26
|
Zylstra AB, Frenje JA, Séguin FH, Rosenberg MJ, Rinderknecht HG, Johnson MG, Casey DT, Sinenian N, Manuel MJE, Waugh CJ, Sio HW, Li CK, Petrasso RD, Friedrich S, Knittel K, Bionta R, McKernan M, Callahan D, Collins GW, Dewald E, Döppner T, Edwards MJ, Glenzer S, Hicks DG, Landen OL, London R, Mackinnon A, Meezan N, Prasad RR, Ralph J, Richardson M, Rygg JR, Sepke S, Weber S, Zacharias R, Moses E, Kilkenny J, Nikroo A, Sangster TC, Glebov V, Stoeckl C, Olson R, Leeper RJ, Kline J, Kyrala G, Wilson D. Charged-particle spectroscopy for diagnosing shock ρR and strength in NIF implosions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10D901. [PMID: 23126905 DOI: 10.1063/1.4729672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign diagnostic. The WRF measures the spectrum of protons from D-(3)He reactions in tuning-campaign implosions containing D and (3)He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total ρR through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.
Collapse
|
27
|
Gatu Johnson M, Frenje JA, Casey DT, Li CK, Séguin FH, Petrasso R, Ashabranner R, Bionta RM, Bleuel DL, Bond EJ, Caggiano JA, Carpenter A, Cerjan CJ, Clancy TJ, Doeppner T, Eckart MJ, Edwards MJ, Friedrich S, Glenzer SH, Haan SW, Hartouni EP, Hatarik R, Hatchett SP, Jones OS, Kyrala G, Le Pape S, Lerche RA, Landen OL, Ma T, MacKinnon AJ, McKernan MA, Moran MJ, Moses E, Munro DH, McNaney J, Park HS, Ralph J, Remington B, Rygg JR, Sepke SM, Smalyuk V, Spears B, Springer PT, Yeamans CB, Farrell M, Jasion D, Kilkenny JD, Nikroo A, Paguio R, Knauer JP, Glebov VY, Sangster TC, Betti R, Stoeckl C, Magoon J, Shoup MJ, Grim GP, Kline J, Morgan GL, Murphy TJ, Leeper RJ, Ruiz CL, Cooper GW, Nelson AJ. Neutron spectrometry--an essential tool for diagnosing implosions at the National Ignition Facility (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10D308. [PMID: 23126835 DOI: 10.1063/1.4728095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
DT neutron yield (Y(n)), ion temperature (T(i)), and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-time-of-flight (nTOF) spectrometers and a magnetic recoil spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the complementarity required for reliable measurements of Y(n), T(i), and dsr. From the measured dsr value, an areal density (ρR) is determined through the relationship ρR(tot) (g∕cm(2)) = (20.4 ± 0.6) × dsr(10-12 MeV). The proportionality constant is determined considering implosion geometry, neutron attenuation, and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration of the as-built spectrometers, which are now performing to the required accuracy. Recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental ignition threshold factor (ITFx), which is a function of dsr (or fuel ρR) and Y(n), has improved almost two orders of magnitude since the first shot in September, 2010.
Collapse
|
28
|
Casey DT, Frenje JA, Gatu Johnson M, Séguin FH, Li CK, Petrasso RD, Glebov VY, Katz J, Knauer JP, Meyerhofer DD, Sangster TC, Bionta RM, Bleuel DL, Döppner T, Glenzer S, Hartouni E, Hatchett SP, Le Pape S, Ma T, MacKinnon A, McKernan MA, Moran M, Moses E, Park HS, Ralph J, Remington BA, Smalyuk V, Yeamans CB, Kline J, Kyrala G, Chandler GA, Leeper RJ, Ruiz CL, Cooper GW, Nelson AJ, Fletcher K, Kilkenny J, Farrell M, Jasion D, Paguio R. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10D912. [PMID: 23126915 DOI: 10.1063/1.4738657] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.
Collapse
|
29
|
Johnson M, Løset M, Brennecke S, Peralta J, Dyer T, East C, Pennell C, Huang RC, Mori T, Beilin L, Blangero J, Moses E. OS049. Exome sequencing identifies likely functional variantsinfluencing preeclampsia and CVD risk. Pregnancy Hypertens 2012; 2:203-4. [PMID: 26105263 DOI: 10.1016/j.preghy.2012.04.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Next-generation sequencing (NGS) in family-based study designs will be pivotal in unlocking the missing heritability of common complex diseases. Whilst our prior linkage- and association-based positional cloning studies in family- and population-based Australian cohorts, respectively, have discovered novel preeclampsia candidate genes (INHBB,ACVR2A,LCT,LRP1B,RND3,GCA,ERAP2,TNFSF13B), the full complement of causal genetic variation remains largely unknown. We have now sequenced the exomes of two Australian preeclampsia families in another step forward to unlocking preeclampsia's complex allelic architecture. OBJECTIVES Identify family-specific exon-centric loci segregating in preeclamptic women only. METHODS The exomes of 18 women (7 preeclamptics,11 controls) from two Australian families contributing to our chromosome 5q (Family 1) and 13q (Family 2) susceptibility loci, respectively, were sequenced using Illumina's TruSeq Exome Enrichment assay and NGS technology. Sequence alignments, quality control assessment and variant calling were conducted on our 8000 parallel processor compute server, MEDUSA. As a first pass, we prioritized exome sequence data to non-synonymous variants within the 1-LOD drop intervals of our 5q and 13q loci. Prioritized exonic variants were also genotyped in the Western Australian Pregnancy (Raine) Cohort to assess their significance against a plethora of cardiovascular disease (CVD) related traits. RESULTS In Family 1 we identified two missense SNPs and in Family 2 we identified one missense SNP to segregate in the preeclamptic women but not in the unaffected women. The first SNP in Family 1 (rs62375061) resides within the LYSMD3 gene, is predicted to "possibly" damage the focal protein and the only public record of this SNP is within the Watson genome. The second SNP in Family 1 (rs111033530) resides within the GPR98 gene, is predicted to "probably" damage the focal protein and is rare (1.7% population prevalence). The SNP in Family 2 (rs1805388) resides within the LIG4 gene, is predicted to be highly deleterious (F-SNP FSS=0.849) and is common (⩾17% population prevalence). In the Raine cohort the LIG4 SNP was also significantly associated with weight (p=0.0085), total cholesterol (p=0.0007), HDL cholesterol (p=0.0067) and LDL cholesterol (p=0.0324). CONCLUSION Our preliminary exome data documents the substantial potential to rapidly identify likely functional variants that influence preeclampsia risk. The GPR98 finding is of major interest to us as a recent genome-wide association study reported a significant association with diastolic blood pressure for a SNP at this same gene locus. Furthermore, our findings implicate LIG4 as a novel candidate susceptibility gene for CVD and add weight to the hypothesis of shared genetic risk factors for preeclampsia and CVD.
Collapse
|
30
|
Johnson M, Brennecke S, Iversen AC, East C, Olsen G, Kent J, Dyer T, Said J, Roten L, Abraham L, Zwart JA, Winsvold B, Håberg A, Huentelman M, Krokan H, Gabrielsen M, Austgulen R, Blangero J, Moses E. OS046. Genome-wide association scans identify novel maternalsusceptibility loci for preeclampsia. Pregnancy Hypertens 2012; 2:202. [PMID: 26105260 DOI: 10.1016/j.preghy.2012.04.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION We have successfully utilized a family-based study design to localize several positional candidate preeclampsia susceptibility genes to chromosomes 2q22(ACVR2A,LCT,LRP1B,RND3,GCA),5q (ERAP2) and 13q(TNFSF13B). We now report on our continued positional cloning efforts using an alternative genome-wide association (GWA) mapping strategy in large Caucasian case-control cohorts from Australia and Norway. OBJECTIVES To identify maternal genetic risk loci for preeclampsia. METHODS The unrelated Australian samples (545 cases,547 controls) were genotyped using Illumina BeadChip technology (700K loci) and have been analyzed using PLINK. All unrelated Norwegian samples were genotyped across several Illumina BeadChip substrates and consist of 847 cases (700K loci) and 638 controls. The Norwegian control samples originate from other HUNT studies pertaining to migraine (n=95,700K loci), lung cancer (n=89,370K loci) and normal brain pathology (n=454,2.5M loci). To analyze a concordant set of 2.5-3 million genotypes across all Norwegian samples we are currently using MaCH to impute those loci not directly genotyped. The Norwegian GWA data will be analyzed in SOLAR utilizing empirical kinship estimates to account for any distant relatedness. RESULTS 1078 Australian samples (538 cases,540 controls) and 648, 175 SNPs passed our quality control metrics. Two SNP associations (rs7579169,p=3.6×10(-7); rs12711941,p=4.3×10(-7)) satisfied our genome-wide significant threshold (p<5.1×10(-7)). These SNPs reside less than 15kb downstream from the 3 terminus of the Inhibin, beta B (INHBB) gene on 2q14.2. Sequencing of the INHBB locus in our patient cohort identified a third intergenic SNP to significantly associate with preeclampsia (rs7576192,p=1.5×10(-7)). These three SNPs confer risk (OR>1.56) and are in strong linkage disequilibrium with each other (r(2)>0.9) but not with any other genotyped SNP ±200kb. The analysis of the Norwegian GWAS is underway. CONCLUSION The Australian GWAS has identified a novel preeclampsia risk locus on chromosome 2q. The INHBB gene closest to our SNP associations is a plausible positional candidate susceptibility gene. There is a substantive body of evidence implicating inhibins, activins and other members of the TGF-βsuperfamily to have a role in the development of preeclampsia. The biological connection between ACVR2A and INHBB leads us to speculate that our linkage-based and GWA-based study designs, respectively, have identified a key biological pathway involved in susceptibility to preeclampsia.
Collapse
|
31
|
Robey HF, Celliers PM, Kline JL, Mackinnon AJ, Boehly TR, Landen OL, Eggert JH, Hicks D, Le Pape S, Farley DR, Bowers MW, Krauter KG, Munro DH, Jones OS, Milovich JL, Clark D, Spears BK, Town RPJ, Haan SW, Dixit S, Schneider MB, Dewald EL, Widmann K, Moody JD, Döppner TD, Radousky HB, Nikroo A, Kroll JJ, Hamza AV, Horner JB, Bhandarkar SD, Dzenitis E, Alger E, Giraldez E, Castro C, Moreno K, Haynam C, LaFortune KN, Widmayer C, Shaw M, Jancaitis K, Parham T, Holunga DM, Walters CF, Haid B, Malsbury T, Trummer D, Coffee KR, Burr B, Berzins LV, Choate C, Brereton SJ, Azevedo S, Chandrasekaran H, Glenzer S, Caggiano JA, Knauer JP, Frenje JA, Casey DT, Johnson MG, Séguin FH, Young BK, Edwards MJ, Van Wonterghem BM, Kilkenny J, MacGowan BJ, Atherton J, Lindl JD, Meyerhofer DD, Moses E. Precision shock tuning on the national ignition facility. PHYSICAL REVIEW LETTERS 2012; 108:215004. [PMID: 23003273 DOI: 10.1103/physrevlett.108.215004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Indexed: 06/01/2023]
Abstract
Ignition implosions on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with the goal of compressing deuterium-tritium fuel to a sufficiently high areal density (ρR) to sustain a self-propagating burn wave required for fusion power gain greater than unity. These implosions are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision to keep the fuel entropy and adiabat low and ρR high. The first series of precision tuning experiments on the National Ignition Facility, which use optical diagnostics to directly measure the strength and timing of all four shocks inside a hohlraum-driven, cryogenic liquid-deuterium-filled capsule interior have now been performed. The results of these experiments are presented demonstrating a significant decrease in adiabat over previously untuned implosions. The impact of the improved shock timing is confirmed in related deuterium-tritium layered capsule implosions, which show the highest fuel compression (ρR~1.0 g/cm(2)) measured to date, exceeding the previous record [V. Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] by more than a factor of 3. The experiments also clearly reveal an issue with the 4th shock velocity, which is observed to be 20% slower than predictions from numerical simulation.
Collapse
|
32
|
Michel P, Divol L, Town RPJ, Rosen MD, Callahan DA, Meezan NB, Schneider MB, Kyrala GA, Moody JD, Dewald EL, Widmann K, Bond E, Kline JL, Thomas CA, Dixit S, Williams EA, Hinkel DE, Berger RL, Landen OL, Edwards MJ, MacGowan BJ, Lindl JD, Haynam C, Suter LJ, Glenzer SH, Moses E. Three-wavelength scheme to optimize hohlraum coupling on the National Ignition Facility. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:046409. [PMID: 21599318 DOI: 10.1103/physreve.83.046409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/04/2011] [Indexed: 05/30/2023]
Abstract
By using three tunable wavelengths on different cones of laser beams on the National Ignition Facility, numerical simulations show that the energy transfer between beams can be tuned to redistribute the energy within the cones of beams most prone to backscatter instabilities. These radiative hydrodynamics and laser-plasma interaction simulations have been tested against large-scale hohlraum experiments with two tunable wavelengths and reproduce the hohlraum energetics and symmetry. Using a third wavelength provides a greater level of control of the laser energy distribution and coupling in the hohlraum, and could significantly reduce stimulated Raman scattering losses and increase the hohlraum radiation drive while maintaining a good implosion symmetry.
Collapse
|
33
|
Moses E. M3.1 Genomics of pre-eclampsia. Pregnancy Hypertens 2010. [DOI: 10.1016/s2210-7789(10)60020-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
34
|
Said J, Higgins J, Moses E, Walker S, Monagle P, Brennecke S. P125 Inherited thrombophilias and adverse pregnancy outcomes: a case-control study in an Australian population. Pregnancy Hypertens 2010. [DOI: 10.1016/s2210-7789(10)60291-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
35
|
Johnson M, Blangero J, East C, Austgulen R, Brennecke S, Moses E. M9.2 Dissecting the allelic architecture of ERAP2: a novel preeclampsia susceptibility gene. Pregnancy Hypertens 2010. [DOI: 10.1016/s2210-7789(10)60036-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Roten L, Forsmo S, Johnson M, Moses E, Austgulen R. P162 Pre-eclampsia susceptibility regions on chromosomes 5q and 13q confirmed in a large Norwegian population-based study. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61653-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
37
|
Alvarez-Lacalle E, Moses E. Slow and fast pulses in 1-D cultures of excitatory neurons. J Comput Neurosci 2009; 26:475-93. [DOI: 10.1007/s10827-008-0123-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 09/29/2008] [Accepted: 11/04/2008] [Indexed: 10/21/2022]
|
38
|
Heestand GM, Haynam CA, Wegner PJ, Bowers MW, Dixit SN, Erbert GV, Henesian MA, Hermann MR, Jancaitis KS, Knittel K, Kohut T, Lindl JD, Manes KR, Marshall CD, Mehta NC, Menapace J, Moses E, Murray JR, Nostrand MC, Orth CD, Patterson R, Sacks RA, Saunders R, Shaw MJ, Spaeth M, Sutton SB, Williams WH, Widmayer CC, White RK, Whitman PK, Yang ST, Van Wonterghem BM. Demonstration of high-energy 2 omega (526.5 nm) operation on the National Ignition Facility Laser System. APPLIED OPTICS 2008; 47:3494-3499. [PMID: 18594596 DOI: 10.1364/ao.47.003494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A single beamline of the National Ignition Facility (NIF) has been operated at a wavelength of 526.5 nm (2 omega) by frequency converting the fundamental 1053 nm (1 omega) wavelength with an 18.2 mm thick type-I potassium dihydrogen phosphate (KDP) second-harmonic generator (SHG) crystal. Second-harmonic energies of up to 17.9 kJ were measured at the final optics focal plane with a conversion efficiency of 82%. For a similarly configured 192-beam NIF, this scales to a total 2 omega energy of 3.4 MJ full NIF equivalent (FNE).
Collapse
|
39
|
Taran M, Gabriel E, Moses E, Soller M. Performance of purebred and crossbred progeny of White Leghorn and New Hampshire sires. Br Poult Sci 2007. [DOI: 10.1080/00071667208415957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
40
|
Haynam CA, Wegner PJ, Auerbach JM, Bowers MW, Dixit SN, Erbert GV, Heestand GM, Henesian MA, Hermann MR, Jancaitis KS, Manes KR, Marshall CD, Mehta NC, Menapace J, Moses E, Murray JR, Nostrand MC, Orth CD, Patterson R, Sacks RA, Shaw MJ, Spaeth M, Sutton SB, Williams WH, Widmayer CC, White RK, Yang ST, Van Wonterghem BM. National Ignition Facility laser performance status. APPLIED OPTICS 2007; 46:3276-303. [PMID: 17514286 DOI: 10.1364/ao.46.003276] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The National Ignition Facility (NIF) is the world's largest laser system. It contains a 192 beam neodymium glass laser that is designed to deliver 1.8 MJ at 500 TW at 351 nm in order to achieve energy gain (ignition) in a deuterium-tritium nuclear fusion target. To meet this goal, laser design criteria include the ability to generate pulses of up to 1.8 MJ total energy, with peak power of 500 TW and temporal pulse shapes spanning 2 orders of magnitude at the third harmonic (351 nm or 3omega) of the laser wavelength. The focal-spot fluence distribution of these pulses is carefully controlled, through a combination of special optics in the 1omega (1053 nm) portion of the laser (continuous phase plates), smoothing by spectral dispersion, and the overlapping of multiple beams with orthogonal polarization (polarization smoothing). We report performance qualification tests of the first eight beams of the NIF laser. Measurements are reported at both 1omega and 3omega, both with and without focal-spot conditioning. When scaled to full 192 beam operation, these results demonstrate, to the best of our knowledge for the first time, that the NIF will meet its laser performance design criteria, and that the NIF can simultaneously meet the temporal pulse shaping, focal-spot conditioning, and peak power requirements for two candidate indirect drive ignition designs.
Collapse
|
41
|
Bibeau C, Bayramian A, Armstrong P, Ault E, Beach R, Benapfl M, Campbell R, Dawson J, Ebbers C, Freitas B, Kent R, Liao Z, Ladran T, Menapace J, Molander B, Moses E, Oberhelman S, Payne S, Peterson N, Schaffers K, Stolz C, Sutton S, Tassano J, Telford S, Utterback E, Randles M, Chai B, Fei Y. The mercury laser system – An average power, gas-cooled, Yb:S-FAP based system with frequency conversion and wavefront correction. ACTA ACUST UNITED AC 2006. [DOI: 10.1051/jp4:2006133161] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
42
|
Landen OL, Glenzer S, Froula D, Dewald E, Suter LJ, Schneider M, Hinkel D, Fernandez J, Kline J, Goldman S, Braun D, Celliers P, Moon S, Robey H, Lanier N, Glendinning G, Blue B, Wilde B, Jones O, Schein J, Divol L, Kalantar D, Campbell K, Holder J, McDonald J, Niemann C, Mackinnon A, Collins R, Bradley D, Eggert J, Hicks D, Gregori G, Kirkwood R, Niemann C, Young B, Foster J, Hansen F, Perry T, Munro D, Baldis H, Grim G, Heeter R, Hegelich B, Montgomery D, Rochau G, Olson R, Turner R, Workman J, Berger R, Cohen B, Kruer W, Langdon B, Langer S, Meezan N, Rose H, Still B, Williams E, Dodd E, Edwards J, Monteil MC, Stevenson M, Thomas B, Coker R, Magelssen G, Rosen P, Stry P, Woods D, Weber S, Alvarez S, Armstrong G, Bahr R, Bourgade JL, Bower D, Celeste J, Chrisp M, Compton S, Cox J, Constantin C, Costa R, Duncan J, Ellis A, Emig J, Gautier C, Greenwood A, Griffith R, Holdner F, Holtmeier G, Hargrove D, James T, Kamperschroer J, Kimbrough J, Landon M, Lee D, Malone R, May M, Montelongo S, Moody J, Ng E, Nikitin A, Pellinen D, Piston K, Poole M, Rekow V, Rhodes M, Shepherd R, Shiromizu S, Voloshin D, Warrick A, Watts P, Weber F, Young P, Arnold P, Atherton L, Bardsley G, Bonanno R, Borger T, Bowers M, Bryant R, Buckman S, Burkhart S, Cooper F, Dixit S, Erbert G, Eder D, Ehrlich B, Felker B, Fornes J, Frieders G, Gardner S, Gates C, Gonzalez M, Grace S, Hall T, Haynam C, Heestand G, Henesian M, Hermann M, Hermes G, Huber S, Jancaitis K, Johnson S, Kauffman B, Kelleher T, Kohut T, Koniges AE, Labiak T, Latray D, Lee A, Lund D, Mahavandi S, Manes KR, Marshall C, McBride J, McCarville T, McGrew L, Menapace J, Mertens E, Munro D, Murray J, Neumann J, Newton M, Opsahl P, Padilla E, Parham T, Parrish G, Petty C, Polk M, Powell C, Reinbachs I, Rinnert R, Riordan B, Ross G, Robert V, Tobin M, Sailors S, Saunders R, Schmitt M, Shaw M, Singh M, Spaeth M, Stephens A, Tietbohl G, Tuck J, Van Wonterghem B, Vidal R, Wegner P, Whitman P, Williams K, Winward K, Work K, Wallace R, Nobile A, Bono M, Day B, Elliott J, Hatch D, Louis H, Manzenares R, O'Brien D, Papin P, Pierce T, Rivera G, Ruppe J, Sandoval D, Schmidt D, Valdez L, Zapata K, MacGowan B, Eckart M, Hsing W, Springer P, Hammel B, Moses E, Miller G. The first experiments on the national ignition facility. ACTA ACUST UNITED AC 2006. [DOI: 10.1051/jp4:2006133009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
43
|
Alvarez-Lacalle E, Dorow B, Eckmann JP, Moses E. Hierarchical structures induce long-range dynamical correlations in written texts. Proc Natl Acad Sci U S A 2006; 103:7956-61. [PMID: 16698933 PMCID: PMC1472411 DOI: 10.1073/pnas.0510673103] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2005] [Indexed: 11/18/2022] Open
Abstract
Thoughts and ideas are multidimensional and often concurrent, yet they can be expressed surprisingly well sequentially by the translation into language. This reduction of dimensions occurs naturally but requires memory and necessitates the existence of correlations, e.g., in written text. However, correlations in word appearance decay quickly, while previous observations of long-range correlations using random walk approaches yield little insight on memory or on semantic context. Instead, we study combinations of words that a reader is exposed to within a "window of attention," spanning about 100 words. We define a vector space of such word combinations by looking at words that co-occur within the window of attention, and analyze its structure. Singular value decomposition of the co-occurrence matrix identifies a basis whose vectors correspond to specific topics, or "concepts" that are relevant to the text. As the reader follows a text, the "vector of attention" traces out a trajectory of directions in this "concept space." We find that memory of the direction is retained over long times, forming power-law correlations. The appearance of power laws hints at the existence of an underlying hierarchical network. Indeed, imposing a hierarchy similar to that defined by volumes, chapters, paragraphs, etc. succeeds in creating correlations in a surrogate random text that are identical to those of the original text. We conclude that hierarchical structures in text serve to create long-range correlations, and use the reader's memory in reenacting some of the multidimensionality of the thoughts being expressed.
Collapse
|
44
|
Abstract
Magnetic stimulation of nerves is attracting increased attention recently, as it has been found to be useful in therapy of neural disorders in humans. In an effort to explain the mechanisms of magnetic stimulation, we focus in this paper on the dependence of magnetic stimulation on neuronal morphology and in particular on the importance of curvature of axonal bundles. Using the theory of passive membrane dynamics, we predict the threshold power (the minimum stimulation power required to initiate an action potential) of specific axonal morphologies. In the experimental section, we show that magnetic stimulation of the frog sciatic nerve follows our theoretical predictions. Furthermore, the voltage length constant of the nerve can be measured based on these results alone.
Collapse
|
45
|
Biron D, Alvarez-Lacalle E, Tlusty T, Moses E. Molecular model of the contractile ring. PHYSICAL REVIEW LETTERS 2005; 95:098102. [PMID: 16197254 DOI: 10.1103/physrevlett.95.098102] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2004] [Indexed: 05/04/2023]
Abstract
We present a model for the actin contractile ring of adherent animal cells. The model suggests that the actin concentration within the ring and consequently the power that the ring exerts both increase during contraction. We demonstrate the crucial role of actin polymerization and depolymerization throughout cytokinesis, and the dominance of viscous dissipation in the dynamics. The physical origin of two phases in cytokinesis dynamics ("biphasic cytokinesis") follows from a limitation on the actin density. The model is consistent with a wide range of measurements of the midzone of dividing animal cells.
Collapse
|
46
|
Owusu-Akyaw M, Afun JVK, Mochiah MB, Adu-Mensah J, Moses E, Bolfrey-Arku G, Osei K, Osei-Yeboah S, Dankyi AA, Adama I, Brandenburg RL, Jordan DL. Survey and Management of Soil Arthropods in Peanut (Arachis hypogaea L.) in Southern Ghana, West Africa. ACTA ACUST UNITED AC 2005. [DOI: 10.3146/0095-3679(2005)32[136:samosa]2.0.co;2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
47
|
Clements CS, Kjer-Nielsen L, Kostenko L, Hoare HL, Dunstone MA, Moses E, Freed K, Brooks AG, Rossjohn J, McCluskey J. Crystal structure of HLA-G: a nonclassical MHC class I molecule expressed at the fetal-maternal interface. Proc Natl Acad Sci U S A 2005; 102:3360-5. [PMID: 15718280 PMCID: PMC552935 DOI: 10.1073/pnas.0409676102] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
HLA-G is a nonclassical major histocompatibility complex class I (MHC-I) molecule that is primarily expressed at the fetal-maternal interface, where it is thought to play a role in protecting the fetus from the maternal immune response. HLA-G binds a limited repertoire of peptides and interacts with the inhibitory leukocyte Ig-like receptors LIR-1 and LIR-2 and possibly with certain natural killer cell receptors. To gain further insights into HLA-G function, we determined the 1.9-A structure of a monomeric HLA-G complexed to a natural endogenous peptide ligand from histone H2A (RIIPRHLQL). An extensive network of contacts between the peptide and the antigen-binding cleft reveal a constrained mode of binding reminiscent of the nonclassical HLA-E molecule, thereby providing a structural basis for the limited peptide repertoire of HLA-G. The alpha3 domain of HLA-G, a candidate binding site for the LIR-1 and -2 inhibitory receptors, is structurally distinct from the alpha3 domains of classical MHC-I molecules, providing a rationale for the observed affinity differences for these ligands. The structural data suggest a head-to-tail mode of dimerization, mediated by an intermolecular disulfide bond, that is consistent with the observation of HLA-G dimers on the cell surface.
Collapse
|
48
|
Abstract
Actin filament length distribution in cells is often regulated to fit specific tasks. In comparison to the well-studied regulation of the average filament length (e.g., using capping proteins), controlling the width of the distribution is less well understood. We utilize two complementary methods to measure the effect of alpha-actinin on the width of the distribution of lengths of F-actin in vitro. Analyzing transmission electron micrographs shows that crosslinking by alpha-actinin reduces the width of the length distribution of F-actin, decreasing the coefficient of variation by two- to threefold. Analysis of fluorescence data from depolymerization assays confirms this observation. We suggest a mechanistic molecular model in which a local (weak) stabilization of crosslinked monomers in the filament is the physical origin of the decrease in the variance of lengths. Although alpha-actinin is known to bind reversibly to F-actin, our model shows that even weak binding can produce this effect, and that in fact it persists throughout a wide range of binding strengths.
Collapse
|
49
|
Kalionis B, Moses E. Advanced molecular techniques in pregnancy research: proteomics and genomics--a workshop report. Placenta 2003; 24 Suppl A:S119-22. [PMID: 12842423 DOI: 10.1053/plac.2002.0936] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
50
|
Biron D, Libros P, Sagi D, Mirelman D, Moses E. Asexual reproduction: 'midwives' assist dividing amoebae. Nature 2001; 410:430. [PMID: 11260701 DOI: 10.1038/35068628] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|