Human regulator of telomere elongation helicase 1 (RTEL1) is required for the nuclear and cytoplasmic trafficking of pre-U2 RNA

PubMed Central

Schertzer, Michael; Jouravleva, Karina; Perderiset, Mylene; Dingli, Florent; Loew, Damarys; Le Guen, Tangui; Bardoni, Barbara; de Villartay, Jean-Pierre; Revy, Patrick; Londoño-Vallejo, Arturo

2015-01-01

Hoyeraal-Hreidarsson syndrome (HHS) is a severe form of Dyskeratosis congenita characterized by developmental defects, bone marrow failure and immunodeficiency and has been associated with telomere dysfunction. Recently, mutations in Regulator of Telomere ELongation helicase 1 (RTEL1), a helicase first identified in Mus musculus as being responsible for the maintenance of long telomeres, have been identified in several HHS patients. Here we show that RTEL1 is required for the export and the correct cytoplasmic trafficking of the small nuclear (sn) RNA pre-U2, a component of the major spliceosome complex. RTEL1-HHS cells show abnormal subcellular partitioning of pre-U2, defects in the recycling of ribonucleotide proteins (RNP) in the cytoplasm and splicing defects. While most of these phenotypes can be suppressed by re-expressing the wild-type protein in RTEL1-HHS cells, expression of RTEL1 mutated variants in immortalized cells provokes cytoplasmic mislocalizations of pre-U2 and other RNP components, as well as splicing defects, thus phenocopying RTEL1-HHS cellular defects. Strikingly, expression of a cytoplasmic form of RTEL1 is sufficient to correct RNP mislocalizations both in RTEL1–HHS cells and in cells expressing nuclear mutated forms of RTEL1. This work unravels completely unanticipated roles for RTEL1 in RNP trafficking and strongly suggests that defects in RNP biogenesis pathways contribute to the pathology of HHS. PMID:25628358

Human regulator of telomere elongation helicase 1 (RTEL1) is required for the nuclear and cytoplasmic trafficking of pre-U2 RNA.

PubMed

Schertzer, Michael; Jouravleva, Karina; Perderiset, Mylene; Dingli, Florent; Loew, Damarys; Le Guen, Tangui; Bardoni, Barbara; de Villartay, Jean-Pierre; Revy, Patrick; Londoño-Vallejo, Arturo

2015-02-18

Hoyeraal-Hreidarsson syndrome (HHS) is a severe form of Dyskeratosis congenita characterized by developmental defects, bone marrow failure and immunodeficiency and has been associated with telomere dysfunction. Recently, mutations in Regulator of Telomere ELongation helicase 1 (RTEL1), a helicase first identified in Mus musculus as being responsible for the maintenance of long telomeres, have been identified in several HHS patients. Here we show that RTEL1 is required for the export and the correct cytoplasmic trafficking of the small nuclear (sn) RNA pre-U2, a component of the major spliceosome complex. RTEL1-HHS cells show abnormal subcellular partitioning of pre-U2, defects in the recycling of ribonucleotide proteins (RNP) in the cytoplasm and splicing defects. While most of these phenotypes can be suppressed by re-expressing the wild-type protein in RTEL1-HHS cells, expression of RTEL1 mutated variants in immortalized cells provokes cytoplasmic mislocalizations of pre-U2 and other RNP components, as well as splicing defects, thus phenocopying RTEL1-HHS cellular defects. Strikingly, expression of a cytoplasmic form of RTEL1 is sufficient to correct RNP mislocalizations both in RTEL1-HHS cells and in cells expressing nuclear mutated forms of RTEL1. This work unravels completely unanticipated roles for RTEL1 in RNP trafficking and strongly suggests that defects in RNP biogenesis pathways contribute to the pathology of HHS. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Analysis of aberrant pre-messenger RNA splicing resulting from mutations in ATP8B1 and efficient in vitro rescue by adapted U1 small nuclear RNA.

PubMed

van der Woerd, Wendy L; Mulder, Johanna; Pagani, Franco; Beuers, Ulrich; Houwen, Roderick H J; van de Graaf, Stan F J

2015-04-01

ATP8B1 deficiency is a severe autosomal recessive liver disease resulting from mutations in the ATP8B1 gene characterized by a continuous phenotypical spectrum from intermittent (benign recurrent intrahepatic cholestasis; BRIC) to progressive familial intrahepatic cholestasis (PFIC). Current therapeutic options are insufficient, and elucidating the molecular consequences of mutations could lead to personalized mutation-specific therapies. We investigated the effect on pre-messenger RNA splicing of 14 ATP8B1 mutations at exon-intron boundaries using an in vitro minigene system. Eleven mutations, mostly associated with a PFIC phenotype, resulted in aberrant splicing and a complete absence of correctly spliced product. In contrast, three mutations led to partially correct splicing and were associated with a BRIC phenotype. These findings indicate an inverse correlation between the level of correctly spliced product and disease severity. Expression of modified U1 small nuclear RNAs (snRNA) complementary to the splice donor sites strongly improved or completely rescued splicing for several ATP8B1 mutations located at donor, as well as acceptor, splice sites. In one case, we also evaluated exon-specific U1 snRNAs that, by targeting nonconserved intronic sequences, might reduce possible off-target events. Although very effective in correcting exon skipping, they also induced retention of the short downstream intron. We systematically characterized the molecular consequences of 14 ATP8B1 mutations at exon-intron boundaries associated with ATP8B1 deficiency and found that the majority resulted in total exon skipping. The amount of correctly spliced product inversely correlated with disease severity. Compensatory modified U1 snRNAs, complementary to mutated donor splice sites, were able to improve exon definition very efficiently and could be a novel therapeutic strategy in ATP8B1 deficiency as well as other genetic diseases. © 2014 by the American Association for the Study

Usb1 controls U6 snRNP assembly through evolutionarily divergent cyclic phosphodiesterase activities.

PubMed

Didychuk, Allison L; Montemayor, Eric J; Carrocci, Tucker J; DeLaitsch, Andrew T; Lucarelli, Stefani E; Westler, William M; Brow, David A; Hoskins, Aaron A; Butcher, Samuel E

2017-09-08

U6 small nuclear ribonucleoprotein (snRNP) biogenesis is essential for spliceosome assembly, but not well understood. Here, we report structures of the U6 RNA processing enzyme Usb1 from yeast and a substrate analog bound complex from humans. Unlike the human ortholog, we show that yeast Usb1 has cyclic phosphodiesterase activity that leaves a terminal 3' phosphate which prevents overprocessing. Usb1 processing of U6 RNA dramatically alters its affinity for cognate RNA-binding proteins. We reconstitute the post-transcriptional assembly of yeast U6 snRNP in vitro, which occurs through a complex series of handoffs involving 10 proteins (Lhp1, Prp24, Usb1 and Lsm2-8) and anti-cooperative interactions between Prp24 and Lhp1. We propose a model for U6 snRNP assembly that explains how evolutionarily divergent and seemingly antagonistic proteins cooperate to protect and chaperone the nascent snRNA during its journey to the spliceosome.The mechanism of U6 small nuclear ribonucleoprotein (snRNP) biogenesis is not well understood. Here the authors characterize the enzymatic activities and structures of yeast and human U6 RNA processing enzyme Usb1, reconstitute post-transcriptional assembly of yeast U6 snRNP in vitro, and propose a model for U6 snRNP assembly.

Preliminary results of calculations for heavy-water nuclear-power-plant reactors employing 235U, 233U, and 232Th as a fuel and meeting requirements of a nonproliferation of nuclear weapons

NASA Astrophysics Data System (ADS)

Ioffe, B. L.; Kochurov, B. P.

2012-02-01

A physical design is developed for a gas-cooled heavy-water nuclear reactor intended for a project of a nuclear power plant. As a fuel, the reactor would employ thorium with a small admixture of enriched uranium that contains not more than 20% of 235U. It operates in the open-cycle mode involving 233U production from thorium and its subsequent burnup. The reactor meets the conditions of a nonproliferation of nuclear weapons: the content of fissionable isotopes in uranium at all stages of the process, including the final one, is below the threshold for constructing an atomic bomb, the amount of product plutonium being extremely small.

Myeloid leukemia factor 1 associates with a novel heterogeneous nuclear ribonucleoprotein U-like molecule.

PubMed

Winteringham, Louise N; Endersby, Raelene; Kobelke, Simon; McCulloch, Ross K; Williams, James H; Stillitano, Justin; Cornwall, Scott M; Ingley, Evan; Klinken, S Peter

2006-12-15

Myeloid leukemia factor 1 (MLF1) is an oncoprotein associated with hemopoietic lineage commitment and acute myeloid leukemia. Here we show that Mlf1 associated with a novel binding partner, Mlf1-associated nuclear protein (Manp), a new heterogeneous nuclear ribonucleoprotein (hnRNP) family member, related to hnRNP-U. Manp localized exclusively in the nucleus and could redirect Mlf1 from the cytoplasm into the nucleus. The nuclear content of Mlf1 was also regulated by 14-3-3 binding to a canonical 14-3-3 binding motif within the N terminus of Mlf1. Significantly Mlf1 contains a functional nuclear export signal and localized primarily to the nuclei of hemopoietic cells. Mlf1 was capable of binding DNA, and microarray analysis revealed that it affected the expression of several genes, including transcription factors. In summary, this study reveals that Mlf1 translocates between nucleus and cytoplasm, associates with a novel hnRNP, and influences gene expression.

Searching for U-235m produced by Nuclear Excitation by Electronic Transition

NASA Astrophysics Data System (ADS)

Chodash, Perry; Norman, Eric; Burke, Jason; Wilks, Scott; Casperson, Robert

2014-09-01

Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that is predicted to occur in numerous isotopes, including U-235. When a nuclear transition matches the energy and the multipolarity of an electronic transition, there is a possibility that NEET will occur. If NEET were to occur in U-235, the nucleus would be excited to its 1/2 + isomeric state that subsequently decays by internal conversion with a decay energy of 77 eV and a half-life of 26 minutes. Theory predicts that NEET can occur in partially ionized uranium plasma with a charge state of 23 +. A pulsed Nd:YAG laser operating at 1064 nm with a pulse energy of 780 mJ and a pulse width of 9 ns was used to generate the uranium plasma. The laser was focused on small samples of both depleted uranium and highly enriched uranium. The plasma conditions created by the intense laser pulse were varied by changing the spot size of the laser on the target. The resulting plasma was collected on a plate and the internal conversion electrons were focused onto a microchannel plate detector by a series of electrostatic lenses. First results will be presented. Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that is predicted to occur in numerous isotopes, including U-235. When a nuclear transition matches the energy and the multipolarity of an electronic transition, there is a possibility that NEET will occur. If NEET were to occur in U-235, the nucleus would be excited to its 1/2 + isomeric state that subsequently decays by internal conversion with a decay energy of 77 eV and a half-life of 26 minutes. Theory predicts that NEET can occur in partially ionized uranium plasma with a charge state of 23 +. A pulsed Nd:YAG laser operating at 1064 nm with a pulse energy of 780 mJ and a pulse width of 9 ns was used to generate the uranium plasma. The laser was focused on small samples of both depleted uranium and highly enriched uranium. The plasma conditions created by the

Positive nuclear BAP1 immunostaining helps differentiate non-small cell lung carcinomas from malignant mesothelioma

PubMed Central

Carbone, Michele; Shimizu, David; Napolitano, Andrea; Tanji, Mika; Pass, Harvey I.; Yang, Haining; Pastorino, Sandra

2016-01-01

The differential diagnosis between pleural malignant mesothelioma (MM) and lung cancer is often challenging. Immunohistochemical (IHC) stains used to distinguish these malignancies include markers that are most often positive in MM and less frequently positive in carcinomas, and vice versa. However, in about 10–20% of the cases, the IHC results can be confusing and inconclusive, and novel markers are sought to increase the diagnostic accuracy. We stained 45 non-small cell lung cancer samples (32 adenocarcinomas and 13 squamous cell carcinomas) with a monoclonal antibody for BRCA1-associated protein 1 (BAP1) and also with an IHC panel we routinely use to help differentiate MM from carcinomas, which include, calretinin, Wilms Tumor 1, cytokeratin 5, podoplanin D2-40, pankeratin CAM5.2, thyroid transcription factor 1, Napsin-A, and p63. Nuclear BAP1 expression was also analyzed in 35 MM biopsies. All 45 non-small cell lung cancer biopsies stained positive for nuclear BAP1, whereas 22/35 (63%) MM biopsies lacked nuclear BAP1 staining, consistent with previous data. Lack of BAP1 nuclear staining was associated with MM (two-tailed Fisher's Exact Test, P = 5.4 × 10−11). Focal BAP1 staining was observed in a subset of samples, suggesting polyclonality. Diagnostic accuracy of other classical IHC markers was in agreement with previous studies. Our study indicated that absence of nuclear BAP1 stain helps differentiate MM from lung carcinomas. We suggest that BAP1 staining should be added to the IHC panel that is currently used to distinguish these malignancies. PMID:27447750

Characterization of the Human Herpesvirus 6 U69 Gene Product and Identification of Its Nuclear Localization Signal▿

PubMed Central

Isegawa, Yuji; Miyamoto, Yoichi; Yasuda, Yoshinari; Semi, Katsunori; Tsujimura, Kenji; Fukunaga, Rikiro; Ohshima, Atsushi; Horiguchi, Yasuhiro; Yoneda, Yoshihiro; Sugimoto, Nakaba

2008-01-01

To elucidate the function of the U69 protein kinase of human herpesvirus 6 (HHV-6) in vivo, we first analyzed its subcellular localization in HHV-6-infected Molt 3 cells by using polyclonal antibodies against the U69 protein. Immunofluorescence studies showed that the U69 signal localized to the nucleus in a mesh-like pattern in both HHV-6-infected and HHV6-transfected cells. A computer program predicted two overlapping classic nuclear localization signals (NLSs) in the N-terminal region of the protein; this NLS motif is highly conserved in the N-terminal region of most of the herpesvirus protein kinases examined to date. An N-terminal deletion mutant form of the protein failed to enter the nucleus, whereas a fusion protein of green fluorescent protein (GFP) and/or glutathione S-transferase (GST) and the U69 N-terminal region was transported into the nucleus, demonstrating that the predicted N-terminal NLSs of the protein actually function as NLSs. The nuclear transport of the GST-GFP fusion protein containing the N-terminal NLS of U69 was inhibited by wheat germ agglutinin and by the Q69L Ran-GTP mutant, indicating that the U69 protein is transported into the nucleus from the cytoplasm via classic nuclear transport machinery. A cell-free import assay showed that the nuclear transport of the U69 protein was mediated by importin α/β in conjunction with the small GTPase Ran. When the import assay was performed with a low concentration of each importin-α subtype, NPI2/importin-α7 elicited more efficient transport activity than did Rch1/importin-α1 or Qip1/importin-α3. These results suggest a relationship between the localization of NPI2/importin-α7 and the cell tropism of HHV-6. PMID:18003734

Mapping the binding site of snurportin 1 on native U1 snRNP by cross-linking and mass spectrometry

PubMed Central

Kühn-Hölsken, Eva; Lenz, Christof; Dickmanns, Achim; Hsiao, He-Hsuan; Richter, Florian M.; Kastner, Berthold; Ficner, Ralf; Urlaub, Henning

2010-01-01

Mass spectrometry allows the elucidation of molecular details of the interaction domains of the individual components in macromolecular complexes subsequent to cross-linking of the individual components. Here, we applied chemical and UV cross-linking combined with tandem mass-spectrometric analysis to identify contact sites of the nuclear import adaptor snurportin 1 to the small ribonucleoprotein particle U1 snRNP in addition to the known interaction of m3G cap and snurportin 1. We were able to define previously unknown sites of protein–protein and protein–RNA interactions on the molecular level within U1 snRNP. We show that snurportin 1 interacts with its central m3G-cap-binding domain with Sm proteins and with its extreme C-terminus with stem-loop III of U1 snRNA. The crosslinking data support the idea of a larger interaction area between snurportin 1 and U snRNPs and the contact sites identified prove useful for modeling the spatial arrangement of snurportin 1 domains when bound to U1 snRNP. Moreover, this suggests a functional nuclear import complex that assembles around the m3G cap and the Sm proteins only when the Sm proteins are bound and arranged in the proper orientation to the cognate Sm site in U snRNA. PMID:20421206

Cell lines that support replication of a novel herpes simplex virus 1 U{sub L}31 deletion mutant can properly target U{sub L}34 protein to the nuclear rim in the absence of U{sub L}31

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang Li; Tanaka, Michiko; Kawaguchi, Yasushi

2004-11-10

Previous results indicated that the herpes simplex virus 1 (HSV-1) U{sub L}31 gene is necessary and sufficient for localization of the U{sub L}34 protein exclusively to the nuclear membrane of infected Hep2 cells. In the current studies, a bacterial artificial chromosome containing the entire HSV-1 strain F genome was used to construct a recombinant viral genome in which a gene encoding kanamycin resistance was inserted in place of 262 codons of the 306 codon U{sub L}31 open reading frame. The deletion virus produced virus titers approximately 10- to 50-fold lower in rabbit skin cells, more than 2000-fold lower in Veromore » cells, and more than 1500-fold lower in CV1 cells, compared to a virus bearing a restored U{sub L}31 gene. The replication of the U{sub L}31 deletion virus was restored on U{sub L}31-complementing cell lines derived either from rabbit skin cells or CV1 cells. Confocal microscopy indicated that the majority of U{sub L}34 protein localized aberrantly in the cytoplasm and nucleoplasm of Vero cells and CV1 cells, whereas U{sub L}34 protein localized at the nuclear membrane in rabbit skin cells, and U{sub L}31 complementing CV1 cells infected with the U{sub L}31 deletion virus. We conclude that rabbit skin cells encode a function that allows proper localization of U{sub L}34 protein to the nuclear membrane. We speculate that this function partially complements that of U{sub L}31 and may explain why U{sub L}31 is less critical for replication in rabbit skin cells as opposed to Vero and CV1 cells.« less

The Nuclear Renaissance in the U.S.

ScienceCinema

Buongiorno, Jacopo

2018-04-23

Nuclear power currently provides 20% of the electricity generation in the U.S. and about 16% worldwide.  As a carbon-free energy source, nuclear is receiving a lot of attention by industry, lawmakers and environmental groups, as they attempt to resolve the issue of man-made climate change.  For the first time in 30 years several U.S. electric utilities have applied for construction and operation licenses of new nuclear power plants.  This talk will review the safety, operational and economic record of the existing U.S. commercial reactor fleet, will provide an overview of the reactor designs considered for the new wave of plant construction, and will discuss several research projects being conducted at the Massachusetts Institute of Technology to support the expansion of nuclear power in the U.S. and overseas.

Nuclear Excitation by Electronic Transition of U-235

NASA Astrophysics Data System (ADS)

Chodash, Perry

2017-01-01

Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that is theorized to exist in numerous isotopes. NEET is the inverse of bound internal conversion and occurs when an electronic transition couples to a nuclear transition causing the nucleus to enter an excited state. This process can only occur for isotopes with low-lying nuclear levels due to the requirement that the electronic and nuclear transitions have similar energies. One of the candidate isotopes for NEET, 235U, has been studied several times over the past 40 years and NEET of 235U has never been conclusively observed. These past experiments generated conflicting results with some experiments claiming to observe NEET of 235U and others setting limits for the NEET rate. If NEET of 235U were to occur, the uranium would be excited to its first excited nuclear state. The first excited nuclear state in 235U is only 76 eV, the second lowest known nuclear state. Additionally, the 76 eV state is a nuclear isomer that decays by internal conversion with a half-life of 26 minutes. In order to measure whether NEET occurs in 235U and at what rate, a uranium plasma was required. The plasma was generated using a Q-switched Nd:YAG laser outputting 789 mJ pulses of 1064 nm light. The laser light was focused onto uranium targets generating an intensity on target of order 1012 W/cm2. The resulting plasma was captured on a catcher plate and electrons emitted from the catcher plate were accelerated and focused onto a microchannel plate detector. Measurements performed using a variety of uranium targets spanning depleted uranium up to 99.4% enriched uranium did not observe a 26 minute decay. An upper limit for the NEET rate of 235U was determined. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. The U.S. DHS, UC Berkeley, the NNIS fellowship and the NSSC further supported this work.

Nuclear Resonance Fluorescence of U-235

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Glen A.; Caggiano, Joseph A.; Hensley, Walter K.

Nuclear resonance fluorescence is a physical process that provides an isotopic-specific signature that could be used for the identification and characterization of materials. The technique involves the detection of prompt discrete-energy photons emitted from a sample which is exposed to photons in the MeV energy range. Potential applications of the technique range from detection of high explosives to characterization of special nuclear materials. One isotope of significant interest is 235U. Pacific Northwest National Laboratory and Passport Systems have collaborated to conduct measurements to search for a nuclear resonance fluorescence response of 235U below 3 MeV using a 200 g samplemore » of highly enriched uranium. Nine 235U resonances between 1650 and 2010 keV were identified in the preliminary analysis. Analysis of the measurement data to determine the integrated cross sections of the resonances is in progress.« less

Projected Costs of U.S. Nuclear Forces, 2017 to 2026

DTIC Science & Technology

2017-02-01

CBO FEBRUARY 2017 Projected Costs of U.S. Nuclear Forces, 2017 to 2026 Nuclear weapons have been a cornerstone of U.S. national security since they...were developed during World War II. In the Cold War, nuclear forces were central to U.S. defense policy, resulting in the buildup of a large...arsenal. Since that time, nuclear forces have figured less prominently than conventional forces, and the United States has not built any new nuclear

Roles for herpes simplex virus type 1 U{sub L}34 and U{sub S}3 proteins in disrupting the nuclear lamina during herpes simplex virus type 1 egress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bjerke, Susan L.; Roller, Richard J.

2006-04-10

Cells infected with wild type HSV-1 showed significant lamin A/C and lamin B rearrangement, while U{sub L}34-null virus-infected cells exhibited few changes in lamin localization, indicating that U{sub L}34 is necessary for lamin disruption. During HSV infection, U{sub S}3 limited the development of disruptions in the lamina, since cells infected with a U{sub S}3-null virus developed large perforations in the lamin layer. U{sub S}3 regulation of lamin disruption does not correlate with the induction of apoptosis. Expression of either U{sub L}34 or U{sub S}3 proteins alone disrupted lamin A/C and lamin B localization. Expression of U{sub L}34 and U{sub S}3more » together had little effect on lamin A/C localization, suggesting a regulatory interaction between the two proteins. The data presented in this paper argue for crucial roles for both U{sub L}34 and U{sub S}3 in regulating the state of the nuclear lamina during viral infection.« less

The herpes simplex virus 1 U{sub S}3 regulates phospholipid synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wild, Peter, E-mail: pewild@access.uzh.ch; Institute of Virology, University of Zuerich; Oliveira, Anna Paula de

2012-10-25

Herpes simplex virus type 1 capsids bud at nuclear and Golgi membranes for envelopment by phospholipid bilayers. In the absence of U{sub S}3, nuclear membranes form multiple folds harboring virions that suggests disturbance in membrane turnover. Therefore, we investigated phospholipid metabolism in cells infected with the U{sub S}3 deletion mutant R7041({Delta}U{sub S}3), and quantified membranes involved in viral envelopment. We report that (i) [{sup 3}H]-choline incorporation into nuclear membranes and cytoplasmic membranes was enhanced peaking at 12 or 20 h post inoculation with wild type HSV-1 and R7041({Delta}U{sub S}3), respectively, (ii) the surface area of nuclear membranes increased until 24more » h of R7041({Delta}U{sub S}3) infection forming folds that equaled {approx}45% of the nuclear surface, (iii) the surface area of viral envelopes between nuclear membranes equaled {approx}2400 R7041({Delta}U{sub S}3) virions per cell, and (iv) during R7041({Delta}U{sub S}3) infection, the Golgi complex expanded dramatically. The data indicate that U{sub S}3 plays a significant role in regulation of membrane biosynthesis.« less

U.S.-Pakistani Nuclear Relations: A Strategic Survey

DTIC Science & Technology

2014-04-01

nuclear   renaissance  at  a  time   when  the   Fukushima   disaster  has  cooled  the...together,  these  trends  have   triggered   U.S.-­‐Pakistani  debate  in  four  key  subject  areas:    (1)   nuclear ...academic  literature  on  South  Asia,  but  Track  II  gatherings  have  explored   several  

The future of U.S.-Russia nuclear arms control

NASA Astrophysics Data System (ADS)

Pifer, Steven

2017-11-01

Nuclear arms control has long made contributions to U.S.-Soviet and U.S.-Russian security, but the current regime is at risk. The 1987 Intermediate-range Nuclear Forces Treaty may be headed for collapse. Both the United States and Russia are modernizing their strategic forces, and the fate of the 2010 New Strategic Arms Reduction Treaty is unclear. In the unlikely case that the sides are prepared to go beyond New START, there are ways to address further reductions and related issues. A collapse of the arms control regime, on the other hand, would mean the end of constraints on U.S. and Russian nuclear forces, a significant loss of transparency, and potential costs to U.S. security.

The United Arab Emirates Nuclear Program and Proposed U.S. Nuclear Cooperation

DTIC Science & Technology

2009-07-17

global efforts to prevent nuclear proliferation” and, “the establishment of reliable sources of nuclear fuel for future civilian light water reactors ...planned nuclear reactor or on handling spent reactor fuel. (...continued) May 4, 2008...contracting between U.S. firms and the UAE related to the UAE’s proposed nuclear program has already taken place. In August 2008, Virginia’s Thorium Power

Nuclear Resonance Fluorescence Response of U-235

NASA Astrophysics Data System (ADS)

Warren, Glen

2008-05-01

Nuclear resonance fluorescence (NRF) is a physical process that provides an isotopic-specific signature that could be used for the identification and characterization of materials. The technique involves the detection of prompt discrete-energy photons emitted from a sample, which is exposed to photons in the MeV energy range. Potential applications of the technique range from detection of high explosives to characterization of special nuclear materials. Pacific Northwest National Laboratory and Passport Systems have collaboratively conducted a set of measurements to search for an NRF response of U-235 in the 1.5 to 9 MeV energy range. Results from these measurements will be presented.

76 FR 31997 - Final Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the U.S...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-02

... NUCLEAR REGULATORY COMMISSION [NRC-2011-0118] Final Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the U.S. Department of Homeland Security on Chemical Facility Anti-Terrorism Standards AGENCY: Nuclear Regulatory Commission. ACTION: Notice of availability. FOR FURTHER...

Nuclear excitation by electronic transition of 235U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chodash, P. A.; Norman, E. B.; Burke, J. T.

Here, nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that can occur in isotopes containing a low-lying nuclear excited state. Over the past 40 yr, several experiments have attempted to measure NEET of 235U and those experiments have yielded conflicting results.

Nuclear excitation by electronic transition of 235U

DOE PAGES

Chodash, P. A.; Norman, E. B.; Burke, J. T.; ...

2016-03-11

Here, nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that can occur in isotopes containing a low-lying nuclear excited state. Over the past 40 yr, several experiments have attempted to measure NEET of 235U and those experiments have yielded conflicting results.

7 CFR 51.1575 - U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large. 51.1575 Section 51.1575 Agriculture Regulations of the Department of... Potatoes Grades § 51.1575 U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade...

7 CFR 51.1576 - U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large. 51.1576 Section 51.1576 Agriculture Regulations of the Department of... Potatoes Grades § 51.1576 U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade...

7 CFR 51.1575 - U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large. 51.1575 Section 51.1575 Agriculture Regulations of the Department of... Potatoes Grades § 51.1575 U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade...

7 CFR 51.1576 - U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large. 51.1576 Section 51.1576 Agriculture Regulations of the Department of... Potatoes Grades § 51.1576 U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade...

7 CFR 51.1575 - U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large. 51.1575 Section 51.1575 Agriculture Regulations of the Department of... Potatoes Grades § 51.1575 U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade...

7 CFR 51.1576 - U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large. 51.1576 Section 51.1576 Agriculture Regulations of the Department of... Potatoes Grades § 51.1576 U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade...

7 CFR 51.1576 - U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large. 51.1576 Section 51.1576 Agriculture Regulations of the Department of...) United States Consumer Standards for Potatoes Grades § 51.1576 U.S. Grade B Small; U.S. Grade B Medium; U...

7 CFR 51.1575 - U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large. 51.1575 Section 51.1575 Agriculture Regulations of the Department of...) United States Consumer Standards for Potatoes Grades § 51.1575 U.S. Grade A Small; U.S. Grade A Medium; U...

7 CFR 51.1576 - U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false U.S. Grade B Small; U.S. Grade B Medium; U.S. Grade B Medium to Large; U.S. Grade B Large. 51.1576 Section 51.1576 Agriculture Regulations of the Department of...) United States Consumer Standards for Potatoes Grades § 51.1576 U.S. Grade B Small; U.S. Grade B Medium; U...

7 CFR 51.1575 - U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false U.S. Grade A Small; U.S. Grade A Medium; U.S. Grade A Medium to Large; U.S. Grade A Large. 51.1575 Section 51.1575 Agriculture Regulations of the Department of...) United States Consumer Standards for Potatoes Grades § 51.1575 U.S. Grade A Small; U.S. Grade A Medium; U...

Nuclear reactor for breeding U.sup.233

DOEpatents

Bohanan, Charles S.; Jones, David H.; Raab, Jr., Harry F.; Radkowsky, Alvin

1976-01-01

A light-water-cooled nuclear reactor capable of breeding U.sup.233 for use in a light-water breeder reactor includes physically separated regions containing U.sup.235 fissile material and U.sup.238 fertile material and Th.sup.232 fertile material and Pu.sup.239 fissile material, if available. Preferably the U.sup.235 fissile material and U.sup.238 fertile material are contained in longitudinally movable seed regions and the Pu.sup.239 fissile material and Th.sup.232 fertile material are contained in blanket regions surrounding the seed regions.

The small molecule Mek1/2 inhibitor U0126 disrupts the chordamesoderm to notochord transition in zebrafish.

PubMed

Hawkins, Thomas A; Cavodeassi, Florencia; Erdélyi, Ferenc; Szabó, Gábor; Lele, Zsolt

2008-04-17

Key molecules involved in notochord differentiation and function have been identified through genetic analysis in zebrafish and mice, but MEK1 and 2 have so far not been implicated in this process due to early lethality (Mek1-/-) and functional redundancy (Mek2-/-) in the knockout animals. Here, we reveal a potential role for Mek1/2 during notochord development by using the small molecule Mek1/2 inhibitor U0126 which blocks phosphorylation of the Mek1/2 target gene Erk1/2 in vivo. Applying the inhibitor from early gastrulation until the 18-somite stage produces a specific and consistent phenotype with lack of dark pigmentation, shorter tail and an abnormal, undulated notochord. Using morphological analysis, in situ hybridization, immunhistochemistry, TUNEL staining and electron microscopy, we demonstrate that in treated embryos the chordamesoderm to notochord transition is disrupted and identify disorganization in the medial layer of the perinotochordal basement mebrane as the probable cause of the undulations and bulges in the notochord. We also examined and excluded FGF as the upstream signal during this process. Using the small chemical U0126, we have established a novel link between MAPK-signaling and notochord differentiation. Our phenotypic analysis suggests a potential connection between the MAPK-pathway, the COPI-mediated intracellular transport and/or the copper-dependent posttranslational regulatory processes during notochord differentiation.

Supporting U.S. Response to the Japanese Nuclear Crisis | ORAU

ScienceCinema

Crapo, John; Jakubowski, Ted

2018-05-01

When an earthquake and tsunami hit off the coast of Japan on March 11, 2011, and triggered a nuclear crisis, the U.S. immediately offered support. Among those tapped to assist was ORAU's National Security and Emergency Management team, which provided NNSA with technical and analytical nuclear incident support. Within 48 hours of the earthquake, ORAU emergency management experts accompanied the DOE Office of Emergency Response in deploying to Japan to support the U.S. Air Force Base in Yokota and the U.S. Embassy. A separate team from ORAU supported the NNSA Nuclear Incident Team, which served as the point of coordination for all support activities both in Japan and in the U.S.

Search for Nuclear Excitation by Electronic Transition in U-235

NASA Astrophysics Data System (ADS)

Chodash, P. A.; Norman, E. B.; Burke, J. T.; Wilks, S. C.; Casperson, R. J.; Swanberg, E. L.; Wakeling, M. A.; Cordeiro, T. J.

2013-10-01

Nuclear excitation by electronic transition (NEET) is a rare nuclear excitation that is predicted to occur in numerous isotopes, including U-235. When a nuclear transition matches the energy and the multipolarity of an electronic transition, there is a possibility that NEET will occur. If NEET were to occur in U-235, the nucleus would be excited to its 1/2 + isomeric state that subsequently decays by internal conversion with a decay energy of 77 eV and a half-life of 26 minutes. Theory predicts that NEET can occur in partially ionized uranium plasma with a charge state of 23 +. A pulsed Nd:YAG laser operating at 1064 nm with a pulse energy of 780 mJ and a pulse width of 9 ns was used to generate the uranium plasma. The plasma was collected on a plate and the internal conversion electrons were focused onto a microchannel plate detector by a series of electrostatic lenses. Depleted uranium and highly enriched uranium samples were used for the experiment. Preliminary results will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. This work was further supported by the U.S. DHS, UC Berkeley, and the NNIS Fellowship.

U.S. Strategic Nuclear Forces: Background, Developments, and Issues

DTIC Science & Technology

2017-02-10

Department of Energy questioned the management practices at the National Nuclear Security Administration (NNSA), which is responsible for the LEP, arguing...U.S. Strategic Nuclear Forces: Background, Developments, and Issues Amy F. Woolf Specialist in Nuclear Weapons Policy February 10, 2017...

Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sun Young; Song, Kyung-A; Samsung Biomedical Research Institute

Highlights: Black-Right-Pointing-Pointer Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. Black-Right-Pointing-Pointer A small molecule and a peptide as EBNA1 dimerization inhibitors identified. Black-Right-Pointing-Pointer Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. Black-Right-Pointing-Pointer Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)'s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation.more » In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459-607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-J{kappa} binding to the J{kappa} site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560-574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated

Materials modification using ions with energies below 1 MeV/u

NASA Astrophysics Data System (ADS)

Karlušić, M.; Jakšić, M.; Buljan, M.; Sancho-Parramon, J.; Bogdanović-Radović, I.; Radić, N.; Bernstorff, S.

2013-12-01

Materials modifications using swift heavy ion beams provided by large scale accelerators have been used for many years in a wide variety of ways, e.g. to produce ion tracks or to modify the shape of nanoparticles. In all those applications the most relevant parameter for the materials modification is the electronic stopping power and not the ion kinetic energy. For many materials, ions with energies below 1 MeV/u delivered from medium and small size accelerators have already sufficiently high electronic stopping power to modify materials in different ways. Also, in this energy range the nuclear stopping power can be large enough to provide additional opportunities for materials modifications. In the present paper, we review recent experimental activities of the Zagreb group where ion beams with energies below 1 MeV/u, obtained from a 6 MV EN Tandem Van de Graaff accelerator have been used. Additionally, we present several novel examples of materials modifications and their analysis with such ion beams.

49 CFR 173.471 - Requirements for U.S. Nuclear Regulatory Commission approved packages.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Requirements for U.S. Nuclear Regulatory...) Materials § 173.471 Requirements for U.S. Nuclear Regulatory Commission approved packages. In addition to the applicable requirements of the U.S. Nuclear Regulatory Commission (NRC) and other requirements of...

49 CFR 173.471 - Requirements for U.S. Nuclear Regulatory Commission approved packages.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Requirements for U.S. Nuclear Regulatory...) Materials § 173.471 Requirements for U.S. Nuclear Regulatory Commission approved packages. In addition to the applicable requirements of the U.S. Nuclear Regulatory Commission (NRC) and other requirements of...

49 CFR 173.471 - Requirements for U.S. Nuclear Regulatory Commission approved packages.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Requirements for U.S. Nuclear Regulatory...) Materials § 173.471 Requirements for U.S. Nuclear Regulatory Commission approved packages. In addition to the applicable requirements of the U.S. Nuclear Regulatory Commission (NRC) and other requirements of...

49 CFR 173.471 - Requirements for U.S. Nuclear Regulatory Commission approved packages.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Requirements for U.S. Nuclear Regulatory...) Materials § 173.471 Requirements for U.S. Nuclear Regulatory Commission approved packages. In addition to the applicable requirements of the U.S. Nuclear Regulatory Commission (NRC) and other requirements of...

U.S. Nuclear Cooperation with India: Issues for Congress

DTIC Science & Technology

2010-05-27

in 2009,” Panorama , February 6, 2009. “Chennai Daily Report: India, Kazakhstan Set To Sign Nuclear Reactor Export Deal,” Chennai Business Line Online...than 5 MW thermal or special nuclear material connected therewith. . U.S. Nuclear Cooperation with India: Issues for Congress Congressional

U.S. Nuclear Cooperation with India: Issues for Congress

DTIC Science & Technology

2010-10-28

India in 2009,” Panorama , February 6, 2009. “Chennai Daily Report: India, Kazakhstan Set To Sign Nuclear Reactor Export Deal,” Chennai Business Line...MW thermal or special nuclear material connected therewith. U.S. Nuclear Cooperation with India: Issues for Congress Congressional Research

The gene for human U2 snRNP auxiliary factor small 35-kDa subunit (U2AF1) maps to the progressive myoclonus epilepsy (EPM1) critical region on chromosome 21q22.3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lalioti, M.D.; Rossier, C.; Antonarakis, S.E.

1996-04-15

We used targeted exon trapping to clone portions of genes from human chromosome 21q22.3. One trapped sequence showed complete homology with the cDNA of human U2AF{sup 35} (M96982; HGM-approved nomenclature U2AF1), which encodes for the small 35-kDa subunit of the U2 snRNP auxiliary factor. Using the U2AF1 cDNA as a probe, we mapped this gene to cosmid Q15D2, a P1, and YAC 350F7 of the Chumakov et al. contig, close to the cystathionine-{beta}-synthase gene (CBS) on 21q22.3. This localization was confirmed by PCR using oligonucleotides from the 3{prime} UTR and by FISH. As U2AF1 associated with a number of differentmore » factors during mRNA splicing, overexpression in trisomy 21 individuals could contribute to some Down syndrome phenotypes by interfering with the splicing process. Furthermore, because this gene maps in the critical region for the progressive myoclonus epilepsy I locus (EPM1), mutation analysis will be carried out in patients to evaluate the potential role of U2AF1 as a candidate for EPM1. 24 refs., 1 fig.« less

U.S. Nuclear Cooperation with India: Issues for Congress

DTIC Science & Technology

2010-04-08

Kazakhstan might start uranium exports to India in 2009,” Panorama , February 6, 2009. “Chennai Daily Report: India, Kazakhstan Set To Sign Nuclear Reactor...reactors producing more than 5 MW thermal or special nuclear material connected therewith. U.S. Nuclear Cooperation with India: Issues for Congress

Alteration of the SETBP1 gene and splicing pathway genes SF3B1, U2AF1, and SRSF2 in childhood acute myeloid leukemia.

PubMed

Choi, Hyun-Woo; Kim, Hye-Ran; Baek, Hee-Jo; Kook, Hoon; Cho, Duck; Shin, Jong-Hee; Suh, Soon-Pal; Ryang, Dong-Wook; Shin, Myung-Geun

2015-01-01

Recurrent somatic SET-binding protein 1 (SETBP1) and splicing pathway gene mutations have recently been found in atypical chronic myeloid leukemia and other hematologic malignancies. These mutations have been comprehensively analyzed in adult AML, but not in childhood AML. We investigated possible alteration of the SETBP1, splicing factor 3B subunit 1 (SF3B1), U2 small nuclear RNA auxiliary factor 1 (U2AF1), and serine/arginine-rich splicing factor 2 (SRSF2) genes in childhood AML. Cytogenetic and molecular analyses were performed to reveal chromosomal and genetic alterations. Sequence alterations in the SETBP1, SF3B1, U2AF1, and SRSF2 genes were examined by using direct sequencing in a cohort of 53 childhood AML patients. Childhood AML patients did not harbor any recurrent SETBP1 gene mutations, although our study did identify a synonymous mutation in one patient. None of the previously reported aberrations in the mutational hotspot of SF3B1, U2AF1, and SRSF2 were identified in any of the 53 patients. Alterations of the SETBP1 gene or SF3B1, U2AF1, and SRSF2 genes are not common genetic events in childhood AML, implying that the mutations are unlikely to exert a driver effect in myeloid leukemogenesis during childhood.

Economic and Market Challenges Facing the U.S. Nuclear Commercial Fleet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szilard, Ronaldo; Sharpe, Phil; Kee, Edward

This report identifies underlying economic and electricity market factors that have led to early retirements of U.S. operating nuclear power plants, assesses the Gap between operating revenues and operating costs for selected nuclear power plants, and discusses a range of actions that might be taken to stop early retirement of operating nuclear power plants. The Kewaunee and Vermont Yankee nuclear power plants were retired early for economic and financial reasons. Early retirement has been announced or proposed for Clinton and Quad Cities in Illinois, Fitzpatrick and Ginna in New York, Fort Calhoun in Nebraska. Other nuclear power plants, including Palisades,more » Davis-Besse, Prairie Island, and Three Mile Island Unit 1, have been identified as facing financial stress that might lead to early retirement. The early retirement of operating nuclear power plants will mean the loss of a large amount of zero-emission electricity, inconsistent with the goal of reducing carbon emissions in the electricity sector. This report provides a high-level view of the major factors driving early retirement: • The U.S. market and private ownership approach to the electricity sector; • Low electricity market prices resulting from low natural gas prices, low demand growth, increased penetration of renewable generation, and negative electricity market prices; and • No compensation to nuclear power plants for public benefits including zero-emission electricity.« less

Enrichment Zoning Options for the Small Nuclear Rocket Engine (SNRE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruce G. Schnitzler; Stanley K. Borowski

2010-07-01

Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. In NASA’s recent Mars Design Reference Architecture (DRA) 5.0 study (NASA-SP-2009-566, July 2009), nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option because of its high thrust and high specific impulse (-900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. An extensive nuclear thermal rocket technology development effortmore » was conducted from 1955-1973 under the Rover/NERVA Program. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art design incorporating lessons learned from the very successful technology development program. Past activities at the NASA Glenn Research Center have included development of highly detailed MCNP Monte Carlo transport models of the SNRE and other small engine designs. Preliminary core configurations typically employ fuel elements with fixed fuel composition and fissile material enrichment. Uniform fuel loadings result in undesirable radial power and temperature profiles in the engines. Engine performance can be improved by some combination of propellant flow control at the fuel element level and by varying the fuel composition. Enrichment zoning at the fuel element level with lower enrichments in the higher power elements at the core center and on the core periphery is particularly effective. Power flattening by enrichment zoning typically results in more uniform propellant exit temperatures and improved engine performance. For the SNRE, element enrichment zoning provided very flat radial power profiles with 551 of

Gauged U(1) clockwork theory

NASA Astrophysics Data System (ADS)

Lee, Hyun Min

2018-03-01

We consider the gauged U (1) clockwork theory with a product of multiple gauge groups and discuss the continuum limit of the theory to a massless gauged U (1) with linear dilaton background in five dimensions. The localization of the lightest state of gauge fields on a site in the theory space naturally leads to exponentially small effective couplings of external matter fields localized away from the site. We discuss the implications of our general discussion with some examples, such as mediators of dark matter interactions, flavor-changing B-meson decays as well as D-term SUSY breaking.

The Future of the U.S. Nuclear Weapons Program

NASA Astrophysics Data System (ADS)

Brooks, Linton F.

2007-03-01

This paper will examine our plans for the future of the U.S. nuclear weapons program including efforts to ``transform'' the stockpile and supporting infrastructure. We proceed from the premise that the United States will need a safe, secure, and reliable nuclear deterrent for the foreseeable future. Moreover, the Stockpile Stewardship Program is working. Today's stockpile---comprised of legacy warheads left over from the Cold War---is safe and reliable. That said, we see increased risk, absent nuclear testing, in assuring the long-term safety and reliability of our current stockpile. Nor is today's nuclear weapons complex sufficiently ``responsive'' to fixing technical problems in the stockpile, or to potential adverse geopolitical change. Our task is to work to ensure that the U.S. nuclear weapons enterprise, including the stockpile and supporting infrastructure, meets long-term national security needs. Our approach is to develop and field replacement warheads for the legacy stockpile---so-called Reliable Replacement Warheads (RRW)---as a means to transform both the nuclear stockpile and supporting infrastructure.

The U. S. nuclear industry; A changing complexion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zorpette, G

This article addresses the changes which have occurred in the U.S. nuclear industry as a response to the decline in the construction of new plants. The author focuses on the segments of the industry which chiefly design and produce nuclear power plants, the architect-engineers and the suppliers, and how they have become more service oriented in response to the construction decline. The movement toward diversification to non-nuclear industries is also discussed.

A Nuclear Energy Renaissance in the U.S.?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kessler, Carol E.; Mahy, Heidi A.; Ankrum, Al

2008-01-01

Is it time for a nuclear energy renaissance? Among other things, nuclear power is a carbon neutral source of base load power. With the growth in energy use expected over the next 20 years and the growing negative impacts of global climate changes, the cost of oil and gas, energy security and diversity concerns, and progress on advanced reactor designs, it may be the right time for nuclear power to enter a new age of growth. Asia and Russia are both planning for a nuclear renaissance. In Europe, Finland and France have both taken steps to pursue new nuclear reactors.more » U.S. utilities are preparing for orders of new reactors; one submitted a request to the U.S. Nuclear Regulatory Commission (NRC) to review its request to construct a new reactor on an existing site. What has the industry been doing since nuclear energy was birthed in the 1960s? In those days a bold new industry boasted that nuclear power in the United States was going to be “too cheap to meter”, but as we all know this did not come about for many reasons. Eventually, it became clear that industry had neglected to do its homework. Critiques of the industry were made on safety, security, environment, economic competitiveness (without government support), and nonproliferation. All of these factors need to be effectively addressed to promote the confidence and support of the public – without which a nuclear power program is not feasible.« less

Old foes, new understandings: nuclear entry of small non-enveloped DNA viruses.

PubMed

Fay, Nikta; Panté, Nelly

2015-06-01

The nuclear import of viral genomes is an important step of the infectious cycle for viruses that replicate in the nucleus of their host cells. Although most viruses use the cellular nuclear import machinery or some components of this machinery, others have developed sophisticated ways to reach the nucleus. Some of these have been known for some time; however, recent studies have changed our understanding of how some non-enveloped DNA viruses access the nucleus. For example, parvoviruses enter the nucleus through small disruptions of the nuclear membranes and nuclear lamina, and adenovirus tugs at the nuclear pore complex, using kinesin-1, to disassemble their capsids and deliver viral proteins and genomes into the nucleus. Here we review recent findings of the nuclear import strategies of three small non-enveloped DNA viruses, including adenovirus, parvovirus, and the polyomavirus simian virus 40. Copyright © 2015 Elsevier B.V. All rights reserved.

77 FR 8943 - U.S. Small Business Administration.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... SMALL BUSINESS ADMINISTRATION National Women's Business Council Meeting U.S. Small Business... notice to announce the location, date, time, and agenda for the next meeting of the National Women's...., Appendix 2), SBA announces the meeting of the National Women's Business Council. The National Women's...

Functional organization of the Sm core in the crystal structure of human U1 snRNP.

PubMed

Weber, Gert; Trowitzsch, Simon; Kastner, Berthold; Lührmann, Reinhard; Wahl, Markus C

2010-12-15

U1 small nuclear ribonucleoprotein (snRNP) recognizes the 5'-splice site early during spliceosome assembly. It represents a prototype spliceosomal subunit containing a paradigmatic Sm core RNP. The crystal structure of human U1 snRNP obtained from natively purified material by in situ limited proteolysis at 4.4 Å resolution reveals how the seven Sm proteins, each recognize one nucleotide of the Sm site RNA using their Sm1 and Sm2 motifs. Proteins D1 and D2 guide the snRNA into and out of the Sm ring, and proteins F and E mediate a direct interaction between the Sm site termini. Terminal extensions of proteins D1, D2 and B/B', and extended internal loops in D2 and B/B' support a four-way RNA junction and a 3'-terminal stem-loop on opposite sides of the Sm core RNP, respectively. On a higher organizational level, the core RNP presents multiple attachment sites for the U1-specific 70K protein. The intricate, multi-layered interplay of proteins and RNA rationalizes the hierarchical assembly of U snRNPs in vitro and in vivo.

On the Search for Nuclear Resonance Fluorescence Signatures of 235U and 238U above 3 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Glen A.; Caggiano, Joseph A.; Bertozzi, William

Nuclear resonance fluorescence is a physical process that provides an isotope-specific signature that could be used for the identification and characterization of materials. The technique involves the detection of prompt discrete-energy photons emitted from a sample that is exposed to MeV-energy photons. Potential applications of the technique range from detection of high explosives to characterization of special nuclear materials such as 235U. Pacific Northwest National Laboratory and Passport Systems have collaborated to conduct a pair of measurements to search for a nuclear resonance fluorescence response of 235U above 3 MeV and of 238U above 5 MeV using an 8 gmore » sample of highly enriched uranium and a 90 g sample of depleted uranium. No new signatures were observed. The minimum detectable integrated cross section for 235U is presented.« less

Properties of a U1 RNA enhancer-like sequence.

PubMed Central

Ciliberto, G; Palla, F; Tebb, G; Mattaj, I W; Philipson, L

1987-01-01

The properties of a X.laevis U1B snRNA gene enhancer have been studied by microinjection in Xenopus oocytes. The enhancer-like sequence, defined as a short DNA stretch that is able to activate transcription in an orientation independent manner, is interchangeable between different U snRNA genes. The enhancer sequence alone does not, however, efficiently activate transcription from an SV40 pol II promoter but regains its activity when combined with the U-gene specific proximal sequence element. DNase I protection experiments show that the X.laevis U1B enhancer can interact specifically with a nuclear factor present in mammalian cells. Images PMID:3031597

On the Search for Nuclear Resonance Fluorescence Signatures of 235U and 238U above 3 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Glen A.; Caggiano, Joseph A.; Bertozzi, William

Abstract–Nuclear resonance fluorescence is a physical process that provides an isotope-specific signature that could be used for the identification and characterization of materials. The technique involves the detection of prompt discrete-energy photons emitted from a sample that is exposed to photons in the MeV energy range. Potential applications of the technique range from detection of high explosives to characterization of special nuclear materials such as 235U. Pacific Northwest National Laboratory and Passport Systems have collaborated to conduct a a pair of measurements to search for a nuclear resonance fluorescence response of 235U above 3 MeV and of 238U above 5more » MeV using an 8 g sample of highly enriched uranium and a 90 g sample of depleted uranium. No new signatures were observed. The minimum detectable integrated cross section for 235U is presented.« less

75 FR 14639 - Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit Nos. 1, 2, and 3...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-003, 50-247, and 50-286; NRC-2010-0137] Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit Nos. 1, 2, and 3; Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear Regulatory Commission (NRC) is considering issuance of an exemption, pursuant to Title 10 of...

75 FR 3761 - Southern Nuclear Operating Company, Inc., Edwin I. Hatch Nuclear Plant, Units 1 and 2...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-22

... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-321 and 50-366; NRC-2010-0024] Southern Nuclear Operating Company, Inc., Edwin I. Hatch Nuclear Plant, Units 1 and 2; Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear Regulatory Commission (NRC) is considering issuance of an Exemption, pursuant to Title 10 of the Code of...

Multi-unit Operations in Non-Nuclear Systems: Lessons Learned for Small Modular Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

OHara J. M.; Higgins, J.; DAgostino, A.

2012-01-17

The nuclear-power community has reached the stage of proposing advanced reactor designs to support power generation for decades to come. Small modular reactors (SMRs) are one approach to meet these energy needs. While the power output of individual reactor modules is relatively small, they can be grouped to produce reactor sites with different outputs. Also, they can be designed to generate hydrogen, or to process heat. Many characteristics of SMRs are quite different from those of current plants and may be operated quite differently. One difference is that multiple units may be operated by a single crew (or a singlemore » operator) from one control room. The U.S. Nuclear Regulatory Commission (NRC) is examining the human factors engineering (HFE) aspects of SMRs to support licensing reviews. While we reviewed information on SMR designs to obtain information, the designs are not completed and all of the design and operational information is not yet available. Nor is there information on multi-unit operations as envisioned for SMRs available in operating experience. Thus, to gain a better understanding of multi-unit operations we sought the lesson learned from non-nuclear systems that have experience in multi-unit operations, specifically refineries, unmanned aerial vehicles and tele-intensive care units. In this paper we report the lessons learned from these systems and the implications for SMRs.« less

Small Business Manufacturing--An Important Component of the U.S. Defense Industrial Base

DTIC Science & Technology

1993-04-01

Armed Forces in 1993, Mr. Williams is assigned to the Assistant Secretary of the Army (Financial Management ) in the Pentagon. - ii - SMALL BUSINESS ...AD-A276 756 1993 Executive Research Project RS1 Small Business Manufacturing -- An Important Component of the U.S. Defense Industrial Base Mr...paper comprises a review of the contribution of the small - and medium-sized manufacturing business sector to the US defense industrial base, the state

Small modular reactor modeling using modelica for nuclear-renewable hybrid energy systems applications

DOE PAGES

Mikkelson, Daniel; Chang, Chih -Wei; Cetiner, Sacit M.; ...

2015-10-01

Here, the U.S. Department of Energy (DOE) supports research and development (R&D) that could lead to more efficient utilization of clean energy generation sources, including renewable and nuclear options, to meet grid demand and industrial thermal energy needs [1]. One hybridization approach being investigated by the DOE Offices of Nuclear Energy (NE) and the DOE Energy Efficiency and Renewable Energy (EERE) is tighter coupling of nuclear and renewable energy sources to better manage overall energy use for the combined electricity, industrial manufacturing, and transportation sectors.

Science, Society, and America's Nuclear Waste: Nuclear Waste, Unit 1. Teacher Guide. Second Edition.

ERIC Educational Resources Information Center

Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

This guide is Unit 1 of the four-part series Science, Society, and America's Nuclear Waste produced by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management. The goal of this unit is to help students establish the relevance of the topic of nuclear waste to their everyday lives and activities. Particular attention is…

The splicing factor U2AF65 stabilizes TRF1 protein by inhibiting its ubiquitin-dependent proteolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jeonghee; Chung, In Kwon, E-mail: topoviro@yonsei.ac.kr

Highlights: •Identification of U2AF65 as a novel TRF1-interacting protein. •U2AF65 stabilizes TRF1 protein by inhibiting its ubiquitin-dependent proteolysis. •U2AF65 interferes with the interaction between TRF1 and Fbx4. •U2AF65 represents a new route for modulating TRF1 function at telomeres. -- Abstract: The human telomeric protein TRF1 is a component of the six-subunit protein complex shelterin, which provides telomere protection by organizing the telomere into a high-order structure. TRF1 functions as a negative regulator of telomere length by controlling the access of telomerase to telomeres. Thus, the cellular abundance of TRF1 at telomeres should be maintained and tightly regulated to ensure propermore » telomere function. Here, we identify U2 small nuclear ribonucleoprotein (snRNP) auxiliary factor 65 (U2AF65), an essential pre-mRNA splicing factor, as a novel TRF1-interacting protein. U2AF65 interacts with TRF1 in vitro and in vivo and is capable of stabilizing TRF1 protein by inhibiting its ubiquitin-dependent proteolysis. We also found that U2AF65 interferes with the interaction between TRF1 and Fbx4, an E3 ubiquitin ligase for TRF1. Depletion of endogenous U2AF65 expression by short interfering RNA (siRNA) reduced the stability of endogenous TRF1 whereas overexpression of U2AF65 significantly extended the half-life of TRF1. These findings demonstrate that U2AF65 plays a critical role in regulating the level of TRF1 through physical interaction and ubiquitin-mediated proteolysis. Hence, U2AF65 represents a new route for modulating TRF1 function at telomeres.« less

75 FR 6223 - PSEG Nuclear LLC; Hope Creek Generating Station and Salem Nuclear Generating Station, Unit Nos. 1...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-08

... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-272, 50-311 and 50-354; NRC-2010-0043] PSEG Nuclear LLC; Hope Creek Generating Station and Salem Nuclear Generating Station, Unit Nos. 1 and 2; Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear Regulatory Commission (NRC) is considering issuance of an Exemption, pursuant...

A U.S. Multicenter Study of Recorded Occupational Radiation Badge Doses in Nuclear Medicine.

PubMed

Villoing, Daphnée; Yoder, R Craig; Passmore, Christopher; Bernier, Marie-Odile; Kitahara, Cari M

2018-05-01

Purpose To summarize occupational badge doses recorded for a sample of U.S. nuclear medicine technologists. Materials and Methods Nine large U.S. medical institutions identified 208 former and current nuclear medicine technologists certified after 1979 and linked these individuals to historic badge dose records maintained by a commercial dosimetry company (Landauer), yielding a total of 2618 annual dose records. The distributions of annual and cumulative occupational doses were described by using summary statistics. Results Between 1992 and 2015, the median annual personal dose equivalent per nuclear medicine technologist was 2.18 mSv (interquartile range [IQR], 1.25-3.47 mSv; mean, 2.69 mSv). Median annual personal dose equivalents remained relatively constant over this period (range, 1.40-3.30 mSv), while maximum values generally increased over time (from 8.00 mSv in 1992 to 13.9 mSv in 2015). The median cumulative personal dose equivalent was 32.9 mSv (IQR, 18.1-65.5 mSv; mean, 51.4 mSv) for 45 technologists who had complete information and remained employed through 2015. Conclusion Occupational radiation doses were well below the established occupational limits and were consistent with those observed for nuclear medicine technologists worldwide and were greater than those observed for nuclear and general medical workers in the United States These results should be informative for radiation monitoring and safety efforts in nuclear medicine departments. © RSNA, 2018 Online supplemental material is available for this article.

The nuclear cap-binding complex interacts with the U4/U6·U5 tri-snRNP and promotes spliceosome assembly in mammalian cells

PubMed Central

Pabis, Marta; Neufeld, Noa; Steiner, Michaela C.; Bojic, Teodora; Shav-Tal, Yaron; Neugebauer, Karla M.

2013-01-01

The nuclear cap-binding complex (CBC) binds to the 7-methyl guanosine cap present on every RNA polymerase II transcript. CBC has been implicated in many aspects of RNA biogenesis; in addition to roles in miRNA biogenesis, nonsense-mediated decay, 3′-end formation, and snRNA export from the nucleus, CBC promotes pre-mRNA splicing. An unresolved question is how CBC participates in splicing. To investigate CBC’s role in splicing, we used mass spectrometry to identify proteins that copurify with mammalian CBC. Numerous components of spliceosomal snRNPs were specifically detected. Among these, three U4/U6·U5 snRNP proteins (hBrr2, hPrp4, and hPrp31) copurified with CBC in an RNA-independent fashion, suggesting that a significant fraction of CBC forms a complex with the U4/U6·U5 snRNP and that the activity of CBC might be associated with snRNP recruitment to pre-mRNA. To test this possibility, CBC was depleted from HeLa cells by RNAi. Chromatin immunoprecipitation and live-cell imaging assays revealed decreased cotranscriptional accumulation of U4/U6·U5 snRNPs on active transcription units, consistent with a requirement for CBC in cotranscriptional spliceosome assembly. Surprisingly, recruitment of U1 and U2 snRNPs was also affected, indicating that RNA-mediated interactions between CBC and snRNPs contribute to splicing. On the other hand, CBC depletion did not impair snRNP biogenesis, ruling out the possibility that decreased snRNP recruitment was due to changes in nuclear snRNP concentration. Taken together, the data support a model whereby CBC promotes pre-mRNA splicing through a network of interactions with and among spliceosomal snRNPs during cotranscriptional spliceosome assembly. PMID:23793891

Structural basis of Brr2-Prp8 interactions and implications for U5 snRNP biogenesis and the spliceosome active site.

PubMed

Nguyen, Thi Hoang Duong; Li, Jade; Galej, Wojciech P; Oshikane, Hiroyuki; Newman, Andrew J; Nagai, Kiyoshi

2013-06-04

The U5 small nuclear ribonucleoprotein particle (snRNP) helicase Brr2 disrupts the U4/U6 small nuclear RNA (snRNA) duplex and allows U6 snRNA to engage in an intricate RNA network at the active center of the spliceosome. Here, we present the structure of yeast Brr2 in complex with the Jab1/MPN domain of Prp8, which stimulates Brr2 activity. Contrary to previous reports, our crystal structure and mutagenesis data show that the Jab1/MPN domain binds exclusively to the N-terminal helicase cassette. The residues in the Jab1/MPN domain, whose mutations in human Prp8 cause the degenerative eye disease retinitis pigmentosa, are found at or near the interface with Brr2, clarifying its molecular pathology. In the cytoplasm, Prp8 forms a precursor complex with U5 snRNA, seven Smproteins, Snu114, and Aar2, but after nuclear import, Brr2 replaces Aar2 to form mature U5 snRNP. Our structure explains why Aar2 and Brr2 are mutually exclusive and provides important insights into the assembly of U5 snRNP.

Nucleolin is a nuclear target of heparan sulfate derived from glypican-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Fang; Belting, Mattias; Fransson, Lars-Åke

The recycling, S-nitrosylated heparan sulfate (HS) proteoglycan glypican-1 releases anhydromannose (anMan)-containing HS chains by a nitrosothiol-catalyzed cleavage in endosomes that can be constitutive or induced by ascorbate. The HS-anMan chains are then transported to the nucleus. A specific nuclear target for HS-anMan has not been identified. We have monitored endosome-to-nucleus trafficking of HS-anMan by deconvolution and confocal immunofluorescence microscopy using an anMan-specific monoclonal antibody in non-growing, ascorbate-treated, and growing, untreated, wild-type mouse embryonic fibroblasts and hypoxia-exposed Alzheimer mouse Tg2576 fibroblasts and human U87 glioblastoma cells. In all cells, nuclear HS-anMan targeted a limited number of sites of variable size wheremore » it colocalized with DNA and nucleolin, an established marker for nucleoli. HS-anMan also colocalized with ethynyl uridine-tagged nascent RNA and two acetylated forms of histone H3. Acute hypoxia increased the formation of HS-anMan in both Tg2576 and U87 cells. A portion of HS-anMan colocalized with nucleolin at small discrete sites, while most of the nucleolin and nascent RNA was dispersed. In U87 cells, HS-anMan, nucleolin and nascent RNA reassembled after prolonged hypoxia. Nucleolar HS may modulate synthesis and/or release of rRNA.« less

History of U.S. Nuclear Weapons Doctrine and a Path Forward

NASA Astrophysics Data System (ADS)

Chyba, Christopher

2007-04-01

During the Cold War, the United States considered a number of approaches for living in a world with nuclear weapons, including disarmament, preventive war, the incorporation of nuclear weapons into military strategy, passive and active defense, and deterrence. With the failure of early approaches to disarmament, and the rejection of preventive war against the Soviet Union (and later, China), deterrence became central to key nuclear relationships, though arms control continued to play an important role. The nuclear nonproliferation treaty made preventing the further spread of nuclear weapons another central component of U.S. policy. The Bush Administration has tried to devise a new policy for the post-Cold War period. Their approach has three salient pillars. First, it is characterized by an overall skepticism toward multilateral agreements, on the grounds that bad actors will not obey them, that agreements can lead to a false sense of security, and that such agreements are too often a way for the Lilliputians of the world to tie down Gulliver. The March 2005 U.S. National Defense Strategy declared that U.S. strength ``will continue to be challenged by those who employ a strategy of the weak, using international fora, judicial processes and terrorism.'' Second, the Bush Administration declared its intention to maintain a military dominance so great that other states simply would not try to catch up. The 2002 National Security Strategy states that ``Our forces will be strong enough to dissuade potential adversaries from pursuing a military build-up in hopes of surpassing, or equaling, the power of the United States.'' Third, the 2002 National Security Strategy (reaffirmed by the 2006 National Security Strategy) moved preventive war (which the strategies called ``preemptive war'') to a central position, rather than deterrence and nonproliferation. In part this was because of the claim that certain ``rogue'' states, and terrorist groups, were not deterrable. This talk

North Korea’s Second Nuclear Test: Implications of U.N. Security Council Resolution 1874

DTIC Science & Technology

2010-04-15

butter” (or in North Korea’s case, rice ) and, in the process, creating a humanitarian disaster. The additional sanctions in U.N. Resolution 1874 target...the May 2009 North Korean nuclear test. See also CRS Report RL34327, Proliferation Security Initiative (PSI), by Mary Beth Nikitin. 72 “Nuclear Black ...Beverages 5,137,988 5,084,449 6,652,041 33 Perfumery, Cosmetic Products 1,322,454 1,672,327 1,688,481 42 Leather Art; Saddlery, Etc. 772,645 1,441,805

Characterization of self-T-cell response and antigenic determinants of U1A protein with bone marrow-derived dendritic cells in NZB x NZW F1 mice.

PubMed

Suen, J L; Wu, C H; Chen, Y Y; Wu, W M; Chiang, B L

2001-07-01

Systemic lupus erythematosus (SLE) is characterized by the existence of a heterogeneous group of autoantibodies directed against nuclear intact structures, such as nucleosomes and small nuclear ribonucleoproteins (snRNPs). Autoantibodies against snRNPs are of special interest because they are detectable in the majority of SLE patients. Although the B-cell antigenic determinants have been well characterized, very limited data have been reported in regard to the T-cell epitopes of snRNPs. Furthermore, several studies have demonstrated that determination of the auto-T-cell epitopes recognized by freshly isolated T cells is difficult from unprimed lupus mice when self-antigen-pulsed B cells or macrophages are used as antigen-presenting cells (APCs) in vitro. In the present study, we showed a novel approach for determining the auto-T-cell epitopes, using bone marrow-derived dendritic cells (BMDCs) pulsed with the murine U1A protein - an immunodominant antigen of the U1 snRNPs - which is capable of activating freshly isolated T cells from unprimed (NZB x NZW) F1 (BWF1) mice in vitro. The T-cell epitope area was found to be located at the C-terminus of U1A, overlapping the T-cell epitope of human U1A that has been reported in human SLE. Identification of the autoreactive T-cell epitope(s) in snRNPs will help to elucidate how reciprocal T-B determinant spreading of snRNPs emerges in lupus. The results presented here also indicate that it is feasible to use this approach to further explore strategies to design immunotherapy for patients with lupus.

A New Class of Orthosteric uPAR•uPA Small-Molecule Antagonists Are Allosteric Inhibitors of the uPAR•Vitronectin Interaction

PubMed Central

Liu, Degang; Zhou, Donghui; Wang, Bo; Knabe, William Eric; Meroueh, Samy O.

2015-01-01

The urokinase receptor (uPAR) is a GPI-anchored cell surface receptor that is at the center of an intricate network of protein-protein interactions. Its immediate binding partners are the serine proteinase urokinase (uPA), and vitronectin (VTN), a component of the extracellular matrix. uPA and VTN bind at distinct sites on uPAR to promote extracellular matrix degradation and integrin signaling, respectively. Here, we report the discovery of a new class of pyrrolone small-molecule inhibitors of the tight ∼1 nM uPAR•uPA protein-protein interaction. These compounds were designed to bind to the uPA pocket on uPAR. The highest affinity compound, namely 7, displaced a fluorescently-labeled α-helical peptide (AE147-FAM) with an inhibition constant Ki of 0.7 µM and inhibited the tight uPAR•uPAATF interaction with an IC50 of 18 µM. Biophysical studies with surface plasmon resonance showed that VTN binding is highly dependent on uPA. This cooperative binding was confirmed as 7, which binds at the uPAR•uPA interface, also inhibited the distal VTN•uPAR interaction. In cell culture, 7 blocked the uPAR•uPA interaction in uPAR-expressing human embryonic kidney (HEK-293) cells, and impaired cell adhesion to VTN, a process that is mediated by integrins. As a result, 7 inhibited integrin signaling in MDA-MB-231 cancer cells as evidenced by a decrease in focal adhesion kinase (FAK) phosphorylation and Rac1 GTPase activation. Consistent with these results, 7 blocked breast MDA-MB-231 cancer cell invasion with IC50 values similar to those observed in ELISA and surface plasmon resonance competition studies. Explicit-solvent molecular dynamics simulations show that the cooperativity between uPA and VTN is attributed to stabilization of uPAR motion by uPA. In addition, free energy calculations revealed that uPA stabilizes the VTN•uPARSMB interaction through more favorable electrostatics and entropy. Disruption of the uPAR•VTNSMB interaction by 7 is consistent with the

A new class of orthosteric uPAR·uPA small-molecule antagonists are allosteric inhibitors of the uPAR·vitronectin interaction.

PubMed

Liu, Degang; Zhou, Donghui; Wang, Bo; Knabe, William Eric; Meroueh, Samy O

2015-06-19

The urokinase receptor (uPAR) is a GPI-anchored cell surface receptor that is at the center of an intricate network of protein-protein interactions. Its immediate binding partners are the serine proteinase urokinase (uPA), and vitronectin (VTN), a component of the extracellular matrix. uPA and VTN bind at distinct sites on uPAR to promote extracellular matrix degradation and integrin signaling, respectively. Here, we report the discovery of a new class of pyrrolone small-molecule inhibitors of the tight ∼1 nM uPAR·uPA protein-protein interaction. These compounds were designed to bind to the uPA pocket on uPAR. The highest affinity compound, namely 7, displaced a fluorescently labeled α-helical peptide (AE147-FAM) with an inhibition constant Ki of 0.7 μM and inhibited the tight uPAR·uPAATF interaction with an IC50 of 18 μM. Biophysical studies with surface plasmon resonance showed that VTN binding is highly dependent on uPA. This cooperative binding was confirmed as 7, which binds at the uPAR·uPA interface, also inhibited the distal VTN·uPAR interaction. In cell culture, 7 blocked the uPAR·uPA interaction in uPAR-expressing human embryonic kidney (HEK-293) cells and impaired cell adhesion to VTN, a process that is mediated by integrins. As a result, 7 inhibited integrin signaling in MDA-MB-231 cancer cells as evidenced by a decrease in focal adhesion kinase (FAK) phosphorylation and Rac1 GTPase activation. Consistent with these results, 7 blocked breast MDA-MB-231 cancer cell invasion with IC50 values similar to those observed in ELISA and surface plasmon resonance competition studies. Explicit-solvent molecular dynamics simulations show that the cooperativity between uPA and VTN is attributed to stabilization of uPAR motion by uPA. In addition, free energy calculations revealed that uPA stabilizes the VTNSMB·uPAR interaction through more favorable electrostatics and entropy. Disruption of the uPAR·VTNSMB interaction by 7 is consistent with the

A conserved intronic U1 snRNP-binding sequence promotes trans-splicing in Drosophila

PubMed Central

Gao, Jun-Li; Fan, Yu-Jie; Wang, Xiu-Ye; Zhang, Yu; Pu, Jia; Li, Liang; Shao, Wei; Zhan, Shuai; Hao, Jianjiang

2015-01-01

Unlike typical cis-splicing, trans-splicing joins exons from two separate transcripts to produce chimeric mRNA and has been detected in most eukaryotes. Trans-splicing in trypanosomes and nematodes has been characterized as a spliced leader RNA-facilitated reaction; in contrast, its mechanism in higher eukaryotes remains unclear. Here we investigate mod(mdg4), a classic trans-spliced gene in Drosophila, and report that two critical RNA sequences in the middle of the last 5′ intron, TSA and TSB, promote trans-splicing of mod(mdg4). In TSA, a 13-nucleotide (nt) core motif is conserved across Drosophila species and is essential and sufficient for trans-splicing, which binds U1 small nuclear RNP (snRNP) through strong base-pairing with U1 snRNA. In TSB, a conserved secondary structure acts as an enhancer. Deletions of TSA and TSB using the CRISPR/Cas9 system result in developmental defects in flies. Although it is not clear how the 5′ intron finds the 3′ introns, compensatory changes in U1 snRNA rescue trans-splicing of TSA mutants, demonstrating that U1 recruitment is critical to promote trans-splicing in vivo. Furthermore, TSA core-like motifs are found in many other trans-spliced Drosophila genes, including lola. These findings represent a novel mechanism of trans-splicing, in which RNA motifs in the 5′ intron are sufficient to bring separate transcripts into close proximity to promote trans-splicing. PMID:25838544

Examining the intersection between splicing, nuclear export and small RNA pathways.

PubMed

Nabih, Amena; Sobotka, Julia A; Wu, Monica Z; Wedeles, Christopher J; Claycomb, Julie M

2017-11-01

Nuclear Argonaute/small RNA pathways in a variety of eukaryotic species are generally known to regulate gene expression via chromatin modulation and transcription attenuation in a process known as transcriptional gene silencing (TGS). However, recent data, including genetic screens, phylogenetic profiling, and molecular mechanistic studies, also point to a novel and emerging intersection between the splicing and nuclear export machinery with nuclear Argonaute/small RNA pathways in many organisms. In this review, we summarize the field's current understanding regarding the relationship between splicing, export and small RNA pathways, and consider the biological implications for coordinated regulation of transcripts by these pathways. We also address the importance and available approaches for understanding the RNA regulatory logic generated by the intersection of these particular pathways in the context of synthetic biology. The interactions between various eukaryotic RNA regulatory pathways, particularly splicing, nuclear export and small RNA pathways provide a type of combinatorial code that informs the identity ("self" versus "non-self") and dictates the fate of each transcript in a cell. Although the molecular mechanisms for how splicing and nuclear export impact small RNA pathways are not entirely clear at this early stage, the links between these pathways are widespread across eukaryotic phyla. The link between splicing, nuclear export, and small RNA pathways is emerging and establishes a new frontier for understanding the combinatorial logic of gene regulation across species that could someday be harnessed for therapeutic, biotechnology and agricultural applications. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

Improved mb-Ms Discrimination Using mb(P-coda) and MsU with Application to the Six North Korean Nuclear Tests

NASA Astrophysics Data System (ADS)

Napoli, V.; Yoo, S. H.; Russell, D. R.

2017-12-01

To improve discrimination of small explosions and earthquakes, we developed a new magnitude scale based on the standard Ms:mb discrimination method. In place of 20 second Ms measurements we developed a unified Rayleigh and Love wave magnitude scale (MsU) that is designed to maximize available information from single stations and then combine magnitude estimates into network averages. Additionally, in place of mb(P) measurements we developed an mb(P-Coda) magnitude scale as the properties of the coda make sparse network mb(P-Coda) more robust and less variable than network mb(P) estimates. A previous mb:MsU study conducted in 2013 in the Korean Peninsula shows that the use of MsU in place of standard 20 second Ms, leads to increased population separation and reduced scattering. The goals of a combined mb(P-coda):MsU scale are reducing scatter, ensuring applicability at small magnitudes with sparse networks, and improving the overall distribution for mb:Ms earthquake and explosion populations. To test this method we are calculating mb(P-coda)and MsU for a catalog earthquakes located in and near the Korean Peninsula, for the six North Korean nuclear tests (4.1 < mb < 6.3) and for the 3 aftershocks to date that occurred after the sixth test (2.6 < ML < 4.0). Compared to the previous 2013 study, we expect to see greater separation in the populations and less scattering with the inclusion of mb(P-coda) and with the implementation of additional filters for MsU to improve signal-to-noise levels; this includes S-transform filtering for polarization and off-azimuth signal reduction at regional distances. As we are expanding our database of mb(P-coda):MsU measurements in the Korean Peninsula to determine the earthquake and explosion distribution, this research will address the limitations and potential for discriminating small magnitude events using sparse networks.

Nuclear export of the small ribosomal subunit requires the Ran–GTPase cycle and certain nucleoporins

PubMed Central

Moy, Terence I.; Silver, Pamela A.

1999-01-01

After their assembly in the nucleolus, ribosomal subunits are exported from the nucleus to the cytoplasm. After export, the 20S rRNA in the small ribosomal subunit is cleaved to yield 18S rRNA and the small 5′ ITS1 fragment. The 5′ ITS1 RNA is normally degraded by the cytoplasmic Xrn1 exonuclease, but in strains lacking XRN1, the 5′ ITS1 fragment accumulates in the cytoplasm. Using the cytoplasmic localization of the 5′ ITS1 fragment as an indicator for the export of the small ribosomal subunit, we have identified genes that are required for ribosome export. Ribosome export is dependent on the Ran–GTPase as mutations in Ran or its regulators caused 5′ ITS1 to accumulate in the nucleoplasm. Mutations in the genes encoding the nucleoporin Nup82 and in the NES exporter Xpo1/Crm1 also caused the nucleoplasmic accumulation of 5′ ITS1. Mutants in a subset of nucleoporins and in the nuclear transport factors Srp1, Kap95, Pse1, Cse1, and Mtr10 accumulate the 5′ ITS1 in the nucleolus and affect ribosome assembly. In contrast, we did not detect nuclear accumulation of 5′ ITS1 in 28 yeast strains that have mutations in other genes affecting nuclear trafficking. PMID:10465789

A General Method for Assessing the Origin of Interstellar Small Bodies: The Case of 1I/2017 U1 (‘Oumuamua)

NASA Astrophysics Data System (ADS)

Zuluaga, Jorge I.; Sánchez-Hernández, Oscar; Sucerquia, Mario; Ferrín, Ignacio

2018-06-01

With the advent of more and deeper sky surveys, the discovery of interstellar small objects entering into the solar system has been finally possible. In 2017 October 19, using observations of the Pan-STARRS survey, a fast moving object, now officially named 1I/2017 U1 (‘Oumuamua), was discovered in a heliocentric unbound trajectory, suggesting an interstellar origin. Assessing the provenance of interstellar small objects is key for understanding their distribution, spatial density, and the processes responsible for their ejection from planetary systems. However, their peculiar trajectories place a limit on the number of observations available to determine a precise orbit. As a result, when its position is propagated ∼105–106 years backward in time, small errors in orbital elements become large uncertainties in position in the interstellar space. In this paper we present a general method for assigning probabilities to nearby stars of being the parent system of an observed interstellar object. We describe the method in detail and apply it for assessing the origin of ‘Oumuamua. A preliminary list of potential progenitors and their corresponding probabilities is provided. In the future, when further information about the object and/or the nearby stars be refined, the probabilities computed with our method can be updated. We provide all the data and codes we developed for this purpose in the form of an open source C/C++/Python package, iWander, which is publicly available at http://github.com/seap-udea/iWander.

Box C/D small nucleolar RNA (snoRNA) U60 regulates intracellular cholesterol trafficking.

PubMed

Brandis, Katrina A; Gale, Sarah; Jinn, Sarah; Langmade, Stephen J; Dudley-Rucker, Nicole; Jiang, Hui; Sidhu, Rohini; Ren, Aileen; Goldberg, Anna; Schaffer, Jean E; Ory, Daniel S

2013-12-13

Mobilization of plasma membrane (PM) cholesterol to the endoplasmic reticulum is essential for cellular cholesterol homeostasis. The mechanisms regulating this retrograde, intermembrane cholesterol transfer are not well understood. Because mutant cells with defects in PM to endoplasmic reticulum cholesterol trafficking can be isolated on the basis of resistance to amphotericin B, we conducted an amphotericin B loss-of-function screen in Chinese hamster ovary (CHO) cells using insertional mutagenesis to identify genes that regulate this trafficking mechanism. Mutant line A1 displayed reduced cholesteryl ester formation from PM-derived cholesterol and increased de novo cholesterol synthesis, indicating a deficiency in retrograde cholesterol transport. Genotypic analysis revealed that the A1 cell line contained one disrupted allele of the U60 small nucleolar RNA (snoRNA) host gene, resulting in haploinsufficiency of the box C/D snoRNA U60. Complementation and mutational studies revealed the U60 snoRNA to be the essential feature from this locus that affects cholesterol trafficking. Lack of alteration in predicted U60-mediated site-directed methylation of 28 S rRNA in the A1 mutant suggests that the U60 snoRNA modulates cholesterol trafficking by a mechanism that is independent of this canonical function. Our study adds to a growing body of evidence for participation of small noncoding RNAs in cholesterol homeostasis and is the first to implicate a snoRNA in this cellular function.

48 CFR 52.219-1 - Small Business Program Representations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... provision: Small Business Program Representations (APR 2011) (a)(1) The North American Industry..., Singapore, Brunei, Japan, China, Taiwan, Laos, Cambodia (Kampuchea), Vietnam, Korea, The Philippines, U.S...

How to find the optimal partner--studies of snurportin 1 interactions with U snRNA 5' TMG-cap analogues containing modified 2-amino group of 7-methylguanosine.

PubMed

Piecyk, Karolina; Niedzwiecka, Anna; Ferenc-Mrozek, Aleksandra; Lukaszewicz, Maciej; Darzynkiewicz, Edward; Jankowska-Anyszka, Marzena

2015-08-01

Snurportin 1 is an adaptor protein that mediates the active nuclear import of uridine-rich small nuclear RNAs (U snRNA) by the importin-β receptor pathway. Its cellular activity influences the overall transport yield of small ribonucleoprotein complexes containing N(2),N(2),7-trimethylguanosine (TMG) capped U snRNA. So far little is still known about structural requirements related to molecular recognition of the trimethylguanosine moiety by snurportin in solution. Since these interactions are of a great biomedical importance, we synthesized a series of new 7-methylguanosine cap analogues with extended substituents at the exocyclic 2-amino group to gain a deeper insight into how the TMG-cap is adapted into the snurportin cap-binding pocket. Prepared chemical tools were applied in binding assays using emission spectroscopy. Surprisingly, our results revealed strict selectivity of snurportin towards the TMG-cap structure that relied mainly on its structural stiffness and compactness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nuclear EGFRvIII resists hypoxic microenvironment induced apoptosis via recruiting ERK1/2 nuclear translocation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Hui; Yang, Jinfeng; Xing, Wenjing

2016-02-05

Glioblastoma (GBM) is the most aggressive type of primary brain tumor. Its interaction with the tumor microenvironment promotes tumor progression. Furthermore, GBM bearing expression of EGFRvIII displays more adaptation to tumor microenvironment related stress. But the mechanisms were poorly understood. Here, we presented evidence that in the human U87MG glioblastoma tumor model, EGFRvIII overexpression led aberrant kinase activation and nuclear translocation of EGFRvIII/ERK1/2 under hypoxia, which induced growth advantage by resisting apoptosis. Additionally, EGFRvIII defective in nuclear entry impaired this capacity in hypoxia adaptation, and partially interrupted ERK1/2 nuclear translocation. Pharmacology or genetic interference ERK1/2 decreased hypoxia resistance triggered bymore » EGFRvIII expression, but not EGFRvIII nuclear translocation. In summary, this study identified a novel role for EGFRvIII in hypoxia tolerance, supporting an important link between hypoxia and subcellular localization alterations of the receptor. - Highlights: • Nuclear translocation of EGFRvIII contributes to GBM cell apoptotic resistance by hypoxia. • Nuclear ERK1/2 facilitates EGFRvIII in hypoxia resistance. • EGFRvIII nuclear translocation is not dependent on ERK1/2.« less

Uncertainty analysis on reactivity and discharged inventory for a pressurized water reactor fuel assembly due to {sup 235,238}U nuclear data uncertainties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Da Cruz, D. F.; Rochman, D.; Koning, A. J.

2012-07-01

This paper discusses the uncertainty analysis on reactivity and inventory for a typical PWR fuel element as a result of uncertainties in {sup 235,238}U nuclear data. A typical Westinghouse 3-loop fuel assembly fuelled with UO{sub 2} fuel with 4.8% enrichment has been selected. The Total Monte-Carlo method has been applied using the deterministic transport code DRAGON. This code allows the generation of the few-groups nuclear data libraries by directly using data contained in the nuclear data evaluation files. The nuclear data used in this study is from the JEFF3.1 evaluation, and the nuclear data files for {sup 238}U and {supmore » 235}U (randomized for the generation of the various DRAGON libraries) are taken from the nuclear data library TENDL. The total uncertainty (obtained by randomizing all {sup 238}U and {sup 235}U nuclear data in the ENDF files) on the reactor parameters has been split into different components (different nuclear reaction channels). Results show that the TMC method in combination with a deterministic transport code constitutes a powerful tool for performing uncertainty and sensitivity analysis of reactor physics parameters. (authors)« less

Selection of Nuclear Fuel for TREAT: UO 2 vs U 3O 8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glazoff, Michael Vasily; Van Rooyen, Isabella Johanna; Coryell, Benjamin David

The Transient Reactor Test (TREAT) that resides at the Materials and Fuels Complex (MFC) at Idaho National Laboratory (INL), first achieved criticality in 1959, and successfully performed many transient tests on nuclear fuel until 1994 when its operations were suspended. Resumption of operations at TREAT was approved in February 2014 to meet the U.S. Department of Energy (DOE) Office of Nuclear Energy’s objectives in transient testing of nuclear fuels. The National Nuclear Security Administration’s is converting TREAT from its existing highly enriched uranium (HEU) core to a new core containing low enriched uranium (LEU) (i.e., U-235< 20% by weight). Themore » TREAT Conversion project is currently progressing with conceptual design phase activities. Dimensional stability of the fuel element assemblies, predictable fuel can oxidation and sufficient heat conductivity by the fuel blocks are some of the critical performance requirements of the new LEU fuel. Furthermore, to enable the design team to design fuel block and can specifications, it is amongst the objectives to evaluate TREAT LEU fuel and cladding material’s chemical interaction. This information is important to understand the viability of Zr-based alloys and fuel characteristics for the fabrication of the TREAT LEU fuel and cladding. Also, it is very important to make the right decision on what type of nuclear fuel will be used at TREAT. In particular, one has to consider different oxides of uranium, and most importantly, UO 2 vs U 3O 8. In this report, the results are documented pertaining to the choice mentioned above (UO 2 vs U 3O 8). The conclusion in favor of using UO 2 was made based on the analysis of historical data, up-to-date literature, and self-consistent calculations of phase equilibria and thermodynamic properties in the U-O and U-O-C systems. The report is organized as follows. First, the criteria that were used to make the choice are analyzed. Secondly, existing historical data and

Two Routes to Genetic Suppression of RNA Trimethylguanosine Cap Deficiency via C-Terminal Truncation of U1 snRNP Subunit Snp1 or Overexpression of RNA Polymerase Subunit Rpo26.

PubMed

Qiu, Zhicheng R; Schwer, Beate; Shuman, Stewart

2015-04-24

The trimethylguanosine (TMG) caps of small nuclear (sn) RNAs are synthesized by the enzyme Tgs1 via sequential methyl additions to the N2 atom of the m(7)G cap. Whereas TMG caps are inessential for Saccharomyces cerevisiae vegetative growth at 25° to 37°, tgs1∆ cells that lack TMG caps fail to thrive at 18°. The cold-sensitive defect correlates with ectopic stoichiometric association of nuclear cap-binding complex (CBC) with the residual m(7)G cap of the U1 snRNA and is suppressed fully by Cbc2 mutations that weaken cap binding. Here, we show that normal growth of tgs1∆ cells at 18° is also restored by a C-terminal deletion of 77 amino acids from the Snp1 subunit of yeast U1 snRNP. These results underscore the U1 snRNP as a focal point for TMG cap function in vivo. Casting a broader net, we conducted a dosage suppressor screen for genes that allowed survival of tgs1∆ cells at 18°. We thereby recovered RPO26 (encoding a shared subunit of all three nuclear RNA polymerases) and RPO31 (encoding the largest subunit of RNA polymerase III) as moderate and weak suppressors of tgs1∆ cold sensitivity, respectively. A structure-guided mutagenesis of Rpo26, using rpo26∆ complementation and tgs1∆ suppression as activity readouts, defined Rpo26-(78-155) as a minimized functional domain. Alanine scanning identified Glu89, Glu124, Arg135, and Arg136 as essential for rpo26∆ complementation. The E124A and R135A alleles retained tgs1∆ suppressor activity, thereby establishing a separation-of-function. These results illuminate the structure activity profile of an essential RNA polymerase component. Copyright © 2015 Qiu et al.

Small Reactor Designs Suitable for Direct Nuclear Thermal Propulsion: Interim Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruce G. Schnitzler

Advancement of U.S. scientific, security, and economic interests requires high performance propulsion systems to support missions beyond low Earth orbit. A robust space exploration program will include robotic outer planet and crewed missions to a variety of destinations including the moon, near Earth objects, and eventually Mars. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, nuclear thermal propulsion (NTP) was again selectedmore » over chemical propulsion as the preferred in-space transportation system option for the human exploration of Mars because of its high thrust and high specific impulse ({approx}900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. The recently announced national space policy2 supports the development and use of space nuclear power systems where such systems safely enable or significantly enhance space exploration or operational capabilities. An extensive nuclear thermal rocket technology development effort was conducted under the Rover/NERVA, GE-710 and ANL nuclear rocket programs (1955-1973). Both graphite and refractory metal alloy fuel types were pursued. The primary and significantly larger Rover/NERVA program focused on graphite type fuels. Research, development, and testing of high temperature graphite fuels was conducted. Reactors and engines employing these fuels were designed, built, and ground tested. The GE-710 and ANL programs focused on an alternative ceramic-metallic 'cermet' fuel type consisting of UO2 (or UN) fuel embedded in a refractory metal matrix such as tungsten. The General Electric program examined closed loop concepts for space or terrestrial

The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.

PubMed

Baniaga, Anthony E; Arrigo, Nils; Barker, Michael S

2016-06-03

The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

75 FR 11136 - Federal Advisory Committee; U.S. Nuclear Command and Control System Comprehensive Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... DEPARTMENT OF DEFENSE Office of the Secretary Federal Advisory Committee; U.S. Nuclear Command and Control System Comprehensive Review Committee; Charter Termination AGENCY: Department of Defense (DoD... terminating the charter for the U.S. Nuclear Command and Control System Comprehensive Review Committee. FOR...

U.S. Strategic Nuclear Policy and Force Structure: Three Analytical Approaches

DTIC Science & Technology

1999-12-01

research rocket fired from Norway, an incident that sparked strong concerns that nuclear war 18 Lachlan Forrow, Bruce Blair, Ira Helfnad, George Lewis...quoted in R. Jeffrey Smith , "Clinton Directive Changes Strategy On Nuclear Arms," Washington Post, 7 December 1997, Al. 86 President William...Meyers, "U.S. Updates Nuclear War Guidelines," New York Times, 8 December 1997, 4. 233 Bell quoted in R. Jeffrey Smith , "Clinton Directive Changes

U.S. Nuclear Engineering Education: Status and Prospects.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Engineering and Technical Systems.

This study examines the status of and outlook for nuclear engineering (NE) in the United States. The study resulted from a concern about the downward trends in student enrollments in NE, in both graduate and undergraduate programs. Concerns have also been expressed about the declining number of U.S. university NE departments and programs, the…

U.S.-Russian cooperation in nuclear disarmament and nonproliferation

NASA Astrophysics Data System (ADS)

Podvig, Pavel

2010-02-01

The United States and Russia, the two largest nuclear powers, have a special obligation to provide leadership in nuclear disarmament and in strengthening the nuclear non-proliferation regime. In the past year the two countries made an effort to restart the arms control process by concluding a new treaty that would bring their legal disarmament obligations in line with the realities of their post-cold war relationships. The process of negotiating deeper nuclear reductions in the new environment turned out to be rather difficult, since the approaches that the countries used in the past are not well suited to dealing with issues like conversion of strategic nuclear delivery systems to conventional missions, tactical nuclear weapons, or dismantlement of nuclear warheads. This presentation considers the recent progress in U.S.-Russian arms control process and outlines the key issues at the negotiations. It also considers prospects for further progress in bilateral nuclear disarmament and issues that will be encountered at later stages of the process. The author argues that success of the arms reductions will depend on whether the United States and Russia will be able to build an institutional framework for cooperation on a range of issues - from traditional arms control to securing nuclear materials and from missile defense to strengthening the international nuclear safeguards. )

Mass and abundance 236U sensitivities at CIRCE

NASA Astrophysics Data System (ADS)

De Cesare, M.; De Cesare, N.; D'Onofrio, A.; Fifield, L. K.; Gialanella, L.; Terrasi, F.

2015-10-01

The actinides (e.g. 236U and xPu isotopes) are present in environmental samples at the ultra trace level since atmospheric tests of NWs (Nuclear Weapons) performed in the past, deliberate dumping of nuclear waste, nuclear fuel reprocessing, on a large scale and operation of NPPs (Nuclear Power Plants) on a small scale have led to the release of a wide range of radioactive nuclides in the environment. Their detection requires the most sensitive AMS (Accelerator Mass Spectrometry) techniques and at the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) in Caserta, Italy, an upgraded actinide AMS system, based on a 3-MV pelletron tandem accelerator, has been operated. In this paper the progress made in order to push the 236U mass sensitivity and 236U/238U isotopic ratio down to the natural levels is reported. A uranium contamination mass of about 0.05 μg and a 236U/238U isotopic ratio sensitivities at the level of 3.2 × 10-13 are presently achievable.

Assessing the impact of nuclear retirements on the U.S. power sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richards, James; Cole, Wesley J.

This work utilizes the Regional Energy Deployment System (ReEDS) model to analyze the impacts of four nuclear retirement scenarios of the U.S. electricity sector, from nuclear plant lifetimes of 50 to 80 years. The analysis finds that longer nuclear lifetimes decrease the amount of renewable and natural gas capacity. Longer nuclear lifetimes also resulted in lower cumulative and annual carbon emissions, lower transmission builds, and higher energy curtailment and water usage.

SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2013-09-25

U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in amore » remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.« less

SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

ScienceCinema

None

2018-01-16

U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in a remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.

78 FR 9938 - U.S.-Korea Free Trade Agreement: Effects on U.S. Small and Medium-Sized Enterprises; Institution...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... Trade Agreement on U.S. small and medium-sized enterprises (SMEs) since entry into force of the... effects of the agreement on the production, distribution, and export strategy of U.S. SMEs, as identified by those SMEs, and describing how U.S. SMEs have benefited from specific provisions of the agreement...

History of Fire Events in the U.S. Commercial Nuclear Industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bijan Najafi; Joglar-Biloch, Francisco; Kassawara, Robert P.

2002-07-01

. EPRI has made significant progress towards improving the quality of the fire events data through use of multiple collection methods as well as its review and verification. To date EPRI has used this data to develop a generic fire ignition frequency model for U.S. nuclear power industry (Ref. 1, 4 and 5) as well as to support other models in support of EPRI Fire Risk Methods such as a cable fire manual suppression model. EPRI will continue its effort to collect and analyze operating data to support risk informed/performance based fire safety engineering, including collection and analysis of impairment data for fire protection systems and features. This paper provides details on the collection and application of fire events to risk informed/performance based fire protection. The paper also provides valuable insights into improving both collection and use of fire events data. (authors)« less

Study of Infrared Emission Spectroscopy for the B1Δg-A1Πu and B'1Σg+-A1Πu Systems of C2

NASA Astrophysics Data System (ADS)

Tang, Jian; Chen, Wang; Kawaguchi, Kentarou; Bernath, Peter F.

2016-06-01

Recently, we carried out the perturbation analysis of C_2 spectra and identified forbidden singlet-triplet intersystem transitions, which aroused further interest in other C_2 spectra for the many low-lying electronic states of this fundamental molecule. In 1988, the B1Δg-A1Πu and B'1Σg+-A1Πu band systems were discovered by Douay et al., who observed eight bands of the B1Δg-A1Πu system with v up to 5 for the B1Δg state and six bands of the B'1Σg+-A1Πu system with v up to 3 for the B'1Σg+ state in the Fourier transform infrared emission spectra of hydrocarbon discharges. In the work presented here, we identified twenty-four bands of the two systems, among which the B'1Σg+ v = 4 and the B1Δg v = 6, 7 and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B1Δg-A1Πu system except for a small perturbation in the B1Δg v = 6 level. The calculated rovibrational term energies up to B1Δg v = 12 showed that the level crossing between the B1Δg and d3Πg states is responsible for many of the prominent perturbations in the Swan system observed previously. Nineteen lines of the B1Δg-a3Πu forbidden transitions were identified and the off-diagonal spin-orbit interaction constant AdB between d3Πg and B1Δg was derived as 8.3(1) wn. For the B'1Σg+-A1Πu system, only individual band analyses for each vibrational level in the B'1Σg+ state could be done satisfactorily and Dunham parameters obtained from these effective parameters showed that the anharmonic vibrational constant ω_e x_e is anomalously small (nearly zero). Inspection of the RKR potential curves for the B'1Σg+ and X1Σg+ states revealed that an avoided crossing may occur around 30000 wn, which is responsible for the anomalous molecular constants in these two states. W. Chen, K. Kawaguchi, P. F. Bernath, and J. Tang, J. Chem. Phys., 141, 064317 (2015) M. Douay, R. Nietmann and P. F. Bernath

Tactical Nuclear Weapons-Does the U.S. Army Still Need Them?

DTIC Science & Technology

1995-05-17

Harry Summers, Colonel, US Army (Ret), "Good Riddance to a Nuclear Disaster ," Army Times, October 14, 1991, p. 78. 140 MAJ Vokac, p. 24. 141 Biddle, p...Role in U.S. Military Strategy?" Comparative Strategy, Vol. 13, pp. 197-209. Summers, Harry, Col. US Army (Ret), "Good Riddance to Nuclear Disaster ," Army

Uranus moon - 1985U1

NASA Technical Reports Server (NTRS)

1986-01-01

Several craters are seen on the surface of 1985U1, one of several small moons of Uranus discovered by Voyager 2. The spacecraft acquired this single image -- the only close-up it obtained of any of the new moons -- on Jan. 24, 1986. At the time, Voyager was at a distance of about 500,000 kilometers (300,000 miles) from 1985U1, yielding a resolution of about 10 km (6 mi) in this clear-filter, narrow-angle image. The moon was found Dec. 3O, 1985; it was the first and largest of nearly a dozen satellites discovered by the spacecraft cameras. This image shows 1985U1 to be a dark, nearly spherical object, with a diameter of about 150 km (90 mi); the dark surface reflects only 7 percent of the incident light. The picture was inserted into the Voyager encounter sequence late in its development. This image has had a complex history, having been recorded on the spacecraft tape recorder and first played back during the late afternoon of Jan. 24. An antenna-pointing problem at one of the Australian tracking stations led to loss of the data, so the image had to be transmitted a second time. It was successfully received shortly before 6 p.m. PST Jan. 26. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

Small collision systems: Theory overview on cold nuclear matter effects

NASA Astrophysics Data System (ADS)

Armesto, Néstor

2018-02-01

Many observables measured at the Relativistic Heavy Ion Collider and the Large Hadron Collider show a smooth transition between proton-proton and protonnucleus collisions (small systems), and nucleus-nucleus collisions (large systems), when represented versus some variable like the multiplicity in the event. In this contribution I review some of the physics mechanisms, named cold nuclear matter effects, that may lead to a collective-like behaviour in small systems beyond the macroscopic description provided by relativistic hydrodynamics. I focus on the nuclear modification of parton densities, single inclusive particle production and correlations.

Benchmarking U.S. Small Wind Costs with the Distributed Wind Taxonomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orrell, Alice C.; Poehlman, Eric A.

The objective of this report is to benchmark costs for small wind projects installed in the United States using a distributed wind taxonomy. Consequently, this report is a starting point to help expand the U.S. distributed wind market by informing potential areas for small wind cost-reduction opportunities and providing a benchmark to track future small wind cost-reduction progress.

76 FR 3678 - Board Meeting: February 16, 2011-Las Vegas, NV, the U.S. Nuclear Waste Technical Review Board...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

... NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: February 16, 2011--Las Vegas, NV, the U.S. Nuclear Waste Technical Review Board Will Meet To Discuss DOE Activities Related to Managing Spent Nuclear...-203, Nuclear Waste Policy Amendments Act of 1987, the U.S. Nuclear Waste Technical Review Board will...

Planning U.S. General Purpose Forces: The Theater Nuclear Forces

DTIC Science & Technology

1977-01-01

usefulness in combat. All U.S. nuclear weapons deployed in Europe are fitted with Permissive Action Links (PAL), coded devices designed to impede...may be proposed. The Standard Missile 2, the Harpoon missile, the Mk48 tor- pedo , and the SUBROC anti-submarine rocket are all being considered for...Permissive Action Link . A coded device attached to nuclear weapons deployed abroad that impedes the unauthorized arming or firing of the weapon. Pershing

U.S./CIS eye joint nuclear rocket venture

NASA Technical Reports Server (NTRS)

Clark, John S.; Mcilwain, Melvin C.; Smetanikov, Vladimir; D'Yakov, Evgenij K.; Pavshuk, Vladimir A.

1993-01-01

An account is given of the significance for U.S. spacecraft development of a nuclear thermal rocket (NTR) reactor concept that has been developed in the (formerly Soviet) Commonwealth of Independent States (CIS). The CIS NTR reactor employs a hydrogen-cooled zirconium hydride moderator and ternary carbide fuels; the comparatively cool operating temperatures associated with this design promise overall robustness.

Assessment of nuclear reactor concepts for low power space applications

NASA Technical Reports Server (NTRS)

Klein, Andrew C.; Gedeon, Stephen R.; Morey, Dennis C.

1988-01-01

The results of a preliminary small reactor concepts feasibility and safety evaluation designed to provide a first order validation of the nuclear feasibility and safety of six small reactor concepts are given. These small reactor concepts have potential space applications for missions in the 1 to 20 kWe power output range. It was concluded that low power concepts are available from the U.S. nuclear industry that have the potential for meeting both the operational and launch safety space mission requirements. However, each design has its uncertainties, and further work is required. The reactor concepts must be mated to a power conversion technology that can offer safe and reliable operation.

10 CFR Appendix A to Part 73 - U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses A Appendix A to Part 73 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Pt. 73, App. A Appendix A to Part 73—U.S. Nuclear Regulatory Commission...

10 CFR Appendix A to Part 73 - U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 2 2013-01-01 2013-01-01 false U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses A Appendix A to Part 73 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Pt. 73, App. A Appendix A to Part 73—U.S. Nuclear Regulatory Commission...

10 CFR Appendix A to Part 73 - U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 2 2014-01-01 2014-01-01 false U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses A Appendix A to Part 73 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Pt. 73, App. A Appendix A to Part 73—U.S. Nuclear Regulatory Commission...

10 CFR Appendix A to Part 73 - U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 2 2012-01-01 2012-01-01 false U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses A Appendix A to Part 73 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Pt. 73, App. A Appendix A to Part 73—U.S. Nuclear Regulatory Commission...

10 CFR Appendix A to Part 73 - U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false U.S. Nuclear Regulatory Commission Offices and Classified Mailing Addresses A Appendix A to Part 73 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PHYSICAL PROTECTION OF PLANTS AND MATERIALS Pt. 73, App. A Appendix A to Part 73—U.S. Nuclear Regulatory Commission...

76 FR 11521 - Prairie Island Nuclear Generating Plant, Unit 1, Northern States Power Company-Minnesota; Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-02

..., Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001..., Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation. [FR Doc. 2011-4557 Filed 3-1... NUCLEAR REGULATORY COMMISSION [Docket No. 50-282; NRC-2011-0040] Prairie Island Nuclear Generating...

A High Accuracy Measurement of the Nuclear Decay of 235mU and Search for the Nuclear Decay of 229mTh

NASA Astrophysics Data System (ADS)

Ponce, Francisco

Among all nuclear decays, there exist two isomeric states with very low-energy that belong to . {229}Th (7.8 ± 0.5 eV) and . {235}U (76.8 ± 0.5 eV) . Of particular interest is . {229}Th, because the decay energy is in the ultraviolet, and therefore in the range of modern tunable lasers. The isomer can potentially be used as the basis for a nuclear clock that is expected to be two orders of magnitude more precise than atomic clocks. However, the . {229m}Th nuclear decay energy is not sufficiently well known to design the necessary laser system for a nuclear clock. This work describes the development of a new technique using superconducting tunnel junction (STJ) detectors to directly measure the nuclear decay of low-energy isomers with a high level of accuracy. The strength of the technique is demonstrated by measuring the decay energy of the . {235}U isomer at 76.737 ± 0.018 eV. Over an order of magnitude more accurate than the current literature value. The technique is then applied to detect the transition in . {229m}Th directly and measure its energy with comparable accuracy. These experiments are unsuccessful and are discussed in light of the recent measurement of the . {229m}Th half-life of 7 ± \\SI{1}{\\micro\\second}.

U bodies respond to nutrient stress in Drosophila

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buckingham, Mickey; Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk

The neurodegenerative disease spinal muscular atrophy (SMA) is caused by mutation of the survival motor neuron 1 (SMN1) gene. Cytoplasmic SMN protein-containing granules, known as U snRNP bodies (U bodies), are thought to be responsible for the assembly and storage of small nuclear ribonucleoproteins (snRNPs) which are essential for pre-mRNA splicing. U bodies exhibit close association with cytoplasmic processing bodies (P bodies), which are involved in mRNA decay and translational repression. The close association of the U body and P body in Drosophila resemble that of the stress granule and P body in yeast and mammalian cells. However, it ismore » unknown whether the U body is responsive to any stress. Using Drosophila oogenesis as a model, here we show that U bodies increase in size following nutritional deprivation. Despite nutritional stress, U bodies maintain their close association with P bodies. Our results show that U bodies are responsive to nutrition changes, presumably through the U body-P body pathway.« less

Recent Developments in MC-ICP-MS for Uranium Isotopic Determination from Small Samples.

NASA Astrophysics Data System (ADS)

Field, P.; Lloyd, N. S.

2016-12-01

V002: Advances in approaches and instruments for isotope studies Session ID#: 12653 Recent Developments in MC-ICP-MS for Uranium Isotopic Determination from small samples.M. Paul Field 1 & Nicholas S. Lloyd. 1 Elemental Scientific Inc., Omaha, Nebraska, USA. field@icpms.com 2 Thermo Fisher Scientific, Hanna-Kunath-Str. 11, 28199 Bremen, Germany. nicholas.lloyd@thermofisher.com Uranium isotope ratio determination for nuclear, nuclear safeguards and for environmental applications can be challenging due to, 1) the large isotopic differences between samples and 2) low abundance of 234U and 236U. For some applications the total uranium quantities can be limited, or it is desirable to run at lower concentrations for radiological protection. Recent developments in inlet systems and detector technologies allow small samples to be analyzed at higher precisions using MC-ICP-MS. Here we evaluate the combination of Elemental Scientific apex omega desolvation system and microFAST-MC dual loop-loading flow-injection system with the Thermo Scientific NEPTUNE Plus MC-ICP-MS. The inlet systems allow for the automated syringe loading and injecting handling of small sample volumes with efficient desolvation to minimize the hydride interference on 236U. The highest ICP ion sampling efficiency is realized using the Thermo Scientific Jet Interface. Thermo Scientific 1013 ohm amplifier technology allows small ion beams to be measured at higher precision, offering the highest signal/noise ratio with a linear and stable response that covers a wide dynamic range (ca. 1 kcps - 30 Mcps). For nanogram quantities of low enriched and depleted uranium standards the 235U was measured with 1013 ohm amplifier technology. The minor isotopes (234U and 236U) were measured by SEM ion counters with RPQ lens filters, which offer the lowest detection limits. For sample amounts ca. 20 ng the minor isotopes can be moved onto 1013 ohm amplifiers and the 235U onto standard 1011 ohm amplifier. To illustrate the

Small molecule antagonists of the urokinase (uPA): urokinase receptor (uPAR) interaction with high reported potencies show only weak effects in cell-based competition assays employing the native uPAR ligand.

PubMed

De Souza, Melissa; Matthews, Hayden; Lee, Jodi A; Ranson, Marie; Kelso, Michael J

2011-04-15

Binding of the urokinase-type plasminogen activator (uPA) to its cell-surface-bound receptor uPAR and upregulation of the plasminogen activation system (PAS) correlates with increased metastasis and poor prognosis in several tumour types. Disruptors of the uPA:uPAR interaction represent promising anti-tumour/metastasis agents and several approaches have been explored for this purpose, including the use of small molecule antagonists. Two highly potent non-peptidic antagonists 1 and 2 (IC(50)1=0.8 nM, IC(50)2=33 nM) from the patent literature were reportedly identified using competition assays employing radiolabelled uPAR-binding uPA fragments and appeared as useful pharmacological tools for studying the PAS. Before proceeding to such studies, confirmation was sought that 1 and 2 retained their potencies in physiologically relevant cell-based competition assays employing uPAR's native binding partner high molecular weight uPA (HMW-uPA). This study describes a new solution phase synthesis of 1, a mixed solid/solution phase synthesis of 2 and reports the activities of 1 and 2 in semi-quantitative competition flow cytometry assays and quantitative cell-based uPA activity assays that employed HMW-uPA as the competing ligand. The flow cytometry experiments revealed that high concentrations of 2 (10-100 μM) are required to compete with HMW-uPA for uPAR binding and that 1 shows no antagonist effects at 100 μM. The cell-based enzyme activity assays similarly revealed that 1 and 2 are poor inhibitors of cell surface-bound HMW-uPA activity (IC(50) >100 μM for 1 and 2). The report highlights the dangers of identifying false-positive lead uPAR antagonists from competition assays employing labelled competing ligands other than the native HMW-uPA. Copyright © 2011 Elsevier Ltd. All rights reserved.

U.S. Nuclear Weapons Modernization - the Stockpile Life Extension Program

NASA Astrophysics Data System (ADS)

Cook, Donald

2016-03-01

Underground nuclear testing of U.S. nuclear weapons was halted by President George H.W. Bush in 1992 when he announced a moratorium. In 1993, the moratorium was extended by President Bill Clinton and, in 1995, a program of Stockpile Stewardship was put in its place. In 1996, President Clinton signed the Comprehensive Nuclear Test Ban Treaty (CTBT). Twenty years have passed since then. Over the same time, the average age of a nuclear weapon in the stockpile has increased from 6 years (1992) to nearly 29 years (2015). At its inception, achievement of the objectives of the Stockpile Stewardship Program (SSP) appeared possible but very difficult. The cost to design and construct several large facilities for precision experimentation in hydrodynamics and high energy density physics was large. The practical steps needed to move from computational platforms of less than 100 Mflops/sec to 10 Teraflops/sec and beyond were unknown. Today, most of the required facilities for SSP are in place and computational speed has been increased by more than six orders of magnitude. These, and the physicists and engineers in the complex of labs and plants within the National Nuclear Security Administration (NNSA) who put them in place, have been the basis for underpinning an annual decision, made by the weapons lab directors for each of the past 20 years, that resort to underground nuclear testing is not needed for maintaining confidence in the safety and reliability of the U.S stockpile. A key part of that decision has been annual assessment of the physical changes in stockpiled weapons. These weapons, quite simply, are systems that invariably and unstoppably age in the internal weapon environment of radioactive materials and complex interfaces of highly dissimilar organic and inorganic materials. Without an ongoing program to rebuild some components and replace other components to increase safety or security, i.e., life extending these weapons, either underground testing would again be

Administrator Highlights U.S.-Georgian Nuclear Security Cooperation in Tbilisi

ScienceCinema

Thomas D'Agostino

2017-12-09

NNSA Administrator Thomas D'Agostino highlighted the strong U.S.-Georgian cooperation on nuclear security issues during a day-long visit to the Republic of Georgia in mid-June. He briefed the media at availability at the Tbilisi airport. In April 2009, President Obama outlined an ambitious agenda to secure vulnerable nuclear material around the world within four years, calling the danger of a terrorist acquiring nuclear weapons "the most immediate and extreme threat to global security." In this year's State of the Union, he called the threat of nuclear weapons, "the greatest danger to the American people." In order to meet that challenge, the President's FY2011 Budget Request includes close to $2.7 billion for the National Nuclear Security Administration's Defense Nuclear Nonproliferation program -- an increase of 25.7 percent over FY2010. Included in that request is NNSA's Second Line of Defense (SLD) program, which works around the world to strengthen the capability of foreign governments to deter, detect, and interdict illicit trafficking in nuclear and other radioactive materials across international borders and through the global maritime shipping system.

Tuned and non-Higgsable U(1)s in F-theory

DOE PAGES

Wang, Yi-Nan

2017-03-01

We study the tuning of U(1) gauge fields in F-theory models on a base of general dimension. We construct a formula that computes the change in Weierstrass moduli when such a U(1) is tuned, based on the Morrison-Park form of a Weierstrass model with an additional rational section. Using this formula, we propose the form of “minimal tuning” on any base, which corresponds to the case where the decrease in the number of Weierstrass moduli is minimal. Applying this result, we discover some universal features of bases with non-Higgsable U(1)s. Mathematically, a generic elliptic fibration over such a base hasmore » additional rational sections. Physically, this condition implies the existence of U(1) gauge group in the low-energy supergravity theory after compactification that cannot be Higgsed away. In particular, we show that the elliptic Calabi-Yau manifold over such a base has a small number of complex structure moduli. We also suggest that non-Higgsable U(1)s can never appear on any toric bases. Finally, we construct the first example of a threefold base with non-Higgsable U(1)s.« less

Nuclear magnetic resonance-based model of a TF1/HmU-DNA complex.

PubMed

Silva, M V; Pasternack, L B; Kearns, D R

1997-12-15

Transcription factor 1 (TF1), a type II DNA-binding protein encoded by the Bacillus subtilis bacteriophage SPO1, has the capacity for sequence-selective DNA binding and a preference for 5-hydroxymethyl-2'-deoxyuridine (HmU)-containing DNA. In NMR studies of the TF1/HmU-DNA complex, intermolecular NOEs indicate that the flexible beta-ribbon and C-terminal alpha-helix are involved in the DNA-binding site of TF1, placing it in the beta-sheet category of DNA-binding proteins proposed to bind by wrapping two beta-ribbon "arms" around the DNA. Intermolecular and intramolecular NOEs were used to generate an energy-minimized model of the protein-DNA complex in which both DNA bending and protein structure changes are evident.

Functional base-pairing interaction between highly conserved elements of U3 small nucleolar RNA and the small ribosomal subunit RNA.

PubMed

Hughes, J M

1996-06-21

The U3 nucleolar RNA has a remarkably wide phyletic distribution extending from the Eukarya to the Archaea. It functions in maturation of the small subunit (SSU) rRNA through a mechanism which is as yet unknown but which involves base-pairing with pre-rRNA. The most conserved part of U3 is within 30 nucleotides of the 5' end, but as yet no function for this domain has been proposed. Elements within this domain are complementary to highly conserved sequences in the SSU rRNA which, in the mature form, fold into a universally conserved pseudoknot. The nature of the complementarity suggests a novel mechanism for U3 function whereby U3 facilitates correct folding of the pseudoknot. Wide phylogenetic comparison provides compelling evidence in support of the interaction in that significant complementary changes have taken place, particularly in the archaeon Sulfolobus, which maintain the base-pairing. Base-substitution mutations in yeast U3 designed to disrupt the base-pairing indicate that the interaction is probably essential. These include cold-sensitivity mutations which exhibit phenotypes similar to U3-depletion, but without impairment of the AO processing step, which occurs within the 5' ETS. These phenotypes are consistent with the destabilization of SSU precursors and partial impairment of the processing steps A1, at the 5' ETS/18 S boundary, and A2, within the ITS1.

76 FR 24065 - Board Workshop: June 6-7, 2011-Arlington, Virginia; the U.S. Nuclear Waste Technical Review Board...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-29

... NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Workshop: June 6-7, 2011--Arlington, Virginia; the U.S. Nuclear Waste Technical Review Board Will Hold a Workshop on Methods for Evaluating Nuclear Waste Streams... 1987, the U.S. Nuclear Waste Technical Review Board will hold a workshop on Monday, June 6, and Tuesday...

A HUMAN FACTORS META MODEL FOR U.S. NUCLEAR POWER PLANT CONTROL ROOM MODERNIZATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joe, Jeffrey C.

Over the last several years, the United States (U.S.) Department of Energy (DOE) has sponsored human factors research and development (R&D) and human factors engineering (HFE) activities through its Light Water Reactor Sustainability (LWRS) program to modernize the main control rooms (MCR) of commercial nuclear power plants (NPP). Idaho National Laboratory (INL), in partnership with numerous commercial nuclear utilities, has conducted some of this R&D to enable the life extension of NPPs (i.e., provide the technical basis for the long-term reliability, productivity, safety, and security of U.S. NPPs). From these activities performed to date, a human factors meta model formore » U.S. NPP control room modernization can now be formulated. This paper discusses this emergent HFE meta model for NPP control room modernization, with the goal of providing an integrated high level roadmap and guidance on how to perform human factors R&D and HFE for those in the U.S. nuclear industry that are engaging in the process of upgrading their MCRs.« less

Analytical design and performance studies of nuclear furnace tests of small nuclear light bulb models

NASA Technical Reports Server (NTRS)

Latham, T. S.; Rodgers, R. J.

1972-01-01

Analytical studies were continued to identify the design and performance characteristics of a small-scale model of a nuclear light bulb unit cell suitable for testing in a nuclear furnace reactor. Emphasis was placed on calculating performance characteristics based on detailed radiant heat transfer analyses, on designing the test assembly for ease of insertion, connection, and withdrawal at the reactor test cell, and on determining instrumentation and test effluent handling requirements. In addition, a review of candidate test reactors for future nuclear light bulb in-reactor tests was conducted.

Atomic Mass and Nuclear Binding Energy for U-287 (Uranium)

NASA Astrophysics Data System (ADS)

Sukhoruchkin, S. I.; Soroko, Z. N.

This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope U-287 (Uranium, atomic number Z = 92, mass number A = 287).

Nuclear Resonance Fluorescence of U-235 above 3 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, Glen A.; Caggiano, Joseph A.; Miller, Erin A.

Pacific Northwest National Laboratory and Passport Systems have collaborated to conduct measurements to search for a nuclear resonance fluorescence response of U-235 from 3 to 5 MeV using an 8 g sample of highly enriched uranium. These new measurements complement previously reported measurements below 3 MeV. Preliminary analysis indicates that no strong resonances exist for U-235 in this energy range. A second set of measurements focused on a signature search in the 5 to 10 MeV range is still under analysis.

Reviews of the Comprehensive Nuclear-Test-Ban Treaty and U.S. security

NASA Astrophysics Data System (ADS)

Jeanloz, Raymond

2017-11-01

Reviews of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) by the National Academy of Sciences concluded that the United States has the technical expertise and physical means to i) maintain a safe, secure and reliable nuclear-weapons stockpile without nuclear-explosion testing, and ii) effectively monitor global compliance once the Treaty enters into force. Moreover, the CTBT is judged to help constrain proliferation of nuclear-weapons technology, so it is considered favorable to U.S. security. Review of developments since the studies were published, in 2002 and 2012, show that the study conclusions remain valid and that technical capabilities are better than anticipated.

7 CFR 51.2541 - U.S. Fancy, U.S. Extra No. 1, U.S. No. 1 And U.S. Select Grades.

Code of Federal Regulations, 2010 CFR

2010-01-01

... PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Grades of Pistachio.... Fancy,” “U.S. Extra No. 1,” “U.S. No. 1,” and “U.S. Select” consists of pistachio nuts in the shell...

Small nucleolar RNA U2_19 promotes hepatocellular carcinoma progression by regulating Wnt/β-catenin signaling.

PubMed

Wang, Haitao; Ma, Pei; Liu, Pengpeng; Chen, Baiyang; Liu, Zhisu

2018-06-02

Emerging evidence suggests that small nucleolar RNAs (snoRNAs) have malfunctioning roles in oncogenesis. In the present study, we investigated the role of box C/D small nucleolar RNA U2_19 (snoU2_19) in the tumorigenesis of hepatocellular carcinoma (HCC). Recently, we screened snoRNAs differential signatures by performing high-throughput small RNA sequence in HCC tissues and validated that upregulated snoU2_19 was associated with aggressive phenotypes in HCC patients. Aberrant snoU2_19 facilitated HCC cell proliferation, inhibited apoptosis and induced cell cycle progression in vitro analyses. We globally investigated the molecular mechanisms of snoU2_19 in HCC and found that snoU2_19 knockdown inhibited Wnt/β-catenin signaling pathway through inducing the translocation of β-catenin in cytoplasm. We concluded that snoU2_19 plays a pathological role in the development and progression of HCC, and is a potential therapeutic target for HCC. Copyright © 2018 Elsevier Inc. All rights reserved.

Administrator Highlights U.S.-Georgian Nuclear Security Cooperation in Tbilisi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas D'Agostino

2010-07-16

NNSA Administrator Thomas D'Agostino highlighted the strong U.S.-Georgian cooperation on nuclear security issues during a day-long visit to the Republic of Georgia in mid-June. He briefed the media at availability at the Tbilisi airport. In April 2009, President Obama outlined an ambitious agenda to secure vulnerable nuclear material around the world within four years, calling the danger of a terrorist acquiring nuclear weapons "the most immediate and extreme threat to global security." In this year's State of the Union, he called the threat of nuclear weapons, "the greatest danger to the American people." In order to meet that challenge, themore » President's FY2011 Budget Request includes close to $2.7 billion for the National Nuclear Security Administration's Defense Nuclear Nonproliferation program -- an increase of 25.7 percent over FY2010. Included in that request is NNSA's Second Line of Defense (SLD) program, which works around the world to strengthen the capability of foreign governments to deter, detect, and interdict illicit trafficking in nuclear and other radioactive materials across international borders and through the global maritime shipping system.« less

U1snRNP-mediated suppression of polyadenylation in conjunction with the RNA structure controls poly (A) site selection in foamy viruses

PubMed Central

2013-01-01

Background During reverse transcription, retroviruses duplicate the long terminal repeats (LTRs). These identical LTRs carry both promoter regions and functional polyadenylation sites. To express full-length transcripts, retroviruses have to suppress polyadenylation in the 5′LTR and activate polyadenylation in the 3′LTR. Foamy viruses have a unique LTR structure with respect to the location of the major splice donor (MSD), which is located upstream of the polyadenylation signal. Results Here, we describe the mechanisms of foamy viruses regulating polyadenylation. We show that binding of the U1 small nuclear ribonucleoprotein (U1snRNP) to the MSD suppresses polyadenylation at the 5′LTR. In contrast, polyadenylation at the 3′LTR is achieved by adoption of a different RNA structure at the MSD region, which blocks U1snRNP binding and furthers RNA cleavage and subsequent polyadenylation. Conclusion Recently, it was shown that U1snRNP is able to suppress the usage of intronic cryptic polyadenylation sites in the cellular genome. Foamy viruses take advantage of this surveillance mechanism to suppress premature polyadenylation at the 5’end of their RNA. At the 3’end, Foamy viruses use a secondary structure to presumably block access of U1snRNP and thereby activate polyadenylation at the end of the genome. Our data reveal a contribution of U1snRNP to cellular polyadenylation site selection and to the regulation of gene expression. PMID:23718736

Photofission cross-section ratio measurement of 235 U/ 238 U using monoenergetic photons in the energy range of 9.0–16.6 MeV

DOE PAGES

Krishichayan,; Bhike, Megha; Finch, S. W.; ...

2017-05-01

Photofission cross-section ratios of 235U and 238U have been measured using monoenergetic photon beams from the High Intensity Gamma-ray Source facility at the Triangle Universities Nuclear Laboratory. These measurements have been performed in small energy steps between 9.0 and 16.6 MeV using a dual-fission ionization chamber. The measured cross-section ratios are compared with the previous experimental data as well as with the recent evaluated nuclear data library ENDF.

U.S. Strategic Nuclear Forces: Background, Developments, and Issues

DTIC Science & Technology

2013-10-22

32 Safety, Security, and Management ...by Amy F. Woolf. 2 Natural Resources Defense Council. Table of U.S. Strategic Offensive Force Loadings. Archive of Nuclear Data. http://www.nrdc.org...12000 14000 16000 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 Year N um be r Launchers Warheads Source: Natural Resources Defense Council

77 FR 39385 - Receipts-Based, Small Business Size Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-03

... Business Size Standard AGENCY: Nuclear Regulatory Commission. ACTION: Direct final rule. SUMMARY: The U.S.... The NRC is increasing its receipts-based, small business size standard from $6.5 million to $7 million to conform to the standard set by the Small Business Administration (SBA). This size standard...

Manned space flight nuclear system safety. Volume 4: Space shuttle nuclear system transportation. Part 1: Space shuttle nuclear safety

NASA Technical Reports Server (NTRS)

1972-01-01

An analysis of the nuclear safety aspects (design and operational considerations) in the transport of nuclear payloads to and from earth orbit by the space shuttle is presented. Three representative nuclear payloads used in the study were: (1) the zirconium hydride reactor Brayton power module, (2) the large isotope Brayton power system and (3) small isotopic heat sources which can be a part of an upper stage or part of a logistics module. Reference data on the space shuttle and nuclear payloads are presented in an appendix. Safety oriented design and operational requirements were identified to integrate the nuclear payloads in the shuttle mission. Contingency situations were discussed and operations and design features were recommended to minimize the nuclear hazards. The study indicates the safety, design and operational advantages in the use of a nuclear payload transfer module. The transfer module can provide many of the safety related support functions (blast and fragmentation protection, environmental control, payload ejection) minimizing the direct impact on the shuttle.

Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacold, J. I.; Lukens, W. W.; Booth, C. H.

Nuclear weapons testing generates large volumes of glassy materials that influence the transport of dispersed actinides in the environment and may carry information on the composition of the detonated device. We determine the oxidation state of U and Fe (which is known to buffer the oxidation state of actinide elements and to affect the redox state of groundwater) in samples of melt glass collected from three U.S. nuclear weapons tests. For selected samples, we also determine the coordination geometry of U and Fe, and we report the oxidation state of Pu from one melt glass sample. We find significant variationsmore » among the melt glass samples and, in particular, find a clear deviation in one sample from the expected buffering effect of Fe(II)/Fe(III) on the oxidation state of uranium. In the first direct measurement of Pu oxidation state in a nuclear test melt glass, we obtain a result consistent with existing literature that proposes Pu is primarily present as Pu(IV) in post-detonation material. In addition, our measurements imply that highly mobile U(VI) may be produced in significant quantities when melt glass is quenched rapidly following a nuclear detonation, though these products may remain immobile in the vitrified matrices. The observed differences in chemical state among the three samples show that redox conditions can vary dramatically across different nuclear test conditions. The local soil composition, associated device materials, and the rate of quenching are all likely to affect the final redox state of the glass. The resulting variations in glass chemistry are significant for understanding and interpreting debris chemistry and the later environmental mobility of dispersed material.« less

Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing

NASA Astrophysics Data System (ADS)

Pacold, J. I.; Lukens, W. W.; Booth, C. H.; Shuh, D. K.; Knight, K. B.; Eppich, G. R.; Holliday, K. S.

2016-05-01

Nuclear weapons testing generates large volumes of glassy materials that influence the transport of dispersed actinides in the environment and may carry information on the composition of the detonated device. We determine the oxidation state of U and Fe (which is known to buffer the oxidation state of actinide elements and to affect the redox state of groundwater) in samples of melt glass collected from three U.S. nuclear weapons tests. For selected samples, we also determine the coordination geometry of U and Fe, and we report the oxidation state of Pu from one melt glass sample. We find significant variations among the melt glass samples and, in particular, find a clear deviation in one sample from the expected buffering effect of Fe(II)/Fe(III) on the oxidation state of uranium. In the first direct measurement of Pu oxidation state in a nuclear test melt glass, we obtain a result consistent with existing literature that proposes Pu is primarily present as Pu(IV) in post-detonation material. In addition, our measurements imply that highly mobile U(VI) may be produced in significant quantities when melt glass is quenched rapidly following a nuclear detonation, though these products may remain immobile in the vitrified matrices. The observed differences in chemical state among the three samples show that redox conditions can vary dramatically across different nuclear test conditions. The local soil composition, associated device materials, and the rate of quenching are all likely to affect the final redox state of the glass. The resulting variations in glass chemistry are significant for understanding and interpreting debris chemistry and the later environmental mobility of dispersed material.

U14 small nucleolar RNA makes multiple contacts with the pre-ribosomal RNA.

PubMed

Morrissey, J P; Tollervey, D

1997-06-01

The small nucleolar RNA (snoRNA) U14 has two regions of extended primary sequence complementarity to the 18S rRNA. The 3' region (domain B) shows the consensus structure for the methylation guide class of snoRNAs, whereas base-pairing between the 5' region (domain A) and the 18S rRNA sequence is required for the formation of functional ribosomes. Between domains A and B lies another essential region (domain Y). Here we report that yeast U14 can be cross-linked in vivo to the pre-rRNA; cross-linking is detected exclusively with the 35S primary transcript. Many nucleotides in U14 that lie outside of domains A and B are cross-linked to the pre-rRNA; in particular the essential domain Y region is cross-linked at several sites. U14 is, therefore, in far more extensive contact with the pre-rRNA than predicted from simple base-pairing models. Moreover, U14 can be cross-linked to other small RNA species. The functional interactions made by U14 during ribosome synthesis are likely to be very complex.

Study on underclad cracking in nuclear reactor vessel steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horiya, T.; Takeda, T.; Yamato, K.

1985-02-01

Susceptibility to underclad cracking in nuclear reactor vessel steels, such as SA533 Grade B Class 1 and SA508 Class 2, was studied in detail. A convenient simulation test method using simulated HAZ specimens of small size has been developed for quantitative evaluation of susceptibility to underclad cracks. The method can predict precisely the cracking behavior in weldments of steels with relative low crack susceptibility. The effect of chemical compositions on susceptibility to the cracking was examined systematically using the developed simulation test method and the following index was obtained from the test results: U = 20(V) + 7(C) + 4(Mo)more » + (Cr) + (Cu) - 0.5(Mn) + 1.5 log(X) X = Al . . . Al/2N less than or equal to 1 X = 2N . . . Al/2N > 1 It was confirmed that the new index (U) is useful for the prediction of crack susceptibility of the nuclear vessel steels; i.e., no crack initiation is detected in weldments in the roller bend test for steels having U value below 0.90.« less

U.S. Nuclear Regulatory Commission natural analogue research program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovach, L.A.; Ott, W.R.

1995-09-01

This article describes the natural analogue research program of the U.S. Nuclear Regulatory Commission (US NRC). It contains information on the regulatory context and organizational structure of the high-level radioactive waste research program plan. It also includes information on the conditions and processes constraining selection of natural analogues, describes initiatives of the US NRC, and describes the role of analogues in the licensing process.

The Common Sense of Small Nuclear Arsenals

DTIC Science & Technology

2012-01-01

affairs. That pattern is continuing and, therefore, is worth examining. In this article I use structural theory to explain what I call “the com­ mon...deterrence and dis­ suasion and then explain small nuclear arsenals in terms of structural theory , relying most heavily on the effects of socialization...deterrence are particularly useful. Dissuasion and general deterrence share many common elements. Both are rooted in deterrence theory and share an

76 FR 42686 - DOE Response to Recommendation 2011-1 of the Defense Nuclear Facilities Safety Board, Safety...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

... DEPARTMENT OF ENERGY DOE Response to Recommendation 2011-1 of the Defense Nuclear Facilities... Nuclear Facilities Safety Board, Office of Health, Safety and Security, U.S. Department of Energy, 1000... Department of Energy (DOE) acknowledges receipt of Defense Nuclear Facilities Safety Board (Board...

Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacold, J. I.; Lukens, W. W.; Booth, C. H.

We report that nuclear weapons testing generates large volumes of glassy materials that influence the transport of dispersed actinides in the environment and may carry information on the composition of the detonated device. We determine the oxidation state of U and Fe (which is known to buffer the oxidation state of actinide elements and to affect the redox state of groundwater) in samples of melt glass collected from three U.S. nuclear weapons tests. For selected samples, we also determine the coordination geometry of U and Fe, and we report the oxidation state of Pu from one melt glass sample. Wemore » find significant variations among the melt glass samples and, in particular, find a clear deviation in one sample from the expected buffering effect of Fe(II)/Fe(III) on the oxidation state of uranium. In the first direct measurement of Pu oxidation state in a nuclear test melt glass, we obtain a result consistent with existing literature that proposes Pu is primarily present as Pu(IV) in post-detonation material. In addition, our measurements imply that highly mobile U(VI) may be produced in significant quantities when melt glass is quenched rapidly following a nuclear detonation, though these products may remain immobile in the vitrified matrices. The observed differences in chemical state among the three samples show that redox conditions can vary dramatically across different nuclear test conditions. The local soil composition, associated device materials, and the rate of quenching are all likely to affect the final redox state of the glass. Lastly, the resulting variations in glass chemistry are significant for understanding and interpreting debris chemistry and the later environmental mobility of dispersed material.« less

Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing

DOE PAGES

Pacold, J. I.; Lukens, W. W.; Booth, C. H.; ...

2016-05-18

We report that nuclear weapons testing generates large volumes of glassy materials that influence the transport of dispersed actinides in the environment and may carry information on the composition of the detonated device. We determine the oxidation state of U and Fe (which is known to buffer the oxidation state of actinide elements and to affect the redox state of groundwater) in samples of melt glass collected from three U.S. nuclear weapons tests. For selected samples, we also determine the coordination geometry of U and Fe, and we report the oxidation state of Pu from one melt glass sample. Wemore » find significant variations among the melt glass samples and, in particular, find a clear deviation in one sample from the expected buffering effect of Fe(II)/Fe(III) on the oxidation state of uranium. In the first direct measurement of Pu oxidation state in a nuclear test melt glass, we obtain a result consistent with existing literature that proposes Pu is primarily present as Pu(IV) in post-detonation material. In addition, our measurements imply that highly mobile U(VI) may be produced in significant quantities when melt glass is quenched rapidly following a nuclear detonation, though these products may remain immobile in the vitrified matrices. The observed differences in chemical state among the three samples show that redox conditions can vary dramatically across different nuclear test conditions. The local soil composition, associated device materials, and the rate of quenching are all likely to affect the final redox state of the glass. Lastly, the resulting variations in glass chemistry are significant for understanding and interpreting debris chemistry and the later environmental mobility of dispersed material.« less

Impact of New Nuclear Data Libraries on Small Sized Long Life CANDLE HTGR Design Parameters

NASA Astrophysics Data System (ADS)

Liem, Peng Hong; Hartanto, Donny; Tran, Hoai Nam

2017-01-01

The impact of new evaluated nuclear data libraries (JENDL-4.0, ENDF/B-VII.0 and JEFF-3.1) on the core characteristics of small-sized long-life CANDLE High Temperature Gas-Cooled Reactors (HTGRs) with uranium and thorium fuel cycles was investigated. The most important parameters of the CANDLE core characteristics investigated here covered (1) infinite multiplication factor of the fresh fuel containing burnable poison, (2) the effective multiplication factor of the equilibrium core, (3) the moving velocity of the burning region, (4) the attained discharge burnup, and (5) the maximum power density. The reference case was taken from the current JENDL-3.3 results. For the uranium fuel cycle, the impact of the new libraries was small, while significant impact was found for thorium fuel cycle. The findings indicated the needs of more accurate nuclear data libraries for nuclides involved in thorium fuel cycle in the future.

Managing the Nuclear Fuel Cycle: Policy Implications of Expanding Global Access to Nuclear Power

DTIC Science & Technology

2008-01-20

critical aspect of the nuclear fuel cycle for the United States, where longstanding nonproliferation policy discouraged commercial nuclear fuel...have U.S. government officials. However, the case of Iran raises perhaps the most critical question in this decade for strengthening the nuclear...slight difference in atomic mass between 235U and 238U. The typical enrichment process requires about 10 lbs of uranium U3O8 to produce 1 lb of low

Affordable Development and Demonstration of a Small Nuclear Thermal Rocket (NTR) Engine and Stage: How Small Is Big Enough?

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.; Sefcik, Robert J.; Fittje, James E.; McCurdy, David R.; Qualls, Arthur L.; Schnitzler, Bruce G.; Werner, James E.; Weitzberg, Abraham; Joyner, Claude R.

2016-01-01

The Nuclear Thermal Rocket (NTR) derives its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine's reactor core. It generates high thrust and has a specific impulse potential of approximately 900 specific impulse - a 100 percent increase over today's best chemical rockets. The Nuclear Thermal Propulsion (NTP) project, funded by NASA's Advanced Exploration Systems (AES) program, includes five key task activities: (1) Recapture, demonstration, and validation of heritage graphite composite (GC) fuel (selected as the Lead Fuel option); (2) Engine Conceptual Design; (3) Operating Requirements Definition; (4) Identification of Affordable Options for Ground Testing; and (5) Formulation of an Affordable Development Strategy. During fiscal year (FY) 2014, a preliminary Design Development Test and Evaluation (DDT&E) plan and schedule for NTP development was outlined by the NASA Glenn Research Center (GRC), Department of Energy (DOE) and industry that involved significant system-level demonstration projects that included Ground Technology Demonstration (GTD) tests at the Nevada National Security Site (NNSS), followed by a Flight Technology Demonstration (FTD) mission. To reduce cost for the GTD tests and FTD mission, small NTR engines, in either the 7.5 or 16.5 kilopound-force thrust class, were considered. Both engine options used GC fuel and a common fuel element (FE) design. The small approximately 7.5 kilopound-force criticality-limited engine produces approximately157 thermal megawatts and its core is configured with parallel rows of hexagonal-shaped FEs and tie tubes (TTs) with a FE to TT ratio of approximately 1:1. The larger approximately 16.5 kilopound-force Small Nuclear Rocket Engine (SNRE), developed by Los Alamos National Laboratory (LANL) at the end of the Rover program, produces approximately 367 thermal megawatts and has a FE to TT ratio of approximately 2:1. Although both engines use a common 35-inch (approximately

Cross section for the subthreshold fission of 236U

NASA Astrophysics Data System (ADS)

Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A.; Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S.

2008-08-01

The cross section for 236U fission in the neutron-energy range E n = 0.001 20 keV was measured by using the INR RAS (Institute of Nuclear Research, Russian Academy of Sciences, Moscow) LSDS-100 neutron spectrometer of the lead slowing-down spectrometer type. The resonance fission areas of the resonances at 5.45 eV and 1.28 keV were found, and the fission widths of these resonances were evaluated. The cross section for the 238U( n, f) fission process was measured, and the threshold sensitivity of the LSDS-100 to small values of fission cross sections was estimated. The well-known intermediate structure in the cross section for the neutron-induced subbarrier fission of 236U was confirmed.

Circ-UBR5: An exonic circular RNA and novel small nuclear RNA involved in RNA splicing.

PubMed

Qin, Meilin; Wei, Gang; Sun, Xiaomeng

2018-06-24

Circular RNAs (circRNAs) are class of non-coding RNAs formed by back-splicing events as loops, and could be found in all types of organisms. They play important and diverse roles in cell development, growth, and tumorigenesis, but functions of the majority of circRNAs remain enigmatic. Particularly functional phenotypes of great majority of circRNAs are not obvious. Here we randomly selected a circRNA circ-UBR5, which has no obvious functional phenotype in non-small cell lung cancer (NSCLC) cells from our previous research findings, to explore its potential function in cells. Differential expression of circ-UBR5 was detected in paired samples of tumorous tissues and adjacent nontumorous tissues from 59 patients with NSCLC by real-time quantitative reverse transcription-polymerase chain reactions (qRT-PCRs). Results showed circ-UBR5 expression was significantly downregulated in NSCLC tissues (p < 0.001) and was correlated with tumor differentiation (p = 0.00126), suggesting circ-UBR5 might serve as an index of NSCLC differentiation. Our findings indicated circ-UBR5 could bind splicing regulatory factor QKI, KH domain containing RNA binding (QKI) and NOVA alternative splicing regulator 1 (NOVA1) and U1 small nuclear RNA (snRNA) in the nucleus, revealing circ-UBR5 might be a novel snRNA involved in RNA splicing regulatory process. Moreover, we first presented a highly efficient strategy for finding specific circRNA binding proteins using Human Protein Microarray (Huprot™ Protoarray). Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

What Are the Security Threats to Further Development of Nuclear Power Plants in the U.S.

DTIC Science & Technology

2010-03-01

as-a-secure- fuel -alternative &catid=94:0409content&itemid=342. (accessed May 2009). Bush, President George W. “Expand the Circle of Development by...SECURITY THREATS TO FURTHER DEVELOPMENT OF NUCLEAR POWER PLANTS IN THE U.S.? by Tammie L. Nottestad March 2010 Thesis Advisor: Robert Looney...Master’s Thesis 4. TITLE AND SUBTITLE What Are the Security Threats to Further Development of Nuclear Power Plants in the U.S.? 6. AUTHOR(S

Concerted evolution of the tandemly repeated genes encoding primate U2 small nuclear RNA (the RNU2 locus) does not prevent rapid diversification of the (CT){sub n} {center_dot} (GA){sub n} microsatellite embedded within the U2 repeat unit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, D.; Weiner, A.M.

1995-12-10

The RNU2 locus encoding human U2 small nuclear RNA (snRNA) is organized as a nearly perfect tandem array containing 5 to 22 copies of a 5.8-kb repeat unit. Just downstream of the U2 snRNA gene in each 5.8-kb repeat unit lies a large (CT){sub n}{center_dot}(GA){sub n} dinucleotide repeat (n {approx} 70). This form of genomic organization, in which one repeat is embedded within another, provides an unusual opportunity to study the balance of forces maintaining the homogeneity of both kinds of repeats. Using a combination of field inversion gel electrophoresis and polymerase chain reaction, we have been able to studymore » the CT microsatellites within individual U2 tandem arrays. We find that the CT microsatellites within an RNU2 allele exhibit significant length polymorphism, despite the remarkable homogeneity of the surrounding U2 repeat units. Length polymorphism is due primarily to loss or gain of CT dinucleotide repeats, but other types of deletions, insertions, and substitutions are also frequent. Polymorphism is greatly reduced in regions where pure (CT){sub n} tracts are interrupted by occasional G residues, suggesting that irregularities stabilize both the length and the sequence of the dinucleotide repeat. We further show that the RNU2 loci of other catarrhine primates (gorilla, chimpanzee, ogangutan, and baboon) contain orthologous CT microsatellites; these also exhibit length polymorphism, but are highly divergent from each other. Thus, although the CT microsatellite is evolving far more rapidly than the rest of the U2 repeat unit, it has persisted through multiple speciation events spanning >35 Myr. The persistence of the CT microsatellite, despite polymorphism and rapid evolution, suggests that it might play a functional role in concerted evolution of the RNU2 loci, perhaps as an initiation site for recombination and/or gene conversion. 70 refs., 5 figs.« less

A Vulnerability Assessment of the U.S. Small Business B2C E-Commerce Network Systems

ERIC Educational Resources Information Center

Zhao, Jensen J.; Truell, Allen D.; Alexander, Melody W.; Woosley, Sherry A.

2011-01-01

Objective: This study assessed the security vulnerability of the U.S. small companies' business-to-consumer (B2C) e-commerce network systems. Background: As the Internet technologies have been changing the way business is conducted, the U.S. small businesses are investing in such technologies and taking advantage of e-commerce to access global…

76 FR 47613 - Board Meeting: September 13-14, 2011-Salt Lake City, UT; the U.S. Nuclear Waste Technical Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-05

... NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: September 13-14, 2011--Salt Lake City, UT; the U.S. Nuclear Waste Technical Review Board Will Meet To Discuss DOE Plans for Used Fuel Disposition R... Amendments Act of 1987, the U.S. Nuclear Waste Technical Review Board will hold a public meeting in Salt Lake...

Neutron capture cross-section measurements for 238U between 0.4 and 1.4 MeV

NASA Astrophysics Data System (ADS)

Krishichayan, Fnu; Finch, S. W.; Howell, C. R.; Tonchev, A. P.; Tornow, W.

2017-09-01

Neutron-induced radiative-capture cross-section data of 238U are crucial for fundamental nuclear physics as well as for Stewardship Science, for advanced-fuel-cycle calculations, and for nuclear astrophysics. Based on different techniques, there are a large number of 238U(n, γ) 239U cross-section data available in the literature. However, there is a lack of systematic and consistent measurements in the 0.1 to 3.0 MeV energy range. The goal of the neutron-capture project at TUNL is to provide accurate 238U(n, γ) 239U cross-section data in this energy range. The 238U samples, sandwiched between gold foils of the same size, were irradiated for 8-14 hours with monoenergetic neutrons. To avoid any contribution from thermal neutrons, the 238U and 197Au targets were placed inside of a thin-walled pill-box made of 238U. Finally, the whole pill-box was wrapped in a gold foil as well. After irradiation, the samples were gamma-counted at the TUNL's low-background counting facility using high-efficient HPGe detectors. The 197Au monitor foils were used to calculate the neutron flux. The experimental technique and 238U(n, γ) 239U cross-section results at 6 energies will be discussed during the meeting.

A microstructural comparison of two nuclear-grade martensitic steels using small-angle neutron scattering

NASA Astrophysics Data System (ADS)

Coppola, R.; Fiori, F.; Little, E. A.; Magnani, M.

1997-06-01

Results are presented of a small-angle neutron scattering (SANS) study on two 10-13% Cr martensitic stainless steels of interest for nuclear applications, viz. DIN 1.4914 (MANET specification, for fusion reactors) and AISI 410. The investigation has focussed principally on microstructural effects associated with the differences in chromium content between the two alloys. The size distribution functions determined from nuclear and magnetic SANS components for the two steels given identical heat treatments are in accord with an interpretation based on the presence of ˜ 1 nm size CCr aggregates in the microstructure. Much larger (˜ 10 nm) scattering inhomogeneities with different magnetic contrast are also present and tentatively identified as carbides.

Redefining the U.S. Agenda for Nuclear Disarmament, Analysis and Reflections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunn, Lewis A.

With Lewis Dunn’s paper on nuclear disarmament diplomacy, we are inaugurating a new monograph series under the auspices of the Center for Global Security Research at Lawrence Livermore National Laboratory. The series will explore complex emerging challenges in the emerging security environment as they bear on issues of deterrence, assurance, and strategic stability. Our goal is to explore these issues deeply enough to provide significant new understanding that is technically informed and policy relevant. Our premise is that thoughtful students of international security affairs continue to value such in-depth analysis as a way to help make sense of the largemore » flow of data and opinion that reaches all of us on a daily basis. Our ambition is to generate four to six such papers per year on especially salient topics. The views expressed in these papers are those of the author and should not be attributed to the Center, the Laboratory, or the U.S. government. This inaugural paper addresses one of the key questions facing national leadership seven to eight years after President Obama’s April 2009 remarks in Prague and his commitment to take practical steps towards the long-term goal of the elimination of nuclear weapons. In the interim, some important steps have been taken. But there have also been many disappointments. The new presidential administration will face a security landscape quite different from that of eight years ago and must reassess U.S. priorities and approaches. As Lewis Dunn argues, some will be tempted to walk away entirely from the disarmament agenda, while others will advocate even more forcefully for unilateral U.S. steps to further reduce the role and number of nuclear weapons in its posture. Dr. Dunn sets out his own vision of how to adapt and carry forward the disarmament agenda, in a manner informed by developments in the security environment that point to a continuing role for nuclear deterrence. The result is both fresh and

ORNL experience and perspectives related to processing of thorium and 233U for nuclear fuel

DOE PAGES

Croff, Allen G.; Collins, Emory D.; Del Cul, G. D.; ...

2016-05-01

Thorium-based nuclear fuel cycles have received renewed attention in both research and public circles since about the year 2000. Much of the attention has been focused on nuclear fission energy production that utilizes thorium as a fertile element for producing fissionable 233U for recycle in thermal reactors, fast reactors, or externally driven systems. Here, lesser attention has been paid to other fuel cycle operations that are necessary for implementation of a sustainable thorium-based fuel cycle such as reprocessing and fabrication of recycle fuels containing 233U.

Why are U.S. nuclear weapon modernization efforts controversial?

NASA Astrophysics Data System (ADS)

Acton, James

2016-03-01

U.S. nuclear weapon modernization programs are focused on extending the lives of existing warheads and developing new delivery vehicles to replace ageing bombers, intercontinental ballistic missiles, and ballistic missile submarines. These efforts are contested and controversial. Some critics argue that they are largely unnecessary, financially wasteful and potentially destabilizing. Other critics posit that they do not go far enough and that nuclear weapons with new military capabilities are required. At its core, this debate centers on three strategic questions. First, what roles should nuclear weapons be assigned? Second, what military capabilities do nuclear weapons need to fulfill these roles? Third, how severe are the unintended escalation risks associated with particular systems? Proponents of scaled-down modernization efforts generally argue for reducing the role of nuclear weapons but also that, even under existing policy, new military capabilities are not required. They also tend to stress the escalation risks of new--and even some existing--capabilities. Proponents of enhanced modernization efforts tend to advocate for a more expansive role for nuclear weapons in national security strategy. They also often argue that nuclear deterrence would be enhanced by lower yield weapons and/or so called bunker busters able to destroy more deeply buried targets. The debate is further fueled by technical disagreements over many aspects of ongoing and proposed modernization efforts. Some of these disagreements--such as the need for warhead life extension programs and their necessary scope--are essentially impossible to resolve at the unclassified level. By contrast, unclassified analysis can help elucidate--though not answer--other questions, such as the potential value of bunker busters.

The radiological impact of electricity generation by U.K. coal and nuclear systems.

PubMed

Robson, A

1984-05-01

Radiological impact is discussed for U.K. coal and nuclear power cycles under normal operation. The type having the greater impact depends on the radiological basis of the comparison, the particular nuclear reactor system considered and whether or not the whole fuel cycle, especially irradiated nuclear fule reprocessing , is included in the analysis. More importantly, the various impacts are shown to be generally acceptable in an absolute sense i.e. exposures are less than and usually low in comparison with radiological safety guidelines and everyday natural radiation exposures.

Structure of a small-molecule inhibitor complexed with GlmU from Haemophilus influenzae reveals an allosteric binding site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mochalkin, Igor; Lightle, Sandra; Narasimhan, Lakshmi

2008-04-02

N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) is an essential enzyme in aminosugars metabolism and an attractive target for antibiotic drug discovery. GlmU catalyzes the formation of uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc), an important precursor in the peptidoglycan and lipopolisaccharide biosynthesis in both Gram-negative and Gram-positive bacteria. Here we disclose a 1.9 {angstrom} resolution crystal structure of a synthetic small-molecule inhibitor of GlmU from Haemophilus influenzae (hiGlmU). The compound was identified through a high-throughput screening (HTS) configured to detect inhibitors that target the uridyltransferase active site of hiGlmU. The original HTS hit exhibited a modest micromolar potency (IC{sub 50} - 18 {mu}M in a racemic mixture) againstmore » hiGlmU and no activity against Staphylococcus aureus GlmU (saGlmU). The determined crystal structure indicated that the inhibitor occupies an allosteric site adjacent to the GlcNAc-1-P substrate-binding region. Analysis of the mechanistic model of the uridyltransferase reaction suggests that the binding of this allosteric inhibitor prevents structural rearrangements that are required for the enzymatic reaction, thus providing a basis for structure-guided design of a new class of mechanism-based inhibitors of GlmU.« less

77 FR 53769 - Receipts-Based, Small Business Size Standard; Confirmation of Effective Date

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-04

...-Based, Small Business Size Standard; Confirmation of Effective Date AGENCY: Nuclear Regulatory Commission. ACTION: Direct final rule; confirmation of effective date. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is confirming the effective date of August 22, 2012, for the direct final rule that appeared...

Import routes and nuclear functions of Argonaute and other small RNA-silencing proteins.

PubMed

Schraivogel, Daniel; Meister, Gunter

2014-09-01

Small RNAs are important regulators of gene expression in many different organisms. Nuclear and cytoplasmic biogenesis enzymes generate functional small RNAs from double-stranded (ds) or single-stranded (ss) RNA precursors, and mature small RNAs are loaded into Argonaute proteins. In the cytoplasm, small RNAs guide Argonaute proteins to complementary RNAs leading to cleavage of these targets, translational silencing, or mRNA decay. In the nucleus Argonaute proteins engage in transcriptional silencing processes such as epigenetic silencing of repetitive elements at the chromatin level. During the past few years many novel functions of small RNA-guided gene silencing proteins in the nucleus have been reported. However, their specific import routes are largely unknown. In this review we summarize the current knowledge on nuclear transport routes that Argonaute and other RNA-silencing proteins take to carry out their various functions in the nucleus. Copyright © 2014 Elsevier Ltd. All rights reserved.

The U(1)-Kepler Problems

NASA Astrophysics Data System (ADS)

Meng, Guowu

2010-12-01

Let n ⩾ 2 be a positive integer. To each irreducible representation σ of U(1), a U(1)-Kepler problem in dimension (2n - 1) is constructed and analyzed. This system is superintegrable and when n = 2 it is equivalent to a MICZ-Kepler problem. The dynamical symmetry group of this system is widetildeU(n, n), and the Hilbert space of bound states {{H}}(σ ) is the unitary highest weight representation of widetildeU(n, n) with the minimal positive Gelfand-Kirillov dimension. Furthermore, it is shown that the correspondence between σ ^* (the dual of σ) and {H}(σ ) is the theta-correspondence for dual pair (U(1), U(n,n))subseteq Sp_{4n}({R}).

Clinical utility of level-of-evidence-1 disease forecast cancer biomarkers uPA and its inhibitor PAI-1.

PubMed

Schmitt, Manfred; Mengele, Karin; Napieralski, Rudolf; Magdolen, Viktor; Reuning, Ute; Gkazepis, Apostolos; Sweep, Fred; Brünner, Nils; Foekens, John; Harbeck, Nadia

2010-11-01

The prognostic and/or predictive value of the cancer biomarkers, urokinase-type plasminogen activator (uPA) and its inhibitor (plasminogen activator inhibitor [PAI]-1), determined by ELISA in tumor-tissue extracts, was demonstrated for several cancer types in numerous clinically relevant retrospective or prospective studies, including a multicenter breast cancer therapy trial (Chemo-N0). Consequently, for the first time ever for any cancer biomarker for breast cancer, uPA and PAI-1 have reached the highest level of evidence, level-of-evidence-1. At present, two other breast cancer therapy trials, NNBC-3 and Plan B, also incorporating uPA and PAI-1 as treatment-assignment tools are in effect. Furthermore, small synthetic molecules targeting uPA are currently in Phase II clinical trials in patients afflicted with advanced cancer of the ovary, breast or pancreas.

77 FR 6131 - Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the Department of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-07

.... Background Nuclear Regulatory Commission Pursuant to Section 103 of the Atomic Energy Act of 1954, as amended... NUCLEAR REGULATORY COMMISSION DEPARTMENT OF HOMELAND SECURITY [NRC-2012-0015] Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the Department of Homeland Security Regarding...

New Realities: Energy Security in the 2010s and Implications for the U.S. Military

DTIC Science & Technology

2014-01-01

a small hydroelectric plant on a tributary of the Hudson...amount to a strong headwind for the viability of the U.S. nuclear industry. Several factors are contributing to this situation. First among...are: (1) A shift in the center of gravity of world oil consumption from the older industrialized nations of the Organization for Economic

Climatic Consequences of Nuclear Conflict

NASA Astrophysics Data System (ADS)

Robock, A.

2011-12-01

A nuclear war between Russia and the United States could still produce nuclear winter, even using the reduced arsenals of about 4000 total nuclear weapons that will result by 2017 in response to the New START treaty. A nuclear war between India and Pakistan, with each country using 50 Hiroshima-sized atom bombs as airbursts on urban areas, could produce climate change unprecedented in recorded human history. This scenario, using much less than 1% of the explosive power of the current global nuclear arsenal, would produce so much smoke from the resulting fires that it would plunge the planet to temperatures colder than those of the Little Ice Age of the 16th to 19th centuries, shortening the growing season around the world and threatening the global food supply. Crop model studies of agriculture in the U.S. and China show massive crop losses, even for this regional nuclear war scenario. Furthermore, there would be massive ozone depletion with enhanced ultraviolet radiation reaching the surface. These surprising conclusions are the result of recent research (see URL) by a team of scientists including those who produced the pioneering work on nuclear winter in the 1980s, using the NASA GISS ModelE and NCAR WACCM GCMs. The soot is self-lofted into the stratosphere, and the effects of regional and global nuclear war would last for more than a decade, much longer than previously thought. Nuclear proliferation continues, with nine nuclear states now, and more working to develop or acquire nuclear weapons. The continued environmental threat of the use of even a small number of nuclear weapons must be considered in nuclear policy deliberations in Russia, the U.S., and the rest of the world.

U, Pu, and Am nuclear signatures of the Thule hydrogen bomb debris.

PubMed

Eriksson, Mats; Lindahl, Patric; Roos, Per; Dahlgaard, Henning; Holm, Elis

2008-07-01

This study concerns an arctic marine environment that was contaminated by actinide elements after a nuclear accident in 1968, the so-called Thule accident In this study we have analyzed five isolated hot particles as well as sediment samples containing particles from the weapon material for the determination of the nuclear fingerprint of the accident. We report that the fissile material in the hydrogen weapons involved in the Thule accident was a mixture of highly enriched uranium and weapon-grade plutonium and that the main fissile material was 235U (about 4 times more than the mass of 239Pu). In the five hot particles examined, the measured uranium atomic ratio was 235U/238U = 1.02 +/- 0.16 and the Pu-isotopic ratios were as follows: 24Pu/239Pu = 0.0551 +/- 0.0008 (atom ratio), 238Pu/239+240Pu = 0.0161 +/- 0.0005 (activity ratio), 241Pu/239+240Pu = 0.87 +/- 0.12 (activity ratio), and 241Am/ 239+240Pu = 0.169 +/- 0.005 (activity ratio) (reference date 2001-10-01). From the activity ratios of 241Pu/241Am, we estimated the time of production of this weapon material to be from the late 1950s to the early 1960s. The results from reanalyzed bulk sediment samples showed the presence of more than one Pu source involved in the accident, confirming earlier studies. The 238Pu/239+240PU activity ratio and the 240Pu/ 239Pu atomic ratio were divided into at least two Pu-isotopic ratio groups. For both Pu-isotopic ratios, one ratio group had identical ratios as the five hot particles described above and for the other groups the Pu isotopic ratios were lower (238Pu/ 239+240PU activity ratio approximately 0.01 and the 240Pu/P239Pu atomic ratio 0.03). On the studied particles we observed that the U/Pu ratio decreased as a function of the time these particles were present in the sediment. We hypothesis that the decrease in the ratio is due to a preferential leaching of U relative to Pu from the particle matrix.

U1 Adaptor Oligonucleotides Targeting BCL2 and GRM1 Suppress Growth of Human Melanoma Xenografts In Vivo

PubMed Central

Goraczniak, Rafal; Wall, Brian A; Behlke, Mark A; Lennox, Kim A; Ho, Eric S; Zaphiros, Nikolas H; Jakubowski, Christopher; Patel, Neil R; Zhao, Steven; Magaway, Carlo; Subbie, Stacey A; Jenny Yu, Lumeng; LaCava, Stephanie; Reuhl, Kenneth R; Chen, Suzie; Gunderson, Samuel I

2013-01-01

U1 Adaptor is a recently discovered oligonucleotide-based gene-silencing technology with a unique mechanism of action that targets nuclear pre-mRNA processing. U1 Adaptors have two distinct functional domains, both of which must be present on the same oligonucleotide to exert their gene-silencing function. Here, we present the first in vivo use of U1 Adaptors by targeting two different human genes implicated in melanomagenesis, B-cell lymphoma 2 (BCL2) and metabotropic glutamate receptor 1 (GRM1), in a human melanoma cell xenograft mouse model system. Using a newly developed dendrimer delivery system, anti-BCL2 U1 Adaptors were very potent and suppressed tumor growth at doses as low as 34 µg/kg with twice weekly intravenous (iv) administration. Anti-GRM1 U1 Adaptors suppressed tumor xenograft growth with similar potency. Mechanism of action was demonstrated by showing target gene suppression in tumors and by observing that negative control U1 Adaptors with just one functional domain show no tumor suppression activity. The anti-BCL2 and anti-GRM1 treatments were equally effective against cell lines harboring either wild-type or a mutant V600E B-RAF allele, the most common mutation in melanoma. Treatment of normal immune-competent mice (C57BL6) indicated no organ toxicity or immune stimulation. These proof-of-concept studies represent an in-depth (over 800 mice in ~108 treatment groups) validation that U1 Adaptors are a highly potent gene-silencing therapeutic and open the way for their further development to treat other human diseases. PMID:23673539

Immunohistochemical expression of WT1 by desmoplastic small round cell tumor: a comparative study with other small round cell tumors.

PubMed

Barnoud, R; Sabourin, J C; Pasquier, D; Ranchère, D; Bailly, C; Terrier-Lacombe, M J; Pasquier, B

2000-06-01

Desmoplastic small round cell tumors (DSRCTs) present a reciprocal chromosomal translocation, t(11;22)(p13;q12), that results in fusion of Ewing's sarcoma and Wilms' tumor (WT1) genes. The authors evaluated 15 DSRCTs and 71 other tumors often considered in the differential diagnosis for immunoreactivity using a polyclonal antibody directed against the WT1 part of the chimeric protein resulting from this translocation. WT1 immunostaining was performed on paraffin material using the WT(C-19) antibody after heat-antigen retrieval. All the DSRCTs (15 of 15, 100%) demonstrated strong WT1 nuclear immunoreactivity. Ten of 14 nephroblastomas (71%) disclosed WT1-positive nuclei in accordance with the staining reported by others, and rare and focal nuclear positivity was detected in two of 17 rhabdomyosarcomas. WT1 immunoreactivity was not observed in Ewing's sarcoma/primitive neuroectodermal tumors (zero of 21, 0%), neuroblastomas (zero of 17, 0%), or rhabdoid tumors of the kidney (zero of two, 0%). In nephroblastoma, differential diagnosis with DSRCT was not difficult: Clinical and morphologic data are not similar for these two entities. The current study validates WT1 immunoreactivity as a useful marker to separate DSRCT from other small round cell tumors.

76 FR 77855 - Criteria for Identifying Material Licensees for the U. S. Nuclear Regulatory Commission's Agency...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-14

... Agencywide Documents Access and Management System (ADAMS) Accession Number: ML112280111) or in the... Management Programs, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, telephone (301) 415-6272... ineffective in correcting their underlying issues. Discussion Criteria for Identifying Nuclear Material...

U.S. Department of Energy facilities needed to advance nuclear power.

PubMed

Ahearne, John F

2011-01-01

This talk is based upon a November 2008 report by the U.S. Department of Energy (DOE) Nuclear Energy Advisory Committee (NEAC). The report has two parts, a policy section and a technology section. Here extensive material from the Technical Subcommittee section of the NEAC report is used. Copyright © 2010 Health Physics Society

75 FR 14206 - FPL Energy Point Beach, LLC; Point Beach Nuclear Plant, Units 1 and 2; Environmental Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-266 And 50-301; NRC-2010-0123 FPL Energy Point Beach, LLC; Point Beach Nuclear Plant, Units 1 and 2; Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear Regulatory Commission (NRC) is considering issuance of an Exemption, pursuant to...

Nuclear resonance fluorescence in U-238 using LaBr detectors for nuclear security

NASA Astrophysics Data System (ADS)

Hayakawa, Takehito; Negm, Hani; Ohgaki, Hideaki; Daito, Izuru; Kii, Toshiteru; Zen, Heishun; Omer, Mohamed; Shizuma, Toshiyuki; Hajima, Ryoichi

2014-09-01

Recently, a nondestructive measurement method of shielded fissional isotopes such as 235U or 239Pu has been proposed for the nuclear security. These isotopes are measured by using nuclear resonance fluorescence (NRF) with monochromatic energy gamma-ray beams generated by laser Compton-scattering (LCS). We have proposed that one measure scattered gamma-rays from NRF with LCS gamma-ray beams using the LaBr3(Ce) detectors. The LaBr3(Ce) crystals include internal radioisotopes of a meta-stable isotope 138La and alpha decay chains from some actinides as 227Ac. There is a broad pump at about 2 MeV. This pump is considered to be an overlap of alpha-rays from decay chains of some actinides but its detailed structure has not been established. Here we have measured NRF spectra of 238U using the LCS gamma-rays with energy of about 2.5 MeV at the HIgS facility of the Duke University. The background has been evaluated using a simulation code GEAT4. The 9 peaks, 8 NRF gamma-rays plus the Compton scattered gamma-ray of the incident beam, are finally assigned in an energy range of about 200 keV at about 2.5 MeV. The 8 integrated NRF cross-sections measured by LaBr3(Ce) have been consistent with results by an HPGe detector. The three levels are newly assigned using the HPGe detector. Two of them are also measured by LaBr3(Ce).

76 FR 9612 - GE Hitachi Nuclear Energy; Acceptance for Docketing of an Application for Renewal of the U.S...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

... NUCLEAR REGULATORY COMMISSION [Docket No. 52-045; NRC-2011-0020] GE Hitachi Nuclear Energy... Certification On December 7, 2010, GE Hitachi Nuclear Energy (GEH) submitted an application to the U.S. Nuclear... and Approvals for Nuclear Power Plants.'' A notice of receipt and availability of this application was...

Study on Ultra-Long Life,Small U-Zr Metallic Fuelled Core With Burnable Poison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenji Tsuji; Hiromitsu Inagaki; Akira Nishikawa

2002-07-01

A conceptual design for a 50 MWe sodium cooled, U-Pu-Zr metallic fuelled, fast reactor core, which aims at a core lifetime of 30 years, has been performed [1]. As for the compensation for a large burn-up reactivity through 30 years, an axially movable reflector, which is located around the core, carries the major part of it and a burnable poison does the rest. This concept has achieved not only a long core lifetime but also a high discharged burn-up. On this study, a conceptual design for a small fast reactor loading U-Zr metallic fuelled core instead of U-Pu-Zr fuelled coremore » has been conducted, based on the original core arrangement of 4S reactor [2]. Within the range of this study including safety requirements, adopting the burnable poison would be effective to construct a core concept that achieves both a long lifetime and a high discharged burn-up. (authors)« less

A Study of Reasons for Participation in Continuing Professional Education in the U.S. Nuclear Power Industry

ERIC Educational Resources Information Center

McCamey, Randy B.

2003-01-01

The need for workers in the U.S. nuclear power industry to continually update their knowledge, skills, and abilities is critical to the safe and reliable operation of the country's nuclear power facilities. To improve their skills, knowledge, and abilities, many professionals in the nuclear power industry participate in continuing professional…

Nuclear import of HIV-1 intracellular reverse transcription complexes is mediated by importin 7

PubMed Central

Fassati, Ariberto; Görlich, Dirk; Harrison, Ian; Zaytseva, Lyubov; Mingot, José-Manuel

2003-01-01

Human immunodeficiency virus type 1 (HIV-1), like other lentiviruses, can infect non-dividing cells. This property depends on the active nuclear import of its intracellular reverse transcription complex (RTC). We have studied nuclear import of purified HIV-1 RTCs in primary macrophages and found that importin 7, an import receptor for ribosomal proteins and histone H1, is involved in the process. Nuclear import of RTCs requires, in addition, energy and the com ponents of the Ran system. Depletion of importin 7 from cultured cells by small interfering RNA inhibits HIV-1 infection. These results provide a new insight into the molecular mechanism for HIV-1 nuclear import and reveal potential targets for therapeutic intervention. PMID:12853482

Development of U-frame bending system for studying the vibration integrity of spent nuclear fuel

NASA Astrophysics Data System (ADS)

Wang, Hong; Wang, Jy-An John; Tan, Ting; Jiang, Hao; Cox, Thomas S.; Howard, Rob L.; Bevard, Bruce B.; Flanagan, Michelle

2013-09-01

A bending fatigue system developed to evaluate the response of spent nuclear fuel rods to vibration loads is presented. A U-frame testing setup is used for imposing bending loads on the fuel rod specimen. The U-frame setup consists of two rigid arms, side connecting plates to the rigid arms, and linkages to a universal testing machine. The test specimen's curvature is obtained through a three-point deflection measurement method. The tests using surrogate specimens with stainless steel cladding revealed increased flexural rigidity under unidirectional cyclic bending, significant effect of cladding-pellets bonding on the response of surrogate rods, and substantial cyclic softening in reverse bending mode. These phenomena may cast light on the expected response of a spent nuclear fuel rod. The developed U-frame system is thus verified and demonstrated to be ready for further pursuit in hot-cell tests.

Health consequences and health systems response to the Pacific U.S. Nuclear Weapons Testing Program.

PubMed

Palafox, Neal A; Riklon, Sheldon; Alik, Wilfred; Hixon, Allen L

2007-03-01

Between 1946 and 1958, the United States detonated 67 thermonuclear devices in the Pacific as part of their U.S. Nuclear Weapons Testing Program (USNWTP). The aggregate explosive power was equal to 7,200 Hiroshima atomic bombs. Recent documents released by the U.S. government suggest that the deleterious effects of the nuclear testing were greater and extended farther than previously known. The Republic of the Marshall Islands (RMI) government and affected communities have sought refress through diplomatic routes with the U.S. government, however, existing medical programs and financial reparations have not adequately addressed many of the health consequences of the USNWTP. Since radiation-induced cancers may have a long latency, a healthcare infrastructure is needed to address both cancer and related health issues. This article reviews the health consequences of the Pacific USNWTP and the current health systems ability to respond.

U.S. Nuclear Power Plants: Continued Life or Replacement After 60? (released in AEO2010)

EIA Publications

2010-01-01

Nuclear power plants generate approximately 20% of U.S. electricity, and the plants in operation today are often seen as attractive assets in the current environment of uncertainty about future fossil fuel prices, high construction costs for new power plants (particularly nuclear plants), and the potential enactment of greenhouse gas regulations. Existing nuclear power plants have low fuel costs and relatively high power output. However, there is uncertainty about how long they will be allowed to continue operating.

A Small U-Shaped Bending-Induced Interference Optical Fiber Sensor for the Measurement of Glucose Solutions.

PubMed

Fang, Yu-Lin; Wang, Chen-Tung; Chiang, Chia-Chin

2016-09-09

The study proposes a small U-shaped bending-induced interference optical fiber sensor; this novel sensor is a probe-type sensor manufactured using a mechanical device, a heat source, optical fiber and a packaging module. This probe-type sensor overcomes the shortcomings of conventional optical fibers, including being difficult to repair and a tendency to be influenced by external forces. We manufactured three types of sensors with different curvature radiuses. Specifically, sensors with three radiuses (1.5 mm, 2.0 mm, and 3.0 mm) were used to measure common water and glucose solutions with concentrations of between 6% and 30% (the interval between concentrations was 4%). The results show that the maximal sensitivity was 0.85 dB/% and that the linearly-dependent coefficient was 0.925. The results further show that not only can the small U-shaped bending-induced interference optical fiber sensor achieve high sensitivity in the measurement of glucose solutions, but that it can also achieve great stability and repeatability.

Constraints on the large-x d/u ratio from electron--nucleus scattering at x>1

DOE Office of Scientific and Technical Information (OSTI.GOV)

O. Hen, A. Accardi, W. Melnitchouk and E. Piasetzky

2011-12-01

Recently the ratio of neutron to proton structure functions F{sub 2}{sup n}/F{sub 2}{sup p} was extracted from a phenomenological correlation between the strength of the nuclear EMC effect and inclusive electron-nucleus cross section ratios at x > 1. Within conventional models of nuclear smearing, this 'in-medium correction' (IMC) extraction constrains the size of nuclear effects in the deuteron structure functions, from which the neutron structure function F{sub 2}{sup n} is usually extracted. The IMC data determine the resulting proton d/u quark distribution ratio, extrapolated to x = 1, to be 0.23 {+-} 0.09 with a 90% confidence level. This ismore » well below the SU(6) symmetry limit of 1/2 and significantly above the scalar diquark dominance limit of 0.« less

Thinking Globally about U.S. Extended Deterrence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, Brad; Santoro, David; Volpe, Tristan

In contrast to the Cold War bilateral global competition between the United States and the Soviet Union, the modern nuclear age features a more complex, multiplayer arena on the regional scale. With the exception of the U.S. and Russia, most major powers retain relatively small nuclear arsenals or technical hedge capabilities. The U.S., with strong interests and security partnerships in Europe, Northeast Asia, and the Middle East, must navigate through long-standing rivalries and active conflicts while attempting to divine the intentions of less experienced nuclear decision makers in charge of weak domestic institutions. As a result, analysts and policymakers mustmore » think globally about U.S. extended deterrence. How have the requirements of extended deterrence and assurance changed? Are there important threads that connect each region? What should the U.S. do differently? To explore these questions, Lawrence Livermore National Laboratory’s Center for Global Security Research, in partnership with the Carnegie Endowment for International Peace and the Pacific Forum CSIS, held a workshop on “Thinking Globally about U.S. Extended Deterrence” in Washington, DC on November 2, 2015. The workshop brought together approximately 40 U.S. and foreign deterrence specialists and government officials, all attending in their private capacities. The participants joined a day of not-for-attribution discussions on the changing deterrence and assurance requirements, the threads that connect the regions, and U.S. strategy to deal with emerging challenges. The following is a summary of key takeaways.« less

The linked units of 5S rDNA and U1 snDNA of razor shells (Mollusca: Bivalvia: Pharidae).

PubMed

Vierna, J; Jensen, K T; Martínez-Lage, A; González-Tizón, A M

2011-08-01

The linkage between 5S ribosomal DNA and other multigene families has been detected in many eukaryote lineages, but whether it provides any selective advantage remains unclear. In this work, we report the occurrence of linked units of 5S ribosomal DNA (5S rDNA) and U1 small nuclear DNA (U1 snDNA) in 10 razor shell species (Mollusca: Bivalvia: Pharidae) from four different genera. We obtained several clones containing partial or complete repeats of both multigene families in which both types of genes displayed the same orientation. We provide a comprehensive collection of razor shell 5S rDNA clones, both with linked and nonlinked organisation, and the first bivalve U1 snDNA sequences. We predicted the secondary structures and characterised the upstream and downstream conserved elements, including a region at -25 nucleotides from both 5S rDNA and U1 snDNA transcription start sites. The analysis of 5S rDNA showed that some nontranscribed spacers (NTSs) are more closely related to NTSs from other species (and genera) than to NTSs from the species they were retrieved from, suggesting birth-and-death evolution and ancestral polymorphism. Nucleotide conservation within the functional regions suggests the involvement of purifying selection, unequal crossing-overs and gene conversions. Taking into account this and other studies, we discuss the possible mechanisms by which both multigene families could have become linked in the Pharidae lineage. The reason why 5S rDNA is often found linked to other multigene families seems to be the result of stochastic processes within genomes in which its high copy number is determinant.

The linked units of 5S rDNA and U1 snDNA of razor shells (Mollusca: Bivalvia: Pharidae)

PubMed Central

Vierna, J; Jensen, K T; Martínez-Lage, A; González-Tizón, A M

2011-01-01

The linkage between 5S ribosomal DNA and other multigene families has been detected in many eukaryote lineages, but whether it provides any selective advantage remains unclear. In this work, we report the occurrence of linked units of 5S ribosomal DNA (5S rDNA) and U1 small nuclear DNA (U1 snDNA) in 10 razor shell species (Mollusca: Bivalvia: Pharidae) from four different genera. We obtained several clones containing partial or complete repeats of both multigene families in which both types of genes displayed the same orientation. We provide a comprehensive collection of razor shell 5S rDNA clones, both with linked and nonlinked organisation, and the first bivalve U1 snDNA sequences. We predicted the secondary structures and characterised the upstream and downstream conserved elements, including a region at −25 nucleotides from both 5S rDNA and U1 snDNA transcription start sites. The analysis of 5S rDNA showed that some nontranscribed spacers (NTSs) are more closely related to NTSs from other species (and genera) than to NTSs from the species they were retrieved from, suggesting birth-and-death evolution and ancestral polymorphism. Nucleotide conservation within the functional regions suggests the involvement of purifying selection, unequal crossing-overs and gene conversions. Taking into account this and other studies, we discuss the possible mechanisms by which both multigene families could have become linked in the Pharidae lineage. The reason why 5S rDNA is often found linked to other multigene families seems to be the result of stochastic processes within genomes in which its high copy number is determinant. PMID:21364693

Photofission cross-section ratio measurement of 235U/238U using monoenergetic photons in the energy range of 9.0-16.6 MeV

NASA Astrophysics Data System (ADS)

Krishichayan; Bhike, Megha; Finch, S. W.; Howell, C. R.; Tonchev, A. P.; Tornow, W.

2017-05-01

Photofission cross-section ratios of 235U and 238U have been measured using monoenergetic photon beams at the HIγS facility of TUNL. These measurements have been performed in small energy steps between 9.0 and 16.6 MeV using a dual-fission ionization chamber. Measured cross-section ratios are compared with the previous experimental data as well as with the recent evaluated nuclear data library ENDF.

Study of infrared emission spectroscopy for the B{sup 1}Δ{sub g}–A{sup 1}Π{sub u} and B{sup ′1}Σ{sub g}{sup +}–A{sup 1}Π{sub u} systems of C{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Wang, E-mail: sc19321@s.okayama-u.ac.jp, E-mail: okakent@okayama-u.ac.jp, E-mail: pbernath@odu.edu; Kawaguchi, Kentarou, E-mail: sc19321@s.okayama-u.ac.jp, E-mail: okakent@okayama-u.ac.jp, E-mail: pbernath@odu.edu; Tang, Jian, E-mail: jtang@okayama-u.ac.jp

Thirteen bands for the B{sup 1}Δ{sub g}–A{sup 1}Π{sub u} system and eleven bands for the B{sup ′1}Σ{sub g}{sup +}–A{sup 1}Π{sub u} system of C{sub 2} were identified in the Fourier transform infrared emission spectra of hydrocarbon discharges. The B{sup ′1}Σ{sub g}{sup +} v = 4 and the B{sup 1}Δ{sub g} v = 6, 7, and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B{sup 1}Δ{sub g}–A{sup 1}Π{sub u} system except for a small perturbation in the B{sup 1}Δ{sub g} v = 6more » level. The calculated rovibrational term energies up to B{sup 1}Δ{sub g} v = 12 showed that the level crossing between the B{sup 1}Δ{sub g} and d{sup 3}Π{sub g} states is responsible for many of the prominent perturbations in the Swan system observed previously. Nineteen forbidden transitions of the B{sup 1}Δ{sub g}–a{sup 3}Π{sub u} transition were identified and the off-diagonal spin-orbit interaction constant A{sub dB} between d{sup 3}Π{sub g} and B{sup 1}Δ{sub g} was derived as 8.3(1) cm{sup −1}. For the B{sup ′1}Σ{sub g}{sup +}–A{sup 1}Π{sub u} system, only individual band analyses for each vibrational level in the B′{sup 1}Σ{sub g}{sup +} state could be done satisfactorily and Dunham parameters obtained from these effective parameters showed that the anharmonic vibrational constant ω{sub e}x{sub e} is anomalously small (nearly zero). Inspection of the RKR (Rydberg-Klein-Rees) potential curves for the B{sup ′1}Σ{sub g}{sup +} and X{sup 1}Σ{sub g}{sup +} states revealed that an avoided crossing or nearly avoided crossing may occur around 30 000 cm{sup −1}, which is responsible for the anomalous molecular constants in these two states.« less

Implementing a Nuclear Power Plant Model for Evaluating Load-Following Capability on a Small Grid

NASA Astrophysics Data System (ADS)

Arda, Samet Egemen

A pressurized water reactor (PWR) nuclear power plant (NPP) model is introduced into Positive Sequence Load Flow (PSLF) software by General Electric in order to evaluate the load-following capability of NPPs. The nuclear steam supply system (NSSS) consists of a reactor core, hot and cold legs, plenums, and a U-tube steam generator. The physical systems listed above are represented by mathematical models utilizing a state variable lumped parameter approach. A steady-state control program for the reactor, and simple turbine and governor models are also developed. Adequacy of the isolated reactor core, the isolated steam generator, and the complete PWR models are tested in Matlab/Simulink and dynamic responses are compared with the test results obtained from the H. B. Robinson NPP. Test results illustrate that the developed models represents the dynamic features of real-physical systems and are capable of predicting responses due to small perturbations of external reactivity and steam valve opening. Subsequently, the NSSS representation is incorporated into PSLF and coupled with built-in excitation system and generator models. Different simulation cases are run when sudden loss of generation occurs in a small power system which includes hydroelectric and natural gas power plants besides the developed PWR NPP. The conclusion is that the NPP can respond to a disturbance in the power system without exceeding any design and safety limits if appropriate operational conditions, such as achieving the NPP turbine control by adjusting the speed of the steam valve, are met. In other words, the NPP can participate in the control of system frequency and improve the overall power system performance.

Loose Words, Not Nukes: The Impact of U.S. Nuclear Force Structure Debate on NATO Perceptions of Extended Deterrence

DTIC Science & Technology

2012-02-15

institutional mechanisms that may result in uncontrollable escalation in the belief there must be an irrevocable structural element of uncertainty...intentionally downplay the role of nuclear capabilities. Current U.S. strategy documents obliquely whisper nuclear linkages (if they are mentioned at...formally distance itself from the legacy (but still operative) NATO first-use declaratory policy.11 The express U.S. distinction exposes a fault line in

A compilation of nuclear weapons test detonation data for U.S. Pacific ocean tests.

PubMed

Simon, S L; Robison, W L

1997-07-01

Prior to December 1993, the explosive yields of 44 of 66 nuclear tests conducted by the United States in the Marshall Islands were still classified. Following a request from the Government of the Republic of the Marshall Islands to the U.S. Department of Energy to release this information, the Secretary of Energy declassified and released to the public the explosive yields of the Pacific nuclear tests. This paper presents a synopsis of information on nuclear test detonations in the Marshall Islands and other locations in the mid-Pacific including dates, explosive yields, locations, weapon placement, and summary statistics.

NIMBY, CLAMP, and the location of new nuclear-related facilities: U.S. national and 11 site-specific surveys.

PubMed

Greenberg, Michael R

2009-09-01

Public and political opposition have made finding locations for new nuclear power plants, waste management, and nuclear research and development facilities a challenge for the U.S. government and the nuclear industry. U.S. government-owned properties that already have nuclear-related activities and commercial nuclear power generating stations are logical locations. Several studies and utility applications to the Nuclear Regulatory Commission suggest that concentrating locations at major plants (CLAMP) has become an implicit siting policy. We surveyed 2,101 people who lived within 50 miles of 11 existing major nuclear sites and 600 who lived elsewhere in the United States. Thirty-four percent favored CLAMP for new nuclear power plants, 52% for waste management facilities, and 50% for new nuclear laboratories. College educated, relatively affluent male whites were the strongest CLAMP supporters. They disproportionately trusted those responsible for the facilities and were not worried about existing nuclear facilities or other local environmental issues. Notably, they were concerned about continuing coal use. Not surprisingly, CLAMP proponents tended to be familiar with their existing local nuclear site. In short, likely CLAMP sites have a large and politically powerful core group to support a CLAMP policy. The challenge to proponents of nuclear technologies will be to sustain this support and expand the base among those who clearly are less connected and receptive to new nearby sites.

AN ULTRA-LOW-MASS AND SMALL-RADIUS COMPACT OBJECT IN 4U 1746-37?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhaosheng; Qu, Zhijie; Guo, Yanjun

Photospheric radius expansion (PRE) bursts have already been used to constrain the masses and radii of neutron stars. RXTE observed three PRE bursts in 4U 1746-37, all with low touchdown fluxes. We discuss here the possibility of a low-mass neutron star in 4U 1746-37 because the Eddington luminosity depends on stellar mass. With typical values of hydrogen mass fraction and color correction factor, a Monte Carlo simulation was applied to constrain the mass and radius of a neutron star in 4U 1746-37. 4U 1746-37 has a high inclination angle. Two geometric effects, the reflection of the far-side accretion disk andmore » the obscuration of the near-side accretion disk, have also been included in the mass and radius constraints of 4U 1746-37. If the reflection of the far-side accretion disk is accounted for, a low-mass compact object (mass of 0.41 ± 0.14 M {sub ☉} and radius of 8.73 ± 1.54 km at 68% confidence) exists in 4U 1746-37. If another effect operated, 4U 1746-37 may contain an ultra-low-mass and small-radius object (M = 0.21 ± 0.06 M {sub ☉}, R = 6.26 ± 0.99 km at 68% confidence). Combining all possibilities, the mass of 4U 1746-37 is 0.41{sub −0.30}{sup +0.70} M{sub ⊙} at 99.7% confidence. For such low-mass neutron stars, it could be reproduced by a self-bound compact star, i.e., a quark star or quark-cluster star.« less

26 CFR 1.88-1 - Nuclear decommissioning costs.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning costs...

26 CFR 1.88-1 - Nuclear decommissioning costs.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning costs...

26 CFR 1.88-1 - Nuclear decommissioning costs.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning costs...

26 CFR 1.88-1 - Nuclear decommissioning costs.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning costs...

26 CFR 1.88-1 - Nuclear decommissioning costs.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning costs...

U.S. Department of Energy Office of Nuclear Technology Research and Eevelopment ((NTRD) comprehensive summary of QA assessments for FY17

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trost, Alan L.

The U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) has developed a research and development (R&D) roadmap for its research, development, and demonstration (RD&D) activities to ensure nuclear energy remains a compelling and viable energy option for the U.S. The roadmap defines NE RD&D activities and objectives that address the challenges to research, develop and demonstrate options to the current U.S commercial fuel cycle to enable the safe, secure, economic, and sustainable expansion of nuclear energy, while minimizing proliferation and terrorism risks expanding the use of nuclear power. The roadmap enables the development of technologies and other solutionsmore » that can improve the reliability, sustain the safety, and extend the life of current reactors. In addition, it will help to develop improvements in the affordability of the new reactors to enable nuclear energy to help meet the Administration’s energy security and climate change goals.« less

Nuclear Coexistence: Rethinking U.S. Policy to Promote Stability in an Era of Proliferation

DTIC Science & Technology

1994-04-01

The Spread of Nuclear Weapons 1989 -90 (Boulder: Westview Press, 1990). 22. See William C. Martel and Steven E. Miller, "Controlling Borders and Nuclear...Security, Fall 1989 , Vol. 14, No. 2, pp. 140-41, for J. Robert Oppenheimer’s concerns about the dangers of the develop- ment of thermonuclear weapons. 4...Paradox of Technology," International Security, Vol. 14, No. 2 (Fall 1989 ), pp. 198-202. 6. Some argue that the U.S. strategy has relatively little

REGIONAL SEISMIC CHEMICAL AND NUCLEAR EXPLOSION DISCRIMINATION: WESTERN U.S. EXAMPLES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, W R; Taylor, S R; Matzel, E

2006-07-07

We continue exploring methodologies to improve regional explosion discrimination using the western U.S. as a natural laboratory. The western U.S. has abundant natural seismicity, historic nuclear explosion data, and widespread mine blasts, making it a good testing ground to study the performance of regional explosion discrimination techniques. We have assembled and measured a large set of these events to systematically explore how to best optimize discrimination performance. Nuclear explosions can be discriminated from a background of earthquakes using regional phase (Pn, Pg, Sn, Lg) amplitude measures such as high frequency P/S ratios. The discrimination performance is improved if the amplitudesmore » can be corrected for source size and path length effects. We show good results are achieved using earthquakes alone to calibrate for these effects with the MDAC technique (Walter and Taylor, 2001). We show significant further improvement is then possible by combining multiple MDAC amplitude ratios using an optimized weighting technique such as Linear Discriminant Analysis (LDA). However this requires data or models for both earthquakes and explosions. In many areas of the world regional distance nuclear explosion data is lacking, but mine blast data is available. Mine explosions are often designed to fracture and/or move rock, giving them different frequency and amplitude behavior than contained chemical shots, which seismically look like nuclear tests. Here we explore discrimination performance differences between explosion types, the possible disparity in the optimization parameters that would be chosen if only chemical explosions were available and the corresponding effect of that disparity on nuclear explosion discrimination. Even after correcting for average path and site effects, regional phase ratios contain a large amount of scatter. This scatter appears to be due to variations in source properties such as depth, focal mechanism, stress drop, in the near

Microstructure of the irradiated U 3Si 2/Al silicide dispersion fuel

NASA Astrophysics Data System (ADS)

Gan, J.; Keiser, D. D.; Miller, B. D.; Jue, J.-F.; Robinson, A. B.; Madden, J. W.; Medvedev, P. G.; Wachs, D. M.

2011-12-01

The silicide dispersion fuel of U 3Si 2/Al is recognized as the best performance fuel for many nuclear research and test reactors with up to 4.8 gU/cm 3 fuel loading. An irradiated U 3Si 2/Al dispersion fuel ( 235U ˜ 75%) from the high-flux side of a fuel plate (U0R040) from the Reduced Enrichment for Research and Test Reactors (RERTR)-8 test was characterized using transmission electron microscopy (TEM). The fuel was irradiated in the Advanced Test Reactor (ATR) for 105 days. The average irradiation temperature and fission density of the U 3Si 2 fuel particles for the TEM sample are estimated to be approximately 110 °C and 5.4 × 10 27 f/m 3. The characterization was performed using a 200-kV TEM. The U/Si ratio for the fuel particle and (Si + Al)/U for the fuel-matrix-interaction layer are approximately 1.1 and 4-10, respectively. The estimated average diameter, number density and volume fraction for small bubbles (<1 μm) in the fuel particle are ˜94 nm, 1.05 × 10 20 m -3 and ˜11%, respectively. The results and their implication on the performance of the U 3Si 2/Al silicide dispersion fuel are discussed.

Projected Growth in Small-Scale, Fossil-Fueled Distributed Generation: Potential Implications for the U.S. Greenhouse Gas Inventory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eberle, Annika; Heath, Garvin A

The generation capacity of small-scale (less than one megawatt) fossil-fueled electricity in the United States is anticipated to grow by threefold to twenty-fold from 2015 to 2040. However, in adherence with internationally agreed upon carbon accounting methods, the Environmental Protection Agency's (EPA's) U.S. Greenhouse Inventory (GHGI) does not currently attribute greenhouse gases (GHGs) from these small-scale distributed generation sources to the electric power sector and instead accounts for these emissions in the sector that uses the distributed generation (e.g., the commercial sector). In addition, no other federal electric-sector GHG emission data product produced by the EPA or the U.S. Energymore » Information Administration (EIA) can attribute these emissions to electricity. We reviewed the technical documentation for eight federal electric-sector GHG emission data products, interviewed the data product owners, collected their GHG emission estimates, and analyzed projections for growth in fossil-fueled distributed generation. We show that, by 2040, these small-scale generators could account for at least about 1%- 5% of total CO2 emissions from the U.S. electric power sector. If these emissions fall outside the electric power sector, the United States may not be able to completely and accurately track changes in electricity-related CO2 emissions, which could impact how the country sets GHG reduction targets and allocates mitigation resources. Because small-scale, fossil-fueled distributed generation is expected to grow in other countries as well, the results of this work also have implications for global carbon accounting.« less

Non-covalent Small-Molecule Kelch-like ECH-Associated Protein 1-Nuclear Factor Erythroid 2-Related Factor 2 (Keap1-Nrf2) Inhibitors and Their Potential for Targeting Central Nervous System Diseases.

PubMed

Pallesen, Jakob S; Tran, Kim T; Bach, Anders

2018-05-29

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) has a protective effect against oxidative stress and plays a major role in inflammation and central nervous system (CNS) diseases. Inhibition of the protein-protein interaction (PPI) between Nrf2 and its repressor protein, Kelch-like ECH-associated protein 1 (Keap1), leads to translocation of Nrf2 from the cytosol to the nucleus and expression of detoxifying antioxidant enzymes. To date, several non-covalent small-molecule Keap1-Nrf2 inhibitors have been identified; however, many of them contain carboxylic acids and are rather large in size, which likely prevents or decreases CNS permeability. This Perspective describes current small-molecule Keap1-Nrf2 inhibitors with experimental evidence for the ability to inhibit the Keap1-Nrf2 interaction by binding to Keap1 in a non-covalent manner. Binding data, biostructural studies, and biological activity are summarized for the inhibitors, and their potential as CNS tool compounds is discussed by analyzing physicochemical properties, including CNS multiparameter optimization (MPO) scoring algorithms. Finally, several strategies for identifying CNS-targeting Keap1 inhibitors are described.

B-meson anomalies and Higgs physics in flavored U(1)' model

NASA Astrophysics Data System (ADS)

Bian, Ligong; Lee, Hyun Min; Park, Chan Beom

2018-04-01

We consider a simple extension of the Standard Model with flavor-dependent U(1)', that has been proposed to explain some of B-meson anomalies recently reported at LHCb. The U(1)' charge is chosen as a linear combination of anomaly-free B_3-L_3 and L_μ -L_τ . In this model, the flavor structure in the SM is restricted due to flavor-dependent U(1)' charges, in particular, quark mixings are induced by a small vacuum expectation value of the extra Higgs doublet. As a result, it is natural to get sizable flavor-violating Yukawa couplings of heavy Higgs bosons involving the bottom quark. In this article, we focus on the phenomenology of the Higgs sector of the model including extra Higgs doublet and singlet scalars. We impose various bounds on the extended Higgs sector from Higgs and electroweak precision data, B-meson mixings and decays as well as unitarity and stability bounds, then discuss the productions and decays of heavy Higgs bosons at the LHC.

Re-refinement of the spliceosomal U4 snRNP core-domain structure

PubMed Central

Li, Jade; Leung, Adelaine K.; Kondo, Yasushi; Oubridge, Chris; Nagai, Kiyoshi

2016-01-01

The core domain of small nuclear ribonucleoprotein (snRNP), comprised of a ring of seven paralogous proteins bound around a single-stranded RNA sequence, functions as the assembly nucleus in the maturation of U1, U2, U4 and U5 spliceosomal snRNPs. The structure of the human U4 snRNP core domain was initially solved at 3.6 Å resolution by experimental phasing using data with tetartohedral twinning. Molecular replacement from this model followed by density modification using untwinned data recently led to a structure of the minimal U1 snRNP at 3.3 Å resolution. With the latter structure providing a search model for molecular replacement, the U4 core-domain structure has now been re-refined. The U4 Sm site-sequence AAUUUUU has been shown to bind to the seven Sm proteins SmF–SmE–SmG–SmD3–SmB–SmD1–SmD2 in an identical manner as the U1 Sm-site sequence AAUUUGU, except in SmD1 where the bound U replaces G. The progression from the initial to the re-refined structure exemplifies a tortuous route to accuracy: where well diffracting crystals of complex assemblies are initially unavailable, the early model errors are rectified by exploiting preliminary interpretations in further experiments involving homologous structures. New insights are obtained from the more accurate model. PMID:26894541

33 CFR 334.830 - Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill. 334.830 Section 334.830 Navigation and Navigable... REGULATIONS § 334.830 Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill...

33 CFR 334.830 - Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill. 334.830 Section 334.830 Navigation and Navigable... REGULATIONS § 334.830 Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill...

33 CFR 334.830 - Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill. 334.830 Section 334.830 Navigation and Navigable... REGULATIONS § 334.830 Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill...

33 CFR 334.830 - Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill. 334.830 Section 334.830 Navigation and Navigable... REGULATIONS § 334.830 Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill...

33 CFR 334.830 - Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill. 334.830 Section 334.830 Navigation and Navigable... REGULATIONS § 334.830 Lake Michigan; small-arms range adjacent to U.S. Naval Training Center, Great Lakes, Ill...

JPRS Report, Nuclear Developments

DTIC Science & Technology

1989-11-29

with foreign companies, will be the first country’s nuclear arsenal. large nuclear power plant in China when completed. It researched and designed...JPRS-TND-89-022 29 NOVEMBER 1989, FOREIGN BROADCAST INFORMATION SERVICE -IPRS Report- Nuclear Developments REPRODUCED BY U.S. DEPARTMENT OF COMMERCE...1 Commission Views West Coast for Nuclear Sites [SAPA] ................................................................. I CHINA Nuclear

Tracing nuclear elements released by Fukushima Nuclear Power Plant accident

NASA Astrophysics Data System (ADS)

Tsujimura, M.; Onda, Y.; Abe, Y.; Hada, M.; Pun, I.

2011-12-01

Radioactive contamination has been detected in Fukushima and the neighboring regions due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami occurred on 11th March 2011. The small experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima Prefecture, located approximately 35 km west from the Fukushima NPP. The tritium (3H) concentration and stable isotopic compositions of deuterium and oxygen-18 have been determined on the water samples of precipitation, soil water at the depths of 10 to 30 cm, groundwater at the depths of 5 m to 50 m, spring water and stream water taken at the watersheds in the recharge and discharge zones from the view point of the groundwater flow system. The tritium concentration of the rain water fell just a few days after the earthquake showed a value of approximately 17 Tritium Unit (T.U.), whereas the average concentration of the tritium in the precipitation was less than 5 T.U. before the Fukushima accident. The spring water in the recharge zone showed a relatively high tritium concentration of approximately 12 T.U., whereas that of the discharge zone showed less than 5 T.U. Thus, the artificial tritium was apparently injected in the groundwater flow system due to the Fukushima NPP accident, whereas that has not reached at the discharge zone yet. The monitoring of the nuclear elements is now on going from the view points of the hydrological cycles and the drinking water security.

39 CFR 1.1 - Establishment of the U.S. Postal Service.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 39 Postal Service 1 2011-07-01 2011-07-01 false Establishment of the U.S. Postal Service. 1.1 Section 1.1 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE POSTAL POLICY (ARTICLE I) § 1.1 Establishment of the U.S. Postal Service. The U.S. Postal Service is...

39 CFR 1.1 - Establishment of the U.S. Postal Service.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Establishment of the U.S. Postal Service. 1.1 Section 1.1 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE POSTAL POLICY (ARTICLE I) § 1.1 Establishment of the U.S. Postal Service. The U.S. Postal Service is...

39 CFR 1.1 - Establishment of the U.S. Postal Service.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 39 Postal Service 1 2012-07-01 2012-07-01 false Establishment of the U.S. Postal Service. 1.1 Section 1.1 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE POSTAL POLICY (ARTICLE I) § 1.1 Establishment of the U.S. Postal Service. The U.S. Postal Service is...

39 CFR 1.1 - Establishment of the U.S. Postal Service.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 39 Postal Service 1 2014-07-01 2014-07-01 false Establishment of the U.S. Postal Service. 1.1 Section 1.1 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE POSTAL POLICY (ARTICLE I) § 1.1 Establishment of the U.S. Postal Service. The U.S. Postal Service is...

39 CFR 1.1 - Establishment of the U.S. Postal Service.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 39 Postal Service 1 2013-07-01 2013-07-01 false Establishment of the U.S. Postal Service. 1.1 Section 1.1 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE POSTAL POLICY (ARTICLE I) § 1.1 Establishment of the U.S. Postal Service. The U.S. Postal Service is...

Multi-tasking Sulf1/Sulf2 enzymes do not only facilitate extracellular cell signalling but also participate in cell cycle related nuclear events.

PubMed

Krishnakumar, Kavithanjali; Chakravorty, Ishani; Foy, Wendy; Allen, Steve; Justo, Tiago; Mukherjee, Abir; Dhoot, Gurtej K

2018-03-01

This study demonstrates highly dynamic spatial and temporal pattern of SULF1/SULF2 expression in a number of neuronal cell types growing in normal culture medium that included their transient nuclear mobilisation. Their nuclear translocation became particularly apparent during cell proliferation as both SULF1/SULF2 demonstrated not only cell membrane associated expression, their known site of function but also transient nuclear mobilisation during nuclear cell division. Nuclear localisation was apparent not only by immunocytochemical staining but also confirmed by immunoblotting staining of isolated nuclear fractions of C6, U87 and N2A cells. Immunocytochemical analysis demonstrated rapid nuclear exit of both SULF1/SULF2 following cell division that was slightly delayed but not blocked in a fraction of the polyploid cells observed in C6 cells. The overexpression of both Sulf1 and Sulf2 genes in C6 and U87 cells markedly promoted in vitro growth of these cells accompanied by nuclear mobilisation while inhibition of both these genes inhibited cell proliferation with little or no nuclear SULF1/SULF2 mobilisation. SULF1/SULF2 activity in these cells thus demonstrated a clear co-ordination of extracellular cell signalling with nuclear events related to cell proliferation. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Helicity Evolution at Small x

NASA Astrophysics Data System (ADS)

Sievert, Michael; Kovchegov, Yuri; Pitonyak, Daniel

2017-01-01

We construct small- x evolution equations which can be used to calculate quark and anti-quark helicity TMDs and PDFs, along with the g1 structure function. These evolution equations resum powers of ln2(1 / x) in the polarization-dependent evolution along with the powers of ln(1 / x) in the unpolarized evolution which includes saturation effects. The equations are written in an operator form in terms of polarization-dependent Wilson line-like operators. While the equations do not close in general, they become closed and self-contained systems of non-linear equations in the large-Nc and large-Nc &Nf limits. After solving the large-Nc equations numerically we obtain the following small- x asymptotics for the flavor-singlet g1 structure function along with quarks hPDFs and helicity TMDs (in absence of saturation effects): g1S(x ,Q2) ΔqS(x ,Q2) g1L S(x ,kT2) (1/x) > αh (1/x) 2.31√{αsNc/2 π. We also give an estimate of how much of the proton's spin may be at small x and what impact this has on the so-called ``spin crisis.'' Work supported by the U.S. DOE, Office of Science, Office of Nuclear Physics under Award Number DE-SC0004286 (YK), the RIKEN BNL Research Center, and TMD Collaboration (DP), and DOE Contract No. DE-SC0012704 (MS).

Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion

NASA Technical Reports Server (NTRS)

Schnitzler, Bruce G.; Borowski, Stanley K.

2012-01-01

Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified as the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine operations and the engine and stage design were

Progression through the spliceosome cycle requires Prp38p function for U4/U6 snRNA dissociation.

PubMed Central

Xie, J; Beickman, K; Otte, E; Rymond, B C

1998-01-01

The elaborate and energy-intensive spliceosome assembly pathway belies the seemingly simple chemistry of pre-mRNA splicing. Prp38p was previously identified as a protein required in vivo and in vitro for the first pre-mRNA cleavage reaction catalyzed by the spliceosome. Here we show that Prp38p is a unique component of the U4/U6.U5 tri-small nuclear ribonucleoprotein (snRNP) particle and is necessary for an essential step late in spliceosome maturation. Without Prp38p activity spliceosomes form, but arrest in a catalytically impaired state. Functional spliceosomes shed U4 snRNA before 5' splice-site cleavage. In contrast, Prp38p-defective spliceosomes retain U4 snRNA bound to its U6 snRNA base-pairing partner. Prp38p is the first tri-snRNP-specific protein shown to be dispensable for assembly, but required for conformational changes which lead to catalytic activation of the spliceosome. PMID:9582287

Anticancer Pyrroloquinazoline LBL1 Targets Nuclear Lamins.

PubMed

Li, Bingbing X; Chen, Jingjin; Chao, Bo; David, Larry L; Xiao, Xiangshu

2018-05-18

Target identification of bioactive compounds is critical for understanding their mechanism of action. We previously discovered a novel pyrroloquinazoline compound LBL1 with significant anticancer activity. However, its molecular targets remain to be established. Herein, we developed a clickable photoaffinity probe based on LBL1. Using extensive chemical, biochemical, and cellular studies with this probe and LBL1, we found that LBL1 targets nuclear lamins, which are type V intermediate filament (IF) proteins. Further studies showed that LBL1 binds to the coiled-coil domain of lamin A. These results revealed that IF proteins can also be targeted with appropriate small molecules besides two other cytoskeletal proteins actin filaments and microtubules, providing a novel avenue to investigate lamin biology and a novel strategy to develop distinct anticancer therapies.

Feasibility of Nuclear Power on U.S. Military Installations. 2nd Revision

DTIC Science & Technology

2011-03-01

Small Modular Reactor , Military Installation Energy, Energy Assurance 16. SECURITY CLASSIFICATION OF: a. REPORT I b. ABSTRACT U c. THIS PAGE i; 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES 98 19a. NAME OF RESPONSIBLE PERSON Knowledge Center/Rhea Stone 19b. TELEPHONE NUMBER (Include area code) 703-824-2110 Standard Form 298 (Rev. 8/98) Prescribed bv ANSI Sid 239.18 Contents Preliminary note: Development and commercial deployment of small modular reactors

Orphan nuclear receptor small heterodimer partner inhibits transforming growth factor-beta signaling by repressing SMAD3 transactivation.

PubMed

Suh, Ji Ho; Huang, Jiansheng; Park, Yun-Yong; Seong, Hyun-A; Kim, Dongwook; Shong, Minho; Ha, Hyunjung; Lee, In-Kyu; Lee, Keesook; Wang, Li; Choi, Hueng-Sik

2006-12-22

Orphan nuclear receptor small heterodimer partner (SHP) is an atypical member of the nuclear receptor superfamily; SHP regulates the nuclear receptor-mediated transcription of target genes but lacks a conventional DNA binding domain. In this study, we demonstrate that SHP represses transforming growth factor-beta (TGF-beta)-induced gene expression through a direct interaction with Smad, a transducer of TGF-beta signaling. Transient transfection studies demonstrate that SHP represses Smad3-induced transcription. In vivo and in vitro protein interaction assays revealed that SHP directly interacts with Smad2 and Smad3 but not with Smad4. Mapping of domains mediating the interaction between SHP and Smad3 showed that the entire N-terminal domain (1-159 amino acids) of SHP and the linker domain of Smad3 are involved in this interaction. In vitro glutathione S-transferase pulldown competition experiments revealed the SHP-mediated repression of Smad3 transactivation through competition with its co-activator p300. SHP also inhibits the activation of endogenous TGF-beta-responsive gene promoters, the p21, Smad7, and plasminogen activator inhibitor-1 (PAI-1) promoters. Moreover, adenovirus-mediated overexpression of SHP decreases PAI-1 mRNA levels, and down-regulation of SHP by a small interfering RNA increases both the transactivation of Smad3 and the PAI-1 mRNA levels. Finally, the PAI-1 gene is expressed in SHP(-/-) mouse hepatocytes at a higher level than in normal hepatocytes. Taken together, these data indicate that SHP is a novel co-regulator of Smad3, and this study provides new insights into regulation of TGF-beta signaling.

(236)U and (239,)(240)Pu ratios from soils around an Australian nuclear weapons test site.

PubMed

Tims, S G; Froehlich, M B; Fifield, L K; Wallner, A; De Cesare, M

2016-01-01

The isotopes (236)U, (239)Pu and (240)Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes potentially constitute artificial tracers of recent soil erosion and sediment movement. Only Accelerator Mass Spectrometry has the requisite sensitivity to measure all three isotopes at these environmental levels. Coupled with its relatively high throughput capabilities, this makes it feasible to conduct studies of erosion across the geographical extent of the Australian continent. In the Australian context, however, global fallout is not the only source of these isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The tests have made a significant contribution to the Pu isotopic abundances present in the region around Maralinga and out to distances ∼1000 km, and impact on the assessment techniques used in the soil and sediment tracer studies. Quantification of the relative fallout contribution derived from detonations at Maralinga is complicated owing to significant contamination around the test site from numerous nuclear weapons safety trials that were also carried out around the site. We show that (236)U can provide new information on the component of the fallout that is derived from the local nuclear weapons tests, and highlight the potential of (236)U as a new fallout tracer. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

A Historical Evaluation of the U16a Tunnel, Nevada National Security Site, Nye County, Nevada Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Robert C.; Drollinger, Harold; Bullard, Thomas F.

2013-01-01

This report presents a historical evaluation of the U16a Tunnel on the Nevada National Security Site in southern Nevada. The work was conducted by the Desert Research Institute at the request of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the U.S. Department of Defense, Defense Threat Reduction Agency. The U16a Tunnel was used for underground nuclear weapons effects tests in Shoshone Mountain in Area 16 of the Nevada National Security Site. Six nuclear tests were conducted in the U16a Tunnel from 1962 to 1971. These tests are Marshmallow, Gum Drop, Double Play, Ming Vase,more » Diamond Dust, and Diamond Mine. The U.S. Department of Defense Threat Reduction Agency, with participation from Lawrence Livermore National Laboratory and Las Alamos National Laboratory, sponsored the tests. Fifteen high explosives tests were also conducted at the tunnel. Two were calibration tests during nuclear testing and the remaining were U.S. Department of Defense, Defense Threat Reduction Agency tunnel defeat tests. The U16a Tunnel complex is on the top and slopes of Shoshone Mountain, encompassing an area of approximately 16.7 hectares (41.1 acres). Major modifications to the landscape are a result of three principal activities, road construction and maintenance, mining activities related to development of the tunnel complex, and site preparation for activities related to testing. Forty-seven cultural features were recorded at the portal and on the slopes of Shoshone Mountain. At the portal area, features relate to the mining, construction, testing, and general every day operational support activities within the tunnel. These include concrete foundations for buildings, equipment pads, and rail lines. Features on the slopes above the tunnel relate to tunnel ventilation, borehole drilling, and data recording. Feature types include soil-covered bunkers, concrete foundations, instrument cable holes, drill holes, and ventilation shafts

78 FR 13712 - U.S. Nuclear Regulatory Commission Planned Monitoring Activities for F-Area Tank Farm at the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-28

... Monitoring Activities for F-Area Tank Farm at the Savannah River Site, Revision 0 AGENCY: Nuclear Regulatory... carrying out its responsibilities for monitoring DOE's waste disposal activities at the F-Area Tank Farm at... the availability of ``U.S. Nuclear Regulatory Commission Plan for Monitoring Disposal Actions Taken by...

Identification of U2AF(35)-dependent exons by RNA-Seq reveals a link between 3′ splice-site organization and activity of U2AF-related proteins

PubMed Central

Kralovicova, Jana; Knut, Marcin; Cross, Nicholas C. P.; Vorechovsky, Igor

2015-01-01

The auxiliary factor of U2 small nuclear RNA (U2AF) is a heterodimer consisting of 65- and 35-kD proteins that bind the polypyrimidine tract (PPT) and AG dinucleotides at the 3′ splice site (3′ss). The gene encoding U2AF35 (U2AF1) is alternatively spliced, giving rise to two isoforms U2AF35a and U2AF35b. Here, we knocked down U2AF35 and each isoform and characterized transcriptomes of HEK293 cells with varying U2AF35/U2AF65 and U2AF35a/b ratios. Depletion of both isoforms preferentially modified alternative RNA processing events without widespread failure to recognize 3′ss or constitutive exons. Over a third of differentially used exons were terminal, resulting largely from the use of known alternative polyadenylation (APA) sites. Intronic APA sites activated in depleted cultures were mostly proximal whereas tandem 3′UTR APA was biased toward distal sites. Exons upregulated in depleted cells were preceded by longer AG exclusion zones and PPTs than downregulated or control exons and were largely activated by PUF60 and repressed by CAPERα. The U2AF(35) repression and activation was associated with a significant interchange in the average probabilities to form single-stranded RNA in the optimal PPT and branch site locations and sequences further upstream. Although most differentially used exons were responsive to both U2AF subunits and their inclusion correlated with U2AF levels, a small number of transcripts exhibited distinct responses to U2AF35a and U2AF35b, supporting the existence of isoform-specific interactions. These results provide new insights into function of U2AF and U2AF35 in alternative RNA processing. PMID:25779042

A SPACESHIP WITH NUCLEAR PROPULSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polorny, J.

1962-01-01

ABS>A proposed space vehicle with nuclear propulsion for a round-trip Martian mission is described. It would be powered by a 270-Mw graphite- moderated, U-fueled nuclear reactor with a core 1 m high by 1 m in diameter, and use gas as propellant. The gas would be heated to the maximum temperature in the reactor and additionally accelerated by an electromagnetic field. To this end, small quantities of K would be injected into the gas stream to increase its electric conductivity. The required electrical energy would be produced by liquid-Na-cooled thermionic converters. The vehicle would weigh 115000 kg, including 43000 kgmore » of H propellant with tankage, and 7000 kg of sustenance material for one year. Chemical rockets would launch the vehicle with a crew of three men into an earth orbit where nuclear propulsion would take over. Upon reactor start-up, three heat exchangers (minimum dimensions 30 x 18 m) would be fanned out. A shielded well with a diameter of 2.5 m would protect the crew from radiation during reactor operation, passage through the earth radiation belts, and at periods of solar flares. (OTS)« less

Effect of hypoxia on the expression of nuclear genes encoding mitochondrial proteins in U87 glioma cells.

PubMed

Minchenko, O H; Riabovol, O O; Tsymbal, D O; Minchenko, D O; Ratushna, O O

2016-01-01

We have studied the effect of hypoxia on the expression of nuclear genes encoding mitochondrial proteins in U87 glioma cells under the inhibition of IRE1 (inositol requiring enzyme-1), which controls cell proliferation and tumor growth as a central mediator of endoplasmic reticulum stress. It was shown that hypoxia down-regulated gene expression of malate dehydrogenase 2 (MDH2), malic enzyme 2 (ME2), mitochondrial aspartate aminotransferase (GOT2), and subunit B of succinate dehydrogenase (SDHB) in control (transfected by empty vector) glioma cells in a gene specific manner. At the same time, the expression level of mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) and subunit D of succinate dehydrogenase (SDHD) genes in these cells does not significantly change in hypoxic conditions. It was also shown that the inhibition of ІRE1 signaling enzyme function in U87 glioma cells decreases the effect of hypoxia on the expression of ME2, GOT2, and SDHB genes and introduces the sensitivity of IDH2 gene to hypoxia. Furthermore, the expression of all studied genes depends on IRE1-mediated endoplasmic reticulum stress signaling in gene specific manner, because ІRE1 knockdown significantly decreases their expression in normoxic conditions, except for IDH2 gene, which expression level is strongly up-regulated. Therefore, changes in the expression level of nuclear genes encoding ME2, MDH2, IDH2, SDHB, SDHD, and GOT2 proteins possibly reflect metabolic reprogramming of mitochondria by hypoxia and IRE1-mediated endoplasmic reticulum stress signaling and correlate with suppression of glioma cell proliferation under inhibition of the IRE1 enzyme function.

Stopping relativistic Xe, Ho, Au, and U nuclei in nuclear emulsions

NASA Technical Reports Server (NTRS)

Waddington, C. J.; Fixsen, D. J.; Freier, P. S.

1985-01-01

Nuclei of Xe-54, Ho-67, Au-79 and U-92 accelerated at the Bevalac to energies between 1200 and 900 MeV/n were stopped in nuclear emulsions. The observed residual ranges were compared with those calculated from various models of energy loss and shown to be most consistent with a calculation that includes those higher order correction terms proposed previously to describe the energy loss of highly changed particles, for which the first Born approximation is not valid.

Stopping relativistic Xe, Ho, Au and U nuclei in nuclear emulsions

NASA Technical Reports Server (NTRS)

Waddington, C. J.; Fixsen, D. J.; Freier, P. S.

1985-01-01

Nuclei of Xe-54, Ho-67, Au-79 and U-92 accelerated at the Bevalac to energies between 1200 and 900 MeV/n were stopped in nuclear emulsions. The observed residual ranges were compared with those calculated from various models of energy loss and shown to be most consistent with a calculation that includes those higher order correction terms proposed previously to describe the energy loss of highly charged particles, for which the first Born approximation is not valid.

Alternative exon definition events control the choice between nuclear retention and cytoplasmic export of U11/U12-65K mRNA

PubMed Central

Verbeeren, Jens; Verma, Bhupendra

2017-01-01

Cellular homeostasis of the minor spliceosome is regulated by a negative feed-back loop that targets U11-48K and U11/U12-65K mRNAs encoding essential components of the U12-type intron-specific U11/U12 di-snRNP. This involves interaction of the U11 snRNP with an evolutionarily conserved splicing enhancer giving rise to unproductive mRNA isoforms. In the case of U11/U12-65K, this mechanism controls the length of the 3′ untranslated region (3′UTR). We show that this process is dynamically regulated in developing neurons and some other cell types, and involves a binary switch between translation-competent mRNAs with a short 3′UTR to non-productive isoforms with a long 3′UTR that are retained in the nucleus or/and spliced to the downstream amylase locus. Importantly, the choice between these alternatives is determined by alternative terminal exon definition events regulated by conserved U12- and U2-type 5′ splice sites as well as sequence signals used for pre-mRNA cleavage and polyadenylation. We additionally show that U11 snRNP binding to the U11/U12-65K mRNA species with a long 3′UTR is required for their nuclear retention. Together, our studies uncover an intricate molecular circuitry regulating the abundance of a key spliceosomal protein and shed new light on the mechanisms limiting the export of non-productively spliced mRNAs from the nucleus to the cytoplasm. PMID:28549066

Alternative exon definition events control the choice between nuclear retention and cytoplasmic export of U11/U12-65K mRNA.

PubMed

Verbeeren, Jens; Verma, Bhupendra; Niemelä, Elina H; Yap, Karen; Makeyev, Eugene V; Frilander, Mikko J

2017-05-01

Cellular homeostasis of the minor spliceosome is regulated by a negative feed-back loop that targets U11-48K and U11/U12-65K mRNAs encoding essential components of the U12-type intron-specific U11/U12 di-snRNP. This involves interaction of the U11 snRNP with an evolutionarily conserved splicing enhancer giving rise to unproductive mRNA isoforms. In the case of U11/U12-65K, this mechanism controls the length of the 3' untranslated region (3'UTR). We show that this process is dynamically regulated in developing neurons and some other cell types, and involves a binary switch between translation-competent mRNAs with a short 3'UTR to non-productive isoforms with a long 3'UTR that are retained in the nucleus or/and spliced to the downstream amylase locus. Importantly, the choice between these alternatives is determined by alternative terminal exon definition events regulated by conserved U12- and U2-type 5' splice sites as well as sequence signals used for pre-mRNA cleavage and polyadenylation. We additionally show that U11 snRNP binding to the U11/U12-65K mRNA species with a long 3'UTR is required for their nuclear retention. Together, our studies uncover an intricate molecular circuitry regulating the abundance of a key spliceosomal protein and shed new light on the mechanisms limiting the export of non-productively spliced mRNAs from the nucleus to the cytoplasm.

Archival and Dissemination of the U.S. and Canadian Experimental Nuclear Reaction Data (EXFOR Project)

NASA Astrophysics Data System (ADS)

Pritychenko, Boris; Hlavac, Stanislav; Schwerer, Otto; Zerkin, Viktor

2017-09-01

The Exchange Format (EXFOR) or experimental nuclear reaction database and the associated Web interface provide access to the wealth of low- and intermediate-energy nuclear reaction physics data. This resource includes numerical data sets and bibliographical information for more than 22,000 experiments since the beginning of nuclear science. Analysis of the experimental data sets, recovery and archiving will be discussed. Examples of the recent developments of the data renormalization, uploads and inverse reaction calculations for nuclear science and technology applications will be presented. The EXFOR database, updated monthly, provides an essential support for nuclear data evaluation, application development and research activities. It is publicly available at the National Nuclear Data Center website http://www.nndc.bnl.gov/exfor and the International Atomic Energy Agency mirror site http://www-nds.iaea.org/exfor. This work was sponsored in part by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-98CH10886 with Brookha ven Science Associates, LLC.

The role of RNA structure in the interaction of U1A protein with U1 hairpin II RNA

PubMed Central

Law, Michael J.; Rice, Andrew J.; Lin, Patti; Laird-Offringa, Ite A.

2006-01-01

The N-terminal RNA Recognition Motif (RRM1) of the spliceosomal protein U1A interacting with its target U1 hairpin II (U1hpII) has been used as a paradigm for RRM-containing proteins interacting with their RNA targets. U1A binds to U1hpII via direct interactions with a 7-nucleotide (nt) consensus binding sequence at the 5′ end of a 10-nt loop, and via hydrogen bonds with the closing C–G base pair at the top of the RNA stem. Using surface plasmon resonance (Biacore), we have examined the role of structural features of U1hpII in binding to U1A RRM1. Mutational analysis of the closing base pair suggests it plays a minor role in binding and mainly prevents “breathing” of the loop. Lengthening the stem and nontarget part of the loop suggests that the increased negative charge of the RNA might slightly aid association. However, this is offset by an increase in dissociation, which may be caused by attraction of the RRM to nontarget parts of the RNA. Studies of a single stranded target and RNAs with untethered loops indicate that structure is not very relevant for association but is important for complex stability. In particular, breaking the link between the stem and the 5′ side of the loop greatly increases complex dissociation, presumably by hindering simultaneous contacts between the RRM and stem and loop nucleotides. While binding of U1A to a single stranded target is much weaker than to U1hpII, it occurs with nanomolar affinity, supporting recent evidence that binding of unstructured RNA by U1A has physiological significance. PMID:16738410

The role of RNA structure in the interaction of U1A protein with U1 hairpin II RNA.

PubMed

Law, Michael J; Rice, Andrew J; Lin, Patti; Laird-Offringa, Ite A

2006-07-01

The N-terminal RNA Recognition Motif (RRM1) of the spliceosomal protein U1A interacting with its target U1 hairpin II (U1hpII) has been used as a paradigm for RRM-containing proteins interacting with their RNA targets. U1A binds to U1hpII via direct interactions with a 7-nucleotide (nt) consensus binding sequence at the 5' end of a 10-nt loop, and via hydrogen bonds with the closing C-G base pair at the top of the RNA stem. Using surface plasmon resonance (Biacore), we have examined the role of structural features of U1hpII in binding to U1A RRM1. Mutational analysis of the closing base pair suggests it plays a minor role in binding and mainly prevents "breathing" of the loop. Lengthening the stem and nontarget part of the loop suggests that the increased negative charge of the RNA might slightly aid association. However, this is offset by an increase in dissociation, which may be caused by attraction of the RRM to nontarget parts of the RNA. Studies of a single stranded target and RNAs with untethered loops indicate that structure is not very relevant for association but is important for complex stability. In particular, breaking the link between the stem and the 5' side of the loop greatly increases complex dissociation, presumably by hindering simultaneous contacts between the RRM and stem and loop nucleotides. While binding of U1A to a single stranded target is much weaker than to U1hpII, it occurs with nanomolar affinity, supporting recent evidence that binding of unstructured RNA by U1A has physiological significance.

76 FR 81994 - UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-29

... NUCLEAR REGULATORY COMMISSION [Docket No. 52-016; NRC-2008-0250] UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit 3; Exemption 1.0 Background: UniStar Nuclear Energy (UNE) submitted to the U.S. Nuclear Regulatory Commission (NRC or the Commission ) a...

Integral cross sections for the direct excitation of the A 3 (sigma) u +, B 3 (pi) g, W 3 (delta) u, B' 3 (sigma) u -, a' 1 (sigma) u -, a 1 (pi) g, w 1 (delta) u, and C 3 (pi) u electronic states in

NASA Technical Reports Server (NTRS)

Johnson, P. V.; Malone, C. P.; Kanik, I.

2005-01-01

Integral cross sections for electron impact excitation out of the ground state (X 1(sigma)g +) to the A 3(sigma)u +, B 3(pi)g, W 3(delta)u, B' 3(sigma)u -, a' 1(sigma)u -, a 1(pi)g, w 1(delta)u, and states in N2 are reported at incident energies ranging between 10 and 100 eV. These data have been derived by integrating differential cross sections previously reported by this group. New differential cross section measurements for the a 1(pi)g state at 200 eV are also presented to extend the range of the reported integral cross sections for this state, which is responsible for the emissions of the Lyman-Birge-Hopfield band system (a 1(pi)g (rightwards arrow) X 1(sigma)g +). The present results are compared and critically evaluated against existing cross sec In general, the present cross sections are smaller than previous results at low impact energies from threshold through the excitation function peak regions. These lower cross sections have potentially significant implications on our understanding of UV emissions in the atmospheres of Earth and Titan.

78 FR 45969 - Trade Barriers That U.S. Small and Medium-Sized Enterprises Perceive as Affecting Exports to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-30

... INTERNATIONAL TRADE COMMISSION [Investigation No. 332-541] Trade Barriers That U.S. Small and... Investigation and Scheduling of Hearing AGENCY: United States International Trade Commission. ACTION... 332(g) of the Tariff Act of 1930 (19 U.S.C. 1332(g)), the U.S. International Trade Commission...

Comparison of Radiation Dose Studies of the 2011 Fukushima Nuclear Accident Prepared by the World Health Organization and the U.S. Department of Defense

DTIC Science & Technology

2012-11-01

R T Comparison of Radiation Dose Studies of the 2011 Fukushima Nuclear Accident Prepared by the World Health Organization and the U.S. Department...AND SUBTITLE Comparison of Radiation Dose Studies of the 2011 Fukushima Nuclear Accident Prepared by the World Health Organization and the U.S...in Japan on March 11, 2011 led to releases of radioactive materials from the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station

Presentation of Fukushima Analyses to U.S. Nuclear Power Plant Simulator Operators and Vendors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osborn, Douglas; Kalinich, Donald A.; Cardoni, Jeffrey N

This document provides Sandia National Laboratories’ meeting notes and presentations at the Society for Modeling and Simulation Power Plant Simulator conference in Jacksonville, FL. The conference was held January 26-28, 2015, and SNL was invited by the U.S. nuclear industry to present Fukushima modeling insights and lessons learned.

Evaluating the Cost, Safety, and Proliferation Risks of Small Floating Nuclear Reactors.

PubMed

Ford, Michael J; Abdulla, Ahmed; Morgan, M Granger

2017-11-01

It is hard to see how our energy system can be decarbonized if the world abandons nuclear power, but equally hard to introduce the technology in nonnuclear energy states. This is especially true in countries with limited technical, institutional, and regulatory capabilities, where safety and proliferation concerns are acute. Given the need to achieve serious emissions mitigation by mid-century, and the multidecadal effort required to develop robust nuclear governance institutions, we must look to other models that might facilitate nuclear plant deployment while mitigating the technology's risks. One such deployment paradigm is the build-own-operate-return model. Because returning small land-based reactors containing spent fuel is infeasible, we evaluate the cost, safety, and proliferation risks of a system in which small modular reactors are manufactured in a factory, and then deployed to a customer nation on a floating platform. This floating small modular reactor would be owned and operated by a single entity and returned unopened to the developed state for refueling. We developed a decision model that allows for a comparison of floating and land-based alternatives considering key International Atomic Energy Agency plant-siting criteria. Abandoning onsite refueling is beneficial, and floating reactors built in a central facility can potentially reduce the risk of cost overruns and the consequences of accidents. However, if the floating platform must be built to military-grade specifications, then the cost would be much higher than a land-based system. The analysis tool presented is flexible, and can assist planners in determining the scope of risks and uncertainty associated with different deployment options. © 2017 Society for Risk Analysis.

The DEAH-box helicase Dhr1 dissociates U3 from the pre-rRNA to promote formation of the central pseudoknot.

PubMed

Sardana, Richa; Liu, Xin; Granneman, Sander; Zhu, Jieyi; Gill, Michael; Papoulas, Ophelia; Marcotte, Edward M; Tollervey, David; Correll, Carl C; Johnson, Arlen W

2015-02-01

In eukaryotes, the highly conserved U3 small nucleolar RNA (snoRNA) base-pairs to multiple sites in the pre-ribosomal RNA (pre-rRNA) to promote early cleavage and folding events. Binding of the U3 box A region to the pre-rRNA is mutually exclusive with folding of the central pseudoknot (CPK), a universally conserved rRNA structure of the small ribosomal subunit essential for protein synthesis. Here, we report that the DEAH-box helicase Dhr1 (Ecm16) is responsible for displacing U3. An active site mutant of Dhr1 blocked release of U3 from the pre-ribosome, thereby trapping a pre-40S particle. This particle had not yet achieved its mature structure because it contained U3, pre-rRNA, and a number of early-acting ribosome synthesis factors but noticeably lacked ribosomal proteins (r-proteins) that surround the CPK. Dhr1 was cross-linked in vivo to the pre-rRNA and to U3 sequences flanking regions that base-pair to the pre-rRNA including those that form the CPK. Point mutations in the box A region of U3 suppressed a cold-sensitive mutation of Dhr1, strongly indicating that U3 is an in vivo substrate of Dhr1. To support the conclusions derived from in vivo analysis we showed that Dhr1 unwinds U3-18S duplexes in vitro by using a mechanism reminiscent of DEAD box proteins.

The DEAH-box Helicase Dhr1 Dissociates U3 from the Pre-rRNA to Promote Formation of the Central Pseudoknot

PubMed Central

Granneman, Sander; Zhu, Jieyi; Gill, Michael; Papoulas, Ophelia; Marcotte, Edward M.; Tollervey, David; Correll, Carl C.; Johnson, Arlen W.

2015-01-01

In eukaryotes, the highly conserved U3 small nucleolar RNA (snoRNA) base-pairs to multiple sites in the pre-ribosomal RNA (pre-rRNA) to promote early cleavage and folding events. Binding of the U3 box A region to the pre-rRNA is mutually exclusive with folding of the central pseudoknot (CPK), a universally conserved rRNA structure of the small ribosomal subunit essential for protein synthesis. Here, we report that the DEAH-box helicase Dhr1 (Ecm16) is responsible for displacing U3. An active site mutant of Dhr1 blocked release of U3 from the pre-ribosome, thereby trapping a pre-40S particle. This particle had not yet achieved its mature structure because it contained U3, pre-rRNA, and a number of early-acting ribosome synthesis factors but noticeably lacked ribosomal proteins (r-proteins) that surround the CPK. Dhr1 was cross-linked in vivo to the pre-rRNA and to U3 sequences flanking regions that base-pair to the pre-rRNA including those that form the CPK. Point mutations in the box A region of U3 suppressed a cold-sensitive mutation of Dhr1, strongly indicating that U3 is an in vivo substrate of Dhr1. To support the conclusions derived from in vivo analysis we showed that Dhr1 unwinds U3-18S duplexes in vitro by using a mechanism reminiscent of DEAD box proteins. PMID:25710520

Nuclear Weapon Tests and their Consequences,

DTIC Science & Technology

Nuclear weapon research, specifically nuclear bomb tests, and the deleterious effects of heightened radioactivity levels on the world’s biology, are...Soviet Union is discussed. The effects of the U.S.A. bombing of Hiroshima and Nagasaki, as well as the U.S.A. bomb test of March 1, 1954, and listed as

A roadmap for nuclear energy technology

NASA Astrophysics Data System (ADS)

Sofu, Tanju

2018-01-01

The prospects for the future use of nuclear energy worldwide can best be understood within the context of global population growth, urbanization, rising energy need and associated pollution concerns. As the world continues to urbanize, sustainable development challenges are expected to be concentrated in cities of the lower-middle-income countries where the pace of urbanization is fastest. As these countries continue their trajectory of economic development, their energy need will also outpace their population growth adding to the increased demand for electricity. OECD IEA's energy system deployment pathway foresees doubling of the current global nuclear capacity by 2050 to reduce the impact of rapid urbanization. The pending "retirement cliff" of the existing U.S. nuclear fleet, representing over 60 percent of the nation's emission-free electricity, also poses a large economic and environmental challenge. To meet the challenge, the U.S. DOE has developed the vision and strategy for development and deployment of advanced reactors. As part of that vision, the U.S. government pursues programs that aim to expand the use of nuclear power by supporting sustainability of the existing nuclear fleet, deploying new water-cooled large and small modular reactors to enable nuclear energy to help meet the energy security and climate change goals, conducting R&D for advanced reactor technologies with alternative coolants, and developing sustainable nuclear fuel cycle strategies. Since the current path relying heavily on water-cooled reactors and "once-through" fuel cycle is not sustainable, next generation nuclear energy systems under consideration aim for significant advances over existing and evolutionary water-cooled reactors. Among the spectrum of advanced reactor options, closed-fuel-cycle systems using reactors with fast-neutron spectrum to meet the sustainability goals offer the most attractive alternatives. However, unless the new public-private partnership models emerge

Evidence of nuclear fusion neutrons in an extremely small plasma focus device operating at 0.1 Joules

NASA Astrophysics Data System (ADS)

Soto, Leopoldo; Pavéz, Cristián; Moreno, José; Altamirano, Luis; Huerta, Luis; Barbaglia, Mario; Clausse, Alejandro; Mayer, Roberto E.

2017-08-01

We report on D-D fusion neutron emission in a plasma device with an energy input of only 0.1 J, within a range where fusion events have been considered very improbable. The results presented here are the consequence of scaling rules we have derived, thus being the key point to assure the same energy density plasma in smaller devices than in large machines. The Nanofocus (NF)—our device—was designed and constructed at the P4 Lab of the Chilean Nuclear Energy Commission. Two sets of independent measurements, with different instrumentation, were made at two laboratories, in Chile and Argentina. The neutron events observed are 20σ greater than the background. The NF plasma is produced from a pulsed electrical discharge using a submillimetric anode, in a deuterium atmosphere, showing empirically that it is, in fact, possible to heat and compress the plasma. The strong evidence presented here stretches the limits beyond what was expected. A thorough understanding of this could possibly tell us where the theoretical limits actually lie, beyond conjectures. Notwithstanding, a window is thus open for low cost endeavours for basic fusion research. In addition, the development of small, portable, safe nonradioactive neutron sources becomes a feasible issue.

Impact Upon U.S. Security of a South African Nuclear Weapons Capability.

DTIC Science & Technology

1981-04-01

Simon Brand, dubbed the international companies as the " engine of growth" for the South African economy. The petroleum market, automobile industry , and...thereby halting the flow of metals key to high technology industries which in turn, are critical to U.S. national security. Should Washington’s...to produce nuclear weapons." * More specifically, we found that South Africa has: A sufficient scientific and industrial base on which to conduct

Study of nuclear matter in hard proton-nuclei and nuclei-nuclei collisions at the U70 accelerator (FLUKTON project proposal)

NASA Astrophysics Data System (ADS)

Antonov, N. N.; Baldin, A. A.; Viktorov, V. A.; Gapienko, V. A.; Gapienko, G. S.; Gres, V. N.; Ilyushin, M. A.; Korotkov, V. A.; Mysnik, A. I.; Prudkoglyad, A. F.; Pryanikov, D. S.; Semak, A. A.; Stavinsky, A. V.; Terekhov, V. I.; Uglekov, V. Ya.; Ukhanov, M. N.; Chuiko, B. V.; Shimansky, S. S.

2017-11-01

A two-arm spectrometer FLUKTON for investigations in the field of relativistic nuclear physics at U70 energies is proposed to be constructed on base of the existing detector SPIN (IHEP, Protvino). The main objective is to obtain new data on clusters of cold superdense nuclear matter. Interaction of a high intensity proton beam with nuclear targets and an ion beam with liquid hydrogen and nuclear targets will be studied.

How small firms contrast with large firms regarding perceptions, practices, and needs in the U.S

Treesearch

Urs Buehlmann; Matthew Bumgardner; Michael Sperber

2013-01-01

As many larger secondary woodworking firms have moved production offshore and been adversely impacted by the recent housing downturn, smaller firms have become important to driving U.S. hardwood demand. This study compared and contrasted small and large firms on a number of factors to help determine the unique characteristics of small firms and to provide insights into...

In Vitro Assembly of Human H/ACA Small Nucleolar RNPs Reveals Unique Features of U17 and Telomerase RNAs

PubMed Central

Dragon, François; Pogačić, Vanda; Filipowicz, Witold

2000-01-01

The H/ACA small nucleolar RNAs (snoRNAs) are involved in pseudouridylation of pre-rRNAs. They usually fold into a two-domain hairpin-hinge-hairpin-tail structure, with the conserved motifs H and ACA located in the hinge and tail, respectively. Synthetic RNA transcripts and extracts from HeLa cells were used to reconstitute human U17 and other H/ACA ribonucleoproteins (RNPs) in vitro. Competition and UV cross-linking experiments showed that proteins of about 60, 29, 23, and 14 kDa interact specifically with U17 RNA. Except for U17, RNPs could be reconstituted only with full-length H/ACA snoRNAs. For U17, the 3′-terminal stem-loop followed by box ACA (U17/3′st) was sufficient to form an RNP, and U17/3′st could compete other full-length H/ACA snoRNAs for assembly. The H/ACA-like domain that constitutes the 3′ moiety of human telomerase RNA (hTR), and its 3′-terminal stem-loop (hTR/3′st), also could form an RNP by binding H/ACA proteins. Hence, the 3′-terminal stem-loops of U17 and hTR have some specific features that distinguish them from other H/ACA RNAs. Antibodies that specifically recognize the human GAR1 (hGAR1) protein could immunoprecipitate H/ACA snoRNAs and hTR from HeLa cell extracts, which demonstrates that hGAR1 is a component of H/ACA snoRNPs and telomerase in vivo. Moreover, we show that in vitro-reconstituted RNPs contain hGAR1 and that binding of hGAR1 does not appear to be a prerequisite for the assembly of the other H/ACA proteins. PMID:10757788

Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruce G. Schnitzler; Stanley K. Borowski

Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified asmore » the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine

Small-molecule kinase inhibitors provide insight into Mps1 cell cycle function.

PubMed

Kwiatkowski, Nicholas; Jelluma, Nannette; Filippakopoulos, Panagis; Soundararajan, Meera; Manak, Michael S; Kwon, Mijung; Choi, Hwan Geun; Sim, Taebo; Deveraux, Quinn L; Rottmann, Sabine; Pellman, David; Shah, Jagesh V; Kops, Geert J P L; Knapp, Stefan; Gray, Nathanael S

2010-05-01

Mps1, a dual-specificity kinase, is required for the proper functioning of the spindle assembly checkpoint and for the maintenance of chromosomal stability. As Mps1 function has been implicated in numerous phases of the cell cycle, the development of a potent, selective small-molecule inhibitor of Mps1 should facilitate dissection of Mps1-related biology. We describe the cellular effects and Mps1 cocrystal structures of new, selective small-molecule inhibitors of Mps1. Consistent with RNAi studies, chemical inhibition of Mps1 leads to defects in Mad1 and Mad2 establishment at unattached kinetochores, decreased Aurora B kinase activity, premature mitotic exit and gross aneuploidy, without any evidence of centrosome duplication defects. However, in U2OS cells having extra centrosomes (an abnormality found in some cancers), Mps1 inhibition increases the frequency of multipolar mitoses. Lastly, Mps1 inhibitor treatment resulted in a decrease in cancer cell viability.

Determination of 238u/235u, 236u/238u and uranium concentration in urine using sf-icp-ms and mc-icp-ms: an interlaboratory comparison.

PubMed

Parrish, Randall R; Thirlwall, Matthew F; Pickford, Chris; Horstwood, Matthew; Gerdes, Axel; Anderson, James; Coggon, David

2006-02-01

Accidental exposure to depleted or enriched uranium may occur in a variety of circumstances. There is a need to quantify such exposure, with the possibility that the testing may post-date exposure by months or years. Therefore, it is important to develop a very sensitive test to measure precisely the isotopic composition of uranium in urine at low levels of concentration. The results of an interlaboratory comparison using sector field (SF)-inductively coupled plasma-mass spectrometry (ICP-MS) and multiple collector (MC)-ICP-MS for the measurement of uranium concentration and U/U and U/U isotopic ratios of human urine samples are presented. Three urine samples were verified to contain uranium at 1-5 ng L and shown to have natural uranium isotopic composition. Portions of these urine batches were doped with depleted uranium (DU) containing small quantities of U, and the solutions were split into 100 mL and 400 mL aliquots that were subsequently measured blind by three laboratories. All methods investigated were able to measure accurately U/U with precisions of approximately 0.5% to approximately 4%, but only selected MC-ICP-MS methods were capable of consistently analyzing U/U to reasonable precision at the approximately 20 fg L level of U abundance. Isotope dilution using a U tracer demonstrates the ability to measure concentrations to better than +/-4% with the MC-ICP-MS method, though sample heterogeneity in urine samples was shown to be problematic in some cases. MC-ICP-MS outperformed SF-ICP-MS methods, as was expected. The MC-ICP-MS methodology described is capable of measuring to approximately 1% precision the U/U of any sample of human urine over the entire range of uranium abundance down to <1 ng L, and detecting very small amounts of DU contained therein.

Precise U and Pu isotope ratio measurements in nuclear samples by hyphenating capillary electrophoresis and MC-ICPMS.

PubMed

Martelat, Benoit; Isnard, Helene; Vio, Laurent; Dupuis, Erwan; Cornet, Terence; Nonell, Anthony; Chartier, Frederic

2018-06-22

Precise isotopic and elemental characterization of spent nuclear fuel is a major concern for the validation of the neutronic calculation codes and waste management strategy in the nuclear industry. Generally, the elements of interest, particularly U and Pu which are the two major elements present in spent fuel, are purified by ion exchange or extractant resins before off-line measurements by thermal ionization mass spectrometry. The aim of the present work was to develop a new analytical approach based on capillary electrophoresis (CE) hyphenated to a multicollector inductively coupled plasma mass spectrometer (MC-ICPMS) for online isotope ratio measurements. An electrophoretic separation protocol of U, Pu and the fraction containing fission products and minor actinides (Am and Cm) was developed using acetic acid as the electrolyte and complexing agent. The instrumentation for CE was designed to be used in a glove box and a laboratory-built interface was developed for hyphenation with MC-ICPMS. The separation was realized with only a few nL of a solution of spent nuclear fuel and the reproducibilities obtained on the U and Pu isotope ratios were on the order of a few ‰ which is comparable to those obtained by thermal ionization mass spectrometer (TIMS). This innovative protocol allowed a tremendous reduction of the analyte masses from μg to ng and also a drastic reduction of the liquid waste production from mL to μL. In addition, the time of analysis was shorted by at least a factor three. All of these improved parameters are of major interest for nuclear applications.

Preserving the nuclear option: The AIAA position paper on space nuclear power

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, D.M.; Bennett, G.L.; El-Genk, M.S.

1996-03-01

In response to published reports about the decline in funding for space nuclear power, the Board of Directors of the American Institute of Aeronautics and Astronautics (AIAA) approved a position paper in March 1995 that recommends (1) development and support of an integrated space nuclear power program by DOE, NASA and DoD; (2) Congressional support for the program; (3) advocacy of the program by government and industry leaders; and (4) continuation of cooperation between the U.S. and other countries to advance nuclear power source technology and to promote safety. This position paper has been distributed to various people having oversightmore » of the U.S. space nuclear power program. {copyright} {ital 1996 American Institute of Physics.}« less

NUCLEAR REACTOR

DOEpatents

Young, G.

1963-01-01

This patent covers a power-producing nuclear reactor in which fuel rods of slightly enriched U are moderated by heavy water and cooled by liquid metal. The fuel rods arranged parallel to one another in a circle are contained in a large outer closed-end conduit that extends into a tank containing the heavy water. Liquid metal is introduced into the large conduit by a small inner conduit that extends within the circle of fuel rods to a point near the lower closed end of the outer conduit. (AEC) Production Reactors

78 FR 35646 - Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-13

... NUCLEAR REGULATORY COMMISSION [Docket Nos.: 50-454, 50-455, 50-456, 50-457; NRC-2013-0126] Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2 AGENCY: Nuclear Regulatory.... Nuclear Regulatory Commission (NRC) has received an application, dated May 29, 2013, from Exelon...

Quantifying Morphological Features of α-U3O8 with Image Analysis for Nuclear Forensics.

PubMed

Olsen, Adam M; Richards, Bryony; Schwerdt, Ian; Heffernan, Sean; Lusk, Robert; Smith, Braxton; Jurrus, Elizabeth; Ruggiero, Christy; McDonald, Luther W

2017-03-07

Morphological changes in U 3 O 8 based on calcination temperature have been quantified enabling a morphological feature to serve as a signature of processing history in nuclear forensics. Five separate calcination temperatures were used to synthesize α-U 3 O 8 , and each sample was characterized using powder X-ray diffraction (p-XRD) and scanning electron microscopy (SEM). The p-XRD spectra were used to evaluate the purity of the synthesized U-oxide; the morphological analysis for materials (MAMA) software was utilized to quantitatively characterize the particle shape and size as indicated by the SEM images. Analysis comparing the particle attributes, such as particle area at each of the temperatures, was completed using the Kolmogorov-Smirnov two sample test (K-S test). These results illustrate a distinct statistical difference between each calcination temperature. To provide a framework for forensic analysis of an unknown sample, the sample distributions at each temperature were compared to randomly selected distributions (100, 250, 500, and 750 particles) from each synthesized temperature to determine if they were statistically different. It was found that 750 particles were required to differentiate between all of the synthesized temperatures with a confidence interval of 99.0%. Results from this study provide the first quantitative morphological study of U-oxides, and reveals the potential strength of morphological particle analysis in nuclear forensics by providing a framework for a more rapid characterization of interdicted uranium oxide samples.

Inhibition of U snRNP assembly by a virus-encoded proteinase.

PubMed

Almstead, Laura L; Sarnow, Peter

2007-05-01

It has been proposed that defects in the assembly of spliceosomal uridine-rich small nuclear ribonucleoprotein (U snRNP) complexes could account for the death of motor neurons in spinal muscular atrophy (SMA). We discovered that infection of cultured cells with poliovirus results in the specific cleavage of the host factor Gemin3 by a virus-encoded proteinase, 2A(pro). Gemin3 is a component of the macromolecular SMN complex that mediates assembly of U snRNP complexes by aiding the heptameric oligomerization of Sm proteins onto U snRNAs. Using in vitro Sm core assembly assays, we found that lowering the intracellular amounts of Gemin3 by either poliovirus infection or small interfering RNA (siRNA)-mediated knockdown of Gemin3 resulted in reduced assembly of U snRNPs. Immunofluorescence analyses revealed a specific redistribution of Sm proteins from the nucleoplasm to the cytoplasmic periphery of the nucleus in poliovirus-infected cells. We propose that defects in U snRNP assembly may be shared features of SMA and poliomyelitis.

Application of ex situ dynamic nuclear polarization in studying small molecules.

PubMed

Ludwig, Christian; Marin-Montesinos, Ildefonso; Saunders, Martin G; Emwas, Abdul-Hamid; Pikramenou, Zoe; Hammond, Stephen P; Günther, Ulrich L

2010-06-14

Dynamic nuclear polarization (DNP) has become an attractive technique to boost the sensitivity of NMR experiments. In the case of ex situ polarizations two-dimensional (2D) spectra are limited by the short lifetime of the polarization after dissolution and sample transfer to a high field NMR magnet. This limitation can be overcome by various approaches. Here we show how the use of (13)C-labelled acetyl tags can help to obtain 2D-HMQC spectra for many small molecules, owing to a nuclear Overhauser enhancement between (13)C spins originating from the long-lived carbonyl carbon, which extends the lifetimes of other (13)C spins with shorter longitudinal relaxation times. We also show an alternative approach of using an optimized polarization matrix.

Nuclear Fuels.

ERIC Educational Resources Information Center

Nash, J. Thomas

1983-01-01

Trends in and factors related to the nuclear industry and nuclear fuel production are discussed. Topics addressed include nuclear reactors, survival of the U.S. uranium industry, production costs, budget cuts by the Department of Energy and U.S. Geological survey for resource studies, mining, and research/development activities. (JN)

Impact of thermal spectrum small modular reactors on performance of once-through nuclear fuel cycles with low-enriched uranium

DOE PAGES

Brown, Nicholas R.; Worrall, Andrew; Todosow, Michael

2016-11-18

Small modular reactors (SMRs) offer potential benefits, such as enhanced operational flexibility. However, it is vital to understand the holistic impact of SMRs on nuclear fuel cycle performance. The focus of this paper is the fuel cycle impacts of light water SMRs in a once-through fuel cycle with low-enriched uranium fuel. A key objective of this paper is to describe preliminary example reactor core physics and fuel cycle analyses conducted in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Options Campaign. The hypothetical light water SMR example case considered in these preliminary scoping studies ismore » a cartridge type one-batch core with slightly less than 5.0% enrichment. Challenges associated with SMRs include increased neutron leakage, fewer assemblies in the core (and therefore fewer degrees of freedom in the core design), complex enrichment and burnable absorber loadings, full power operation with inserted control rods, the potential for frequent load-following operation, and shortened core height. Each of these will impact the achievable discharge burnup in the reactor and the fuel cycle performance. This paper summarizes a list of the factors relevant to SMR fuel, core, and operation that will impact fuel cycle performance. The high-level issues identified and preliminary scoping calculations in this paper are intended to inform on potential fuel cycle impacts of one-batch thermal spectrum SMRs. In particular, this paper highlights the impact of increased neutron leakage and reduced number of batches on the achievable burnup of the reactor. Fuel cycle performance metrics for a hypothetical example SMR are compared with those for a conventional three-batch light water reactor in the following areas: nuclear waste management, environmental impact, and resource utilization. The metrics performance for such an SMR is degraded for the mass of spent nuclear fuel and high-level waste disposed of, mass of depleted uranium

Right-handed neutrino dark matter in a U(1) extension of the Standard Model

NASA Astrophysics Data System (ADS)

Cox, Peter; Han, Chengcheng; Yanagida, Tsutomu T.

2018-01-01

We consider minimal U(1) extensions of the Standard Model in which one of the right-handed neutrinos is charged under the new gauge symmetry and plays the role of dark matter. In particular, we perform a detailed phenomenological study for the case of a U(1)(B‑L)3 flavoured B‑L symmetry. If perturbativity is required up to high-scales, we find an upper bound on the dark matter mass of mχlesssim2 TeV, significantly stronger than that obtained in simplified models. Furthermore, if the U(1)(B‑L)3 breaking scalar has significant mixing with the SM Higgs, there are already strong constraints from direct detection. On the other hand, there remains significant viable parameter space in the case of small mixing, which may be probed in the future via LHC Z' searches and indirect detection. We also comment on more general anomaly-free symmetries consistent with a TeV-scale RH neutrino dark matter candidate, and show that if two heavy RH neutrinos for leptogenesis are also required, one is naturally led to a single-parameter class of U(1) symmetries.

Nano and micro U1-xThxO2 solid solutions: From powders to pellets

NASA Astrophysics Data System (ADS)

Balice, Luca; Bouëxière, Daniel; Cologna, Marco; Cambriani, Andrea; Vigier, Jean-François; De Bona, Emanuele; Sorarù, Gian Domenico; Kübel, Christian; Walter, Olaf; Popa, Karin

2018-01-01

Nuclear fuels production, structural materials, separation techniques, and waste management, all may benefit from an extensive knowledge in the nano-nuclear technology. In this line, we present here the production of U1-xThxO2 (x = 0 to 1) mixed oxides nanocrystals (NC's) through the hydrothermal decomposition of the oxalates in hot compressed water at 250 °C. Particles of spherical shape and size of about 5.5-6 nm are obtained during the hydrothermal decomposition process. The powdery nanocrystalline products were consolidated by spark plasma sintering into homogeneous mixed oxides pellets with grain sizes in the 0.4 to 5.5 μm range. Grain growth and mechanical properties were studied as a function of composition and size. No grain size effect was observed on the hardness or elastic modulus.

Correct mRNA Processing at a Mutant TT Splice Donor in FANCC Ameliorates the Clinical Phenotype in Patients and Is Enhanced by Delivery of Suppressor U1 snRNAs

PubMed Central

Hartmann, Linda; Neveling, Kornelia; Borkens, Stephanie; Schneider, Hildegard; Freund, Marcel; Grassman, Elke; Theiss, Stephan; Wawer, Angela; Burdach, Stefan; Auerbach, Arleen D.; Schindler, Detlev; Hanenberg, Helmut; Schaal, Heiner

2010-01-01

The U1 small nuclear RNA (U1 snRNA) as a component of the major U2-dependent spliceosome recognizes 5′ splice sites (5′ss) containing GT as the canonical dinucleotide in the intronic positions +1 and +2. The c.165+1G>T germline mutation in the 5′ss of exon 2 of the Fanconi anemia C (FANCC) gene commonly predicted to prevent correct splicing was identified in nine FA patients from three pedigrees. RT-PCR analysis of the endogenous FANCC mRNA splicing pattern of patient-derived fibroblasts revealed aberrant mRNA processing, but surprisingly also correct splicing at the TT dinucleotide, albeit with lower efficiency. This consequently resulted in low levels of correctly spliced transcript and minute levels of normal posttranslationally processed FANCD2 protein, indicating that this naturally occurring TT splicing might contribute to the milder clinical manifestations of the disease in these patients. Functional analysis of this FANCC 5′ss within splicing reporters revealed that both the noncanonical TT dinucleotide and the genomic context of FANCC were required for the residual correct splicing at this mutant 5′ss. Finally, use of lentiviral vectors as a delivery system to introduce expression cassettes for TT-adapted U1 snRNAs into primary FANCC patient fibroblasts allowed the correction of the DNA-damage-induced G2 cell-cycle arrest in these cells, thus representing an alternative transcript-targeting approach for genetic therapy of inherited splice-site mutations. PMID:20869034

Infrared radiative decay dynamics from the γ 1u (3P2), H 1u (3P1), and 1u (1D2) ion-pair states of I2 observed by a perturbation facilitated optical-optical double resonance technique

NASA Astrophysics Data System (ADS)

Hoshino, Shoma; Araki, Mitsunori; Nakano, Yukio; Ishiwata, Takashi; Tsukiyama, Koichi

2016-01-01

We report the spectroscopic and temporal analyses on the amplified spontaneous emission (ASE) from the single rovibrational levels of the Ω = 1u ion-pair series, γ 1u (3P2), H 1u (3P1), and 1u (1D2), of I2 by using a perturbation facilitated optical-optical double resonance technique through the c 1 Π g ˜ B 3 Π ( 0u + ) hyperfine mixed valence state as the intermediate state. The ASE detected in the infrared region was assigned to the parallel transitions from the Ω = 1u ion-pair states down to the nearby Ω = 1g ion-pair states. The subsequent ultraviolet (UV) fluorescence from the Ω = 1g states was also observed and the relative vibrational populations in the Ω = 1g states were derived through the Franck-Condon simulation of the intensity pattern of the vibrational progression. In the temporal profiles of the UV fluorescence, an obvious delay in the onset of the fluorescence was recognized after the excitation laser pulse. These results revealed that ASE is a dominant energy relaxation process between the Ω = 1u and 1g ion-pair states of I2. Finally, the lifetimes of the relevant ion-pair states were evaluated by temporal analyses of the UV fluorescence. The propensity was found which was the longer lifetime in the upper level of the ASE transitions tends to give intense ASE.

The minor spliceosomal protein U11/U12-31K is an RNA chaperone crucial for U12 intron splicing and the development of dicot and monocot plants.

PubMed

Kwak, Kyung Jin; Jung, Hyun Ju; Lee, Kwang Ho; Kim, Young Soon; Kim, Won Yong; Ahn, Sung Ju; Kang, Hunseung

2012-01-01

U12 intron-specific spliceosomes contain U11 and U12 small nuclear ribonucleoproteins and mediate the removal of U12 introns from precursor-mRNAs. Among the several proteins unique to the U12-type spliceosomes, an Arabidopsis thaliana AtU11/U12-31K protein has been shown to be indispensible for proper U12 intron splicing and for normal growth and development of Arabidopsis plants. Here, we assessed the functional roles of the rice (Oryza sativa) OsU11/U12-31K protein in U12 intron splicing and development of plants. The U11/U12-31K transcripts were abundantly expressed in the shoot apical meristems (SAMs) of Arabidopsis and rice. Ectopic expression of OsU11/U12-31K in AtU11/U12-31K-defecient Arabidopsis mutant complemented the incorrect U12 intron splicing and abnormal development phenotypes of the Arabidopsis mutant plants. Impaired cell division activity in the SAMs and inflorescence stems observed in the AtU11/U12-31K-deficient mutant was completely recovered to normal by the expression of OsU11/U12-31K. Similar to Arabidopsis AtU11/U12-31K, rice OsU11/U12-31K was determined to harbor RNA chaperone activity. Collectively, the present findings provide evidence for the emerging idea that the U11/U12-31K protein is an indispensible RNA chaperone that functions in U12 intron splicing and is necessary for normal development of monocotyledonous plants as well as dicotyledonous plants.

Cancer Mortality through 2005 among a Pooled Cohort of U.S. Nuclear Workers Exposed to External Ionizing Radiation.

PubMed

Schubauer-Berigan, Mary K; Daniels, Robert D; Bertke, Stephen J; Tseng, Chih-Yu; Richardson, David B

2015-06-01

Nuclear workers worldwide have been studied for decades to estimate associations between their exposure to ionizing radiation and cancer. The low-level exposure of these workers requires pooling of large cohorts studied over many years to obtain risk estimates with appropriate latency and good precision. We assembled a pooled cohort of 119,195 U.S. nuclear workers at four Department of Energy nuclear weapons facilities (Hanford site, Idaho National Laboratory, Oak Ridge National Laboratory and Savannah River site) and at the Portsmouth Naval Shipyard. The cohort was followed at the start of the workers beginning their radiation work (at earliest, between 1944 and 1952) through 2005, and we compared its mortality to that of the U.S. We also conducted regression-modeling analysis to evaluate dose-response associations for external radiation exposure and outcomes: all cancers, smoking- and nonsmoking-related cancers, all lymphatic and hematopoietic cancers, leukemia (excluding chronic lymphocytic), multiple myeloma, cardiovascular disease and others. The mean dose observed among the cohort was 20 mSv. For most outcomes, mortality was below expectation compared to the general population, but mesothelioma and pleura cancers were highly elevated. We found an excess relative risk (ERR) per 10 mSv of 0.14% [95% confidence interval (CI): -0.17%, 0.48%] for all cancers excluding leukemia. Estimates were higher for nonsmoking-related cancers (0.70%, 95% CI: 0.058%, 1.5%) and lower for smoking-related cancers (-0.079%, 95% CI: -0.43%, 0.32%). The ERR per 10 mSv was 1.7% (95% CI: -0.22%, 4.7%) for leukemia, which was similar to the estimate of 1.8% (95% CI: 0.027%, 4.4%) for all lymphatic and hematopoietic cancers. The ERR per 10 mSv for multiple myeloma was 3.9% (95% CI: 0.60%, 9.5%). The ERR per 10 mSv for cardiovascular disease was 0.026% (-0.25%, 0.32%). Little evidence of heterogeneity was seen by facility, birth cohort or sex for most outcomes. The estimates observed here

Induction of polyploidy by nuclear fusion mechanism upon decreased expression of the nuclear envelope protein LAP2β in the human osteosarcoma cell line U2OS.

PubMed

Ben-Shoshan, Shirley Oren; Simon, Amos J; Jacob-Hirsch, Jasmine; Shaklai, Sigal; Paz-Yaacov, Nurit; Amariglio, Ninette; Rechavi, Gideon; Trakhtenbrot, Luba

2014-01-28

Polyploidy has been recognized for many years as an important hallmark of cancer cells. Polyploid cells can arise through cell fusion, endoreplication and abortive cell cycle. The inner nuclear membrane protein LAP2β plays key roles in nuclear envelope breakdown and reassembly during mitosis, initiation of replication and transcriptional repression. Here we studied the function of LAP2β in the maintenance of cell ploidy state, a role which has not yet been assigned to this protein. By knocking down the expression of LAP2β, using both viral and non-viral RNAi approaches in osteosarcoma derived U2OS cells, we detected enlarged nuclear size, nearly doubling of DNA content and chromosomal duplications, as analyzed by fluorescent in situ hybridization and spectral karyotyping methodologies. Spectral karyotyping analyses revealed that near-hexaploid karyotypes of LAP2β knocked down cells consisted of not only seven duplicated chromosomal markers, as could be anticipated by genome duplication mechanism, but also of four single chromosomal markers. Furthermore, spectral karyotyping analysis revealed that both of two near-triploid U2OS sub-clones contained the seven markers that were duplicated in LAP2β knocked down cells, whereas the four single chromosomal markers were detected only in one of them. Gene expression profiling of LAP2β knocked down cells revealed that up to a third of the genes exhibiting significant changes in their expression are involved in cancer progression. Our results suggest that nuclear fusion mechanism underlies the polyploidization induction upon LAP2β reduced expression. Our study implies on a novel role of LAP2β in the maintenance of cell ploidy status. LAP2β depleted U2OS cells can serve as a model to investigate polyploidy and aneuploidy formation by nuclear fusion mechanism and its involvement in cancerogenesis.

Space disposal of nuclear wastes. Volume 1: Socio-political aspects

NASA Technical Reports Server (NTRS)

Laporte, T.; Rochlin, G. I.; Metlay, D.; Windham, P.

1976-01-01

The history and interpretation of radioactive waste management in the U.S., criteria for choosing from various options for waste disposal, and the impact of nuclear power growth from 1975 to 2000 are discussed. Preconditions for the existence of high level wastes in a form suitable for space disposal are explored. The role of the NASA space shuttle program in the space disposal of nuclear wastes, and the impact on program management, resources and regulation are examined.

Novel Humoral Prognostic Markers in Small-Cell Lung Carcinoma: A Prospective Study

PubMed Central

Gozzard, Paul; Chapman, Caroline; Vincent, Angela; Lang, Bethan; Maddison, Paul

2015-01-01

Purpose Favourable small cell lung carcinoma (SCLC) survival outcomes have been reported in patients with paraneoplastic neurological disorders (PNDs) associated with neuronal antibodies (Neur-Abs), but the presence of a PND might have expedited diagnosis. Our aim was to establish whether neuronal antibodies, independent of clinical neurological features, correlate with SCLC survival. Experimental Design 262 consecutive SCLC patients were examined: of these, 24 with neurological disease were excluded from this study. The remaining 238 were tested for a broad array of Neur-Abs at the time of cancer diagnosis; survival time was established from follow-up clinical data. Results Median survival of the non-PND cohort (n = 238) was 9.5 months. 103 patients (43%) had one or more antigen-defined Neur-Abs. We found significantly longer median survival in 23 patients (10%) with HuD/anti-neuronal nuclear antibody type 1 (ANNA-1, 13.0 months P = 0.037), but not with any of the other antigen-defined antibodies, including the PND-related SOX2 (n = 56, 24%). An additional 28 patients (12%) had uncharacterised anti-neuronal nuclear antibodies (ANNA-U); their median survival time was longer still (15.0 months, P = 0.0048), contrasting with the survival time in patients with non-neuronal anti-nuclear antibodies (detected using HEp-2 cells, n = 23 (10%), 9.25 months). In multivariate analyses, both ANNA-1 and ANNA-U independently reduced the mortality hazard by a ratio of 0.532 (P = 0.01) and 0.430 (P<0.001) respectively. Conclusions ANNAs, including the newly described ANNA-U, may be key components of the SCLC immunome and have a potential role in predicting SCLC survival; screening for them could add prognostic value that is similar in magnitude to that of limited staging at diagnosis. PMID:26606748

Supersymmetric U(1)Y‧⊗ U(1)B-L extension of the Standard Model

NASA Astrophysics Data System (ADS)

Montero, J. C.; Pleitez, V.; Sánchez-Vega, B. L.; Rodriguez, M. C.

2017-06-01

We build a supersymmetric version with SU(3)C ⊗ SU(2)L ⊗ U(1)Y‧⊗ U(1)B-L gauge symmetry, where Y‧ is a new charge and B and L are the usual baryonic and leptonic numbers. The model has three right-handed neutrinos with identical B - L charges, and can accommodate all fermion masses at the tree level. In particular, the type I seesaw mechanism is implemented for the generation of the active neutrino masses. We obtain the mass spectra of all sectors and for the scalar one we also give the flat directions allowed by the model.

Prediction of U-Mo dispersion nuclear fuels with Al-Si alloy using artificial neural network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Susmikanti, Mike, E-mail: mike@batan.go.id; Sulistyo, Jos, E-mail: soj@batan.go.id

2014-09-30

Dispersion nuclear fuels, consisting of U-Mo particles dispersed in an Al-Si matrix, are being developed as fuel for research reactors. The equilibrium relationship for a mixture component can be expressed in the phase diagram. It is important to analyze whether a mixture component is in equilibrium phase or another phase. The purpose of this research it is needed to built the model of the phase diagram, so the mixture component is in the stable or melting condition. Artificial neural network (ANN) is a modeling tool for processes involving multivariable non-linear relationships. The objective of the present work is to developmore » code based on artificial neural network models of system equilibrium relationship of U-Mo in Al-Si matrix. This model can be used for prediction of type of resulting mixture, and whether the point is on the equilibrium phase or in another phase region. The equilibrium model data for prediction and modeling generated from experimentally data. The artificial neural network with resilient backpropagation method was chosen to predict the dispersion of nuclear fuels U-Mo in Al-Si matrix. This developed code was built with some function in MATLAB. For simulations using ANN, the Levenberg-Marquardt method was also used for optimization. The artificial neural network is able to predict the equilibrium phase or in the phase region. The develop code based on artificial neural network models was built, for analyze equilibrium relationship of U-Mo in Al-Si matrix.« less

Regulation of Small Ubiquitin-Like Modifier-1, Nuclear Receptor Coreceptor, Histone Deacetylase 3, and Peroxisome Proliferator-Activated Receptor-γ in Human Adipose Tissue

PubMed Central

Bodles-Brakhop, Angela M.; Yao-Borengasser, Aiwei; Zhu, Beibei; Starnes, Catherine P.; McGehee, Robert E.; Peterson, Charlotte A.; Kern, Philip A.

2012-01-01

Abstract Background This study investigated the regulation of peroxisome proliferator-activated receptor-γ (PPARγ), the histone deacetylase 3 (HDAC3)–nuclear receptor coreceptor (NCoR) complex (a corepressor of transcription used by PPARγ), and small ubiquitin-like modifier-1 (SUMO-1) (a posttranslational modifier of PPARγ) in human adipose tissue and both adipocyte and macrophage cell lines. The objective was to determine whether there were alterations in the human adipose tissue gene expression levels of PPARγ, HDAC3, NCoR, and SUMO-1 associated either with obesity or with treatment of impaired glucose tolerance (IGT) subjects with insulin-sensitizing medications. Methods We obtained subcutaneous adipose tissue biopsies from 86 subjects with a wide range of body mass index (BMI) and insulin sensitivity (SI). Additionally, adipose tissue biopsies were obtained from a randomized subgroup of IGT subjects before and after 10 weeks of treatment with either pioglitazone or metformin. Results The adipose mRNA levels of PPARγ, NCoR, HDAC3, and SUMO-1 correlated strongly with each other (P<0.0001); however, SUMO-1, NCoR, and HDAC3 gene expression were not significantly associated with BMI or SI. Pioglitazone increased SUMO-1 expression by 23% (P<0.002) in adipose tissue and an adipocyte cell line (P<0.05), but not in macrophages. Small interfering RNA (siRNA)-mediated knockdown of SUMO-1 decreased PPARγ, HDAC3, and NCoR in THP-1 cells and increased tumor necrosis factor-α (TNF-α) induction in response to lipopolysaccharide (LPS). Conclusions These results suggest that the coordinate regulation of SUMO-1, PPARγ1/2, HDAC3, and NCoR may be more tightly controlled in macrophages than in adipocytes in human adipose and that these modulators of PPARγ activity may be particularly important in the negative regulation of macrophage-mediated adipose inflammation by pioglitazone. PMID:22651256

Modelling the thermal conductivity of (U xTh 1-x)O 2 and (U xPu 1-x)O 2

DOE PAGES

Cooper, M. W. D.; Middleburgh, S. C.; Grimes, R. W.

2015-07-15

The degradation of thermal conductivity due to the non-uniform cation lattice of (U xTh 1-x)O 2 and (U xPu 1-x)O 2 solid solutions has been investigated by molecular dynamics, using the non-equilibrium method, from 300 to 2000 K. Degradation of thermal conductivity is predicted in (U xTh 1-x)O 2 and (U xPu 1-x)O 2 as compositions deviate from the pure end members: UO 2, PuO 2 and ThO 2. The reduction in thermal conductivity is most apparent at low temperatures where phonon-defect scattering dominates over phonon-phonon interactions. The effect is greater for (U xTh 1-x)O 2 than U xPu 1-x)Omore » 2 due to the greater mismatch in cation size. Parameters for an analytical expressions have been developed that describe the predicted thermal conductivities over the full temperature and compositional ranges. Finally, these expressions may be used in higher level fuel performance codes.« less

78 FR 66950 - Trade Barriers That U.S. Small and Medium-Sized Enterprises Perceive as Affecting Exports to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-07

... INTERNATIONAL TRADE COMMISSION [Investigation No. 332-541] Trade Barriers That U.S. Small and.... ADDRESSES: All written submissions should be addressed to the Secretary, United States International Trade... held at the U.S. International Trade Commission Building, 500 E Street SW., Washington, DC, beginning...

Rationally designed small molecules targeting the RNA that causes myotonic dystrophy type 1 are potently bioactive.

PubMed

Childs-Disney, Jessica L; Hoskins, Jason; Rzuczek, Suzanne G; Thornton, Charles A; Disney, Matthew D

2012-05-18

RNA is an important drug target, but it is difficult to design or discover small molecules that modulate RNA function. In the present study, we report that rationally designed, modularly assembled small molecules that bind the RNA that causes myotonic dystrophy type 1 (DM1) are potently bioactive in cell culture models. DM1 is caused when an expansion of r(CUG) repeats, or r(CUG)(exp), is present in the 3' untranslated region (UTR) of the dystrophia myotonica protein kinase (DMPK) mRNA. r(CUG)(exp) folds into a hairpin with regularly repeating 5'CUG/3'GUC motifs and sequesters muscleblind-like 1 protein (MBNL1). A variety of defects are associated with DM1, including (i) formation of nuclear foci, (ii) decreased translation of DMPK mRNA due to its nuclear retention, and (iii) pre-mRNA splicing defects due to inactivation of MBNL1, which controls the alternative splicing of various pre-mRNAs. Previously, modularly assembled ligands targeting r(CUG)(exp) were designed using information in an RNA motif-ligand database. These studies showed that a bis-benzimidazole (H) binds the 5'CUG/3'GUC motif in r(CUG)(exp.) Therefore, we designed multivalent ligands to bind simultaneously multiple copies of this motif in r(CUG)(exp). Herein, we report that the designed compounds improve DM1-associated defects including improvement of translational and pre-mRNA splicing defects and the disruption of nuclear foci. These studies may establish a foundation to exploit other RNA targets in genomic sequence.

U.S. and Russian Collaboration in the Area of Nuclear Forensics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kristo, M J

2007-10-22

Nuclear forensics has become increasingly important in the fight against illicit trafficking in nuclear and other radioactive materials. The illicit trafficking of nuclear materials is, of course, an international problem; nuclear materials may be mined and milled in one country, manufactured in a second country, diverted at a third location, and detected at a fourth. There have been a number of articles in public policy journals in the past year that call for greater interaction between the U. S. and the rest of the world on the topic of nuclear forensics. Some believe that such international cooperation would help providemore » a more certain capability to identify the source of the nuclear material used in a terrorist event. An improved international nuclear forensics capability would also be important as part of the IAEA verification toolkit, particularly linked to increased access provided by the additional protocol. A recent study has found that, although international progress has been made in securing weapons-usable HEU and Pu, the effort is still insufficient. They found that nuclear material, located in 40 countries, could be obtained by terrorists and criminals and used for a crude nuclear weapon. Through 2006, the IAEA Illicit Trafficking Database had recorded a total of 607 confirmed events involving illegal possession, theft, or loss of nuclear and other radioactive materials. Although it is difficult to predict the future course of such illicit trafficking, increasingly such activities are viewed as significant threats that merit the development of special capabilities. As early as April, 1996, nuclear forensics was recognized at the G-8 Summit in Moscow as an important element of an illicit nuclear trafficking program. Given international events over the past several years, the value and need for nuclear forensics seems greater than ever. Determining how and where legitimate control of nuclear material was lost and tracing the route of the

Metric Issues for Small Business.

DTIC Science & Technology

1981-08-01

time, it seems that small business is meeting the problens (f ()ijutarv, metric conversion within its own resources ( manager ",a1, t, ,’bral, an...AD-AI07 861 UNITED STATES METRIC BOARD ARLINGTON VA FIG 5/3 METRIC ISSUES FOR SMALL BUSINESS . (U) UNCASIF AUG a I EHEHEi-17i i/ll/l///i//,° i MENNEN...METRIC ISSUES FOR SMALL BUSINESS EXECUTIVE SUMMARY DTIC ifELECT A This o@~ant )u enapo.I fW pu~~w Z. Ias ,!W% si~ts La-i UNITED STATES METRIC BOARD

33 CFR 334.630 - Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base... Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base...

33 CFR 334.630 - Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base... Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base...

33 CFR 334.630 - Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base... Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base...

33 CFR 334.630 - Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base... Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base...

Optimization of small long-life PWR based on thorium fuel

NASA Astrophysics Data System (ADS)

Subkhi, Moh Nurul; Suud, Zaki; Waris, Abdul; Permana, Sidik

2015-09-01

A conceptual design of small long-life Pressurized Water Reactor (PWR) using thorium fuel has been investigated in neutronic aspect. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.2, while the multi-energy-group diffusion calculations were optimized in three-dimension X-Y-Z geometry of core by COREBN. The excess reactivity of thorium nitride with ZIRLO cladding is considered during 5 years of burnup without refueling. Optimization of 350 MWe long life PWR based on 5% 233U & 2.8% 231Pa, 6% 233U & 2.8% 231Pa and 7% 233U & 6% 231Pa give low excess reactivity.

Mild hydrothermal crystal growth of new uranium(IV) fluorides, Na3.13Mg1.43U6F30 and Na2.50Mn1.75U6F30: Structures, optical and magnetic properties

NASA Astrophysics Data System (ADS)

Yeon, Jeongho; Smith, Mark D.; Tapp, Joshua; Möller, Angela; zur Loye, Hans-Conrad

2016-04-01

Two new uranium(IV) fluorides, Na3.13Mg1.43U6F30 (1) and Na2.50Mn1.75U6F30 (2), were synthesized through an in situ mild hydrothermal route, and were structurally characterized by single crystal X-ray diffraction. The compounds exhibit complex crystal structures composed of corner- or edge-shared UF9 and MF6 (M=Mg, Mn) polyhedra, forming hexagonal channels in the three-dimensional framework, in which ordered or disordered divalent metal and sodium atoms reside. The large hexagonal voids contain the nearly regular M(II)F6 octahedra and sodium ions, whereas the small hexagonal cavities include M(II) and sodium ions on a mixed-occupied site. Magnetic susceptibility measurements yielded effective magnetic moments of 8.36 and 11.6 μB for 1 and 2, respectively, confirming the presence and oxidation states of U(IV) and Mn(II). The large negative Weiss constants indicate the spin gap between a triplet and a singlet state in the U(IV). Magnetization data as a function of applied fields revealed that 2 exhibits paramagnetic behavior due to the nonmagnetic singlet ground state of U(IV) at low temperature. UV-vis diffuse reflectance and X-ray photoelectron spectroscopy data were also analyzed.

Symmetry enriched U(1) quantum spin liquids

NASA Astrophysics Data System (ADS)

Zou, Liujun; Wang, Chong; Senthil, T.

2018-05-01

We classify and characterize three-dimensional U (1 ) quantum spin liquids [deconfined U (1 ) gauge theories] with global symmetries. These spin liquids have an emergent gapless photon and emergent electric/magnetic excitations (which we assume are gapped). We first discuss in great detail the case with time-reversal and SO(3 ) spin rotational symmetries. We find there are 15 distinct such quantum spin liquids based on the properties of bulk excitations. We show how to interpret them as gauged symmetry-protected topological states (SPTs). Some of these states possess fractional response to an external SO (3 ) gauge field, due to which we dub them "fractional topological paramagnets." We identify 11 other anomalous states that can be grouped into three anomaly classes. The classification is further refined by weakly coupling these quantum spin liquids to bosonic symmetry protected topological (SPT) phases with the same symmetry. This refinement does not modify the bulk excitation structure but modifies universal surface properties. Taking this refinement into account, we find there are 168 distinct such U (1 ) quantum spin liquids. After this warm-up, we provide a general framework to classify symmetry enriched U (1 ) quantum spin liquids for a large class of symmetries. As a more complex example, we discuss U (1 ) quantum spin liquids with time-reversal and Z2 symmetries in detail. Based on the properties of the bulk excitations, we find there are 38 distinct such spin liquids that are anomaly-free. There are also 37 anomalous U (1 ) quantum spin liquids with this symmetry. Finally, we briefly discuss the classification of U (1 ) quantum spin liquids enriched by some other symmetries.

Annealing tests of in-pile irradiated oxide coated U-Mo/Al-Si dispersed nuclear fuel

NASA Astrophysics Data System (ADS)

Zweifel, T.; Valot, Ch.; Pontillon, Y.; Lamontagne, J.; Vermersch, A.; Barrallier, L.; Blay, T.; Petry, W.; Palancher, H.

2014-09-01

U-Mo/Al based nuclear fuels have been worldwide considered as a promising high density fuel for the conversion of high flux research reactors from highly enriched uranium to lower enrichment. In this paper, we present the annealing test up to 1800 °C of in-pile irradiated U-Mo/Al-Si fuel plate samples. More than 70% of the fission gases (FGs) are released during two major FG release peaks around 500 °C and 670 °C. Additional characterisations of the samples by XRD, EPMA and SEM suggest that up to 500 °C FGs are released from IDL/matrix interfaces. The second peak at 670 °C representing the main release of FGs originates from the interaction between U-Mo and matrix in the vicinity of the cladding.

Role of the nuclear migration protein Lis1 in cell morphogenesis in Ustilago maydis

PubMed Central

Valinluck, Michael; Ahlgren, Sara; Sawada, Mizuho; Locken, Kristopher; Banuett, Flora

2010-01-01

Ustilago maydis is a basidiomycete fungus that exhibits a yeast-like and a filamentous form. Growth of the fungus in the host leads to additional morphological transitions. The different morphologies are characterized by distinct nuclear movements. Dynein and α-tubulin are required for nuclear movements and for cell morphogenesis of the yeast-like form. Lis1 is a microtubule plus-end tracking protein (+TIPs) conserved in eukaryotes and required for nuclear migration and spindle positioning. Defects in nuclear migration result in altered cell fate and aberrant development in metazoans, slow growth in fungi and disease in humans (e.g. lissencephaly). Here we investigate the role of the human LIS1 homolog in U. maydis and demonstrate that it is essential for cell viability, not previously seen in other fungi. With a conditional null mutation we show that lis1 is necessary for nuclear migration in the yeast-like cell and during the dimorphic transition. Studies of asynchronous exponentially growing cells and time-lapse microscopy uncovered novel functions of lis1: It is necessary for cell morphogenesis, positioning of the septum and cell wall integrity. lis1-depleted cells exhibit altered axes of growth and loss of cell polarity leading to grossly aberrant cells with clusters of nuclei and morphologically altered buds devoid of nuclei. Altered septum positioning and cell wall deposition contribute to the aberrant morphology. lis1-depleted cells lyse, indicative of altered cell wall properties or composition. We also demonstrate, with indirect immunofluorescence to visualize tubulin, that lis1 is necessary for the normal organization of the microtubule cytoskeleton: lis1-depleted cells contain more and longer microtubules that can form coils perpendicular to the long axis of the cell. We propose that lis1 controls microtubule dynamics and thus the regulated delivery of vesicles to growth sites and other cell domains that govern nuclear movements. PMID:20524583

Deterring War or Courting Disaster: An Analysis of Nuclear Weapons in the Indian Ocean

DTIC Science & Technology

2015-03-01

16 II. DETERRING WAR BETWEEN THE U.S. AND U.S.S.R. ...................................17 A. DETERRENCE THEORY AND THE...thesis will show, the literature and theory developed around the Cold War does not accommodate the relatively small size and relative inexperience of...and theory regarding sea-based nuclear weapons. Close examination of the Indian Ocean rivalries and the assumptions underpinning the belief in

Nuclear threats from small states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahan, J.H.

1994-06-13

What are the policy implications regarding proliferation and counter proliferation of nuclear weapons among Third World states. How does deterrence operate outside the parameters of superpower confrontation as defined by the cold war elaborate system of constraints enforced by concepts like mutual assured destruction, and counter-value and counter-force targeting. How can US policymakers devise contingencies for dealing with nuclear threats posed by countries like North Korea, Libya, Iraq, Iran, and Syria. These are some of the unsettling but nevertheless important questions addressed by the author in this monograph. In his analysis, Mr. Jerome Kahan examines the likelihood that one ormore » more of these countries will use nuclear weapons before the year 2000. He also offers a framework that policymakers and planners might use in assessing US interests in preempting the use of nuclear weapons or in retaliating for their use. Ironically, with the end of the cold war, it is imperative that defense strategists, policymakers, and military professionals think about the `unthinkable`. In the interest of fostering debate on this important subject, the Strategic Studies Institute commends this insightful monograph.« less

The Storage, Transportation, and Disposal of Nuclear Waste

NASA Astrophysics Data System (ADS)

Younker, J. L.

2002-12-01

The U.S. Congress established a comprehensive federal policy to dispose of wastes from nuclear reactors and defense facilities, centered on deep geologic disposal of high-level radioactive waste. Site screening led to selection of three potential sites and in 1987, Congress directed the Secretary of Energy to characterize only one site: Yucca Mountain in Nevada. For more than 20 years, teams of scientists and engineers have been evaluating the potential suitability of the site. On the basis of their work, the U.S. Secretary of Energy, Spencer Abraham, concluded in February 2002 that a safe repository can be sited at Yucca Mountain. On July 23, 2002, President Bush signed Joint Resolution 87 approving the site at Yucca Mountain for development of a repository, which allows the U.S. Department of Energy (DOE) to prepare and submit a license application to the U.S. Nuclear Regulatory Commission (NRC). Concerns have been raised relative to the safe transportation of nuclear materials. The U.S. history of transportation of nuclear materials demonstrates that high-level nuclear materials can be safely transported. Since the 1960s, over 1.6 million miles have been traveled by more than 2,700 spent nuclear fuel shipments, and there has never been an accident severe enough to cause a release of radioactive materials. The DOE will use NRC-certified casks that must be able to withstand very stringent tests. The same design features that allow the casks to survive severe accidents also limit their vulnerability to sabotage. In addition, the NRC will approve all shipping routes and security plans. With regard to long-term safety, the Yucca Mountain disposal system has five key attributes. First, the arid climate and geology of Yucca Mountain combine to ensure that limited water will enter the emplacement tunnels. Second, the DOE has designed a waste package and drip shield that are expected to have very long lifetimes in the repository environment. Third, waste form

Fanconi anemia FANCD2 and FANCI proteins regulate the nuclear dynamics of splicing factors.

PubMed

Moriel-Carretero, María; Ovejero, Sara; Gérus-Durand, Marie; Vryzas, Dimos; Constantinou, Angelos

2017-12-04

Proteins disabled in the cancer-prone disorder Fanconi anemia (FA) ensure the maintenance of chromosomal stability during DNA replication. FA proteins regulate replication dynamics, coordinate replication-coupled repair of interstrand DNA cross-links, and mitigate conflicts between replication and transcription. Here we show that FANCI and FANCD2 associate with splicing factor 3B1 (SF3B1), a key spliceosomal protein of the U2 small nuclear ribonucleoprotein (U2 snRNP). FANCI is in close proximity to SF3B1 in the nucleoplasm of interphase and mitotic cells. Furthermore, we find that DNA replication stress induces the release of SF3B1 from nuclear speckles in a manner that depends on FANCI and on the activity of the checkpoint kinase ATR. In chromatin, both FANCD2 and FANCI associate with SF3B1, prevent accumulation of postcatalytic intron lariats, and contribute to the timely eviction of splicing factors. We propose that FANCD2 and FANCI contribute to the organization of functional domains in chromatin, ensuring the coordination of DNA replication and cotranscriptional processes. © 2017 Moriel-Carretero et al.

Nuclear criticality safety calculational analysis for small-diameter containers

DOE Office of Scientific and Technical Information (OSTI.GOV)

LeTellier, M.S.; Smallwood, D.J.; Henkel, J.A.

This report documents calculations performed to establish a technical basis for the nuclear criticality safety of favorable geometry containers, sometimes referred to as 5-inch containers, in use at the Portsmouth Gaseous Diffusion Plant. A list of containers currently used in the plant is shown in Table 1.0-1. These containers are currently used throughout the plant with no mass limits. The use of containers with geometries or material types other than those addressed in this evaluation must be bounded by this analysis or have an additional analysis performed. The following five basic container geometries were modeled and bound all container geometriesmore » in Table 1.0-1: (1) 4.32-inch-diameter by 50-inch-high polyethylene bottle; (2) 5.0-inch-diameter by 24-inch-high polyethylene bottle; (3) 5.25-inch-diameter by 24-inch-high steel can ({open_quotes}F-can{close_quotes}); (4) 5.25-inch-diameter by 15-inch-high steel can ({open_quotes}Z-can{close_quotes}); and (5) 5.0-inch-diameter by 9-inch-high polybottle ({open_quotes}CO-4{close_quotes}). Each container type is evaluated using five basic reflection and interaction models that include single containers and multiple containers in normal and in credible abnormal conditions. The uranium materials evaluated are UO{sub 2}F{sub 2}+H{sub 2}O and UF{sub 4}+oil materials at 100% and 10% enrichments and U{sub 3}O{sub 8}, and H{sub 2}O at 100% enrichment. The design basis safe criticality limit for the Portsmouth facility is k{sub eff} + 2{sigma} < 0.95. The KENO study results may be used as the basis for evaluating general use of these containers in the plant.« less

FIMP and muon ( g - 2) in a U(1) Lμ- Lτ model

NASA Astrophysics Data System (ADS)

Biswas, Anirban; Choubey, Sandhya; Khan, Sarif

2017-02-01

The tightening of the constraints on the standard thermal WIMP scenario has forced physicists to propose alternative dark matter (DM) models. One of the most popular alternate explanations of the origin of DM is the non-thermal production of DM via freeze-in. In this scenario the DM never attains thermal equilibrium with the thermal soup because of its feeble coupling strength (˜10-12) with the other particles in the thermal bath and is generally called the Feebly Interacting Massive Particle (FIMP). In this work, we present a gauged U(1) Lμ- Lτ extension of the Standard Model (SM) which has a scalar FIMP DM candidate and can consistently explain the DM relic density bound. In addition, the spontaneous breaking of the U(1) Lμ- Lτ gauge symmetry gives an extra massive neutral gauge boson Z μτ which can explain the muon ( g - 2) data through its additional one-loop contribution to the process. Lastly, presence of three right-handed neutrinos enable the model to successfully explain the small neutrino masses via the Type-I seesaw mechanism. The presence of the spontaneously broken U(1) Lμ- Lτ gives a particular structure to the light neutrino mass matrix which can explain the peculiar mixing pattern of the light neutrinos.

Can Sisyphus succeed? Getting U.S. high-level nuclear waste into a geological repository.

PubMed

North, D Warner

2013-01-01

The U.S. government has the obligation of managing the high-level radioactive waste from its defense activities and also, under existing law, from civilian nuclear power generation. This obligation is not being met. The January 2012 Final Report from the Blue Ribbon Commission on America's Nuclear Future provides commendable guidance but little that is new. The author, who served on the federal Nuclear Waste Technical Review Board from 1989 to 1994 and subsequently on the Board on Radioactive Waste Management of the National Research Council from 1994 to 1999, provides a perspective both on the Commission's recommendations and a potential path toward progress in meeting the federal obligation. By analogy to Sisyphus of Greek mythology, our nation needs to find a way to roll the rock to the top of the hill and have it stay there, rather than continuing to roll back down again. © 2012 Society for Risk Analysis.

Successful Recovery of Nuclear Protein-Coding Genes from Small Insects in Museums Using Illumina Sequencing.

PubMed

Kanda, Kojun; Pflug, James M; Sproul, John S; Dasenko, Mark A; Maddison, David R

2015-01-01

In this paper we explore high-throughput Illumina sequencing of nuclear protein-coding, ribosomal, and mitochondrial genes in small, dried insects stored in natural history collections. We sequenced one tenebrionid beetle and 12 carabid beetles ranging in size from 3.7 to 9.7 mm in length that have been stored in various museums for 4 to 84 years. Although we chose a number of old, small specimens for which we expected low sequence recovery, we successfully recovered at least some low-copy nuclear protein-coding genes from all specimens. For example, in one 56-year-old beetle, 4.4 mm in length, our de novo assembly recovered about 63% of approximately 41,900 nucleotides in a target suite of 67 nuclear protein-coding gene fragments, and 70% using a reference-based assembly. Even in the least successfully sequenced carabid specimen, reference-based assembly yielded fragments that were at least 50% of the target length for 34 of 67 nuclear protein-coding gene fragments. Exploration of alternative references for reference-based assembly revealed few signs of bias created by the reference. For all specimens we recovered almost complete copies of ribosomal and mitochondrial genes. We verified the general accuracy of the sequences through comparisons with sequences obtained from PCR and Sanger sequencing, including of conspecific, fresh specimens, and through phylogenetic analysis that tested the placement of sequences in predicted regions. A few possible inaccuracies in the sequences were detected, but these rarely affected the phylogenetic placement of the samples. Although our sample sizes are low, an exploratory regression study suggests that the dominant factor in predicting success at recovering nuclear protein-coding genes is a high number of Illumina reads, with success at PCR of COI and killing by immersion in ethanol being secondary factors; in analyses of only high-read samples, the primary significant explanatory variable was body length, with small beetles

Successful Recovery of Nuclear Protein-Coding Genes from Small Insects in Museums Using Illumina Sequencing

PubMed Central

Dasenko, Mark A.

2015-01-01

In this paper we explore high-throughput Illumina sequencing of nuclear protein-coding, ribosomal, and mitochondrial genes in small, dried insects stored in natural history collections. We sequenced one tenebrionid beetle and 12 carabid beetles ranging in size from 3.7 to 9.7 mm in length that have been stored in various museums for 4 to 84 years. Although we chose a number of old, small specimens for which we expected low sequence recovery, we successfully recovered at least some low-copy nuclear protein-coding genes from all specimens. For example, in one 56-year-old beetle, 4.4 mm in length, our de novo assembly recovered about 63% of approximately 41,900 nucleotides in a target suite of 67 nuclear protein-coding gene fragments, and 70% using a reference-based assembly. Even in the least successfully sequenced carabid specimen, reference-based assembly yielded fragments that were at least 50% of the target length for 34 of 67 nuclear protein-coding gene fragments. Exploration of alternative references for reference-based assembly revealed few signs of bias created by the reference. For all specimens we recovered almost complete copies of ribosomal and mitochondrial genes. We verified the general accuracy of the sequences through comparisons with sequences obtained from PCR and Sanger sequencing, including of conspecific, fresh specimens, and through phylogenetic analysis that tested the placement of sequences in predicted regions. A few possible inaccuracies in the sequences were detected, but these rarely affected the phylogenetic placement of the samples. Although our sample sizes are low, an exploratory regression study suggests that the dominant factor in predicting success at recovering nuclear protein-coding genes is a high number of Illumina reads, with success at PCR of COI and killing by immersion in ethanol being secondary factors; in analyses of only high-read samples, the primary significant explanatory variable was body length, with small beetles

RanGTPase regulates the interaction between the inner nuclear membrane proteins, Samp1 and Emerin.

PubMed

Vijayaraghavan, Balaje; Figueroa, Ricardo A; Bergqvist, Cecilia; Gupta, Amit J; Sousa, Paulo; Hallberg, Einar

2018-06-01

Samp1, spindle associated membrane protein 1, is a type II integral membrane protein localized in the inner nuclear membrane. Recent studies have shown that the inner nuclear membrane protein, Emerin and the small monomeric GTPase, Ran are direct binding partners of Samp1. Here we addressed the question whether Ran could regulate the interaction between Samp1 and Emerin in the inner nuclear membrane. To investigate the interaction between Samp1 and Emerin in live cells, we performed FRAP experiments in cells overexpressing YFP-Emerin. We compared the mobility of YFP-Emerin in Samp1 knock out cells and cells overexpressing Samp1. The results showed that the mobility of YFP-Emerin was higher in Samp1 knock out cells and lower in cells overexpressing Samp1, suggesting that Samp1 significantly attenuates the mobility of Emerin in the nuclear envelope. FRAP experiments using tsBN2 cells showed that the mobility of Emerin depends on RanGTP. Consistently, in vitro binding experiments showed that the affinity between Samp1 and Emerin is decreased in the presence of Ran, suggesting that Ran attenuates the interaction between Samp1 and Emerin. This is the first demonstration that Ran can regulate the interaction between two proteins in the nuclear envelope. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Space Nuclear Facility test capability at the Baikal-1 and IGR sites Semipalatinsk-21, Kazakhstan

NASA Astrophysics Data System (ADS)

Hill, T. J.; Stanley, M. L.; Martinell, J. S.

1993-01-01

The International Space Technology Assessment Program was established 1/19/92 to take advantage of the availability of Russian space technology and hardware. DOE had two delegations visit CIS and assess its space nuclear power and propulsion technologies. The visit coincided with the Conference on Nuclear Power Engineering in Space Nuclear Rocket Engines at Semipalatinsk-21 (Kurchatov, Kazakhstan) on Sept. 22-25, 1992. Reactor facilities assessed in Semipalatinski-21 included the IVG-1 reactor (a nuclear furnace, which has been modified and now called IVG-1M), the RA reactor, and the Impulse Graphite Reactor (IGR), the CIS version of TREAT. Although the reactor facilities are being maintained satisfactorily, the support infrastructure appears to be degrading. The group assessment is based on two half-day tours of the Baikals-1 test facility and a brief (2 hr) tour of IGR; because of limited time and the large size of the tour group, it was impossible to obtain answers to all prepared questions. Potential benefit is that CIS fuels and facilities may permit USA to conduct a lower priced space nuclear propulsion program while achieving higher performance capability faster, and immediate access to test facilities that cannot be available in this country for 5 years. Information needs to be obtained about available data acquisition capability, accuracy, frequency response, and number of channels. Potential areas of interest with broad application in the U.S. nuclear industry are listed.

The Threats to Survival in a Nuclear Environment.

DTIC Science & Technology

1987-05-01

second threat to survival in a nuclear attack is the blast or shock wave. Deen and Browning, in How to Survive a Nuclear Disaster , state, "It has been... Nuclear Disaster . Piscataway, NJ: A Grayson-Russell Book, New Century P’u-S1Tshers, 198t. 1S. Martin, Thomas 1., Jr. and Latham, Ronald C. Strategqy

Recruitment of phosphorylated small heat shock protein Hsp27 to nuclear speckles without stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryantsev, A.L.; Chechenova, M.B.; Shelden, E.A.

During stress, the mammalian small heat shock protein Hsp27 enters cell nuclei. The present study examines the requirements for entry of Hsp27 into nuclei of normal rat kidney (NRK) renal epithelial cells, and for its interactions with specific nuclear structures. We find that phosphorylation of Hsp27 is necessary for the efficient entry into nuclei during heat shock but not sufficient for efficient nuclear entry under control conditions. We further report that Hsp27 is recruited to an RNAse sensitive fraction of SC35 positive nuclear speckles, but not other intranuclear structures, in response to heat shock. Intriguingly, Hsp27 phosphorylation, in the absencemore » of stress, is sufficient for recruitment to speckles found in post-anaphase stage mitotic cells. Additionally, pseudophosphorylated Hsp27 fused to a nuclear localization peptide (NLS) is recruited to nuclear speckles in unstressed interphase cells, but wildtype and nonphosphorylatable Hsp27 NLS fusion proteins are not. The expression of NLS-Hsp27 mutants does not enhance colony forming abilities of cells subjected to severe heat shock, but does regulate nuclear speckle morphology. These data demonstrate that phosphorylation, but not stress, mediates Hsp27 recruitment to an RNAse soluble fraction of nuclear speckles and support a site-specific role for Hsp27 within the nucleus.« less

Structural basis for the regulation of nuclear import of Epstein-Barr virus nuclear antigen 1 (EBNA1) by phosphorylation of the nuclear localization signal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakada, Ryohei; Hirano, Hidemi; Structural Biology Research Center, Graduate School of Science, Nagoya University

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is expressed in every EBV-positive tumor and is essential for the maintenance, replication, and transcription of the EBV genome in the nucleus of host cells. EBNA1 is a serine phosphoprotein, and it has been shown that phosphorylation of S385 in the nuclear localization signal (NLS) of EBNA1 increases the binding affinity to the nuclear import adaptor importin-α1 as well as importin-α5, and stimulates nuclear import of EBNA1. To gain insights into how phosphorylation of the EBNA1 NLS regulates nuclear import, we have determined the crystal structures of two peptide complexes of importin-α1: onemore » with S385-phosphorylated EBNA1 NLS peptide, determined at 2.0 Å resolution, and one with non-phosphorylated EBNA1 NLS peptide, determined at 2.2 Å resolution. The structures show that EBNA1 NLS binds to the major and minor NLS-binding sites of importin-α1, and indicate that the binding affinity of the EBNA1 NLS to the minor NLS-binding site could be enhanced by phosphorylation of S385 through electrostatic interaction between the phosphate group of phospho-S385 and K392 of importin-α1 (corresponding to R395 of importin-α5) on armadillo repeat 8. - Highlights: • Nuclear import of EBNA1 can be regulated by phosphorylation of NLS. • Crystal structures of importin-α1 bound to the NLS peptides of EBNA1 are solved. • Structures provide insights into how phosphorylation can regulate nuclear import.« less

Selective inhibitors of nuclear export show that CRM1/XPO1 is a target in chronic lymphocytic leukemia

PubMed Central

Lapalombella, Rosa; Sun, Qingxiang; Williams, Katie; Tangeman, Larissa; Jha, Shruti; Zhong, Yiming; Goettl, Virginia; Mahoney, Emilia; Berglund, Caroline; Gupta, Sneha; Farmer, Alicia; Mani, Rajeswaran; Johnson, Amy J.; Lucas, David; Mo, Xiaokui; Daelemans, Dirk; Sandanayaka, Vincent; Shechter, Sharon; McCauley, Dilara; Shacham, Sharon; Kauffman, Michael

2012-01-01

The nuclear export protein XPO1 is overexpressed in cancer, leading to the cytoplasmic mislocalization of multiple tumor suppressor proteins. Existing XPO1-targeting agents lack selectivity and have been associated with significant toxicity. Small molecule selective inhibitors of nuclear export (SINEs) were designed that specifically inhibit XPO1. Genetic experiments and X-ray structures demonstrate that SINE covalently bind to a cysteine residue in the cargo-binding groove of XPO1, thereby inhibiting nuclear export of cargo proteins. The clinical relevance of SINEs was explored in chronic lymphocytic leukemia (CLL), a disease associated with recurrent XPO1 mutations. Evidence is presented that SINEs can restore normal regulation to the majority of the dysregulated pathways in CLL both in vitro and in vivo and induce apoptosis of CLL cells with a favorable therapeutic index, with enhanced killing of genomically high-risk CLL cells that are typically unresponsive to traditional therapies. More importantly, SINE slows disease progression, and improves overall survival in the Eμ-TCL1-SCID mouse model of CLL with minimal weight loss or other toxicities. Together, these findings demonstrate that XPO1 is a valid target in CLL with minimal effects on normal cells and provide a basis for the development of SINEs in CLL and related hematologic malignancies. PMID:23034282

General U(1)×U(1) F-theory compactifications and beyond: geometry of unHiggsings and novel matter structure

DOE PAGES

Cvetic, Mirjam; Klevers, Denis; Piragua, Hernan; ...

2015-11-30

We construct the general form of an F-theory compactification with two U(1) factors based on a general elliptically fibered Calabi-Yau manifold with Mordell-Weil group of rank two. This construction produces broad classes of models with diverse matter spectra, including many that are not realized in earlier F-theory constructions with U(1)×U(1) gauge symmetry. Generic U(1)×U(1) models can be related to a Higgsed non-Abelian model with gauge group SU(2)×SU(2)×SU(3), SU(2) 3×SU(3), or a subgroup thereof. The nonlocal horizontal divisors of the Mordell-Weil group are replaced with local vertical divisors associated with the Cartan generators of non-Abelian gauge groups from Kodaira singularities. Wemore » give a global resolution of codimension two singularities of the Abelian model; we identify the full anomaly free matter content, and match it to the unHiggsed non-Abelian model. The non-Abelian Weierstrass model exhibits a new algebraic description of the singularities in the fibration that results in the first explicit construction of matter in the symmetric representation of SU(3). This matter is realized on double point singularities of the discriminant locus. In conclusion, the construction suggests a generalization to U(1) k factors with k > 2, which can be studied by Higgsing theories with larger non-Abelian gauge groups.« less

The ``Nuclear Renaissance'' and the Spread of Nuclear Weapons

NASA Astrophysics Data System (ADS)

Lyman, Edwin S.

2007-05-01

As interest grows around the world in nuclear power as an energy source that could help control greenhouse gas emissions, some have proclaimed the arrival of a ``nuclear renaissance.'' But can the increased risks of more nuclear power be managed? The political crisis surrounding Iran's pursuit of uranium enrichment has exposed weaknesses in the nuclear nonproliferation regime. Also, al Qaeda's declared interest in weapons of mass destruction raises the concern that terrorists could acquire nuclear weapons by stealing materials from poorly secured facilities. Growth of nuclear energy would require the construction of many additional uranium enrichment plants. And the generation of more spent nuclear fuel without a credible waste disposal strategy would increase political support for reprocessing, which separates large quantities of weapon-usable plutonium from spent fuel. There is little evidence that the various institutional arrangements and technical schemes proposed to mitigate the security risks of a major nuclear expansion would be effective. This talk will focus on the measures necessary to allow large-scale global growth of nuclear power without resulting in an unacceptably high risk of nuclear proliferation and nuclear terrorism, and will discuss the feasibility of such measures. <small>To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.OSS07.E1.2small>

33 CFR 334.630 - Tampa Bay south of MacDill Air Force Base, Fla.; small-arms firing range and aircraft jettison, U...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base... Force Base, Fla.; small-arms firing range and aircraft jettison, U.S. Air Force, MacDill Air Force Base...″, longitude 82°33′02.44″; and thence to a point on the shore line of MacDill Air Force Base at latitude 27°50...

Spent Nuclear Fuel

EIA Publications

2015-01-01

Spent nuclear fuel data are collected by the U.S. Energy Information Administration (EIA) for the Department of Energy's Office of Standard Contract Management (Office of the General Counsel) on the Form GC-859, "Nuclear Fuel Data Survey." The data include detailed characteristics of spent nuclear fuel discharged from commercial U.S. nuclear power plants and currently stored at commercial sites in the United States. Utilities were not required to report spent nuclear fuel assemblies shipped to away-from-reactor, off-site facilities.

Components of the CCR4-NOT complex function as nuclear hormone receptor coactivators via association with the NRC-interacting Factor NIF-1.

PubMed

Garapaty, Shivani; Mahajan, Muktar A; Samuels, Herbert H

2008-03-14

CCR4-NOT is an evolutionarily conserved, multicomponent complex known to be involved in transcription as well as mRNA degradation. Various subunits (e.g. CNOT1 and CNOT7/CAF1) have been reported to be involved in influencing nuclear hormone receptor activities. Here, we show that CCR4/CNOT6 and RCD1/CNOT9, members of the CCR4-NOT complex, potentiate nuclear receptor activity. RCD1 interacts in vivo and in vitro with NIF-1 (NRC-interacting factor), a previously characterized nuclear receptor cotransducer that activates nuclear receptors via its interaction with NRC. As with NIF-1, RCD1 and CCR4 do not directly associate with nuclear receptors; however, they enhance ligand-dependent transcriptional activation by nuclear hormone receptors. CCR4 mediates its effect through the ligand binding domain of nuclear receptors and small interference RNA-mediated silencing of endogenous CCR4 results in a marked decrease in nuclear receptor activation. Furthermore, knockdown of CCR4 results in an attenuated stimulation of RARalpha target genes (e.g. Sox9 and HoxA1) as shown by quantitative PCR assays. The silencing of endogenous NIF-1 also resulted in a comparable decrease in the RAR-mediated induction of both Sox9 and HoxA1. Furthermore, CCR4 associates in vivo with NIF-1. In addition, the CCR4-enhanced transcriptional activation by nuclear receptors is dependent on NIF-1. The small interference RNA-mediated knockdown of NIF-1 blocks the ligand-dependent potentiating effect of CCR4. Our results suggest that CCR4 plays a role in the regulation of certain endogenous RARalpha target genes and that RCD1 and CCR4 might mediate their function through their interaction with NIF-1.

Spin Tests of 1/20-Scale Models of the Chance Vought Revised XF6U-1 and F6U-1 Airplanes, TED No. NACA 2390

NASA Technical Reports Server (NTRS)

Klinar, Walter J.; Berman, Theodore

1948-01-01

An investigation has been conducted in the Langley 20-foot free-spinning tunnel on the 1/20-scale model of the Chance Vought XF6U-1 airplane altered to represent the XF6U-1 airplane as it will be spin-tested in flight, and also altered to represent the F6U-1 airplane as it will be produced for service use. Spin tests were made to determine the effects of control settings and movements at the normal loading. The results show that the spins obtained on the revised XF6U-1 airplane will be oscillatory in roll and yaw and that recoveries by rudder reversal will be rapid. Model test results indicate that the F6U-1 airplane will probably not spin. Inasmuch as the results of this investigation show that the new designs are as good as or better than the original XF6U-1 design in regard to spin recovery, it is felt that the conclusions and recommendations reached for the original design can be applied to the new designs for all loading conditions.

Dynamics and regulation of nuclear import and nuclear movements of HIV-1 complexes

PubMed Central

Burdick, Ryan C.; Chen, Jianbo; Sastri, Jaya; Hu, Wei-Shau

2017-01-01

The dynamics and regulation of HIV-1 nuclear import and its intranuclear movements after import have not been studied. To elucidate these essential HIV-1 post-entry events, we labeled viral complexes with two fluorescently tagged virion-incorporated proteins (APOBEC3F or integrase), and analyzed the HIV-1 dynamics of nuclear envelope (NE) docking, nuclear import, and intranuclear movements in living cells. We observed that HIV-1 complexes exhibit unusually long NE residence times (1.5±1.6 hrs) compared to most cellular cargos, which are imported into the nuclei within milliseconds. Furthermore, nuclear import requires HIV-1 capsid (CA) and nuclear pore protein Nup358, and results in significant loss of CA, indicating that one of the viral core uncoating steps occurs during nuclear import. Our results showed that the CA-Cyclophilin A interaction regulates the dynamics of nuclear import by delaying the time of NE docking as well as transport through the nuclear pore, but blocking reverse transcription has no effect on the kinetics of nuclear import. We also visualized the translocation of viral complexes docked at the NE into the nucleus and analyzed their nuclear movements and determined that viral complexes exhibited a brief fast phase (<9 min), followed by a long slow phase lasting several hours. A comparison of the movement of viral complexes to those of proviral transcription sites supports the hypothesis that HIV-1 complexes quickly tether to chromatin at or near their sites of integration in both wild-type cells and cells in which LEDGF/p75 was deleted using CRISPR/cas9, indicating that the tethering interactions do not require LEDGF/p75. These studies provide novel insights into the dynamics of viral complex-NE association, regulation of nuclear import, viral core uncoating, and intranuclear movements that precede integration site selection. PMID:28827840

77 FR 70847 - Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations, Inc., Indian Point Nuclear...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-27

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-247; NRC-2012-0284] Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations, Inc., Indian Point Nuclear Generating Unit No. 2, Request for Action AGENCY: Nuclear Regulatory Commission. ACTION: Request for Action; receipt. SUMMARY: The U.S. Nuclear...

7 CFR 51.302 - U.S. No. 1.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false U.S. No. 1. 51.302 Section 51.302 Agriculture... Standards for Grades of Apples Grades § 51.302 U.S. No. 1. “U.S. No. 1” consists of apples which meet the... color is required for all varieties listed in table I of § 51.305. Apples of this grade are free from...

7 CFR 51.302 - U.S. No. 1.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false U.S. No. 1. 51.302 Section 51.302 Agriculture... Standards for Grades of Apples Grades § 51.302 U.S. No. 1. “U.S. No. 1” consists of apples which meet the... color is required for all varieties listed in table I of § 51.305. Apples of this grade are free from...

7 CFR 51.302 - U.S. No. 1.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1. 51.302 Section 51.302 Agriculture... Standards for Grades of Apples Grades § 51.302 U.S. No. 1. “U.S. No. 1” consists of apples which meet the... color is required for all varieties listed in table I of § 51.305. Apples of this grade are free from...

Optimization of small long-life PWR based on thorium fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subkhi, Moh Nurul, E-mail: nsubkhi@students.itb.ac.id; Physics Dept., Faculty of Science and Technology, State Islamic University of Sunan Gunung Djati Bandung Jalan A.H Nasution 105 Bandung; Suud, Zaki, E-mail: szaki@fi.itb.ac.id

2015-09-30

A conceptual design of small long-life Pressurized Water Reactor (PWR) using thorium fuel has been investigated in neutronic aspect. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.2, while the multi-energy-group diffusion calculations were optimized in three-dimension X-Y-Z geometry of core by COREBN. The excess reactivity of thorium nitride with ZIRLO cladding is considered during 5 years of burnup without refueling. Optimization of 350 MWe long life PWR based on 5% {sup 233}U & 2.8% {sup 231}Pa, 6% {sup 233}U & 2.8% {sup 231}Pa and 7% {sup 233}U & 6% {supmore » 231}Pa give low excess reactivity.« less

75 FR 13327 - Tennessee Valley Authority; Browns Ferry Nuclear Plant, Units 1, 2, and 3; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-19

... the rule's compliance date for all operating nuclear power plants, but noted that the Commission's... compliance date (Reference: June 4, 2009, letter from R. W. Borchardt, NRC, to M. S. Fertel, Nuclear Energy... the U.S. Nuclear Regulatory Commission (NRC, the Commission) now or hereafter in effect. The facility...

Neutrino masses, dark matter and leptogenesis with U(1) B - L gauge symmetry

NASA Astrophysics Data System (ADS)

Geng, Chao-Qiang; Okada, Hiroshi

2018-06-01

We propose a model with an U(1) B - L gauge symmetry, in which small neutrino masses, dark matter and the matter-antimatter asymmetry in the Universe can be simultaneously explained. In particular, the neutrino masses are generated radiatively, while the matter-antimatter asymmetry is led by the leptogenesis mechanism, at TeV scale. We also explore allowed regions of the model parameters and discuss some phenomenological effects, including lepton flavor violating processes.

Spark plasma sintering and microstructural analysis of pure and Mo doped U3Si2 pellets

NASA Astrophysics Data System (ADS)

Lopes, Denise Adorno; Benarosch, Anna; Middleburgh, Simon; Johnson, Kyle D.

2017-12-01

U3Si2 has been considered as an alternative fuel for Light Water Reactors (LWRs) within the Accident Tolerant Fuels (ATF) initiative, begun after the Fukushima-Daiichi Nuclear accidents. Its main advantages are high thermal conductivity and high heavy metal density. Despite these benefits, U3Si2 presents an anisotropic crystallographic structure and low solubility of fission products, which can result in undesirable effects under irradiation conditions. In this paper, spark plasma sintering (SPS) of U3Si2 pellets is studied, with evaluation of the resulting microstructure. Additionally, exploiting the short sintering time in SPS, a molybdenum doped pellet was produced to investigate the early stages of the Mo-U3Si2 interaction, and analyze how this fission product is accommodated in the fuel matrix. The results show that pellets of U3Si2 with high density (>95% TD) can be obtained with SPS in the temperature range of 1200°C-1300 °C. Moreover, the short time employed in this technique was found to generate a unique microstructure for this fuel, composed mainly of closed nano-pores (<1 μm) and small average grain size (∼4.5 μm). The addition of Mo (1.5 at%) demonstrated no solubility of Mo in the U3Si2 matrix. The interaction of this fission product with the fuel matrix at 1200 °C formed, in the early stages, the stoichiometric U2Mo3Si4 ternary as well as precipitates of free uranium with small quantities of dissolved Si and Mo at the front of the reaction.

Characterization of Elements Regulating the Nuclear-to-Cytoplasmic Translocation of ICP0 in Late Herpes Simplex Virus 1 Infection.

PubMed

Samrat, Subodh Kumar; Ha, Binh L; Zheng, Yi; Gu, Haidong

2018-01-15

Infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) is an immediate early protein containing a RING-type E3 ubiquitin ligase. It targets several host factors for proteasomal degradation and subsequently activates viral expression. ICP0 has a nuclear localization sequence and functions in the nucleus early during infection. However, later in infection, ICP0 is found solely in the cytoplasm. The molecular mechanism and biological function of the ICP0 nuclear-to-cytoplasmic translocation are not well understood. In this study, we sought to characterize elements important for this translocation. We found that (i) in human embryonic lung fibroblast (HEL) cells, ICP0 C-terminal residues 741 to 775 were necessary but not sufficient for the nuclear-to-cytoplasmic translocation; (ii) the loss of ICP0 E3 ubiquitin ligase activity, which led to defective viral replication in nonpermissive cells, also caused mutant ICP0 to be retained in the nucleus of HEL cells; (iii) in permissive U2OS cells, however, ICP0 lacking E3 ligase activity was translocated to the cytoplasm at a pace faster than that of wild-type ICP0, suggesting that nuclear retention of ICP0 occurs in an ICP0 E3 ligase-dependent manner; and (iv) the ICP0 C terminus and late viral proteins cooperate in order to overcome nuclear retention and stimulate ICP0 cytoplasmic translocation. Taken together, less ICP0 nuclear retention may contribute to the permissiveness of U2OS cells to HSV-1 in the absence of functional ICP0. IMPORTANCE A distinct characteristic for eukaryotes is the compartmentalization of cell metabolic pathways, which allows greater efficiency and specificity of cellular functions. ICP0 of HSV-1 is a multifunctional viral protein that travels through different compartments as infection progresses. Its main regulatory functions are carried out in the nucleus, but it is translocated to the cytoplasm late during HSV-1 infection. To understand the biological significance of cytoplasmic ICP0 in

(234)U/(238)U signatures associated with uranium ore bodies: part 1 Ranger 3.

PubMed

Lowson, Richard T; McIntyre, Mark G

2013-04-01

The Ranger 3 ore body is an early Proterozoic U ore body in the Alligator Rivers U province, Northern Territory, Australia. It has surface expression with a redox front located between 30 and 50 m below the surface. The ground water U concentration and (234)U/(238)U AR signature in the top 10 m of the weathered zone are reported for 357 samples collected over 4 wet seasons, at 5 depths, along a transect in-line with the hydraulic gradient and along the centre line of the ore body and its associated dispersion halo. The results show that the weathered zone displays a general U isotope feature for this type of ore body with the (234)U/(238)U AR for the ground water and amorphous phase of the solid matrix being less than 1. The ground water (234)U/(238)U AR is independent of the annual monsoonal climate and depth within the range surface to 10 m. In the vicinity of the U ore body the ground water (234)U/(238)U AR is 0.75 and is very similar to the (234)U/(238)U AR of the amorphous phase of the solid (0.76). The (234)U/(238)U ARs of the amorphous phase and ground water rise and separate to values of 0.88 and 1.02 at the end of the transect. The rise and separation in (234)U/(238)U AR are interpreted as evidence that the source of the U in the ground water is from the water-soluble sub-phase of the amorphous phase and that the ground water flow is too fast to allow the processes occurring across the solid-water interface to reach chemical equilibrium. The data set is a robust characterisation of the coarse and fine detail of the (234)U/(238)U AR signature in the weathered zone of U ore bodies. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Consequences of Nuclear Terrorism,

DTIC Science & Technology

1979-08-01

attention from focusing for a length of time on a single nuclear incident would also have an effect . 7v . 19 III. THE CONSEQUENCES * We presume now in our...AD-AI61 788 THE CONSEQUENCES OF NUCLEAR TERRORISMC) RND CORP 1/1 SANTA MONICA CA 8 M JENKCINS AUG 79 RAVD/P-6373p UNCLASSIFIED F/G 15/7 M - Kill...111 *-*------1*- .29 .;-.R ~in 1111111U :NA2,NAL tiuRLAUOf STANDARDS !Q61 A I 11111 7l 4’ THE CONSEQUENCES OF NUCLEAR TERRORISM Brian Michael Jenkins

Managing the Nuclear Fuel Cycle: Policy Implications of Expanding Global Access to Nuclear Power

DTIC Science & Technology

2009-07-01

inalienable right and, by and large, neither have U.S. government officials. However, the case of Iran raises perhaps the most critical question in this...slight difference in atomic mass between 235U and 238U. The typical enrichment process requires about 10 lbs of uranium U3O8 to produce 1 lb of low...thermal neutrons but can induce fission in all actinides , including all plutonium isotopes. Therefore, nuclear fuel for a fast reactor must have a

78 FR 38783 - Grant Applications; Small Community Air Service Development Program under 49 U.S.C. 41743 et seq.;

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-27

...; Small Community Air Service Development Program under 49 U.S.C. 41743 et seq.; Order Soliciting Small Community Grant Proposals Issued by the Department of Transportation on the 24th day of June, 2013. By this order, the Department invites proposals from communities and/or consortia of communities interested in...

A Delayed Neutron Counting System for the Analysis of Special Nuclear Materials

NASA Astrophysics Data System (ADS)

Sellers, Madison Theresa

3.6%. The system has accurately determined 235U content over three orders of magnitude with 235U amounts as low as 10 ng. The results have also been proven to be independent of small variations in total analyte volume and geometry, indicating that it is an ideal technique for the analysis of samples containing SNM in a variety of different matrices. The Analytical Sciences Group at RMC plans to continue DNC system development to include 233U and 239pu analysis and mixtures of SNM isotopes. Keywords: delayed neutron counting, special nuclear materials, nuclear forensics.

10 CFR 9.1 - Scope and purpose.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Scope and purpose. 9.1 Section 9.1 Energy NUCLEAR... Freedom of Information Act, 5 U.S.C. 552, concerning the availability to the public of Nuclear Regulatory... 1974, 5 U.S.C. 552a, concerning disclosure and availability of certain Nuclear Regulatory Commission...