Fang; Liang, Yundan; Zhou, Bin; Wang, Yanyun; Sun, Yinghe; Zhu, Jingqiang; Zhang, Lin; Gao, Linbo

    2015-09-01

    Tumor suppressor p53 directly regulated the abundance of the miR-34b/c. The interaction might contribute to certain cancer. We hypothesized that rs4938723 in the promoter region of pri-miR-34b/c and TP-53 Arg72Pro may be related to the risk of papillary thyroid carcinoma (PTC). A total of 784 patients with PTC and 1006 healthy controls were recruited to participate in this study. The variants were discriminated using a polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). Additionally, the relative expression levels of miR-34b/c and TP-53 in 44 paired samples were revealed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). A significantly increased risk of PTC was observed in the miR-34b/c rs4938723 CT, CC, and CT/CC genotypes compared with the TT genotype (CT vs TT: adjusted odds ratio [OR] = 1.51, 95%confidence interval [CI] = 1.23-1.85; CC vs TT: adjusted OR = 1.89, 95%CI = 1.39-2.63; CT/CC vs TT: adjusted OR = 1.59, 95%CI = 1.30-1.92, respectively). Significantly increased PTC susceptibility was also associated with the TP-53 Arg72Pro CC and CG/CC genotypes compared with the GG genotype (CC vs GG: adjusted OR = 2.04, 95%CI = 1.54-2.70; CG/CC vs GG: adjusted OR = 1.35, 95%CI = 1.11-1.67, respectively). Stratification analysis revealed that patients carrying the TP-53 Arg72Pro C allele and CC genotype had a significantly increased risk for developing N1 (C vs. G: OR = 1.27, 95%CI = 1.03-1.56; CC vs. GG: OR = 1.62, 95%CI = 1.07-2.46, respectively). Combined analysis showed that the genotypes of rs4938723 CT/CC + TP-53CG/CC increased the risk of PTC compared with rs4938723TT + TP-53GG (OR = 2.25, 95%CI = 1.67-3.03). Additionally, level of miR-34b was significantly upregulated in PTC patients.These findings indicate that the miR-34b/c rs4938723 and TP-53 Arg72Pro polymorphisms may contribute to the susceptibility of PTC.

  8. Designing of the 14 MeV neutron moderator for BNCT

    Institute of Scientific and Technical Information of China (English)

    CHENG Dao-Wen; LU Jing-Bin; YANG Dong; LIU Yu-Min; WANG Hui-Dong; MA Ke-Yan

    2012-01-01

    In boron neutron capture therapy (BNCT),the ratio of the fast neutron flux to the neutron flux in the tumor (RFNT) must be less than 3%.If a D-T neutron generator is used in BNCT,the 14 MeV neutron moderator must be optimized to reduce the RFNT.Based on the neutron moderation theory and the simulation results,tungsten,lead and diamond were used to moderate the 14 MeV neutrons.Satisfying RFNT of less than 3%,the maximum neutron flux in the tumor was achieved with a three-layer moderator comprised of a 3 cm thick tungsten layer,a 14 cm thick lead layer and a 21 cm thick diamond layer.

  9. Design and Construction of the 3.2 Mev High Voltage Column for Darht II

    CERN Document Server

    Peters, C; Yu, S; Eylon, S; Henestroza, E

    2000-01-01

    A 3.2 MeV injector has been designed and built for the Darht II Project at Los Alamos Lab. The installation of the complete injector system is nearing completion at this time. The requirements for the injector are to produce a 3.2 MeV, 2000 ampere electron pulse with a flattop width of at least 2-microseconds and emittance of less than 0.15 p cm-rad normalized. A large high voltage column has been built and installed. The column is vertically oriented, is 4.4 meters long, 1.2 meters in diameter, and weights 5700 kilograms. A novel method of construction has been employed which utilizes bonded mycalex insulating rings. This paper will describe the design, construction, and testing completed during construction. Mechanical aspects of the design will be emphasized.

  10. Structural damage in InGaN induced by MeV heavy ion irradiation

    Science.gov (United States)

    Zhang, L. M.; Fadanelli, R. C.; Hu, P.; Zhao, J. T.; Wang, T. S.; Zhang, C. H.

    2015-08-01

    In0.18Ga0.82N films were irradiated with 4 MeV 84Kr and 8.9 MeV 209Bi ions to various fluences at room temperature. The irradiated films were analyzed by means of Rutherford backscattering/channeling (RBS/C) and high resolution X-ray diffraction (HRXRD). The RBS/C measurements show that under the irradiation conditions, the relative lattice disorder in the films, obtained from the normalized backscattering yield, exhibits a rapid increase in the range from ∼2% to 68%. There is also an increasing lattice expansion of the films with increasing ion fluence, as determined by the HRXRD measurements. At a comparable level of lattice disorder, the Kr irradiation leads to a more pronounced lattice expansion than the Bi irradiation. This may be attributed to a larger portion of the single interstitials in the films produced by the lighter Kr ion irradiation.

  11. Photoluminescence study of 1018 meV defect lines from ion-implanted silicon

    CERN Document Server

    Lee, H S; Seong, E Z; Kim, S M; Lim, H J

    1999-01-01

    We investigated the defects of ion-implanted silicon with boron and argon ions using photoluminescence method. The 1018 meV line, so called I sub 1 line, and its phonon side bands were observed in both boron- and argon-implanted silicon crystals. In argon-implanted silicon crystals, we observed 1009 meV line (I sub r - Ar) and its phonon side bands which arose from argon-I sub 1 complex in addition to the splitting of the I sub 1 line. Annealing temperature dependence of the intensities of the I sub 1 and I sub 1 -Ar lines in argon-implanted silicon was very similar for both Czochralski and float zone silicon crystals whereas that of boron-implanted silicon was very different between the two growing methods. We discussed on the origin of the defects responsible for the I sub 1 and I sub 1 - Ar lines.

  12. Cross sections from proton irradiation of thorium at 800 MeV

    CERN Document Server

    Engle, Jonathan W; Weidner, John W; Wolfsberg, Laura E; Fassbender, Michael E; Jackman, Kevin; Couture, Aaron; Bitteker, Leo J; Ullmann, John L; Gulley, Mark S; Pillai, Chandra; John, Kevin D; Birnbaum, Eva R; Nortier, Francois M

    2013-01-01

    Nuclear formation cross sections are reported for 65 nuclides produced from 800-MeV proton irradiation of thorium foils. These data are useful as benchmarks for computational predictions in the ongoing process of theoretical code development and also to the design of spallation-based radioisotope production currently being considered for multiple radiotherapeutic pharmaceutical agents. Measured data are compared with the predictions of three MCNP6 event generators and used to evaluate the potential for 800-MeV productions of radioisotopes of interest for medical radiotherapy. In only a few instances code predictions are discrepant from measured values by more than a factor of two, demonstrating satisfactory predictive power across a large mass range. Similarly, agreement between measurements presented here and those previously reported is good, lending credibility to predictions of target yields and radioimpurities for high-energy accelerator-produced radionuclides.

  13. Cross sections from 800 MeV proton irradiation of terbium

    Energy Technology Data Exchange (ETDEWEB)

    Engle, J.W., E-mail: jwengle@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mashnik, S.G.; Bach, H.; Couture, A.; Jackman, K.; Gritzo, R.; Ballard, B.D.; Fassbender, M.; Smith, D.M.; Bitteker, L.J.; Ullmann, J.L.; Gulley, M.S.; Pillai, C.; John, K.D.; Birnbaum, E.R. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Nortier, F.M., E-mail: meiring@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-11-02

    Terbium foils were irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 35 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini and INCL + ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  14. A novel way of constraining WIMPs annihilations in the Sun: MeV neutrinos

    CERN Document Server

    Bernal, Nicolas; Palomares-Ruiz, Sergio

    2012-01-01

    Annihilation of dark matter particles accumulated in the Sun would produce a flux of high-energy neutrinos whose prospects of detection in neutrino telescopes and detectors have been extensively discussed in the literature. However, for many channels into Standard Model particles, there would also be a flux of neutrinos in the MeV range from the decays at rest of muons and positively charged pions. These low-energy neutrinos have never been considered before and they open the possibility to also constrain dark matter annihilation in the Sun into e+e-, mu+mu- or light quarks. Here we perform a detailed analysis using the recent Super-Kamiokande data in the few tens of MeV range to set limits on the WIMP-nucleon scattering cross section for different annihilation channels.

  15. The optimization for the conceptual design of a 300 MeV proton synchrotron

    CERN Document Server

    An, Yuwen; Wang, Sheng; Huang, Liangsheng

    2016-01-01

    A research complex for aerospace radiation effects research has been proposed in Harbin Institute of Technology. Its core part is a proton accelerator complex, which consists of a 10 MeV injector, a 300 MeV synchrotron and beam transport lines. The proton beam extracted from the synchrotron is utilized for the radiation effects research. Based on the conceptual design [1], the design study for optimizing the synchrotron has been done. A new lattice design was worked out, and the multi-turn injection and slow extraction system were optimized with the new lattice design. In order to improve the time structure of the extracted beam, a RF knock-out method is employed. To meet the requirement of accurate control of dose, the frequency of the RF kicker is well investigated.

  16. Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

    CERN Document Server

    Webb, Timothy; Beezhold, Wendland; De Veaux, Linda C; Harmon, Frank; Petrisko, Jill E; Spaulding, Randy

    2005-01-01

    An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.

  17. Polarization transfer for inclusive proton-nucleus inelastic scattering at 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Fergerson, R.; McGill, J.; Glashausser, C.; Jones, K.; Nanda, S.; Sun Zuxun; Barlett, M.; Hoffmann, G.; Marshall, J.; McClelland, J.; and others

    1988-11-01

    The polarization-transfer observables D/sub N//sub N/, D/sub S//sub S/, D/sub L//sub L/, D/sub L//sub S/, and D/sub S//sub L/ have been measured at 800 MeV for polarized proton inelastic scattering from /sup 1/H, /sup 2/H, and /sup 12/C with energy losses up to about 400 MeV. The scattering angles in the laboratory were 5/sup 0/, 11/sup 0/, and 20/sup 0/. No large differences between the observables for the three targets were seen. The data for /sup 12/C in the quasielastic region are reasonably well explained by nonrelativistic and relativistic models of one-step quasifree scattering. Specifically nuclear effects appear small in both the quasielastic and delta regions.

  18. Beam characteristics of a new generation 50 MeV racetrack microtron.

    Science.gov (United States)

    Masterson, M E; Chui, C S; Febo, R; Hung, J D; Fuks, Z; Mohan, R; Ling, C C; Kutcher, G J; Bjork, S; Enstrom, J

    1995-06-01

    The first of a new generation of microtron accelerators has been installed and tested. It is currently in use for multisegment conformal radiotherapy at our institution. The unit produces x rays and electrons from 10 to 50 MeV in 5 MeV increments. It incorporates a 64 leaf, doubly focused multileaf collimator (MLC), which can be used to shape x-ray and electron beams. Both x-ray and electron beams are produced by magnetically scanning the electron beams from the accelerator. The new generation unit incorporates a purging magnet to sweep away any primary or secondary electrons that pass through the target(s). In this paper, the beam characteristics of the accelerator that were studied during acceptance testing are described. Representative examples of depth doses, beam profiles, output factors, and elementary beam distributions are presented and discussed, in comparison with the earlier generation of microtron accelerators and with other radiotherapy machines.

  19. Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

    Energy Technology Data Exchange (ETDEWEB)

    S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

    2012-07-01

    A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

  20. Modification and alignment of beam line of 10 MeV RF electron beam accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Barnwal, R; Ghodke, S R; Bhattacharjee, D; Kumar, M; Jayaprakash, D; Chindarkar, A R; Mishra, R L; Kumar, M; P, Dixit K; S, Acharya; Barje, S R; Lawangare, N K; C, Saroj P; Nimje, V T; Chandan, S; Tillu, A R; V, Sharma; Chavan, R B [Accelerator and Pulse Power Division, BARC, Mumbai, India-400085 (India); Dolas, S [Centre for Design and Manufacturing, BARC, Mumbai, India-400085 (India); Kulkarni, S Y [SAMEER, IIT Powai campus, Mumbai, India-400076 (India)], E-mail: rajesh_barc47@indiatimes.com (and others)

    2008-05-01

    A 10 MeV, 10 kW RF industrial Electron linac designed and developed at BARC is installed at the Electron Beam Center Kharghar, Navi Mumbai. The entire RF accelerator assembly consists of Electron gun, RF source, RF linac structure, Beam diagnostic chamber, Drift tube, Scanning magnet, Beam sensing aperture, Scan horn, and is spread over two floors at EBC. The paper discusses in detail about the alignment procedure adopted for the equipments of 10 MeV RF beamline. The complete electron beamline will be maintained under ultra high vacuum of the order of 10-7 torr. The paper discusses about the present problem of alignment, measurement technique of alignment, reason for misalignment, possible ways to solve the problem, equipment used for alignment, supports and arrestors, verification of alignment under vacuum.

  1. Modification & alignment of beam line of 10 MeV RF electron beam accelerator

    Science.gov (United States)

    Barnwal, R.; Ghodke, S. R.; Bhattacharjee, D.; Kumar, M.; Jayaprakash, D.; Chindarkar, A. R.; Mishra, R. L.; Dolas, S.; Kulkarni, S. Y.; Kumar, M.; P, Dixit K.; S, Acharya; Barje, S. R.; Lawangare, N. K.; C, Saroj P.; Nimje, V. T.; Chandan, S.; Tillu, A. R.; V, Sharma; Chavan, R. B.; V, Yadav; P, Roychowdhury; Mittal, K. C.; Chakravarthy, D. P.; Ray, A. K.

    2008-05-01

    A 10 MeV, 10 kW RF industrial Electron linac designed and developed at BARC is installed at the Electron Beam Center Kharghar, Navi Mumbai. The entire RF accelerator assembly consists of Electron gun, RF source, RF linac structure, Beam diagnostic chamber, Drift tube, Scanning magnet, Beam sensing aperture, Scan horn, and is spread over two floors at EBC. The paper discusses in detail about the alignment procedure adopted for the equipments of 10 MeV RF beamline. The complete electron beamline will be maintained under ultra high vacuum of the order of 10-7 torr. The paper discusses about the present problem of alignment, measurement technique of alignment, reason for misalignment, possible ways to solve the problem, equipment used for alignment, supports & arrestors, verification of alignment under vacuum

  2. A 7MeV S-Band 2998MHz Variable Pulse Length Linear Accelerator System

    CERN Document Server

    Hernandez, Michael; Mishin, Andrey V; Saverskiy, Aleksandr J; Skowbo, Dave; Smith, Richard

    2005-01-01

    American Science and Engineering High Energy Systems Division (AS&E HESD) has designed and commissioned a variable pulse length 7 MeV electron accelerator system. The system is capable of delivering a 7 MeV electron beam with a pulse length of 10 nS FWHM and a peak current of 1 ampere. The system can also produce electron pulses with lengths of 20, 50, 100, 200, 400 nS and 3 uS FWHM with corresponding lower peak currents. The accelerator system consists of a gridded electron gun, focusing coil, an electrostatic deflector system, Helmholtz coils, a standing wave side coupled S-band linac, a 2.6 MW peak power magnetron, an RF circulator, a fast toroid, vacuum system and a PLC/PC control system. The system has been operated at repetition rates up to 250pps. The design, simulations and experimental results from the accelerator system are presented in this paper.

  3. Commissioning of a 6 MeV X-Band SW Accelerating Guide

    CERN Document Server

    Jin, Q; Sun, X; Tao, X; Tong, D

    2004-01-01

    A 6 MeV, X-band on-axis SW electron linear accelerating guide is being developed in Accelerator laboratory of Tsinghua University. It can be suitable for portable radiation therapy and radiography. The design, manufacture and high power test of the guide are given in this paper. The guide is 38 cm long and contains 25 accelerating cells with 24 coupling cells, operated in the π/2 mode. The RF power source is a pulsed magnetron at 9300 MHz with 1.5 MW peak power. The results of beam tests are following: the electron energy is more than 6 MeV at 50 mA and focal spot size is less than φ 1.5 mm without any focusing solenoid.

  4. Modification of ROSPEC to cover neutrons from thermal to 18 MeV.

    Science.gov (United States)

    Ing, H; Djeffal, S; Clifford, T; Li, L; Noulty, R; Machrafi, R

    2007-01-01

    Rotating Spectrometer (ROSPEC) is a neutron spectrometer designed to measure neutron energy distributions, and provide accurate neutron dosimetry. It is a completely self-contained unit and measures neutron energy via recoiling protons in gas proportional counters. Each of the four original gas counters is dedicated to a particular neutron energy range dictated by sensitivity to gamma rays at the low energy end of the spectrum and by proton collisions with the counter walls at the high energy end. Introduced originally in 1992, ROSPEC has a proven operational record with a program of continued upgrades. The operating range of the original ROSPEC spans 50 keV-4.5 MeV. The range of the ROSPEC has now been extended down to include epithermal and thermal neutrons by adding two 2 in. (3)He counters. Also, an optional simple scintillation spectrometer was designed to extend the upper limit of ROSPEC up to 18 MeV.

  5. Variation Tendency of the Align Network for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Daeil; Kwon, Hyeokjung; Kim, Hansung; Seo, Donghyuk; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, the variation tendency of the align networks is checked and the survey results are considered to compensate the position of the accelerator components in the tunnel. Two years ago, the align networks on the tunnel were installed and checked to align the accelerator components. In recent survey of align networks, the displacement by temperature was confirmed according to comparison of the position. When the accelerator components are realigned, the displacement should be used to compensate position of the accelerator components. 100MeV proton linac for KOMAC (Korea Multi-purpose Accelerator Complex) has been operated at the Gyeong-ju. Linac is composed of a 50keV proton injector, a 3MeV RFQ, DTL tanks and a beam dump. The align networks were built to align the accelerator components. The survey work of align networks should be accomplished whenever need the alignment of the accelerator by using the laser tracker.

  6. Ion beam induced luminescence from diamond using an MeV ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Jamieson, D. N.; Prawer, S.; Allen, M.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.

  7. Analysing powers and spin correlations in deuteron-proton charge exchange at 726 MeV

    CERN Document Server

    Dymov, S; Bagdasarian, Z; Barsov, S; Carbonell, J; Chiladze, D; Engels, R; Gebel, R; Grigoryev, K; Hartmann, M; Kacharava, A; Khoukaz, A; Komarov, V; Kulessa, P; Kulikov, A; Kurbatov, V; Lomidze, N; Lorentz, B; Macharashvili, G; Mchedlishvili, D; Merzliakov, S; Mielke, M; Mikirtychyants, M; Mikirtychyants, S; Nioradze, M; Ohm, H; Prasuhn, D; Rathmann, F; Serdyuk, V; Seyfarth, H; Shmakova, V; Ströher, H; Tabidze, M; Trusov, S; Tsirkov, D; Uzikov, Yu; Valdau, Yu; Weidemann, C; Wilkin, C

    2015-01-01

    The charge exchange of vector polarised deuterons on a polarised hydrogen target has been studied in a high statistics experiment at the COSY-ANKE facility at a deuteron beam energy of Td = 726 MeV. By selecting two fast protons at low relative energy E_{pp}, the measured analysing powers and spin correlations are sensitive to interference terms between specific neutron-proton charge-exchange amplitudes at a neutron kinetic energy of Tn ~ 1/2 Td =363 MeV. An impulse approximation calculation, which takes into account corrections due to the angular distribution in the diproton, describes reasonably the dependence of the data on both E_{pp} and the momentum transfer. This lends broad support to the current neutron-proton partial-wave solution that was used in the estimation.

  8. The LENS 7 MeV, 10 mA Proton Linac

    CERN Document Server

    Derenchuk, Vladimir Peter; Bogdanov, Alexander; Jones, William P; Rinckel, Thomas; Solberg, Keith

    2005-01-01

    The Indiana University Cyclotron Facility (IUCF) has constructed and placed in operation a Low Energy Neutron Source (LENS) using a 10 mA, 7 MeV proton beam incident on a beryllium target. The proton delivery system (PDS) consists of a 25 keV proton injector, an AccSys Technology, Inc. PL7 Linac* and a beam transport line with non-linear beam spreading.** The accelerator and beamline equipment used in this construction are refurbished and upgraded components from the IUCF CIS/Cooler synchrotron*** facility. After commissioning the beam current at 7 MeV will be 10 mA with a pulse width of up to 300 μs and > 1% duty factor. The PDS was constructed and commissioning started in 2004. First operating results will be described.

  9. Cross Sections from 800 MeV Proton Irradiation of Terbium

    CERN Document Server

    Engle, J W; Bach, H; Couture, A; Jackman, K; Gritzo, R; Ballard, B D; Faßbender, M; Smith, D M; Bitteker, L J; Ullmann, J L; Gulley, M; Pillai, C; John, K D; Birnbaum, E R; Nortier, F M

    2012-01-01

    A single terbium foil was irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 36 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini, and INCL+ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  10. Measurements of the neutron activation cross sections for Bi and Co at 386 MeV.

    Science.gov (United States)

    Yashima, H; Sekimoto, S; Ninomiya, K; Kasamatsu, Y; Shima, T; Takahashi, N; Shinohara, A; Matsumura, H; Satoh, D; Iwamoto, Y; Hagiwara, M; Nishiizumi, K; Caffee, M W; Shibata, S

    2014-10-01

    Neutron activation cross sections for Bi and Co at 386 MeV were measured by activation method. A quasi-monoenergetic neutron beam was produced using the (7)Li(p,n) reaction. The energy spectrum of these neutrons has a high-energy peak (386 MeV) and a low-energy tail. Two neutron beams, 0° and 25° from the proton beam axis, were used for sample irradiation, enabling a correction for the contribution of the low-energy neutrons. The neutron-induced activation cross sections were estimated by subtracting the reaction rates of irradiated samples for 25° irradiation from those of 0° irradiation. The measured cross sections were compared with the findings of other studies, evaluated in relation to nuclear data files and the calculated data by Particle and Heavy Ion Transport code System code.

  11. The New Sorgentina Fusion Source-NSFS: 14 MeV neutrons for fusion and beyond

    Science.gov (United States)

    Pietropaolo, A.; Console Camprini, P.; Agostini, P.; Amendola, R.; Angelone, M.; Bernardi, D.; Bruni, F.; Capogni, M.; Colognesi, D.; Faccini, R.; Filabozzi, A.; Flammini, D.; Fiori, F.; Frisoni, M.; Grazzi, F.; Pillon, M.; Pizzuto, A.; Quintieri, L.; Sacchetti, F.; Valente, P.

    2016-09-01

    The importance of the design for the realization of an intense 14 MeV neutron facility devoted to test and validate materials suitable for harsh neutron environments, such as a fusion reactor, is well established. The “New Sorgentina” Fusion Source (NSFS) is a project that proposes an intense D-T 14 MeV neutron source achievable with T and D ion beams impinging on 2 m radius rotating targets. NSFS may produce about 1015 n/s at the target and has to be intended as an European facility that maybe realized in a few years, once provided a preliminary technological program devoted to the operation of the ion source in continuous mode, target heat loading/removal, target and tritium handling, inventor as well as site licensing. In this contribution, the main characteristics of NSFS project will be presented and its possible use as a multipurpose facility outlined.

  12. The X(3872) and the 3941 MeV peak in omega+J/Psi

    CERN Document Server

    Bugg, D V

    2004-01-01

    Belle data for the pi-pi mass spectrum in X(3872) -> pi\\pi + JPsi are well fitted by rho + J/\\Psi with JPC = 1++, but are poorly fitted by the pi-pi S-wave. Formulae for partial wave amplitudes are given for all likely JPC and decay modes of the 3941 MeV peak in omega + J/Psi. Angular correlations involving up to five angles may allow a spin-parity determination, even with quite low statistics. Special attention is given to the case where X(3872) is a cusp or quasi-bound state with the same quantum numbers as the 3941 MeV peak.

  13. Reaction cross sections for protons in the energy range 220-570 MeV

    CERN Document Server

    Renberg, P U; Measday, D F; Pepin, M; Serre, Claude; Schwaller, P

    1972-01-01

    Proton reaction cross sections have been measured for targets of natural isotopic abundance of the following elements and compounds: He, Be, C, Al, Fe, Cu, Ge, Sn, Pb, H/sub 2/O, B/sub 4/C and NaI. Data for proton energies between 220 and 570 MeV have been obtained with two types of transmission-counter assembly. The total errors are of the order of +or-3%. A slight increase of the reaction cross sections with energy is observed for most of the elements studied. The results interpreted in terms of the semi-classical theory of reaction cross section as function of energy clearly demonstrate the onset of pion- production above 250 MeV. (32 refs).

  14. Measurement of neutron-induced fission cross-sections of Th232, U238, U233 and Np237 relative to U235 from 1 MeV to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shcherbakov, O.A.; Laptev, A.B.; Petrov, G.A. [Petersburg Nuclear Physics Inst., Gatchina, Leningrad district (Russian Federation); Fomichev, A.V.; Donets, A.Y.; Osetrov, O.I.

    1998-11-01

    The measurements of neutron-induced cross-section ratios for Th232, U238, U233 and Np237 relative to U235 have been carried out in the energy range from 1 MeV up to 200 MeV using the neutron time-of-flight spectrometer GNEIS based on 1 GeV proton synchrocyclotron. Below 20 MeV, the results of present measurements are roughly in agreement with evaluated data though there are some discrepances to be resolved. (author)

  15. Phenomenological Study of 3He Photodisintegration up to 150 MeV

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng-Bin; ZHU Zhi-Yuan

    2008-01-01

    @@ A parametrization of 3He(γ,p)2H cross section data at laboratory photon energies between 9 and 150MeV is carried out with a simple phenomenological function. The differential cross section data are normalized to the total cross-section values, which are consistent with the measurement from monochromatic photon beams. The obtained results give a good representation of the experimental points.

  16. Scattering of {sup 8}He on {sup 208}Pb at 22 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Marquinez-Duran, G.; Sanchez-Benitez, A. M.; Martel, I.; Berjillos, R.; Duenas, J. A.; Parkar, V. V. [Depto. de Fisica Aplicada, Universidad de Huelva, 21071 Huelva (Spain); Acosta, L. [Depto. de Fisica Aplicada, Universidad de Huelva, 21071 Huelva, Spain and Laboratori Nazionali del Sud, INFN, Via Santa Sofia 62, 95123, Catania (Italy); Rusek, K. [Heavy Ion Laboratory, University of Warsaw (Poland); Alvarez, M. A. G.; Gomez-Camacho, J. [Centro Nacional de Aceleradores, 41092, Sevilla, Spain and Depto. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Borge, M. J. G.; Cruz, C.; Cubero, M.; Pesudo, V.; Tengblad, O. [Instituto de Estructura de la Materia, CSIC, 28006 Madrid (Spain); Chbihi, A. [GANIL, CEA and IN2P3-CNRS, B.P. 5027, 14076 Caen cedex (France); Fernandez-Garcia, J. P.; Moro, A. M. [Depto. de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Fernandez-Martinez, B.; Labrador, J. A. [Centro Nacional de Aceleradores, 41092, Sevilla (Spain); and others

    2013-06-10

    The skin nucleus {sup 8}He is investigated by measuring the angular distribution of the elasticly scattered {sup 8}He and the {sup 6,4}He fragments produced in the collision with a {sup 208}Pb target at 22 MeV, just above the Coulomb barrier. The experiment was carried out at SPIRAL/GANIL in 2010. Here we present preliminary results for the elastic scattering.

  17. 19. 7 MeV resonance in the system /sup 16/O + /sup 12/C

    Energy Technology Data Exchange (ETDEWEB)

    Wilschut, H.W.; Braun-Munzinger, P.; Berkowitz, G.M.; Freifelder, R.H.; Karp, J.S.; Renner, T.R. (State Univ. of New York, Stony Brook (USA). Dept. of Physics)

    1982-06-10

    The 19.7 MeV structure in the system /sup 12/C + /sup 16/O is investigated by measuring angular distributions and excitation functions for elastic and inelastic scattering with very high resolution. From a quasi phase shift analysis, it is deduced that the structure is a true resonance with Jsup(..pi..) = 14/sup +/. The deduced small elastic partial width indicates that the structure of this state is intermediate between a molecular and a compound nuclear state.

  18. Shielding studies for 2.5 MeV neutrons using GEANT4

    Science.gov (United States)

    Tovar, Felipe; Castro-Colin, Miguel; Sajo-Bohus, Laszlo

    2008-10-01

    By means of the software GEANT4, a toolkit based on the Monte Carlo method, we seek to study the dispersive effects that 2.5 MeV neutrons have, as well the gamma-yield, after interacting with various attenuating materials with simple geometrical configurations. A simulated mass of Uranium-238 is considered in the study with the purpose of observing the behavior of its characteristic yield after fast neutron irradiation.

  19. THE ORIGIN OF THE COSMIC GAMMA-RAY BACKGROUND IN THE MeV RANGE

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Lapuente, Pilar [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, c/. Serrano 121, E-28006, Madrid (Spain); The, Lih-Sin; Hartmann, Dieter H.; Ajello, Marco [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Canal, Ramon [Institut de Ciències del Cosmos (UB-IEEC), c/. Martí i Franqués 1, E-08028, Barcelona (Spain); Röpke, Friedrich K.; Ohlmann, Sebastian T. [Institute of Theoretical Physics and Astrophysics, University of Würzburg, D-97074, Würzburg (Germany); Hillebrandt, Wolfgang [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching bei München (Germany)

    2016-04-01

    There has been much debate about the origin of the diffuse γ-ray background in the MeV range. At lower energies, AGNs and Seyfert galaxies can explain the background, but not above ≃0.3 MeV. Beyond ∼10 MeV blazars appear to account for the flux observed. That leaves an unexplained gap for which different candidates have been proposed, including annihilations of WIMPS. One candidate is Type Ia supernovae (SNe Ia). Early studies concluded that they were able to account for the γ-ray background in the gap, while later work attributed a significantly lower contribution to them. All those estimates were based on SN Ia explosion models that did not reflect the full 3D hydrodynamics of SN Ia explosions. In addition, new measurements obtained since 2010 have provided new, direct estimates of high-z SN Ia rates beyond z ∼ 2. We take into account these new advances to see the predicted contribution to the gamma-ray background. We use here a wide variety of explosion models and a plethora of new measurements of SN Ia rates. SNe Ia still fall short of the observed background. Only for a fit, which would imply ∼150% systematic error in detecting SN Ia events, do the theoretical predictions approach the observed fluxes. This fit is, however, at odds at the highest redshifts with recent SN Ia rate estimates. Other astrophysical sources such as flat-spectrum radio quasars do match the observed flux levels in the MeV regime, while SNe Ia make up to 30%–50% of the observed flux.

  20. Design and Installation of a 10 MeV Small Medical Cyclotron Electrical System

    Institute of Scientific and Technical Information of China (English)

    CAI; Hong-ru; GE; Tao; WU; Long-cheng; LI; Zheng-guo; LIU; Geng-shou

    2012-01-01

    <正>The electrical and pneumatic system of the 10 MeV small medical cyclotron is to provide safe and reliable power supply and relay protection to ensure the stable operation of equipments as well as personnel safety. Based on the equipment installation and operation status of the machine, the computational load of electrical system is designed to be 130 kW. The load grade is three-level, which adopts three-phase

  1. Biomedical user facility at the 400-MeV Linac at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Chu, W.T.

    1993-12-01

    In this paper, general requirements are discussed on a biomedical user facility at the Fermilab`s 400-MeV Linac, which meets the needs of biology and biophysics experiments, and a conceptual design and typical operations requirements of the facility is presented. It is assumed that no human patient treatment will take place in this facility. If human patients were treated, much greater attention would have to be paid to safeguarding the patients.

  2. Proton-deuteron breakup cross sections in collinear geometry at 28. 6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Birchall, J.; Svenne, J.P.; de Jong, M.S.; McKee, J.S.C.; Ramsay, W.D.; Al-Ghazi, M.S.A.L.; Videla, N.

    1979-10-01

    Deuteron breakup cross sections induced by 28.6 MeV protons have been measured in collinear and noncollinear geometry and the results compared with an exact three-body calculation using the Doleschall code. This calculation includes two-body interactions in S and P waves and, in addition, a tensor force. The agreement with experiment in all cases is excellent. No evidence is seen for a collinearity enhancement.

  3. The measurement of KNN and KLL in at 800 MeV

    Science.gov (United States)

    Glass, G.; Bhatia, T. S.; Hiebert, J. C.; Northcliffe, L. C.; Tippens, W. B.; Verwest, B. J.; Hollas, C. L.; Newsom, C. R.; Ransome, R. D.; Riley, P. J.; Pepin, G. P.; Bonner, B. E.; Simmons, J. E.

    1983-09-01

    The spin-transfer parameters KNN and KLL have been measured for ? at 0° and 800 MeV for neutron momenta between 700 and {1200 MeV}/{c}. Peak values of KNN and KLL are -0.30 ± 0.05 and -0.5 ± 0.1 respectively. These results are in substantial disagreement with VerWest's field theoretic model.

  4. Isotopic Production Cross Sections in Proton-Nucleus Collisions at 200 MeV

    CERN Document Server

    Machner, H; Baruth-Ram, K; Carter, J; Cowley, A A; Goldenbaum, F; Nangu, B M; Pilcher, J V; Sellschop, J P Friedel; Sideras-Haddad, E; Smit, F D; Spoelstra, B; Steyn, D

    2006-01-01

    Intermediate mass fragments (IMF) from the interaction of $^{27}$Al, $^{59}$Co and $^{197}$Au with 200 MeV protons were measured in an angular range from 20 degree to 120 degree in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double differential cross sections, energy differential cross sections and total cross sections were extracted.

  5. Large-angle. pi. /sup +/p elastic scattering at 66. 8 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Brack, J.T.; Kraushaar, J.J.; Rilett, D.J.; Ristinen, R.A.; Ottewell, D.F.; Smith, G.R.; Jeppesen, R.G.; Stevenson, N.R.

    1988-11-01

    Pion-proton elastic scattering measurements at six angles from 101/sup 0/ to 147/sup 0/ center of mass at 66.8 MeV verify previously published differential cross sections which are at variance with earlier data of others and with generally accepted phase-shift solutions which incorporate these earlier data. The present single-arm measurements were made with solid targets and an array of scintillation counters which measured the time of flight of scattered pions.

  6. Nuclear multifragmentation by 700–1500 MeV photons: New data of GRAAL experiment

    Energy Technology Data Exchange (ETDEWEB)

    Nedorezov, V. G., E-mail: vladimir@cpc.inr.ac.ru; Lapik, A. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Collaboration: GRAAL Collaboration

    2015-12-15

    The cross sections of carbon nucleus photodisintegration into protons and neutrons with high multiplicity for photon energies from 700 to 1500 MeV were measured. The experiment was performed at the tagged photon beam of the GRAAL setup using the wide-aperture detector LAGRANγE. It was shown that multifragmentation up to complete disintegration into separate nucleons is initiated by elementary reactions of meson photoproduction with a subsequent intranuclear cascade.

  7. Study of the narrow structure at 1685 MeV in γp→ηp

    Energy Technology Data Exchange (ETDEWEB)

    Anisovich, A.V. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Klempt, E. [Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Kuznetsov, V. [Institute for Nuclear Research, 117312 Moscow (Russian Federation); Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Nikonov, V.A. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Polyakov, M.V., E-mail: maxim.polyakov@tp2.rub.de [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Sarantsev, A.V., E-mail: andsar@hiskp.uni-bonn.de [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Thoma, U. [Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany)

    2013-02-12

    Results of a coupled channel isobar analysis of new high-statistics data on γp→pη from MAMI are presented. A fit using known broad resonances and only standard background amplitudes cannot describe the relatively narrow peaking structure in the cross section in the mass region of 1660–1750 MeV which follows a minimum. An improved description of the data can be reached by either assuming the existence of a narrow resonance at a mass of about 1700 MeV with small photo-coupling or by a threshold effect. In the latter case the observed structure is explained by a strong (resonant or non-resonant) γp→ωp coupling in the S{sub 11} partial wave. When the beam asymmetry data, published by part of the GRAAL Collaboration, are included in the fit, the solution with a narrow P{sub 11} state is slightly preferred. In that fit, mass and width of the hypothetical resonance are determined to M∼1694 MeV and Γ∼40 MeV, respectively, and the photo-coupling to √(Br{sub ηN})A{sub 1/2}{sup p}∼2.6⋅10{sup −3} GeV{sup −1/2}. High-precision measurements of the target asymmetry and F-observable are mandatory to establish the possible existence of such a narrow state and to provide the necessary information to define which partial wave is responsible for the structure observed in the data.

  8. Pulsed 5 MeV standing wave electron linac for radiation processing

    Science.gov (United States)

    Auditore, L.; Barnà, R. C.; de Pasquale, D.; Italiano, A.; Trifirò, A.; Trimarchi, M.

    2004-03-01

    Several modern applications of radiation processing require compact and self-contained electron accelerators. To match these requirements, a 5MeV, 1kW electron linac has been developed at the Dipartimento di Fisica (Università di Messina) and will be described in this paper. This standing wave accelerator, driven by a 3GHz, 2.5MW magnetron generator, has an autofocusing structure and will be used to study several applications of radiation processing.

  9. Design of 200 MeV energy spectrum analytic system of linac in NSRL

    CERN Document Server

    Lu Ping; Li We Imin; Xu Hong Liang; Liu Zu Ping; Pei Yuan Ji; Hong Jun; Wang Jun Hua; He Duo Hui

    2002-01-01

    Energy spectrum analytic system of 200 MeV linear accelerator in NSRL is used to detect the beam energy and to guild the machine adjustment. The author shows the former status of the system, and analyses some of its shortcomings. In the NSRL project-II, the system is redesigned, and has been installed recently. The author also describes the results of physics computation and some newest preliminary experiments

  10. Measurement of Neutron Transmission for Tungsten With 2.8 MeV Neutrons

    Institute of Scientific and Technical Information of China (English)

    REN; Jie; RUAN; Xi-chao; BAO; Jie; NIE; Yang-bo; ZHOU; Zu-ying

    2012-01-01

    <正>The neutron transmission for different thickness of tungsten plates for 2.8 MeV neutrons was measured with TOF technique using the d-D reaction neutron source at the 600 kV Cococroft-Walton accelerator at CIAE. The sensitivity for distinguishing the thickness of the tungsten plate was determined with this method. The tungsten plate was put at the beam direction and 1.7 m from the neutron source, and

  11. Pion-Nucleus potentials in the energy range of 0-80 MeV

    Science.gov (United States)

    Meirav, O.; Friedman, E.; Altman, A.; Hannah, M.; Johnson, R. R.; Gill, D. R.

    1987-12-01

    Data for the elastic scattering of 30-80 MeV positive and negative pions by a wide range of nuclei is analysed with an Ericson-Ericson MSU type optical potential. By use of consistent sets of data for π+ and π- and of experimental results for total reaction cross sections we obtain for the first time optical potentials that describe well all the data without the need of introducing non-standard charge-dependent effects.

  12. Polarization observables for the reaction pp -> pp. pi. /sup 0/ at 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Riley, P.J.; Bachman, M.; Hollas, C.L.; McNaughton, K.H.; Xu Shenwu; Bonner, B.E.; Van Dyck, O.B.; McGill, J.; McNaughton, M.W.; Peng, J.C.

    1987-10-22

    The Wolfenstein polarization observables D/sub NN/, D/sub S..cap omega../ and D/sub L..cap omega../, where ..cap omega.. denotes a mixture of S and L polarization components, the induced polarization P, and the analysing power A have been measured for the reaction pp -> pp..pi../sup 0/ at 800, 733, and 647 MeV. Comparisons are made to theoretical predictions of the model of Dubach, Kloet and Silbar.

  13. The viable motheaten (mev) mouse--a new model for arthritis.

    Science.gov (United States)

    Kovarik, J; Kuntz, L; Ryffel, B; Borel, J F

    1994-10-01

    Homozygous mev mice are first identified at the age of 3-4 days by focal depigmentation of the skin, followed by patchy absence of hair and by necrotic lesions on paws, tail and ears. Of particular interest are the inflammatory reactions in the paws of these animals which consist mainly of polymorphonuclear and mononuclear cell infiltration in the subcutaneous tissue extending to the periosteum and joint, resulting in focal destructive arthritis and osteomylitis. These lesions are to some extent reminiscent of an acute form of rheumatoid-like arthritis. Since mev mice are sterile, a limited number of symptomatic offspring can be obtained by cross-breeding their heterozygous siblings which are phenotypically not distinguishable from mice lacking this mutation. In order to produce a sufficient number of diseased animals for performing pharmacological studies, we have established a model by transferring this disease in lethally irradiated, 8- to 10-week-old syngeneic mice which were grafted with mev spleen cells. Such reconstituted recipients develop first inflammatory symptoms of the paws 2 to 3 weeks after cell transfer. The arthritic inflammation finally affects all paws and toes by 30 to 50 days. This procedure increased the number of mev-like mice expressing arthritis, allowing assessment of the effects of standard reference drugs used in the therapy of rheumatoid arthritis (RA). The immunosuppressants cyclosporin and rapamycin and the steroid dexamethasone at therapeutic concentrations exert a strong inhibitory effect on the development of arthritis in this novel model. In contrast, the non-steroidal anti-inflammatory drug phenylbutazone shows only a moderate effect. These results indicate the particular sensitivity of this model for efficacy of potentially new therapeutic but non-cytostatic compounds for clinical use.

  14. Radiation Damage of F8 Lead Glass with 20 MeV Electrons

    CERN Document Server

    Schaefer, B D; McChesney, P; Shepherd, M R; Frye, J M

    2011-01-01

    Using a 20 MeV linear accelerator, we investigate the effects of electromagnetic radiation on the optical transparency of F8 lead glass. Specifically, we measure the change in attenuation length as a function of radiation dose. Comparing our results to similar work that utilized a proton beam, we conclude that F8 lead glass is more susceptible to proton damage than electron damage.

  15. Radiation damage of F8 lead glass with 20 MeV electrons

    Science.gov (United States)

    Schaefer, B. D.; Mitchell, R. E.; McChesney, P.; Shepherd, M. R.; Frye, J. M.

    2012-03-01

    Using a 20 MeV linear accelerator, we investigate the effects of electromagnetic radiation on the optical transparency of F8 lead glass. Specifically, we measure the change in attenuation length as a function of radiation dose. Comparing our results to similar work that utilized a proton beam, we conclude that F8 lead glass is more susceptible to proton damage than electron damage.

  16. Nucleon structure with pion mass down to 149 MeV

    CERN Document Server

    Green, Jeremy; Krieg, Stefan; Negele, John; Pochinsky, Andrew; Syritsyn, Sergey

    2012-01-01

    We present isovector nucleon observables: the axial, tensor, and scalar charges and the Dirac radius. Using the BMW clover-improved Wilson action and pion masses as low as 149 MeV, we achieve good control over chiral extrapolation to the physical point. Our analysis is done using three different source-sink separations in order to identify excited-state effects, and we make use of the summation method to reduce their size.

  17. Analyzing power in n vector+d elastic scattering at 67 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ruehl, H.; Dechant, B.; Krug, J.; Luebcke, W.; Spangardt, G.; Steinke, M.; Stephan, M.; Kamke, D. (Bochum Univ. (Germany, F.R.). Inst. fuer Experimentalphysik 1); Balewski, J.; Bodek, K.; Jarczyk, L.; Strzalkowski, A. (Uniwersytet Jagiellonski, Krakow (Poland). Inst. Fizyki); Hajdas, W.; Kistryn, S.; Mueller, R.; Lang, J. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Mittelenergiephysik); Henneck, R. (Basel Univ. (Switzerland). Inst. fuer Physik); Witala, H.; Cornelius, T.; Gloeckle, W. (Bochum Univ. (Germany, F.R.). Inst. fuer Theoretische Physik 2)

    1991-03-18

    The analyzing power A{sub y} of {sup 2}H(n vector, n){sup 2}H elastic scattering at E{sub n}=67 MeV has been measured in the angular range 30deg<{theta}{sub c.m.}<165deg. The data are in good agreement with the results of our rigorous three-nucleon calculations employing the PARIS and the BONN B potential. (orig.).

  18. Impurity/defect interactions during MeV Si{sup +} ion implantation annealing

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, A.; Koveshnikov, S.; Christensen, K. [North Carolina State Univ., Raleigh, NC (United States)] [and others

    1995-08-01

    Ion implantation of dopant atoms at MeV energies is currently being explored in several integrated circuit device manufacturing processes. MeV implantation offers immediate advantages such as vertical well modulation, latch-up protection, device structure isolation, and reduced temperature processing. Simultaneously, it presents an opportunity to achieve {open_quotes}proximity{close_quotes} gettering of impurities from the active device region by placing high impurity solubility and/or secondary defect gettering sites within microns of the surface. If the MeV implanted species is a dopant ion, all three gettering mechanisms, i.e, segregation, relaxation and injection, can be involved in the gettering process, complicating the analysis and optimization of the process. However, investigation of gettering using non-dopant Si{sup +} ion damage allows the relaxation component of the gettering process to be isolated and examined separately. In general, gettering is verified by a reduction in impurity concentration in the region of interest, usually the device region, and/or a build-up of concentration/precipitation in a non-device sink region. An alternate and more meaningful approach is to use simple devices as materials characterization probes via changes in the electrical activity of the gettering sites. Device space charge probes also allow the evolution of the defect sites upon contamination to be tracked. We report here results of the electrical, structural, and chemical characterization of MeV implanted Si{sup +} damage using Deep Level Transient Spectroscopy (DLTS), Transmission Electron Microscopy (TEM), and Secondary Ion Mass Spectroscopy (SIMS). The damage has been characterized both as a function of annealing from 600 to 1100{degrees}C for 1 hr, and after contamination with Fe followed by low temperature gettering annealing.

  19. Installation and Test of 100 MeV Cyclotron Safety Interlock System

    Institute of Scientific and Technical Information of China (English)

    HOU; Shi-gang; SONG; Guo-fang; LI; Zhen-guo; WANG; Feng; LV; Yin-long; XING; Jian-sheng; CAI; Hong-ru; YIN; Zhi-guo; WU; Long-cheng; XIE; Huai-dong; GE; Tao; CAO; Lei; FU; Xiao-liang; WEN; Li-peng

    2013-01-01

    The safety system is an important part of BRIF project,which will play a key role for protection of staff,and equipments.100 MeV cyclotron will deliver proton beam of 200μA with energy of 100 MeV.Radiation caused by beam loss will be occurred when the machine running or commissioning,which is hazard to staff and device,so a set of interlock system is designed for protecting people and apparatus.

  20. Cavity Formation in Aluminium Irradiated with a Pulsating Beam of 225 MeV Electrons

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Bilde-Sørensen, Jørgen; Leffers, Torben

    1984-01-01

    High-purity aluminium was irradiated with a pulsating beam of 225 MeV electrons to a maximum dose of 0.035 dpa with a helium generation rate of up to 17 appm/dpa. The irradiated samples contained cavities in the size range 5 to 70 nm. In a zone of up to 14 μm from the grain boundaries cavity size...

  1. R&D of the Fluoroscopes of 100 MeV Cyclotron Beam Lines

    Institute of Scientific and Technical Information of China (English)

    YIN; Meng; GUAN; Feng-ping; XIE; Huai-dong; ZHENG; Xia; XING; Jian-sheng; LV; Yin-long

    2013-01-01

    Beijing Radioactive Ion-beam Facility(BRIF)consists of a 100 MeV H-cyclotron CYCIAE-100and nine beam lines.All the beam lines provide the channels of the proton beam or the neutron beam to the terminal of physics experiment.There are many beam diagnosis monitors distributing along the beam lines,including,Faraday cups,beam position monitors,fluoroscopes,collimators,emittance measurement

  2. Preliminary Design of 3.5-MeV Helium RFQ for Fusion Materials Radiation Damage Study

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yongsub; Jang, Jiho; Kwon, Hyeokjung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    This work briefly summarized a 3.5 MeV helium RFQ design for alpha irradiation study. We have studied a 3.5-MeV helium RFQ for the fusion material damage study, especially for the alpha particle effects produced by DT reaction. The total length is about 3.7 m, which is compact to be installed in a general experiment hall with a reasonable radiation shielding. For the ion source of He, we are considering a microwave ion source. KOMAC (KOrea Multi-purpose Accelerator Complex) has developed a 100-MeV proton linac which includes a 50-keV ion source, a 3-MeV RFQ (Radio Frequency Quadrupole), and a 100-MeV DTL (drift tube linac). The RFQ technology can be also used to MeV ion beam applications. Especially helium beam with the kinetic energy of 3.5 MeV can be used to study the alpha particle irradiation from DT nuclear fusion reaction on the first wall of the fusion reactor.

  3. X-ray observations of MeV electron precipitation with a balloon-borne germanium spectrometer

    Science.gov (United States)

    Millan, R. M.; Lin, R. P.; Smith, D. M.; Lorentzen, K. R.; McCarthy, M. P.

    2002-12-01

    The high-resolution germanium detector aboard the MAXIS (MeV Auroral X-ray Imaging and Spectroscopy) balloon payload detected nine X-ray bursts with significant flux extending above 0.5 MeV during an 18 day flight over Antarctica. These minutes-to-hours-long events are characterized by an extremely flat spectrum (~E-2) similar to the first MeV event discovered in 1996, indicating that the bulk of parent precipitating electrons is at relativistic energies. The MeV bursts were detected between magnetic latitudes 58°-68° (L-values of 3.8-6.7) but only in the late afternoon/dusk sectors (14:30-00:00 MLT), suggesting scattering by EMIC (electromagnetic ion cyclotron) waves as a precipitation mechanism. We estimate the average flux of precipitating E >= 0.5 MeV electrons to be ~360 cm-2s-1, corresponding to about 5 × 1025 such electrons precipitated during the eight days at L = 3.8-6.7, compared to ~2 × 1025 trapped 0.5-3.6 MeV electrons estimated from dosimeter measurements on a GPS spacecraft. These observations show that MeV electron precipitation events are a primary loss mechanism for outer zone relativistic electrons.

  4. Simulations of Beam Quality in a 13 MeV PET Cyclotron

    Directory of Open Access Journals (Sweden)

    A. Pramudita

    2015-12-01

    Full Text Available Simulation of the trajectories of negative hydrogen ion (H− beam in a 13 MeV PET cyclotron (DECY-13 were carried out by using the Runge-Kutta (RK4 approximation method and Scilab 5.4.1. The magnetic and electric fields were calculated using Opera-3d/TOSCA softwares at 1 mm resolution. The cyclotron is of a fourth-harmonics type, meaning that the acceleration occurs four times per cycle, with a radiofrequency (RF field of 77.66 MHz frequency and 40 kV amplitude. The calculations and simulations show that the maximum distance between the ion source and the puller is about 6 mm, while the maximum width of the beam at 13 MeV is about 10 mm, and the initial phase between the RF field and the beam ranges from -10° to 10°, with a yield of about 10% of the beam from the ion source getting accelerated to 13 MeV.

  5. Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Katayama, Tadashi; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1993-10-01

    In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (J.P.N.).

  6. Comprehensive Measurement of Neutron Yield Produced by 62 MeV Protons on Beryllium Target

    CERN Document Server

    Osipenko, M; Alba, R; Ricco, G; Schillaci, M; Barbagallo, M; Boccaccio, P; Celentano, A; Colonna, N; Cosentino, L; Del Zoppo, A; Di Pietro, A; Esposito, J; Figuera, P; Finocchiaro, P; Kostyukov, A; Maiolino, C; Santonocito, D; Scuderi, V; Viberti, C M

    2013-01-01

    A low-power prototype of neutron amplifier, based on a 70 MeV, high current proton cyclotron being installed at LNL for the SPES RIB facility, was recently proposed within INFN-E project. This prototype uses a thick Beryllium converter to produce a fast neutron spectrum feeding a sub-critical reactor core. To complete the design of such facility the new measurement of neutron yield from a thick Beryllium target was performed at LNS. This measurement used liquid scintillator detectors to identify produced neutrons by Pulse Shape Discrimination and Time of Flight technique to measure neutron energy in the range 0.5-62 MeV. To extend the covered neutron energy range He3 detector was used to measure neutrons below 0.5 MeV. The obtained yields were normalized to the charge deposited by the proton beam on the metallic Beryllium target. These techniques allowed to achieve a wide angular coverage from 0 to 150 degrees and to explore almost complete neutron energy interval.

  7. MeV Argon ion beam generation with narrow energy spread

    CERN Document Server

    Xu, Jiancai; Shen, Baifei; Zhang, Hui; Li, Shun; Yu, Yong; Li, Jinfeng; Lu, Xiaoming; Wang, Cheng; Wang, Xinliang; Liang, Xiaoyan; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2016-01-01

    Laser driven particle acceleration has shown remarkable progresses in generating multi-GeV electron bunches and 10s of MeV ion beams based on high-power laser facilities. Intense laser pulse offers the acceleration field of 1012 Volt per meter, several orders of magnitude larger than that in conventional accelerators, enabling compact devices. Here we report that a highly-collimated argon ion beam with narrow energy spread is produced by irradiating a 45-fs fully-relativistic laser pulse onto an argon cluster target. The highly-charged (Argon ion with charge state of 16+) heavy ion beam has a minimum absolute energy spread of 0.19 MeV per nucleon at the energy peak of 0.39 MeV per nucleon. we identify a novel scheme from particle-in-cell simulations that greatly reduces the beam energy spread. The laser-driven intense plasma wakefield has a strong modulation on the ion beam in a way that the low energy part is cut off. The pre-accelerated argon ion beam from Coulomb explosion thus becomes more mono-energetic ...

  8. Simulation of Electron Behavior in PIG Ion Source for 9MeV Cyclotron

    CERN Document Server

    Ghergherehchi, Mitra; Yeon, Yeong- Heum; Chai, Jong- Seo

    2013-01-01

    In this paper, we focus on a PIG source for producing intense H-ions inside a 9MeV cyclotron. The properties of the PIG ion source were simulated for a variety of electric field distributions and magnetic field strengths using CST Particle Studio. After analyzing secondary electron emission (SEE) as a function of both magnetic and electric field strengths, we found that for the modeled PIG geometry a magnetic field strength of 0.2 T provided the best results in term of number of secondary electrons. Furthermore, at 0.2 T the number of secondary electrons proved to be greatest regardless of the cathode potential. Also the modified PIG ion source with quartz insulation tubes was tested in KIRAMS-13 cyclotron by varying gas flow rate and arc current, respectively. The capacity of the designed ion source was also demonstrated by producing plasma inside the constructed 9MeV cyclotron. As a result, the ion source is verified to be capable to produce intense H- beam and high ion beam current for the desired 9 MeV cy...

  9. Temperature and 8 MeV electron irradiation effects on GaAs solar cells

    Indian Academy of Sciences (India)

    Asha Rao; Sheeja Krishnan; Ganesh Sajeev; K Siddappa

    2010-06-01

    GaAs solar cells hold the record for the highest single band-gap cell efficiency. Successful application of these cells in advanced space-borne systems demand characterization of cell properties like dark current under different ambient conditions and the stability of the cells against particle irradiation in space. In this paper, the results of the studies carried out on the effect of 8 MeV electron irradiation on the electrical properties of GaAs solar cells are presented. The – (current–voltage) characteristics of the cells under dark and AM1.5 illumination condition are studied and 8 MeV electron irradiation was carried out on the cells where they were exposed to graded doses of electrons from 1 to 100 kGy. The devices were also characterized using capacitance measurements at various frequencies before and after irradiation. The effect of electron irradiation on the solar cell parameters was studied. It is found that only small changes were observed in the GaAs solar cell parameters up to an electron dose of 100 kGy, exhibiting good tolerance for electrons of 8 MeV energy.

  10. Design study of a 9 MeV compact cyclotron system for PET

    Science.gov (United States)

    Lee, Byeong-No; Shin, Seung-Wook; Song, Hoseung; Kim, Hyun-Wook; Chai, Jong-Seo

    2013-06-01

    A cyclotron is an accelerator which can be applied to both cancer diagnosis and treatment. Among commercially sold cyclotrons, the major energy is used for positron emission tomography (PET) ranges from 10 to 20 MeV. In this research, 9 MeV compact cyclotron for PET was designed. The research was conducted on the response cross section and the yield for the energy distribution to decide the design features. Also, it was determined the specifications on the basis of the fluoro-deoxy-glucose (FDG) maximum dose. The machine, which has a 20 uA beam current, is designed to be installed in small-to-medium-sized hospitals in local cities because of its relatively light weight (6 tons). This compact cyclotron, which provides 9-MeV proton beams, is composed of a azimuthally varying field (AVF) electromagnet, 83-MHz RF systems with a 20 kW amplifier, a panning ion gauge (PIG) type ion-source for negative hydrogen, and a double-stage high-vacuum system. The basic model design was done by using 3-D CAD program, CATIA and all the field calculations were performed using commercial electromagnetic field analysis code, OPERA-3D TOSCA. From this research, we expect a time reduction for FDG production, a decrease of radioactive exposure for workers, and an equipment cost reduction.

  11. Release the beams! - Linac4 ready to hit the 50 MeV mark

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    The Linac4 accelerator is now prepared to reach 50 MeV. This milestone energy - expected in the coming weeks - will allow the machine to act as a replacement for the ageing Linac2, four years before it takes over at the head of the accelerator chain in 2020.    Inside the Linac4 tunnel, the final DTL cavities will guide beams to 50 MeV.  (Image: Stephan Russenschuck.) The Linac4 accelerator will bring H- ion beams (hydrogen atoms with an extra electron) up to 160 MeV for injection into the PS Booster. As a key part of the LHC injector upgrade programme, Linac4 will allow the PS Booster to double its beam brightness, which will contribute to increasing the LHC’s luminosity. Linac4 will soon bring beams up to 50 MeV - the current energy delivered by the Linac2 accelerator. This milestone follows on from another recent accomplishment: the installation and commissioning of the final Drift Tube Linac (DTL) tank. Using an innovati...

  12. EXPERIMENTAL ANALYSES OF SPALLATION NEUTRONS GENERATED BY 100 MEV PROTONS AT THE KYOTO UNIVERSITY CRITICAL ASSEMBLY

    Directory of Open Access Journals (Sweden)

    CHEOL HO PYEON

    2013-02-01

    Full Text Available Neutron spectrum analyses of spallation neutrons are conducted in the accelerator-driven system (ADS facility at the Kyoto University Critical Assembly (KUCA. High-energy protons (100 MeV obtained from the fixed field alternating gradient accelerator are injected onto a tungsten target, whereby the spallation neutrons are generated. For neutronic characteristics of spallation neutrons, the reaction rates and the continuous energy distribution of spallation neutrons are measured by the foil activation method and by an organic liquid scintillator, respectively. Numerical calculations are executed by MCNPX with JENDL/HE-2007 and ENDF/B-VI libraries to evaluate the reaction rates of activation foils (bismuth and indium set at the target and the continuous energy distribution of spallation neutrons set in front of the target. For the reaction rates by the foil activation method, the C/E values between the experiments and the calculations are found around a relative difference of 10%, except for some reactions. For continuous energy distribution by the organic liquid scintillator, the spallation neutrons are observed up to 45 MeV. From these results, the neutron spectrum information on the spallation neutrons generated at the target are attained successfully in injecting 100 MeV protons onto the tungsten target.

  13. New applications of 10 MeV electrons for reeled goods

    Science.gov (United States)

    Günthard, C.; Lee, D. W.

    2000-03-01

    Because of their high penetration capability, electron beams produced by 10 MeV machines are increasingly used for the sterilization processing of medical devices. Worldwide there are already more than 20 such machines in action for this purpose. But compared with electron beam sterilization, the physical crosslinking of plastic products with 10 MeV has not been as much investigated as in the range of low and medium energy. So the products with high wall thickness or big dimensions are still chemically crosslinked as the penetration and power of the beam of existing accelerators was not sufficient for those products. But now radiation crosslinking is possible also for higher dimensions of reeled goods due to higher beam power up to 150 kW, and one machine with different handling systems can be used for sterilization and modification of plastic products. The aim of our work is to examine the homogeneous crosslinking of industrial products by a 10 MeV/150 kW electron beam as for instance for XLPE-c pipes and heat shrinkable tubes. Furthermore the uniformity of crosslinking especially along the roundness is measured, which is one of the essential quality characteristics.

  14. Ion desorption from frozen H 2O irradiated by MeV heavy ions

    Science.gov (United States)

    Collado, V. M.; Farenzena, L. S.; Ponciano, C. R.; Silveira, E. F. da; Wien, K.

    2004-10-01

    Nitrogen (0.13-0.85 MeV) and 252Cf fission fragments (˜65 MeV) beams are employed to sputter positive and negative secondary ions from frozen water. Desorption yields are measured for different ice temperatures and projectile energies. Target surface is continuously refreshed by condensed water while the target temperature varies and ice thickness changes. In both projectile energy ranges, the preferentially ejected ions are H +, H2+ and (H 2O) nH +-cluster ions. The yields of the corresponding negative ions H - and (H 2O) nO - or (H 2O) nOH - are 1-2 orders of magnitude lower. The (H 2O) nH + desorption yields decrease exponentially as the cluster size, n, increases. In the low energy range, the desorption of positive ion clusters may occur in a two-step process: first, desorption of preformed H 2O clusters and, then, ionization by H + or H 3O + capture. For 0.81 MeV N + projectile ions, the cluster ion emission contributes with 0.05% to the total H 2O desorbed yield. There are indications that emission of the (H 2O) nH + disappears for an electronic energy loss lower than 20 eV/Å. For the high energy range, desorption of small ion clusters is particularly enhanced, revealing that a fragmentation process also exists.

  15. Measurement of 15 MeV gamma-rays with the Ge cluster detectors of EUROBALL

    CERN Document Server

    Million, B; Camera, F; Brambilla, S; Gadea, A; Giugni, D; Herskind, B; Kmiecik, M; Isocrate, R; Leoni, S; Maj, A; Prelz, F; Wieland, O

    2000-01-01

    A measurement of the response to 15.1 MeV gamma-rays has been made for the Ge cluster detectors in the EUROBALL array. Each cluster detector consists of seven germanium capsules surrounded by a single anticompton shield of BGO. The reaction D( sup 1 sup 1 B,gamma) sup 1 sup 2 C+n at E sub b sub e sub a sub m =19.1 MeV has been employed. The 'adding-back' of signals simultaneously present in the capsules composing each cluster detector has been made on an event by event basis. The intensity in full-energy peak increases by a factor of three as compared to that of the spectrum obtained by summing the individual spectra of the 7 capsules. The pulse height to energy conversion is found to be very linear from few hundreds keV to 15 MeV. The efficiency is discussed relative to that of large volume BaF sub 2 scintillators.

  16. High-quality beam generation using an RF gun and a 150 MeV microtron

    Science.gov (United States)

    Kuroda, R.; Washio, M.; Kashiwagi, S.; Kobuki, T.; Ben-Zvi, I.; Wang, X. J.; Hori, T.; Sakai, F.; Tsunemi, A.; Urakawa, J.; Hirose, T.

    2000-11-01

    Low-emittance sub-picosecond electron pulses are expected to be used in a wide field, such as free electron laser, laser acceleration, femtosecond X-ray generation by Inverse Compton scattering, pulse radiolysis, etc. In order to produce the low-emittance sub-picosecond electron pulse, we are developing a compact Racetrack Microtron (RTM) with a new 5 MeV injection system adopting a laser photo cathode RF gun (Washio et al., Seventh China-Japan Bilateral Symposium on Radiation Chemistry, October 28, Cengdu, China, 1996). The operation of RTM has been kept under a steady state of beam loading for long pulse mode so far (Washio et al., J. Surf. Sci. Soc. Jpn. 19 (2) (1998) 23). In earlier work (Washio et al., PAC99, March 31, New York, USA, 1999), we have succeeded in the numerical simulation for the case of single short pulse acceleration. Finally, the modified RTM was demonstrated as a useful accelerator for a picosecond electron pulse generation under a transient state of beam loading. In the simulation, a picosecond electron pulse was accelerated to 149.6 MeV in RTM for the injection of 5 MeV electron bunch with a pulse length of 10 ps (FWHM), a charge of 1 nC per pulse, and an emittance of 3 πmm mrad.

  17. Bremsstrahlung component of the diffuse galactic gamma-ray emission at MeV energies

    Energy Technology Data Exchange (ETDEWEB)

    Sacher, W.; Schoenfelder, V.

    1984-04-15

    Recently the galactic plane has been resolved at low and medium ..gamma..-ray energies in the directions toward the center and anticenter. Spectral measurements are now available at those energies, where the contribution of ..pi../sup 0/-decay from nuclear reactions of cosmic-ray protons (and heavier nuclei) with interstellar matter can be neglected. Under the assumption that most of the observed ..gamma..-ray flux below 30 MeV is produced by electron bremsstrahlung, restrictions on the energy spectrum of cosmic-ray electrons in interstellar space below 100 MeV are derived. The most accurate bremsstrahlung production cross sections of Koch and Motz and of Blumental and Gould are used in order to derive the bremsstrahlung production spectrum in interstellar space down to 10 keV-photon energies. If the low-energy ..gamma..-ray emission, as seen by most observers, is indeed produced by electron bremsstrahlung, then a high interstellar electron flux at MeV energy results, which-at higher energies-connects to the upper limit derived by Cummings, Stone, and Vogt. Such a high low-energy electron flux would be able to explain the ionization rate of 1 x 10/sup -15/ ion pairs (H-atom/sup -1/ s/sup -1/) in H I regions. Because of uncertainties in the low-energy ..gamma..-ray measurements, however, no definite conclusion is possible yet.

  18. New COMPTEL results on pulsar studies at MeV energies

    Science.gov (United States)

    Hermsen, W.; Kuiper, L.; Schoenfelder, V.; Strong, A. W.; Bennett, K.; Much, R.; McConnell, M.; Ryan, J.; Carraminana, A.

    1997-01-01

    The Compton telescope (COMPTEL) onboard the Compton Gamma Ray Observatory (CGRO) detected the pulsar PSR B1951-32 at MeV energies, and found indications of a signal from PSR B0656+14. In the combined spectra from COMPTEL and the energetic gamma ray experiment telescope (EGRET) onboard CGRO, it can be seen that the maximum luminosities of these objects are reached in the COMPTEL energy range. These spectra can be compared with those from four other pulsars observed in MeV energies with COMPTEL. The spectral properties of five of the six pulsars, Vela, PSR B1509-58, PSR B1951-32 and PSR B0656+14, require breaks and bends at MeV energies. The sixth pulsar, the Crab pulsar, approximately follows a power law flux relation from keV to GeV energies. It is concluded that this spectral behavior may play a role in the discrimination between current gamma ray emission models.

  19. 1 MeV, 10 kW DC electron accelerator for industrial applications

    Science.gov (United States)

    Nayak, B.; Acharya, S.; Bhattacharjee, D.; Bakhtsingh, R. I.; Rajan, R.; Sharma, D. K.; Dewangan, S.; Sharma, V.; Patel, R.; Tiwari, R.; Benarjee, S.; Srivastava, S. K.

    2016-03-01

    Several modern applications of radiation processing like medical sterilization, rubber vulcanization, polymerization, cross-linking and pollution control from thermal power stations etc. require D.C. electron accelerators of energy ranging from a few hundred keVs to few MeVs and power from a few kilowatts to hundreds of kilowatts. To match these requirements, a 3 MeV, 30 kW DC electron linac has been developed at BARC, Mumbai and current operational experience of 1 MeV, 10 kW beam power will be described in this paper. The LINAC composed mainly of Electron Gun, Accelerating Tubes, Magnets, High Voltage source and provides 10 kW beam power at the Ti beam window stably after the scanning section. The control of the LINAC is fully automated. Here Beam Optics study is carried out to reach the preferential parameters of Accelerating as well as optical elements. Beam trials have been conducted to find out the suitable operation parameters of the system.

  20. Trends and applications for MeV electrostatic ion beam accelerators

    Science.gov (United States)

    Norton, G. A.; Stodola, S. E.

    2014-08-01

    The 1970s into the 1980s saw a major broadening of applications for electrostatic accelerators. Prior to this time, all accelerators were used primarily for nuclear structure research. In the 70s there was a significant move into production ion implantation with the necessary MeV ion beam analysis techniques such as RBS and ERD. Accelerators are still being built for these materials analysis techniques today. However, there is still a great ongoing expansion of applications for these machines. At the present time, the demand for electrostatic accelerators is near an all time high. The number of applications continues to grow. This paper will touch on some of the current applications which are as diverse as nuclear fission reactor developments and pharmacokinetics. In the field of nuclear engineering, MeV ion beams from electrostatic accelerators are being used in material damage studies and for iodine and actinide accelerator mass spectrometry (AMS). In the field of pharmacokinetics, electrostatic MeV accelerators are being used to detect extremely small amounts of above background 14C. This has significantly reduced the time required to reach first in human studies. These and other applications will be discussed.