Genetic and Pathological Follow-Up Study of Goats Experimentally and Naturally Exposed to a Sheep Scrapie Isolate

Science.gov (United States)

Maestrale, Caterina; Cancedda, Maria G.; Pintus, Davide; Masia, Mariangela; Nonno, Romolo; Ru, Giuseppe; Carta, Antonello; Demontis, Francesca; Santucciu, Cinzia

2015-01-01

ABSTRACT Thirty-seven goats carrying different prion protein genotypes (PRNP) were orally infected with a classical scrapie brain homogenate from wild-type (ARQ/ARQ) sheep and then mated to obtain 2 additional generations of offspring, which were kept in the same environment and allowed to be naturally exposed to scrapie. Occurrence of clinical or subclinical scrapie was observed in the experimentally infected goats (F0) and in only one (F1b) of the naturally exposed offspring groups. In both groups (F0 and F1b), goats carrying the R154H, H154H, R211Q, and P168Q-P240P dimorphisms died of scrapie after a longer incubation period than wild-type, G37V, Q168Q-P240P, and S240P goats. In contrast, D145D and Q222K goats were resistant to infection. The immunobiochemical signature of the scrapie isolate and its pathological aspects observed in the sheep donors were substantially maintained over 2 goat generations, i.e., after experimental and natural transmission. This demonstrates that the prion protein gene sequence, which is shared by sheep and goats, is more powerful than any possible but unknown species-related factors in determining scrapie phenotypes. With regard to genetics, our study confirms that the K222 mutation protects goats even against ovine scrapie isolates, and for the first time, a possible association of D145 mutation with scrapie resistance is shown. In addition, it is possible that the sole diverse frequencies of these genetic variants might, at least in part, shape the prevalence of scrapie among naturally exposed progenies in affected herds. IMPORTANCE This study was aimed at investigating the genetic and pathological features characterizing sheep-to-goat transmission of scrapie. We show that in goats with different prion protein gene mutations, the K222 genetic variant is associated with scrapie resistance after natural and experimental exposure to ovine prion infectivity. In addition, we observed for the first time a protective effect of the D145

Scrapie prion liposomes and rods exhibit target sizes of 55,000 Da

International Nuclear Information System (INIS)

Bellinger-Kawahara, C.G.; Kempner, E.; Groth, D.; Gabizon, R.; Prusiner, S.B.

1988-01-01

Scrapie is a degenerative neurologic disease in sheep and goats which can be experimentally transmitted to laboratory rodents. Considerable evidence suggests that the scrapie agent is composed largely, if not entirely, of an abnormal isoform of the prion protein (PrPSc). Inactivation of scrapie prions by ionizing radiation exhibited single-hit kinetics and gave a target size of 55,000 +/- 9000 mol wt. The inactivation profile was independent of the form of the prion. Scrapie agent infectivity in brain homogenates, microsomal fractions, detergent-extracted microsomes, purified amyloid rods, and liposomes exhibited the same inactivation profile. Our data are consistent with the hypothesis that the infectious particle causing scrapie contains approximately 2 PrPSc molecules

Epidemiological analysis of data for scrapie in Great Britain

NARCIS (Netherlands)

Hagenaars, T.H.J.; Donnelly, C.; Ferguson, N.M.

2006-01-01

In recent years, the control or eradication of scrapie and any other transmissible spongiform encephalopathies (TSEs) possibly circulating in the sheep population has become a priority in Britain and elsewhere in Europe. A better understanding of the epidemiology of scrapie would greatly aid the

Comparison of strategies for substantiating freedom from scrapie in a sheep flock.

Science.gov (United States)

Durand, Benoit; Martinez, Marie-José; Calavas, Didier; Ducrot, Christian

2009-04-30

combining data sources allows substantiating a flock is free from scrapie within a reasonable time frame. Qualification schemes could thus be a useful tool for voluntary or mandatory scrapie control programmes. However, there is no general strategy that would always minimize the costs and choice of the strategy should be adapted to local genetic conditions.

Scrapie-specific pathology of sheep lymphoid tissues.

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Gillian McGovern

Full Text Available Transmissible spongiform encephalopathies (TSEs or prion diseases often result in accumulation of disease-associated PrP (PrP(d in the lymphoreticular system (LRS, specifically in association with follicular dendritic cells (FDCs and tingible body macrophages (TBMs of secondary follicles. We studied the effects of sheep scrapie on lymphoid tissue in tonsils and lymph nodes by light and electron microscopy. FDCs of sheep were grouped according to morphology as immature, mature or regressing. Scrapie was associated with FDC dendrite hypertrophy and electron dense deposit or vesicles. PrP(d was located using immunogold labelling at the plasmalemma of FDC dendrites and, infrequently, mature B cells. Abnormal electron dense deposits surrounding FDC dendrites were identified as immunoglobulins suggesting that excess immune complexes are retained and are indicative of an FDC dysfunction. Within scrapie-affected lymph nodes, macrophages outside the follicle and a proportion of germinal centre TBMs accumulated PrP(d within endosomes and lysosomes. In addition, TBMs showed PrP(d in association with the cell membrane, non-coated pits and vesicles, and also with discrete, large and random endoplasmic reticulum networks, which co-localised with ubiquitin. These observations suggest that PrP(d is internalised via the caveolin-mediated pathway, and causes an abnormal disease-related alteration in endoplasmic reticulum structure. In contrast to current dogma, this study shows that sheep scrapie is associated with cytopathology of germinal centres, which we attribute to abnormal antigen complex trapping by FDCs and abnormal endocytic events in TBMs. The nature of the sub-cellular changes in FDCs and TBMs differs from those of scrapie infected neurones and glial cells suggesting that different PrP(d/cell membrane interactions occur in different cell types.

Genetic Resistance to Scrapie Infection in Experimentally Challenged Goats

Science.gov (United States)

Lacroux, Caroline; Perrin-Chauvineau, Cécile; Corbière, Fabien; Aron, Naima; Aguilar-Calvo, Patricia; Torres, Juan Maria; Costes, Pierrette; Brémaud, Isabelle; Lugan, Séverine; Schelcher, François; Barillet, Francis

2014-01-01

In goats, several field studies have identified coding mutations of the gene encoding the prion protein (I/M142, N/D146, S/D146, R/Q211, and Q/K222) that are associated with a lower risk of developing classical scrapie. However, the data related to the levels of resistance to transmissible spongiform encephalopathies (TSEs) of these different PRNP gene mutations are still considered insufficient for developing large-scale genetic selection against scrapie in this species. In this study, we inoculated wild-type (WT) PRNP (I142R154R211Q222) goats and homozygous and/or heterozygous I/M142, R/H154, R/Q211, and Q/K222 goats with a goat natural scrapie isolate by either the oral or the intracerebral (i.c.) route. Our results indicate that the I/M142 PRNP polymorphism does not provide substantial resistance to scrapie infection following intracerebral or oral inoculation. They also demonstrate that H154, Q211, and K222 PRNP allele carriers are all resistant to scrapie infection following oral exposure. However, in comparison to WT animals, the H154 and Q211 allele carriers displayed only moderate increases in the incubation period following i.c. challenge. After i.c. challenge, heterozygous K222 and a small proportion of homozygous K222 goats also developed the disease, but with incubation periods that were 4 to 5 times longer than those in WT animals. These results support the contention that the K222 goat prion protein variant provides a strong but not absolutely protective effect against classical scrapie. PMID:24284317

Extended scrapie incubation time in goats singly heterozygous for PRNP S146 or K222

Science.gov (United States)

Scrapie is the transmissible spongiform encephalopathy (TSE) of sheep and goats, and scrapie eradication in sheep is based in part on strong genetic resistance to classical scrapie. Goats may serve as a scrapie reservoir, and to date there has been no experimental inoculation confirming strong genet...

Immunohistochemical detection of prion protein in lymphoid tissues of sheep with natural scrapie

NARCIS (Netherlands)

Keulen, van L.J.M.; Schreuder, B.E.C.; Meloen, R.H.; Mooij-Harkes, G.; Vromans, M.E.W.; Langeveld, J.P.M.

1996-01-01

The scrapie-associated form of the prion protein (PrP(Sc)) accumulates in the brain and lymphoid tissues of sheep with scrapie. In order to assess whether detecting PrP(Sc) in lymphoid tissue could he used as a diagnostic test for scrapie, we studied the localization and distribution of PrP(Sc) in

The placenta shed from goats with classical scrapie is infectious to goat kids and lambs.

Science.gov (United States)

Schneider, David A; Madsen-Bouterse, Sally A; Zhuang, Dongyue; Truscott, Thomas C; Dassanayake, Rohana P; O'Rourke, Katherine I

2015-08-01

The placenta of domestic sheep plays a key role in horizontal transmission of classical scrapie. Domestic goats are frequently raised with sheep and are susceptible to classical scrapie, yet potential routes of transmission from goats to sheep are not fully defined. Sparse accumulation of disease-associated prion protein in cotyledons casts doubt about the role of the goat's placenta. Thus, relevant to mixed-herd management and scrapie-eradication efforts worldwide, we determined if the goat's placenta contains prions orally infectious to goat kids and lambs. A pooled cotyledon homogenate, prepared from the shed placenta of a goat with naturally acquired classical scrapie disease, was used to orally inoculate scrapie-naïve prion genotype-matched goat kids and scrapie-susceptible lambs raised separately in a scrapie-free environment. Transmission was detected in all four goats and in two of four sheep, which importantly identifies the goat's placenta as a risk for horizontal transmission to sheep and other goats.

Discrepant epidemiological patterns between classical and atypical scrapie in sheep flocks under French TSE control measures.

Science.gov (United States)

Fediaevsky, Alexandre; Gasqui, Patrick; Calavas, Didier; Ducrot, Christian

2010-09-01

The occurrence of secondary cases of atypical and classical scrapie was examined in 340 outbreaks of atypical and 296 of classical sheep scrapie detected in France during active surveillance programmes between 2002 and 2007. The prevalence of atypical scrapie in these flocks was 0.05% under selective culling and 0.07% under intensified monitoring i.e. not significantly different from that detected during active surveillance of the general population (P>0.5), whereas these figures were much higher for classical scrapie (3.67% and 0.25%, respectively, Pclassical scrapie but were not more efficient than active surveillance in detecting cases of atypical scrapie. Copyright 2009 Elsevier Ltd. All rights reserved.

Scrapie e seu diagnóstico diferencial em ovinos no Mato Grosso do Sul Scrapie and differential diagnosis in sheep in Mato Grosso do Sul, Brazil

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Héllen M. Martins

2012-12-01

Full Text Available Scrapie é uma doença infecciosa, neurodegenerativa fatal, causada pelo príon scrapie (PrPsc. Apresenta-se tanto na forma clássica em ovinos e caprinos geneticamente susceptíveis quanto na forma atípica em ovinos. A primeira notificação oficial do Brasil à Organização Mundial de Saúde Animal (OIE, um caso da forma clássica diagnosticado no Rio Grande do Sul ocorreu em 1985, mas a doença já havia sido diagnosticada no mesmo Estado em 1978. Este trabalho objetivou descrever dois surtos de Scrapie em ovinos em Mato Grosso do Sul (MS, Brasil e investigar, por meio de imuno-histoquímica (IHQ a presença de PrPsc no Sistema Nervoso Central (SNC de ovinos examinados entre 2003 e 2010. Na primeira parte observaram-se dois ovinos com sinais clínicos típicos de scrapie, detalhando-se os sinais neurológicos, dados epidemiológicos, histopatológicos e amostras teciduais em duplicata desses ovinos foram encaminhadas para realização de diagnóstico de Raiva e para diagnóstico IHQ para príon. Na segunda parte realizou-se levantamento de laudos de necropsia e diagnósticos histopatológicos de ovinos, no período de maio de 2003 a março de 2010. Amostras de sistema nervoso central de 51 casos foram selecionados, incluindo os dois já com diagnóstico de Scrapie mencionados acima; os tecido de todos esses ovinos foram submetidos à IHQ para detecção de proteína priônica. Os 49 ovinos avaliados apresentaram resultado negativo na IHQ para príon.Scrapie is a fatal neurodegenerative infectious disease, caused by the scrapie prion (PrPsc, that can both in the as the classic form in genetically susceptible sheep and goats and in the atypical form in sheep. The first official notification of scrapie from Brazil was made to the World Organization for Animal Health (OIE in 1985, in the state of Rio Grande do Sul, although the disease was first documented in this Brazilian state in 1978. The objective this paper was to describe two outbreaks

Prenatal transmission of scrapie in sheep and goats: A case study ...

African Journals Online (AJOL)

... or unwashed in vivo derived embryos are hazards for the transmission of scrapie. Evidence from causal reasoning, including experience from other prion diseases, shows that mechanisms exist for prenatal transmission and transmission by semen and embryos in both sheep and goats. Keywords: Goat, Prenatal, Scrapie, ...

Immunohistochemical distinction between preclinical bovine spongiform encephalopathy and scrapie infection in sheep

NARCIS (Netherlands)

Thuring, C.M.A.; Keulen, van L.J.M.; Langeveld, J.P.M.; Vromans, M.E.W.; Zijderveld, van F.G.; Sweeney, T.

2005-01-01

Sheep are susceptible experimentally to bovine spongiform encephalopathy (BSE), the clinical signs being indistinguishable from those of scrapie. Because of the possibility of natural ovine BSE infection, laboratory tests are needed to distinguish between scrapie and BSE infection. The objectives of

Using mass spectrometry to determine the relative susceptibility of PrP polymorphisms to atypical scrapie

Science.gov (United States)

A novel form of scrapie was described in 1998 and referred to as Nor98 for the country of origin and date of its discovery. Since then it has been found in numerous countries, including New Zealand and Australia, and has been renamed atypical scrapie. Unlike classical scrapie, the epidemiology of th...

Epidemiological characteristics of classical scrapie outbreaks in 30 sheep flocks in the United Kingdom.

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K Marie McIntyre

Full Text Available Most previous analyses of scrapie outbreaks have focused on flocks run by research institutes, which may not reflect the field situation. Within this study, we attempt to rectify this deficit by describing the epidemiological characteristics of 30 sheep flocks naturally-infected with classical scrapie, and by exploring possible underlying causes of variation in the characteristics between flocks, including flock-level prion protein (PrP genotype profile. In total, the study involved PrP genotype data for nearly 8600 animals and over 400 scrapie cases.We found that most scrapie cases were restricted to just two PrP genotypes (ARQ/VRQ and VRQ/VRQ, though two flocks had markedly different affected genotypes, despite having similar underlying genotype profiles to other flocks of the same breed; we identified differences amongst flocks in the age of cases of certain PrP genotypes; we found that the age-at-onset of clinical signs depended on peak incidence and flock type; we found evidence that purchasing infected animals is an important means of introducing scrapie to a flock; we found some evidence that flock-level PrP genotype profile and flock size account for variation in outbreak characteristics; identified seasonality in cases associated with lambing time in certain flocks; and we identified one case that was homozygous for phenylalanine at codon 141, a polymorphism associated with a very high risk of atypical scrapie, and 28 cases that were heterozygous at this codon.This paper presents the largest study to date on commercially-run sheep flocks naturally-infected with classical scrapie, involving 30 study flocks, more than 400 scrapie cases and over 8500 PrP genotypes. We show that some of the observed variation in epidemiological characteristics between farms is related to differences in their PrP genotype profile; although much remains unexplained and may instead be attributed to the stochastic nature of scrapie dynamics.

Quantitative detection and biological propagation of scrapie seeding activity in vitro facilitate use of prions as model pathogens for disinfection.

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Sandra Pritzkow

Full Text Available Prions are pathogens with an unusually high tolerance to inactivation and constitute a complex challenge to the re-processing of surgical instruments. On the other hand, however, they provide an informative paradigm which has been exploited successfully for the development of novel broad-range disinfectants simultaneously active also against bacteria, viruses and fungi. Here we report on the development of a methodological platform that further facilitates the use of scrapie prions as model pathogens for disinfection. We used specifically adapted serial protein misfolding cyclic amplification (PMCA for the quantitative detection, on steel wires providing model carriers for decontamination, of 263K scrapie seeding activity converting normal protease-sensitive into abnormal protease-resistant prion protein. Reference steel wires carrying defined amounts of scrapie infectivity were used for assay calibration, while scrapie-contaminated test steel wires were subjected to fifteen different procedures for disinfection that yielded scrapie titre reductions of ≤10(1- to ≥10(5.5-fold. As confirmed by titration in hamsters the residual scrapie infectivity on test wires could be reliably deduced for all examined disinfection procedures, from our quantitative seeding activity assay. Furthermore, we found that scrapie seeding activity present in 263K hamster brain homogenate or multiplied by PMCA of scrapie-contaminated steel wires both triggered accumulation of protease-resistant prion protein and was further propagated in a novel cell assay for 263K scrapie prions, i.e., cerebral glial cell cultures from hamsters. The findings from our PMCA- and glial cell culture assays revealed scrapie seeding activity as a biochemically and biologically replicative principle in vitro, with the former being quantitatively linked to prion infectivity detected on steel wires in vivo. When combined, our in vitro assays provide an alternative to titrations of biological

Prion protein and scrapie susceptibility

NARCIS (Netherlands)

Smits, M.A.; Bossers, A.; Schreuder, B.E.C.

1997-01-01

This article presents briefly current views on the role of prion protein (PrP) in Transmissible Spongiform Encephalopathies or prion diseases and the effect of PrP polymoryhisms on the susceptibility to these diseases, with special emphasis on sheep scrapie. The PrP genotype of sheep apears to be a

Secretome analysis of the thermophilic xylanase hyper-producer Thermomyces lanuginosus SSBP cultivated on corn cobs.

Science.gov (United States)

Winger, A M; Heazlewood, J L; Chan, L J G; Petzold, C J; Permaul, K; Singh, S

2014-11-01

Thermomyces lanuginosus is a thermophilic fungus known for its ability to produce industrially important enzymes including large amounts of xylanase, the key enzyme in hemicellulose hydrolysis. The secretome of T. lanuginosus SSBP was profiled by shotgun proteomics to elucidate important enzymes involved in hemicellulose saccharification and to characterise the presence of other industrially interesting enzymes. This study reproducibly identified a total of 74 proteins in the supernatant following growth on corn cobs. An analysis of proteins revealed nine glycoside hydrolase (GH) enzymes including xylanase GH11, β-xylosidase GH43, β-glucosidase GH3, α-galactosidase GH36 and trehalose hydrolase GH65. Two commercially produced Thermomyces enzymes, lipase and amylase, were also identified. In addition, other industrially relevant enzymes not currently explored in Thermomyces were identified including glutaminase, fructose-bisphosphate aldolase and cyanate hydratase. Overall, these data provide insight into the novel ability of a cellulase-free fungus to utilise lignocellulosic material, ultimately producing a number of enzymes important to various industrial processes.

Identification of prion protein gene polymorphisms in goats from Italian scrapie outbreaks

NARCIS (Netherlands)

Acutis, P.L.; Bossers, A.; Priem, J.; Riina, M.V.; Peletto, S.; Mazza, M.; Casalone, C.; Forloni, G.; Ru, G.; Caramelli, M.

2006-01-01

Susceptibility to scrapie in sheep is influenced by polymorphisms of the prion protein (PrP) gene, whereas no strong association between genetics and scrapie has yet been determined in goats due to the limited number of studies on these animals. In this case¿control study on 177 goats from six

An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

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Lisa Boden

Full Text Available Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS. However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years. Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic. The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

Resistance to classical scrapie in experimentally challenged goats carrying mutation K222 of the prion protein gene

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Acutis Pier Luigi

2012-02-01

Full Text Available Abstract Susceptibility of sheep to scrapie, a transmissible spongiform encephalopathy of small ruminants, is strongly influenced by polymorphisms of the prion protein gene (PRNP. Breeding programs have been implemented to increase scrapie resistance in sheep populations; though desirable, a similar approach has not yet been applied in goats. European studies have now suggested that several polymorphisms can modulate scrapie susceptibility in goats: in particular, PRNP variant K222 has been associated with resistance in case-control studies in Italy, France and Greece. In this study we investigated the resistance conferred by this variant using a natural Italian goat scrapie isolate to intracerebrally challenge five goats carrying genotype Q/Q 222 (wild type and five goats carrying genotype Q/K 222. By the end of the study, all five Q/Q 222 goats had died of scrapie after a mean incubation period of 19 months; one of the five Q/K 222 goats died after 24 months, while the other four were alive and apparently healthy up to the end of the study at 4.5 years post-challenge. All five of these animals were found to be scrapie negative. Statistical analysis showed that the probability of survival of the Q/K 222 goats versus the Q/Q 222 goats was significantly higher (p = 0.002. Our study shows that PRNP gene mutation K222 is strongly associated with resistance to classical scrapie also in experimental conditions, making it a potentially positive target for selection in the frame of breeding programs for resistance to classical scrapie in goats.

Screening of intact yeasts and cell extracts to reduce Scrapie prions during biotransformation of food waste.

Science.gov (United States)

Huyben, David; Boqvist, Sofia; Passoth, Volkmar; Renström, Lena; Allard Bengtsson, Ulrika; Andréoletti, Olivier; Kiessling, Anders; Lundh, Torbjörn; Vågsholm, Ivar

2018-02-08

Yeasts can be used to convert organic food wastes to protein-rich animal feed in order to recapture nutrients. However, the reuse of animal-derived waste poses a risk for the transmission of infectious prions that can cause neurodegeneration and fatality in humans and animals. The aim of this study was to investigate the ability of yeasts to reduce prion activity during the biotransformation of waste substrates-thereby becoming a biosafety hurdle in such a circular food system. During pre-screening, 30 yeast isolates were spiked with Classical Scrapie prions and incubated for 72 h in casein substrate, as a waste substitute. Based on reduced Scrapie seeding activity, waste biotransformation and protease activities, intact cells and cell extracts of 10 yeasts were further tested. Prion analysis showed that five yeast species reduced Scrapie seeding activity by approximately 1 log10 or 90%. Cryptococcus laurentii showed the most potential to reduce prion activity since both intact and extracted cells reduced Scrapie by 1 log10 and achieved the highest protease activity. These results show that select forms of yeast can act as a prion hurdle during the biotransformation of waste. However, the limited ability of yeasts to reduce prion activity warrants caution as a sole barrier to transmission as higher log reductions are needed before using waste-cultured yeast in circular food systems.

Cloning of a Gene Whose Expression is Increased in Scrapie and in Senile Plaques in Human Brain

Science.gov (United States)

Wietgrefe, S.; Zupancic, M.; Haase, A.; Chesebro, B.; Race, R.; Frey, W.; Rustan, T.; Friedman, R. L.

1985-12-01

A complementary DNA library was constructed from messenger RNA's extracted from the brains of mice infected with the scrapie agent. The library was differentially screened with the objectives of finding clones that might be used as markers of infection and finding clones of genes whose increased expression might be correlated with the pathological changes common to scrapie and Alzheimer's disease. A gene was identified whose expression is increased in scrapie. The complementary DNA corresponding to this gene hybridized preferentially and focally to cells in the brains of scrapie-infected animals. The cloned DNA also hybridized to the neuritic plaques found with increased frequency in brains of patients with Alzheimer's disease.

Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats

OpenAIRE

Mazza, Maria; Guglielmetti, Chiara; Ingravalle, Francesco; Brusadore, Sonia; Langeveld, Jan P. M.; Ekateriniadou, Loukia V.; Andréoletti, Olivier; Casalone, Cristina; Acutis, Pier Luigi

2017-01-01

The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres s...

Selection for scrapie resistance and simultaneous restriction of inbreeding in the rare sheep breed "Mergellander"

NARCIS (Netherlands)

Windig, J.J.; Meuleman, H.; Lansbergen, L.M.T.E.

2007-01-01

Scrapie is a fatal infectious neurodegenerative disease for which susceptibility is associated with polymorphisms in the ovine prion protein (PrP) gene. Scrapie-eradication programmes are based on eliminating the susceptible VRQ allele and/or breeding for the resistant ARR allele. In rare breeds or

Changes in HSP gene and protein expression in natural scrapie with brain damage

Science.gov (United States)

2011-01-01

Heat shock proteins (Hsp) perform cytoprotective functions such as apoptosis regulation and inflammatory response control. These proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. Several studies have proposed the implication of Hsp in prion diseases. We analysed the gene expression and protein distribution of different members of the Hsp27, Hsp70, and Hsp90 families in the central nervous system of sheep naturally infected with scrapie. Different expression profiles were observed in the areas analysed. Whereas changes in transcript levels were not observed in the cerebellum or medulla oblongata, a significant decrease in HSP27 and HSP90 was detected in the prefrontal cortex. In contrast, HSP73 was over-expressed in diencephalons of scrapie animals. Western blotting did not reveal significant differences in Hsp90 and Hsp70 protein expression between scrapie and control animals. Expression rates identified by real-time RT-PCR and western blotting were compared with the extent of classical scrapie lesions using stepwise regression. Changes in Hsp gene and protein expression were associated with prion protein deposition, gliosis and spongiosis rather than with apoptosis. Finally, immunohistochemistry revealed intense Hsp70 and Hsp90 immunolabelling in Purkinje cells of scrapie sheep. In contrast, controls displayed little or no staining in these cells. The observed differences in gene expression and protein distribution suggest that the heat shock proteins analysed play a role in the natural form of the disease. PMID:21314976

Changes in HSP gene and protein expression in natural scrapie with brain damage

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Serrano Carmen

2011-01-01

Full Text Available Abstract Heat shock proteins (Hsp perform cytoprotective functions such as apoptosis regulation and inflammatory response control. These proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. Several studies have proposed the implication of Hsp in prion diseases. We analysed the gene expression and protein distribution of different members of the Hsp27, Hsp70, and Hsp90 families in the central nervous system of sheep naturally infected with scrapie. Different expression profiles were observed in the areas analysed. Whereas changes in transcript levels were not observed in the cerebellum or medulla oblongata, a significant decrease in HSP27 and HSP90 was detected in the prefrontal cortex. In contrast, HSP73 was over-expressed in diencephalons of scrapie animals. Western blotting did not reveal significant differences in Hsp90 and Hsp70 protein expression between scrapie and control animals. Expression rates identified by real-time RT-PCR and western blotting were compared with the extent of classical scrapie lesions using stepwise regression. Changes in Hsp gene and protein expression were associated with prion protein deposition, gliosis and spongiosis rather than with apoptosis. Finally, immunohistochemistry revealed intense Hsp70 and Hsp90 immunolabelling in Purkinje cells of scrapie sheep. In contrast, controls displayed little or no staining in these cells. The observed differences in gene expression and protein distribution suggest that the heat shock proteins analysed play a role in the natural form of the disease.

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks.

Science.gov (United States)

Fragkiadaki, Eirini G; Vaccari, Gabriele; Ekateriniadou, Loukia V; Agrimi, Umberto; Giadinis, Nektarios D; Chiappini, Barbara; Esposito, Elena; Conte, Michela; Nonno, Romolo

2011-09-30

One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

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Fragkiadaki Eirini G

2011-09-01

Full Text Available Abstract One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats.

Science.gov (United States)

Mazza, Maria; Guglielmetti, Chiara; Ingravalle, Francesco; Brusadore, Sonia; Langeveld, Jan P M; Ekateriniadou, Loukia V; Andréoletti, Olivier; Casalone, Cristina; Acutis, Pier Luigi

2017-07-01

The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres seems to be formed nearly totally by the 222Q variant provides evidence that the 222K PrP variant confers resistance to conversion to PrPres formation and reinforces the view that this mutation has a protective role against classical scrapie in goats.

Spatial reversal learning in preclinical scrapie-inoculated mice.

Science.gov (United States)

Lysons, A M; Woollard, S J

1996-04-10

Acquisition and reversal of a two-choice spatial discrimination were tested in scrapie-inoculated mice. Both acquisition and reversal were normal in mice tested 138 and 103 days prior to the onset of clinical symptoms. At 65 days before onset of clinical symptoms, scrapie-inoculated mice required more trails to criterion in reversal learning, but this effect was not significant in a second experiment (68 days preclinical) and was transient: no effect was seen 33 days before symptoms. However, the course of reversal learning was abnormal in all three late preclinical groups (68, 65 and 33 days before symptoms). Reversal learning in these three groups was characterized by a rapid extinction of the original discrimination, followed by a period, absent in controls, during which performance showed no further improvement. This effect corresponds in time of onset to the appearance of characteristic neuropathological features.

Gene Expression Profiling and Association with Prion-Related Lesions in the Medulla Oblongata of Symptomatic Natural Scrapie Animals

Science.gov (United States)

Filali, Hicham; Martin-Burriel, Inmaculada; Harders, Frank; Varona, Luis; Lyahyai, Jaber; Zaragoza, Pilar; Pumarola, Martí; Badiola, Juan J.; Bossers, Alex; Bolea, Rosa

2011-01-01

The pathogenesis of natural scrapie and other prion diseases remains unclear. Examining transcriptome variations in infected versus control animals may highlight new genes potentially involved in some of the molecular mechanisms of prion-induced pathology. The aim of this work was to identify disease-associated alterations in the gene expression profiles of the caudal medulla oblongata (MO) in sheep presenting the symptomatic phase of natural scrapie. The gene expression patterns in the MO from 7 sheep that had been naturally infected with scrapie were compared with 6 controls using a Central Veterinary Institute (CVI) custom designed 4×44K microarray. The microarray consisted of a probe set on the previously sequenced ovine tissue library by CVI and was supplemented with all of the Ovis aries transcripts that are currently publicly available. Over 350 probe sets displayed greater than 2-fold changes in expression. We identified 148 genes from these probes, many of which encode proteins that are involved in the immune response, ion transport, cell adhesion, and transcription. Our results confirm previously published gene expression changes that were observed in murine models with induced scrapie. Moreover, we have identified new genes that exhibit differential expression in scrapie and could be involved in prion neuropathology. Finally, we have investigated the relationship between gene expression profiles and the appearance of the main scrapie-related lesions, including prion protein deposition, gliosis and spongiosis. In this context, the potential impacts of these gene expression changes in the MO on scrapie development are discussed. PMID:21629698

Scrapie resistant goats: Keep your herd healthy and help your business with a new gene test

Science.gov (United States)

Classical scrapie is an infectious disease of goats and sheep that causes slowly progressive but ultimately fatal degeneration of the brain, with advanced cases often hindering their ability to move properly. Currently, a single diagnosis of classical scrapie results in permanent quarantine or eutha...

Scrapie infectivity is quickly cleared in tissues of orally-infected farmed fish

Directory of Open Access Journals (Sweden)

Faoro Franco

2006-06-01

Full Text Available Abstract Background Scrapie and bovine spongiform encephalopathy (BSE belongs to the group of animal transmissible spongiform encephalopathy (TSE. BSE epidemic in the UK and elsewhere in Europe has been linked to the use of bovine meat and bone meals (MBM in the feeding of cattle. There is concern that pigs, poultry and fish bred for human consumption and fed with infected MBM would eventually develop BSE or carry residual infectivity without disease. Although there has been no evidence of infection in these species, experimental data on the susceptibility to the BSE agent of farm animals other than sheep and cow are limited only to pigs and domestic chicken. In the framework of a EU-granted project we have challenged two species of fish largely used in human food consumption, rainbow trout (Oncorhynchus mykiss and turbot (Scophthalmus maximus, with a mouse-adapted TSE strain (scrapie 139A, to assess the risk related to oral consumption of TSE contaminated food. In trout, we also checked the "in vitro" ability of the pathological isoform of the mouse prion protein (PrPSc to cross the intestinal epithelium when added to the mucosal side of everted intestine. Results Fish challenged with a large amount of scrapie mouse brain homogenate by either oral or parenteral routes, showed the ability to clear the majority of infectivity load. None of the fish tissues taken at different time points after oral or parenteral inoculation was able to provoke scrapie disease after intracerebral inoculation in recipient mice. However, a few recipient mice were positive for PrPSc and spongiform lesions in the brain. We also showed a specific binding of PrPSc to the mucosal side of fish intestine in the absence of an active uptake of the prion protein through the intestinal wall. Conclusion These results indicate that scrapie 139A, and possibly BSE, is quickly removed from fish tissues despite evidence of a prion like protein in fish and of a specific binding of Pr

Detection of PrPres in genetically susceptible fetuses from sheep with natural scrapie.

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María Carmen Garza

Full Text Available Scrapie is a transmissible spongiform encephalopathy with a wide PrPres dissemination in many non-neural tissues and with high levels of transmissibility within susceptible populations. Mechanisms of transmission are incompletely understood. It is generally assumed that it is horizontally transmitted by direct contact between animals or indirectly through the environment, where scrapie can remain infectious for years. In contrast, in utero vertical transmission has never been demonstrated and has rarely been studied. Recently, the use of the protein misfolding cyclic amplification technique (PMCA has allowed prion detection in various tissues and excretions in which PrPres levels have been undetectable by traditional assays. The main goal of this study was to detect PrPres in fetal tissues and the amniotic fluid from natural scrapie infected ewes using the PMCA technique. Six fetuses from three infected pregnant ewes in an advanced clinical stage of the disease were included in the study. From each fetus, amniotic fluid, brain, spleen, ileo-cecal valve and retropharyngeal lymph node samples were collected and analyzed using Western blotting and PMCA. Although all samples were negative using Western blotting, PrPres was detected after in vitro amplification. Our results represent the first time the biochemical detection of prions in fetal tissues, suggesting that the in utero transmission of scrapie in natural infected sheep might be possible.

Prions in milk from ewes incubating natural scrapie.

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Caroline Lacroux

2008-12-01

Full Text Available Since prion infectivity had never been reported in milk, dairy products originating from transmissible spongiform encephalopathy (TSE-affected ruminant flocks currently enter unrestricted into the animal and human food chain. However, a recently published study brought the first evidence of the presence of prions in mammary secretions from scrapie-affected ewes. Here we report the detection of consistent levels of infectivity in colostrum and milk from sheep incubating natural scrapie, several months prior to clinical onset. Additionally, abnormal PrP was detected, by immunohistochemistry and PET blot, in lacteal ducts and mammary acini. This PrP(Sc accumulation was detected only in ewes harbouring mammary ectopic lymphoid follicles that developed consequent to Maedi lentivirus infection. However, bioassay revealed that prion infectivity was present in milk and colostrum, not only from ewes with such lympho-proliferative chronic mastitis, but also from those displaying lesion-free mammary glands. In milk and colostrum, infectivity could be recovered in the cellular, cream, and casein-whey fractions. In our samples, using a Tg 338 mouse model, the highest per ml infectious titre measured was found to be equivalent to that contained in 6 microg of a posterior brain stem from a terminally scrapie-affected ewe. These findings indicate that both colostrum and milk from small ruminants incubating TSE could contribute to the animal TSE transmission process, either directly or through the presence of milk-derived material in animal feedstuffs. It also raises some concern with regard to the risk to humans of TSE exposure associated with milk products from ovine and other TSE-susceptible dairy species.

Short-term study of the uptake of PrPSc by the Peyer’s patches in hamsters after oral exposure to scrapie

DEFF Research Database (Denmark)

Bergström, Ann-Louise; Jensen, Tim Kåre; Heegaard, Peter M. H.

2006-01-01

The disease-associated prion protein (PrPSc) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrPSc detection in the Peyer's patches after oral exposure to scrapie is 69 days post-infection. To ......The disease-associated prion protein (PrPSc) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrPSc detection in the Peyer's patches after oral exposure to scrapie is 69 days post...

Prion protein genotype survey confirms low frequency of scrapie-resistant K222 allele in British goat herds

NARCIS (Netherlands)

Goldmann, W.; Stewart, P.; Marier, E.; Konold, T.; Street, S.; Windl, O.; Ortiz-Pelaez, A.; Langeveld, J.

2016-01-01

Scrapie in goats is a transmissible, fatal prion disease, which is endemic in the British goat population. The recent success in defining caprine PRNP gene variants that provide resistance to experimental and natural classical scrapie has prompted the authors to conduct a survey of PRNP genotypes

Evaluation of two commercial, rapid, ELISA kits testing or scrapie in retro-pharyngeal lymph nodes in sheep

NARCIS (Netherlands)

Kittelberger, R.; McIntuyre, L.; Watts, S.; MacDiarmid, S.; Hannah, M.J.; Jenner, J.; Bueno, R.; Swainsbury, R.; Langeveld, J.P.M.; Keulen, van L.J.M.; Zijderveld, van F.G.; Wemheuer, W.M.; Richt, J.A.; Sorenson, S.J.; Pigott, C.J.; O'Keefe, J.S.

2014-01-01

AIMS: To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN)

Scrapie e seu diagnóstico diferencial em ovinos no Mato Grosso do Sul

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Héllen M. Martins

2012-12-01

Full Text Available Scrapie é uma doença infecciosa, neurodegenerativa fatal, causada pelo príon scrapie (PrPsc. Apresenta-se tanto na forma clássica em ovinos e caprinos geneticamente susceptíveis quanto na forma atípica em ovinos. A primeira notificação oficial do Brasil à Organização Mundial de Saúde Animal (OIE, um caso da forma clássica diagnosticado no Rio Grande do Sul ocorreu em 1985, mas a doença já havia sido diagnosticada no mesmo Estado em 1978. Este trabalho objetivou descrever dois surtos de Scrapie em ovinos em Mato Grosso do Sul (MS, Brasil e investigar, por meio de imuno-histoquímica (IHQ a presença de PrPsc no Sistema Nervoso Central (SNC de ovinos examinados entre 2003 e 2010. Na primeira parte observaram-se dois ovinos com sinais clínicos típicos de scrapie, detalhando-se os sinais neurológicos, dados epidemiológicos, histopatológicos e amostras teciduais em duplicata desses ovinos foram encaminhadas para realização de diagnóstico de Raiva e para diagnóstico IHQ para príon. Na segunda parte realizou-se levantamento de laudos de necropsia e diagnósticos histopatológicos de ovinos, no período de maio de 2003 a março de 2010. Amostras de sistema nervoso central de 51 casos foram selecionados, incluindo os dois já com diagnóstico de Scrapie mencionados acima; os tecido de todos esses ovinos foram submetidos à IHQ para detecção de proteína priônica. Os 49 ovinos avaliados apresentaram resultado negativo na IHQ para príon.

The scrapie disease process is unaffected by ionizing radiation

International Nuclear Information System (INIS)

Fraser, H.; Farquhar, C.F.; McConnell, I.; Davies, D.

1989-01-01

The incubation period of scrapie, its degenerative neuropathology and the replication of its causal unconventional virus are all tightly controlled parameters of the experimental disease in mice. Each parameter can vary depending on the strain and dose of virus, on the route of infection, and on the host genotype. Exposure to whole-body gamma-irradiation from Cesium 137 has no effect on the progress or development of the disease, based on the three independent indices of incubation period, neuropathology, or infectibility by high or low doses of virus. These results are based on an extensive series of experiments in many mouse strains and are consistent using different strains (ME7, 22A, 79A, 87V) and doses of virus, routes of infection, timing and dose of radiation (3-15 Gy) administered as single or fractionated exposures with or without bone-marrow (b.m.) replacement therapy. Levels of infection in the spleen are unaltered after lethal whole-body irradiation of the scrapie-infected host, despite several-fold reductions in tissue mass due to the loss of proliferating myeloid and lymphoid precursor cells and their progeny. Contrary to our earlier suggestion, scrapie infection with the 22A virus does not reduce the effectiveness of post-exposure bone-marrow replacements to recolonize an infected host after repeated ionizing radiation totalling 15Gy. This work narrows the search for the candidate cells and biosynthetic systems which replicate the virus in the lymphoreticular and central nervous systems. Many programmed cellular events are radiation sensitive but protein synthesis is extremely radioresistant

Intraepithelial and interstitial deposition of pathological prion protein in kidneys of scrapie-affected sheep.

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Ciriaco Ligios

Full Text Available Prions have been documented in extra-neuronal and extra-lymphatic tissues of humans and various ruminants affected by Transmissible Spongiform Encephalopathy (TSE. The presence of prion infectivity detected in cervid and ovine blood tempted us to reason that kidney, the organ filtrating blood derived proteins, may accumulate disease associated PrP(Sc. We collected and screened kidneys of experimentally, naturally scrapie-affected and control sheep for renal deposition of PrP(Sc from distinct, geographically separated flocks. By performing Western blot, PET blot analysis and immunohistochemistry we found intraepithelial (cortex, medulla and papilla and occasional interstitial (papilla deposition of PrP(Sc in kidneys of scrapie-affected sheep. Interestingly, glomerula lacked detectable signals indicative of PrP(Sc. PrP(Sc was also detected in kidneys of subclinical sheep, but to significantly lower degree. Depending on the stage of the disease the incidence of PrP(Sc in kidney varied from approximately 27% (subclinical to 73.6% (clinical in naturally scrapie-affected sheep. Kidneys from flocks without scrapie outbreak were devoid of PrP(Sc. Here we demonstrate unexpectedly frequent deposition of high levels of PrP(Sc in ovine kidneys of various flocks. Renal deposition of PrP(Sc is likely to be a pre-requisite enabling prionuria, a possible co-factor of horizontal prion-transmission in sheep.

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

OpenAIRE

Fragkiadaki Eirini G; Vaccari Gabriele; Ekateriniadou Loukia V; Agrimi Umberto; Giadinis Nektarios D; Chiappini Barbara; Esposito Elena; Conte Michela; Nonno Romolo

2011-01-01

Abstract One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates ...

Medulla oblongata transcriptome changes during presymptomatic natural scrapie and their association with prion-related lesions.

Science.gov (United States)

Filali, Hicham; Martin-Burriel, Inmaculada; Harders, Frank; Varona, Luis; Serrano, Carmen; Acín, Cristina; Badiola, Juan J; Bossers, Alex; Bolea, Rosa

2012-08-16

The pathogenesis of natural scrapie and other prion diseases is still poorly understood. Determining the variations in the transcriptome in the early phases of the disease might clarify some of the molecular mechanisms of the prion-induced pathology and allow for the development of new biomarkers for diagnosis and therapy. This study is the first to focus on the identification of genes regulated during the preclinical phases of natural scrapie in the ovine medulla oblongata (MO) and the association of these genes with prion deposition, astrocytosis and spongiosis. A custom microarray platform revealed that 86 significant probes had expression changes greater than 2-fold. From these probes, we identified 32 genes with known function; the highest number of regulated genes was included in the phosphoprotein-encoding group. Genes encoding extracellular marker proteins and those involved in the immune response and apoptosis were also differentially expressed. In addition, we investigated the relationship between the gene expression profiles and the appearance of the main scrapie-associated brain lesions. Quantitative Real-time PCR was used to validate the expression of some of the regulated genes, thus showing the reliability of the microarray hybridization technology. Genes involved in protein and metal binding and oxidoreductase activity were associated with prion deposition. The expression of glial fibrillary acidic protein (GFAP) was associated with changes in the expression of genes encoding proteins with oxidoreductase and phosphatase activity, and the expression of spongiosis was related to genes encoding extracellular matrix components or transmembrane transporters. This is the first genome-wide expression study performed in naturally infected sheep with preclinical scrapie. As in previous studies, our findings confirm the close relationship between scrapie and other neurodegenerative diseases.

Lack of prion accumulation in lymphoid tissues of PRNP ARQ/ARR sheep intracranially inoculated with the agent of scrapie.

Science.gov (United States)

Greenlee, Justin J; Kunkle, Robert A; Richt, Jürgen A; Nicholson, Eric M; Hamir, Amir N

2014-01-01

Sheep scrapie is a transmissible spongiform encephalopathy that can be transmitted horizontally. The prion protein gene (PRNP) profoundly influences the susceptibility of sheep to the scrapie agent and the tissue levels and distribution of PrPSc in affected sheep. The purpose of this study was to compare the survival time and PrPSc tissue distribution in sheep with highly resistant and highly susceptible PRNP genotypes after intracranial inoculation of the agent of scrapie. Five sheep each of genotype VRQ/VRQ, VRQ/ARR or ARQ/ARR were inoculated. Sheep were euthanized when clinical signs of scrapie became severe. Clinical signs, microscopic lesions, and western blot profiles were uniform across genotypes and consistent with manifestations of classical scrapie. Mean survival time differences were associated with the 171 polymorphic site with VRQ/VRQ sheep surviving 18 months, whereas VRQ/ARR and ARQ/ARR sheep survived 60 and 56 months, respectively. Labeling of PrPSc by immunohistochemistry revealed similar accumulations in central nervous system tissues regardless of host genotype. Immunoreactivity for PrPSc in lymphoid tissue was consistently abundant in VRQ/VRQ, present but confined to tonsil or retropharyngeal lymph node in 4/5 VRQ/ARR, and totally absent in ARQ/ARR sheep. The results of this study demonstrate the susceptibility of sheep with the ARQ/ARR genotype to scrapie by the intracranial inoculation route with PrPSc accumulation in CNS tissues, but prolonged incubation times and lack of PrPSc in lymphoid tissue.

Goats singly heterozygous for PRNP S146 or K222 orally inoculated with classical scrapie at birth show no disease at ages well beyond six years

Science.gov (United States)

Scrapie is a transmissible spongiform encephalopathy of sheep and goats, and scrapie eradication programs in many parts of the world rely on strong genetic resistance to classical scrapie in sheep. However, the utility of putative resistance alleles in goats has been a focus of research because goat...

Evidence for more cost-effective surveillance options for bovine spongiform encephalopathy (BSE) and scrapie in Great Britain.

Science.gov (United States)

Wall, Ben A; Arnold, Mark E; Radia, Devi; Gilbert, Will; Ortiz-Pelaez, Angel; Stärk, Katharina Dc; Van Klink, Ed; Guitian, Javier

2017-08-10

Transmissible spongiform encephalopathies (TSEs) are an important public health concern. Since the emergence of bovine spongiform encephalopathy (BSE) during the 1980s and its link with human Creutzfeldt-Jakob disease, active surveillance has been a key element of the European Union's TSE control strategy. Success of this strategy means that now, very few cases are detected compared with the number of animals tested. Refining surveillance strategies would enable resources to be redirected towards other public health priorities. Cost-effectiveness analysis was performed on several alternative strategies involving reducing the number of animals tested for BSE and scrapie in Great Britain and, for scrapie, varying the ratio of sheep sampled in the abattoir to fallen stock (which died on the farm). The most cost-effective strategy modelled for BSE involved reducing the proportion of fallen stock tested from 100% to 75%, producing a cost saving of ca GBP 700,000 per annum. If 50% of fallen stock were tested, a saving of ca GBP 1.4 million per annum could be achieved. However, these reductions are predicted to increase the period before surveillance can detect an outbreak. For scrapie, reducing the proportion of abattoir samples was the most cost-effective strategy modelled, with limited impact on surveillance effectiveness. This article is copyright of The Authors, 2017.

Quantitating PrP Polymorphisms Present in Prions from Heterozygous Scrapie-Infected Sheep.

Science.gov (United States)

Silva, Christopher J; Erickson-Beltran, Melissa L; Hui, Colleen; Badiola, Juan José; Nicholson, Eric M; Requena, Jesús R; Bolea, Rosa

2017-01-03

Scrapie is a prion (PrP Sc ) disease of sheep. The incubation period of sheep scrapie is strongly influenced by polymorphisms at positions 136, 154, and 171 of a sheep's normal cellular prion protein (PrP C ). Chymotrypsin was used to digest sheep recombinant PrP to identify a set of characteristic peptides [M 132 LGSXMSRPL 141 (X = A or V), Y 153 XENMY 158 (X,= H or R), and Y 166 RPVDXY 172 (X = H, K, Q, or R)] that could be used to detect and quantitate polymorphisms at positions 136, 154, and 171 of sheep PrP C or PrP Sc . These peptides were used to develop a multiple reaction monitoring method (MRM) to detect the amounts of a particular polymorphism in a sample of PrP Sc isolated from sheep heterozygous for their PrP C proteins. The limit of detection for these peptides was less than 50 attomole. Spinal cord tissue from heterozygous (ARQ/VRQ or ARH/ARQ) scrapie-infected Rasa Aragonesa sheep was analyzed using this MRM method. Both sets of heterozygotes show the presence of both polymorphisms in PrP Sc . This was true for samples containing both proteinase K (PK)-sensitive and PK-resistant PrP Sc and samples containing only the PK-resistant PrP Sc . These results show that heterozygous animals contain PrP Sc that is composed of significant amounts of both PrP polymorphisms.

Deletion of protease-activated receptor 2 prolongs survival of scrapie-inoculated mice

Czech Academy of Sciences Publication Activity Database

Matěj, R.; Olejár, Tomáš; Janoušková, O.; Holada, K.

2012-01-01

Roč. 93, č. 9 (2012), s. 2057-2061 ISSN 0022-1317 Institutional support: RVO:67985823 Keywords : protease-activated receptor (PAR2) * scrapie * neurodegenerative disorders Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.127, year: 2012

A bovine cell line that can be infected by natural sheep scrapie prions.

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Anja M Oelschlegel

Full Text Available Cell culture systems represent a crucial part in basic prion research; yet, cell lines that are susceptible to prions, especially to field isolated prions that were not adapted to rodents, are very rare. The purpose of this study was to identify and characterize a cell line that was susceptible to ruminant-derived prions and to establish a stable prion infection within it. Based on species and tissue of origin as well as PrP expression rate, we pre-selected a total of 33 cell lines that were then challenged with natural and with mouse propagated BSE or scrapie inocula. Here, we report the successful infection of a non-transgenic bovine cell line, a sub-line of the bovine kidney cell line MDBK, with natural sheep scrapie prions. This cell line retained the scrapie infection for more than 200 passages. Selective cloning resulted in cell populations with increased accumulation of PrPres, although this treatment was not mandatory for retaining the infection. The infection remained stable, even under suboptimal culture conditions. The resulting infectivity of the cells was confirmed by mouse bioassay (Tgbov mice, Tgshp mice. We believe that PES cells used together with other prion permissive cell lines will prove a valuable tool for ongoing efforts to understand and defeat prions and prion diseases.

Evaluation of efficacy of prion reduction filters using blood from an endogenously infected 263K scrapie hamster model.

Science.gov (United States)

McLeod, Neil P; Nugent, Philip; Dixon, Douglas; Dennis, Mike; Cornwall, Mark; Mallinson, Gary; Watkins, Nicholas; Thomas, Stephen; Sutton, J Mark

2015-10-01

The P-Capt prion reduction filter (MacoPharma) removes prion infectivity in model systems. This independent evaluation assesses prion removal from endogenously infected animal blood, using CE-marked P-Capt filters, and replicates the proposed use of the filter within the UK Blood Services. Two units of blood, generated from 263K scrapie-infected hamsters, were processed using leukoreduction filters (LXT-quadruple, MacoPharma). Approximately 100 mL of the removed plasma was added back to the red blood cells (RBCs) and the blood was filtered through a P-Capt filter. Samples of unfiltered whole blood, the prion filter input (RBCs plus plasma and SAGM [RBCPS]), and prion-filtered leukoreduced blood (PFB) were injected intracranially into hamsters. Clinical symptoms were monitored for 500 ± 1 day, and brains were assessed for spongiosis and prion protein deposit. In Filtration Run 1, none of the 50 challenged animals were diagnosed with scrapie after inoculation with the RBCPS fraction, while two of 190 hamsters injected with PFB were infected. In Filtration Run 2, one of 49 animals injected with RBCPS and two of 193 hamsters injected with PFB were infected. Run 1 reduced the infectious dose (ID) by 1.467 log (>1.187 log and <0.280 log for leukoreduction and prion filtration, respectively). Run 2 reduced prion infectivity by 1.424 log (1.127 and 0.297 log, respectively). Residual infectivity was estimated at 0.212 ± 0.149 IDs/mL (Run 1) and 0.208 ± 0.147 IDs/mL (Run 2). Leukoreduction removed the majority of infectivity from 263K scrapie hamster blood. The P-Capt filter removed a proportion of the remaining infectivity, but residual infectivity was observed in two independent processes. © 2015 AABB.

Scrapie affects the maturation cycle and immune complex trapping by follicular dendritic cells in mice.

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Gillian McGovern

2009-12-01

Full Text Available Transmissible spongiform encephalopathies (TSEs or prion diseases are infectious neurological disorders of man and animals, characterised by abnormal disease-associated prion protein (PrP(d accumulations in the brain and lymphoreticular system (LRS. Prior to neuroinvasion, TSE agents often accumulate to high levels within the LRS, apparently without affecting immune function. However, our analysis of scrapie-affected sheep shows that PrP(d accumulations within the LRS are associated with morphological changes to follicular dendritic cells (FDCs and tingible body macrophages (TBMs. Here we examined FDCs and TBMs in the mesenteric lymph nodes (MLNs of scrapie-affected mice by light and electron microscopy. In MLNs from uninfected mice, FDCs could be morphologically categorised into immature, mature and regressing forms. However, in scrapie-affected MLNs this maturation cycle was adversely affected. FDCs characteristically trap and retain immune complexes on their surfaces, which they display to B-lymphocytes. In scrapie-affected MLNs, some FDCs were found where areas of normal and abnormal immune complex retention occurred side by side. The latter co-localised with PrP(d plasmalemmal accumulations. Our data suggest this previously unrecognised morphology represents the initial stage of an abnormal FDC maturation cycle. Alterations to the FDCs included PrP(d accumulation, abnormal cell membrane ubiquitin and excess immunoglobulin accumulation. Regressing FDCs, in contrast, appeared to lose their membrane-attached PrP(d. Together, these data suggest that TSE infection adversely affects the maturation and regression cycle of FDCs, and that PrP(d accumulation is causally linked to the abnormal pathology observed. We therefore support the hypothesis that TSEs cause an abnormality in immune function.

Dysfunction of mitochondrial dynamics in the brains of scrapie-infected mice

International Nuclear Information System (INIS)

Choi, Hong-Seok; Choi, Yeong-Gon; Shin, Hae-Young; Oh, Jae-Min; Park, Jeong-Ho; Kim, Jae-Il; Carp, Richard I.; Choi, Eun-Kyoung; Kim, Yong-Sun

2014-01-01

Highlights: • Mfn1 and Fis1 are significantly increased in the hippocampal region of the ME7 prion-infected brain, whereas Dlp1 is significantly decreased in the infected brain. • Dlp1 is significantly decreased in the cytosolic fraction of the hippocampus in the infected brain. • Neuronal mitochondria in the prion-infected brains are enlarged and swollen compared to those of control brains. • There are significantly fewer mitochondria in the ME7-infected brain compared to the number in control brain. - Abstract: Mitochondrial dysfunction is a common and prominent feature of many neurodegenerative diseases, including prion diseases; it is induced by oxidative stress in scrapie-infected animal models. In previous studies, we found swelling and dysfunction of mitochondria in the brains of scrapie-infected mice compared to brains of controls, but the mechanisms underlying mitochondrial dysfunction remain unclear. To examine whether the dysregulation of mitochondrial proteins is related to the mitochondrial dysfunction associated with prion disease, we investigated the expression patterns of mitochondrial fusion and fission proteins in the brains of ME7 prion-infected mice. Immunoblot analysis revealed that Mfn1 was up-regulated in both whole brain and specific brain regions, including the cerebral cortex and hippocampus, of ME7-infected mice compared to controls. Additionally, expression levels of Fis1 and Mfn2 were elevated in the hippocampus and the striatum, respectively, of the ME7-infected brain. In contrast, Dlp1 expression was significantly reduced in the hippocampus in the ME7-infected brain, particularly in the cytosolic fraction. Finally, we observed abnormal mitochondrial enlargement and histopathological change in the hippocampus of the ME7-infected brain. These observations suggest that the mitochondrial dysfunction, which is presumably caused by the dysregulation of mitochondrial fusion and fission proteins, may contribute to the

Dysfunction of mitochondrial dynamics in the brains of scrapie-infected mice

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Choi, Hong-Seok [Department of Microbiology, College of Medicine, Hallym University, 1 Okcheon-dong, Chuncheon, Gangwon-do 200-702 (Korea, Republic of); Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Choi, Yeong-Gon; Shin, Hae-Young; Oh, Jae-Min [Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Park, Jeong-Ho [Department of Microbiology, College of Medicine, Hallym University, 1 Okcheon-dong, Chuncheon, Gangwon-do 200-702 (Korea, Republic of); Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Kim, Jae-Il [Department of Food Science and Nutrition, Pukyong National University, 599-1 Daeyeon-3-dong, Nam-gu, Busan 608-737 (Korea, Republic of); Carp, Richard I. [New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314 (United States); Choi, Eun-Kyoung, E-mail: ekchoi@hallym.ac.kr [Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of); Kim, Yong-Sun, E-mail: yskim@hallym.ac.kr [Department of Microbiology, College of Medicine, Hallym University, 1 Okcheon-dong, Chuncheon, Gangwon-do 200-702 (Korea, Republic of); Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyang-dong, Dongan-gu, Anyang, Gyeonggi-do 431-060 (Korea, Republic of)

2014-05-30

Highlights: • Mfn1 and Fis1 are significantly increased in the hippocampal region of the ME7 prion-infected brain, whereas Dlp1 is significantly decreased in the infected brain. • Dlp1 is significantly decreased in the cytosolic fraction of the hippocampus in the infected brain. • Neuronal mitochondria in the prion-infected brains are enlarged and swollen compared to those of control brains. • There are significantly fewer mitochondria in the ME7-infected brain compared to the number in control brain. - Abstract: Mitochondrial dysfunction is a common and prominent feature of many neurodegenerative diseases, including prion diseases; it is induced by oxidative stress in scrapie-infected animal models. In previous studies, we found swelling and dysfunction of mitochondria in the brains of scrapie-infected mice compared to brains of controls, but the mechanisms underlying mitochondrial dysfunction remain unclear. To examine whether the dysregulation of mitochondrial proteins is related to the mitochondrial dysfunction associated with prion disease, we investigated the expression patterns of mitochondrial fusion and fission proteins in the brains of ME7 prion-infected mice. Immunoblot analysis revealed that Mfn1 was up-regulated in both whole brain and specific brain regions, including the cerebral cortex and hippocampus, of ME7-infected mice compared to controls. Additionally, expression levels of Fis1 and Mfn2 were elevated in the hippocampus and the striatum, respectively, of the ME7-infected brain. In contrast, Dlp1 expression was significantly reduced in the hippocampus in the ME7-infected brain, particularly in the cytosolic fraction. Finally, we observed abnormal mitochondrial enlargement and histopathological change in the hippocampus of the ME7-infected brain. These observations suggest that the mitochondrial dysfunction, which is presumably caused by the dysregulation of mitochondrial fusion and fission proteins, may contribute to the

Aberrant ERK 1/2 complex activation and localization in scrapie-infected GT1-1 cells

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Didonna Alessandro

2010-08-01

Full Text Available Abstract Background Fatal neurodegenerative disorders such as Creutzfeldt-Jakob and Gerstmann-Sträussler-Scheinker diseases in humans, scrapie and bovine spongiform encephalopathy in animals, are characterized by the accumulation in the brain of a pathological form of the prion protein (PrP denominated PrPSc. The latter derives from the host cellular form, PrPC, through a process whereby portions of its α-helical and coil structures are refolded into β-sheet structures. Results In this work, the widely known in vitro model of prion replication, hypothalamic GT1-1 cell line, was used to investigate cellular and molecular responses to prion infection. The MAP kinase cascade was dissected to assess the phosphorylation levels of src, MEK 1/2 and ERK 1/2 signaling molecules, both before and after prion infection. Our findings suggest that prion replication leads to a hyper-activation of this pathway. Biochemical analysis was complemented with immunofluorescence studies to map the localization of the ERK complex within the different cellular compartments. We showed how the ERK complex relocates in the cytosol upon prion infection. We correlated these findings with an impairment of cell growth in prion-infected GT1-1 cells as probed by MTT assay. Furthermore, given the persistent urgency in finding compounds able to cure prion infected cells, we tested the effects on the ERK cascade of two molecules known to block prion replication in vitro, quinacrine and Fab D18. We were able to show that while these two compounds possess similar effects in curing prion infection, they affect the MAP kinase cascade differently. Conclusions Taken together, our results help shed light on the molecular events involved in neurodegeneration and neuronal loss in prion infection and replication. In particular, the combination of chronic activation and aberrant localization of the ERK complex may lead to a lack of essential neuroprotective and survival factors

Prion protein gene variability in Spanish goats. Inference through susceptibility to classical scrapie strains and pathogenic distribution of peripheral PrP(sc..

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Cristina Acín

Full Text Available Classical scrapie is a neurological disorder of the central nervous system (CNS characterized by the accumulation of an abnormal, partially protease resistant prion protein (PrP(sc in the CNS and in some peripheral tissues in domestic small ruminants. Whereas the pathological changes and genetic susceptibility of ovine scrapie are well known, caprine scrapie has been less well studied. We report here a pathological study of 13 scrapie-affected goats diagnosed in Spain during the last 9 years. We used immunohistochemical and biochemical techniques to discriminate between classical and atypical scrapie and bovine spongiform encephalopathy (BSE. All the animals displayed PrP(sc distribution patterns and western blot characteristics compatible with classical scrapie. In addition, we determined the complete open reading frame sequence of the PRNP in these scrapie-affected animals. The polymorphisms observed were compared with those of the herd mates (n = 665 and with the frequencies of healthy herds (n = 581 of native Spanish goats (Retinta, Pirenaica and Moncaina and other worldwide breeds reared in Spain (Saanen, Alpine and crossbreed. In total, sixteen polymorphic sites were identified, including the known amino acid substitutions at codons G37V, G127S, M137I, I142M, H143R, R151H, R154H, R211Q, Q222K, G232W, and P240S, and new polymorphisms at codons G74D, M112T, R139S, L141F and Q215R. In addition, the known 42, 138 and 179 silent mutations were detected, and one new one is reported at codon 122. The genetic differences observed in the population studied have been attributed to breed and most of the novel polymorphic codons show frequencies lower than 5%. This work provides the first basis of polymorphic distribution of PRNP in native and worldwide goat breeds reared in Spain.

Primary transmission of chronic wasting disease versus scrapie prions from small ruminants to transgenic mice expressing ovine or cervid prion protein.

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Madsen-Bouterse, Sally A; Schneider, David A; Zhuang, Dongyue; Dassanayake, Rohana P; Balachandran, Aru; Mitchell, Gordon B; O'Rourke, Katherine I

2016-09-01

Development of mice expressing either ovine (Tg338) or cervid (TgElk) prion protein (PrP) have aided in characterization of scrapie and chronic wasting disease (CWD), respectively. Experimental inoculation of sheep with CWD prions has demonstrated the potential for interspecies transmission but, infection with CWD versus classical scrapie prions may be difficult to differentiate using validated diagnostic platforms. In this study, mouse bioassay in Tg338 and TgElk was utilized to evaluate transmission of CWD versus scrapie prions from small ruminants. Mice (≥5 per homogenate) were inoculated with brain homogenates from clinically affected sheep or goats with naturally acquired classical scrapie, white-tailed deer with naturally acquired CWD (WTD-CWD) or sheep with experimentally acquired CWD derived from elk (sheep-passaged-CWD). Survival time (time to clinical disease) and attack rates (brain accumulation of protease resistant PrP, PrPres) were determined. Inoculation with classical scrapie prions resulted in clinical disease and 100 % attack rates in Tg338, but no clinical disease at endpoint (>300 days post-inoculation, p.i.) and low attack rates (6.8 %) in TgElk. Inoculation with WTD-CWD prions yielded no clinical disease or brain PrPres accumulation in Tg338 at endpoint (>500 days p.i.), but rapid onset of clinical disease (~121 days p.i.) and 100 % attack rate in TgElk. Sheep-passaged-CWD resulted in transmission to both mouse lines with 100 % attack rates at endpoint in Tg338 and an attack rate of ~73 % in TgElk with some culled due to clinical disease. These primary transmission observations demonstrate the potential of bioassay in Tg338 and TgElk to help differentiate possible infection with CWD versus classical scrapie prions in sheep and goats.

Determining the relative susceptibility of four prion protein genotypes to atypical scrapie

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Atypical scrapie is a sheep prion (PrPSc) disease whose epidemiology is consistent with a sporadic origin and is associated with specific polymorphisms of the normal cellular prion protein (PrPC). We describe a mass spectrometry-based method of detecting and quantifying the polymorphisms of sheep P...

Membrane toxicity of abnormal prion protein in adrenal chromaffin cells of scrapie infected sheep.

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Gillian McGovern

Full Text Available Transmissible spongiform encephalopathies (TSEs or prion diseases are associated with accumulations of disease specific PrP (PrP(d in the central nervous system (CNS and often the lymphoreticular system (LRS. Accumulations have additionally been recorded in other tissues including the peripheral nervous system and adrenal gland. Here we investigate the effect of sheep scrapie on the morphology and the accumulation of PrP(d in the adrenal medulla of scrapie affected sheep using light and electron microscopy. Using immunogold electron microscopy, non-fibrillar forms of PrP(d were shown to accumulate mainly in association with chromaffin cells, occasional nerve endings and macrophages. PrP(d accumulation was associated with distinctive membrane changes of chromaffin cells including increased electron density, abnormal linearity and invaginations. Internalisation of PrP(d from the chromaffin cell plasma membrane occurred in association with granule recycling following hormone exocytosis. PrP(d accumulation and internalisation from membranes is similarly associated with perturbations of membrane structure and trafficking in CNS neurons and tingible body macrophages of the LRS. These data suggest that a major toxic effect of PrP(d is at the level of plasma membranes. However, the precise nature of PrP(d-membrane toxicity is tissue and cell specific suggesting that the normal protein may act as a multi-functional scaffolding molecule. We further suggest that the co-localisation of PrP(d with exocytic granules of the hormone trafficking system may provide an additional source of infectivity in blood.

Comparisons of TRAC-PD2 calculations with Semiscale Mod-3 small-break tests

International Nuclear Information System (INIS)

Gilbert, J.S.; Sahota, M.S.; Boyack, B.E.; Booker, C.P.; Meier, J.K.

1981-01-01

Five experiments conducted in the Semiscale Mod-3 facility at the Idaho National Engineering Laboratory (INEL) were calculated using the latest released version of the Transient Reactor Analysis Code (TRAC-PD2). The results were used to assess TRAC-PD2 predictions of thermal-hydraulic phenomena and the effects of pump operation on system response during slow transients. Tests S-SB-P1, S-SB-P2, and S-SB-P7 simulated equivalent 2.5% communicative cold-leg breaks for early pump-trip (pumps-off), intermediate pump-trip (pumps-on), and late pump-trip (pumps-on) operation, respectively. Tests S-SB-P3 and S-SB-P4 simulated equivalent 2.5% communicative hot-leg breaks for pumps-off and pumps-on operation, respectively. Parameters examined in the study included primary system mass distribution, mass inventory, and void fraction distribution

Prion protein genotype survey confirms low frequency of scrapie-resistant K222 allele in British goat herds.

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Goldmann, W; Marier, E; Stewart, P; Konold, T; Street, S; Langeveld, J; Windl, O; Ortiz-Pelaez, A

2016-02-13

Scrapie in goats is a transmissible, fatal prion disease, which is endemic in the British goat population. The recent success in defining caprine PRNP gene variants that provide resistance to experimental and natural classical scrapie has prompted the authors to conduct a survey of PRNP genotypes in 10 goat breeds and 52 herds to find goats with the resistant K222 allele. They report here the frequencies in 1236 tested animals of the resistance-associated K222 and several other alleles by breed and herd. Eight animals were found to be heterozygous QK222 goats (0.64 per cent genotype frequency, 95 per cent CI 0.28 to 1.27 per cent) but no homozygous KK222 goats were detected. The K222 allele was found in Saanen, Toggenburg and Anglo-Nubian goats. The fact that only a few goats with the K222 allele have been identified does not preclude the possibility to design and implement successful breeding programmes at national level. British Veterinary Association.

Predicting the impact of selection for scrapie resistance on PRNP genotype frequencies in goats.

Science.gov (United States)

Sacchi, Paola; Rasero, Roberto; Ru, Giuseppe; Aiassa, Eleonora; Colussi, Silvia; Ingravalle, Francesco; Peletto, Simone; Perrotta, Maria Gabriella; Sartore, Stefano; Soglia, Dominga; Acutis, Pierluigi

2018-03-06

The European Union has implemented breeding programmes to increase scrapie resistance in sheep. A similar approach can be applied also in goats since the K222 allele provides a level of resistance equivalent to that of ARR in sheep. The European Food Safety Authority stated that breeding for resistance could be offered as an option for Member States to control classical scrapie in goats. We assessed the impact of different breeding strategies on PRNP genotype frequencies using a mathematical model that describes in detail the evolution of K222 in two goat breeds, Chamois Coloured and Saanen. Different patterns of age structure and replacement rate were modelled as factors affecting response to selection. Breeding for scrapie resistance can be implemented in goats, even though the initial K222 frequencies in these breeds are not particularly favourable and the rate at which the resistant animals increase, both breeding and slaughtered for meat production, is slow. If the goal is not to achieve the fixation of resistance allele, it is advisable to carry out selection only until a desired frequency of K222-carriers has been attained. Nucleus selection vs. selection on the overall populations is less expensive but takes longer to reach the desired output. The programme performed on the two goat breeds serves as a model of the response the selection could have in other breeds that show different initial frequencies and population structure. In this respect, the model has a general applicability.

IMPY, a potential β-amyloid imaging probe for detection of prion deposits in scrapie-infected mice

International Nuclear Information System (INIS)

Song, P.-J.; Bernard, Serge; Sarradin, Pierre; Vergote, Jackie; Barc, Celine; Chalon, Sylvie; Kung, M.-P.; Kung, Hank F.; Guilloteau, Denis

2008-01-01

Introduction: A potential single-photon emission computed tomography imaging agent for labeling of Aβ plaques of Alzheimer's disease, IMPY (2-(4'-dimethylaminophenyl)-6-iodo-imidazo[1,2-a]pyridine), would be effective in detection of prion amyloid deposits in transmissible spongiform encephalopathies (TSEs). Methods: In vitro autoradiographic studies were carried out with [ 125 I]IMPY on brain sections from scrapie-infected mice and age-matched controls. Competition study was performed to evaluate the prion deposit binding specificity with nonradioactive IMPY. Results: Binding of [ 125 I]IMPY was observed in infected brain sections, while on age-matched control brain sections, there was no or very low labeling. Prion deposit binding was confirmed by histoblots with prion protein-specific monoclonal antibody 2D6. In the presence of nonradioactive IMPY, the binding of [ 125 I]IMPY was significantly inhibited in all regions studied. Conclusions: These findings indicate that IMPY can detect the prion deposits in vitro in scrapie-infected mice. Labeled with 123 I, this ligand may be useful to quantitate prion deposit burdens in TSEs by in vivo imaging

RECTAL BIOPSY IN SHEEP AND GOATS FOR MONITORING AND ANTE-MORTEM DIAGNOSIS OF SCRAPIE: NUMBER OF LYMPHOID FOLLICLES IN TWO CONSECUTIVE COLLECTIONS

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Helen Caroline Raksa

2016-07-01

O acúmulo da PrPSc em tecidos linfoides levou ao desenvolvimento de procedimentos de biopsia para o diagnóstico ante mortem da scrapie em ovinos, utilizando tecidos acessíveis como a tonsila(5 e terceira pálpebra(6, e a técnica de imuno-histoquímica (IHQ. Por outro lado, a grande área de folículos linfoides presente no reto de ovinos(7 tornou a biopsia retal uma possibilidade de diagnóstico ante mortem da scrapie. Amostras da mucosa retal têm sido colhidas e analisadas por meio de provas de IHQ para avaliar a presença de PrPSc no tecido linfoide associado à mucosa retoanal (RAMALT, do inglês Recto-Anal Mucosa Associated Lymphoid Tissue(8,9. No Brasil, o primeiro relato de scrapie foi em 1978, em um ovino Hampshire Down, importado da Inglaterra(10. Segundo a OIE, de 2008 a 2014 foram sacrificados 41 animais no país, em surtos de scrapie(11. Desde 2008, o diagnóstico de scrapie é realizado por meio da técnica de IHQ a partir de amostras do SNC e tecidos linfoides(12. Porém, no caso de tecidos linfoides associados à mucosa retal, pode haver necessidade de novas colheitas em curtos intervalos de tempo devido à escassez de tecido para o diagnóstico da doença que, segundo Leal et al.(13, deve ser de no mínimo três folículos linfoides (FL por amostra. Visando ao reconhecimento de boas técnicas para o monitoramento e o diagnóstico ante mortem da scrapie, o presente estudo teve por objetivo avaliar a quantidade de tecido linfoide associado à mucosa retal obtido pela técnica de biopsia retal e com vistas à avaliação imuno-histoquímica, bem como a possibilidade de se realizarem dois procedimentos de biopsia consecutivos, em diferentes intervalos de tempo, em ovinos e caprinos.

Co-existence of scrapie prion protein types 1 and 2 in sporadic Creutzfeldt-Jakob disease: its effect on the phenotype and prion-type characteristics

NARCIS (Netherlands)

Cali, I.; Castellani, R.; Alshekhlee, A.; Cohen, Y.; Blevins, J.; Yuan, J.; Langeveld, J.P.M.; Parchi, P.; Safar, J.G.; Zou, W.Q.; Gambetti, P.

2009-01-01

Five phenotypically distinct subtypes have been identified in sporadic Creutzfeldt-Jakob disease (sCJD), based on the methionine/valine polymorphic genotype of codon 129 of the prion protein (PrP) gene and the presence of either one of the two protease K-resistant scrapie prion protein (PrPSc) types

Accumulation of pathological prion protein PrPSc in the skin of animals with experimental and natural scrapie.

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Achim Thomzig

2007-05-01

Full Text Available Prion infectivity and its molecular marker, the pathological prion protein PrP(Sc, accumulate in the central nervous system and often also in lymphoid tissue of animals or humans affected by transmissible spongiform encephalopathies. Recently, PrP(Sc was found in tissues previously considered not to be invaded by prions (e.g., skeletal muscles. Here, we address the question of whether prions target the skin and show widespread PrP(Sc deposition in this organ in hamsters perorally or parenterally challenged with scrapie. In hamsters fed with scrapie, PrP(Sc was detected before the onset of symptoms, but the bulk of skin-associated PrP(Sc accumulated in the clinical phase. PrP(Sc was localized in nerve fibres within the skin but not in keratinocytes, and the deposition of PrP(Sc in skin showed no dependence from the route of infection and lymphotropic dissemination. The data indicated a neurally mediated centrifugal spread of prions to the skin. Furthermore, in a follow-up study, we examined sheep naturally infected with scrapie and detected PrP(Sc by Western blotting in skin samples from two out of five animals. Our findings point to the skin as a potential reservoir of prions, which should be further investigated in relation to disease transmission.

IMPY, a potential {beta}-amyloid imaging probe for detection of prion deposits in scrapie-infected mice

Energy Technology Data Exchange (ETDEWEB)

Song, P.-J. [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France); Bernard, Serge [IFR135, F-37000 Tours (France); INRA, UR1282, IASP, 37380 Nouzilly (France)], E-mail: bernard@tours.inra.fr; Sarradin, Pierre [INRA, UR1282, IASP, 37380 Nouzilly (France); Vergote, Jackie [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France); Barc, Celine [INRA, UR1282, IASP, 37380 Nouzilly (France); Chalon, Sylvie [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France); Kung, M.-P.; Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Guilloteau, Denis [INSERM, U619, F-37000 Tours (France); Universite Francois-Rabelais, F-37000 Tours (France); IFR135, F-37000 Tours (France)

2008-02-15

Introduction: A potential single-photon emission computed tomography imaging agent for labeling of A{beta} plaques of Alzheimer's disease, IMPY (2-(4'-dimethylaminophenyl)-6-iodo-imidazo[1,2-a]pyridine), would be effective in detection of prion amyloid deposits in transmissible spongiform encephalopathies (TSEs). Methods: In vitro autoradiographic studies were carried out with [{sup 125}I]IMPY on brain sections from scrapie-infected mice and age-matched controls. Competition study was performed to evaluate the prion deposit binding specificity with nonradioactive IMPY. Results: Binding of [{sup 125}I]IMPY was observed in infected brain sections, while on age-matched control brain sections, there was no or very low labeling. Prion deposit binding was confirmed by histoblots with prion protein-specific monoclonal antibody 2D6. In the presence of nonradioactive IMPY, the binding of [{sup 125}I]IMPY was significantly inhibited in all regions studied. Conclusions: These findings indicate that IMPY can detect the prion deposits in vitro in scrapie-infected mice. Labeled with {sup 123}I, this ligand may be useful to quantitate prion deposit burdens in TSEs by in vivo imaging.

Dynamics of a scrapie outbreak in a flock of Romanov sheep-estimation of transmission parameters

NARCIS (Netherlands)

Hagenaars, T.H.J.; Donelly, C.A.; Ferguson, N.M.; Anderson, R.M.

2003-01-01

Knowledge of epidemiological mechanisms and parameters underlying scrapie transmission in sheep flocks remains very limited at present. Here we introduce a method for fitting stochastic transmission models to outbreak data to estimate bounds on key transmission parameters. We apply this method to

Medulla oblongata transcriptome changes during presymptomatic natural scrapie and their associaition with prion-related lesions.

NARCIS (Netherlands)

Filali, H.; Martin-Burriel, I.; Harders, F.; Varona, L.; Serrano, C.; Acín, C.; Badiola, J.J.; Bossers, A.; Bolea, R.

2012-01-01

Background The pathogenesis of natural scrapie and other prion diseases is still poorly understood. Determining the variations in the transcriptome in the early phases of the disease might clarify some of the molecular mechanisms of the prion-induced pathology and allow for the development of new

White blood cell-based detection of asymptomatic scrapie infection by ex vivo assays.

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Sophie Halliez

Full Text Available Prion transmission can occur by blood transfusion in human variant Creutzfeldt-Jakob disease and in experimental animal models, including sheep. Screening of blood and its derivatives for the presence of prions became therefore a major public health issue. As infectious titer in blood is reportedly low, highly sensitive and robust methods are required to detect prions in blood and blood derived products. The objectives of this study were to compare different methods--in vitro, ex vivo and in vivo assays--to detect prion infectivity in cells prepared from blood samples obtained from scrapie infected sheep at different time points of the disease. Protein misfolding cyclic amplification (PMCA and bioassays in transgenic mice expressing the ovine prion protein were the most efficient methods to identify infected animals at any time of the disease (asymptomatic to terminally-ill stages. However scrapie cell and cerebellar organotypic slice culture assays designed to replicate ovine prions in culture also allowed detection of prion infectivity in blood cells from asymptomatic sheep. These findings confirm that white blood cells are appropriate targets for preclinical detection and introduce ex vivo tools to detect blood infectivity during the asymptomatic stage of the disease.

Scrapie infectivity is quickly cleared in tissues of orally-infected farmed fish

OpenAIRE

Ingrosso, Loredana; Novoa, Beatriz; Valle, Andrea Z Dalla; Cardone, Franco; Aranguren, Raquel; Sbriccoli, Marco; Bevivino, Simona; Iriti, Marcello; Liu, Quanguo; Vetrugno, Vito; Lu, Mei; Faoro, Franco; Ciappellano, Salvatore; Figueras, Antonio; Pocchiari, Maurizio

2006-01-01

Abstract Background Scrapie and bovine spongiform encephalopathy (BSE) belongs to the group of animal transmissible spongiform encephalopathy (TSE). BSE epidemic in the UK and elsewhere in Europe has been linked to the use of bovine meat and bone meals (MBM) in the feeding of cattle. There is concern that pigs, poultry and fish bred for human consumption and fed with infected MBM would eventually develop BSE or carry residual infectivity without disease. Although there has been no evidence of...

EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on the risk of transmission of classical scrapie via in vivo derived embryo transfer in ovine animals

DEFF Research Database (Denmark)

Hald, Tine; Baggesen, Dorte Lau

. Under natural exposure conditions, animals that are heterozygous or homozygous A136R154R171 display respectively a low or negligible risk of being infected. The genetic control of the susceptibility to classical scrapie is also likely to impact on the risk of transmitting the disease via embryo transfer......The risk of transmission of classical scrapie via the transfer of in vivo derived embryo in ovines was assessed, taking into account the scientific information made available since the last EFSA opinion on this topic (2010) (see http://www.efsa.europa.eu/en/efsajournal/pub/1429.htm). The potential...... impact of PrP genotype of the embryo and/or of the ram and donor ewe on this risk was also assessed. The new data made available over the last three years further reinforce the view that classical scrapie could be vertically transmitted in sheep. Since the possibility of such vertical transmission...

Scrapie susceptibility-linked polymorphisms modulate the in vitro conversion of sheep prion protein to protease-resistant forms

NARCIS (Netherlands)

Bossers, A.; Belt, P.B.G.M.; Raymond, G.J.; Caughey, B.; Vries, de R.; Smits, M.

1997-01-01

Prion diseases are natural transmissible neurodegenerative disorders in humans and animals. They are characterized by the accumulation of a protease-resistant scrapie-associated prion protein (PrPSc) of the host-encoded cellular prion protein (PrPC) mainly in the central nervous system.

Gene expression profiling en association with prion-related lesions in the medulla oblongata of symptomatic natural scrapie animals.

NARCIS (Netherlands)

Filali, H.; Martin-Burriel, I.; Harders, F.; Varona, L.; Lyahyai, J.; Zaragoza, P.; Pumarola, M.; Badiola, J.J.; Bossers, A.; Bolea, R.

2011-01-01

The pathogenesis of natural scrapie and other prion diseases remains unclear. Examining transcriptome variations in infected versus control animals may highlight new genes potentially involved in some of the molecular mechanisms of prion-induced pathology. The aim of this work was to identify

9 CFR 54.11 - Approval of laboratories to run official scrapie tests and official genotype tests.

Science.gov (United States)

2010-01-01

... request approval to conduct one or more types of scrapie test or genotype test on one or more types of... type of test and for each type of tissue for which they request approval. (c) The Administrator may... the laboratory and shall give the director an opportunity to respond. If there are conflicts as to any...

Caprine prion genen polymorphisms are associated with decreased incidence of classical scrapie in goat herds in the United Kingdom.

NARCIS (Netherlands)

Goldmann, W.; Ryan, K.; Stewart, P.; Parnham, D.; Xicohtencatl, R.; Fernandez, N.; Saunders, G.; Windl, O.; Gonzalez, L.; Bossers, A.

2011-01-01

The application of genetic breeding programmes to eradicate transmissible spongiform encephalopathies in goats is an important aim for reasons of animal welfare as well as human food safety and food security. Based on the positive impact of Prnp genetics on sheep scrapie in Europe in the past

Genetic profile of scrapie codons 146, 211 and 222 in the PRNP gene locus in three breeds of dairy goats.

Science.gov (United States)

Vouraki, Sotiria; Gelasakis, Athanasios I; Alexandri, Panoraia; Boukouvala, Evridiki; Ekateriniadou, Loukia V; Banos, Georgios; Arsenos, Georgios

2018-01-01

Polymorphisms at PRNP gene locus have been associated with resistance against classical scrapie in goats. Genetic selection on this gene within appropriate breeding programs may contribute to the control of the disease. The present study characterized the genetic profile of codons 146, 211 and 222 in three dairy goat breeds in Greece. A total of 766 dairy goats from seven farms were used. Animals belonged to two indigenous Greek, Eghoria (n = 264) and Skopelos (n = 287) and a foreign breed, Damascus (n = 215). Genomic DNA was extracted from blood samples from individual animals. Polymorphisms were detected in these codons using Real-Time PCR analysis and four different Custom TaqMan® SNP Genotyping Assays. Genotypic, allelic and haplotypic frequencies were calculated based on individual animal genotypes. Chi-square tests were used to examine Hardy-Weinberg equilibrium state and compare genotypic distribution across breeds. Genetic distances among the three breeds, and between these and 30 breeds reared in other countries were estimated based on haplotypic frequencies using fixation index FST with Arlequin v3.1 software; a Neighbor-Joining tree was created using PHYLIP package v3.695. Level of statistical significance was set at P = 0.01. All scrapie resistance-associated alleles (146S, 146D, 211Q and 222K) were detected in the studied population. Significant frequency differences were observed between the indigenous Greek and Damascus breeds. Alleles 222K and 146S had the highest frequency in the two indigenous and the Damascus breed, respectively (ca. 6.0%). The studied breeds shared similar haplotypic frequencies with most South Italian and Turkish breeds but differed significantly from North-Western European, Far East and some USA goat breeds. Results suggest there is adequate variation in the PRNP gene locus to support breeding programs for enhanced scrapie resistance in goats reared in Greece. Genetic comparisons among goat breeds indicate that separate

Na+/K+-ATPase is present in scrapie-associated fibrils, modulates PrP misfolding in vitro and links PrP function and dysfunction.

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James F Graham

Full Text Available Transmissible spongiform encephalopathies are characterised by widespread deposition of fibrillar and/or plaque-like forms of the prion protein. These aggregated forms are produced by misfolding of the normal prion protein, PrP(C, to the disease-associated form, PrP(Sc, through mechanisms that remain elusive but which require either direct or indirect interaction between PrP(C and PrP(Sc isoforms. A wealth of evidence implicates other non-PrP molecules as active participants in the misfolding process, to catalyse and direct the conformational conversion of PrP(C or to provide a scaffold ensuring correct alignment of PrP(C and PrP(Sc during conversion. Such molecules may be specific to different scrapie strains to facilitate differential prion protein misfolding. Since molecular cofactors may become integrated into the growing protein fibril during prion conversion, we have investigated the proteins contained in prion disease-specific deposits by shotgun proteomics of scrapie-associated fibrils (SAF from mice infected with 3 different strains of mouse-passaged scrapie. Concomitant use of negative control preparations allowed us to identify and discount proteins that are enriched non-specifically by the SAF isolation protocol. We found several proteins that co-purified specifically with SAF from infected brains but none of these were reproducibly and demonstrably specific for particular scrapie strains. The α-chain of Na(+/K(+-ATPase was common to SAF from all 3 strains and we tested the ability of this protein to modulate in vitro misfolding of recombinant PrP. Na(+/K(+-ATPase enhanced the efficiency of disease-specific conversion of recombinant PrP suggesting that it may act as a molecular cofactor. Consistent with previous results, the same protein inhibited fibrillisation kinetics of recombinant PrP. Since functional interactions between PrP(C and Na(+/K(+-ATPase have previously been reported in astrocytes, our data highlight this molecule as

Sheep scrapie susceptibility-linked polymorphisms do not modulate the initial binding of cellular to disease-associated prion protein prior to conversion

NARCIS (Netherlands)

Rigter, A.; Bossers, A.

2005-01-01

Conversion of the host-encoded protease-sensitive cellular prion protein (PrPC) into the scrapie-associated protease-resistant isoform (PrPSc) of prion protein (PrP) is the central event in transmissible spongiform encephalopathies or prion diseases. Differences in transmissibility and

Effect of Polymorphisms at Codon 146 of the Goat PRNP Gene on Susceptibility to Challenge with Classical Scrapie by Different Routes.

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Papasavva-Stylianou, Penelope; Simmons, Marion Mathieson; Ortiz-Pelaez, Angel; Windl, Otto; Spiropoulos, John; Georgiadou, Soteria

2017-11-15

This report presents the results of experimental challenges of goats with scrapie by both the intracerebral (i.c.) and oral routes, exploring the effects of polymorphisms at codon 146 of the goat PRNP gene on resistance to disease. The results of these studies illustrate that while goats of all genotypes can be infected by i.c. challenge, the survival distribution of the animals homozygous for asparagine at codon 146 was significantly shorter than those of animals of all other genotypes (chi-square value, 10.8; P = 0.001). In contrast, only those animals homozygous for asparagine at codon 146 (NN animals) succumbed to oral challenge. The results also indicate that any cases of infection in non-NN animals can be detected by the current confirmatory test (immunohistochemistry), although successful detection with the rapid enzyme-linked immunosorbent assay (ELISA) was more variable and dependent on the polymorphism. Together with data from previous studies of goats exposed to infection in the field, these data support the previously reported observations that polymorphisms at this codon have a profound effect on susceptibility to disease. It is concluded that only animals homozygous for asparagine at codon 146 succumb to scrapie under natural conditions. IMPORTANCE In goats, like in sheep, there are PRNP polymorphisms that are associated with susceptibility or resistance to scrapie. However, in contrast to the polymorphisms in sheep, they are more numerous in goats and may be restricted to certain breeds or geographical regions. Therefore, eradication programs must be specifically designed depending on the identification of suitable polymorphisms. An initial analysis of surveillance data suggested that such a polymorphism in Cypriot goats may lie in codon 146. In this study, we demonstrate experimentally that NN animals are highly susceptible after i.c. inoculation. The presence of a D or S residue prolonged incubation periods significantly, and prions were detected

Primary transmission of chronic wasting disease versus scrapie prions from small ruminants to transgenic mice expressing ovine and cervid prion protein

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Identifying transmissible spongiform encephalopathy (TSE) reservoirs that could lead to disease re-emergence is imperative to U.S. scrapie eradication efforts. Transgenic mice expressing the cervid (TgElk) or ovine (Tg338) prion protein have aided characterization of chronic wasting disease (CWD) an...

Epigenetic dominance of prion conformers.

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Eri Saijo

2013-10-01

Full Text Available Although they share certain biological properties with nucleic acid based infectious agents, prions, the causative agents of invariably fatal, transmissible neurodegenerative disorders such as bovine spongiform encephalopathy, sheep scrapie, and human Creutzfeldt Jakob disease, propagate by conformational templating of host encoded proteins. Once thought to be unique to these diseases, this mechanism is now recognized as a ubiquitous means of information transfer in biological systems, including other protein misfolding disorders such as those causing Alzheimer's and Parkinson's diseases. To address the poorly understood mechanism by which host prion protein (PrP primary structures interact with distinct prion conformations to influence pathogenesis, we produced transgenic (Tg mice expressing different sheep scrapie susceptibility alleles, varying only at a single amino acid at PrP residue 136. Tg mice expressing ovine PrP with alanine (A at (OvPrP-A136 infected with SSBP/1 scrapie prions propagated a relatively stable (S prion conformation, which accumulated as punctate aggregates in the brain, and produced prolonged incubation times. In contrast, Tg mice expressing OvPrP with valine (V at 136 (OvPrP-V136 infected with the same prions developed disease rapidly, and the converted prion was comprised of an unstable (U, diffusely distributed conformer. Infected Tg mice co-expressing both alleles manifested properties consistent with the U conformer, suggesting a dominant effect resulting from exclusive conversion of OvPrP-V136 but not OvPrP-A136. Surprisingly, however, studies with monoclonal antibody (mAb PRC5, which discriminates OvPrP-A136 from OvPrP-V136, revealed substantial conversion of OvPrP-A136. Moreover, the resulting OvPrP-A136 prion acquired the characteristics of the U conformer. These results, substantiated by in vitro analyses, indicated that co-expression of OvPrP-V136 altered the conversion potential of OvPrP-A136 from the S to

PrP protein is associated with follicular dendritic cells of spleens and lymph nodes in uninfected and scrapie-infected mice

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McBride, P. A.; Eikelenboom, P.; Kraal, G.; Fraser, H.; Bruce, M. E.

1992-01-01

Abnormal forms of a host protein, PrP, accumulate in the central nervous system in scrapie-affected animals. Here, PrP protein was detected immunocytochemically in tissue sections of spleen, lymph node, Peyer's patches, thymus, and pancreas from uninfected mice and from mice infected with a range of

Explaining the heterogeneous scrapie surveillance figures across Europe: a meta-regression approach

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Ru Giuseppe

2007-06-01

Full Text Available Abstract Background Two annual surveys, the abattoir and the fallen stock, monitor the presence of scrapie across Europe. A simple comparison between the prevalence estimates in different countries reveals that, in 2003, the abattoir survey appears to detect more scrapie in some countries. This is contrary to evidence suggesting the greater ability of the fallen stock survey to detect the disease. We applied meta-analysis techniques to study this apparent heterogeneity in the behaviour of the surveys across Europe. Furthermore, we conducted a meta-regression analysis to assess the effect of country-specific characteristics on the variability. We have chosen the odds ratios between the two surveys to inform the underlying relationship between them and to allow comparisons between the countries under the meta-regression framework. Baseline risks, those of the slaughtered populations across Europe, and country-specific covariates, available from the European Commission Report, were inputted in the model to explain the heterogeneity. Results Our results show the presence of significant heterogeneity in the odds ratios between countries and no reduction in the variability after adjustment for the different risks in the baseline populations. Three countries contributed the most to the overall heterogeneity: Germany, Ireland and The Netherlands. The inclusion of country-specific covariates did not, in general, reduce the variability except for one variable: the proportion of the total adult sheep population sampled as fallen stock by each country. A large residual heterogeneity remained in the model indicating the presence of substantial effect variability between countries. Conclusion The meta-analysis approach was useful to assess the level of heterogeneity in the implementation of the surveys and to explore the reasons for the variation between countries.

No evidence for involvement of plasma proteins or blood-borne cells in amyloid plaque formation in scrapie-affected mice. An immunohistoperoxidase study

NARCIS (Netherlands)

Eikelenboom, P.; Scott, J. R.; McBride, P. A.; Rozemuller, J. M.; Bruce, M. E.; Fraser, H.

1987-01-01

The present study was designed to investigate blood-brain permeability and the possible involvement of plasma proteins and blood-borne cells in amyloid plaque formation in scrapie-affected mice. No abnormal extravasation of intravenously injected horseradish peroxidase (HRP) was found and with

Accumulation and aberrant composition of cholesteryl esters in Scrapie-infected N2a cells and C57BL/6 mouse brains

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Di Bari Michele A

2011-08-01

Full Text Available Abstract Objective Cholesterol changes have been described in prion-cell models and in experimental rodent scrapie; yet, the pattern of this association is still controversial. Methods To shed light on the matter, we analysed and compared cholesterol variations in ScN2a cells and in brains of Scrapie-infected C57Bl/6 mice, using two different methods: a fluorimetric-enzymatic cholesterol assay, and high performance liquid chromatography-mass spectroscopy (HPLC-MS. Results Compared to uninfected controls, similar cholesterol metabolism anomalies were observed in infected cells and brains by both methods; however, only HPLC-MS revealed statistically significant cholesterol variations, particularly in the cholesteryl esters (CE fraction. HPLC-MS analyses also revealed different fatty acid composition of the CE fraction in cells and brains. In N2a cells, their profile reflected that of serum, while in normal brains cholesteryl-linoleate only was found at detectable levels. Following prion infection, most CE species were increased in the CE pool of ScN2a cells, whereas a conspicuous amount of cholesteryl-arachidonate only was found to contribute to the cerebral increase of CE. Of interest, oral pravastatin administration to Scrapie-infected mice, was associated with a significant reduction of cerebral free cholesterol (FC along with a concomitant further increase of the CE pool, which included increased amounts of both cholesteryl-linoleate and cholesteryl-arachidonate. Conclusion Although mechanistic studies are needed to establish the pathophysiological relevance of changes in cerebral CE concentrations, to the best of our knowledge this is the first report to provide evidence of increased cholesterol esterification in brains of prion-infected mice, untreated and treated with pravastatin.

In-situ spectroscopic investigation of transmissible spongiform encephalopathies: application of Fourier-transform infrared spectroscopy to a scrapie-hamster model

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Kneipp, Janina; Lasch, Peter; Beekes, Michael; Naumann, Dieter

2002-03-01

Transmissible spongiform encephalopathies (TSE), such as BSE in cattle, scrapie in sheep and goats, and Creutzfeldt-Jakob disease in man are a group of fatal infectious diseases of the central nervous system that are far from being fully understood. Presuming the pathological changes to originate from small disease-specific compositional and structural modifications at the molecular level, Fourier-transform infrared (FTIR) spectroscopy can be used to achieve insight into biochemical parameters underlying pathogenesis. We have developed an FTIR microspectroscopy-based strategy which, as a combination of image reconstruction and multivariate pattern recognition methods, permitted the comparison of identical substructures in the cerebellum of healthy and TSE-infected Syrian hamsters in the terminal stage of the disease. Here we present FTIR data about the pathological changes of scrapie-infected and normal tissue of the gray matter structures stratum granulosum and stratum moleculare. IR spectroscopy was also applied to tissue pieces of the medulla oblongata of infected and control Syrian hamsters. Mapping data were analyzed with cluster analysis and imaging methods. We found variations in the spectra of the infected tissue, which are due to changes in carbohydrates, nucleic acids, phospholipids, and proteins.

Identification of seven haplotypes of the caprine PrP gene at codons 127, 142, 154, 211, 222 and 240 in French Alpine and Saanen breeds and their association with classical scrapie.

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Barillet, F; Mariat, D; Amigues, Y; Faugeras, R; Caillat, H; Moazami-Goudarzi, K; Rupp, R; Babilliot, J M; Lacroux, C; Lugan, S; Schelcher, F; Chartier, C; Corbière, F; Andréoletti, O; Perrin-Chauvineau, C

2009-03-01

In sheep, susceptibility to scrapie is mainly influenced by polymorphisms of the PrP gene. In goats, there are to date few data related to scrapie susceptibility association with PrP gene polymorphisms. In this study, we first investigated PrP gene polymorphisms of the French Alpine and Saanen breeds. Based on PrP gene open reading frame sequencing of artificial insemination bucks (n=404), six encoding mutations were identified at codons 127, 142, 154, 211, 222 and 240. However, only seven haplotypes could be detected: four (GIH(154)RQS, GIRQ(211)QS, GIRRK(222)S and GIRRQP(240)) derived from the wild-type allele (G(127)I(142)R(154)R(211)Q(222)S(240)) by a single-codon mutation, and two (S(127)IRRQP(240) and GM(142)RRQP(240)) by a double-codon mutation. A case-control study was then implemented in a highly affected Alpine and Saanen breed herd (90 cases/164 controls). Mutations at codon 142 (I/M), 154 (R/H), 211 (R/Q) and 222 (Q/K) were found to induce a significant degree of protection towards natural scrapie infection. Compared with the baseline homozygote wild-type genotype I(142)R(154)R(211)Q(222)/IRRQ goats, the odds of scrapie cases in IRQ(211)Q/IRRQ and IRRK(222)/IRRQ heterozygous animals were significantly lower [odds ratio (OR)=0.133, PFrench Alpine and Saanen breeds were low (0.5-18.5 %), which prevent us from assessing the influence of all the possible genotypes in natural exposure conditions.

Thermodynamic compatibility and interactions between Speckled Sugar bean protein and xanthan gum for production of multilayer O/W emulsion.

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Rahmati, Nazanin Fatemeh; Koocheki, Arash; Varidi, Mehdi; Kadkhodaee, Rassoul

2018-03-01

Thermodynamic compatibility and probable interactions between Speckled Sugar been protein (SSBP) and xanthan gum for production of multilayer O/W emulsion (30% oil) were investigated. Different interactions were observed between SSBP and xanthan at different pH (3-7) including electrostatic interactions and hydrogen bonding. These interactions were predominant at pH 3. When low xanthan gum concentration (0.1%) was used, phase separation and complex coacervation observed at this pH (negative effect of interactions). However, at pH 5, only 0.1% xanthan was enough to drastically reduce non-dissolved protein and its precipitation which normally occurs at this pH. In addition, incompatibility or segregative phase behavior which normally occurs when protein and polysaccharide have same charges was not observed (positive effects of interactions). Protein-gum interactions influenced emulsion properties (zeta potential, particle size, PDI, rheology, emulsion capacity, heat stability and creaming rate). Interactions had considerable influence on emulsion shelf life and produced completely stable emulsions at all pH values. Results confirmed that SSBP-xanthan gum mixture has a high potential for production of multilayer emulsions.

Prion seeding activities of mouse scrapie strains with divergent PrPSc protease sensitivities and amyloid plaque content using RT-QuIC and eQuIC.

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Sarah Vascellari

Full Text Available Different transmissible spongiform encephalopathy (TSE-associated forms of prion protein (e.g. PrP(Sc can vary markedly in ultrastructure and biochemical characteristics, but each is propagated in the host. PrP(Sc propagation involves conversion from its normal isoform, PrP(C, by a seeded or templated polymerization mechanism. Such a mechanism is also the basis of the RT-QuIC and eQuIC prion assays which use recombinant PrP (rPrP(Sen as a substrate. These ultrasensitive detection assays have been developed for TSE prions of several host species and sample tissues, but not for murine models which are central to TSE pathogenesis research. Here we have adapted RT-QuIC and eQuIC to various murine prions and evaluated how seeding activity depends on glycophosphatidylinositol (GPI anchoring and the abundance of amyloid plaques and protease-resistant PrP(Sc (PrP(Res. Scrapie brain dilutions up to 10(-8 and 10(-13 were detected by RT-QuIC and eQuIC, respectively. Comparisons of scrapie-affected wild-type mice and transgenic mice expressing GPI anchorless PrP showed that, although similar concentrations of seeding activity accumulated in brain, the heavily amyloid-laden anchorless mouse tissue seeded more rapid reactions. Next we compared seeding activities in the brains of mice with similar infectivity titers, but widely divergent PrP(Res levels. For this purpose we compared the 263K and 139A scrapie strains in transgenic mice expressing P101L PrP(C. Although the brains of 263K-affected mice had little immunoblot-detectable PrP(Res, RT-QuIC indicated that seeding activity was comparable to that associated with a high-PrP(Res strain, 139A. Thus, in this comparison, RT-QuIC seeding activity correlated more closely with infectivity than with PrP(Res levels. We also found that eQuIC, which incorporates a PrP(Sc immunoprecipitation step, detected seeding activity in plasma from wild-type and anchorless PrP transgenic mice inoculated with 22L, 79A and/or RML

Accumulation and dissemination of prion protein in experimental sheep scrapie in the natural host

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Warner Richard

2009-02-01

Full Text Available Abstract Background In order to study the sites of uptake and mechanisms of dissemination of scrapie prions in the natural host under controlled conditions, lambs aged 14 days and homozygous for the VRQ allele of the PrP gene were infected by the oral route. Infection occurred in all lambs with a remarkably short and highly consistent incubation period of approximately 6 months. Challenge of lambs at approximately eight months of age resulted in disease in all animals, but with more variable incubation periods averaging significantly longer than those challenged at 14 days. This model provides an excellent system in which to study the disease in the natural host by virtue of the relatively short incubation period and close resemblance to natural infection. Results Multiple sites of prion uptake were identified, of which the most important was the Peyer's patch of the distal ileum. Neuroinvasion was detected initially in the enteric nervous system prior to infection of the central nervous system. At end stage disease prion accumulation was widespread throughout the entire neuraxis, but vacuolar pathology was absent in most animals that developed disease at 6–7 months of age. Conclusion Initial spread of detectable PrP was consistent with drainage in afferent lymph to dependent lymph nodes. Subsequent accumulation of prions in lymphoid tissue not associated with the gut is consistent with haematogenous spread. In addition to macrophages and follicular dendritic cells, prion containing cells consistent with afferent lymph dendritic cells were identified and are suggested as a likely vehicle for carriage of prions from initial site of uptake to the lymphoreticular system, and as potential carriers of prion protein in blood. It is apparent that spongiform change, the characteristic lesion of scrapie and other prion diseases, is not responsible for the clinical signs in sheep, but may develop in an age dependent manner.

Substitutions of PrP N-terminal histidine residues modulate scrapie disease pathogenesis and incubation time in transgenic mice.

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Eigenbrod, Sabina; Frick, Petra; Bertsch, Uwe; Mitteregger-Kretzschmar, Gerda; Mielke, Janina; Maringer, Marko; Piening, Niklas; Hepp, Alexander; Daude, Nathalie; Windl, Otto; Levin, Johannes; Giese, Armin; Sakthivelu, Vignesh; Tatzelt, Jörg; Kretzschmar, Hans; Westaway, David

2017-01-01

Prion diseases have been linked to impaired copper homeostasis and copper induced-oxidative damage to the brain. Divalent metal ions, such as Cu2+ and Zn2+, bind to cellular prion protein (PrPC) at octapeptide repeat (OR) and non-OR sites within the N-terminal half of the protein but information on the impact of such binding on conversion to the misfolded isoform often derives from studies using either OR and non-OR peptides or bacterially-expressed recombinant PrP. Here we created new transgenic mouse lines expressing PrP with disrupted copper binding sites within all four histidine-containing OR's (sites 1-4, H60G, H68G, H76G, H84G, "TetraH>G" allele) or at site 5 (composed of residues His-95 and His-110; "H95G" allele) and monitored the formation of misfolded PrP in vivo. Novel transgenic mice expressing PrP(TetraH>G) at levels comparable to wild-type (wt) controls were susceptible to mouse-adapted scrapie strain RML but showed significantly prolonged incubation times. In contrast, amino acid replacement at residue 95 accelerated disease progression in corresponding PrP(H95G) mice. Neuropathological lesions in terminally ill transgenic mice were similar to scrapie-infected wt controls, but less severe. The pattern of PrPSc deposition, however, was not synaptic as seen in wt animals, but instead dense globular plaque-like accumulations of PrPSc in TgPrP(TetraH>G) mice and diffuse PrPSc deposition in (TgPrP(H95G) mice), were observed throughout all brain sections. We conclude that OR and site 5 histidine substitutions have divergent phenotypic impacts and that cis interactions between the OR region and the site 5 region modulate pathogenic outcomes by affecting the PrP globular domain.

A "shotgun" method for tracing the birth locations of sheep from flock tags, applied to scrapie surveillance in Great Britain.

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Birch, Colin P D; Del Rio Vilas, Victor J; Chikukwa, Ambrose C

2010-09-01

Movement records are often used to identify animal sample provenance by retracing the movements of individuals. Here we present an alternative method, which uses the same identity tags and movement records as are used to retrace movements, but ignores individual movement paths. The first step uses a simple query to identify the most likely birth holding for every identity tag included in a database recording departures from agricultural holdings. The second step rejects a proportion of the birth holding locations to leave a list of birth holding locations that are relatively reliable. The method was used to trace the birth locations of sheep sampled for scrapie in abattoirs, or on farm as fallen stock. Over 82% of the sheep sampled in the fallen stock survey died at the holding of birth. This lack of movement may be an important constraint on scrapie transmission. These static sheep provided relatively reliable birth locations, which were used to define criteria for selecting reliable traces. The criteria rejected 16.8% of fallen stock traces and 11.9% of abattoir survey traces. Two tests provided estimates that selection reduced error in fallen stock traces from 11.3% to 3.2%, and in abattoir survey traces from 8.1% to 1.8%. This method generated 14,591 accepted traces of fallen stock from samples taken during 2002-2005 and 83,136 accepted traces from abattoir samples. The absence or ambiguity of flock tag records at the time of slaughter prevented the tracing of 16-24% of abattoir samples during 2002-2004, although flock tag records improved in 2005. The use of internal scoring to generate and evaluate results from the database query, and the confirmation of results by comparison with other database fields, are analogous to methods used in web search engines. Such methods may have wide application in tracing samples and in adding value to biological datasets. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

A Bayesian zero-truncated approach for analysing capture-recapture count data from classical scrapie surveillance in France.

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Vergne, Timothée; Calavas, Didier; Cazeau, Géraldine; Durand, Benoît; Dufour, Barbara; Grosbois, Vladimir

2012-06-01

Capture-recapture (CR) methods are used to study populations that are monitored with imperfect observation processes. They have recently been applied to the monitoring of animal diseases to evaluate the number of infected units that remain undetected by the surveillance system. This paper proposes three bayesian models to estimate the total number of scrapie-infected holdings in France from CR count data obtained from the French classical scrapie surveillance programme. We fitted two zero-truncated Poisson (ZTP) models (with and without holding size as a covariate) and a zero-truncated negative binomial (ZTNB) model to the 2006 national surveillance count dataset. We detected a large amount of heterogeneity in the count data, making the use of the simple ZTP model inappropriate. However, including holding size as a covariate did not bring any significant improvement over the simple ZTP model. The ZTNB model proved to be the best model, giving an estimation of 535 (CI(95%) 401-796) infected and detectable sheep holdings in 2006, although only 141 were effectively detected, resulting in a holding-level prevalence of 4.4‰ (CI(95%) 3.2-6.3) and a sensitivity of holding-level surveillance of 26% (CI(95%) 18-35). The main limitation of the present study was the small amount of data collected during the surveillance programme. It was therefore not possible to build complex models that would allow depicting more accurately the epidemiological and detection processes that generate the surveillance data. We discuss the perspectives of capture-recapture count models in the context of animal disease surveillance. Copyright © 2012 Elsevier B.V. All rights reserved.

Creutzfeldt-Jakob disease a case report, with special attention to the electroencephalogram in this disorder and to its possible relationships to kuru, scrapie and «mad cow disease»

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A.H. Chapman

1993-06-01

Full Text Available A case of Creutzfeldt-Jakob disease in a 58-year-old Brazillian cattle rancher and businessman is presented. The EEG was normal, which is consistent with the fact that it was made during the first half of his illness; in a later stage suppression of normal rhythms by slow moderate voltage waves would be expected. The resemblances of kuru, scrapie and "mad cow disease» to C-J disease are discussed. In each of these 4 illnesses the patient or affected animal (scrapie and «mad cow disease" (a has a widespread spongiform encephalopathy and consequent dementia, myoclonic epilepsy and cerebellar and corticospinal symptoms, (b Each illness is caused by a virus (or virus-like organism called a PrP or prion which is unusually resistant to heat and entirely resistant to ultraviolet light and x-rays, (c This causative agent can be transmitted to other mammals by intracerebral injection or, in the proved cases of 3 of them, by the oral route. Unresolved questions about C-J disease include the following: Are C-J disease, kuru, scrapie and "mad cow disease" essentially similar illnesses caused by the same virus or by subtle variants of it? What is the incubation period of C-J disease, and does its virus exist for long periods of time in some asymptomatic persons, some of whom may never become neurologically ill? How does this virus enter the bodies of most persons with C-J disease, and why does the clinical disease characteristically occur only in middle age?

Phylogenetic and functional analysis of the bacteriophage P1 single-stranded DNA-binding protein

DEFF Research Database (Denmark)

Bendtsen, Jannick Dyrløv; Nilsson, A.S.; Lehnherr, H.

2002-01-01

and does not represent a recent acquirement of the phage. The P1 and E. coli SSB proteins are fully functionally interchangeable. SSB-P1 is nonessential for phage growth in an exponentially growing E. coli host, and it is sufficient to promote bacterial growth in the absence of the E. coli SSB protein....... Expression studies showed that the P1 ssb gene is transcribed only, in an rpoS-independent fashion, during stationary-phase growth in E. coli. Mixed infection experiments demonstrated that a wild-type phage has a selective advantage over an ssb-null mutant when exposed to a bacterial host in the stationary...

Producing chicken eggs containing isoflavone as functional food due to feeding effect of soy sauce by-product

Science.gov (United States)

Mahfudz, L. D.; Sarjana, T. A.; Muryani, R.; Suthama, N.

2018-01-01

The present study was aimed to verify the impact of feeding soy sauce by-product in producing isoflavone-enriched chicken eggs as functional food. Experiment used 200 laying hens of 80-week old with average body weight of 1,932.75±189.50 g. Experimental diets were formulated using yellow corn, rice bran, soybean meal, fish meal, meat bone meal, poultry meal, premix, CaCO3, and soy sauce by-product (SSBP). A completely randomized design with 4 treatments and 5 replication (10 birds each), was assigned in this experiment. Inclusion levels of SSBP were the treatments, namely, none (T0), 10 (T1), 12.5 (T2), and 15.0% (T3). Parameters observed were colour, index, and weight of egg yolk, and isoflavone content. Analysis of variance was applied and continued to Duncan test at 5% probability. Results indicated that yolk colour index and weight were not affected by the treatments, but isoflavone content was significantly (P<0.05) increased by feeding SSBP. Egg yolk isoflavone in T2 (0.41 mg/g) and T3 (0.47 mg/g) were higher than those in T0 (0.31 mg/g) and T1 (0.35 mg/g). In conclusion, dietary inclusion of soy sauce by-product at higher level (12.5 and 15.0%) can produce isoflavone-enriched eggs as functional food.

PrP expression, PrPSc accumulation and innervation of splenic compartments in sheep experimentally infected with scrapie.

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Randi Sørby

Full Text Available BACKGROUND: In prion disease, the peripheral expression of PrP(C is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrP(Sc accumulation, localisation of nerve fibres and PrP(C expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep. METHODOLOGY/PRINCIPAL FINDINGS: Laser microdissection and quantitative PCR were used to determine PrP mRNA levels and results were compared with immunohistochemical protocols to distinguish PrP(C and PrP(Sc in tissue compartments of the spleen. In sheep experimentally infected with scrapie, the major sites of accumulation of PrP(Sc in the spleen, namely the lymphoid nodules and the marginal zone, expressed low levels of PrP mRNA. Double immunohistochemical labelling for PrP(Sc and the pan-nerve fibre marker, PGP, was used to evaluate the density of innervation of splenic tissue compartments and the intimacy of association between PrP(Sc and nerves. Some nerve fibres were observed to accompany blood vessels into the PrP(Sc-laden germinal centres. However, the close association between nerves and PrP(Sc was most apparent in the marginal zone. Other sites of close association were adjacent to the wall of the central artery of PALS and the outer rim of germinal centres. CONCLUSIONS/SIGNIFICANCE: The findings suggest that the degree of PrP(Sc accumulation does not depend on the expression level of PrP(C. Though several splenic compartments may contribute to neuroinvasion, the marginal zone may play a central role in being the compartment with most apparent association between nerves and PrP(Sc.

Telmisartan in daily clinical practice: Factors affecting efficacy in treatment of primary arterial hypertension

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Bergovac M

2009-01-01

Full Text Available Background: Telmisartan provides effective treatment of hypertension in a broad spectrum of patients. Aims: To evaluate factors affecting the efficacy of telmisartan in daily clinical practice. Setting and Design: Prospective practice-based 12-week uncontrolled cohort study. Materials and Methods: Consecutive incident/prevalent outpatients with mild to moderate essential hypertension were started on telmisartan 40 mg/day with optional up-titration to 80 mg/day in order to achieve seated systolic (SSBP and diastolic (SDBP blood pressure < 140/90 mm Hg. Intent-to-treat (ITT, N=282 and per protocol (PP, N=275 efficacy assessment was based on SSBP/SDBP reduction and delivered doses. Results: SSBP/SDBP decreased (165.2±13.1 / 98.3±6.7 mm Hg to 137.9±13.2 / 82.6±7.3 mm Hg, whilst telmisartan was up-titrated in 40.5% of patients during the study. Multivariate (practically identical ITT and PP analysis indicated poorer response in obese vs. non-obese patients: lesser SDBP reduction (by around 2.2-2.3 mm Hg, P < 0.05 with higher odds of dose up-titration (odds ratio, OR around 1.90, P < 0.05; and better response in: a patients started on telmisartan monotherapy than when added to a preexisting treatment: greater SSBP/SDBP reduction (by around 4.0 and 3.0 mm Hg, respectively, P < 0.05 with comparable odds of up-titration; b diabetics vs. non-diabetics: greater SDBP reduction (by around 3.6-3.7 mm Hg, P < 0.05 with comparable odds of up-titration; c men vs. women: slightly greater SDBP reduction (by around 1.2 mm Hg, 0.05 P < 0.1 with lower odds of up-titration (OR around 0.51, P < 0.05. Conclusion: Previous unsuccessful treatment, obesity, diabetes and gender should be considered in order to optimize the use of telmisartan for mild to moderate essential hypertension in daily clinical practice.

Methodological approach for substantiating disease freedom in a heterogeneous small population. Application to ovine scrapie, a disease with a strong genetic susceptibility.

Science.gov (United States)

Martinez, Marie-José; Durand, Benoit; Calavas, Didier; Ducrot, Christian

2010-06-01

Demonstrating disease freedom is becoming important in different fields including animal disease control. Most methods consider sampling only from a homogeneous population in which each animal has the same probability of becoming infected. In this paper, we propose a new methodology to calculate the probability of detecting the disease if it is present in a heterogeneous population of small size with potentially different risk groups, differences in risk being defined using relative risks. To calculate this probability, for each possible arrangement of the infected animals in the different groups, the probability that all the animals tested are test-negative given this arrangement is multiplied by the probability that this arrangement occurs. The probability formula is developed using the assumption of a perfect test and hypergeometric sampling for finite small size populations. The methodology is applied to scrapie, a disease affecting small ruminants and characterized in sheep by a strong genetic susceptibility defining different risk groups. It illustrates that the genotypes of the tested animals influence heavily the confidence level of detecting scrapie. The results present the statistical power for substantiating disease freedom in a small heterogeneous population as a function of the design prevalence, the structure of the sample tested, the structure of the herd and the associated relative risks. (c) 2010 Elsevier B.V. All rights reserved.

Distinct transmissibility features of TSE sources derived from ruminant prion diseases by the oral route in a transgenic mouse model (TgOvPrP4 overexpressing the ovine prion protein.

Directory of Open Access Journals (Sweden)

Jean-Noël Arsac

Full Text Available Transmissible spongiform encephalopathies (TSEs are a group of fatal neurodegenerative diseases associated with a misfolded form of host-encoded prion protein (PrP. Some of them, such as classical bovine spongiform encephalopathy in cattle (BSE, transmissible mink encephalopathy (TME, kuru and variant Creutzfeldt-Jakob disease in humans, are acquired by the oral route exposure to infected tissues. We investigated the possible transmission by the oral route of a panel of strains derived from ruminant prion diseases in a transgenic mouse model (TgOvPrP4 overexpressing the ovine prion protein (A136R154Q171 under the control of the neuron-specific enolase promoter. Sources derived from Nor98, CH1641 or 87V scrapie sources, as well as sources derived from L-type BSE or cattle-passaged TME, failed to transmit by the oral route, whereas those derived from classical BSE and classical scrapie were successfully transmitted. Apart from a possible effect of passage history of the TSE agent in the inocula, this implied the occurrence of subtle molecular changes in the protease-resistant prion protein (PrPres following oral transmission that can raises concerns about our ability to correctly identify sheep that might be orally infected by the BSE agent in the field. Our results provide proof of principle that transgenic mouse models can be used to examine the transmissibility of TSE agents by the oral route, providing novel insights regarding the pathogenesis of prion diseases.

9 CFR 54.7 - Procedures for destruction of animals.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

9 CFR 54.3 - Animals eligible for indemnity payments.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Animals eligible for indemnity payments. 54.3 Section 54.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... SCRAPIE Scrapie Indemnification Program § 54.3 Animals eligible for indemnity payments. (a) Indemnity may...

Chronic wasting disease and atypical forms of bovine spongiform encephalopathy and scrapie are not transmissible to mice expressing wild-type levels of human prion protein.

Science.gov (United States)

Wilson, Rona; Plinston, Chris; Hunter, Nora; Casalone, Cristina; Corona, Cristiano; Tagliavini, Fabrizio; Suardi, Silvia; Ruggerone, Margherita; Moda, Fabio; Graziano, Silvia; Sbriccoli, Marco; Cardone, Franco; Pocchiari, Maurizio; Ingrosso, Loredana; Baron, Thierry; Richt, Juergen; Andreoletti, Olivier; Simmons, Marion; Lockey, Richard; Manson, Jean C; Barron, Rona M

2012-07-01

The association between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) has demonstrated that cattle transmissible spongiform encephalopathies (TSEs) can pose a risk to human health and raises the possibility that other ruminant TSEs may be transmissible to humans. In recent years, several novel TSEs in sheep, cattle and deer have been described and the risk posed to humans by these agents is currently unknown. In this study, we inoculated two forms of atypical BSE (BASE and H-type BSE), a chronic wasting disease (CWD) isolate and seven isolates of atypical scrapie into gene-targeted transgenic (Tg) mice expressing the human prion protein (PrP). Upon challenge with these ruminant TSEs, gene-targeted Tg mice expressing human PrP did not show any signs of disease pathology. These data strongly suggest the presence of a substantial transmission barrier between these recently identified ruminant TSEs and humans.

EPA Region 1 Sole Source Aquifers

Science.gov (United States)

This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of drinking water for a given aquifer service area; that is, an aquifer which is needed to supply 50% or more of the drinking water for the area and for which there are no reasonable alternative sources should the aquifer become contaminated.The aquifers were defined by a EPA hydrogeologist. Aquifer boundaries were then drafted by EPA onto 1:24000 USGS quadrangles. For the coastal sole source aquifers the shoreline as it appeared on the quadrangle was used as a boundary. Delineated boundaries were then digitized into ARC/INFO.

Variation in the prion protein sequence in Dutch goat breeds

NARCIS (Netherlands)

Windig, J.J.; Hoving, R.A.H.; Priem, J.; Bossers, A.; Keulen, van L.J.M.; Langeveld, J.P.M.

2016-01-01

Scrapie is a neurodegenerative disease occurring in goats and sheep. Several haplotypes of the prion protein increase resistance to scrapie infection and may be used in selective breeding to help eradicate scrapie. In this study, frequencies of the allelic variants of the PrP gene are determined

ITER Safety Task NID-5A, Subtask 1-1: Source terms and energies - initial tritium source terms. Final report

International Nuclear Information System (INIS)

Fong, C.; Kalyanam, K.M.; Tanaka, M.R.; Sood, S.; Natalizio, A.; Delisle, M.

1995-02-01

The overall objective of the Early Safety and Environmental Characterization Study (ESECS) is to assess the environmental impact of tritium using appropriate assumptions on a hypothetical site for ITER, having the r eference s ite characteristics as proposed by the JCT. The objective of this work under the above subtask 1-1, NID-5a, is to determine environmental source terms (i.e., process source term x containment release fraction) for the fuel cycle and cooling systems. The work is based on inventories and process source terms (i.e., inventory x mobilization fraction), provided by others (under Task NID 3b). The results of this work form the basis for the determination, by others, of the off-site dose (i.e., environmental source term x dose/release ratio). For the determination of the environmental source terms, the TMAP4 code has been utilized (ref 1). This code is approved by ITER for safety assessment. Volume 3 is a compilation of appendices giving detailed results of the study

ITER Safety Task NID-5A, Subtask 1-1: Source terms and energies - initial tritium source terms. Final report

International Nuclear Information System (INIS)

Fong, C.; Kalyanam, K.M.; Tanaka, M.R.; Sood, S.; Natalizio, A.; Delisle, M.

1995-02-01

The overall objective of the Early Safety and Environmental Characterization Study (ESECS) is to assess the environmental impact of tritium using appropriate assumptions on a hypothetical site for ITER, having the r eference s ite characteristics as proposed by the JCT. The objective of this work under the above subtask 1-1, NID-5a, is to determine environmental source terms (i.e., process source term x containment release fraction) for the fuel cycle and cooling systems. The work is based on inventories and process source terms (i.e., inventory x mobilization fraction), provided by others (under Task NID 3b). The results of this work form the basis for the determination, by others, of the off-site dose (i.e., environmental source term x dose/release ratio). For the determination of the environmental source terms, the TMAP4 code has been utilized (ref 1). This code is approved by ITER for safety assessment. 6 refs

Genetic, histochemical and biochemical studies on goat TSE cases from Cyprus.

Science.gov (United States)

Niedermeyer, Susanne; Eiden, Martin; Toumazos, Pavlos; Papasavva-Stylianou, Penelope; Ioannou, Ioannis; Sklaviadis, Theodoros; Panagiotidis, Cynthia; Langeveld, Jan; Bossers, Alex; Kuczius, Thorsten; Kaatz, Martin; Groschup, Martin H; Fast, Christine

2016-10-06

Scrapie and bovine spongiform encephalopathy (BSE) are transmissible spongiform encephalopathies (TSE's) affecting sheep and goats. Susceptibility of goats to scrapie is influenced by polymorphisms of the prion protein gene (PRNP) of the host. Five polymorphisms are associated with reduced susceptibility to TSE's. In the study presented here caprine samples from a scrapie eradication program on Cyprus were genotyped and further characterized using BioRad TeSeE rapid test, histological, immunohistochemical and biochemical methods. In total 42 goats from 20 flocks were necropsied from which 25 goats showed a positive result in the rapid test, a spongiform encephalopathy and an accumulation of pathological prion protein (PrP Sc ) in the obex. PrP Sc deposits were demonstrated in the placenta, peripheral nervous and lymphoreticular system. Two animals showed PrP Sc -accumulations in peripheral tissues only. By discriminatory immunoblots a scrapie infection could be confirmed for all cases. Nevertheless, slight deviations in the glycosylation pattern might indicate the presence of different scrapie strains. Furthermore scrapie samples from goats in the current study demonstrated less long term resistance to proteinase K than ovine or caprine BSE control samples. Reduced scrapie susceptibility according to the PRNP genotype was demonstrated (Fishers Exact test, p goats with at least one polymorphism (p = 0.023) at the six codons examined and in particular for those with polymorphisms at codon 146 (p = 0.016). This work characterizes scrapie in goats having implications for breeding and surveillance strategies.

Prion structure investigated in situ, ex vivo, and in vitro by FTIR spectroscopy

Science.gov (United States)

Kneipp, Janina; Miller, Lisa M.; Spassov, Sashko; Sokolowski, Fabian; Lasch, Peter; Beekes, Michael; Naumann, Dieter

2004-07-01

Syrian hamster nervous tissue was investigated by FTIR microspectroscopy with conventional and synchrotron infrared light sources. Various tissue structures from the cerebellum and medulla oblongata of scrapie-infected and control hamsters were investigated at a spatial resolution of 50 μm. Single neurons in dorsal root ganglia of scrapie-infected hamsters were analyzed by raster scan mapping at 6 μm spatial resolution. These measurements enabled us to (i) scrutinize structural differences between infected and non-infected tissue and (ii) analyze for the first time the distribution of different protein structures in situ within single nerve cells. Single nerve cells exhibited areas of increased β-sheet content, which co-localized consistently with accumulations of the pathological prion protein (PrPSc). Spectral data were also obtained from purified, partly proteinase K digested PrPSc isolated from scrapie-infected nervous tissue of hamsters to elucidate similarities/dissimilarities between prion structure in situ and ex vivo. A further comparison is drawn to the recombinant Syrian hamster prion protein SHaPrP90-232, whose in vitro transition from the predominantly a-helical isoform to β-sheet rich oligomeric structures was also investigated by FTIR spectroscopy.

ITER Safety Task NID-5A, Subtask 1-1: Source terms and energies - initial tritium source terms. Final report

International Nuclear Information System (INIS)

Fong, C.; Kalyanam, K.M.; Tanaka, M.R.; Sood, S.; Natalizio, A.; Delisle, M.

1995-02-01

The overall objective of the Early Safety and Environmental Characterization Study (ESECS) is to assess the environmental impact of tritium using appropriate assumptions on a hypothetical site for ITER, having the r eference s ite characteristics as proposed by the JCT. The objective of this work under the above subtask 1-1, NID-5a, is to determine environmental source terms (i.e., process source term x containment release fraction) for the fuel cycle and cooling systems. The work is based on inventories and process source terms (i.e., inventory x mobilization fraction), provided by others (under Task NID 3b). The results of this work form the basis for the determination, by others, of the off-site dose (i.e., environmental source term x dose/release ratio). For the determination of the environmental source terms, the TMAP4 code has been utilized (ref 1). This code is approved by ITER for safety assessment. Volume 2 is a compilation of appendices giving detailed results of the study. 5 figs

Pseudo-dynamic source modelling with 1-point and 2-point statistics of earthquake source parameters

KAUST Repository

Song, S. G.

2013-12-24

Ground motion prediction is an essential element in seismic hazard and risk analysis. Empirical ground motion prediction approaches have been widely used in the community, but efficient simulation-based ground motion prediction methods are needed to complement empirical approaches, especially in the regions with limited data constraints. Recently, dynamic rupture modelling has been successfully adopted in physics-based source and ground motion modelling, but it is still computationally demanding and many input parameters are not well constrained by observational data. Pseudo-dynamic source modelling keeps the form of kinematic modelling with its computational efficiency, but also tries to emulate the physics of source process. In this paper, we develop a statistical framework that governs the finite-fault rupture process with 1-point and 2-point statistics of source parameters in order to quantify the variability of finite source models for future scenario events. We test this method by extracting 1-point and 2-point statistics from dynamically derived source models and simulating a number of rupture scenarios, given target 1-point and 2-point statistics. We propose a new rupture model generator for stochastic source modelling with the covariance matrix constructed from target 2-point statistics, that is, auto- and cross-correlations. Our sensitivity analysis of near-source ground motions to 1-point and 2-point statistics of source parameters provides insights into relations between statistical rupture properties and ground motions. We observe that larger standard deviation and stronger correlation produce stronger peak ground motions in general. The proposed new source modelling approach will contribute to understanding the effect of earthquake source on near-source ground motion characteristics in a more quantitative and systematic way.

Pseudo-dynamic source modelling with 1-point and 2-point statistics of earthquake source parameters

KAUST Repository

Song, S. G.; Dalguer, L. A.; Mai, Paul Martin

2013-01-01

statistical framework that governs the finite-fault rupture process with 1-point and 2-point statistics of source parameters in order to quantify the variability of finite source models for future scenario events. We test this method by extracting 1-point

Gene and protein patterns of potential prion-related markers in the central nervous system of clinical and preclinical infected sheep

Science.gov (United States)

2013-01-01

The molecular pathogenic mechanisms of prion diseases are far from clear. Genomic analyses have revealed genetic biomarkers potentially involved in prion neuropathology in naturally scrapie-infected sheep, a good animal model of infectious prionopathies. However, these biomarkers must be validated in independent studies at different stages of the disease. The gene and protein expression profiles and protein distribution of six potential genetic biomarkers (i.e., CAPN6, COL1A2, COL3A1, GALA1, MT2A and MTNR1B) are presented here for both the early and terminal stages of scrapie in five different brain regions. Gene transcription changes were confirmed in the medulla oblongata, and the expression profiles were generally similar in other central nervous system regions. The changes were more substantial in clinical animals compared to preclinical animals. The expression of the CAPN6 protein increased in the spinal cord and cerebellum of the clinical and preclinical brains. The distribution of the GALA1 was identified in glial cells from the cerebellum of scrapie-infected animals, GALA1 protein expression was increased in clinical animals in the majority of regions, and the increase of MT2A was in agreement with previous reports. The downregulation of MTNR1B was especially marked in the Purkinje cells. Finally, although collagen genes were downregulated the protein immunostaining did not reveal significant changes between the scrapie-infected and control animals. In conclusion, this study of gene transcription and protein expression and distribution confirm CAPN6, GALA1, MTNR1B and MT2A as potential targets for further prion disease research. PMID:23497022

Version 1 of the Hubble Source Catalog

Science.gov (United States)

Whitmore, Bradley C.; Allam, Sahar S.; Budavári, Tamás; Casertano, Stefano; Downes, Ronald A.; Donaldson, Thomas; Fall, S. Michael; Lubow, Stephen H.; Quick, Lee; Strolger, Louis-Gregory; Wallace, Geoff; White, Richard L.

2016-06-01

The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope (HST) by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive (HLA) into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160,000 HST exposures. Source lists from Data Release 8 of the HLA are matched using an algorithm developed by Budavári & Lubow. The mean photometric accuracy for the catalog as a whole is better than 0.10 mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10 mas, with a value for the mode (I.e., most common value) of 2.3 mas. The absolute astrometric accuracy is better than 0''\\hspace{-0.5em}. 1 for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. We provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog.

Introduction to the m = 1 helicity source

International Nuclear Information System (INIS)

Platts, D.A.; Jarboe, T.R.; Wright, B.L.

1985-01-01

The m = 1 Helicity Source, formerly called the Kinked Z-pinch, was developed as part of the Electrode Studies program at Los Alamos. The Electrode Studies program was initiated to study the control of electrode erosion in long discharge duration spheromak sources. Erosion control is necessary to reduce plasma impurities and to obtain adequate electrode lifetimes. The first task of the Electrode Studies program is to determine, from among a variety of configurations including the coaxial one, a helicity source geometry with good prospects for erosion control. The more efficient the helicity source the easier it will be to control erosion, but the source most also be easy to diagnose and modify if it is to be a useful test bed. The various erosion control techniques which have been proposed will require extensive experimentation to evaluate and optimize. Proposed techniques include, using refractory metals, profiling of the electrodes and magnetic fields, and various gas injection schemes including porous electrodes. It is considered necessary to do these experiments on an optimized helicity source so that the electrode geometries and plasma properties will be relevant. Therefore the present Electrode Studies program is aimed at developing an improved helicity source design

Advanced Photon Source research: Volume 1, Number 1, April 1998

International Nuclear Information System (INIS)

1998-04-01

The following articles are included in this publication: (1) The Advanced Photon Source: A Brief Overview; (2) MAD Analysis of FHIT at the Structural Biology Center; (3) Advances in High-Energy-Resolution X-ray Scattering at Beamline 3-ID; (4) X-ray Imaging and Microspectroscopy of the Mycorrhyizal Fungus-Plant Symbiosis; (5) Measurement and Control of Particle-beam Trajectories in the Advanced Photon Storage Ring; (6) Beam Acceleration and Storage at the Advanced Photon Source; and (7) Experimental Facilities Operations and Current Status

High-Throughput Screening of Compounds for Anti-Transmissible Spongiform Encephalopathy Activity Using Cell-Culture and Cell-Free Models and Infected Animals

National Research Council Canada - National Science Library

Caughey, Byron

2006-01-01

.... One therapeutic approach is the inhibitors of PrPSc accumulation indeed many inhibitors of PrPSc accumulation in scrapie-infected cells also have anti-scrapie activity in rodents During This year...

Oxygen ion source and RFQ for Linac 1

CERN Multimedia

Photographic Service

1986-01-01

As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions. In 1984, its Cockcroft-Walton preinjector was replaced by an RFQ. In the foreground at the right is the oxygen ion source. A 90 deg bending magnet selects O6+ ions which are preaccelerated in an RFQ and enter Linac 1, at the far left. In the background is the proton and negative hydrogen ion source, followed by the 520 keV RFQ-1 and a bending magnet towards the entrance of Linac 1.

Applications of Indus-1 synchrotron radiation source

International Nuclear Information System (INIS)

Nandedkar, R.V.

2003-01-01

Indus-1 is a 450 MeV electron storage ring. This is a soft X-ray and Vacuum Ultra Violet radiation source with the critical wavelength being 61 A. In this source, the first beam was stored in mid-1999 and was then made available, after initial storage and beam cleaning of the vacuum components, for beamline installation in the early 2000. Two beamlines are commissioned and are working. Other beamlines are in the advanced stage of commissioning. For Indus-1, the injection system consists of a 20 MeV classical microtron as a preinjector and a booster synchrotron that can go up to 700 MeV. For Indus-1, the injection into the storage ring is at full 450 MeV from this booster synchrotron

Development of an Assay for the Detection of PrPres in Blood and Urine Based on PMCA Assay an ELISA Methods

National Research Council Canada - National Science Library

Rohwer, Robert G; Gregori, Luisa L

2005-01-01

.... The assay is been developed with test material from two animal models: the hamster infected with the 263K strain of scrapie and the sheep either naturally or experimentally infected with scrapie...

Polymorphisms at Amino Acid Residues 141 and 154 Influence Conformational Variation in Ovine PrP

Science.gov (United States)

Yang, Sujeong; Thackray, Alana M.; Hopkins, Lee; Monie, Tom P.; Burke, David F.; Bujdoso, Raymond

2014-01-01

Polymorphisms in ovine PrP at amino acid residues 141 and 154 are associated with susceptibility to ovine prion disease: Leu141Arg154 with classical scrapie and Phe141Arg154 and Leu141His154 with atypical scrapie. Classical scrapie is naturally transmissible between sheep, whereas this may not be the case with atypical scrapie. Critical amino acid residues will determine the range or stability of structural changes within the ovine prion protein or its functional interaction with potential cofactors, during conversion of PrPC to PrPSc in these different forms of scrapie disease. Here we computationally identified that regions of ovine PrP, including those near amino acid residues 141 and 154, displayed more conservation than expected based on local structural environment. Molecular dynamics simulations showed these conserved regions of ovine PrP displayed genotypic differences in conformational repertoire and amino acid side-chain interactions. Significantly, Leu141Arg154 PrP adopted an extended beta sheet arrangement in the N-terminal palindromic region more frequently than the Phe141Arg154 and Leu141His154 variants. We supported these computational observations experimentally using circular dichroism spectroscopy and immunobiochemical studies on ovine recombinant PrP. Collectively, our observations show amino acid residues 141 and 154 influence secondary structure and conformational change in ovine PrP that may correlate with different forms of scrapie. PMID:25126555

Cytosolic PrP Can Participate in Prion-Mediated Toxicity

Science.gov (United States)

Thackray, Alana M.; Zhang, Chang; Arndt, Tina

2014-01-01

ABSTRACT Prion diseases are characterized by a conformational change in the normal host protein PrPC. While the majority of mature PrPC is tethered to the plasma membrane by a glycosylphosphatidylinositol anchor, topological variants of this protein can arise during its biosynthesis. Here we have generated Drosophila transgenic for cytosolic ovine PrP in order to investigate its toxic potential in flies in the absence or presence of exogenous ovine prions. While cytosolic ovine PrP expressed in Drosophila was predominantly detergent insoluble and showed resistance to low concentrations of proteinase K, it was not overtly detrimental to the flies. However, Drosophila transgenic for cytosolic PrP expression exposed to classical or atypical scrapie prion inocula showed a faster decrease in locomotor activity than similar flies exposed to scrapie-free material. The susceptibility to classical scrapie inocula could be assessed in Drosophila transgenic for panneuronal expression of cytosolic PrP, whereas susceptibility to atypical scrapie required ubiquitous PrP expression. Significantly, the toxic phenotype induced by ovine scrapie in cytosolic PrP transgenic Drosophila was transmissible to recipient PrP transgenic flies. These data show that while cytosolic PrP expression does not adversely affect Drosophila, this topological PrP variant can participate in the generation of transmissible scrapie-induced toxicity. These observations also show that PrP transgenic Drosophila are susceptible to classical and atypical scrapie prion strains and highlight the utility of this invertebrate host as a model of mammalian prion disease. IMPORTANCE During prion diseases, the host protein PrPC converts into an abnormal conformer, PrPSc, a process coupled to the generation of transmissible prions and neurotoxicity. While PrPC is principally a glycosylphosphatidylinositol-anchored membrane protein, the role of topological variants, such as cytosolic PrP, in prion-mediated toxicity and

Generalized cerebral atrophy seen on MRI in a naturally exposed animal model for creutzfeldt-jakob disease

Directory of Open Access Journals (Sweden)

Dasanu Constantin A

2010-11-01

Full Text Available Abstract Background Magnetic resonance imaging has been used in the diagnosis of human prion diseases such as sCJD and vCJD, but patients are scanned only when clinical signs appear, often at the late stage of disease. This study attempts to answer the questions "Could MRI detect prion diseases before clinical symptoms appear?, and if so, with what confidence?" Methods Scrapie, the prion disease of sheep, was chosen for the study because sheep can fit into a human sized MRI scanner (and there were no large animal MRI scanners at the time of this study, and because the USDA had, at the time of the study, a sizeable sample of scrapie exposed sheep, which we were able to use for this purpose. 111 genetically susceptible sheep that were naturally exposed to scrapie were used in this study. Results Our MRI findings revealed no clear, consistent hyperintense or hypointense signal changes in the brain on either clinically affected or asymptomatic positive animals on any sequence. However, in all 37 PrPSc positive sheep (28 asymptomatic and 9 symptomatic, there was a greater ventricle to cerebrum area ratio on MRI compared to 74 PrPSc negative sheep from the scrapie exposed flock and 6 control sheep from certified scrapie free flocks as defined by immunohistochemistry (IHC. Conclusions Our findings indicate that MRI imaging can detect diffuse cerebral atrophy in asymptomatic and symptomatic sheep infected with scrapie. Nine of these 37 positive sheep, including 2 one-year old animals, were PrPSc positive only in lymph tissues but PrPSc negative in the brain. This suggests either 1 that the cerebral atrophy/neuronal loss is not directly related to the accumulation of PrPSc within the brain or 2 that the amount of PrPSc in the brain is below the detectable limits of the utilized immunohistochemistry assay. The significance of these findings remains to be confirmed in human subjects with CJD.

Variation in the prion protein sequence in Dutch goat breeds.

Science.gov (United States)

Windig, J J; Hoving, R A H; Priem, J; Bossers, A; van Keulen, L J M; Langeveld, J P M

2016-10-01

Scrapie is a neurodegenerative disease occurring in goats and sheep. Several haplotypes of the prion protein increase resistance to scrapie infection and may be used in selective breeding to help eradicate scrapie. In this study, frequencies of the allelic variants of the PrP gene are determined for six goat breeds in the Netherlands. Overall frequencies in Dutch goats were determined from 768 brain tissue samples in 2005, 766 in 2008 and 300 in 2012, derived from random sampling for the national scrapie surveillance without knowledge of the breed. Breed specific frequencies were determined in the winter 2013/2014 by sampling 300 breeding animals from the main breeders of the different breeds. Detailed analysis of the scrapie-resistant K222 haplotype was carried out in 2014 for 220 Dutch Toggenburger goats and in 2015 for 942 goats from the Saanen derived White Goat breed. Nine haplotypes were identified in the Dutch breeds. Frequencies for non-wild type haplotypes were generally low. Exception was the K222 haplotype in the Dutch Toggenburger (29%) and the S146 haplotype in the Nubian and Boer breeds (respectively 7 and 31%). The frequency of the K222 haplotype in the Toggenburger was higher than for any other breed reported in literature, while for the White Goat breed it was with 3.1% similar to frequencies of other Saanen or Saanen derived breeds. Further evidence was found for the existence of two M142 haplotypes, M142 /S240 and M142 /P240 . Breeds vary in haplotype frequencies but frequencies of resistant genotypes are generally low and consequently selective breeding for scrapie resistance can only be slow but will benefit from animals identified in this study. The unexpectedly high frequency of the K222 haplotype in the Dutch Toggenburger underlines the need for conservation of rare breeds in order to conserve genetic diversity rare or absent in other breeds. © 2016 Blackwell Verlag GmbH.

Preinjector for Linac 1, ion source

CERN Multimedia

1974-01-01

For a description of the Linac 1 preinjector, please see first 7403070X. Inside the drum-shaped container shown in 7403081X, is the ion source with its associated electronics. It sits at the HV end of the accelerating column seen also in 7403081.

Nonsafety loads on glass 1E power sources, revisited

International Nuclear Information System (INIS)

Lewin, J.

1980-01-01

The supply of some nonsafety loads from class 1E power sources is allowed by industry standards (IEEE Standards 308 and 384) and by US Nuclear Regulatory Commission Regulatory Guides 1.32 and 1.75. This has been questioned as a possible source of degradation of the class 1E system, and this power deals with assessment of the effects of this practice on the reliability of the power supply for engineered safety features (ESF) systems

Discovery of a novel, monocationic, small-molecule inhibitor of scrapie prion accumulation in cultured sheep microglia and Rov cells.

Directory of Open Access Journals (Sweden)

James B Stanton

Full Text Available Prion diseases, including sheep scrapie, are neurodegenerative diseases with the fundamental pathogenesis involving conversion of normal cellular prion protein (PrP(C to disease-associated prion protein (PrP(Sc. Chemical inhibition of prion accumulation is widely investigated, often using rodent-adapted prion cell culture models. Using a PrP(Sc-specific ELISA we discovered a monocationic phenyl-furan-benzimidazole (DB772, which has previously demonstrated anti-pestiviral activity and represents a chemical category previously untested for anti-prion activity, that inhibited PrP(Sc accumulation and prion infectivity in primary sheep microglial cell cultures (PRNP 136VV/154RR/171QQ and Rov9 cultures (VRQ-ovinized RK13 cells. We investigated potential mechanisms of this anti-prion activity by evaluating PrP(C expression with quantitative RT-PCR and PrP ELISA, comparing the concentration-dependent anti-prion and anti-pestiviral effects of DB772, and determining the selectivity index. Results demonstrate at least an approximate two-log inhibition of PrP(Sc accumulation in the two cell systems and confirmed that the inhibition of PrP(Sc accumulation correlates with inhibition of prion infectivity. PRNP transcripts and total PrP protein concentrations within cell lysates were not decreased; thus, decreased PrP(C expression is not the mechanism of PrP(Sc inhibition. PrP(Sc accumulation was multiple logs more resistant than pestivirus to DB772, suggesting that the anti-PrP(Sc activity was independent of anti-pestivirus activity. The anti-PrP(Sc selectivity index in cell culture was approximately 4.6 in microglia and 5.5 in Rov9 cells. The results describe a new chemical category that inhibits ovine PrP(Sc accumulation in primary sheep microglia and Rov9 cells, and can be used for future studies into the treatment and mechanism of prion diseases.

Herschel-ATLAS : Planck sources in the phase 1 fields

NARCIS (Netherlands)

Herranz, D.; González-Nuevo, J.; Clements, D.; De, Zotti G.; Lopez-Caniego, M.; Lapi, A.; Rodighiero, G.; Danese, L.; Fu, H.; Cooray, A.; Baes, M.; Bendo, G.; Bonavera, L.; Carrera, F.; Dole, H.; Eales, S.; Ivison, R.; Jarvis, M.; Lagache, G.; Massardi, M.; Michalowski, M.; Negrello, M.; Rigby, E.E.; Scott, D.; Valiante, E.; Valtchanov, I.; Werf, van der P.P.; Auld, R.; Buttiglione, S.; Dariush, A.; Dunne, L.; Hopwood, R.; Hoyos, C.; Ibar, E.; Maddox, S.

2013-01-01

We present the results of a cross-correlation of the Planck Early Release Compact Source catalogue (ERCSC) with the catalogue of Herschel-ATLAS sources detected in the phase 1 fields, covering 134.55{deg}$^{2}$. There are 28 ERCSC sources detected by Planck at 857 GHz in this area. As many as 16 of

Polymorphisms of the prion protein gene Arabi sheep breed in Iran

African Journals Online (AJOL)

Novin

2011-11-09

Nov 9, 2011 ... Key words: Prion protein gene (Prnp), polymorphisms, susceptibility, scrapie. INTRODUCTION. Scrapie is an invariably fatal .... consists of a DNA denaturation step (5 min at 95°C), followed by 30 amplification cycles ...

Prions and neuro degenerative diseases

African Journals Online (AJOL)

user

2011-03-28

Mar 28, 2011 ... scrapie (a fatal disease of sheep and goats), mad cow disease, Creutzfeldt-Jacob disease, fatal familial insomnia, kuru .... The scrapie agent is extremely resistant to heat ... movement, or the stress of handling, the animal may.

Proceedings of the workshop on ion source issues relevant to a pulsed spallation neutron source: Part 1: Workshop summary

International Nuclear Information System (INIS)

Schroeder, L.; Leung, K.N.; Alonso, J.

1994-10-01

The workshop reviewed the ion-source requirements for high-power accelerator-driven spallation neutron facilities, and the performance of existing ion sources. Proposals for new facilities in the 1- to 5-MW range call for a widely differing set of ion-source requirements. For example, the source peak current requirements vary from 40 mA to 150 mA, while the duty factor ranges from 1% to 9%. Much of the workshop discussion centered on the state-of-the-art of negative hydrogen ion source (H - ) technology and the present experience with Penning and volume sources. In addition, other ion source technologies, for positive ions or CW applications were reviewed. Some of these sources have been operational at existing accelerator complexes and some are in the source-development stage on test stands

Background gas density and beam losses in NIO1 beam source

Energy Technology Data Exchange (ETDEWEB)

Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Veltri, P.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), C.so Stati Uniti 4, 35127 Padova (Italy); Cavenago, M. [INFN-LNL, v.le dell’Università 2, I-35020 Legnaro (PD) (Italy)

2016-02-15

NIO1 (Negative Ion Optimization 1) is a versatile ion source designed to study the physics of production and acceleration of H- beams up to 60 keV. In ion sources, the gas is steadily injected in the plasma source to sustain the discharge, while high vacuum is maintained by a dedicated pumping system located in the vessel. In this paper, the three dimensional gas flow in NIO1 is studied in the molecular flow regime by the Avocado code. The analysis of the gas density profile along the accelerator considers the influence of effective gas temperature in the source, of the gas temperature accommodation by collisions at walls, and of the gas particle mass. The calculated source and vessel pressures are compared with experimental measurements in NIO1 during steady gas injection.

Nasu 1.4 GHz Interferometer Transient Radio Source Survey and Improvement in Detection of Radio Sources

International Nuclear Information System (INIS)

Matsumura, Nobuo; Kuniyoshi, Masaya; Takefuji, Kazuhiro; Niinuma, Kotaro; Kida, Sumiko; Takeuchi, Akihiko; Asuma, Kuniyuki; Daishido, Tsuneaki

2006-01-01

We have surveyed 1.4GHz transient radio sources in Nasu Pulsar Observatory. To investigate such sources, both immediacy and accuracy are severely maintained. We have developed Data Transfer System and improved antenna control system. Now we have received the fringe data from transient radio source candidates. To get reliable information, we carefully analyze with Fringe Band Pass Filter software and Fringe Fitting method

1+-n+ ECR ION SOURCE DEVELOPMENT TEST STAND

International Nuclear Information System (INIS)

Donald P. May

2006-01-01

A test stand for the investigation of 1+-n+ charge boosting using an ECR ion sources is currently being assembled at the Texas A and M Cyclotron Institute. The ultimate goal is to relate the charge-boosting of ions of stable species to possible charge-boosting of ions of radioactive species extracted from the diverse, low-charge-state ion sources developed for radioactive ion beams

Characterisation of new monoclonal antibodies reacting with prions from both human and animal brain tissues

DEFF Research Database (Denmark)

Hvass, Henriette Cordes; Bergström, Ann-Louise; Ohm, Jakob

2008-01-01

spongiform encephalopathy (bovine brain), scrapie (ovine brain) and experimental scrapie in hamster and in mice. The antibodies were also used for PET-blotting in which PrPSc blotted from brain tissue sections onto a nitrocellulose membrane is visualized with antibodies after protease and denaturant...

Phase 1 immobilized low-activity waste operational source term

International Nuclear Information System (INIS)

Burbank, D.A.

1998-01-01

This report presents an engineering analysis of the Phase 1 privatization feeds to establish an operational source term for storage and disposal of immobilized low-activity waste packages at the Hanford Site. The source term information is needed to establish a preliminary estimate of the numbers of remote-handled and contact-handled waste packages. A discussion of the uncertainties and their impact on the source term and waste package distribution is also presented. It should be noted that this study is concerned with operational impacts only. Source terms used for accident scenarios would differ due to alpha and beta radiation which were not significant in this study

Polymorphisms of the prion protein gene Arabi sheep breed in Iran ...

African Journals Online (AJOL)

Ovine scrapie is a neurodegenerative disease caused by polymorphisms of the prion protein gene (Prnp); especially the amino acid residue alterations at codons 136, 154, and 174, in sheep have been found to be associated with susceptibility to scrapie disease. We studied Prnp polymorphisms in local sheep of ...

Source term determination from subcritical multiplication measurements at Koral-1 reactor

International Nuclear Information System (INIS)

Blazquez, J.B.; Barrado, J.M.

1978-01-01

By using an AmBe neutron source two independent procedures have been settled for the zero-power experimental fast-reactor Coral-1 in order to measure the source term which appears in the point kinetical equations. In the first one, the source term is measured when the reactor is just critical with source by taking advantage of the wide range of the linear approach to critical for Coral-1. In the second one, the measurement is made in subcritical state by making use of the previous calibrated control rods. Several applications are also included such as the measurement of the detector dead time, the determinations of the reactivity of small samples and the shape of the neutron importance of the source. (author)

Multi-pass 1.9 um Tm:YLF slab laser pump source

CSIR Research Space (South Africa)

Strauss

2010-09-01

Full Text Available stream_source_info Strauss1_2010.pdf.txt stream_content_type text/plain stream_size 4116 Content-Encoding ISO-8859-1 stream_name Strauss1_2010.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Multi-Pass 1.9 ?m Tm...:YLF Slab Laser Pump Source H.J. Strauss1, S.C. Burd2, W. Koen1, M.J.D. Esser1, C. Jacobs1, O.J.P. Collett1, K. Nyangaza1, D. Preussler1 and C. Bollig1 1 Laser Centre, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, South...

Improvements of the versatile multiaperture negative ion source NIO1

Science.gov (United States)

Cavenago, M.; Serianni, G.; De Muri, M.; Veltri, P.; Antoni, V.; Baltador, C.; Barbisan, M.; Brombin, M.; Galatá, A.; Ippolito, N.; Kulevoy, T.; Pasqualotto, R.; Petrenko, S.; Pimazzoni, A.; Recchia, M.; Sartori, E.; Taccogna, F.; Variale, V.; Zaniol, B.; Barbato, P.; Baseggio, L.; Cervaro, V.; Fasolo, D.; Franchin, L.; Ghiraldelli, R.; Laterza, B.; Maniero, M.; Martini, D.; Migliorato, L.; Minarello, A.; Molon, F.; Moro, G.; Patton, T.; Ravarotto, D.; Rizzieri, R.; Rizzolo, A.; Sattin, M.; Stivanello, F.; Zucchetti, S.

2017-08-01

The ion source NIO1 (Negative Ion Optimization 1) was developed and installed as a reduced-size model of multi-aperture sources used in neutral beam injectors. NIO1 beam optics is optimized for a 135 mA H- current (subdivided in 9 beamlets) at a Vs = 60 kV extraction voltage, with an electron-to-ion current ratio Rj up to 2. Depending on gas pressure used, NIO1 was up to now operated with Vs qualitative agreement with theoretical and numerical models. A second bias voltage was tested for hydrogen. Beam footprints and a spectral emission sample are shown.

EPA Region 1 Sole Source Aquifers

Data.gov (United States)

U.S. Environmental Protection Agency — This coverage contains boundaries of EPA-approved sole source aquifers. Sole source aquifers are defined as an aquifer designated as the sole or principal source of...

VizieR Online Data Catalog: The Chandra Source Catalog, Release 1.1 (Evans+ 2012)

Science.gov (United States)

Evans, I. N.; Primini, F. A.; Glotfelty, C. S.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G.; Grier, J. D.; Hain, R. M.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Kashyap, V. L.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Mossman, A. E.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A.; Sundheim, B. A.; Tibbetts, M. S.; van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2014-01-01

This version of the catalog is release 1.1. It includes the information contained in release 1.0.1, plus point and compact source data extracted from HRC imaging observations, and catch-up ACIS observations released publicly prior to the end of 2009. (1 data file).

Department of Agriculture Semiannual Regulatory Agenda

Science.gov (United States)

2010-12-20

... Import Restrictions on Certain 0579-AC74 Live Fish 189 Scrapie in Sheep and Goats 0579-AC92 190 Plant..., Farming Experience as an Eligibility Requirement; 5201, Eligibility of Equine Farmers and Ranchers for... Phone: 301 734-8695 RIN: 0579-AC74 189. SCRAPIE IN SHEEP AND GOATS Legal Authority: 7 USC 8301 to 8317...

76 FR 39998 - Semiannual Regulatory Agenda, Spring 2011

Science.gov (United States)

2011-07-07

... Import Restrictions on Certain Live Fish. 14 Scrapie in Sheep and Goats 0579-AC92 15 Plant Pest... Land Sales Program Down Payment Loan Program; 5101, Farming Experience as an Eligibility Requirement..., Phone: 301 734-8695. RIN: 0579-AC74 14. Scrapie in Sheep and Goats Legal Authority: 7 U.S.C. 8301 to...

77 FR 7890 - Semiannual Regulatory Agenda, Fall 2011

Science.gov (United States)

2012-02-13

... Encephalopathy; Importation of Bovines and Bovine Products. 181 Scrapie in Sheep and Goats 0579-AC92 182 Plant... Payment Loan Program; 5101, Farming Experience as an Eligibility Requirement; and 5201, Eligibility of...: 301 734- 7837. RIN: 0579-AC68 181. Scrapie in Sheep and Goats Legal Authority: 7 U.S.C. 8301 to 8317...

Effects of polymorphisms in ovine and caprine prion protein alleles on cell-free conversion

Directory of Open Access Journals (Sweden)

Eiden Martin

2011-02-01

Full Text Available Abstract In sheep polymorphisms of the prion gene (PRNP at the codons 136, 154 and 171 strongly influence the susceptibility to scrapie and bovine spongiform encephalopathy (BSE infections. In goats a number of other gene polymorphisms were found which are suspected to trigger similar effects. However, no strong correlation between polymorphisms and TSE susceptibility in goats has yet been obtained from epidemiological studies and only a low number of experimental challenge data are available at present. We have therefore studied the potential impact of these polymorphisms in vitro by cell-free conversion assays using mouse scrapie strain Me7. Mouse scrapie brain derived PrPSc served as seeds and eleven recombinant single mutation variants of sheep and goat PrPC as conversion targets. With this approach it was possible to assign reduced conversion efficiencies to specific polymorphisms, which are associated to low frequency in scrapie-affected goats or found only in healthy animals. Moreover, we could demonstrate a dominant-negative inhibition of prion polymorphisms associated with high susceptibility by alleles linked to low susceptibility in vitro.

26 CFR 1.933-1 - Exclusion of certain income from sources within Puerto Rico.

Science.gov (United States)

2010-04-01

... Puerto Rico. 1.933-1 Section 1.933-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... Exclusion of certain income from sources within Puerto Rico. (a) General rule. (1) An individual (whether a United States citizen or an alien), who is a bona fide resident of Puerto Rico during the entire taxable...

Systems analysis and engineering of the X-1 Advanced Radiation Source

International Nuclear Information System (INIS)

Rochau, G.E.; Hands, J.A.; Raglin, P.S.; Ramirez, J.J.

1998-01-01

The X-1 Advanced Radiation Source, which will produce ∼ 16 MJ in x-rays, represents the next step in providing US Department of Energy's Stockpile Stewardship program with the high-energy, large volume, laboratory x-ray sources needed for the Radiation Effects Science and Simulation (RES), Inertial Confinement Fusion (ICF), and Weapon Physics (WP) Programs. Advances in fast pulsed power technology and in z-pinch hohlraums on Sandia National Laboratories' Z Accelerator in 1997 provide sufficient basis for pursuing the development of X-1. This paper will introduce the X-1 Advanced Radiation Source Facility Project, describe the systems analysis and engineering approach being used, and identify critical technology areas being researched

Optimization of superconducting bending magnets for a 1.0 to 1.5 GeV compact light source

International Nuclear Information System (INIS)

Green, M.A.; Garren, A.A.

1995-06-01

Compact light sources are being proposed for protein crystallography, medical imaging, nano-machining and other areas of study that require intense sources of x rays at energies up to 35 keV. In order for a synchrotron light source to be attractive, its capital cost must, be kept low. The proposed compact light source has superconducting bending elements to bend the stored beam and produce the x rays. Additional focusing for the machine is provided by conventional quadrupoles. An important part of the cost optimization of a compact light source is the cost of the bending magnets. In the case of a machine with superconducting bending elements, the bending magnet system can represent close to half of the storage ring cost. The compact light source storage rings studied here have a range of stored electron energies from 1.0 to 1.5 GeV. For a number of reasons, it is desirable to keep the storage ring circumference below 30 meters. Cost optimization parameters include: (1) the number of superconducting bending elements in the ring, and (2) the central induction of the dipole. A machine design that features two superconducting dipoles in a single cryostat vacuum vessel is also discussed

Prion remains infectious after passage through digestive system of American crows (Corvus brachyrhynchos.

Directory of Open Access Journals (Sweden)

Kurt C VerCauteren

Full Text Available Avian scavengers, such as American crows (Corvus brachyrhynchos, have potential to translocate infectious agents (prions of transmissible spongiform encephalopathy (TSE diseases including chronic wasting disease, scrapie, and bovine spongiform encephalopathy. We inoculated mice with fecal extracts obtained from 20 American crows that were force-fed material infected with RML-strain scrapie prions. These mice all evinced severe neurological dysfunction 196-231 d postinoculation (x =198; 95% CI: 210-216 and tested positive for prion disease. Our results suggest a large proportion of crows that consume prion-positive tissue are capable of passing infectious prions in their feces (ˆp=1.0; 95% CI: 0.8-1.0. Therefore, this common, migratory North American scavenger could play a role in the geographic spread of TSE diseases.

A new method for the characterization of strain-specific conformational stability of protease-sensitive and protease-resistant PrPSc.

Directory of Open Access Journals (Sweden)

Laura Pirisinu

Full Text Available Although proteinacious in nature, prions exist as strains with specific self-perpetuating biological properties. Prion strains are thought to be associated with different conformers of PrP(Sc, a disease-associated isoform of the host-encoded cellular protein (PrP(C. Molecular strain typing approaches have been developed which rely on the characterization of protease-resistant PrP(Sc. However, PrP(Sc is composed not only of protease-resistant but also of protease-sensitive isoforms. The aim of this work was to develop a protocol for the molecular characterization of both, protease-resistant and protease-sensitive PrP(Sc aggregates. We first set up experimental conditions which allowed the most advantageous separation of PrP(C and PrP(Sc by means of differential centrifugation. The conformational solubility and stability assay (CSSA was then developed by measuring PrP(Sc solubility as a function of increased exposure to GdnHCl. Brain homogenates from voles infected with human and sheep prion isolates were analysed by CSSA and showed strain-specific conformational stabilities, with mean [GdnHCl](1/2 values ranging from 1.6 M for MM2 sCJD to 2.1 for scrapie and to 2.8 M for MM1/MV1 sCJD and E200K gCJD. Interestingly, the rank order of [GdnHCl](1/2 values observed in the human and sheep isolates used as inocula closely matched those found following transmission in voles, being MM1 sCJD the most resistant (3.3 M, followed by sheep scrapie (2.2 M and by MM2 sCJD (1.6 M. In order to test the ability of CSSA to characterise protease-sensitive PrP(Sc, we analysed sheep isolates of Nor98 and compared them to classical scrapie isolates. In Nor98, insoluble PrP(Sc aggregates were mainly protease-sensitive and showed a conformational stability much lower than in classical scrapie. Our results show that CSSA is able to reveal strain-specified PrP(Sc conformational stabilities of protease-resistant and protease-sensitive PrP(Sc and that it is a valuable tool

Research Activities Using Indus-1 Synchrotron Radiation Source

International Nuclear Information System (INIS)

Lodha, G. S.; Deb, S. K.

2010-01-01

Indus-1 is an efficient SR source in the soft x-ray / vacuum ultra violet region of the electromagnetic spectrum. For Indus-1, the higher order energy contamination in soft x-ray region, heat load and radiation safety problems are also significantly low. At present, soft x-ray-VUV reflectivity, angle integrated and angle resolved photo electron spectroscopy (ARPES), photo physics and high resolution vacuum ultra violet spectroscopy, beamlines are operational. The paper presents some of the recent studies carried out using In-dus-1.

SM-1 negative ion source

International Nuclear Information System (INIS)

Huang Zhenjun; Wang Jianzhen

1987-01-01

The working principle and characteristics of SM-1 Negative Ion Source is mainly introduced. In the instrument, there is a device to remove O 3 . This instrument can keep high density of negative ions which is generated by the electrical coronas setting out electricity at negative high voltage and can remove the O 3 component which is harmful to the human body. The density of negative ions is higher than 2.5 x 10 6 p./cm 3 while that of O 3 components is less than 1 ppb at the distance of 50 cm from the panel of the instrument. The instrument sprays negative ions automatically without the help of electric fan, so it works noiselessly. It is widely used in national defence, industry, agriculture, forestry, stock raising, sidelines and in the places with an equipment of low density of negative ion or high concentration of O 3 components. Besides, the instrument may also be used to treat diseases, to prevent against rot, to arrest bacteria, to purify air and so on

Development of a 1-m plasma source for heavy ion beam charge neutralization

Science.gov (United States)

Efthimion, Philip C.; Gilson, Erik P.; Grisham, Larry; Davidson, Ronald C.; Yu, Simon; Waldron, William; Grant Logan, B.

2005-05-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ˜0.1-1 m would be suitable for achieving a high level of charge neutralization. A radio frequency (RF) source was constructed at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization. Pulsing the source enabled operation at pressures ˜10 -6 Torr with plasma densities of 10 11 cm -3. Near 100% ionization was achieved. The plasma was 10 cm in length, but future experiments require a source 1 m long. The RF source does not easily scale to the length. Consequently, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO 3 to form metal plasma. A 1 m long section of the drift tube inner surface of NTX will be covered with ceramic. A high voltage (˜1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. Plasma densities of 10 12 cm -3 and neutral pressures ˜10 -6 Torr are expected. A test stand to produce 20 cm long plasma is being constructed and will be tested before a 1 m long source is developed.

Development of a 1-m plasma source for heavy ion beam charge neutralization

International Nuclear Information System (INIS)

Efthimion, Philip C.; Gilson, Erik P.; Grisham, Larry; Davidson, Ronald C.; Yu, Simon; Waldron, William; Grant Logan, B.

2005-01-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ∼0.1-1 m would be suitable for achieving a high level of charge neutralization. A radio frequency (RF) source was constructed at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization. Pulsing the source enabled operation at pressures ∼10 -6 Torr with plasma densities of 10 11 cm -3 . Near 100% ionization was achieved. The plasma was 10 cm in length, but future experiments require a source 1 m long. The RF source does not easily scale to the length. Consequently, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO 3 to form metal plasma. A 1 m long section of the drift tube inner surface of NTX will be covered with ceramic. A high voltage (∼1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. Plasma densities of 10 12 cm -3 and neutral pressures ∼10 -6 Torr are expected. A test stand to produce 20 cm long plasma is being constructed and will be tested before a 1 m long source is developed

40 CFR Table 1 to Subpart Nnnnnn... - HAP Emissions Sources

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 14 2010-07-01 2010-07-01 false HAP Emissions Sources 1 Table 1 to Subpart NNNNNN of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...: Chromium Compounds Pt. 63, Subpt. NNNNNN, Table 1 Table 1 to Subpart NNNNNN of Part 63—HAP Emissions...

The surface oxide as a source of oxygen on Rh(1 1 1)

Energy Technology Data Exchange (ETDEWEB)

Lundgren, E. [Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Box 118, S-221 00 Lund (Sweden)]. E-mail: edvin.lundgren@sljus.lu.se; Gustafson, J. [Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Box 118, S-221 00 Lund (Sweden); Resta, A. [Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Box 118, S-221 00 Lund (Sweden); Weissenrieder, J. [Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Box 118, S-221 00 Lund (Sweden); Mikkelsen, A. [Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Box 118, S-221 00 Lund (Sweden); Andersen, J.N. [Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Box 118, S-221 00 Lund (Sweden); Koehler, L. [Institut fuer Materialphysik and Centre for Computational Materials Science, Universitaet Wien, A-1090 Vienna (Austria); Kresse, G. [Institut fuer Materialphysik and Centre for Computational Materials Science, Universitaet Wien, A-1090 Vienna (Austria); Klikovits, J. [Institut fuer Allgemeine Physik, Technische Universitaet Wien, A-1040 Vienna (Austria); Biederman, A. [Institut fuer Allgemeine Physik, Technische Universitaet Wien, A-1040 Vienna (Austria); Schmid, M. [Institut fuer Allgemeine Physik, Technische Universitaet Wien, A-1040 Vienna (Austria); Varga, P. [Institut fuer Allgemeine Physik, Technische Universitaet Wien, A-1040 Vienna (Austria)

2005-06-15

The reduction of a thin surface oxide on the Rh(1 1 1) surface by CO is studied in situ by photoemission spectroscopy, scanning tunneling microscopy, and density functional theory. CO molecules are found not to adsorb on the surface oxide at a sample temperature of 100 K, in contrast to on the clean and chemisorbed oxygen covered surface. Despite this behavior, the surface oxide may still be reduced by CO, albeit in a significantly different fashion as compared to the reduction of a phase containing only chemisorbed on surface oxygen. The experimental observations combined with theoretical considerations concerning the stability of the surface oxide, result in a model of the reduction process at these pressures suggesting that the surface oxide behaves as a source of oxygen for the CO-oxidation reaction.

Multiband Diagnostics of Unidentified 1FGL Sources with Suzaku and Swift X-Ray Observations

Science.gov (United States)

Takeuchi, Y.; Kataoka, J.; Maeda, K.; Takahashi, Y.; Nakamori, T.; Tahara, M.

2013-10-01

We have analyzed all the archival X-ray data of 134 unidentified (unID) gamma-ray sources listed in the first Fermi/LAT (1FGL) catalog and subsequently followed up by the Swift/XRT. We constructed the spectral energy distributions (SEDs) from radio to gamma-rays for each X-ray source detected, and tried to pick up unique objects that display anomalous spectral signatures. In these analyses, we target all the 1FGL unID sources, using updated data from the second Fermi/LAT (2FGL) catalog on the Large Area Telescope (LAT) position and spectra. We found several potentially interesting objects, particularly three sources, 1FGL J0022.2-1850, 1FGL J0038.0+1236, and 1FGL J0157.0-5259, which were then more deeply observed with Suzaku as a part of an AO-7 program in 2012. We successfully detected an X-ray counterpart for each source whose X-ray spectra were well fitted by a single power-law function. The positional coincidence with a bright radio counterpart (currently identified as an active galactic nucleus, AGN) in the 2FGL error circles suggests these sources are definitely the X-ray emission from the same AGN, but their SEDs show a wide variety of behavior. In particular, the SED of 1FGL J0038.0+1236 is not easily explained by conventional emission models of blazars. The source 1FGL J0022.2-1850 may be in a transition state between a low-frequency peaked and a high-frequency peaked BL Lac object, and 1FGL J0157.0-5259 could be a rare kind of extreme blazar. We discuss the possible nature of these three sources observed with Suzaku, together with the X-ray identification results and SEDs of all 134 sources observed with the Swift/XRT.

Ion Source Physics and Technology (1/2)

CERN Multimedia

CERN. Geneva

2016-01-01

This series of lectures starts with an introduction in some aspects of atomic and plasma physics as base for the ion source physics. The main part covers aspects of ion source physics, technology and operation. Several source types are presented. Some information on infrastructure and supporting services (as high voltage, cooling, microwaves etc) are given to better understand the source environment. The last part on engineering aims to show that, in the field of ion sources, many different technologies are combined in a quite small environment, which is challenging and interesting at the same time.

9 CFR 79.3 - General restrictions.

Science.gov (United States)

2010-01-01

....3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... only if they are identified to their flock of birth.— (1) High-risk, scrapie-positive, or suspect... any animal born after 1-1-2002, the certificate must include the flock of birth and the flock of...

Dislocation Climb Sources Activated by 1 MeV Electron Irradiation of Copper-Nickel Alloys

DEFF Research Database (Denmark)

Barlow, P.; Leffers, Torben

1977-01-01

Climb sources emitting dislocation loops are observed in Cu-Ni alloys during irradiation with 1 MeV electrons in a high voltage electron microscope. High source densities are found in alloys containing 5, 10 and 20% Ni, but sources are also observed in alloys containing 1 and 2% Ni. The range of ...

Microdosimetry computation code of internal sources - MICRODOSE 1

International Nuclear Information System (INIS)

Li Weibo; Zheng Wenzhong; Ye Changqing

1995-01-01

This paper describes a microdosimetry computation code, MICRODOSE 1, on the basis of the following described methods: (1) the method of calculating f 1 (z) for charged particle in the unit density tissues; (2) the method of calculating f(z) for a point source; (3) the method of applying the Fourier transform theory to the calculation of the compound Poisson process; (4) the method of using fast Fourier transform technique to determine f(z) and, giving some computed examples based on the code, MICRODOSE 1, including alpha particles emitted from 239 Pu in the alveolar lung tissues and from radon progeny RaA and RAC in the human respiratory tract. (author). 13 refs., 6 figs

Scorpius X-1 - an evolving double radio source

International Nuclear Information System (INIS)

Geldzahler, B.J.; Fomalont, E.B.; National Radio Astronomy Observatory, Charlottesville, VA)

1986-01-01

The radio emission from Sco X-1 has been monitored with the VLA over a 5 yr period with 0.4 arcsec resolution at 4.85 GHz. The source contains three components: an unresolved radio core coincident with the stellar binary system; an unresolved lobe northeast of the core; and an extended lobe southwest of the core. All radio components are approximately comoving with the binary system and are thus undoubtedly associated with it. The northeast lobe is moving away from the core at a rate of 0.013-0.017 arcsec/yr, which corresponds to a velocity of 31-41 km/sec, assuming a distance of 500 pc to Sco X-1. The relative velocity of a hot spot in the southwest lobe with respect to the core is less than 70 km/sec. The flux density in the lobes appears to vary by about 20 percent over time scales of 1 yr, and the variations between the lobes may be correlated. The twin-exhaust beam model where energy is transported from the core to the lobes in narrow beams is the most acceptable model for the evolution of the source. However, interstellar density (greater than 0.6/cu cm) is needed to restrain the velocity of the northeast lobe (presumably the working surface of the beam). 16 references

Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock.

Science.gov (United States)

Harrington, Robert D; Herrmann-Hoesing, Lynn M; White, Stephen N; O'Rourke, Katherine I; Knowles, Donald P

2009-01-22

Selective breeding of sheep for arginine (R) at prion gene (PRNP) codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV) may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1) associated with the presence of OPPV provirus and 2) associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05). Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05). These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.

Identifying sources and estimating glandular output of salivary TIMP-1

DEFF Research Database (Denmark)

Holten-Andersen, Lars; Jensen, Siri Beier; Jensen, Allan Bardow

2008-01-01

saliva (267.01 ng/min). Conclusion. This study shows that saliva contains authentic TIMP-1, the concentration of which was found to depend on gland type and salivary flow. Stimulated whole saliva is suggested as a reliable and easily accessible source for TIMP-1 determinations in bodily fluids....

Target station design for a 1 MW pulsed spallation neutron source

International Nuclear Information System (INIS)

Russell, G.J.; Baker, G.D.; Brewton, R.J.

1993-01-01

Target stations are vital components of the 1 MW, next generation spallation neutron source proposed for LANSCE. By and large, target stations design determines the overall performance of the facility. Many traditional concepts will probably have to be rethought, and many new concepts will have to be put forward to meet the 1 MW challenge. This article gives a brief overview of the proposed neutron spallation source from the target station viewpoint, as well as the general philosophy adopted for the design of the LANSCE-II target stations. Some of the saliant concepts and features envisioned for LANSCE-II are briefly described

TEMPS, 1-Group Time-Dependent Pulsed Source Neutron Transport

International Nuclear Information System (INIS)

Ganapol, B.D.

1988-01-01

1 - Description of program or function: TEMPS numerically determines the scalar flux as given by the one-group neutron transport equation with a pulsed source in an infinite medium. Standard plane, point, and line sources are considered as well as a volume source in the negative half-space in plane geometry. The angular distribution of emitted neutrons can either be isotropic or mono-directional (beam) in plane geometry and isotropic in spherical and cylindrical geometry. A general anisotropic scattering Kernel represented in terms of Legendre polynomials can be accommodated with a time- dependent number of secondaries given by c(t)=c 0 (t/t 0 ) β , where β is greater than -1 and less than infinity. TEMPS is designed to provide the flux to a high degree of accuracy (4-5 digits) for use as a benchmark to which results from other numerical solutions or approximations can be compared. 2 - Method of solution: A semi-analytic Method of solution is followed. The main feature of this approach is that no discretization of the transport or scattering operators is employed. The numerical solution involves the evaluation of an analytical representation of the solution by standard numerical techniques. The transport equation is first reformulated in terms of multiple collisions with the flux represented by an infinite series of collisional components. Each component is then represented by an orthogonal Legendre series expansion in the variable x/t where the distance x and time t are measured in terms of mean free path and mean free time, respectively. The moments in the Legendre reconstruction are found from an algebraic recursion relation obtained from Legendre expansion in the direction variable mu. The multiple collision series is evaluated first to a prescribed relative error determined by the number of digits desired in the scalar flux. If the Legendre series fails to converge in the plane or point source case, an accelerative transformation, based on removing the

High-Throughput Screening of Compounds for Anti-Transmissible Spongiform Encephalopathy Activity Using Cell-Culture and Cell-Free Models and Infected Animals

Science.gov (United States)

2008-07-01

polyphenols were selected as PrPSc inhibitors against both strains of mouse scrapie in the SCDB assay. Tannin (tannic acid), the most potent inhibitor...of human prion disease is contingent on post-mortem (or biopsy) analysis of brain, despite a number of clinical and paraclinical laboratory features... analysis of the scrapie-associated protein PrP 27-30 in water by infrared spectroscopy. Biochemistry 30, 7672–7680 (1991). The first study revealing

MEG source imaging method using fast L1 minimum-norm and its applications to signals with brain noise and human resting-state source amplitude images.

Science.gov (United States)

Huang, Ming-Xiong; Huang, Charles W; Robb, Ashley; Angeles, AnneMarie; Nichols, Sharon L; Baker, Dewleen G; Song, Tao; Harrington, Deborah L; Theilmann, Rebecca J; Srinivasan, Ramesh; Heister, David; Diwakar, Mithun; Canive, Jose M; Edgar, J Christopher; Chen, Yu-Han; Ji, Zhengwei; Shen, Max; El-Gabalawy, Fady; Levy, Michael; McLay, Robert; Webb-Murphy, Jennifer; Liu, Thomas T; Drake, Angela; Lee, Roland R

2014-01-01

The present study developed a fast MEG source imaging technique based on Fast Vector-based Spatio-Temporal Analysis using a L1-minimum-norm (Fast-VESTAL) and then used the method to obtain the source amplitude images of resting-state magnetoencephalography (MEG) signals for different frequency bands. The Fast-VESTAL technique consists of two steps. First, L1-minimum-norm MEG source images were obtained for the dominant spatial modes of sensor-waveform covariance matrix. Next, accurate source time-courses with millisecond temporal resolution were obtained using an inverse operator constructed from the spatial source images of Step 1. Using simulations, Fast-VESTAL's performance was assessed for its 1) ability to localize multiple correlated sources; 2) ability to faithfully recover source time-courses; 3) robustness to different SNR conditions including SNR with negative dB levels; 4) capability to handle correlated brain noise; and 5) statistical maps of MEG source images. An objective pre-whitening method was also developed and integrated with Fast-VESTAL to remove correlated brain noise. Fast-VESTAL's performance was then examined in the analysis of human median-nerve MEG responses. The results demonstrated that this method easily distinguished sources in the entire somatosensory network. Next, Fast-VESTAL was applied to obtain the first whole-head MEG source-amplitude images from resting-state signals in 41 healthy control subjects, for all standard frequency bands. Comparisons between resting-state MEG sources images and known neurophysiology were provided. Additionally, in simulations and cases with MEG human responses, the results obtained from using conventional beamformer technique were compared with those from Fast-VESTAL, which highlighted the beamformer's problems of signal leaking and distorted source time-courses. © 2013.

Data Release Report for Source Physics Experiment 1 (SPE-1), Nevada National Security Site

Energy Technology Data Exchange (ETDEWEB)

Townsend, Margaret [NSTec; Mercadente, Jennifer [NSTec

2014-04-28

The first Source Physics Experiment shot (SPE-1) was conducted in May 2011. The explosive source was a ~100-kilogram TNT-equivalent chemical set at a depth of 60 meters. It was recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 meters) and far-field (more than 100 meters) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes around the shot and a set of singlecomponent vertical accelerometers on the surface. The far-field network comprised a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 meters to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the first Source Physics Experiment and the various types of near-field and far-field data that are available.

VizieR Online Data Catalog: Hubble Source Catalog (V1 and V2) (Whitmore+, 2016)

Science.gov (United States)

Whitmore, B. C.; Allam, S. S.; Budavari, T.; Casertano, S.; Downes, R. A.; Donaldson, T.; Fall, S. M.; Lubow, S. H.; Quick, L.; Strolger, L.-G.; Wallace, G.; White, R. L.

2016-10-01

The HSC v1 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR8 (data release 8). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). The HSC v2 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR9.1 (data release 9.1). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). Hubble Source Catalog Acknowledgement: Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESAC/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). (2 data files).

Efficient source for the production of ultradense deuterium D(-1) for laser-induced fusion (ICF)

International Nuclear Information System (INIS)

Andersson, Patrik U.; Loenn, Benny; Holmlid, Leif

2011-01-01

A novel source which simplifies the study of ultradense deuterium D(-1) is now described. This means one step further toward deuterium fusion energy production. The source uses internal gas feed and D(-1) can now be studied without time-of-flight spectral overlap from the related dense phase D(1). The main aim here is to understand the material production parameters, and thus a relatively weak laser with focused intensity ≤10 12 W cm -2 is employed for analyzing the D(-1) material. The properties of the D(-1) material at the source are studied as a function of laser focus position outside the emitter, deuterium gas feed, laser pulse repetition frequency and laser power, and temperature of the source. These parameters influence the D(-1) cluster size, the ionization mode, and the laser fragmentation patterns.

Efficient source for the production of ultradense deuterium D(-1) for laser-induced fusion (ICF)

Science.gov (United States)

Andersson, Patrik U.; Lönn, Benny; Holmlid, Leif

2011-01-01

A novel source which simplifies the study of ultradense deuterium D(-1) is now described. This means one step further toward deuterium fusion energy production. The source uses internal gas feed and D(-1) can now be studied without time-of-flight spectral overlap from the related dense phase D(1). The main aim here is to understand the material production parameters, and thus a relatively weak laser with focused intensity ≤1012 W cm-2 is employed for analyzing the D(-1) material. The properties of the D(-1) material at the source are studied as a function of laser focus position outside the emitter, deuterium gas feed, laser pulse repetition frequency and laser power, and temperature of the source. These parameters influence the D(-1) cluster size, the ionization mode, and the laser fragmentation patterns.

Protecting effect of PrP codons M142 and K222 in goats orally challenged with bovine spongiform encephalopathy prions.

Science.gov (United States)

Fast, C; Goldmann, W; Berthon, P; Tauscher, K; Andréoletti, O; Lantier, I; Rossignol, C; Bossers, A; Jacobs, J G; Hunter, N; Groschup, M H; Lantier, F; Langeveld, J P M

2017-09-19

Breeding towards genetic resistance to prion disease is effective in eliminating scrapie. In sheep, classical forms of scrapie have been eradicated almost completely in several countries by breeding programs using a prion protein (PrP) gene (PRNP) amino acid polymorphism. For goats, field and experimental studies have provided evidence for several amino acid polymorphisms that are associated with resistance to scrapie, but only limited data are available concerning the susceptibility of caprine PRNP genotypes to BSE. In this study, goat kids representing five PRNP genotypes based on three polymorphisms (M142, Q211 and K222 and the wild type I142, R211 and Q222) were orally challenged with bovine or goat BSE. Wild type goats were killed with clinical signs between 24-28 months post inoculation (mpi) to both challenges, and goats with genotype R/Q211 succumbed between 29-36 mpi. I/M142 goats developed clinical signs at 44-45 mpi and M/M142 goats remained healthy until euthanasia at 48 mpi. None of the Q/K222 goats showed definite clinical signs. Taken together the highest attack ratios were seen in wild type and R/Q211 goats, and the lowest in I/M142, M/M142 and Q/K222. In all genotype groups, one or more goats remained healthy within the incubation period in both challenges and without detectable PrP deposition in the tissues. Our data show that both the K222 and M142 polymorphisms lengthen the incubation period significantly compared to wild type animals, but only K222 was associated with a significant increase in resistance to BSE infection after oral exposure to both BSE sources.

Chemical composition and sources of PM1 and PM2.5 in Beijing in autumn.

Science.gov (United States)

Zhang, Yanyun; Lang, Jianlei; Cheng, Shuiyuan; Li, Shengyue; Zhou, Ying; Chen, Dongsheng; Zhang, Hanyu; Wang, Haiyan

2018-02-20

Beijing, the capital of China, suffers from severe atmospheric aerosol pollution; nevertheless, a comprehensive study of the constituents and sources of PM 1 is still lacking, and the differences between PM 1 and PM 2.5 are still unclear. In this study, an intensive observation was conducted to reveal the pollution characteristics of PM 1 and PM 2.5 in Beijing in autumn. Positive matrix factorization (PMF), backward trajectories and a potential source contribution function (PSCF) model were used to identify the source categories and source areas of PM 1 and PM 2.5 . The results showed that the average concentrations of PM 1 and PM 2.5 reached 78.20μg/m 3 and 95.47μg/m 3 during the study period, respectively. PM 1 contributed greatly to PM 2.5 . The PM 1 /PM 2.5 value increased from 73.6% to 90.1% with PM 1 concentration growing from 150μg/m 3 . Higher secondary inorganic aerosol (SIA) proportions (31.3%-70.8%) were found in PM 1 . The higher fraction of SIA, OC, EC and typical elements in PM 1 illustrated that anthropogenic components accumulated more in smaller size particles. Three typical weather patterns causing the heavy pollution in autumn were found as follows: (1) Siberian high and uniform high pressure field, (2) cold front and low-voltage system, and (3) uniform low pressure field. A PMF analysis indicated that secondary aerosols and coal combustion, vehicle, industry, biomass burning, and dust were the important sources of PM, accounting for 53.8%, 8.0%, 13.0%, 13.2% and 12.0% of PM 1 , respectively, and for 47.5%, 9.9%, 12.4%, 8.4% and 21.8% of PM 2.5 , respectively. The HYSPLIT and chemical components analysis indicated the potential contribution from biomass burning and fertilization ammonia emissions to PM 1 in autumn. The source areas were similar for PM 1 and PM 1-2.5 under general polluted conditions, but during the heavily polluted periods, the source areas were distributed in farther regions from Beijing for PM 1 than for PM 1-2.5 . Copyright

SOURCE 1ST 2.0: development and beta testing

International Nuclear Information System (INIS)

Barber, D.H.; Iglesias, F.C.; Hoang, Y.; Dickson, L.W.; Dickson, R.S.; Richards, M.J.; Gibb, R.A.

1999-01-01

SOURCE 1ST 2.0 is the Industry Standard fission product release code that is being developed by Ontario Power Generation, New Brunswick Power, Hydro-Quebec, and Atomic Energy of Canada Ltd. This paper is a report on recent progress on requirement specification, code development, and module verification and validation activities. The theoretical basis for each model in the code is described in a module Software Theory Manual. The development of SOURCE IST 2.0 has required code design decisions about how to implement the software requirements. Development and module testing of the β1 release of SOURCE IST 2.0 (released in July 1999) have led to some interesting insights into fission product release modelling. The beta testing process has allowed code developers and analysts to refine the software requirements for the code. The need to verify physical reference data has guided some decisions on the code and data structure design. Examples of these design decisions are provided. Module testing, and verification and validation activities are discussed. These activities include code-targeted testing, stress testing, code inspection, comparison of code with requirements, and comparison of code results with independent algebraic, numerical, or semi-algebraic calculations. The list of isotopes to be modelled by SOURCE IST 2.0 provides an example of a subset of a reference data set. Isotopes are present on the list for a variety of reasons: personnel or public dose, equipment dose (for environmental qualification), fission rate and actinide modelling, or stable (or long-lived) targets for activation processes. To accommodate controlled changes to the isotope list, the isotope list and associated nuclear data are contained in a reference data file. The questions of multiple computing platforms, and of Year 2000 compliance have been addressed by programming rules for the code. By developing and testing modules on most of the different platforms on which the code is intended

Efficient 1.6 Micron Laser Source for Methane DIAL

Science.gov (United States)

Shuman, Timothy; Burnham, Ralph; Nehrir, Amin R.; Ismail, Syed; Hair, Johnathan W.

2013-01-01

Methane is a potent greenhouse gas and on a per molecule basis has a warming influence 72 times that of carbon dioxide over a 20 year horizon. Therefore, it is important to look at near term radiative effects due to methane to develop mitigation strategies to counteract global warming trends via ground and airborne based measurements systems. These systems require the development of a time-resolved DIAL capability using a narrow-line laser source allowing observation of atmospheric methane on local, regional and global scales. In this work, a demonstrated and efficient nonlinear conversion scheme meeting the performance requirements of a deployable methane DIAL system is presented. By combining a single frequency 1064 nm pump source and a seeded KTP OPO more than 5 mJ of 1.6 µm pulse energy is generated with conversion efficiencies in excess of 20%. Even without active cavity control instrument limited linewidths (50 pm) were achieved with an estimated spectral purity of 95%. Tunable operation over 400 pm (limited by the tuning range of the seed laser) was also demonstrated. This source demonstrated the critical needs for a methane DIAL system motivating additional development of the technology.

Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation.

Science.gov (United States)

Han, B X; Kalvas, T; Tarvainen, O; Welton, R F; Murray, S N; Pennisi, T R; Santana, M; Stockli, M P

2012-02-01

The H(-) injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with ∼38 mA beam current in the linac at 60 Hz with a pulse length of up to ∼1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

A 1.5 GeV high brilliance synchrotron light source with combined function lattice

International Nuclear Information System (INIS)

Eriksson, M.; Lindgren, L.J.; Andersson, Aa.; Roejsel, P.; Werin, S.

1988-01-01

A 1.5 GeV synchrotron light source with a combined function lattice is studied. The light source will offer X-ray radiation with λc=1.0 angstrom from a superconducting wiggler and high brilliance VUV-radiation from undulators. The magnet lattice, magnet design and ring performance is discussed. (authors)

Modeling a point-source release of 1,1,1-trichloroethane using EPA's SCREEN model

International Nuclear Information System (INIS)

Henriques, W.D.; Dixon, K.R.

1994-01-01

Using data from the Environmental Protection Agency's Toxic Release Inventory 1988 (EPA TRI88), pollutant concentration estimates were modeled for a point source air release of 1,1,1-trichloroethane at the Savannah River Plant located in Aiken, South Carolina. Estimates were calculating using the EPA's SCREEN model utilizing typical meteorological conditions to determine maximum impact of the plume under different mixing conditions for locations within 100 meters of the stack. Input data for the SCREEN model were then manipulated to simulate the impact of the release under urban conditions (for the purpose of assessing future landuse considerations) and under flare release options to determine if these parameters lessen or increase the probability of human or wildlife exposure to significant concentrations. The results were then compared to EPA reference concentrations (RfC) in order to assess the size of the buffer around the stack which may potentially have levels that exceed this level of safety

Nitrogen Source Stabilization of Quorum Sensing in the Pseudomonas aeruginosa Bioaugmentation Strain SD-1.

Science.gov (United States)

Wang, Mei-Zhen; Lai, Bai-Min; Dandekar, Ajai A; Yang, Yu-Sheng; Li, Na; Yin, Jun; Shen, Dong-Sheng

2017-08-15

Pseudomonas aeruginosa SD-1 is efficient at degrading aromatic compounds and can therefore contribute to the bioremediation of wastewater. P. aeruginosa uses quorum sensing (QS) to regulate the production of numerous secreted "public goods." In wastewater bioaugmentation applications, there are myriad nitrogen sources, and we queried whether various nitrogen sources impact the stabilities of both QS and the bacterial populations. In a laboratory strain of P. aeruginosa , PAO1, the absence of a nitrogen source has been shown to destabilize these populations through the emergence of QS mutant "cheaters." We tested the ability of SD-1 to grow in casein broth, a condition that requires QS for growth, when the nitrogen source with either NH 4 Cl, NaNO 3 , or NaNO 2 or with no added nitrogen source. There was great variability in susceptibility to invasion by QS mutant cheaters and, by extension, the stability of the SD-1 population. When grown with NH 4 Cl as an extra nitrogen source, no population collapse was observed; by contrast, two-thirds of cultures grown in the presence of NaNO 2 collapsed. In the populations that collapsed, the frequency of social cheaters exceeded 40%. NaNO 3 and NaNO 2 directly favor QS mutants of P. aeruginosa SD-1. Although the mechanism by which these nitrogen sources act is not clear, these data indicate that the metabolism of nitrogen can affect the stability of bacterial populations, an important observation for continuing industrial applications with this species. IMPORTANCE Bioaugmentation as a method to help remediate wastewater pollutant streams holds significant potential to enhance traditional methods of treatment. Addition of microbes that can catabolize organic pollutants can be an effective method to remove several toxic compounds. Such bioaugmented strains of bacteria have been shown to be susceptible to competition from the microbiota that are present in wastewater streams, limiting their potential effectiveness. Here, we

Ovine progressive pneumonia provirus levels are unaffected by the prion 171R allele in an Idaho sheep flock

Directory of Open Access Journals (Sweden)

Herrmann-Hoesing Lynn M

2009-01-01

Full Text Available Abstract Selective breeding of sheep for arginine (R at prion gene (PRNP codon 171 confers resistance to classical scrapie. However, other effects of 171R selection are uncertain. Ovine progressive pneumonia/Maedi-Visna virus (OPPV may infect up to 66% of a flock thus any affect of 171R selection on OPPV susceptibility or disease progression could have major impact on the sheep industry. Hypotheses that the PRNP 171R allele is 1 associated with the presence of OPPV provirus and 2 associated with higher provirus levels were tested in an Idaho ewe flock. OPPV provirus was found in 226 of 358 ewes by quantitative PCR. The frequency of ewes with detectable provirus did not differ significantly among the 171QQ, 171QR, and 171RR genotypes (p > 0.05. Also, OPPV provirus levels in infected ewes were not significantly different among codon 171 genotypes (p > 0.05. These results show that, in the flock examined, the presence of OPPV provirus and provirus levels are not related to the PRNP 171R allele. Therefore, a genetic approach to scrapie control is not expected to increase or decrease the number of OPPV infected sheep or the progression of disease. This study provides further support to the adoption of PRNP 171R selection as a scrapie control measure.

Modification of 300kV RF Ion Source for 1-MV Electrostatic Accelerator at KOMAC

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae-Il; Kwon, Hyeok-Jung; Park, Sae-Hoon; Cho, Yong-Sub [KOMAC, Gyeongju (Korea, Republic of)

2015-05-15

The specifications of the 1-MV electrostatic accelerator are shown as below. High voltage power supply is electron transformer rectifier (ELV) type which was developed in Nuclear Physics Institute (Novosibirsk) for industrial electron accelerators. And accelerator column consists of alumina and metal electrode rings were 0.5m-long brazed structure which can be installed horizontally. In case of ion source for 1-MV electrostatic accelerator, it is chosen a thonemann type rf ion source and 300-kV test-stand was made up to confirm the stable operating conditions. High voltage power supply is fabricated by domestic company, and its operation has been confirming at KOMAC site. Equally, the ion source of 300-kV test-stand should be modified to install into the high voltage power supply. In this paper, modification of ion source of 300-kV test-stand for 1-MV electrostatic accelerator is presented and its processes are considered. 300-kV RF ion source and power supply are testing for the 1-MV electrostatic accelerator and trying for combination between them. The 1-MV electrostatic accelerator will be fabricated with domestic companies and tested in the beam application research building at KOMAC.

Modification of 300kV RF Ion Source for 1-MV Electrostatic Accelerator at KOMAC

International Nuclear Information System (INIS)

Kim, Dae-Il; Kwon, Hyeok-Jung; Park, Sae-Hoon; Cho, Yong-Sub

2015-01-01

The specifications of the 1-MV electrostatic accelerator are shown as below. High voltage power supply is electron transformer rectifier (ELV) type which was developed in Nuclear Physics Institute (Novosibirsk) for industrial electron accelerators. And accelerator column consists of alumina and metal electrode rings were 0.5m-long brazed structure which can be installed horizontally. In case of ion source for 1-MV electrostatic accelerator, it is chosen a thonemann type rf ion source and 300-kV test-stand was made up to confirm the stable operating conditions. High voltage power supply is fabricated by domestic company, and its operation has been confirming at KOMAC site. Equally, the ion source of 300-kV test-stand should be modified to install into the high voltage power supply. In this paper, modification of ion source of 300-kV test-stand for 1-MV electrostatic accelerator is presented and its processes are considered. 300-kV RF ion source and power supply are testing for the 1-MV electrostatic accelerator and trying for combination between them. The 1-MV electrostatic accelerator will be fabricated with domestic companies and tested in the beam application research building at KOMAC

Narrow Wavelength, Frequency Modulated Source at 1.5 Wavelength, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Ultrastable, narrow linewidth, tunable, high reliability sources at 1.5 or 2mm are needed for high performance LIDARs for several NASA applications, including wind...

Extraneural manifestations of prion infection in GPI-anchorless transgenic mice

International Nuclear Information System (INIS)

Lee, Andrew M.; Paulsson, Johan F.; Cruite, Justin; Andaya, Abegail A.; Trifilo, Matthew J.; Oldstone, Michael B.A.

2011-01-01

Earlier studies indicated that transgenic (tg) mice engineered to express prion protein (PrP) lacking the glycophosphatidylinositol (GPI -/- ) membrane anchor formed abnormal proteinase-resistant prion (PrPsc) amyloid deposits in their brains and hearts when infected with the RML strain of murine scrapie. In contrast, RML scrapie infection of normal mice with a GPI-anchored PrP did not deposit amyloid with PrPsc in the brain or the heart. Here we report that scrapie-infected GPI -/- PrP tg mice also deposit PrP and transmissible infectious material in the gut, kidneys, and islets of Langerhans. Similar to previously reported amyloid deposits in the brain and heart, amyloid deposits were found in the gut; however, no amyloid deposited in the islets. By high-resolution electron microscopy, we show PrP is located primarily in α cells and also β cells. Islets contain abundant insulin and there is no abnormality in glucose metabolism in infected GPI -/- PrP tg mice.

Current status of securing Category 1 and 2 radioactive sources in Taiwan

Energy Technology Data Exchange (ETDEWEB)

Cheng, Y-F.; Tsai, C-H. [Atomic Energy Council of Executive Yuan of Taiwan (China)

2014-07-01

For enhancing safe and secure management of Category 1 and 2 radioactive sources against theft or unauthorized removal, AEC (Atomic Energy Council) of Taiwan have been regulating the import/export of the sources ever since 2005, in compliance with the IAEA's (International Atomic Energy Agency) 'Guidance on the Import and Export of Radioactive Sources'. Furthermore in consulting the IAEA Nuclear Security Series No.11 report, administrative regulations on the program of securing the sources have been embodied into AECL's regulatory system since 2012, for the purpose of enforcing medical and non-medical licensees and industrial radiographers to establish their own radioactive source security programs. Regulations require that security functions such as access control, detection, delay, response and communication and security management measures are to be implemented within the programs. This paper is to introduce the current status in implementing the security control measures in Taiwan. (author)

Spectral intensity dependence an isotropy of sources stronger than 0.1 Jy at 2700 MHz

International Nuclear Information System (INIS)

Balonek, T.J.; Broderick, J.J.; Condon, J.J.; Crawford, D.F.; Jauncey, D.L.

1975-01-01

The 1000-foot (305 m) telescope of the National Astronomy and Ionosphere Center was used to measure 430 MHz flux densities of sources stronger than 0.1 Jy at 2700 MHz. Distributions of the resulting two-point spectral indices α (430, 2700) of sources in the intensity range 0.1less than or equal toS<0.35 Jy were compared with α (318, 2700) distributions of sources stronger than 0.35 Jy at 2700 MHz. The median normal-component spectral index and fraction of flat-spectrum sources in the faintest sample do not continue the previously discovered trend toward increased spectral steepening of faint sources. This result differs from the prediction of simple evolutionary cosmological models and therefore favors the alternative explanation that local source-density inhomogeneities are responsible for the observed intensity dependence of spectral indices

Feasibility study for the spallation neutron source (SNQ). Pt. 1

International Nuclear Information System (INIS)

Bauer, G.S.; Sebening, H.; Vetter, J.E.; Willax, H.

1981-06-01

A concept for a new neutron source for fundamental research has been developed and is described in this report. The spallation neutron source SNQ is characterized in its first stage by a time average thermal neutron flux of 7 x 10 14 cm -2 s -1 and a peak flux of 1.3 x 10 16 cm -2 s -1 at 100 Hz repetition rate. The scientific case is presented with particular emphasis on solid state and nuclear physics. In these research domains, unique conditions are given for experimental use. The proposed machine consists in its basic stage of a 1.1 GeV, 5 mA time average, 100 mA peak current proton linear accelerator, a rotating lead target, and H 2 O and D 2 O moderators. Additional beam channels are provided for experiments with protons at 350 MeV and at the final energy. Construction of the SNQ is considered feasible within eight years at a cost of 680 million DM. As future options, use of uranium as a target material, increase of the accelerator beam power by a factor of 2, addition of a pulse compressor and a second target station for pulsed neutron and neutrino research are described. As a back-up solution to the rotating target, a liquid metal target was studied. (orig.) [de

The Central Point Source in G76.9++1.0 V. R. Marthi1,∗ , J. N. ...

Indian Academy of Sciences (India)

Astr. (2011) 32, 451–455 c Indian Academy of Sciences. The Central Point Source in G76.9++1.0. V. R. Marthi1,∗. , J. N. Chengalur1, Y. Gupta1 ... emission has indeed been seen at 2 GHz with the Green Bank Telescope. (GBT), establishing the fact that scattering is responsible for its non- detection at low radio frequencies.

Source apportionment of fine (PM1.8) and ultrafine (PM0.1) airborne particulate matter during a severe winter pollution episode.

Science.gov (United States)

Kleeman, Michael J; Riddle, Sarah G; Robert, Michael A; Jakober, Chris A; Fine, Phillip M; Hays, Michael D; Schauer, James J; Hannigan, Michael P

2009-01-15

Size-resolved samples of airborne particulate matter (PM) collected during a severe winter pollution episode at three sites in the San Joaquin Valley of California were extracted with organic solvents and analyzed for detailed organic compounds using GC-MS. Six particle size fractions were characterized with diameter (Dp) < 1.8 microm; the smallest size fraction was 0.056 < Dp < 0.1 microm which accounts for the majority of the mass in the ultrafine (PM0.1) size range. Source profiles for ultrafine particles developed during previous studies were applied to the measurements at each sampling site to calculate source contributions to organic carbon (OC) and elemental carbon (EC) concentrations. Ultrafine EC concentrations ranged from 0.03 microg m(-3) during the daytime to 0.18 microg m(-3) during the nighttime. Gasoline fuel, diesel fuel, and lubricating oil combustion products accounted for the majority of the ultrafine EC concentrations, with relatively minor contributions from biomass combustion and meat cooking. Ultrafine OC concentrations ranged from 0.2 microg m(-3) during the daytime to 0.8 microg m(-3) during the nighttime. Wood combustion was found to be the largest source of ultrafine OC. Meat cooking was also identified as a significant potential source of PM0.1 mass but further study is required to verify the contributions from this source. Gasoline fuel, diesel fuel, and lubricating oil combustion products made minor contributions to PM0.1 OC mass. Total ultrafine particulate matter concentrations were dominated by contributions from wood combustion and meat cooking during the current study. Future inhalation exposure studies may wish to target these sources as potential causes of adverse health effects.

Feasibility study of a 1-MW pulsed spallation source

International Nuclear Information System (INIS)

Cho, Y.; Chae, Y.C.; Crosbie, E.

1995-01-01

A feasibility study of a 1-MW pulsed spallation source based on a rapidly cycling proton synchrotron (RCS) has been completed. The facility consists of a 400-MeV HP - linac, a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV, and two neutron-generating target stations. The design time-averaged current of the accelerator system is 0.5 mA, or 1.04x1014 protons per pulse. The linac system consists of an H - ion source, a 2-MeV RFQ, a 70-MeV DTL and a 330-MeV CCL. Transverse phase space painting to achieve a Kapchinskij-Vladimirskij (K-V) distribution of the injected particles in the RCS is accomplished by charge exchange injection and programming of the closed orbit during injection. The synchrotron lattice uses FODO cells of ∼90 degrees phase advance. Dispersion-free straight sections are obtained by using a missing magnet scheme. Synchrotron magnets are powered by a dual-frequency resonant circuit that excites the magnets at a 20-Hz rate and de-excites them at a 60-Hz rate, resulting in an effective rate of 30 Hz, and reducing the required peak rf voltage by 1/3. A key feature, of the design of this accelerator system is that beam losses are from injection to extraction, reducing activation to levels consistent with hands-on maintenance. Details of the study are presented

Development of sup 1 sup 9 sup 2 Ir radiation sources for intravascular irradiation

CERN Document Server

Kogure, H; Iwamoto, S; Iwata, K; Kawauchi, Y; Nagata, Y; Sorita, T; Suzuki, K

2003-01-01

Intravascular brachytherapy is a novel therapy for preventing the restenosis of coronary artery by use of low-dose irradiation. JAERI and Kyoto University have been developing sup 1 sup 9 sup 2 Ir radiation sources by the cooperative research project entitled as 'The research on safety and effectiveness of the intravascular brachytherapy for preventing restenosis of the coronary artery disease' since 1998. The radiation source was introduced into the stenosis through a catheter (a guide-tube to insert directly into vascular) to irradiate the diseased part. Ten sup 1 sup 9 sup 2 Ir seed sources (phi 0.4 mm x 2.5 mm) were positioned between nylon spacers (phi 0.3 mm x 1.0 mm) in a flexible covering tube and the tube was plugged with a core-wire; the tube was shrunk to fix the inside materials and the size is 0.46 mm in diameter and 3 m in length. The physically optimal design was determined to insert the radiation source easily into vascular and to get the dose uniformity in the diseased part. The production me...

Inelastic scattering research at a 1 MW long pulse spallation neutron source

International Nuclear Information System (INIS)

Carlile, C.J.

1995-01-01

The brief was, with respect to the LPSS bench mark design supplied (60 Hz, 1 MW, Imsec proton pulse, with a split, non-fissile target and 4 moderators in a flux trap geometry design), to identify a set of instruments, and to assess their performance with respect to existing spectrometers on other sources. Any modifications to the existing instruments which would make them more effective on the bench-mark source, or conversely, any modifications to the source bench-mark required by the proposed instruments were to be identified, as were any uncertainties in the estimated performances, or any R ampersand D needed to make the proposed instruments viable. Any new instrument concepts specifically matched to the long pulse itself were to be identified and assessed. This process was to result in an indicative list of instruments for the source. A figure of around 10 spectrometers was to be aimed for

Measurement and diagnosis system for 1.2 MV repetitive pulsed power source

International Nuclear Information System (INIS)

Li Yawei; Deng Jianjun; Xie Min; Feng Zongming; Liu Yuntao; Ma Chenggang

2010-01-01

In order to analyze the discharge performance and improve the design of the power system, a set of measurement and diagnosis system for the 1.2 MV repetitive pulsed power source, which supplies the drive power for a high power microwave source, has been designed by studying the high-voltage, high-current testing technology, data acquisition, signal processing, fault diagnosis, virtual instruments and electromagnetic compatibility technology, etc. A resistive-capacitive divider and a Rogowski coil are adopted in measurement; ADLINK corporation's PXI chips are used in data acquisition; data transmission system, condition monitoring and data analysis are developed by LabVIEW. This system can realize on-line monitoring and data analysis for the repetitive pulsed power source. (authors)

Long pulse characteristics of 5 MW ion source for SST-1 neutral beam injector

Energy Technology Data Exchange (ETDEWEB)

Jana, M.R. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)], E-mail: mukti@ipr.res.in; Mattoo, S.K.; Chakraborty, A.K.; Baruah, U.K.; Patel, G.B.; Jayakumar, P.K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2008-10-15

We present characteristics of a 5 MW ion source for SST-1 neutral beam injector. Before the source could be tested for its performance, it was conditioned by 480 arc discharges of 1 s and beam extraction of hydrogen species at various beam voltages ranging between 19 kV and 56 kV. Breakdown free beam extraction could be secured only after about 3000 beam second extraction. The ion source is capable of delivering 1.7 MW of neutral beam power at 55 kV with horizontal and vertical focal length of 5.4 m and 7 m respectively. Beam divergence is {approx}0.97 deg. Steady-state beam energy of 31 MJ at 41 kV was achieved during 14 s long beam extraction. We have not noticed any deterioration of beam parameters, including beam divergence during long pulse operation. These results indicate that 0.5 MW of neutral beam power at 30 kV required for heating of plasma in SST-1 can be delivered.

Long pulse characteristics of 5 MW ion source for SST-1 neutral beam injector

International Nuclear Information System (INIS)

Jana, M.R.; Mattoo, S.K.; Chakraborty, A.K.; Baruah, U.K.; Patel, G.B.; Jayakumar, P.K.

2008-01-01

We present characteristics of a 5 MW ion source for SST-1 neutral beam injector. Before the source could be tested for its performance, it was conditioned by 480 arc discharges of 1 s and beam extraction of hydrogen species at various beam voltages ranging between 19 kV and 56 kV. Breakdown free beam extraction could be secured only after about 3000 beam second extraction. The ion source is capable of delivering 1.7 MW of neutral beam power at 55 kV with horizontal and vertical focal length of 5.4 m and 7 m respectively. Beam divergence is ∼0.97 deg. Steady-state beam energy of 31 MJ at 41 kV was achieved during 14 s long beam extraction. We have not noticed any deterioration of beam parameters, including beam divergence during long pulse operation. These results indicate that 0.5 MW of neutral beam power at 30 kV required for heating of plasma in SST-1 can be delivered.

A 1990 global emission inventory of anthropogenic sources of carbon monoxide on 1o x 1o developed in the framework of EDGAR/GEIA

International Nuclear Information System (INIS)

Olivier, J.G.J.; Bouwman, A.F.; Bloos, J.P.J.; Berdowski, J.J.M.; Visschedijk, A.J.H.

1999-01-01

A global emission inventory of carbon monoxide (CO) emissions with 1 o x 1 o latitude-longitude resolution was compiled for 1990 on a sectoral basis. The sectoral sources considered include large-scale biomass burning (29%, of which savanna burning, 18%, and deforestation, 11%), fossil fuel combustion (27%, predominantly in road transport), biofuel combustion (19%, predominantly fuelwood combustion), agricultural waste burning (21%) and industrial process sources (4%). The inventory was compiled using mostly national statistics as activity data, emission factors at global or country level, and specific grid maps to convert, by sector, country total emissions to the 1 o x 1 o grid. A special effort was made to compile a global inventory of biofuel use, since this was considered to be a significant source on a global level, and a major source in some regions such as India and China. The global anthropogenic source of CO in 1990 is estimated at about 974 Tg CO yr -1 . The inventory is available on a sectoral basis on a 1 o x 1 o grid for input to global atmospheric models and on a regional/country basis for policy analysis. (author)

The Chandra Source Catalog 2.0: Estimating Source Fluxes

Science.gov (United States)

Primini, Francis Anthony; Allen, Christopher E.; Miller, Joseph; Anderson, Craig S.; Budynkiewicz, Jamie A.; Burke, Douglas; Chen, Judy C.; Civano, Francesca Maria; D'Abrusco, Raffaele; Doe, Stephen M.; Evans, Ian N.; Evans, Janet D.; Fabbiano, Giuseppina; Gibbs, Danny G., II; Glotfelty, Kenny J.; Graessle, Dale E.; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; Houck, John C.; Lauer, Jennifer L.; Laurino, Omar; Lee, Nicholas P.; Martínez-Galarza, Juan Rafael; McCollough, Michael L.; McDowell, Jonathan C.; McLaughlin, Warren; Morgan, Douglas L.; Mossman, Amy E.; Nguyen, Dan T.; Nichols, Joy S.; Nowak, Michael A.; Paxson, Charles; Plummer, David A.; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael; Van Stone, David W.; Zografou, Panagoula

2018-01-01

The Second Chandra Source Catalog (CSC2.0) will provide information on approximately 316,000 point or compact extended x-ray sources, derived from over 10,000 ACIS and HRC-I imaging observations available in the public archive at the end of 2014. As in the previous catalog release (CSC1.1), fluxes for these sources will be determined separately from source detection, using a Bayesian formalism that accounts for background, spatial resolution effects, and contamination from nearby sources. However, the CSC2.0 procedure differs from that used in CSC1.1 in three important aspects. First, for sources in crowded regions in which photometric apertures overlap, fluxes are determined jointly, using an extension of the CSC1.1 algorithm, as discussed in Primini & Kashyap (2014ApJ...796…24P). Second, an MCMC procedure is used to estimate marginalized posterior probability distributions for source fluxes. Finally, for sources observed in multiple observations, a Bayesian Blocks algorithm (Scargle, et al. 2013ApJ...764..167S) is used to group observations into blocks of constant source flux.In this poster we present details of the CSC2.0 photometry algorithms and illustrate their performance in actual CSC2.0 datasets.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

Construction and operation of the Spallation Neutron Source: Draft environmental impact statement. Volume 1

International Nuclear Information System (INIS)

1998-12-01

DOE proposes to construct and operate a state-of-the-art, short-pulsed spallation neutron source comprised of an ion source, a linear accelerator, a proton accumulator ring, and an experiment building containing a liquid mercury target and a suite of neutron scattering instrumentation. The proposed Spallation Neutron Source would be designed to operate at a proton beam power of 1 megawatt. The design would accommodate future upgrades to a peak operating power of 4 megawatts. These upgrades may include construction of a second proton accumulation ring and a second target. The US needs a high-flux, short-pulsed neutron source to provide the scientific and industrial research communities with a much more intense source of pulsed neutrons for neutron scattering research than is currently available, and to assure the availability of a state-of-the-art facility in the decades ahead. This next-generation neutron source would create new scientific and engineering opportunities. In addition, it would help replace the neutron science capacity that will be lost by the eventual shutdown of existing sources as they reach the end of their useful operating lives in the first half of the next century. This document analyzes the potential environmental impacts from the proposed action and the alternatives. The analysis assumes a facility operating at a power of 1 MW and 4 MW over the life of the facility. The two primary alternatives analyzed in this EIS are: the proposed action (to proceed with building the Spallation Neutron Source) and the No-Action Alternative. The No-Action Alternative describes the expected condition of the environment if no action were taken. Four siting alternatives for the Spallation Neutron Source are evaluated: Oak Ridge National Laboratory, Oak Ridge, TN, (preferred alternative); Argonne National Laboratory, Argonne, IL (US); Brookhaven National Laboratory, Upton, NY; and Los Alamos National Laboratory, Los Alamos, NM

(2+1-dimensional regular black holes with nonlinear electrodynamics sources

Directory of Open Access Journals (Sweden)

Yun He

2017-11-01

Full Text Available On the basis of two requirements: the avoidance of the curvature singularity and the Maxwell theory as the weak field limit of the nonlinear electrodynamics, we find two restricted conditions on the metric function of (2+1-dimensional regular black hole in general relativity coupled with nonlinear electrodynamics sources. By the use of the two conditions, we obtain a general approach to construct (2+1-dimensional regular black holes. In this manner, we construct four (2+1-dimensional regular black holes as examples. We also study the thermodynamic properties of the regular black holes and verify the first law of black hole thermodynamics.

Make-up of injector test stand (ITS-1) and preliminary results with Model-I ion source

International Nuclear Information System (INIS)

Matsuda, S.; Ito, T.; Kondo, U.; Ohara, Y.; Oga, T.; Shibata, T.; Shirakata, H.; Sugawara, T.; Tanaka, S.

Constitution of the 1-st injector test stand (ITS-1) in the Thermonuclear Division, JAERI, and the performance of the Model-I ion source are described. Heating a plasma by neutral beam injection is one of the promising means in the thermonuclear fusion devices. Purpose of the test stand is to develop the ion sources used in such injection systems. The test stand was completed in February 1975, which is capable of testing the ion sources up to 12 amps at 30 kV. A hydrogen ion beam of 5.5 amps at 25 kV was obtained in the Model-I ion source

Using Bayesian Belief Network (BBN) modelling for Rapid Source Term Prediction. RASTEP Phase 1

International Nuclear Information System (INIS)

Knochenhauer, M.; Swaling, V.H.; Alfheim, P.

2012-09-01

The project is connected to the development of RASTEP, a computerized source term prediction tool aimed at providing a basis for improving off-site emergency management. RASTEP uses Bayesian belief networks (BBN) to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, timing, and pathway of released radio-nuclides). The output is a set of possible source terms with associated probabilities. In the NKS project, a number of complex issues associated with the integration of probabilistic and deterministic analyses are addressed. This includes issues related to the method for estimating source terms, signal validation, and sensitivity analysis. One major task within Phase 1 of the project addressed the problem of how to make the source term module flexible enough to give reliable and valid output throughout the accident scenario. Of the alternatives evaluated, it is recommended that RASTEP is connected to a fast running source term prediction code, e.g., MARS, with a possibility of updating source terms based on real-time observations. (Author)

Using Bayesian Belief Network (BBN) modelling for Rapid Source Term Prediction. RASTEP Phase 1

Energy Technology Data Exchange (ETDEWEB)

Knochenhauer, M.; Swaling, V.H.; Alfheim, P. [Scandpower AB, Sundbyberg (Sweden)

2012-09-15

The project is connected to the development of RASTEP, a computerized source term prediction tool aimed at providing a basis for improving off-site emergency management. RASTEP uses Bayesian belief networks (BBN) to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, timing, and pathway of released radio-nuclides). The output is a set of possible source terms with associated probabilities. In the NKS project, a number of complex issues associated with the integration of probabilistic and deterministic analyses are addressed. This includes issues related to the method for estimating source terms, signal validation, and sensitivity analysis. One major task within Phase 1 of the project addressed the problem of how to make the source term module flexible enough to give reliable and valid output throughout the accident scenario. Of the alternatives evaluated, it is recommended that RASTEP is connected to a fast running source term prediction code, e.g., MARS, with a possibility of updating source terms based on real-time observations. (Author)

Final environmental impact statement, construction and operation of the Spallation Neutron Source. Volume 1

International Nuclear Information System (INIS)

1999-04-01

DOE proposes to construct and operate a state-of-the-art, short-pulsed, spallation neutron source comprised of an ion source, a linear accelerator, a proton accumulator ring, and an experiment building containing a liquid mercury target and a suite of neutron scattering instrumentation. The proposed Spallation neutron Source would be designed to operate at a proton beam power of 1 megawatt. The design would accommodate future upgrades to a peak operating power of 4 megawatts. These upgrades may include construction of a second proton accumulator ring and a second target. This document analyzes the potential environmental impacts from the proposed action and the alternatives. The analysis assumes a facility operating at a power of 1 MW and 4 MW over the life of the facility. The two primary alternatives analyzed in this FEIS are: the proposed action (to proceed with building the Spallation Neutron Source) and the No-Action Alternative. The No-Action Alternative describes the expected condition of the environment if no action were taken. Four siting alternatives for the Spallation Neutron Source are evaluated: Oak Ridge National Laboratory, Oak Ridge, TN, (preferred alternative); Argonne National Laboratory, Argonne, IL; Brookhaven National Laboratory, Upton, NY; and Los Alamos National Laboratory, Los Alamos, NM

Different cAMP sources are critically involved in G protein-coupled receptor CRHR1 signaling.

Science.gov (United States)

Inda, Carolina; Dos Santos Claro, Paula A; Bonfiglio, Juan J; Senin, Sergio A; Maccarrone, Giuseppina; Turck, Christoph W; Silberstein, Susana

2016-07-18

Corticotropin-releasing hormone receptor 1 (CRHR1) activates G protein-dependent and internalization-dependent signaling mechanisms. Here, we report that the cyclic AMP (cAMP) response of CRHR1 in physiologically relevant scenarios engages separate cAMP sources, involving the atypical soluble adenylyl cyclase (sAC) in addition to transmembrane adenylyl cyclases (tmACs). cAMP produced by tmACs and sAC is required for the acute phase of extracellular signal regulated kinase 1/2 activation triggered by CRH-stimulated CRHR1, but only sAC activity is essential for the sustained internalization-dependent phase. Thus, different cAMP sources are involved in different signaling mechanisms. Examination of the cAMP response revealed that CRH-activated CRHR1 generates cAMP after endocytosis. Characterizing CRHR1 signaling uncovered a specific link between CRH-activated CRHR1, sAC, and endosome-based signaling. We provide evidence of sAC being involved in an endocytosis-dependent cAMP response, strengthening the emerging model of GPCR signaling in which the cAMP response does not occur exclusively at the plasma membrane and introducing the notion of sAC as an alternative source of cAMP. © 2016 Inda et al.

Laboratory Examinations of Transmissible Spongiform Encephalopathies in Denmark during 2013

DEFF Research Database (Denmark)

Jensen, Tim Kåre

of Denmark (DTU-VET). The report is made to fulfil the demands given by the EU Commission (Regulation No 999/2001 of the European Parliament and the Council of 22. May 2001) and the Office Inter-national des Epizooties (OIE) (Manual of Diagnostic Tests and Vaccines for Terrestrial Ani-mals, 5th edition 2008......, Chapter 2.4.6 and Chapter 2.7.13) regarding diagnostic examinations. The DTU-VET is the national reference laboratory of bovine spongiform encephalopathy (BSE) and TSE/Scrapie, and therefore the results of all neuropathological examinations on BSE and Scrapie in Denmark are given in the present report...

Laboratory Examinations of Transmissible Spongiform Encephalopathies in Denmark during 2014

DEFF Research Database (Denmark)

Jensen, Tim Kåre

of Denmark (DTU-VET). The report is made to fulfil the demands given by the EU Commission (Regulation No 999/2001 of the European Parliament and the Council of 22. May 2001) and the Office Inter-national des Epizooties (OIE) (Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, 5th edition 2008......, Chapter 2.4.6 and Chapter 2.7.13) regarding diagnostic examinations. The DTU-VET is the national reference laboratory of bovine spongiform encephalopathy (BSE) and TSE/Scrapie, and therefore the results of all neuropathological examinations on BSE and Scrapie in Denmark are given in the present report...

Laboratory Examinations of Transmissible Spongiform Encephalopathies in Denmark during 2012

DEFF Research Database (Denmark)

Jensen, Tim Kåre

of Denmark (DTU-VET). The report is made to fulfil the demands given by the EU Commission (Regulation No 999/2001 of the European Parliament and the Council of 22. May 2001) and the Office Inter-national des Epizooties (OIE) (Manual of Diagnostic Tests and Vaccines for Terrestrial Ani-mals, 5th edition 2008......, Chapter 2.4.6 and Chapter 2.7.13) regarding diagnostic examinations. The DTU-VET is the national reference laboratory of bovine spongiform encephalopathy (BSE) and TSE/Scrapie, and therefore the results of all neuropathological examinations on BSE and Scrapie in Denmark are given in the present report...

Regulation of human cerebrospinal fluid malate dehydrogenase 1 in sporadic Creutzfeldt-Jakob disease patients.

Science.gov (United States)

Schmitz, Matthias; Llorens, Franc; Pracht, Alexander; Thom, Tobias; Correia, Ângela; Zafar, Saima; Ferrer, Isidre; Zerr, Inga

2016-11-14

The identification of reliable diagnostic biomarkers in differential diagnosis of neurodegenerative diseases is an ongoing topic. A previous two-dimensional proteomic study on cerebrospinal fluid (CSF) revealed an elevated level of an enzyme, mitochondrial malate dehydrogenase 1 (MDH1), in sporadic Creutzfeldt-Jakob disease (sCJD) patients. Here, we could demonstrate the expression of MDH1 in neurons as well as in the neuropil. Its levels are lower in sCJD brains than in control brains. An examination of CSF-MDH1 in sCJD patients by ELISA revealed a significant elevation of CSF-MDH1 levels in sCJD patients (independently from the PRNP codon 129 MV genotype or the prion protein scrapie (PrP Sc ) type) in comparison to controls. In combination with total tau (tau), CSF-MDH1 detection exhibited a high diagnostic accuracy for sCJD diagnosis with a sensitivity of 97.5% and a specificity of 95.6%. A correlation study of MDH1 level in CSF with other neurodegenerative marker proteins revealed a significant positive correlation between MDH1 concentration with tau, 14-3-3 and neuron specific enolase level. In conclusion, our study indicated the potential of MDH1 in combination with tau as an additional biomarker in sCJD improving diagnostic accuracy of tau markedly.

Theoretical and experimental determination of dosimetric characteristics for brachyseedTM Pd-103, model Pd-1, source

International Nuclear Information System (INIS)

Meigooni, A.S.; Zhang Hualin; Perry, Candace; Dini, S.A.; Koona, R.A.

2003-01-01

Dosimetric characteristics of the BrachySeed TM Pd-103, Model Pd-1 source have been determined using both theoretical and experimental methods. Dose rate constant, radial dose function, and anisotropy functions of the source have been obtained following the TG-43 recommendations. Derivation of the dose rate constant was based on recent NIST WAFAC calibration performed in accordance with their 1999 Standard. Measurements were performed in Solid Water TM using LiF TLD chips. Theoretical simulation calculations were performed in both Solid Water TM and water phantom materials using MCNP4C2 Monte Carlo code using DLC-200 interaction data. The results of the Monte Carlo simulation indicated a dose rate constant of 0.65 cGy h -1 U -1 and 0.61 cGy h -1 U -1 in water and Solid Water TM , respectively. The measured dose rate constant in Solid Water TM was found to be 0.63±7% cGy h -1 U -1 , which is within the experimental uncertainty of the Monte-Carlo simulated results. The anisotropy functions of the source were calculated in both water and in Solid Water TM at the radial distances of 1 to 7 cm. Measurements were made in Solid Water TM at distances of 2, 3, 5, and 7 cm. The Monte-Carlo calculated anisotropy constant of the new source was found to be 0.98 in water. The tabulated data and 5th order polynomial fit coefficients for the radial dose function along with the dose rate constant and anisotropy functions are provided to support clinical use of this source

Sod1 deficiency reduces incubation time in mouse models of prion disease.

Directory of Open Access Journals (Sweden)

Shaheen Akhtar

Full Text Available Prion infections, causing neurodegenerative conditions such as Creutzfeldt-Jakob disease and kuru in humans, scrapie in sheep and BSE in cattle are characterised by prolonged and variable incubation periods that are faithfully reproduced in mouse models. Incubation time is partly determined by genetic factors including polymorphisms in the prion protein gene. Quantitative trait loci studies in mice and human genome-wide association studies have confirmed that multiple genes are involved. Candidate gene approaches have also been used and identified App, Il1-r1 and Sod1 as affecting incubation times. In this study we looked for an association between App, Il1-r1 and Sod1 representative SNPs and prion disease incubation time in the Northport heterogeneous stock of mice inoculated with the Chandler/RML prion strain. No association was seen with App, however, significant associations were seen with Il1-r1 (P = 0.02 and Sod1 (P<0.0001 suggesting that polymorphisms at these loci contribute to the natural variation observed in incubation time. Furthermore, following challenge with Chandler/RML, ME7 and MRC2 prion strains, Sod1 deficient mice showed highly significant reductions in incubation time of 20, 13 and 24%, respectively. No differences were detected in Sod1 expression or activity. Our data confirm the protective role of endogenous Sod1 in prion disease.

Fully probabilistic seismic source inversion – Part 1: Efficient parameterisation

Directory of Open Access Journals (Sweden)

S. C. Stähler

2014-11-01

Full Text Available Seismic source inversion is a non-linear problem in seismology where not just the earthquake parameters themselves but also estimates of their uncertainties are of great practical importance. Probabilistic source inversion (Bayesian inference is very adapted to this challenge, provided that the parameter space can be chosen small enough to make Bayesian sampling computationally feasible. We propose a framework for PRobabilistic Inference of Seismic source Mechanisms (PRISM that parameterises and samples earthquake depth, moment tensor, and source time function efficiently by using information from previous non-Bayesian inversions. The source time function is expressed as a weighted sum of a small number of empirical orthogonal functions, which were derived from a catalogue of >1000 source time functions (STFs by a principal component analysis. We use a likelihood model based on the cross-correlation misfit between observed and predicted waveforms. The resulting ensemble of solutions provides full uncertainty and covariance information for the source parameters, and permits propagating these source uncertainties into travel time estimates used for seismic tomography. The computational effort is such that routine, global estimation of earthquake mechanisms and source time functions from teleseismic broadband waveforms is feasible.

Preliminary design of experiment ALVAND 1 and low beta plasma source

International Nuclear Information System (INIS)

Anvari, A.; Azodi, H.; Naraghi, M.; Taherzadeh, M.; Torabi-Fard, A.

1975-12-01

The ultimate goal of a two years program, namely ''ALVAND PROJECT'' and problems concerned with the achievement of controlled thermonuclear reactions in Iran is covered. The report consists of six sections. The introduction deals with the advantages of a linear theta pinch and its comparison with toroidal and mirror devices. Attention has been paid to two important properties of the ALVAND 1 device, namely, its property of carrying out important missions in support of high beta controlled thermonuclear research and also its acting as a source for developing different diagnostic apparatus and excercising different measurement techniques. Expected plasma parameters for ALVAND 1 are given in the third section. In the fourth section the low beta plasma source and the important diagnostic techniques that may be developed are discussed. References are given in the fifth section. The calculation of the minimum required radius of a toroidal theta pinch reactor has been given in an appendix, which covers at the same time 2 schematic figures. Finally a program schedule is presented in section six

Molecular beam (1-50eV) production by duoplasmatron source

International Nuclear Information System (INIS)

Delmas, M.; Gautherin, G.; Lejeune, C.

1974-01-01

The duoplasmatron discharge is commonly used to produce intense ion beams. A theoretical model of this discharge has been previously developed. The analysis of charge exchange processes between ions and neutral within the discharge shows that the source is able to deliver intense neutral beams (10 16 part s -1 ), the energy being in the range 1-50 eV. The intensity and energy distribution may be controlled from the discharge parameter variations. An experimental device has been realized in order to separate the neutral beam and the flux of charged particles; these latter are injected axially in a toroidal magnetic field configuration [fr

Automatic sup sup 1 sup sup 8 F positron source supply system for a monoenergetic positron beam

CERN Document Server

Saito, F; Itoh, Y; Goto, A; Fujiwara, I; Kurihara, T; Iwata, R; Nagashima, Y; Hyodo, T

2000-01-01

A system which supplies an intense sup sup 1 sup sup 8 F (half life 110 min) positron source produced by an AVF cyclotron through sup sup 1 sup sup 8 O(p,n) sup sup 1 sup sup 8 F reaction has been constructed. Produced sup sup 1 sup sup 8 F is transferred to a low background experiment hall through a capillary. It is electro-deposited on a graphite rod and used for a source of a slow positron beam. In the meantime the next batch of target sup sup 1 sup sup 8 O water is loaded and proton irradiation proceeds. This system makes it possible to perform continuous positron beam experiments using the 18 F positron source.

Source splitting via the point source method

International Nuclear Information System (INIS)

Potthast, Roland; Fazi, Filippo M; Nelson, Philip A

2010-01-01

We introduce a new algorithm for source identification and field splitting based on the point source method (Potthast 1998 A point-source method for inverse acoustic and electromagnetic obstacle scattering problems IMA J. Appl. Math. 61 119–40, Potthast R 1996 A fast new method to solve inverse scattering problems Inverse Problems 12 731–42). The task is to separate the sound fields u j , j = 1, ..., n of n element of N sound sources supported in different bounded domains G 1 , ..., G n in R 3 from measurements of the field on some microphone array—mathematically speaking from the knowledge of the sum of the fields u = u 1 + ... + u n on some open subset Λ of a plane. The main idea of the scheme is to calculate filter functions g 1 ,…, g n , n element of N, to construct u l for l = 1, ..., n from u| Λ in the form u l (x) = ∫ Λ g l,x (y)u(y)ds(y), l=1,... n. (1) We will provide the complete mathematical theory for the field splitting via the point source method. In particular, we describe uniqueness, solvability of the problem and convergence and stability of the algorithm. In the second part we describe the practical realization of the splitting for real data measurements carried out at the Institute for Sound and Vibration Research at Southampton, UK. A practical demonstration of the original recording and the splitting results for real data is available online

Experimental determination of dosimetric characterization of a newly designed encapsulated interstitial brachytherapy source of 103Pd-model Pd-1

International Nuclear Information System (INIS)

Nath, Ravinder; Yue Ning; Roa, Eduardo

2002-01-01

A newly designed encapsulated 103 Pd source has been introduced (BrachySeed trade mark sign -Pd-103, also named Model Pd-1, manufactured by DRAXIMAGE Inc. and distributed by Cytogen Corp.) for interstitial brachytherapy to provide more isotropic dose distributions. In this work, the dosimetric characteristics of the 103 Pd source were measured with micro LiF TLD chips and dosimetry parameters were characterized based upon the American Association of Physicists in Medicine (AAPM) Task Group No. 43 formalism. The dose rate constant of the sources was determined to be 0.66±0.05 cGy h-1 U-1. The radial dose function was measured and was found to be similar to that of the Theragenics Model 200 103 Pd source. The anisotropy constant for the Model Pd-1 source was determined to be 1.03

The LBL [Lawrence Berkeley Laboratory] 1-2 GeV synchrotron radiation source

International Nuclear Information System (INIS)

Cornacchia, M.

1987-03-01

A description is presented of the conceptual design of the 1 to 2 GeV Synchrotron Radiation Source proposed for construction at Lawrence Berkeley Laboratory. This facility is designed to produce ultraviolet and soft x-ray radiation. The accelerator complex consists of an injection system (linac plus booster synchrotron) and a low-emittance storage ring optimized for insertion devices. Eleven straight sections are available for undulators and wigglers, and up to 48 photon beam lines may ultimately emanate from bending magnets. Design features of the radiation source are the high brightness of the photon beams, the very short pulses (tens of picoseconds), and the tunability of the radiation

Borehole disposal of spent radiation sources: 1. Principles

International Nuclear Information System (INIS)

Blerk, J.J. van; Kozak, M.W.

2000-01-01

Large numbers of spent radiation sources from the medical and other technical professions exist in many countries, even countries that do not possess facilities related to the nuclear fuel cycle, that have to be disposed. This is particularly the case in Africa, South America and some members of the Russian Federation. Since these sources need to be handled separately from the other types of radioactive waste, mainly because of their activity to volume ratio, countries (even those with access to operational repositories) find it difficult to manage and dispose this waste. This has led to the use of boreholes as disposal units for these spent sources by some members of the Russian Federation and in South Africa. However, the relatively shallow boreholes used by these countries are not suitable for the disposal of isotopes with long half-lifes, such as 226 Ra and 241 Am. With this in mind the Atomic Energy Corporation of South Africa initiated the development of the BOSS disposal concept - an acronym for Borehole disposal Of Spent Sources - as part of an International Atomic Energy Agency (IAEA) AFRA I-14 Technical Corporation (TC) project. In this paper, the principles of this disposal concept, which is still under development, will be discussed. (author)

In vitro prion protein conversion suggests risk of bighorn sheep (Ovis canadensis) to transmissible spongiform encephalopathies

Science.gov (United States)

Johnson, Christopher J.; Morawski, A.R.; Carlson, C.M.; Chang, H.

2013-01-01

Background: Transmissible spongiform encephalopathies (TSEs) affect both domestic sheep (scrapie) and captive and free-ranging cervids (chronic wasting disease; CWD). The geographical range of bighorn sheep (Ovis canadensis; BHS) overlaps with states or provinces that have contained scrapie-positive sheep or goats and areas with present epizootics of CWD in cervids. No TSEs have been documented in BHS, but the susceptibility of this species to TSEs remains unknown. Results: We acquired a library of BHS tissues and found no evidence of preexisting TSEs in these animals. The prion protein gene (Prnp) in all BHS in our library was identical to scrapie-susceptible domestic sheep (A136R 154Q171). Using an in vitro prion protein conversion assay, which has been previously used to assess TSE species barriers and, in our study appears to recollect known species barriers in mice, we assessed the potential transmissibility of TSEs to BHS. As expected based upon Prnp genotype, we observed BHS prion protein conversion by classical scrapie agent and evidence for a species barrier between transmissible mink encephalopathy (TME) and BHS. Interestingly, our data suggest that the species barrier of BHS to white-tailed deer or wapiti CWD agents is likely low. We also used protein misfolding cyclic amplification to confirm that CWD, but not TME, can template prion protein misfolding in A136R 154Q171genotype sheep. Conclusions: Our results indicate the in vitro conversion assay used in our study does mimic the species barrier of mice to the TSE agents that we tested. Based on Prnp genotype and results from conversion assays, BHS are likely to be susceptible to infection by classical scrapie. Despite mismatches in amino acids thought to modulate prion protein conversion, our data indicate that A136R154Q171 genotype sheep prion protein is misfolded by CWD agent, suggesting that these animals could be susceptible to CWD. Further investigation of TSE transmissibility to BHS, including

Supplemental shielding of BMIT SOE-1 at the Canadian Light Source

International Nuclear Information System (INIS)

Bassey, Bassey; Abueidda, Abdallah; Cubbon, Grant; Street, Darin; Sabbir Ahmed, Asm; Wysokinski, Tomasz W.; Belev, George; Chapman, Dean

2014-01-01

High field superconducting wiggler beamlines present shielding challenges due to the high critical energy of the synchrotron spectrum. An unexpected, but predictable, weakness in the secondary optical enclosure (SOE-1) was discovered on the BioMedical Imaging and Therapy (BMIT) insertion device (ID) beamline 05ID-2 at the Canadian Light Source (CLS). SOE-1 is a monochromatic beam hutch; the beam in it is supplied by three monochromators housed in an upstream primary optical enclosure (POE-3). The initial shielding of SOE-1 was based on a shielding calculation against target scattered and direct monochromatic (fundamental and harmonics) beams from the monochromators in POE-3. During a radiation survey of the hutch, radiation above the expected level was measured at the downstream end of SOE-1. This increment in radiation level is attributed to scattered white beam into SOE-1 by a K-Edge subtraction (KES) monochromator's crystal (a single crystal monochromator) in POE-3. Though this is peculiar to the BMIT beamline 05ID-2, it may not be uncommon for other beamlines that use single crystal monochromators. Calculations of the level of expected leakage radiation due to the scattered white beam arriving on the downstream wall of the SOE-1 are presented, as well as the supplemental shielding that will reduce the leakage to less than 1 μSv/h as required at the CLS. Also presented are the installed supplemental shielding, and a comparison of the calculations and measurements of the dose rates on the back wall of SOE-1 End Wall, before and after installation of the supplemental shielding. - Highlights: • We discovered an unexpected weakness in the shielding of BMIT SOE-1 End Wall. • We predicted the source of the weakness-scattering of white beam into SOE-1. • White beam scattered into SOE-1 by the crystal of a single crystal monochromator. • We calculated and installed the required supplemental shielding. • With the installed supplemental shielding, we have

Finding X-ray counterparts for unidentified sources in the 105 months BAT survey - 1

Science.gov (United States)

Stephen, J. B.; Bassani, L.; Malizia, A.; Masetti, N.; Ubertini, P.

2018-02-01

We provide X-ray counterparts for the unidentified Swift/BAT sources listed in the 105 month catalogue (Oh et al. 2018, ApJS in press). These associations were found by cross-correlating the list of U1,U2 and U3 sources with the ROSAT Bright (RASSBSC, Voges et al. 1999, A & A, 349, 389) and the XMM-Newton Slew (XMMSlew, Saxton et al. 2008, A & A, 480, 611) catalogues.

Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

Science.gov (United States)

Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

2010-02-01

Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

L1-norm locally linear representation regularization multi-source adaptation learning.

Science.gov (United States)

Tao, Jianwen; Wen, Shiting; Hu, Wenjun

2015-09-01

In most supervised domain adaptation learning (DAL) tasks, one has access only to a small number of labeled examples from target domain. Therefore the success of supervised DAL in this "small sample" regime needs the effective utilization of the large amounts of unlabeled data to extract information that is useful for generalization. Toward this end, we here use the geometric intuition of manifold assumption to extend the established frameworks in existing model-based DAL methods for function learning by incorporating additional information about the target geometric structure of the marginal distribution. We would like to ensure that the solution is smooth with respect to both the ambient space and the target marginal distribution. In doing this, we propose a novel L1-norm locally linear representation regularization multi-source adaptation learning framework which exploits the geometry of the probability distribution, which has two techniques. Firstly, an L1-norm locally linear representation method is presented for robust graph construction by replacing the L2-norm reconstruction measure in LLE with L1-norm one, which is termed as L1-LLR for short. Secondly, considering the robust graph regularization, we replace traditional graph Laplacian regularization with our new L1-LLR graph Laplacian regularization and therefore construct new graph-based semi-supervised learning framework with multi-source adaptation constraint, which is coined as L1-MSAL method. Moreover, to deal with the nonlinear learning problem, we also generalize the L1-MSAL method by mapping the input data points from the input space to a high-dimensional reproducing kernel Hilbert space (RKHS) via a nonlinear mapping. Promising experimental results have been obtained on several real-world datasets such as face, visual video and object. Copyright © 2015 Elsevier Ltd. All rights reserved.

Operational experience of SST1 NBI control system with prototype Ion source

International Nuclear Information System (INIS)

Patel, V B; Patel, P J; Singh, N P; Tripathi, V; Thakkar, D; Gupta, L N; Prahlad, V; Sharma, S K; Bandyopadyay, M; Chakraborty, A K; Baruah, U K; Mattoo, S K; Patel, G B; Onali, Raja

2010-01-01

This paper presents operational experience of integrated control of the arc-filament and High-voltage power supply of Steady State Tokamak (SST)-1 NBI system using Versa Module Europa (VME) system on prototype Ion source. The control algorithm is implemented on the VxWorks operating system using 'C' language. This paper also describes the operating sequence and controls on power supply system. Discharge and Filament power supplies are controlled in such a way so that necessary discharge current can be available in Ion Source. The discharge current is controlled by manipulating the filament current. Close loop control is implemented on each filament power supply with feedback from Discharge Current to control the overall discharge inside the ion source. Necessary actions for shut OFF and subsequent Turn ON are also taken during breakdowns between the Grids of the ion source. Total numbers of breakdowns are also monitored. Shot is terminated, if the breakdown count is higher than the set value. This control system can be programmed to restart High-voltage power supply within 5mS after breakdown occurs. This control system is capable to handle the all types of dynamics in the system. This paper also presents results of experiment.

Small-angle scattering instruments on a 1 MW long pulse spallation source

Energy Technology Data Exchange (ETDEWEB)

Olah, G.A. [Los Alamos National Lab., Chemical Science and Tehcnology Div., Biosciences and Biotechnology Group, Los aalamos, NM (United States); Hjelm, R.P. [Los Alamos National Lab., Neutron Scattering Center, Los Alamos, NM (United States); Seeger, P.A.

1995-11-01

We have designed and optimized two small-angle neutron scattering instruments for installation at a 1 MW long pulse spallation source. The first of these instruments measures a Q-domain from 0.002 to 0.44 A{sup -1}, and the second instrument from 0.00069-0.17 A{sup -1}, Design characteristics were determined and optimization was done using a Monte Carlo instrument simulation package under development at Los alamos. A performance comparison was made between these instruments with D11 at the ILL by evaluating the scattered intensity and rms resolution for the instrument response function at different Q values for various instrument configurations needed to spn a Q-range of 0.0007-0.44 A{sup -1}. We concluded that the first of these instruments outperforms D11 in both intensity and resolution over most of the Q-domain and that the second is comparable to D11. Comparisons were also made of the performance of the optimized long pulse instruments with different reflectors and with a short pulse source, from which we concluded that there is an optimal moderator-reflector combination, and that a short pulse does not substantially improve the instrument performance. (author) 7 figs., 2 tabs., 9 refs.

Small-angle scattering instruments on a 1 MW long pulse spallation source

International Nuclear Information System (INIS)

Olah, G.A.; Hjelm, R.P.; Seeger, P.A.

1995-01-01

We have designed and optimized two small-angle neutron scattering instruments for installation at a 1 MW long pulse spallation source. The first of these instruments measures a Q-domain from 0.002 to 0.44 A -1 , and the second instrument from 0.00069-0.17 A -1 , Design characteristics were determined and optimization was done using a Monte Carlo instrument simulation package under development at Los alamos. A performance comparison was made between these instruments with D11 at the ILL by evaluating the scattered intensity and rms resolution for the instrument response function at different Q values for various instrument configurations needed to spn a Q-range of 0.0007-0.44 A -1 . We concluded that the first of these instruments outperforms D11 in both intensity and resolution over most of the Q-domain and that the second is comparable to D11. Comparisons were also made of the performance of the optimized long pulse instruments with different reflectors and with a short pulse source, from which we concluded that there is an optimal moderator-reflector combination, and that a short pulse does not substantially improve the instrument performance. (author) 7 figs., 2 tabs., 9 refs

The Source of Time-Correlated Photons at 1.064 μm and its Applications

Directory of Open Access Journals (Sweden)

Gostev P.P.

2015-01-01

Full Text Available The source of time-correlated photon-pairs at 1064 nm is described. The source consists of the spontaneous parametric down-conversion (SPDC generator, pumped by cw laser operating at 532 nm, and the measuring and control appliances. One of the main parts of the electronic systems is the “time-to-digital converter” which is designed and built by our group. The system allows to create and detect correlation of photon pairs with resolution better than 1 ns. We adduce the results of a quantum key distribution through open air. The key length was about 5000 bits and the accuracy ~0.1%.

Calculation of the source term for a S1B-sequence at a VVER-1000 type reactor. Part 1

International Nuclear Information System (INIS)

Sdouz, G.

1990-10-01

The behaviour of the source term in a VVER-1000 type reactor is calculated using the 'Source Term Code Package' (STCP). The input data are based on the russian plant Zaporozhye-5. The selected accident sequence is a small break LOCA in the hot leg followed by loss offsite and onsite electric power (S 1 B-sequence). According to the course of the calculation the results are presented and analyzed for each program. Except for the noble gases all release fractions are lower than 10 -4 . 18 refs., 10 tabs. (Author)

Development of high resolution vacuum ultraviolet beam line at Indus-1 synchrotron source

International Nuclear Information System (INIS)

Shukla, R.P.; Das, N.C.; Udupa, D.V.; Saraswathy, P.; Sunanda, K.; Jha, S.N.; Shastri, Aparna; Singh, Paramjeet; Mallick, Manika; Mishra, A.P.; Sahoo, N.K.; Sinha, A.K.; Bhatt, S.; Sahni, V.C.

2005-07-01

High resolution vacuum ultraviolet beamline at Indus-1 450 MeV synchrotron source has been developed for carrying out absorption spectral studies of atoms and molecules. The beamline consists of three major parts i.e. a focusing optical system, an absorption cell and a high resolution 6.65 m vacuum ultraviolet spectrometer in Eagle mount. The wavelength range of the spectrometer is from 700 A to 2000 A and the resolution of the spectrometer is 0.01 A. Using the synchrotron source Indus-1, the absorption spectra of oxygen, ammonia and carbon disulphide have been recorded at the wavelength band of 1750 A, 1881 A and 3100 A respectively. Details of different aspects of design and development of the high resolution VUV beamline are described in this report. (author)

Indoor and Outdoor Levels and Sources of Submicron Particles (PM1) at Homes in Edmonton, Canada.

Science.gov (United States)

Bari, Md Aynul; Kindzierski, Warren B; Wallace, Lance A; Wheeler, Amanda J; MacNeill, Morgan; Héroux, Marie-Ève

2015-06-02

Exposure to submicron particles (PM1) is of interest due to their possible chronic and acute health effects. Seven consecutive 24-h PM1 samples were collected during winter and summer 2010 in a total of 74 nonsmoking homes in Edmonton, Canada. Median winter concentrations of PM1 were 2.2 μg/m(3) (interquartile range, IQR = 0.8-6.1 μg/m(3)) and 3.3 μg/m(3) (IQR = 1.5-6.9 μg/m(3)) for indoors and outdoors, respectively. In the summer, indoor (median 4.4 μg/m(3), IQR = 2.4-8.6 μg/m(3)) and outdoor (median 4.3 μg/m(3), IQR = 2.6-7.4 μg/m(3)) levels were similar. Positive matrix factorization (PMF) was applied to identify and apportion indoor and outdoor sources of elements in PM1 mass. Nine sources contributing to both indoor and outdoor PM1 concentrations were identified including secondary sulfate, soil, biomass smoke and environmental tobacco smoke (ETS), traffic, settled and mixed dust, coal combustion, road salt/road dust, and urban mixture. Three additional indoor sources were identified i.e., carpet dust, copper-rich, and silver-rich. Secondary sulfate, soil, biomass smoke and ETS contributed more than 70% (indoors: 0.29 μg/m(3), outdoors: 0.39 μg/m(3)) of measured elemental mass in PM1. These findings can aid understanding of relationships between submicron particles and health outcomes for indoor/outdoor sources.

Strategic positioning. Part 1: The sources of value under managed care.

Science.gov (United States)

Kauer, R T; Berkowitz, E

1997-01-01

Part 1 of this series organizes and discusses the sources of value against a background of an evolving managed care market. Part 2 will present, in more detail, the marketing and financial challenges to organizational positioning and performance across the four stages of managed care. What are the basic principles or tenets of value and how do they apply to the health care industry? Why is strategic positioning so important to health care organizations struggling in a managed care environment and what are the sources of value? Service motivated employees and the systems that educate them represent a stronger competitive advantage than having assets and technology that are available to anyone. As the health care marketplace evolves, organizations must develop a strategic position that will provide such value and for which the customer will be willing to pay.

26 CFR 1.863-6 - Income from sources within a foreign country.

Science.gov (United States)

2010-04-01

...) INCOME TAX (CONTINUED) INCOME TAXES Regulations Applicable to Taxable Years Prior to December 30, 1996 § 1.863-6 Income from sources within a foreign country. The principles applied in sections 861 through 863 and section 865 and the regulations thereunder for determining the gross and the taxable income...

Characteristics and source apportionment of PM1 emissions at a roadside station.

Science.gov (United States)

Cheng, Y; Zou, S C; Lee, S C; Chow, J C; Ho, K F; Watson, J G; Han, Y M; Zhang, R J; Zhang, F; Yau, P S; Huang, Y; Bai, Y; Wu, W J

2011-11-15

The mass concentrations of PM(1) (particles less than 1.0 μm in aerodynamic diameter), organic carbon (OC), elemental carbon (EC), water-soluble ions, and up to 25 elements were reported for 24h aerosol samples collected every sixth day at a roadside sampling station in Hong Kong from October 2004 to September 2005. Annual average PM(1) mass concentration was 44.5 ± 19.5 μg m(-3). EC, OM (organic matter, OC × 1.2), and SO(4)(=) were the dominant components, accounting for ∼ 36%, ∼ 26%, and ∼ 24% of PM(1), respectively. Other components, i.e., NO(3)(-), NH(4)(+), geological material, trace elements and unidentified material, comprised the remaining ∼ 14%. Annual average OC/EC ratio (0.6 ± 0.3) was low, indicating that primary vehicle exhaust was the major source of carbonaceous aerosols. The seasonal variations of pollutants were due to gas-particle partitioning processes or a change in air mass rather than secondary aerosol produced locally. Vehicle exhaust, secondary aerosols, and waste incinerator/biomass burning were dominant air pollution sources, accounting for ∼ 38%, ∼ 22% and ∼ 16% of PM(1), respectively. Pollution episodes during summer (May-August) which were frequently accompanied by tropical storms or typhoons were dominated by vehicle emissions. During winter (November-February) pollution episodes coincided with northeasterly monsoons were characterized by secondary aerosols and incinerator/biomass burning emissions. Copyright © 2011 Elsevier B.V. All rights reserved.

Theoretical and experimental determination of dosimetric characteristics for brachyseed{sup TM} Pd-103, model Pd-1, source

Energy Technology Data Exchange (ETDEWEB)

Meigooni, A.S. E-mail: alimeig@pop.uky.edu; Zhang Hualin; Perry, Candace; Dini, S.A.; Koona, R.A

2003-05-01

Dosimetric characteristics of the BrachySeed{sup TM} Pd-103, Model Pd-1 source have been determined using both theoretical and experimental methods. Dose rate constant, radial dose function, and anisotropy functions of the source have been obtained following the TG-43 recommendations. Derivation of the dose rate constant was based on recent NIST WAFAC calibration performed in accordance with their 1999 Standard. Measurements were performed in Solid Water{sup TM} using LiF TLD chips. Theoretical simulation calculations were performed in both Solid Water{sup TM} and water phantom materials using MCNP4C2 Monte Carlo code using DLC-200 interaction data. The results of the Monte Carlo simulation indicated a dose rate constant of 0.65 cGy h{sup -1} U{sup -1} and 0.61 cGy h{sup -1} U{sup -1} in water and Solid Water{sup TM}, respectively. The measured dose rate constant in Solid Water{sup TM} was found to be 0.63{+-}7% cGy h{sup -1} U{sup -1}, which is within the experimental uncertainty of the Monte-Carlo simulated results. The anisotropy functions of the source were calculated in both water and in Solid Water{sup TM} at the radial distances of 1 to 7 cm. Measurements were made in Solid Water{sup TM} at distances of 2, 3, 5, and 7 cm. The Monte-Carlo calculated anisotropy constant of the new source was found to be 0.98 in water. The tabulated data and 5th order polynomial fit coefficients for the radial dose function along with the dose rate constant and anisotropy functions are provided to support clinical use of this source.

Effect of nitrogen sources on biomass, lipid and docosahexanoic acid production by Aurantiochytrium sp. SW1

Science.gov (United States)

Auma, Khairunnisa; Hamid, Aidil Abdul; Yusoff, Wan Mohtar Wan

2018-04-01

A local isolate, Aurantiochytrium sp. SW1 has been verified to have high content of docosahexanoic acid (DHA). However, the effect of different nitrogen sources on biomass, lipid concentration and DHA content in Aurantiochytrium sp. SW1 is still unknown. Hence, this study is focused in using six different organic and inorganic nitrogen sources to grow Aurantiochytrium sp. SW1 in optimized Burja medium. Monosodium glutamate (MSG) gave the highest biomass concentration of 15.97 g/L followed by ammonium nitrate (NH4NO3) with 13.37 g/L at 96 hr. These two nitrogen sources had significant effect on the biomass concentration (pDHA content in lipid showed cultivation using MSG reached 47.9% (4.95 g/L). Statistical analysis using least significant difference (LSD) showed significant lipid production (pDHA productivity (0.052 g/L hr-1) was obtained in medium containing MSG. This study proves that nitrogen component in the medium significantly affects the biomass concentration, lipid and DHA content.

Actinide Source Term Program, position paper. Revision 1

International Nuclear Information System (INIS)

Novak, C.F.; Papenguth, H.W.; Crafts, C.C.; Dhooge, N.J.

1994-01-01

The Actinide Source Term represents the quantity of actinides that could be mobilized within WIPP brines and could migrate with the brines away from the disposal room vicinity. This document presents the various proposed methods for estimating this source term, with a particular focus on defining these methods and evaluating the defensibility of the models for mobile actinide concentrations. The conclusions reached in this document are: the 92 PA open-quotes expert panelclose quotes model for mobile actinide concentrations is not defensible; and, although it is extremely conservative, the open-quotes inventory limitsclose quotes model is the only existing defensible model for the actinide source term. The model effort in progress, open-quotes chemical modeling of mobile actinide concentrationsclose quotes, supported by a laboratory effort that is also in progress, is designed to provide a reasonable description of the system and be scientifically realistic and supplant the open-quotes Inventory limitsclose quotes model

The 100 strongest radio point sources in the field of the Large Magellanic Cloud at 1.4 GHz

Directory of Open Access Journals (Sweden)

Payne J.L.

2009-01-01

Full Text Available We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC. The observations making up the mosaic were made using Australia Telescope Compact Array (ATCA over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 1000 at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H ii regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index (α of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.

The 100 Strongest Radio Point Sources in the Field of the Large Magellanic Cloud at 1.4 GHz

Directory of Open Access Journals (Sweden)

Payne, J. L.

2009-06-01

Full Text Available We present the 100 strongest 1.4~GHz point sources from a new mosaicimage in the direction of the Large Magellanic Cloud (LMC. The observationsmaking up the mosaic were made using Australia Telescope Compact Array (ATCAover a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 10arcsec at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact HII regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index ($alpha$ of -0.53 and present a 1.4 GHz image showing source locationin the direction of the LMC.

Spark-protected ion-source control and monitoring system at 1.5 MV

International Nuclear Information System (INIS)

Bogaty, J.M.; Zolecki, R.

1981-01-01

The Heavy Ion Fusion Program at Argonne National Laboratory utilizes a 1.5-MV Xe ion preaccelerator. Reliable beam transport requires accurate measurements and precise control of various ion-source parameters. This paper discusses the use of a multiplexed fiberoptic data-transmission system and low-cost digital stepper motors for control functions. Techniques are discussed which allow TTL and CMOS semiconductor curcuits to survive the destructive sparks which can occur in the 1.5-MV preaccelerator

Source apportionment of PAHs and n-alkanes bound to PM1 collected near the Venice highway.

Science.gov (United States)

Valotto, Gabrio; Rampazzo, Giancarlo; Gonella, Francesco; Formenton, Gianni; Ficotto, Silvia; Giraldo, Giorgia

2017-04-01

n-Alkanes and polycyclic aromatic hydrocarbons (PAHs) bound to atmospheric particulate matter (PM 1 ) were investigated in a traffic site located in an urban area of Venice Province (Eastern Po Valley, Italy) during the cold season. Considering the critical situation affecting the Veneto Region concerning the atmospheric pollution and the general lack of information on PM 1 composition and emission in this area, this experimental study aims at determining the source profile, their relative contributions and the dispersion of finer particles. Four sources were identified and quantified using the Positive Matrix Factorization receptor model: (1) mixed combustions related to the residential activities, (2) agricultural biomass burning in addition to the resuspension of anthropogenic and natural debris carried by the wind, (3) gasoline and (4) diesel traffic-related combustions. The role of local atmospheric circulation was also investigated to identify the pollutant sources. Copyright © 2016. Published by Elsevier B.V.

Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency

International Nuclear Information System (INIS)

Kim, T. S.; Jeong, S. H.; Chang, D. H.; In, S. R.; Park, M.; Jung, B. K.; Lee, K. W.; Wang, S. J.; Bae, Y. S.; Park, H. T.; Kim, J. S.; Cho, W.; Choi, D. J.

2016-01-01

Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP

Comparison of the hypothetical (57)Co brachytherapy source with the (192)Ir source.

Science.gov (United States)

Toossi, Mohammad Taghi Bahreyni; Ghorbani, Mahdi; Rostami, Atefeh; Khosroabadi, Mohsen; Khademi, Sara; Knaup, Courtney

2016-01-01

The (57)Co radioisotope has recently been proposed as a hypothetical brachytherapy source due to its high specific activity, appropriate half-life (272 days) and medium energy photons (114.17 keV on average). In this study, Task Group No. 43 dosimetric parameters were calculated and reported for a hypothetical (57)Co source. A hypothetical (57)Co source was simulated in MCNPX, consisting of an active cylinder with 3.5 mm length and 0.6 mm radius encapsulated in a stainless steel capsule. Three photon energies were utilized (136 keV [10.68%], 122 keV [85.60%], 14 keV [9.16%]) for the (57)Co source. Air kerma strength, dose rate constant, radial dose function, anisotropy function, and isodose curves for the source were calculated and compared to the corresponding data for a (192)Ir source. The results are presented as tables and figures. Air kerma strength per 1 mCi activity for the (57)Co source was 0.46 cGyh(-1) cm 2 mCi(-1). The dose rate constant for the (57)Co source was determined to be 1.215 cGyh(-1)U(-1). The radial dose function for the (57)Co source has an increasing trend due to multiple scattering of low energy photons. The anisotropy function for the (57)Co source at various distances from the source is more isotropic than the (192)Ir source. The (57)Co source has advantages over (192)Ir due to its lower energy photons, longer half-life, higher dose rate constant and more isotropic anisotropic function. However, the (192)Ir source has a higher initial air kerma strength and more uniform radial dose function. These properties make (57)Co a suitable source for use in brachytherapy applications.

Large aperture contact ionized Cs+1 ion source for an induction linac

International Nuclear Information System (INIS)

Abbott, S.; Chupp, W.; Faltens, A.; Herrmannsfeldt, W.; Hoyer, E.; Keefe, D.; Kim, C.H.; Rosenblum, S.; Shiloh, J.

1979-03-01

A 500 KeV one-ampere Cs +1 ion beam has been generated by contact ionization with a 30 cm dia. iridium hot plate. Reproducibility of space charge limited ion current wave forms at repetition rates up to 1 Hz has been verified. The beam is characterized to be very bright and suitable as an ion source for the induction linac based heavy ion fusion scheme. The hot anode plate was found to be reliable and self-cleaning during the operation

Chemical characterisation and source apportionment of PM1 during massive loading at an urban location in Indo-Gangetic Plain: impact of local sources and long-range transport

Directory of Open Access Journals (Sweden)

Prashant Rajput

2016-07-01

Full Text Available This study assesses temporal variability and source contributions of PM1 (particles with aerodynamic diameter ≤ 1.0 µm samples (n=51; November 2009–February 2010 from an urban location at Kanpur (26.30°N; 80.13°E; 142 m above mean sea-level in the Indo-Gangetic Plain (IGP. A study period from November to February is preferred owing to massive loading of particulate matter in entire IGP. PM1 varies from 18 to 348 (Avg±SD: 113±72 µg m−3 in this study. A total of 11 trace metals, five major elements and four water-soluble inorganic species (WSIS have been measured. Mass fraction of total metals (∑metals=trace+major centres at 18±14 %, of which nearly 15 % is contributed by major elements. Furthermore, ∑WSIS contributes about 26 % to PM1 mass concentration. Abundance pattern among assessed WSIS in this study follows the order: ≈> > Cl−. The K-to-PM1 mass fraction (Avg: 2 % in conjunction with air-mass back trajectories (AMBT indicates that the prevailing north-westerly winds transport biomass burning derived pollutants from upwind IGP. A recent version of positive matrix factorisation (PMF 5.0 has been utilised to quantify the contribution of fine-mode aerosols from various sources. The contribution from each source is highly variable and shows a strong dependence on AMBT. Events with predominant contribution from biomass burning emission (>70 % indicate origin of air-masses from source region upwind in IGP. One of the most interesting features of our study relates to the observation that secondary aerosols (contributing as high as ~60 % to PM1 loading are predominantly derived from stationary combustion sources (/ ratio: 0.30±0.23. Thus, our study highlights a high concentration of PM1 loading and atmospheric fog prevalent during wintertime can have a severe impact on atmospheric chemistry in the air-shed of IGP.

Rationale for a spallation neutron source target system test facility at the 1-MW Long-Pulse Spallation Source

International Nuclear Information System (INIS)

Sommer, W.F.

1995-12-01

The conceptual design study for a 1-MW Long-Pulse Spallation Source at the Los Alamos Neutron Science Center has shown the feasibility of including a spallation neutron test facility at a relatively low cost. This document presents a rationale for developing such a test bed. Currently, neutron scattering facilities operate at a maximum power of 0.2 MW. Proposed new designs call for power levels as high as 10 MW, and future transmutation activities may require as much as 200 MW. A test bed will allow assessment of target neutronics; thermal hydraulics; remote handling; mechanical structure; corrosion in aqueous, non-aqueous, liquid metal, and molten salt systems; thermal shock on systems and system components; and materials for target systems. Reliable data in these areas are crucial to the safe and reliable operation of new high-power facilities. These tests will provide data useful not only to spallation neutron sources proposed or under development, but also to other projects in accelerator-driven transmutation technologies such as the production of tritium

40 CFR Table 1 to Subpart Xxxx of... - Emission Limits for Tire Production Affected Sources

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Emission Limits for Tire Production Affected Sources 1 Table 1 to Subpart XXXX of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION.... 63, Subpt. XXXX, Table 1 Table 1 to Subpart XXXX of Part 63—Emission Limits for Tire Production...

Paradox of Genetic Diversity in the Case of Prionic Diseases in Sheep Breeds from Romania

Directory of Open Access Journals (Sweden)

Gheorghe Hrinca

2016-05-01

Full Text Available The main target of this debate is the revaluation of the biodiversity concept and especially of its significance in the animal husbandry field. The paper analyzes the genetic diversity at the determinant locus of scrapie (PrP in the sheep breeds from Romania: Palas Merino, Tsigai, Tsurcana, Botosani Karakul, Palas Meat Breed and Palas Milk Breed. The prionic genetic diversity (d has been quantified by means of informational energy (e. This study highlights the impact of increasing the genetic diversity from the PrP locus level on the health status of ovine species and especially on human food safety. The informational statistics processing shows that the resistance / susceptibility to scrapie is in relation to the degree of prionic genetic diversity. The limitation of genetic diversity by selecting the individuals possessing the ARR allele in both homozygous status and in combination with alleles ARQ, ARH AHQ confers to sheep herds certain levels of resistance to contamination with scrapie disease. Instead, promoting to reproduction also individuals possessing the VRQ allele in all possible genotypic combinations (including ARR allele increases genetic diversity but also has as effect increasing the susceptibility of sheep to prion disease onset. From the point of view of morbid phenomenon, the Botosani Karakul breed is clearly advantaged compared to all other indigenous sheep breeds from Romania. For methodological coherency in the interpretative context of this issue, the genetic diversity was analyzed in association with the heterozygosity degree of breeds and their Hardy-Weinberg genetic equilibrium at the PrP locus level. Finally, the paper refers to decisions that the improvers must take to achieve the genetic prophylaxis in the scrapie case taking into account the polymorphism degree of prion protein.

Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols treated with different phosphorus rates and sources for varied soil-source contact periods

Directory of Open Access Journals (Sweden)

Irio Fernando de Freitas

2013-06-01

Full Text Available Despite the large number of studies addressing the quantification of phosphorus (P availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR and Mixed Resin (MR, to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2 + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV, a sandy clay loam Red Yellow Latosol (LVA, and a sandy loam Yellow Latosol (LA, to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais at two P rates (75 and 150 mg dm-3, plus three control treatments (each soil without P application after four contact periods (15, 30, 60, and 120 days of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction. These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay and LVA (medium texture for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of

Ion source requirements for pulsed spallation neutron sources

International Nuclear Information System (INIS)

Alonso, J.R.

1995-10-01

The neutron scattering community has endorsed the need for a high- power (1 to 5 MW) accelerator-driven source of neutrons for materials research. Properly configured, the accelerator could produce very short (sub-microsecond) bursts of cold neutrons, said time structure offering advantages over the continuous flux from a reactor for a large class of experiments. The recent cancellation of the ANS reactor project has increased the urgency to develop a comprehensive strategy based on the best technological scenarios. Studies to date have built on the experience from ISIS (the 160 KW source in the UK), and call for a high-current (approx. 100 mA peak) H - source-linac combination injecting into one or more accumulator rings in which beam may be further accelerated. The 1 to 5 GeV proton beam is extracted in a single turn and brought to the target-moderator stations. The high current, high duty-factor, high brightness and high reliability required of the ion source present a very large challenge to the ion source community. A workshop held in Berkeley in October 1994, analyzed in detail the source requirements for proposed accelerator scenarios, the present performance capabilities of different H - source technologies, and identified necessary R ampersand D efforts to bridge the gap

Processing of Bi2.1Sr1.8Ca1.1Cu2O8 source material for float-zone fiber growth

International Nuclear Information System (INIS)

Peszkin, P.N.; Raymakers, R.J.; Feigelson, R.S.; Moulton, L.V.; Lu, Z.

1991-01-01

Bi 2.1 Sr 1.8 Ca 1.1 Cu 2 O 8 fibers having excellent superconducting properties can be grown by a laser-heated float zone process. In order to maintain stable growth conditions and thereby obtain fibers free of diameter fluctuations and voids, dense ceramic starting material containing only the 2212 phase is required. In this study various processing parameters, including calcining and sintering temperatures and times, grain size of the powders used, and pressing pressures were optimized to yield dense, chemically homogeneous starting material. It was found that under most conditions there was no increase in the density on sintering. Retrograde densification was the usual situation except at higher pressures and was found to depend on pressing pressure, calcination history, and sintering temperature. Cold-pressing at higher pressures (100 000 psi) yielded denser but chemically inhomogeneous material. Ceramic samples sintered for long times (>48 h) yielded source rods that produced instabilities during fiber growth, presumably due to preferential loss of mass during sintering

1H 0707-495 in 2011: an X-ray source within a gravitational radius of the event horizon

NARCIS (Netherlands)

Fabian, A.C.; Zoghbi, A.; Wilkins, D.; Dwelly, T.; Uttley, P.; Schartel, N.; Miniutti, G.; Gallo, L.; Grupe, D.; Komossa, S.; Santos-Lleó, M.

2012-01-01

The narrow-line Seyfert 1 Galaxy 1H 0707−495 went into a low state from 2010 December to 2011 February, discovered by a monitoring campaign using the X-Ray Telescope on the Swift satellite. We triggered a 100 ks XMM-Newton observation of the source in 2011 January, revealing the source to have

Chemical characterization of PM1.0 aerosol in Delhi and source apportionment using positive matrix factorization.

Science.gov (United States)

Jaiprakash; Singhai, Amrita; Habib, Gazala; Raman, Ramya Sunder; Gupta, Tarun

2017-01-01

Fine aerosol fraction (particulate matter with aerodynamic diameter <= 1.0 μm (PM) 1.0 ) over the Indian Institute of Technology Delhi campus was monitored day and night (10 h each) at 30 m height from November 2009 to March 2010. The samples were analyzed for 5 ions (NH 4 + , NO 3 - , SO 4 2- , F - , and Cl - ) and 12 trace elements (Na, K, Mg, Ca, Pb, Zn, Fe, Mn, Cu, Cd, Cr, and Ni). Importantly, secondary aerosol (sulfate and nitrate) formation was observed during dense foggy events, supporting the fog-smog-fog cycle. A total of 76 samples were used for source apportionment of PM mass. Six factors were resolved by PMF analyses and were identified as secondary aerosol, secondary chloride, biomass burning, soil dust, iron-rich source, and vehicular emission. The geographical location of the sources and/or preferred transport pathways was identified by conditional probability function (for local sources) and potential source contribution function (for regional sources) analyses. Medium- and small-scale metal processing (e.g. steel sheet rolling) industries in Haryana and National Capital Region (NCR) Delhi, coke and petroleum refining in Punjab, and thermal power plants in Pakistan, Punjab, and NCR Delhi were likely contributors to secondary sulfate, nitrate, and secondary chloride at the receptor site. The agricultural residue burning after harvesting season (Sept-Dec and Feb-Apr) in Punjab, and Haryana contributed to potassium at receptor site during November-December and March 2010. The soil dust from North and East Pakistan, and Rajasthan, North-East Punjab, and Haryana along with the local dust contributed to soil dust at the receptor site, during February and March 2010. A combination of temporal behavior and air parcel trajectory ensemble analyses indicated that the iron-rich source was most likely a local source attributed to emissions from metal processing facilities. Further, as expected, the vehicular emissions source did not show any seasonality and

Electron density and temperature in NIO1 RF source operated in oxygen and argon

Science.gov (United States)

Barbisan, M.; Zaniol, B.; Cavenago, M.; Pasqualotto, R.; Serianni, G.; Zanini, M.

2017-08-01

The NIO1 experiment, built and operated at Consorzio RFX, hosts an RF negative ion source, from which it is possible to produce a beam of maximum 130 mA in H- ions, accelerated up to 60 kV. For the preliminary tests of the extraction system the source has been operated in oxygen, whose high electronegativity allows to reach useful levels of extracted beam current. The efficiency of negative ions extraction is strongly influenced by the electron density and temperature close to the Plasma Grid, i.e. the grid of the acceleration system which faces the source. To support the tests, these parameters have been measured by means of the Optical Emission Spectroscopy diagnostic. This technique has involved the use of an oxygen-argon mixture to produce the plasma in the source. The intensities of specific Ar I and Ar II lines have been measured along lines of sight close to the Plasma Grid, and have been interpreted with the ADAS package to get the desired information. This work will describe the diagnostic hardware, the analysis method and the measured values of electron density and temperature, as function of the main source parameters (RF power, pressure, bias voltage and magnetic filter field). The main results show that not only electron density but also electron temperature increase with RF power; both decrease with increasing magnetic filter field. Variations of source pressure and plasma grid bias voltage appear to affect only electron temperature and electron density, respectively.

[Characteristics and sources apportionment of OC and EC in PM1.1 from Nanjing].

Science.gov (United States)

Jiang, Wen-juan; Guo, Zhao-bing; Liu, Feng-ling; Rui, Mao-ling; Shi, Lei; Zeng, Gang; Guo, Zi-yan

2015-03-01

The concentrations of OC and EC in PM1.1 collected from Nanshi (NS) and Nanhua (NH) in 2011 were analyzed using DRI Model 2001A Thermal Optical Carbon Analyzer. In addition, source apportionment was simultaneously evaluated. The results showed that the annual average concentrations of OC and EC in PM1.1 were 10. 10 μg x m(-3) and 2.52 μg x m(-3) in NS area, and 11.22 μg x m(-3) and 3.12 μg x m(-3) in NH area, respectively. This result indicated that OC and EC pollution in NH was more serious than that in NS area. Meanwhile, the concentrations of OC and EC in winter and spring were obviously higher compared to those in summer in these two sampling sites, which was mainly ascribed to the increased coal combustion and the unfavorable emission condition of air pollutants in summer and spring. We noted that the SOC/TOC value was the highest in summer and the lowest in winter. In addition, the SOC concentration was observed to show a positive correlation with ozone concentrations, which indicated that the photochemical reaction was a main way of SOC formation in autumn.

Intense, broadband, pulsed I-R source at the National Synchrotron Light Source

International Nuclear Information System (INIS)

Williams, G.P.

1984-01-01

We describe a broadband (1 μm to 1 mm) synchrotron radiation infrared source, pulsed each 20 to 180 nseconds and delivering about 10 15 photons/sec/1% bandpass into f10 optics. The source size is diffraction limited. This source is thus 100 to 1000 times brighter than a 2000 0 K black body, very stable and capable of being used for calibration

Ion source requirements for pulsed spallation neutron sources

International Nuclear Information System (INIS)

Alonso, J.R.

1996-01-01

The neutron scattering community has endorsed the need for a high-power (1 to 5 MW) accelerator-driven source of neutrons for materials research. Properly configured, the accelerator could produce very short (sub-microsecond) bursts of cold neutrons, said time structure offering advantages over the continuous flux from a reactor for a large class of experiments. The recent cancellation of the ANS reactor project has increased the urgency to develop a comprehensive strategy based on the best technological scenarios. Studies to date have built on the experience from ISIS (the 160 kW source in the UK), and call for a high-current (approx. 100 mA peak) H - source-linac combination injecting into one or more accumulator rings in which beam may be further accelerated. The 1 to 5 GeV proton beam is extracted in a single turn and brought to the target-moderator stations. The high current, high duty-factor, high brightness and high reliability required of the ion source present a very large challenge to the ion source community. A workshop held in Berkeley in October 1994, analyzed in detail the source requirements for proposed accelerator scenarios, the present performance capabilities of different H - source technologies, and identified necessary R ampersand D efforts to bridge the gap. copyright 1996 American Institute of Physics

Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

International Nuclear Information System (INIS)

Park, Sae-Hoon; Kim, Yu-Seok; Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub

2015-01-01

In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber

Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

Energy Technology Data Exchange (ETDEWEB)

Park, Sae-Hoon; Kim, Yu-Seok [Dongguk University, Gyeonju (Korea, Republic of); Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Multipurpose Accelerator Complex, Gyeongju (Korea, Republic of)

2015-10-15

In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber.

Genetic evidence for susceptibility and resistance against scrapie in ...

Indian Academy of Sciences (India)

Sharda Choudhary1 Neelam Gupta2 Geetika Jethra1 Digpal Singh Gour3. National Research Centre on Seed Spices, Tabiji, Ajmer 305 206, India; Indian council of Agricultural Research, PUSA, New Delhi 110 114, India; Escuela de Ingenieria en Alimentos, Biotecnologia y Agronomia, Instituto Tecnologico y de Estudios ...

GANIL Workshop on Ion Sources; Journees Sources d'Ions

Energy Technology Data Exchange (ETDEWEB)

Leroy, Renan [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

1999-07-01

The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+{yields}n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed.

Applications of New Chemical Heat Sources Phase 1

National Research Council Canada - National Science Library

Bell, William

2001-01-01

Report developed under Small Business Innovative Research (SBIR) contract. This project has examined the application of new chemical heat sources, with emphasis on portable heaters for military field rations...

The Einstein Observatory catalog of IPC x ray sources. Volume 1E: Documentation

Science.gov (United States)

Harris, D. E.; Forman, W.; Gioia, I. M.; Hale, J. A.; Harnden, F. R., Jr.; Jones, C.; Karakashian, T.; Maccacaro, T.; Mcsweeney, J. D.; Primini, F. A.

1993-01-01

The Einstein Observatory (HEAO-2, launched November 13, 1978) achieved radically improved sensitivity over previous x-ray missions through the use of focusing optics, which simultaneously afforded greatly reduced background and produced true images. During its 2.5-yr mission, the Einstein X-Ray Telescope was pointed toward some 5,000 celestial targets, most of which were detected, and discovered several thousand additional 'serendipitous' sources in the observed fields. This catalog contains contour diagrams and source data, obtained with the imaging proportional counter in the 0.16 to 3.5 keV energy band, and describes methods for recovering upper limits for any sky position within the observed images. The main catalog consists of six volumes (numbered 2 through 7) of right ascension ordered pages, each containing data for one observation. Along with the primary documentation describing how the catalog was constructed, volume 1 contains a complete source list, results for merged fields, a reference system to published papers, and data useful for calculating upper limits and fluxes.

Plume rise from multiple sources

International Nuclear Information System (INIS)

Briggs, G.A.

1975-01-01

A simple enhancement factor for plume rise from multiple sources is proposed and tested against plume-rise observations. For bent-over buoyant plumes, this results in the recommendation that multiple-source rise be calculated as [(N + S)/(1 + S)]/sup 1/3/ times the single-source rise, Δh 1 , where N is the number of sources and S = 6 (total width of source configuration/N/sup 1/3/ Δh 1 )/sup 3/2/. For calm conditions a crude but simple method is suggested for predicting the height of plume merger and subsequent behavior which is based on the geometry and velocity variations of a single buoyant plume. Finally, it is suggested that large clusters of buoyant sources might occasionally give rise to concentrated vortices either within the source configuration or just downwind of it

Study of source size in p bar p collisions at √s =1.8 TeV using pion interferometry

International Nuclear Information System (INIS)

Alexopoulos, T.; Allen, C.; Anderson, E.W.; Balamurali, V.; Banerjee, S.; Beery, P.D.; Bhat, P.; Bishop, J.M.; Biswas, N.N.; Bujak, A.; Carmony, D.D.; Carter, T.; Choi, Y.; Cole, P.; DeBonte, R.; DeCarlo, V.; Erwin, A.R.; Findeisen, C.; Goshaw, A.T.; Gutay, L.J.; Hirsch, A.S.; Hojvat, C.; Jennings, J.R.; Kenney, V.P.; Lindsey, C.S.; Loomis, C.; LoSecco, J.M.; McMahon, T.; McManus, A.P.; Morgan, N.K.; Nelson, K.; Oh, S.H.; Porile, N.T.; Reeves, D.; Rimai, A.; Robertson, W.R.; Scharenberg, R.P.; Stampke, S.R.; Stringfellow, B.C.; Thompson, M.A.; Turkot, F.; Walker, W.D.; Wang, C.H.; Warchol, J.; Wesson, D.K.; Zhan, Y.H.

1993-01-01

Experiment E735 collected data for ∼10 7 interactions at the C0 intersection of the Fermilab p bar p collider with √s =1.8 TeV. The Bose-Einstein correlations between pairs of identical pions were measured in a limited aperture spectrometer and used to estimate the size and lifetime of the source. The aperture shape limited the sensitivity primarily to the source dimension R along the incident p bar p direction. Both this dimension and the lifetime appear to depend strongly on pion multiplicity. Efforts were also made to obtain some information on the transverse source size, energy density, and the dependence of source size and strength on dipion momentum. Fits to the entire data sample yielded a value R=1.06±0.07 fm for the average source dimension and a value τ=0.74±0.06 fm for the average source lifetime with left-angle dN c /dη right-angle=14.4

Cost Comparison of B-1B Non-Mission-Capable Drivers Using Finite Source Queueing with Spares

Science.gov (United States)

2012-09-06

COMPARISON OF B-1B NON-MISSION-CAPABLE DRIVERS USING FINITE SOURCE QUEUEING WITH SPARES GRADUATE RESEARCH PAPER Presented to the Faculty...step into the lineup making large-number approximations unusable. Instead, a finite source queueing model including spares is incorporated...were reported as flying time accrued since last occurrence. Service time was given in both start-stop format and MX man-hours utilized. Service time was

9 CFR 79.5 - Issuance of certificates.

Science.gov (United States)

2010-01-01

... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS SCRAPIE IN SHEEP AND... the consignee. Certificates must indicate the flock of birth for any breeding sheep born after January...

41 CFR 304-6.1 - May we accept a monetary payment in the form of cash from a non-Federal source?

Science.gov (United States)

2010-07-01

... payment in the form of cash from a non-Federal source? 304-6.1 Section 304-6.1 Public Contracts and Property Management Federal Travel Regulation System PAYMENT OF TRAVEL EXPENSES FROM A NON-FEDERAL SOURCE... of cash from a non-Federal source? No, you may not accept a monetary payment in the form of cash from...

Large source test stand for H-(D-) ion source

International Nuclear Information System (INIS)

Larson, R.; McKenzie-Wilson, R.

1981-01-01

The Brookhaven National Laboratory Neutral Beam Group has constructed a large source test stand for testing of the various source modules under development. The first objective of the BNL program is to develop a source module capable of delivering 10A of H - (D - ) at 25 kV operating in the steady state mode with satisfactory gas and power efficiency. The large source test stand contains gas supply and vacuum pumping systems, source cooling systems, magnet power supplies and magnet cooling systems, two arc power supplies rated at 25 kW and 50 kW, a large battery driven power supply and an extractor electrode power supply. Figure 1 is a front view of the vacuum vessel showing the control racks with the 36'' vacuum valves and refrigerated baffles mounted behind. Figure 2 shows the rear view of the vessel with a BNL Mk V magnetron source mounted in the source aperture and also shows the cooled magnet coils. Currently two types of sources are under test: a large magnetron source and a hollow cathode discharge source

On the nature of emission of the star-gas-dust complex of the W1 radio source

International Nuclear Information System (INIS)

Udal'tsov, V.A.; Kovalenko, A.V.

1982-01-01

The brightness distribution of the radio source W 1 at 102 MHz has been investigated with the 187x384 m radio telescope in Pushchino. It is shown that W 1 is genetically connected with the stellar association Ceph IV as well as with the extended emission nebula GS 285 which consists of numerous nebulae, including two bright ones, Sharpless (S) 171 and NGC 7822. The radio emission of the nebula S 171 is shown to be thermal, and there is no Supernova remnant in it, in contrast with the other authors' suggestion. By two independent methods, the distance to S 171 has been evaluated to be 840 pc. The emission of NGC 7822 is mainly thermal. The extended nebula GS 285 is a thermal source, not a remnant of a Supernova that had exploded in a dense gas - dust medium, as was believed by other authors. Attention is drawn to the wrong identification by many authors of the radio source in the S 171 region with the nebula NGC 7822. It is shown that when measuring the difference of spectral indices of two sources, the calibration error may be eliminated if their calibration at given frequency is made by means of the same source [ru

Oxidative capacity of the Mexico City atmosphere – Part 1: A radical source perspective

Directory of Open Access Journals (Sweden)

R. Volkamer

2010-07-01

Full Text Available A detailed analysis of OH, HO₂ and RO₂ radical sources is presented for the near field photochemical regime inside the Mexico City Metropolitan Area (MCMA. During spring of 2003 (MCMA-2003 field campaign an extensive set of measurements was collected to quantify time-resolved RO_x (sum of OH, HO₂, RO₂ radical production rates from day- and nighttime radical sources. The Master Chemical Mechanism (MCMv3.1 was constrained by measurements of (1 concentration time-profiles of photosensitive radical precursors, i.e., nitrous acid (HONO, formaldehyde (HCHO, ozone (O₃, glyoxal (CHOCHO, and other oxygenated volatile organic compounds (OVOCs; (2 respective photolysis-frequencies (J-values; (3 concentration time-profiles of alkanes, alkenes, and aromatic VOCs (103 compound are treated and oxidants, i.e., OH- and NO₃ radicals, O₃; and (4 NO, NO₂, meteorological and other parameters. The RO_x production rate was calculated directly from these observations; the MCM was used to estimate further RO_x production from unconstrained sources, and express overall RO_x production as OH-equivalents (i.e., taking into account the propagation efficiencies of RO₂ and HO₂ radicals into OH radicals.

Daytime radical production is found to be about 10–25 times higher than at night; it does not track the abundance of sunlight. 12-h average daytime contributions of individual sources are: Oxygenated VOC other than HCHO about 33%; HCHO and O₃ photolysis each about 20%; O₃/alkene reactions and HONO photolysis each about 12%, other sources <3%. Nitryl chloride photolysis could potentially contribute ~15% additional radicals, while NO₂* + water makes – if any – a very small contribution (~2%. The peak radical production of ~7.5 10⁷ molec cm⁻³ s⁻¹ is

The Chandra Source Catalog: Source Variability

Science.gov (United States)

Nowak, Michael; Rots, A. H.; McCollough, M. L.; Primini, F. A.; Glotfelty, K. J.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Evans, I.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Plummer, D. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2009-09-01

The Chandra Source Catalog (CSC) contains fields of view that have been studied with individual, uninterrupted observations that span integration times ranging from 1 ksec to 160 ksec, and a large number of which have received (multiple) repeat observations days to years later. The CSC thus offers an unprecedented look at the variability of the X-ray sky over a broad range of time scales, and across a wide diversity of variable X-ray sources: stars in the local galactic neighborhood, galactic and extragalactic X-ray binaries, Active Galactic Nuclei, etc. Here we describe the methods used to identify and quantify source variability within a single observation, and the methods used to assess the variability of a source when detected in multiple, individual observations. Three tests are used to detect source variability within a single observation: the Kolmogorov-Smirnov test and its variant, the Kuiper test, and a Bayesian approach originally suggested by Gregory and Loredo. The latter test not only provides an indicator of variability, but is also used to create a best estimate of the variable lightcurve shape. We assess the performance of these tests via simulation of statistically stationary, variable processes with arbitrary input power spectral densities (here we concentrate on results of red noise simulations) at variety of mean count rates and fractional root mean square variabilities relevant to CSC sources. We also assess the false positive rate via simulations of constant sources whose sole source of fluctuation is Poisson noise. We compare these simulations to an assessment of the variability found in real CSC sources, and estimate the variability sensitivities of the CSC.

Detailed design of the RF source for the 1 MV neutral beam test facility

International Nuclear Information System (INIS)

Marcuzzi, D.; Palma, M. Dalla; Pavei, M.; Heinemann, B.; Kraus, W.; Riedl, R.

2009-01-01

In the framework of the EU activities for the development of the Neutral Beam Injector for ITER, the detailed design of the Radio Frequency (RF) driven negative ion source to be installed in the 1 MV ITER Neutral Beam Test Facility (NBTF) has been carried out. Results coming from ongoing R and D on IPP test beds [A. Staebler et al., Development of a RF-Driven Ion Source for the ITER NBI System, this conference] and the design of the new ELISE facility [B. Heinemann et al., Design of the Half-Size ITER Neutral Beam Source Test Facility ELISE, this conference] brought several modifications to the solution based on the previous design. An assessment was carried out regarding the Back-Streaming positive Ions (BSI+) that impinge on the back plates of the ion source and cause high and localized heat loads. This led to the redesign of most heated components to increase cooling, and to different choices for the plasma facing materials to reduce the effects of sputtering. The design of the electric circuit, gas supply and the other auxiliary systems has been optimized. Integration with other components of the beam source has been revised, with regards to the interfaces with the supporting structure, the plasma grid and the flexible connections. In the paper the design will be presented in detail, as well as the results of the analyses performed for the thermo-mechanical verification of the components.

The LBL 1-2 GeV synchrotron radiation source

International Nuclear Information System (INIS)

Selph, F.B.

1987-06-01

The design of the 1 to 2 GeV Synchrotron Radiation Source to be built at the Lawrence Berkeley Laboratory is described. The goal of this facility is to provide very high brightness photon beams in the ultraviolet and soft x-ray regions. The photon energy range to be served is from 0.5 eV to 10 keV, with the brightest beams available in the 1 eV to 1 keV interval. For time-resolved experiments, beam pulses of a few tens of picoseconds will be available. Emphasis will be on the use of undulators and wigglers to produce high quality, intense beams. Initially, four of the former and one of the latter devices will be installed, with six long straight sections left open for future installations. In addition, provision is being made for 48 beamlines from bending magnets. The storage ring is optimized for operation at 1.5 GeV, with a maximum energy of 1.9 GeV. The injection system includes a 1.5 GeV booster synchrotron for full energy injection at the nominal operating energy of the storage ring. Filling time for the maximum storage ring intensity of 400 mA is about 2 minutes, and beam lifetime will be about 6 hours. Attention has been given to the extraordinary requirements for beam stability, and to the need to independently control photon beam alignment. Typical rms beam size in insertion regions is 201 μm horizontal, and 38 μm vertical. The manner in which this design achieves very high spectral brightness from undulators and wigglers, while maintaining a modest value for the beam current, will be described. Primarily, this requires that the design of the lattice, the arrangement of bending magnets, focusing quadrupoles and straight sections, be done with this in mind

Radio measurements in the fields of gamma-ray sources. Pt. 1

International Nuclear Information System (INIS)

Sieber, W.; Schlickeiser, R.

1982-01-01

The γ-ray source CG 195+04 has been searched for radio counterparts at wavelengths between 2.8 cm and 18 cm with the 100-m telescope of the Max-Planck-Institut fuer Radioastronomie, Bonn. We have detected a number of sources and measured their spectra. Our positions may form the basis for future surveys in other frequency ranges. Different physical emission models suggest compactness of the γ-ray source. (orig.)

CHANDRA ACIS SURVEY OF X-RAY POINT SOURCES: THE SOURCE CATALOG

Energy Technology Data Exchange (ETDEWEB)

Wang, Song; Liu, Jifeng; Qiu, Yanli; Bai, Yu; Yang, Huiqin; Guo, Jincheng; Zhang, Peng, E-mail: jfliu@bao.ac.cn, E-mail: songw@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2016-06-01

The Chandra archival data is a valuable resource for various studies on different X-ray astronomy topics. In this paper, we utilize this wealth of information and present a uniformly processed data set, which can be used to address a wide range of scientific questions. The data analysis procedures are applied to 10,029 Advanced CCD Imaging Spectrometer observations, which produces 363,530 source detections belonging to 217,828 distinct X-ray sources. This number is twice the size of the Chandra Source Catalog (Version 1.1). The catalogs in this paper provide abundant estimates of the detected X-ray source properties, including source positions, counts, colors, fluxes, luminosities, variability statistics, etc. Cross-correlation of these objects with galaxies shows that 17,828 sources are located within the D {sub 25} isophotes of 1110 galaxies, and 7504 sources are located between the D {sub 25} and 2 D {sub 25} isophotes of 910 galaxies. Contamination analysis with the log N –log S relation indicates that 51.3% of objects within 2 D {sub 25} isophotes are truly relevant to galaxies, and the “net” source fraction increases to 58.9%, 67.3%, and 69.1% for sources with luminosities above 10{sup 37}, 10{sup 38}, and 10{sup 39} erg s{sup −1}, respectively. Among the possible scientific uses of this catalog, we discuss the possibility of studying intra-observation variability, inter-observation variability, and supersoft sources (SSSs). About 17,092 detected sources above 10 counts are classified as variable in individual observation with the Kolmogorov–Smirnov (K–S) criterion ( P {sub K–S} < 0.01). There are 99,647 sources observed more than once and 11,843 sources observed 10 times or more, offering us a wealth of data with which to explore the long-term variability. There are 1638 individual objects (∼2350 detections) classified as SSSs. As a quite interesting subclass, detailed studies on X-ray spectra and optical spectroscopic follow-up are needed to

A STATISTICAL APPROACH TO RECOGNIZING SOURCE CLASSES FOR UNASSOCIATED SOURCES IN THE FIRST FERMI-LAT CATALOG

Energy Technology Data Exchange (ETDEWEB)

Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Allafort, A.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Buehler, R. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Antolini, E.; Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Baldini, L.; Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bouvier, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Brandt, T. J. [CNRS, IRAP, F-31028 Toulouse Cedex 4 (France); Brigida, M. [Dipartimento di Fisica ' M. Merlin' dell' Universita e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P., E-mail: monzani@slac.stanford.edu, E-mail: vilchez@cesr.fr, E-mail: salvetti@lambrate.inaf.it, E-mail: elizabeth.c.ferrara@nasa.gov [Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); and others

2012-07-01

The Fermi Large Area Telescope (LAT) First Source Catalog (1FGL) provided spatial, spectral, and temporal properties for a large number of {gamma}-ray sources using a uniform analysis method. After correlating with the most-complete catalogs of source types known to emit {gamma} rays, 630 of these sources are 'unassociated' (i.e., have no obvious counterparts at other wavelengths). Here, we employ two statistical analyses of the primary {gamma}-ray characteristics for these unassociated sources in an effort to correlate their {gamma}-ray properties with the active galactic nucleus (AGN) and pulsar populations in 1FGL. Based on the correlation results, we classify 221 AGN-like and 134 pulsar-like sources in the 1FGL unassociated sources. The results of these source 'classifications' appear to match the expected source distributions, especially at high Galactic latitudes. While useful for planning future multiwavelength follow-up observations, these analyses use limited inputs, and their predictions should not be considered equivalent to 'probable source classes' for these sources. We discuss multiwavelength results and catalog cross-correlations to date, and provide new source associations for 229 Fermi-LAT sources that had no association listed in the 1FGL catalog. By validating the source classifications against these new associations, we find that the new association matches the predicted source class in {approx}80% of the sources.

A STATISTICAL APPROACH TO RECOGNIZING SOURCE CLASSES FOR UNASSOCIATED SOURCES IN THE FIRST FERMI-LAT CATALOG

International Nuclear Information System (INIS)

Ackermann, M.; Ajello, M.; Allafort, A.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Buehler, R.; Antolini, E.; Bonamente, E.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bouvier, A.; Brandt, T. J.; Brigida, M.; Bruel, P.

2012-01-01

The Fermi Large Area Telescope (LAT) First Source Catalog (1FGL) provided spatial, spectral, and temporal properties for a large number of γ-ray sources using a uniform analysis method. After correlating with the most-complete catalogs of source types known to emit γ rays, 630 of these sources are 'unassociated' (i.e., have no obvious counterparts at other wavelengths). Here, we employ two statistical analyses of the primary γ-ray characteristics for these unassociated sources in an effort to correlate their γ-ray properties with the active galactic nucleus (AGN) and pulsar populations in 1FGL. Based on the correlation results, we classify 221 AGN-like and 134 pulsar-like sources in the 1FGL unassociated sources. The results of these source 'classifications' appear to match the expected source distributions, especially at high Galactic latitudes. While useful for planning future multiwavelength follow-up observations, these analyses use limited inputs, and their predictions should not be considered equivalent to 'probable source classes' for these sources. We discuss multiwavelength results and catalog cross-correlations to date, and provide new source associations for 229 Fermi-LAT sources that had no association listed in the 1FGL catalog. By validating the source classifications against these new associations, we find that the new association matches the predicted source class in ∼80% of the sources.

The Sponge-associated Bacterium Bacillus licheniformis SAB1: A Source of Antimicrobial Compounds

Directory of Open Access Journals (Sweden)

Prabha Devi

2010-04-01

Full Text Available Several bacterial cultures were isolated from sponge Halichondria sp., collected from the Gujarat coast of the Indo Pacific region. These bacterial cultures were fermented in the laboratory (100 mL and the culture filtrate was assayed for antibiotic activity against 16 strains of clinical pathogens. Bacillus sp. (SAB1, the most potent of them and antagonistic to several clinically pathogenic Gram-positive, Gram-negative bacteria and the fungus Aspergillus fumigatus was chosen for further investigation. Analysis of the nucleotide sequence of the 16S rDNA gene of Bacillus sp. SAB1 showed a strong similarity (100% with the 16S rDNA gene of Bacillus licheniformis HNL09. The bioactive compounds produced by Bacillus licheniformis SAB1 (GenBank accession number: DQ071568 were identified as indole (1, 3-phenylpropionic acid (2 and a dimer 4,4′-oxybis[3-phenylpropionic acid] (3 on the basis of their Fourier Transform Infrared (FTIR, Nuclear Magnetic Resonance (NMR and Electrospray Ionization Mass Spectrometer (ESI-MS data. There is a single reference on the natural occurrence of compound 3 from the leaves of a terrestrial herb Aptenia cordifolia in the literature, so to the best of our knowledge, this is a first report of its natural occurrence from a marine source. The recovery of bacterial strains with antimicrobial activity suggests that marine-invertebrates remain a rich source for the isolation of culturable isolates capable of producing novel bioactive secondary metabolites.

THE CHANDRA SOURCE CATALOG

International Nuclear Information System (INIS)

Evans, Ian N.; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G.; Grier, John D.; Hain, Roger M.; Harbo, Peter N.; He Xiangqun; Karovska, Margarita; Kashyap, Vinay L.; Davis, John E.; Houck, John C.; Hall, Diane M.

2010-01-01

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public Advanced CCD Imaging Spectrometer imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents ∼<30''. The catalog (1) provides access to the best estimates of the X-ray source properties for detected sources, with good scientific fidelity, and directly supports scientific analysis using the individual source data; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources, so that users can perform detailed further analysis using existing tools. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1σ uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of ∼<1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics, derived from the observations in which the source is detected. In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra from each observation in which a

The Chandra Source Catalog

Science.gov (United States)

Evans, Ian N.; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Grier, John D.; Hain, Roger M.; Hall, Diane M.; Harbo, Peter N.; He, Xiangqun Helen; Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael S.; Van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2010-07-01

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public Advanced CCD Imaging Spectrometer imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents lsim30''. The catalog (1) provides access to the best estimates of the X-ray source properties for detected sources, with good scientific fidelity, and directly supports scientific analysis using the individual source data; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources, so that users can perform detailed further analysis using existing tools. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1σ uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of lsim1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics, derived from the observations in which the source is detected. In addition to these traditional catalog elements, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra from each observation in which a

Non-proximate mass spectrometry using a heated 1-m long PTFE tube and an air-tight APCI ion source

International Nuclear Information System (INIS)

Usmanov, Dilshadbek T.; Hiraoka, Kenzo; Wada, Hiroshi; Matsumura, Masaya; Sanada-Morimura, Sachiyo; Nonami, Hiroshi; Yamabe, Shinichi

2017-01-01

Direct and rapid trace-level gas analysis is highly needed in various fields such as safety and security, quality control, food analysis, and forensic medicine. In many cases, the real samples are bulky and are not accessible to the space-limited ion source of the mass spectrometer. In order to circumvent this problem, we developed an airtight atmospheric-pressure chemical ionization (APCI) ion source equipped with a flexible 1-m-long, 2-mm-i.d. PTFE sniffing tube. The ambient air bearing sample gas was sucked into the heated PTFE tube (130 °C) and was transported to the air-tight ion source without using any extra pumping system or a Venturi device. Analytes were ionized by an ac corona discharge located at 1.5 mm from the inlet of the mass spectrometer. By using the airtight ion source, all the ionized gas in the ion source was introduced into the vacuum of the mass spectrometer via only the evacuation of the mass spectrometer (1.6 l min"−"1). Sub-pg limits of detection were obtained for carbaryl and trinitrotoluene. Owing to its flexibility and high sensitivity, the sniffing tube coupled with a mass spectrometer can be used as the stethoscope for the high-sensitive gas analysis. The experimental results obtained for drugs, hydrogen peroxide and small alkanes were discussed by DFT calculations. - Highlights: • Non-proximate mass spectrometry for the trace-level gas analysis was developed. • Using a 1-m long flexible PTFE tube, it can be applicable to complicated-shape real-world samples. • By atmospheric pressure chemical ionization in the airtight ion source, sub-pg limits of detection were attained. • Adsorption of less-volatility compounds was negligible with the tube temperature at 130° C. • Novel experimental results obtained were fully examined by density functional theory calculations.

Non-proximate mass spectrometry using a heated 1-m long PTFE tube and an air-tight APCI ion source

Energy Technology Data Exchange (ETDEWEB)

Usmanov, Dilshadbek T. [Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511 (Japan); Institute of Ion-Plasma and Laser Technologies, Durmon Yoli Street 33, 100125, Tashkent (Uzbekistan); Hiraoka, Kenzo, E-mail: hiraoka@yamanashi.ac.jp [Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511 (Japan); Wada, Hiroshi [Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 496 Izumi, Chikugo, Fukuoka 833-0041 (Japan); Matsumura, Masaya; Sanada-Morimura, Sachiyo [Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, Suya 2421, shiKo, Kumamoto 861-1192 (Japan); Nonami, Hiroshi [Plant Biophysics/Biochemistry Research Laboratory, Faculty of Agriculture, Ehime University, 3-5-7 T Tarumi, 790-0905, Matsuyama (Japan); Yamabe, Shinichi, E-mail: yamabesh@gmail.com [Department of Material Science, Nara Institute of Science and Technology, Takayama-cho, 8916-5, Ikoma, Nara, 630−0101 (Japan)

2017-06-22

Direct and rapid trace-level gas analysis is highly needed in various fields such as safety and security, quality control, food analysis, and forensic medicine. In many cases, the real samples are bulky and are not accessible to the space-limited ion source of the mass spectrometer. In order to circumvent this problem, we developed an airtight atmospheric-pressure chemical ionization (APCI) ion source equipped with a flexible 1-m-long, 2-mm-i.d. PTFE sniffing tube. The ambient air bearing sample gas was sucked into the heated PTFE tube (130 °C) and was transported to the air-tight ion source without using any extra pumping system or a Venturi device. Analytes were ionized by an ac corona discharge located at 1.5 mm from the inlet of the mass spectrometer. By using the airtight ion source, all the ionized gas in the ion source was introduced into the vacuum of the mass spectrometer via only the evacuation of the mass spectrometer (1.6 l min{sup −1}). Sub-pg limits of detection were obtained for carbaryl and trinitrotoluene. Owing to its flexibility and high sensitivity, the sniffing tube coupled with a mass spectrometer can be used as the stethoscope for the high-sensitive gas analysis. The experimental results obtained for drugs, hydrogen peroxide and small alkanes were discussed by DFT calculations. - Highlights: • Non-proximate mass spectrometry for the trace-level gas analysis was developed. • Using a 1-m long flexible PTFE tube, it can be applicable to complicated-shape real-world samples. • By atmospheric pressure chemical ionization in the airtight ion source, sub-pg limits of detection were attained. • Adsorption of less-volatility compounds was negligible with the tube temperature at 130° C. • Novel experimental results obtained were fully examined by density functional theory calculations.

Specification of brachytherapy sources

Energy Technology Data Exchange (ETDEWEB)

1984-10-01

BCRU recommends that the following specification of gamma-ray brachytherapy sources be adopted. Unless otherwise stated, the output of a cylindrical source should be specified in air kerma rate at a point in free space at a distance of 1 m from the source on the radial plane of symmetry, i.e. the plane bisecting the active length and perpendicular to the cylindrical axis of the source. For a wire source the output should be specified for a 1 cm length. For any other construction of source, the point at which the output is specified should be stated. It is also recommended that the units in which the air kerma rate is expressed should be micrograys per hour (..mu..Gy/h).

9 CFR 71.20 - Approval of livestock facilities.

Science.gov (United States)

2010-01-01

... OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL... as 9 CFR 54.7(e)(2) if the disease of concern is scrapie and the quarantined animal gave birth or...

TOWARD IDENTIFYING THE UNASSOCIATED GAMMA-RAY SOURCE 1FGL J1311.7-3429 WITH X-RAY AND OPTICAL OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Kataoka, J.; Takahashi, Y.; Maeda, K. [Research Institute for Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555 (Japan); Yatsu, Y.; Kawai, N. [Tokyo Institute of Technology, 2-12-1, Ohokayama, Meguro, Tokyo 152-8551 (Japan); Urata, Y.; Tsai, A. [Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China); Cheung, C. C. [National Research Council Research Associate, National Academy of Sciences, Washington, DC 20001 (United States); Totani, T.; Makiya, R. [Department of Astronomy, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Hanayama, H.; Miyaji, T., E-mail: kataoka.jun@waseda.jp [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa, 907-0024 (Japan)

2012-10-01

We present deep optical and X-ray follow-up observations of the bright unassociated Fermi-LAT gamma-ray source 1FGL J1311.7-3429. The source was already known as an unidentified EGRET source (3EG J1314-3431, EGR J1314-3417), hence its nature has remained uncertain for the past two decades. For the putative counterpart, we detected a quasi-sinusoidal optical modulation of {Delta}m {approx} 2 mag with a period of {approx_equal}1.5 hr in the Rc, r', and g' bands. Moreover, we found that the amplitude of the modulation and peak intensity changed by {approx}>1 mag and {approx}0.5 mag, respectively, over our total six nights of observations from 2012 March to May. Combined with Swift UVOT data, the optical-UV spectrum is consistent with a blackbody temperature, kT {approx_equal} 1 eV and the emission volume radius R{sub bb} {approx_equal} 1.5 Multiplication-Sign 10{sup 4} d{sub kpc} km (d{sub kpc} is the distance to the source in units of 1 kpc). In contrast, deep Suzaku observations conducted in 2009 and 2011 revealed strong X-ray flares with a light curve characterized with a power spectrum density of P(f) {proportional_to} f {sup -2.0{+-}0.4}, but the folded X-ray light curves suggest an orbital modulation also in X-rays. Together with the non-detection of a radio counterpart, and significant curved spectrum and non-detection of variability in gamma-rays, the source may be the second 'radio-quiet' gamma-ray emitting millisecond pulsar candidate after 1FGL J2339.7-0531, although the origin of flaring X-ray and optical variability remains an open question.

Langmuir probe study of a magnetically enhanced RF plasma source at pressures below 0.1 Pa

Science.gov (United States)

Kousal, Jaroslav; Tichý, Milan; Šebek, Ondřej; Čechvala, Juraj; Biederman, Hynek

2011-08-01

The majority of plasma polymerization sources operate at pressures higher than 1 Pa. At these pressures most common deposition methods do not show significant directionality. One way of enhancing the directional effects is to decrease the working pressure to increase the mean free path of the reactive molecules. The plasma source used in this work was designed to study the plasma polymerization process at pressures below 0.1 Pa. The source consists of the classical radio frequency (RF) (13.56 MHz, capacitive coupled) tubular reactor enhanced by an external magnetic circuit. The working gas is introduced into the discharge by a capillary. This forms a relatively localized zone of higher pressure where the monomer is activated. Due to the magnetic field, the plasma is constricted near the axis of the reactor with nearly collisionless gas flow. The plasma parameters were obtained using a double Langmuir probe. Plasma density in the range ni = 1013-1016 m-3 was obtained in various parts of the discharge under typical conditions. The presence of the magnetic field led to the presence of relatively strong electric fields (103 V m-1) and relatively high electron energies up to several tens of eV in the plasma.

Langmuir probe study of a magnetically enhanced RF plasma source at pressures below 0.1 Pa

Energy Technology Data Exchange (ETDEWEB)

Kousal, Jaroslav; Tichy, Milan; Sebek, Ondrej; Cechvala, Juraj; Biederman, Hynek, E-mail: jaroslav.kousal@mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 180 00, Prague 8 (Czech Republic)

2011-08-15

The majority of plasma polymerization sources operate at pressures higher than 1 Pa. At these pressures most common deposition methods do not show significant directionality. One way of enhancing the directional effects is to decrease the working pressure to increase the mean free path of the reactive molecules. The plasma source used in this work was designed to study the plasma polymerization process at pressures below 0.1 Pa. The source consists of the classical radio frequency (RF) (13.56 MHz, capacitive coupled) tubular reactor enhanced by an external magnetic circuit. The working gas is introduced into the discharge by a capillary. This forms a relatively localized zone of higher pressure where the monomer is activated. Due to the magnetic field, the plasma is constricted near the axis of the reactor with nearly collisionless gas flow. The plasma parameters were obtained using a double Langmuir probe. Plasma density in the range n{sub i} = 10{sup 13}-10{sup 16} m{sup -3} was obtained in various parts of the discharge under typical conditions. The presence of the magnetic field led to the presence of relatively strong electric fields (10{sup 3} V m{sup -1}) and relatively high electron energies up to several tens of eV in the plasma.

Assessment of light extinction at a European polluted urban area during wintertime: Impact of PM1 composition and sources.

Science.gov (United States)

Vecchi, R; Bernardoni, V; Valentini, S; Piazzalunga, A; Fermo, P; Valli, G

2018-02-01

In this paper, results from receptor modelling performed on a well-characterised PM 1 dataset were combined to chemical light extinction data (b ext ) with the aim of assessing the impact of different PM 1 components and sources on light extinction and visibility at a European polluted urban area. It is noteworthy that, at the state of the art, there are still very few papers estimating the impact of different emission sources on light extinction as we present here, although being among the major environmental challenges at many polluted areas. Following the concept of the well-known IMPROVE algorithm, here a tailored site-specific approach (recently developed by our group) was applied to assess chemical light extinction due to PM 1 components and major sources. PM 1 samples collected separately during daytime and nighttime at the urban area of Milan (Italy) were chemically characterised for elements, major ions, elemental and organic carbon, and levoglucosan. Chemical light extinction was estimated and results showed that at the investigated urban site it is heavily impacted by ammonium nitrate and organic matter. Receptor modelling (i.e. Positive Matrix Factorization, EPA-PMF 5.0) was effective to obtain source apportionment; the most reliable solution was found with 7 factors which were tentatively assigned to nitrates, sulphates, wood burning, traffic, industry, fine dust, and a Pb-rich source. The apportionment of aerosol light extinction (b ext,aer ) according to resolved sources showed that considering all samples together nitrate contributed at most (on average 41.6%), followed by sulphate, traffic, and wood burning accounting for 18.3%, 17.8% and 12.4%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

X-ray sources associated with young stellar objects in the star formation region CMa R1

Science.gov (United States)

Santos-Silva, Thais; Gregorio-Hetem, Jane; Montmerle, Thierry

2013-07-01

In previous works we studied the star formation scenario in the molecular cloud Canis Major R1 (CMa R1), derived from the existence of young stellar population groups near the Be stars Z CMa and GU CMa. Using data from the ROSAT X-ray satellite, having a field-of-view of ~ 1° in diameter, Gregorio-Hetem et al. (2009) discovered in this region young stellar objects mainly grouped in two clusters of different ages, with others located in between. In order to investigate the nature of these objects and to test a possible scenario of sequential star formation in this region, four fields (each 30 arcmin diameter, with some overlap) have been observed with the XMM-Newton satellite, with a sensitivity about 10 times better than ROSAT. The XMM-Newton data are currently under analysis. Preliminary results indicate the presence of about 324 sources, most of them apparently having one or more near-infrared counterparts showing typical colors of young stars. The youth of the X-ray sources was also confirmed by X-ray hardness ratio diagrams (XHRD), in different energy bands, giving an estimate of their Lx/Lbol ratios. In addition to these results, we present a detailed study of the XMM field covering the cluster near Z CMa. Several of these sources were classified as T Tauri and Herbig Ae/Be stars, using optical spectroscopy obtained with Gemini telescopes, in order to validate the use of XHRD applied to the entire sample. This classification is also used to confirm the relation between the luminosities in the near-infrared and X-ray bands expected for the T Tauri stars in CMa R1. In the present work we show the results of the study based on the spectra of about 90 sources found nearby Z CMa. We checked that the X-ray spectra (0.3 to 10 keV) of young objects is different from that observed in field stars and extragalactic objects. Some of the candidates also have light curve showing flares that are typical of T Tauri stars, which confirms the young nature of these X

Model description for calculating the source term of the Angra 1 environmental control system

International Nuclear Information System (INIS)

Oliveira, L.F.S. de; Amaral Neto, J.D.; Salles, M.R.

1988-01-01

This work presents the model used for evaluation of source term released from Angra 1 Nuclear Power Plant in case of an accident. After that, an application of the model for the case of a Fuel Assembly Drop Accident Inside the Fuel Handling Building during reactor refueling is presented. (author) [pt

Model-Based Least Squares Reconstruction of Coded Source Neutron Radiographs: Integrating the ORNL HFIR CG1D Source Model

Energy Technology Data Exchange (ETDEWEB)

Santos-Villalobos, Hector J [ORNL; Gregor, Jens [University of Tennessee, Knoxville (UTK); Bingham, Philip R [ORNL

2014-01-01

At the present, neutron sources cannot be fabricated small and powerful enough in order to achieve high resolution radiography while maintaining an adequate flux. One solution is to employ computational imaging techniques such as a Magnified Coded Source Imaging (CSI) system. A coded-mask is placed between the neutron source and the object. The system resolution is increased by reducing the size of the mask holes and the flux is increased by increasing the size of the coded-mask and/or the number of holes. One limitation of such system is that the resolution of current state-of-the-art scintillator-based detectors caps around 50um. To overcome this challenge, the coded-mask and object are magnified by making the distance from the coded-mask to the object much smaller than the distance from object to detector. In previous work, we have shown via synthetic experiments that our least squares method outperforms other methods in image quality and reconstruction precision because of the modeling of the CSI system components. However, the validation experiments were limited to simplistic neutron sources. In this work, we aim to model the flux distribution of a real neutron source and incorporate such a model in our least squares computational system. We provide a full description of the methodology used to characterize the neutron source and validate the method with synthetic experiments.

Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods

Science.gov (United States)

Ali, A. Md; Solomatine, D. P.; Di Baldassarre, G.

2015-01-01

Topographic data, such as digital elevation models (DEMs), are essential input in flood inundation modelling. DEMs can be derived from several sources either through remote sensing techniques (spaceborne or airborne imagery) or from traditional methods (ground survey). The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the Shuttle Radar Topography Mission (SRTM), the light detection and ranging (lidar), and topographic contour maps are some of the most commonly used sources of data for DEMs. These DEMs are characterized by different precision and accuracy. On the one hand, the spatial resolution of low-cost DEMs from satellite imagery, such as ASTER and SRTM, is rather coarse (around 30 to 90 m). On the other hand, the lidar technique is able to produce high-resolution DEMs (at around 1 m), but at a much higher cost. Lastly, contour mapping based on ground survey is time consuming, particularly for higher scales, and may not be possible for some remote areas. The use of these different sources of DEM obviously affects the results of flood inundation models. This paper shows and compares a number of 1-D hydraulic models developed using HEC-RAS as model code and the aforementioned sources of DEM as geometric input. To test model selection, the outcomes of the 1-D models were also compared, in terms of flood water levels, to the results of 2-D models (LISFLOOD-FP). The study was carried out on a reach of the Johor River, in Malaysia. The effect of the different sources of DEMs (and different resolutions) was investigated by considering the performance of the hydraulic models in simulating flood water levels as well as inundation maps. The outcomes of our study show that the use of different DEMs has serious implications to the results of hydraulic models. The outcomes also indicate that the loss of model accuracy due to re-sampling the highest resolution DEM (i.e. lidar 1 m) to lower resolution is much less than the loss of model accuracy due

Platelet and Erythrocyte Sources of S1P Are Redundant for Vascular Development and Homeostasis, but Both Rendered Essential After Plasma S1P Depletion in Anaphylactic Shock.

Science.gov (United States)

Gazit, Salomé L; Mariko, Boubacar; Thérond, Patrice; Decouture, Benoit; Xiong, Yuquan; Couty, Ludovic; Bonnin, Philippe; Baudrie, Véronique; Le Gall, Sylvain M; Dizier, Blandine; Zoghdani, Nesrine; Ransinan, Jessica; Hamilton, Justin R; Gaussem, Pascale; Tharaux, Pierre-Louis; Chun, Jerold; Coughlin, Shaun R; Bachelot-Loza, Christilla; Hla, Timothy; Ho-Tin-Noé, Benoit; Camerer, Eric

2016-09-30

Sphingosine-1-phosphate (S1P) signaling is essential for vascular development and postnatal vascular homeostasis. The relative importance of S1P sources sustaining these processes remains unclear. To address the level of redundancy in bioactive S1P provision to the developing and mature vasculature. S1P production was selectively impaired in mouse platelets, erythrocytes, endothelium, or smooth muscle cells by targeted deletion of genes encoding sphingosine kinases -1 and -2. S1P deficiency impaired aggregation and spreading of washed platelets and profoundly reduced their capacity to promote endothelial barrier function ex vivo. However, and in contrast to recent reports, neither platelets nor any other source of S1P was essential for vascular development, vascular integrity, or hemostasis/thrombosis. Yet rapid and profound depletion of plasma S1P during systemic anaphylaxis rendered both platelet- and erythrocyte-derived S1P essential for survival, with a contribution from blood endothelium observed only in the absence of circulating sources. Recovery was sensitive to aspirin in mice with but not without platelet S1P, suggesting that platelet activation and stimulus-response coupling is needed. S1P deficiency aggravated vasoplegia in this model, arguing a vital role for S1P in maintaining vascular resistance during recovery from circulatory shock. Accordingly, the S1P2 receptor mediated most of the survival benefit of S1P, whereas the endothelial S1P1 receptor was dispensable for survival despite its importance for maintaining vascular integrity. Although source redundancy normally secures essential S1P signaling in developing and mature blood vessels, profound depletion of plasma S1P renders both erythrocyte and platelet S1P pools necessary for recovery and high basal plasma S1P levels protective during anaphylactic shock. © 2016 American Heart Association, Inc.

An accelerator neutron source for BNCT. Technical progress report, 1 June 1993--31 May 1994

International Nuclear Information System (INIS)

Blue, T.E.; Vafai, K.

1994-02-01

This is the progress report for the project entitled, ''An Accelerator Neutron Source for BNCT.'' The progress report is for the period from July 1, 1993 to date. The overall objective of our research project is to develop an Accelerator Epithermal Neutron Irradiation Facility (AENIF) for Boron Neutron Capture Therapy (BNCT). The AENIF consists of a 2.5 MeV high current proton accelerator, a lithium target to produce source neutrons, and a moderator/reflector assembly to obtain from the energetic source neutrons an epithermal neutron field suitable for BNCT treatments. Our project goals are to develop the non-accelerator components of the AENIF, and to specifically include in our development: (1) design, numerical simulation, and experimental verification of a target assembly which is capable of removing 75 kW of beam power; (2) re-optimization of the moderator assembly design based on in-phantom dose assessments using neutron spectra calculated in phantom and an energy-dependent neutron Relative Biological Effectiveness (RBE); (3) construction of a prototype moderator assembly and confirmation of its design by measurements; (4) design of the shielding of the accelerator and treatment rooms for an AENIF; and (5) design of a high energy beam transport system which is compatible with the shielding design and the thermal-hydraulic design

Fluorescent Immunoassay Development for PrPSc Detection and Antemortem Diagnosis of TSEs

National Research Council Canada - National Science Library

Carp, Richard I

2005-01-01

.... During the second year of this contract, we have focused on the development of an immunological method to isolate blood PrP from normal and scrapie-infected animals and the assembly of an optical...

Calculation of the isotope concentrations, source terms and radiation shielding of the SAFARI-1 irradiation products

International Nuclear Information System (INIS)

Stoker, C.C.; Ball, G.

2000-01-01

The ever increasing expansion of the irradiation product portfolio of the SAFARI-1 reactor leads to the need to routinely calculate the radio-isotope concentrations and source terms for the materials irradiated in the reactor accurately. In addition to this, the required shielding for the transportation and processing of these irradiation products needs to be determined. In this paper the calculational methodology applied is described with special attention given to the spectrum dependence of the one-group cross sections of selected SAFARI-1 irradiation materials and the consequent effect on the determination of the isotope concentrations and source terms. Comparisons of the calculated isotopic concentrations and dose rates with experimental analysis and measurements provide confidence in the calculational methodologies and data used. (author)

Radioactive source recovery program responses to neutron source emergencies

International Nuclear Information System (INIS)

Dinehart, S.M.; Hatler, V.A.; Gray, D.W.; Guillen, A.D.

1997-01-01

Recovery of neutron sources containing Pu 239 and Be is currently taking place at Los Alamos National Laboratory. The program was initiated in 1979 by the Department of Energy (DOE) to dismantle and recover sources owned primarily by universities and the Department of Defense. Since the inception of this program, Los Alamos has dismantled and recovered more than 1000 sources. The dismantlement and recovery process involves the removal of source cladding and the chemical separation of the source materials to eliminate neutron emissions. While this program continues for the disposal of 239 Pu/Be sources, there is currently no avenue for the disposition of any sources other than those containing Pu 239 . Increasingly, there have been demands from agencies both inside and outside the Federal Government and from the public to dispose of unwanted sources containing 238 Pu/Be and 241 Am/Be. DOE is attempting to establish a formal program to recover these sources and is working closely with the Nuclear Regulatory Commission (NRC) on a proposed Memorandum of Understanding to formalize an Acceptance Program. In the absence of a formal program to handle 238 Pu/Be and 241 Am/Be neutron sources, Los Alamos has responded to several emergency requests to receive and recover sources that have been determined to be a threat to public health and safety. This presentation will: (1) review the established 239 Pu neutron source recovery program at Los Alamos, (2) detail plans for a more extensive neutron source disposal program, and (3) focus on recent emergency responses

Calibration and check light source

Energy Technology Data Exchange (ETDEWEB)

Nejedla, B; Krotil, J

1979-02-15

The light source is designed for calibrating photomultipliers and checking the function of the thermoluminescent dosemeters evaluation equipment. The check light source consists of a polymer material-based (polyvinyl toluene) plastic scintillator and a 2-phenyl-5-(4-bisphenyl)-1,3,4-oxadiazol and/or paraterphenyl activator, and of emission spectrum shifters for response in the green and the blue light regions. The plastic scintillator is sealed in a case to whose bottom a radiation source is fixed, such as a /sup 90/Sr-/sup 90/Y source of an activity of 1.85x10/sup 3/s/sup -1/ to 0.74x10/sup 9/s/sup -1/.

Advanced Light Source, a 1-2 GeV synchrotron radiation facility

International Nuclear Information System (INIS)

Berkner, K.H.

1985-01-01

The Advanced Light Source (ALS), a dedicated synchrotron radiation facility optimized to generate soft x-ray and vacuum ultraviolet (XUV) light using magnetic insertion devices, was proposed by the Lawrence Berkeley Laboratory in 1982. It consists of a 1.3-GeV injection system, an electron storage ring optimized at 1.3 GeV (with the capability of 1.9-GeV operation), and a number of photon beamlines emanating from twelve 6-meter-long straight sections. In addition, 24 bending-magnet ports will be available for development. The ALS was conceived as a research tool whose range and power would stimulate fundamentally new research in fields from biology to materials science. The conceptual design and associated cost estimate for the ALS have been completed and reviewed by the US Department of Energy (DOE), but Title I activities have not yet begun. The focus in this study is on the history of the ALS as an example of how a technical construction project was conceived, designed, proposed, and validated within the framework of a national laboratory funded largely by the DOE

Cobalt source calibration

International Nuclear Information System (INIS)

Rizvi, H.M.

1999-01-01

The data obtained from these tests determine the dose rate of the two cobalt sources in SRTC. Building 774-A houses one of these sources while the other resides in room C-067 of Building 773-A. The data from this experiment shows the following: (1) The dose rate of the No.2 cobalt source in Building 774-A measured 1.073 x 10 5 rad/h (June 17, 1999). The dose rate of the Shepherd Model 109 Gamma cobalt source in Building 773-A measured 9.27 x 10 5 rad/h (June 25, 1999). These rates come from placing the graduated cylinder containing the dosimeter solution in the center of the irradiation chamber. (2) Two calibration tests in the 774-A source placed the graduated cylinder with the dosimeter solution approximately 1.5 inches off center in the axial direction. This movement of the sample reduced the measured dose rate 0.92% from 1.083 x 10 5 rad/h to 1.073 x 10 5 rad/h. and (3) A similar test in the cobalt source in 773-A placed the graduated cylinder approximately 2.0 inches off center in the axial direction. This change in position reduced the measured dose rate by 10.34% from 1.036 x 10 6 to 9.27 x 10 5 . This testing used chemical dosimetry to measure the dose rate of a radioactive source. In this method, one determines the dose by the chemical change that takes place in the dosimeter. For this calibration experiment, the author used a Fricke (ferrous ammonium sulfate) dosimeter. This solution works well for dose rates to 10 7 rad/h. During irradiation of the Fricke dosimeter solution the Fe 2+ ions ionize to Fe 3+ . When this occurs, the solution acquires a slightly darker tint (not visible to the human eye). To determine the magnitude of the change in Fe ions, one places the solution in an UV-VIS Spectrophotometer. The UV-VIS Spectrophotometer measures the absorbency of the solution. Dividing the absorbency by the total time (in minutes) of exposure yields the dose rate

H- radio frequency source development at the Spallation Neutron Source.

Science.gov (United States)

Welton, R F; Dudnikov, V G; Gawne, K R; Han, B X; Murray, S N; Pennisi, T R; Roseberry, R T; Santana, M; Stockli, M P; Turvey, M W

2012-02-01

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent ∼38 mA peak current in the linac and an availability of ∼90%. H(-) beam pulses (∼1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, ∼60 kW) of a copper antenna that has been encased with a thickness of ∼0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of ∼99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of ∼75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance∕installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to ∼100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

A 1D ion species model for an RF driven negative ion source

Science.gov (United States)

Turner, I.; Holmes, A. J. T.

2017-08-01

A one-dimensional model for an RF driven negative ion source has been developed based on an inductive discharge. The RF source differs from traditional filament and arc ion sources because there are no primary electrons present, and is simply composed of an antenna region (driver) and a main plasma discharge region. However the model does still make use of the classical plasma transport equations for particle energy and flow, which have previously worked well for modelling DC driven sources. The model has been developed primarily to model the Small Negative Ion Facility (SNIF) ion source at CCFE, but may be easily adapted to model other RF sources. Currently the model considers the hydrogen ion species, and provides a detailed description of the plasma parameters along the source axis, i.e. plasma temperature, density and potential, as well as current densities and species fluxes. The inputs to the model are currently the RF power, the magnetic filter field and the source gas pressure. Results from the model are presented and where possible compared to existing experimental data from SNIF, with varying RF power, source pressure.

A 2-gigawatt, 1-microsecond, microwave source

Energy Technology Data Exchange (ETDEWEB)

Caryotakis, G; Jongewaard, E; Phillips, R; Scheitrum, G; Tantawi, S [Stanford Univ., CA (United States). Stanford Linear Accelerator Center; Luhmann, Jr, N C [Univ. of California, Davis, CA (United States)

1997-12-31

For the last decade or more, researchers in a number of US government laboratories have been attempting to develop L-band microwave sources capable of generating one or more gigawatts, with one-microsecond pulses. In order to produce the required high beam currents, the common approach has been to employ field emission cathodes. For this and other reasons the devices which have been built (MILOs, RKAs, relativistic magnetrons) have operated with a poor vacuum, a condition not consistent with the necessity to hold off the very high rf and dc gradients encountered at these power levels. As a result, the microsecond goal has never been attained. Although in some cases several gigawatts have been generated, pulse duration is limited to about 100 ns. This condition is referred to as ``pulse shortening``. The proposed source is based on periodic magnetic (PPM) focusing and is an outgrowth of work performed at SLAC on very high peak power X-band klystrons for a future electron-positron linear collider. These tubes must be focused with permanent magnets, for economic reasons. The new device (GMBK, for Gigawatt Multiple Beam Klystron) is entirely within the state-of-the-art and need only depend on good vacuum tube practice to perform to its specification. It employs thermionic cathodes, loaded to about 40 A/cm{sup 2}, a current density which is within the state-of-the-art for microsecond pulses. (author). 8 figs.

The 1.4-2.7 micron spectrum of the point source at the galactic center

Science.gov (United States)

Treffers, R. R.; Fink, U.; Larson, H. P.; Gautier, T. N., III

1976-01-01

The spectrum of the 2-micron point source at the galactic center is presented over the range from 1.4 to 2.7 microns. The two-level-transition CO band heads are seen near 2.3 microns, confirming that the radiation from this source is due to a cool supergiant star. The heliocentric radial velocity is found to be - 173 (+ or -90) km/s and is consistent with the star being in orbit about a dense galactic nucleus. No evidence is found for Brackett-gamma emission, and no interstellar absorption features are seen. Upper limits for the column densities of interstellar H2, CH4, CO, and NH3 are derived.

Operation of Slovenske elektrarne sources in the 1st half of 2009

International Nuclear Information System (INIS)

Hroch, A.

2009-01-01

Comparing the net production of electricity in SE in the first months of 2009 with 2008 we can see a decrease due to the shutdown of Unit 2 of V1 and only a short increase in week No. 14 and 17 caused by spring rains. The first three months were also influenced by a temporary fees of an electricity producer for system services in electricity export (so called export fees) that disadvantage the sources in Slovakia even at times when the market prices significantly decreased on a year- on- year basis. (author)

Implications on 1 + 1 D Tsunami Runup Modeling due to Time Features of the Earthquake Source

Science.gov (United States)

Fuentes, M.; Riquelme, S.; Ruiz, J.; Campos, J.

2018-04-01

The time characteristics of the seismic source are usually neglected in tsunami modeling, due to the difference in the time scale of both processes. Nonetheless, there are just a few analytical studies that intended to explain separately the role of the rise time and the rupture velocity. In this work, we extend an analytical 1 + 1 D solution for the shoreline motion time series, from the static case to the kinematic case, by including both rise time and rupture velocity. Our results show that the static case corresponds to a limit case of null rise time and infinite rupture velocity. Both parameters contribute in shifting the arrival time, but maximum runup may be affected by very slow ruptures and long rise time. Parametric analysis reveals that runup is strictly decreasing with the rise time while is highly amplified in a certain range of slow rupture velocities. For even lower rupture velocities, the tsunami excitation vanishes and for larger, quicker approaches to the instantaneous case.

Implications on 1 + 1 D Tsunami Runup Modeling due to Time Features of the Earthquake Source

Science.gov (United States)

Fuentes, M.; Riquelme, S.; Ruiz, J.; Campos, J.

2018-02-01

The time characteristics of the seismic source are usually neglected in tsunami modeling, due to the difference in the time scale of both processes. Nonetheless, there are just a few analytical studies that intended to explain separately the role of the rise time and the rupture velocity. In this work, we extend an analytical 1 + 1 D solution for the shoreline motion time series, from the static case to the kinematic case, by including both rise time and rupture velocity. Our results show that the static case corresponds to a limit case of null rise time and infinite rupture velocity. Both parameters contribute in shifting the arrival time, but maximum runup may be affected by very slow ruptures and long rise time. Parametric analysis reveals that runup is strictly decreasing with the rise time while is highly amplified in a certain range of slow rupture velocities. For even lower rupture velocities, the tsunami excitation vanishes and for larger, quicker approaches to the instantaneous case.

Characteristics of miniature electronic brachytherapy x-ray sources based on TG-43U1 formalism using Monte Carlo simulation techniques

International Nuclear Information System (INIS)

Safigholi, Habib; Faghihi, Reza; Jashni, Somaye Karimi; Meigooni, Ali S.

2012-01-01

Purpose: The goal of this study is to determine a method for Monte Carlo (MC) characterization of the miniature electronic brachytherapy x-ray sources (MEBXS) and to set dosimetric parameters according to TG-43U1 formalism. TG-43U1 parameters were used to get optimal designs of MEBXS. Parameters that affect the dose distribution such as anode shapes, target thickness, target angles, and electron beam source characteristics were evaluated. Optimized MEBXS designs were obtained and used to determine radial dose functions and 2D anisotropy functions in the electron energy range of 25-80 keV. Methods: Tungsten anode material was considered in two different geometries, hemispherical and conical-hemisphere. These configurations were analyzed by the 4C MC code with several different optimization techniques. The first optimization compared target thickness layers versus electron energy. These optimized thicknesses were compared with published results by Ihsan et al.[Nucl. Instrum. Methods Phys. Res. B 264, 371-377 (2007)]. The second optimization evaluated electron source characteristics by changing the cathode shapes and electron energies. Electron sources studied included; (1) point sources, (2) uniform cylinders, and (3) nonuniform cylindrical shell geometries. The third optimization was used to assess the apex angle of the conical-hemisphere target. The goal of these optimizations was to produce 2D-dose anisotropy functions closer to unity. An overall optimized MEBXS was developed from this analysis. The results obtained from this model were compared to known characteristics of HDR 125 I, LDR 103 Pd, and Xoft Axxent electronic brachytherapy source (XAEBS) [Med. Phys. 33, 4020-4032 (2006)]. Results: The optimized anode thicknesses as a function of electron energy is fitted by the linear equation Y (μm) = 0.0459X (keV)-0.7342. The optimized electron source geometry is obtained for a disk-shaped parallel beam (uniform cylinder) with 0.9 mm radius. The TG-43 distribution

Characteristics of miniature electronic brachytherapy x-ray sources based on TG-43U1 formalism using Monte Carlo simulation techniques

Energy Technology Data Exchange (ETDEWEB)

Safigholi, Habib; Faghihi, Reza; Jashni, Somaye Karimi; Meigooni, Ali S. [Faculty of Engineering, Science and Research Branch, Islamic Azad University, Fars, 73481-13111, Persepolis (Iran, Islamic Republic of); Department of Nuclear Engineering and Radiation Research Center, Shiraz University, 71936-16548, Shiraz (Iran, Islamic Republic of); Shiraz University of Medical Sciences, 71348-14336, Shiraz (Iran, Islamic Republic of); Department of Radiation therapy, Comprehensive Cancer Center of Nevada, 3730 South Eastern Avenue, Las Vegas, Nevada 89169 (United States)

2012-04-15

Purpose: The goal of this study is to determine a method for Monte Carlo (MC) characterization of the miniature electronic brachytherapy x-ray sources (MEBXS) and to set dosimetric parameters according to TG-43U1 formalism. TG-43U1 parameters were used to get optimal designs of MEBXS. Parameters that affect the dose distribution such as anode shapes, target thickness, target angles, and electron beam source characteristics were evaluated. Optimized MEBXS designs were obtained and used to determine radial dose functions and 2D anisotropy functions in the electron energy range of 25-80 keV. Methods: Tungsten anode material was considered in two different geometries, hemispherical and conical-hemisphere. These configurations were analyzed by the 4C MC code with several different optimization techniques. The first optimization compared target thickness layers versus electron energy. These optimized thicknesses were compared with published results by Ihsan et al.[Nucl. Instrum. Methods Phys. Res. B 264, 371-377 (2007)]. The second optimization evaluated electron source characteristics by changing the cathode shapes and electron energies. Electron sources studied included; (1) point sources, (2) uniform cylinders, and (3) nonuniform cylindrical shell geometries. The third optimization was used to assess the apex angle of the conical-hemisphere target. The goal of these optimizations was to produce 2D-dose anisotropy functions closer to unity. An overall optimized MEBXS was developed from this analysis. The results obtained from this model were compared to known characteristics of HDR {sup 125}I, LDR {sup 103}Pd, and Xoft Axxent electronic brachytherapy source (XAEBS) [Med. Phys. 33, 4020-4032 (2006)]. Results: The optimized anode thicknesses as a function of electron energy is fitted by the linear equation Y ({mu}m) = 0.0459X (keV)-0.7342. The optimized electron source geometry is obtained for a disk-shaped parallel beam (uniform cylinder) with 0.9 mm radius. The TG-43

Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas.

Science.gov (United States)

Whittington, Richard J; Paul-Pont, Ika; Evans, Olivia; Hick, Paul; Dhand, Navneet K

2018-04-10

Marine herpesviruses are responsible for epizootics in economically, ecologically and culturally significant taxa. The recent emergence of microvariants of Ostreid herpesvirus 1 (OsHV-1) in Pacific oysters Crassostrea gigas has resulted in socioeconomic losses in Europe, New Zealand and Australia however, there is no information on their origin or mode of transmission. These factors need to be understood because they influence the way the disease may be prevented and controlled. Mortality data obtained from experimental populations of C. gigas during natural epizootics of OsHV-1 disease in Australia were analysed qualitatively. In addition we compared actual mortality data with those from a Reed-Frost model of direct transmission and analysed incubation periods using Sartwell's method to test for the type of epizootic, point source or propagating. We concluded that outbreaks were initiated from an unknown environmental source which is unlikely to be farmed oysters in the same estuary. While direct oyster-to-oyster transmission may occur in larger oysters if they are in close proximity (< 40 cm), it did not explain the observed epizootics, point source exposure and indirect transmission being more common and important. A conceptual model is proposed for OsHV-1 index case source and transmission, leading to endemicity with recurrent seasonal outbreaks. The findings suggest that prevention and control of OsHV-1 in C. gigas will require multiple interventions. OsHV-1 in C. gigas, which is a sedentary animal once beyond the larval stage, is an informative model when considering marine host-herpesvirus relationships.

Dietary items as possible sources of "1"3"7Cs in large carnivores in the Gorski Kotar forest ecosystem, Western Croatia

International Nuclear Information System (INIS)

Šprem, Nikica; Piria, Marina; Barišić, Domagoj; Kusak, Josip; Barišić, Delko

2016-01-01

The mountain forest ecosystem of Gorski Kotar is distant from any significant sources of environmental pollution, though recent findings have revealed that this region is among the most intense "1"3"7Cs contaminated area in Croatia. Therefore, the aim of this study was to investigate "1"3"7Cs and "4"0K load in three large predator species in the mountain forest ecosystem. Radionuclides mass activities were determined by the gamma-spectrometric method in the muscle tissue of brown bear (47), wolf (7), lynx (1) and golden jackal (2). The highest "1"3"7Cs mass activity was found in lynx (153 Bq kg"−"1), followed by brown bear (132 Bq kg"−"1), wolf (22.2 Bq kg"−"1), and golden jackal (2.48 Bq kg"−"1). Analysis of 63 samples of dietary items suggests that they are not all potentially dominant sources of "1"3"7Cs for wildlife. The most important source of radionuclides for the higher parts of the food-chain from the study area were found to be the mushroom species wood hedgehog (Hydnum repandum), with a transfer factor TF of 5.166, and blueberry (Vaccinium myrtillus) as a plant species (TF = 2.096). Food items of animal origin indicated higher mass activity of radionuclides and therefore are possible moderate bioindicators of environmental pollution. The results also revealed that possible unknown wild animal food sources are a caesium source in the study region, and further study is required to illuminate this issue. - Highlights: • Radionuclide mass activities were determined by the gamma-spectrometric method. • The highest "1"3"7Cs mass activity in brown bear was 132, wolf 22.2 and lynx 153 Bq kg"−"1. • The best bioindicators are a wood hedgehog (TF = 5.166) and blueberry (TF = 2.096).

Search for the sources of the solar wind in the 9.1 cm brightness temperature

International Nuclear Information System (INIS)

George, R.G.

1975-01-01

The sources of solar wind streams have been the object of intensive research for many years, but the various ideas of where and how streams originate on the sun are still incomplete and contradictory. The present study is an attempt to find the solar wind sources by mathematically approximating the 9.1 cm brightness temperature which would be expected at the foot of spacecraft-measured solar wind streams and by then comparing it with actual radio brightness temperature measurements. Several significant results were found from an analysis of the correlation results. Most plasma emanating from the sun was found to come from high solar latitudes and to deviate significantly from the normally expected east-west path in the low corona. Magnetic channelng causes correlation studies to fail when the sun's magnetic configuration is unstable. The travel time of the plasma from the sun's 9.1 cm emission level to the earth is often more than a month

Study of the production yields of "1"8F, "1"1C, "1"3N and "1"5O positron emitters from plasma-laser proton sources at ELI-Beamlines for labeling of PET radiopharmaceuticals

International Nuclear Information System (INIS)

Amato, Ernesto; Italiano, Antonio; Margarone, Daniele; Pagano, Benedetta; Baldari, Sergio; Korn, Georg

2016-01-01

The development of novel compact PET radionuclide production systems is of great interest to promote the diffusion of PET diagnostics, especially in view of the continuous development of microfluidics labeling approaches. We studied the feasibility to produce clinically-relevant amounts of PET isotopes by means of laser-accelerated proton sources such that expected at the ELI-Beamlines facility. "1"8F, "1"1C, "1"3N and "1"5O production yields were calculated through the TALYS software, by taking into account the broad proton spectra expected. With the hypothesized proton fluencies, clinically-relevant amounts of radionuclides can be obtained, suitable to prepare single doses of "1"8F-, "1"1C- and "1"3N-labeled radiopharmaceuticals exploiting fast and efficient microfluidic labeling systems.

Design of 1+ Ion Source Coupling First Design of the Resonant Ionization Laser Ion Source For the Multi-Mega Watt Target Station

CERN Document Server

A. Olivier-Kaiser, F. Le Blanc, C. Lau

The realisation of next-generation ion sources suitable for the EURISOL multi-mega-watt (MMW) target station needs exhaustive studies and developments. An exhaustive review was carried out to evaluate the capability of the ion-sources to operate under the irradiation conditions of the MMW target station. In addition, selectivity must be taken into account to avoid the spread of unwanted radioactivity out of the target-ion-source system (TIS).These studies led to consider RILIS (Resonance Ionization Laser Ion Source) as the reference ion source for this target station.

Dark Energy Survey Year 1 Results: Cross-Correlation Redshifts in the DES -- Calibration of the Weak Lensing Source Redshift Distributions

Energy Technology Data Exchange (ETDEWEB)

Davis, C.; et al.

2017-10-06

We present the calibration of the Dark Energy Survey Year 1 (DES Y1) weak lensing source galaxy redshift distributions from clustering measurements. By cross-correlating the positions of source galaxies with luminous red galaxies selected by the redMaGiC algorithm we measure the redshift distributions of the source galaxies as placed into different tomographic bins. These measurements constrain any such shifts to an accuracy of $\\sim0.02$ and can be computed even when the clustering measurements do not span the full redshift range. The highest-redshift source bin is not constrained by the clustering measurements because of the minimal redshift overlap with the redMaGiC galaxies. We compare our constraints with those obtained from $\\texttt{COSMOS}$ 30-band photometry and find that our two very different methods produce consistent constraints.

Fundamental neutron physics at a 1 MW long pulse spallation neutron source

International Nuclear Information System (INIS)

Greene, G.L.

1995-01-01

Modern neutron sources and modern neutron science share a common origin in mid twentieth century scientific investigations concerned with the study of the fundamental interactions between elementary particles. Since the time of that common origin, neutron science and the study of elementary particles have evolved into quite disparate disciplines. The neutron became recognized as a powerful tool for the study of condensed matter with modern neutron sources being primarily used (and primarily justified) as tools for condensed matter research. The study of elementary particles has, of course, led to the development of rather different tools and is now dominated by activities carried out at extremely high energies. Notwithstanding this trend, the study of fundamental interactions using neutrons has continued and remains a vigorous activity at many contemporary neutron sources. This research, like neutron scattering research, has benefited enormously by the development of modern high flux neutron facilities. Future sources, particularly high power spallation sources, offer exciting possibilities for the continuation of this program of research

Microwave assisted synthesis of cyclic carbonates from olefins with sodium bicarbonates as the C1 source.

Science.gov (United States)

Yang, Xiaoqing; Wu, Jie; Mao, Xianwen; Jamison, Timothy F; Hatton, T Alan

2014-03-25

An effective transformation of alkenes into cyclic carbonates has been achieved using NaHCO3 as the C1 source in acetone-water under microwave heating, with selectivities and yields significantly surpassing those obtained using conventional heating.

An Oblivious O(1)-Approximation for Single Source Buy-at-Bulk

KAUST Repository

Goel, Ashish

2009-10-01

We consider the single-source (or single-sink) buy-at-bulk problem with an unknown concave cost function. We want to route a set of demands along a graph to or from a designated root node, and the cost of routing x units of flow along an edge is proportional to some concave, non-decreasing function f such that f(0) = 0. We present a polynomial time algorithm that finds a distribution over trees such that the expected cost of a tree for any f is within an O(1)-factor of the optimum cost for that f. The previous best simultaneous approximation for this problem, even ignoring computation time, was O(log |D|), where D is the multi-set of demand nodes. We design a simple algorithmic framework using the ellipsoid method that finds an O(1)-approximation if one exists, and then construct a separation oracle using a novel adaptation of the Guha, Meyerson, and Munagala [10] algorithm for the single-sink buy-at-bulk problem that proves an O(1) approximation is possible for all f. The number of trees in the support of the distribution constructed by our algorithm is at most 1 + log |D|. © 2009 IEEE.

[Unconventional disease agents--a danger for humans and animals?].

Science.gov (United States)

Kaaden, O R

1994-02-01

The occurrence of bovine spongiform encephalopathy (BSE) in Great Britain in 1985/86, has focused again the public concern as well as scientific interest to the Scrapie disease of sheep and goat known more than 150 years. The agents of scrapie and BSE are characterized by unusual biological and physical-chemical properties, especially their high tenacity. Therefore, they are also designated "unconventional agents of viruses". Different theories have been proposed about their infectious characteristics--especially because of the apparent or real missing of an agent-specific nucleic acid--which are named Virinos, Prions or Nemavirus. The broad host range of Scrapie respective BSE, which includes domestic and wild ruminants, Suidae, Felidae, Mustelidae, small rodents, birds and non-primates, has created some concern since there might be an aetiological correlation between the transmissible spongiform encephalopathies of man (Creutzfeld-Jakob- and Gerstmann-Sträussler-Scheinker-Disease) and that of animals. Although at present neither epidemiological nor molecular biological evidence whatsoever was proved, the hypothesis cannot be completely disproved. The probability of infection through digestive tract seems to be rather unlikely but special precautions should be taken as far as production, investigation and application of human medicine drugs of animal origin. Furthermore, research about the aetiology of "unconventional agents" and pathogenesis of resulting diseases is necessary and should be intensified in Germany. Finally, only an early intra vitam-Diagnose and in vitro detection can avoid an further spread of this new category of diseases.

Project planning workshop 6-GeV synchrotron light source: Volume 1

International Nuclear Information System (INIS)

1986-01-01

A model 6 GeV synchrotron light source is described, and the costs, schedule, and manpower associated with producing such a synthrotron light source are summarized. A program consisting of a two-year pre-construction phase, a five-year construction phase, and a three-year post-construction phase and costing a total of $379.6 million is assumed

Superconducting ECR ion source system

International Nuclear Information System (INIS)

Sharma, S.C.; Gore, J.A.; Gupta, A.K.; Saxena, A.

2017-01-01

In order to cover the entire mass range of the elements across the periodic table, an ECR based heavy ion accelerator programme, consisting of a superconducting ECR (Electron Cyclotron Resonance) source and a room temperature RFQ (Radio Frequency Quadrupole) followed by low and high beta superconducting resonator cavities has been proposed. The 18 GHz superconducting ECR ion source system has already been commissioned and being operated periodically at FOTIA beam hall. This source is capable of delivering ion beams right from proton to uranium with high currents and high charge states over a wide mass range (1/7 ≤ q/m ≤ 1/2) across the periodic table, including U"3"4"+ (q/m∼1/7) with 100 pna yield. The normalized transverse beam emittance from ECR source is expected to be <1.0 pi mm mrad. ECR ion sources are quite robust, making them suitable for operating for weeks continuously without any interruption

Microglia and macrophages are major sources of locally produced transforming growth factor-beta1 after transient middle cerebral artery occlusion in rats

DEFF Research Database (Denmark)

Lehrmann, E; Kiefer, R; Christensen, Thomas

1998-01-01

The potentially neurotrophic cytokine transforming growth factor-beta1 (TGF-beta1) is locally expressed following human stroke and experimental ischemic lesions, but the cellular source(s) and profile of induction have so far not been established in experimental focal cerebral ischemia. This stud...

CD4 T cells remain the major source of HIV-1 during end stage disease.

NARCIS (Netherlands)

M.E. van der Ende (Marchina); M. Schutten (Martin); B. Raschdorff; G. Grosschupff; P. Racz; A.D.M.E. Osterhaus (Albert); K. Tenner-Racz

1999-01-01

textabstractOBJECTIVE: To assess the source of HIV-1 production in lymphoid tissue biopsies from HIV-infected patients, with no prior anti-retroviral protease inhibitor treatment, with a CD4 cell count > 150 x 10(6)/l (group I) or < 50 x 10(6)/l (group II), co-infected with Mycobacterium

Biological effects of implanted nuclear energy sources for artificial heart devices. Progress report, September 1, 1974--August 31, 1975

International Nuclear Information System (INIS)

Kallfelz, F.A.; Wentworth, R.A.; Cady, K.B.

1975-01-01

Results are reported from a study of the biological effects of radiation from mock plutonium power sources in dogs and a study of the feasibility of a tissue heat sink for waste heat from such sources in calves. It is also designed to evaluate effects of heat and radiation from plutonium sources in calves. The work is part of a program to evaluate the use of plutonium as a power source for an artificial heart device. A total of 60 dogs have been implanted with mock plutonium sources (producing a similar radiation flux as plutonium but having no associated heat) at levels of from 1 to 70 times the expected radiation flux from a 30 watt plutonium source. Results up to 4.5 years after implantation indicate that mammals may be able to tolerate the radiation flux from such sources. Results in calves indicate that 30 watts of additional endogenous heat can be dissipated to a connective tissue covered heat exchanger with a surface area of 494 cm 2 providing a heat flux of 0.06 watts/cm 2 . (U.S.)

Detailed Source-Specific Molecular Composition of Ambient Aerosol Organic Matter Using Ultrahigh Resolution Mass Spectrometry and 1H NMR

Directory of Open Access Journals (Sweden)

Amanda S. Willoughby

2016-06-01

Full Text Available Organic aerosols (OA are universally regarded as an important component of the atmosphere that have far-ranging impacts on climate forcing and human health. Many of these impacts are related to OA molecular characteristics. Despite the acknowledged importance, current uncertainties related to the source apportionment of molecular properties and environmental impacts make it difficult to confidently predict the net impacts of OA. Here we evaluate the specific molecular compounds as well as bulk structural properties of total suspended particulates in ambient OA collected from key emission sources (marine, biomass burning, and urban using ultrahigh resolution mass spectrometry (UHR-MS and proton nuclear magnetic resonance spectroscopy (1H NMR. UHR-MS and 1H NMR show that OA within each source is structurally diverse, and the molecular characteristics are described in detail. Principal component analysis (PCA revealed that (1 aromatic nitrogen species are distinguishing components for these biomass burning aerosols; (2 these urban aerosols are distinguished by having formulas with high O/C ratios and lesser aromatic and condensed aromatic formulas; and (3 these marine aerosols are distinguished by lipid-like compounds of likely marine biological origin. This study provides a unique qualitative approach for enhancing the chemical characterization of OA necessary for molecular source apportionment.

Abstracts of the 1. National congress of hydrogen and sustainable energy sources

International Nuclear Information System (INIS)

2005-01-01

The First Argentine National Congress of Hydrogen and Sustainable Energy Sources was organized by the Instituto of Sustainable Energy and Development CNEA, in San Carlos de Bariloche, between the 8th and 10th of June of 2005. In this event 88 papers were presented in the following sessions, on these subjects: 1.-Hydrogen-Materials Interaction. 2.-Materials Damage. 3.-Production and Purification. 4.-Storage and Transportation. 5.-Fuel Cells. 6.-Prototypes and Demonstration Plants. 7.-Eolic Energy. 8.-Solar Energy. 9.-Biomass. 10.-Small Hydroelectric Plants. 11.-Other Activities. 12.-Hybrid Fuels. 13.- Reforming, Materials, Catalysis, Processes. 14.-Projections and Energy Prospective

Tetrode bias power supply for Indus-1, synchrotron radiation source

International Nuclear Information System (INIS)

Tripathi, A.; Badapanda, M.K.; Tyagi, R.; Upadhyay, R.; Bohrey, A.; Hannurkar, P.R.

2009-01-01

An AC regulator based 7 kV, 3 A high voltage DC power supply is designed, fabricated and tested on dummy load for BEL make Tetrode type 15000CX, used in the high power RF amplifier at 31.613 MHz employed with INDUS-1, Synchrotron Radiation Source (SRS). Various protections features like over voltage, under voltage, over current, phase failure and phase reversal are incorporated in this power supply and presented in this paper. As Tetrode amplifier requires various other power supplies in addition to this bias power supply and they are operated in a particular sequence for its healthy operation, suitable interlock arrangements have been incorporated and also presented in this paper. The reliable operation of protection and interlock features incorporated in this power supply has been checked with dummy load under simulated conditions. Three numbers of series limiting inductors, one in each phase, have been incorporated in this power supply to limit fault currents under unfavourable conditions and there by increasing the overall life of this power supply. It will replace existing 7 kV, 3 A HVDC power supply, which is in operation for more than fifteen years with Indus-1 SRS and is likely to be helpful in reducing the down time of Indus-1 SRS. It has better performance features than the existing power supply. The long term voltage stability better than 0.3 % and output ripple less than 0.3 % have been achieved for this Tetrode bias power supply. This power supply is likely to be integrated with INDUS-1 SRS soon. (author)

The 1H(t,n)3He reaction as monoenergetic neutron source in the (10/20) MeV energy interval

International Nuclear Information System (INIS)

Zago, G.

1981-01-01

The 1 H(t,n) 3 He reaction, considered as a neutron source in the (10/20) MeV energy interval, is a ''white'' neutron source having intensity, mean energy, and directionality which may prove advantageous in technological and biomedical researches. (author)

H- source developments

International Nuclear Information System (INIS)

Allison, P.W.

1978-01-01

The design and operation of a Penning discharge, cold cathode, surface plasma H - ion source are described. A high current density, about 2 A/cm 2 , is extracted from the source by putting about 20 keV across the 2 to 2 1 / 2 mm gap

H{sup -} radio frequency source development at the Spallation Neutron Source

Energy Technology Data Exchange (ETDEWEB)

Welton, R. F.; Gawne, K. R.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Roseberry, R. T.; Santana, M.; Stockli, M. P. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471 (United States); Dudnikov, V. G. [Muons, Inc., 552 N. Batavia Avenue, Batavia, Illinois 60510 (United States); Turvey, M. W. [Villanova University, 800E. Lancaster Ave, Villanova, Pennsylvania 19085 (United States)

2012-02-15

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

First Fermi-LAT Catalog of Sources above 10 GeV (1FHL)

Data.gov (United States)

National Aeronautics and Space Administration — This catalog of LAT sources above 10 GeV reports the locations, spectra, and variability properties of the 514 sources significantly detected in this range during...

Detecting new γ-ray sources based on multi-frequency data the case of 1WHSPJ031423.9+061956

Science.gov (United States)

Arsioli, Bruno; Chang, Yu Ling

2015-12-01

We use the Fermi Science Tools in an attempt to unveil faint γ-ray blazars that may be above the threshold for detectability with Fermi-LAT and are not identified by automated methods. Our search for new sources in the 100MeV-300GeV band is mainly driven by the 1/2WHSP catalogs, which list high synchrotron peaked blazars expected to be emitters of VHE photons. Here we present the γ-ray detection of 1WHSP J031423.9+061956, modelling its high energy spectrum as a power law. We describe an example where multi-frequency selection, performed at much lower energies (from radio to X-ray), helps to pin-point a high energy source. The 1/2WHSP catalogs are built with the aim of providing a list of TeV targets for the VHE arrays of Cherenkov telescopes. Moreover, these catalogs provide useful seeds for identifying new high energy sources within the raw-data from Fermi. With the aid of multi-frequency data, we can explore the very high energy domain in greater details, improving the description of the γ-ray sky.

Tandem Terminal Ion Source

International Nuclear Information System (INIS)

Harper, G.C.; Lindner, C.E.; Myers, A.W.; Wechel, T.D. van

2000-01-01

OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the 7 Be(γ) 8 B experiment. Most of the runs used 1 H + at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used 2 H + at terminal voltage of 1.4 MV. The other run used 4 He + at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal

Tandem Terminal Ion Source

International Nuclear Information System (INIS)

None

2000-01-01

OAK-B135 Tandem Terminal Ion Source. The terminal ion source (TIS) was used in several experiments during this reporting period, all for the(sup 7)Be((gamma))(sup 8)B experiment. Most of the runs used(sup 1)H(sup+) at terminal voltages from 0.3 MV to 1.5 MV. One of the runs used(sup 2)H(sup+) at terminal voltage of 1.4 MV. The other run used(sup 4)He(sup+) at a terminal voltage of 1.37 MV. The list of experiments run with the TIS to date is given in table 1 below. The tank was opened four times for unscheduled source repairs. On one occasion the tank was opened to replace the einzel lens power supply which had failed. The 10 kV unit was replaced with a 15 kV unit. The second time the tank was opened to repair the extractor supply which was damaged by a tank spark. On the next occasion the tank was opened to replace a source canal which had sputtered away. Finally, the tank was opened to replace the discharge bottle which had been coated with aluminum sputtered from the exit canal

Galactic Bulge Giants: Probing Stellar and Galactic Evolution. 1. Catalogue of Spitzer IRAC and MIPS Sources (PREPRINT)

Science.gov (United States)

2010-12-29

1997), the 2 Micron All Sky Survey ( 2MASS ; Skrutskie et al. 2006), the Midcourse Space Experiment (MSX) catalogue, and the Infra- Red Astronomical...made for these sources with a search radius of 3.′′0 with DENIS and 2MASS , and 30.′′0 for identification with an MSX or IRAS counterpart. The... 2MASS and DENIS counterpart (depending on the field, between 3.1% and 6.7% of the sources), or (ii) a DENIS and 2MASS counterpart at a distance

Identifying Methane Sources with an Airborne Pulsed IPDA Lidar System Operating near 1.65 µm

Science.gov (United States)

Yerasi, A.; Bartholomew, J.; Tandy, W., Jr.; Emery, W. J.

2016-12-01

Methane is a powerful greenhouse gas that is predicted to play an important role in future global climate trends. It would therefore be beneficial to locate areas that produce methane in significant amounts so that these trends can be better understood. In this investigation, some initial performance test results of a lidar system called the Advanced Leak Detector Lidar - Natural Gas (ALDL-NG) are discussed. The feasibility of applying its fundamental principle of operation to methane source identification is also explored. The ALDL-NG was originally created by the Ball Aerospace & Technologies Corp. to reveal leaks emanating from pipelines that transport natural gas, which is primarily composed of methane. It operates in a pulsed integrated path differential absorption (IPDA) configuration and it is carried by a piloted, single-engine aircraft. In order to detect the presence of natural gas leaks, the laser wavelengths of its online and offline channels operate in the 1.65 µm region. The functionality of the ALDL-NG was tested during a recent field campaign in Colorado. It was determined that the ambient concentration of methane in the troposphere ( 1.8 ppm) could indeed be retrieved from ALDL-NG data with a lower-than-expected uncertainty ( 0.2 ppm). Furthermore, when the ALDL-NG scanned over areas that were presumed to be methane sources (feedlots, landfills, etc.), significantly higher concentrations of methane were retrieved. These results are intriguing because the ALDL-NG was not specifically designed to observe anything beyond natural gas pipelines. Nevertheless, they strongly indicate that utilizing an airborne pulsed IPDA lidar system operating near 1.65 µm may very well be a viable technique for identifying methane sources. Perhaps future lidar systems could build upon the heritage of the ALDL-NG and measure methane concentration with even better precision for a variety of scientific applications.

Argonne inverted sputter source

International Nuclear Information System (INIS)

Yntema, J.L.; Billquist, P.J.

1983-01-01

The emittance of the inverted sputter source with immersion lenses was measured to be about 5π mm mrad MeV/sup 1/2/ at the 75% level over a wide range of beam intensities. The use of the source in experiments with radioactive sputter targets and hydrogen loaded targets is described. Self contamination of the source is discussed

Prion Protein Self Interactions; a gateway to novel therapeutic strategies?

NARCIS (Netherlands)

Rigter, A.; Langeveld, J.P.M.; Zijderveld, van F.G.; Bossers, A.

2010-01-01

Transmissible spongiform encephalopathies (TSEs) or prion diseases are fatal neurodegenerative disorders and include among others Creutzfeldt–Jakob disease in humans, bovine spongiform encephalopathy (BSE) in cattle, and scrapie in sheep. The central event in disease development in TSEs is the

Bovine Spongiform Encephalopathy: Atypical Pros and Cons

Science.gov (United States)

Transmissible spongiform encephalopathies (TSEs) are fatal neurologic diseases that affect several mammalian species including human beings. Four animal TSE agents have been reported: scrapie of sheep and goats; chronic wasting disease (CWD) of deer, elk, and moose; transmissible mink encephalopath...

Pathogenesis of bovine spongiform encephalopathy in sheep

NARCIS (Netherlands)

Keulen, van L.J.M.; Vromans, M.E.W.; Dolstra, C.H.; Bossers, A.; Zijderveld, van F.G.

2008-01-01

The pathogenesis of bovine spongiform encephalopathy (BSE) in sheep was studied by immunohistochemical detection of scrapie-associated prion protein (PrPSc) in the gastrointestinal, lymphoid and neural tissues following oral inoculation with BSE brain homogenate. First accumulation of PrPSc was

Relativistic-klystron two-beam-accelerator as a power source for a 1 TeV next linear collider: A systems study

International Nuclear Information System (INIS)

Yu, S.; Goffeney, N.; Deadrick, F.

1994-10-01

A physics, engineering, and costing study has been conducted to explore the feasibility of a relativistic-klystron two-beam-accelerator system as a power source candidate for a 1 TeV linear collider. We present a point design example which has acceptable transverse and longitudinal beam stability properties. Preliminary ''bottom-up'' cost estimate yields the full power source system at less than 1 billion dollars. The overall efficiency for rf production is estimated to be 36%

Charged particle equilibrium corrections for photon sources from 400 keV to 1.4 MeV

Science.gov (United States)

Vasudevan, Latha

Lack of charged particle equilibrium (CPE) has practical importance in radiological health protection, in nuclear medicine, and radiobiology where small radioactive point sources irradiate the human body accidentally or may be introduced into the body for diagnostic, therapeutic, or analytical purposes. The absorbed dose under CPE is readily calculated from knowledge of the photon energy fluence and mass-absorption coefficient of the material. When estimating absorbed dose rates at points close to the source, the primary radiation field varies appreciably over the region within the range of secondary particles. Under such conditions, CPE does not exist and prediction of absorbed dose becomes difficult. However, if one applies correction factors for non-CPE conditions, absorbed dose rates can be calculated fairly easily. In this dissertation, a CPE model was developed for non-CPE conditions to predict the fraction of charged particle equilibrium (GammaCPE) attained in a water medium for point sources of energies in the range from 400 keV to 1.4 MeV using EGS4-DOSRZ Monte Carlo calculation. A new methodology to calculate absorbed dose and kerma along the central axis of the cylindrical phantom was presented and the results were found to be in excellent agreement with published values. In order to corroborate with the EGS4-DOSRZ calculation, another model based on the Klein-Nishina single scattering cross section was developed to quantify the GammaCPE attained in water for point sources. A CPE path length coefficient (mu cm-1) was found for each photon energy and compared with published values. This coefficient was used to determine dose rates averaged over 1 cm2 at depths that are of interest in skin dose exposures. Experimental measurements of CPE were carried out for a Co-60 point source using GAFCHROMICRTM MD-55 film (1990) as the dosimetry media. The films were read using a document scanner. Dose rates obtained using the scanner method were compared with those

Detection of X-ray flares from AX J1714.1-3912, the unidentified source near RX J1713.7-3946

Science.gov (United States)

Miceli, Marco; Bamba, Aya

2018-04-01

Context. Molecular clouds are predicted to emit nonthermal X-rays when they are close to particle-accelerating supernova remnants (SNRs), and the hard X-ray source AX J1714.1-3912, near the SNR RX J1713.7-3946, has long been considered a candidate for diffuse nonthermal emission associated with cosmic rays diffusing from the remnant to a closeby molecular cloud. Aim. We aim at ascertaining the nature of this source by analyzing two dedicated X-ray observations performed with Suzaku and Chandra. Methods: We extracted images from the data in various energy bands, spectra, and light curves and studied the long-term evolution of the X-ray emission on the basis of the 4.5 yr time separation between the two observations. Results: We found that there is no diffuse emission associated with AX J1714.1-3912, which is instead the point-like source CXOU J171343.9-391205. We discovered rapid time variability (timescale 103 s), together with a high intrinsic absorption and a hard nonthermal spectrum (power law with photon index Γ 1.4). We also found that the X-ray flux of the source drops down by 1-2 orders of magnitude on a timescale of a few years. Conclusions: Our results suggest a possible association between AX J1714.1-3912 and a previously unknown supergiant fast X-ray transient, although further follow-up observations are necessary to prove this association definitively.

Prion Protein Devoid of the Octapeptide Repeat Region Delays Bovine Spongiform Encephalopathy Pathogenesis in Mice.

Science.gov (United States)

Hara, Hideyuki; Miyata, Hironori; Das, Nandita Rani; Chida, Junji; Yoshimochi, Tatenobu; Uchiyama, Keiji; Watanabe, Hitomi; Kondoh, Gen; Yokoyama, Takashi; Sakaguchi, Suehiro

2018-01-01

Conformational conversion of the cellular isoform of prion protein, PrP C , into the abnormally folded, amyloidogenic isoform, PrP Sc , is a key pathogenic event in prion diseases, including Creutzfeldt-Jakob disease in humans and scrapie and bovine spongiform encephalopathy (BSE) in animals. We previously reported that the octapeptide repeat (OR) region could be dispensable for converting PrP C into PrP Sc after infection with RML prions. We demonstrated that mice transgenically expressing mouse PrP with deletion of the OR region on the PrP knockout background, designated Tg(PrPΔOR)/ Prnp 0 / 0 mice, did not show reduced susceptibility to RML scrapie prions, with abundant accumulation of PrP Sc ΔOR in their brains. We show here that Tg(PrPΔOR)/ Prnp 0 / 0 mice were highly resistant to BSE prions, developing the disease with markedly elongated incubation times after infection with BSE prions. The conversion of PrPΔOR into PrP Sc ΔOR was markedly delayed in their brains. These results suggest that the OR region may have a crucial role in the conversion of PrP C into PrP Sc after infection with BSE prions. However, Tg(PrPΔOR)/ Prnp 0 / 0 mice remained susceptible to RML and 22L scrapie prions, developing the disease without elongated incubation times after infection with RML and 22L prions. PrP Sc ΔOR accumulated only slightly less in the brains of RML- or 22L-infected Tg(PrPΔOR)/ Prnp 0 / 0 mice than PrP Sc in control wild-type mice. Taken together, these results indicate that the OR region of PrP C could play a differential role in the pathogenesis of BSE prions and RML or 22L scrapie prions. IMPORTANCE Structure-function relationship studies of PrP C conformational conversion into PrP Sc are worthwhile to understand the mechanism of the conversion of PrP C into PrP Sc We show here that, by inoculating Tg(PrPΔOR)/ Prnp 0 / 0 mice with the three different strains of RML, 22L, and BSE prions, the OR region could play a differential role in the conversion of

Design of a 'two-ion-source' charge breeder with a dual frequency ECR ion source

International Nuclear Information System (INIS)

Naik, D.; Naik, V.; Chakrabarti, A.; Dechoudhury, S.; Nayak, S.K.; Pandey, H.K.; Nakagawa, T.

2005-01-01

A charge breeder, 'two-ion-source' has been designed which consists of a surface ionisation source followed by an ECR ion source working in two-frequency mode. In this system low charge state ion beam (1+)of radioactive atoms are obtained from the first ion source close to the target chamber and landed into the ECR where those are captured and become high charged state after undergoing a multi ionisation process. This beam dynamics design has been done to optimise the maximum possible transfer of 1 + beam from the first ion source into the ECR, its full capture within the ECR zone and design of an efficient dual frequency ECR. The results shows that 1 + beam of 100 nA and 1μA (A=100) are successfully transmitted and it's beam size at the centre of ECR zone are 12 mm and 21 mm respectively, which are very less than 65 mm width ECR zone of dual frequency ECR heating at 14 GHz and 10 GHz. (author)

Sources of pulsed radiation

International Nuclear Information System (INIS)

Sauer, M.C. Jr.

1981-01-01

Characteristics of various sources of pulsed radiation are examined from the viewpoint of their importance to the radiation chemist, and some examples of uses of such sources are mentioned. A summary is given of the application of methods of physical dosimetry to pulsed sources, and the calibration of convenient chemical dosimeters by physical dosimetry is outlined. 7 figures, 1 table

Cardiac MOLLI T1 mapping at 3.0 T: comparison of patient-adaptive dual-source RF and conventional RF transmission.

Science.gov (United States)

Rasper, Michael; Nadjiri, Jonathan; Sträter, Alexandra S; Settles, Marcus; Laugwitz, Karl-Ludwig; Rummeny, Ernst J; Huber, Armin M

2017-06-01

To prospectively compare image quality and myocardial T 1 relaxation times of modified Look-Locker inversion recovery (MOLLI) imaging at 3.0 T (T) acquired with patient-adaptive dual-source (DS) and conventional single-source (SS) radiofrequency (RF) transmission. Pre- and post-contrast MOLLI T 1 mapping using SS and DS was acquired in 27 patients. Patient wise and segment wise analysis of T 1 times was performed. The correlation of DS MOLLI measurements with a reference spin echo sequence was analysed in phantom experiments. DS MOLLI imaging reduced T 1 standard deviation in 14 out of 16 myocardial segments (87.5%). Significant reduction of T 1 variance could be obtained in 7 segments (43.8%). DS significantly reduced myocardial T 1 variance in 16 out of 25 patients (64.0%). With conventional RF transmission, dielectric shading artefacts occurred in six patients causing diagnostic uncertainty. No according artefacts were found on DS images. DS image findings were in accordance with conventional T 1 mapping and late gadolinium enhancement (LGE) imaging. Phantom experiments demonstrated good correlation of myocardial T 1 time between DS MOLLI and spin echo imaging. Dual-source RF transmission enhances myocardial T 1 homogeneity in MOLLI imaging at 3.0 T. The reduction of signal inhomogeneities and artefacts due to dielectric shading is likely to enhance diagnostic confidence.

The prion protein has RNA binding and chaperoning properties characteristic of nucleocapsid protein NCP7 of HIV-1.

Science.gov (United States)

Gabus, C; Derrington, E; Leblanc, P; Chnaiderman, J; Dormont, D; Swietnicki, W; Morillas, M; Surewicz, W K; Marc, D; Nandi, P; Darlix, J L

2001-06-01

Transmissible spongiform encephalopathies are fatal neurodegenerative diseases associated with the accumulation of a protease-resistant form of the prion protein (PrP). Although PrP is conserved in vertebrates, its function remains to be identified. In vitro PrP binds large nucleic acids causing the formation of nucleoprotein complexes resembling human immunodeficiency virus type 1 (HIV-1) nucleocapsid-RNA complexes and in vivo MuLV replication accelerates the scrapie infectious process, suggesting possible interactions between retroviruses and PrP. Retroviruses, including HIV-1 encode a major nucleic acid binding protein (NC protein) found within the virus where 2000 NC protein molecules coat the dimeric genome. NC is required in virus assembly and infection to chaperone RNA dimerization and packaging and in proviral DNA synthesis by reverse transcriptase (RT). In HIV-1, 5'-leader RNA/NC interactions appear to control these viral processes. This prompted us to compare and contrast the interactions of human and ovine PrP and HIV-1 NCp7 with HIV-1 5'-leader RNA. Results show that PrP has properties characteristic of NCp7 with respect to viral RNA dimerization and proviral DNA synthesis by RT. The NC-like properties of huPrP map to the N-terminal region of huPrP. Interestingly, PrP localizes in the membrane and cytoplasm of PrP-expressing cells. These findings suggest that PrP is a multifunctional protein possibly participating in nucleic acid metabolism.

The P1-approximation for the Distribution of Neutrons from a Pulsed Source in Hydrogen

International Nuclear Information System (INIS)

Claesson, A.

1963-12-01

The asymptotic distribution of neutrons from a pulsed, high energy source in an infinite moderator has been obtained earlier in a 'diffusion' approximation. In that paper the cross section was assumed to be constant over the whole energy region and the time derivative of the first moment was disregarded. Here, first, an analytic expression is obtained for the density in a P 1 -approximation. However, the result is very complicated, and it is shown that an asymptotic solution can be found in a simpler way. By taking into account the low hydrogen scattering cross section at the source energy it follows that the space dependence of the distribution is less than that obtained earlier. The importance of keeping the time derivative of the first moment is further shown in a perturbation approximation

Inactivation of Prions and Amyloid Seeds with Hypochlorous Acid.

Directory of Open Access Journals (Sweden)

Andrew G Hughson

2016-09-01

Full Text Available Hypochlorous acid (HOCl is produced naturally by neutrophils and other cells to kill conventional microbes in vivo. Synthetic preparations containing HOCl can also be effective as microbial disinfectants. Here we have tested whether HOCl can also inactivate prions and other self-propagating protein amyloid seeds. Prions are deadly pathogens that are notoriously difficult to inactivate, and standard microbial disinfection protocols are often inadequate. Recommended treatments for prion decontamination include strongly basic (pH ≥~12 sodium hypochlorite bleach, ≥1 N sodium hydroxide, and/or prolonged autoclaving. These treatments are damaging and/or unsuitable for many clinical, agricultural and environmental applications. We have tested the anti-prion activity of a weakly acidic aqueous formulation of HOCl (BrioHOCl that poses no apparent hazard to either users or many surfaces. For example, BrioHOCl can be applied directly to skin and mucous membranes and has been aerosolized to treat entire rooms without apparent deleterious effects. Here, we demonstrate that immersion in BrioHOCl can inactivate not only a range of target microbes, including spores of Bacillus subtilis, but also prions in tissue suspensions and on stainless steel. Real-time quaking-induced conversion (RT-QuIC assays showed that BrioHOCl treatments eliminated all detectable prion seeding activity of human Creutzfeldt-Jakob disease, bovine spongiform encephalopathy, cervine chronic wasting disease, sheep scrapie and hamster scrapie; these findings indicated reductions of ≥103- to 106-fold. Transgenic mouse bioassays showed that all detectable hamster-adapted scrapie infectivity in brain homogenates or on steel wires was eliminated, representing reductions of ≥~105.75-fold and >104-fold, respectively. Inactivation of RT-QuIC seeding activity correlated with free chlorine concentration and higher order aggregation or destruction of proteins generally, including prion

Mapping of possible prion protein self interaction domains using peptide arrays

NARCIS (Netherlands)

Rigter, A.; Langeveld, J.P.M.; Timmers-Parohi, D.; Jacobs, J.G.; Moonen, P.L.J.M.; Bossers, A.

2007-01-01

Background The common event in transmissible spongiform encephalopathies (TSEs) or prion diseases is the conversion of host-encoded protease sensitive cellular prion protein (PrPC) into strain dependent isoforms of scrapie associated protease resistant isoform (PrPSc) of prion protein (PrP). These

Note: Development of ESS Bilbao's proton ion source: Ion Source Hydrogen Positive

International Nuclear Information System (INIS)

Miracoli, R.; Feuchtwanger, J.; Arredondo, I.; Belver, D.; Gonzalez, P. J.; Corres, J.; Djekic, S.; Echevarria, P.; Eguiraun, M.; Garmendia, N.; Muguira, L.

2014-01-01

The Ion Source Hydrogen positive is a 2.7 GHz off-resonance microwave discharge ion source. It uses four coils to generate an axial magnetic field in the plasma chamber around 0.1 T that exceeds the ECR resonance field. A new magnetic system was designed as a combination of the four coils and soft iron in order to increase the reliability of the source. The description of the simulations of the magnetic field and the comparison with the magnetic measurements are presented. Moreover, results of the initial commissioning of the source for extraction voltage until 50 kV will be reported

Repetitive immunization enhances the susceptibility of mice to peripherally administered prions.

Directory of Open Access Journals (Sweden)

Juliane Bremer

Full Text Available The susceptibility of humans and animals to prion infections is determined by the virulence of the infectious agent, by genetic modifiers, and by hitherto unknown host and environmental risk factors. While little is known about the latter two, the activation state of the immune system was surmised to influence prion susceptibility. Here we administered prions to mice that were repeatedly immunized by two initial injections of CpG oligodeoxynucleotides followed by repeated injections of bovine serum albumin/alum. Immunization greatly reduced the required dosage of peripherally administered prion inoculum necessary to induce scrapie in 50% of mice. No difference in susceptibility was observed following intracerebral prion challenge. Due to its profound impact onto scrapie susceptibility, the host immune status may determine disease penetrance after low-dose prion exposure, including those that may give rise to iatrogenic and variant Creutzfeldt-Jakob disease.

GANIL Workshop on Ion Sources

International Nuclear Information System (INIS)

Leroy, Renan

1999-01-01

The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+→n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed

Sources of ambient concentrations and chemical composition of PM 2.5-0.1 in Cork Harbour, Ireland

Science.gov (United States)

Hellebust, S.; Allanic, A.; O'Connor, I. P.; Jourdan, C.; Healy, D.; Sodeau, J. R.

2010-02-01

Particulate matter (PM 10-2.5 and PM 2.5-0.1) has been collected over a period of one year in Cork Harbour, Ireland, using a high-volume cascade impactor and polyurethane foam collection substrate. Collected PM 2.5-0.1 was analysed for water-soluble inorganic ions and metal content using ion chromatography and inductively coupled plasma-optical emission spectroscopy. On average approximately 50% by mass of the chemical content of PM was identified. The motivation for the study was to assess the potential impact of shipping emissions on air quality in Cork Harbour and City, with a view to informing public health impacts. The average ambient concentration of PM 10 between May 2007 and April 2008 was 4.6 µgm - 3 and the maximum concentration measured in one sample, representing a 4 day collection period, was 16 µgm - 3 . The major inorganic constituents identified in PM collected in Haulbowline Island in Cork Harbour were sulfate, ammonium, nitrate, chloride and sodium ions, which were mainly attributable to sea salt and secondary inorganic aerosols from regional sources. The results were analysed by principal component analysis for the purpose of source apportionment. Four factors were identified explaining over 80% of the data set variance. The factors were: shipping, sea salt, crustal material and secondary inorganic aerosols (SIA). The smaller size fraction was frequently observed to dominate, as the average concentration was 2.77 µgm - 3 for PM 2.5-0.1 compared to 1.9 µgm - 3 for PM 10-2.5. Fresh ship plumes were not found to make a significant contribution to primary PM 2.5-0.1 concentrations adjacent to the shipping channel. However, this was partially attributed to the ultrafine nature of ship emissions and the majority of the toxic metal content was attributed to emissions associated with heavy oil combustion sources, which include ship engines.

Geochemical Constrains on MORB Composition and Magma Sources at East Pacific Rise Between 1°S and 2°S

Science.gov (United States)

Zhang, Wei; Zeng, Zhigang; Cui, Lukai; Yin, Xuebo

2018-04-01

The East Pacific Rise (EPR) is a typical fast spreading ridge. To gain a better understanding of the magmatism under ridges, Mid Ocean Ridge Basalts (MORBs) with remarkably heterogeneous compositions are obtained from (EPR) 1°-2°S and multielement geochemical and radioisotope analyses are conducted. Results show that these MORBs have wide variation ranges in trace element concentrations and isotopic ratios. Sample 07 has low concentrations of incompatible elements, and very low 87Sr/86Sr, and high 143Nd/144Nd from 0.70213 to 0.702289 and 0.513234 to 0.513289, respectively. However, other samples show enrichment in incompatible elements to varying degrees, and medium values of 87Sr/86Sr and 143Nd/144Nd from 0.702440 to 0.702680 and 0.513086 to 0.513200, respectively. This study proposes that one depleted source and two enriched sources contribute to the formation of MORBs from EPR 1°-2°S. Samples 02 and 10 are formed by mixing between one enriched source and one depleted source, while sample 07 is crystallized from the depleted source with no mixing process involved. However, the formation of samples 06 and 11 are different, and thus further research is required to determine genesis.

Classification of X-ray sources in the XMM-Newton serendipitous source catalog: Objects of special interest

Energy Technology Data Exchange (ETDEWEB)

Lin, Dacheng; Webb, Natalie A.; Barret, Didier, E-mail: dlin@ua.edu [CNRS, IRAP, 9 Avenue du Colonel Roche, BP 44346, F-31028 Toulouse Cedex 4 (France)

2014-01-01

We analyze 18 sources that showed interesting properties of periodicity, very soft spectra, and/or large long-term variability in X-rays in our project of classification of sources from the 2XMMi-DR3 catalog, but were poorly studied in the literature, in order to investigate their nature. Two hard sources show X-ray periodicities of ∼1.62 hr (2XMM J165334.4–414423) and ∼2.1 hr (2XMM J133135.2–315541) and are probably magnetic cataclysmic variables. One source, 2XMM J123103.2+110648, is an active galactic nucleus (AGN) candidate showing very soft X-ray spectra (kT ∼ 0.1 keV) and exhibiting an intermittent ∼3.8 hr quasi-periodic oscillation. There are six other very soft sources (with kT < 0.2 keV), which might be in other galaxies with luminosities between ∼10{sup 38}-10{sup 42} erg s{sup –1}. They probably represent a diverse group that might include objects such as ultrasoft AGNs and cool thermal disk emission from accreting intermediate-mass black holes. Six highly variable sources with harder spectra are probably in nearby galaxies with luminosities above 10{sup 37} erg s{sup –1} and thus are great candidates for extragalactic X-ray binaries. One of them (2XMMi J004211.2+410429, in M31) is probably a new-born persistent source, having been X-ray bright and hard in 0.3-10 keV for at least four years since it was discovered entering an outburst in 2007. Three highly variable hard sources appear at low galactic latitudes and have maximum luminosities below ∼10{sup 34} erg s{sup –1} if they are in our Galaxy. Thus, they are great candidates for cataclysmic variables or very faint X-ray transients harboring a black hole or neutron star. Our interpretations of these sources can be tested with future long-term X-ray monitoring and multi-wavelength observations.

Beam property measurement of a 300-kV ion source test stand for a 1-MV electrostatic accelerator

Science.gov (United States)

Park, Sae-Hoon; Kim, Dae-Il; Kim, Yu-Seok

2016-09-01

The KOMAC (Korea Multi-purpose Accelerator Complex) has been developing a 300-kV ion source test stand for a 1-MV electrostatic accelerator for industrial purposes. A RF ion source was operated at 200 MHz with its matching circuit. The beam profile and emittance were measured behind an accelerating column to confirm the beam property from the RF ion source. The beam profile was measured at the end of the accelerating tube and at the beam dump by using a beam profile monitor (BPM) and wire scanner. An Allison-type emittance scanner was installed behind the beam profile monitor (BPM) to measure the beam density in phase space. The measurement results for the beam profile and emittance are presented in this paper.

Pantechnik new superconducting ion source: PantechniK Indian Superconducting Ion Source

International Nuclear Information System (INIS)

Gaubert, G.; Bieth, C.; Bougy, W.; Brionne, N.; Donzel, X.; Leroy, R.; Sineau, A.; Vallerand, C.; Villari, A. C. C.; Thuillier, T.

2012-01-01

The new ECR ion source PantechniK Indian Superconducting Ion Source (PKISIS) was recently commissioned at Pantechnik. Three superconducting coils generate the axial magnetic field configuration, while the radial magnetic field is done with the multi-layer permanent magnets. Special care was devoted to the design of the hexapolar structure, allowing a maximum magnetic field of 1.32 T at the wall of the 82 mm diameter plasma chamber. The three superconducting coils using low temperature superconducting wires are cooled by a single double stage cryo-cooler (4.2 K). Cryogen-free technology is used, providing reliability and easy maintenance at low cost. The maximum installed RF power (18.0 GHz) is of 2 kW. Metallic beams can be produced with an oven (T max = 1400 deg. C) installed with an angle of 5 deg. with respect to the source axis or a sputtering system, mounted on the axis of the source. The beam extraction system is constituted of three electrodes in accel-decel configuration. The new source of Pantechnik is conceived for reaching optimum performances at 18 GHz RF frequencies. PKISIS magnetic fields are 2.1 T axial B inj and 1.32 T radial field in the wall, variable B min with an independent coil and a large and opened extraction region. Moreover, PKISIS integrates modern design concepts, like RF direct injection (2 kW availability), dc-bias moving disk, out-of-axis oven and axial sputtering facility for metal beams. Finally, PKISIS is also conceived in order to operate in a high-voltage platform with minor power consumption.

Chemical Composition and Source Apportionment of high temporal resolution PM1 data for January-August 2017 in Delhi, India

Science.gov (United States)

Bhandari, S.; Wang, D. S.; Gani, S.; Seraj, S.; Arub, Z.; Habib, G.; Apte, J.; Hildebrandt Ruiz, L.

2017-12-01

Exposure to fine particulate matter (PM) poses significant health risks, especially to residents in heavily populated areas. The current understanding of the sources and dynamics of PM pollution in developing countries like India is limited. Delhi, India is the second most populated city in the world that has extremely high winter PM concentrations and frequent severe pollution episodes. This study reports on composition measurements of submicron aerosol at 1 minute time resolution from January to August of 2017, collected at the Indian Institute of Technology Delhi using an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) and black carbon (BC) measurements using an Aethalometer. Source apportionment was conducted on organic and inorganic mass spectra measured by the ACSM and black carbon data measured using Positive Matrix Factorization (PMF). High concentrations of particulate matter were observed with total PM1 at times exceeding 200 µg m-3 in winter. A significant drop in PM1 concentrations was observed in the winter-spring transition. As observed elsewhere, organic species dominated the submicron mass, contributing 60% of the total mass over the duration of the campaign. However, this fractional contribution varied substantially over the day: from 48% early in the morning to 73% late at night. Along with diurnal variation in total PM1 mass loadings, particulate chloride levels also exhibited a strong diurnal cycle, with concentrations as high as 50 µg m-3 observed in the early mornings of January 2017. Literature review on identification of winter chloride sources in Delhi points to local and regional sources such as biomass/open-waste burning and coal combustion. PMF receptor modeling identified several factors with distinct diurnal patterns. While hydrocarbon-like organic aerosol (HOA) factor has the largest mass fraction contribution, PMF results consistently suggest chloride presence as attributable to ammonium chloride. Interestingly, aerosol

The Railgun and Its Power Source,

Science.gov (United States)

1987-06-01

inductor 66 3.1.3 The ANU homopolar generator power source 67 3.1.4 Features of an ideal power source 69 3.1.5 Desirable power source pulse energy...3.3.2 Homopolar generators 75 3.3.3 Ordinary large alternators 77 3.3.4 The compulsator 77 3.4 Explosive magnetic flux compression 80 3.5 Minimum mass of...discharge of lead-acid batteries 99 4.4.4 Design and performance of a high rate lead-acid cell 101 4.5 Motor -generator instead of batteries 103 4.5.1

Quantitative Risk Assessment of Bovine Spongiform Encephalopathy

Science.gov (United States)

Tsutsui, Toshiyuki; Kasuga, Fumiko

Bovine spongiform encephalopathy (BSE) is a progressive neurological disease of cattle affecting the central nervous system and was first diagnosed in the United Kingdom (UK) in 1986 (Wells et al., 1987). This disease is one of the transmissible spongiform encephalopathy (TSE) which includes Creutzfeldt-Jakob disease (CJD) in humans and scrapie in sheep. The causative agent of TSE is considered to be an abnormal form of prion protein. However, the details of its pathogenic mechanism have not been fully identified. Scrapie, which causes neurological symptoms in sheep and goats, has existed in the UK for 200 years (Hoinville, 1996) and spread across the rest of the world in the 1900s (Detwiler & Baylis, 2003). There has been no report so far that scrapie can be transmitted to humans. Initially, BSE was also considered as a disease affecting only animals. However, a variant type of Creutzfeldt-Jakob disease (vCJD) was first reported in the UK, and exposure to a BSE agent was suspected (Collinge, Sidle, Meads, Ironside, & Hill, 1996). vCJD is clinically and pathologically different from the sporadic type of CJD, and age at clinical onset of vCJD is younger than sporadic type (Will et al., 1996). Since the UK government announced the possible association between BSE and vCJD in 1996, BSE has become a huge public health concern all over the world. Of particular concern about vCJD, the fatal disease in younger age, distorted consumer confidence in beef safety, and as a result reduced beef consumption has been seen in many BSE-affected countries.

The Impact of Diet Wheat Source on the Onset of Type 1 Diabetes Mellitus-Lessons Learned from the Non-Obese Diabetic (NOD) Mouse Model.

Science.gov (United States)

Gorelick, Jonathan; Yarmolinsky, Ludmila; Budovsky, Arie; Khalfin, Boris; Klein, Joshua D; Pinchasov, Yosi; Bushuev, Maxim A; Rudchenko, Tatiana; Ben-Shabat, Shimon

2017-05-10

Nutrition, especially wheat consumption, is a major factor involved in the onset of type 1 diabetes (T1D) and other autoimmune diseases such as celiac. While modern wheat cultivars possess similar gliadin proteins associated with the onset of celiac disease and T1D, alternative dietary wheat sources from Israeli landraces and native ancestral species may be lacking the epitopes linked with T1D, potentially reducing the incidence of T1D. The Non-Obese Diabetic (NOD) mouse model was used to monitor the effects of dietary wheat sources on the onset and development of T1D. The effects of modern wheat flour were compared with those from either T. aestivum , T. turgidum spp. dicoccoides , or T. turgidum spp. dicoccum landraces or a non-wheat diet. Animals which received wheat from local landraces or ancestral species such as emmer displayed a lower incidence of T1D and related complications compared to animals fed a modern wheat variety. This study is the first report of the diabetogenic properties of various dietary wheat sources and suggests that alternative dietary wheat sources may lack T1D linked epitopes, thus reducing the incidence of T1D.

Space power distribution of soft x-ray source ANGARA-5-1

Energy Technology Data Exchange (ETDEWEB)

Dyabilin, K S [High Energy Density Research Center, Moscow (Russian Federation); Fortov, V E; Grabovskij, E V; Lebedev, M E; Smirnov, V P [Troitsk Inst. of Innovative and Fusion Research, Troitsk (Russian Federation)

1997-12-31

The contribution deals with the investigation of shock waves in condensed targets generated by intense pulses of soft X radiation. Main attention is paid to the spatial distribution of the soft x-ray power, which influence strongly the shock wave front uniformity. Hot z-pinch plasma with the temperature of 60-100 eV produced by imploding double liner in the ANGARA-5-1 machine was used as a source of x rays. The maximum pinch current was as high as 3.5 MA. In order to eliminate the thermal heating of the targets, thick stepped Al/Pb, Sn/Pb, or pure Pb targets were used. The velocity of shock waves was determined by means of optical methods. Very uniform shock waves and shock pressures of up to several hundreds of GPa have been achieved. (J.U.). 3 figs., 2 refs.

Glypican-1 mediates both prion protein lipid raft association and disease isoform formation.

Directory of Open Access Journals (Sweden)

David R Taylor

2009-11-01

Full Text Available In prion diseases, the cellular form of the prion protein, PrP(C, undergoes a conformational conversion to the infectious isoform, PrP(Sc. PrP(C associates with lipid rafts through its glycosyl-phosphatidylinositol (GPI anchor and a region in its N-terminal domain which also binds to heparan sulfate proteoglycans (HSPGs. We show that heparin displaces PrP(C from rafts and promotes its endocytosis, suggesting that heparin competes with an endogenous raft-resident HSPG for binding to PrP(C. We then utilised a transmembrane-anchored form of PrP (PrP-TM, which is targeted to rafts solely by its N-terminal domain, to show that both heparin and phosphatidylinositol-specific phospholipase C can inhibit its association with detergent-resistant rafts, implying that a GPI-anchored HSPG targets PrP(C to rafts. Depletion of the major neuronal GPI-anchored HSPG, glypican-1, significantly reduced the raft association of PrP-TM and displaced PrP(C from rafts, promoting its endocytosis. Glypican-1 and PrP(C colocalised on the cell surface and both PrP(C and PrP(Sc co-immunoprecipitated with glypican-1. Critically, treatment of scrapie-infected N2a cells with glypican-1 siRNA significantly reduced PrP(Sc formation. In contrast, depletion of glypican-1 did not alter the inhibitory effect of PrP(C on the beta-secretase cleavage of the Alzheimer's amyloid precursor protein. These data indicate that glypican-1 is a novel cellular cofactor for prion conversion and we propose that it acts as a scaffold facilitating the interaction of PrP(C and PrP(Sc in lipid rafts.

/sup 1/H(t,n)/sup 3/He reaction as monoenergetic neutron source in the (10/20) MeV energy interval

Energy Technology Data Exchange (ETDEWEB)

Zago, G. (Padua Univ. (Italy). Ist. di Fisica)

1981-11-14

The /sup 1/H(t,n)/sup 3/He reaction, considered as a neutron source in the (10/20) MeV energy interval, is a ''white'' neutron source having intensity, mean energy, and directionality which may prove advantageous in technological and biomedical researches.

DNA polymerase beta participates in mitochondrial DNA repair

DEFF Research Database (Denmark)

Sykora, P; Kanno, S; Akbari, M

2017-01-01

We have detected DNA polymerase beta (Polβ), known as a key nuclear base excision repair (BER) protein, in mitochondrial protein extracts derived from mammalian tissue and cells. Manipulation of the N-terminal sequence affected the amount of Polβ in the mitochondria. Using Polβ fragments, mitocho......We have detected DNA polymerase beta (Polβ), known as a key nuclear base excision repair (BER) protein, in mitochondrial protein extracts derived from mammalian tissue and cells. Manipulation of the N-terminal sequence affected the amount of Polβ in the mitochondria. Using Polβ fragments......, mitochondrial-specific protein partners were identified, with the interactors mainly functioning in DNA maintenance and mitochondrial import. Of particular interest was the identification of the proteins TWINKLE, SSBP1 and TFAM, all of which are mitochondria specific DNA effectors and are known to function...... in the nucleoid. Polβ directly interacted with, and influenced the activity of, the mitochondrial helicase TWINKLE. Human kidney cells with Polβ knock-out (KO) had higher endogenous mtDNA damage. Mitochondrial extracts derived from heterozygous Polβ mouse tissue and KO cells had lower nucleotide incorporation...

Amidation and structure relaxation abolish the neurotoxicity of the prion peptide PrP106-126 in vivo and in vitro

DEFF Research Database (Denmark)

Bergstrøm, Linda Alice; Hvass, Henriette Cordes; Zsurger, N.

2005-01-01

One of the major pathological hallmarks of transmissible spongiform encephalopathies (TSEs) is the accumulation of a pathogenic (scrapie) isoform (PrPSc) of the cellular prion protein (PrPC) primarily in the central nervous system. The synthetic prion peptide PrP106-126 shares many characteristics...

A review of polarized ion sources

International Nuclear Information System (INIS)

Schmor, P.W.

1995-06-01

The two main types of polarized ion sources in use on accelerators today are the Atomic Beam Polarized Ion Source (ABIS) source and the Optically Pumped Polarized Ion Source (OPPIS). Both types can provide beams of nuclearly polarized light ions which are either positively or negatively charged. Heavy ion polarized ion sources for accelerators are being developed. (author). 35 refs., 1 tab

Radio and X-ray properties of the source G29.37+0.1 linked to HESS J1844-030

Science.gov (United States)

Castelletti, G.; Supan, L.; Petriella, A.; Giacani, E.; Joshi, B. C.

2017-06-01

Aims: We report on the first detailed multiwavelength study of the radio source G29.37+0.1, which is an as-yet-unclassified object linked to the very-high-energy γ-emitting source HESS J1844-030. The origin of the multiwavelength emission toward G29.37+0.1 has not been clarified so far, leaving open the question about the physical relationship between these sources. Methods: Using observations carried out with the Giant Metrewave Radio Telescope (GMRT), we performed high-quality full-synthesis imaging at 610 MHz of the field containing G29.37+0.1. The obtained data, combined with observations at 1400 MHz from The Multi-Array Galactic Plane Imaging Survey (MAGPIS) were used to investigate in detail the properties of its radio emission. Additionally, we reprocessed archival data obtained with the XMM-Newton and Chandra observatories in order to get a multiwavelength view of this unusual source. Results: The radio source G29.37+0.1 mainly consists of a bright twisted structure, named the S-shaped feature. The high sensitivity of the new GMRT observations allowed the identification of potential lobes, jets, and a nuclear central region in the S-shaped morphology of G29.37+0.1. We also highlight the detection of diffuse and low surface brightness emission enveloping the brightest emitting regions. The brightest emission in G29.37+0.1 has a radio synchrotron spectral index α = 0.59 ± 0.09. Variations in the spectral behaviour are observed across the whole radio source with the flattest spectral features in the central nuclear and jets components (α 0.3). These results lead us to conclude that the brightest radio emission from G29.37+0.1 likely represents a newly recognized radio galaxy. The identification of optical and infrared counterparts to the emission arising from the core of G29.37+0.1 strengthens our interpretation of an extragalactic origin of the radio emission. We performed several tests to explain the physical mechanism responsible for the observed X

Safety and security of radioactive sources in Taiwan

International Nuclear Information System (INIS)

Tsay Yeousong; Guan Channan; Cheng Yungfu

2008-01-01

In Taiwan, the safety and security of radioactive sources is a high priority issue. Ionizing Radiation Protection Act (IRPA) and correlating regulations had been in place for effective control of the safety and security of radioactive sources since 2003. For increased control of sealed radioactive sources, Atomic Energy Council (AEC) established in March 2004 an online reporting system through the Internet, assisting source owners in reporting their sources every month. To conform to the Code of Conduct on the Safety and Security of Radioactive Sources and the Categorization of radioactive sources, published by the International Atomic Energy Agency (IAEA), AEC has taken the following actions: 1. Established an inventory of Categories 1 and 2 radioactive sources, and implemented the Import/Export Provisions of the Code. 2. Required that each licensee shall control access to Categories 1 and 2 radioactive sources, and AEC will conduct project inspection on Categories 1 and 2 radioactive sources. 3. Using a new radiation warning symbol by ISO for Categories 1 and 2 radioactive sources. The reinforcement of orphaned source control was implemented as early as 1995. All steel mills have installed radiation detectors to scan incoming metal scrap to prevent accidental smelting of radioactive sources. The results of this effort will be discussed in the paper. The above measures are examples for demonstrating AEC's commitment to reinforced control of radioactive sources. AEC will continue to protect public safety and security, ensuring that Taiwan's regulatory system in radiation protection conforms to international standards. (author)

Simple, high current, antimony ion source

International Nuclear Information System (INIS)

Sugiura, H.

1979-01-01

A simple metal ion source capable of producing a continuous, uncontaminated, high current beam of Sb ions is presented. It produced a total ion current of 200 μA at 1 kV extraction voltage. A discharge occurred in the source at a pressure of 6 x 10 -4 Torr. The ion current extracted from the source increased with the 3/2 power of the extraction voltage. The perveance of the source and ion density in the plasma were 8 x 10 -9 and 1.8 x 10 11 cm -3 , respectively

A STUDY OF BROADBAND FARADAY ROTATION AND POLARIZATION BEHAVIOR OVER 1.3–10 GHz IN 36 DISCRETE RADIO SOURCES

International Nuclear Information System (INIS)

Anderson, C. S.; Gaensler, B. M.; Feain, I. J.

2016-01-01

We present a broadband polarization analysis of 36 discrete polarized radio sources over a very broad, densely sampled frequency band. Our sample was selected on the basis of polarization behavior apparent in narrowband archival data at 1.4 GHz: half the sample shows complicated frequency-dependent polarization behavior (i.e., Faraday complexity) at these frequencies, while half shows comparatively simple behavior (i.e., they appear Faraday simple ). We re-observed the sample using the Australia Telescope Compact Array in full polarization, with 6 GHz of densely sampled frequency coverage spanning 1.3–10 GHz. We have devised a general polarization modeling technique that allows us to identify multiple polarized emission components in a source, and to characterize their properties. We detect Faraday complex behavior in almost every source in our sample. Several sources exhibit particularly remarkable polarization behavior. By comparing our new and archival data, we have identified temporal variability in the broadband integrated polarization spectra of some sources. In a number of cases, the characteristics of the polarized emission components, including the range of Faraday depths over which they emit, their temporal variability, spectral index, and the linear extent of the source, allow us to argue that the spectropolarimetric data encode information about the magneto-ionic environment of active galactic nuclei themselves. Furthermore, the data place direct constraints on the geometry and magneto-ionic structure of this material. We discuss the consequences of restricted frequency bands on the detection and interpretation of polarization structures, and the implications for upcoming spectropolarimetric surveys.

Dark Energy Survey Year 1 Results: Redshift distributions of the weak lensing source galaxies

Energy Technology Data Exchange (ETDEWEB)

Hoyle, B.; et al.

2017-08-04

We describe the derivation and validation of redshift distribution estimates and their uncertainties for the galaxies used as weak lensing sources in the Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (BPZ) code is used to assign galaxies to four redshift bins between z=0.2 and 1.3, and to produce initial estimates of the lensing-weighted redshift distributions $n^i_{PZ}(z)$ for bin i. Accurate determination of cosmological parameters depends critically on knowledge of $n^i$ but is insensitive to bin assignments or redshift errors for individual galaxies. The cosmological analyses allow for shifts $n^i(z)=n^i_{PZ}(z-\\Delta z^i)$ to correct the mean redshift of $n^i(z)$ for biases in $n^i_{\\rm PZ}$. The $\\Delta z^i$ are constrained by comparison of independently estimated 30-band photometric redshifts of galaxies in the COSMOS field to BPZ estimates made from the DES griz fluxes, for a sample matched in fluxes, pre-seeing size, and lensing weight to the DES weak-lensing sources. In companion papers, the $\\Delta z^i$ are further constrained by the angular clustering of the source galaxies around red galaxies with secure photometric redshifts at 0.15

Dark Energy Survey Year 1 Results: Redshift distributions of the weak lensing source galaxies

Science.gov (United States)

Hoyle, B.; Gruen, D.; Bernstein, G. M.; Rau, M. M.; De Vicente, J.; Hartley, W. G.; Gaztanaga, E.; DeRose, J.; Troxel, M. A.; Davis, C.; Alarcon, A.; MacCrann, N.; Prat, J.; Sánchez, C.; Sheldon, E.; Wechsler, R. H.; Asorey, J.; Becker, M. R.; Bonnett, C.; Carnero Rosell, A.; Carollo, D.; Carrasco Kind, M.; Castander, F. J.; Cawthon, R.; Chang, C.; Childress, M.; Davis, T. M.; Drlica-Wagner, A.; Gatti, M.; Glazebrook, K.; Gschwend, J.; Hinton, S. R.; Hoormann, J. K.; Kim, A. G.; King, A.; Kuehn, K.; Lewis, G.; Lidman, C.; Lin, H.; Macaulay, E.; Maia, M. A. G.; Martini, P.; Mudd, D.; Möller, A.; Nichol, R. C.; Ogando, R. L. C.; Rollins, R. P.; Roodman, A.; Ross, A. J.; Rozo, E.; Rykoff, E. S.; Samuroff, S.; Sevilla-Noarbe, I.; Sharp, R.; Sommer, N. E.; Tucker, B. E.; Uddin, S. A.; Varga, T. N.; Vielzeuf, P.; Yuan, F.; Zhang, B.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Busha, M. T.; Capozzi, D.; Carretero, J.; Crocce, M.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Estrada, J.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jarvis, M.; Jeltema, T.; Johnson, M. W. G.; Johnson, M. D.; Kirk, D.; Krause, E.; Kuhlmann, S.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Lima, M.; March, M.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Miquel, R.; Nord, B.; O'Neill, C. R.; Plazas, A. A.; Romer, A. K.; Sako, M.; Sanchez, E.; Santiago, B.; Scarpine, V.; Schindler, R.; Schubnell, M.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D. L.; Vikram, V.; Walker, A. R.; Weller, J.; Wester, W.; Wolf, R. C.; Yanny, B.; Zuntz, J.; DES Collaboration

2018-04-01

We describe the derivation and validation of redshift distribution estimates and their uncertainties for the populations of galaxies used as weak lensing sources in the Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (BPZ) code is used to assign galaxies to four redshift bins between z ≈ 0.2 and ≈1.3, and to produce initial estimates of the lensing-weighted redshift distributions n^i_PZ(z)∝ dn^i/dz for members of bin i. Accurate determination of cosmological parameters depends critically on knowledge of ni but is insensitive to bin assignments or redshift errors for individual galaxies. The cosmological analyses allow for shifts n^i(z)=n^i_PZ(z-Δ z^i) to correct the mean redshift of ni(z) for biases in n^i_PZ. The Δzi are constrained by comparison of independently estimated 30-band photometric redshifts of galaxies in the COSMOS field to BPZ estimates made from the DES griz fluxes, for a sample matched in fluxes, pre-seeing size, and lensing weight to the DES weak-lensing sources. In companion papers, the Δzi of the three lowest redshift bins are further constrained by the angular clustering of the source galaxies around red galaxies with secure photometric redshifts at 0.15 < z < 0.9. This paper details the BPZ and COSMOS procedures, and demonstrates that the cosmological inference is insensitive to details of the ni(z) beyond the choice of Δzi. The clustering and COSMOS validation methods produce consistent estimates of Δzi in the bins where both can be applied, with combined uncertainties of σ _{Δ z^i}=0.015, 0.013, 0.011, and 0.022 in the four bins. Repeating the photo-z proceedure instead using the Directional Neighborhood Fitting (DNF) algorithm, or using the ni(z) estimated from the matched sample in COSMOS, yields no discernible difference in cosmological inferences.

School Principals' Sources of Knowledge

Science.gov (United States)

Perkins, Arland Early

2014-01-01

The purpose of this study was to determine what sources of professional knowledge are available to principals in 1 rural East Tennessee school district. Qualitative research methods were applied to gain an understanding of what sources of knowledge are used by school principals in 1 rural East Tennessee school district and the barriers they face…

Performance evaluation of wideband bio-impedance spectroscopy using constant voltage source and constant current source

International Nuclear Information System (INIS)

Mohamadou, Youssoufa; Oh, Tong In; Wi, Hun; Sohal, Harsh; Farooq, Adnan; Woo, Eung Je; McEwan, Alistair Lee

2012-01-01

Current sources are widely used in bio-impedance spectroscopy (BIS) measurement systems to maximize current injection for increased signal to noise while keeping within medical safety specifications. High-performance current sources based on the Howland current pump with optimized impedance converters are able to minimize stray capacitance of the cables and setup. This approach is limited at high frequencies primarily due to the deteriorated output impedance of the constant current source when situated in a real measurement system. For this reason, voltage sources have been suggested, but they require a current sensing resistor, and the SNR reduces at low impedance loads due to the lower current required to maintain constant voltage. In this paper, we compare the performance of a current source-based BIS and a voltage source-based BIS, which use common components. The current source BIS is based on a Howland current pump and generalized impedance converters to maintain a high output impedance of more than 1 MΩ at 2 MHz. The voltage source BIS is based on voltage division between an internal current sensing resistor (R s ) and an external sample. To maintain high SNR, R s is varied so that the source voltage is divided more or less equally. In order to calibrate the systems, we measured the transfer function of the BIS systems with several known resistor and capacitor loads. From this we may estimate the resistance and capacitance of biological tissues using the least-squares method to minimize error between the measured transimpedance excluding the system transfer function and that from an impedance model. When tested on realistic loads including discrete resistors and capacitors, and saline and agar phantoms, the voltage source-based BIS system had a wider bandwidth of 10 Hz to 2.2 MHz with less than 1% deviation from the expected spectra compared to more than 10% with the current source. The voltage source also showed an SNR of at least 60 dB up to 2.2 MHz

Neutron sources and applications

Energy Technology Data Exchange (ETDEWEB)

Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

1994-01-01

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

Neutron sources and applications

International Nuclear Information System (INIS)

Price, D.L.; Rush, J.J.

1994-01-01

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications

Derivation of the source term, dose results and associated radiological consequences for the Greek Research Reactor – 1

Energy Technology Data Exchange (ETDEWEB)

Pappas, Charalampos, E-mail: chpappas@ipta.demokritos.gr; Ikonomopoulos, Andreas; Sfetsos, Athanasios; Andronopoulos, Spyros; Varvayanni, Melpomeni; Catsaros, Nicolas

2014-07-01

Highlights: • Source term derivation of postulated accident sequences in a research reactor. • Various containment ventilation scenarios considered for source term calculations. • Source term parametric analysis performed in case of lack of ventilation. • JRODOS employed for dose calculations under eighteen modeled scenarios. • Estimation of radiological consequences during typical and adverse weather scenarios. - Abstract: The estimated source term, dose results and radiological consequences of selected accident sequences in the Greek Research Reactor – 1 are presented and discussed. A systematic approach has been adopted to perform the necessary calculations in accordance with the latest computational developments and IAEA recommendations. Loss-of-coolant, reactivity insertion and fuel channel blockage accident sequences have been selected to derive the associated source terms under three distinct containment ventilation scenarios. Core damage has been conservatively assessed for each accident sequence while the ventilation has been assumed to function within the efficiency limits defined at the Safety Analysis Report. In case of lack of ventilation a parametric analysis is also performed to examine the dependency of the source term on the containment leakage rate. A typical as well as an adverse meteorological scenario have been defined in the JRODOS computational platform in order to predict the effective, lung and thyroid doses within a region defined by a 15 km radius downwind from the reactor building. The radiological consequences of the eighteen scenarios associated with the accident sequences are presented and discussed.

Design parameters and source terms: Volume 1, Design parameters: Revision 0

International Nuclear Information System (INIS)

1987-10-01

The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites

Item Strength Influences Source Confidence and Alters Source Memory zROC Slopes

Science.gov (United States)

Starns, Jeffrey J.; Ksander, John C.

2016-01-01

Increasing the number of study trials creates a crossover pattern in source memory zROC slopes; that is, the slope is either below or above 1 depending on which source receives stronger learning. This pattern can be produced if additional learning affects memory processes such as the relative contribution of recollection and familiarity to source…

Linac4 H− ion sources

International Nuclear Information System (INIS)

Lettry, J.; Aguglia, D.; Andersson, P.; Bertolo, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; David, N.; Chaudet, E.; Fink, D. A.; Garlasche, M.; Grudiev, A.; Guida, R.; Hansen, J.; Haase, M.; Jones, A.; Koszar, I.; Lallement, J.-B.; Lombardi, A. M.; Machado, C.

2016-01-01

CERN’s 160 MeV H − linear accelerator (Linac4) is a key constituent of the injector chain upgrade of the Large Hadron Collider that is being installed and commissioned. A cesiated surface ion source prototype is being tested and has delivered a beam intensity of 45 mA within an emittance of 0.3 π ⋅ mm ⋅ mrad. The optimum ratio of the co-extracted electron- to ion-current is below 1 and the best production efficiency, defined as the ratio of the beam current to the 2 MHz RF-power transmitted to the plasma, reached 1.1 mA/kW. The H − source prototype and the first tests of the new ion source optics, electron-dump, and front end developed to minimize the beam emittance are presented. A temperature regulated magnetron H − source developed by the Brookhaven National Laboratory was built at CERN. The first tests of the magnetron operated at 0.8 Hz repetition rate are described

Prions And Prion Diseases | Obi | African Journal of Clinical and ...

African Journals Online (AJOL)

Patients also may experience involuntary jerking movements called myoclonus, unusual sensation, insomnia, and confusion or memory problems. In the later stages of the disease, patients may have severe mental impairment (dementia) and may lose the ability to move or speak. Well known prion diseases include scrapie ...

PrPCWD lymphoid cell targets in early and advanced chronic wasting disease of mule deer

NARCIS (Netherlands)

Sigurdson, C.J.; Barillas-Mury, C.; Miller, M.W.; Oesch, B.; Keulen, van L.J.M.; Langeveld, J.P.M.; Hoover, E.A.

2002-01-01

Up to 15% of free-ranging mule deer in northeastern Colorado and southeastern Wyoming, USA, are afflicted with a prion disease, or transmissible spongiform encephalopathy (TSE), known as chronic wasting disease (CWD). CWD is similar to a subset of TSEs including scrapie and variant Creutzfeldt¿Jakob

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Scrapie disease is considered endemic in Sicily since 1997, following the administration of an infected vaccine. ... Istituto Zooprofilattico Sperimentale of Sicily, Adelmo Mirri, via Gino Marinuzzi 3, 90129 Palermo, Italy; Public Veterinary Service, ASP 9 Trapani, 91017 Pantelleria, Italy; The Roslin Institute, R(D)SVS University ...

Mychonastes afer HSO-3-1 as a potential new source of biodiesel

Directory of Open Access Journals (Sweden)

Yuan Cheng

2011-11-01

Full Text Available Abstract Background Biodiesel is considered to be a promising future substitute for fossil fuels, and microalgae are one source of biodiesel. The ratios of lipid, carbohydrates and proteins are different in different microalgal species, and finding a good strain for oil production remains a difficult prospect. Strains producing valuable co-products would improve the viability of biofuel production. Results In this study, we performed sequence analysis of the 18S rRNA gene and internal transcribed spacer (ITS of an algal strain designated HSO-3-1, and found that it was closely related to the Mychonastes afer strain CCAP 260/6. Morphology and cellular structure observation also supported the identification of strain HSO-3-1 as M. afer. We also investigated the effects of nitrogen on the growth and lipid accumulation of the naturally occurring M. afer HSO-3-1, and its potential for biodiesel production. In total, 17 fatty acid methyl esters (FAMEs were identified in M. afer HSO-3-1, using gas chromatography/mass spectrometry. The total lipid content of M. afer HSO-3-1 was 53.9% of the dry cell weight, and we also detected nervonic acid (C24:1, which has biomedical applications, making up 3.8% of total fatty acids. The highest biomass and lipid yields achieved were 3.29 g/l and 1.62 g/l, respectively, under optimized conditions. Conclusion The presence of octadecenoic and hexadecanoic acids as major components, with the presence of a high-value component, nervonic acid, renders M. afer HSO-3-1 biomass an economic feedstock for biodiesel production.

19 CFR 10.532 - Integrated Sourcing Initiative.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Integrated Sourcing Initiative. 10.532 Section 10... Trade Agreement Rules of Origin § 10.532 Integrated Sourcing Initiative. (a) For purposes of General... Sourcing Initiative if: (1) The good, in its condition as imported, is both classified in a tariff...

Recent developments in laser-driven polarized sources

International Nuclear Information System (INIS)

Young, L.; Coulter, K.P.; Holt, R.J.; Kinney, E.R.; Kowalczyk, R.S.; Potterveld, D.H.; Zghiche, A.

1990-01-01

Recent progress in the performance of laser-driven sources of polarized hydrogen and deuterium is described. The current status of the prototype source, I = 2.5 x 10 17 s -1 , polarization = 0.29 (including atomic fraction), is comparable to classical Stern-Gerlach sources. A scheme to improve source performance by approximately an order of magnitude, using a combination of optical-pumping spin-exchange and RF transitions, is outlined. 8 refs., 2 figs., 1 tab

The Isolation and Detection of Staphylococcus aureus Enterotoxins A-E and TSST-1 Genes from Different Sources by PCR Method

Directory of Open Access Journals (Sweden)

Norouzi J

2012-09-01

Full Text Available Background and Objectives: Enterotoxins and toxic shock syndrome toxin–1 (TSST-1 are an important virulence factor of S. aureus. The purpose of this study was to analyze the presence of S. aureus enterotoxin (sea-see and tst genes in the samples that collected from different sources with PCR method. Methods: During 5 months from 150 collected samples, 80 strains were identified as S. aureus. PCR reaction was used for investigation on the presence of genes for staphylococcal enterotoxins (A-E and toxic shock syndrome toxin-1 (TSST-1. Results: Fifty three samples (66.25% out of 80 samples were positive for one or more ETs and TSST-1 genes. of these positive strains, 17 (32.07% were positive for sea 39 (73.58% for seb, 30 (56.6% for sec, 2 (3.7% for sed, 21 (39.62% for see, and 14 (26.41% for tst. Enterotoxins and tst in 40 samples (75.47% observed.Conclusion: In this study, high prevalence of S. aureus, its enterotoxin, and tst genes were observed in clinical samples, food samples, and healthy people. This fact emphasizes on the role of human as original source and carrier of S. aureus. Also, use of PCR reaction for detection of these genes in S. aureus that isolated from various sources is recommended.

Toward unfolding the prion misfolding mystery: protein free radical chemistry in transmissible spongiform encephalopathies

International Nuclear Information System (INIS)

Yang Chiming

2003-01-01

Owing to the high oxygen-respiration in the brain of mammals, oxidative damage to prion protein has been suggested to be an additional factor. A large body of intriguing features of scrapie and prion diseases have provided multiple lines of indirect chemistry evidence, suggesting that the infectious agents may be putative forms of sequence-specific prion radicals (SSPR) and/or their immediate precursors in the transmissible spongiform encephalopathies (TSE). Here a molecular mechanism corresponding to the self-replication of scrapie protein mediated by prion free-radical processes, consonant with 'protein-only' hypotheses is proposed. This new theory may not only aid our understanding of the occurrence of prions, but also provides new insight into the possible chemistry principles underlying the neutrodegenerative disorders. It is anticipated that future studies based on this suggestion and chemistry principles of genetic diseases may allow us to determine an effective approach to stop mad cow disease and its human version, new variant of Creutzfeldt-Jakob disease (v CJD)

Aerosols transmit prions to immunocompetent and immunodeficient mice.

Directory of Open Access Journals (Sweden)

Johannes Haybaeck

Full Text Available Prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. However, prions are not generally considered to be airborne. Here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing PrP(C, efficiently develop scrapie upon exposure to aerosolized prions. NSE-PrP transgenic mice, which express PrP(C selectively in neurons, were also susceptible to airborne prions. Aerogenic infection occurred also in mice lacking B- and T-lymphocytes, NK-cells, follicular dendritic cells or complement components. Brains of diseased mice contained PrP(Sc and transmitted scrapie when inoculated into further mice. We conclude that aerogenic exposure to prions is very efficacious and can lead to direct invasion of neural pathways without an obligatory replicative phase in lymphoid organs. This previously unappreciated risk for airborne prion transmission may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories.

The P{sub 1}-approximation for the Distribution of Neutrons from a Pulsed Source in Hydrogen

Energy Technology Data Exchange (ETDEWEB)

Claesson, A

1963-12-15

The asymptotic distribution of neutrons from a pulsed, high energy source in an infinite moderator has been obtained earlier in a 'diffusion' approximation. In that paper the cross section was assumed to be constant over the whole energy region and the time derivative of the first moment was disregarded. Here, first, an analytic expression is obtained for the density in a P{sub 1} -approximation. However, the result is very complicated, and it is shown that an asymptotic solution can be found in a simpler way. By taking into account the low hydrogen scattering cross section at the source energy it follows that the space dependence of the distribution is less than that obtained earlier. The importance of keeping the time derivative of the first moment is further shown in a perturbation approximation.

BERKELEY: Light Source anniversary

International Nuclear Information System (INIS)

Anon.

1994-01-01

The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed

BERKELEY: Light Source anniversary

Energy Technology Data Exchange (ETDEWEB)

Anon.

1994-10-15

The staff of the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory has been too busy to celebrate the first anniversary of the facility's transition from a US Department of Energy construction project to operating third-generation synchrotron radiation source. Based on a 1.5-GeV, low-emittance electron storage ring that accommodates up to ten insertion-device radiation sources optimized primarily for the soft X-ray and vacuum ultra-violet regions of the spectrum, the ALS has completed.

Primary calibration of coiled 103Pd brachytherapy sources

International Nuclear Information System (INIS)

Paxton, Adam B.; Culberson, Wesley S.; DeWerd, Larry A.; Micka, John A.

2008-01-01

Coiled 103 Pd brachytherapy sources have been developed by RadioMed Corporation for use as low-dose-rate (LDR) interstitial implants. The coiled sources are provided in integer lengths from 1 to 6 cm and address many common issues seen with traditional LDR brachytherapy sources. The current standard for determining the air-kerma strength (S K ) of low-energy LDR brachytherapy sources is the National Institute of Standards and Technology's Wide-Angle Free-Air Chamber (NIST WAFAC). Due to geometric limitations, however, the NIST WAFAC is unable to determine the S K of sources longer than 1 cm. This project utilized the University of Wisconsin's Variable-Aperture Free-Air Chamber (UW VAFAC) to determine the S K of the longer coiled sources. The UW VAFAC has shown agreement in S K values of 1 cm length coils to within 1% of those determined with the NIST WAFAC, but the UW VAFAC does not share the same geometric limitations as the NIST WAFAC. A new source holder was constructed to hold the coiled sources in place during measurements with the UW VAFAC. Correction factors for the increased length of the sources have been determined and applied to the measurements. Using the new source holder and corrections, the S K of 3 and 6 cm coiled sources has been determined. Corrected UW VAFAC data and ionization current measurements from well chambers have been used to determine calibration coefficients for use in the measurement of 3 and 6 cm coiled sources in well chambers. Thus, the UW VAFAC has provided the first transferable, primary measurement of low-energy LDR brachytherapy sources with lengths greater than 1 cm

Agronomic Performance of Flue-Cured Tobacco F1 Hybrids Obtained with Different Sources of Male Sterile Cytoplasm

Directory of Open Access Journals (Sweden)

Berbec A

2014-12-01

Full Text Available Four cytoplasmic male sterile (cms F1flue-cured hybrids cv. Wiaelica × cv. Virginia Golta (VG, the male fertile analogue and the parental varieties were tested at two locations in Poland in a replicated field trial. The cms sources in the hybrids wereN. suaveolens,N. amplexicaulis,N. bigeloviiand aN. tabacumcms mutant. Under the slight to moderate pressure from black root rot present at the trial sites the hybrids showed a moderate tolerance of the disease characteristic of VG as opposed to medium strong susceptibility of Wislica. Apart from the effect of black root rot tolerance the vegetative vigor of the hybrids (plant height, leaf size, earliness was affected by cytoplasm source. The F1hybrid withN. suaveolens cytoplasm flowered approximately three days later than the remaining hybrids. Of the cms hybrids tested cmsN. bigelovii produced the tallest plants with largest mid-position leaves. Yields of cured leaves were largely influenced by black root rot and were generally higher in VG and in the hybrids than in Wislica. Leaf yields and curability were generally little affected by cms source under low pressure from black root rot. At the site with a relatively high level of black root rot infestation the yields of cmsN. suaveolens were slightly lower but the percentage of light grades slightly higher compared to those of other cms hybrids. CmsN. suaveolens was the best hybrid in terms of money returns at the low black root rot field but it was the poorest hybrid performer under high pressure from the disease. Contents of nitrogen, sugars, nicotine and ash was little affected by source of cms. There was an increased incidence of potato virus Y (PVY and white spots in cmsN. suaveolens and, to a lesser extent, in cmsN. bigelovii as compared to the remaining disease-free entries.

Puzzling accretion onto a black hole in the ultraluminous X-ray source M 101 ULX-1.

Science.gov (United States)

Liu, Ji-Feng; Bregman, Joel N; Bai, Yu; Justham, Stephen; Crowther, Paul

2013-11-28

There are two proposed explanations for ultraluminous X-ray sources (ULXs) with luminosities in excess of 10(39) erg s(-1). They could be intermediate-mass black holes (more than 100-1,000 solar masses, M sun symbol) radiating at sub-maximal (sub-Eddington) rates, as in Galactic black-hole X-ray binaries but with larger, cooler accretion disks. Alternatively, they could be stellar-mass black holes radiating at Eddington or super-Eddington rates. On its discovery, M 101 ULX-1 had a luminosity of 3 × 10(39) erg s(-1) and a supersoft thermal disk spectrum with an exceptionally low temperature--uncomplicated by photons energized by a corona of hot electrons--more consistent with the expected appearance of an accreting intermediate-mass black hole. Here we report optical spectroscopic monitoring of M 101 ULX-1. We confirm the previous suggestion that the system contains a Wolf-Rayet star, and reveal that the orbital period is 8.2 days. The black hole has a minimum mass of 5 M sun symbol, and more probably a mass of 20 M sun symbol-30 M sun symbol, but we argue that it is very unlikely to be an intermediate-mass black hole. Therefore, its exceptionally soft spectra at high Eddington ratios violate the expectations for accretion onto stellar-mass black holes. Accretion must occur from captured stellar wind, which has hitherto been thought to be so inefficient that it could not power an ultraluminous source.

Fast temperature optimization of multi-source hyperthermia applicators with reduced-order modeling of 'virtual sources'

International Nuclear Information System (INIS)

Cheng, K-S; Stakhursky, Vadim; Craciunescu, Oana I; Stauffer, Paul; Dewhirst, Mark; Das, Shiva K

2008-01-01

proposed approach of using virtual sources reduces the number of variables that must be optimized to achieve a tumor-focused temperature distribution, thereby reducing the calculation time required in real-time control applications to about 1/3 to 1/4 of that required for full optimization

Improved cycling and high rate performance of core-shell LiFe1/3Mn1/3Co1/3PO4/carbon nanocomposites for lithium-ion batteries: Effect of the carbon source

International Nuclear Information System (INIS)

Li, Huanhuan; Chen, Yi; Chen, Long; Jiang, Haobin; Wang, Yaping; Wang, Hongbo; Li, Guochun; Li, Yunxing; Yuan, Yuan

2014-01-01

Highlights: • We report a fast microwave heating way to prepare LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /C. • The effects of different carbon sources were discussed in detail. • LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP2000 shows a discharge capacity of 160 mA h g −1 at 0.1 C. • LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP2000 elucidates excellent cyclic stability. • LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP2000 exhibits attractive rate capability. - Abstract: Core-shell type olivine solid solutions, LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /C, are synthesized via a very simple and rapid microwave heating route with different carbon sources. The obatined LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /C materials are characterized thoroughly by various analytical techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy-dispersive spectroscopy instrument. The particle sizes and distribution of the carbon layer of BP2000 carbon black coated LiFe 1/3 Mn 1/3 Co 1/3 PO 4 (LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP) are more uniform than that obtained from acetylene black (LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /AB) and Super P (LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /SP). Moreover, the LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP nanocomposite shows superior electrochemical properties such as high discharge capacity of 160 mA h g −1 at 0.1 C, excellent cyclic stability (143 mA h g −1 at 0.1 C after 30 cycles) and rate capability (76 mAh g −1 at 20 C), which are better than other two samples. Cyclic voltammetric and electrical tests disclose that the Li-ion diffusion, the reversibility of lithium extraction/insertion and electrical conductivity are significantly improved in LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP composite. Electrochemical impedance spectroscopy illustrates that LiFe 1/3 Mn 1/3 Co 1/3 PO 4 /BP composite electrode possesses low contact and charge-transfer impedances, which can lead to rapid electron transport during the electrochemical lithium insertion/extraction reaction. It is believed that olivine solid

Photon acceleration-based radiation sources

International Nuclear Information System (INIS)

Hoffman, J. R.; Muggli, P.; Katsouleas, T.; Mori, W. B.; Joshi, C.

1999-01-01

The acceleration and deceleration of photons in a plasma provides the means for a series of new radiation sources. Previous work on a DC to AC Radiation Converter (DARC source) has shown variable acceleration of photons having zero frequency (i.e., an electrostatic field) to between 6 and 100 GHz (1-3). These sources all had poor guiding characteristics resulting in poor power coupling from the source to the load. Continuing research has identified a novel way to integrate the DARC source into a waveguide. The so called ''pin structure'' uses stainless steel pins inserted through the narrow side of an X band waveguide to form the electrostatic field pattern (k≠0, ω=0). The pins are spaced such that the absorption band resulting from this additional periodic structure is outside of the X band range (8-12 GHz), in which the normal waveguide characteristics are left unchanged. The power of this X band source is predicted theoretically to scale quadratically with the pin bias voltage as -800 W/(kV) 2 and have a pulse width of -1 ns. Cold tests and experimental results are presented. Applications for a high power, short pulse radiation source extends to the areas of landmine detection, improved radar resolution, and experimental investigations of molecular systems

Fundamental-mode sources in approach to critical experiments

International Nuclear Information System (INIS)

Goda, J.; Busch, R.

2000-01-01

An equivalent fundamental-mode source is an imaginary source that is distributed identically in space, energy, and angle to the fundamental-mode fission source. Therefore, it produces the same neutron multiplication as the fundamental-mode fission source. Even if two source distributions produce the same number of spontaneous fission neutrons, they will not necessarily contribute equally toward the multiplication of a given system. A method of comparing the relative importance of source distributions is needed. A factor, denoted as g* and defined as the ratio of the fixed-source multiplication to the fundamental-mode multiplication, is used to convert a given source strength to its equivalent fundamental-mode source strength. This factor is of interest to criticality safety as it relates to the 1/M method of approach to critical. Ideally, a plot of 1/M versus κ eff is linear. However, since 1/M = (1 minus κ eff )/g*, the plot will be linear only if g* is constant with κ eff . When g* increases with κ eff , the 1/M plot is said to be conservative because the critical mass is underestimated. However, it is possible for g* to decrease with κ eff yielding a nonconservative 1/M plot. A better understanding of g* would help predict whether a given approach to critical will be conservative or nonconservative. The equivalent fundamental-mode source strength g*S can be predicted by experiment. The experimental method was tested on the XIX-1 core on the Fast Critical Assembly at the Japan Atomic Energy Research Institute. The results showed a 30% difference between measured and calculated values. However, the XIX-1 reactor had significant intermediate-energy neutrons. The presence of intermediate-energy neutrons may have made the cross-section set used for predicted values less than ideal for the system

Control system for 5 MW neutral beam ion source for SST1

Science.gov (United States)

Patel, G. B.; Onali, Raja; Sharma, Vivek; Suresh, S.; Tripathi, V.; Bandyopadhyay, M.; Singh, N. P.; Thakkar, Dipal; Gupta, L. N.; Singh, M. J.; Patel, P. J.; Chakraborty, A. K.; Baruah, U. K.; Mattoo, S. K.

2006-01-01

This article describes the control system for a 5MW ion source of the NBI (neutral beam injector) for steady-state superconducting tokamak-1 (SST-1). The system uses both hardware and software solutions. It comprises a DAS (data acquisition system) and a control system. The DAS is used to read the voltage and current signals from eight filament heater power supplies and 24 discharge power supplies. The control system is used to adjust the filament heater current in order to achieve an effective control on the discharge current in the plasma box. The system consists of a VME (Verse Module Eurocard) system and C application program running on a VxWorks™ real-time operating system. A PID (proportional, integral, and differential) algorithm is used to control the filament heater current. Experiments using this system have shown that the discharge current can be controlled within 1% accuracy for a PID loop time of 20ms. Response of the control system to the pressure variation of the gas in the chamber has also been studied and compared with the results obtained from those of an uncontrolled system. The present approach increases the flexibility of the control system. It not only eases the control of the plasma but also allows an easy changeover to various operation scenarios.

Source fabrication and lifetime for Li⁺ ion beams extracted from alumino-silicate sources

Energy Technology Data Exchange (ETDEWEB)

Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W

2012-03-05

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm² have been measured from lithium alumino-silicate ion sources at a temperature of ~1275 °C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm², and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, ≤0.25 mm thick, has a measured lifetime of ~40 h at ~1275 °C, when pulsed at 0.05 Hz and with pulse length of ~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Finally, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

Source fabrication and lifetime for Li⁺ ion beams extracted from alumino-silicate sources

Energy Technology Data Exchange (ETDEWEB)

Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W.

2012-04-01

A space-charge-limited beam with current densities (J) exceeding 1 mA/cm² have been measured from lithium alumino-silicate ion sources at a temperature of ~1275 °C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm², and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, ≤0.25 mm thick, has a measured lifetime of ~40 h at ~1275 °C, when pulsed at 0.05 Hz and with pulse length of ~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. Finally, the source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

Construction report of the PF slow-positron source. 1

International Nuclear Information System (INIS)

Enomoto, Atsushi; Kurihara, Toshikazu; Kobayashi, Hitoshi

1993-12-01

The slow positron source utilizing the electron beam of the 2.5 GeV electron beam accelerator which is the synchrotron radiation injector is being constructed. The outline of the project and the present state of construction are reported. As of November, 1993, by injecting the electron beam of about 10 W to the targets for producing positrons, the slow positrons of 4 x 10 4 e + /s has been obtained in the laboratory. Finally, with the electron beam of 30 kW, it is aimed at to obtain the slow positron beam of 2 x 10 9 e + /s. In the slow positron source, the electron beam from the 2.5 GeV linear accelerator is used as the primary beam. This beam is led to the target with electromagnets. Radiation shields were strengthened, and the electrostatic lens system was attached to efficiently extract and send out slow positrons. The conveying system for slow positrons is explained. Primary electron beam, target and moderator for producing slow positrons, the change to continuous current of pulsed slow positron beam and the heightening of luminance of slow positron beam, and the experiment on the utilization of slow positron beam, and the control system for positron conveyance path are reported. (K.I.)

Negative effects of item repetition on source memory.

Science.gov (United States)

Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L; Johnson, Marcia K

2012-08-01

In the present study, we explored how item repetition affects source memory for new item-feature associations (picture-location or picture-color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item repetition also had a negative effect on source memory when different source dimensions were used in Phases 1 and 2 (Experiment 3) and when participants were explicitly instructed to learn source information in Phase 2 (Experiments 4 and 5). Importantly, when the order between Phases 1 and 2 was reversed, such that item repetition occurred after the encoding of critical item-source combinations, item repetition no longer affected source memory (Experiment 6). Overall, our findings did not support predictions based on item predifferentiation, within-dimension source interference, or general interference from multiple traces of an item. Rather, the findings were consistent with the idea that prior item repetition reduces attention to subsequent presentations of the item, decreasing the likelihood that critical item-source associations will be encoded.

Laser ion source with solenoid field

Science.gov (United States)

Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

2014-11-01

Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

Proposal for a source of polarized protons; Projet de source de protons polarises

Energy Technology Data Exchange (ETDEWEB)

Abragam, A.; Winter, J. M. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Saclay, BP2, Gif-sur-Yvette (France)

1959-07-01

Proposal for a source of polarized protons based on the theory of adiabatic fast passage due to F. Bloch. Reprint of a paper published in 'Physical review letters', vol 1, n. 10, 15 Nov 1958, p. 374-375 [French] On propose une methode nouvelle pour la realisation d'une source de protons polarises basee sur la theorie du passage adiabatique de F. Bloch. Reproduction d'un article publie dans 'Physical review letters', vol 1, n. 10, 15 nov 1958, p. 374-375.