Neutron single-particle strengths at N = 40 , 42: Neutron knockout from Ni 68 , 70 ground and isomeric states

DOE PAGES

Recchia, F.; Weisshaar, D.; Gade, A.; ...

2016-11-28

The distribution of single-particle strength in 67,69Ni was characterized with one-neutron knockout reactions from intermediate-energy 68,70Ni secondary beams, selectively populating neutron-hole configurations at N = 39 and 41, respectively. The spectroscopic strengths deduced from the measured partial cross sections to the individual final states, as tagged by their γ-ray decays, is used to identify and quantify neutron configurations in the wave functions. While 69Ni compares well to shell-model predictions, the results for 67Ni challenge the validity of current effective shell-model Hamiltonians by revealing discrepancies that cannot be explained so far. Furthermore, these results suggest that our understanding of the low-lyingmore » states in the neutron-rich, semi-magic Ni isotopes may be incomplete and requires further investigation on both the experimental and theoretical sides.« less

New insight into the role of the β3 subunit of the GABAA-R in development, behavior, body weight regulation, and anesthesia revealed by conditional gene knockout

PubMed Central

Ferguson, Carolyn; Hardy, Steven L; Werner, David F; Hileman, Stanley M; DeLorey, Timothy M; Homanics, Gregg E

2007-01-01

Background The β3 subunit of the γ-aminobutyric acid type A receptor (GABAA-R) has been reported to be important for palate formation, anesthetic action, and normal nervous system function. This subunit has also been implicated in the pathogenesis of Angelman syndrome and autism spectrum disorder. To further investigate involvement of this subunit, we previously produced mice with a global knockout of β3. However, developmental abnormalities, compensation, reduced viability, and numerous behavioral abnormalities limited the usefulness of that murine model. To overcome many of these limitations, a mouse line with a conditionally inactivated β3 gene was engineered. Results Gene targeting and embryonic stem cell technologies were used to create mice in which exon 3 of the β3 subunit was flanked by loxP sites (i.e., floxed). Crossing the floxed β3 mice to a cre general deleter mouse line reproduced the phenotype of the previously described global knockout. Pan-neuronal knockout of β3 was achieved by crossing floxed β3 mice to Synapsin I-cre transgenic mice. Palate development was normal in pan-neuronal β3 knockouts but ~61% died as neonates. Survivors were overtly normal, fertile, and were less sensitive to etomidate. Forebrain selective knockout of β3 was achieved using α CamKII-cre transgenic mice. Palate development was normal in forebrain selective β3 knockout mice. These knockouts survived the neonatal period, but ~30% died between 15–25 days of age. Survivors had reduced reproductive fitness, reduced sensitivity to etomidate, were hyperactive, and some became obese. Conclusion Conditional inactivation of the β3 gene revealed novel insight into the function of this GABAA-R subunit. The floxed β3 knockout mice described here will be very useful for conditional knockout studies to further investigate the role of the β3 subunit in development, ethanol and anesthetic action, normal physiology, and pathophysiologic processes. PMID:17927825

Separated Response Function Ratios in Exclusive, Forward π ± Electroproduction

DOE PAGES

Huber, G. M.; Blok, H. P.; Butuceanu, C.; ...

2014-05-05

The study of exclusive π ± electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio R L = σ π- L / σ π+ L is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of R T = σ π- T / σ π+ T from unity at small –t, to 1/4 at large –t, would suggest a transition from coupling to a (virtual)more » pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π ± electroproduction on the deuteron at central Q 2 values of 0.6, 1.0, 1.6 GeV 2 at W = 1.95 GeV, and Q 2 = 2.45 GeV 2 at W = 2.22 GeV. In this paper, we present the L and T cross sections, with emphasis on R L and R T, and compare them with theoretical calculations. Finally, results for the separated ratio R L indicate dominance of the pion-pole diagram at low –t, while results for R T are consistent with a transition between pion knockout and quark knockout mechanisms.« less

Mendel: a simple excel workbook to compare the observed and expected distributions of genotypes/phenotypes in transgenic and knockout mouse crosses involving up to three unlinked loci by means of a χ2 test.

PubMed

Montoliu, Lluís

2012-06-01

The analysis of transgenic and knockout mice always involves the establishment of matings with individuals carrying different loci, segregating independently, whose presence is expected among the progeny, according to a Mendelian distribution. The appearance of distorted inheritance ratios suggests the existence of unexpected lethal or sub-lethal phenotypes associated with some genotypes. These situations are common in a number of cases, including: testing transgenic founder mice for germ-line transmission of their transgenes; setting up heterozygous crosses to obtain homozygous individuals, both for transgenic and knockout mice; establishing matings between floxed mouse lines and suitable cre transgenic mouse lines, etc. The Pearson's χ(2) test can be used to assess the significance of the observed frequencies of genotypes/phenotypes in relation to the expected values, in order to determine whether the observed cases fit the expected distribution. Here, I describe a simple Excel workbook to compare the observed and expected distributions of genotypes/phenotypes in transgenic and knockout mouse crosses involving up to three unlinked loci by means of a χ(2) test. The file is freely available for download from my laboratory's web page at: http://www.cnb.csic.es/~montoliu/Mendel.xls .

Search for excited states in 25O

NASA Astrophysics Data System (ADS)

Jones, M. D.; Fossez, K.; Baumann, T.; DeYoung, P. A.; Finck, J. E.; Frank, N.; Kuchera, A. N.; Michel, N.; Nazarewicz, W.; Rotureau, J.; Smith, J. K.; Stephenson, S. L.; Stiefel, K.; Thoennessen, M.; Zegers, R. G. T.

2017-11-01

Background: Theoretical calculations suggest the presence of low-lying excited states in 25O. Previous experimental searches by means of proton knockout on 26F produced no evidence for such excitations. Purpose: We search for excited states in 25O using the 24O(d ,p ) 25O reaction. The theoretical analysis of excited states in unbound O,2725 is based on the configuration interaction approach that accounts for couplings to the scattering continuum. Method: We use invariant-mass spectroscopy to measure neutron-unbound states in 25O. For the theoretical approach, we use the complex-energy Gamow Shell Model and Density Matrix Renormalization Group method with a finite-range two-body interaction optimized to the bound states and resonances of O-2623, assuming a core of 22O. We predict energies, decay widths, and asymptotic normalization coefficients. Results: Our calculations in a large s p d f space predict several low-lying excited states in 25O of positive and negative parity, and we obtain an experimental limit on the relative cross section of a possible Jπ=1/2 + state with respect to the ground state of 25O at σ1 /2 +/σg .s .=0 .25-0.25+1.0 . We also discuss how the observation of negative parity states in 25O could guide the search for the low-lying negative parity states in 27O. Conclusion: Previous experiments based on the proton knockout of 26F suffered from the low cross sections for the population of excited states in 25O because of low spectroscopic factors. In this respect, neutron transfer reactions carry more promise.

Knockout beyond the dripline

NASA Astrophysics Data System (ADS)

Bonaccorso, A.; Charity, R. J.; Kumar, R.; Salvioni, G.

2015-02-01

In this contribution, we will describe neutron and proton removal from 9C and 7Be which are two particularly interesting nuclei entering the nucleo-synthesis pp-chain [1, 2]. Neutron and proton removal reactions have been used in the past twenty years to probe the single-particle structure of exotic nuclei. The core parallel-momentum distribution can give information on the angular momentum and spin of the nucleon initial state while the total removal cross section is sensitive to the asymptotic part of the initial wave function and also to the reaction mechanism. Because knockout is a peripheral reaction from which the Asymptotic Normalization Constant (ANC) of the single-particle wave function can be extracted, it has been used as an indirect method to obtain the rate of reactions like 8B ( p ,γ)9C or 7Be ( p ,γ)8B . Nucleon removal has recently been applied by the HiRA collaboration [3] to situations in which the remaining "core" is beyond the drip line, such as 8C and 6Be , unbound by one or more protons, and whose excitation-energy spectrum can be obtained by the invariant-mass method. By gating on the ground-state peak, "core" parallel-momentum distributions and total knockout cross sections have been obtained similar to previous studies with well-bound "cores". In addition for each projectile, knock out to final bound states has also been obtained in several cases. We will report on the theoretical description and comparison to this experimental data for a few cases for which advances in the accuracy of the transfer-to-the continuum model [4, 5] have been made [6]. These include the use, when available, of "ab-initio" overlaps for the initial state [7] and in particular their ANC values [8]. Also, the construction of a nucleus-target folding potential for the treatment of the core-target S-matrix [9] using for the cores "ab-initio" densities [10] and state-of-the-art n-9Be optical potentials [11]. Preliminary results and open problems will be discussed.

Description of Light Ion Production Cross Sections and Fluxes on the Mars Surface using the QMSFRG Model

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Kim, Myung-Hee; Schneider, Irene; Hassler, Donald M.

2006-01-01

The atmosphere of Mars significantly attenuates the heavy ion component of the primary galactic cosmic rays (GCR), however increases the fluence of secondary light ions (neutrons, and hydrogen and helium isotopes) because of particle production processes. We describe results of the quantum multiple scattering fragmentation (QMSFRG) model for the production of light nuclei through the distinct mechanisms of nuclear abrasion and ablation, coalescence, and cluster knockout. The QMSFRG model is shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections. We use the QMSFRG model and the space radiation transport code, HZETRN to make predictions of the light particle environment on the Martian surface at solar minimum and maximum. The radiation assessment detector (RAD) experiment will be launched in 2009 as part of the Mars Science Laboratory (MSL). We make predictions of the expected results for time dependent count-rates to be observed by RAD experiment. Finally, we consider sensitivity assessments of the impact of the Martian atmospheric composition on particle fluxes at the surface.

Polarization Raman spectroscopy to explain rodent models of brittle bone

NASA Astrophysics Data System (ADS)

Makowski, Alexander J.; Nyman, Jeffry S.; Mahadevan-Jansen, Anita

2013-03-01

Activation Transcription Factor 4 (Atf-4) is essential for osteoblast maturation and proper collagen synthesis. We recently found that these bones demonstrate a rare brittleness phenotype, which is independent of bone strength. We utilized a confocal Renishaw Raman microscope (50x objective; NA=.75) to evaluate embedded, polished cross-sections of mouse tibia from both wild-type and knockout mice at 8 weeks of age (24 mice, n<=8 per group). Analysis of peak ratios indicated statistically significant changes in both mineral and collagen; however, compositional changes did not fully encompass biomechanical differences. To investigate the impact of material organization, we acquired colocalized spectra aligning the polarization angle parallel and perpendicular to the long bone axis from wet intact femurs. To validate our results, we used MMP9-/- mice, which have a brittleness phenotype that is not explained by compositional Raman measures. Polarization angle difference spectra show marked significant changes in orientation of these compositional differences when comparing wild type to knockout bones. Relative to wild-type, Atf4 -/- and MMP9 -/- bones show significant differences (t-test; p<0.05) in prominent collagen peaks. Further investigation of known peak ratios illustrates that this physical anisotropy of molecular organization is tightly clustered in brittle knockout bones. Such findings could have alternate interpretations about net collagen orientation or the angular distribution of collagen molecules. Use of polarization specific Raman measurements has implicated a structural profile that furthers our understanding of models of bone brittleness. Polarization content of Raman spectra may prove significant in future studies of brittle fracture and human fracture risk.

FOCuS: a metaheuristic algorithm for computing knockouts from genome-scale models for strain optimization.

PubMed

Mutturi, Sarma

2017-06-27

Although handful tools are available for constraint-based flux analysis to generate knockout strains, most of these are either based on bilevel-MIP or its modifications. However, metaheuristic approaches that are known for their flexibility and scalability have been less studied. Moreover, in the existing tools, sectioning of search space to find optimal knocks has not been considered. Herein, a novel computational procedure, termed as FOCuS (Flower-pOllination coupled Clonal Selection algorithm), was developed to find the optimal reaction knockouts from a metabolic network to maximize the production of specific metabolites. FOCuS derives its benefits from nature-inspired flower pollination algorithm and artificial immune system-inspired clonal selection algorithm to converge to an optimal solution. To evaluate the performance of FOCuS, reported results obtained from both MIP and other metaheuristic-based tools were compared in selected case studies. The results demonstrated the robustness of FOCuS irrespective of the size of metabolic network and number of knockouts. Moreover, sectioning of search space coupled with pooling of priority reactions based on their contribution to objective function for generating smaller search space significantly reduced the computational time.

Final-state interactions in two-nucleon knockout reactions

NASA Astrophysics Data System (ADS)

Colle, Camille; Cosyn, Wim; Ryckebusch, Jan

2016-03-01

Background: Exclusive two-nucleon knockout after electroexcitation of nuclei [A (e ,e'N N ) in brief] is considered to be a primary source of information about short-range correlations (SRCs) in nuclei. For a proper interpretation of the data, final-state interactions (FSIs) need to be theoretically controlled. Purpose: Our goal is to quantify the role of FSI effects in exclusive A (e ,e'p N ) reactions for four target nuclei representative of the whole mass region. Our focus is on processes that are SRC driven. We investigate the role of FSIs for two characteristic detector setups corresponding to "small" and "large" coverage of the available phase space. Method: Use is made of a factorized expression for the A (e ,e'p N ) cross section that is proportional to the two-body center-of-mass (c.m.) momentum distribution of close-proximity pairs. The A (e ,e'p p ) and A (e ,e'p n ) reactions for the target nuclei 12C,27Al,56Fe, and 208Pb are investigated. The elastic attenuation mechanisms in the FSIs are included using the relativistic multiple-scattering Glauber approximation (RMSGA). Single-charge exchange (SCX) reactions are also included. We introduce the nuclear transparency TAp N, defined as the ratio of exclusive (e ,e'p N ) cross sections on nuclei to those on "free" nucleon pairs, as a measure for the aggregated effect of FSIs in p N knockout reactions from nucleus A . A toy model is introduced in order to gain a better understanding of the A dependence of TAp N. Results: The transparency TAp N drops from 0.2 -0.3 for 12C to 0.04 -0.07 for 208Pb. For all considered kinematics, the mass dependence of TAp N can be captured by the power law TAp N∝A-λ with 0.4 ≲λ ≲0.5 . Apart from an overall reduction factor, we find that FSIs only modestly affect the distinct features of SRC-driven A (e ,e'p N ) which are dictated by the c.m. distribution of close-proximity pairs. Conclusion: The SCX mechanisms represent a relatively small (order of a few percent) contribution of SRC-driven A (e ,e'p N ) processes. The mass dependence of FSI effects in exclusive A (e ,e'p N ) can be captured in a robust power law and is in agreement with the predictions obtained in a toy model.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

NASA Astrophysics Data System (ADS)

Gran, R.; Betancourt, M.; Elkins, M.; Rodrigues, P. A.; Akbar, F.; Aliaga, L.; Andrade, D. A.; Bashyal, A.; Bellantoni, L.; Bercellie, A.; Bodek, A.; Bravar, A.; Budd, H.; Vera, G. F. R. Caceres; Cai, T.; Carneiro, M. F.; Coplowe, D.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Gallagher, H.; Ghosh, A.; Haider, H.; Han, J. Y.; Harris, D. A.; Henry, S.; Jena, D.; Kleykamp, J.; Kordosky, M.; Le, T.; Leistico, J. R.; Lovlein, A.; Lu, X.-G.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Nguyen, C.; Norrick, A.; Nuruzzaman, Olivier, A.; Paolone, V.; Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Ruterbories, D.; Schellman, H.; Salinas, C. J. Solano; Su, H.; Sultana, M.; Falero, S. Sánchez; Valencia, E.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Minerva Collaboration

2018-06-01

We report on multinucleon effects in low momentum transfer (<0.8 GeV /c ) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer.

PubMed

Gran, R; Betancourt, M; Elkins, M; Rodrigues, P A; Akbar, F; Aliaga, L; Andrade, D A; Bashyal, A; Bellantoni, L; Bercellie, A; Bodek, A; Bravar, A; Budd, H; Vera, G F R Caceres; Cai, T; Carneiro, M F; Coplowe, D; da Motta, H; Dytman, S A; Díaz, G A; Felix, J; Fields, L; Fine, R; Gallagher, H; Ghosh, A; Haider, H; Han, J Y; Harris, D A; Henry, S; Jena, D; Kleykamp, J; Kordosky, M; Le, T; Leistico, J R; Lovlein, A; Lu, X-G; Maher, E; Manly, S; Mann, W A; Marshall, C M; McFarland, K S; McGowan, A M; Messerly, B; Miller, J; Mislivec, A; Morfín, J G; Mousseau, J; Naples, D; Nelson, J K; Nguyen, C; Norrick, A; Nuruzzaman; Olivier, A; Paolone, V; Patrick, C E; Perdue, G N; Ramírez, M A; Ransome, R D; Ray, H; Ren, L; Rimal, D; Ruterbories, D; Schellman, H; Salinas, C J Solano; Su, H; Sultana, M; Falero, S Sánchez; Valencia, E; Wolcott, J; Wospakrik, M; Yaeggy, B

2018-06-01

We report on multinucleon effects in low momentum transfer (<0.8  GeV/c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

Anti-Atherosclerotic Action of Agmatine in ApoE-Knockout Mice

PubMed Central

Olszanecki, Rafał; Totoń-Żurańska, Justyna; Stachowicz, Aneta; Suski, Maciej; Gębska, Anna; Gajda, Mariusz; Jawień, Jacek; Korbut, Ryszard

2017-01-01

Atherosclerosis is an inflammatory disease in which dysfunction of mitochondria play an important role, and disorders of lipid management intensify this process. Agmatine, an endogenous polyamine formed by decarboxylation of arginine, exerts a protective effect on mitochondria and modulates fatty acid metabolism. We investigated the effect of exogenous agmatine on the development of atherosclerosis and changes in lipid profile in apolipoprotein E knockout (apoE-/-) mice. Agmatine caused an approximate 40% decrease of atherosclerotic lesions, as estimated by en face and cross-section methods with an influence on macrophage but not on smooth muscle content in the plaques. Agmatine treatment did not changed gelatinase activity within the plaque area. What is more, the action of agmatine was associated with an increase in the number of high density lipoproteins (HDL) in blood. Real-Time PCR analysis showed that agmatine modulates liver mRNA levels of many factors involved in oxidation of fatty acid and cholesterol biosynthesis. Two-dimensional electrophoresis coupled with mass spectrometry identified 27 differentially expressed mitochondrial proteins upon agmatine treatment in the liver of apoE-/- mice, mostly proteins related to metabolism and apoptosis. In conclusion, prolonged administration of agmatine inhibits atherosclerosis in apoE-/- mice; however, the exact mechanisms linking observed changes and elevations of HDL plasma require further investigation. PMID:28777310

Anti-Atherosclerotic Action of Agmatine in ApoE-Knockout Mice.

PubMed

Wiśniewska, Anna; Olszanecki, Rafał; Totoń-Żurańska, Justyna; Kuś, Katarzyna; Stachowicz, Aneta; Suski, Maciej; Gębska, Anna; Gajda, Mariusz; Jawień, Jacek; Korbut, Ryszard

2017-08-04

Atherosclerosis is an inflammatory disease in which dysfunction of mitochondria play an important role, and disorders of lipid management intensify this process. Agmatine, an endogenous polyamine formed by decarboxylation of arginine, exerts a protective effect on mitochondria and modulates fatty acid metabolism. We investigated the effect of exogenous agmatine on the development of atherosclerosis and changes in lipid profile in apolipoprotein E knockout (apoE-/-) mice. Agmatine caused an approximate 40% decrease of atherosclerotic lesions, as estimated by en face and cross-section methods with an influence on macrophage but not on smooth muscle content in the plaques. Agmatine treatment did not changed gelatinase activity within the plaque area. What is more, the action of agmatine was associated with an increase in the number of high density lipoproteins (HDL) in blood. Real-Time PCR analysis showed that agmatine modulates liver mRNA levels of many factors involved in oxidation of fatty acid and cholesterol biosynthesis. Two-dimensional electrophoresis coupled with mass spectrometry identified 27 differentially expressed mitochondrial proteins upon agmatine treatment in the liver of apoE-/- mice, mostly proteins related to metabolism and apoptosis. In conclusion, prolonged administration of agmatine inhibits atherosclerosis in apoE-/- mice; however, the exact mechanisms linking observed changes and elevations of HDL plasma require further investigation.

Targeted Inactivation of a Developmentally Regulated Neural Plectin Isoform (Plectin 1c) in Mice Leads to Reduced Motor Nerve Conduction Velocity*

PubMed Central

Fuchs, Peter; Zörer, Michael; Reipert, Siegfried; Rezniczek, Günther A.; Propst, Friedrich; Walko, Gernot; Fischer, Irmgard; Bauer, Jan; Leschnik, Michael W.; Lüscher, Bernhard; Thalhammer, Johann G.; Lassmann, Hans; Wiche, Gerhard

2009-01-01

Cytolinker proteins stabilize cells mechanically, regulate cytoskeleton dynamics, and provide scaffolds for signaling molecules. For plectin, the prototype of these proteins, an unusual diversity of isoforms has been reported, which show distinct expression patterns, subcellular localizations, and functions. Plectin has been shown to have important functions in skin and muscle, but little is known about its role in neural cells. To address this issue, we generated two knock-out mouse lines, one which was selectively lacking plectin 1c (P1c), the major isoform expressed in neural cells, and another in which plectin was conditionally deleted in neuronal precursor cells. Using isoform-specific antibodies, we found P1c to be expressed late in development and to associate with postsynaptic dendrites of central nervous system neurons, motorneurons of spinal cord, sciatic nerve axons, and Schwann cells. Motor nerve conduction velocity was found significantly reduced in sciatic nerve from P1c-deficient as well as from conditional knock-out mice. This defect was traceable to an increased number of motor nerve fibers with small cross-sectional areas; the thicknesses of axons and of myelin sheaths were unaffected. This is the first report demonstrating an important role of plectin in a major nerve function. PMID:19625254

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

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

Gran, R.; Betancourt, M.; Elkins, M.

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Anti-Neutrino Charged-Current Reactions on Scintillator with Low Momentum Transfer

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

Gran, R.; et al.

2018-03-25

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Anti-Neutrino Charged-Current Reactions on Scintillator with Low Momentum Transfer

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

Gran, R.; et al.

2018-06-01

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

DOE PAGES

Gran, R.; Betancourt, M.; Elkins, M.; ...

2018-06-01

We report on multi-nucleon effects in low momentum transfer (more » $< 0.8$ GeV/c) anti-neutrino interactions on scintillator. These data are from the 2010-11 anti-neutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well-described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasi-elastic, $$\\Delta$$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this anti-neutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for anti-neutrino scattering off nuclei.« less

Angiopoietin-1 deficiency increases tumor metastasis in mice.

PubMed

Michael, Iacovos P; Orebrand, Martina; Lima, Marta; Pereira, Beatriz; Volpert, Olga; Quaggin, Susan E; Jeansson, Marie

2017-08-11

Angipoietin-1 activation of the tyrosine kinase receptor Tek expressed mainly on endothelial cells leads to survival and stabilization of endothelial cells. Studies have shown that Angiopoietin-1 counteracts permeability induced by a number of stimuli. Here, we test the hypothesis that loss of Angiopoietin-1/Tek signaling in the vasculature would increase metastasis. Angiopoietin-1 was deleted in mice just before birth using floxed Angiopoietin-1 and Tek mice crossed to doxycycline-inducible bitransgenic ROSA-rtTA/tetO-Cre mice. By crossing Angiopoietin-1 knockout mice to the MMTV-PyMT autochthonous mouse breast cancer model, we investigated primary tumor growth and metastasis to the lung. Furthermore, we utilized B16F10 melanoma cells subcutaneous and experimental lung metastasis models in Angiopoietin-1 and Tek knockout mice. We found that primary tumor growth in MMTV-PyMT mice was unaffected, while metastasis to the lung was significantly increased in Angiopoietin-1 knockout MMTV-PyMT mice. In addition, angiopoietin-1 deficient mice exhibited a significant increase in lung metastasis of B16F10 melanoma cells, compared to wild type mice 3 weeks after injection. Additional experiments showed that this was likely an early event due to increased attachment or extravasation of tumor cells, since seeding of tumor cells was significantly increased 4 and 24 h post tail vein injection. Finally, using inducible Tek knockout mice, we showed a significant increase in tumor cell seeding to the lung, suggesting that Angiopoietin-1/Tek signaling is important for vascular integrity to limit metastasis. This study show that loss of the Angiopoietin-1/Tek vascular growth factor system leads to increased metastasis without affecting primary tumor growth.

Pion Elastic Scattering and the (pion Pion' Proton) Reaction on HELIUM-4 in the DELTA(3,3) Region

NASA Astrophysics Data System (ADS)

Jones, Mark Kevin

This dissertation presents measurements and analyses of pi^+ and pi ^{-} elastic scattering, and ( pi^{+}, pi^ {+^'}p) and ( pi^{-},pi^{-^ '}p) reactions on ^4 He. Both experiments were done at the Los Alamos Meson Physics Facility using the Energetic Pion Channel and Spectrometer. The ^4He( pi,pi) elastic scattering cross sections were measured for pi^{+} scattering at scattering angles theta _{lab} = 110^circ -170^circ and five incident energies between T_{pi } = 90 and 180 MeV. Elastic pi ^{-} cross sections were measured only at T_{pi} = 180 MeV. The ^4He(pi, pi' p) angular correlation functions were measured for pi^{+} and pi^{-} at T_{pi} = 180 and theta_{pi^' } = 30^circ, 40 ^circ, 60^circ , 80^circ and at T _pi = 140 MeV and theta_{pi^'} = 40^circ. Using scintillators at eight angles the protons were detected in coincidence with the inelastically scattered pions. In the ^4He(pi, pi^' p) experiment unexpectedly large ratios R_{pi p} = {sigma(pi^{+}, pi^{+} p)}over{sigma( pi^{-},pi^{-} p)} of up to 50 were observed near the quasi -free angle in the angular correlation functions summed over 30.5 to 39.5 MeV in ^4He excitation energy. The (pi,pi' p) data were analyzed by a distorted wave impulse approximation code 3DEE (Ch 82), (Re 82). 3DEE models the ( pi,pi' p) reaction as a pion -induced proton knock-out and includes distortions in the incident pion, the outgoing pion, and the emitted proton waves. The calculations give R_{pi p} between 6 and 9 at all proton and pion angles. The pi^{+} calculations reproduce the absolute pi^ {+} cross sections fairly well. The pi^{-} calculations have a peak in the angular correlation function near the quasi-free angle, in contrast to the pi^ {-} data which displays a flat distribution. At proton angles near 180^circ in the center of mass of the struck mass 4 system, the measured pi^{-} cross sections are larger than the pi^ {+} cross section which is the reverse of the ratio at 0^circ. These features of the measured pi^- cross sections indicate that interference between a quasi -free process and another process is important in the ( pi,pi^' p) reaction. The measurement of ^4He( pi,pi) elastic scattering data at theta_pi = 110 ^circ-170^circ extends the angular range of previous ^4He(pi,pi) data measured at EPICS. The experiment provides high quality elastic scattering data at backward angles. The pi^{-} elastic cross section at T_pi = 180 MeV measured for this dissertation when extrapolated to theta _{cm} = 180^circ is about a factor of two smaller than the cross section measured previously at CERN (Ref. (Bi 78)). The data were analyzed using a microscopic optical model and by a phase shift fit.

Lithium ameliorates open-field and elevated plus maze behaviors, and brain phospho-glycogen synthase kinase 3-beta expression in fragile X syndrome model mice.

PubMed

Chen, Xi; Sun, Weiwen; Pan, Ying; Yang, Quan; Cao, Kaiyi; Zhang, Jin; Zhang, Yizhi; Chen, Mincong; Chen, Feidi; Huang, Yueling; Dai, Lijun; Chen, Shengqiang

2013-10-01

To investigate whether lithium modifies open-field and elevated plus maze behavior, and brain phospho-glycogen synthase kinase 3 (P-GSK3beta) expression in Fmr1 knockout mice. One hundred and eighty FVB mice, including knockout and wild type, with an age of 30 days were used. An open-field and elevated plus maze was utilized to test behavior, while western blot was used to measure the P-GSK3beta expression. Six groups were formed: control (saline), lithium chloride 30, 60, 90, 120, and 200 mg/kg. The experiments were carried out in the Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China between January and June 2012. Lithium significantly decreased total distance, crossing, central area time, and center entry in the open-field test (p<0.05), and significantly reduced open-arm tracking, open-arm entry, and open-arm time in the elevated plus maze (p<0.05) in knockout mice. In wild type mice, significant changes were observed in both behavior tests in some treatment groups. Lithium ameliorated P-GSK3beta expression in the hippocampus of all the treatment groups in knockout mice (p<0.05). However, lithium did not modify either GSK3beta expression in tissues of knockout mice, or P-GSK3beta or GSK3beta expression in tissues of wild type mice. Lithium ameliorated open-field and elevated plus maze behaviors of Fmr1 knockout mice. This effect may be related to its enhancement of P-GSK3beta expression. Our findings suggest that lithium might have a therapeutic effect in fragile X syndrome.

Transport of Light Ions in Matter

NASA Technical Reports Server (NTRS)

Wilson, J. W.; Cucinotta, F. A.; Tai, H.; Shinn, J. L.; Chun, S. Y.; Tripathi, R. K.; Sihver, L.

1998-01-01

A recent set of light ion experiments are analyzed using the Green's function method of solving the Boltzmann equation for ions of high charge and energy (the GRNTRN transport code) and the NUCFRG2 fragmentation database generator code. Although the NUCFRG2 code reasonably represents the fragmentation of heavy ions, the effects of light ion fragmentation requires a more detailed nuclear model including shell structure and short range correlations appearing as tightly bound clusters in the light ion nucleus. The most recent NTJCFRG2 code is augmented with a quasielastic alpha knockout model and semiempirical adjustments (up to 30 percent in charge removal) in the fragmentation process allowing reasonable agreement with the experiments to be obtained. A final resolution of the appropriate cross sections must await the full development of a coupled channel reaction model in which shell structure and clustering can be accurately evaluated.

A Stochastic Model of Space Radiation Transport as a Tool in the Development of Time-Dependent Risk Assessment

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; Nounu, Hatem N.; Ponomarev, Artem L.; Cucinotta, Francis A.

2011-01-01

A new computer model, the GCR Event-based Risk Model code (GERMcode), was developed to describe biophysical events from high-energy protons and heavy ions that have been studied at the NASA Space Radiation Laboratory (NSRL) [1] for the purpose of simulating space radiation biological effects. In the GERMcode, the biophysical description of the passage of heavy ions in tissue and shielding materials is made with a stochastic approach that includes both ion track structure and nuclear interactions. The GERMcode accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model [2]. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections

Nox Complex signal and MAPK cascade pathway are cross-linked and essential for pathogenicity and conidiation of mycoparasite Coniothyrium minitans

USDA-ARS?s Scientific Manuscript database

The NADPH oxidase complex of a sclerotial mycoparasite Coniothyrium minitans, an important biocontrol agent against crop diseases caused by Sclerotinia sclerotiorum, was identified and its functions involved in conidiation and mycoparasitism were studied. Gene knock-out and complementation experimen...

Molecular Mechanisms Underlying Genomic Instability in Brca-Deficient Cells

DTIC Science & Technology

2014-11-01

breeding of various HR knockouts with 53BP1 nulls. These mice have been generated and drug sensitivity data with these crosses have been included in...overcome the HR defects in BRCA1-defi- cient cells, we crossed PTIPf/f and BRCA1f(D11)/f(D11) mice with CD19 CRE transgenic mice to simultaneously...http://dx. doi.org/10.1073/pnas.1305362110. Bryant, H.E., Schultz, N., Thomas, H.D., Parker, K.M., Flower , D., Lopez, E., Kyle, S., Meuth, M., Curtin

Absence of Wip1 partially rescues Atm deficiency phenotypes in mice

PubMed Central

Darlington, Yolanda; Nguyen, Thuy-Ai; Moon, Sung-Hwan; Herron, Alan; Rao, Pulivarthi; Zhu, Chengming; Lu, Xiongbin; Donehower, Lawrence A.

2011-01-01

Wildtype p53-Induced Phosphatase 1 (WIP1) is a serine/threonine phosphatase that dephosphorylates proteins in the ataxia telangiectasia mutated (ATM)-initiated DNA damage response pathway. WIP1 may play a homeostatic role in ATM signaling by returning the cell to a normal pre-stress state following completion of DNA repair. To better understand the effects of WIP1 on ATM signaling, we crossed Atm-deficient mice to Wip1-deficient mice and characterized phenotypes of the double knockout progeny. We hypothesized that the absence of Wip1 might rescue Atm deficiency phenotypes. Atm null mice, like ATM-deficient humans with the inherited syndrome ataxia telangiectasia, exhibit radiation sensitivity, fertility defects, and are T-cell lymphoma prone. Most double knockout mice were largely protected from lymphoma development and had a greatly extended lifespan compared to Atm null mice. Double knockout mice had increased p53 and H2AX phosphorylation and p21 expression compared to their Atm null counterparts, indicating enhanced p53 and DNA damage responses. Additionally, double knockout splenocytes displayed reduced chromosomal instability compared to Atm null mice. Finally, doubly null mice were partially rescued from infertility defects observed in Atm null mice. These results indicate that inhibition of WIP1 may represent a useful strategy for cancer treatment in general and A-T patients in particular. PMID:21765465

Injury profile of mixed martial arts competitors.

PubMed

McClain, Rance; Wassermen, Jason; Mayfield, Carlene; Berry, Andrew C; Grenier, Greg; Suminski, Richard R

2014-11-01

To provide an updated comprehensive profile of mixed martial arts (MMAs) injuries. Correlational and multivariate analyses were conducted on cross-sectional data to examine injuries sustained during 711 MMA bouts. One physician diagnosed any injuries occurring during the bouts. Various sports venues in Kansas and Missouri holding MMA competitions. Male and female and amateur and professional MMA competitors contributing to 1422 fight participations (fight participations = 711 bouts × 2 fighters/bout). State, level (amateur or professional), gender, number of rounds, and bout outcome (knockout/technical knockout [KO/TKO] vs other outcomes [eg, decision]). Injuries/fight participations, injury sustained (yes vs no), and fighter referred to emergency room (ER; yes vs no). The overall injury rate was 8.5% of fight participations (121 injuries/1422 fight participations) or 5.6% of rounds (121/2178 rounds). Injury rates were similar between men and women, but a greater percentage of the injuries caused an altered mental state in men. The risk of being injured was significantly greater for bouts held in Kansas, at the professional level, lasting more rounds, and ending in a KO/TKO. Fighters also were more likely to be referred to the ER if they participated in longer bouts ending in a KO/TKO. The observed injury rate was lower than previously reported suggesting recent regulatory changes have made MMA a safer sport. Increased clinical awareness and additional research should be extended to head-related injuries in MMAs especially those associated with KOs/TKOs.

Secondary Neutron Production from Space Radiation Interactions: Advances in Model and Experimental Data Base Development

NASA Technical Reports Server (NTRS)

Heilbronn, Lawrence H.; Townsend, Lawrence W.; Braley, G. Scott; Iwata, Yoshiyuki; Iwase, Hiroshi; Nakamura, Takashi; Ronningen, Reginald M.; Cucinotta, Francis A.

2003-01-01

For humans engaged in long-duration missions in deep space or near-Earth orbit, the risk from exposure to galactic and solar cosmic rays is an important factor in the design of spacecraft, spacesuits, and planetary bases. As cosmic rays are transported through shielding materials and human tissue components, a secondary radiation field is produced. Neutrons are an important component of that secondary field, especially in thickly-shielded environments. Calculations predict that 50% of the dose-equivalent in a lunar or Martian base comes from neutrons, and a recent workshop held at the Johnson Space Center concluded that as much as 30% of the dose in the International Space Station may come from secondary neutrons. Accelerator facilities provide a means for measuring the effectiveness of various materials in their ability to limit neutron production, using beams and energies that are present in cosmic radiation. The nearly limitless range of beams, energies, and target materials that are present in space, however, means that accelerator-based experiments will not provide a complete database of cross sections and thick-target yields that are necessary to plan and design long-duration missions. As such, accurate nuclear models of neutron production are needed, as well as data sets that can be used to compare with, and verify, the predictions from such models. Improvements in a model of secondary neutron production from heavy-ion interactions are presented here, along with the results from recent accelerator-based measurements of neutron-production cross sections. An analytical knockout-ablation model capable of predicting neutron production from high-energy hadron-hadron interactions (both nucleon-nucleus and nucleus-nucleus collisions) has been previously developed. In the knockout stage, the collision between two nuclei result in the emission of one or more nucleons from the projectile and/or target. The resulting projectile and target remnants, referred to as prefragments, then decay by the emission of nucleons, composites, and gamma rays. Recent improvements to the model have incorporated coalescence effects, which effectively tie up single nucleons in the formation of composites during final-state interactions. Comparison of the improved model s predictions with neutron production data near 0 deg in the CA-40+ H reaction at 357 and 565 MeV/nucleon show marked improvement.

Efficient generation of P53 biallelic knockout Diannan miniature pigs via TALENs and somatic cell nuclear transfer.

PubMed

Shen, Youfeng; Xu, Kaixiang; Yuan, Zaimei; Guo, Jianxiong; Zhao, Heng; Zhang, Xuezeng; Zhao, Lu; Qing, Yubo; Li, Honghui; Pan, Weirong; Jia, Baoyu; Zhao, Hong-Ye; Wei, Hong-Jiang

2017-11-03

Pigs have many features that make them attractive as biomedical models for various diseases, including cancer. P53 is an important tumor suppressor gene that exerts a central role in protecting cells from oncogenic transformation and is mutated in a large number of human cancers. P53 mutations occur in almost every type of tumor and in over 50% of all tumors. In a recent publication, pigs with a mutated P53 gene were generated that resulted in lymphoma and renal and osteogenic tumors. However, approximately 80% of human tumors have dysfunctional P53. A P53-deficient pig model is still required to elucidate. Transcription activator-like effector nucleases (TALENs) were designed to target porcine P53 exon 4. The targeting activity was evaluated using a luciferase SSA recombination assay. P53 biallelic knockout (KO) cell lines were established from single-cell colonies of fetal fibroblasts derived from Diannan miniature pigs followed by electroporation with TALENs plasmids. One cell line was selected as the donor cell line for somatic cell nuclear transfer (SCNT) for the generation of P53 KO pigs. P53 KO stillborn fetuses and living piglets were obtained. Gene typing of the collected cloned individuals was performed by T7EI assay and sequencing. Fibroblast cells from Diannan miniature piglets with a P53 biallelic knockout or wild type were analyzed for the P53 response to doxorubicin treatment by confocal microscopy and western blotting. The luciferase SSA recombination assay revealed that the targeting activities of the designed TALENs were 55.35-fold higher than those of the control. Eight cell lines (8/19) were mutated for P53, and five of them were biallelic knockouts. One of the biallelic knockout cell lines was selected as nuclear donor cells for SCNT. The cloned embryos were transferred into five recipient gilts, three of them becoming pregnant. Five live fetuses were obtained from one surrogate by caesarean section after 38 days of gestation for genotyping. Finally, six live piglets and one stillborn piglet were collected from two recipients by caesarean section. Sequencing analyses of the target site confirmed the P53 biallelic knockout in all fetuses and piglets, consistent with the genotype of the donor cells. The qPCR analysis showed that the expression of the P53 mRNA had significant reduction in various tissues of the knockout piglets. Furthermore, confocal microscopy and western blotting analyses demonstrated that the fibroblast cells of Diannan miniature piglets with a P53 biallelic knockout were defective in mediating DNA damage when incubated with doxorubicin. TALENs combined with SCNT was successfully used to generate P53 KO Diannan miniature pigs. Although these genetically engineered Diannan miniature pigs had no tumorigenic signs, the P53 gene was dysfunctional. We believe that these pigs will provide powerful new resources for preclinical oncology and basic cancer research.

MicroRNA-590 Inhibits Lipoprotein Lipase Expression and Prevents Atherosclerosis in apoE Knockout Mice

PubMed Central

Lv, Yun-Cheng; Wang, Zong-Bao; Yao, Feng; Xie, Wei; Tan, Yu-Lin; Li, Liang; Zhang, Min; Lan, Gang; Gong, Duo; Cheng, Hai-Peng; Zhong, Hui-Juan; Liu, Dan; Huang, Chong; Li, Zhao-Xia; Zheng, Xi-Long; Yin, Wei-Dong; Tang, Chao-Ke

2015-01-01

Recent studies have suggested that miR-590 may play critical roles in cardiovascular disease. This study was designed to determine the effects of miR-590 on lipoprotein lipase (LPL) expression and development of atherosclerosis in apolipoprotein E knockout (apoE−/−) mice and explore the potential mechanisms. En face analysis of the whole aorta revealed that miR-590 significantly decreased aortic atherosclerotic plaque size and lipid content in apoE−/− mice. Double immunofluorescence staining in cross-sections of the proximal aorta showed that miR-590 agomir reduced CD68 and LPL expression in macrophages in atherosclerotic lesions. MiR-590 agomir down-regulated LPL mRNA and protein expression as analyzed by RT-qPCR and western blotting analyses, respectively. Consistently, miR-590 decreased the expression of CD36 and scavenger receptor A1 (SRA1) mRNA and protein. High-performance liquid chromatography (HPLC)analysis confirmed that treatment with miR-590 agomir reduced lipid levels either in plasma orinabdominal cavity macrophages of apoE−/− mice. ELISA analysis showed that miR-590 agomir decreased plasma levels of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1), interleukin-1β (IL-1β)and interleukin-6 (IL-6). In contrast, treatment with miR-590 antagomir prevented or reversed these effects. Taken together, these results reveal a novel mechanism of miR-590 effects, and may provide new insights into the development of strategies for attenuating lipid accumulation and pro-inflammatory cytokine secretion. PMID:26397958

Neutron knockout from 68,70Ni ground and isomeric states.

NASA Astrophysics Data System (ADS)

Recchia, F.; Weisshaar, D.; Gade, A.; Tostevin, J. A.; Janssens, R. V. F.; Albers, M.; Bader, V. M.; Baugher, T.; Bazin, D.; Berryman, J. S.; Brown, B. A.; Campbell, C. M.; Carpenter, M. P.; Chen, J.; Chiara, C. J.; Crawford, H. L.; Hoffman, C. R.; Kondev, F. G.; Korichi, A.; Langer, C.; Lauritsen, T.; Liddick, S. N.; Lunderberg, E.; Noji, S.; Prokop, C.; Stroberg, S. R.; Suchyta, S.; Wimmer, K.; Zhu, S.

2018-02-01

Neutron-rich isotopes are an important source of new information on nuclear physics. Specifically, the spin-isospin components in the nucleon-nucleon (NN) interaction, e.g., the proton-neutron tensor force, are expected to modify shell structure in exotic nuclei. These potential changes in the intrinsic shell structure are of fundamental interest. The study of the excitation energy of states corresponding to specific configurations in even-even isotopes, together with the single-particle character of the first excited states of odd-A, neutron-rich Ni isotopes, probes the evolution of the neutron orbitals around the Fermi surface as a function of the neutron number a step forward in the understanding of the region and the nature of the NN interaction at large N/Z ratios. In an experiment carried out at the National Superconducting Cyclotron Laboratory [1], new spectroscopic information was obtained for 68Ni and the distribution of single-particle strengths in 67,69Ni was characterized by means of single-neutron knockout from 68,70Ni secondary beams. The spectroscopic strengths, deduced from the measured partial cross sections to the individual states tagged by their de-exciting gamma rays, is used to identify and quantify configurations that involve neutron excitations across the N = 40 harmonic oscillator shell closure. The de-excitation γ rays were measured with the GRETINA tracking array [2]. The results challenge the validity of the most current shell-model Hamiltonians and effective interactions, highlighting shortcomings that cannot yet be explained. These results suggest that our understanding of the low-energy states in such nuclei is not complete and requires further investigation.

Na+/H+ exchanger isoform 1-induced osteopontin expression facilitates cardiac hypertrophy through p90 ribosomal S6 kinase.

PubMed

Abdulrahman, Nabeel; Jaspard-Vinassa, Beatrice; Fliegel, Larry; Jabeen, Aayesha; Riaz, Sadaf; Gadeau, Alain-Pierre; Mraiche, Fatima

2018-05-01

Cardiovascular diseases are the leading cause of death worldwide. One in three cases of heart failure is due to dilated cardiomyopathy. The Na + /H + exchanger isoform 1 (NHE1), a multifunctional protein and the key pH regulator in the heart, has been demonstrated to be increased in this condition. We have previously demonstrated that elevated NHE1 activity induced cardiac hypertrophy in vivo. Furthermore, the overexpression of active NHE1 elicited modulation of gene expression in cardiomyocytes including an upregulation of myocardial osteopontin (OPN) expression. To determine the role of OPN in inducing NHE1-mediated cardiomyocyte hypertrophy, double transgenic mice expressing active NHE1 and OPN knockout were generated and assessed by echocardiography and the cardiac phenotype. Our studies showed that hearts expressing active NHE1 exhibited cardiac remodeling indicated by increased systolic and diastolic left ventricular internal diameter and increased ventricular volume. Moreover, these hearts demonstrated impaired function with decreased fractional shortening and ejection fraction. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) mRNA was upregulated, and there was an increase in heart cell cross-sectional area confirming the cardiac hypertrophic effect. Moreover, NHE1 transgenic mice also showed increased collagen deposition, upregulation of CD44 and phosphorylation of p90 ribosomal s6 kinase (RSK), effects that were regressed in OPN knockout mice. In conclusion, we developed an interesting comparative model of active NHE1 transgenic mouse lines which express a dilated hypertrophic phenotype expressing CD44 and phosphorylated RSK, effects which were regressed in absence of OPN.

Improved Antibodies Against ERBB4/HER4 | NCI Technology Transfer Center | TTC

Cancer.gov

The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Section on Molecular Neurobiology seeks parties interested in licensing or collaborative research to further evaluate or commercialize specific rabbit monoclonal antibodies generated against the ErbB4 receptor (also known as HER4) that have been validated for specificity using tissue sections and extracts from ErbB4 knockout mice.

Spectroscopic factors in the N =20 island of inversion: The Nilsson strong-coupling limit

NASA Astrophysics Data System (ADS)

Macchiavelli, A. O.; Crawford, H. L.; Campbell, C. M.; Clark, R. M.; Cromaz, M.; Fallon, P.; Jones, M. D.; Lee, I. Y.; Richard, A. L.; Salathe, M.

2017-11-01

Spectroscopic factors, extracted from one-neutron knockout and Coulomb dissociation reactions, for transitions from the ground state of 33Mg to the ground-state rotational band in 32Mg, and from 32Mg to low-lying negative-parity states in 31Mg, are interpreted within the rotational model. Associating the ground state of 33Mg and the negative-parity states in 31Mg with the 3/2 [321 ] Nilsson level, the strong coupling limit gives simple expressions that relate the amplitudes (Cj ℓ) of this wave function with the measured cross sections and derived spectroscopic factors (Sj ℓ). To obtain a consistent agreement with the data within this framework, we find that one requires a modified 3/2 [321 ] wave function with an increased contribution from the spherical 2 p3 /2 orbit as compared to a standard Nilsson calculation. This is consistent with the findings of large-scale shell model calculations and can be traced to weak binding effects that lower the energy of low-ℓ orbitals.

Severe Intestinal Inflammation in the Small Intestine of Mice Induced by Controllable Deletion of Claudin-7.

PubMed

Li, Wen-Jing; Xu, Chang; Wang, Kun; Li, Teng-Yan; Wang, Xiao-Nan; Yang, Hui; Xing, Tiaosi; Li, Wen-Xia; Chen, Yan-Hua; Gao, Hong; Ding, Lei

2018-05-01

As a potential tumor suppressor gene, Claudin-7 (Cldn7), which is a component of tight junctions, may play an important role in colorectal cancer occurrence and development. To generate a knockout mouse model of inducible conditional Cldn7 in the intestine and analyze the phenotype of the mice after induction with tamoxifen. We constructed Cldn7-flox transgenic mice and crossed them with Villin-CreERT2 mice. The Cldn7 inducible conditional knockout mice appeared normal and were well developed at birth. We induced Cldn7 gene deletion by injecting different dosages of tamoxifen into the mice and then conducted a further phenotypic analysis. After induction for 5 days in succession at a dose of 200 µl tamoxifen in sunflower oil at 10 mg/ml per mouse every time, the mice appeared dehydrated, had a lower temperature, and displayed inactivity or death. The results of hematoxylin-eosin staining showed that the intestines of the Cldn7 inducible conditional knockout mice had severe intestinal defects that included epithelial cell sloughing, necrosis, inflammation and hyperplasia. Owing to the death of ICKO mice, we adjusted the dose of tamoxifen to a dose of 100 µl in sunflower oil at 10 mg/ml per mouse (aged more than 8 weeks old) every 4 days. And we could induce atypical hyperplasia and adenoma in the intestine. Immunofluorescent staining indicated that the intestinal epithelial structure was destroyed. Electron microscopy experimental analysis indicated that the intercellular gap along the basolateral membrane of Cldn7 inducible conditional knockout mice in the intestine was increased and that contact between the cells and matrix was loosened. We generated a model of intestinal Cldn7 inducible conditional knockout mice. Intestinal Cldn7 deletion induced by tamoxifen initiated inflammation and hyperplasia in mice.

Generation of ER{alpha}-floxed and knockout mice using the Cre/LoxP system

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

Antonson, P., E-mail: per.antonson@ki.se; Omoto, Y.; Humire, P.

2012-08-10

Highlights: Black-Right-Pointing-Pointer ER{alpha} floxed and knockout mice were generated. Black-Right-Pointing-Pointer Disruption of the ER{alpha} gene results in sterility in both male and female mice. Black-Right-Pointing-Pointer ER{alpha}{sup -/-} mice have ovaries with hemorrhagic follicles and hypoplastic uterus. Black-Right-Pointing-Pointer Female ER{alpha}{sup -/-} mice develop obesity. -- Abstract: Estrogen receptor alpha (ER{alpha}) is a nuclear receptor that regulates a range of physiological processes in response to estrogens. In order to study its biological role, we generated a floxed ER{alpha} mouse line that can be used to knock out ER{alpha} in selected tissues by using the Cre/LoxP system. In this study, we established amore » new ER{alpha} knockout mouse line by crossing the floxed ER{alpha} mice with Cre deleter mice. Here we show that genetic disruption of the ER{alpha} gene in all tissues results in sterility in both male and female mice. Histological examination of uterus and ovaries revealed a dramatically atrophic uterus and hemorrhagic cysts in the ovary. These results suggest that infertility in female mice is the result of functional defects of the reproductive tract. Moreover, female knockout mice are hyperglycemic, develop obesity and at the age of 4 months the body weight of these mice was more than 20% higher compared to wild type littermates and this difference increased over time. Our results demonstrate that ER{alpha} is necessary for reproductive tract development and has important functions as a regulator of metabolism in females.« less

Thymosin Beta-4 Induces Mouse Hair Growth

PubMed Central

Hou, Fang; Zhang, Zhipeng; Nuo, Mingtu; Guo, Xudong; Liu, Dongjun

2015-01-01

Thymosin beta-4 (Tβ4) is known to induce hair growth and hair follicle (HF) development; however, its mechanism of action is unknown. We generated mice that overexpressed Tβ4 in the epidermis, as well as Tβ4 global knockout mice, to study the role of Tβ4 in HF development and explore the mechanism of Tβ4 on hair growth. To study Tβ4 function, we depilated control and experimental mice and made tissue sections stained with hematoxylin and eosin (H&E). To explore the effect of Tβ4 on hair growth and HF development, the mRNA and protein levels of Tβ4 and VEGF were detected by real-time PCR and western blotting in control and experimental mice. Protein expression levels and the phosphorylation of P38, ERK and AKT were also examined by western blotting. The results of depilation indicated that hair re-growth was faster in Tβ4-overexpressing mice, but slower in knockout mice. Histological examination revealed that Tβ4-overexpressing mice had a higher number of hair shafts and HFs clustered together to form groups, while the HFs of control mice and knockout mice were separate. Hair shafts in knockout mice were significantly reduced in number compared with control mice. Increased Tβ4 expression at the mRNA and protein levels was confirmed in Tβ4-overexpressing mice, which also had increased VEGF expression. On the other hand, knockout mice had reduced levels of VEGF expression. Mechanistically, Tβ4-overexpressing mice showed increased protein expression levels and phosphorylation of P38, ERK and AKT, whereas knockout mice had decreased levels of both expression and phosphorylation of these proteins. Tβ4 appears to regulate P38/ERK/AKT signaling via its effect on VEGF expression, with a resultant effect on the speed of hair growth, the pattern of HFs and the number of hair shafts. PMID:26083021

Thymosin Beta-4 Induces Mouse Hair Growth.

PubMed

Gao, Xiaoyu; Liang, Hao; Hou, Fang; Zhang, Zhipeng; Nuo, Mingtu; Guo, Xudong; Liu, Dongjun

2015-01-01

Thymosin beta-4 (Tβ4) is known to induce hair growth and hair follicle (HF) development; however, its mechanism of action is unknown. We generated mice that overexpressed Tβ4 in the epidermis, as well as Tβ4 global knockout mice, to study the role of Tβ4 in HF development and explore the mechanism of Tβ4 on hair growth. To study Tβ4 function, we depilated control and experimental mice and made tissue sections stained with hematoxylin and eosin (H&E). To explore the effect of Tβ4 on hair growth and HF development, the mRNA and protein levels of Tβ4 and VEGF were detected by real-time PCR and western blotting in control and experimental mice. Protein expression levels and the phosphorylation of P38, ERK and AKT were also examined by western blotting. The results of depilation indicated that hair re-growth was faster in Tβ4-overexpressing mice, but slower in knockout mice. Histological examination revealed that Tβ4-overexpressing mice had a higher number of hair shafts and HFs clustered together to form groups, while the HFs of control mice and knockout mice were separate. Hair shafts in knockout mice were significantly reduced in number compared with control mice. Increased Tβ4 expression at the mRNA and protein levels was confirmed in Tβ4-overexpressing mice, which also had increased VEGF expression. On the other hand, knockout mice had reduced levels of VEGF expression. Mechanistically, Tβ4-overexpressing mice showed increased protein expression levels and phosphorylation of P38, ERK and AKT, whereas knockout mice had decreased levels of both expression and phosphorylation of these proteins. Tβ4 appears to regulate P38/ERK/AKT signaling via its effect on VEGF expression, with a resultant effect on the speed of hair growth, the pattern of HFs and the number of hair shafts.

Nano-Computed Tomography: Technique and Applications.

PubMed

Kampschulte, M; Langheinirch, A C; Sender, J; Litzlbauer, H D; Althöhn, U; Schwab, J D; Alejandre-Lafont, E; Martels, G; Krombach, G A

2016-02-01

Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE (-/-)/LDLR(-/-) double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques. Nano-computed tomography is a high resolution CT-technology for 3D imaging at sub-micrometer resolution. The technical concept bases on a further development of the established ex-vivo-micro-CT technology. By improvement of the spatial resolution, structures at a cellular level become visible (e.g. osteocyte lacunae). © Georg Thieme Verlag KG Stuttgart · New York.

Bypass of a psoralen DNA interstrand cross-link by DNA polymerases beta, iota, and kappa in vitro

PubMed Central

Smith, Leigh A.; Makarova, Alena V.; Samson, Laura; Thiesen, Katherine E.; Dhar, Alok; Bessho, Tadayoshi

2012-01-01

Repair of DNA inter-strand cross-links in mammalian cells involves several biochemically distinctive processes, including the release of one of the cross-linked strands and translesion DNA synthesis (TLS). In this report, we investigated in vitro TLS activity of psoralen DNA inter-strand cross-link by three DNA repair polymerases, DNA polymerase beta, kappa and iota. DNA polymerase beta is capable of bypassing a psoralen cross-link with a low efficiency. Cell extracts prepared from DNA polymerase beta knockout mouse embryonic fibroblast showed a reduced bypass activity of the psoralen cross-link and purified DNA polymerase beta restored the bypass activity. In addition, DNA polymerase iota mis-incorporated thymine across the psoralen cross-link and DNA polymerase kappa extended these mis-paired primer ends, suggesting that DNA polymerase iota may serve as an inserter and DNA polymerase kappa may play a role as an extender in the repair of psoralen DNA inter-strand cross-links. The results demonstrated here indicate that multiple DNA polymerases could participate in TLS steps in mammalian DNA inter-strand cross-link repair. PMID:23106263

Increased 4-hydroxynonenal protein adducts in male GSTA4–4/PPAR-alpha double knockout mice enhance injury during early stages of alcoholic liver disease

USDA-ARS?s Scientific Manuscript database

To test the significance of lipid peroxidation in the development of alcoholic liver injury, an ethanol (EtOH) liquid diet was fed to male wild type 129/SvJ mice, and glutathione S-transferase A4-4 null (GSTA4-/-) mice for 40 d. GSTA4-/- mice were also crossed with peroxisome proliferator-activated ...

Dynamics of the quasielastic 16O (e, e' p) reaction at Q2 ≈ 0.8 (GeV/c)2

NASA Astrophysics Data System (ADS)

Fissum, K. G.; Liang, M.; Anderson, B. D.; Aniol, K. A.; Auerbach, L.; Baker, F. T.; Berthot, J.; Bertozzi, W.; Bertin, P.-Y.; Bimbot, L.; Boeglin, W. U.; Brash, E. J.; Breton, V.; Breuer, H.; Burtin, E.; Calarco, J. R.; Cardman, L. S.; Cates, G. D.; Cavata, C.; Chang, C. C.; Chen, J.-P.; Cisbani, E.; Dale, D. S.; de Jager, C. W.; de Leo, R.; Deur, A.; Diederich, B.; Djawotho, P.; Domingo, J.; Ducret, J.-E.; Epstein, M. B.; Ewell, L. A.; Finn, J. M.; Fonvieille, H.; Frois, B.; Frullani, S.; Gao, J.; Garibaldi, F.; Gasparian, A.; Gilad, S.; Gilman, R.; Glamazdin, A.; Glashausser, C.; Gomez, J.; Gorbenko, V.; Gorringe, T.; Hersman, F. W.; Holmes, R.; Holtrop, M.; D'Hose, N.; Howell, C.; Huber, G. M.; Hyde-Wright, C. E.; Iodice, M.; Jaminion, S.; Jones, M. K.; Joo, K.; Jutier, C.; Kahl, W.; Kato, S.; Kelly, J. J.; Kerhoas, S.; Khandaker, M.; Khayat, M.; Kino, K.; Korsch, W.; Kramer, L.; Kumar, K. S.; Kumbartzki, G.; Laveissière, G.; Leone, A.; Lerose, J. J.; Levchuk, L.; Lindgren, R. A.; Liyanage, N.; Lolos, G. J.; Lourie, R. W.; Madey, R.; Maeda, K.; Malov, S.; Manley, D. M.; Margaziotis, D. J.; Markowitz, P.; Martino, J.; McCarthy, J. S.; McCormick, K.; McIntyre, J.; van der Meer, R. L.; Meziani, Z.-E.; Michaels, R.; Mougey, J.; Nanda, S.; Neyret, D.; Offermann, E. A.; Papandreou, Z.; Perdrisat, C. F.; Perrino, R.; Petratos, G. G.; Platchkov, S.; Pomatsalyuk, R.; Prout, D. L.; Punjabi, V. A.; Pussieux, T.; Quéméner, G.; Ransome, R. D.; Ravel, O.; Roblin, Y.; Roche, R.; Rowntree, D.; Rutledge, G. A.; Rutt, P. M.; Saha, A.; Saito, T.; Sarty, A. J.; Serdarevic-Offermann, A.; Smith, T. P.; Soldi, A.; Sorokin, P.; Souder, P.; Suleiman, R.; Templon, J. A.; Terasawa, T.; Todor, L.; Tsubota, H.; Ueno, H.; Ulmer, P. E.; Urciuoli, G. M.; Vernin, P.; van Verst, S.; Vlahovic, B.; Voskanyan, H.; Watson, J. W.; Weinstein, L. B.; Wijesooriya, K.; Wojtsekhowski, B.; Zainea, D. G.; Zeps, V.; Zhao, J.; Zhou, Z.-L.; Udías, J. M.; Vignote, J. R.; Ryckebusch, J.; Debruyne, D.

2004-09-01

The physics program in Hall A at Jefferson Lab commenced in the summer of 1997 with a detailed investigation of the 16O (e, e' p) reaction in quasielastic, constant (q,ω) kinematics at Q2 ≈0.8 (GeV/c)2 , q≈1 GeV/c , and ω≈445 MeV . Use of a self-calibrating, self-normalizing, thin-film waterfall target enabled a systematically rigorous measurement. Five-fold differential cross-section data for the removal of protons from the 1p -shell have been obtained for 0< pmiss <350 MeV/c . Six-fold differential cross-section data for 0< Emiss <120 MeV were obtained for 0< pmiss <340 MeV/c . These results have been used to extract the ALT asymmetry and the RL , RT , RLT , and RL+TT effective response functions over a large range of Emiss and pmiss . Detailed comparisons of the 1p -shell data with Relativistic Distorted-Wave Impulse Approximation (RDWIA), Relativistic Optical-Model Eikonal Approximation (ROMEA), and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations indicate that two-body currents stemming from meson-exchange currents (MEC) and isobar currents (IC) are not needed to explain the data at this Q2 . Further, dynamical relativistic effects are strongly indicated by the observed structure in ALT at pmiss ≈300 MeV/c . For 25< Emiss <50 MeV and pmiss ≈50 MeV/c , proton knockout from the 1 s1/2 -state dominates, and ROMEA calculations do an excellent job of explaining the data. However, as pmiss increases, the single-particle behavior of the reaction is increasingly hidden by more complicated processes, and for 280< pmiss <340 MeV/c , ROMEA calculations together with two-body currents stemming from MEC and IC account for the shape and transverse nature of the data, but only about half the magnitude of the measured cross section. For 50< Emiss <120 MeV and 145< pmiss <340 MeV/c , (e, e' pN) calculations which include the contributions of central and tensor correlations (two-nucleon correlations) together with MEC and IC (two-nucleon currents) account for only about half of the measured cross section. The kinematic consistency of the 1p -shell normalization factors extracted from these data with respect to all available 16O (e, e' p) data is also examined in detail. Finally, the Q2 -dependence of the normalization factors is discussed.

Prostaglandin E2 Activates YAP and a Positive-Signaling Loop to Promote Colon Regeneration After Colitis but Also Carcinogenesis in Mice.

PubMed

Kim, Han-Byul; Kim, Minchul; Park, Young-Soo; Park, Intae; Kim, Tackhoon; Yang, Sung-Yeun; Cho, Charles J; Hwang, DaeHee; Jung, Jin-Hak; Markowitz, Sanford D; Hwang, Sung Wook; Yang, Suk-Kyun; Lim, Dae-Sik; Myung, Seung-Jae

2017-02-01

Prostaglandin E 2 (PGE 2 ) is mediator of inflammation that regulates tissue regeneration, but its continual activation has been associated with carcinogenesis. Little is known about factors in the PGE 2 signaling pathway that contribute to tumor formation. We investigated whether yes-associated protein 1 (YAP1), a transcriptional co-activator in the Hippo signaling pathway, mediates PGE 2 function. DLD-1 and SW480 colon cancer cell lines were transfected with vectors expressing transgenes or small hairpin RNAs and incubated with recombinant PGE 2 , with or without pharmacologic inhibitors of signaling proteins, and analyzed by immunoblot, immunofluorescence, quantitative reverse-transcription polymerase chain reaction, transcriptional reporter, and proliferation assays. Dextran sodium sulfate (DSS) was given to induce colitis in C57/BL6 (control) mice, as well as in mice with disruption of the hydroxyprostaglandin dehydrogenase 15 gene (15-PGDH-knockout mice), Yap1 gene (YAP-knockout mice), and double-knockout mice. Some mice also were given indomethacin to block PGE 2 synthesis. 15-PGDH knockout mice were crossed with mice with intestine-specific disruption of the salvador family WW domain containing 1 gene (Sav1), which encodes an activator of Hippo signaling. We performed immunohistochemical analyses of colon biopsy samples from 26 patients with colitis-associated cancer and 51 age-and sex-matched patients with colorectal cancer (without colitis). Incubation of colon cancer cell lines with PGE 2 led to phosphorylation of cyclic adenosine monophosphate-responsive element binding protein 1 and increased levels of YAP1 messenger RNA, protein, and YAP1 transcriptional activity. This led to increased transcription of the prostaglandin-endoperoxide synthase 2 gene (PTGS2 or cyclooxygenase 2) and prostaglandin E-receptor 4 gene (PTGER4 or EP4). Incubation with PGE 2 promoted proliferation of colon cancer cell lines, but not cells with knockdown of YAP1. Control mice developed colitis after administration of DSS, but injection of PGE 2 led to colon regeneration in these mice. However, YAP-knockout mice did not regenerate colon tissues and died soon after administration of DSS. 15-PGDH-knockout mice regenerated colon tissues more rapidly than control mice after withdrawal of DSS, and had faster recovery of body weight, colon length, and colitis histology scores. These effects were reversed by injection of indomethacin. SAV1-knockout or 15-PGDH-knockout mice did not develop spontaneous tumors after colitis induction, but SAV1/15-PGDH double-knockout mice developed polyps that eventually progressed to carcinoma in situ. Administration of indomethacin to these mice prevented spontaneous tumor formation. Levels of PGE 2 correlated with those of YAP levels in human sporadic colorectal tumors and colitis-associated tumors. PGE 2 signaling increases the expression and transcriptional activities of YAP1, leading to increased expression of cyclooxygenase 2 and EP4 to activate a positive signaling loop. This pathway promotes proliferation of colon cancer cell lines and colon tissue regeneration in mice with colitis. Constitutive activation of this pathway led to formation of polyps and colon tumors in mice. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Deficiency of Rac1 Blocks NADPH Oxidase Activation, Inhibits Endoplasmic Reticulum Stress, and Reduces Myocardial Remodeling in a Mouse Model of Type 1 Diabetes

PubMed Central

Li, Jianmin; Zhu, Huaqing; Shen, E; Wan, Li; Arnold, J. Malcolm O.; Peng, Tianqing

2010-01-01

OBJECTIVE Our recent study demonstrated that Rac1 and NADPH oxidase activation contributes to cardiomyocyte apoptosis in short-term diabetes. This study was undertaken to investigate if disruption of Rac1 and inhibition of NADPH oxidase would prevent myocardial remodeling in chronic diabetes. RESEARCH DESIGN AND METHODS Diabetes was induced by injection of streptozotocin in mice with cardiomyocyte-specific Rac1 knockout and their wild-type littermates. In a separate experiment, wild-type diabetic mice were treated with vehicle or apocynin in drinking water. Myocardial hypertrophy, fibrosis, endoplasmic reticulum (ER) stress, inflammatory response, and myocardial function were investigated after 2 months of diabetes. Isolated adult rat cardiomyocytes were cultured and stimulated with high glucose. RESULTS In diabetic hearts, NADPH oxidase activation, its subunits' expression, and reactive oxygen species production were inhibited by Rac1 knockout or apocynin treatment. Myocardial collagen deposition and cardiomyocyte cross-sectional areas were significantly increased in diabetic mice, which were accompanied by elevated expression of pro-fibrotic genes and hypertrophic genes. Deficiency of Rac1 or apocynin administration reduced myocardial fibrosis and hypertrophy, resulting in improved myocardial function. These effects were associated with a normalization of ER stress markers' expression and inflammatory response in diabetic hearts. In cultured cardiomyocytes, high glucose–induced ER stress was inhibited by blocking Rac1 or NADPH oxidase. CONCLUSIONS Rac1 via NADPH oxidase activation induces myocardial remodeling and dysfunction in diabetic mice. The role of Rac1 signaling may be associated with ER stress and inflammation. Thus, targeting inhibition of Rac1 and NADPH oxidase may be a therapeutic approach for diabetic cardiomyopathy. PMID:20522592

Identification of Mom12 and Mom13, two novel modifier loci of Apc (Min) -mediated intestinal tumorigenesis.

PubMed

Crist, Richard C; Roth, Jacquelyn J; Lisanti, Michael P; Siracusa, Linda D; Buchberg, Arthur M

2011-04-01

Colorectal cancer is a heterogeneous disease resulting from a combination of genetic and environmental factors. The C57BL/6J (B6) Apc (Min/+) mouse develops polyps throughout the gastrointestinal tract and has been a valuable model for understanding the genetic basis of intestinal tumorigenesis. Apc (Min/+) mice have been used to study known oncogenes and tumor suppressor genes on a controlled genetic background. These studies often utilize congenic knockout alleles, which can carry an unknown amount of residual donor DNA. The Apc (Min) model has also been used to identify modifer loci, known as Modifier of Min (Mom) loci, which alter Apc (Min) -mediated intestinal tumorigenesis. B6 mice carrying a knockout allele generated in WW6 embryonic stem cells were crossed to B6 Apc (Min/+) mice to determine the effect on polyp multiplicity. The newly generated colony developed significantly more intestinal polyps than Apc (Min/+) controls. Polyp multiplicity did not correlate with inheritance of the knockout allele, suggesting the presence of one or more modifier loci segregating in the colony. Genotyping of simple sequence length polymorphism (SSLP) markers revealed residual 129X1/SvJ genomic DNA within the congenic region of the parental knockout line. An analysis of polyp multiplicity data and SSLP genotyping indicated the presence of two Mom loci in the colony: 1) Mom12, a dominant modifier linked to the congenic region on chromosome 6, and 2) Mom13, which is unlinked to the congenic region and whose effect is masked by Mom12. The identification of Mom12 and Mom13 demonstrates the potential problems resulting from residual heterozygosity present in congenic lines.

β1/2 or M2/3 Receptors Are Required for Different Gastrointestinal Motility Responses Induced by Acupuncture at Heterotopic or Homotopic Acupoints

PubMed Central

Yu, Xiaochun; Cui, Changxiang; Yang, Zhaokun; Shi, Hong; Jing, Xianghong; Zhu, Bing

2016-01-01

Acupuncture at homotopic acupoints or heterotopic acupoints is known to either inhibit or facilitate gastrointestinal motility, depending on the acupoint location. However, little effort has been made to investigate the roles of specific receptors (such as adrenergic and muscarinic acetylcholine receptors) in mediating the effects of acupuncture at heterotopic and homotopic acupoints. Different adrenergic receptor subtypes or cholinergic receptor subtypes are predominantly expressed in various sections of the gut, resulting in variations between the effects of acupuncture at heterotopic or homotopic acupoints on gastrointestinal motility. Here, we investigated the role of β1/β2 receptors and M2/M3 receptors in gastrointestinal motility regulated by acupuncture at ST37, a heterotopic acupoint, and ST25, a homotopic acupoint, by simultaneously recording intraluminal pressures in the distal colon and stomach or jejunum and examining fecal phenol red excretion in β1/2 receptor-knockout mice and M2/3 receptor-knockout mice. We found that knockout of the M2/3 receptor significantly inhibited ST37 acupuncture-induced enhancement of gastric motility, jejunal motility, and colonic motility. Additionally, knocking out of the β1/2 receptor significantly diminished the ST25 acupuncture-induced inhibition of gastric motility and jejunal motility without significantly altering the enhancement of colonic motility induced by acupuncture at ST25. Acupuncture at ST37 significantly accelerated gastrointestinal transition in β1/2 receptor-knockout mice and their wild-type littermates. However, this acceleration of gastrointestinal transition was markedly diminished in M2/3 receptor-knockout mice relative to their wild-type littermates. Acupuncture at ST25 significantly increased gastrointestinal transition in β1/2 receptor-knockout mice and significantly decreased gastrointestinal transition in M2/3 receptor-knockout mice without altering gastrointestinal transition in wild-type littermates of either. Our study revealed that M2/3 receptors are required for the gastrointestinal motility associated with whole gastrointestinal transition enhanced by acupuncture at heterotopic acupoints, whereas β1/2 receptors are required for the same gastrointestinal motility processes inhibited by acupuncture at homotopic acupoints. Therefore, our findings reveal important biological mechanisms underlying acupuncture treatment of disorders involving gastrointestinal motility dysfunction. PMID:27978539

Environment Mediated Drug Resistance in Neuroblastoma

DTIC Science & Technology

2015-12-01

activate STAT3 and MYC in neuroblastomas independently of IL6). Figure 9: Effect of IL-6 knockout crossing with NB- Tag mice. (A) MRI of abdominal...production. (D) Representative MRI images of NB-Tag and NB- Tag/IL-6KO pre-chemotherapy, post 3 and 6 weeks of chemotherapy. Task 6. Contribution of bone...described (16). Cells were lysed in radioimmunoprecipitation assay (RIPA) buffer supplemented with 1 tablet of complete mini-EDTA protease inhibitor

Role of WNT16 in the Regulation of Periosteal Bone Formation in Female Mice

PubMed Central

Wergedal, Jon E.; Kesavan, Chandrasekhar; Brommage, Robert; Das, Subhashri

2015-01-01

In this study, we evaluated the role of WNT16 in regulating bone size, an important determinant of bone strength. Mice with targeted disruption of the Wnt16 gene exhibited a 24% reduction in tibia cross-sectional area at 12 weeks of age compared with that of littermate wild-type (WT) mice. Histomorphometric studies revealed that the periosteal bone formation rate and mineral apposition rate were reduced (P < .05) by 55% and 32%, respectively, in Wnt16 knockout (KO) vs WT mice at 12 weeks of age. In contrast, the periosteal tartrate resistant acid phosphatase-labeled surface was increased by 20% in the KO mice. Because mechanical strain is an important physiological regulator of periosteal bone formation (BF), we determined whether mechanical loading–induced periosteal BF is compromised in Wnt16 KO mice. Application of 4800-μe strain to the right tibia using a 4-point bending loading method for 2 weeks (2-Hz frequency, 36 cycles per day, 6 days/wk) produced a significant increase in cross-sectional area (11% above that of the unloaded left tibia, P < .05, n = 6) in the WT but not in the KO mice (−0.2% change). Histomorphometric analyses revealed increases in the periosteal bone formation rate and mineral apposition rate in the loaded bones of WT but not KO mice. Wnt16 KO mice showed significant (20%–70%) reductions in the expression levels of markers of canonical (β-catenin and Axin2) but not noncanonical (Nfatc1 and Tnnt2) WNT signaling in the periosteum at 5 weeks of age. Our findings suggest that WNT16 acting via canonical WNT signaling regulates mechanical strain-induced periosteal BF and bone size. PMID:25521583

Functional characterization of Autographa californica multiple nucleopolyhedrovirus gp16 (ac130)

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

Yang, Ming; Huang, Cui; Qian, Duo-Duo

2014-09-15

To investigate the function of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) gp16, multiple gp16-knockout and repair mutants were constructed and characterized. No obvious difference in productivity of budded virus, DNA synthesis, late gene expression and morphogenesis was observed between gp16-knockout and repair viruses, but gp16 deletion resulted in six hours of lengthening in ST{sub 50} to the third instar Spodoptera exigua larvae in bioassays. GP16 was fractionated mainly in the light membrane fraction, by subcellular fractionation. A GP16-EGFP fusion protein was predominantly localized close around the nuclear membrane in infected cells, being coincident with formation of the vesicles associated with themore » nuclear membrane, which hosted nucleocapsids released from the nucleus. These data suggest that gp16 is not required for viral replication, but may be involved in membrane trafficking associated with the envelopment/de-envelopment of budded viruses when they cross over the nuclear membrane and pass through cytoplasm. - Highlights: • gp16 knockout and repair mutants of AcMNPV were constructed and characterized. • AcMNPV gp16 is not essential to virus replication. • Deletion of gp16 resulted in time lengthening to kill S. exigua larvae. • GP16 was localized close around the nuclear membrane of infected cells. • GP16 was fractionated in the light membrane fraction in subcellular fractionation.« less

Strong morphological defects in conditional Arabidopsis abp1 knock-down mutants generated in absence of functional ABP1 protein.

PubMed

Michalko, Jaroslav; Glanc, Matouš; Perrot-Rechenmann, Catherine; Friml, Jiří

2016-01-01

The Auxin Binding Protein 1 (ABP1) is one of the most studied proteins in plants. Since decades ago, it has been the prime receptor candidate for the plant hormone auxin with a plethora of described functions in auxin signaling and development. The developmental importance of ABP1 has recently been questioned by identification of Arabidopsis thaliana abp1 knock-out alleles that show no obvious phenotypes under normal growth conditions. In this study, we examined the contradiction between the normal growth and development of the abp1 knock-outs and the strong morphological defects observed in three different ethanol-inducible abp1 knock-down mutants ( abp1-AS, SS12K, SS12S). By analyzing segregating populations of abp1 knock-out vs. abp1 knock-down crosses we show that the strong morphological defects that were believed to be the result of conditional down-regulation of ABP1 can be reproduced also in the absence of the functional ABP1 protein. This data suggests that the phenotypes in  abp1 knock-down lines are due to the off-target effects and asks for further reflections on the biological function of ABP1 or alternative explanations for the missing phenotypic defects in the abp1 loss-of-function alleles.

GABAA receptor γ2 subunit knockdown mice have enhanced anxiety-like behavior but unaltered hypnotic response to benzodiazepines

PubMed Central

Chandra, Dev; Korpi, Esa R; Miralles, Celia P; De Blas, Angel L; Homanics, Gregg E

2005-01-01

Background Gamma-aminobutyric acid type A receptors (GABAA-Rs) are the major inhibitory receptors in the mammalian brain and are modulated by a number of sedative/hypnotic drugs including benzodiazepines and anesthetics. The significance of specific GABAA-Rs subunits with respect to behavior and in vivo drug responses is incompletely understood. The γ2 subunit is highly expressed throughout the brain. Global γ2 knockout mice are insensitive to the hypnotic effects of diazepam and die perinatally. Heterozygous γ2 global knockout mice are viable and have increased anxiety-like behaviors. To further investigate the role of the γ2 subunit in behavior and whole animal drug action, we used gene targeting to create a novel mouse line with attenuated γ2 expression, i.e., γ2 knockdown mice. Results Knockdown mice were created by inserting a neomycin resistance cassette into intron 8 of the γ2 gene. Knockdown mice, on average, showed a 65% reduction of γ2 subunit mRNA compared to controls; however γ2 gene expression was highly variable in these mice, ranging from 10–95% of normal. Immunohistochemical studies demonstrated that γ2 protein levels were also variably reduced. Pharmacological studies using autoradiography on frozen brain sections demonstrated that binding of the benzodiazepine site ligand Ro15-4513 was decreased in mutant mice compared to controls. Behaviorally, knockdown mice displayed enhanced anxiety-like behaviors on the elevated plus maze and forced novelty exploration tests. Surprisingly, mutant mice had an unaltered response to hypnotic doses of the benzodiazepine site ligands diazepam, midazolam and zolpidem as well as ethanol and pentobarbital. Lastly, we demonstrated that the γ2 knockdown mouse line can be used to create γ2 global knockout mice by crossing to a general deleter cre-expressing mouse line. Conclusion We conclude that: 1) insertion of a neomycin resistance gene into intron 8 of the γ2 gene variably reduced the amount of γ2, and that 2) attenuated expression of γ2 increased anxiety-like behaviors but did not lead to differences in the hypnotic response to benzodiazepine site ligands. This suggests that reduced synaptic inhibition can lead to a phenotype of increased anxiety-like behavior. In contrast, normal drug effects can be maintained despite a dramatic reduction in GABAA-R targets. PMID:15850489

Disruption of estrogen receptor signaling enhances intestinal neoplasia in Apc(Min/+) mice.

PubMed

Cleveland, Alicia G; Oikarinen, Seija I; Bynoté, Kimberly K; Marttinen, Maija; Rafter, Joseph J; Gustafsson, Jan-Ake; Roy, Shyamal K; Pitot, Henry C; Korach, Kenneth S; Lubahn, Dennis B; Mutanen, Marja; Gould, Karen A

2009-09-01

Estrogen receptors (ERs) [ERalpha (Esr1) and ERbeta (Esr2)] are expressed in the human colon, but during the multistep process of colorectal carcinogenesis, expression of both ERalpha and ERbeta is lost, suggesting that loss of ER function might promote colorectal carcinogenesis. Through crosses between an ERalpha knockout and Apc(Min) mouse strains, we demonstrate that ERalpha deficiency is associated with a significant increase in intestinal tumor multiplicity, size and burden in Apc(Min/+) mice. Within the normal intestinal epithelium of Apc(Min/+) mice, ERalpha deficiency is associated with an accumulation of nuclear beta-catenin, an indicator of activation of the Wnt-beta-catenin-signaling pathway, which is known to play a critical role in intestinal cancers. Consistent with the hypothesis that ERalpha deficiency is associated with activation of Wnt-beta-catenin signaling, ERalpha deficiency in the intestinal epithelium of Apc(Min/+) mice also correlated with increased expression of Wnt-beta-catenin target genes. Through crosses between an ERbeta knockout and Apc(Min) mouse strains, we observed some evidence that ERbeta deficiency is associated with an increased incidence of colon tumors in Apc(Min/+) mice. This effect of ERbeta deficiency does not involve modulation of Wnt-beta-catenin signaling. Our studies suggest that ERalpha and ERbeta signaling modulate colorectal carcinogenesis, and ERalpha does so, at least in part, by regulating the activity of the Wnt-beta-catenin pathway.

Disruption of estrogen receptor signaling enhances intestinal neoplasia in ApcMin/+ mice

PubMed Central

Cleveland, Alicia G.; Oikarinen, Seija I.; Bynoté, Kimberly K.; Marttinen, Maija; Rafter, Joseph J.; Gustafsson, Jan-Åke; Roy, Shyamal K.; Pitot, Henry C.; Korach, Kenneth S.; Lubahn, Dennis B.; Mutanen, Marja; Gould, Karen A.

2009-01-01

Estrogen receptors (ERs) [ERα (Esr1) and ERβ (Esr2)] are expressed in the human colon, but during the multistep process of colorectal carcinogenesis, expression of both ERα and ERβ is lost, suggesting that loss of ER function might promote colorectal carcinogenesis. Through crosses between an ERα knockout and ApcMin mouse strains, we demonstrate that ERα deficiency is associated with a significant increase in intestinal tumor multiplicity, size and burden in ApcMin/+ mice. Within the normal intestinal epithelium of ApcMin/+ mice, ERα deficiency is associated with an accumulation of nuclear β-catenin, an indicator of activation of the Wnt–β-catenin-signaling pathway, which is known to play a critical role in intestinal cancers. Consistent with the hypothesis that ERα deficiency is associated with activation of Wnt–β-catenin signaling, ERα deficiency in the intestinal epithelium of ApcMin/+ mice also correlated with increased expression of Wnt–β-catenin target genes. Through crosses between an ERβ knockout and ApcMin mouse strains, we observed some evidence that ERβ deficiency is associated with an increased incidence of colon tumors in ApcMin/+ mice. This effect of ERβ deficiency does not involve modulation of Wnt–β-catenin signaling. Our studies suggest that ERα and ERβ signaling modulate colorectal carcinogenesis, and ERα does so, at least in part, by regulating the activity of the Wnt–β-catenin pathway. PMID:19520794

VEGF and VEGFB Play Balancing Roles in Adipose Differentiation, Gene Expression, and Function.

PubMed

Jin, Honghong; Li, Dan; Wang, Xutong; Jia, Jia; Chen, Yang; Yao, Yapeng; Zhao, Chunlan; Lu, Xiaodan; Zhang, Shujie; Togo, Jacques; Ji, Yan; Zhang, Luqing; Feng, Xuechao; Zheng, Yaowu

2018-05-01

Obesity is the result of abnormal adipose development and energy metabolism. Using vascular endothelial growth factor (VEGF) B-knockout and inducible VEGF downregulation mouse models, we have shown that VEGFB inactivation caused expansion of white adipose, whitening of brown adipose, an increase in fat accumulation, and a reduction in energy consumption. At the same time, expression of the white adipose-associated genes was increased and brown adipose-associated genes decreased. VEGF repression, in contrast, induced brown adipose expansion and brown adipocyte development in white adipose, increased energy expenditure, upregulated brown adipose-associated genes, and downregulated white adipose-associated genes. When VEGFB-knockout and VEGF-repressed mice are crossed together, VEGF and VEGFB can counteractively regulate large numbers of genes and efficiently reverse each other's roles. These genes, under counteractive VEGF and VEGFB regulations, include transcription factors, adhesion molecules, and metabolic enzymes. This balancing role is confirmed by morphologic and functional changes. This study reports that VEGF and VEGFB counteractively regulate adipose development and function in energy metabolism.

Transglutaminase-2 differently regulates cartilage destruction and osteophyte formation in a surgical model of osteoarthritis.

PubMed

Orlandi, A; Oliva, F; Taurisano, G; Candi, E; Di Lascio, A; Melino, G; Spagnoli, L G; Tarantino, U

2009-04-01

Osteoarthritis is a progressive joint disease characterized by cartilage degradation and bone remodeling. Transglutaminases catalyze a calcium-dependent transamidation reaction that produces covalent cross-linking of available substrate glutamine residues and modifies the extracellular matrix. Increased transglutaminases-mediated activity is reported in osteoarthritis, but the relative contribution of transglutaminases-2 (TG2) is uncertain. We describe TG2 expression in human femoral osteoarthritis and in wild-type and homozygous TG2 knockout mice after surgically-induced knee joint instability. Increased TG2 levels were observed in human and wild-type murine osteoarthritic cartilage compared to the respective controls. Histomorphometrical but not X-ray investigation documented in osteoarthritic TG2 knockout mice reduced cartilage destruction and an increased osteophyte formation compared to wild-type mice. These differences were associated with increased TGFbeta-1 expression. In addition to confirming its important role in osteoarthritis development, our results demonstrated that TG2 expression differently influences cartilage destruction and bone remodeling, suggesting new targeted TG2-related therapeutic strategies.

Lacrimal gland-derived IL-22 regulates IL-17-mediated ocular mucosal inflammation

PubMed Central

Ji, Yong Woo; Mittal, Sharad K.; Hwang, Ho Sik; Chang, Eun-Ju; Lee, Joon H.; Seo, Yuri; Yeo, Areum; Noh, Hyemi; Lee, Hye Sun; Chauhan, Sunil K.; Lee, Hyung Keun

2016-01-01

Inflammatory damage of mucosal surface of the eye is a hallmark of dry eye disease (DED), and in severe cases can lead to significant discomfort, visual impairment, and blindness. DED is a multifactorial autoimmune disorder with a largely unknown pathogenesis. Using a cross-sectional patient study and a well-characterized murine model of DED, herein we investigated the immunoregulatory function of interleukin-22 (IL-22) in the pathogenesis of DED. We found that IL-22 levels were elevated in lacrimal fluids of DED patients and inversely correlated with severity of disease. Acinar cells of the lacrimal glands, not inflammatory immune cells, are the primary source of IL-22, which suppresses inflammation in ocular surface epithelial cells upon desiccating stress. Moreover, loss of function analyses using IL-22 knock-out mice demonstrated that IL-22 is essential for suppression of ocular surface infiltration of Th17 cells and inhibition of DED induction. Our novel findings elucidate immunoregulatory function of lacrimal gland-derived IL-22 in inhibiting IL-17-mediated ocular surface epitheliopathy in DED thus making IL-22 a new relevant therapeutic target. PMID:28051088

Morphological observation of the stria vascularis in midkine and pleiotrophin knockout mice.

PubMed

Sone, Michihiko; Muramatsu, Hisako; Muramatsu, Takashi; Nakashima, Tsutomu

2011-02-01

Midkine and Pleiotrophin are low molecular weight basic proteins with closely related structures and serve as growth/differentiation factors. They have been reported to be expressed in the cochlea during the embryonic and perinatal periods. In the present study, we focused on the roles of midkine and pleiotrophin in the stria vascularis and investigated morphological changes using mice deficient in these genes. Midkine knockout, pleiotrophin knockout, and double knockout mice were used and compared to wild-type mice. Auditory brain stem responses (ABRs) and cochlear blood flows were measured in each type of mice. Pathological changes in the stria vascularis were examined by light microscopy, including immunohistochemical staining with anti-Kir4.1 antibody, and electron microscopy. Hearing thresholds examined by ABRs were significantly higher in midkine knockout and pleiotrophin knockout mice than in wild-type mice. Double knockout mice showed higher thresholds compared to midkine knockout and pleiotrophin knockout mice. Blood flow in the lateral walls did not significantly differ and light microscopy examination showed an almost normal appearance of the stria vascularis in these knockout mice. However, the expression of Kir4.1 was weak in the knockout mice and severe vacuolar degeneration was observed by electron microscopy in the intermediate cells of the double knockout mice. The present study demonstrates that midkine and pleiotrophin play some roles for the morphological maintenance of intermediate cell in the stria vascularis. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Deletion of Dual Specificity Phosphatase 1 Does Not Predispose Mice to Increased Spontaneous Osteoarthritis

PubMed Central

Pest, Michael Andrew; Pest, Courtney Alice; Bellini, Melina Rodrigues; Feng, Qingping; Beier, Frank

2015-01-01

Background Osteoarthritis (OA) is a degenerative joint disease with poorly understood etiology and pathobiology. Mitogen activated protein kinases (MAPKs) including ERK and p38 play important roles in the mediation of downstream pathways involved in cartilage degenerative processes. Dual specificity phosphatase 1 (DUSP1) dephosphorylates the threonine/serine and tyrosine sites on ERK and p38, causing deactivation of downstream signalling. In this study we examined the role of DUSP1 in spontaneous OA development at 21 months of age using a genetically modified mouse model deficient in Dusp1 (DUSP1 knockout mouse). Results Utilizing histochemical stains of paraffin embedded knee joint sections in DUSP1 knockout and wild type female and male mice, we showed similar structural progression of cartilage degeneration associated with OA at 21 months of age. A semi-quantitative cartilage degeneration scoring system also demonstrated similar scores in the various aspects of the knee joint articular cartilage in DUSP1 knockout and control mice. Examination of overall articular cartilage thickness in the knee joint demonstrated similar results between DUSP1 knockout and wild type mice. Immunostaining for cartilage neoepitopes DIPEN, TEGE and C1,2C was similar in the cartilage lesion sites and chondrocyte pericellular matrix of both experimental groups. Likewise, immunostaining for phosphoERK and MMP13 showed similar intensity and localization between groups. SOX9 immunostaining demonstrated a decreased number of positive cells in DUSP1 knockout mice, with correspondingly decreased staining intensity. Analysis of animal walking patterns (gait) did not show a discernable difference between groups. Conclusion Loss of DUSP1 does not cause changes in cartilage degeneration and gait in a mouse model of spontaneous OA at 21 months of age. Altered staining was observed in SOX9 immunostaining which may prove promising for future studies examining the role of DUSPs in cartilage and OA, as well as models of post-traumatic OA. PMID:26562438

Streptococcus iniae cpsG alters capsular carbohydrate composition and is a cause of serotype switching in vaccinated fish.

PubMed

Heath, Candice; Gillen, Christine M; Chrysanthopoulos, Panagiotis; Walker, Mark J; Barnes, Andrew C

2016-09-25

Streptococcus iniae causes septicaemia and meningitis in marine and freshwater fish wherever they are farmed in warm-temperate and tropical regions. Although serotype specific, vaccination with bacterins (killed bacterial cultures) is largely successful and vaccine failure occurs only occasionally through emergence of new capsular serotypes. Previously we showed that mutations in vaccine escapes are restricted to a limited repertoire of genes within the 20-gene capsular polysaccharide (cps) operon. cpsG, a putative UDP-galactose 4-epimerase, has three sequence types based on the insertion or deletion of the three amino acids leucine, serine and lysine in the substrate binding site of the protein. To elucidate the role of cpsG in capsular polysaccharide (CPS) biosynthesis and capsular composition, we first prepared isogenic knockout and complemented mutants of cpsG by allelic exchange mutagenesis. Deletion of cpsG resulted in changes to colony morphology and cell buoyant density, and also significantly decreased galactose content relative to glucose in the capsular polysaccharide as determined by GC-MS, consistent with epimerase activity of CpsG. There was also a metabolic penalty of cpsG knockout revealed by slower growth in complex media, and reduced proliferation in whole fish blood. Moreover, whilst antibodies raised in fish against the wild type cross-reacted in whole cell and cps ELISA, they did not cross-opsonise the mutant in a peripheral blood neutrophil opsonisation assay, consistent with reported vaccine escape. We have shown here that mutation in cpsG results in altered CPS composition and this in turn results in poor cross-opsonisation that explains some of the historic vaccination failure on fish farms in Australia. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Conditional N-WASP knockout in mouse brain implicates actin cytoskeleton regulation in hydrocephalus pathology.

PubMed

Jain, Neeraj; Lim, Lee Wei; Tan, Wei Ting; George, Bhawana; Makeyev, Eugene; Thanabalu, Thirumaran

2014-04-01

Cerebrospinal fluid (CSF) is produced by the choroid plexus and moved by multi-ciliated ependymal cells through the ventricular system of the vertebrate brain. Defects in the ependymal layer functionality are a common cause of hydrocephalus. N-WASP (Neural-Wiskott Aldrich Syndrome Protein) is a brain-enriched regulator of actin cytoskeleton and N-WASP knockout caused embryonic lethality in mice with neural tube and cardiac abnormalities. To shed light on the role of N-WASP in mouse brain development, we generated N-WASP conditional knockout mouse model N-WASP(fl/fl); Nestin-Cre (NKO-Nes). NKO-Nes mice were born with Mendelian ratios but exhibited reduced growth characteristics compared to their littermates containing functional N-WASP alleles. Importantly, all NKO-Nes mice developed cranial deformities due to excessive CSF accumulation and did not survive past weaning. Coronal brain sections of these animals revealed dilated lateral ventricles, defects in ciliogenesis, loss of ependymal layer integrity, reduced thickness of cerebral cortex and aqueductal stenosis. Immunostaining for N-cadherin suggests that ependymal integrity in NKO-Nes mice is lost as compared to normal morphology in the wild-type controls. Moreover, scanning electron microscopy and immunofluorescence analyses of coronal brain sections with anti-acetylated tubulin antibodies revealed the absence of cilia in ventricular walls of NKO-Nes mice indicative of ciliogenesis defects. N-WASP deficiency does not lead to altered expression of N-WASP regulatory proteins, Fyn and Cdc42, which have been previously implicated in hydrocephalus pathology. Taken together, our results suggest that N-WASP plays a critical role in normal brain development and implicate actin cytoskeleton regulation as a vulnerable axis frequently deregulated in hydrocephalus. Copyright © 2014 Elsevier Inc. All rights reserved.

Pituitary-adrenal responses to oxotremorine and acute stress in male and female M1 muscarinic receptor knockout mice: comparisons to M2 muscarinic receptor knockout mice.

PubMed

Rhodes, M E; Rubin, R T; McKlveen, J M; Karwoski, T E; Fulton, B A; Czambel, R K

2008-05-01

Both within the brain and in the periphery, M(1) muscarinic receptors function primarily as postsynaptic receptors and M(2) muscarinic receptors function primarily as presynaptic autoreceptors. In addition to classical parasympathetic effectors, cholinergic stimulation of central muscarinic receptors influences the release of adrenocorticotrophic hormone (ACTH) and corticosterone. We previously reported that oxotremorine administration to male and female M(2) receptor knockout and wild-type mice increased ACTH to a significantly greater degree in knockout males compared to all other groups, and that M(2) knockout mice of both sexes were significantly more responsive to the mild stress of saline injection than were wild-type mice. These results accord with the primary function of M(2) receptors as presynaptic autoreceptors. In the present study, we explored the role of the M(1) receptor in pituitary-adrenal responses to oxotremorine and saline in male and female M(1) knockout and wild-type mice. Because these mice responded differently to the mild stress of saline injection than did the M(2) knockout and wild-type mice, we also determined hormone responses to restraint stress in both M(1) and M(2) knockout and wild-type mice. Male and female M(1) knockout and wild-type mice were equally unresponsive to the stress of saline injection. Oxotremorine increased both ACTH and corticosterone in M(1) wild-type mice to a significantly greater degree than in knockout mice. In both M(1) knockout and wild-type animals, ACTH responses were greater in males compared to females, and corticosterone responses were greater in females compared to males. Hormone responses to restraint stress were increased in M(2) knockout mice and decreased in M(1) knockout mice compared to their wild-type counterparts. These findings suggest that M(1) and M(2) muscarinic receptor subtypes differentially influence male and female pituitary-adrenal responses to cholinergic stimulation and stress. The decreased pituitary-adrenal sensitivity to oxotremorine and restraint stress noted in M(1) knockout mice is consistent with M(1) being primarily a postsynaptic receptor. Conversely, the increased pituitary-adrenal sensitivity to these challenges noted in M(2) knockout mice is consistent with M(2) being primarily a presynaptic autoreceptor.

Structural and Functional Analysis of HIV-1 Coreceptors: Roles of Charged Residues and Posttranslational Modifications on Coreceptor Activity

DTIC Science & Technology

2000-01-01

various organs and to sites of inflammation. They may have additional functions. For example analysis of CXCR4 knockout mice show that CXCR4, which...SDF-1 knockout mice had similar phenotypes (195). Homozygous knockout of CXCR4 or SDF-1 results in embyonic lethality. Though CCR5 appears to be...dispensable, other chemokine receptors have vital functions. CXCR5 knockout mice have B-cell homing defects (118), and CXCR2 knockout mice

Morphologic and Histologic Comparison of Hypertrophic Scar in Nude Mice, T-Cell Receptor, and Recombination Activating Gene Knockout Mice.

PubMed

Momtazi, Moein; Ding, Jie; Kwan, Peter; Anderson, Colin C; Honardoust, Dariush; Goekjian, Serge; Tredget, Edward E

2015-12-01

Proliferative scars in nude mice have demonstrated morphologic and histologic similarities to human hypertrophic scar. Gene knockout technology provides the opportunity to study the effect of deleting immune cells in various disease processes. The authors' objective was to test whether grafting human skin onto T-cell receptor (TCR) αβ-/-γδ-/-, recombination activating gene (RAG)-1-/-, and RAG-2γ-/-c-/- mice results in proliferative scars consistent with human hypertrophic scar and to characterize the morphologic, histologic, and cellular changes that occur after removing immune cells. Nude TCRαβ-/-γδ-/-, RAG-1-/-, and RAG-2-/-γc-/- mice (n = 20 per strain) were grafted with human skin and euthanized at 30, 60, 120, and 180 days. Controls (n = 5 per strain) were autografted with mouse skin. Scars and normal skin were harvested at each time point. Sections were stained with hematoxylin and eosin, Masson's trichrome, and immunohistochemistry for anti-human leukocyte antigen-ABC, α-smooth muscle actin, decorin, and biglycan. TCRαβ-/-γδ-/-, RAG-1-/-, and RAG-2-/-γc-/- mice grafted with human skin developed firm, elevated scars with histologic and immunohistochemical similarities to human hypertrophic scar. Autografted controls showed no evidence of pathologic scarring. Knockout animals demonstrated a capacity for scar remodeling not observed in nude mice where reductions in α-smooth muscle actin staining pattern and scar thickness occurred over time. Human skin transplanted onto TCRαβ-/-γδ-/-, RAG-1-/-, and RAG-2-/-γc-/- mice results in proliferative scars with morphologic and histologic features of human hypertrophic scar. Remodeling of proliferative scars generated in knockout animals is analogous to changes in human hypertrophic scar. These animal models may better represent the natural history of human hypertrophic scar.

Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation

PubMed Central

Reno, Candace M.; Puente, Erwin C.; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J.; Routh, Vanessa H.; Kahn, Barbara B.

2017-01-01

GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. PMID:27797912

Improved microarray methods for profiling the yeast knockout strain collection

PubMed Central

Yuan, Daniel S.; Pan, Xuewen; Ooi, Siew Loon; Peyser, Brian D.; Spencer, Forrest A.; Irizarry, Rafael A.; Boeke, Jef D.

2005-01-01

A remarkable feature of the Yeast Knockout strain collection is the presence of two unique 20mer TAG sequences in almost every strain. In principle, the relative abundances of strains in a complex mixture can be profiled swiftly and quantitatively by amplifying these sequences and hybridizing them to microarrays, but TAG microarrays have not been widely used. Here, we introduce a TAG microarray design with sophisticated controls and describe a robust method for hybridizing high concentrations of dye-labeled TAGs in single-stranded form. We also highlight the importance of avoiding PCR contamination and provide procedures for detection and eradication. Validation experiments using these methods yielded false positive (FP) and false negative (FN) rates for individual TAG detection of 3–6% and 15–18%, respectively. Analysis demonstrated that cross-hybridization was the chief source of FPs, while TAG amplification defects were the main cause of FNs. The materials, protocols, data and associated software described here comprise a suite of experimental resources that should facilitate the use of TAG microarrays for a wide variety of genetic screens. PMID:15994458

Generation and Characterization of Transgenic Mice Expressing Mouse Ins1 Promoter for Pancreatic β-Cell-Specific Gene Overexpression and Knockout.

PubMed

Cheng, Yulong; Su, Yutong; Shan, Aijing; Jiang, Xiuli; Ma, Qinyun; Wang, Weiqing; Ning, Guang; Cao, Yanan

2015-07-01

The technologies for pancreatic β-cell-specific gene overexpression or knockout are fundamental for investigations of functional genes in vivo. Here we generated the Ins1-Cre-Dsred and Ins1-rtTA mouse models, which expressed the Cre recombinase or reverse tetracycline regulatable transactivator (rtTA) without hGH minigene under the control of mouse Ins1 promoter. Our data showed that the Cre-mediated recombination and rtTA-mediated activation could be efficiently detected at embryonic day 13.5 when these models were crossed with the reporter mice (ROSA(mT/mG) or tetO-HIST1H2BJ/GFP). The Cre and rtTA expression was restricted to β-cells without leakage in the brain and other tissues. Moreover, both the transgenic lines showed normal glucose tolerance and insulin secretion. These results suggested that the Ins1-Cre-Dsred and Ins1-rtTA mice could be used to knock out or overexpress target genes in embryos and adults to facilitate β-cell researches.

Reversal of mineral ion homeostasis and soft-tissue calcification of klotho knockout mice by deletion of vitamin D 1α-hydroxylase

PubMed Central

Ohnishi, Mutsuko; Nakatani, Teruyo; Lanske, Beate; Razzaque, M. Shawkat

2011-01-01

Changes in the expression of klotho, a β-glucuronidase, contribute to the development of features that resemble those of premature aging, as well as chronic renal failure. Klotho knockout mice have increased expression of the sodium/phosphate cotransporter (NaPi2a) and 1α-hydroxylase in their kidneys, along with increased serum levels of phosphate and 1,25-dihydroxyvitamin D. These changes are associated with widespread soft-tissue calcifications, generalized tissue atrophy, and a shorter lifespan in the knockout mice. To determine the role of the increased vitamin D activities in klotho knockout animals, we generated klotho and 1α-hydroxylase double-knockout mice. These double mutants regained body weight and developed hypophosphatemia with a complete elimination of the soft-tissue and vascular calcifications that were routinely found in klotho knockout mice. The markedly increased serum fibroblast growth factor 23 and the abnormally low serum parathyroid hormone levels, typical of klotho knockout mice, were significantly reversed in the double-knockout animals. These in vivo studies suggest that vitamin D has a pathologic role in regulating abnormal mineral ion metabolism and soft-tissue anomalies of klotho-deficient mice. PMID:19225558

Dissociation kinetics of excited ions: PEPICO measurements of Os3(CO)12 - The 7-35 eV single ionization binding energy region.

PubMed

Schalk, Oliver; Josefsson, Ida; Geng, Ting; Richter, Robert; Sa'adeh, Hanan; Thomas, Richard D; Mucke, Melanie

2018-02-28

In this article, we study the photoinduced dissociation pathways of a metallocarbonyl, Os 3 (CO) 12 , in particular the consecutive loss of CO groups. To do so, we performed photoelectron-photoion coincidence (PEPICO) measurements in the single ionization binding energy region from 7 to 35 eV using 45-eV photons. Zero-energy ion appearance energies for the dissociation steps were extracted by modeling the PEPICO data using the statistical adiabatic channel model. Upon ionization to the excited ionic states above 13 eV binding energy, non-statistical behavior was observed and assigned to prompt CO loss. Double ionization was found to be dominated by the knockout process with an onset of 20.9 ± 0.4 eV. The oscillator strength is significantly larger for energies above 26.6 ± 0.4 eV, corresponding to one electron being ejected from the Os 3 center and one from the CO ligands. The cross section for double ionization was found to increase linearly up to 35 eV ionization energy, at which 40% of the generated ions are doubly charged.

Evidence of reactive astrocytes but not peripheral immune system activation in a mouse model of Fragile X Syndrome

PubMed Central

Yuskaitis, Christopher J.; Beurel, Eleonore; Jope, Richard S.

2010-01-01

Fragile X syndrome (FXS) is the most common form of inherited mental retardation and is one of the few known genetic causes of autism. FXS results from the loss of Fmr1 gene function, thus Fmr1 knockout mice provide a model to study impairments associated with FXS and autism and to test potential therapeutic interventions. The inhibitory serine-phosphorylation of glycogen synthase kinase-3 (GSK3) is lower in brain regions of Fmr1 knockout mice than wild-type mice and the GSK3 inhibitor lithium rescues several behavioral impairments in Fmr1 knockout mice. Therefore, we examined if the serine-phosphorylation of GSK3 in Fmr1 knockout mice also was altered outside the brain and if administration of lithium ameliorated the macroorchidism phenotype. Additionally, since GSK3 regulates numerous functions of the immune system and immune alterations have been associated with autism, we tested if immune function is altered in Fmr1 knockout mice. The inhibitory serine-phosphorylation of GSK3 was significantly lower in the testis and liver of Fmr1 knockout mice than wild-type mice, and chronic lithium treatment reduced macroorchidism in Fmr1 knockout mice. No alterations in peripheral immune function were identified in Fmr1 knockout mice. However, examination of glia, the immune cells of the brain, revealed reactive astrocytes in several brain regions of Fmr1 knockout mice and treatment with lithium reduced this in the striatum and cerebellum. These results provide further evidence of the involvement of dysregulated GSK3 in FXS, and demonstrate that lithium administration reduces macroorchidism and reactive astrocytes in Fmr1 knockout mice. PMID:20600866

HZEFRG1 - SEMIEMPIRICAL NUCLEAR FRAGMENTATION MODEL

NASA Technical Reports Server (NTRS)

Townsend, L. W.

1994-01-01

The high charge and energy (HZE), Semiempirical Nuclear Fragmentation Model, HZEFRG1, was developed to provide a computationally efficient, user-friendly, physics-based program package for generating nuclear fragmentation databases. These databases can then be used in radiation transport applications such as space radiation shielding and dosimetry, cancer therapy with laboratory heavy ion beams, and simulation studies of detector design in nuclear physics experiments. The program provides individual element and isotope production cross sections for the breakup of high energy heavy ions by the combined nuclear and Coulomb fields of the interacting nuclei. The nuclear breakup contributions are estimated using an energy-dependent abrasion-ablation model of heavy ion fragmentation. The abrasion step involves removal of nucleons by direct knockout in the overlap region of the colliding nuclei. The abrasions are treated on a geometric basis and uniform spherical nuclear density distributions are assumed. Actual experimental nuclear radii obtained from tabulations of electron scattering data are incorporated. Nuclear transparency effects are included by using an energy-dependent, impact-parameter-dependent average transmission factor for the projectile and target nuclei, which accounts for the finite mean free path of nucleons in nuclear matter. The ablation step, as implemented by Bowman, Swiatecki, and Tsang (LBL report no. LBL-2908, July 1973), was treated as a single-nucleon emission for every 10 MeV of excitation energy. Fragmentation contributions from electromagnetic dissociation (EMD) processes, arising from the interacting Coulomb fields, are estimated by using the Weiszacker-Williams theory, extended to include electric dipole and electric quadrupole contributions to one-nucleon removal cross sections. HZEFRG1 consists of a main program, seven function subprograms, and thirteen subroutines. Each is fully commented and begins with a brief description of its functionality. The inputs, which are provided interactively by the user in response to on-screen questions, consist of the projectile kinetic energy in units of MeV/nucleon and the masses and charges of the projectile and target nuclei. With proper inputs, HZEFRG1 first calculates the EMD cross sections and then begins the calculations for nuclear fragmentation by searching through a specified number of isotopes for each charge number (Z) from Z=1 (hydrogen) to the charge of the incident fragmenting nucleus (Zp). After completing the nuclear fragmentation cross sections, HZEFRG1 sorts through the results and writes the sorted output to a file in descending order, based on the charge number of the fragmented nucleus. Details of the theory, extensive comparisons of its predictions with available experimental cross section data, and a complete description of the code implementing it are given in the program documentation. HZEFRG1 is written in ANSI FORTRAN 77 to be machine independent. It was originally developed on a DEC VAX series computer, and has been successfully implemented on a DECstation running RISC ULTRIX 4.3, a Sun4 series computer running SunOS 4.1, an HP 9000 series computer running HP-UX 8.0.1, a Cray Y-MP series computer running UNICOS, and IBM PC series computers running MS-DOS 3.3 and higher. HZEFRG1 requires 1Mb of RAM for execution. In addition, a FORTRAN 77 compiler is required to create an executable. A sample output run is included on the distribution medium for numerical comparison. The standard distribution medium for this program is a 3.5 inch 1.44Mb MS-DOS format diskette. Alternate distribution media and formats are available upon request. HZEFRG1 was completed in 1992.

Effect of AVE 0991 angiotensin-(1-7) receptor agonist treatment on elemental and biomolecular content and distribution in atherosclerotic plaques of apoE-knockout mice

NASA Astrophysics Data System (ADS)

Kowalska, J.; Gajda, M.; Jawień, J.; Kwiatek, W. M.; Appel, K.; Dumas, P.

2013-12-01

Gene-targeted apolipoprotein E-knockout (apoE-KO) mice display early and highly progressive vascular lesions containing lipid deposits and they became a reliable animal model to study atherosclerosis. The aim of the present study was to investigate the effect of AVE 0991 angiotensin-(1-7) receptor agonist on the distribution of selected pro- and anti- inflammatory elements as well as biomolecules in atherosclerotic plaques of apoE-knockout mice. Synchrotron radiation-based X-ray fluorescence (micro-XRF) and Fourier Transform Infrared (micro-FTIR) microspectroscopies were applied. Two-month-old apoE-KO mice were fed for following four months diet supplemented with AVE 0991 (0.58 μmol/kg b.w. per day). Histological sections of ascending aortas were analyzed spectroscopically. The distribution of P, Ca, Fe and Zn were found to correspond with histological structure of the lesion. Significantly lower contents of P, Ca, Zn and significantly higher content of Fe were observed in animals treated with AVE 0991. Biomolecular analysis showed lower lipids saturation level and lower lipid to protein ratio in AVE 0991 treated group. Protein secondary structure was studied according to the composition of amide I band (1660 cm-1) and it demonstrated higher proportion of β-sheet structure as compared to α-helix in both studied groups.

Mouse model of fragile X syndrome: behavioral and hormonal response to stressors.

PubMed

Nielsen, Darci M; Evans, Jeffrey J; Derber, William J; Johnston, Kenzie A; Laudenslager, Mark L; Crnic, Linda S; Maclean, Kenneth N

2009-06-01

Fragile X syndrome, a form of mental retardation caused by inadequate levels of fragile X mental retardation protein (FMRP), is characterized by extreme sensitivity to sensory stimuli and increased behavioral and hormonal reactivity to stressors. Fmr1 knockout mice lack FMRP and exhibit abnormal responses to auditory stimuli. This study sought to determine whether Fmr1 knockout mice on an F1 hybrid background are normal in their response to footshock. Knockout mice were also examined for signs of hyperexcitation across an extended trial range, and serum corticosterone levels were evaluated in response to various stressors. The ability to acquire conditioned taste aversion was also assessed. Knockout mice exhibited no impairment in associative aversive learning or memory, since they successfully expressed conditioned taste aversion. Footshock-sensitivity, freezing behavior, and corticosterone response to various stressors did not differ between knockout and wild-type mice. However, knockout mice exhibited significantly increased responses during the extended test. The knockout mice's increased responsiveness to footshock in the extended test may be an indication of increased vulnerability to stress or enhanced emotional reactivity. Copyright (c) 2009 APA, all rights reserved.

Understanding the Etiology of Tuberous Sclerosis Complex

DTIC Science & Technology

2011-07-01

heterotopic nodules. Indeed, the cortex of TSC individuals contains pockets of abnormal cells with hyperactive mTOR in an otherwise structurally normal...phosphorylated S6 (phospho-S6). mTOR hyperactivity leads to enhanced S6 phosphorylation. Immunostaining in postnatal day (P) 28 sections from...respectively. In addiiton, hamartin is lost and mTOR hyperactive. Figure 2: In utero single-cell knockout of Tsc1 in cortical cells. (A) Diagram

Cytotoxicity of the indole alkaloid reserpine from Rauwolfia serpentina against drug-resistant tumor cells.

PubMed

Abdelfatah, Sara A A; Efferth, Thomas

2015-02-15

The antihypertensive reserpine is an indole alkaloid from Rauwolfia serpentina and exerts also profound activity against cancer cells in vitro and in vivo. The present investigation was undertaken to investigate possible modes of action to explain its activity toward drug-resistant tumor cells. Sensitive and drug-resistant tumor cell lines overexpressing P-glycoprotein (ABCB1/MDR1), breast cancer resistance protein (ABCG2/BCRP), mutation-activated epidermal growth factor receptor (EGFR), wild-type and p53-knockout cells as well as the NCI panel of cell lines from different tumor origin were analyzed. Reserpine's cytotoxicity was investigated by resazurin and sulforhodamine assays, flow cytometry, and COMPARE and hierarchical cluster analyses of transcriptome-wide microarray-based RNA expressions. P-glycoprotein- or BCRP overexpressing tumor cells did not reveal cross-resistance to reserpine. EGFR-overexpressing cells were collateral sensitive and p53- Knockout cells cross-resistant to this drug compared to their wild-type parental cell lines. Reserpine increased the uptake of doxorubicin in P-glycoprotein-overexpressing cells, indicating that reserpine inhibited the efflux function of P-glycoprotein. Using molecular docking, we found that reserpine bound with even higher binding energy to P-glycoprotein and EGFR than the control drugs verapamil (P-glycoprotein inhibitor) and erlotinib (EGFR inhibitor). COMPARE and cluster analyses of microarray data showed that the mRNA expression of a panel of genes predicted the sensitivity or resistance of the NCI tumor cell line panel with statistical significance. The genes belonged to diverse pathways and biological functions, e.g. cell survival and apoptosis, EGFR activation, regulation of angiogenesis, cell mobility, cell adhesion, immunological functions, mTOR signaling, and Wnt signaling. The lack of cross-resistance to most resistance mechanisms and the collateral sensitivity in EGFR-transfectants compared to wild-type cells speak for a promising role of reserpine in cancer chemotherapy. Reserpine deserves further consideration for cancer therapy in the clinical setting. Copyright © 2015 Elsevier GmbH. All rights reserved.

Cancer resistance of SR/CR mice in the genetic knockout backgrounds of leukocyte effector mechanisms: determinations for functional requirements.

PubMed

Sanders, Anne M; Stehle, John R; Blanks, Michael J; Riedlinger, Gregory; Kim-Shapiro, Jung W; Monjazeb, Arta M; Adams, Jonathan M; Willingham, Mark C; Cui, Zheng

2010-03-31

Spontaneous Regression/Complete Resistant (SR/CR) mice are a colony of cancer-resistant mice that can detect and rapidly destroy malignant cells with innate cellular immunity, predominately mediated by granulocytes. Our previous studies suggest that several effector mechanisms, such as perforin, granzymes, or complements, may be involved in the killing of cancer cells. However, none of these effector mechanisms is known as critical for granulocytes. Additionally, it is unclear which effector mechanisms are required for the cancer killing activity of specific leukocyte populations and the survival of SR/CR mice against the challenges of lethal cancer cells. We hypothesized that if any of these effector mechanisms was required for the resistance to cancer cells, its functional knockout in SR/CR mice should render them sensitive to cancer challenges. This was tested by cross breeding SR/CR mice into the individual genetic knockout backgrounds of perforin (Prf-/-), superoxide (Cybb-/), or inducible nitric oxide (Nos2-/). SR/CR mice were bred into individual Prf-/-, Cybb-/-, or Nos2-/- genetic backgrounds and then challenged with sarcoma 180 (S180). Their overall survival was compared to controls. The cancer killing efficiency of purified populations of macrophages and neutrophils from these immunodeficient mice was also examined. When these genetically engineered mice were challenged with cancer cells, the knockout backgrounds of Prf-/-, Cybb-/-, or Nos2-/- did not completely abolish the SR/CR cancer resistant phenotype. However, the Nos2-/- background did appear to weaken the resistance. Incidentally, it was also observed that the male mice in these immunocompromised backgrounds tended to be less cancer-resistant than SR/CR controls. Despite the previously known roles of perforin, superoxide or nitric oxide in the effector mechanisms of innate immune responses, these effector mechanisms were not required for cancer-resistance in SR/CR mice. The resistance was functional when any one of these effector mechanisms was completely absent, except some noticeably reduced penetrance, but not abolishment, of the phenotype in the male background in comparison to female background. These results also indicate that some other effector mechanism(s) of granulocytes may be involved in the killing of cancer cells in SR/CR mice.

Cytoprotective role of autophagy against BH3 mimetic gossypol in ATG5 knockout cells generated by CRISPR-Cas9 endonuclease.

PubMed

Kim, Na-Yeon; Han, Byeal-I; Lee, Michael

2016-01-01

Previously, we demonstrated the association between autophagy and gossypol-induced growth inhibition of mutant BRAF melanoma cells. Here, we investigate the role of autophagy in ATG5 knockout cell lines generated by the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas-mediated genome editing. The MTT assay revealed that the inhibitory effect of gossypol was weaker on ATG5 knockout cells than that on the wild type (WT) cells. The conversion of non-autophagic LC3-I to autophagic LC3-II and RT-PCR confirmed the functional gene knockout. However, Cyto-ID autophagy assay revealed that gossypol induced ATG5- and LC3-independent autophagy in ATG5 knockout cells. Moreover, gossypol acts as an autophagy inducer in ATG5 knockout cells while blocking the later stages of the autophagy process in WT cells, which was determined by measuring autophagic flux after co-treatment of gossypol with chloroquine (late-stage autophagy inhibitor). On the other hand, inhibition of autophagy with 3-MA or Beclin-1 siRNA caused a partial increase in the sensitivity to gossypol in ATG5 knockout cells, but not in the WT cells. Together, our findings suggest that the resistance to gossypol in ATG5 knockout cells is associated with increased cytoprotective autophagy, independent of ATG5. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Photoeffect cross sections of some rare-earth elements at 145.4 keV

NASA Astrophysics Data System (ADS)

Umesh, T. K.; Ranganathaiah, C.; Sanjeevaiah, B.

1985-08-01

Total attenuation cross sections in the elements La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, and Er were derived from the measured total cross sections of their simple oxide compounds, by employing the mixture rule at 145.4-keV photon energy. The compound cross sections have been measured by performing transmission experiments in a good geometry setup. From the derived total cross sections of elements, photoeffect cross sections have been obtained by subtracting the theoretical scattering cross sections. A good agreement is observed between the present data of photoeffect cross sections and Scofield's theoretical data.

Structural and Functional Analysis of HIV-1 Coreceptors: Roles of Charged Residues and Posttranslational Modifications on Coreceptor Activity

DTIC Science & Technology

2000-01-01

to sites of inflammation. They may have additional functions. For example analysis of CXCR4 knockout mice show that CXCR4, which is chemotactic for... mice had similar phenotypes (195). Homozygous knockout of CXCR4 or SDF-1 results in embyonic lethality. Though CCR5 appears to be dispensable, other...chemokine receptors have vital functions. CXCR5 knockout mice have B-cell homing defects (118), and CXCR2 knockout mice overproduce B-cells and

[Preliminary exploration on knockout drops (Meng Han Agents)].

PubMed

Zhang, Z

1996-05-01

This author points out, based on relevant materials, that knockout drops were vertigo powder. Due to homophonic reasons in Chinese language, the term "mingxuan" was transliterated into the former Chinese term (menghan). Knockout drops for medicinal use were merely made up of compound recipes containing stramonium flowers. The knockout drops in old fictions and opera books were powder of stramonium flower. The ingredients and application of such recipes are discussed here, the anti-remedies for such recipes are also mentioned.

Electron-Impact Ionization Cross Section Database

National Institute of Standards and Technology Data Gateway

SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

RNaseT2 knockout rats exhibit hippocampal neuropathology and deficits in memory.

PubMed

Sinkevicius, Kerstin W; Morrison, Thomas R; Kulkarni, Praveen; Caffrey Cagliostro, Martha K; Iriah, Sade; Malmberg, Samantha; Sabrick, Julia; Honeycutt, Jennifer A; Askew, Kim L; Trivedi, Malav; Ferris, Craig F

2018-06-27

RNASET2 deficiency in humans is associated with infant cystic leukoencephalopathy, which causes psychomotor impairment, spasticity and epilepsy. A zebrafish mutant model suggests that loss of RNASET2 function leads to neurodegeneration due to the accumulation of non-degraded RNA in the lysosomes. The goal of this study was to characterize the first rodent model of RNASET2 deficiency. The brains of 3- and 12-month-old RNaseT2 knockout rats were studied using multiple magnetic resonance imaging modalities and behavioral tests. While T1- and T2-weighted images of RNaseT2 knockout rats exhibited no evidence of cystic lesions, the prefrontal cortex and hippocampal complex were enlarged in knockout animals. Diffusion-weighted imaging showed altered anisotropy and putative gray matter changes in the hippocampal complex of the RNaseT2 knockout rats. Immunohistochemistry for glial fibrillary acidic protein (GFAP) showed the presence of hippocampal neuroinflammation. Decreased levels of lysosome-associated membrane protein 2 (LAMP2) and elevated acid phosphatase and β-N-acetylglucosaminidase (NAG) activities indicated that the RNASET2 knockout rats likely had altered lysosomal function and potential defects in autophagy. Object recognition tests confirmed that RNaseT2 knockout rats exhibited memory deficits. However, the Barnes maze, and balance beam and rotarod tests indicated there were no differences in spatial memory or motor impairments, respectively. Overall, patients with RNASET2 deficiency exhibited a more severe neurodegeneration phenotype than was observed in the RNaseT2 knockout rats. However, the vulnerability of the knockout rat hippocampus as evidenced by neuroinflammation, altered lysosomal function and cognitive defects indicates that this is still a useful in vivo model to study RNASET2 function. © 2018. Published by The Company of Biologists Ltd.

Deficiency in the manganese efflux transporter SLC30A10 induces severe hypothyroidism in mice.

PubMed

Hutchens, Steven; Liu, Chunyi; Jursa, Thomas; Shawlot, William; Chaffee, Beth K; Yin, Weiling; Gore, Andrea C; Aschner, Michael; Smith, Donald R; Mukhopadhyay, Somshuvra

2017-06-09

Manganese is an essential metal that becomes toxic at elevated levels. Loss-of-function mutations in SLC30A10, a cell-surface-localized manganese efflux transporter, cause a heritable manganese metabolism disorder resulting in elevated manganese levels and parkinsonian-like movement deficits. The underlying disease mechanisms are unclear; therefore, treatment is challenging. To understand the consequences of loss of SLC30A10 function at the organism level, we generated Slc30a10 knock-out mice. During early development, knock-outs were indistinguishable from controls. Surprisingly, however, after weaning and compared with controls, knock-out mice failed to gain weight, were smaller, and died prematurely (by ∼6-8 weeks of age). At 6 weeks, manganese levels in the brain, blood, and liver of the knock-outs were ∼20-60-fold higher than controls. Unexpectedly, histological analyses revealed that the brain and liver of the knock-outs were largely unaffected, but their thyroid exhibited extensive alterations. Because hypothyroidism leads to growth defects and premature death in mice, we assayed for changes in thyroid and pituitary hormones. At 6 weeks and compared with controls, the knock-outs had markedly reduced thyroxine levels (∼50-80%) and profoundly increased thyroid-stimulating hormone levels (∼800-1000-fold), indicating that Slc30a10 knock-out mice develop hypothyroidism. Importantly, a low-manganese diet produced lower tissue manganese levels in the knock-outs and rescued the phenotype, suggesting that manganese toxicity was the underlying cause. Our unanticipated discovery highlights the importance of determining the role of thyroid dysfunction in the onset and progression of manganese-induced disease and identifies Slc30a10 knock-out mice as a new model for studying thyroid biology. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism

PubMed Central

Lei, Tianluo; Zhou, Lei; Layton, Anita T.; Zhou, Hong; Zhao, Xuejian; Bankir, Lise

2011-01-01

Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts. PMID:21849488

Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism.

PubMed

Lei, Tianluo; Zhou, Lei; Layton, Anita T; Zhou, Hong; Zhao, Xuejian; Bankir, Lise; Yang, Baoxue

2011-12-01

Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts.

Renal Dysfunction Induced by Kidney-Specific Gene Deletion of Hsd11b2 as a Primary Cause of Salt-Dependent Hypertension.

PubMed

Ueda, Kohei; Nishimoto, Mitsuhiro; Hirohama, Daigoro; Ayuzawa, Nobuhiro; Kawarazaki, Wakako; Watanabe, Atsushi; Shimosawa, Tatsuo; Loffing, Johannes; Zhang, Ming-Zhi; Marumo, Takeshi; Fujita, Toshiro

2017-07-01

Genome-wide analysis of renal sodium-transporting system has identified specific variations of Mendelian hypertensive disorders, including HSD11B2 gene variants in apparent mineralocorticoid excess. However, these genetic variations in extrarenal tissue can be involved in developing hypertension, as demonstrated in former studies using global and brain-specific Hsd11b2 knockout rodents. To re-examine the importance of renal dysfunction on developing hypertension, we generated kidney-specific Hsd11b2 knockout mice. The knockout mice exhibited systemic hypertension, which was abolished by reducing salt intake, suggesting its salt-dependency. In addition, we detected an increase in renal membrane expressions of cleaved epithelial sodium channel-α and T53-phosphorylated Na + -Cl - cotransporter in the knockout mice. Acute intraperitoneal administration of amiloride-induced natriuresis and increased urinary sodium/potassium ratio more in the knockout mice compared with those in the wild-type control mice. Chronic administration of amiloride and high-KCl diet significantly decreased mean blood pressure in the knockout mice, which was accompanied with the correction of hypokalemia and the resultant decrease in Na + -Cl - cotransporter phosphorylation. Accordingly, a Na + -Cl - cotransporter blocker hydrochlorothiazide significantly decreased mean blood pressure in the knockout mice. Chronic administration of mineralocorticoid receptor antagonist spironolactone significantly decreased mean blood pressure of the knockout mice along with downregulation of cleaved epithelial sodium channel-α and phosphorylated Na + -Cl - cotransporter expression in the knockout kidney. Our data suggest that kidney-specific deficiency of 11β-HSD2 leads to salt-dependent hypertension, which is attributed to mineralocorticoid receptor-epithelial sodium channel-Na + -Cl - cotransporter activation in the kidney, and provides evidence that renal dysfunction is essential for developing the phenotype of apparent mineralocorticoid excess. © 2017 American Heart Association, Inc.

Behavioral and neurochemical characterization of mice deficient in the phosphodiesterase-1B (PDE1B) enzyme.

PubMed

Siuciak, J A; McCarthy, S A; Chapin, D S; Reed, T M; Vorhees, C V; Repaske, D R

2007-07-01

PDE1B is a calcium-dependent cyclic nucleotide phosphodiesterase that is highly expressed in the striatum. In order to investigate the physiological role of PDE1B in the central nervous system, PDE1B knockout mice (C57BL/6N background) were assessed in behavioral tests and their brains were assayed for monoamine content. In a variety of well-characterized behavioral tasks, including the elevated plus maze (anxiety-like behavior), forced swim test (depression-like behavior), hot plate (nociception) and two cognition models (passive avoidance and acquisition of conditioned avoidance responding), PDE1B knockout mice performed similarly to wild-type mice. PDE1B knockout mice showed increased baseline exploratory activity when compared to wild-type mice. When challenged with amphetamine (AMPH) and methamphetamine (METH), male and female PDE1B knockout mice showed an exaggerated locomotor response. Male PDE1B knockout mice also showed increased locomotor responses to higher doses of phencyclidine (PCP) and MK-801; however, this effect was not consistently observed in female knockout mice. In the striatum, increased dopamine turnover (DOPAC/DA and HVA/DA ratios) was found in both male and female PDE1B knockout mice. Striatal serotonin (5-HT) levels were also decreased in PDE1B knockout mice, although levels of the metabolite, 5HIAA, were unchanged. The present studies demonstrate increased striatal dopamine turnover in PDE1B knockout mice associated with increased baseline motor activity and an exaggerated locomotor response to dopaminergic stimulants such as methamphetamine and amphetamine. These data further support a role for PDE1B in striatal function.

Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation.

PubMed

Reno, Candace M; Puente, Erwin C; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J; Routh, Vanessa H; Kahn, Barbara B; Fisher, Simon J

2017-03-01

GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. © 2017 by the American Diabetes Association.

Double knockout of pendrin and Na-Cl cotransporter (NCC) causes severe salt wasting, volume depletion, and renal failure.

PubMed

Soleimani, Manoocher; Barone, Sharon; Xu, Jie; Shull, Gary E; Siddiqui, Faraz; Zahedi, Kamyar; Amlal, Hassane

2012-08-14

The Na-Cl cotransporter (NCC), which is the target of inhibition by thiazides, is located in close proximity to the chloride-absorbing transporter pendrin in the kidney distal nephron. Single deletion of pendrin or NCC does not cause salt wasting or excessive diuresis under basal conditions, raising the possibility that these transporters are predominantly active during salt depletion or in response to excess aldosterone. We hypothesized that pendrin and NCC compensate for loss of function of the other under basal conditions, thereby masking the role that each plays in salt absorption. To test our hypothesis, we generated pendrin/NCC double knockout (KO) mice by crossing pendrin KO mice with NCC KO mice. Pendrin/NCC double KO mice displayed severe salt wasting and sharp increase in urine output under basal conditions. As a result, animals developed profound volume depletion, renal failure, and metabolic alkalosis without hypokalemia, which were all corrected with salt replacement. We propose that the combined inhibition of pendrin and NCC can provide a strong diuretic regimen without causing hypokalemia for patients with fluid overload, including patients with congestive heart failure, nephrotic syndrome, diuretic resistance, or generalized edema.

Selective deletion of Smad4 in postnatal germ cells does not affect spermatogenesis or fertility in mice.

PubMed

Hao, Xiao-Xia; Chen, Su-Ren; Tang, Ji-Xin; Li, Jian; Cheng, Jin-Mei; Jin, Cheng; Wang, Xiu-Xia; Liu, Yi-Xun

2016-07-01

SMAD4 is the central component of canonical signaling in the transforming growth factor beta (TGFβ) superfamily. Loss of Smad4 in Sertoli cells affects the expansion of the fetal testis cords, whereas selective deletion of Smad4 in Leydig cells alone does not appreciably alter fetal or adult testis development. Loss of Smad4 in Sertoli and Leydig cells, on the other hand, leads to testicular dysgenesis, and tumor formation in mice. Within the murine testes, Smad4 is also expressed in germ cells of the seminiferous tubules. We therefore, crossed Ngn3-Cre or Stra8-Cre transgenic mice with Smad4-flox mice to generate conditional knockout animals in which Smad4 was specifically deleted in postnatal germ cells to further uncover cell type-specific requirement of Smad4. Unexpectedly, these germ-cell-knockout mice were fertile and did not exhibit any detectable abnormalities in spermatogenesis, indicating that Smad4 is not required for the production of sperm; instead, these data indicate a cell type-specific requirement of Smad4 primarily during testis development. Mol. Reprod. Dev. 83: 615-623, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Next-generation mammalian genetics toward organism-level systems biology.

PubMed

Susaki, Etsuo A; Ukai, Hideki; Ueda, Hiroki R

2017-01-01

Organism-level systems biology in mammals aims to identify, analyze, control, and design molecular and cellular networks executing various biological functions in mammals. In particular, system-level identification and analysis of molecular and cellular networks can be accelerated by next-generation mammalian genetics. Mammalian genetics without crossing, where all production and phenotyping studies of genome-edited animals are completed within a single generation drastically reduce the time, space, and effort of conducting the systems research. Next-generation mammalian genetics is based on recent technological advancements in genome editing and developmental engineering. The process begins with introduction of double-strand breaks into genomic DNA by using site-specific endonucleases, which results in highly efficient genome editing in mammalian zygotes or embryonic stem cells. By using nuclease-mediated genome editing in zygotes, or ~100% embryonic stem cell-derived mouse technology, whole-body knock-out and knock-in mice can be produced within a single generation. These emerging technologies allow us to produce multiple knock-out or knock-in strains in high-throughput manner. In this review, we discuss the basic concepts and related technologies as well as current challenges and future opportunities for next-generation mammalian genetics in organism-level systems biology.

Double knockout of pendrin and Na-Cl cotransporter (NCC) causes severe salt wasting, volume depletion, and renal failure

PubMed Central

Soleimani, Manoocher; Barone, Sharon; Xu, Jie; Shull, Gary E.; Siddiqui, Faraz; Zahedi, Kamyar; Amlal, Hassane

2012-01-01

The Na-Cl cotransporter (NCC), which is the target of inhibition by thiazides, is located in close proximity to the chloride-absorbing transporter pendrin in the kidney distal nephron. Single deletion of pendrin or NCC does not cause salt wasting or excessive diuresis under basal conditions, raising the possibility that these transporters are predominantly active during salt depletion or in response to excess aldosterone. We hypothesized that pendrin and NCC compensate for loss of function of the other under basal conditions, thereby masking the role that each plays in salt absorption. To test our hypothesis, we generated pendrin/NCC double knockout (KO) mice by crossing pendrin KO mice with NCC KO mice. Pendrin/NCC double KO mice displayed severe salt wasting and sharp increase in urine output under basal conditions. As a result, animals developed profound volume depletion, renal failure, and metabolic alkalosis without hypokalemia, which were all corrected with salt replacement. We propose that the combined inhibition of pendrin and NCC can provide a strong diuretic regimen without causing hypokalemia for patients with fluid overload, including patients with congestive heart failure, nephrotic syndrome, diuretic resistance, or generalized edema. PMID:22847418

An inducible knockout mouse to model the cell-autonomous role of PTEN in initiating endometrial, prostate and thyroid neoplasias.

PubMed

Mirantes, Cristina; Eritja, Núria; Dosil, Maria Alba; Santacana, Maria; Pallares, Judit; Gatius, Sónia; Bergadà, Laura; Maiques, Oscar; Matias-Guiu, Xavier; Dolcet, Xavier

2013-05-01

PTEN is one of the most frequently mutated tumor suppressor genes in human cancers. The role of PTEN in carcinogenesis has been validated by knockout mouse models. PTEN heterozygous mice develop neoplasms in multiple organs. Unfortunately, the embryonic lethality of biallelic excision of PTEN has inhibited the study of complete PTEN deletion in the development and progression of cancer. By crossing PTEN conditional knockout mice with transgenic mice expressing a tamoxifen-inducible Cre-ER(T) under the control of a chicken actin promoter, we have generated a tamoxifen-inducible mouse model that allows temporal control of PTEN deletion. Interestingly, administration of a single dose of tamoxifen resulted in PTEN deletion mainly in epithelial cells, but not in stromal, mesenchymal or hematopoietic cells. Using the mT/mG double-fluorescent Cre reporter mice, we demonstrate that epithelial-specific PTEN excision was caused by differential Cre activity among tissues and cells types. Tamoxifen-induced deletion of PTEN resulted in extremely rapid and consistent formation of endometrial in situ adenocarcinoma, prostate intraepithelial neoplasia and thyroid hyperplasia. We also analyzed the role of PTEN ablation in other epithelial cells, such as the tubular cells of the kidney, hepatocytes, colonic epithelial cells or bronchiolar epithelium, but those tissues did not exhibit neoplastic growth. Finally, to validate this model as a tool to assay the efficacy of anti-tumor drugs in PTEN deficiency, we administered the mTOR inhibitor everolimus to mice with induced PTEN deletion. Everolimus dramatically reduced the progression of endometrial proliferations and significantly reduced thyroid hyperplasia. This model could be a valuable tool to study the cell-autonomous mechanisms involved in PTEN-loss-induced carcinogenesis and provides a good platform to study the effect of anti-neoplastic drugs on PTEN-negative tumors.

An inducible knockout mouse to model the cell-autonomous role of PTEN in initiating endometrial, prostate and thyroid neoplasias

PubMed Central

Mirantes, Cristina; Eritja, Núria; Dosil, Maria Alba; Santacana, Maria; Pallares, Judit; Gatius, Sónia; Bergadà, Laura; Maiques, Oscar; Matias-Guiu, Xavier; Dolcet, Xavier

2013-01-01

SUMMARY PTEN is one of the most frequently mutated tumor suppressor genes in human cancers. The role of PTEN in carcinogenesis has been validated by knockout mouse models. PTEN heterozygous mice develop neoplasms in multiple organs. Unfortunately, the embryonic lethality of biallelic excision of PTEN has inhibited the study of complete PTEN deletion in the development and progression of cancer. By crossing PTEN conditional knockout mice with transgenic mice expressing a tamoxifen-inducible Cre-ERT under the control of a chicken actin promoter, we have generated a tamoxifen-inducible mouse model that allows temporal control of PTEN deletion. Interestingly, administration of a single dose of tamoxifen resulted in PTEN deletion mainly in epithelial cells, but not in stromal, mesenchymal or hematopoietic cells. Using the mT/mG double-fluorescent Cre reporter mice, we demonstrate that epithelial-specific PTEN excision was caused by differential Cre activity among tissues and cells types. Tamoxifen-induced deletion of PTEN resulted in extremely rapid and consistent formation of endometrial in situ adenocarcinoma, prostate intraepithelial neoplasia and thyroid hyperplasia. We also analyzed the role of PTEN ablation in other epithelial cells, such as the tubular cells of the kidney, hepatocytes, colonic epithelial cells or bronchiolar epithelium, but those tissues did not exhibit neoplastic growth. Finally, to validate this model as a tool to assay the efficacy of anti-tumor drugs in PTEN deficiency, we administered the mTOR inhibitor everolimus to mice with induced PTEN deletion. Everolimus dramatically reduced the progression of endometrial proliferations and significantly reduced thyroid hyperplasia. This model could be a valuable tool to study the cell-autonomous mechanisms involved in PTEN-loss-induced carcinogenesis and provides a good platform to study the effect of anti-neoplastic drugs on PTEN-negative tumors. PMID:23471917

Inactivation of p53 by Human T-Cell Lymphotropic Virus Type 1 Tax Requires Activation of the NF-κB Pathway and Is Dependent on p53 Phosphorylation

PubMed Central

Pise-Masison, Cynthia A.; Mahieux, Renaud; Jiang, Hua; Ashcroft, Margaret; Radonovich, Michael; Duvall, Janet; Guillerm, Claire; Brady, John N.

2000-01-01

p53 plays a key role in guarding cells against DNA damage and transformation. We previously demonstrated that the human T-cell lymphotropic virus type 1 (HTLV-1) Tax can inactivate p53 transactivation function in lymphocytes. The present study demonstrates that in T cells, Tax-induced p53 inactivation is dependent upon NF-κB activation. Analysis of Tax mutants demonstrated that Tax inactivation of p53 function correlates with the ability of Tax to induce NF-κB but not p300 binding or CREB transactivation. The Tax-induced p53 inactivation can be overcome by overexpression of a dominant IκB mutant. Tax-NF-κB-induced p53 inactivation is not due to p300 squelching, since overexpression of p300 does not recover p53 activity in the presence of Tax. Further, using wild-type and p65 knockout mouse embryo fibroblasts (MEFs), we demonstrate that the p65 subunit of NF-κB is critical for Tax-induced p53 inactivation. While Tax can inactivate endogenous p53 function in wild-type MEFs, it fails to inactivate p53 function in p65 knockout MEFs. Importantly, Tax-induced p53 inactivation can be restored by expression of p65 in the knockout MEFs. Finally, we present evidence that phosphorylation of serines 15 and 392 correlates with inactivation of p53 by Tax in T cells. This study provides evidence that the divergent NF-κB proliferative and p53 cell cycle arrest pathways may be cross-regulated at several levels, including posttranslational modification of p53. PMID:10779327

Studies of an Androgen-Binding Protein Knockout Corroborate a Role for Salivary ABP in Mouse Communication

PubMed Central

Chung, Amanda G.; Belone, Phillip M.; Bímová, Barbora Vošlajerová; Karn, Robert C.; Laukaitis, Christina M.

2017-01-01

The house mouse Androgen-binding protein (Abp) gene family is comprised of 64 paralogs, 30 Abpa and 34 Abpbg, encoding the alpha (ABPA) and beta-gamma (ABPBG) protein subunits that are disulfide-bridged to form dimers in secretions. Only 14 Abp genes are expressed in distinct patterns in the lacrimal (11) and submandibular glands (3). We created a knockout mouse line lacking two of the three genes expressed in submandibular glands, Abpa27 and Abpbg27, by replacing them with the neomycin resistance gene. The knockout genotype (−/−) showed no Abpa27 or Abpbg27 transcripts in submandibular gland complementary DNA (cDNA) libraries and there was a concomitant lack of protein expression of ABPA27 and ABPBG27 in the −/− genotype saliva, shown by elimination of these two proteins from the saliva proteome and the loss of cross-reactive material in the acinar cells of the submandibular glands. We also observed a decrease in BG26 protein in the −/− animals, suggesting monomer instability. Overall, we observed no major phenotypic changes in the −/− genotype, compared with their +/+ and +/− siblings raised in a laboratory setting, including normal growth curves, tissue histology, fecundity, and longevity. The only difference is that male and female C57BL/6 mice preferred saliva of the opposite sex containing ABP statistically significantly more than saliva of the opposite sex without ABP in a Y-maze test. These results show for the first time that mice can sense the presence of ABP between saliva targets with and without ABPs, and that they spend more time investigating the target containing ABP. PMID:28159752

Studies of an Androgen-Binding Protein Knockout Corroborate a Role for Salivary ABP in Mouse Communication.

PubMed

Chung, Amanda G; Belone, Phillip M; Bímová, Barbora Vošlajerová; Karn, Robert C; Laukaitis, Christina M

2017-04-01

The house mouse Androgen-binding protein ( Abp ) gene family is comprised of 64 paralogs, 30 Abpa and 34 Abpbg , encoding the alpha (ABPA) and beta-gamma (ABPBG) protein subunits that are disulfide-bridged to form dimers in secretions. Only 14 Abp genes are expressed in distinct patterns in the lacrimal (11) and submandibular glands (3). We created a knockout mouse line lacking two of the three genes expressed in submandibular glands, Abpa27 and Abpbg27 , by replacing them with the neomycin resistance gene. The knockout genotype (-/-) showed no Abpa27 or Abpbg27 transcripts in submandibular gland complementary DNA (cDNA) libraries and there was a concomitant lack of protein expression of ABPA27 and ABPBG27 in the -/- genotype saliva, shown by elimination of these two proteins from the saliva proteome and the loss of cross-reactive material in the acinar cells of the submandibular glands. We also observed a decrease in BG26 protein in the -/- animals, suggesting monomer instability. Overall, we observed no major phenotypic changes in the -/- genotype, compared with their +/+ and +/- siblings raised in a laboratory setting, including normal growth curves, tissue histology, fecundity, and longevity. The only difference is that male and female C57BL/6 mice preferred saliva of the opposite sex containing ABP statistically significantly more than saliva of the opposite sex without ABP in a Y-maze test. These results show for the first time that mice can sense the presence of ABP between saliva targets with and without ABPs, and that they spend more time investigating the target containing ABP. Copyright © 2017 by the Genetics Society of America.

Caffeine, Adenosine Receptors and Estrogen in Toxin Models of Parkinson’s Disease

DTIC Science & Technology

2005-10-01

right). Adjacent coronal brain sections were processed for A2A receptor immunohistochemsitry (B) with a HRP-coupled secondary antibody yielding a...declines steadily with increasing intake of caffeine or of coffee (but not decaffeinated coffee). The mechanisms that underlie this epidemiological...ad Sju - 5261.[7 of decaffeinated coffee was not associated with an Furthermore. A2A knockout mice (lacking function- altered risk of PD). clearly

Reducing cross-sectional data using a genetic algorithm method and effects on cross-section geometry and steady-flow profiles

USGS Publications Warehouse

Berenbrock, Charles E.

2015-01-01

The effects of reduced cross-sectional data points on steady-flow profiles were also determined. Thirty-five cross sections of the original steady-flow model of the Kootenai River were used. These two methods were tested for all cross sections with each cross section resolution reduced to 10, 20 and 30 data points, that is, six tests were completed for each of the thirty-five cross sections. Generally, differences from the original water-surface elevation were smaller as the number of data points in reduced cross sections increased, but this was not always the case, especially in the braided reach. Differences were smaller for reduced cross sections developed by the genetic algorithm method than the standard algorithm method.

Selective Attention to Visual Stimuli Using Auditory Distractors Is Altered in Alpha-9 Nicotinic Receptor Subunit Knock-Out Mice.

PubMed

Terreros, Gonzalo; Jorratt, Pascal; Aedo, Cristian; Elgoyhen, Ana Belén; Delano, Paul H

2016-07-06

During selective attention, subjects voluntarily focus their cognitive resources on a specific stimulus while ignoring others. Top-down filtering of peripheral sensory responses by higher structures of the brain has been proposed as one of the mechanisms responsible for selective attention. A prerequisite to accomplish top-down modulation of the activity of peripheral structures is the presence of corticofugal pathways. The mammalian auditory efferent system is a unique neural network that originates in the auditory cortex and projects to the cochlear receptor through the olivocochlear bundle, and it has been proposed to function as a top-down filter of peripheral auditory responses during attention to cross-modal stimuli. However, to date, there is no conclusive evidence of the involvement of olivocochlear neurons in selective attention paradigms. Here, we trained wild-type and α-9 nicotinic receptor subunit knock-out (KO) mice, which lack cholinergic transmission between medial olivocochlear neurons and outer hair cells, in a two-choice visual discrimination task and studied the behavioral consequences of adding different types of auditory distractors. In addition, we evaluated the effects of contralateral noise on auditory nerve responses as a measure of the individual strength of the olivocochlear reflex. We demonstrate that KO mice have a reduced olivocochlear reflex strength and perform poorly in a visual selective attention paradigm. These results confirm that an intact medial olivocochlear transmission aids in ignoring auditory distraction during selective attention to visual stimuli. The auditory efferent system is a neural network that originates in the auditory cortex and projects to the cochlear receptor through the olivocochlear system. It has been proposed to function as a top-down filter of peripheral auditory responses during attention to cross-modal stimuli. However, to date, there is no conclusive evidence of the involvement of olivocochlear neurons in selective attention paradigms. Here, we studied the behavioral consequences of adding different types of auditory distractors in a visual selective attention task in wild-type and α-9 nicotinic receptor knock-out (KO) mice. We demonstrate that KO mice perform poorly in the selective attention paradigm and that an intact medial olivocochlear transmission aids in ignoring auditory distractors during attention. Copyright © 2016 the authors 0270-6474/16/367198-12$15.00/0.

Development of a Markerless Knockout Method for Actinobacillus succinogenes

PubMed Central

Joshi, Rajasi V.; Schindler, Bryan D.; McPherson, Nikolas R.; Tiwari, Kanupriya

2014-01-01

Actinobacillus succinogenes is one of the best natural succinate-producing organisms, but it still needs engineering to further increase succinate yield and productivity. In this study, we developed a markerless knockout method for A. succinogenes using natural transformation or electroporation. The Escherichia coli isocitrate dehydrogenase gene with flanking flippase recognition target sites was used as the positive selection marker, making use of A. succinogenes's auxotrophy for glutamate to select for growth on isocitrate. The Saccharomyces cerevisiae flippase recombinase (Flp) was used to remove the selection marker, allowing its reuse. Finally, the plasmid expressing flp was cured using acridine orange. We demonstrate that at least two consecutive deletions can be introduced into the same strain using this approach, that no more than a total of 1 kb of DNA is needed on each side of the selection cassette to protect from exonuclease activity during transformation, and that no more than 200 bp of homologous DNA is needed on each side for efficient recombination. We also demonstrate that electroporation can be used as an alternative transformation method to obtain knockout mutants and that an enriched defined medium can be used for direct selection of knockout mutants on agar plates with high efficiency. Single-knockout mutants of the fumarate reductase and of the pyruvate formate lyase-encoding genes were obtained using this knockout strategy. Double-knockout mutants were also obtained by deleting the citrate lyase-, β-galactosidase-, and aconitase-encoding genes in the pyruvate formate lyase knockout mutant strain. PMID:24610845

Development of a markerless knockout method for Actinobacillus succinogenes.

PubMed

Joshi, Rajasi V; Schindler, Bryan D; McPherson, Nikolas R; Tiwari, Kanupriya; Vieille, Claire

2014-05-01

Actinobacillus succinogenes is one of the best natural succinate-producing organisms, but it still needs engineering to further increase succinate yield and productivity. In this study, we developed a markerless knockout method for A. succinogenes using natural transformation or electroporation. The Escherichia coli isocitrate dehydrogenase gene with flanking flippase recognition target sites was used as the positive selection marker, making use of A. succinogenes's auxotrophy for glutamate to select for growth on isocitrate. The Saccharomyces cerevisiae flippase recombinase (Flp) was used to remove the selection marker, allowing its reuse. Finally, the plasmid expressing flp was cured using acridine orange. We demonstrate that at least two consecutive deletions can be introduced into the same strain using this approach, that no more than a total of 1 kb of DNA is needed on each side of the selection cassette to protect from exonuclease activity during transformation, and that no more than 200 bp of homologous DNA is needed on each side for efficient recombination. We also demonstrate that electroporation can be used as an alternative transformation method to obtain knockout mutants and that an enriched defined medium can be used for direct selection of knockout mutants on agar plates with high efficiency. Single-knockout mutants of the fumarate reductase and of the pyruvate formate lyase-encoding genes were obtained using this knockout strategy. Double-knockout mutants were also obtained by deleting the citrate lyase-, β-galactosidase-, and aconitase-encoding genes in the pyruvate formate lyase knockout mutant strain.

Hepatic changes in metabolic gene expression in old ghrelin and ghrelin receptor knockout mice

USDA-ARS?s Scientific Manuscript database

Ghrelin knockout (GKO) and ghrelin receptor (growth hormone secretagogue receptor) knockout (GHSRKO) mice exhibit enhanced insulin sensitivity, but the mechanism is unclear. Insulin sensitivity declines with age and is inversely associated with accumulation of lipid in liver, a key glucoregulatory ...

Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

DOE R&D Accomplishments Database

Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

1957-07-22

In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

Study of BenW (n = 1-12) clusters: An electron collision perspective

NASA Astrophysics Data System (ADS)

Modak, Paresh; Kaur, Jaspreet; Antony, Bobby

2017-08-01

This article explores electron scattering cross sections by Beryllium-Tungsten clusters (BenW). Beryllium and tungsten are important elements for plasma facing wall components, especially for the deuterium/tritium phase of ITER and in the recently installed JET. The present study focuses on different electron impact interactions in terms of elastic cross section (Qel), inelastic cross section (Qinel), ionization cross section (Qion), and momentum transfer cross section (Qmtcs) for the first twelve clusters belonging to the BenW family. It also predicts the evolution of the cross section with the size of the cluster. These cross sections are used as an input to model processes in plasma. The ionization cross section presented here is compared with the available reported data. This is the first comprehensive report on cross section data for all the above-mentioned scattering channels, to the best of our knowledge. Such broad analysis of cross section data gives vital insight into the study of local chemistry of electron interactions with BenW (n = 1-12) clusters in plasma.

Averaging cross section data so we can fit it

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

Brown, D.

2014-10-23

The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

New cross sections for H on H2 collisional transitions

NASA Astrophysics Data System (ADS)

Zou, Qianxia

2011-12-01

The cross section for H on H2 collisions is important for astrophysics as well as our understanding of the simple chemical systems. This is the simplest atom-molecule cross section. With a new H3 potential surface by Mielke et al., we have modified the ABC code by Skouteris, Castillo and Manolopoulos to calculate new cross sections. These cross sections are compared to previous cross section calculations.

A computer program for analyzing channel geometry

USGS Publications Warehouse

Regan, R.S.; Schaffranek, R.W.

1985-01-01

The Channel Geometry Analysis Program (CGAP) provides the capability to process, analyze, and format cross-sectional data for input to flow/transport simulation models or other computational programs. CGAP allows for a variety of cross-sectional data input formats through use of variable format specification. The program accepts data from various computer media and provides for modification of machine-stored parameter values. CGAP has been devised to provide a rapid and efficient means of computing and analyzing the physical properties of an open-channel reach defined by a sequence of cross sections. CGAP 's 16 options provide a wide range of methods by which to analyze and depict a channel reach and its individual cross-sectional properties. The primary function of the program is to compute the area, width, wetted perimeter, and hydraulic radius of cross sections at successive increments of water surface elevation (stage) from data that consist of coordinate pairs of cross-channel distances and land surface or channel bottom elevations. Longitudinal rates-of-change of cross-sectional properties are also computed, as are the mean properties of a channel reach. Output products include tabular lists of cross-sectional area, channel width, wetted perimeter, hydraulic radius, average depth, and cross-sectional symmetry computed as functions of stage; plots of cross sections; plots of cross-sectional area and (or) channel width as functions of stage; tabular lists of cross-sectional area and channel width computed as functions of stage for subdivisions of a cross section; plots of cross sections in isometric projection; and plots of cross-sectional area at a fixed stage as a function of longitudinal distance along an open-channel reach. A Command Procedure Language program and Job Control Language procedure exist to facilitate program execution on the U.S. Geological Survey Prime and Amdahl computer systems respectively. (Lantz-PTT)

Multistrand superconductor cable

DOEpatents

Borden, A.R.

1984-03-08

Improved multistrand Rutherford-type superconductor cable is produced by using strands which are preformed, prior to being wound into the cable, so that each strand has a variable cross section, with successive portions having a substantially round cross section, a transitional oval cross section, a rectangular cross section, a transitional oval cross section, a round cross section and so forth, in repetitive cycles along the length of the strand. The cable is wound and flattened so that the portions of rectangular cross section extend across the two flat sides of the cable at the strand angle. The portions of round cross section are bent at the edges of the flattened cable, so as to extend between the two flat sides. The rectangular portions of the strands slide easil

Fanconi anemia (FA) binding protein FAAP20 stabilizes FA complementation group A (FANCA) and participates in interstrand cross-link repair.

PubMed

Leung, Justin Wai Chung; Wang, Yucai; Fong, Ka Wing; Huen, Michael Shing Yan; Li, Lei; Chen, Junjie

2012-03-20

The Fanconi anemia (FA) pathway participates in interstrand cross-link (ICL) repair and the maintenance of genomic stability. The FA core complex consists of eight FA proteins and two Fanconi anemia-associated proteins (FAAP24 and FAAP100). The FA core complex has ubiquitin ligase activity responsible for monoubiquitination of the FANCI-FANCD2 (ID) complex, which in turn initiates a cascade of biochemical events that allow processing and removal of cross-linked DNA and thereby promotes cell survival following DNA damage. Here, we report the identification of a unique component of the FA core complex, namely, FAAP20, which contains a RAD18-like ubiquitin-binding zinc-finger domain. Our data suggest that FAAP20 promotes the functional integrity of the FA core complex via its direct interaction with the FA gene product, FANCA. Indeed, somatic knockout cells devoid of FAAP20 displayed the hallmarks of FA cells, including hypersensitivity to DNA cross-linking agents, chromosome aberrations, and reduced FANCD2 monoubiquitination. Taking these data together, our study indicates that FAAP20 is an important player involved in the FA pathway.

Fanconi anemia (FA) binding protein FAAP20 stabilizes FA complementation group A (FANCA) and participates in interstrand cross-link repair

PubMed Central

Leung, Justin Wai Chung; Wang, Yucai; Fong, Ka Wing; Huen, Michael Shing Yan; Li, Lei; Chen, Junjie

2012-01-01

The Fanconi anemia (FA) pathway participates in interstrand cross-link (ICL) repair and the maintenance of genomic stability. The FA core complex consists of eight FA proteins and two Fanconi anemia-associated proteins (FAAP24 and FAAP100). The FA core complex has ubiquitin ligase activity responsible for monoubiquitination of the FANCI-FANCD2 (ID) complex, which in turn initiates a cascade of biochemical events that allow processing and removal of cross-linked DNA and thereby promotes cell survival following DNA damage. Here, we report the identification of a unique component of the FA core complex, namely, FAAP20, which contains a RAD18-like ubiquitin-binding zinc-finger domain. Our data suggest that FAAP20 promotes the functional integrity of the FA core complex via its direct interaction with the FA gene product, FANCA. Indeed, somatic knockout cells devoid of FAAP20 displayed the hallmarks of FA cells, including hypersensitivity to DNA cross-linking agents, chromosome aberrations, and reduced FANCD2 monoubiquitination. Taking these data together, our study indicates that FAAP20 is an important player involved in the FA pathway. PMID:22396592

Global Gene Expression Profiling in PAI-1 Knockout Murine Heart and Kidney: Molecular Basis of Cardiac-Selective Fibrosis

PubMed Central

Ghosh, Asish K.; Murphy, Sheila B.; Kishore, Raj; Vaughan, Douglas E.

2013-01-01

Fibrosis is defined as an abnormal matrix remodeling due to excessive synthesis and accumulation of extracellular matrix proteins in tissues during wound healing or in response to chemical, mechanical and immunological stresses. At present, there is no effective therapy for organ fibrosis. Previous studies demonstrated that aged plasminogen activator inhibitor-1(PAI-1) knockout mice develop spontaneously cardiac-selective fibrosis without affecting any other organs. We hypothesized that differential expressions of profibrotic and antifibrotic genes in PAI-1 knockout hearts and unaffected organs lead to cardiac selective fibrosis. In order to address this prediction, we have used a genome-wide gene expression profiling of transcripts derived from aged PAI-1 knockout hearts and kidneys. The variations of global gene expression profiling were compared within four groups: wildtype heart vs. knockout heart; wildtype kidney vs. knockout kidney; knockout heart vs. knockout kidney and wildtype heart vs. wildtype kidney. Analysis of illumina-based microarray data revealed that several genes involved in different biological processes such as immune system processing, response to stress, cytokine signaling, cell proliferation, adhesion, migration, matrix organization and transcriptional regulation were affected in hearts and kidneys by the absence of PAI-1, a potent inhibitor of urokinase and tissue-type plasminogen activator. Importantly, the expressions of a number of genes, involved in profibrotic pathways including Ankrd1, Pi16, Egr1, Scx, Timp1, Timp2, Klf6, Loxl1 and Klotho, were deregulated in PAI-1 knockout hearts compared to wildtype hearts and PAI-1 knockout kidneys. While the levels of Ankrd1, Pi16 and Timp1 proteins were elevated during EndMT, the level of Timp4 protein was decreased. To our knowledge, this is the first comprehensive report on the influence of PAI-1 on global gene expression profiling in the heart and kidney and its implication in fibrogenesis and several other biological processes. The significance of these observations in the light of heart-specific profibrotic signaling and fibrogenesis are discussed. PMID:23724005

Liver-derived systemic factors drive β-cell hyperplasia in insulin resistant states

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

El Ouaamari, Abdelfattah; Kawamori, Dan; Dirice, Ercument

2013-02-21

Integrative organ cross-talk regulates key aspects of energy homeostasis and its dysregulation may underlie metabolic disorders such as obesity and diabetes. To test the hypothesis that cross-talk between the liver and pancreatic islets modulates β-cell growth in response to insulin resistance, we used the Liver-specific Insulin Receptor Knockout (LIRKO) mouse, a unique model that exhibits dramatic islet hyperplasia. Using complementary in vivo parabiosis and transplantation assays, and in vitro islet culture approaches, we demonstrate that humoral, non-neural, non-cell autonomous factor(s) induce β-cell proliferation in LIRKO mice. Furthermore, we report that a hepatocyte-derived factor(s) stimulates mouse and human β-cell proliferation inmore » ex vivo assays, independent of ambient glucose and insulin levels. These data implicate the liver as a critical source of β-cell growth factors in insulin resistant states.« less

Describing the role of Drosophila melanogaster ABC transporters in insecticide biology using CRISPR-Cas9 knockouts.

PubMed

Denecke, Shane; Fusetto, Roberto; Batterham, Philip

2017-12-01

ABC transporters have a well-established role in drug resistance, effluxing xenobiotics from cells and tissues within the organism. More recently, research has been dedicated to understanding the role insect ABC transporters play in insecticide toxicity, but progress in understanding the contribution of specific transporters has been hampered by the lack of functional genetic tools. Here, we report knockouts of three Drosophila melanogaster ABC transporter genes, Mdr49, Mdr50, and Mdr65, that are homologous to the well-studied mammalian ABCB1 (P-glycoprotein). Each knockout mutant was created in the same wild type background and tested against a panel of insecticides representing different chemical classes. Mdr65 knockouts were more susceptible to all neuroactive insecticides tested, but Mdr49 and Mdr50 knockouts showed increased susceptibility or resistance depending on the insecticide used. Mdr65 was chosen for further analysis. Calculation of LC 50 values for the Mdr65 knockout allowed the substrate specificity of this transporter to be examined. No obvious distinguishing structural features were shared among MDR65 substrates. A role for Mdr65 in insecticide transport was confirmed by testing the capacity of the knockout to synergize with the ABC inhibitor verapamil and by measuring the levels of insecticide retained in the body of knockout flies. These data unambiguously establish the influence of ABC transporters on the capacity of wild type D. melanogaster to tolerate insecticide exposure and suggest that both tissue and substrate specificity underpin this capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multi-level Modeling of Light-Induced Stomatal Opening Offers New Insights into Its Regulation by Drought

PubMed Central

Sun, Zhongyao; Jin, Xiaofen; Albert, Réka; Assmann, Sarah M.

2014-01-01

Plant guard cells gate CO2 uptake and transpirational water loss through stomatal pores. As a result of decades of experimental investigation, there is an abundance of information on the involvement of specific proteins and secondary messengers in the regulation of stomatal movements and on the pairwise relationships between guard cell components. We constructed a multi-level dynamic model of guard cell signal transduction during light-induced stomatal opening and of the effect of the plant hormone abscisic acid (ABA) on this process. The model integrates into a coherent network the direct and indirect biological evidence regarding the regulation of seventy components implicated in stomatal opening. Analysis of this signal transduction network identified robust cross-talk between blue light and ABA, in which [Ca2+]c plays a key role, and indicated an absence of cross-talk between red light and ABA. The dynamic model captured more than 1031 distinct states for the system and yielded outcomes that were in qualitative agreement with a wide variety of previous experimental results. We obtained novel model predictions by simulating single component knockout phenotypes. We found that under white light or blue light, over 60%, and under red light, over 90% of all simulated knockouts had similar opening responses as wild type, showing that the system is robust against single node loss. The model revealed an open question concerning the effect of ABA on red light-induced stomatal opening. We experimentally showed that ABA is able to inhibit red light-induced stomatal opening, and our model offers possible hypotheses for the underlying mechanism, which point to potential future experiments. Our modelling methodology combines simplicity and flexibility with dynamic richness, making it well suited for a wide class of biological regulatory systems. PMID:25393147

Cross-Regulation between the phz1 and phz2 Operons Maintain a Balanced Level of Phenazine Biosynthesis in Pseudomonas aeruginosa PAO1

PubMed Central

Jiang, Bei; Xiao, Bo; Liu, Linde; Ge, Yihe; Hu, Xiaomei

2016-01-01

Gene duplication often provides selective advantages for the survival of microorganisms in adapting to varying environmental conditions. P. aeruginosa PAO1 possesses two seven-gene operons [phz1 (phzA1B1C1D1E1F1G1) and phz2 (phzA2B2C2D2E2F2G2)] that are involved in the biosynthesis of phenazine-1-carboxylic acid and its derivatives. Although the two operons are highly homologous and their functions are well known, it is unclear how the two phz operons coordinate their expressions to maintain the phenazine biosynthesis. By constructing single and double deletion mutants of the two phz operons, we found that the phz1-deletion mutant produced the same or less amount of phenazine-1-carboxylic acid and pyocyanin in GA medium than the phz2-knockout mutant while the phz1-phz2 double knockout mutant did not produce any phenazines. By generating phzA1 and phzA2 translational and transcriptional fusions with a truncated lacZ reporter, we found that the expression of the phz1 operon increased significantly at the post-transcriptional level and did not alter at the transcriptional level in the absence of the phz2 operon. Surprisingly, the expression the phz2 operon increased significantly at the post-transcriptional level and only moderately at the transcriptional level in the absence of the phz1 operon. Our findings suggested that a complex cross-regulation existed between the phz1 and phz2 operons. By mediating the upregulation of one phz operon expression while the other was deleted, this crosstalk would maintain the homeostatic balance of phenazine biosynthesis in P. aeruginosa PAO1. PMID:26735915

An intact Pms2 ATPase domain is not essential for male fertility

PubMed Central

Fischer, Jared M; Dudley, Sandra; Miller, Ashleigh J; Liskay, R Michael

2016-01-01

The DNA mismatch repair (MMR) machinery in mammals plays critical roles in both mutation avoidance and spermatogenesis. Meiotic analysis of knockout mice of two different MMR genes, Mlh1 and Mlh3, revealed both male and female infertility associated with a defect in meiotic crossing over. In contrast, another MMR gene knockout, Pms2 (Pms2ko/ko), which contained a deletion of a portion of the ATPase domain, produced animals that were male sterile but female fertile. However, the meiotic phenotype of Pms2ko/ko males was less clear-cut than for Mlh1- or Mlh3-deficient meiosis. More recently, we generated a different Pms2 mutant allele (Pms2cre), which results in deletion of the same portion of the ATPase domain. Surprisingly, Pms2cre/cre male mice were completely fertile, suggesting that the ATPase domain of Pms2 is not required for male fertility. To explore the difference in male fertility, we examined the Pms2 RNA and found that alternative splicing of the Pms2cre allele results in a predicted Pms2 containing the C-terminus, which contains the Mlh1-interaction domain, a possible candidate for stabilizing Mlh1 levels. To study further the basis of male fertility, we examined Mlh1 levels in testes and found that whereas Pms2 loss in Pms2ko/ko mice results in severely reduced levels of Mlh1 expression in the testes, Mlh1 levels in Pms2cre/cre testes were reduced to a lesser extent. Thus, we propose that a primary function of Pms2 during spermatogenesis is to stabilize Mlh1 levels prior to its critical crossing over function with Mlh3. PMID:26753533

An intact Pms2 ATPase domain is not essential for male fertility.

PubMed

Fischer, Jared M; Dudley, Sandra; Miller, Ashleigh J; Liskay, R Michael

2016-03-01

The DNA mismatch repair (MMR) machinery in mammals plays critical roles in both mutation avoidance and spermatogenesis. Meiotic analysis of knockout mice of two different MMR genes, Mlh1 and Mlh3, revealed both male and female infertility associated with a defect in meiotic crossing over. In contrast, another MMR gene knockout, Pms2 (Pms2(ko/ko)), which contained a deletion of a portion of the ATPase domain, produced animals that were male sterile but female fertile. However, the meiotic phenotype of Pms2(ko/ko) males was less clear-cut than for Mlh1- or Mlh3-deficient meiosis. More recently, we generated a different Pms2 mutant allele (Pms2(cre)), which results in deletion of the same portion of the ATPase domain. Surprisingly, Pms2(cre/cre) male mice were completely fertile, suggesting that the ATPase domain of Pms2 is not required for male fertility. To explore the difference in male fertility, we examined the Pms2 RNA and found that alternative splicing of the Pms2(cre) allele results in a predicted Pms2 containing the C-terminus, which contains the Mlh1-interaction domain, a possible candidate for stabilizing Mlh1 levels. To study further the basis of male fertility, we examined Mlh1 levels in testes and found that whereas Pms2 loss in Pms2(ko/ko) mice results in severely reduced levels of Mlh1 expression in the testes, Mlh1 levels in Pms2(cre/cre) testes were reduced to a lesser extent. Thus, we propose that a primary function of Pms2 during spermatogenesis is to stabilize Mlh1 levels prior to its critical crossing over function with Mlh3. Copyright © 2015 Elsevier B.V. All rights reserved.

Ion dipole capture cross sections at low ion and rotational energies - Comparison of integrated capture cross sections with reaction cross sections for NH3 and H2O parent-ion collisions.

NASA Technical Reports Server (NTRS)

Dugan, J. V., Jr.; Canright, R. B., Jr.

1972-01-01

The numerical capture cross section is calculated from the capture ratio, defined as the fraction of trajectories reaching a prescribed minimum separation of 3 A. The calculated capture cross sections for a rotational temperature of 77 K suggest large reaction cross sections in 80 K experiments for the large dipole-moment target, methyl cyanide.

Reduced Extinction of Hippocampal-Dependent Memories in CPEB Knockout Mice

ERIC Educational Resources Information Center

Zearfoss, N. Ruth; Richter, Joel D.; Berger-Sweeney, Joanne

2006-01-01

CPEB is a sequence-specific RNA binding protein that regulates translation at synapses. In neurons of CPEB knockout mice, synaptic efficacy is reduced. Here, we have performed a battery of behavioral tests and find that relative to wild-type animals, CPEB knockout mice, although similar on many baseline behaviors, have reduced extinction of…

TransOmic analysis of forebrain sections in Sp2 conditional knockout embryonic mice using IR-MALDESI imaging of lipids and LC-MS/MS label-free proteomics

PubMed Central

Loziuk, Philip; Meier, Florian; Johnson, Caroline

2016-01-01

Quantitative methods for detection of biological molecules are needed more than ever before in the emerging age of “omics” and “big data.” Here, we provide an integrated approach for systematic analysis of the “lipidome” in tissue. To test our approach in a biological context, we utilized brain tissue selectively deficient for the transcription factor Specificity Protein 2 (Sp2). Conditional deletion of Sp2 in the mouse cerebral cortex results in developmental deficiencies including disruption of lipid metabolism. Silver (Ag) cationization was implemented for infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) to enhance the ion abundances for olefinic lipids, as these have been linked to regulation by Sp2. Combining Ag-doped and conventional IR-MALDESI imaging, this approach was extended to IR-MALDESI imaging of embryonic mouse brains. Further, our imaging technique was combined with bottom-up shotgun proteomic LC-MS/MS analysis and western blot for comparing Sp2 conditional knockout (Sp2-cKO) and wild-type (WT) cortices of tissue sections. This provided an integrated omics dataset which revealed many specific changes to fundamental cellular processes and biosynthetic pathways. In particular, step-specific altered abundances of nucleotides, lipids, and associated proteins were observed in the cerebral cortices of Sp2-cKO embryos. PMID:26942738

Sex- and age-related differences in mid-thigh composition and muscle quality determined by computed tomography in middle-aged and elderly Japanese.

PubMed

Kasai, Takehiro; Ishiguro, Naoki; Matsui, Yasumoto; Harada, Atsushi; Takemura, Marie; Yuki, Atsumu; Kato, Yuki; Otsuka, Rei; Ando, Fujiko; Shimokata, Hiroshi

2015-06-01

Sex- and age-related differences in mid-thigh composition and muscle quality remain unclear. The present study aimed to clarify these differences using computed tomography in middle-aged and elderly Japanese. A total of 2310 participants (age 40-89 years), who were randomly selected from the local residents, underwent computed tomography examination of the right mid-thigh. Thigh circumference and cross-sectional areas of the thigh, muscle, quadriceps, non-quadriceps, fat, and bone were measured. Knee extension strength and muscle quality index (knee extension strength/quadriceps cross-sectional area) were also assessed. Sex- and age-related differences in these indices were analyzed. The thigh cross-sectional area in men and women decreased by 0.6% and 0.5%/year, respectively, because of a decrease in muscle cross-sectional area (men 75.2%, women 40.6%), fat cross-sectional area (men 24.4%, women 59.6%) and bone cross-sectional area (men 0.5%, women -0.2%). Muscle cross-sectional area in men and women decreased by 0.6% and 0.4%/year, respectively, because of a decrease in quadriceps cross-sectional area (men 65.6%, women 81.6%) and non-quadriceps cross-sectional area (men 34.4%, women 18.4%). Muscle quality in men and women decreased by 0.4% and 0.3%/year, respectively. Thigh cross-sectional area decreased with age mainly because of a decrease in muscle cross-sectional area in men and fat cross-sectional area in women. The rate of decrease in muscle cross-sectional area was 1.5-fold higher in men than in women. Muscle cross-sectional area decreased with age mainly because of a decrease in quadriceps cross-sectional area, especially in women. Decrease in muscle quality with age was similar in both sexes. © 2014 Japan Geriatrics Society.

Overload-mediated skeletal muscle hypertrophy is not impaired by loss of myofiber STAT3.

PubMed

Pérez-Schindler, Joaquín; Esparza, Mary C; McKendry, James; Breen, Leigh; Philp, Andrew; Schenk, Simon

2017-09-01

Although the signal pathways mediating muscle protein synthesis and degradation are well characterized, the transcriptional processes modulating skeletal muscle mass and adaptive growth are poorly understood. Recently, studies in mouse models of muscle wasting or acutely exercised human muscle have suggested a potential role for the transcription factor signal transducer and activator of transcription 3 (STAT3), in adaptive growth. Hence, in the present study we sought to define the contribution of STAT3 to skeletal muscle adaptive growth. In contrast to previous work, two different resistance exercise protocols did not change STAT3 phosphorylation in human skeletal muscle. To directly address the role of STAT3 in load-induced (i.e., adaptive) growth, we studied the anabolic effects of 14 days of synergist ablation (SA) in skeletal muscle-specific STAT3 knockout (mKO) mice and their floxed, wild-type (WT) littermates. Plantaris muscle weight and fiber area in the nonoperated leg (control; CON) was comparable between genotypes. As expected, SA significantly increased plantaris weight, muscle fiber cross-sectional area, and anabolic signaling in WT mice, although interestingly, this induction was not impaired in STAT3 mKO mice. Collectively, these data demonstrate that STAT3 is not required for overload-mediated hypertrophy in mouse skeletal muscle. Copyright © 2017 the American Physiological Society.

The Ubiquitin Ligase Nedd4-1 Participates in Denervation-Induced Skeletal Muscle Atrophy in Mice

PubMed Central

Nagpal, Preena; Plant, Pamela J.; Correa, Judy; Bain, Alexandra; Takeda, Michiko; Kawabe, Hiroshi; Rotin, Daniela; Bain, James R.; Batt, Jane A. E.

2012-01-01

Skeletal muscle atrophy is a consequence of muscle inactivity resulting from denervation, unloading and immobility. It accompanies many chronic disease states and also occurs as a pathophysiologic consequence of normal aging. In all these conditions, ubiquitin-dependent proteolysis is a key regulator of the loss of muscle mass, and ubiquitin ligases confer specificity to this process by interacting with, and linking ubiquitin moieties to target substrates through protein∶protein interaction domains. Our previous work suggested that the ubiquitin-protein ligase Nedd4-1 is a potential mediator of skeletal muscle atrophy associated with inactivity (denervation, unloading and immobility). Here we generated a novel tool, the Nedd4-1 skeletal muscle-specific knockout mouse (myoCre;Nedd4-1flox/flox) and subjected it to a well validated model of denervation induced skeletal muscle atrophy. The absence of Nedd4-1 resulted in increased weights and cross-sectional area of type II fast twitch fibres of denervated gastrocnemius muscle compared with wild type littermates controls, at seven and fourteen days following tibial nerve transection. These effects are not mediated by the Nedd4-1 substrates MTMR4, FGFR1 and Notch-1. These results demonstrate that Nedd4-1 plays an important role in mediating denervation-induced skeletal muscle atrophy in vivo. PMID:23110050

Pushing through evolution? Incidence and fight records of left-oriented fighters in professional boxing history.

PubMed

Loffing, Florian; Hagemann, Norbert

2015-05-01

The fighting hypothesis proposes that left-oriented athletes enjoy a negative frequency-dependent advantage in combat sports such as boxing. Supporting evidence, however, is restricted to cross-sectional frequency data from small samples. Here, we examined the incidence and fight records of 2,403 left- and right-oriented fighters who were listed in the annual ratings of professional boxing from 1924 to 2012. Unexpectedly, left-oriented boxers were overrepresented in no more than 7 of the 89 years considered, their percentages varied up to 30% and increased over the entire period, and frequencies varied substantially between weight divisions. In support of the fighting hypothesis, lose-win ratios indicated larger fighting strength in left- compared to right-oriented boxers, which, however, was not reflected in different proportions of wins and losses by knockout. Our findings are partly consistent with an assumed left-oriented fighters' advantage in combat sports. Such advantage could be explained by negative frequency-dependent selection mechanisms; however, our study also revealed potential limits of the fighting hypothesis such that alternative explanations cannot be fully excluded. We propose that interference by factors not related to performance could also limit the suitability of data from elite sporting competition for testing evolutionary models of human handedness.

Adaptive bi-level programming for optimal gene knockouts for targeted overproduction under phenotypic constraints

PubMed Central

2013-01-01

Background Optimization procedures to identify gene knockouts for targeted biochemical overproduction have been widely in use in modern metabolic engineering. Flux balance analysis (FBA) framework has provided conceptual simplifications for genome-scale dynamic analysis at steady states. Based on FBA, many current optimization methods for targeted bio-productions have been developed under the maximum cell growth assumption. The optimization problem to derive gene knockout strategies recently has been formulated as a bi-level programming problem in OptKnock for maximum targeted bio-productions with maximum growth rates. However, it has been shown that knockout mutants in fact reach the steady states with the minimization of metabolic adjustment (MOMA) from the corresponding wild-type strains instead of having maximal growth rates after genetic or metabolic intervention. In this work, we propose a new bi-level computational framework--MOMAKnock--which can derive robust knockout strategies under the MOMA flux distribution approximation. Methods In this new bi-level optimization framework, we aim to maximize the production of targeted chemicals by identifying candidate knockout genes or reactions under phenotypic constraints approximated by the MOMA assumption. Hence, the targeted chemical production is the primary objective of MOMAKnock while the MOMA assumption is formulated as the inner problem of constraining the knockout metabolic flux to be as close as possible to the steady-state phenotypes of wide-type strains. As this new inner problem becomes a quadratic programming problem, a novel adaptive piecewise linearization algorithm is developed in this paper to obtain the exact optimal solution to this new bi-level integer quadratic programming problem for MOMAKnock. Results Our new MOMAKnock model and the adaptive piecewise linearization solution algorithm are tested with a small E. coli core metabolic network and a large-scale iAF1260 E. coli metabolic network. The derived knockout strategies are compared with those from OptKnock. Our preliminary experimental results show that MOMAKnock can provide improved targeted productions with more robust knockout strategies. PMID:23368729

Adaptive bi-level programming for optimal gene knockouts for targeted overproduction under phenotypic constraints.

PubMed

Ren, Shaogang; Zeng, Bo; Qian, Xiaoning

2013-01-01

Optimization procedures to identify gene knockouts for targeted biochemical overproduction have been widely in use in modern metabolic engineering. Flux balance analysis (FBA) framework has provided conceptual simplifications for genome-scale dynamic analysis at steady states. Based on FBA, many current optimization methods for targeted bio-productions have been developed under the maximum cell growth assumption. The optimization problem to derive gene knockout strategies recently has been formulated as a bi-level programming problem in OptKnock for maximum targeted bio-productions with maximum growth rates. However, it has been shown that knockout mutants in fact reach the steady states with the minimization of metabolic adjustment (MOMA) from the corresponding wild-type strains instead of having maximal growth rates after genetic or metabolic intervention. In this work, we propose a new bi-level computational framework--MOMAKnock--which can derive robust knockout strategies under the MOMA flux distribution approximation. In this new bi-level optimization framework, we aim to maximize the production of targeted chemicals by identifying candidate knockout genes or reactions under phenotypic constraints approximated by the MOMA assumption. Hence, the targeted chemical production is the primary objective of MOMAKnock while the MOMA assumption is formulated as the inner problem of constraining the knockout metabolic flux to be as close as possible to the steady-state phenotypes of wide-type strains. As this new inner problem becomes a quadratic programming problem, a novel adaptive piecewise linearization algorithm is developed in this paper to obtain the exact optimal solution to this new bi-level integer quadratic programming problem for MOMAKnock. Our new MOMAKnock model and the adaptive piecewise linearization solution algorithm are tested with a small E. coli core metabolic network and a large-scale iAF1260 E. coli metabolic network. The derived knockout strategies are compared with those from OptKnock. Our preliminary experimental results show that MOMAKnock can provide improved targeted productions with more robust knockout strategies.

Continuum analyzing power for 4He(p-->,p') at 100 MeV

NASA Astrophysics Data System (ADS)

Lawrie, J. J.; Whittal, D. M.; Cowley, A. A.

1990-08-01

Distorted-wave impulse approximation calculations of the continuum analyzing power for the inclusive reaction 4He(p-->,p') at an incident energy of 100 MeV are presented. In addition to the quasifree knockout of nucleons, contributions from the knockout of deuteron, triton, and helion clusters are taken into account, together with a breakup component. Whereas nucleon knockout by itself does not account for the experimentally observed analyzing power, the inclusion of clusters has a large effect. Thus a simple knockout model is able to provide a reasonable description of the experimental continuum analyzing power.

Genetic deletion of CB1 receptors improves non-associative learning.

PubMed

Degroot, Aldemar; Salhoff, Craig; Davis, Richard J; Nomikos, George G

2005-07-01

Habituation (a form of non-associative learning) was measured by assessing locomotion in novel activity monitors in CB1 receptor knockout mice and juxtaposed to habituation measured in muscarinic M2, M4, and double M2/M4 receptor knockout mice. M2 and M2/M4, but not M4, receptor knockout mice appeared to have an impaired ability to habituate, whereas CB1 receptor knockout mice showed enhanced habituation compared to wild-type animals. We conclude that CB1 receptor gene invalidation improves habituation tentatively through an increase in cholinergic neurotransmission.

Reduced extinction of hippocampal-dependent memories in CPEB knockout mice.

PubMed

Berger-Sweeney, Joanne; Zearfoss, N Ruth; Richter, Joel D

2006-01-01

CPEB is a sequence-specific RNA binding protein that regulates translation at synapses. In neurons of CPEB knockout mice, synaptic efficacy is reduced. Here, we have performed a battery of behavioral tests and find that relative to wild-type animals, CPEB knockout mice, although similar on many baseline behaviors, have reduced extinction of memories on two hippocampal-dependent tasks. A corresponding microarray analysis reveals that about 0.14% of hippocampal genes have an altered expression in the CPEB knockout mouse. These data suggest that CPEB-dependent local protein synthesis may be an important cellular mechanism underlying extinction of hippocampal-dependent memories.

Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections

NASA Technical Reports Server (NTRS)

Diana, L. M.; Chaplin, R. L.; Brooks, D. L.; Adams, J. T.; Reyna, L. K.

1990-01-01

An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease.

Nano-fabricated plasmonic optical transformer

DOEpatents

Choo, Hyuck; Cabrini, Stefano; Schuck, P. James; Liang, Xiaogan; Yablonovitch, Eli

2015-06-09

The present invention provides a plasmonic optical transformer to produce a highly focuses optical beam spot, where the transformer includes a first metal layer, a dielectric layer formed on the first metal layer, and a second metal layer formed on the dielectric layer, where the first metal layer, the dielectric layer, and the second layer are patterned to a shape including a first section having a first cross section, a second section following the first section having a cross-section tapering from the first section to a smaller cross-section, and a third section following the second section having a cross-section matching the tapered smaller cross-section of the second section.

Geologic cross section C-C' through the Appalachian basin from Erie County, north-central Ohio, to the Valley and Ridge province, Bedford County, south-central Pennsylvania

USGS Publications Warehouse

Ryder, Robert T.; Trippi, Michael H.; Swezey, Christopher S.; Crangle, Robert D.; Hope, Rebecca S.; Rowan, Elisabeth L.; Lentz, Erika E.

2012-01-01

Geologic cross section C-C' is the third in a series of cross sections constructed by the U.S. Geological Survey (USGS) to document and improve understanding of the geologic framework and petroleum systems of the Appalachian basin. Cross section C-C' provides a regional view of the structural and stratigraphic framework of the Appalachian basin from north-central Ohio to the Valley and Ridge province in south-central Pennsylvania, a distance of approximately 260 miles (mi). This cross section is a companion to cross sections E-E' and D-D' that are located about 50 to 125 mi and 25 to 50 mi, respectively, to the southwest. Cross section C-C' contains much information that is useful for evaluating energy resources in the Appalachian basin. Although specific petroleum systems are not identified on the cross section, many of their key elements (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and preferred migration pathways) may be evaluated by burial history, thermal history, and fluid flow models based on what is shown on the cross section. Cross section C-C' also provides a general framework (stratigraphic units and general rock types) for the coal-bearing section, although the cross section lacks the detail to illustrate key elements of coal systems (such as paleoclimate, coal quality, and coal rank). In addition, cross section C-C' may be used as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste or for the sequestration of carbon dioxide.

CRISPR/Cas9-mediated gene knockout is insensitive to target copy number but is dependent on guide RNA potency and Cas9/sgRNA threshold expression level

PubMed Central

Yuen, Garmen; Khan, Fehad J.; Gao, Shaojian; Stommel, Jayne M.; Batchelor, Eric; Wu, Xiaolin

2017-01-01

Abstract CRISPR/Cas9 is a powerful gene editing tool for gene knockout studies and functional genomic screens. Successful implementation of CRISPR often requires Cas9 to elicit efficient target knockout in a population of cells. In this study, we investigated the role of several key factors, including variation in target copy number, inherent potency of sgRNA guides, and expression level of Cas9 and sgRNA, in determining CRISPR knockout efficiency. Using isogenic, clonal cell lines with variable copy numbers of an EGFP transgene, we discovered that CRISPR knockout is relatively insensitive to target copy number, but is highly dependent on the potency of the sgRNA guide sequence. Kinetic analysis revealed that most target mutation occurs between 5 and 10 days following Cas9/sgRNA transduction, while sgRNAs with different potencies differ by their knockout time course and by their terminal-phase knockout efficiency. We showed that prolonged, low level expression of Cas9 and sgRNA often fails to elicit target mutation, particularly if the potency of the sgRNA is also low. Our findings provide new insights into the behavior of CRISPR/Cas9 in mammalian cells that could be used for future improvement of this platform. PMID:29036671

CRISPR/Cas9-mediated gene knockout is insensitive to target copy number but is dependent on guide RNA potency and Cas9/sgRNA threshold expression level.

PubMed

Yuen, Garmen; Khan, Fehad J; Gao, Shaojian; Stommel, Jayne M; Batchelor, Eric; Wu, Xiaolin; Luo, Ji

2017-11-16

CRISPR/Cas9 is a powerful gene editing tool for gene knockout studies and functional genomic screens. Successful implementation of CRISPR often requires Cas9 to elicit efficient target knockout in a population of cells. In this study, we investigated the role of several key factors, including variation in target copy number, inherent potency of sgRNA guides, and expression level of Cas9 and sgRNA, in determining CRISPR knockout efficiency. Using isogenic, clonal cell lines with variable copy numbers of an EGFP transgene, we discovered that CRISPR knockout is relatively insensitive to target copy number, but is highly dependent on the potency of the sgRNA guide sequence. Kinetic analysis revealed that most target mutation occurs between 5 and 10 days following Cas9/sgRNA transduction, while sgRNAs with different potencies differ by their knockout time course and by their terminal-phase knockout efficiency. We showed that prolonged, low level expression of Cas9 and sgRNA often fails to elicit target mutation, particularly if the potency of the sgRNA is also low. Our findings provide new insights into the behavior of CRISPR/Cas9 in mammalian cells that could be used for future improvement of this platform. Published by Oxford University Press on behalf of Nucleic Acids Research 2017.

Pyviko: an automated Python tool to design gene knockouts in complex viruses with overlapping genes.

PubMed

Taylor, Louis J; Strebel, Klaus

2017-01-07

Gene knockouts are a common tool used to study gene function in various organisms. However, designing gene knockouts is complicated in viruses, which frequently contain sequences that code for multiple overlapping genes. Designing mutants that can be traced by the creation of new or elimination of existing restriction sites further compounds the difficulty in experimental design of knockouts of overlapping genes. While software is available to rapidly identify restriction sites in a given nucleotide sequence, no existing software addresses experimental design of mutations involving multiple overlapping amino acid sequences in generating gene knockouts. Pyviko performed well on a test set of over 240,000 gene pairs collected from viral genomes deposited in the National Center for Biotechnology Information Nucleotide database, identifying a point mutation which added a premature stop codon within the first 20 codons of the target gene in 93.2% of all tested gene-overprinted gene pairs. This shows that Pyviko can be used successfully in a wide variety of contexts to facilitate the molecular cloning and study of viral overprinted genes. Pyviko is an extensible and intuitive Python tool for designing knockouts of overlapping genes. Freely available as both a Python package and a web-based interface ( http://louiejtaylor.github.io/pyViKO/ ), Pyviko simplifies the experimental design of gene knockouts in complex viruses with overlapping genes.

Erythropoiesis and Blood Pressure Are Regulated via AT1 Receptor by Distinctive Pathways.

PubMed

Kato, Hideki; Ishida, Junji; Matsusaka, Taiji; Ishimaru, Tomohiro; Tanimoto, Keiji; Sugiyama, Fumihiro; Yagami, Ken-Ichi; Nangaku, Masaomi; Fukamizu, Akiyoshi

2015-01-01

The renin-angiotensin system (RAS) plays a central role in blood pressure regulation. Although clinical and experimental studies have suggested that inhibition of RAS is associated with progression of anemia, little evidence is available to support this claim. Here we report that knockout mice that lack angiotensin II, including angiotensinogen and renin knockout mice, exhibit anemia. The anemia of angiotensinogen knockout mice was rescued by angiotensin II infusion, and rescue was completely blocked by simultaneous administration of AT1 receptor blocker. To genetically determine the responsible receptor subtype, we examined AT1a, AT1b, and AT2 knockout mice, but did not observe anemia in any of them. To investigate whether pharmacological AT1 receptor inhibition recapitulates the anemic phenotype, we administered AT1 receptor antagonist in hypotensive AT1a receptor knockout mice to inhibit the remaining AT1b receptor. In these animals, hematocrit levels barely decreased, but blood pressure further decreased to the level observed in angiotensinogen knockout mice. We then generated AT1a and AT1b double-knockout mice to completely ablate the AT1 receptors; the mice finally exhibited the anemic phenotype. These results provide clear evidence that although erythropoiesis and blood pressure are negatively controlled through the AT1 receptor inhibition in vivo, the pathways involved are complex and distinct, because erythropoiesis is more resistant to AT1 receptor inhibition than blood pressure control.

Thyroid Hormone Receptor α- and β-Knockout Xenopus tropicalis Tadpoles Reveal Subtype-Specific Roles During Development.

PubMed

Nakajima, Keisuke; Tazawa, Ichiro; Yaoita, Yoshio

2018-02-01

Thyroid hormone (TH) binds TH receptor α (TRα) and β (TRβ) to induce amphibian metamorphosis. Whereas TH signaling has been well studied, functional differences between TRα and TRβ during this process have not been characterized. To understand how each TR contributes to metamorphosis, we generated TRα- and TRβ-knockout tadpoles of Xenopus tropicalis and examined developmental abnormalities, histology of the tail and intestine, and messenger RNA expression of genes encoding extracellular matrix-degrading enzymes. In TRβ-knockout tadpoles, tail regression was delayed significantly and a healthy notochord was observed even 5 days after the initiation of tail shortening (stage 62), whereas in the tails of wild-type and TRα-knockout tadpoles, the notochord disappeared after ∼1 day. The messenger RNA expression levels of genes encoding extracellular matrix-degrading enzymes (MMP2, MMP9TH, MMP13, MMP14, and FAPα) were obviously reduced in the tail tip of TRβ-knockout tadpoles, with the shortening tail. The reduction in olfactory nerve length and head narrowing by gill absorption were also affected. Hind limb growth and intestinal shortening were not compromised in TRβ-knockout tadpoles, whereas tail regression and olfactory nerve shortening appeared to proceed normally in TRα-knockout tadpoles, except for the precocious development of hind limbs. Our results demonstrated the distinct roles of TRα and TRβ in hind limb growth and tail regression, respectively. Copyright © 2018 Endocrine Society.

Multistrand superconductor cable

DOEpatents

Borden, Albert R.

1985-01-01

Improved multistrand Rutherford-type superconductor cable is produced by using strands which are preformed, prior to being wound into the cable, so that each strand has a variable cross section, with successive portions having a substantially round cross section, a transitional oval cross section, a rectangular cross section, a transitional oval cross section, a round cross section and so forth, in repetitive cycles along the length of the strand. The cable is wound and flattened so that the portions of rectangular cross section extend across the two flat sides of the cable at the strand angle. The portions of round cross section are bent at the edges of the flattened cable, so as to extend between the two flat sides. The rectangular portions of the strands slide easily over one another, so as to facilitate flexing and bending of the cable, while also minimizing the possibility of causing damage to the strands by such flexing or bending. Moreover, the improved cable substantially maintains its compactness and cross-sectional shape when the cable is flexed or bent.

Knockout of the Na,K-ATPase α2-isoform in cardiac myocytes delays pressure overload-induced cardiac dysfunction

PubMed Central

Rindler, Tara N.; Lasko, Valerie M.; Nieman, Michelle L.; Okada, Motoi; Lorenz, John N.

2013-01-01

The α2-isoform of the Na,K-ATPase (α2) is the minor isoform of the Na,K-ATPase expressed in the cardiovascular system and is thought to play a critical role in the regulation of cardiovascular hemodynamics. However, the organ system/cell type expressing α2 that is required for this regulation has not been fully defined. The present study uses a heart-specific knockout of α2 to further define the tissue-specific role of α2 in the regulation of cardiovascular hemodynamics. To accomplish this, we developed a mouse model using the Cre/loxP system to generate a tissue-specific knockout of α2 in the heart using β-myosin heavy chain Cre. We have achieved a 90% knockout of α2 expression in the heart of the knockout mice. Interestingly, the heart-specific knockout mice exhibit normal basal cardiac function and systolic blood pressure, and in addition, these mice develop ACTH-induced hypertension in response to ACTH treatment similar to control mice. Surprisingly, the heart-specific knockout mice display delayed onset of cardiac dysfunction compared with control mice in response to pressure overload induced by transverse aortic constriction; however, the heart-specific knockout mice deteriorated to control levels by 9 wk post-transverse aortic constriction. These results suggest that heart expression of α2 does not play a role in the regulation of basal cardiovascular function or blood pressure; however, heart expression of α2 plays a role in the hypertrophic response to pressure overload. This study further emphasizes that the tissue localization of α2 determines its unique roles in the regulation of cardiovascular function. PMID:23436327

Neuron-specific (pro)renin receptor knockout prevents the development of salt-sensitive hypertension

PubMed Central

Li, Wencheng; Peng, Hua; Mehaffey, Eamonn P.; Kimball, Christie D.; Grobe, Justin L.; van Gool, Jeanette M.G.; Sullivan, Michelle N.; Earley, Scott; Danser, A.H. Jan; Ichihara, Atsuhiro; Feng, Yumei

2013-01-01

The (pro)renin receptor, which binds both renin and prorenin, is a newly discovered component of the renin angiotensin system that is highly expressed in the central nervous system. The significance of brain PRRs in mediating local angiotensin II formation and regulating blood pressure remains unclear. The current study was performed to test the hypothesis that PRR-mediated, non-proteolytic activation of prorenin is the main source of angiotensin II in the brain. Thus, PRR knockout in the brain is expected to prevent angiotensin II formation and development of deoxycorticosterone acetate salt induced hypertension. A neuron-specific PRR (ATP6AP2) knockout mouse model was generated using the Cre-LoxP system. Physiological parameters were recorded by telemetry. (Pro)renin receptor expression, detected by immunostaining and RT-PCR, was significantly decreased in the brains of knockout compared with wide-type mice. Intracerebroventricular infusion of mouse prorenin increased blood pressure and angiotensin II formation in wild type mice. This hypertensive response was abolished in (pro)renin receptor knockout mice in association with a reduction in angiotensin II levels. Deoxycorticosterone acetate salt increased (pro)renin receptor expression and angiotensin II formation in the brains of wild-type mice, an effect that was attenuated in (pro)renin receptor knockout mice. (Pro)renin receptor knockout in neurons prevented the development of Deoxycorticosterone acetate salt-induced hypertension as well as activation of cardiac and vasomotor sympathetic tone. In conclusion, non-proteolytic activation of prorenin through binding to the PRR mediates angiotensin II formation in the brain. Neuron-specific PRR knockout prevents the development of deoxycorticosterone acetate salt-induced hypertension, possibly through diminished angiotensin II formation. PMID:24246383

Changes in blood carnitine and acylcarnitine profiles of very long-chain acyl-CoA dehydrogenase-deficient mice subjected to stress.

PubMed

Spiekerkoetter, U; Tokunaga, C; Wendel, U; Mayatepek, E; Exil, V; Duran, M; Wijburg, F A; Wanders, R J A; Strauss, A W

2004-03-01

In humans with deficiency of the very long-chain acyl-CoA dehydrogenase (VLCAD), C14-C18 acylcarnitines accumulate. In this paper we have used the VLCAD knockout mouse as a model to study changes in blood carnitine and acylcarnitine profiles under stress. VLCAD knockout mice exhibit stress-induced hypoglycaemia and skeletal myopathy; symptoms resembling human VLCADD. To study the extent of biochemical derangement in response to different stressors, we determined blood carnitine and acylcarnitine profiles after exercise on a treadmill, fasting, or exposure to cold. Even in a nonstressed, well-fed state, knockout mice presented twofold higher C14-C18 acylcarnitines and a lower free carnitine of 72% as compared to wild-type littermates. After 1 h of intense exercise, the C14-C18 acylcarnitines in blood significantly increased, but free carnitine remained unchanged. After 8 h of fasting at 4 degrees C, the long-chain acylcarnitines were elevated 5-fold in knockout mice in comparison with concentrations in unstressed wild-type mice (P < 0.05), and four out of 12 knockout mice died. Free carnitine decreased to 44% as compared with unstressed wild-type mice. An increase in C14-C18 acylcarnitines and a decrease of free carnitine were also observed in fasted heterozygous and wild-type mice. Long-chain acylcarnitines in blood increase in knockout mice in response to different stressors and concentrations correlate with the clinical condition. A decrease in blood free carnitine in response to severe stress is observed in knockout mice but also in wild-type littermates. Monitoring blood acylcarnitine profiles in response to different stressors may allow systematic analysis of therapeutic interventions in VLCAD knockout mice.

Object recognition impairment in Fmr1 knockout mice is reversed by amphetamine: involvement of dopamine in the medial prefrontal cortex.

PubMed

Ventura, R; Pascucci, T; Catania, M V; Musumeci, S A; Puglisi-Allegra, S

2004-09-01

Fragile X syndrome is an X-linked form of mental retardation including, among others, symptoms such as stereotypic behaviour, hyperactivity, hyperarousal, and cognitive deficits. We hypothesized that hyperactivity and/or compromised attentional, cognitive functions may lead to impaired performance in cognitive tasks in Fmr1 knockout mice, the most widely used animal model of fragile X syndrome, and suggested that psychostimulant treatment may improve performance by acting on one or both components. Since hyperactivity and cognitive functions have been suggested to depend on striatal and prefrontal cortex dopaminergic dysfunction, we assessed whether amphetamine produced beneficial, positive effects by acting on dopaminergic corticostriatal systems. Our results show that Fmr1 knockout mice are not able to discriminate between a familiar object and a novel one in the object recognition test, thus showing a clear-cut cognitive impairment that, to date, has been difficult to demonstrate in other cognitive tasks. Amphetamine improved performance of Fmr1 knockout mice, leading to enhanced ability to discriminate novel versus familiar objects, without significantly affecting locomotor activity. In agreement with behavioural data, amphetamine produced a greater increase in dopamine release in the prefrontal cortex of Fmr1 knockout compared with the wild-type mice, while a weak striatal dopaminergic response was observed in Fmr1 knockout mice. Our data support the view that the psychostimulant ameliorates performance in Fmr1 knockout mice by improving merely cognitive functions through its action on prefrontal cortical dopamine, irrespective of its action on motor hyperactivity. These results indicate that prefrontal cortical dopamine plays a major role in cognitive impairments characterizing Fmr1 knockout mice, thus pointing to an important aetiological factor in the fragile X syndrome.

Phenotypic assessment of THC discriminative stimulus properties in fatty acid amide hydrolase knockout and wildtype mice.

PubMed

Walentiny, D Matthew; Vann, Robert E; Wiley, Jenny L

2015-06-01

A number of studies have examined the ability of the endogenous cannabinoid anandamide to elicit Δ(9)-tetrahydrocannabinol (THC)-like subjective effects, as modeled through the THC discrimination paradigm. In the present study, we compared transgenic mice lacking fatty acid amide hydrolase (FAAH), the enzyme primarily responsible for anandamide catabolism, to wildtype counterparts in a THC discrimination procedure. THC (5.6 mg/kg) served as a discriminative stimulus in both genotypes, with similar THC dose-response curves between groups. Anandamide fully substituted for THC in FAAH knockout, but not wildtype, mice. Conversely, the metabolically stable anandamide analog O-1812 fully substituted in both groups, but was more potent in knockouts. The CB1 receptor antagonist rimonabant dose-dependently attenuated THC generalization in both groups and anandamide substitution in FAAH knockouts. Pharmacological inhibition of monoacylglycerol lipase (MAGL), the primary catabolic enzyme for the endocannabinoid 2-arachidonoylglycerol (2-AG), with JZL184 resulted in full substitution for THC in FAAH knockout mice and nearly full substitution in wildtypes. Quantification of brain endocannabinoid levels revealed expected elevations in anandamide in FAAH knockout mice compared to wildtypes and equipotent dose-dependent elevations in 2-AG following JZL184 administration. Dual inhibition of FAAH and MAGL with JZL195 resulted in roughly equipotent increases in THC-appropriate responding in both groups. While the notable similarity in THC's discriminative stimulus effects across genotype suggests that the increased baseline brain anandamide levels (as seen in FAAH knockout mice) do not alter THC's subjective effects, FAAH knockout mice are more sensitive to the THC-like effects of pharmacologically induced increases in anandamide and MAGL inhibition (e.g., JZL184). Copyright © 2015 Elsevier Ltd. All rights reserved.

A minor role of WNK3 in regulating phosphorylation of renal NKCC2 and NCC co-transporters in vivo.

PubMed

Oi, Katsuyuki; Sohara, Eisei; Rai, Tatemitsu; Misawa, Moko; Chiga, Motoko; Alessi, Dario R; Sasaki, Sei; Uchida, Shinichi

2012-02-15

Mutations in WNK1 and WNK4 kinase genes have been shown to cause a human hereditary hypertensive disease, pseudohypoaldosteronism type II (PHAII). We previously discovered that WNK kinases phosphorylate and activate OSR1/SPAK kinases that regulate renal SLC12A family transporters such as NKCC2 and NCC, and clarified that the constitutive activation of this cascade causes PHAII. WNK3, another member of the WNK kinase family, was reported to be a strong activator of NCC/NKCC2 when assayed in Xenopus oocytes, suggesting that WNK3 also plays a major role in regulating blood pressure and sodium reabsorption in the kidney. However, it remains to be determined whether WNK3 is in fact involved in the regulation of these transporters in vivo. To clarify this issue, we generated and analyzed WNK3 knockout mice. Surprisingly, phosphorylation and expression of OSR1, SPAK, NKCC2 and NCC did not decrease in knockout mouse kidney under normal and low-salt diets. Similarly, expression of epithelial Na channel and Na/H exchanger 3 were not affected in knockout mice. Na(+) and K(+) excretion in urine in WNK3 knockout mice was not affected under different salt diets. Blood pressure in WNK3 knockout mice was not lower under normal diet. However, lower blood pressure was observed in WNK3 knockout mice fed low-salt diet. WNK4 and WNK1 expression was slightly elevated in the knockout mice under low-salt diet, suggesting compensation for WNK3 knockout by these WNKs. Thus, WNK3 may have some role in the WNK-OSR1/SPAK-NCC/NKCC2 signal cascade in the kidney, but its contribution to total WNK kinase activity may be minimal.

The guinea pig ileum lacks the direct, high-potency, M(2)-muscarinic, contractile mechanism characteristic of the mouse ileum.

PubMed

Griffin, Michael T; Matsui, Minoru; Ostrom, Rennolds S; Ehlert, Frederick J

2009-10-01

We explored whether the M(2) muscarinic receptor in the guinea pig ileum elicits a highly potent, direct-contractile response, like that from the M(3) muscarinic receptor knockout mouse. First, we characterized the irreversible receptor-blocking activity of 4-DAMP mustard in ileum from muscarinic receptor knockout mice to verify its M(3) selectivity. Then, we used 4-DAMP mustard to inactivate M(3) responses in the guinea pig ileum to attempt to reveal direct, M(2) receptor-mediated contractions. The muscarinic agonist, oxotremorine-M, elicited potent contractions in ileum from wild-type, M(2) receptor knockout, and M(3) receptor knockout mice characterized by negative log EC(50) (pEC (50)) values +/- SEM of 6.75 +/- 0.03, 6.26 +/- 0.05, and 6.99 +/- 0.08, respectively. The corresponding E (max) values in wild-type and M(2) receptor knockout mice were approximately the same, but that in the M(3) receptor knockout mouse was only 36% of wild type. Following 4-DAMP mustard treatment, the concentration-response curve of oxotremorine-M in wild-type ileum resembled that of the M(3) knockout mouse in terms of its pEC (50), E (max), and inhibition by selective muscarinic antagonists. Thus, 4-DAMP mustard treatment appears to inactivate M(3) responses selectively and renders the muscarinic contractile behavior of the wild-type ileum similar to that of the M(3) knockout mouse. Following 4-DAMP mustard treatment, the contractile response of the guinea pig ileum to oxotremorine-M exhibited low potency and a competitive-antagonism profile consistent with an M(3) response. The guinea pig ileum, therefore, lacks a direct, highly potent, M(2)-contractile component but may have a direct, lower potency M(2) component.

Myostatin knockout using zinc-finger nucleases promotes proliferation of ovine primary satellite cells in vitro.

PubMed

Salabi, Fatemeh; Nazari, Mahmood; Chen, Qing; Nimal, Jonathan; Tong, Jianming; Cao, Wen G

2014-12-20

Myostatin (MSTN) has previously been shown to negatively regulate the proliferation and differentiation of skeletal muscle cells. Satellite cells are quiescent muscle stem cells that promote muscle growth and repair. Because the mechanism of MSTN in the biology of satellite cells is not well understood, this study was conducted to generate MSTN mono-allelic knockout satellite cells using the zinc-finger nuclease mRNA (MSTN-KO ZFN mRNA) and also to investigate the effect of this disruption on the proliferation and differentiation of sheep primary satellite cells (PSCs). Nineteen biallelic and four mono-allelic knockout cell clones were obtained after sequence analysis. The homologous mono-allelic knockout cells with 5-bp deletion were used to further evaluations. The results demonstrated that mono-allelic knockout of MSTN gene leads to translation inhibition. Real-time quantitative PCR results indicated that knockout of MSTN contributed to an increase in CDK2 and follistatin and a decrease in p21 at the transcript level in proliferation conditions. Moreover, MSTN knockout significantly increased the proliferation of mutant clones (P < 0.01). Consistent with the observed increase in CDK2 and decrease in p21 in cells lacking MSTN, cell cycle analysis showed that MSTN negatively regulated the G1 to S progression. In addition, knockout of myostatin resulted in a remarkable increase in MyoD and MyoG expression under differentiating conditions but had no effect on Myf5 expression. These results expanded our understanding of the regulation mechanism of MSTN. Furthermore, the MSTN-KO ZFN mRNA system in PSCs could be used to generate transgenic sheep in the future.

Differential sensitivity of Pak5, Pak6, and Pak5/Pak6 double-knockout mice to the stimulant effects of amphetamine and exercise-induced alterations in body weight.

PubMed

Furnari, Melody A; Jobes, Michelle L; Nekrasova, Tanya; Minden, Audrey; Wagner, George C

2014-04-01

PAK5 and PAK6 are protein kinases highly expressed in the brain. Previously, we observed that Pak6 knockout mice gained significantly more weight during development than Pak5 knockout mice as well as wild-type controls and double-knockout mice lacking both Pak5 and Pak6. In this study, we assessed the effects of exercise on food intake and weight gain of these mice as well as their sensitivity to the stimulant effects of amphetamine. Mice of each genotype were placed in cages with free access to run wheel exercise or in cages without run wheels for a total of 74 days. Food and fluid intake as well as body weight of each mouse were measured on a weekly basis. Finally, mice were given a high dose of amphetamine and activity levels were observed immediately thereafter for 90 minutes. Brains and testes of mice were assayed for protein levels of the estrogen alpha and progesterone receptors. While run wheel mice consumed significantly more food, they weighed less than non-run wheel mice. In addition, although Pak6 knockout mice consumed the same amount of food as wild-type mice, they were significantly heavier regardless of run wheel condition. Pak5 knockout mice were found to be more active than other genotypes after amphetamine treatment. Finally, protein levels of the progesterone and estrogen alpha receptors were altered in brain and testes of the Pak6 knockout mice. Collectively, these data suggest that PAK6 play a role in weight gain unrelated to exercise and caloric intake and that Pak5 knockout mice are more sensitive to the stimulant effects of amphetamine.

Distinct Roles of Opioid and Dopamine Systems in Lateral Hypothalamic Intracranial Self-Stimulation.

PubMed

Ide, Soichiro; Takahashi, Takehiro; Takamatsu, Yukio; Uhl, George R; Niki, Hiroaki; Sora, Ichiro; Ikeda, Kazutaka

2017-05-01

Opioid and dopamine systems play crucial roles in reward. Similarities and differences in the neural mechanisms of reward that are mediated by these 2 systems have remained largely unknown. Thus, in the present study, we investigated the differences in reward function in both µ-opioid receptor knockout mice and dopamine transporter knockout mice, important molecules in the opioid and dopamine systems. Mice were implanted with electrodes into the right lateral hypothalamus (l hour). Mice were then trained to put their muzzle into the hole in the head-dipping chamber for intracranial electrical stimulation, and the influences of gene knockout were assessed. Significant differences are observed between opioid and dopamine systems in reward function. µ-Opioid receptor knockout mice exhibited enhanced intracranial electrical stimulation, which induced dopamine release. They also exhibited greater motility under conditions of "despair" in both the tail suspension test and water wheel test. In contrast, dopamine transporter knockout mice maintained intracranial electrical stimulation responding even when more active efforts were required to obtain the reward. The absence of µ-opioid receptor or dopamine transporter did not lead to the absence of intracranial electrical stimulation responsiveness but rather differentially altered it. The present results in µ-opioid receptor knockout mice are consistent with the suppressive involvement of µ-opioid receptors in both positive incentive motivation associated with intracranial electrical stimulation and negative incentive motivation associated with depressive states. In contrast, the results in dopamine transporter knockout mice are consistent with the involvement of dopamine transporters in positive incentive motivation, especially its persistence. Differences in intracranial electrical stimulation in µ-opioid receptor and dopamine transporter knockout mice underscore the multidimensional nature of reward. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Quasifree (p ,p N ) scattering of light neutron-rich nuclei near N =14

NASA Astrophysics Data System (ADS)

Díaz Fernández, P.; Alvarez-Pol, H.; Crespo, R.; Cravo, E.; Atar, L.; Deltuva, A.; Aumann, T.; Avdeichikov, V.; Beceiro-Novo, S.; Bemmerer, D.; Benlliure, J.; Bertulani, C. A.; Boillos, J. M.; Boretzky, K.; Borge, M. J. G.; Caamaño, M.; Cabanelas, P.; Caesar, C.; Casarejos, E.; Catford, W.; Cederkäll, J.; Chartier, M.; Chulkov, L. V.; Cortina-Gil, D.; Datta Pramanik, U.; Dillmann, I.; Elekes, Z.; Enders, J.; Ershova, O.; Estradé, A.; Farinon, F.; Fernández-Domínguez, B.; Fraile, L. M.; Freer, M.; Galaviz, D.; Geissel, H.; Gernhäuser, R.; Golubev, P.; Göbel, K.; Hagdahl, J.; Heftrich, T.; Heil, M.; Heine, M.; Heinz, A.; Henriques, A.; Holl, M.; Hufnagel, A.; Ignatov, A.; Johansson, H. T.; Jonson, B.; Jurčiukonis, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Kelic-Heil, A.; Knyazev, A.; Kröll, T.; Kurz, N.; Labiche, M.; Langer, C.; Le Bleis, T.; Lemmon, R.; Lindberg, S.; Machado, J.; Marganiec, J.; Moro, A. M.; Movsesyan, A.; Nacher, E.; Najafi, A.; Nikolskii, E.; Nilsson, T.; Nociforo, C.; Panin, V.; Paschalis, S.; Perea, A.; Petri, M.; Pietras, B.; Pietri, S.; Plag, R.; Reifarth, R.; Ribeiro, G.; Rigollet, C.; Rossi, D.; Röder, M.; Savran, D.; Scheit, H.; Simon, H.; Sorlin, O.; Syndikus, I.; Taylor, J. T.; Tengblad, O.; Thies, R.; Togano, Y.; Vandebrouck, M.; Velho, P.; Volkov, V.; Wagner, A.; Wamers, F.; Weick, H.; Wheldon, C.; Wilson, G.; Winfield, J. S.; Woods, P.; Yakorev, D.; Zhukov, M.; Zilges, A.; Zuber, K.; R³B Collaboration

2018-02-01

Background: For many years, quasifree scattering reactions in direct kinematics have been extensively used to study the structure of stable nuclei, demonstrating the potential of this approach. The R 3B collaboration has performed a pilot experiment to study quasifree scattering reactions in inverse kinematics for a stable 12C beam. The results from that experiment constitute the first quasifree scattering results in inverse and complete kinematics. This technique has lately been extended to exotic beams to investigate the evolution of shell structure, which has attracted much interest due to changes in shell structure if the number of protons or neutrons is varied. Purpose: In this work we investigate for the first time the quasifree scattering reactions (p ,p n ) and (p ,2 p ) simultaneously for the same projectile in inverse and complete kinematics for radioactive beams with the aim to study the evolution of single-particle properties from N =14 to N =15 . Method: The structure of the projectiles 23O, 22O, and 21N has been studied simultaneously via (p ,p n ) and (p ,2 p ) quasifree knockout reactions in complete inverse kinematics, allowing the investigation of proton and neutron structure at the same time. The experimental data were collected at the R3B -LAND setup at GSI at beam energies of around 400 MeV/u. Two key observables have been studied to shed light on the structure of those nuclei: the inclusive cross sections and the corresponding momentum distributions. Conclusions: The knockout reactions (p ,p n ) and (p ,2 p ) with radioactive beams in inverse kinematics have provided important and complementary information for the study of shell evolution and structure. For the (p ,p n ) channels, indications of a change in the structure of these nuclei moving from N =14 to N =15 have been observed, i.e., from the 0 d5 /2 shell to the 1 s1 /2 . This supports previous observations of a subshell closure at N =14 for neutron-rich oxygen isotopes and its weakening for the nitrogen isotopes.

The Krüppel-like factor 2 and Krüppel-like factor 4 genes interact to maintain endothelial integrity in mouse embryonic vasculogenesis

PubMed Central

2013-01-01

Background Krüppel-like Factor 2 (KLF2) plays an important role in vessel maturation during embryonic development. In adult mice, KLF2 regulates expression of the tight junction protein occludin, which may allow KLF2 to maintain vascular integrity. Adult tamoxifen-inducible Krüppel-like Factor 4 (KLF4) knockout mice have thickened arterial intima following vascular injury. The role of KLF4, and the possible overlapping functions of KLF2 and KLF4, in the developing vasculature are not well-studied. Results Endothelial breaks are observed in a major vessel, the primary head vein (PHV), in KLF2-/-KLF4-/- embryos at E9.5. KLF2-/-KLF4-/- embryos die by E10.5, which is earlier than either single knockout. Gross hemorrhaging of multiple vessels may be the cause of death. E9.5 KLF2-/-KLF4+/- embryos do not exhibit gross hemorrhaging, but cross-sections display disruptions of the endothelial cell layer of the PHV, and these embryos generally also die by E10.5. Electron micrographs confirm that there are gaps in the PHV endothelial layer in E9.5 KLF2-/-KLF4-/- embryos, and show that the endothelial cells are abnormally bulbous compared to KLF2-/- and wild-type (WT). The amount of endothelial Nitric Oxide Synthase (eNOS) mRNA, which encodes an endothelial regulator, is reduced by 10-fold in E9.5 KLF2-/-KLF4-/- compared to KLF2-/- and WT embryos. VEGFR2, an eNOS inducer, and occludin, a tight junction protein, gene expression are also reduced in E9.5 KLF2-/-KLF4-/- compared to KLF2-/- and WT embryos. Conclusions This study begins to define the roles of KLF2 and KLF4 in the embryonic development of blood vessels. It indicates that the two genes interact to maintain an intact endothelial layer. KLF2 and KLF4 positively regulate the eNOS, VEGFR2 and occludin genes. Down-regulation of these genes in KLF2-/-KLF4-/- embryos may result in the observed loss of vascular integrity. PMID:24261709

AMPX: a modular code system for generating coupled multigroup neutron-gamma libraries from ENDF/B

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

Greene, N.M.; Lucius, J.L.; Petrie, L.M.

1976-03-01

AMPX is a modular system for producing coupled multigroup neutron-gamma cross section sets. Basic neutron and gamma cross-section data for AMPX are obtained from ENDF/B libraries. Most commonly used operations required to generate and collapse multigroup cross-section sets are provided in the system. AMPX is flexibly dimensioned; neutron group structures, and gamma group structures, and expansion orders to represent anisotropic processes are all arbitrary and limited only by available computer core and budget. The basic processes provided will (1) generate multigroup neutron cross sections; (2) generate multigroup gamma cross sections; (3) generate gamma yields for gamma-producing neutron interactions; (4) combinemore » neutron cross sections, gamma cross sections, and gamma yields into final ''coupled sets''; (5) perform one-dimensional discrete ordinates transport or diffusion theory calculations for neutrons and gammas and, on option, collapse the cross sections to a broad-group structure, using the one-dimensional results as weighting functions; (6) plot cross sections, on option, to facilitate the ''evaluation'' of a particular multigroup set of data; (7) update and maintain multigroup cross section libraries in such a manner as to make it not only easy to combine new data with previously processed data but also to do it in a single pass on the computer; and (8) output multigroup cross sections in convenient formats for other codes. (auth)« less

Trunk Muscle Size and Composition Assessment in Older Adults with Chronic Low Back Pain: An Intra-Examiner and Inter-Examiner Reliability Study.

PubMed

Sions, Jaclyn Megan; Smith, Andrew Craig; Hicks, Gregory Evan; Elliott, James Matthew

2016-08-01

To evaluate intra- and inter-examiner reliability for the assessment of relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area, i.e., total cross-sectional area minus intramuscular fat, from T1-weighted magnetic resonance images obtained in older adults with chronic low back pain. Reliability study. n = 13 (69.3 ± 8.2 years old) After lumbar magnetic resonance imaging, two examiners produced relative cross-sectional area measurements of multifidi, erector spinae, psoas, and quadratus lumborum by tracing regions of interest just inside fascial borders. Pixel-intensity summaries were used to determine muscle-to-fat infiltration indices; relative muscle cross-sectional area was calculated. Intraclass correlation coefficients were used to estimate intra- and inter-examiner reliability; standard error of measurement was calculated. Intra-examiner intraclass correlation coefficient point estimates for relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area were excellent for multifidi and erector spinae across levels L2-L5 (ICC = 0.77-0.99). At L3, intra-examiner reliability was excellent for relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area for both psoas and quadratus lumborum (ICC = 0.81-0.99). Inter-examiner intraclass correlation coefficients ranged from poor to excellent for relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area. Assessment of relative cross-sectional area, muscle-to-fat infiltration indices, and relative muscle cross-sectional area in older adults with chronic low back pain can be reliably determined by one examiner from T1-weighted images. Such assessments provide valuable information, as muscle-to-fat infiltration indices and relative muscle cross-sectional area indicate that a substantial amount of relative cross-sectional area may be magnetic resonance-visible intramuscular fat in older adults with chronic low back pain. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enhanced serotonin response in the hippocampus of Galphaz protein knock-out mice.

PubMed

Oleskevich, Sharon; Leck, Kwong-Joo; Matthaei, Klaus; Hendry, Ian A

2005-06-21

The serotonin-1A [5-hydroxytryptamine 1A (5HT1A)] receptor is important for emotional and homeostatic processes in the central nervous system. In the hippocampus, the 5HT1A receptor couples to inhibitory Gi/o proteins to decrease pyramidal cell excitability. Here we investigate the 5HT1A receptor in a mouse deficient in the alpha-subunit of Gz protein (Galphaz knock-out). Behavioural tests showed heightened anxiety and depression-like behaviour in the Galphaz knock-out mice. Whole-cell recording in CA1 pyramidal neurons showed a significantly greater 5HT1A receptor-mediated potassium current in Galphaz knock-out mice. The effect was independent of 5HT4 receptors as the slow after-hyperpolarization was unaffected and a slow depolarization was absent in the Galphaz knock-out mice. Other receptors linked to Gi/o proteins [gamma-aminobutyric acid type B receptor (GABAB), adenosine A1 and muscarinic acetylcholine receptors] were not affected in Galphaz knock-out mice. These results suggest that the 5HT1A receptor may be linked to Galphaz protein, as reported previously in cell culture but shown here in an intact neural network.

Calculation of total and ionization cross sections for electron scattering by primary benzene compounds

NASA Astrophysics Data System (ADS)

Singh, Suvam; Naghma, Rahla; Kaur, Jaspreet; Antony, Bobby

2016-07-01

The total and ionization cross sections for electron scattering by benzene, halobenzenes, toluene, aniline, and phenol are reported over a wide energy domain. The multi-scattering centre spherical complex optical potential method has been employed to find the total elastic and inelastic cross sections. The total ionization cross section is estimated from total inelastic cross section using the complex scattering potential-ionization contribution method. In the present article, the first theoretical calculations for electron impact total and ionization cross section have been performed for most of the targets having numerous practical applications. A reasonable agreement is obtained compared to existing experimental observations for all the targets reported here, especially for the total cross section.

Parameterized Cross Sections for Pion Production in Proton-Proton Collisions

NASA Technical Reports Server (NTRS)

Blattnig, Steve R.; Swaminathan, Sudha R.; Kruger, Adam T.; Ngom, Moussa; Norbury, John W.; Tripathi, R. K.

2000-01-01

An accurate knowledge of cross sections for pion production in proton-proton collisions finds wide application in particle physics, astrophysics, cosmic ray physics, and space radiation problems, especially in situations where an incident proton is transported through some medium and knowledge of the output particle spectrum is required when given the input spectrum. In these cases, accurate parameterizations of the cross sections are desired. In this paper much of the experimental data are reviewed and compared with a wide variety of different cross section parameterizations. Therefore, parameterizations of neutral and charged pion cross sections are provided that give a very accurate description of the experimental data. Lorentz invariant differential cross sections, spectral distributions, and total cross section parameterizations are presented.

Conditional disruption of the prolyl hydroxylase domain-containing protein 2 (Phd2) gene defines its key role in skeletal development.

PubMed

Cheng, Shaohong; Xing, Weirong; Pourteymoor, Sheila; Mohan, Subburaman

2014-10-01

We have previously shown that the increase in osterix (Osx) expression during osteoblast maturation is dependent on the activity of the prolyl hydroxylase domain-containing protein 2 (Phd2), a key regulator of protein levels of the hypoxia-inducible factor family proteins in many tissues. In this study, we generated conditional Phd2 knockout mice (cKO) in osteoblast lineage cells by crossing floxed Phd2 mice with a Col1α2-iCre line to investigate the function of Phd2 in vivo. The cKO mice developed short stature and premature death at 12 to 14 weeks of age. Bone mineral content, bone area, and bone mineral density were decreased in femurs and tibias, but not vertebrae of the cKO mice compared to WT mice. The total volume (TV), bone volume (BV), and bone volume fraction (BV/TV) in the femoral trabecular bones of cKO mice were significantly decreased. Cross-sectional area of the femoral mid-diaphysis was also reduced in the cKO mice. The reduced bone size and trabecular bone volume in the cKO mice were a result of impaired bone formation but not bone resorption as revealed by dynamic histomorphometric analyses. Bone marrow stromal cells derived from cKO mice formed fewer and smaller nodules when cultured with mineralization medium. Quantitative RT-PCR and immunohistochemistry detected reduced expression of Osx, osteocalcin, and bone sialoprotein in cKO bone cells. These data indicate that Phd2 plays an important role in regulating bone formation in part by modulating expression of Osx and bone formation marker genes. © 2014 American Society for Bone and Mineral Research.

Cold Shock as a Screen for Genes Involved in Cold Acclimatization in Neurospora crassa

PubMed Central

Watters, Michael K.; Manzanilla, Victor; Howell, Holly; Mehreteab, Alexander; Rose, Erik; Walters, Nicole; Seitz, Nicholas; Nava, Jacob; Kekelik, Sienna; Knuth, Laura; Scivinsky, Brianna

2018-01-01

When subjected to rapid drops of temperature (cold shock), Neurospora responds with a temporary shift in its morphology. This report is the first to examine this response genetically. We report here the results of a screen of selected mutants from the Neurospora knockout library for alterations in their morphological response to cold shock. Three groups of knockouts were selected to be subject to this screen: genes previously suspected to be involved in hyphal development as well as knockouts resulting in morphological changes; transcription factors; and genes homologous to E. coli genes known to alter their expression in response to cold shock. A total of 344 knockout strains were subjected to cold shock. Of those, 118 strains were identified with altered responses. We report here the cold shock morphologies and GO categorizations of strains subjected to this screen. Of strains with knockouts in genes associated with hyphal growth or morphology, 33 of 131 tested (25%) showed an altered response to cold shock. Of strains with knockouts in transcription factor genes, 30 of 145 (20%) showed an altered response to cold shock. Of strains with knockouts in genes homologous to E. coli genes which display altered levels of transcription in response to cold shock, a total of 55 of 68 tested (81%) showed an altered cold shock response. This suggests that the response to cold shock in these two organisms is largely shared in common. PMID:29563189

An investigation of MCNP6.1 beryllium oxide S(α, β) cross sections

DOE PAGES

Sartor, Raymond F.; Glazener, Natasha N.

2016-03-08

In MCNP6.1, materials are constructed by identifying the constituent isotopes (or elements in a few cases) individually. This list selects the corresponding microscopic cross sections calculated from the free-gas model to create the material macroscopic cross sections. Furthermore, the free-gas model and the corresponding material macroscopic cross sections assume that the interactions of atoms do not affect the nuclear cross sections.

DBCC Software as Database for Collisional Cross-Sections

NASA Astrophysics Data System (ADS)

Moroz, Daniel; Moroz, Paul

2014-10-01

Interactions of species, such as atoms, radicals, molecules, electrons, and photons, in plasmas used for materials processing could be very complex, and many of them could be described in terms of collisional cross-sections. Researchers involved in plasma simulations must select reasonable cross-sections for collisional processes for implementing them into their simulation codes to be able to correctly simulate plasmas. However, collisional cross-section data are difficult to obtain, and, for some collisional processes, the cross-sections are still not known. Data on collisional cross-sections can be obtained from numerous sources including numerical calculations, experiments, journal articles, conference proceedings, scientific reports, various universities' websites, national labs and centers specifically devoted to collecting data on cross-sections. The cross-sections data received from different sources could be partial, corresponding to limited energy ranges, or could even not be in agreement. The DBCC software package was designed to help researchers in collecting, comparing, and selecting cross-sections, some of which could be constructed from others or chosen as defaults. This is important as different researchers may place trust in different cross-sections or in different sources. We will discuss the details of DBCC and demonstrate how it works and why it is beneficial to researchers working on plasma simulations.

The role of the SIBLING, Bone Sialoprotein in skeletal biology - Contribution of mouse experimental genetics.

PubMed

Bouleftour, Wafa; Juignet, Laura; Bouet, Guenaelle; Granito, Renata Neves; Vanden-Bossche, Arnaud; Laroche, Norbert; Aubin, Jane E; Lafage-Proust, Marie-Hélène; Vico, Laurence; Malaval, Luc

2016-01-01

Bone Sialoprotein (BSP) is a member of the "Small Integrin-Binding Ligand N-linked Glycoproteins" (SIBLING) extracellular matrix protein family of mineralized tissues. BSP has been less studied than other SIBLING proteins such as Osteopontin (OPN), which is coexpressed with it in several skeletal cell types. Here we review the contribution of genetically engineered mice (BSP gene knockout and overexpression) to the understanding of the role of BSP in the bone organ. The studies made so far highlight the role of BSP in skeletal mineralization, as well as its importance for proper osteoblast and osteoclast differentiation and activity, most prominently in primary/repair bone. The absence of BSP also affects the local environment of the bone tissue, in particular hematopoiesis and vascularization. Interestingly, lack of BSP induces an overexpression of OPN, and the cognate protein could be responsible for some aspects of the BSP gene knockout skeletal phenotype, while replacing BSP for some of its functions. Such interplay between the partly overlapping functions of SIBLING proteins, as well as the network of cross-regulations in which they are involved should now be the focus of further work. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Maternal loading with very low-density lipoproteins stimulates fetal surfactant synthesis.

PubMed

Ryan, Alan J; Medh, Jheem D; McCoy, Diann M; Salome, Ronald G; Mallampalli, Rama K

2002-08-01

We examined whether administration of very low-density lipoproteins (VLDL) to pregnant rats increases surfactant phosphatidylcholine (PtdCho) content in fetal pre-type II alveolar epithelial cells. VLDL-triglycerides are hydrolyzed to fatty acids by lipoprotein lipase (LPL), an enzyme activated by heparin. Fatty acids released by LPL can incorporate into the PtdCho molecule or activate the key biosynthetic enzyme cytidylyltransferase (CCT). Dams were given BSA, heparin, VLDL, or VLDL with heparin intravenously. Radiolabeled VLDL given to the pregnant rat crossed the placenta and was distributed systemically in the fetus and incorporated into disaturated PtdCho (DSPtdCho) in pre-type II cells. Maternal administration of VLDL with heparin increased DSPtdCho content in cells by 45% compared with control (P < 0.05). VLDL produced a dose-dependent, saturable, and selective increase in CCT activity. VLDL did not significantly alter immunoreactive CCT content but increased palmitic, stearic, and oleic acids in pre-type II cells. Furthermore, hypertriglyceridemic apolipoprotein E knockout mice contained significantly greater levels of DSPtdCho content in alveolar lavage and CCT activity compared with either LDL receptor knockout mice or wild-type controls that have normal serum triglycerides. Thus the nutritional or genetic modulation of serum VLDL-triglycerides provides specific fatty acids that stimulate PtdCho synthesis and CCT activity thereby increasing surfactant content.

ADAM10 is essential for cranial neural crest-derived maxillofacial bone development.

PubMed

Tan, Yu; Fu, Runqing; Liu, Jiaqiang; Wu, Yong; Wang, Bo; Jiang, Ning; Nie, Ping; Cao, Haifeng; Yang, Zhi; Fang, Bing

2016-07-08

Growth disorders of the craniofacial bones may lead to craniofacial deformities. The majority of maxillofacial bones are derived from cranial neural crest cells via intramembranous bone formation. Any interruption of the craniofacial skeleton development process might lead to craniofacial malformation. A disintegrin and metalloprotease (ADAM)10 plays an essential role in organ development and tissue integrity in different organs. However, little is known about its function in craniofacial bone formation. Therefore, we investigated the role of ADAM10 in the developing craniofacial skeleton, particularly during typical mandibular bone development. First, we showed that ADAM10 was expressed in a specific area of the craniofacial bone and that the expression pattern dynamically changed during normal mouse craniofacial development. Then, we crossed wnt1-cre transgenic mice with adam10-flox mice to generate ADAM10 conditional knockout mice. The stereomicroscopic, radiographic, and von Kossa staining results showed that conditional knockout of ADAM10 in cranial neural crest cells led to embryonic death, craniofacial dysmorphia and bone defects. Furthermore, we demonstrated that impaired mineralization could be triggered by decreased osteoblast differentiation, increased cell death. Overall, these findings show that ADAM10 plays an essential role in craniofacial bone development. Copyright © 2016 Elsevier Inc. All rights reserved.

Geologic Cross Section E-E' through the Appalachian Basin from the Findlay Arch, Wood County, Ohio, to the Valley and Ridge Province, Pendleton County, West Virginia

USGS Publications Warehouse

Ryder, Robert T.; Swezey, Christopher S.; Crangle, Robert D.; Trippi, Michael H.

2008-01-01

Geologic cross section E-E' is the first in a series of cross sections planned by the U.S. Geological Survey (USGS) to document and improve understanding of the geologic framework and petroleum systems of the Appalachian basin. Cross section E-E' provides a regional view of the structural and stratigraphic framework of the basin from the Findlay arch in northwestern Ohio to the Valley and Ridge province in eastern West Virginia, a distance of approximately 380 miles (mi) (fig. 1, on sheet 1). Cross section E-E' updates earlier geologic cross sections through the central Appalachian basin by Renfro and Feray (1970), Bennison (1978), and Bally and Snelson (1980) and a stratigraphic cross section by Colton (1970). Although other published cross sections through parts of the basin show more structural detail (for example, Shumaker, 1985; Kulander and Dean, 1986) and stratigraphic detail (for example, Ryder, 1992; de Witt and others, 1993; Hettinger, 2001), these other cross sections are of more limited extent geographically and stratigraphically. Although specific petroleum systems in the Appalachian basin are not identified on the cross section, many of their key elements (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and preferred migration pathways) may be evaluated by burial history, thermal history, and fluid flow models based on information shown on the cross section. Cross section E-E' lacks the detail to illustrate key elements of coal systems (such as paleoclimate, coal quality, and coal rank), but it does provide a general framework (stratigraphic units and general rock types) for the coal-bearing section. Also, cross section E-E' may be used as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste (for example, Colton, 1961; Lloyd and Reid, 1990) or for the sequestration of carbon dioxide (for example, Smith and others, 2002; Lucier and others, 2006).

A STAT-1 Knockout Mouse Model for Machupo Virus Pathogenesis

DTIC Science & Technology

2011-06-14

hemorrhagic fever viruses, including Ebola, Marburg, Junín, and Crimean - Congo Hemorrhagic Fever viruses [11-14...Akerstrom S, Klingstrom J, Mirazimi A: Crimean - Congo hemorrhagic fever virus infection is lethal for adult type I interferon receptor-knockout mice. J...Shieh WJ, Camus G, Stroher U, Zaki S, Jones SM: Pathogenesis and immune response of Crimean - Congo hemorrhagic fever virus in a STAT-1 knockout

A comparison of total reaction cross section models used in particle and heavy ion transport codes

NASA Astrophysics Data System (ADS)

Sihver, Lembit; Lantz, M.; Takechi, M.; Kohama, A.; Ferrari, A.; Cerutti, F.; Sato, T.

To be able to calculate the nucleon-nucleus and nucleus-nucleus total reaction cross sections with precision is very important for studies of basic nuclear properties, e.g. nuclear structure. This is also of importance for particle and heavy ion transport calculations because, in all particle and heavy ion transport codes, the probability function that a projectile particle will collide within a certain distance x in the matter depends on the total reaction cross sections. Furthermore, the total reaction cross sections will also scale the calculated partial fragmentation cross sections. It is therefore crucial that accurate total reaction cross section models are used in the transport calculations. In this paper, different models for calculating nucleon-nucleus and nucleus-nucleus total reaction cross sections are compared and discussed.

Vertically stabilized elongated cross-section tokamak

DOEpatents

Sheffield, George V.

1977-01-01

This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

Embryonic Lethality Due to Arrested Cardiac Development in Psip1/Hdgfrp2 Double-Deficient Mice.

PubMed

Wang, Hao; Shun, Ming-Chieh; Dickson, Amy K; Engelman, Alan N

2015-01-01

Hepatoma-derived growth factor (HDGF) related protein 2 (HRP2) and lens epithelium-derived growth factor (LEDGF)/p75 are closely related members of the HRP2 protein family. LEDGF/p75 has been implicated in numerous human pathologies including cancer, autoimmunity, and infectious disease. Knockout of the Psip1 gene, which encodes for LEDGF/p75 and the shorter LEDGF/p52 isoform, was previously shown to cause perinatal lethality in mice. The function of HRP2 was by contrast largely unknown. To learn about the role of HRP2 in development, we knocked out the Hdgfrp2 gene, which encodes for HRP2, in both normal and Psip1 knockout mice. Hdgfrp2 knockout mice developed normally and were fertile. By contrast, the double deficient mice died at approximate embryonic day (E) 13.5. Histological examination revealed ventricular septal defect (VSD) associated with E14.5 double knockout embryos. To investigate the underlying molecular mechanism(s), RNA recovered from ventricular tissue was subjected to RNA-sequencing on the Illumina platform. Bioinformatic analysis revealed several genes and biological pathways that were significantly deregulated by the Psip1 knockout and/or Psip1/Hdgfrp2 double knockout. Among the dozen genes known to encode for LEDGF/p75 binding factors, only the expression of Nova1, which encodes an RNA splicing factor, was significantly deregulated by the knockouts. However the expression of other RNA splicing factors, including the LEDGF/p52-interacting protein ASF/SF2, was not significantly altered, indicating that deregulation of global RNA splicing was not a driving factor in the pathology of the VSD. Tumor growth factor (Tgf) β-signaling, which plays a key role in cardiac morphogenesis during development, was the only pathway significantly deregulated by the double knockout as compared to control and Psip1 knockout samples. We accordingly speculate that deregulated Tgf-β signaling was a contributing factor to the VSD and prenatal lethality of Psip1/Hdgfrp2 double-deficient mice.

Differential cytokine expression in skin graft healing in inducible nitric oxide synthase knockout mice.

PubMed

Most, D; Efron, D T; Shi, H P; Tantry, U S; Barbul, A

2001-10-01

Inducible nitric oxide synthase (iNOS) and its product, nitric oxide, have been shown to play important roles in wound biology. The present study was performed to investigate the role of iNOS in modulating the cytokine cascade during the complex process of skin graft wound healing.Fifteen iNOS-knockout mice and 15 wild-type C57BL/6J mice were subjected to autogenous 1-cm2 intrascapular full-thickness skin grafts. Three animals in each group were killed on postoperative days 3, 5, 7, 10, and 14. Specimens were then analyzed using nonisotopic in situ hybridization versus mRNA of tumor growth factor-beta1, vascular endothelial growth factor, iNOS, endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha, and basic fibroblast growth factor, as well as positive and negative control probes. Positive cells in both grafts and wound beds were counted using a Leica microgrid. Scar thickness was measured with a Leica micrometer. Data were analyzed using the unpaired Student's t test. Expression of iNOS was 2- to 4-fold higher in knockout mice than in wild-type mice on postoperative days 5, 7, and 14. Expression of eNOS was 2- to 2.5-fold higher in knockout mice than in wild-type mice on postoperative days 5 and 7. Tumor necrosis factor-alpha expression was 2- to 7-fold higher in knockout mice than in wild-type mice on all postoperative days. In contrast, expression levels of angiogenic/fibrogenic cytokines (vascular endothelial growth factor, basis fibroblast growth factor, and tumor growth factor-beta1) were 2.5- to 4-fold higher in wild-type mice than in knockout mice. Scars were 1.5- to 2.5-fold thicker in knockout mice than in wild-type mice at all time points. All of the above results represent statistically significant differences (p < 0.05). Significantly different patterns of cytokine expression were seen in knockout and wild-type mice. Although the scar layer was thicker in knockout mice, it showed much greater infiltration with inflammatory cells. These data further delineate the modulatory effect of iNOS and nitric oxide in healing skin grafts.

BACKSCAT Lidar Simulation Version 3.0: Technical Documentation and Users Guide

DTIC Science & Technology

1992-12-03

Raman Cross Section of Some Simple Gases, J. Opt. Soc. Am., 63:73. 20 Penny, C.M., St. Peters, R.L., and Lapp, M., (1974) Absolute Rotational Raman...of the molecule, and the remaining columns list the relative normalized cross sections for the respective excitation wavelength. The absolute Raman...cross section is obtained by simply multiplying the relative normalized cross section for a molecular species of interest by the absolute cross section

Energy and Mass-Number Dependence of Hadron-Nucleus Total Reaction Cross Sections

NASA Astrophysics Data System (ADS)

Kohama, Akihisa; Iida, Kei; Oyamatsu, Kazuhiro

2016-09-01

We thoroughly investigate how proton-nucleus total reaction cross sections depend on the target mass number A and the proton incident energy. In doing so, we systematically analyze nuclear reaction data that are sensitive to nuclear size, namely, proton-nucleus total reaction cross sections and differential elastic cross sections, using a phenomenological black-sphere approximation of nuclei that we are developing. In this framework, the radius of the black sphere is found to be a useful length scale that simultaneously accounts for the observed proton-nucleus total reaction cross section and first diffraction peak in the proton elastic differential cross section. This framework, which is shown here to be applicable to antiprotons, is expected to be applicable to any kind of projectile that is strongly attenuated in the nucleus. On the basis of a cross-section formula constructed within this framework, we find that a less familiar A1/6 dependence plays a crucial role in describing the energy dependence of proton-nucleus total reaction cross sections.

Activation cross section and isomeric cross-section ratio for the 151Eu(n,2n)150m,gEu process

NASA Astrophysics Data System (ADS)

Luo, Junhua; Li, Suyuan; Jiang, Li

2018-07-01

The cross sections of 151Eu(n,2n)150m,gEu reactions and their isomeric cross section ratios σm/σt have been measured experimentally. Cross sections are measured, relative to a reference 93Nb(n,2n)92mNb reaction cross section, by means of the activation technique at three neutron energies 13.5, 14.1, and 14.8 MeV. Monoenergetic neutron beams were formed via the 3H(d,n)4He reaction and both Eu2O3 samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The activities induced in the reaction products were measured using high-resolution gamma ray spectroscopy. Cross sections were also evaluated theoretically using the numerical nuclear model code, TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Total reaction cross sections in CEM and MCNP6 at intermediate energies

DOE PAGES

Kerby, Leslie M.; Mashnik, Stepan G.

2015-05-14

Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used inmore » the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.« less

Total reaction cross sections in CEM and MCNP6 at intermediate energies

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

Kerby, Leslie M.; Mashnik, Stepan G.

Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used inmore » the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.« less

Proton-Nucleus Elastic Cross Sections Using Two-Body In-Medium Scattering Amplitudes

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

2001-01-01

Recently, a method was developed of extracting nucleon-nucleon (NN) cross sections in the medium directly from experiment. The in-medium NN cross sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the Langley Research Center. The ratio of the real to the imaginary part of the two-body scattering amplitude in the medium was investigated. These ratios are used in combination with the in-medium NN cross sections to calculate elastic proton-nucleus cross sections. The agreement is excellent with the available experimental data. These cross sections are needed for the radiation risk assessment of space missions.

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

Singh, Suvam; Naghma, Rahla; Kaur, Jaspreet

The total and ionization cross sections for electron scattering by benzene, halobenzenes, toluene, aniline, and phenol are reported over a wide energy domain. The multi-scattering centre spherical complex optical potential method has been employed to find the total elastic and inelastic cross sections. The total ionization cross section is estimated from total inelastic cross section using the complex scattering potential-ionization contribution method. In the present article, the first theoretical calculations for electron impact total and ionization cross section have been performed for most of the targets having numerous practical applications. A reasonable agreement is obtained compared to existing experimental observationsmore » for all the targets reported here, especially for the total cross section.« less

Temperature dependence of the HNO3 UV absorption cross sections

NASA Technical Reports Server (NTRS)

Burkholder, James B.; Talukdar, Ranajit K.; Ravishankara, A. R.; Solomon, Susan

1993-01-01

The temperature dependence of the HNO3 absorption cross sections between 240 and 360 K over the wavelength range 195 to 350 nm has been measured using a diode array spectrometer. Absorption cross sections were determined using both (1) absolute pressure measurements at 298 K and (2) a dual absorption cell arrangement in which the absorption spectrum at various temperatures is measured relative to the room temperature absorption spectrum. The HNO3 absorption spectrum showed a temperature dependence which is weak at short wavelengths but stronger at longer wavelengths which are important for photolysis in the lower stratosphere. The 298 K absorption cross sections were found to be larger than the values currently recommended for atmospheric modeling (DeMore et al., 1992). Our absorption cross section data are critically compared with the previous measurements of both room temperature and temperature-dependent absorption cross sections. Temperature-dependent absorption cross sections of HNO3 are recommended for use in atmospheric modeling. These temperature dependent HNO3 absorption cross sections were used in a two-dimensional dynamical-photochemical model to demonstrate the effects of the revised absorption cross sections on loss rate of HNO3 and the abundance of NO2 in the stratosphere.

Cross sections for direct and dissociative ionization of NH3 and CS2 by electron impact

NASA Technical Reports Server (NTRS)

Rao, M. V. V. S.; Srivastava, S. K.

1991-01-01

A crossed electron beam-molecular beam collision geometry is used to measure cross sections for the production of positive ions by electron impact on NH3 and CS2. Ionization cross-section data for NH3 and the values of various cross sections are presented, as well as ionization efficiency curves for CS2. Considerable differences are found between the various results on NH3. The present values are close to the data of Djuric et al. (1981). The semiempirical calculations of Hare and Meath (1987) differ considerably in the absolute values of cross sections. Discrepancies were observed in comparisons of cross sections of other fragment ions resulting from the ionization and dissociate ionization of NH3.

Distribution of Nidogen in the Murine Eye and Ocular Phenotype of the Nidogen-1 Knockout Mouse

PubMed Central

May, Christian Albrecht

2012-01-01

Distribution and lack of nidogen-1, part of numerous basement membranes, were studied in the mouse eye. For that purpose, eyes of C57BL/6 and nidogen-1 knockout mice were stained immunohistochemically for nidogen-1, and intraocular pressure measurements and light- and electron microscopy were used to study the nidogen-1 knockout animals. In normal mice, nidogen-1 was present in many basement membranes, but showed irregularities underneath the corneal epithelium, in Bruch's membrane and in the iris. Homozygous knockout of nidogen-1 in the mouse showed only mild pathological changes. In the anterior eye segment, small interruptions were noted in the nonpigmented ciliary epithelium without further consequences. In the posterior eye segment, interruptions of the inner limiting membrane led to small retinal ectopias and subsequent changes in the optic nerve. In summary, the knockout of nidogen-1 showed mild but significant morphological changes pointing to the importance of this protein which can in part, but not completely; be replaced by nidogen-2. PMID:24555126

Dcdc2 knockout mice display exacerbated developmental disruptions following knockdown of Dcx

PubMed Central

Wang, Yu; Yin, Xiuyin; Rosen, Glenn; Gabel, Lisa; Guadiana, Sarah M.; Sarkisian, Matthew R; Galaburda, Albert M.; LoTurco, Joseph J.

2011-01-01

The dyslexia-associated gene DCDC2 is a member of the DCX family of genes known to play roles in neurogenesis, neuronal migration and differentiation. Here we report the first phenotypic analysis of a Dcdc2 knockout mouse. Comparisons between Dcdc2 knockout mice and wild type littermates revealed no significant differences in neuronal migration, neocortical lamination, neuronal cilliogenesis or dendritic differentiation. Considering previous studies showing genetic interactions and potential functional redundancy among members of the DCX family, we tested whether decreasing Dcx expression by RNAi would differentially impair neurodevelopment in Dcdc2 knockouts and wild type mice. Consistent with this hypothesis, we found that deficits in neuronal migration, and dendritic growth caused by RNAi of Dcx were more severe in Dcdc2 knockouts than in wild type mice with the same transfection. These results indicate that Dcdc2 is not required for neurogenesis, neuronal migration or differentiation in mice, but may have partial functional redundancy with Dcx. PMID:21689730

Nuclear Forensics and Radiochemistry: Cross Sections

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

Rundberg, Robert S.

The neutron activation of components in a nuclear device can provide useful signatures of weapon design or sophistication. This lecture will cover some of the basics of neutron reaction cross sections. Nuclear reactor cross sections will also be presented to illustrate the complexity of convolving neutron energy spectra with nuclear excitation functions to calculate useful effective reactor cross sections. Deficiencies in the nuclear database will be discussed along with tools available at Los Alamos to provide new neutron cross section data.

Fragmentation Cross Sections of Medium-Energy 35Cl, 40Ar, and 48TiBeams on Elemental Targets

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

Zeitlin, C.; Guetersloh, S.; Heilbronn, L.

Charge-changing and fragment production cross sections at 0degrees have been obtained for interactions of 290, 400, and 650MeV/nucleon 40Ar beams, 650 and 1000 MeV/nucleon 35Cl beams, and a 1000MeV/nucleon 48Ti beam. Targets of C, CH2, Al, Cu, Sn, and Pb were used.Using standard analysis methods, we obtain fragment cross sections forcharges as low as 8 for Cl and Ar beams, and as low as 10 for the Tibeam. Using data obtained with small-acceptance detectors, we reportfragment production cross sections for charges as low as 5, corrected foracceptance using a simple model of fragment angular distributions. Withthe lower-charged fragment cross sections,more » we cancompare the data topredictions from several models (including NUCFRG2, EPAX2, and PHITS) ina region largely unexplored in earlier work. As found in earlier workwith other beams, NUCFRG2 and PHITS predictions agree reasonably wellwith the data for charge-changing cross sections, but do not accuratelypredict the fragment production cross sections. The cross sections forthe lightest fragments demonstrate the inadequacy of several models inwhich the cross sections fall monotonically with the charge of thefragment. PHITS, despite not agreeing particularly well with the fragmentproduction cross sections on average, nonetheless qualitativelyreproduces somesignificant features of the data that are missing from theother models.« less

Cross section and γ-ray spectra for U238(n,γ) measured with the DANCE detector array at the Los Alamos Neutron Science Center

NASA Astrophysics Data System (ADS)

Ullmann, J. L.; Kawano, T.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; O'Donnell, J. M.; Rundberg, R. S.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Chyzh, A.; Wu, C. Y.; Baramsai, B.; Mitchell, G. E.; Krtička, M.

2014-03-01

Background: Accurate knowledge of the U238(n,γ) cross section is important for developing theoretical nuclear reaction models and for applications. However, capture cross sections are difficult to calculate accurately and often must be measured. Purpose: We seek to confirm previous measurements and test cross-section calculations with an emphasis on the unresolved resonance region from 1 to 500 keV. Method: Cross sections were measured from 10 eV to 500 keV using the DANCE detector array at the LANSCE spallation neutron source. The measurements used a thin target, 48 mg/cm2 of depleted uranium. Gamma cascade spectra were also measured to provide an additional constraint on calculations. The data are compared to cross-section calculations using the code CoH3 and cascade spectra calculations made using the code dicebox. Results: This new cross-section measurement confirms the previous data. The measured gamma-ray spectra suggest the need for additional low-lying dipole strength in the radiative strength function. New Hauser-Feshbach calculations including this strength accurately predict the capture cross section without renormalization. Conclusions: The present cross-section data confirm previous measurements. Including additional low-lying dipole strength in the radiative strength function may lead to more accurate cross-section calculations in nuclei where <Γγ> has not been measured.

High resolution absorption cross sections in the transmission window region of the Schumann-Runge bands and Herzberg continuum of O2

NASA Technical Reports Server (NTRS)

Yoshino, K.; Esmond, J. R.; Cheung, A. S.-C.; Freeman, D. E.; Parkinson, W. H.

1992-01-01

Results are presented on measurements, conducted in the wavelength region 180-195 nm, and at different pressures of oxygen (between 2.5-760 torr) in order to separate the pressure-dependent absorption from the main cross sections, of the absorption cross sections of the Schumann-Runge bands in the window region between the rotational lines of S-R bands of O2. The present cross sections supersede the earlier published cross sections (Yoshino et al., 1983). The combined cross sections are presented graphically; they are available at wavenumber intervals of about 0.1/cm from the National Space Science Data Center. The Herzberg continuum cross sections are derived after subtracting calculated contributions from the Schumann-Runge bands. These are significantly smaller than any previous measurements.

CEPXS

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

2015-10-19

CEPXS is a multigroup-Legendre cross-section generating code. The cross sections produced by CEPXS enable coupled electron-photon transport calculations to be performed with multigroup radiation transport codes, e.g. MITS and SCEPTRE. CEPXS generates multigroup-Legendre cross sections for photons, electrons and positrons over the energy range from 100 MeV to 1.0 keV. The continuous slowing-down approximation is used for those electron interactions that result in small-energy losses. The extended transport correction is applied to the forward-peaked elastic scattering cross section for electrons. A standard multigroup-Legendre treatment is used for the other coupled electron-photon cross sections. CEPXS extracts electron cross-section information from themore » DATAPAC data set and photon cross-section information from Biggs-Lighthill data. The model that is used for ionization/relaxation in CEPXS is essentially the same as that employed in ITS.« less

Partial Photoneutron Cross Sections for 207,208Pb

NASA Astrophysics Data System (ADS)

Kondo, T.; Utsunomiya, H.; Goriely, S.; Iwamoto, C.; Akimune, H.; Yamagata, T.; Toyokawa, H.; Harada, H.; Kitatani, F.; Lui, Y.-W.; Hilaire, S.; Koning, A. J.

2014-05-01

Using linearly-polarized laser-Compton scattering γ-rays, partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near neutron threshold by measuring anisotropies in photoneutron emission. Separately, total photoneutron cross sections were measured for 207,208Pb with a high-efficiency 4π neutron detector. The partial cross section measurement provides direct evidence for the presence of pygmy dipole resonance (PDR) in 207,208Pb in the vicinity of neutron threshold. The strength of PDR amounts to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to M1 cross sections less than 10% of the total photoneutron cross sections.

Methionine Sulfoxide Reductase A Knockout Mice Show Progressive Hearing Loss and Sensitivity to Acoustic Trauma.

PubMed

Alqudah, Safa; Chertoff, Mark; Durham, Dianne; Moskovitz, Jackob; Staecker, Hinrich; Peppi, Marcello

2018-06-21

Methionine sulfoxide reductases (MsrA and MsrB) protect the biological activity of proteins from oxidative modifications to methionine residues and are important for protecting against the pathological effects of neurodegenerative diseases. In the current study, we characterized the auditory phenotype of the MsrA knockout mouse. Young MsrA knockout mice showed small high-frequency threshold elevations for auditory brainstem response and distortion product otoacoustic emission compared to those of wild-type mice, which progressively worsened in older MsrA knockout mice. MsrA knockout mice showed an increased sensitivity to noise at young and older ages, suggesting that MsrA is part of a mechanism that protects the cochlea from acoustic damage. MsrA mRNA in the cochlea was increased following acoustic stimulation. Finally, expression of mRNA MsrB1 was compromised at 6 months old, but not in younger MsrA knockout mice (compared to controls). The identification of MsrA in the cochlea as a protective mediator from both early onset hearing loss and acoustic trauma expands our understanding of the pathways that may induce protection from acoustic trauma and foster further studies on how to prevent the damaging effect of noise exposure through Msr-based therapy. © 2018 S. Karger AG, Basel.

Alterations of amino acids and monoamine metabolism in male Fmr1 knockout mice: a putative animal model of the human fragile X mental retardation syndrome.

PubMed

Gruss, M; Braun, K

2001-01-01

The Fragile X syndrome, a common form of mental retardation in humans, is caused by silencing the fragile X mental retardation (FMR1) gene leading to the absence of the encoded fragile X mental retardation protein 1 (FMRP). We describe morphological and behavioral abnormalities for both affected humans and Fmr1 knockout mice, a putative animal model for the human Fragile X syndrome. The aim of the present study was to identify possible neurochemical abnormalities in Fmr1 knockout mice, with particular focus on neurotransmission. Significant region-specific differences of basal neurotransmitter and metabolite levels were found between wildtype and Fmr1 knockout animals, predominantly in juveniles (post-natal days 28 to 31). Adults (postnatal days 209 to 221) showed only few abnormalities as compared with the wildtype. In juvenile knockout mice, aspartate and taurine were especially increased in cortical regions, striatum, hippocampus, cerebellum, and brainstem. In addition, juveniles showed an altered balance between excitatory and inhibitory amino acids in the caudal cortex, hippocampus, and brainstem. We detected very few differences in monoamine turnover in both age stages. The results presented here provide the first evidence that lack of FMRP expression in FMRP knockout mice is accompanied by age-dependent, region-specific alterations in neurotransmission.

Knockouts of high-ranking males have limited impact on baboon social networks.

PubMed

Franz, Mathias; Altmann, Jeanne; Alberts, Susan C

Social network structures can crucially impact complex social processes such as collective behaviour or the transmission of information and diseases. However, currently it is poorly understood how social networks change over time. Previous studies on primates suggest that `knockouts' (due to death or dispersal) of high-ranking individuals might be important drivers for structural changes in animal social networks. Here we test this hypothesis using long-term data on a natural population of baboons, examining the effects of 29 natural knockouts of alpha or beta males on adult female social networks. We investigated whether and how knockouts affected (1) changes in grooming and association rates among adult females, and (2) changes in mean degree and global clustering coefficient in these networks. The only significant effect that we found was a decrease in mean degree in grooming networks in the first month after knockouts, but this decrease was rather small, and grooming networks rebounded to baseline levels by the second month after knockouts. Taken together our results indicate that the removal of high-ranking males has only limited or no lasting effects on social networks of adult female baboons. This finding calls into question the hypothesis that the removal of high-ranking individuals has a destabilizing effect on social network structures in social animals.

A Review of Gene Knockout Strategies for Microbial Cells.

PubMed

Tang, Phooi Wah; Chua, Pooi San; Chong, Shiue Kee; Mohamad, Mohd Saberi; Choon, Yee Wen; Deris, Safaai; Omatu, Sigeru; Corchado, Juan Manuel; Chan, Weng Howe; Rahim, Raha Abdul

2015-01-01

Predicting the effects of genetic modification is difficult due to the complexity of metabolic net- works. Various gene knockout strategies have been utilised to deactivate specific genes in order to determine the effects of these genes on the function of microbes. Deactivation of genes can lead to deletion of certain proteins and functions. Through these strategies, the associated function of a deleted gene can be identified from the metabolic networks. The main aim of this paper is to review the available techniques in gene knockout strategies for microbial cells. The review is done in terms of their methodology, recent applications in microbial cells. In addition, the advantages and disadvantages of the techniques are compared and discuss and the related patents are also listed as well. Traditionally, gene knockout is done through wet lab (in vivo) techniques, which were conducted through laboratory experiments. However, these techniques are costly and time consuming. Hence, various dry lab (in silico) techniques, where are conducted using computational approaches, have been developed to surmount these problem. The development of numerous techniques for gene knockout in microbial cells has brought many advancements in the study of gene functions. Based on the literatures, we found that the gene knockout strategies currently used are sensibly implemented with regard to their benefits.

Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis

PubMed Central

Sun, Xingshen; Sui, Hongshu; Fisher, John T.; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M.; Lei-Butters, Diana C.; Griffin, Michelle A.; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J.; Meyerholz, David K.; Engelhardt, John F.

2010-01-01

Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments. PMID:20739752

Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis.

PubMed

Sun, Xingshen; Sui, Hongshu; Fisher, John T; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M; Lei-Butters, Diana C; Griffin, Michelle A; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J; Meyerholz, David K; Engelhardt, John F

2010-09-01

Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments.

Evaluation and Design of Genome-Wide CRISPR/SpCas9 Knockout Screens

PubMed Central

Hart, Traver; Tong, Amy Hin Yan; Chan, Katie; Van Leeuwen, Jolanda; Seetharaman, Ashwin; Aregger, Michael; Chandrashekhar, Megha; Hustedt, Nicole; Seth, Sahil; Noonan, Avery; Habsid, Andrea; Sizova, Olga; Nedyalkova, Lyudmila; Climie, Ryan; Tworzyanski, Leanne; Lawson, Keith; Sartori, Maria Augusta; Alibeh, Sabriyeh; Tieu, David; Masud, Sanna; Mero, Patricia; Weiss, Alexander; Brown, Kevin R.; Usaj, Matej; Billmann, Maximilian; Rahman, Mahfuzur; Costanzo, Michael; Myers, Chad L.; Andrews, Brenda J.; Boone, Charles; Durocher, Daniel; Moffat, Jason

2017-01-01

The adaptation of CRISPR/SpCas9 technology to mammalian cell lines is transforming the study of human functional genomics. Pooled libraries of CRISPR guide RNAs (gRNAs) targeting human protein-coding genes and encoded in viral vectors have been used to systematically create gene knockouts in a variety of human cancer and immortalized cell lines, in an effort to identify whether these knockouts cause cellular fitness defects. Previous work has shown that CRISPR screens are more sensitive and specific than pooled-library shRNA screens in similar assays, but currently there exists significant variability across CRISPR library designs and experimental protocols. In this study, we reanalyze 17 genome-scale knockout screens in human cell lines from three research groups, using three different genome-scale gRNA libraries. Using the Bayesian Analysis of Gene Essentiality algorithm to identify essential genes, we refine and expand our previously defined set of human core essential genes from 360 to 684 genes. We use this expanded set of reference core essential genes, CEG2, plus empirical data from six CRISPR knockout screens to guide the design of a sequence-optimized gRNA library, the Toronto KnockOut version 3.0 (TKOv3) library. We then demonstrate the high effectiveness of the library relative to reference sets of essential and nonessential genes, as well as other screens using similar approaches. The optimized TKOv3 library, combined with the CEG2 reference set, provide an efficient, highly optimized platform for performing and assessing gene knockout screens in human cell lines. PMID:28655737

Trpc2 Depletion Protects RBC from Oxidative Stress-Induced Hemolysis

PubMed Central

Hirschler-Laszkiewicz, Iwona; Zhang, Wenyi; Keefer, Kerry; Conrad, Kathleen; Tong, Qin; Chen, Shu-jen; Bronson, Sarah; Cheung, Joseph Y.; Miller, Barbara A.

2011-01-01

Transient receptor potential channels Trpc2 and Trpc3 are expressed on normal murine erythroid precursors, and erythropoietin stimulates an increase in intracellular calcium ([Ca2+]i) through TRPC2 and TRPC3. Because modulation of [Ca2+]i is an important signaling pathway in erythroid proliferation and differentiation, Trpc2, Trpc3, and Trpc2/Trpc3 double knockout mice were utilized to explore the roles of these channels in erythropoiesis. Trpc2, Trpc3, and Trpc2/Trpc3 double knockout mice were not anemic, and had similar red blood cell counts, hemoglobins, and reticulocyte counts as wild type littermate controls. Although the erythropoietin induced increase in [Ca2+]i was reduced, these knockout mice showed no defects in red cell production. The major phenotypic difference at steady state was that the mean corpuscular volume, mean corpuscular hemoglobin, and hematocrit of red cells were significantly greater in Trpc2 and Trpc2/Trpc3 double knockout mice, and mean corpuscular hemoglobin concentration was significantly reduced. All hematological parameters in Trpc3 knockout mice were similar to controls. When exposed to phenyhydrazine, unlike the Trpc3 knockouts, Trpc2 and Trpc2/Trpc3 double knockout mice showed significant resistance to hemolysis. This was associated with significant reduction in hydrogen peroxide-induced calcium influx in erythroblasts. While erythropoietin induced calcium influx through TRPC2 or TRPC3 is not critical for erythroid production, these data demonstrate that TRPC2 plays an important role in oxidative stress-induced hemolysis which may be related to reduced calcium entry in red cells in the presence of Trpc2 depletion. PMID:21924222

TRPV2 KNOCKOUT MICE ARE SUSCEPTIBLE TO PERINATAL LETHALITY BUT DISPLAY NORMAL THERMAL AND MECHANICAL NOCICEPTION

PubMed Central

Park, Una; Vastani, Nisha; Guan, Yun; Raja, Srinivasa N.; Koltzenburg, Martin; Caterina, Michael J.

2011-01-01

TRPV2 is a nonselective cation channel expressed prominently in medium- to large-diameter sensory neurons that can be activated by extreme heat (>52°C). These features suggest that TRPV2 might be a transducer of noxious heat in vivo. TRPV2 can also be activated by hypoosmolarity or cell stretch, suggesting potential roles in mechanotransduction. To address the physiological functions of TRPV2 in somatosensation, we generated TRPV2 knockout mice and examined their behavioral and electrophysiological responses to heat and mechanical stimuli. TRPV2 knockout mice showed reduced embryonic weight and perinatal viability. As adults, surviving knockout mice also exhibited a slightly reduced body weight. TRPV2 knockout mice showed normal behavioral responses to noxious heat over a broad range of temperatures and normal responses to punctate mechanical stimuli, both in the basal state and under hyperalgesic conditions such as peripheral inflammation and L5 spinal nerve ligation. Moreover, behavioral assays of TRPV1/TRPV2 double knockout mice or of TRPV2 knockout mice treated with resiniferatoxin to desensitize TRPV1-expressing afferents revealed no thermosensory consequences of TRPV2 absence. In line with behavioral findings, electrophysiological recordings from skin afferents showed that C-fiber responses to heat and C- and Aδ-fiber responses to noxious mechanical stimuli were unimpaired in the absence of TRPV2. The prevalence of thermosensitive Aδ-fibers was too low to permit comparison between genotypes. Thus, TRPV2 is important for perinatal viability but is not essential for heat or mechanical nociception or hypersensitivity in the adult mouse. PMID:21832173

Characterization of the first knock-out aldh7a1 zebrafish model for pyridoxine-dependent epilepsy using CRISPR-Cas9 technology

PubMed Central

Zabinyakov, Nikita; Bullivant, Garrett; Cao, Feng; Fernandez Ojeda, Matilde; Jia, Zheng Ping; Wen, Xiao-Yan; Dowling, James J.; Salomons, Gajja S.

2017-01-01

Pyridoxine dependent epilepsy (PDE) is caused by likely pathogenic variants in ALDH7A1 (PDE-ALDH7A1) and inherited autosomal recessively. Neurotoxic alpha-amino adipic semialdehyde (alpha-AASA), piperideine 6-carboxylate and pipecolic acid accumulate in body fluids. Neonatal or infantile onset seizures refractory to anti-epileptic medications are clinical features. Treatment with pyridoxine, arginine and lysine-restricted diet does not normalize neurodevelopmental outcome or accumulation of neurotoxic metabolites. There is no animal model for high throughput drug screening. For this reason, we developed and characterized the first knock-out aldh7a1 zebrafish model using CRISPR-Cas9 technology. Zebrafish aldh7a1 mutants were generated by using a vector free method of CRISPR-Cas9 mutagenesis. Genotype analysis of aldh7a1 knock-out zebrafish was performed by high resolution melt analysis, direct sequencing and QIAxcel system. Electroencephalogram was performed. Alpha-AASA, piperideine 6-carboxylate and pipecolic acid, were measured by liquid chromatography-tandem mass spectrometry. Our knock-out aldh7a1 zebrafish has homozygous 5 base pair (bp) mutation in ALDH7A1. Knock-out aldh7a1 embryos have spontaneous rapid increase in locomotion and a rapid circling swim behavior earliest 8-day post fertilization (dpf). Electroencephalogram revealed large amplitude spike discharges compared to wild type. Knock-out aldh7a1 embryos have elevated alpha-AASA, piperideine 6-carboxylate and pipecolic acid compared to wild type embryos at 3 dpf. Knock-out aldh7a1 embryos showed no aldh7a1 protein by western blot compared to wild type. Our knock-out aldh7a1 zebrafish is a well characterized model for large-scale drug screening using behavioral and biochemical features and accurately recapitulates the human PDE-ALDH7A1 disease. PMID:29053735

Characterization of the first knock-out aldh7a1 zebrafish model for pyridoxine-dependent epilepsy using CRISPR-Cas9 technology.

PubMed

Zabinyakov, Nikita; Bullivant, Garrett; Cao, Feng; Fernandez Ojeda, Matilde; Jia, Zheng Ping; Wen, Xiao-Yan; Dowling, James J; Salomons, Gajja S; Mercimek-Andrews, Saadet

2017-01-01

Pyridoxine dependent epilepsy (PDE) is caused by likely pathogenic variants in ALDH7A1 (PDE-ALDH7A1) and inherited autosomal recessively. Neurotoxic alpha-amino adipic semialdehyde (alpha-AASA), piperideine 6-carboxylate and pipecolic acid accumulate in body fluids. Neonatal or infantile onset seizures refractory to anti-epileptic medications are clinical features. Treatment with pyridoxine, arginine and lysine-restricted diet does not normalize neurodevelopmental outcome or accumulation of neurotoxic metabolites. There is no animal model for high throughput drug screening. For this reason, we developed and characterized the first knock-out aldh7a1 zebrafish model using CRISPR-Cas9 technology. Zebrafish aldh7a1 mutants were generated by using a vector free method of CRISPR-Cas9 mutagenesis. Genotype analysis of aldh7a1 knock-out zebrafish was performed by high resolution melt analysis, direct sequencing and QIAxcel system. Electroencephalogram was performed. Alpha-AASA, piperideine 6-carboxylate and pipecolic acid, were measured by liquid chromatography-tandem mass spectrometry. Our knock-out aldh7a1 zebrafish has homozygous 5 base pair (bp) mutation in ALDH7A1. Knock-out aldh7a1 embryos have spontaneous rapid increase in locomotion and a rapid circling swim behavior earliest 8-day post fertilization (dpf). Electroencephalogram revealed large amplitude spike discharges compared to wild type. Knock-out aldh7a1 embryos have elevated alpha-AASA, piperideine 6-carboxylate and pipecolic acid compared to wild type embryos at 3 dpf. Knock-out aldh7a1 embryos showed no aldh7a1 protein by western blot compared to wild type. Our knock-out aldh7a1 zebrafish is a well characterized model for large-scale drug screening using behavioral and biochemical features and accurately recapitulates the human PDE-ALDH7A1 disease.

Decreased APOE-containing HDL subfractions and cholesterol efflux capacity of serum in mice lacking Pcsk9

PubMed Central

2013-01-01

Background Studies in animals showed that PCSK9 is involved in HDL metabolism. We investigated the molecular mechanism by which PCSK9 regulates HDL cholesterol concentration and also whether Pcsk9 inactivation might affect cholesterol efflux capacity of serum and atherosclerotic fatty streak volume. Methods Mass spectrometry and western blot were used to analyze the level of apolipoprotein E (APOE) and A1 (APOA1). A mouse model overexpressing human LDLR was used to test the effect of high levels of liver LDLR on the concentration of HDL cholesterol and APOE-containing HDL subfractions. Pcsk9 knockout males lacking LDLR and APOE were used to test whether LDLR and APOE are necessary for PCSK9-mediated HDL cholesterol regulation. We also investigated the effects of Pcsk9 inactivation on cholesterol efflux capacity of serum using THP-1 and J774.A1 macrophage foam cells and atherosclerotic fatty streak volume in the aortic sinus of Pcsk9 knockout males fed an atherogenic diet. Results APOE and APOA1 were reduced in the same HDL subfractions of Pcsk9 knockout and human LDLR transgenic male mice. In Pcsk9/Ldlr double-knockout mice, HDL cholesterol concentration was lower than in Ldlr knockout mice and higher than in wild-type controls. In Pcsk9/Apoe double-knockout mice, HDL cholesterol concentration was similar to that of Apoe knockout males. In Pcsk9 knockout males, THP-1 macrophage cholesterol efflux capacity of serum was reduced and the fatty streak lesion volume was similar to wild-type controls. Conclusions In mice, LDLR and APOE are important factors for PCSK9-mediated HDL regulation. Our data suggest that, although LDLR plays a major role in PCSK9-mediated regulation of HDL cholesterol concentration, it is not the only mechanism and that, regardless of mechanism, APOE is essential. Pcsk9 inactivation decreases the HDL cholesterol concentration and cholesterol efflux capacity in serum, but does not increase atherosclerotic fatty streak volume. PMID:23883163

Geologic Cross Section D-D' Through the Appalachian Basin from the Findlay Arch, Sandusky County, Ohio, to the Valley and Ridge Province, Hardy County, West Virginia

USGS Publications Warehouse

Ryder, Robert T.; Crangle, Robert D.; Trippi, Michael H.; Swezey, Christopher S.; Lentz, Erika E.; Rowan, Elisabeth L.; Hope, Rebecca S.

2009-01-01

Geologic cross section D-D' is the second in a series of cross sections constructed by the U.S. Geological Survey to document and improve understanding of the geologic framework and petroleum systems of the Appalachian basin. Cross section D-D' provides a regional view of the structural and stratigraphic framework of the Appalachian basin from the Findlay arch in northwestern Ohio to the Valley and Ridge province in eastern West Virginia, a distance of approximately 290 miles. The information shown on the cross section is based on geological and geophysical data from 13 deep drill holes, several of which penetrate the Paleozoic sedimentary rocks of the basin and bottom in Mesoproterozoic (Grenville-age) crystalline basement rocks. This cross section is a companion to cross section E-E' (Ryder and others, 2008) that is located about 25 to 50 mi to the southwest. Although specific petroleum systems in the Appalachian basin are not identified on the cross section, many of their key elements (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and preferred migration pathways) may be evaluated by burial history, thermal history, and fluid flow models based on information shown on the cross section. Cross section D-D' lacks the detail to illustrate key elements of coal systems (such as paleoclimate, coal quality, and coal rank), but it does provide a general geologic framework (stratigraphic units and general rock types) for the coal-bearing section. Also, cross section D-D' may be used as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste or for the sequestration of carbon dioxide.

Electron impact excitation of SO2 - Differential, integral, and momentum transfer cross sections

NASA Technical Reports Server (NTRS)

Vuskovic, L.; Trajmar, S.

1982-01-01

Electron impact excitation of the electronic states of SO2 was investigated. Differential, integral, and inelastic momentum transfer cross sections were obtained by normalizing the relative measurements to the elastic cross sections. The cross sections are given for seven spectral ranges of the energy-loss spectra extending from the lowest electronic state to near the first ionization limit. Most of the regions represent the overlap of several electronic transitions. No measurements for these cross sections have been reported previously.

Proton-Nucleus Total Cross Sections in Coupled-Channel Approach

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

2000-01-01

Recently, nucleon-nucleon (N-N) cross sections in the medium have been extracted directly from experiment. The in-medium N-N cross sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the Langley Research Center. In the present study the ratio of the real to the imaginary part of the two-body scattering amplitude in the medium was investigated. These ratios are used in combination with the in-medium N-N cross sections to calculate total proton-nucleus cross sections. The agreement is excellent with the available experimental data. These cross sections are needed for the radiation risk assessment of space missions.

Calculation of total electron excitation cross-sections and partial electron ionization cross-sections for the elements. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Green, T. J.

1973-01-01

Computer programs were used to calculate the total electron excitation cross-section for atoms and the partial ionization cross-section. The approximations to the scattering amplitude used are as follows: (1) Born, Bethe, and Modified Bethe for non-exchange excitation; (2) Ochkur for exchange excitation; and (3) Coulomb-Born of non-exchange ionization. The amplitudes are related to the differential cross-sections which are integrated to give the total excitation (or partial ionization) cross-section for the collision. The atomic wave functions used are Hartree-Fock-Slater functions for bound states and the coulomb wave function for the continuum. The programs are presented and the results are examined.

Electron impact scattering study of hypohalous acids HOX (X = F, Cl, Br, I)

NASA Astrophysics Data System (ADS)

Yadav, Hitesh; Bhutadia, Harshad; Prajapati, Dinesh; Desai, Hardik; Vinodkumar, Minaxi; Vinodkumar, P. C.

2018-05-01

In this article we aim to report total cross sections (TCS) QT, total elastic cross sections (Qel), total inelastic cross sections (Qinel) i.e. (total ionizations cross sections (Qion)+total electronic excitation cross sections (Qexc)) from threshold of the target to 5000 eV energy range. We have used a well-defined theoretical methodology Spherical Complex Optical Potential (SCOP) to compute QT, Qel and Qinel and Complex Scattering Potential - ionization contribution (CSP - ic) method to report the (Qion). The cross-sectional data reported here for the Hypohalous Acids is for the first time and the present data can become a guideline for the experimentalist to study these targets.

Rayleigh scattering cross sections of combustion species at 266, 355, and 532 nm for thermometry applications.

PubMed

Sutton, Jeffrey A; Driscoll, James F

2004-11-15

Rayleigh scattering cross sections are measured for nine combustion species (Ar, N2, O2, CO2, CO, H2, H2O, CH4, and C3H8) at wavelengths of 266, 355, and 532 nm and at temperatures ranging from 295 to 1525 K. Experimental results show that, as laser wavelengths become shorter, polarization effects become important and the depolarization ratio of the combustion species must be accounted for in the calculation of the Rayleigh scattering cross section. Temperature effects on the scattering cross section are also measured. Only a small temperature dependence is measured for cross sections at 355 nm, resulting in a 2-8% increase in cross section at temperatures of 1500 K. This temperature dependence increases slightly for measurements at 266 nm, resulting in a 5-11% increase in cross sections at temperatures of 1450 K.

Cross sections for n+{sup 14}N from an R-matrix analysis of the {sup 15}N system

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

Hale, G.M.; Young, P.G.; Chadwick, M.B.

1994-06-01

As part of the Hiroshima-Nagasaki Dose Reevaluation Program, a new evaluation of the neutron cross sections for {sup 14}N was made for ENDF/B-VI, based at energies below 2.5 MeV on a multichannel R-matrix analysis of reactions in the {sup 15}N system. The types of data used in the analysis, and the resulting cross sections and resonance structure for {sup 15}N are briefly described. The resonant features of the neutron cross sections were especially well determined by including precise, high-resolution neutron total cross section measurements from ORNL. While the new evaluated cross section appear to be significant improvements over the earliermore » ones, they still need to be tested more extensively against recent measurements of the differential elastic cross section from Oak Ridge.« less

Electron impact cross sections for the 2,2P state excitation of lithium

NASA Technical Reports Server (NTRS)

Vuskovic, L.; Trajmar, S.; Register, D. F.

1982-01-01

Electron impact excitation of the 2p 2P state of Li was studied at 10, 20, 60, 100, 150 and 200 eV. Relative differential cross sections in the angular range 3-120 deg were measured and then normalized to the absolute scale by using the optical f value. Integral and momentum transfer cross sections were obtained by extrapolating the differential cross sections to 0 deg and to 180 deg. The question of normalizing electron-metal-atom collision cross sections in general was examined and the method of normalization to optical f values in particular was investigated in detail. It has been concluded that the extrapolation of the apparent generalized oscillator strength (obtained from the measured differential cross sections) to the zero momentum transfer limit with an expression using even powers of the momentum transfer and normalization of the limit to the optical f value yields reliable absolute cross sections.

The 75As(n,2n) Cross Sections into the 74As Isomer and Ground State

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

Younes, W; Garrett, P E; Becker, J A

2003-06-30

The {sup 75}As(n, 2n) cross section for the population of the T{sub 1/2} = 26.8-ns isomer at E{sub x} = 259.3 keV in {sup 74}As has been measured as a function of incident neutron energy, from threshold to E{sub n} = 20 MeV. The cross section was measured using the GEANIE spectrometer at LANSCE/WNR. For convenience, the {sup 75}As(n, 2n) population cross section for the {sup 74}As ground state has been deduced as the difference between the previously-known (n, 2n) reaction cross section and the newly measured {sup 75}As(n, 2n){sup 74}As{sup m} cross section. The (n, 2n) reaction, ground-state, andmore » isomer population cross sections are tabulated in this paper.« less

Total and partial photoneutron cross sections for Pb isotopes

NASA Astrophysics Data System (ADS)

Kondo, T.; Utsunomiya, H.; Goriely, S.; Daoutidis, I.; Iwamoto, C.; Akimune, H.; Okamoto, A.; Yamagata, T.; Kamata, M.; Itoh, O.; Toyokawa, H.; Lui, Y.-W.; Harada, H.; Kitatani, F.; Hilaire, S.; Koning, A. J.

2012-07-01

Using quasimonochromatic laser-Compton scattering γ rays, total photoneutron cross sections were measured for 206,207,208Pb near neutron threshold with a high-efficiency 4π neutron detector. Partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly polarized γ rays. The E1 strength dominates over the M1 strength in the neutron channel where E1 photoneutron cross sections show extra strength of the pygmy dipole resonance in 207,208Pb near the neutron threshold corresponding to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to an M1 cross section less than 10% of the total photoneutron cross section.

Mental Visualization of Objects from Cross-Sectional Images

ERIC Educational Resources Information Center

Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

2012-01-01

We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

Viscous Flow through Pipes of Various Cross-Sections

ERIC Educational Resources Information Center

Lekner, John

2007-01-01

An interesting variety of pipe cross-sectional shapes can be generated, for which the Navier-Stokes equations can be solved exactly. The simplest cases include the known solutions for elliptical and equilateral triangle cross-sections. Students can find pipe cross-sections from solutions of Laplace's equation in two dimensions, and then plot the…

Activation cross section and isomeric cross section ratio for the 76Ge(n,2n)75m,gGe process

NASA Astrophysics Data System (ADS)

Luo, Junhua; Jiang, Li; Wang, Xinxing

2018-04-01

We measured neutron-induced reaction cross sections for the 76Ge(n,2n)75m,gGe reactions and their isomeric cross section ratios σm/σg at three neutron energies between 13 and 15MeV by an activation and off-line γ-ray spectrometric technique using the K-400 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). Ge samples and Nb monitor foils were activated together to determine the reaction cross section and the incident neutron flux. The monoenergetic neutron beams were formed via the 3H( d, n)4He reaction. The pure cross section of the ground state was derived from the absolute cross section of the metastable state and the residual nuclear decay analysis. The cross sections were also calculated using the nuclear model code TALYS-1.8 with different level density options at neutron energies varying from the reaction threshold to 20MeV. Results are discussed and compared with the corresponding literature data.

O2 absorption cross sections /187-225 nm/ from stratospheric solar flux measurements

NASA Technical Reports Server (NTRS)

Herman, J. R.; Mentall, J. E.

1982-01-01

The absorption cross sections of molecular oxygen are calculated in the wavelength range from 187 to 230 nm from solar flux measurements obtained within the stratosphere. Within the Herzberg continuum wavelength region the molecular oxygen cross sections are found to be about 30% smaller than the laboratory results of Shardanand and Rao (1977) from 200 to 210 nm and about 50% smaller than those of Hasson and Nicholls (1971). At wavelengths longer than 210 nm the cross sections agree with those of Shardanand and Rao. The effective absorption cross sections of O2 in the Schumann-Runge band region from 187 to 200 nm are calculated and compared to the empirical fit given by Allen and Frederick (1982). The calculated cross sections indicate that the transmissivity of the atmosphere may be underestimated by the use of the Allen and Frederic cross sections between 195 and 200 nm. The ozone column content between 30 and 40 km and the relative ozone cross sections are determined from the same solar flux data set.

Using thermochonology to validate a balanced cross section along the Karnali River, far-western Nepal

NASA Astrophysics Data System (ADS)

Battistella, C.; Robinson, D.; McQuarrie, N.; Ghoshal, S.

2017-12-01

Multiple valid balanced cross sections can be produced from mapped surface and subsurface data. By integrating low temperature thermochronologic data, we are better able to predict subsurface geometries. Existing valid balanced cross section for far western Nepal are few (Robinson et al., 2006) and do not incorporate thermochronologic data because the data did not exist. The data published along the Simikot cross section along the Karnali River since then include muscovite Ar, zircon U-Th/He and apatite fission track. We present new mapping and a new valid balanced cross section that takes into account the new field data as well as the limitations that thermochronologic data places on the kinematics of the cross section. Additional constrains include some new geomorphology data acquired since 2006 that indicate areas of increased vertical uplift, which indicate locations of buried ramps in the Main Himalayan thrust and guide the locations of Lesser Himalayan ramps in the balanced cross section. Future work will include flexural modeling, new low temperature thermochronometic data, and 2-D thermokinematic models from a sequentially forward modeled balanced cross sections in far western Nepal.

Scattered light and accuracy of the cross-section measurements of weak absorptions: Gas and liquid phase UV absorption cross sections of CH3CFCl2

NASA Technical Reports Server (NTRS)

Fahr, A.; Braun, W.; Kurylo, M. J.

1993-01-01

Ultraviolet absorption cross sections of CH3CFCl2(HCFC-141b) were determined in the gas phase (190-260 nm) and liquid phase (230-260 mm) at 298 K. The liquid phase absorption cross sections were then converted into accurate gas phase values using a previously described procedure. It has been demonstrated that scattered light from the shorter-wavelength region (as little as several parts per thousand) can seriously compromise the absorption cross-section measurement, particularly at longer wavelengths where cross sections are low, and can be a source of discrepancies in the cross sections of weakly absorbing halocarbons reported in the literature. A modeling procedure was developed to assess the effect of scattered light on the measured absorption cross section in our experiments, thereby permitting appropriate corrections to be made on the experimental values. Modeled and experimental results were found to be in good agreement. Experimental results from this study were compared with other available determinations and provide accurate input for calculating the atmospheric lifetime of HCFC-141b.

Low-energy proton induced M X-ray production cross sections for 70Yb, 81Tl and 82Pb

NASA Astrophysics Data System (ADS)

Shehla; Mandal, A.; Kumar, Ajay; Roy Chowdhury, M.; Puri, Sanjiv; Tribedi, L. C.

2018-07-01

The cross sections for production of Mk (k = Mξ, Mαβ, Mγ, Mm1) X-rays of 70Yb, 81Tl and 82Pb induced by 50-250 keV protons have been measured in the present work. The experimental cross sections have been compared with the earlier reported values and those calculated using the ionization cross sections based on the ECPSSR (Perturbed (P) stationary(S) state(S), incident ion energy (E) loss, Coulomb (C) deflection and relativistic (R) correction) model, the X-ray emission rates based on the Dirac-Fock model, the fluorescence and Coster-Kronig yields based on the Dirac-Hartree-Slater (DHS) model. In addition, the present measured proton induced X-ray production cross sections have also been compared with those calculated using the Dirac-Hartree-Slater (DHS) model based ionization cross sections and those based on the Plane wave Born Approximation (PWBA). The measured M X-ray production cross sections are, in general, found to be higher than the ECPSSR and DHS model based values and lower than the PWBA model based cross sections.

Positron induced scattering cross sections for hydrocarbons relevant to plasma

NASA Astrophysics Data System (ADS)

Singh, Suvam; Antony, Bobby

2018-05-01

This article explores positron scattering cross sections by simple hydrocarbons such as ethane, ethene, ethyne, propane, and propyne. Chemical erosion processes occurring on the surface due to plasma-wall interactions are an abundant source of hydrocarbon molecules which contaminate the hydrogenic plasma. These hydrocarbons play an important role in the edge plasma region of Tokamak and ITER. In addition to this, they are also one of the major components in the planetary atmospheres and astrophysical mediums. The present work focuses on calculation of different positron impact interactions with simple hydrocarbons in terms of the total cross section (Qtot), elastic cross section (Qel), direct ionization cross section (Qion), positronium formation cross section (Qps), and total ionization cross section (Qtion). Knowing that the positron-plasma study is one of the trending fields, the calculated data have diverse plasma and astrophysical modeling applications. A comprehensive study of Qtot has been provided where the inelastic cross sections have been reported for the first time. Comparisons are made with those available from the literature, and a good agreement is obtained with the measurements.

AtSIG6 and other members of the sigma gene family jointly but differentially determine plastid target gene expression in Arabidopsis thaliana

PubMed Central

Bock, Sylvia; Ortelt, Jennifer; Link, Gerhard

2014-01-01

Plants contain a nuclear gene family for plastid sigma factors, i.e., proteins that associate with the “bacterial-type” organellar RNA polymerase and confer the ability for correct promoter binding and transcription initiation. Questions that are still unresolved relate to the “division of labor” among members of the sigma family, both in terms of their range of target genes and their temporal and spatial activity during development. Clues to the in vivo role of individual sigma genes have mainly come from studies of sigma knockout lines. Despite its obvious strengths, however, this strategy does not necessarily trace-down causal relationships between mutant phenotype and a single sigma gene, if other family members act in a redundant and/or compensatory manner. We made efforts to reduce the complexity by genetic crosses of Arabidopsis single mutants (with focus on a chlorophyll-deficient sig6 line) to generate double knockout lines. The latter typically had a similar visible phenotype as the parental lines, but tended to be more strongly affected in the transcript patterns of both plastid and sigma genes. Because triple mutants were lethal under our growth conditions, we exploited a strategy of transformation of single and double mutants with RNAi constructs that contained sequences from the unconserved sigma region (UCR). These RNAi/knockout lines phenotypically resembled their parental lines, but were even more strongly affected in their plastid transcript patterns. Expression patterns of sigma genes revealed both similarities and differences compared to the parental lines, with transcripts at reduced or unchanged amounts and others that were found to be present in higher (perhaps compensatory) amounts. Together, our results reveal considerable flexibility of gene activity at the levels of both sigma and plastid gene expression. A (still viable) “basal state” seems to be reached, if 2–3 of the 6 Arabidopsis sigma genes are functionally compromised. PMID:25505479

Comparison of Whole Body SOD1 Knockout with Muscle-Specific SOD1 Knockout Mice Reveals a Role for Nerve Redox Signaling in Regulation of Degenerative Pathways in Skeletal Muscle.

PubMed

Sakellariou, Giorgos K; McDonagh, Brian; Porter, Helen; Giakoumaki, Ifigeneia I; Earl, Kate E; Nye, Gareth A; Vasilaki, Aphrodite; Brooks, Susan V; Richardson, Arlan; Van Remmen, Holly; McArdle, Anne; Jackson, Malcolm J

2018-02-01

Lack of Cu,Zn-superoxide dismutase (CuZnSOD) in homozygous knockout mice (Sod1 -/- ) leads to accelerated age-related muscle loss and weakness, but specific deletion of CuZnSOD in skeletal muscle (mSod1KO mice) or neurons (nSod1KO mice) resulted in only mild muscle functional deficits and failed to recapitulate the loss of mass and function observed in Sod1 -/- mice. To dissect any underlying cross-talk between motor neurons and skeletal muscle in the degeneration in Sod1 -/- mice, we characterized neuromuscular changes in the Sod1 -/- model compared with mSod1KO mice and examined degenerative molecular mechanisms and pathways in peripheral nerve and skeletal muscle. In contrast to mSod1KO mice, myofiber atrophy in Sod1 -/- mice was associated with increased muscle oxidative damage, neuromuscular junction degeneration, denervation, nerve demyelination, and upregulation of proteins involved in maintenance of myelin sheaths. Proteomic analyses confirmed increased proteasomal activity and adaptive stress responses in muscle of Sod1 -/- mice that were absent in mSod1KO mice. Peripheral nerve from neither Sod1 -/- nor mSod1KO mice showed increased oxidative damage or molecular responses to increased oxidation compared with wild type mice. Differential cysteine (Cys) labeling revealed a specific redox shift in the catalytic Cys residue of peroxiredoxin 6 (Cys47) in the peripheral nerve from Sod1 -/- mice. Innovation and Conclusion: These findings demonstrate that neuromuscular integrity, redox mechanisms, and pathways are differentially altered in nerve and muscle of Sod1 -/- and mSod1KO mice. Results support the concept that impaired redox signaling, rather than oxidative damage, in peripheral nerve plays a key role in muscle loss in Sod1 -/- mice and potentially sarcopenia during aging. Antioxid. Redox Signal. 28, 275-295.

Electron induced inelastic and ionization cross section for plasma modeling

NASA Astrophysics Data System (ADS)

Verma, Pankaj; Mahato, Dibyendu; Kaur, Jaspreet; Antony, Bobby

2016-09-01

The present paper reports electron impact total inelastic and ionization cross section for silicon, germanium, and tin tetrahalides at energies varying from ionization threshold of the target to 5000 eV. These cross section data over a wide energy domain are very essential to understand the physico-chemical processes involved in various environments such as plasma modeling, semiconductor etching, atmospheric sciences, biological sciences, and radiation physics. However, the cross section data on the above mentioned molecules are scarce. In the present article, we report the computation of total inelastic cross section using spherical complex optical potential formalism and the estimation of ionization cross section through a semi-empirical method. The present ionization cross section result obtained for SiCl4 shows excellent agreement with previous measurements, while other molecules have not yet been investigated experimentally. Present results show more consistent behaviour than previous theoretical estimates. Besides cross sections, we have also studied the correlation of maximum ionization cross section with the square root of the ratio of polarizability to ionization potential for the molecules with known polarizabilities. A linear relation is observed between these quantities. This correlation is used to obtain approximate polarizability volumes for SiBr4, SiI4, GeCl4, GeBr4, and GeI4 molecules.

Breakup and fusion cross sections of the 6Li nucleus with targets of mass A = 58, 144 and 208

NASA Astrophysics Data System (ADS)

Mukeru, B.; Rampho, G. J.; Lekala, M. L.

2018-04-01

We use the continuum discretized coupled channels method to investigate the effects of continuum-continuum coupling on the breakup and fusion cross sections of the weakly bound 6Li nucleus with the 58Ni, 144Sm and 208Pb nuclear targets. The cross sections were analyzed at incident energies E cm below, close to and above the Coulomb barrier V B. We found that for the medium and heavy targets, the breakup cross sections are enhanced at energies below the Coulomb barrier (E cm/V B ≤ 0.8) owing to these couplings. For the lighter target, relatively small enhancement of the breakup cross sections appear at energies well below the barrier (E cm/V B ≤ 0.6). At energies E cm/V B > 0.8 for medium and heavy targets, and E cm/V B > 0.6 for the light target, the continuum-continuum couplings substantially suppress the breakup cross sections. On the other hand, the fusion cross sections are enhanced at energies E cm/V B < 1.4, E cm/V B < 1.2 and E cm/V B < 0.8 for the light, medium and heavy target, respectively. The enhancement decreases as the target mass increases. Above the indicated respective energies, these couplings suppress the fusion cross sections. We also compared the breakup and fusion cross sections, and found that below the barrier, the breakup cross sections are more dominant regardless of whether continuum-continuum couplings are included.

Simple, empirical approach to predict neutron capture cross sections from nuclear masses

NASA Astrophysics Data System (ADS)

Couture, A.; Casten, R. F.; Cakirli, R. B.

2017-12-01

Background: Neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40 % , and has limited predictive power, with predictions from different models rapidly differing by an order of magnitude a few nucleons from the last measurement. Purpose: To develop a new approach to predicting neutron capture cross sections over broad ranges of nuclei that accounts for their values where known and which has reliable predictive power with small uncertainties for many nuclei where they are unknown. Methods: Experimental neutron capture cross sections were compared to empirical mass observables in regions of similar structure. Results: We present an extremely simple method, based solely on empirical mass observables, that correlates neutron capture cross sections in the critical energy range from a few keV to a couple hundred keV. We show that regional cross sections are compactly correlated in medium and heavy mass nuclei with the two-neutron separation energy. These correlations are easily amenable to predict unknown cross sections, often converting the usual extrapolations to more reliable interpolations. It almost always reproduces existing data to within 25 % and estimated uncertainties are below about 40 % up to 10 nucleons beyond known data. Conclusions: Neutron capture cross sections display a surprisingly strong connection to the two-neutron separation energy, a nuclear structure property. The simple, empirical correlations uncovered provide model-independent predictions of neutron capture cross sections, extending far from stability, including for nuclei of the highest sensitivity to r -process nucleosynthesis.

Kinematic Modeling of Central Nepal: Thermochronometer Cooling Ages as a Constraint for Balanced Cross Sections

NASA Astrophysics Data System (ADS)

Olree, E.; Robinson, D. M.; McQuarrie, N.; Ghoshal, S.; Olsen, J.

2016-12-01

Using balanced cross sections, one can visualize a valid and admissible interpretation of the surface and subsurface data. Khanal (2014) and Cross (2014) produced two valid and admissible cross sections along the Marsyandi River in central Nepal. However, thermochronologic data adds another dimension that must be adhered to when producing valid and admissible balanced cross sections. Since the previous cross sections were produced, additional zircon-helium (ZHe) cooling ages along the Marsyandi River show ages of 1 Ma near the Main Central thrust in the hinterland to 4 Ma near the Main Boundary thrust closer to the foreland. This distribution of cooling ages requires recent uplift in the hinterland, which is not present in the cross sections. Although a restored version of the Khanal (2014) cross section is sequentially deformed using 2D Move, the kinematic sequence implied in the cross section is inconsistent with the ZHe age distribution. The hinterland dipping duplex proposed by Khanal would require cooling ages that are oldest near the Main Central thrust and young southwards toward the active ramp located 80 km north of the Main Frontal thrust. Instead, the 4 Ma age near the Main Boundary thrust and the increasingly younger ages to the north could be produced by either a foreland-dipping Lesser Himalayan duplex, which would keep active uplift in the north, or by translation of the hinterland dipping duplex southward over the ramp, moving the active thrust ramp northward. To address this problem, a new balanced cross section was produced using both new mapping through the region and the ZHe age distribution as additional constraints. The section was then restored and sequentially deformed in 2D Move. This study illustrates that multiple cross sections can be viable and admissible; however, they can still be incorrect. Thermochronology places additional constraints on the permissible geometries, and thus increases our ability to predict subsurface geometries. The next step of this project is to link the uplift and erosion implied by the kinematic sequence of the new cross section to the measured cooling history by importing the cross section kinematics into advection diffusion modeling software that predicts cooling ages.

Fragmentation of Ar-40 at 100 GeV/c

NASA Technical Reports Server (NTRS)

Lindstrom, P. J.; Greiner, D. E.; Heckman, H. H.; Cork, B.; Bieser, F. S.

1975-01-01

The delta Z is greater than or equal to 1 reaction cross section for 1.8 GeV/n Ar-40 have been measured on targets ranging from H to Pb. Comparing these cross sections with H-1, C-12, and O-16 reaction cross sections at relativistic energies yields a formula for nucleus-nucleus reaction cross sections.

Temperature-dependent absorption cross sections for hydrogen peroxide vapor

NASA Technical Reports Server (NTRS)

Nicovich, J. M.; Wine, P. H.

1988-01-01

Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

Measurements of absolute absorption cross sections of ozone in the 185- to 254-nm wavelength region and the temperature dependence

NASA Technical Reports Server (NTRS)

Yoshino, K.; Esmond, J. R.; Freeman, D. E.; Parkinson, W. H.

1993-01-01

Laboratory measurements of the relative absorption cross sections of ozone at temperatures 195, 228, and 295 K have been made throughout the 185 to 254 nm wavelength region. The absolute absorption cross sections at the same temperatures have been measured at several discrete wavelengths in the 185 to 250 nm region. The absolute cross sections of ozone have been used to put the relative cross sections on a firm absolute basis throughout the 185 to 255 nm region. These recalibrated cross sections are slightly lower than those of Molina and Molina (1986), but the differences are within a few percent and would not be significant in atmospheric applications.

Fragmentation cross sections of O-16 between 0.9 and 200 GeV/nucleon

NASA Technical Reports Server (NTRS)

Hirzebruch, S. E.; Heinrich, W.; Tolstov, K. D.; Kovalenko, A. D.; Benton, E. V.

1995-01-01

Inclusive cross sections for high energy interactions at 0.9, 2.3, 3.6, and 13.5 GeV/nucleon of O-16 with C, CR-39 (C12H18O7), CH2, Al, Cu, Ag, and Pb targets were measured. The total charge-changing cross sections and partial charge-changing cross sections for the production of fragments with charge Z = 6 and Z = 7 are compared to previous experiments at 60 and 200 GeV/nucleon. The contributions of Coulomb dissociation to the total cross sections are calculated. Using factorization rules the partial electromagnetic cross sections are separated from the nuclear components. Energy dependence of both components are investigated and discussed.

Nuclear annihilation by antinucleons

DOE PAGES

Lee, Teck-Ghee; Wong, Cheuk-Yin

2016-01-25

We examine the momentum dependence ofmore » $$\\bar{p}$$p and $$\\bar{n}$$p annihilation cross sections by considering the transmission through a nuclear potential and the $$\\bar {p}$$p Coulomb interaction. Compared to the $$\\bar{n}$$p annihilation cross section, the $$\\bar{p}$$p annihilation cross section is significantly enhanced by the Coulomb interaction for projectile momenta below p lab < 500 MeV/c, and the two annihilation cross sections approach the Pomeranchuk's equality limit [JETP 30, 423 (1956)] at p lab ~500 MeV/c. Using these elementary cross sections as the basic input data, the extended Glauber model is employed to evaluate the annihilation cross sections for $$\\bar{n}$$ and $$\\bar{p}$$ interaction with nuclei and the results compare well with experimental data.« less

Using 171,173Yb(d,p) to benchmark a surrogate reaction for neutron capture

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

Hatarik, R; Bersntein, L; Burke, J

2008-08-08

Neutron capture cross sections on unstable nuclei are important for many applications in nuclear structure and astrophysics. Measuring these cross sections directly is a major challenge and often impossible. An indirect approach for measuring these cross sections is the surrogate reaction method, which makes it possible to relate the desired cross section to a cross section of an alternate reaction that proceeds through the same compound nucleus. To benchmark the validity of using the (d,p{gamma}) reaction as a surrogate for (n,{gamma}), the {sup 171,173}Yb(d,p{gamma}) reactions were measured with the goal to reproduce the known [1] neutron capture cross section ratiosmore » of these nuclei.« less

Photoeffect cross sections of several rare-earth elements for 323-keV photons

NASA Astrophysics Data System (ADS)

Umesh, T. K.; Anasuya, S. J.; Shylaja Kumari, J.; Gowda, Channe; Gopinathan Nair, K. P.; Gowda, Ramakrishna

1992-02-01

Total-attenuation cross sections of the oxides of rare-earth elements such as La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, and Er, and also NaNO3 and NaNO2 have been measured in a narrow-beam geometry setup at 323 keV. The total-attenuation cross section for oxygen was obtained as the difference in NaNO3 and NaNO2 cross sections. Using this, the total-attenuation cross sections of the individual lanthanides have been obtained with the aid of the mixture rule. From these, the photoeffect cross sections were derived by subtracting the scattering contribution. These values are found to agree well with Scofield's theoretical data [University of California Report No. UCRL 51326, 1973 (unpublished)].

One-jet inclusive cross section at order a(s)-cubed - Gluons only

NASA Technical Reports Server (NTRS)

Ellis, Stephen D.; Kunszt, Zoltan; Soper, Davison E.

1989-01-01

A complete calculation of the hadron jet cross-section at one order beyond the Born approximation is performed for the simplified case in which there are only gluons. The general structure of the differences from the lowest-order cross-section are described. This step allows two important improvements in the understanding of the theoretical hadron jet cross-section: first, the cross section at this order displays explicit dependence on the jet cone size, so that explicit account can be taken of the differences in jet definitions employed by different experiments; second, the magnitude of the uncertainty of the theoretical cross-section due to the arbitrary choice of the factorization scale has been reduced by a factor of two to three.

Solid oxide fuel cell with transitioned cross-section for improved anode gas management at the open end

DOEpatents

Zafred, Paolo R [Murrysville, PA; Draper, Robert [Pittsburgh, PA

2012-01-17

A solid oxide fuel cell (400) is made having a tubular, elongated, hollow, active section (445) which has a cross-section containing an air electrode (452) a fuel electrode (454) and solid oxide electrolyte (456) between them, where the fuel cell transitions into at least one inactive section (460) with a flattened parallel sided cross-section (462, 468) each cross-section having channels (472, 474, 476) in them which smoothly communicate with each other at an interface section (458).

Nuclear reactor control column

DOEpatents

Bachovchin, Dennis M.

1982-01-01

The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

[Upregulation of P2X3 receptors in dorsal root ganglion of TRPV1 knockout female mice].

PubMed

Fang, Xiao; Shi, Xiao-Han; Huang, Li-Bin; Rong, Wei-Fang; Ma, Bei

2014-08-25

The study was aimed to investigate the changes in mechanical pain threshold in the condition of chronic inflammatory pain after transient receptor potential vanilloid 1 (TRPV1) gene was knockout. Hind-paw intraplantar injection of complete freund's adjuvant (CFA, 20 μL) produced peripheral inflammation in wild-type and TRPV1 knockout female mice. The mechanical pain thresholds were measured during the 8 days after injection and pre-injection by using Von-Frey hair. Nine days after injection, mice were killed and the differences of expression of c-Fos and P2X3 receptor in the dorsal root ganglia (DRG) and spinal cord dorsal horn were examined by Western blotting between the two groups. Compared with that in wild-type mice, the mechanical pain threshold was increased significantly in TRPV1 knockout mice (P < 0.05); 3 days after CFA injection, the baseline mechanical pain threshold in the TRPV1 knockout mice group was significantly higher than that in the wild-type mice group (P < 0.05); The result of Western blotting showed that the expression of c-Fos protein both in DRG and spinal cord dorsal horn of TRPV1 knockout mice group was decreased significantly compared with that in wild-type mice group (P < 0.01, P < 0.05), while the expression of P2X3 receptor in DRG of TRPV1 knockout mice group was increased significantly compared with that in wild-type mice group (P < 0.05). Our findings indicate that TRPV1 may influence the peripheral mechanical pain threshold by mediating the expression of c-Fos protein both in DRG and spinal cord dorsal horn and changing the expression of P2X3 receptor in DRG.

Glutaminyl Cyclase Knock-out Mice Exhibit Slight Hypothyroidism but No Hypogonadism

PubMed Central

Schilling, Stephan; Kohlmann, Stephanie; Bäuscher, Christoph; Sedlmeier, Reinhard; Koch, Birgit; Eichentopf, Rico; Becker, Andreas; Cynis, Holger; Hoffmann, Torsten; Berg, Sabine; Freyse, Ernst-Joachim; von Hörsten, Stephan; Rossner, Steffen; Graubner, Sigrid; Demuth, Hans-Ulrich

2011-01-01

Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamate (pGlu) residues at the N terminus of peptides and proteins. Hypothalamic pGlu hormones, such as thyrotropin-releasing hormone and gonadotropin-releasing hormone are essential for regulation of metabolism and fertility in the hypothalamic pituitary thyroid and gonadal axes, respectively. Here, we analyzed the consequences of constitutive genetic QC ablation on endocrine functions and on the behavior of adult mice. Adult homozygous QC knock-out mice are fertile and behave indistinguishably from wild type mice in tests of motor function, cognition, general activity, and ingestion behavior. The QC knock-out results in a dramatic drop of enzyme activity in the brain, especially in hypothalamus and in plasma. Other peripheral organs like liver and spleen still contain QC activity, which is most likely caused by its homolog isoQC. The serum gonadotropin-releasing hormone, TSH, and testosterone concentrations were not changed by QC depletion. The serum thyroxine was decreased by 24% in homozygous QC knock-out animals, suggesting a mild hypothyroidism. QC knock-out mice were indistinguishable from wild type with regard to blood glucose and glucose tolerance, thus differing from reports of thyrotropin-releasing hormone knock-out mice significantly. The results suggest a significant formation of the hypothalamic pGlu hormones by alternative mechanisms, like spontaneous cyclization or conversion by isoQC. The different effects of QC depletion on the hypothalamic pituitary thyroid and gonadal axes might indicate slightly different modes of substrate conversion of both enzymes. The absence of significant abnormalities in QC knock-out mice suggests the presence of a therapeutic window for suppression of QC activity in current drug development. PMID:21330373

Hyperactivity of newborn Pten knock-out neurons results from increased excitatory synaptic drive.

PubMed

Williams, Michael R; DeSpenza, Tyrone; Li, Meijie; Gulledge, Allan T; Luikart, Bryan W

2015-01-21

Developing neurons must regulate morphology, intrinsic excitability, and synaptogenesis to form neural circuits. When these processes go awry, disorders, including autism spectrum disorder (ASD) or epilepsy, may result. The phosphatase Pten is mutated in some patients having ASD and seizures, suggesting that its mutation disrupts neurological function in part through increasing neuronal activity. Supporting this idea, neuronal knock-out of Pten in mice can cause macrocephaly, behavioral changes similar to ASD, and seizures. However, the mechanisms through which excitability is enhanced following Pten depletion are unclear. Previous studies have separately shown that Pten-depleted neurons can drive seizures, receive elevated excitatory synaptic input, and have abnormal dendrites. We therefore tested the hypothesis that developing Pten-depleted neurons are hyperactive due to increased excitatory synaptogenesis using electrophysiology, calcium imaging, morphological analyses, and modeling. This was accomplished by coinjecting retroviruses to either "birthdate" or birthdate and knock-out Pten in granule neurons of the murine neonatal dentate gyrus. We found that Pten knock-out neurons, despite a rapid onset of hypertrophy, were more active in vivo. Pten knock-out neurons fired at more hyperpolarized membrane potentials, displayed greater peak spike rates, and were more sensitive to depolarizing synaptic input. The increased sensitivity of Pten knock-out neurons was due, in part, to a higher density of synapses located more proximal to the soma. We determined that increased synaptic drive was sufficient to drive hypertrophic Pten knock-out neurons beyond their altered action potential threshold. Thus, our work contributes a developmental mechanism for the increased activity of Pten-depleted neurons. Copyright © 2015 the authors 0270-6474/15/350943-17$15.00/0.

The Expression of TALEN before Fertilization Provides a Rapid Knock-Out Phenotype in Xenopus laevis Founder Embryos.

PubMed

Miyamoto, Kei; Suzuki, Ken-Ichi T; Suzuki, Miyuki; Sakane, Yuto; Sakuma, Tetsushi; Herberg, Sarah; Simeone, Angela; Simpson, David; Jullien, Jerome; Yamamoto, Takashi; Gurdon, J B

2015-01-01

Recent advances in genome editing using programmable nucleases have revolutionized gene targeting in various organisms. Successful gene knock-out has been shown in Xenopus, a widely used model organism, although a system enabling less mosaic knock-out in founder embryos (F0) needs to be explored in order to judge phenotypes in the F0 generation. Here, we injected modified highly active transcription activator-like effector nuclease (TALEN) mRNA to oocytes at the germinal vesicle (GV) stage, followed by in vitro maturation and intracytoplasmic sperm injection, to achieve a full knock-out in F0 embryos. Unlike conventional injection methods to fertilized embryos, the injection of TALEN mRNA into GV oocytes allows expression of nucleases before fertilization, enabling them to work from an earlier stage. Using this procedure, most of developed embryos showed full knock-out phenotypes of the pigmentation gene tyrosinase and/or embryonic lethal gene pax6 in the founder generation. In addition, our method permitted a large 1 kb deletion. Thus, we describe nearly complete gene knock-out phenotypes in Xenopus laevis F0 embryos. The presented method will help to accelerate the production of knock-out frogs since we can bypass an extra generation of about 1 year in Xenopus laevis. Meantime, our method provides a unique opportunity to rapidly test the developmental effects of disrupting those genes that do not permit growth to an adult able to reproduce. In addition, the protocol shown here is considerably less invasive than the previously used host transfer since our protocol does not require surgery. The experimental scheme presented is potentially applicable to other organisms such as mammals and fish to resolve common issues of mosaicism in founders.

Behavioral characterization of mice deficient in the phosphodiesterase-10A (PDE10A) enzyme on a C57/Bl6N congenic background.

PubMed

Siuciak, Judith A; McCarthy, Sheryl A; Chapin, Douglas S; Martin, Ashley N; Harms, John F; Schmidt, Christopher J

2008-02-01

The phenotype of genetically modified animals is strongly influenced by both the genetic background of the animal as well as environmental factors. We have previously reported the behavioral and neurochemical characterization of PDE10A knockout mice maintained on a DBA1LacJ (PDE10A(DBA)) genetic background. The aim of the present studies was to assess the behavioral and neurochemical phenotype of PDE10A knockout mice on an alternative congenic C57BL/6N (PDE10A(C57)) genetic background. Consistent with our previous results, PDE10A(C57) knockout mice showed a decrease in exploratory locomotor activity and a delay in the acquisition of conditioned avoidance responding. Also consistent with previous studies, the elimination of PDE10A did not alter basal levels of striatal cGMP or cAMP or affect behavior in several other well-characterized behavioral assays. PDE10A(C57) knockout mice showed a blunted response to MK-801, although to a lesser degree than previously observed in the PDE10A(DBA) knockout mice, and no differences were observed following a PCP challenge. PDE10A(C57) knockout mice showed a significant change in striatal dopamine turnover, which was accompanied by an enhanced locomotor response to AMPH, These studies demonstrate that while many of the behavioral effects of the PDE10A gene deletion appear to be independent of genetic background, the impact of the deletion on behavior can vary in magnitude. Furthermore, the effects on the dopaminergic system appear to be background-dependent, with significant effects observed only in knockout mice on the C57BL6N genetic background.

CRISPR/Cas9 knockout of HAS2 in rat chondrosarcoma chondrocytes demonstrates the requirement of hyaluronan for aggrecan retention

PubMed Central

Huang, Yi; Askew, Emily B.; Knudson, Cheryl B.; Knudson, Warren

2016-01-01

Hyaluronan (HA) plays an essential role in cartilage where it functions to retain aggrecan. Previous studies have suggested that aggrecan is anchored indirectly to the plasma membrane of chondrocytes via its binding to cell-associated HA. However, reagents used to test these observations such as hyaluronidase and HA oligosaccharides are short term and may have side activities that complicate interpretation. Using the CRISPR/Cas9 gene editing approach, a model system was developed by generating HA-deficient chondrocyte cell lines. HA synthase-2 (Has2)-specific single guide RNA was introduced into two different variant lines of rat chondrosarcoma chondrocytes; knockout clones were isolated and characterized. Two other members of the HA synthase gene family were expressed at very low relative copy number but showed no compensatory response in the Has2 knockouts. Wild type chondrocytes of both variants exhibited large pericellular matrices or coats extending from the plasma membrane. Addition of purified aggrecan monomer expanded the size of these coats as the proteoglycan became retained within the pericellular matrix. Has2 knockout chondrocytes lost all capacity to assemble a particle-excluding pericellular matrix and more importantly, no matrices formed around the knockout cells following the addition of purified aggrecan. When grown as pellet cultures so as to generate a bioengineered neocartilage tissue, the Has2 knockout chondrocytes assumed a tightly-compacted morphology as compared to the wild type cells. When knockout chondrocytes were transduced with Adeno-ZsGreen1-mycHas2, the cell-associated pericellular matrices were restored including the capacity to bind and incorporate additional exogenous aggrecan into the matrix. These results suggest that HA is essential for aggrecan retention and maintaining cell separation during tissue formation. PMID:27094859

Vasoactive intestinal peptide-null mice demonstrate enhanced sweet taste preference, dysglycemia, and reduced taste bud leptin receptor expression.

PubMed

Martin, Bronwen; Shin, Yu-Kyong; White, Caitlin M; Ji, Sunggoan; Kim, Wook; Carlson, Olga D; Napora, Joshua K; Chadwick, Wayne; Chapter, Megan; Waschek, James A; Mattson, Mark P; Maudsley, Stuart; Egan, Josephine M

2010-05-01

It is becoming apparent that there is a strong link between taste perception and energy homeostasis. Recent evidence implicates gut-related hormones in taste perception, including glucagon-like peptide 1 and vasoactive intestinal peptide (VIP). We used VIP knockout mice to investigate VIP's specific role in taste perception and connection to energy regulation. Body weight, food intake, and plasma levels of multiple energy-regulating hormones were measured and pancreatic morphology was determined. In addition, the immunocytochemical profile of taste cells and gustatory behavior were examined in wild-type and VIP knockout mice. VIP knockout mice demonstrate elevated plasma glucose, insulin, and leptin levels, with no islet beta-cell number/topography alteration. VIP and its receptors (VPAC1, VPAC2) were identified in type II taste cells of the taste bud, and VIP knockout mice exhibit enhanced taste preference to sweet tastants. VIP knockout mouse taste cells show a significant decrease in leptin receptor expression and elevated expression of glucagon-like peptide 1, which may explain sweet taste preference of VIP knockout mice. This study suggests that the tongue can play a direct role in modulating energy intake to correct peripheral glycemic imbalances. In this way, we could view the tongue as a sensory mechanism that is bidirectionally regulated and thus forms a bridge between available foodstuffs and the intricate hormonal balance in the animal itself.

A mental retardation gene, motopsin/neurotrypsin/prss12, modulates hippocampal function and social interaction

PubMed Central

Mitsui, Shinichi; Osako, Yoji; Yokoi, Fumiaki; Dang, Mai T.; Yuri, Kazunari; Li, Yuqing; Yamaguchi, Nozomi

2010-01-01

Motopsin is a mosaic serine protease secreted from neuronal cells in various brain regions including the hippocampus. The loss of motopsin function causes nonsyndromic mental retardation in humans and impairs long-term memory formation in Drosophila. To understand motopsin’s function in the mammalian brain, motopsin knockout mice were generated. Motopsin knockout mice did not have significant deficit in memory formation, as was tested using in the Morris water maze, passive avoidance, and Y-maze tests. A social recognition test showed that the motopsin knockout mice had the ability to recognize two stimulator mice, suggesting normal social memory. In a social novelty test, motopsin knockout mice spent a longer time investigating a familiar mouse than wild-type mice did. In a resident-intruder test, motopsin knockout mice showed prolonged social interaction compared to wild-type mice. Consistent with the behavioral deficit, spine density was significantly decreased on apical dendrites, but not on basal dendrites, of hippocampal pyramidal neurons of motopsin knockout mice. In contrast, pyramidal neurons at the cingulate cortex showed normal spine density. Spatial learning and social interaction induced the phosphorylation of cAMP responsive element binding protein (CREB) in hippocampal neurons of wild-type mice, whereas the phosphorylation of CREB was markedly decreased in mutant mouse brains. Our results indicate that an extracellular protease, motopsin, preferentially affects social behaviors, and modulates the functions of hippocampal neurons. PMID:20092579

Studies of UCP2 transgenic and knockout mice reveal that liver UCP2 is not essential for the antiobesity effects of fish oil.

PubMed

Tsuboyama-Kasaoka, Nobuyo; Sano, Kayo; Shozawa, Chikako; Osaka, Toshimasa; Ezaki, Osamu

2008-03-01

Uncoupling protein 2 (UCP2) is a possible target molecule for energy dissipation. Many dietary fats, including safflower oil and lard, induce obesity in C57BL/6 mice, whereas fish oil does not. Fish oil increases UCP2 expression in hepatocytes and may enhance UCP2 activity by activating the UCP2 molecule or altering the lipid bilayer environment. To examine the role of liver UCP2 in obesity, we created transgenic mice that overexpressed human UCP2 in hepatocytes and examined whether UCP2 transgenic mice showed less obesity when fed a high-fat diet (safflower oil or lard). In addition, we examined whether fish oil had antiobesity effects in UCP2 knockout mice. UCP2 transgenic and wild-type mice fed a high-fat diet (safflower oil or lard) developed obesity to a similar degree. UCP2 knockout and wild-type mice fed fish oil had lower rates of obesity than mice fed safflower oil. Remarkably, safflower oil did not induce obesity in female UCP2 knockout mice, an unexpected phenotype for which we presently have no explanation. However, this unexpected effect was not observed in male UCP2 knockout mice or in UCP2 knockout mice fed a high-lard diet. These data indicate that liver UCP2 is not essential for fish oil-induced decreases in body fat.

A Protocol for Multiple Gene Knockout in Mouse Small Intestinal Organoids Using a CRISPR-concatemer.

PubMed

Merenda, Alessandra; Andersson-Rolf, Amanda; Mustata, Roxana C; Li, Taibo; Kim, Hyunki; Koo, Bon-Kyoung

2017-07-12

CRISPR/Cas9 technology has greatly improved the feasibility and speed of loss-of-function studies that are essential in understanding gene function. In higher eukaryotes, paralogous genes can mask a potential phenotype by compensating the loss of a gene, thus limiting the information that can be obtained from genetic studies relying on single gene knockouts. We have developed a novel, rapid cloning method for guide RNA (gRNA) concatemers in order to create multi-gene knockouts following a single round of transfection in mouse small intestinal organoids. Our strategy allows for the concatemerization of up to four individual gRNAs into a single vector by performing a single Golden Gate shuffling reaction with annealed gRNA oligos and a pre-designed retroviral vector. This allows either the simultaneous knockout of up to four different genes, or increased knockout efficiency following the targeting of one gene by multiple gRNAs. In this protocol, we show in detail how to efficiently clone multiple gRNAs into the retroviral CRISPR-concatemer vector and how to achieve highly efficient electroporation in intestinal organoids. As an example, we show that simultaneous knockout of two pairs of genes encoding negative regulators of the Wnt signaling pathway (Axin1/2 and Rnf43/Znrf3) renders intestinal organoids resistant to the withdrawal of key growth factors.

Abrogation of both short and long forms of latent transforming growth factor-β binding protein-1 causes defective cardiovascular development and is perinatally lethal.

PubMed

Horiguchi, Masahito; Todorovic, Vesna; Hadjiolova, Krassimira; Weiskirchen, Ralf; Rifkin, Daniel B

2015-04-01

Latent transforming growth factor-β binding protein-1 (LTBP-1) is an extracellular protein that is structurally similar to fibrillin and has an important role in controlling transforming growth factor-β (TGF-β) signaling by storing the cytokine in the extracellular matrix and by being involved in the conversion of the latent growth factor to its active form. LTBP-1 is found as both short (LTBP-1S) and long (LTBP-1L) forms, which are derived through the use of separate promoters. There is controversy regarding the importance of LTBP-1L, as Ltbp1L knockout mice showed multiple cardiovascular defects but the complete null mice did not. Here, we describe a third line of Ltbp1 knockout mice generated utilizing a conditional knockout strategy that ablated expression of both L and S forms of LTBP-1. These mice show severe developmental cardiovascular abnormalities and die perinatally; thus these animals display a phenotype similar to previously reported Ltbp1L knockout mice. We reinvestigated the other "complete" knockout line and found that these mice express a splice variant of LTBP-1L and, therefore, are not complete Ltbp1 knockouts. Our results clarify the phenotypes of Ltbp1 null mice and re-emphasize the importance of LTBP-1 in vivo. Copyright © 2015. Published by Elsevier B.V.

Exacerbated febrile responses to LPS, but not turpentine, in TNF double receptor-knockout mice.

PubMed

Leon, L R; Kozak, W; Peschon, J; Kluger, M J

1997-02-01

We examined the effects of injections of systemic [lipopolysaccharide (LPS), 2.5 mg/kg or 50 pg/kg ip] or local (turpentine, 100 microl sc) inflammatory stimuli on fever, motor activity, body weight, and food intake in tumor necrosis factor (TNF) double receptor (TNFR)-knockout mice. A high dose of LPS resulted in exacerbated fevers in TNFR-knockout mice compared with wild-type mice for the early phase of fever (3-15 h); the late phase of fever (16-24 h) and fevers to a low dose of LPS were similar in both groups. Motor activity, body weight, and food intake were similarly reduced in both groups of mice after LPS administration. In response to turpentine, TNFR-knockout and wild-type mice developed virtually identical responses to all variables monitored. These results suggest that 1) TNF modulates fevers to LPS dose dependently, 2) TNF does not modulate fevers to a subcutaneous injection of turpentine, and 3) knockout mice may develop cytokine redundancy in the regulation of the acute phase response to intraperitoneally injected LPS or subcutaneously injected turpentine.

The bcl-2 knockout mouse exhibits marked changes in osteoblast phenotype and collagen deposition in bone as well as a mild growth plate phenotype

PubMed Central

BOOT-HANDFORD, R. P.; MICHAELIDIS, T. M.; HILLARBY, M. C.; ZAMBELLI, A.; DENTON, J.; HOYLAND, J. A.; FREEMONT, A. J.; GRANT, M. E.; WALLIS, G. A.

1998-01-01

Histological examination of long bones from 1-day-old bcl-2 knockout and age-matched control mice revealed no obvious differences in length of bone, growth plate architecture or stage of endochondral ossification. In 35-day-old bcl-2 knockout mice that are growth retarded or ‘dwarfed’, the proliferative zone of the growth plate appeared slightly thinner and the secondary centres of ossification less well developed than their age-matched wild-type controls. The most marked histological effects of bcl-2 ablation were on osteoblasts and bone. 35-day-old knockout mouse bones exhibited far greater numbers of osteoblasts than controls and the osteoblasts had a cuboidal phenotype in comparison with the normal flattened cell appearance. In addition, the collagen deposited by the osteoblasts in the bcl-2 knockout mouse bone was disorganized in comparison with control tissue and had a pseudo-woven appearance. The results suggest an important role for Bcl-2 in controlling osteoblast phenotype and bone deposition in vivo. PMID:10193316

CRISPR-Cas9-mediated gene knockout in primary human airway epithelial cells reveals a proinflammatory role for MUC18.

PubMed

Chu, H W; Rios, C; Huang, C; Wesolowska-Andersen, A; Burchard, E G; O'Connor, B P; Fingerlin, T E; Nichols, D; Reynolds, S D; Seibold, M A

2015-10-01

Targeted knockout of genes in primary human cells using CRISPR-Cas9-mediated genome-editing represents a powerful approach to study gene function and to discern molecular mechanisms underlying complex human diseases. We used lentiviral delivery of CRISPR-Cas9 machinery and conditional reprogramming culture methods to knockout the MUC18 gene in human primary nasal airway epithelial cells (AECs). Massively parallel sequencing technology was used to confirm that the genome of essentially all cells in the edited AEC populations contained coding region insertions and deletions (indels). Correspondingly, we found mRNA expression of MUC18 was greatly reduced and protein expression was absent. Characterization of MUC18 knockout cell populations stimulated with TLR2, 3 and 4 agonists revealed that IL-8 (a proinflammatory chemokine) responses of AECs were greatly reduced in the absence of functional MUC18 protein. Our results show the feasibility of CRISPR-Cas9-mediated gene knockouts in AEC culture (both submerged and polarized), and suggest a proinflammatory role for MUC18 in airway epithelial response to bacterial and viral stimuli.

MONOAMINE OXIDASE: From Genes to Behavior

PubMed Central

Shih, J. C.; Chen, K.; Ridd, M. J.

2010-01-01

Cloning of MAO (monoamine oxidase) A and B has demonstrated unequivocally that these enzymes are made up of different polypeptides, and our understanding of MAO structure, regulation, and function has been significantly advanced by studies using their cDNA. MAO A and B genes are located on the X-chromosome (Xp11.23) and comprise 15 exons with identical intron-exon organization, which suggests that they are derived from the same ancestral gene. MAO A and B knockout mice exhibit distinct differences in neurotransmitter metabolism and behavior. MAO A knock-out mice have elevated brain levels of serotonin, norephinephrine, and dopamine and manifest aggressive behavior similar to human males with a deletion of MAO A. In contrast, MAO B knock-out mice do not exhibit aggression and only levels of phenylethylamine are increased. Mice lacking MAO B are resistant to the Parkinsongenic neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine. Both MAO A and B knock-out mice show increased reactivity to stress. These knock-out mice are valuable models for investigating the role of monoamines in psychoses and neurodegenerative and stress-related disorders. PMID:10202537

12/15-Lipoxygenase Inhibition or Knockout Reduces Warfarin-Associated Hemorrhagic Transformation After Experimental Stroke.

PubMed

Liu, Yu; Zheng, Yi; Karatas, Hulya; Wang, Xiaoying; Foerch, Christian; Lo, Eng H; van Leyen, Klaus

2017-02-01

For stroke prevention, patients with atrial fibrillation typically receive oral anticoagulation. The commonly used anticoagulant warfarin increases the risk of hemorrhagic transformation (HT) when a stroke occurs; tissue-type plasminogen activator treatment is therefore restricted in these patients. This study was designed to test the hypothesis that 12/15-lipoxygenase (12/15-LOX) inhibition would reduce HT in warfarin-treated mice subjected to experimental stroke. Warfarin was dosed orally in drinking water, and international normalized ratio values were determined using a Coaguchek device. C57BL6J mice or 12/15-LOX knockout mice were subjected to transient middle cerebral artery occlusion with 3 hours severe ischemia (model A) or 2 hours ischemia and tissue-type plasminogen activator infusion (model B), with or without the 12/15-LOX inhibitor ML351. Hemoglobin was determined in brain homogenates, and hemorrhage areas on the brain surface and in brain sections were measured. 12/15-LOX expression was detected by immunohistochemistry. Warfarin treatment resulted in reproducible increased international normalized ratio values and significant HT in both models. 12/15-LOX knockout mice suffered less HT after severe ischemia, and ML351 reduced HT in wild-type mice. When normalized to infarct size, ML351 still independently reduced hemorrhage. HT after tissue-type plasminogen activator was similarly reduced by ML351. In addition to its benefits in infarct size reduction, 12/15-LOX inhibition also may independently reduce HT in warfarin-treated mice. ML351 should be further evaluated as stroke treatment in anticoagulated patients suffering a stroke, either alone or in conjunction with tissue-type plasminogen activator. © 2017 American Heart Association, Inc.

Fragmentation cross sections of medium-energy {sup 35}Cl, {sup 40}Ar, and {sup 48}Ti beams on elemental targets

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

Zeitlin, C.; Guetersloh, S.; Heilbronn, L.

Charge-changing and fragment production cross sections at 0 deg. have been obtained for interactions of 290, 400, and 650 MeV/nucleon {sup 40}Ar beams, 650 and 1000 MeV/nucleon {sup 35}Cl beams, and a 1000 MeV/nucleon {sup 48}Ti beam. Targets of C, CH{sub 2}, Al, Cu, Sn, and Pb were used. Using standard analysis methods, we obtained fragment cross sections for charges as low as 8 for Cl and Ar beams and as low as 10 for the Ti beam. Using data obtained with small-acceptance detectors, we report fragment production cross sections for charges as low as 5, corrected for acceptance usingmore » a simple model of fragment angular distributions. With the lower-charged fragment cross sections, we can compare the data to predictions from several models (including NUCFRG2, EPAX2, and PHITS) in a region largely unexplored in earlier work. As found in earlier work with other beams, NUCFRG2 and PHITS predictions agree reasonably well with the data for charge-changing cross sections, but these models do not accurately predict the fragment production cross sections. The cross sections for the lightest fragments demonstrate the inadequacy of several models in which the cross sections fall monotonically with the charge of the fragment. PHITS, despite its not agreeing particularly well with the fragment production cross sections on average, nonetheless qualitatively reproduces some significant features of the data that are missing from the other models.« less

Influence of strut cross-section of stents on local hemodynamics in stented arteries

NASA Astrophysics Data System (ADS)

Jiang, Yongfei; Zhang, Jun; Zhao, Wanhua

2016-05-01

Stenting is a very effective treatment for stenotic vascular diseases, but vascular geometries altered by stent implantation may lead to flow disturbances which play an important role in the initiation and progression of restenosis, especially in the near wall in stented arterial regions. So stent designs have become one of the indispensable factors needed to be considered for reducing the flow disturbances. In this paper, the structural designs of strut cross-section are considered as an aspect of stent designs to be studied in details. Six virtual stents with different strut cross-section are designed for deployments in the same ideal arterial model. Computational fluid dynamics (CFD) methods are performed to study how the shape and the aspect ratio (AR) of strut cross-section modified the local hemodynamics in the stented segments. The results indicate that stents with different strut cross-sections have different influence on the hemodynamics. Stents with streamlined cross-sectional struts for circular arc or elliptical arc can significantly enhance wall shear stress (WSS) in the stented segments, and reduce the flow disturbances around stent struts. The performances of stents with streamlined cross-sectional struts are better than that of stents with non-streamlined cross-sectional struts for rectangle. The results also show that stents with a larger AR cross-section are more conductive to improve the blood flow. The present study provides an understanding of the flow physics in the vicinity of stent struts and indicates that the shape and AR of strut cross-section ought to be considered as important factors to minimize flow disturbance in stent designs.

The Production of FRW Universe and Decay to Particles in Multiverse

NASA Astrophysics Data System (ADS)

Ghaffary, Tooraj

2017-09-01

In this study, first, it will be shown that as the Hubble parameter, " H", increases the production cross section for closed and flat Universes increases rapidly at smaller values of " H" and becomes constant for higher values of " H". However in the case of open Universe, the production cross section has been encountered a singularity. Before this singularity, as the H parameter increases, the cross section increases, for smaller H, ( H < 2.5), exhibits a turn-over at moderate values of H, (2.5 < H < 3.5), decreases for larger amount of H After that and for a special value of H, the cross section has been encountered with a singularity. Although the cross section cannot be defined at this singularity but before and after this point, it is certainly equal to zero. After this singularity, the cross section increases rapidly, when H increases. It is shown that if the production cross section of Universe happens before this singularity, it can't achieve to higher values of Hubble parameter after singularity. More over if the production cross section of Universe situates after the singularity, it won't get access to values of Hubble parameter less than the singularity. After that the thermal distribution for particles inside the FRW Universes are obtained. It is found that a large amount of particles are produced near apparent horizon due to their variety in their energy and their probabilities. Finally, comparing the particle production cross sections for flat, closed and open Universes, it is concluded that as the value of k increases, the cross section decreases.

Poster - 18: New features in EGSnrc for photon cross sections

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

Ali, Elsayed; Mainegra-Hing, Ernesto; Rogers, Davi

2016-08-15

Purpose: To implement two new features in the EGSnrc Monte Carlo system. The first is an option to account for photonuclear attenuation, which can contribute a few percent to the total cross section at the higher end of the energy range of interest to medical physics. The second is an option to use exact NIST XCOM photon cross sections. Methods: For the first feature, the photonuclear total cross sections are generated from the IAEA evaluated data. In the current, first-order implementation, after a photonuclear event, there is no energy deposition or secondary particle generation. The implementation is validated against deterministicmore » calculations and experimental measurements of transmission signals. For the second feature, before this work, if the user explicitly requested XCOM photon cross sections, EGSnrc still used its own internal incoherent scattering cross sections. These differ by up to 2% from XCOM data between 30 keV and 40 MeV. After this work, exact XCOM incoherent scattering cross sections are an available option. Minor interpolation artifacts in pair and triplet XCOM cross sections are also addressed. The default for photon cross section in EGSnrc is XCOM except for the new incoherent scattering cross sections, which have to be explicitly requested. The photonuclear, incoherent, pair and triplet data from this work are available for elements and compounds for photon energies from 1 keV to 100 GeV. Results: Both features are implemented and validated in EGSnrc.Conclusions: The two features are part of the standard EGSnrc distribution as of version 4.2.3.2.« less

Cross sections for H(-) and Cl(-) production from HCl by dissociative electron attachment

NASA Technical Reports Server (NTRS)

Orient, O. J.; Srivastava, S. K.

1985-01-01

A crossed target beam-electron beam collision geometry and a quadrupole mass spectrometer have been used to conduct dissociative electron attachment cross section measurements for the case of H(-) and Cl(-) production from HCl. The relative flow technique is used to determine the absolute values of cross sections. A tabulation is given of the attachment energies corresponding to various cross section maxima. Error sources contributing to total errors are also estimated.

Measurements of neutron capture cross sections on 70Zn at 0.96 and 1.69 MeV

NASA Astrophysics Data System (ADS)

Punte, L. R. M.; Lalremruata, B.; Otuka, N.; Suryanarayana, S. V.; Iwamoto, Y.; Pachuau, Rebecca; Satheesh, B.; Thanga, H. H.; Danu, L. S.; Desai, V. V.; Hlondo, L. R.; Kailas, S.; Ganesan, S.; Nayak, B. K.; Saxena, A.

2017-02-01

The cross sections of the 70Zn(n ,γ )Zn71m (T1 /2=3.96 ±0.05 -h ) reaction have been measured relative to the 197Au(n ,γ )198Au cross sections at 0.96 and 1.69 MeV using a 7Li(p ,n )7Be neutron source and activation technique. The cross section of this reaction has been measured for the first time in the MeV region. The new experimental cross sections have been compared with the theoretical prediction by talys-1.6 with various level-density models and γ -ray strength functions as well as the tendl-2015 library. The talys-1.6 calculation with the generalized superfluid level-density model and Kopecky-Uhl generalized Lorentzian γ -ray strength function predicted the new experimental cross sections at both incident energies. The 70Zn(n ,γ ) g+m 71Zn total capture cross sections have also been derived by applying the evaluated isomeric ratios in the tendl-2015 library to the measured partial capture cross sections. The spectrum averaged total capture cross sections derived in the present paper agree well with the jendl-4.0 library at 0.96 MeV, whereas it lies between the tendl-2015 and the jendl-4.0 libraries at 1.69 MeV.

Semi-empirical scaling for ion-atom single charge exchange cross sections in the intermediate velocity regime

NASA Astrophysics Data System (ADS)

Friedman, B.; DuCharme, G.

2017-06-01

We present a semi-empirical scaling law for non-resonant ion-atom single charge exchange cross sections for collisions with velocities from {10}7 {{t}}{{o}} {10}9 {cm} {{{s}}}-1 and ions with positive charge q< 8. Non-resonant cross sections tend to have a velocity peak at collision velocities v≲ 1 {{a}}{{u}} with exponential decay around this peak. We construct a scaling formula for the location of this peak then choose a functional form for the cross section curve and scale it. The velocity at which the cross section peaks, v m, is proportional to the energy defect of the collision, {{Δ }}E, which we predict with the decay approximation. The value of the cross section maximum is proportional to the charge state q, inversely proportional to the target ionization energy I T, and inversely proportional to v m. For the shape of the cross section curve, we use a function that decays exponentially asymptotically at high and low velocities. We scale this function with parameters {v}{{m}},{I}{{T}},{Z}{{T}},{and} {Z}{{P}}, where the {Z}{{T},{{P}}} are the target and projectile atomic numbers. For the more than 100 cross section curves that we use to find the scaling rules, the scaling law predicts cross sections within a little over a factor of 2 on average.

Sonographic evaluation of the greater occipital nerve in unilateral occipital neuralgia.

PubMed

Cho, John Chin-Suk; Haun, Daniel W; Kettner, Norman W

2012-01-01

Occipital neuralgia is a headache that may result from greater occipital nerve entrapment. Entrapped peripheral nerves typically have an increase in cross-sectional area. The purpose of this study was to measure the cross-sectional area and circumference of symptomatic and asymptomatic greater occipital nerves in patients with unilateral occipital neuralgia and to correlate the greater occipital nerve cross-sectional area with headache severity, sex, and body mass index. Both symptomatic and contralateral asymptomatic greater occipital nerve cross-sectional areas and circumferences were measured by a single examiner using sonography in 17 patients. The Wilcoxon signed rank test and Spearman rank order correlation coefficient were used to analyze the data. Significant differences between the cross-sectional areas and circumferences of the symptomatic and asymptomatic greater occipital nerves were noted (P < .001). No difference existed in cross-sectional area (P = .40) or circumference (P = .10) measurements of the nerves between male and female patients. A significant correlation existed between the body mass index and symptomatic (r = 0.424; P = .045) and asymptomatic (r = 0.443; P = .037) cross-sectional areas. There was no correlation shown between the cross-sectional area of the symptomatic nerve and the severity of Headache Impact Test 6 scores (r = -0.342; P = .179). We report sonographic evidence showing an increased cross-sectional area and circumference of the symptomatic greater occipital nerve in patients with unilateral occipital neuralgia.

Annular-Cross-Section CFE Chamber

NASA Technical Reports Server (NTRS)

Sharnez, Rizwan; Sammons, David W.

1994-01-01

Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

Semi-empirical and empirical L X-ray production cross sections for elements with 50 ⩽ Z ⩽ 92 for protons of 0.5 3.0 MeV

NASA Astrophysics Data System (ADS)

Nekab, M.; Kahoul, A.

2006-04-01

We present in this contribution, semi-empirical production cross sections of the main X-ray lines Lα, Lβ and Lγ for elements from Sn to U and for protons with energies varying from 0.5 to 3.0 MeV. The theoretical X-ray production cross sections are firstly calculated from the theoretical ionization cross sections of the L i ( i = 1, 2, 3) subshell within the ECPSSR theory. The semi-empirical Lα, Lβ and Lγ cross sections are then deduced by fitting the available experimental data normalized to their corresponding theoretical values and give the better representation of the experimental data in some cases. On the other hand, the experimental data are directly fitted to deduce the empirical L X-ray production cross sections. A comparison is made between the semi-empirical cross sections, the empirical cross sections reported in this work and the empirical ones reported by Reis and Jesus [M.A. Reis, A.P. Jesus, Atom. Data Nucl. Data Tables 63 (1996) 1] and those of Strivay and Weber [Strivay, G. Weber, Nucl. Instr. and Meth. B 190 (2002) 112].

Measurement of electron impact collisional excitation cross sections of Ni to Ge-like gold

DOE PAGES

May, M. J.; Beiersdorfer, P.; Jordan, N.; ...

2017-03-01

We have measured the collisional excitation cross sections for the 3d→4f and 3d→5f excitations in Au ions near the Ni-like charge state by using beam plasmas created in the Livermore electron beam ion trap EBIT-I. The cross sections have been experimentally determined at approximately 1, 2 and 3 keV above the threshold energy, ET, for the 3d→4f excitations (ET ~2.5 keV) and at approximately 0.1, 1 and 2 keV above the threshold energy for the 3d→5f excitations (ET ~3.3 keV). The cross section measurements were made possible by using the GSFC x-ray microcalorimeter at the Livermore EBIT facility. The absolutemore » cross sections are determined from the ratio of the intensity of the collisionally excited bound-bound transitions to the intensity of the radiative recombination lines produced in EBIT-I plasmas. The effects of polarization and Auger decay channels are accounted for in the cross section determination. Measured cross sections are compared with those from HULLAC, DWS and FAC calculations. Finally, the measurements demonstrate that some errors exist in the calculated excitation cross sections.« less

Measurement of electron impact collisional excitation cross sections of Ni to Ge-like gold

NASA Astrophysics Data System (ADS)

May, M. J.; Beiersdorfer, P.; Jordan, N.; Scofield, J. H.; Reed, K. J.; Brown, G. V.; Hansen, S. B.; Porter, F. S.; Kelley, R.; Kilbourne, C. A.; Boyce, K. R.

2017-03-01

We have measured the collisional excitation cross sections for the 3d→4f and 3d→5f excitations in Au ions near the Ni-like charge state by using beam plasmas created in the Livermore electron beam ion trap EBIT-I. The cross sections have been experimentally determined at approximately 1, 2 and 3 keV above the threshold energy, ET, for the 3d→4f excitations (ET ˜ 2.5 keV) and at approximately 0.1, 1 and 2 keV above the threshold energy for the 3d→5f excitations (ET ˜ 3.3 keV). The cross section measurements were made possible by using the GSFC x-ray microcalorimeter at the Livermore EBIT facility. The absolute cross sections are determined from the ratio of the intensity of the collisionally excited bound-bound transitions to the intensity of the radiative recombination lines produced in EBIT-I plasmas. The effects of polarization and Auger decay channels are accounted for in the cross section determination. Measured cross sections are compared with those from HULLAC, DWS and FAC calculations. The measurements demonstrate that some errors exist in the calculated excitation cross sections.

Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

NASA Astrophysics Data System (ADS)

Pritychenko, B.; Mughabghab, S. F.

2012-12-01

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

A method for calculating proton-nucleus elastic cross-sections

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

2002-01-01

Recently [Nucl. Instr. and Meth. B 145 (1998) 277; Extraction of in-medium nucleon-nucleon amplitude from experiment, NASA-TP, 1998], we developed a method of extracting nucleon-nucleon (N-N) cross-sections in the medium directly from experiment. The in-medium N-N cross-sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the NASA Langley Research Center. We investigated [Proton-nucleus total cross-sections in coupled-channel approach, NASA/TP, 2000; Nucl. Instr. and Meth. B 173-174 (2001) 391] the ratio of real to imaginary part of the two body scattering amplitude in the medium. These ratios are used in combination with the in-medium N-N cross-sections to calculate proton-nucleus elastic cross-sections. The agreement is excellent with the available experimental data. These cross-sections are needed for the radiation risk assessment of space missions. c2002 Elsevier Science B.V. All rights reserved.

Single step sequential polydimethylsiloxane wet etching to fabricate a microfluidic channel with various cross-sectional geometries

NASA Astrophysics Data System (ADS)

Wang, C.-K.; Liao, W.-H.; Wu, H.-M.; Lo, Y.-H.; Lin, T.-R.; Tung, Y.-C.

2017-11-01

Polydimethylsiloxane (PDMS) has become a widely used material to construct microfluidic devices for various biomedical and chemical applications due to its desirable material properties and manufacturability. PDMS microfluidic devices are usually fabricated using soft lithography replica molding methods with master molds made of photolithogrpahy patterned photoresist layers on silicon wafers. The fabricated microfluidic channels often have rectangular cross-sectional geometries with single or multiple heights. In this paper, we develop a single step sequential PDMS wet etching process that can be used to fabricate microfluidic channels with various cross-sectional geometries from single-layer PDMS microfluidic channels. The cross-sections of the fabricated channel can be non-rectangular, and varied along the flow direction. Furthermore, the fabricated cross-sectional geometries can be numerically simulated beforehand. In the experiments, we fabricate microfluidic channels with various cross-sectional geometries using the developed technique. In addition, we fabricate a microfluidic mixer with alternative mirrored cross-sectional geometries along the flow direction to demonstrate the practical usage of the developed technique.

The formation of excited atoms during charge exchange between hydrogen ions and alkali atoms. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Nieman, R. A.

1971-01-01

The charge exchange cross sections for protons and various alkali atoms are calculated using the classical approximation of Gryzinski. It is assumed that the hydrogen atoms resulting from charge exchange exist in all possible excited states. Charge transfer collisions between protons and potassium as well as protons and sodium atoms are studied. The energy range investigated is between 4 and 30 keV. The theoretical calculations of the capture cross section and the cross section for the creation of metastable 2S hydrogen are compared to experimental values. Good quantitative agreement is found for the capture cross section but only qualitative agreement for the metastable cross section. Analysis of the Lyman alpha window in molecular oxygen suggests that measured values of the metastable cross section may be in error. Thick alkali target data are also presented. This allows the determination of the total electron loss cross section. Finally, some work was done with H2(+).

Angular distributions for H- formation in single collisions of H+ on Mg

NASA Astrophysics Data System (ADS)

Alvarez, I.; Cisneros, C.; Russek, A.

1982-07-01

Absolute differential cross sections have been measured for H- formation in single collisions of H+ on Mg in the energy range from 0.5 to 5.0 keV. Total cross sections, obtained by direct integration of these differential cross sections, are in good agreement with earlier total-cross-section measurements of Morgan and Eriksen in the energy range common to the two experiments and are in good agreement with the calculated total cross sections of Olson and Liu. The differential cross sections are strongly peaked in the forward direction. The functional form and scaling properties of this forward peak strongly indicate that it is a glory maximum, which occurs when the classical deflection function changes over from attractive to repulsive at some finite impact parameter. The differential cross sections from 1.0 to 5.0 keV show no other structure, but below 1.0 keV a τ-dependent structure is observed which becomes more pronounced as the collision energy decreases. 1982 The American Physical Society.

Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

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

Younes, W; Britt, H C

In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated crossmore » sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.« less

Effect of reagent rotation on the integral cross-sections and isotopic branching of the reactions H - + HD and D - + HD

NASA Astrophysics Data System (ADS)

Zhang, Wei; Liu, Yufang; He, Xiaohu

2010-04-01

A quasi-classical trajectory (QCT) method has been used to calculate integral reaction cross-section for H - + HD and D - + HD. The influence of rotation of the reagent on the integral reaction cross-section and the product branching ratios of the title reactions are discussed. The results indicate that the reactive cross-section of H(D) - + HD → HH(D) + D - decreases with an increase of the j for E tran ⩽ 1.5 eV. The results also show that the reactive cross-section of D(H) - + HD → DD(H) + H - decreases with an increase of the j for E tran ⩽ 1.0 eV and that the integral cross-sections of title reactions are sensitive to the reagent rotation.

Evaluation of cross sections for neutron-induced reactions in sodium. [10/sup -5/ eV to 20 MeV

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

Larson, D.C.

1980-09-01

An evaluation of the neutron-induced cross sections of /sup 23/Na has been done for the energy range from 10/sup -5/ eV to 20 MeV. All significant cross sections are given, including differential cross sections for production of gamma rays. The recommended values are based on experimental data where available, and use results of a consistent model code analysis of available data to predict cross sections where there are no experimental data. This report describes the evaluation that was submitted to the Cross Section Evaluation Working Group (CSEWG) for consideration as a part of the Evaluated Nuclear Data File, Version V,more » and subsequently issued as MAT 1311. 126 references, 130 figures, 14 tables.« less

Three-dimensional object surface identification

NASA Astrophysics Data System (ADS)

Celenk, Mehmet

1995-03-01

This paper describes a computationally efficient matching method for inspecting 3D objects using their serial cross sections. Object regions of interest in cross-sectional binary images of successive slices are aligned with those of the models. Cross-sectional differences between the object and the models are measured in the direction of the gradient of the cross section boundary. This is repeated in all the cross-sectional images. The model with minimum average cross-sectional difference is selected as the best match to the given object (i.e., no defect). The method is tested using various computer generated surfaces and matching results are presented. It is also demonstrated using Symult S-2010 16-node system that the method is suitable for parallel implementation in massage passing processors with the maximum attainable speedup (close to 16 for S-2010).

Polynomial coefficients for calculating O2 Schumann-Runge cross sections at 0.5/cm resolution

NASA Technical Reports Server (NTRS)

Minschwaner, K.; Anderson, G. P.; Hall, L. A.; Yoshino, K.

1992-01-01

O2 cross sections from 49,000 to 57,000/cm have been fitted with temperature dependent polynomial expressions, providing an accurate and efficient means of determining Schumann-Runge band cross sections for temperatures between 130 and 500 K. The least squares fits were carried out on a 0.5/cm spectral grid, using cross sections obtained from a Schumann-Runge line-by-line model that incorporates the most recent spectroscopic data. The O2 cross sections do not include the underlying Herzberg continuum, but they do contain contributions from the temperature dependent Schumann-Runge continuum. The cross sections are suitable for use in UV transmission calculations at high spectral resolution. They should also prove useful for updating existing parameterizations of ultraviolet transmission and O2 photolysis.

An Equivalent cross-section Framework for improving computational efficiency in Distributed Hydrologic Modelling

NASA Astrophysics Data System (ADS)

Khan, Urooj; Tuteja, Narendra; Ajami, Hoori; Sharma, Ashish

2014-05-01

While the potential uses and benefits of distributed catchment simulation models is undeniable, their practical usage is often hindered by the computational resources they demand. To reduce the computational time/effort in distributed hydrological modelling, a new approach of modelling over an equivalent cross-section is investigated where topographical and physiographic properties of first-order sub-basins are aggregated to constitute modelling elements. To formulate an equivalent cross-section, a homogenization test is conducted to assess the loss in accuracy when averaging topographic and physiographic variables, i.e. length, slope, soil depth and soil type. The homogenization test indicates that the accuracy lost in weighting the soil type is greatest, therefore it needs to be weighted in a systematic manner to formulate equivalent cross-sections. If the soil type remains the same within the sub-basin, a single equivalent cross-section is formulated for the entire sub-basin. If the soil type follows a specific pattern, i.e. different soil types near the centre of the river, middle of hillslope and ridge line, three equivalent cross-sections (left bank, right bank and head water) are required. If the soil types are complex and do not follow any specific pattern, multiple equivalent cross-sections are required based on the number of soil types. The equivalent cross-sections are formulated for a series of first order sub-basins by implementing different weighting methods of topographic and physiographic variables of landforms within the entire or part of a hillslope. The formulated equivalent cross-sections are then simulated using a 2-dimensional, Richards' equation based distributed hydrological model. The simulated fluxes are multiplied by the weighted area of each equivalent cross-section to calculate the total fluxes from the sub-basins. The simulated fluxes include horizontal flow, transpiration, soil evaporation, deep drainage and soil moisture. To assess the accuracy of equivalent cross-section approach, the sub-basins are also divided into equally spaced multiple hillslope cross-sections. These cross-sections are simulated in a fully distributed settings using the 2-dimensional, Richards' equation based distributed hydrological model. The simulated fluxes are multiplied by the contributing area of each cross-section to get total fluxes from each sub-basin referred as reference fluxes. The equivalent cross-section approach is investigated for seven first order sub-basins of the McLaughlin catchment of the Snowy River, NSW, Australia, and evaluated in Wagga-Wagga experimental catchment. Our results show that the simulated fluxes using an equivalent cross-section approach are very close to the reference fluxes whereas computational time is reduced of the order of ~4 to ~22 times in comparison to the fully distributed settings. The transpiration and soil evaporation are the dominant fluxes and constitute ~85% of actual rainfall. Overall, the accuracy achieved in dominant fluxes is higher than the other fluxes. The simulated soil moistures from equivalent cross-section approach are compared with the in-situ soil moisture observations in the Wagga-Wagga experimental catchment in NSW, and results found to be consistent. Our results illustrate that the equivalent cross-section approach reduces the computational time significantly while maintaining the same order of accuracy in predicting the hydrological fluxes. As a result, this approach provides a great potential for implementation of distributed hydrological models at regional scales.

Assessment of experimental d-PIGE γ-ray production cross sections for 12C, 14N and 16O and comparison with absolute thick target yields

NASA Astrophysics Data System (ADS)

Csedreki, L.; Halász, Z.; Kiss, Á. Z.

2016-08-01

Measured differential cross sections for deuteron induced γ-ray emission from the reactions 12C(d,pγ)13C, (Eγ = 3089 keV), 14N(d,pγ)15N (Eγ = 8310 keV) and 16O(d,pγ)17O (Eγ = 871 keV) available in the literature were assessed. In order to cross check the assessed γ-ray production cross section data, thick target γ-yields calculated from the differential cross sections were compared with available measured thick target yields. Recommended differential cross section data for each reaction were deduced for particle induced γ-ray emission (PIGE) applications.

Population of positive-parity states in {sup 53}Sc through one-proton knockout.

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

McDaniel, S.; Gade, A.; Janssens, R. V. F.

2010-02-01

The one-proton knockout reaction {sup 9}Be({sup 54}Ti,{sup 53}Sc+{gamma})X at 72 MeV/nucleon has been measured. The location of the first 3/2{sup -} state at 2110(3) keV was confirmed, and new {gamma}-ray transitions were observed at 1111(2), 1273(2), 1539(4), and 2495(5) keV. Large spectroscopic strength to excited states in {sup 53}Sc was found and attributed to the knockout of sd-shell protons.

Population of positive-parity states in {sup 53}Sc through one-proton knockout

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

McDaniel, S.; Gade, A.; Brown, B. A.

2010-02-15

The one-proton knockout reaction {sup 9}Be({sup 54}Ti,{sup 53}Sc+{gamma})X at 72 MeV/nucleon has been measured. The location of the first 3/2{sup -} state at 2110(3) keV was confirmed, and new {gamma}-ray transitions were observed at 1111(2), 1273(2), 1539(4), and 2495(5) keV. Large spectroscopic strength to excited states in {sup 53}Sc was found and attributed to the knockout of sd-shell protons.

Electron-impact excitation cross sections for the b /sup 3/. sigma. /sub u//sup +/ state of H/sub 2/

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

Khakoo, M.A.; Trajmar, S.; McAdams, R.

1987-04-01

Differential and integral cross sections for electron-impact excitation of the b /sup 3/..sigma../sub u//sup +/ state of H/sub 2/ have been determined in the 20--100-eV impact energy region. The calibration of the cross sections was achieved through the H/sub 2/ elastic scattering cross sections, which in turn were normalized to absolute He elastic scattering cross sections. Comparison is made with available experimental data and with theoretical results applying Born-Ochkur-Rudge, distorted-wave, and close-coupling approximations.

New Tools to Prepare ACE Cross-section Files for MCNP Analytic Test Problems

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

Brown, Forrest B.

Monte Carlo calculations using one-group cross sections, multigroup cross sections, or simple continuous energy cross sections are often used to: (1) verify production codes against known analytical solutions, (2) verify new methods and algorithms that do not involve detailed collision physics, (3) compare Monte Carlo calculation methods with deterministic methods, and (4) teach fundamentals to students. In this work we describe 2 new tools for preparing the ACE cross-section files to be used by MCNP ® for these analytic test problems, simple_ace.pl and simple_ace_mg.pl.

Measurement of Charged and Neutral Current e-p Deep Inelastic Scattering Cross Sections at High Q2

NASA Astrophysics Data System (ADS)

Derrick, M.; Krakauer, D.; Magill, S.; Mikunas, D.; Musgrave, B.; Repond, J.; Stanek, R.; Talaga, R. L.; Zhang, H.; Ayad, R.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Bruni, P.; Cara Romeo, G.; Castellini, G.; Chiarini, M.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; Gialas, I.; Giusti, P.; Iacobucci, G.; Laurenti, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Nemoz, C.; Palmonari, F.; Polini, A.; Sartorelli, G.; Timellini, R.; Zamora Garcia, Y.; Zichichi, A.; Bargende, A.; Crittenden, J.; Desch, K.; Diekmann, B.; Doeker, T.; Eckert, M.; Feld, L.; Frey, A.; Geerts, M.; Geitz, G.; Grothe, M.; Haas, T.; Hartmann, H.; Haun, D.; Heinloth, K.; Hilger, E.; Jakob, H.-P.; Katz, U. F.; Mari, S. M.; Mass, A.; Mengel, S.; Mollen, J.; Paul, E.; Rembser, Ch.; Schattevoy, R.; Schramm, D.; Stamm, J.; Wedemeyer, R.; Campbell-Robson, S.; Cassidy, A.; Dyce, N.; Foster, B.; George, S.; Gilmore, R.; Heath, G. P.; Heath, H. F.; Llewellyn, T. J.; Morgado, C. J.; Norman, D. J.; O'Mara, J. A.; Tapper, R. J.; Wilson, S. S.; Yoshida, R.; Rau, R. R.; Arneodo, M.; Iannotti, L.; Schioppa, M.; Susinno, G.; Bernstein, A.; Caldwell, A.; Cartiglia, N.; Parsons, J. A.; Ritz, S.; Sciulli, F.; Straub, P. B.; Wai, L.; Yang, S.; Zhu, Q.; Borzemski, P.; Chwastowski, J.; Eskreys, A.; Piotrzkowski, K.; Zachara, M.; Zawiejski, L.; Adamczyk, L.; Bednarek, B.; Jeleń, K.; Kisielewska, D.; Kowalski, T.; Rulikowska-Zarȩbska, E.; Suszycki, L.; ZajaÇ, J.; Kotański, A.; Przybycień, M.; Bauerdick, L. A.; Behrens, U.; Beier, H.; Bienlein, J. K.; Coldewey, C.; Deppe, O.; Desler, K.; Drews, G.; Flasiński, M.; Gilkinson, D. J.; Glasman, C.; Göttlicher, P.; Grosse-Knetter, J.; Gutjahr, B.; Hain, W.; Hasell, D.; Hessling, H.; Hultschig, H.; Iga, Y.; Joos, P.; Kasemann, M.; Klanner, R.; Koch, W.; Köpke, L.; Kötz, U.; Kowalski, H.; Labs, J.; Ladage, A.; Löhr, B.; Löwe, M.; Lüke, D.; Mańczak, O.; Ng, J. S.; Nickel, S.; Notz, D.; Ohrenberg, K.; Roco, M.; Rohde, M.; Roldán, J.; Schneekloth, U.; Schulz, W.; Selonke, F.; Stiliaris, E.; Surrow, B.; Voss, T.; Westphal, D.; Wolf, G.; Youngman, C.; Zhou, J. F.; Grabosch, H. J.; Kharchilava, A.; Leich, A.; Mattingly, M.; Meyer, A.; Schlenstedt, S.; Wulff, N.; Barbagli, G.; Pelfer, P.; Anzivino, G.; Maccarrone, G.; de Pasquale, S.; Votano, L.; Bamberger, A.; Eisenhardt, S.; Freidhof, A.; Söldner-Rembold, S.; Schroeder, J.; Trefzger, T.; Brook, N. H.; Bussey, P. J.; Doyle, A. T.; Fleck, J. I.; Saxon, D. H.; Utley, M. L.; Wilson, A. S.; Dannemann, A.; Holm, U.; Horstmann, D.; Neumann, T.; Sinkus, R.; Wick, K.; Badura, E.; Burow, B. D.; Hagge, L.; Lohrmann, E.; Mainusch, J.; Milewski, J.; Nakahata, M.; Pavel, N.; Poelz, G.; Schott, W.; Zetsche, F.; Bacon, T. C.; Butterworth, I.; Gallo, E.; Harris, V. L.; Hung, B. Y.; Long, K. R.; Miller, D. B.; Morawitz, P. P.; Prinias, A.; Sedgbeer, J. K.; Whitfield, A. F.; Mallik, U.; McCliment, E.; Wang, M. Z.; Wang, S. M.; Wu, J. T.; Zhang, Y.; Cloth, P.; Filges, D.; An, S. H.; Hong, S. M.; Nam, S. W.; Park, S. K.; Suh, M. H.; Yon, S. H.; Imlay, R.; Kartik, S.; Kim, H.-J.; McNeil, R. R.; Metcalf, W.; Nadendla, V. K.; Barreiro, F.; Cases, G.; Graciani, R.; Hernández, J. M.; Hervás, L.; Labarga, L.; del Peso, J.; Puga, J.; Terron, J.; de Trocóniz, J. F.; Smith, G. R.; Corriveau, F.; Hanna, D. S.; Hartmann, J.; Hung, L. W.; Lim, J. N.; Matthews, C. G.; Patel, P. M.; Sinclair, L. E.; Stairs, D. G.; St. Laurent, M.; Ullmann, R.; Zacek, G.; Bashkirov, V.; Dolgoshein, B. A.; Stifutkin, A.; Bashindzhagyan, G. L.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Y. A.; Kobrin, V. D.; Kuzmin, V. A.; Proskuryakov, A. S.; Savin, A. A.; Shcheglova, L. M.; Solomin, A. N.; Zotov, N. P.; Botje, M.; Chlebana, F.; Dake, A.; Engelen, J.; de Kamps, M.; Kooijman, P.; Kruse, A.; Tiecke, H.; Verkerke, W.; Vreeswijk, M.; Wiggers, L.; de Wolf, E.; van Woudenberg, R.; Acosta, D.; Bylsma, B.; Durkin, L. S.; Honscheid, K.; Li, C.; Ling, T. Y.; McLean, K. W.; Murray, W. N.; Park, I. H.; Romanowski, T. A.; Seidlein, R.; Bailey, D. S.; Blair, G. A.; Byrne, A.; Cashmore, R. J.; Cooper-Sarkar, A. M.; Daniels, D.; Devenish, R. C.; Harnew, N.; Lancaster, M.; Luffman, P. E.; Lindemann, L.; McFall, J. D.; Nath, C.; Noyes, V. A.; Quadt, A.; Uijterwaal, H.; Walczak, R.; Wilson, F. F.; Yip, T.; Abbiendi, G.; Bertolin, A.; Brugnera, R.; Carlin, R.; dal Corso, F.; de Giorgi, M.; Dosselli, U.; Limentani, S.; Morandin, M.; Posocco, M.; Stanco, L.; Stroili, R.; Voci, C.; Bulmahn, J.; Butterworth, J. M.; Feild, R. G.; Oh, B. Y.; Whitmore, J. J.; D'Agostini, G.; Marini, G.; Nigro, A.; Tassi, E.; Hart, J. C.; McCubbin, N. A.; Prytz, K.; Shah, T. P.; Short, T. L.; Barberis, E.; Dubbs, T.; Heusch, C.; van Hook, M.; Hubbard, B.; Lockman, W.; Rahn, J. T.; Sadrozinski, H. F.-W.; Seiden, A.; Biltzinger, J.; Schwarzer, O.; Seifert, R. J.; Walenta, A. H.; Zech, G.; Abramowicz, H.; Briskin, G.; Dagan, S.; Levy, A.; Hasegawa, T.; Hazumi, M.; Ishii, T.; Kuze, M.; Mine, S.; Nagasawa, Y.; Nakao, M.; Suzuki, I.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Chiba, M.; Hamatsu, R.; Hirose, T.; Homma, K.; Kitamura, S.; Nakamitsu, Y.; Yamauchi, K.; Cirio, R.; Costa, M.; Ferrero, M. I.; Lamberti, L.; Maselli, S.; Peroni, C.; Sacchi, R.; Solano, A.; Staiano, A.; Dardo, M.; Bailey, D. C.; Bandyopadhyay, D.; Benard, F.; Brkic, M.; Crombie, M. B.; Gingrich, D. M.; Hartner, G. F.; Joo, K. K.; Levman, G. M.; Martin, J. F.; Orr, R. S.; Sampson, C. R.; Teuscher, R. J.; Catterall, C. D.; Jones, T. W.; Kaziewicz, P. B.; Lane, J. B.; Saunders, R. L.; Shulman, J.; Blankenship, K.; Kochocki, J.; Lu, B.; Mo, L. W.; Bogusz, W.; Charchuła, K.; Ciborowski, J.; Gajewski, J.; Grzelak, G.; Kasprzak, M.; Krzyżanowski, M.; Muchorowski, K.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Wróblewski, A. K.; Zakrzewski, J. A.; Żarnecki, A. F.; Adamus, M.; Eisenberg, Y.; Karshon, U.; Revel, D.; Zer-Zion, D.; Ali, I.; Badgett, W. F.; Behrens, B.; Dasu, S.; Fordham, C.; Foudas, C.; Goussiou, A.; Loveless, R. J.; Reeder, D. D.; Silverstein, S.; Smith, W. H.; Vaiciulis, A.; Wodarczyk, M.; Tsurugai, T.; Bhadra, S.; Cardy, M. L.; Fagerstroem, C.-P.; Frisken, W. R.; Furutani, K. M.; Khakzad, M.; Schmidke, W. B.

1995-08-01

Deep inelastic e-p scattering has been studied in both the charged current (CC) and neutral current (NC) reactions at momentum transfers squared Q2 above 400 GeV2 using the ZEUS detector at the HERA ep collider. The CC and NC total cross sections, the NC to CC cross section ratio, and the differential cross sections dσ/dQ2 are presented. From the Q2 dependence of the CC cross section, the mass term in the CC propagator is determined to be MW = 76+/-16+/-13 GeV.

Effects of silicon cross section and neutron spectrum on the radial uniformity in neutron transmutation doping.

PubMed

Kim, Haksung; Ho Pyeon, Cheol; Lim, Jae-Yong; Misawa, Tsuyoshi

2012-01-01

The effects of silicon cross section and neutron spectrum on the radial uniformity of a Si-ingot are examined experimentally with various neutron spectrum conditions. For the cross section effect, the numerical results using silicon single crystal cross section reveal good agreements with experiments within relative difference of 6%, whereas the discrepancy is approximately 20% in free-gas cross section. For the neutron spectrum effect, the radial uniformity in hard neutron spectrum is found to be more flattening than that in soft spectrum. Copyright © 2011 Elsevier Ltd. All rights reserved.

Electron-Impact Total Ionization Cross Sections of CH and C2H2

PubMed Central

Kim, Yong-Ki; Ali, M. Asgar; Rudd, M. Eugene

1997-01-01

Electron-impact total ionization cross sections for the CH radical and C2H2 (acetylene) have been calculated using the Binary-Encounter-Bethe (BEB) model. The BEB model combines the Mott cross section and the asymptotic form of the Bethe theory, and has been shown to generate reliable ionization cross sections for a large variety of molecules. The BEB cross sections for CH and C2H2 are in good agreement with the available experimental data from ionization thresholds to hundreds of eV in incident energies. PMID:27805116

Total reaction cross sections and neutron-removal cross sections of neutron-rich light nuclei measured by the COMBAS fragment-separator

NASA Astrophysics Data System (ADS)

Hue, B. M.; Isataev, T.; Erdemchimeg, B.; Artukh, A. G.; Aznabaev, D.; Davaa, S.; Klygin, S. A.; Kononenko, G. A.; Khuukhenkhuu, G.; Kuterbekov, K.; Lukyanov, S. M.; Mikhailova, T. I.; Maslov, V. A.; Mendibaev, K.; Sereda, Yu M.; Penionzhkevich, Yu E.; Vorontsov, A. N.

2017-12-01

Preliminary results of measurements of the total reaction cross sections σR and neutron removal cross section σ-xn for weakly bound 6He, 8Li, 9Be and 10Be nuclei at energy range (20-35) A MeV with 28Si target is presented. The secondary beams of light nuclei were produced by bombardment of the 22Ne (35 A MeV) primary beam on Be target and separated by COMBAS fragment-separator. In dispersive focal plane a horizontal slit defined the momentum acceptance as 1% and a wedge degrader of 200 μm Al was installed. The Bρ of the second section of the fragment-separator was adjusted for measurements in energy range (20-35) A MeV. Two-neutron removal cross sections for 6He and 10Be and one -neutron removal cross sections 8Li and 9Be were measured.

Bodies with noncircular cross sections and bank-to-turn missiles

NASA Technical Reports Server (NTRS)

Jackson, C. M., Jr.; Sawyer, W. C.

1986-01-01

An evaluation is made of prospective missile applications for noncircular cross section bodies, and of recent developments in bank-to-turn missile configuration aerodynamics. The discussion encompasses cross-flow analysis techniques, as well as study results obtained for bodies with elliptical and square cross sections and with variable cross sections. Attention is given to both the performance advantages and the stability and control problems of bank-to-turn missile configurations; the aerodynamic data presented for monoplanar configurations extend to those incorporating airbreathing propulsion systems.

Zinc Finger Nuclease Mediated Knockout of ADP-Dependent Glucokinase in Cancer Cell Lines: Effects on Cell Survival and Mitochondrial Oxidative Metabolism

PubMed Central

Richter, Susan; Morrison, Shona; Connor, Tim; Su, Jiechuang; Print, Cristin G.; Ronimus, Ron S.; McGee, Sean L.; Wilson, William R.

2013-01-01

Zinc finger nucleases (ZFN) are powerful tools for editing genes in cells. Here we use ZFNs to interrogate the biological function of ADPGK, which encodes an ADP-dependent glucokinase (ADPGK), in human tumour cell lines. The hypothesis we tested is that ADPGK utilises ADP to phosphorylate glucose under conditions where ATP becomes limiting, such as hypoxia. We characterised two ZFN knockout clones in each of two lines (H460 and HCT116). All four clones had frameshift mutations in all alleles at the target site in exon 1 of ADPGK, and were ADPGK-null by immunoblotting. ADPGK knockout had little or no effect on cell proliferation, but compromised the ability of H460 cells to survive siRNA silencing of hexokinase-2 under oxic conditions, with clonogenic survival falling from 21±3% for the parental line to 6.4±0.8% (p = 0.002) and 4.3±0.8% (p = 0.001) for the two knockouts. A similar increased sensitivity to clonogenic cell killing was observed under anoxia. No such changes were found when ADPGK was knocked out in HCT116 cells, for which the parental line was less sensitive than H460 to anoxia and to hexokinase-2 silencing. While knockout of ADPGK in HCT116 cells caused few changes in global gene expression, knockout of ADPGK in H460 cells caused notable up-regulation of mRNAs encoding cell adhesion proteins. Surprisingly, we could discern no consistent effect on glycolysis as measured by glucose consumption or lactate formation under anoxia, or extracellular acidification rate (Seahorse XF analyser) under oxic conditions in a variety of media. However, oxygen consumption rates were generally lower in the ADPGK knockouts, in some cases markedly so. Collectively, the results demonstrate that ADPGK can contribute to tumour cell survival under conditions of high glycolytic dependence, but the phenotype resulting from knockout of ADPGK is cell line dependent and appears to be unrelated to priming of glycolysis in these lines. PMID:23799003

Genetic background can result in a marked or minimal effect of gene knockout (GPR55 and CB2 receptor) in experimental autoimmune encephalomyelitis models of multiple sclerosis.

PubMed

Sisay, Sofia; Pryce, Gareth; Jackson, Samuel J; Tanner, Carolyn; Ross, Ruth A; Michael, Gregory J; Selwood, David L; Giovannoni, Gavin; Baker, David

2013-01-01

Endocannabinoids and some phytocannabinoids bind to CB1 and CB2 cannabinoid receptors, transient receptor potential vanilloid one (TRPV1) receptor and the orphan G protein receptor fifty-five (GPR55). Studies using C57BL/10 and C57BL/6 (Cnr2 (tm1Zim)) CB2 cannabinoid receptor knockout mice have demonstrated an immune-augmenting effect in experimental autoimmune encephalomyelitis (EAE) models of multiple sclerosis. However, other EAE studies in Biozzi ABH mice often failed to show any treatment effect of either CB2 receptor agonism or antagonism on inhibition of T cell autoimmunity. The influence of genetic background on the induction of EAE in endocannabinoid system-related gene knockout mice was examined. It was found that C57BL/6.GPR55 knockout mice developed less severe disease, notably in female mice, following active induction with myelin oligodendrocyte glycoprotein 35-55 peptide. In contrast C57BL/6.CB2 (Cnr2 (Dgen)) receptor knockout mice developed augmented severity of disease consistent with the genetically and pharmacologically-distinct, Cnr2 (tm1Zim) mice. However, when the knockout gene was bred into the ABH mouse background and EAE induced with spinal cord autoantigens the immune-enhancing effect of CB2 receptor deletion was lost. Likewise CB1 receptor and transient receptor potential vanilloid one knockout mice on the ABH background demonstrated no alteration in immune-susceptibility, in terms of disease incidence and severity of EAE, in contrast to that reported in some C57BL/6 mouse studies. Furthermore the immune-modulating influence of GPR55 was marginal on the ABH mouse background. Whilst sedative doses of tetrahydrocannabinol could induce immunosuppression, this was associated with a CB1 receptor rather than a CB2 receptor-mediated effect. These data support the fact that non-psychoactive doses of medicinal cannabis have a marginal influence on the immune response in MS. Importantly, it adds a note of caution for the translational value of some transgenic/gene knockout and other studies on low-EAE susceptibility backgrounds with inconsistent disease course and susceptibility.

Genetic Background Can Result in a Marked or Minimal Effect of Gene Knockout (GPR55 and CB2 Receptor) in Experimental Autoimmune Encephalomyelitis Models of Multiple Sclerosis

PubMed Central

Jackson, Samuel J.; Tanner, Carolyn; Ross, Ruth A.; Michael, Gregory J.; Selwood, David L.; Giovannoni, Gavin; Baker, David

2013-01-01

Endocannabinoids and some phytocannabinoids bind to CB1 and CB2 cannabinoid receptors, transient receptor potential vanilloid one (TRPV1) receptor and the orphan G protein receptor fifty-five (GPR55). Studies using C57BL/10 and C57BL/6 (Cnr2 tm1Zim) CB2 cannabinoid receptor knockout mice have demonstrated an immune-augmenting effect in experimental autoimmune encephalomyelitis (EAE) models of multiple sclerosis. However, other EAE studies in Biozzi ABH mice often failed to show any treatment effect of either CB2 receptor agonism or antagonism on inhibition of T cell autoimmunity. The influence of genetic background on the induction of EAE in endocannabinoid system-related gene knockout mice was examined. It was found that C57BL/6.GPR55 knockout mice developed less severe disease, notably in female mice, following active induction with myelin oligodendrocyte glycoprotein 35-55 peptide. In contrast C57BL/6.CB2 (Cnr2 Dgen) receptor knockout mice developed augmented severity of disease consistent with the genetically and pharmacologically-distinct, Cnr2 tm1Zim mice. However, when the knockout gene was bred into the ABH mouse background and EAE induced with spinal cord autoantigens the immune-enhancing effect of CB2 receptor deletion was lost. Likewise CB1 receptor and transient receptor potential vanilloid one knockout mice on the ABH background demonstrated no alteration in immune-susceptibility, in terms of disease incidence and severity of EAE, in contrast to that reported in some C57BL/6 mouse studies. Furthermore the immune-modulating influence of GPR55 was marginal on the ABH mouse background. Whilst sedative doses of tetrahydrocannabinol could induce immunosuppression, this was associated with a CB1 receptor rather than a CB2 receptor-mediated effect. These data support the fact that non-psychoactive doses of medicinal cannabis have a marginal influence on the immune response in MS. Importantly, it adds a note of caution for the translational value of some transgenic/gene knockout and other studies on low-EAE susceptibility backgrounds with inconsistent disease course and susceptibility. PMID:24130809

Cross sections for the dissociative attachment of electrons to NO

NASA Technical Reports Server (NTRS)

Krishnakumar, E.; Srivastava, S. K.

1988-01-01

Cross sections for the production of O(-) by electron attachment to NO are reported. It is found that the maximum value of the cross section is about 52 percent higher than the measurement of Rapp and Briglia (1965). Cross sections for the process of polar dissociation, e + NO yields N(+) + O(_), have also been measured, and the threshold energy for this process has been obtained.

Hypothyroidism Compromises Hypothalamic Leptin Signaling in Mice

PubMed Central

Groba, Claudia; Mayerl, Steffen; van Mullem, Alies A.; Visser, Theo J.; Darras, Veerle M.; Habenicht, Andreas J.

2013-01-01

The impact of thyroid hormone (TH) on metabolism and energy expenditure is well established, but the role of TH in regulating nutritional sensing, particularly in the central nervous system, is only poorly defined. Here, we studied the consequences of hypothyroidism on leptin production as well as leptin sensing in congenital hypothyroid TRH receptor 1 knockout (Trhr1 ko) mice and euthyroid control animals. Hypothyroid mice exhibited decreased circulating leptin levels due to a decrease in fat mass and reduced leptin expression in white adipose tissue. In neurons of the hypothalamic arcuate nucleus, hypothyroid mice showed increased leptin receptor Ob-R expression and decreased suppressor of cytokine signaling 3 transcript levels. In order to monitor putative changes in central leptin sensing, we generated hypothyroid and leptin-deficient animals by crossing hypothyroid Trhr1 ko mice with the leptin-deficient ob/ob mice. Hypothyroid Trhr1/ob double knockout mice showed a blunted response to leptin treatment with respect to body weight and food intake and exhibited a decreased activation of phospho-signal transducer and activator of transcription 3 as well as a up-regulation of suppressor of cytokine signaling 3 upon leptin treatment, particularly in the arcuate nucleus. These data indicate alterations in the intracellular processing of the leptin signal under hypothyroid conditions and thereby unravel a novel mode of action by which TH affects energy metabolism. PMID:23518925

Ground beetle communities in a mountain river subjected to restoration: The Raba River, Polish Carpathians.

PubMed

Bednarska, Agnieszka J; Wyżga, Bartłomiej; Mikuś, Paweł; Kędzior, Renata

2018-01-01

Effects of passive restoration of mountain rivers on the organisms inhabiting exposed riverine sediments are considerably less understood than those concerning aquatic biota. Thus, the effects of a recovery of the Raba River after abandonment of maintenance of its channelization scheme on ground beetle (Coleoptera: Carabidae) communities were investigated by comparing 6 unmanaged cross-sections and 6 cross-sections from adjacent channelized reaches. In each cross-section, ground beetles were collected from 12 sampling sites in spring, summer, and autumn, and 8 habitat parameters characterizing the cross-sections and sampling sites were determined. Within a few years after abandonment of the Raba River channelization scheme, the width of this gravel-bed river increased up to three times and its multi-thread pattern became re-established. Consequently, unmanaged river cross-sections had significantly larger channel width and more low-flow channels and eroding cutbanks than channelized cross-sections. Moreover, sampling sites in the unmanaged cross-sections were typified by significantly steeper average surface slope and larger average distance from low-flow channels than the sites in channelized cross-sections. In total, 3992 individuals from 78 taxa were collected during the study. The ground beetle assemblages were significantly more abundant and richer in species in the unmanaged than in the channelized cross-sections but no significant differences in carabid diversity indices between the two cross-section types were recorded. Redundancy Analysis indicated active river zone width as the only variable explaining differences in abundance and species richness among the cross-sections. Multiple regression analysis indicated species diversity to predominantly depend on the degree of plant cover and substrate grain size. The study showed that increased availability of exposed sediments in the widened river reaches allowed ground beetles to increase their abundance and species richness within a few years after the onset of river restoration, but more time may be needed for development of more diverse carabid communities. Copyright © 2017 Elsevier B.V. All rights reserved.

Method Development for Binding Media Analysis in Painting Cross-Sections by Desorption Electrospray Ionization-Mass Spectrometry (DESI-MS).

PubMed

Watts, Kristen; Lagalante, Anthony

2018-06-06

Art conservation science is in need of a relatively nondestructive way of rapidly identifying the binding media within a painting cross-section and isolating binding media to specific layers within the cross-section. Knowledge of the stratigraphy of cross-sections can be helpful for removing possible unoriginal paint layers on the artistic work. Desorption electrospray ionization-mass spectrometry (DESI-MS) was used in ambient mode to study cross-sections from mock-up layered paint samples and samples from a 17th century baroque painting. The DESI spray was raster scanned perpendicular to the cross-section layers to maximize lateral resolution then analyzed with a triple quadrupole mass analyzer in linear ion trap mode. From these scans, isobaric mass maps were created to map the locations of masses indicative of particular binding media onto the cross-sections. Line paint-outs of pigments in different binding media showed specific and unique ions to distinguish between the modern acrylic media and the lipid containing binding media. This included: OP (EO) 9 surfactant in positive ESI for acrylic (m/z 621), and oleic (m/z 281), stearic (m/z 283), and azelaic (m/z 187) acids in negative ESI for oil and egg tempera. DESI-MS maps of mock-up cross-sections of layered pigmented binding media showed correlation between these ions and the layers with a spatial resolution of 100 μm. DESI-MS is effective in monitoring binding media within an intact painting cross-section via mass spectrometric methods. This includes distinguishing between lipid-containing and modern binding materials present in a known mockup cross section matrix as well as identifying lipid binding media in a 17th century baroque era painting. This article is protected by copyright. All rights reserved.

Production cross sections of cosmic antiprotons in the light of new data from the NA61 and LHCb experiments

NASA Astrophysics Data System (ADS)

Korsmeier, Michael; Donato, Fiorenza; Di Mauro, Mattia

2018-05-01

The cosmic-ray flux of antiprotons is measured with high precision by the space-borne particle spectrometers AMS-02. Its interpretation requires a correct description of the dominant production process for antiprotons in our Galaxy, namely, the interaction of cosmic-ray proton and helium with the interstellar medium. In light of new cross section measurements by the NA61 experiment of p +p →p ¯+X and the first ever measurement of p +He →p ¯+X by the LHCb experiment, we update the parametrization of proton-proton and proton-nucleon cross sections. We find that the LHCb p He data constrain a shape for the cross section at high energies and show for the first time how well the rescaling from the p p channel applies to a helium target. By using p p , p He and p C data we estimate the uncertainty on the Lorentz invariant cross section for p +He →p ¯+X . We use these new cross sections to compute the source term for all the production channels, considering also nuclei heavier than He both in cosmic rays and the interstellar medium. The uncertainties on the total source term are up to ±20 % and slightly increase below antiproton energies of 5 GeV. This uncertainty is dominated by the p +p →p ¯+X cross section, which translates into all channels since we derive them using the p p cross sections. The cross sections to calculate the source spectra from all relevant cosmic-ray isotopes are provided in Supplemental Material. We finally quantify the necessity of new data on antiproton production cross sections, and pin down the kinematic parameter space which should be covered by future data.

Electron impact ionization cross sections of beryllium-tungsten clusters*

NASA Astrophysics Data System (ADS)

Sukuba, Ivan; Kaiser, Alexander; Huber, Stefan E.; Urban, Jan; Probst, Michael

2016-01-01

We report calculated electron impact ionization cross sections (EICSs) of beryllium-tungsten clusters, BenW with n = 1,...,12, from the ionization threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The positions of the maxima of DM and BEB cross sections are mostly close to each other. The DM cross sections are more sensitive with respect to the cluster size. For the clusters smaller than Be4W they yield smaller cross sections than BEB and vice versa larger cross sections than BEB for clusters larger than Be6W. The maximum cross section values for the singlet-spin groundstate clusters range from 7.0 × 10-16 cm2 at 28 eV (BeW) to 54.2 × 10-16 cm2 at 43 eV (Be12W) for the DM cross sections and from 13.5 × 10-16 cm2 at 43 eV (BeW) to 38.9 × 10-16 cm2 at 43 eV (Be12W) for the BEB cross sections. Differences of the EICSs in different isomers and between singlet and triplet states are also explored. Both the DM and BEB cross sections could be fitted perfectly to a simple expression used in modeling and simulation codes in the framework of nuclear fusion research. Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2015-60583-7

Automatic arteriovenous crossing phenomenon detection on retinal fundus images

NASA Astrophysics Data System (ADS)

Hatanaka, Yuji; Muramatsu, Chisako; Hara, Takeshi; Fujita, Hiroshi

2011-03-01

Arteriolosclerosis is one cause of acquired blindness. Retinal fundus image examination is useful for early detection of arteriolosclerosis. In order to diagnose the presence of arteriolosclerosis, the physicians find the silver-wire arteries, the copper-wire arteries and arteriovenous crossing phenomenon on retinal fundus images. The focus of this study was to develop the automated detection method of the arteriovenous crossing phenomenon on the retinal images. The blood vessel regions were detected by using a double ring filter, and the crossing sections of artery and vein were detected by using a ring filter. The center of that ring was an interest point, and that point was determined as a crossing section when there were over four blood vessel segments on that ring. And two blood vessels gone through on the ring were classified into artery and vein by using the pixel values on red and blue component image. Finally, V2-to-V1 ratio was measured for recognition of abnormalities. V1 was the venous diameter far from the blood vessel crossing section, and V2 was the venous diameter near from the blood vessel crossing section. The crossing section with V2-to-V1 ratio over 0.8 was experimentally determined as abnormality. Twenty four images, including 27 abnormalities and 54 normal crossing sections, were used for preliminary evaluation of the proposed method. The proposed method was detected 73% of crossing sections when the 2.8 sections per image were mis-detected. And, 59% of abnormalities were detected by measurement of V1-to-V2 ratio when the 1.7 sections per image were mis-detected.

Curcumin Protects against Atherosclerosis in Apolipoprotein E-Knockout Mice by Inhibiting Toll-like Receptor 4 Expression.

PubMed

Zhang, Shanshan; Zou, Jun; Li, Peiyang; Zheng, Xiumei; Feng, Dan

2018-01-17

Toll-like receptor 4 (TLR4) has been reported to play a critical role in the pathogenesis of atherosclerosis, the current study aimed to investigate whether curcumin suppresses atherosclerosis development in ApoE-knockout (ApoE -/- ) mice by inhibiting TLR4 expression. ApoE -/- mice were fed a high-fat diet supplemented with or without curcumin (0.1% w/w) for 16 weeks. Curcumin supplementation significantly reduced TLR4 expression and macrophage infiltration in atherosclerotic plaques. Curcumin also reduced aortic interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) expression, nuclear factor-κB (NF-κB) activity, and plasma IL-1β, TNF-α, soluble VCAM-1 and ICAM-1 levels. In addition, aortic sinus sections revealed that curcumin treatment reduced the extent of atherosclerotic lesions and inhibited atherosclerosis development. In vitro, curcumin inhibited NF-κB activation in macrophages and reduced TLR4 expression induced by lipopolysaccharide. Our results indicate that curcumin protects against atherosclerosis at least partially by inhibiting TLR4 expression and its related inflammatory reaction.

Electron impact excitation of H2 - Rydberg band systems and the benchmark dissociative cross section for H Lyman-alpha

NASA Technical Reports Server (NTRS)

Shemansky, D. E.; Hall, D. T.; Ajello, J. M.

1985-01-01

The cross sections sigma R 1 (2p) for excitation of H Ly-alpha emission produced by electron impact on H2 is reexamined. A more accurate estimate for sigma R 1 (2p) is obtained based on Born approximation estimates of the H2 Rydberg system cross sections using measured relative excitation functions. The obtained value is (8.18 + or -1.2) x 10 to the -18th sq cm at 100 eV, a factor of 0.69 below the value universally applied to cross section measurements over the past decade. Cross sections for the H2 Rydberg systems fixed in magnitude by the Born approximation have also been obtained using experimentally determined excitation functions. Accurate analytic expressions for these cross sections allow the direct calculation of rate coefficients.

Creation of problem-dependent Doppler-broadened cross sections in the KENO Monte Carlo code

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

Hart, Shane W. D.; Celik, Cihangir; Maldonado, G. Ivan

2015-11-06

In this paper, we introduce a quick method for improving the accuracy of Monte Carlo simulations by generating one- and two-dimensional cross sections at a user-defined temperature before performing transport calculations. A finite difference method is used to Doppler-broaden cross sections to the desired temperature, and unit-base interpolation is done to generate the probability distributions for double differential two-dimensional thermal moderator cross sections at any arbitrarily user-defined temperature. The accuracy of these methods is tested using a variety of contrived problems. In addition, various benchmarks at elevated temperatures are modeled, and results are compared with benchmark results. Lastly, the problem-dependentmore » cross sections are observed to produce eigenvalue estimates that are closer to the benchmark results than those without the problem-dependent cross sections.« less

Measurement of neutrino-induced charged-current charged pion production cross sections on mineral oil at Eν˜1GeV

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Mauger, C.; McGary, V. T.; McGregor, G.; Metcalf, W.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Mousseau, J.; Nelson, R. H.; Nienaber, P.; Nowak, J. A.; Osmanov, B.; Ouedraogo, S.; Patterson, R. B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Schirato, R.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; van de Water, R.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.

2011-03-01

Using a high-statistics, high-purity sample of νμ-induced charged current, charged pion events in mineral oil (CH2), MiniBooNE reports a collection of interaction cross sections for this process. This includes measurements of the CCπ+ cross section as a function of neutrino energy, as well as flux-averaged single- and double-differential cross sections of the energy and direction of both the final-state muon and pion. In addition, each of the single-differential cross sections are extracted as a function of neutrino energy to decouple the shape of the MiniBooNE energy spectrum from the results. In many cases, these cross sections are the first time such quantities have been measured on a nuclear target and in the 1 GeV energy range.

Communication: Electron ionization of DNA bases.

PubMed

Rahman, M A; Krishnakumar, E

2016-04-28

No reliable experimental data exist for the partial and total electron ionization cross sections for DNA bases, which are very crucial for modeling radiation damage in genetic material of living cell. We have measured a complete set of absolute partial electron ionization cross sections up to 500 eV for DNA bases for the first time by using the relative flow technique. These partial cross sections are summed to obtain total ion cross sections for all the four bases and are compared with the existing theoretical calculations and the only set of measured absolute cross sections. Our measurements clearly resolve the existing discrepancy between the theoretical and experimental results, thereby providing for the first time reliable numbers for partial and total ion cross sections for these molecules. The results on fragmentation analysis of adenine supports the theory of its formation in space.

Photon scattering cross sections of H2 and He measured with synchrotron radiation

NASA Technical Reports Server (NTRS)

Ice, G. E.

1977-01-01

Total (elastic + inelastic) differential photon scattering cross sections have been measured for H2 gas and He, using an X-ray beam. Absolute measured cross sections agree with theory within the probable errors. Relative cross sections (normalized to theory at large S) agree to better than one percent with theoretical values calculated from wave functions that include the effect of electron-electron Coulomb correlation, but the data deviate significantly from theoretical independent-particle (e.g., Hartree-Fock) results. The ratios of measured absolute He cross sections to those of H2, at any given S, also agree to better than one percent with theoretical He-to-H2 cross-section ratios computed from correlated wave functions. It appears that photon scattering constitutes a very promising tool for probing electron correlation in light atoms and molecules.

Electron impact ionisation cross section for organoplatinum compounds

NASA Astrophysics Data System (ADS)

Mahato, Dibyendu; Naghma, Rahla; Alam, Mohammad Jane; Ahmad, Shabbir; Antony, Bobby

2016-11-01

This article reports electron impact ionisation cross sections for platinum-based drugs viz., cisplatin (H6N2Cl2Pt), carboplatin (C6H12N2O4Pt), oxaliplatin (C8H14N2O4Pt), nedaplatin (C2H8N2O3Pt) and satraplatin (C10H22ClN2O4Pt) complexes used in the cancer chemotherapy. The multi-scattering centre spherical complex optical potential formalism is used to obtain the inelastic cross section for these large molecules upon electron impact. The ionisation cross section is derived from the inelastic cross section employing complex scattering potential-ionisation contribution method. Comparison is made with previous results, where ever available and overall a reasonable agreement is observed. This is the first attempt to report total ionisation cross sections for nedaplatin and satraplatin complexes.

Effect of wave function on the proton induced L XRP cross sections for 62Sm and 74W

NASA Astrophysics Data System (ADS)

Shehla, Kaur, Rajnish; Kumar, Anil; Puri, Sanjiv

2015-08-01

The Lk(k= 1, α, β, γ) X-ray production cross sections have been calculated for 74W and 62Sm at different incident proton energies ranging 1-5 MeV using theoretical data sets of different physical parameters, namely, the Li(i=1-3) sub-shell X-ray emission rates based on the Dirac-Fork (DF) model, the fluorescence and Coster Kronig yields based on the Dirac- Hartree-Slater (DHS) model and two sets the proton ionization cross sections based on the DHS model and the ECPSSR in order to assess the influence of the wave function on the XRP cross sections. The calculated cross sections have been compared with the measured cross sections reported in the recent compilation to check the reliability of the calculated values.

Comparative analysis of characteristic electron energy loss spectra and inelastic scattering cross-section spectra of Fe

NASA Astrophysics Data System (ADS)

Parshin, A. S.; Igumenov, A. Yu.; Mikhlin, Yu. L.; Pchelyakov, O. P.; Zhigalov, V. S.

2016-05-01

The inelastic electron scattering cross section spectra of Fe have been calculated based on experimental spectra of characteristic reflection electron energy loss as dependences of the product of the inelastic mean free path by the differential inelastic electron scattering cross section on the electron energy loss. It has been shown that the inelastic electron scattering cross-section spectra have certain advantages over the electron energy loss spectra in the analysis of the interaction of electrons with substance. The peaks of energy loss in the spectra of characteristic electron energy loss and inelastic electron scattering cross sections have been determined from the integral and differential spectra. It has been shown that the energy of the bulk plasmon is practically independent of the energy of primary electrons in the characteristic electron energy loss spectra and monotonically increases with increasing energy of primary electrons in the inelastic electron scattering cross-section spectra. The variation in the maximum energy of the inelastic electron scattering cross-section spectra is caused by the redistribution of intensities over the peaks of losses due to various excitations. The inelastic electron scattering cross-section spectra have been analyzed using the decomposition of the spectra into peaks of the energy loss. This method has been used for the quantitative estimation of the contributions from different energy loss processes to the inelastic electron scattering cross-section spectra of Fe and for the determination of the nature of the energy loss peaks.

Peeling Off Neutron Skins from Neutron-Rich Nuclei: Constraints on the Symmetry Energy from Neutron-Removal Cross Sections

NASA Astrophysics Data System (ADS)

Aumann, T.; Bertulani, C. A.; Schindler, F.; Typel, S.

2017-12-01

An experimentally constrained equation of state of neutron-rich matter is fundamental for the physics of nuclei and the astrophysics of neutron stars, mergers, core-collapse supernova explosions, and the synthesis of heavy elements. To this end, we investigate the potential of constraining the density dependence of the symmetry energy close to saturation density through measurements of neutron-removal cross sections in high-energy nuclear collisions of 0.4 to 1 GeV /nucleon . We show that the sensitivity of the total neutron-removal cross section is high enough so that the required accuracy can be reached experimentally with the recent developments of new detection techniques. We quantify two crucial points to minimize the model dependence of the approach and to reach the required accuracy: the contribution to the cross section from inelastic scattering has to be measured separately in order to allow a direct comparison of experimental cross sections to theoretical cross sections based on density functional theory and eikonal theory. The accuracy of the reaction model should be investigated and quantified by the energy and target dependence of various nucleon-removal cross sections. Our calculations explore the dependence of neutron-removal cross sections on the neutron skin of medium-heavy neutron-rich nuclei, and we demonstrate that the slope parameter L of the symmetry energy could be constrained down to ±10 MeV by such a measurement, with a 2% accuracy of the measured and calculated cross sections.

Semi-empirical scaling for ion–atom single charge exchange cross sections in the intermediate velocity regime

DOE PAGES

Friedman, B.; DuCharme, G.

2017-05-11

We present a semi-empirical scaling law for non-resonant ion–atom single charge exchange cross sections for collisions with velocities frommore » $${10}^{7}\\,{\\rm{t}}{\\rm{o}}\\,{10}^{9}\\,\\mathrm{cm}\\,{{\\rm{s}}}^{-1}$$ and ions with positive charge $$q\\lt 8$$. Non-resonant cross sections tend to have a velocity peak at collision velocities $$v\\lesssim 1\\ {\\rm{a}}{\\rm{u}}$$ with exponential decay around this peak. We construct a scaling formula for the location of this peak then choose a functional form for the cross section curve and scale it. The velocity at which the cross section peaks, v m, is proportional to the energy defect of the collision, $${\\rm{\\Delta }}E$$, which we predict with the decay approximation. The value of the cross section maximum is proportional to the charge state q, inversely proportional to the target ionization energy I T, and inversely proportional to v m. For the shape of the cross section curve, we use a function that decays exponentially asymptotically at high and low velocities. We scale this function with parameters $${v}_{{\\rm{m}}},{I}_{{\\rm{T}}},{Z}_{{\\rm{T}}},\\mathrm{and}\\ {Z}_{{\\rm{P}}}$$, where the $${Z}_{{\\rm{T}},{\\rm{P}}}$$ are the target and projectile atomic numbers. In conclusion, for the more than 100 cross section curves that we use to find the scaling rules, the scaling law predicts cross sections within a little over a factor of 2 on average.« less

The phosphatase JKAP/DUSP22 inhibits T-cell receptor signalling and autoimmunity by inactivating Lck.

PubMed

Li, Ju-Pi; Yang, Chia-Yu; Chuang, Huai-Chia; Lan, Joung-Liang; Chen, Der-Yuan; Chen, Yi-Ming; Wang, Xiaohong; Chen, Alice J; Belmont, John W; Tan, Tse-Hua

2014-04-09

JNK pathway-associated phosphatase (JKAP, also known as DUSP22 or JSP-1) is a JNK activator. The in vivo role of JKAP in immune regulation remains unclear. Here we report that JKAP directly inactivates Lck by dephosphorylating tyrosine-394 residue during T-cell receptor (TCR) signalling. JKAP-knockout T cells display enhanced cell proliferation and cytokine production. JKAP-knockout mice show enhanced T-cell-mediated immune responses and are more susceptible to experimental autoimmune encephalomyelitis (EAE). In addition, the recipient mice that are adoptively transferred with JKAP-knockout T cells show exacerbated EAE symptoms. Aged JKAP-knockout mice spontaneously develop inflammation and autoimmunity. Thus, our results indicate that JKAP is an important phosphatase that inactivates Lck in the TCR signalling turn-off stage, leading to suppression of T-cell-mediated immunity and autoimmunity.

IL-6-Type Cytokine Signaling in Adipocytes Induces Intestinal GLP-1 Secretion.

PubMed

Wueest, Stephan; Laesser, Céline I; Böni-Schnetzler, Marianne; Item, Flurin; Lucchini, Fabrizio C; Borsigova, Marcela; Müller, Werner; Donath, Marc Y; Konrad, Daniel

2018-01-01

We recently showed that interleukin (IL)-6-type cytokine signaling in adipocytes induces free fatty acid release from visceral adipocytes, thereby promoting obesity-induced hepatic insulin resistance and steatosis. In addition, IL-6-type cytokines may increase the release of leptin from adipocytes and by those means induce glucagon-like peptide 1 (GLP-1) secretion. We thus hypothesized that IL-6-type cytokine signaling in adipocytes may regulate insulin secretion. To this end, mice with adipocyte-specific knockout of gp130, the signal transducer protein of IL-6, were fed a high-fat diet for 12 weeks. Compared with control littermates, knockout mice showed impaired glucose tolerance and circulating leptin, GLP-1, and insulin levels were reduced. In line, leptin release from isolated adipocytes was reduced, and intestinal proprotein convertase subtilisin/kexin type 1 ( Pcsk1 ) expression, the gene encoding PC1/3, which controls GLP-1 production, was decreased in knockout mice. Importantly, treatment with the GLP-1 receptor antagonist exendin 9-39 abolished the observed difference in glucose tolerance between control and knockout mice. Ex vivo, supernatant collected from isolated adipocytes of gp130 knockout mice blunted Pcsk1 expression and GLP-1 release from GLUTag cells. In contrast, glucose- and GLP-1-stimulated insulin secretion was not affected in islets of knockout mice. In conclusion, adipocyte-specific IL-6 signaling induces intestinal GLP-1 release to enhance insulin secretion, thereby counteracting insulin resistance in obesity. © 2017 by the American Diabetes Association.

Knockout mutations of insulin-like peptide genes enhance sexual receptivity in Drosophila virgin females.

PubMed

Watanabe, Kazuki; Sakai, Takaomi

2016-01-01

In the fruitfly Drosophila melanogaster, females take the initiative to mate successfully because they decide whether to mate or not. However, little is known about the molecular and neuronal mechanisms regulating sexual receptivity in virgin females. Genetic tools available in Drosophila are useful for identifying molecules and neural circuits involved in the regulation of sexual receptivity. We previously demonstrated that insulin-producing cells (IPCs) in the female brain are critical to the regulation of female sexual receptivity. Ablation and inactivation of IPCs enhance female sexual receptivity, suggesting that neurosecretion from IPCs inhibits female sexual receptivity. IPCs produce and release insulin-like peptides (Ilps) that modulate various biological processes such as metabolism, growth, lifespan and behaviors. Here, we report a novel role of the Ilps in sexual behavior in Drosophila virgin females. Compared with wild-type females, females with knockout mutations of Ilps showed a high mating success rate toward wild-type males, whereas wild-type males courted wild-type and Ilp-knockout females to the same extent. Wild-type receptive females retard their movement during male courtship and this reduced female mobility allows males to copulate. Thus, it was anticipated that knockout mutations of Ilps would reduce general locomotion. However, the locomotor activity in Ilp-knockout females was significantly higher than that in wild-type females. Thus, our findings indicate that the high mating success rate in Ilp-knockout females is caused by their enhanced sexual receptivity, but not by improvement of their sex appeal or by general sluggishness.

[Quantitative changes of main components of erythrocyte membranes which define architectonics of cells under pttg gene knockout].

PubMed

Kaniuka, O P; Filiak, Ie Z; Kulachkovs'kyĭ, O R; Osyp, Iu L; Sybirna, N O

2014-01-01

A pttg gene knockout affects the functional state of erythron in mice which could be associated with structural changes in the structure of erythrocyte membranes. The pttg gene knockout causes a significant modification of fatty acids composition of erythrocyte membrane lipids by reducing the content of palmitic acid and increasing of polyunsaturated fatty acids amount by 18%. Analyzing the erythrocyte surface architectonics of mice under pttg gene knockout, it was found that on the background of reduction of the functionally complete biconcave discs population one could observe an increase of the number of transformed cells at different degeneration stages. Researches have shown that in mice with a pttg gene knockout compared with a control group of animals cytoskeletal protein--beta-spectrin was reduced by 17.03%. However, there is a reduction of membrane protein band 3 by 33.04%, simultaneously the content of anion transport protein band 4.5 increases by 35.2% and protein band 4.2 by 32.1%. The lectin blot analysis has helped to reveal changes in the structure of the carbohydrate determinants of erythrocyte membrane glycoproteins under conditions of directed pttg gene inactivation, accompanied by changes in the type of communication, which joins the terminal residue in carbohydrate determinant of glycoproteins. Thus, a significant redistribution of protein and fatty acids contents in erythrocyte membranes that manifested in the increase of the deformed shape of red blood cells is observed underpttg gene knockout.

Single-step generation of gene knockout-rescue system in pluripotent stem cells by promoter insertion with CRISPR/Cas9.

PubMed

Matsunaga, Taichi; Yamashita, Jun K

2014-02-07

Specific gene knockout and rescue experiments are powerful tools in developmental and stem cell biology. Nevertheless, the experiments require multiple steps of molecular manipulation for gene knockout and subsequent rescue procedures. Here we report an efficient and single step strategy to generate gene knockout-rescue system in pluripotent stem cells by promoter insertion with CRISPR/Cas9 genome editing technology. We inserted a tetracycline-regulated inducible gene promoter (tet-OFF/TRE-CMV) upstream of the endogenous promoter region of vascular endothelial growth factor receptor 2 (VEGFR2/Flk1) gene, an essential gene for endothelial cell (EC) differentiation, in mouse embryonic stem cells (ESCs) with homologous recombination. Both homo- and hetero-inserted clones were efficiently obtained through a simple selection with a drug-resistant gene. The insertion of TRE-CMV promoter disrupted endogenous Flk1 expression, resulting in null mutation in homo-inserted clones. When the inserted TRE-CMV promoter was activated with doxycycline (Dox) depletion, Flk1 expression was sufficiently recovered from the downstream genomic Flk1 gene. Whereas EC differentiation was almost completely perturbed in homo-inserted clones, Flk1 rescue with TRE-CMV promoter activation restored EC appearance, indicating that phenotypic changes in EC differentiation can be successfully reproduced with this knockout-rescue system. Thus, this promoter insertion strategy with CRISPR/Cas9 would be a novel attractive method for knockout-rescue experiments. Copyright © 2014 Elsevier Inc. All rights reserved.

The role of system Xc- in methamphetamine-induced dopaminergic neurotoxicity in mice.

PubMed

Dang, Duy-Khanh; Shin, Eun-Joo; Tran, Hai-Quyen; Kim, Dae-Joong; Jeong, Ji Hoon; Jang, Choon-Gon; Nah, Seung-Yeol; Sato, Hideyo; Nabeshima, Toshitaka; Yoneda, Yukio; Kim, Hyoung-Chun

2017-09-01

The cystine/glutamate antiporter (system Xc - , Sxc) transports cystine into cell in exchange for glutamate. Since xCT is a specific subunit of Sxc, we employed xCT knockout mice and investigated whether this antiporter affected methamphetamine (MA)-induced dopaminergic neurotoxicity. MA treatment significantly increased striatal oxidative burdens in wild type mice. xCT inhibitor [i.e., S-4-carboxy-phenylglycine (CPG), sulfasalazine] or an xCT knockout significantly protected against these oxidative burdens. MA-induced increases in Iba-1 expression and Iba-1-labeled microglial immunoreactivity (Iba-1-IR) were significantly attenuated by CPG or sulfasalazine administration or xCT knockout. CPG or sulfasalazine significantly attenuated MA-induced TUNEL-positive cell populations in the striatum of Taconic ICR mice. The decrease in excitatory amino acid transporter-2 (or glutamate transporter-1) expression and increase in glutamate release were attenuated by CPG, sulfasalazine or xCT knockout. In addition, CPG, sulfasalazine or xCT knockout significantly protected against dopaminergic loss (i.e., decreases in tyrosine hydroxylase expression and immunoreactivity, and an increase in dopamine turnover rate) induced by MA. However, CPG, sulfasalazine or xCT knockout did not significantly affect the impaired glutathione system [i.e., decrease in reduced glutathione (GSH) and increase in oxidized glutathione (GSSG)] induced by MA. Our results suggest that Sxc mediates MA-induced neurotoxicity via facilitating oxidative stress, microgliosis, proapoptosis, and glutamate-related toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cells Lacking β-Actin are Genetically Reprogrammed and Maintain Conditional Migratory Capacity*

PubMed Central

Tondeleir, Davina; Lambrechts, Anja; Müller, Matthias; Jonckheere, Veronique; Doll, Thierry; Vandamme, Drieke; Bakkali, Karima; Waterschoot, Davy; Lemaistre, Marianne; Debeir, Olivier; Decaestecker, Christine; Hinz, Boris; Staes, An; Timmerman, Evy; Colaert, Niklaas; Gevaert, Kris; Vandekerckhove, Joël; Ampe, Christophe

2012-01-01

Vertebrate nonmuscle cells express two actin isoforms: cytoplasmic β- and γ-actin. Because of the presence and localized translation of β-actin at the leading edge, this isoform is generally accepted to specifically generate protrusive forces for cell migration. Recent evidence also implicates β-actin in gene regulation. Cell migration without β-actin has remained unstudied until recently and it is unclear whether other actin isoforms can compensate for this cytoplasmic function and/or for its nuclear role. Primary mouse embryonic fibroblasts lacking β-actin display compensatory expression of other actin isoforms. Consistent with this preservation of polymerization capacity, β-actin knockout cells have unchanged lamellipodial protrusion rates despite a severe migration defect. To solve this paradox we applied quantitative proteomics revealing a broad genetic reprogramming of β-actin knockout cells. This also explains why reintroducing β-actin in knockout cells does not restore the affected cell migration. Pathway analysis suggested increased Rho-ROCK signaling, consistent with observed phenotypic changes. We therefore developed and tested a model explaining the phenotypes in β-actin knockout cells based on increased Rho-ROCK signaling and increased TGFβ production resulting in increased adhesion and contractility in the knockout cells. Inhibiting ROCK or myosin restores migration of β-actin knockout cells indicating that other actins compensate for β-actin in this process. Consequently, isoactins act redundantly in providing propulsive forces for cell migration, but β-actin has a unique nuclear function, regulating expression on transcriptional and post-translational levels, thereby preventing myogenic differentiation. PMID:22448045

Measured microwave scattering cross sections of three meteorite specimens

NASA Technical Reports Server (NTRS)

Hughes, W. E.

1972-01-01

Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

Asymptotic form for the cross section for the Coulomb interacting rearrangement collisions.

NASA Technical Reports Server (NTRS)

Omidvar, K.

1973-01-01

It is shown that in a rearrangement collision leading to the formation of highly excited hydrogenlike states the cross section at high energies behaves as 1/n-squared, with n the principal quantum number, thus invalidating the Brinkman-Kramers approximation for large n. Similarly, in high-energy inelastic electron-hydrogenlike-atom collisions the exchange cross section for sufficiently large n dominates the direct excitation cross section.

Study of the angular coefficients and corresponding helicity cross sections of the W boson in hadron collisions

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

Strologas, John; Errede, Steven; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801

We present the standard model prediction for the eight angular coefficients of the W boson, which completely describes its differential cross section in hadron collisions. These coefficients are ratios of the W helicity cross sections and the total unpolarized cross section. We also suggest a technique to experimentally extract the coefficients, which we demonstrate in the Collins-Soper azimuthal-angle analysis.

Fragmentation Cross Sections of 290 and 400 MeV/nucleon 12C Beamson Elemental Targets

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

Zeitlin, C.; Guetersloh, S.; Heilbronn, L.

Charge-changing and fragment production cross sections at 0circ have been obtained for interactions of 290 MeV/nucleon and 400MeV/nucleon carbon beams with C, CH2, Al, Cu, Sn, and Pb targets. Thesebeams are relevant to cancer therapy, space radiation, and the productionof radioactive beams. We compare to previously published results using Cand CH2 targets at similar beam energies. Due to ambiguities arising fromthe presence of multiple fragments on many events, previous publicationshave reported only cross sections for B and Be fragments. In this work wehave extracted cross sections for all fragment species, using dataobtained at three distinct values of angular acceptance, supplementedmore » bydata taken with the detector stack placed off the beam axis. A simulationof the experiment with the PHITS Monte Carlo code shows fair agreementwith the data obtained with the large acceptance detectors, but agreementis poor at small acceptance. The measured cross sections are alsocompared to the predictions of the one-dimensional cross section modelsEPAX2 and NUCFRG2; the latter is presently used in NASA's space radiationtransport calculations. Though PHITS and NUCFRG2 reproduce thecharge-changing cross sections with reasonable accuracy, none of themodels is able to accurately predict the fragment cross sections for allfragment species and target materials.« less

Extracting Cross-Sectional Clinical Images Based on Their Principal Axes of Inertia

PubMed Central

Fan, Yuzhou; Djuric, Marija; Li, Zhiyu; Antonijevic, Djordje; Milenkovic, Petar; Sun, Yueyang; Li, Ruining

2017-01-01

Cross-sectional imaging is considered the gold standard in diagnosing a range of diseases. However, despite its widespread use in clinical practice and research, no widely accepted method is available to reliably match cross-sectional planes in several consecutive scans. This deficiency can impede comparison between cross-sectional images and ultimately lead to misdiagnosis. Here, we propose and demonstrate a method for finding the same imaging plane in images obtained during separate scanning sessions. Our method is based on the reconstruction of a “virtual organ” from which arbitrary cross-sectional images can be extracted, independent of the axis orientation in the original scan or cut; the key is to establish unique body coordinates of the organ from its principal axes of inertia. To verify our method a series of tests were performed, and the same cross-sectional plane was successfully extracted. This new approach offers clinicians access, after just a single scanning session, to the morphology and structure of a lesion through cross-sectional images reconstructed along arbitrary axes. It also aids comparable detection of morphological and structural changes in the same imaging plane from scans of the same patient taken at different times—thus potentially reducing the misdiagnosis rate when cross-sectional images are interpreted. PMID:29410714

Extracting Cross-Sectional Clinical Images Based on Their Principal Axes of Inertia.

PubMed

Fan, Yuzhou; Luo, Liangping; Djuric, Marija; Li, Zhiyu; Antonijevic, Djordje; Milenkovic, Petar; Sun, Yueyang; Li, Ruining; Fan, Yifang

2017-01-01

Cross-sectional imaging is considered the gold standard in diagnosing a range of diseases. However, despite its widespread use in clinical practice and research, no widely accepted method is available to reliably match cross-sectional planes in several consecutive scans. This deficiency can impede comparison between cross-sectional images and ultimately lead to misdiagnosis. Here, we propose and demonstrate a method for finding the same imaging plane in images obtained during separate scanning sessions. Our method is based on the reconstruction of a "virtual organ" from which arbitrary cross-sectional images can be extracted, independent of the axis orientation in the original scan or cut; the key is to establish unique body coordinates of the organ from its principal axes of inertia. To verify our method a series of tests were performed, and the same cross-sectional plane was successfully extracted. This new approach offers clinicians access, after just a single scanning session, to the morphology and structure of a lesion through cross-sectional images reconstructed along arbitrary axes. It also aids comparable detection of morphological and structural changes in the same imaging plane from scans of the same patient taken at different times-thus potentially reducing the misdiagnosis rate when cross-sectional images are interpreted.

Use of the Bethe equation for inner-shell ionization by electron impact

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

Powell, Cedric J.; Llovet, Xavier; Salvat, Francesc

2016-05-14

We analyzed calculated cross sections for K-, L-, and M-shell ionization by electron impact to determine the energy ranges over which these cross sections are consistent with the Bethe equation for inner-shell ionization. Our analysis was performed with K-shell ionization cross sections for 26 elements, with L-shell ionization cross sections for seven elements, L{sub 3}-subshell ionization cross sections for Xe, and M-shell ionization cross sections for three elements. The validity (or otherwise) of the Bethe equation could be checked with Fano plots based on a linearized form of the Bethe equation. Our Fano plots, which display theoretical cross sections andmore » available measured cross sections, reveal two linear regions as predicted by de Heer and Inokuti [in Electron Impact Ionization, edited by T. D. Märk and G. H. Dunn, (Springer-Verlag, Vienna, 1985), Chap. 7, pp. 232–276]. For each region, we made linear fits and determined values of the two element-specific Bethe parameters. We found systematic variations of these parameters with atomic number for both the low- and the high-energy linear regions of the Fano plots. We also determined the energy ranges over which the Bethe equation can be used.« less

Cross-Sectional Analysis of Longitudinal Mediation Processes.

PubMed

O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

2018-01-01

Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

Single- and double-photoionization cross sections of atomic nitrogen from threshold to 31 A

NASA Technical Reports Server (NTRS)

Samson, James A. R.; Angel, G. C.

1990-01-01

The relative photoionization cross section of atomic nitrogen for the production of singly and doubly charged ions has been measured from 44.3 to 275 A and from 520 to 852 A. The results have been made absolute by normalization to one-half of the molecular nitrogen cross section at short wavelengths. The smoothed atomic nitrogen cross sections sigma can be accurately represented, at short wavelengths, by the equation sigma(Mb) = 36,700 x (E exp-2.3) as a function of the photon energy E (eV), thereby allowing the cross sections to be extrapolated to the nitrogen K edge at 31 A.

Analysis of the effectiveness of various cross-sections in large-span post-tensioned ceilings

NASA Astrophysics Data System (ADS)

Bednarz, K.

2018-03-01

The correct construction of large span, slim post-tensioned concrete slabs is conditioned by an appropriate cross-section selection. It is generally accepted that the thinnest slab can be constructed using the full cross-section as the largest compression stress storage. However, completely different cross-sections may help to overcome large spans. The paper presents the results of the computational analysis of several types of cross-sections (full, with internal relieving inserts and ribbed) in the application to a post-tensioned slab with a span of 15.0m. Based on the results presented, appropriate conclusions were drawn.

Calculation of the Coulomb Fission Cross Sections for Pb-Pb and Bi-Pb Interactions at 158 A GeV

NASA Technical Reports Server (NTRS)

Poyser, William J.; Ahern, Sean C.; Norbury, John W.; Tripathi, R. K.

2002-01-01

The Weizsacker-Williams (WW) method of virtual quanta is used to make approximate cross section calculations for peripheral relativistic heavy-ion collisions. We calculated the Coulomb fission cross sections for projectile ions of Pb-208 and Bi-209 with energies of 158 A GeV interacting with a Pb-208 target. We also calculated the electromagnetic absorption cross section for Pb-208 ion interacting as described. For comparison we use both the full WW method and a standard approximate WW method. The approximate WW method in larger cross sections compared to the more accurate full WW method.

Lidar cross-sections of soot fractal aggregates: Assessment of equivalent-sphere models

NASA Astrophysics Data System (ADS)

Ceolato, Romain; Gaudfrin, Florian; Pujol, Olivier; Riviere, Nicolas; Berg, Matthew J.; Sorensen, Christopher M.

2018-06-01

This work assesses the ability of equivalent-sphere models to reproduce the optical properties of soot aggregates relevant for lidar remote sensing, i.e. the backscattering and extinction cross sections. Lidar cross-sections are computed with a spectral discrete dipole approximation model over the visible-to-infrared (400-5000 nm) spectrum and compared with equivalent-sphere approximations. It is shown that the equivalent-sphere approximation, applied to fractal aggregates, has a limited ability to calculate such cross-sections well. The approximation should thus be used with caution for the computation of broadband lidar cross-sections, especially backscattering, at small and intermediate wavelengths (e.g. UV to visible).

Electron capture cross sections by O+ from atomic He

NASA Astrophysics Data System (ADS)

Joseph, Dwayne C.; Saha, Bidhan C.

2009-11-01

The adiabatic representation is used in both the quantal and semi classical molecular orbital close coupling methods (MOCC) to evaluate charge exchange cross sections. Our results show good agreement with experimental cross sections

Single-level resonance parameters fit nuclear cross-sections

NASA Technical Reports Server (NTRS)

Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

1970-01-01

Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

[Effect of resin infiltration on microhardness of artificial caries lesions].

PubMed

Liu, Yonghong; Deng, Hui; Tang, Longmei; Zhang, Zhiyong

2015-12-01

To compare the changes of enamel surface and cross-sectional microhardness of artificial caries immediately and after the twice demineralization through coating resin infiltration, fluoride varnish and fissure sealant. A total of forty bovine lower incisors enamel samples with artificial caries lesions by the demineralization liquid were used in the experiment. The specimens were then randomly divided into four groups as group A(resin infiltration), B(fluoride varnish), C (fissure sealant), D(control), 10 specimens in each group. The samples were sectioned vertically into two halves through the centre. One half of each sample the surface and cross-sectional microhardness was measured. The other half was put into demineralization liquid for 14 days, then the surface and cross-sectional microhardness was measured again. The cross section morphology of the samples was observed by scanning electron microscope. The surface of enamel had the highest microhardness value, and with the increase of cross- sectional depth, the microhardness value declined gradually. Variance analysis showed that the difference was statistically significant in the cross-section of different depth among the four groups(P<0.05). The microhardness values of the surface and the cross- section at 40 µm of each group in immediate measure showed the values were significantly higher in group A, B and C than in group D. There was no significant difference in the microhardness value of cross-section at 80 µm between group A[(324 ± 17) kg/mm(2)] and group C[(316 ± 20) kg/mm(2)], but they were significantly higher than group D. There was no significant difference between group B[(303 ± 13) kg/mm(2)] and group D[(294 ± 23) kg/mm(2)]. At 120 µm level, the microhardness value of group A was significantly higher than those of the other three groups. After the twice demineralization, the enamel surface microhardness value of the specimens was the same as the first measurement. In the cross-section at 40 µm level, the microhardness value was equal to the value of cross-section at 80 µm level of the first measurement. In the cross- section at 80 µm and 120 µm level, the microhardness value of group A was significantly higher than those of the other three groups. Resin infiltration can effectively strengthen microhardness of enamel surface and cross-section of different depth of artificial caries.

Examination of the 22C radius determination with interaction cross sections

NASA Astrophysics Data System (ADS)

Nagahisa, T.; Horiuchi, W.

2018-05-01

A nuclear radius of 22C is investigated with the total reaction cross sections at medium- to high-incident energies in order to resolve the radius puzzle in which two recent interaction cross-section measurements using 1H and 12C targets show the quite different radii. The cross sections of 22C are calculated consistently for these target nuclei within a reliable microscopic framework, the Glauber theory. To describe appropriately such a reaction involving a spatially extended nucleus, the multiple scattering processes within the Glauber theory are fully taken into account, that is, the multidimensional integration in the Glauber amplitude is evaluated using a Monte Carlo technique without recourse to the optical-limit approximation. We discuss the sensitivity of the spatially extended halo tail to the total reaction cross sections. The root-mean-square matter radius obtained in this study is consistent with that extracted from the recent cross-section measurement on 12C target. We show that the simultaneous reproduction of the two recent measured cross sections is not feasible within this framework.

Measurement of the Am 242 m neutron-induced reaction cross sections

DOE PAGES

Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; ...

2017-02-17

The neutron-induced reaction cross sections of 242mAm were measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. A new neutron-capture cross section was determined, and the absolute scale was set according to a concurrent measurement of the well-known 242mAm(n,f) cross section. The (n,γ) cross section was measured from thermal energy to an incident energy of 1 eV at which point the data quality was limited by the reaction yield in the laboratory. Our new 242mAm fission cross section was normalized to ENDF/B-VII.1 tomore » set the absolute scale, and it agreed well with the (n,f) cross section from thermal energy to 1 keV. Lastly, the average absolute capture-to-fission ratio was determined from thermal energy to E n = 0.1 eV, and it was found to be 26(4)% as opposed to the ratio of 19% from the ENDF/B-VII.1 evaluation.« less

Mixed Legendre moments and discrete scattering cross sections for anisotropy representation

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

Calloo, A.; Vidal, J. F.; Le Tellier, R.

2012-07-01

This paper deals with the resolution of the integro-differential form of the Boltzmann transport equation for neutron transport in nuclear reactors. In multigroup theory, deterministic codes use transfer cross sections which are expanded on Legendre polynomials. This modelling leads to negative values of the transfer cross section for certain scattering angles, and hence, the multigroup scattering source term is wrongly computed. The first part compares the convergence of 'Legendre-expanded' cross sections with respect to the order used with the method of characteristics (MOC) for Pressurised Water Reactor (PWR) type cells. Furthermore, the cross section is developed using piecewise-constant functions, whichmore » better models the multigroup transfer cross section and prevents the occurrence of any negative value for it. The second part focuses on the method of solving the transport equation with the above-mentioned piecewise-constant cross sections for lattice calculations for PWR cells. This expansion thereby constitutes a 'reference' method to compare the conventional Legendre expansion to, and to determine its pertinence when applied to reactor physics calculations. (authors)« less

Thermoelastic damping in microrings with circular cross-section

NASA Astrophysics Data System (ADS)

Li, Pu; Fang, Yuming; Zhang, Jianrun

2016-01-01

Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular cross-section. The temperature field in the rectangular cross-section is one-dimensional. This paper deals with TED in the microrings with circular cross-section. The temperature field in the circular cross-section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with circular cross-section. Only the two-dimensional heat conduction in the circular cross-section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

Measurement of 208Pb(n ,γ )209Pb Maxwellian averaged neutron capture cross section

NASA Astrophysics Data System (ADS)

Weissman, L.; Tessler, M.; Arenshtam, A.; Eliyahu, I.; Halfon, S.; Guerrero, C.; Kaizer, B.; Kijel, D.; Kreisel, A.; Palchan, T.; Paul, M.; Perry, A.; Schimel, G.; Silverman, I.; Shor, A.; Tamim, N.; Vaintraub, S.

2017-07-01

The doubly magic 208Pb nucleus is a bottleneck at the termination of the s -process path due to its very low neutron capture cross section. This cross section is also important for the decomposition of s , r processes and U/Th radiogenic decay contributions to the Pb-Bi solar abundances. The 208Pb(n ,γ )209Pb cross section was measured at the Soreq Applied Research Accelerator Facility Phase I using an intense quasi-Maxwellian neutron source produced by irradiation of the liquid-lithium target with a 1.5-mA continuous-wave proton beam at 1.94 MeV. The cross section was measured by counting the β activity from the irradiated lead target. The measurement allowed us to evaluate the Maxwellian averaged cross section (MACS) at 30 keV obtaining a value of 0.33(2) mb. This has been compared with the earlier activation and time-of-flight measurements found in the literature. The MACS cross-sectional value of the 63Cu(n ,γ )64Cu reaction was determined in the same experiment and is compared to a recent published value.

Multidimensional analysis of fast-spectrum material replacement measurements for systematic estimation of cross section uncertainties

NASA Technical Reports Server (NTRS)

Klann, P. G.; Lantz, E.; Mayo, W. T.

1973-01-01

A series of central core and core-reflector interface sample replacement experiments for 16 materials performed in the NASA heavy-metal-reflected, fast spectrum critical assembly (NCA) were analyzed in four and 13 groups using the GAM 2 cross-section set. The individual worths obtained by TDSN and DOT multidimensional transport theory calculations showed significant differences from the experimental results. These were attributed to cross-section uncertainties in the GAM 2 cross sections. Simultaneous analysis of the measured and calculated sample worths permitted separation of the worths into capture and scattering components which systematically provided fast spectrum averaged correction factors to the magnitudes of the GAM 2 absorption and scattering cross sections. Several Los Alamos clean critical assemblies containing Oy, Ta, and Mo as well as one of the NCA compositions were reanalyzed using the corrected cross sections. In all cases the eigenvalues were significantly improved and were recomputed to within 1 percent of the experimental eigenvalue. A comparable procedure may be used for ENDF cross sections when these are available.

Single and double capture in F9+ + Ar collisions: Comparison of total capture with capture occurring from the Ar K shell

NASA Astrophysics Data System (ADS)

La Mantia, David; Kumara, Nuwan; Kayani, Asghar; Simon, Anna; Tanis, John

2016-05-01

Total cross sections for single and double capture, as well as the corresponding cross sections for capture resulting in the emission of an Ar K x ray, were measured. This work was performed at Western Michigan University with the use of the tandem Van de Graaff accelerator. A 45 MeV beam of fully-stripped fluorine ions was collided with argon gas molecules in a differentially pumped cell. Surface barrier detectors were used to observe the charge changed projectiles and a Si(Li) x-ray detector, placed at 90o to the incident beam, were used to measure coincidences with Ar K x rays. The total capture cross sections are compared to previously measured cross sections in the existing literature. The coincidence cross sections, considerably smaller than the total cross sections, are found to be nearly equal for single and double capture in contrast to the total cross sections, which vary by about an order of magnitude. Possible reasons for this behavior are discussed. Supported in part by the NSF.

On the correlation of absorption cross-section with plasmonic color generation.

PubMed

Rezaei, Soroosh Daqiqeh; Ho, Jinfa; Ng, Ray Jia Hong; Ramakrishna, Seeram; Yang, Joel K W

2017-10-30

Through numerical simulations, we investigate the correlation between the absorption cross-section and the color saturation of plasmonic nanostructures of varying density. Understanding this correlation, enables the prediction of an optimal nanostructure separation, or combinations of different nanostructure sizes for plasmonic color printing applications. Here, we use metal-insulator-metal (MIM) aluminum nanostructures that support gap-plasmons. Large absorption cross-sections were observed that exceed twelve times the physical cross-section of the nanostructure disks. We derive a set of equations to determine the optimal separation for a periodic array using the absorption cross-section of an individual structure to realize saturated colors. Using the optimum pitch and enabled by the large absorption cross-sections of our structures, we employ color mixing strategies to realize a wider color gamut. The simulated color gamut exceeds the sRGB gamut for some colors, and includes dark tones. Color mixing using structures with large absorption cross-sections is a practical approach to generate a broad range of colors, in comparison to fabricating structures with continuously varying sizes.

Shell-model computed cross sections for charged-current scattering of astrophysical neutrinos off 40Ar

NASA Astrophysics Data System (ADS)

Kostensalo, Joel; Suhonen, Jouni; Zuber, K.

2018-03-01

Charged-current (anti)neutrino-40Ar cross sections for astrophysical neutrinos have been calculated. The initial and final nuclear states were calculated using the nuclear shell model. The folded solar-neutrino scattering cross section was found to be 1.78 (23 ) ×10-42cm2 , which is higher than what the previous papers have reported. The contributions from the 1- and 2- multipoles were found to be significant at supernova-neutrino energies, confirming the random-phase approximation (RPA) result of a previous study. The effects of neutrino flavor conversions in dense stellar matter (matter oscillations) were found to enhance the neutrino-scattering cross sections significantly for both the normal and inverted mass hierarchies. For the antineutrino scattering, only a small difference between the nonoscillating and inverted-hierarchy cross sections was found, while the normal-hierarchy cross section was 2-3 times larger than that of the nonoscillating cross section, depending on the adopted parametrization of the Fermi-Dirac distribution. This property of the supernova-antineutrino signal could probably be used to distinguish between the two hierarchies in megaton LAr detectors.

The importance of immunohistochemical analyses in evaluating the phenotype of Kv channel knockout mice.

PubMed

Menegola, Milena; Clark, Eliana; Trimmer, James S

2012-06-01

To gain insights into the phenotype of voltage-gated potassium (Kv)1.1 and Kv4.2 knockout mice, we used immunohistochemistry to analyze the expression of component principal or α subunits and auxiliary subunits of neuronal Kv channels in knockout mouse brains. Genetic ablation of the Kv1.1 α subunit did not result in compensatory changes in the expression levels or subcellular distribution of related ion channel subunits in hippocampal medial perforant path and mossy fiber nerve terminals, where high levels of Kv1.1 are normally expressed. Genetic ablation of the Kv4.2 α subunit did not result in altered neuronal cytoarchitecture of the hippocampus. Although Kv4.2 knockout mice did not exhibit compensatory changes in the expression levels or subcellular distribution of the related Kv4.3 α subunit, we found dramatic decreases in the cellular and subcellular expression of specific Kv channel interacting proteins (KChIPs) that reflected their degree of association and colocalization with Kv4.2 in wild-type mouse and rat brains. These studies highlight the insights that can be gained by performing detailed immunohistochemical analyses of Kv channel knockout mouse brains. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

Different roles of axon guidance cues and patterned spontaneous activity in establishing receptive fields in the mouse superior colliculus.

PubMed

Liu, Mingna; Wang, Lupeng; Cang, Jianhua

2014-01-01

Visual neurons in the superior colliculus (SC) respond to both bright (On) and dark (Off) stimuli in their receptive fields. This receptive field property is due to proper convergence of On- and Off-centered retinal ganglion cells to their target cells in the SC. In this study, we have compared the receptive field structure of individual SC neurons in two lines of mutant mice that are deficient in retinotopic mapping: the ephrin-A knockouts that lack important retinocollicular axonal guidance cues and the nAChR-β2 knockouts that have altered activity-dependent refinement of retinocollicular projections. We find that even though the receptive fields are much larger in the ephrin-A knockouts, their On-Off overlap remains unchanged. These neurons also display normal level of selectivity for stimulus direction and orientation. In contrast, the On-Off overlap is disrupted in the β2 knockouts. Together with the previous finding of disrupted direction and orientation selectivity in the β2 knockout mice, our results indicate that molecular guidance cues and activity-dependent processes play different roles in the development of receptive field properties in the SC.

Olivocochlear neuron central anatomy is normal in alpha 9 knockout mice.

PubMed

Brown, M Christian; Vetter, Douglas E

2009-03-01

Olivocochlear (OC) neurons were studied in a transgenic mouse with deletion of the alpha 9 nicotinic acetylcholine receptor subunit. In this alpha 9 knockout mouse, the peripheral effects of OC stimulation are lacking and the peripheral terminals of OC neurons under outer hair cells have abnormal morphology. To account for this mouse's apparently normal hearing, it has been proposed to have central compensation via collateral branches to the cochlear nucleus. We tested this idea by staining OC neurons for acetylcholinesterase and examining their morphology in knockout mice, wild-type mice of the same background strain, and CBA/CaJ mice. Knockout mice had normal OC systems in terms of numbers of OC neurons, dendritic patterns, and numbers of branches to the cochlear nucleus. The branch terminations were mainly to edge regions and to a lesser extent the core of the cochlear nucleus, and were similar among the strains in terms of the distribution and staining density. These data demonstrate that there are no obvious changes in the central morphology of the OC neurons in alpha 9 knockout mice and make less attractive the idea that there is central compensation for deletion of the peripheral receptor in these mice.

Highly Efficient Genome Editing via CRISPR/Cas9 to Create Clock Gene Knockout Cells.

PubMed

Korge, Sandra; Grudziecki, Astrid; Kramer, Achim

2015-10-01

Targeted genome editing using CRISPR/Cas9 is a relatively new, revolutionary technology allowing for efficient and directed alterations of the genome. It has been widely used for loss-of-function studies in animals and cell lines but has not yet been used to study circadian rhythms. Here, we describe the application of CRISPR/Cas9 genome editing for the generation of an F-box and leucine-rich repeat protein 3 (Fbxl3) knockout in a human cell line. Genomic alterations at the Fbxl3 locus occurred with very high efficiency (70%-100%) and specificity at both alleles, resulting in insertions and deletions that led to premature stop codons and hence FBXL3 knockout. Fbxl3 knockout cells displayed low amplitude and long period oscillations of Bmal1-luciferase reporter activity as well as increased CRY1 protein stability in line with previously published phenotypes for Fbxl3 knockout in mice. Thus, CRISPR/Cas9 genome editing should be highly valuable for studying circadian rhythms not only in human cells but also in classic model systems as well as nonmodel organisms. © 2015 The Author(s).

Sequence determinants of improved CRISPR sgRNA design.

PubMed

Xu, Han; Xiao, Tengfei; Chen, Chen-Hao; Li, Wei; Meyer, Clifford A; Wu, Qiu; Wu, Di; Cong, Le; Zhang, Feng; Liu, Jun S; Brown, Myles; Liu, X Shirley

2015-08-01

The CRISPR/Cas9 system has revolutionized mammalian somatic cell genetics. Genome-wide functional screens using CRISPR/Cas9-mediated knockout or dCas9 fusion-mediated inhibition/activation (CRISPRi/a) are powerful techniques for discovering phenotype-associated gene function. We systematically assessed the DNA sequence features that contribute to single guide RNA (sgRNA) efficiency in CRISPR-based screens. Leveraging the information from multiple designs, we derived a new sequence model for predicting sgRNA efficiency in CRISPR/Cas9 knockout experiments. Our model confirmed known features and suggested new features including a preference for cytosine at the cleavage site. The model was experimentally validated for sgRNA-mediated mutation rate and protein knockout efficiency. Tested on independent data sets, the model achieved significant results in both positive and negative selection conditions and outperformed existing models. We also found that the sequence preference for CRISPRi/a is substantially different from that for CRISPR/Cas9 knockout and propose a new model for predicting sgRNA efficiency in CRISPRi/a experiments. These results facilitate the genome-wide design of improved sgRNA for both knockout and CRISPRi/a studies. © 2015 Xu et al.; Published by Cold Spring Harbor Laboratory Press.

Knockout of Eva1a leads to rapid development of heart failure by impairing autophagy

PubMed Central

Zhang, Shu; Lin, Xin; Li, Ge; Shen, Xue; Niu, Di; Lu, Guang; Fu, Xin; Chen, Yingyu; Cui, Ming; Bai, Yun

2017-01-01

EVA1A (Eva-1 homologue A) is a novel lysosome and endoplasmic reticulum-associated protein that can regulate cell autophagy and apoptosis. Eva1a is expressed in the myocardium, but its function in myocytes has not yet been investigated. Therefore, we generated inducible, cardiomyocyte-specific Eva1a knockout mice with an aim to determine the role of Eva1a in cardiac remodelling in the adult heart. Data from experiments showed that loss of Eva1a in the adult heart increased cardiac fibrosis, promoted cardiac hypertrophy, and led to cardiomyopathy and death. Further investigation suggested that this effect was associated with impaired autophagy and increased apoptosis in Eva1a knockout hearts. Moreover, knockout of Eva1a activated Mtor signalling and the subsequent inhibition of autophagy. In addition, Eva1a knockout hearts showed disorganized sarcomere structure and mitochondrial misalignment and aggregation, leading to the lack of ATP generation. Collectively, these data demonstrated that Eva1a improves cardiac function and inhibits cardiac hypertrophy and fibrosis by increasing autophagy. In conclusion, our results demonstrated that Eva1a may have an important role in maintaining cardiac homeostasis. PMID:28151473

[Design of cross-sectional anatomical model focused on drainage pathways of paranasal sinuses].

PubMed

Zha, Y; Lv, W; Gao, Y L; Zhu, Z Z; Gao, Z Q

2018-05-01

Objective: To design and produce cross-sectional anatomical models of paranasal sinuses for the purpose of demonstrating drainage pathways of each nasal sinus for the young doctors. Method: We reconstructed the three-dimensional model of sinuses area based on CT scan data, and divided it into 5 thick cross-sectional anatomy models by 4 coronal plane，which cross middle points of agger nasi cell, ethmoid bulla, posterior ethmoid sinuses and sphenoid sinus respectively. Then a 3D printerwas used to make anatomical cross-sectional anatomical models. Result: Successfully produced a digital 3D printing cross-sectional models of paranasal sinuses. Sinus drainage pathways were observed on the models. Conclusion: The cross-sectional anatomical models made by us can exactly and intuitively demonstrate the ostia of each sinus cell and they can help the young doctors to understand and master the key anatomies and relationships which are important to the endoscopic sinus surgery. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Determining the partial photoionization cross-sections of ethyl radicals.

PubMed

FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

2007-12-13

Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

Research on the Cross Section Precision of High-strength Steel Tube with Rectangular Section in Rotary Draw Bending

NASA Astrophysics Data System (ADS)

Yang, Hongliang; Zhao, Hao; Xing, Zhongwen

2017-11-01

For the demand of energy conservation and security improvement, high-strength steel (HSS) is increasingly being used to produce safety related automotive components. However, cross-section distortion occurs easily in bending of HSS tube with rectangular section (RS), affecting the forming precision. HSS BR1500HS tube by rotary draw bending is taken as the study object and a description method of cross-section distortion is proposed in this paper. The influence on cross-section precision of geometric parameters including cross-section position, thickness of tube, bend radius etc. are studied by experiment. Besides, simulation of the rotary draw bending of HSS tube with rectangular section by ABAQUS are carried out and compared to the experiment. The results by simulation agree well with the experiment and show that the cross-section is approximately trapezoidal after distortion; the maximum of distortion exists at 45 ∼ 60° of the bending direction; and the absolute and relative distortion values increase with the decreasing of tube thickness or bending radius. Therefore, the results can provide a reference for the design of geometric parameters of HSS tube with rectangular section in rotary draw bending.

Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

USGS Publications Warehouse

Sweetkind, D.S.; Dickerson, R.P.; Blakely, R.J.; Denning, Paul

2001-01-01

This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3? x 3? area (approximately 70,000 km2) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative. The region transected by the cross sections includes part of the southern Basin and Range Province, the northwest-trending Walker Lane belt, the Death Valley region, and the northern Mojave Desert. The region is structurally complex, where a locally thick Tertiary volcanic and sedimentary section unconformably overlies previously deformed Proterozoic through Paleozoic rocks. All of these rocks have been deformed by complex Neogene ex-tensional normal and strike-slip faults. These cross sections form a three-dimensional network that portrays the interpreted stratigraphic and structural relations in the region; the sections form part of the geologic framework that will be incorporated in a complex numerical model of ground-water flow in the Death Valley region.

Morphology of Mesiobuccal Root Canals of Maxillary First Molars: a comparison of CBCT scanning and Cross-sectioning.

PubMed

Lyra, Carina Maria; Delai, Débora; Pereira, Keila Cristina Rausch; Pereira, Guy Martins; Pasternak Júnior, Bráulio; Oliveira, César Augusto Pereira

2015-10-01

The aim of this study was to evaluate the mesiobuccal root of maxillary first molars, according to the root canal configuration, prevalence and location of isthmuses at 3 and 6 mm from the apex, comparing cone-beam computed tomography (CBCT) analysis and cross sectioning of roots by thirds. Images of the mesiobuccal root of 100 maxillary first molars were acquired by CBCT and then roots were cross-sectioned into two parts, starting at 3 mm from the apex. Data were recorded and analyzed according to Weine's classification for root canal configuration, and Hsu and Kim's classification for isthmuses. In the analysis of CBCT images, 8 root canals were classified as type I, 57 as type II, 35 as type III. In the cross-sectioning technique, 19 root canals were classified as type I, 60 as type II, 20 as type III and 1 as type IV. The classification of isthmuses was predominantly type I in both CBCT and cross-sectioning evaluations for sections at 3 mm from the apex, while for sections at 6 mm from the apex, the classification of isthmuses was predominantly types V and II in CBCT and cross-sectioning evaluations, respectively. The cross-sectioning technique showed better results in detection of the internal morphology of root canals than CBCT scanning.

Generation of Collapsed Cross Sections for Hatch 1 Cycles 1-3

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

Ade, Brian J

2012-11-01

Under NRC JCN V6361, Oak Ridge National Laboratory (ORNL) was tasked to develop and run SCALE/TRITON models for generation of collapsed few-group cross sections and to convert the cross sections to PMAXS format using the GENPMAXS conversion utility for use in PARCS/PATHS simulations of Hatch Unit 1, cycles 1-3. This letter report documents the final models used to produce the Hatch collapsed cross sections.

Bodies with noncircular cross sections and bank-to-turn missiles

NASA Technical Reports Server (NTRS)

Jackson, C. M., Jr.; Sawyer, W. C.

1992-01-01

A development status evaluation is presented for the aerodynamics of missile configurations with noncircular cross-sections and bank-to-turn maneuvering systems, giving attention to cases with elliptical and square cross-sections, as well as bodies with variable cross-sections. The assessment of bank-to-turn missile performance notes inherent stability/control problems. A summary and index are provided for aerodynamic data on monoplanar configurations, including those which incorporate airbreathing propulsion systems.

Measurement of the inclusive jet cross section at the CERN pp collider

NASA Astrophysics Data System (ADS)

Arnison, G.; Albrow, M. G.; Allkofer, O. C.; Astbury, A.; Aubert, B.; Bacci, C.; Batley, J. R.; Bauer, G.; Bettini, A.; Bézaguet, A.; Bock, R. K.; Bos, K.; Buckley, E.; Bunn, J.; Busetto, G.; Catz, P.; Cennini, P.; Centro, S.; Ceradini, F.; Ciapetti, G.; Cittolin, S.; Clarke, D.; Cline, D.; Cochet, C.; Colas, J.; Colas, P.; Corden, M.; Cox, G.; Dallman, D.; Dau, D.; Debeer, M.; Debrion, J. P.; Degiorgi, M.; della Negra, M.; Demoulin, M.; Denby, B.; Denegri, D.; Diciaccio, A.; Dobrzynski, L.; Dorenbosch, J.; Dowell, J. D.; Duchovni, E.; Edgecock, R.; Eggert, K.; Eisenhandler, E.; Ellis, N.; Erhard, P.; Faissner, H.; Fince Keeler, M.; Flynn, P.; Fontaine, G.; Frey, R.; Frühwirth, R.; Garvey, J.; Gee, D.; Geer, S.; Ghesquière, C.; Ghez, P.; Ghio, F.; Giacomelli, P.; Gibson, W. R.; Giraud-Héraud, Y.; Givernaud, A.; Gonidec, A.; Goodman, M.; Grassmann, H.; Grayer, G.; Guryn, W.; Hansl-Kozanecka, T.; Haynes, W.; Haywood, S. J.; Hoffmann, H.; Holthuizen, D. J.; Homer, R. J.; Homer, R. J.; Honma, A.; Jank, W.; Jimack, M.; Jorat, G.; Kalmus, P. I. P.; Karimäri, V.; Keeler, R.; Kenyon, I.; Kernan, A.; Kienzle, W.; Kinnunen, R.; Kozanecki, W.; Kroll, J.; Kryn, D.; Kyberd, P.; Lacava, F.; Laugier, J. P.; Lees, J. P.; Leuchs, R.; Levegrun, S.; Lévêque, A.; Levi, M.; Linglin, D.; Locci, E.; Long, K.; Markiewicz, T.; Markytan, M.; Martin, T.; Maurin, F.; McMahon, T.; Mendiburu, J.-P.; Meneguzzo, A.; Meyer, O.; Meyer, T.; Minard, M.-N.; Mohammadi, M.; Morgan, K.; Moricca, M.; Moser, H.; Mours, B.; Muller, Th.; Nandi, A.; Naumann, L.; Norton, A.; Paoluzi, L.; Pascoli, D.; Pauss, F.; Perault, C.; Piano Mortari, G.; Pietarinen, E.; Pigot, C.; Pimiä, M.; Pitman, D.; Placci, A.; Porte, J.-P.; Radermacher, E.; Ransdell, J.; Redelberger, T.; Reithler, H.; Revol, J. P.; Richman, J.; Rijssenbeek, M.; Rohlf, J.; Rossi, P.; Roberts, C.; Ruhm, W.; Rubbia, C.; Sajot, G.; Salvini, G.; Sass, J.; Sadoulet, B.; Samyn, D.; Savoy-Navarro, A.; Schinzel, D.; Schwartz, A.; Scott, W.; Scott, W.; Shah, T. P.; Sheer, I.; Siotis, I.; Smith, D.; Sobie, R.; Sphicas, P.; Strauss, J.; Streets, J.; Stubenrauch, C.; Summers, D.; Sumorok, K.; Szonczo, F.; Tao, C.; Ten Have, I.; Thompson, G.; Tscheslog, E.; Tuominiemi, J.; van Eijk, B.; Verecchia, P.; Vialle, J. P.; Virdee, T. S.; von der Schmitt, H.; von Schlippe, W.; Vrana, J.; Vuillemin, V.; Wahl, H. D.; Watkins, P.; Wilke, R.; Wilson, J.; Wingerter, I.; Wimpenny, S. J.; Wulz, C.-E.; Wyatt, T.; Yvert, M.; Zacharov, I.; Zaganidis, N.; Zanello, L.; Zotto, P.

1986-05-01

The inclusive jet cross section has been measured in the UA1 experiment at the CERN pp Collider at centre-of-mass energies √s = 546 GeV and √s = 630 eV. The cross sections are found to be consistent with QCD predictions, The observed change in the cross section with the centre-of-mass energy √s is accounted for in terms of xT scaling.

Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

NASA Technical Reports Server (NTRS)

Norbury, John W.; Adamczyk, Anne; Dick, Frank

2008-01-01

Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

Asymptotic form for the cross section for the Coulomb interacting rearrangement collisions

NASA Technical Reports Server (NTRS)

Omidvar, K.

1973-01-01

It is shown that in a rearrangement collision leading to the formation of the highly excited hydrogenlike states the cross section in all orders of the Born approximation behaves as 1/n sq, with n the principal quantum number, thus invalidating the Brinkman-Kramers approximation for large n. Similarly, in high energy inelastic electron-hydrogenlike atom collisions the exchange cross section for sufficiently large n dominates the direct excitation cross section.

Fe L-shell Excitation Cross Section Measurements on EBIT-I

NASA Astrophysics Data System (ADS)

Chen, Hui; Beiersdorfer, P.; Brown, G.; Boyce, K.; Kelley, R.; Kilbourne, C.; Porter, F.; Gu, M. F.; Kahn, S.

2006-09-01

We report the measurement of electron impact excitation cross sections for the strong iron L-shell 3-2 lines of Fe XVII to Fe XXIV at the LLNL EBIT-I electron beam ion trap using a crystal spectrometer and NASA-Goddard Space Flight Center's 6x6 pixel array microcalorimeter. The cross sections were determined by direct normalization to the well-established cross sections for radiative electron capture. Our results include the excitation cross section for over 50 lines at multiple electron energies. Although we have found that for 3C line in Fe XVII the measured cross sections differ significantly from theory, in most cases the measurements and theory agree within 20%. This work was performed under the auspices of the U.S. DOE by LLNL under contract No. W-7405-Eng-48 and supported by NASA APRA grants to LLNL, GSFC, and Stanford University.

Higgs boson production at hadron colliders at N3LO in QCD

NASA Astrophysics Data System (ADS)

Mistlberger, Bernhard

2018-05-01

We present the Higgs boson production cross section at Hadron colliders in the gluon fusion production mode through N3LO in perturbative QCD. Specifically, we work in an effective theory where the top quark is assumed to be infinitely heavy and all other quarks are considered to be massless. Our result is the first exact formula for a partonic hadron collider cross section at N3LO in perturbative QCD. Furthermore, our result is an analytic computation of a hadron collider cross section involving elliptic integrals. We derive numerical predictions for the Higgs boson cross section at the LHC. Previously this result was approximated by an expansion of the cross section around the production threshold of the Higgs boson and we compare our findings. Finally, we study the impact of our new result on the state of the art prediction for the Higgs boson cross section at the LHC.

Studies of electron-molecule collisions - Applications to e-H2O

NASA Technical Reports Server (NTRS)

Brescansin, L. M.; Lima, M. A. P.; Gibson, T. L.; Mckoy, V.; Huo, W. M.

1986-01-01

Elastic differential and momentum transfer cross sections for the elastic scattering of electrons by H2O are reported for collision energies from 2 to 20 eV. These fixed-nuclei static-exchange cross sections were obtained using the Schwinger variational approach. In these studies the exchange potential is directly evaluated and not approximated by local models. The calculated differential cross sections, obtained with a basis set expansion of the scattering wave function, agree well with available experimental data at intermediate and larger angles. As used here, the results cannot adequately describe the divergent cross sections at small angles. An interesting feature of the calculated cross sections, particularly at 15 and 20 eV, is their significant backward peaking. This peaking occurs in the experimentally inaccessible region beyond a scattering angle of 120 deg. The implication of this feature for the determination of momentum transfer cross sections is described.

Cross section data sets for electron collisions with H2, O2, CO, CO2, N2O and H2O

NASA Astrophysics Data System (ADS)

Anzai, K.; Kato, H.; Hoshino, M.; Tanaka, H.; Itikawa, Y.; Campbell, L.; Brunger, M. J.; Buckman, S. J.; Cho, H.; Blanco, F.; Garcia, G.; Limão-Vieira, P.; Ingólfsson, O.

2012-02-01

We review earlier cross section data sets for electron-collisions with H2, O2, CO, CO2, H2O and N2O, updated here by experimental results for their electronic states. Based on our recent measurements of differential cross sections for the electronic states of those molecules, integral cross sections (ICSs) are derived by applying a generalized oscillator strength analysis and then assessed against theory (BE f-scaling [Y.-K. Kim, J. Chem. Phys. 126, 064305 (2007)]). As they now represent benchmark electronic state cross sections, those ICSs for the above molecules are added into the original cross section sets taken from the data reviews for H2, O2, CO2 and H2O (the Itikawa group), and for CO and N2O (the Zecca group).

Heavy fragment production cross sections from 1.05 GeV/nucleon 56Fe in C, Al, Cu, Pb, and CH2 targets

NASA Technical Reports Server (NTRS)

Zeitlin, C.; Heilbronn, L.; Miller, J.; Rademacher, S. E.; Borak, T.; Carter, T. R.; Frankel, K. A.; Schimmerling, W.; Stronach, C. E.; Chatterjee, A. (Principal Investigator)

1997-01-01

We have obtained charge-changing cross sections and partial cross sections for fragmentation of 1.05 GeV/nucleon Fe projectiles incident on H, C, Al, Cu, and Pb nuclei. The energy region covered by this experiment is critical for an understanding of galactic cosmic ray propagation and space radiation biophysics. Surviving primary beam particles and fragments with charges from 12 to 25 produced within a forward cone of half-angle 61 mrad were detected using a silicon detector telescope to identify their charge and the cross sections were calculated after correction of the measured yields for finite target thickness effects. The cross sections are compared to model calculations and to previous measurements. Cross sections for the production of fragments with even-numbered nuclear charges are seen to be enhanced in almost all cases.

Activation cross section and isomeric cross section ratios for the (n ,2 n ) reaction on 153Eu

NASA Astrophysics Data System (ADS)

Luo, Junhua; Jiang, Li; Li, Suyuan

2017-10-01

The 153Eu(n ,2 n ) m1,m2,g152Eu cross section was measured by means of the activation technique at three neutron energies in the range 13-15 MeV. The quasimonoenergetic neutron beam was formed via the 3H(d ,n ) 4He reaction, in the Pd-300 Neutron Generator at the Chinese Academy of Engineering Physics (CAEP). The activities induced in the reaction products were measured using high-resolution γ-ray spectroscopy. The cross section of the population of the second high-spin (8-) isomeric state was measured along with the reaction cross section populating both the ground (3-) and the first isomeric state (0-). Cross sections were also evaluated theoretically using the numerical code TALYS-1.8, with different level density options at neutron energies varying from the reaction threshold to 20 MeV. Results are discussed and compared with the corresponding literature.

Progress on China nuclear data processing code system

NASA Astrophysics Data System (ADS)

Liu, Ping; Wu, Xiaofei; Ge, Zhigang; Li, Songyang; Wu, Haicheng; Wen, Lili; Wang, Wenming; Zhang, Huanyu

2017-09-01

China is developing the nuclear data processing code Ruler, which can be used for producing multi-group cross sections and related quantities from evaluated nuclear data in the ENDF format [1]. The Ruler includes modules for reconstructing cross sections in all energy range, generating Doppler-broadened cross sections for given temperature, producing effective self-shielded cross sections in unresolved energy range, calculating scattering cross sections in thermal energy range, generating group cross sections and matrices, preparing WIMS-D format data files for the reactor physics code WIMS-D [2]. Programming language of the Ruler is Fortran-90. The Ruler is tested for 32-bit computers with Windows-XP and Linux operating systems. The verification of Ruler has been performed by comparison with calculation results obtained by the NJOY99 [3] processing code. The validation of Ruler has been performed by using WIMSD5B code.

Electron-induced scattering dynamics of Boron, Aluminium and Gallium trihalides in the intermediate energy domain

NASA Astrophysics Data System (ADS)

Verma, Pankaj; Alam, Mohammad Jane; Ahmad, Shabbir; Antony, Bobby

2018-05-01

This article is focused on the calculation of electron-induced ionisation and total scattering cross sections by Boron, Aluminium and Gallium trihalide molecules in the intermediate energy domain. The computational formalism, spherical complex optical potential has been employed for the study of these two scattering cross sections. The ionisation cross section has been derived from the inelastic cross section using a semi-empirical method called complex scattering potential-ionisation contribution (CSP-ic) method. We have also calculated the ionisation cross section using the BEB theory with Hartree-Fock and density functional theory (DFT- ωB97XD) orbitals so that a comparison can be made with the cross sections predicted by CSP-ic method. For this theoretical study, we have also calculated polarisability and bond length of some targets which were not found in literature using DFT/B3LYP in Gaussian 09 software.

Medium modified two-body scattering amplitude from proton-nucleus total cross-sections

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

2001-01-01

Recently (R.K. Tripathi, J.W. Wilson, F.A. Cucinotta, Nucl. Instr. and Meth. B 145 (1998) 277; R.K. Tripathi, F.A. Cucinotta, J.W. Wilson, NASA-TP-1998-208438), we have extracted nucleon-nucleon (N-N) cross-sections in the medium directly from experiment. The in-medium N-N cross-sections form the basic ingredients of several heavy-ion scattering approaches including the coupled-channel approach developed at the NASA Langley Research Center. Here, we investigate the ratio of real to imaginary part of the two-body scattering amplitude in the medium. These ratios are used in combination with the in-medium N-N cross-sections to calculate total proton-nucleus cross-sections. The agreement is excellent with the available experimental data. These cross-sections are needed for the radiation risk assessment of space missions. c2001 Elsevier Science B.V. All rights reserved.

Interactions of relativistic neon to nickel projectiles in hydrogen, elemental production cross sections

NASA Astrophysics Data System (ADS)

Knott, C. N.; Albergo, S.; Caccia, Z.; Chen, C.-X.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T. G.; Insolia, A.; Jones, F. C.; Lindstrom, P. J.; Mitchell, J. W.; Potenza, R.; Romanski, J.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.

1996-01-01

This paper reports the elemental production cross sections for 17 projectile-energy combinations with energies between 338 and 894 MeV/nucleon interacting in a liquid hydrogen target. These results were obtained from two runs at the LBL Bevalac using projectiles ranging from 22Ne to 58Ni. Cross sections were measured for all fragment elements with charges greater than or equal to half the charge of the projectile. The results show that, over the energy and ion range investigated, the general decrease in cross section with decreasing fragment charge is strongly modified by the isospin of the projectile ion. Significant additional modifications of the cross sections due to the internal structure of the nucleus have also been seen. These include both pairing and shell effects. Differences in the cross sections due to the differing energies of the projectile are also considerable.

242Pu absolute neutron-capture cross section measurement

NASA Astrophysics Data System (ADS)

Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.

2017-09-01

The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. During target fabrication, a small amount of 239Pu was added to the active target so that the absolute scale of the 242Pu(n,γ) cross section could be set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. The relative scale of the 242Pu(n,γ) cross section covers four orders of magnitude for incident neutron energies from thermal to ≈ 40 keV. The cross section reported in ENDF/B-VII.1 for the 242Pu(n,γ) En,R = 2.68 eV resonance was found to be 2.4% lower than the new absolute 242Pu(n,γ) cross section.

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

Vonach, H.; Tagesen, S.

Starting with a discussion of the requirements and goals for high quality general-purpose evaluations the paper will describe the procedures chosen in our evaluation work for JEFF for producing new general evaluations with complete covariance information for all cross sections (file 3 data). Key problems essential for the goal of making the best possible use of the existing theoretical and experimental knowledge on neutron interactions with the respective nuclide will be addressed, especially the problem of assigning covariances to calculated cross sections, necessary checking procedures for all experimental data and various possibilities to amend the experimental database beyond the obviousmore » use of EXFOR data for the respective cross sections. In this respect both, the use of elemental cross sections in isotopic evaluations and the use of implicit cross-section data (that is data which can be converted into cross sections by simple methods) will be discussed in some detail.« less

Communication: Electron ionization of DNA bases

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

Rahman, M. A.; Krishnakumar, E., E-mail: ekkumar@tifr.res.in

2016-04-28

No reliable experimental data exist for the partial and total electron ionization cross sections for DNA bases, which are very crucial for modeling radiation damage in genetic material of living cell. We have measured a complete set of absolute partial electron ionization cross sections up to 500 eV for DNA bases for the first time by using the relative flow technique. These partial cross sections are summed to obtain total ion cross sections for all the four bases and are compared with the existing theoretical calculations and the only set of measured absolute cross sections. Our measurements clearly resolve themore » existing discrepancy between the theoretical and experimental results, thereby providing for the first time reliable numbers for partial and total ion cross sections for these molecules. The results on fragmentation analysis of adenine supports the theory of its formation in space.« less

Low- ν Flux and Total Charged-current Cross Sections in MINERvA

NASA Astrophysics Data System (ADS)

Ren, Lu

2014-03-01

The MINER νA experiment measures neutrino and antineutrino interaction cross sections on carbon and other nuclei. Cross section measurements require accurate knowledge of the incident neutrino flux. The ``low- ν'' flux technique uses a standard-candle cross section for events with low energy transfer to to the hadronic system to determine the incident flux. MINER νA will use low- ν fluxes for neutrinos and antineutrinos to tune production models used in beam simulations and to extract total cross sections as a function of energy. We present the low- ν flux technique adapted for the MINER νA data samples and preliminary results for the extracted low- ν fluxes in MINER νA. MINER νA will extend the range of antineutino charged-current cross section measurements to lower energies which are of interest to future accelerator oscillation experiments.

α-induced reaction cross sections in the mass range A ≈ 20 - 50: a critical review

NASA Astrophysics Data System (ADS)

Mohr, Peter

2018-01-01

In a recent review it was shown that the cross sections of α-induced reactions in the A ≈ 20 - 50 mass range follow a general and smooth trend in most cases. For comparison of cross sections of different targets at various energies the method of reduced cross sections σ red and reduced energies E red was used. Four outliers were identified: 36Ar and 40Ar with unusal small cross sections and 23Na and 33S with unusual huge cross sections. New data for 23Na were presented at this NPA-7 conference; contrary to the previous data, these new data fit into the general systematics. In addition, a relation between the most effective energy E 0 for astrophysical reaction rates (the so-called Gamow window) and the reduced energy E red is presented.

Effect of wave function on the proton induced L XRP cross sections for {sub 62}Sm and {sub 74}W

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

Shehla,; Kaur, Rajnish; Kumar, Anil

The L{sub k}(k= 1, α, β, γ) X-ray production cross sections have been calculated for {sub 74}W and {sub 62}Sm at different incident proton energies ranging 1-5 MeV using theoretical data sets of different physical parameters, namely, the Li(i=1-3) sub-shell X-ray emission rates based on the Dirac-Fork (DF) model, the fluorescence and Coster Kronig yields based on the Dirac- Hartree-Slater (DHS) model and two sets the proton ionization cross sections based on the DHS model and the ECPSSR in order to assess the influence of the wave function on the XRP cross sections. The calculated cross sections have been compared withmore » the measured cross sections reported in the recent compilation to check the reliability of the calculated values.« less

Novel mTORC1 and 2 Signaling Pathways in Polycystic Kidney Disease (PKD)

DTIC Science & Technology

2017-09-01

AWARD NUMBER: W81XWH-16-1-0172 TITLE: Novel mTORC1 and 2 Signaling Pathways in Polycystic Kidney Disease (PKD) PRINCIPAL INVESTIGATOR: Charles...TITLE AND SUBTITLE 5a. CONTRACT NUMBER W81XWH-16-1-0172 Novel mTORC1 and 2 Signaling Pathways in Polycystic Kidney Disease (PKD) 5b. GRANT NUMBER 5c...investigate the effects of mTORC1 (Raptor) knockout, mTORC2 (Rictor) knockout or combined mTORC1 and 2 knockout on cyst growth and kidney function. The

Novel Therapeutic Targets to Inhibit Tumor Microenvironment-Induced Castration Resistant Prostate Cancer

DTIC Science & Technology

2016-10-01

MAPK4. We are also in the process of generating MAPK4-knockout LNCaP cells using the CRISPR /Cas9 system. Altogether, we hope that we can generate the...engineered LNCaP cells that are stable for either total loss of MAPK4 ( CRISPR /Cas9 knockout) or with inducible knockdown of MAPK4 (Dox-inducible...knockdown or CRISPR /Cas9 mediated knockout of MAPK4 (we are working on them). Major Task 2: Determine whether inhibition of MAPK4 (in PCa) and TGF-β

Proton Knock-Out in Hall A

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

Kees de Jager

Proton knock-out is studied in a broad program in Hall A at Jefferson Lab. The first experiment performed in Hall A studied the {sup 16}O(e,e'p) reaction. Since then proton knock-out experiments have studied a variety of aspects of that reaction, from single-nucleon properties to its mechanism, such as final-state interactions and two-body currents, in nuclei from {sup 2}H to {sup 16}O. In this review the results of this program will be summarized and an outlook given of future accomplishments.

Geologic Cross Section I–I′ Through the Appalachian Basin from the Eastern Margin of the Illinois Basin, Jefferson County, Kentucky, to the Valley and Ridge Province, Scott County, Virginia

USGS Publications Warehouse

Ryder, Robert T.; Trippi, Michael H.; Swezey, Christopher S.

2015-12-08

Cross section I‒I ’ contains much information that is useful for evaluating energy resources in the Appalachian basin. Many of the key elements of the Appalachian basin petroleum systems (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and petroleum migration pathways) may be evaluated by burial history, thermal history, and fluid flow models on the basis of what is shown on the cross section. Cross section I‒I’ also provides a stratigraphic and structural framework for the Pennsylvanian coal-bearing section. In addition, geologists and engineers could use cross section I‒I’ as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste or for the sequestration of carbon dioxide.

Validity of Hansen-Roach cross sections in low-enriched uranium systems

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

Busch, R.D.; O'Dell, R.D.

Within the nuclear criticality safety community, the Hansen-Roach 16 group cross section set has been the standard'' for use in k{sub eff} calculations over the past 30 years. Yet even with its widespread acceptance, there are still questions about its validity and adequacy, about the proper procedure for calculating the potential scattering cross section, {sigma}{sub p}, for uranium and plutonium, and about the concept of resonance self shielding and its impact on cross sections. This paper attempts to address these questions. It provides a brief background on the Hansen-Roach cross sections. Next is presented a review of resonances in crossmore » sections, self shielding of these resonances, and the use of {sigma}{sub p} to characterize resonance self shielding. Three prescriptions for calculating {sigma}{sub p} are given. Finally, results of several calculations of k{sub eff} on low-enriched uranium systems are provided to confirm the validity of the Hansen-Roach cross sections when applied to such systems.« less

Effect of knockout of α2δ-1 on action potentials in mouse sensory neurons.

PubMed

Margas, Wojciech; Ferron, Laurent; Nieto-Rostro, Manuela; Schwartz, Arnold; Dolphin, Annette C

2016-08-05

Gene deletion of the voltage-gated calcium channel auxiliary subunit α2δ-1 has been shown previously to have a cardiovascular phenotype, and a reduction in mechano- and cold sensitivity, coupled with delayed development of neuropathic allodynia. We have also previously shown that dorsal root ganglion (DRG) neuron calcium channel currents were significantly reduced in α2δ-1 knockout mice. To extend our findings in these sensory neurons, we have examined here the properties of action potentials (APs) in DRG neurons from α2δ-1 knockout mice in comparison to their wild-type (WT) littermates, in order to dissect how the calcium channels that are affected by α2δ-1 knockout are involved in setting the duration of individual APs and their firing frequency. Our main findings are that there is reduced Ca(2+) entry on single AP stimulation, particularly in the axon proximal segment, reduced AP duration and reduced firing frequency to a 400 ms stimulation in α2δ-1 knockout neurons, consistent with the expected role of voltage-gated calcium channels in these events. Furthermore, lower intracellular Ca(2+) buffering also resulted in reduced AP duration, and a lower frequency of AP firing in WT neurons, mimicking the effect of α2δ-1 knockout. By contrast, we did not obtain any consistent evidence for the involvement of Ca(2+)-activation of large conductance calcium-activated potassium (BK) and small conductance calcium-activated potassium (SK) channels in these events. In conclusion, the reduced Ca(2+) elevation as a result of single AP stimulation is likely to result from the reduced duration of the AP in α2δ-1 knockout sensory neurons.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. © 2016 The Authors.

GLT-1: The elusive presynaptic glutamate transporter

PubMed Central

Rimmele, Theresa S.; Rosenberg, Paul A.

2016-01-01

Historically, glutamate uptake in the CNS was mainly attributed to glial cells for three reasons: 1) none of the glutamate transporters were found to be located in presynaptic terminals of excitatory synapses; 2) the putative glial transporters, GLT-1 and GLAST are expressed at high levels in astrocytes; 3) studies of the constitutive GLT-1 knockout as well as pharmacological studies demonstrated that >90% of glutamate uptake into forebrain synaptosomes is mediated by the operation of GLT-1. Here we summarize the history leading up to the recognition of GLT-1a as a presynaptic glutamate transporter. A major issue now is understanding the physiological and pathophysiologial significance of the expression of GLT-1 in presynaptic terminals. To elucidate the cell-type specific functions of GLT-1, a conditional knockout was generated with which to inactivate the GLT-1 gene in different cell types using Cre/lox technology. Astrocytic knockout led to an 80% reduction of GLT-1 expression, resulting in intractable seizures and early mortality as seen also in the constitutive knockout. Neuronal knockout was associated with no obvious phenotype. Surprisingly, synaptosomal uptake capacity (Vmax) was found to be significantly reduced, by 40%, in the neuronal knockout, indicating that the contribution of neuronal GLT-1 to synaptosomal uptake is disproportionate to its protein expression (5–10%). Conversely, the contribution of astrocytic GLT-1 to synaptosomal uptake was much lower than expected. In contrast, the loss of uptake into liposomes prepared from brain protein from astrocyte and neuronal knockouts was proportionate with the loss of GLT-1 protein, suggesting that a large portion of GLT-1 in astrocytic membranes in synaptosomal preparations is not functional, possibly because of a failure to reseal. These results suggest the need to reinterpret many previous studies using synaptosomal uptake to investigate glutamate transport itself as well as changes in glutamate homeostasis associated with normal functions, neurodegeneration, and response to drugs. PMID:27129805

Changes in the expression of neurotransmitter receptors in Parkin and DJ-1 knockout mice--A quantitative multireceptor study.

PubMed

Cremer, J N; Amunts, K; Schleicher, A; Palomero-Gallagher, N; Piel, M; Rösch, F; Zilles, K

2015-12-17

Parkinson's disease (PD) is a well-characterized neurological disorder with regard to its neuropathological and symptomatic appearance. At the genetic level, mutations of particular genes, e.g. Parkin and DJ-1, were found in human hereditary PD with early onset. Neurotransmitter receptors constitute decisive elements in neural signal transduction. Furthermore, since they are often altered in neurological and psychiatric diseases, receptors have been successful targets for pharmacological agents. However, the consequences of PD-associated gene mutations on the expression of transmitter receptors are largely unknown. Therefore, we studied the expression of 16 different receptor binding sites of the neurotransmitters glutamate, GABA, acetylcholine, adrenaline, serotonin, dopamine and adenosine by means of quantitative receptor autoradiography in Parkin and DJ-1 knockout mice. These knockout mice exhibit electrophysiological and behavioral deficits, but do not show the typical dopaminergic cell loss. We demonstrated differential changes of binding site densities in eleven brain regions. Most prominently, we found an up-regulation of GABA(B) and kainate receptor densities in numerous cortical areas of Parkin and DJ-1 knockout mice, as well as increased NMDA but decreased AMPA receptor densities in different brain regions of the Parkin knockout mice. The alterations of three different glutamate receptor types may indicate the potential relevance of the glutamatergic system in the pathogenesis of PD. Furthermore, the cholinergic M1, M2 and nicotinic receptors as well as the adrenergic α2 and the adenosine A(2A) receptors showed differentially increased densities in Parkin and DJ-1 knockout mice. Taken together, knockout of the PD-associated genes Parkin or DJ-1 results in differential changes of neurotransmitter receptor densities, highlighting a possible role of altered non-dopaminergic, and in particular of glutamatergic neurotransmission in PD pathogenesis. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Increased Contextual Fear Conditioning in iNOS Knockout Mice: Additional Evidence for the Involvement of Nitric Oxide in Stress-Related Disorders and Contribution of the Endocannabinoid System

PubMed Central

Gomes, Felipe V.; Silva, Andréia L.; Uliana, Daniela L.; Camargo, Laura H. A.; Guimarães, Francisco S.; Cunha, Fernando Q.; Joca, Sâmia R. L.; Resstel, Leonardo B. M.

2015-01-01

Background: Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expression and extinction of contextual fear conditioning of inducible nitric oxide knockout mice and possible involvement of endocannabinoids in these responses. Methods: We evaluated the effects of a preferential neuronal nitric oxide synthase inhibitor, 7-nitroindazol, nitric oxide synthase activity, and mRNA changes of nitrergic and endocannabinoid systems components in the medial prefrontal cortex and hippocampus of wild-type and knockout mice. The effects of URB597, an inhibitor of the fatty acid amide hydrolase enzyme, which metabolizes the endocannabinoid anandamide, WIN55,212-2, a nonselective cannabinoid agonist, and AM281, a selective CB1 antagonist, on contextual fear conditioning were also evaluated. Results: Contextual fear conditioning expression was similar in wild-type and knockout mice, but the latter presented extinction deficits and increased basal nitric oxide synthase activity in the medial prefrontal cortex. 7-Nitroindazol decreased fear expression and facilitated extinction in wild-type and knockout mice. URB597 decreased fear expression in wild-type and facilitated extinction in knockout mice, whereas WIN55,212-2 and AM281 increased it in wild-type mice. Nonconditioned knockout mice showed changes in the mRNA expression of nitrergic and endocannabinoid system components in the medial prefrontal cortex and hippocampus that were modified by fear conditioning. Conclusion: These data reinforce the involvement of the nitric oxide and endocannabinoids (anandamide) in stress-related disorders and point to a deregulation of the endocannabinoid system in situations where nitric oxide signaling is increased. PMID:25618404

Increased Contextual Fear Conditioning in iNOS Knockout Mice: Additional Evidence for the Involvement of Nitric Oxide in Stress-Related Disorders and Contribution of the Endocannabinoid System.

PubMed

Lisboa, Sabrina F; Gomes, Felipe V; Silva, Andréia L; Uliana, Daniela L; Camargo, Laura H A; Guimarães, Francisco S; Cunha, Fernando Q; Joca, Sâmia R L; Resstel, Leonardo B M

2015-01-24

Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expression and extinction of contextual fear conditioning of inducible nitric oxide knockout mice and possible involvement of endocannabinoids in these responses. We evaluated the effects of a preferential neuronal nitric oxide synthase inhibitor, 7-nitroindazol, nitric oxide synthase activity, and mRNA changes of nitrergic and endocannabinoid systems components in the medial prefrontal cortex and hippocampus of wild-type and knockout mice. The effects of URB597, an inhibitor of the fatty acid amide hydrolase enzyme, which metabolizes the endocannabinoid anandamide, WIN55,212-2, a nonselective cannabinoid agonist, and AM281, a selective CB1 antagonist, on contextual fear conditioning were also evaluated. Contextual fear conditioning expression was similar in wild-type and knockout mice, but the latter presented extinction deficits and increased basal nitric oxide synthase activity in the medial prefrontal cortex. 7-Nitroindazol decreased fear expression and facilitated extinction in wild-type and knockout mice. URB597 decreased fear expression in wild-type and facilitated extinction in knockout mice, whereas WIN55,212-2 and AM281 increased it in wild-type mice. Nonconditioned knockout mice showed changes in the mRNA expression of nitrergic and endocannabinoid system components in the medial prefrontal cortex and hippocampus that were modified by fear conditioning. These data reinforce the involvement of the nitric oxide and endocannabinoids (anandamide) in stress-related disorders and point to a deregulation of the endocannabinoid system in situations where nitric oxide signaling is increased. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Altered Sleep and Affect in the Neurotensin Receptor 1 Knockout Mouse

PubMed Central

Fitzpatrick, Karrie; Winrow, Christopher J.; Gotter, Anthony L.; Millstein, Joshua; Arbuzova, Janna; Brunner, Joseph; Kasarskis, Andrew; Vitaterna, Martha H.; Renger, John J.; Turek, Fred W.

2012-01-01

Study Objective: Sleep and mood disorders have long been understood to have strong genetic components, and there is considerable comorbidity of sleep abnormalities and mood disorders, suggesting the involvement of common genetic pathways. Here, we examine a candidate gene implicated in the regulation of both sleep and affective behavior using a knockout mouse model. Design: Previously, we identified a quantitative trait locus (QTL) for REM sleep amount, REM sleep bout number, and wake amount in a genetically segregating population of mice. Here, we show that traits mapping to this QTL correlated with an expression QTL for neurotensin receptor 1 (Ntsr1), a receptor for neurotensin, a ligand known to be involved in several psychiatric disorders. We examined sleep as well as behaviors indicative of anxiety and depression in the NTSR1 knockout mouse. Measurements and Results: NTSR1 knockouts had a lower percentage of sleep time spent in REM sleep in the dark phase and a larger diurnal variation in REM sleep duration than wild types under baseline conditions. Following sleep deprivation, NTSR1 knockouts exhibited more wake and less NREM rebound sleep. NTSR1 knockouts also showed increased anxious and despair behaviors. Conclusions: Here we illustrate a link between expression of the Ntsr1 gene and sleep traits previously associated with a particular QTL. We also demonstrate a relationship between Ntsr1 and anxiety and despair behaviors. Given the considerable evidence that anxiety and depression are closely linked with abnormalities in sleep, the data presented here provide further evidence that neurotensin and Ntsr1 may be a component of a pathway involved in both sleep and mood disorders. Citation: Fitzpatrick K; Winrow CJ; Gotter AL; Millstein J; Arbuzova J; Brunner J; Kasarskis A; Vitaterna MH; Renger JJ; Turek FW. Altered sleep and affect in the neurotensin receptor 1 knockout mouse. SLEEP 2012;35(7):949-956. PMID:22754041

Severe hypertriglyceridemia, reduced high density lipoprotein, and neonatal death in lipoprotein lipase knockout mice. Mild hypertriglyceridemia with impaired very low density lipoprotein clearance in heterozygotes.

PubMed Central

Weinstock, P H; Bisgaier, C L; Aalto-Setälä, K; Radner, H; Ramakrishnan, R; Levak-Frank, S; Essenburg, A D; Zechner, R; Breslow, J L

1995-01-01

Lipoprotein lipase (LPL)-deficient mice have been created by gene targeting in embryonic stem cells. At birth, homozygous knockout pups have threefold higher triglycerides and sevenfold higher VLDL cholesterol levels than controls. When permitted to suckle, LPL-deficient mice become pale, then cyanotic, and finally die at approximately 18 h of age. Before death, triglyceride levels are severely elevated (15,087 +/- 3,805 vs 188 +/- 71 mg/dl in controls). Capillaries in tissues of homozygous knockout mice are engorged with chylomicrons. This is especially significant in the lung where marginated chylomicrons prevent red cell contact with the endothelium, a phenomenon which is presumably the cause of cyanosis and death in these mice. Homozygous knockout mice also have diminished adipose tissue stores as well as decreased intracellular fat droplets. By crossbreeding with transgenic mice expressing human LPL driven by a muscle-specific promoter, mouse lines were generated that express LPL exclusively in muscle but not in any other tissue. This tissue-specific LPL expression rescued the LPL knockout mice and normalized their lipoprotein pattern. This supports the contention that hypertriglyceridemia caused the death of these mice and that LPL expression in a single tissue was sufficient for rescue. Heterozygous LPL knockout mice survive to adulthood and have mild hypertriglyceridemia, with 1.5-2-fold elevated triglyceride levels compared with controls in both the fed and fasted states on chow, Western-type, or 10% sucrose diets. In vivo turnover studies revealed that heterozygous knockout mice had impaired VLDL clearance (fractional catabolic rate) but no increase in transport rate. In summary, total LPL deficiency in the mouse prevents triglyceride removal from plasma, causing death in the neonatal period, and expression of LPL in a single tissue alleviates this problem. Furthermore, half-normal levels of LPL cause a decrease in VLDL fractional catabolic rate and mild hypertriglyceridemia, implying that partial LPL deficiency has physiological consequences. Images PMID:8675619

Automated Cross-Sectional Measurement Method of Intracranial Dural Venous Sinuses.

PubMed

Lublinsky, S; Friedman, A; Kesler, A; Zur, D; Anconina, R; Shelef, I

2016-03-01

MRV is an important blood vessel imaging and diagnostic tool for the evaluation of stenosis, occlusions, or aneurysms. However, an accurate image-processing tool for vessel comparison is unavailable. The purpose of this study was to develop and test an automated technique for vessel cross-sectional analysis. An algorithm for vessel cross-sectional analysis was developed that included 7 main steps: 1) image registration, 2) masking, 3) segmentation, 4) skeletonization, 5) cross-sectional planes, 6) clustering, and 7) cross-sectional analysis. Phantom models were used to validate the technique. The method was also tested on a control subject and a patient with idiopathic intracranial hypertension (4 large sinuses tested: right and left transverse sinuses, superior sagittal sinus, and straight sinus). The cross-sectional area and shape measurements were evaluated before and after lumbar puncture in patients with idiopathic intracranial hypertension. The vessel-analysis algorithm had a high degree of stability with <3% of cross-sections manually corrected. All investigated principal cranial blood sinuses had a significant cross-sectional area increase after lumbar puncture (P ≤ .05). The average triangularity of the transverse sinuses was increased, and the mean circularity of the sinuses was decreased by 6% ± 12% after lumbar puncture. Comparison of phantom and real data showed that all computed errors were <1 voxel unit, which confirmed that the method provided a very accurate solution. In this article, we present a novel automated imaging method for cross-sectional vessels analysis. The method can provide an efficient quantitative detection of abnormalities in the dural sinuses. © 2016 by American Journal of Neuroradiology.

A computational study on the influence of insect wing geometry on bee flight mechanics

PubMed Central

Feaster, Jeffrey; Bayandor, Javid

2017-01-01

ABSTRACT Two-dimensional computational fluid dynamics (CFD) is applied to better understand the effects of wing cross-sectional morphology on flow field and force production. This study investigates the influence of wing cross-section on insect scale flapping flight performance, for the first time, using a morphologically representative model of a bee (Bombus pensylvanicus) wing. The bee wing cross-section was determined using a micro-computed tomography scanner. The results of the bee wing are compared with flat and elliptical cross-sections, representative of those used in modern literature, to determine the impact of profile variation on aerodynamic performance. The flow field surrounding each cross-section and the resulting forces are resolved using CFD for a flight speed range of 1 to 5 m/s. A significant variation in vortex formation is found when comparing the ellipse and flat plate with the true bee wing. During the upstroke, the bee and approximate wing cross-sections have a much shorter wake structure than the flat plate or ellipse. During the downstroke, the flat plate and elliptical cross-sections generate a single leading edge vortex, while the approximate and bee wings generate numerous, smaller structures that are shed throughout the stroke. Comparing the instantaneous aerodynamic forces on the wing, the ellipse and flat plate sections deviate progressively with velocity from the true bee wing. Based on the present findings, a simplified cross-section of an insect wing can misrepresent the flow field and force production. We present the first aerodynamic study using a true insect wing cross-section and show that the wing corrugation increases the leading edge vortex formation frequency for a given set of kinematics. PMID:29061734

A computational study on the influence of insect wing geometry on bee flight mechanics.

PubMed

Feaster, Jeffrey; Battaglia, Francine; Bayandor, Javid

2017-12-15

Two-dimensional computational fluid dynamics (CFD) is applied to better understand the effects of wing cross-sectional morphology on flow field and force production. This study investigates the influence of wing cross-section on insect scale flapping flight performance, for the first time, using a morphologically representative model of a bee ( Bombus pensylvanicus ) wing. The bee wing cross-section was determined using a micro-computed tomography scanner. The results of the bee wing are compared with flat and elliptical cross-sections, representative of those used in modern literature, to determine the impact of profile variation on aerodynamic performance. The flow field surrounding each cross-section and the resulting forces are resolved using CFD for a flight speed range of 1 to 5 m/s. A significant variation in vortex formation is found when comparing the ellipse and flat plate with the true bee wing. During the upstroke, the bee and approximate wing cross-sections have a much shorter wake structure than the flat plate or ellipse. During the downstroke, the flat plate and elliptical cross-sections generate a single leading edge vortex, while the approximate and bee wings generate numerous, smaller structures that are shed throughout the stroke. Comparing the instantaneous aerodynamic forces on the wing, the ellipse and flat plate sections deviate progressively with velocity from the true bee wing. Based on the present findings, a simplified cross-section of an insect wing can misrepresent the flow field and force production. We present the first aerodynamic study using a true insect wing cross-section and show that the wing corrugation increases the leading edge vortex formation frequency for a given set of kinematics. © 2017. Published by The Company of Biologists Ltd.

Knock-Outs, Stick-Outs, Cut-Outs: Clipping Paths Separate Objects from Background.

ERIC Educational Resources Information Center

Wilson, Bradley

1998-01-01

Outlines a six-step process that allows computer operators, using Photoshop software, to create "knock-outs" to precisely define the path that will serve to separate the object from the background. (SR)

A 23-GROUP NEUTRON THERMALIZATION CROSS SECTION LIBRARY

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

Doctor, R.D.; Boling, M.A.

1963-07-15

A set of 23-group neutron cross sections for use in the calculation of neutron thermalization and thermal neutron spectral effects in SNAP reactors is compiled. The sources and methods used to obtain the cross sections are described. (auth)

An evaluation of the reliability of muscle fiber cross-sectional area and fiber number measurements in rat skeletal muscle

USDA-ARS?s Scientific Manuscript database

Background: The reliability of estimating muscle fiber cross-sectional area (measure of muscle fiber size) and fiber number from only a subset of fibers in rat hindlimb muscle cross-sections has not been systematically evaluated. This study examined the variability in mean estimates of fiber cross-s...

Generating gene knockout rats by homologous recombination in embryonic stem cells

PubMed Central

Tong, Chang; Huang, Guanyi; Ashton, Charles; Li, Ping; Ying, Qi-Long

2013-01-01

We describe here a detailed protocol for generating gene knockout rats by homologous recombination in embryonic stem (ES) cells. This protocol comprises the following procedures: derivation and expansion of rat ES cells, construction of gene-targeting vectors, generation of gene-targeted rat ES cells and, finally, production of gene-targeted rats. The major differences between this protocol and the classical mouse gene-targeting protocol include ES cell culture methods, drug selection scheme, colony picking and screening strategies. This ES cell–based gene-targeting technique allows sophisticated genetic modifications to be performed in the rat, as many laboratories have been doing in the mouse for the past two decades. Recently we used this protocol to generate Tp53 (also known as p53) gene knockout rats. The entire process requires ~1 year to complete, from derivation of ES cells to generation of knockout rats. PMID:21637202

CRISPR/Cas9-mediated gene knockout of NANOG and NANOGP8 decreases the malignant potential of prostate cancer cells.

PubMed

Kawamura, Norihiko; Nimura, Keisuke; Nagano, Hiromichi; Yamaguchi, Sohei; Nonomura, Norio; Kaneda, Yasufumi

2015-09-08

NANOG expression in prostate cancer is highly correlated with cancer stem cell characteristics and resistance to androgen deprivation. However, it is not clear whether NANOG or its pseudogenes contribute to the malignant potential of cancer. We established NANOG- and NANOGP8-knockout DU145 prostate cancer cell lines using the CRISPR/Cas9 system. Knockouts of NANOG and NANOGP8 significantly attenuated malignant potential, including sphere formation, anchorage-independent growth, migration capability, and drug resistance, compared to parental DU145 cells. NANOG and NANOGP8 knockout did not inhibit in vitro cell proliferation, but in vivo tumorigenic potential decreased significantly. These phenotypes were recovered in NANOG- and NANOGP8-rescued cell lines. These results indicate that NANOG and NANOGP8 proteins are expressed in prostate cancer cell lines, and NANOG and NANOGP8 equally contribute to the high malignant potential of prostate cancer.

Mapping pathological phenotypes in a mouse model of CDKL5 disorder.

PubMed

Amendola, Elena; Zhan, Yang; Mattucci, Camilla; Castroflorio, Enrico; Calcagno, Eleonora; Fuchs, Claudia; Lonetti, Giuseppina; Silingardi, Davide; Vyssotski, Alexei L; Farley, Dominika; Ciani, Elisabetta; Pizzorusso, Tommaso; Giustetto, Maurizio; Gross, Cornelius T

2014-01-01

Mutations in cyclin-dependent kinase-like 5 (CDKL5) cause early-onset epileptic encephalopathy, a neurodevelopmental disorder with similarities to Rett Syndrome. Here we describe the physiological, molecular, and behavioral phenotyping of a Cdkl5 conditional knockout mouse model of CDKL5 disorder. Behavioral analysis of constitutive Cdkl5 knockout mice revealed key features of the human disorder, including limb clasping, hypoactivity, and abnormal eye tracking. Anatomical, physiological, and molecular analysis of the knockout uncovered potential pathological substrates of the disorder, including reduced dendritic arborization of cortical neurons, abnormal electroencephalograph (EEG) responses to convulsant treatment, decreased visual evoked responses (VEPs), and alterations in the Akt/rpS6 signaling pathway. Selective knockout of Cdkl5 in excitatory and inhibitory forebrain neurons allowed us to map the behavioral features of the disorder to separable cell-types. These findings identify physiological and molecular deficits in specific forebrain neuron populations as possible pathological substrates in CDKL5 disorder.

Skeletal muscle-specific HMG-CoA reductase knockout mice exhibit rhabdomyolysis: A model for statin-induced myopathy.

PubMed

Osaki, Yoshinori; Nakagawa, Yoshimi; Miyahara, Shoko; Iwasaki, Hitoshi; Ishii, Akiko; Matsuzaka, Takashi; Kobayashi, Kazuto; Yatoh, Shigeru; Takahashi, Akimitsu; Yahagi, Naoya; Suzuki, Hiroaki; Sone, Hirohito; Ohashi, Ken; Ishibashi, Shun; Yamada, Nobuhiro; Shimano, Hitoshi

2015-10-23

HMG-CoA reductase (HMGCR) catalyzes the conversion of HMG-CoA to mevalonic acid (MVA); this is the rate-limiting enzyme of the mevalonate pathway that synthesizes cholesterol. Statins, HMGCR inhibitors, are widely used as cholesterol-reducing drugs. However, statin-induced myopathy is the most adverse side effect of statins. To eludicate the mechanisms underlying statin the myotoxicity and HMGCR function in the skeletal muscle, we developed the skeletal muscle-specific HMGCR knockout mice. Knockout mice exhibited postnatal myopathy with elevated serum creatine kinase levels and necrosis. Myopathy in knockout mice was completely rescued by the oral administration of MVA. These results suggest that skeletal muscle toxicity caused by statins is dependent on the deficiencies of HMGCR enzyme activity and downstream metabolites of the mevalonate pathway in skeletal muscles rather than the liver or other organs. Copyright © 2015 Elsevier Inc. All rights reserved.

Transgenic and gene knockout mice in gastric cancer research

PubMed Central

Jiang, Yannan; Yu, Yingyan

2017-01-01

Mouse models are useful tool for carcinogenic study. They will greatly enrich the understanding of pathogenesis and molecular mechanisms for gastric cancer. However, only few of mice could develop gastric cancer spontaneously. With the development and improvement of gene transfer technology, investigators created a variety of transgenic and knockout/knockin mouse models of gastric cancer, such as INS-GAS mice and gastrin knockout mice. Combined with helicobacter infection and carcinogens treatment, these transgenic/knockout/knockin mice developed precancerous or cancerous lesions, which are proper for gene function study or experimental therapy. Here we review the progression of genetically engineered mouse models on gastric cancer research, and emphasize the effects of chemical carcinogens or infectious factors on carcinogenesis of genetically modified mouse. We also emphasize the histological examination on mouse stomach. We expect to provide researchers with some inspirations on this field. PMID:27713138

Simple, empirical approach to predict neutron capture cross sections from nuclear masses

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

Couture, Aaron Joseph; Casten, Richard F.; Cakirli, R. B.

Here, neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40%, and has limited predictive power, with predictions from different models rapidly differing by an order ofmore » magnitude a few nucleons from the last measurement.« less

Simple, empirical approach to predict neutron capture cross sections from nuclear masses

DOE PAGES

Couture, Aaron Joseph; Casten, Richard F.; Cakirli, R. B.

2017-12-20

Here, neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40%, and has limited predictive power, with predictions from different models rapidly differing by an order ofmore » magnitude a few nucleons from the last measurement.« less

Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

NASA Technical Reports Server (NTRS)

Townsend, L. W.; Wilson, J. W.

1985-01-01

A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

Eikonal approximation for proton-helium electron-capture processes

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

Kobayashi, K.; Toshima, N.; Ishihara, T.

1985-09-01

We calculate the capture cross sections for H/sup +/+He..-->..H+He/sup +/, treating the passive electron explicitly in a distorted-wave formalism based on the eikonal approximation. It is found that the shape of the differential cross sections is influenced considerably by the interaction between the passive electron and the incident proton, while the integrated cross sections are much less sensitive to that. The differential cross section at 293 keV agrees well with the experimental data except at extremely small scattering angles. The forward peak is reproduced well at higher energies. The integrated cross sections are in excellent agreement with experiments for themore » incident energy above 250 keV.« less

Systematics of isotopic production cross sections from interactions of relativistic 40Ca in hydrogen

NASA Astrophysics Data System (ADS)

Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T. G.; Insolia, A.; Knott, C. N.; Lindstrom, P. J.; McMahon, M.; Mitchell, J. W.; Potenza, R.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.

1997-09-01

The isotopic production cross sections for 40Ca projectiles at 357, 565, and 763 MeV/nucleon interacting in a liquid hydrogen target have been measured by the Transport Collaboration at the LBL HISS facility. The systematics of these cross sections are studied, and the results indicate that nuclear structure effects are present in the isotope production process during the relativistic collisions. The newly measured cross sections are also compared with those predicted by semiempirical and parametric formulas, but the predictions do not fully describe the systematics such as the energy dependence. The consequences of the cross section systematics in galactic cosmic ray studies are also discussed.

Experimental study of low-energy charge transfer in nitrogen

NASA Technical Reports Server (NTRS)

Smith, A.

1979-01-01

Total charge transfer cross sections were obtained for the N2(+)-N2 system with relative translational ion energies between 9 and 441 eV. Data were obtained to examine the dependence of total cross section on ion energy. The effect of ion excitation on the cross sections was studied by varying the electron ionization energy in the mass spectrometer ion source over an electron energy range between 14.5 and 32.1 eV. The dependence of total cross section on the neutralization chamber gas pressure was examined by obtaining data at pressure values from 9.9 to 0.000199 torr. Cross section values obtained were compared with experimental and theoretical results of other investigations.

Collisional Dynamics of the Rubidium 5(2)P Levels

DTIC Science & Technology

1995-08-01

prepare the rubidium sample. This work established the cross-section for He collisions and bounded the cross-sections for Ne and Ar. Krause (49...continued the work by improving the measurement of the cross-sections and by adding the cross-sections for Kr, Xe and Rb collision partners. Krause ...number density of ,-r 1010 per cm 3 . This is an order of magnitude lower than the concentration reported by Krause (49) to prevent self trapping

Temperature dependence of the ozone absorption cross section at the 253.7-nm mercury line

NASA Technical Reports Server (NTRS)

Barnes, J.; Mauersberger, K.

1987-01-01

The temperature dependence of the ozone absorption cross section at 253.7 nm has been measured between 195 and 351 K. The experimental technique employed circumvents the necessity to determine the absolute ozone concentration for each temperature measurement. Below 273 K the cross section increases approximately 0.6 percent, while toward higher temperatures the cross section decreases rapidly. In a comparison, good agreement with other recently made measurements is shown.

Reaction mechanisms in 12C(γ,pp) near 200 MeV

NASA Astrophysics Data System (ADS)

Hackett, E. D.; McDonald, W. J.; Opper, A. K.; Quraan, M. A.; Rodning, N. L.; Rozon, F. M.; Feldman, G.; Kolb, N. R.; Pywell, R. E.; Skopik, D. M.; Tiller, D. E.; Vogt, J. M.; Korkmaz, E.; O'rielly, G. V.

1996-03-01

Inclusive 12C(γ,pp) cross sections have been measured with tagged photons in the range Eγ=187-227 MeV using the Saskatchewan-Alberta Large Acceptance Detector (SALAD). The large angular acceptance allowed the measurement of noncoplanar pp emission. The cross sections were compared to a Monte Carlo intranuclear cascade calculation. Agreement was reasonable for the shapes of the cross sections but the calculated total cross section was 3.9 times larger than the data.

Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector

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

de Florian, D.

This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplifiedmore » template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond.« less

Improvement of one-nucleon removal and total reaction cross sections in the Liège intranuclear-cascade model using Hartree-Fock-Bogoliubov calculations

NASA Astrophysics Data System (ADS)

Rodríguez-Sánchez, Jose Luis; David, Jean-Christophe; Mancusi, Davide; Boudard, Alain; Cugnon, Joseph; Leray, Sylvie

2017-11-01

The prediction of one-nucleon-removal cross sections by the Liège intranuclear-cascade model has been improved using a refined description of the matter and energy densities in the nuclear surface. Hartree-Fock-Bogoliubov calculations with the Skyrme interaction are used to obtain a more realistic description of the radial-density distributions of protons and neutrons, as well as the excitation-energy uncorrelation at the nuclear surface due to quantum effects and short-range correlations. The results are compared with experimental data covering a large range of nuclei, from carbon to uranium, and projectile kinetic energies. We find that the new approach is in good agreement with experimental data of one-nucleon-removal cross sections covering a broad range in nuclei and energies. The new ingredients also improve the description of total reaction cross sections induced by protons at low energies, the production cross sections of heaviest residues close to the projectile, and the triple-differential cross sections for one-proton removal. However, other observables such as quadruple-differential cross sections of coincident protons do not present any sizable sensitivity to the new approach. Finally, the model is also tested for light-ion-induced reactions. It is shown that the new parameters can give a reasonable description of the nucleus-nucleus total reaction cross sections at high energies.

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

Friedman, B.; DuCharme, G.

We present a semi-empirical scaling law for non-resonant ion–atom single charge exchange cross sections for collisions with velocities frommore » $${10}^{7}\\,{\\rm{t}}{\\rm{o}}\\,{10}^{9}\\,\\mathrm{cm}\\,{{\\rm{s}}}^{-1}$$ and ions with positive charge $$q\\lt 8$$. Non-resonant cross sections tend to have a velocity peak at collision velocities $$v\\lesssim 1\\ {\\rm{a}}{\\rm{u}}$$ with exponential decay around this peak. We construct a scaling formula for the location of this peak then choose a functional form for the cross section curve and scale it. The velocity at which the cross section peaks, v m, is proportional to the energy defect of the collision, $${\\rm{\\Delta }}E$$, which we predict with the decay approximation. The value of the cross section maximum is proportional to the charge state q, inversely proportional to the target ionization energy I T, and inversely proportional to v m. For the shape of the cross section curve, we use a function that decays exponentially asymptotically at high and low velocities. We scale this function with parameters $${v}_{{\\rm{m}}},{I}_{{\\rm{T}}},{Z}_{{\\rm{T}}},\\mathrm{and}\\ {Z}_{{\\rm{P}}}$$, where the $${Z}_{{\\rm{T}},{\\rm{P}}}$$ are the target and projectile atomic numbers. In conclusion, for the more than 100 cross section curves that we use to find the scaling rules, the scaling law predicts cross sections within a little over a factor of 2 on average.« less

Cross Section Sensitivity and Propagated Errors in HZE Exposures

NASA Technical Reports Server (NTRS)

Heinbockel, John H.; Wilson, John W.; Blatnig, Steve R.; Qualls, Garry D.; Badavi, Francis F.; Cucinotta, Francis A.

2005-01-01

It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates.

Macrosegregation Due to Convection in Al-19Cu Alloy Directionally Solidified Through an Abrupt Expansion in Cross-Section: A Comparison with Al-7Si

NASA Astrophysics Data System (ADS)

Ghods, M.; Lauer, M.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

2017-10-01

Hypoeutectic Al-19 wt.% Cu alloys were directionally solidified at two different growth speeds in cylindrical molds that featured an abrupt increase in cross-section, from 3.2 to 9.5 mm in diameter. The effects of thermosolutal convection and shrinkage flow induced by the cross-section change on macrosegregation were investigated. Dendrite clustering and extensive radial macrosegregation were seen, particularly in the larger cross-section after expansion. Negative longitudinal macrosegregation right after the cross-section increase was observed; the extent of macrosegregation, however, decreases with increasing growth speed. Both thermal and flow effects due to cross-section change were seen to influence the radial macrosegregation immediately before, and after the expansion. Radial macrosegregation pattern was found to be changing as the mushy zone enters the larger cross-section region above the cross-section change where the solidification is in its unsteady state. The effect of the solutal expansion coefficient on macrosegregation was studied by comparing the degree of thermosolutal convection in Al-19 wt.% Cu with a previous study in which we investigated Al-7 wt.% Si. A two-dimensional model accounting for both shrinkage and thermosolutal convection was used to simulate the resulting steepling, as well as the axial and radial macrosegregation. The experimentally observed macrosegregation associated with the expansion during directional solidification is well predicted by the numerical simulations.

Total Cross Sections as a Surrogate for Neutron Capture: An Opportunity to Accurately Constrain (n,γ) Cross Sections for Nuclides Beyond the Reach of Direct Measurements

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

Koehler, Paul E.

2014-03-05

There are many (n,γ) cross sections of great interest to radiochemical diagnostics and to nuclear astrophysics which are beyond the reach of current measurement techniques, and likely to remain so for the foreseeable future. In contrast, total neutron cross sections currently are feasible for many of these nuclides and provide almost all the information needed to accurately calculate the (n,γ) cross sections via the nuclear statistical model (NSM). I demonstrate this for the case of 151Sm; NSM calculations constrained using average resonance parameters obtained from total cross section measurements made in 1975, are in excellent agreement with recent 151Sm (n,γ)more » measurements across a wide range of energy. Furthermore, I demonstrate through simulations that total cross section measurements can be made at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center for samples as small as 10μg. Samples of this size should be attainable for many nuclides of interest. Finally, I estimate that over half of the radionuclides identified ~20 years ago as having (n,γ) cross sections of importance to s-process nucleosynthesis studies (24/43) and radiochemical diagnostics (11/19), almost none of which have been measured, can be constrained using this technique.« less

Bridging the Gap Between Understanding and Doing in Structural Geology - Coring the Subsurface with Scratch-Art

NASA Astrophysics Data System (ADS)

Bilsley, N. A.; Cook, H. M.

2016-12-01

Although most geology students feel the joy of interpreting geologic cross sections, few experience the challenges career geologists face in order to create these visual representations. Without a hefty budget and a drill rig, students generally miss out on the challenge of extrapolating subsurficial features from limited datasets, and jump to narrating geologic time through beautifully pre-drawn cross sections. Although this method allows students to practice relative dating techniques, they miss the practical step of learning how we have come to understand what the subsurface looks like in the first place. This activity was designed to close that gap, while giving students the opportunity to engage in peer learning by strategizing in groups, critiquing each other's work, and evaluating their own work. Broken into groups, students are instructed to create a geologic cross section that must include specific structural features. The cross sections are traded with another group, who reviews and provides feedback on the drawing before returning it back to the original group. The feedback is reviewed and incorporated, before the cross sections are colored and covered with black coated, clear scratch-art paper. The hidden cross sections are traded with a new group, who must decide where and how deep to scratch, or "core", on their cross section. Utilizing the data obtained from the cores, the students interpret and draw a new cross section. Finally, the scratch-art paper is removed, and the original cross section revealed. The differences between the original and interpreted subsurface as well as evaluation of sampling methods (e.g. location and depth of cores) are discussed within the groups and with the class. This activity bridges the gap between developing the intuition needed to create cross sections with realistic geoscientific techniques and utilizing cross sections to understand geologic time. In addition, not only does the activity require few supplies and minimal time of the instructor, but its peer-based learning approach stimulates creativity, allows students to effectively generate and communicate constructive feedback, and encourages students to evaluate and critique their methods and assumptions.

Electron collisions with ethylene

NASA Astrophysics Data System (ADS)

Panajotovic, R.; Kitajima, M.; Tanaka, H.; Jelisavcic, M.; Lower, J.; Campbell, L.; Brunger, M. J.; Buckman, S. J.

2003-04-01

We have measured absolute elastic scattering and vibrational excitation cross sections for electron impact on ethylene. The experimental data have been obtained on two different crossed-beam electron spectrometers and they cover the energy range from 1 to 100 eV and scattering angles between 10° and 130°. Both differential (in angle) and energy-dependent cross sections have been measured. The differential cross sections have also been analysed using a molecular phase shift analysis technique in order to derive the integral elastic and elastic momentum transfer cross sections. Comparison is made with earlier data, where available, and also with a number of recent theoretical calculations.

Deficiency of eNOS exacerbates early-stage NAFLD pathogenesis by changing the fat distribution.

PubMed

Nozaki, Yuichi; Fujita, Koji; Wada, Koichiro; Yoneda, Masato; Shinohara, Yoshiyasu; Imajo, Kento; Ogawa, Yuji; Kessoku, Takaomi; Nakamuta, Makoto; Saito, Satoru; Masaki, Naohiko; Nagashima, Yoji; Terauchi, Yasuo; Nakajima, Atsushi

2015-12-17

Although many factors and molecules that are closely associated with non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) have been reported, the role of endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) in the pathogenesis of NAFLD/NASH remains unclear. We therefore investigated the role of eNOS-derived NO in NAFLD pathogenesis using systemic eNOS-knockout mice fed a high-fat diet. eNOS-knockout and wild-type mice were fed a basal diet or a high-fat diet for 12 weeks. Lipid accumulation and inflammation were evaluated in the liver, and various factors that are closely associated with NAFLD/NASH and hepatic tissue blood flow were analyzed. Lipid accumulation and inflammation were more extensive in the liver and lipid accumulation was less extensive in the visceral fat tissue in eNOS-knockout mice, compared with wild-type mice, after 12 weeks of being fed a high-fat diet. While systemic insulin resistance was comparable between the eNOS-knockout and wild-type mice fed a high-fat diet, hepatic tissue blood flow was significantly suppressed in the eNOS-knockout mice, compared with the wild-type mice, in mice fed a high-fat diet. The microsomal triglyceride transfer protein activity was down-regulated in eNOS-knockout mice, compared with wild-type mice, in mice fed a high-fat diet. A deficiency of eNOS-derived NO may exacerbate the early-stage of NASH pathogenesis by changing the fat distribution in a mouse model via the regulation of hepatic tissue blood flow.

Decreased consumption of sweet fluids in mu opioid receptor knockout mice: a microstructural analysis of licking behavior

PubMed Central

Ostlund, Sean B.; Kosheleff, Alisa; Maidment, Nigel T.; Murphy, Niall P.

2013-01-01

Summary Rationale Evidence suggests that the palatability of food (i.e., the hedonic impact produced by its sensory features) can promote feeding and may underlie compulsive eating, leading to obesity. Pharmacological studies implicate opioid transmission in the hedonic control of feeding, though these studies often rely on agents lacking specificity for particular opioid receptors. Objectives Here, we investigated the role of mu opioid receptors (MORs) specifically in determining hedonic responses to palatable sweet stimuli. Methods In Experiment 1, licking microstructure when consuming sucrose solution (2 to 20 %) was compared in MOR knockout and wildtype mice as a function of sucrose concentration and level of food deprivation. In Experiment 2, a similar examination was conducted using the palatable but calorie-free stimulus sucralose (0.001 to 1%), allowing study of licking behavior independent of homeostatic variables. Results In Experiment 1, MOR knockout mice exhibited several alterations in sucrose licking. Although wildtype mice exhibited a two-fold increase in the burst length when food deprived, relative to the nondeprived test, this aspect of sucrose licking was generally insensitive to manipulations of food deprivation for MOR knockout mice. Furthermore, during concentration testing, their rate of sucrose licking was less than half that of wildtype mice. During sucralose testing (Experiment 2), MOR knockout mice licked at approximately half the wildtype rate, providing more direct evidence that MOR knockout mice were impaired in processing stimulus palatability. Conclusions These results suggest that transmission through MORs mediates hedonic responses to palatable stimuli, and therefore likely contributes to normal and pathological eating. PMID:23568577

Age- and region-specific imbalances of basal amino acids and monoamine metabolism in limbic regions of female Fmr1 knock-out mice.

PubMed

Gruss, Michael; Braun, Katharina

2004-07-01

The Fragile X syndrome, a common form of mental retardation in humans, originates from the loss of expression of the Fragile X mental retardation gene leading to the absence of the encoded Fragile X mental retardation protein 1 (FMRP). A broad pattern of morphological and behavioral abnormalities is well described for affected humans as well as Fmr1 knock-out mice, a transgenic animal model for the human Fragile X syndrome. In the present study, we examined neurochemical differences between female Fmr1 knock-out and wildtype mice with particular focus on neurotransmission. Significant age- and region-specific differences of basal tissue neurotransmitter and metabolite levels measured by high performance liquid chromatography were found. Those differences were more numerous in juvenile animals (postnatal day (PND) 28-31) compared to adults (postnatal day 209-221). In juvenile female knock-out mice, especially aspartate and taurine were increased in cortical regions, striatum, cerebellum, and brainstem. Furthermore, compared to the wildtype animals, the juvenile knock-out mice displayed an increased level of neuronal inhibition in the hippocampus and brainstem reflected by decreased ratios of (aspartate + glutamate)/(taurine + GABA), as well as an increased dopamine (DA) turnover in cortical regions, striatum, and hippocampus. These results provide the first evidence that the lack of FMRP expression in female Fmr1 knock-out mice is accompanied by age-dependent, region-specific alterations in brain amino acids, and monoamine turnover, which might be related to the reported synaptical and behavioural alterations in these animals.

Discrete change in volatile anesthetic sensitivity in mice with inactivated tandem pore potassium ion channel TRESK.

PubMed

Chae, Yun Jeong; Zhang, Jianan; Au, Paul; Sabbadini, Marta; Xie, Guo-Xi; Yost, C Spencer

2010-12-01

We investigated the role of tandem pore potassium ion channel (K2P) TRESK in neurobehavioral function and volatile anesthetic sensitivity in genetically modified mice. Exon III of the mouse TRESK gene locus was deleted by homologous recombination using a targeting vector. The genotype of bred mice (wild type, knockout, or heterozygote) was determined using polymerase chain reaction. Morphologic and behavioral evaluations of TRESK knockout mice were compared with wild-type littermates. Sensitivity of bred mice to isoflurane, halothane, sevoflurane, and desflurane were studied by determining the minimum alveolar concentration preventing movement to tail clamping in 50% of each genotype. With the exception of decreased number of inactive periods and increased thermal pain sensitivity (20% decrease in latency with hot plate test), TRESK knockout mice had healthy development and behavior. TRESK knockout mice showed a statistically significant 8% increase in isoflurane minimum alveolar concentration compared with wild-type littermates. Sensitivity to other volatile anesthetics was not significantly different. Spontaneous mortality of TRESK knockout mice after initial anesthesia testing was nearly threefold higher than that of wild-type littermates. TRESK alone is not critical for baseline central nervous system function but may contribute to the action of volatile anesthetics. The inhomogeneous change in anesthetic sensitivity corroborates findings in other K2P knockout mice and supports the theory that the mechanism of volatile anesthetic action involves multiple targets. Although it was not shown in this study, a compensatory effect by other K2P channels may also contribute to these observations.

Starch Binding Domain-containing Protein 1 Plays a Dominant Role in Glycogen Transport to Lysosomes in Liver*

PubMed Central

Sun, Tao; Yi, Haiqing; Yang, Chunyu; Kishnani, Priya S.; Sun, Baodong

2016-01-01

A small portion of cellular glycogen is transported to and degraded in lysosomes by acid α-glucosidase (GAA) in mammals, but it is unclear why and how glycogen is transported to the lysosomes. Stbd1 has recently been proposed to participate in glycogen trafficking to lysosomes. However, our previous study demonstrated that knockdown of Stbd1 in GAA knock-out mice did not alter lysosomal glycogen storage in skeletal muscles. To further determine whether Stbd1 participates in glycogen transport to lysosomes, we generated GAA/Stbd1 double knock-out mice. In fasted double knock-out mice, glycogen accumulation in skeletal and cardiac muscles was not affected, but glycogen content in liver was reduced by nearly 73% at 3 months of age and by 60% at 13 months as compared with GAA knock-out mice, indicating that the transport of glycogen to lysosomes was suppressed in liver by the loss of Stbd1. Exogenous expression of human Stbd1 in double knock-out mice restored the liver lysosomal glycogen content to the level of GAA knock-out mice, as did a mutant lacking the Atg8 family interacting motif (AIM) and another mutant that contains only the N-terminal 24 hydrophobic segment and the C-terminal starch binding domain (CBM20) interlinked by an HA tag. Our results demonstrate that Stbd1 plays a dominant role in glycogen transport to lysosomes in liver and that the N-terminal transmembrane region and the C-terminal CBM20 domain are critical for this function. PMID:27358407

Global Nav1.7 Knockout Mice Recapitulate the Phenotype of Human Congenital Indifference to Pain

PubMed Central

Gingras, Jacinthe; Smith, Sarah; Matson, David J.; Johnson, Danielle; Nye, Kim; Couture, Lauren; Feric, Elma; Yin, Ruoyuan; Moyer, Bryan D.; Peterson, Matthew L.; Rottman, James B.; Beiler, Rudolph J.; Malmberg, Annika B.; McDonough, Stefan I.

2014-01-01

Clinical genetic studies have shown that loss of Nav1.7 function leads to the complete loss of acute pain perception. The global deletion is reported lethal in mice, however, and studies of mice with promoter-specific deletions of Nav1.7 have suggested that the role of Nav1.7 in pain transduction depends on the precise form of pain. We developed genetic and animal husbandry strategies that overcame the neonatal-lethal phenotype and enabled construction of a global Nav1.7 knockout mouse. Knockouts were anatomically normal, reached adulthood, and had phenotype wholly analogous to human congenital indifference to pain (CIP): compared to littermates, knockouts showed no defects in mechanical sensitivity or overall movement yet were completely insensitive to painful tactile, thermal, and chemical stimuli and were anosmic. Knockouts also showed no painful behaviors resulting from peripheral injection of nonselective sodium channel activators, did not develop complete Freund’s adjuvant-induced thermal hyperalgesia, and were insensitive to intra-dermal histamine injection. Tetrodotoxin-sensitive sodium current recorded from cell bodies of isolated sensory neurons and the mechanically-evoked spiking of C-fibers in a skin-nerve preparation each were reduced but not eliminated in tissue from knockouts compared to littermates. Results support a role for Nav1.7 that is conserved between rodents and humans and suggest several possibly translatable biomarkers for the study of Nav1.7-targeted therapeutics. Results further suggest that Nav1.7 may retain its key role in persistent as well as acute forms of pain. PMID:25188265

Altered sleep and affect in the neurotensin receptor 1 knockout mouse.

PubMed

Fitzpatrick, Karrie; Winrow, Christopher J; Gotter, Anthony L; Millstein, Joshua; Arbuzova, Janna; Brunner, Joseph; Kasarskis, Andrew; Vitaterna, Martha H; Renger, John J; Turek, Fred W

2012-07-01

Sleep and mood disorders have long been understood to have strong genetic components, and there is considerable comorbidity of sleep abnormalities and mood disorders, suggesting the involvement of common genetic pathways. Here, we examine a candidate gene implicated in the regulation of both sleep and affective behavior using a knockout mouse model. Previously, we identified a quantitative trait locus (QTL) for REM sleep amount, REM sleep bout number, and wake amount in a genetically segregating population of mice. Here, we show that traits mapping to this QTL correlated with an expression QTL for neurotensin receptor 1 (Ntsr1), a receptor for neurotensin, a ligand known to be involved in several psychiatric disorders. We examined sleep as well as behaviors indicative of anxiety and depression in the NTSR1 knockout mouse. NTSR1 knockouts had a lower percentage of sleep time spent in REM sleep in the dark phase and a larger diurnal variation in REM sleep duration than wild types under baseline conditions. Following sleep deprivation, NTSR1 knockouts exhibited more wake and less NREM rebound sleep. NTSR1 knockouts also showed increased anxious and despair behaviors. Here we illustrate a link between expression of the Ntsr1 gene and sleep traits previously associated with a particular QTL. We also demonstrate a relationship between Ntsr1 and anxiety and despair behaviors. Given the considerable evidence that anxiety and depression are closely linked with abnormalities in sleep, the data presented here provide further evidence that neurotensin and Ntsr1 may be a component of a pathway involved in both sleep and mood disorders.

First measurement of the charged current cross section at HERA

NASA Astrophysics Data System (ADS)

Ahmed, T.; Andreev, V.; Andrieu, B.; Appuhn, R.-D.; Arpagaus, M.; Babaev, A.; Bán, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Barth, M.; Bassler, U.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besançon, M.; Biddulph, P.; Bizot, J. C.; Blobel, V.; Borras, K.; Boudry, V.; Braemer, A.; Brasse, F.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Brune, C.; Büngener, L.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, Ch.; Cozzika, G.; Criegee, L.; Cussans, D. G.; Cvach, J.; Dagoret, S.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; Daum, K.; David, M.; Deffur, E.; Delcourt, B.; Del Buono, L.; De Roeck, A.; De Wolf, E.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Ehrlichmann, H.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrarotto, F.; Flamm, K.; Flauger, W.; Fleischer, M.; Flieser, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formánek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gebauer, M.; Gellrich, A.; Genzel, H.; Gerhards, R.; Goerlach, U.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goldner, D.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Grindhammer, G.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Hampel, M.; Hanlon, E. M.; Hapke, M.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladký, J.; Hoeger, K. C.; Höppner, M.; Huet, Ph.; Hufnagel, H.; Ibbotson, M.; Itterbeck, H.; Jabiol, M.-A.; Jacholkowska, A.; Jacobsson, C.; Jaffre, M.; Janoth, J.; Jansen, T.; Jönsson, L.; Johannsen, K.; Johnson, D. P.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kant, D.; Kazarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Keuker, C.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Ko, W.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Krüner-Marquis, M.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurča, T.; Kurzhöfer, J.; Kuznik, B.; Lacour, D.; Lamarche, F.; Lander, R.; Landon, M. P. J.; Lange, W.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Leverenz, C.; Levonian, S.; Ley, Ch.; Lindner, A.; Lindström, G.; Linsel, F.; Lipinski, J.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Lüke, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Mercer, D.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Milstead, D.; Moreau, F.; Morris, J. V.; Müller, G.; Murín, P.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Nawrath, G.; Newman, P. R.; Newton, D.; Neyret, D.; Nguyen, H. K.; Niebergall, F.; Niebuhr, C.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg-Werther, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Panitch, A.; Pascaud, C.; Patel, G. D.; Peppel, E.; Perez, E.; Phillips, J. P.; Pichler, Ch.; Pitzl, D.; Pope, G.; Prell, S.; Prosi, R.; Rädel, G.; Raupach, F.; Reimer, P.; Reinshagen, S.; Ribarics, P.; Riech, V.; Riedlberger, J.; Riess, S.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rosenbauer, K.; Rostovtsev, A.; Royon, C.; Rüter, K.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Sahlmann, N.; Sanchez, E.; Sankey, D. P. C.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schöning, A.; Schröder, V.; Schulz, M.; Schwab, B.; Schwind, A.; Seehausen, U.; Sefkow, F.; Sell, R.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Shtarkov, L. N.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Stella, B.; Stephens, K.; Stier, J.; Stiewe, J.; Stösslein, U.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Tapprogge, S.; Taylor, R. E.; Tchernyshov, V.; Thiebaux, C.; Thompson, G.; Tichomirov, I.; Truöl, P.; Turnau, J.; Tutas, J.; Usik, A.; Valkar, S.; Valkarova, A.; Vallée, C.; Van Esch, P.; Van Mechelen, P.; Vartapetian, A.; Vazdik, Y.; Vecko, M.; Verrecchia, P.; Villet, G.; Wacker, K.; Wagener, A.; Walker, I. W.; Walther, A.; Weber, G.; Weber, M.; Weber, M.; Wegener, D.; Wegner, A.; Wellisch, H. P.; West, L. R.; Willard, S.; Winde, M.; Winter, G.-G.; Wolff, Th.; Wright, A. E.; Wünsch, E.; Wulff, N.; Yiou, T. P.; Žáček, J.; Zhang, Z.; Zimmer, M.; Zimmermann, W.; Zomer, F.; Zuber, K.; H1 Collaboration

1994-03-01

The cross section of the charged current process e-p → ve + hadrons is measured at HERA for transverse momenta of the hadron system larger than 25 GeV. The size of the cross section exhibits the W propagator.

Inclined Bodies of Various Cross Sections at Supersonic Speeds

NASA Technical Reports Server (NTRS)

Jorgensen, Leland H.

1958-01-01

To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

Electron collisions with phenol: Total, integral, differential, and momentum transfer cross sections and the role of multichannel coupling effects on the elastic channel

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

Costa, Romarly F. da; Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-580 Santo André, São Paulo; Oliveira, Eliane M. de

2015-03-14

We report theoretical and experimental total cross sections for electron scattering by phenol (C{sub 6}H{sub 5}OH). The experimental data were obtained with an apparatus based in Madrid and the calculated cross sections with two different methodologies, the independent atom method with screening corrected additivity rule (IAM-SCAR), and the Schwinger multichannel method with pseudopotentials (SMCPP). The SMCPP method in the N{sub open}-channel coupling scheme, at the static-exchange-plus-polarization approximation, is employed to calculate the scattering amplitudes at impact energies ranging from 5.0 eV to 50 eV. We discuss the multichannel coupling effects in the calculated cross sections, in particular how the numbermore » of excited states included in the open-channel space impacts upon the convergence of the elastic cross sections at higher collision energies. The IAM-SCAR approach was also used to obtain the elastic differential cross sections (DCSs) and for correcting the experimental total cross sections for the so-called forward angle scattering effect. We found a very good agreement between our SMCPP theoretical differential, integral, and momentum transfer cross sections and experimental data for benzene (a molecule differing from phenol by replacing a hydrogen atom in benzene with a hydroxyl group). Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. We also have a good agreement among the present SMCPP calculated total cross section (which includes elastic, 32 inelastic electronic excitation processes and ionization contributions, the latter estimated with the binary-encounter-Bethe model), the IAM-SCAR total cross section, and the experimental data when the latter is corrected for the forward angle scattering effect [Fuss et al., Phys. Rev. A 88, 042702 (2013)].« less

Torsional Buckling Tests of a Simulated Solar Array

NASA Technical Reports Server (NTRS)

Thornton, E. A.

1996-01-01

Spacecraft solar arrays are typically large structures supported by long, thin deployable booms. As such, they may be particularly susceptible to abnormal structural behavior induced by mechanical and thermal loading. One example is the Hubble Space Telescope solar arrays which consist of two split tubes fit one inside the other called BiSTEMs. The original solar arrays on the Hubble Space Telescope were found to be severely twisted following deployment and later telemetry data showed the arrays were vibrating during daylight to night and night to daylight transition. The solar array twist however can force the BiSTEM booms to change in cross-section and cause tile solar arrays to react unpredictably to future loading. The solar arrays were redesigned to correct for tile vibration, however, upon redeployment they again twisted. To assess the influence of boom cross-sectional configuration, experiments were conducted on two types of booms, (1)booms with closed cross-sections, and (2) booms with open cross-sections. Both models were subjected to compressive loading and imposed tip deflections. An existing analytical model by Chung and Thornton was used to define the individual load ranges for each model solar array configuration. The load range for the model solar array using closed cross-section booms was 0-120 Newtons and 0-160 Newtons for the model solar array using open cross-section booms. The results indicate the model solar array with closed cross-section booms buckled only in flexure. However, the results of the experiment with open cross-section booms indicate the model solar array buckled only in torsion and with imposed tip deflections the cross section can degrade by rotation of the inner relative to the outer STEM. For tile Hubble Space Telescope solar arrays the results of these experiments indicate the twisting resulted from the initial mechanical loading of the open cross-section booms.

Augmented Cross-Sectional Studies with Abbreviated Follow-up for Estimating HIV Incidence

PubMed Central

Claggett, B.; Lagakos, S.W.; Wang, R.

2011-01-01

Summary Cross-sectional HIV incidence estimation based on a sensitive and less-sensitive test offers great advantages over the traditional cohort study. However, its use has been limited due to concerns about the false negative rate of the less-sensitive test, reflecting the phenomenon that some subjects may remain negative permanently on the less-sensitive test. Wang and Lagakos (2010) propose an augmented cross-sectional design which provides one way to estimate the size of the infected population who remain negative permanently and subsequently incorporate this information in the cross-sectional incidence estimator. In an augmented cross-sectional study, subjects who test negative on the less-sensitive test in the cross-sectional survey are followed forward for transition into the nonrecent state, at which time they would test positive on the less-sensitive test. However, considerable uncertainty exists regarding the appropriate length of follow-up and the size of the infected population who remain nonreactive permanently to the less-sensitive test. In this paper, we assess the impact of varying follow-up time on the resulting incidence estimators from an augmented cross-sectional study, evaluate the robustness of cross-sectional estimators to assumptions about the existence and the size of the subpopulation who will remain negative permanently, and propose a new estimator based on abbreviated follow-up time (AF). Compared to the original estimator from an augmented cross-sectional study, the AF Estimator allows shorter follow-up time and does not require estimation of the mean window period, defined as the average time between detectability of HIV infection with the sensitive and less-sensitive tests. It is shown to perform well in a wide range of settings. We discuss when the AF Estimator would be expected to perform well and offer design considerations for an augmented cross-sectional study with abbreviated follow-up. PMID:21668904

Augmented cross-sectional studies with abbreviated follow-up for estimating HIV incidence.

PubMed

Claggett, B; Lagakos, S W; Wang, R

2012-03-01

Cross-sectional HIV incidence estimation based on a sensitive and less-sensitive test offers great advantages over the traditional cohort study. However, its use has been limited due to concerns about the false negative rate of the less-sensitive test, reflecting the phenomenon that some subjects may remain negative permanently on the less-sensitive test. Wang and Lagakos (2010, Biometrics 66, 864-874) propose an augmented cross-sectional design that provides one way to estimate the size of the infected population who remain negative permanently and subsequently incorporate this information in the cross-sectional incidence estimator. In an augmented cross-sectional study, subjects who test negative on the less-sensitive test in the cross-sectional survey are followed forward for transition into the nonrecent state, at which time they would test positive on the less-sensitive test. However, considerable uncertainty exists regarding the appropriate length of follow-up and the size of the infected population who remain nonreactive permanently to the less-sensitive test. In this article, we assess the impact of varying follow-up time on the resulting incidence estimators from an augmented cross-sectional study, evaluate the robustness of cross-sectional estimators to assumptions about the existence and the size of the subpopulation who will remain negative permanently, and propose a new estimator based on abbreviated follow-up time (AF). Compared to the original estimator from an augmented cross-sectional study, the AF estimator allows shorter follow-up time and does not require estimation of the mean window period, defined as the average time between detectability of HIV infection with the sensitive and less-sensitive tests. It is shown to perform well in a wide range of settings. We discuss when the AF estimator would be expected to perform well and offer design considerations for an augmented cross-sectional study with abbreviated follow-up. © 2011, The International Biometric Society.

Bridge-scour analysis using the water surface profile (WSPRO) model

USGS Publications Warehouse

Mueller, David S.; ,

1993-01-01

A program was developed to extract hydraulic information required for bridge-scour computations, from the Water-Surface Profile computation model (WSPRO). The program is written in compiled BASIC and is menu driven. Using only ground points, the program can compute average ground elevation, cross-sectional area below a specified datum, or create a Drawing Exchange Format (DXF) fie of cross section. Using both ground points ad hydraulic information form the equal-conveyance tubes computed by WSPRO, the program can compute hydraulic parameters at a user-specified station or in a user-specified subsection of the cross section. The program can identify the maximum velocity in a cross section and the velocity and depth at a user-specified station. The program also can identify the maximum velocity in the cross section and the average velocity, average depth, average ground elevation, width perpendicular to the flow, cross-sectional area of flow, and discharge in a subsection of the cross section. This program does not include any help or suggestions as to what data should be extracted; therefore, the used must understand the scour equations and associated variables to the able to extract the proper information from the WSPRO output.

Double differential cross sections for proton induced electron emission from molecular analogues of DNA constituents for energies in the Bragg peak region

NASA Astrophysics Data System (ADS)

Rudek, Benedikt; Bennett, Daniel; Bug, Marion U.; Wang, Mingjie; Baek, Woon Yong; Buhr, Ticia; Hilgers, Gerhard; Champion, Christophe; Rabus, Hans

2016-09-01

For track structure simulations in the Bragg peak region, measured electron emission cross sections of DNA constituents are required as input for developing parameterized model functions representing the scattering probabilities. In the present work, double differential cross sections were measured for the electron emission from vapor-phase pyrimidine, tetrahydrofuran, and trimethyl phosphate that are structural analogues to the base, the sugar, and the phosphate residue of the DNA, respectively. The range of proton energies was from 75 keV to 135 keV, the angles ranged from 15° to 135°, and the electron energies were measured from 10 eV to 200 eV. Single differential and total electron emission cross sections are derived by integration over angle and electron energy and compared to the semi-empirical Hansen-Kocbach-Stolterfoht (HKS) model and a quantum mechanical calculation employing the first Born approximation with corrected boundary conditions (CB1). The CB1 provides the best prediction of double and single differential cross section, while total cross sections can be fitted with semi-empirical models. The cross sections of the three samples are proportional to their total number of valence electrons.

Compound-nuclear Reactions with Unstable Isotopes: Constraining Capture Cross Sections with Indirect Data and Theory

NASA Astrophysics Data System (ADS)

Escher, Jutta

2016-09-01

Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Several indirect methods have recently been proposed to determine neutron capture cross sections for unstable isotopes. These methods aim at constraining statistical calculations of capture cross sections with data obtained from the decay of the compound nucleus relevant to the desired reaction. Each method produces this compound nucleus in a different manner (via a light-ion reaction, a photon-induced reaction, or β decay) and requires additional ingredients to yield the sought-after cross section. This contribution focuses on the process of determining capture cross sections from inelastic scattering and transfer experiments. Specifically, theoretical descriptions of the (p,d) transfer reaction have been developed to complement recent measurements in the Zr-Y region. The procedure for obtaining constraints for unknown capture cross sections is illustrated. The main advantages and challenges of this approach are compared to those of the proposed alternatives. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Mental visualization of objects from cross-sectional images

PubMed Central

Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

2011-01-01

We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object representation. Participants used a hand-held device to reveal a hidden object as a sequence of cross-sectional images. The process of localization was manipulated by contrasting two displays, in-situ vs. ex-situ, which differed in whether cross sections were presented at their source locations or displaced to a remote screen. The process of integration was manipulated by varying the structural complexity of target objects and their components. Experiments 1 and 2 demonstrated visualization of 2D and 3D line-segment objects and verified predictions about display and complexity effects. In Experiments 3 and 4, the visualized forms were familiar letters and numbers. Errors and orientation effects showed that displacing cross-sectional images to a remote display (ex-situ viewing) impeded the ability to determine spatial relationships among pattern components, a failure of integration at the object level. PMID:22217386

Roof Plans: Section "CC", Roof Plan; Roof Framing Plans: Section ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Roof Plans: Section "C-C", Roof Plan; Roof Framing Plans: Section "C-C", Section "D-D"; Roof Framing Sections: Cross Section "G-G", Cross Section "H-H" - Fort Washington, Fort Washington Light, Northeast side of Potomac River at Fort Washington Park, Fort Washington, Prince George's County, MD

Dopamine transporter and vesicular monoamine transporter knockout mice : implications for Parkinson's disease.

PubMed

Miller, G W; Wang, Y M; Gainetdinov, R R; Caron, M G

2001-01-01

One of the most valuable methods for understanding the function of a particular protein is the generation of animals that have had the gene encoding for the protein of interest disrupted, commonly known as a "quo;knockout"quo; or null mutant. By incorporating a sequence of DNA (typically encoding antibiotic resistance to aid in the selection of the mutant gene) into embryonic stem cells by homologous recombination, the normal transcription of the gene is effectively blocked (Fig. 1). Since a particular protein is encoded by two copies of a gene, it is necessary to have the gene on both alleles "quo;knocked out."quo; This is performed by cross-breeding animals with one affected allele (heterozygote) to generate offspring that have inherited two mutant alleles (homozygote). This procedure has been used to generate animals lacking either the plasma membrane dopamine transporter (DAT; Fig. 2) or the vesicular monoamine transporter (VMAT2; Fig. 3). Both DAT and VMAT2 are essential for dopamine homeostasis and are thought to participate in the pathogenesis of Parkinson's disease (1-5). Fig. 1. Maps of the targeting vector and the mock construct. The mouse genomic fragment (clone 11) was isolated from a Stratagene 129 SvJ library by standard colony hybridization using a PCR probe from the 5' end of rat cDNA. The restriction site abbreviations are as follows: H, HindIII; N, NotI; Sc, SacI; Sn, SnaI; X, XbaI; and Xh, XhoI. The region between HindIII and SnaI on clone 11 containing the coding sequence from transmembrane domains 3 and 4 of VMAT2 was deleted and replaced with PGK-neo. The 3' fragment of clone 11 was reserved as an external probe for Southern analysis. To facilitate PCR screening of embryonic stem cell clones, a mock construct containing the SnaI/XbaI fragment and part of the Neo cassette was generated as a positive control. pPNT and pGEM4Z were used to construct knockout and mock vectors, respectively. (Reproduced with permission from ref. 1). Fig. 2. DAT and VMAT2 expression in wild-type and DAT knockout midbrain. DAT immunoreactivity in wild-type (A) and DAT knockout midbrain (B). VMAT2 immunoreactivity in wild-type (C) and DAT knockout midbrain (D). Robust immunoreactivity was observed in the ventral tegmental area and substantia nigra pars compacta and reticulata in the wild-type brain. Note absence of DAT immunoreactivity and modest reduction of VMAT2 immunoreactivity in the DAT knockout. Fig. 3. Characterization of VMAT2 gene disruption. (A) Southern blot analysis of mouse genomic DNA. The Southern blot was prepared with 15 μg of genomic DNA per lane and probed with a 1.4-kb 3' external genomic fragment. +/+, wild type littermates; +/-, heterozygote; -/-, homozygote. (B) RT-PCR analysis of mouse brain poly(A)+ RNA. For each reverse transcription assay, 0.5 μg of poly(A)+ RNA was used. Equal volumes of cDNA templates were used for each PCR assay. The PCR primers used flank the neomycin cassette for the purpose of detecting potential readthrough of the neomycin DNA. The heterozygote has a reduced amount of transcripts compared with the wild-type littermate; the homozygote is devoid of VMAT2 transcripts. G3PDH was used as internal control. (C) Western blot analysis of wholebrain synaptic vesicles. Samples (25 μg) of vesicles were solubilized and separated by SDS-PAGE, transferred to nitrocellulose, subjected to Western blot analysis with anti-VMAT2-Ct (top) or anti-a-tubulin (bottom) antibodies, and developed with chemiluminescence. Molecular mass markers (kDa) are shown to the left. To confirm equal loading and transfer of proteins, the blots were stripped and reprobed with an antibody to α-tubulin. (Reproduced with permission from ref. 1). The importance of DAT in neuronal function is highlighted in animals in which DAT has been genetically deleted (DAT KO) (3). In the homozygote DAT KO mice, released dopamine remains in the extracellular space up to 300 times longer than normal. As expected, these animals display behaviors consistent with persistent activation of dopamine receptors, such as hyperlocomotion. Genetic deletion of VMAT2 reveals the essential role of vesicular storage and release of monoamines. Homozygote VMAT2 knockout mice survive for only a few days, whereas heterozygotes appear normal. Studies performed in homozygote pups and heterozygote adults clearly show that the level of VMAT2 expression calibrates the level of vesicular filling (1,2,bi4). With only 50% of normal VMAT2, heterozygote animals have reduced vesicular filling and release. These alterations in presynaptic monoamine function in the heterozygotes are thought to be responsible for the observed sensitization to the psychostimulants cocaine and amphetamine and to ethanol (1). Knockout animals also appear to parallel the changes that occur in reserpinized animals, suggesting that the adverse actions of this drug are mediated by VMAT2.

Nucleon-Nucleon Total Cross Section

NASA Technical Reports Server (NTRS)

Norbury, John W.

2008-01-01

The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

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

Zissa, D.E.; Barnes, V.E.; Carmony, D.D.

The elastic and topological p-barp cross sections have been measured at 48.9 GeV/c in the Fermilab proportional-wire-chamber--30-in.-bubble-chamber hybrid spectrometer. The elastic cross section is 7.81 +- 0.24 mb and the slope of the elastic differential cross section at t=0 is 13.4 +- 0.8 GeV/sup -2/. Further, the moments of the inelastic topological-cross-section distribution are =5.69 +- 0.03, /D=2.10 +- 0.02, and f/sup c/c/sub 2/=1.67 +- 0.12.

Total photoionization cross sections of atomic oxygen from threshold to 44.3 A

NASA Technical Reports Server (NTRS)

Angel, G. C.; Samson, James A. R.

1988-01-01

Synchrotron radiation was used to obtain the relative photoionization cross section of atomic oxygen for the production of singly charged ions over the 44.3-910.5-A wavelength range. Measurement of the contribution of multiple ionization to the cross sections has made possible the determination of total photoionization cross sections below 250 A. The series of autoionizing resonances leading to the 4P state of the oxygen ion has been observed using an ionization-type experimental procedure for the first time.

Evaluation of fusion-evaporation cross-section calculations

NASA Astrophysics Data System (ADS)

Blank, B.; Canchel, G.; Seis, F.; Delahaye, P.

2018-02-01

Calculated fusion-evaporation cross sections from five different codes are compared to experimental data. The present comparison extents over a large range of nuclei and isotopic chains to investigate the evolution of experimental and calculated cross sections. All models more or less overestimate the experimental cross sections. We found reasonable agreement by using the geometrical average of the five model calculations and dividing the average by a factor of 11.2. More refined analyses are made for example for the 100Sn region.

Measurement of the antineutrino neutral-current elastic differential cross section

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Brown, B. C.; Bugel, L.; Cheng, G.; Church, E. D.; Conrad, J. M.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Huelsnitz, W.; Ignarra, C.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Katori, T.; Kobilarcik, T.; Louis, W. C.; Mariani, C.; Marsh, W.; Mills, G. B.; Mirabal, J.; Moore, C. D.; Mousseau, J.; Nienaber, P.; Osmanov, B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Ray, H.; Roe, B. P.; Russell, A. D.; Shaevitz, M. H.; Spitz, J.; Stancu, I.; Tayloe, R.; Van de Water, R. G.; Wascko, M. O.; White, D. H.; Wickremasinghe, D. A.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2015-01-01

We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section (d σν ¯N →ν ¯N/d Q2) on CH2 by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of the antineutrino neutral current elastic to antineutrino charged current quasielastic cross sections are also presented.

Electron-Impact Cross Sections for Dipole- and Spin-Allowed Excitations of Hydrogen, Helium, and Lithium.

PubMed

Stone, Philip M; Kim, Yong-Ki; Desclaux, J P

2002-01-01

Electron-impact excitation cross sections are presented for the dipole- and spin allowed transitions from the ground states to the np (2)P states for hydrogen and lithium, and to the 1snp (1)P states for helium, n = 2 through 10. Two scaling formulas developed earlier by Kim [Phys. Rev. A 64, 032713 (2001)] for plane-wave Born cross sections are used. The scaled Born cross sections are in excellent agreement with available theoretical and experimental data.

M shell X-ray production cross sections and fluorescence yields for the elements with 71 <= Z <= 92 using 5.96 keV photons

NASA Astrophysics Data System (ADS)

Puri, S.; Mehta, D.; Chand, B.; Singh, Nirmal; Mangal, P. C.; Trehan, P. N.

1993-03-01

Total M X-ray production (XRP) cross sections for ten elements in the atomic number region 71 ≤ Z ≤ 92 were measured at 5.96 keV incident photon energy. The average M shell fluorescence yields < overlineωM> have also been computed using the present measured cross section values and the theoretical M shell photoionisation cross sections. The results are compared with theoretical values.

Measurement of the antineutrino neutral-current elastic differential cross section

DOE PAGES

Aguilar-Arevalo, A.  A.; Brown, B.  C.; Bugel, L.; ...

2015-01-08

We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section (dσ ν-barN→ν-barN/dQ 2) on CH 2 by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of the antineutrino neutral current elastic to antineutrino charged current quasi elastic cross sections are also presented.

RANKL-mediated osteoclastogenic differentiation of macrophages in the abdominal aorta of angiotensin II-infused apolipoprotein E knockout mice.

PubMed

Tanaka, Teruyoshi; Kelly, Matthew; Takei, Yuichiro; Yamanouchi, Dai

2018-04-20

Osteoclastogenic activation of macrophages (OCG) occurs in human abdominal aortic aneurysms (AAAs) and in calcium chloride-induced degenerative AAAs in mice, which have increased matrix metalloproteinase activity. As the activity of OCG in dissecting aneurysms is not clear, we tested the hypothesis that OCG contributes to angiotensin II (Ang II)-induced dissecting aneurysm (Ang II-induced AAA) in apolipoprotein E knockout mice. AAAs were produced in apolipoprotein E knockout mice via the administration of Ang II. Additionally, receptor activator of nuclear factor kB ligand (RANKL)-neutralizing antibody (5 mg/kg) was administered to one group of mice 7 days prior to Ang II infusion. Aneurysmal sections were probed for presence of RANKL and tartrate-resistant acid phosphatase via immunohistochemistry and immunofluorescence staining. Mouse aortas were also examined for RANKL and matrix metalloproteinase 9 expression via Western blot. In vitro murine vascular smooth muscle cells (MOVAS) and murine macrophages (RAW 264.7) were analyzed for the expression of osteogenic factors via Western blot, qPCR, and flow cytometry in response to Ang II or RANKL stimulation. The signaling pathway that mediates Ang II-induced RANKL expression in MOVAS cells was also investigated via application of TG101348, a Janus kinase 2 (JAK2) inhibitor, and Western blot analysis. Immunohistochemical staining of Ang II-induced AAA sections revealed OCG as evidenced by increased RANKL and tartrate-resistant acid phosphatase expression compared with control mice. Immunofluorescence staining of AAA sections revealed co-localization of vascular smooth muscle cells and RANKL, revealing vascular smooth muscle cells as one potential source of RANKL. Systemic administration of RANKL-neutralizing antibody suppressed Ang II-induced AAA, with significant reduction of the maximum diameter of the abdominal aorta compared with vehicle controls (1.5 ± 0.4 mm vs 2.2 ± 0.2 mm). Ang II (1 μM) treatment induced a significant increase in RANKL messenger RNA expression levels in MOVAS cells compared with the vehicle control (1.0 ± 0.2 vs 2.8 ± 0.2). The activities of JAK2 and signal transducer and activator of transcription 5 (STAT5) were also significantly increased by Ang II treatment. Inhibition of JAK2/STAT5 suppressed Ang II-induced RANKL expression, suggesting the involvement of the JAK2/STAT5 signaling pathway. OCG with increased RANKL expression was present in Ang II-induced AAA, and neutralization of RANKL suppressed AAA formation. As neutralization of RANKL has been used clinically to treat osteoporosis and other osteoclast-related diseases, additional study of the effectiveness of RANKL neutralization in AAA is warranted. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Uncertainty quantification in (α,n) neutron source calculations for an oxide matrix

DOE PAGES

Pigni, M. T.; Croft, S.; Gauld, I. C.

2016-04-25

Here we present a methodology to propagate nuclear data covariance information in neutron source calculations from (α,n) reactions. The approach is applied to estimate the uncertainty in the neutron generation rates for uranium oxide fuel types due to uncertainties on 1) 17,18O( α,n) reaction cross sections and 2) uranium and oxygen stopping power cross sections. The procedure to generate reaction cross section covariance information is based on the Bayesian fitting method implemented in the R-matrix SAMMY code. The evaluation methodology uses the Reich-Moore approximation to fit the 17,18O(α,n) reaction cross-sections in order to derive a set of resonance parameters andmore » a related covariance matrix that is then used to calculate the energydependent cross section covariance matrix. The stopping power cross sections and related covariance information for uranium and oxygen were obtained by the fit of stopping power data in the -energy range of 1 keV up to 12 MeV. Cross section perturbation factors based on the covariance information relative to the evaluated 17,18O( α,n) reaction cross sections, as well as uranium and oxygen stopping power cross sections, were used to generate a varied set of nuclear data libraries used in SOURCES4C and ORIGEN for inventory and source term calculations. The set of randomly perturbed output (α,n) source responses, provide the mean values and standard deviations of the calculated responses reflecting the uncertainties in nuclear data used in the calculations. Lastly, the results and related uncertainties are compared with experiment thick target (α,n) yields for uranium oxide.« less

[Relationship between image quality and cross-sectional area of phantom in three-dimensional positron emission tomography scan].

PubMed

Osawa, Atsushi; Miwa, Kenta; Wagatsuma, Kei; Takiguchi, Tomohiro; Tamura, Shintaro; Akimoto, Kenta

2012-01-01

The image quality in (18)FDG PET/CT often degrades as the body size increases. The purpose of this study was to evaluate the relationship between image quality and the body size using original phantoms of variable cross-sectional areas in PET/CT. We produced five water phantoms with different cross-sectional areas. The long axis of phantom was 925 mm, and the cross-sectional area was from 324 to 1189 cm(2). These phantoms with the sphere (diameter 10 mm) were filled with (18)F-FDG solution. The radioactivity concentration of background in the phantom was 1.37, 2.73, 4.09 and 5.46 kBq/mL. The scanning duration was 30 min in list mode acquisition for each measurement. Background variability (N(10 mm)), noise equivalent count rates (NECR(phantom)), hot sphere contrast (Q(H,10 mm)) as physical evaluation and visual score of sphere detection were measured, respectively. The relationship between image quality and the various cross-sectional areas was also analyzed under the above-mentioned conditions. As cross-sectional area increased, NECR(phantom) progressively decreased. Furthermore, as cross-sectional area increased, N(10 mm) increased and Q(H,10 mm) decreased. Image quality became degraded as body weight increased because noise and contrast contributed to image quality. The visual score of sphere detection deteriorated in high background radioactivity concentration because a false positive detection in cross-sectional area of the phantom increased. However, additional increases in scanning periods could improve the visual score. We assessed tendencies in the relationship between image quality and body size in PET/CT. Our results showed that time adjustment was more effective than dose adjustment for stable image quality of heavier patients in terms of the large cross-sectional area.

Biomechanical Factors Associated With Jump Height: A Comparison of Cross-Sectional and Pre-to-Posttraining Change Findings.

PubMed

Marshall, Brendan M; Moran, Kieran A

2015-12-01

Previous studies investigating the biomechanical factors associated with maximal countermovement jump height have typically used cross-sectional data. An alternative but less common approach is to use pre-to-posttraining change data, where the relationship between an improvement in jump height and a change in a factor is examined more directly. Our study compared the findings of these approaches. Such an evaluation is necessary because cross-sectional studies are currently a primary source of information for coaches when examining what factors to train to enhance performance. The countermovement jump of 44 males was analyzed before and after an 8-week training intervention. Correlations with jump height were calculated using both cross-sectional (pretraining data only) and pre-to-posttraining change data. Eight factors identified in the cross-sectional analysis were not significantly correlated with a change in jump height in the pre-to-post analysis. Additionally, only 6 of 11 factors identified in the pre-to-post analysis were identified in the cross-sectional analysis. These findings imply that (a) not all factors identified in a cross-sectional analysis may be critical to jump height improvement and (b) cross-sectional analyses alone may not provide an insight into all of the potential factors to train to enhance jump height. Coaches must be aware of these limitations when examining cross-sectional studies to identify factors to train to enhance jump ability. Additional findings highlight that although exercises prescribed to improve jump height should aim to enhance concentric power production at all joints, a particular emphasis on enhancing hip joint peak power may be warranted.

Validation of Cross Sections with Criticality Experiment and Reaction Rates: the Neptunium Case

NASA Astrophysics Data System (ADS)

Leong, L. S.; Tassan-Got, L.; Audouin, L.; Berthier, B.; Le Naour, C.; Stéphan, C.; Paradela, C.; Tarrío, D.; Duran, I.

2014-04-01

The 237Np neutron-induced fission cross section has been recently measured in a large energy range (from eV to GeV) at the n_TOF facility at CERN. When compared to previous measurements the n_TOF fission cross section appears to be higher by 5-7% beyond the fission threshold. To check the relevance of the n_TOF data, we considered a criticality experiment performed at Los Alamos with a 6 kg sphere of 237Np, surrounded by uranium highly enriched in 235U so as to approach criticality with fast neutrons. The multiplication factor keff of the calculation is in better agreement with the experiment when we replace the ENDF/B-VII.0 evaluation of the 237Np fission cross section by the n_TOF data. We also explored the hypothesis of deficiencies of the inelastic cross section in 235U which has been invoked by some authors to explain the deviation of 750 pcm. The large modification needed to reduce the deviation seems to be incompatible with existing inelastic cross section measurements. Also we show that the νbar of 237Np can hardly be incriminated because of the high accuracy of the existing data. Fission rate ratios or averaged fission cross sections measured in several fast neutron fields seem to give contradictory results on the validation of the 237Np cross section but at least one of the benchmark experiments, where the active deposits have been well calibrated for the number of atoms, favors the n_TOF data set. These outcomes support the hypothesis of a higher fission cross section of 237Np.

Optical model potential analysis of n ¯ A and n A interactions

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

Lee, Teck-Ghee; Wong, Cheuk-Yin

In this study, we use a momentum-dependent optical model potential to analyze the annihilation cross sections of the antineutronmore » $$\\overline{n}$$ on C, Al, Fe, Cu, Ag, Sn, and Pb nuclei for projectile momenta p lab ≲ 500 MeV / c . We obtain a good description of annihilation cross section data of Barbina et al. [Nucl. Phys. A 612, 346 (1997)] and of Astrua et al. [Nucl. Phys. A 697, 209 (2002)] which exhibit an interesting dependence of the cross sections on p lab as well as on the target mass number A. We also obtain the neutron (n) nonelastic reaction cross sections for the same targets. Comparing the $nA$ reaction cross sections σ$$nA\\atop{rec}$$ to the $$\\overline{n}A$$ annihilation cross sections σ $$\\overline{n}A$$ ann, we find that σ $$\\overline{n}A$$ ann is significantly larger than σ$$nA\\atop{rec}$$, that is, theσ $$\\overline{n}A$$ ann / σ$$nA\\atop{rec}$$ cross section ratio lies between the values of about 1.5 to 4.0 in the momentum region where comparison is possible. The dependence of the $$\\overline{n}$$ annihilation cross section on the projectile charge is also examined in comparison with the antiproton $$\\overline{p}$$. Here we predict the $$\\overline{p}A$$ annihilation cross section on the simplest assumption that both $$\\overline{p}A$$ and $$\\overline{n}A$$ interactions have the same nuclear part of the optical potential but differ only in the electrostatic Coulomb interaction. Finally, deviation from a such simple model extrapolation in measurements will provide new information on the difference between $$\\overline{n}A$$ and $$\\overline{p}A$$ potentials.« less

Optical model potential analysis of n ¯A and n A interactions

NASA Astrophysics Data System (ADS)

Lee, Teck-Ghee; Wong, Cheuk-Yin

2018-05-01

We use a momentum-dependent optical model potential to analyze the annihilation cross sections of the antineutron n ¯ on C, Al, Fe, Cu, Ag, Sn, and Pb nuclei for projectile momenta plab ≲500 MeV /c . We obtain a good description of annihilation cross section data of Barbina et al. [Nucl. Phys. A 612, 346 (1997), 10.1016/S0375-9474(96)00331-4] and of Astrua et al. [Nucl. Phys. A 697, 209 (2002), 10.1016/S0375-9474(01)01252-0] which exhibit an interesting dependence of the cross sections on plab as well as on the target mass number A . We also obtain the neutron (n ) nonelastic reaction cross sections for the same targets. Comparing the n A reaction cross sections σrecn A to the n ¯A annihilation cross sections σannn ¯A, we find that σannn ¯A is significantly larger than σrecn A, that is, the σannn ¯A/σrecn A cross section ratio lies between the values of about 1.5 to 4.0 in the momentum region where comparison is possible. The dependence of the n ¯ annihilation cross section on the projectile charge is also examined in comparison with the antiproton p ¯. Here we predict the p ¯A annihilation cross section on the simplest assumption that both p ¯A and n ¯A interactions have the same nuclear part of the optical potential but differ only in the electrostatic Coulomb interaction. Deviation from a such simple model extrapolation in measurements will provide new information on the difference between n ¯A and p ¯A potentials.

Optical model potential analysis of n ¯ A and n A interactions

DOE PAGES

Lee, Teck-Ghee; Wong, Cheuk-Yin

2018-05-25

In this study, we use a momentum-dependent optical model potential to analyze the annihilation cross sections of the antineutronmore » $$\\overline{n}$$ on C, Al, Fe, Cu, Ag, Sn, and Pb nuclei for projectile momenta p lab ≲ 500 MeV / c . We obtain a good description of annihilation cross section data of Barbina et al. [Nucl. Phys. A 612, 346 (1997)] and of Astrua et al. [Nucl. Phys. A 697, 209 (2002)] which exhibit an interesting dependence of the cross sections on p lab as well as on the target mass number A. We also obtain the neutron (n) nonelastic reaction cross sections for the same targets. Comparing the $nA$ reaction cross sections σ$$nA\\atop{rec}$$ to the $$\\overline{n}A$$ annihilation cross sections σ $$\\overline{n}A$$ ann, we find that σ $$\\overline{n}A$$ ann is significantly larger than σ$$nA\\atop{rec}$$, that is, theσ $$\\overline{n}A$$ ann / σ$$nA\\atop{rec}$$ cross section ratio lies between the values of about 1.5 to 4.0 in the momentum region where comparison is possible. The dependence of the $$\\overline{n}$$ annihilation cross section on the projectile charge is also examined in comparison with the antiproton $$\\overline{p}$$. Here we predict the $$\\overline{p}A$$ annihilation cross section on the simplest assumption that both $$\\overline{p}A$$ and $$\\overline{n}A$$ interactions have the same nuclear part of the optical potential but differ only in the electrostatic Coulomb interaction. Finally, deviation from a such simple model extrapolation in measurements will provide new information on the difference between $$\\overline{n}A$$ and $$\\overline{p}A$$ potentials.« less

Systematic effects on cross section data derived from reaction rates in reactor spectra and a re-analysis of 241Am reactor activation measurements

NASA Astrophysics Data System (ADS)

Žerovnik, Gašper; Schillebeeckx, Peter; Becker, Björn; Fiorito, Luca; Harada, Hideo; Kopecky, Stefan; Radulović, Vladimir; Sano, Tadafumi

2018-01-01

Methodologies to derive cross section data from spectrum integrated reaction rates were studied. The Westcott convention and some of its approximations were considered. Mostly measurements without and with transmission filter are combined to determine the reaction cross section at thermal energy together with the resonance integral. The accuracy of the results strongly depends on the assumptions that are made about the neutron energy distribution, which is mostly parameterised as a sum of a thermal and an epi-thermal component. Resonance integrals derived from such data can be strongly biased and should only be used in case no other data are available. The cross section at thermal energy can be biased for reaction cross sections which are dominated by low energy resonances. The amplitude of the effect is related to the lower energy limit that is used for the epi-thermal component of the neutron energy distribution. It is less affected by the assumptions on the shape of the energy distribution. When the energy dependence of the cross section is known and information about the neutron energy distribution is available, a method to correct for a bias on the cross section at thermal energy is proposed. Reactor activation measurements to determine the thermal 241Am(n, γ) cross section reported in the literature were reviewed. In case enough information was available, the results were corrected to account for possible biases and included in a least squares fit. These data combined with results of time-of-flight measurements give a capture cross section 720 (14) b for 241Am(n, γ) at thermal energy.

Some peculiarities of interactions of weakly bound lithium nuclei at near-barrier energies

NASA Astrophysics Data System (ADS)

Kabyshev, A. M.; Kuterbekov, K. A.; Sobolev, Yu G.; Penionzhkevich, Yu E.; Kubenova, M. M.; Azhibekov, A. K.; Mukhambetzhan, A. M.; Lukyanov, S. M.; Maslov, V. A.; Kabdrakhimova, G. D.

2018-02-01

This paper presents new experimental data on the total cross sections of 9Li + 28Si reactions at low energies as well as the analysis of previously obtained data for 6,7Li. Based on a large collection of data (authors’ and literature data) we carried out a comparative analysis of the two main experimental interaction cross sections (angular distributions of the differential cross sections and total reaction cross sections) for weakly bound lithium (6-9Li, 11Li) nuclei in the framework of Kox parameterization and the macroscopic optical model. We identified specific features of these interactions and predicted the experimental trend in the total reaction cross sections for Li isotopes at energies close to the Coulomb barrier.

Single nucleon emission in relativistic nucleus-nucleus reactions

NASA Technical Reports Server (NTRS)

Norbury, John W.; Townsend, Lawrence W.

1992-01-01

Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors.

Two-photon excitation cross-section in light and intermediate atoms

NASA Technical Reports Server (NTRS)

Omidvar, K.

1980-01-01

The method of explicit summation over the intermediate states is used along with LS coupling to derive an expression for two-photon absorption cross section in light and intermediate atoms in terms of integrals over radial wave functions. Two selection rules, one exact and one approximate, are also derived. In evaluating the radial integrals, for low-lying levels, the Hartree-Fock wave functions, and for high-lying levels, hydrogenic wave functions obtained by the quantum defect method are used. A relationship between the cross section and the oscillator strengths is derived. Cross sections due to selected transitions in nitrogen, oxygen, and chlorine are given. The expression for the cross section is useful in calculating the two-photon absorption in light and intermediate atoms.

Excitation of vibrational quanta in furfural by intermediate-energy electrons

NASA Astrophysics Data System (ADS)

Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Lima, M. A. P.; García, G.; Blanco, F.; Brunger, M. J.

2015-12-01

We report cross sections for electron-impact excitation of vibrational quanta in furfural, at intermediate incident electron energies (20, 30, and 40 eV). The present differential cross sections are measured over the scattered electron angular range 10°-90°, with corresponding integral cross sections subsequently being determined. Furfural is a viable plant-derived alternative to petrochemicals, being produced via low-temperature plasma treatment of biomass. Current yields, however, need to be significantly improved, possibly through modelling, with the present cross sections being an important component of such simulations. To the best of our knowledge, there are no other cross sections for vibrational excitation of furfural available in the literature, so the present data are valuable for this important molecule.

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

Pritychenko, B.; Mughabghab, S.F.

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present papermore » contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.« less

Nuclear Data Matters - The obvious case of a bad mixing ratio for 58Co

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

Hoffman, R. D.; Nesaraja, Caroline D.; Mattoon, Caleb

We present results of modeled cross sections for neutron- and proton-induced reactions leading to the final product nucleus 58Co. In each case the gamma-cascade branching ratios given in the ENSDF database circa 2014 predict modeled nuclear cross sections leading to the ground and first excited metastable state that are incompatible with measured cross sections found in the NNDC experimental cross section database EXFOR. We show that exploring the uncertainty in the mixing ratio used to calculate the gamma-cascade branching ratios for the 53.15 keV 2 nd excited state leads to changes in the predicted partial cross sections by amounts thatmore » give good agreement with measured data.« less

Nuclear stopping in central Xe+Sn collisions: Confrontation with experimental data

NASA Astrophysics Data System (ADS)

Rajni, Vermani, Yogesh K.

2018-05-01

The influence of symmetry energy and cross section on nuclear stopping is studied in central 54129Xe+50 120Sn Sn collisions at Fermi energies (Elab≈ 20-100 MeV/nucleon). The analysis is conducted using isospin dependent quantum molecular dynamics (IQMD) transport model. Model calculations are done using reduced isospin dependent nucleon-nucleon cross section (σiso) and isospin independent cross section (σnoiso). Calculations using the two versions of cross section are analyzed with and without symmetry energy (Esym). The results are then compared with the experimental data taken with 4π multidetector INDRA. From this comparison, we conclude that nuclear stopping and related production of light charged particles (LCPs) are strongly influenced by isospin dependence of nucleon-nucleon cross section.

Towards the high-accuracy determination of the 238U fission cross section at the threshold region at CERN - n_TOF

NASA Astrophysics Data System (ADS)

Diakaki, M.; Audouin, L.; Berthoumieux, E.; Calviani, M.; Colonna, N.; Dupont, E.; Duran, I.; Gunsing, F.; Leal-Cidoncha, E.; Le Naour, C.; Leong, L. S.; Mastromarco, M.; Paradela, C.; Tarrio, D.; Tassan-Got, L.; Aerts, G.; Altstadt, S.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Badurek, G.; Barbagallo, M.; Baumann, P.; Becares, V.; Becvar, F.; Belloni, F.; Berthier, B.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calvino, F.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Cerutti, F.; Chiaveri, E.; Chin, M.; Cortes, G.; Cortes-Giraldo, M. A.; Cosentino, L.; Couture, A.; Cox, J.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dressler, R.; Dridi, W.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Finocchiaro, P.; Fraval, K.; Fujii, K.; Furman, W.; Ganesan, S.; Garcia, A. R.; Giubrone, G.; Gomez-Hornillos, M. B.; Goncalves, I. F.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gurusamy, P.; Haight, R.; Heil, M.; Heinitz, S.; Igashira, M.; Isaev, S.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Kaeppeler, F.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Kivel, N.; Kokkoris, M.; Konovalov, V.; Krticka, M.; Kroll, J.; Lampoudis, C.; Langer, C.; Lederer, C.; Leeb, H.; Lo Meo, S.; Losito, R.; Lozano, M.; Manousos, A.; Marganiec, J.; Martinez, T.; Marrone, S.; Massimi, C.; Mastinu, P.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Moreau, C.; Mosconi, M.; Musumarra, A.; O'Brien, S.; Pancin, J.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perkowski, J.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, L.; Poch, A.; Pretel, C.; Praena, J.; Quesada, J.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rudolf, G.; Rubbia, C.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tavora, L.; Terlizzi, R.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Wallner, A.; Walter, S.; Ware, T.; Weigand, M.; Weiß, C.; Wiesher, M.; Wisshak, K.; Wright, T.; Zugec, P.

2016-03-01

The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN - n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

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.

Radiative neutron capture cross sections on 176Lu at DANCE

NASA Astrophysics Data System (ADS)

Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

2016-03-01

The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

Material mechanical characterization method for multiple strains and strain rates

DOEpatents

Erdmand, III, Donald L.; Kunc, Vlastimil; Simunovic, Srdjan; Wang, Yanli

2016-01-19

A specimen for measuring a material under multiple strains and strain rates. The specimen including a body having first and second ends and a gage region disposed between the first and second ends, wherein the body has a central, longitudinal axis passing through the first and second ends. The gage region includes a first gage section and a second gage section, wherein the first gage section defines a first cross-sectional area that is defined by a first plane that extends through the first gage section and is perpendicular to the central, longitudinal axis. The second gage section defines a second cross-sectional area that is defined by a second plane that extends through the second gage section and is perpendicular to the central, longitudinal axis and wherein the first cross-sectional area is different in size than the second cross-sectional area.

Identification of essential genes and synthetic lethal gene combinations in Escherichia coli K-12.

PubMed

Mori, Hirotada; Baba, Tomoya; Yokoyama, Katsushi; Takeuchi, Rikiya; Nomura, Wataru; Makishi, Kazuichi; Otsuka, Yuta; Dose, Hitomi; Wanner, Barry L

2015-01-01

Here we describe the systematic identification of single genes and gene pairs, whose knockout causes lethality in Escherichia coli K-12. During construction of precise single-gene knockout library of E. coli K-12, we identified 328 essential gene candidates for growth in complex (LB) medium. Upon establishment of the Keio single-gene deletion library, we undertook the development of the ASKA single-gene deletion library carrying a different antibiotic resistance. In addition, we developed tools for identification of synthetic lethal gene combinations by systematic construction of double-gene knockout mutants. We introduce these methods herein.

The groEL2 gene, but not groEL1, is required for biosynthesis of the secondary metabolite myxovirescin in Myxococcus xanthus DK1622.

PubMed

Wang, Yan; Li, Xi; Zhang, Wenyan; Zhou, Xiuwen; Li, Yue-zhong

2014-03-01

Myxococcus xanthus DK1622 possesses two copies of the groEL gene: groEL1, which participates in development, and groEL2, which is involved in the predatory ability of cells. In this study, we determined that the groEL2 gene is required for the biosynthesis of the secondary metabolite myxovirescin (TA), which plays essential roles in predation. The groEL2-knockout mutant strain was defective in producing a zone of inhibition and displayed decreased killing ability against Escherichia coli, while the groEL1-knockout mutant strain exhibited little difference from the wild-type strain DK1622. HPLC revealed that deletion of the groEL2 gene blocked the production of TA, which was present in the groEL1-knockout mutant. The addition of exogenous TA rescued the inhibition and killing abilities of the groEL2-knockout mutant against E. coli. Analysis of GroEL domain-swapping mutants indicated that the C-terminal equatorial domain of GroEL2 was essential for TA production, while the N-terminal equatorial or apical domains of GroEL2 were not sufficient to rescue TA production of the groEL2 knockout.

The role of nuclear factor E2-Related factor 2 and uncoupling protein 2 in glutathione metabolism: Evidence from an in vivo gene knockout study.

PubMed

Chen, Yanyan; Xu, Yuanyuan; Zheng, Hongzhi; Fu, Jingqi; Hou, Yongyong; Wang, Huihui; Zhang, Qiang; Yamamoto, Masayuki; Pi, Jingbo

2016-09-09

Nuclear factor E2-related factor 2 (NRF2) and uncoupling protein 2 (UCP2) are indicated to protect from oxidative stress. They also play roles in the homeostasis of glutathione. However, the detailed mechanisms are not well understood. In the present study, we found Nrf2-knockout (Nrf2-KO) mice exhibited altered glutathione homeostasis and reduced expression of various genes involved in GSH biosynthesis, regeneration, utilization and transport in the liver. Ucp2-knockout (Ucp2-KO) mice exhibited altered glutathione homeostasis in the liver, spleen and blood, as well as increased transcript of cystic fibrosis transmembrane conductance regulator in the liver, a protein capable of mediating glutathione efflux. Nrf2-Ucp2-double knockout (DKO) mice showed characteristics of both Nrf2-KO and Ucp2-KO mice. But no significant difference was observed in DKO mice when compared with Nrf2-KO or Ucp2-KO mice, except in blood glutathione levels. These data suggest that ablation of Nrf2 and Ucp2 leads to disrupted GSH balance, which could result from altered expression of genes involved in GSH metabolism. DKO may not evoke more severe oxidative stress than the single gene knockout. Copyright © 2016 Elsevier Inc. All rights reserved.

The Role of ARX in Human Pancreatic Endocrine Specification

PubMed Central

Gage, Blair K.; Asadi, Ali; Baker, Robert K.; Webber, Travis D.; Wang, Rennian; Itoh, Masayuki; Hayashi, Masaharu; Miyata, Rie; Akashi, Takumi; Kieffer, Timothy J.

2015-01-01

The in vitro differentiation of human embryonic stem cells (hESCs) offers a model system to explore human development. Humans with mutations in the transcription factor Aristaless Related Homeobox (ARX) often suffer from the syndrome X-linked lissencephaly with ambiguous genitalia (XLAG), affecting many cell types including those of the pancreas. Indeed, XLAG pancreatic islets lack glucagon and pancreatic polypeptide-positive cells but retain somatostatin, insulin, and ghrelin-positive cells. To further examine the role of ARX in human pancreatic endocrine development, we utilized genomic editing in hESCs to generate deletions in ARX. ARX knockout hESCs retained pancreatic differentiation capacity and ARX knockout endocrine cells were biased toward somatostatin-positive cells (94% of endocrine cells) with reduced pancreatic polypeptide (rarely detected), glucagon (90% reduced) and insulin-positive (65% reduced) lineages. ARX knockout somatostatin-positive cells shared expression patterns with human fetal and adult δ-cells. Differentiated ARX knockout cells upregulated PAX4, NKX2.2, ISL1, HHEX, PCSK1, PCSK2 expression while downregulating PAX6 and IRX2. Re-expression of ARX in ARX knockout pancreatic progenitors reduced HHEX and increased PAX6 and insulin expression following differentiation. Taken together these data suggest that ARX plays a key role in pancreatic endocrine fate specification of pancreatic polypeptide, somatostatin, glucagon and insulin positive cells from hESCs. PMID:26633894

The Role of ARX in Human Pancreatic Endocrine Specification.

PubMed

Gage, Blair K; Asadi, Ali; Baker, Robert K; Webber, Travis D; Wang, Rennian; Itoh, Masayuki; Hayashi, Masaharu; Miyata, Rie; Akashi, Takumi; Kieffer, Timothy J

2015-01-01

The in vitro differentiation of human embryonic stem cells (hESCs) offers a model system to explore human development. Humans with mutations in the transcription factor Aristaless Related Homeobox (ARX) often suffer from the syndrome X-linked lissencephaly with ambiguous genitalia (XLAG), affecting many cell types including those of the pancreas. Indeed, XLAG pancreatic islets lack glucagon and pancreatic polypeptide-positive cells but retain somatostatin, insulin, and ghrelin-positive cells. To further examine the role of ARX in human pancreatic endocrine development, we utilized genomic editing in hESCs to generate deletions in ARX. ARX knockout hESCs retained pancreatic differentiation capacity and ARX knockout endocrine cells were biased toward somatostatin-positive cells (94% of endocrine cells) with reduced pancreatic polypeptide (rarely detected), glucagon (90% reduced) and insulin-positive (65% reduced) lineages. ARX knockout somatostatin-positive cells shared expression patterns with human fetal and adult δ-cells. Differentiated ARX knockout cells upregulated PAX4, NKX2.2, ISL1, HHEX, PCSK1, PCSK2 expression while downregulating PAX6 and IRX2. Re-expression of ARX in ARX knockout pancreatic progenitors reduced HHEX and increased PAX6 and insulin expression following differentiation. Taken together these data suggest that ARX plays a key role in pancreatic endocrine fate specification of pancreatic polypeptide, somatostatin, glucagon and insulin positive cells from hESCs.

Cystatin C deficiency suppresses tumor growth in a breast cancer model through decreased proliferation of tumor cells.

PubMed

Završnik, Janja; Butinar, Miha; Prebanda, Mojca Trstenjak; Krajnc, Aleksander; Vidmar, Robert; Fonović, Marko; Grubb, Anders; Turk, Vito; Turk, Boris; Vasiljeva, Olga

2017-09-26

Cysteine cathepsins are proteases that, in addition to their important physiological functions, have been associated with multiple pathologies, including cancer. Cystatin C (CstC) is a major endogenous inhibitor that regulates the extracellular activity of cysteine cathepsins. We investigated the role of cystatin C in mammary cancer using CstC knockout mice and a mouse model of breast cancer induced by expression of the polyoma middle T oncoprotein (PyMT) in the mammary epithelium. We showed that the ablation of CstC reduced the rate of mammary tumor growth. Notably, a decrease in the proliferation of CstC knockout PyMT tumor cells was demonstrated ex vivo and in vitro , indicating a role for this protease inhibitor in signaling pathways that control cell proliferation. An increase in phosphorylated p-38 was observed in CstC knockout tumors, suggesting a novel function for cystatin C in cancer development, independent of the TGF-β pathway. Moreover, proteomic analysis of the CstC wild-type and knockout PyMT primary cell secretomes revealed a decrease in the levels of 14-3-3 proteins in the secretome of knock-out cells, suggesting a novel link between cysteine cathepsins, cystatin C and 14-3-3 proteins in tumorigenesis, calling for further investigations.

Acute multi-sgRNA knockdown of KEOPS complex genes reproduces the microcephaly phenotype of the stable knockout zebrafish model.

PubMed

Jobst-Schwan, Tilman; Schmidt, Johanna Magdalena; Schneider, Ronen; Hoogstraten, Charlotte A; Ullmann, Jeremy F P; Schapiro, David; Majmundar, Amar J; Kolb, Amy; Eddy, Kaitlyn; Shril, Shirlee; Braun, Daniela A; Poduri, Annapurna; Hildebrandt, Friedhelm

2018-01-01

Until recently, morpholino oligonucleotides have been widely employed in zebrafish as an acute and efficient loss-of-function assay. However, off-target effects and reproducibility issues when compared to stable knockout lines have compromised their further use. Here we employed an acute CRISPR/Cas approach using multiple single guide RNAs targeting simultaneously different positions in two exemplar genes (osgep or tprkb) to increase the likelihood of generating mutations on both alleles in the injected F0 generation and to achieve a similar effect as morpholinos but with the reproducibility of stable lines. This multi single guide RNA approach resulted in median likelihoods for at least one mutation on each allele of >99% and sgRNA specific insertion/deletion profiles as revealed by deep-sequencing. Immunoblot showed a significant reduction for Osgep and Tprkb proteins. For both genes, the acute multi-sgRNA knockout recapitulated the microcephaly phenotype and reduction in survival that we observed previously in stable knockout lines, though milder in the acute multi-sgRNA knockout. Finally, we quantify the degree of mutagenesis by deep sequencing, and provide a mathematical model to quantitate the chance for a biallelic loss-of-function mutation. Our findings can be generalized to acute and stable CRISPR/Cas targeting for any zebrafish gene of interest.

Neutral endopeptidase knockout induces hyperalgesia in a model of visceral pain, an effect related to bradykinin and nitric oxide.

PubMed

Fischer, Hanspeter S; Zernig, Gerald; Hauser, Kurt F; Gerard, Craig; Hersh, Louis B; Saria, Alois

2002-01-01

Neutral endopeptidase (EC3.4.24.11, NEP, enkephalinase) is a zinc-metalloendopeptidase, cleaving a variety of substrates like enkephalins, substance P, and bradykinin. In the brain, NEP is a key enzyme in the degradation of enkephalins. Pharmacological inhibition of NEP-activity causes analgesia resulting from enhanced extracellular enkephalin concentrations. Recently, transgenic mice lacking the enzyme NEP have been developed (Lu, 1995). The present study was designed to investigate the nociceptive behavior of these NEP-knockout mice. Interestingly, NEP-deficient mice did not respond with decreased pain perception, but exhibited hyperalgesia in the hot-plate jump, warm-water tail-withdrawal, and mostnotablyin theacetic-acid writhing test. Inhibition of aminopeptidase N by bestatin reduced writhing in both strains, whereas NEP-inhibition by thiorphan reduced writhing selectively in wild-type mice. Naloxone increased writhing in wild-type but not in knockouts, whereas the bradykinin B2-receptor antagonist HOE140 reduced writhing selectively in NEP-knockouts. Similarly, the nitric oxide synthase inhibitor L-NAME reduced writhing in NEP-knockouts. These results indicate that genetic elimination of NEP, in contrast to pharmacological inhibition, leads to bradykinin-induced hyperalgesia instead of enkephalin-mediated analgesia. Nitric oxide (NO) is suggested to be involved in this process.

Target sequencing and CRISPR/Cas editing reveal simultaneous loss of UTX and UTY in urothelial bladder cancer.

PubMed

Ahn, Jinwoo; Kim, Kwang Hyun; Park, Sanghui; Ahn, Young-Ho; Kim, Ha Young; Yoon, Hana; Lee, Ji Hyun; Bang, Duhee; Lee, Dong Hyeon

2016-09-27

UTX is a histone demethylase gene located on the X chromosome and is a frequently mutated gene in urothelial bladder cancer (UBC). UTY is a paralog of UTX located on the Y chromosome. We performed target capture sequencing on 128 genes in 40 non-metastatic UBC patients. UTX was the most frequently mutated gene (30%, 12/40). Of the genetic alterations identified, 75% were truncating mutations. UTY copy number loss was detected in 8 male patients (22.8%, 8/35). Of the 9 male patients with UTX mutations, 6 also had copy number loss (66.7%). To evaluate the functional roles of UTX and UTY in tumor progression, we designed UTX and UTY single knockout and UTX-UTY double knockout experiments using a CRISPR/Cas9 lentiviral system, and compared the proliferative capacities of two UBC cell lines in vitro. Single UTX or UTY knockout increased cell proliferation as compared to UTX-UTY wild-type cells. UTX-UTY double knockout cells exhibited greater proliferation than single knockout cells. These findings suggest both UTX and UTY function as dose-dependent suppressors of UBC development. While UTX escapes X chromosome inactivation in females, UTY may function as a male homologue of UTX, which could compensate for dosage imbalances.

Cathepsin K Knockout Alleviates Pressure Overload–Induced Cardiac Hypertrophy

PubMed Central

Hua, Yinan; Xu, Xihui; Shi, Guo-Ping; Chicco, Adam J.; Ren, Jun; Nair, Sreejayan

2014-01-01

Evidence from human and animal studies has documented elevated levels of lysosomal cysteine protease cathepsin K in failing hearts. Here, we hypothesized that ablation of cathepsin K mitigates pressure overload–induced cardiac hypertrophy. Cathepsin K knockout mice and their wild-type littermates were subjected to abdominal aortic constriction, resulting in cardiac remodeling (heart weight, cardiomyocyte size, left ventricular wall thickness, and end diastolic and end systolic dimensions) and decreased fractional shortening, the effects of which were significantly attenuated or ablated by cathepsin K knockout. Pressure overload dampened cardiomyocyte contractile function along with decreased resting Ca2+ levels and delayed Ca2+ clearance, which were partly resolved by cathepsin K knockout. Cardiac mammalian target of rapamycin and extracellular signal-regulated kinases (ERK) signaling cascades were upregulated by pressure overload, the effects of which were attenuated by cathepsin K knockout. In cultured H9c2 myoblast cells, silencing of cathepsin K blunted, whereas cathepsin K transfection mimicked phenylephrine–induced hypertrophic response, along with elevated phosphorylation of mammalian target of rapamycin and ERK. In addition, cathepsin K protein levels were markedly elevated in human hearts of end-stage dilated cardiomyopathy. Collectively, our data suggest that cathepsin K ablation mitigates pressure overload–induced hypertrophy, possibly via inhibition of the mammalian target of rapamycin and ERK pathways. PMID:23529168

Role of AMACR (α-methylacyl-CoA racemase) and MFE-1 (peroxisomal multifunctional enzyme-1) in bile acid synthesis in mice.

PubMed

Autio, Kaija J; Schmitz, Werner; Nair, Remya R; Selkälä, Eija M; Sormunen, Raija T; Miinalainen, Ilkka J; Crick, Peter J; Wang, Yuqin; Griffiths, William J; Reddy, Janardan K; Baes, Myriam; Hiltunen, J Kalervo

2014-07-01

Cholesterol is catabolized to bile acids by peroxisomal β-oxidation in which the side chain of C27-bile acid intermediates is shortened by three carbon atoms to form mature C24-bile acids. Knockout mouse models deficient in AMACR (α-methylacyl-CoA racemase) or MFE-2 (peroxisomal multifunctional enzyme type 2), in which this β-oxidation pathway is prevented, display a residual C24-bile acid pool which, although greatly reduced, implies the existence of alternative pathways of bile acid synthesis. One alternative pathway could involve Mfe-1 (peroxisomal multifunctional enzyme type 1) either with or without Amacr. To test this hypothesis, we generated a double knockout mouse model lacking both Amacr and Mfe-1 activities and studied the bile acid profiles in wild-type, Mfe-1 and Amacr single knockout mouse line and Mfe-1 and Amacr double knockout mouse lines. The total bile acid pool was decreased in Mfe-1-/- mice compared with wild-type and the levels of mature C24-bile acids were reduced in the double knockout mice when compared with Amacr-deficient mice. These results indicate that Mfe-1 can contribute to the synthesis of mature bile acids in both Amacr-dependent and Amacr-independent pathways.

Total and Compound Formation Cross Sections for Americium Nuclei: Recommendations for Coupled-Channels Calculations

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

Escher, J. E.

Calculations for total cross sections and compound-nucleus (CN) formation cross sections for americium isotopes are described, for use in the 2017 NA-22 evaluation effort. The code ECIS 2006 was used in conjunction with Frank Dietrich's wrapper `runtemplate'.

Investigation of complete and incomplete fusion in the 7Li+124Sn reaction near Coulomb barrier energies

NASA Astrophysics Data System (ADS)

Parkar, V. V.; Sharma, Sushil K.; Palit, R.; Upadhyaya, S.; Shrivastava, A.; Pandit, S. K.; Mahata, K.; Jha, V.; Santra, S.; Ramachandran, K.; Nag, T. N.; Rath, P. K.; Kanagalekar, Bhushan; Trivedi, T.

2018-01-01

The complete and incomplete fusion cross sections for the 7Li+124Sn reaction were measured using online and offline characteristic γ -ray detection techniques. The complete fusion (CF) cross sections at energies above the Coulomb barrier were found to be suppressed by ˜26 % compared to the coupled channel calculations. This suppression observed in complete fusion cross sections is found to be commensurate with the measured total incomplete fusion (ICF) cross sections. There is a distinct feature observed in the ICF cross sections, i.e., t capture is found to be dominant compared to α capture at all the measured energies. A simultaneous explanation of complete, incomplete, and total fusion (TF) data was also obtained from the calculations based on the continuum discretized coupled channel method with short range imaginary potentials. The cross section ratios of CF/TF and ICF/TF obtained from the data as well as the calculations showed the dominance of ICF at below-barrier energies and CF at above-barrier energies.

The evaluation of experimental data in fast range for n + 56Fe(n,inl)

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

Qian, Jing; Herman, M.; Ge, Zhigang

Iron is one of the five materials selected for evaluation within the pilot international evaluation project CIELO. Analysis of experimental data for n+ 56Fe reaction is the basis for constraining theoretical calculations and eventual creation of the evaluated file. The detail analysis was performed for inelastic cross sections of neutron induced reactions with 56Fe in the fast range up to 20 MeV where there are significant differences among the main evaluated libraries, mainly caused by the different inelastic scattering cross section measurements. Gamma-ray production cross sections provide a way to gain experimental information about the inelastic cross section. Large discrepanciesmore » between experimental data for the 847-keV gamma ray produced in the 56Fe(n,n 1'γ) reaction were analyzed. In addition, experimental data for elastic scattering cross section between 9.41~11 MeV were used to deduce the inelastic cross section from the unitarity constrain.« less

The evaluation of experimental data in fast range for n + 56Fe(n,inl)

DOE PAGES

Qian, Jing; Herman, M.; Ge, Zhigang; ...

2017-09-13

Iron is one of the five materials selected for evaluation within the pilot international evaluation project CIELO. Analysis of experimental data for n+ 56Fe reaction is the basis for constraining theoretical calculations and eventual creation of the evaluated file. The detail analysis was performed for inelastic cross sections of neutron induced reactions with 56Fe in the fast range up to 20 MeV where there are significant differences among the main evaluated libraries, mainly caused by the different inelastic scattering cross section measurements. Gamma-ray production cross sections provide a way to gain experimental information about the inelastic cross section. Large discrepanciesmore » between experimental data for the 847-keV gamma ray produced in the 56Fe(n,n 1'γ) reaction were analyzed. In addition, experimental data for elastic scattering cross section between 9.41~11 MeV were used to deduce the inelastic cross section from the unitarity constrain.« less

Neutron-induced fission-cross-section measurements and calculations of selected transplutonic isotopes

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

White, R.M.; Browne, J.C.

1982-08-27

The neutron-induced fission cross sections of /sup 242m/Am and /sup 245/Cm have been measured over an energy range of 10/sup -4/ eV to approx. 20 MeV in a series of experiments at three facilities during the past several years. The combined results of these measurements, in which only sub-milligram quantities of enriched isotopes were used, yield cross sections with uncertainties of approximately 5% below 10 MeV relative to the /sup 235/U standard cross section used to normalize the data. We summarize the resonance analysis of the /sup 242m/Am(n,f) cross section in the eV region. Hauser-Feshbach statistical calculations of the detailedmore » fission cross sections of /sup 235/U and /sup 245/Cm have been carried out over the energy region from 0.1 to 5 MeV and these results are compared with our experimental data.« less

Statistical Features of the Thermal Neutron Capture Cross Sections

DOE PAGES

Hussein, M. S.; Carlson, B. V.; Kerman, A. K.

2016-02-01

In this paper, we discuss the existence of huge thermal neutron capture cross sections in several nuclei. The values of the cross sections are several orders of magnitude bigger than expected at these very low energies. We lend support to the idea that this phenomenon is random in nature and is similar to what we have learned from the study of parity violation in the actinide region. The idea of statistical doorways is advanced as a unified concept in the delineation of large numbers in the nuclear world. The average number of maxima per unit mass, < n A >more » in the capture cross section is calculated and related to the underlying cross section correlation function and found to be < n A > = 3/(π√2γ A), where γ A is a characteristic mass correlation width which designates the degree of remnant coherence in the system. Finally, we trace this coherence to nucleosynthesis which produced the nuclei whose neutron capture cross sections are considered here.« less

Photodissociation of anisole and absolute photoionization cross-section of the phenoxy radical.

PubMed

Xu, Hong; Pratt, S T

2013-11-21

We have studied the photodissociation dynamics of anisole (C6H5OCH3) at 193 nm and determined the absolute photoionization cross-section of the phenoxy radical at 118.2 nm (10.486 eV) relative to the known cross-section of the methyl radical. Even at this energy, there is extensive fragmentation of the phenoxy radical upon photoionization, which is attributed to ionizing transitions that populate low-lying excited electronic states of the cation. For phenoxy radicals with less than ∼1 eV of internal energy, we find a cross-section for the production of the phenoxy cation of 14.8 ± 3.8 Mb. For radicals with higher internal energy, dissociative ionization is the dominant process, and for internal energies of ∼2.7-3.7 eV, we find a total cross-section (photoionization plus dissociative ionization) of 22.3 ± 4.1 Mb. The results are discussed relative to the recently reported photoionization cross-section of phenol.

Electron-impact total ionization cross sections of DNA sugar-phosphate backbone and an additivity principle

NASA Technical Reports Server (NTRS)

Huo, Winifred M.; Dateo, Christopher E.

2005-01-01

The improved binary-encounter dipole (iBED) model [W.M. Huo, Phys. Rev. A64, 042719-1 (2001)l is used to study the total ionization cross sections of the DNA sugar-phosphate backbone by electron impact. Calculations using neutral fragments found that the total ionization cross sections of C3' - and C5', -deoxyribose-phospate, two conformers of the sugar-phosphate backbone, are close to each other. Furthermore, the sum of the ionization cross sections of the separate deoxyribose and phosphate fragments is in close agreement with the C3' - and C5" -deoxyribose-phospate cross sections, differing by less than 10%. The result implies that certain properties of the-DNA, like the total singly ionization cross section, are localized properties and a building-up or additivity principle may apply. This allows us to obtain accurate properties of larger molecular systems built up from the results of smaller subsystem fragments. Calculations are underway using a negatively charged sugar-phosphate backbone with a metal counter-ion.

How to Use Benchmark and Cross-section Studies to Improve Data Libraries and Models

NASA Astrophysics Data System (ADS)

Wagner, V.; Suchopár, M.; Vrzalová, J.; Chudoba, P.; Svoboda, O.; Tichý, P.; Krása, A.; Majerle, M.; Kugler, A.; Adam, J.; Baldin, A.; Furman, W.; Kadykov, M.; Solnyshkin, A.; Tsoupko-Sitnikov, S.; Tyutyunikov, S.; Vladimirovna, N.; Závorka, L.

2016-06-01

Improvements of the Monte Carlo transport codes and cross-section libraries are very important steps towards usage of the accelerator-driven transmutation systems. We have conducted a lot of benchmark experiments with different set-ups consisting of lead, natural uranium and moderator irradiated by relativistic protons and deuterons within framework of the collaboration “Energy and Transmutation of Radioactive Waste”. Unfortunately, the knowledge of the total or partial cross-sections of important reactions is insufficient. Due to this reason we have started extensive studies of different reaction cross-sections. We measure cross-sections of important neutron reactions by means of the quasi-monoenergetic neutron sources based on the cyclotrons at Nuclear Physics Institute in Řež and at The Svedberg Laboratory in Uppsala. Measurements of partial cross-sections of relativistic deuteron reactions were the second direction of our studies. The new results obtained during last years will be shown. Possible use of these data for improvement of libraries, models and benchmark studies will be discussed.

Statistical Features of the Thermal Neutron Capture Cross Sections

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

Hussein, M. S.; Carlson, B. V.; Kerman, A. K.

In this paper, we discuss the existence of huge thermal neutron capture cross sections in several nuclei. The values of the cross sections are several orders of magnitude bigger than expected at these very low energies. We lend support to the idea that this phenomenon is random in nature and is similar to what we have learned from the study of parity violation in the actinide region. The idea of statistical doorways is advanced as a unified concept in the delineation of large numbers in the nuclear world. The average number of maxima per unit mass, < n A >more » in the capture cross section is calculated and related to the underlying cross section correlation function and found to be < n A > = 3/(π√2γ A), where γ A is a characteristic mass correlation width which designates the degree of remnant coherence in the system. Finally, we trace this coherence to nucleosynthesis which produced the nuclei whose neutron capture cross sections are considered here.« less

Proton Magnetic Form Factor from Existing Elastic e-p Cross Section Data

NASA Astrophysics Data System (ADS)

Ou, Longwu; Christy, Eric; Gilad, Shalev; Keppel, Cynthia; Schmookler, Barak; Wojtsekhowski, Bogdan

2015-04-01

The proton magnetic form factor GMp, in addition to being an important benchmark for all cross section measurements in hadron physics, provides critical information on proton structure. Extraction of GMp from e-p cross section data is complicated by two-photon exchange (TPE) effects, where available calculations still have large theoretical uncertainties. Studies of TPE contributions to e-p scattering have observed no nonlinear effects in Rosenbluth separations. Recent theoretical investigations show that the TPE correction goes to 0 when ɛ approaches 1, where ɛ is the virtual photon polarization parameter. In this talk, existing e-p elastic cross section data are reanalyzed by extrapolating the reduced cross section for ɛ approaching 1. Existing polarization transfer data, which is supposed to be relatively immune to TPE effects, are used to produce a ratio of electric and magnetic form factors. The extrapolated reduced cross section and polarization transfer ratio are then used to calculate GEp and GMp at different Q2 values.

First measurement of the muon antineutrino double-differential charged-current quasielastic cross section

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Brown, B. C.; Bugel, L.; Cheng, G.; Church, E. D.; Conrad, J. M.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Huelsnitz, W.; Ignarra, C.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Katori, T.; Kobilarcik, T.; Louis, W. C.; Mariani, C.; Marsh, W.; Mills, G. B.; Mirabal, J.; Moore, C. D.; Mousseau, J.; Nienaber, P.; Osmanov, B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Ray, H.; Roe, B. P.; Russell, A. D.; Shaevitz, M. H.; Spitz, J.; Stancu, I.; Tayloe, R.; Van de Water, R. G.; Wascko, M. O.; White, D. H.; Wickremasinghe, D. A.; Zeller, G. P.; Zimmerman, E. D.

2013-08-01

The largest sample ever recorded of ν¯μ charged-current quasielastic (CCQE, ν¯μ+p→μ++n) candidate events is used to produce the minimally model-dependent, flux-integrated double-differential cross section (d2σ)/(dTμdcos⁡θμ) for ν¯μ CCQE for a mineral oil target. This measurement exploits the large statistics of the MiniBooNE antineutrino mode sample and provides the most complete information of this process to date. In order to facilitate historical comparisons, the flux-unfolded total cross section σ(Eν) and single-differential cross section (dσ)/(dQ2) on both mineral oil and on carbon are also reported. The observed cross section is somewhat higher than the predicted cross section from a model assuming independently acting nucleons in carbon with canonical form factor values. The shape of the data are also discrepant with this model. These results have implications for intranuclear processes and can help constrain signal and background processes for future neutrino oscillation measurements.

Ab initio Potential-Energy Surfaces and Electron-Spin-Exchange Cross Sections for H-O2 Interactions

NASA Technical Reports Server (NTRS)

Stallcop, James R.; Partridge, Harry; Levin, Eugene

1996-01-01

Accurate quartet- and doublet-state potential-energy surfaces for the interaction of a hydrogen atom and an oxygen molecule in their ground states have been determined from an ab initio calculation using large-basis sets and the internally contracted multireference configuration interaction method. These potential surfaces have been used to calculate the H-O2 electron-spin-exchange cross section; the square root of the cross section (in a(sub 0)), not taking into account inelastic effects, can be obtained approximately from the expressions 2.390E(sup -1/6) and 5.266-0.708 log10(E) at low and high collision energies E (in E(sub h)), respectively. These functional forms, as well as the oscillatory structure of the cross section found at high energies, are expected from the nature of the interaction energy. The mean cross section (the cross section averaged over a Maxwellian velocity distribution) agrees reasonably well with the results of measurements.

Scattering Cross Section of Sound Waves by the Modal Element Method

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.; Kreider, Kevin L.

1994-01-01

#he modal element method has been employed to determine the scattered field from a plane acoustic wave impinging on a two dimensional body. In the modal element method, the scattering body is represented by finite elements, which are coupled to an eigenfunction expansion representing the acoustic pressure in the infinite computational domain surrounding the body. The present paper extends the previous work by developing the algorithm necessary to calculate the acoustics scattering cross section by the modal element method. The scattering cross section is the acoustical equivalent to the Radar Cross Section (RCS) in electromagnetic theory. Since the scattering cross section is evaluated at infinite distance from the body, an asymptotic approximation is used in conjunction with the standard modal element method. For validation, the scattering cross section of the rigid circular cylinder is computed for the frequency range 0.1 is less than or equal to ka is less than or equal to 100. Results show excellent agreement with the analytic solution.

Total photoionization cross sections of atomic oxygen from threshold to 44.3A

NASA Technical Reports Server (NTRS)

Angel, G. C.; Samson, James A. R.

1987-01-01

The relative cross section of atomic oxygen for the production of singly charged ions has been remeasured in more detail and extended to cover the wavelength range 44.3 to 910.5 A by the use of synchrotron radiation. In addition, the contribution of multiple ionization to the cross sections has been measured allowing total photoionization cross sections to be obtained below 250 A. The results have been made absolute by normalization to previously measured data. The use of synchrotron radiation has enabled measurements of the continuum cross section to be made between the numerous autoionizing resonances that occur near the ionization thresholds. This in turn has allowed a more critical comparison of the various theoretical estimates of the cross section to be made. The series of autoionizing resonances leading to the 4-P state of the oxygen ion have been observed for the first time in an ionization type experiment and their positions compared with both theory and previous photographic recordings.

Status of the R-matrix Code AMUR toward a consistent cross-section evaluation and covariance analysis for the light nuclei

NASA Astrophysics Data System (ADS)

Kunieda, Satoshi

2017-09-01

We report the status of the R-matrix code AMUR toward consistent cross-section evaluation and covariance analysis for the light-mass nuclei. The applicable limit of the code is extended by including computational capability for the charged-particle elastic scattering cross-sections and the neutron capture cross-sections as example results are shown in the main texts. A simultaneous analysis is performed on the 17O compound system including the 16O(n,tot) and 13C(α,n)16O reactions together with the 16O(n,n) and 13C(α,α) scattering cross-sections. It is found that a large theoretical background is required for each reaction process to obtain a simultaneous fit with all the experimental cross-sections we analyzed. Also, the hard-sphere radii should be assumed to be different from the channel radii. Although these are technical approaches, we could learn roles and sources of the theoretical background in the standard R-matrix.

Changes in channel geometry of six eruption-affected tributaries of the Lewis River, 1980-82, Mount St. Helens, Washington

USGS Publications Warehouse

Martinson, H.A.; Finneran, S.D.; Topinka, L.J.

1984-01-01

The May 18, 1980, eruption of Mount St. Helens generated a lateral blast, lahars and tephra deposits that altered tributary channels in the Lewis River drainage basin. In order to assess potential flood hazards, study channel adjustments, and construct a sediment budget for the perturbed drainages on the east and southeast flanks of the volcano, channel cross sections were monumented and surveyed on Pine Creek, Muddy River, and Smith Creek during September and October of 1980. Additional cross sections were monumented and surveyed on Swift Creek, Bean Creek, and Clearwater Creek during the summer of 1981. The network of 88 channel cross sections has been resurveyed annually. Selected cross sections have been surveyed more frequently, following periods of higher flow. The repetitive cross-section surveys provide measurements of bank erosion or accretion and of channel erosion or aggradation. The report presents channel cross-section profiles constructed from the survey data collected during water years 1980-82. (USGS)