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Sample records for 858-386-6078 krissy bartels

  1. Atmosphere-Ionosphere Coupling due to Atmospheric Tides (Julius Bartels Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Forbes, Jeffrey M.

    2016-04-01

    Within the last decade, a new realization has arrived on the scene of ionosphere-thermosphere (IT) science: terrestrial weather significantly influences space weather. The aspect of space weather referred to here consists of electron density variability that translates to uncertainties in navigation and communications systems, and neutral density variability that translates to uncertainties in orbital and reentry predictions. In the present context "terrestrial weather" primarily refers to the meteorological conditions that determine the spatial-temporal distribution of tropospheric water vapor and latent heating associated with tropical convection, and the middle atmosphere disturbances associated with sudden stratosphere warmings. The net effect of these processes is a spatially- and temporally-evolving spectrum of waves (gravity waves, tides, planetary waves, Kelvin waves) that grows in amplitude with height and enters the IT system near ~100 km. Some members of the wave spectrum penetrate all the way to the base of the exosphere (ca. 500 km). Along the way, nonlinear interactions between different wave components occur, modifying the interacting waves and giving rise to secondary waves. Finally, the IT wind perturbations carried by the waves can redistribute ionospheric plasma, either through the electric fields generated via the dynamo mechanism between 100 and 150 km, or directly by moving plasma along magnetic field lines at higher levels. Additionally, the signatures of wave-driven dynamo currents are reflected in magnetic perturbations observed at the ground. This is how terrestrial atmospheric variability, through the spectrum of vertically- propagating waves that it produces, can effectively drive IT space weather. The primary objective of this Julius Bartels Lecture is to provide an overview of the global observational evidence for the IT consequences of these upward-propagating waves. In honor of Julius Bartels, who performed much research (including

  2. BarTeL, a Genetically Versatile, Bioluminescent and Granule Neuron Precursor-Targeted Mouse Model for Medulloblastoma

    PubMed Central

    Mahdi, Min Y.; Gonzalez-Gomez, Ignacio; Asgharzadeh, Shahab; D’Apuzzo, Massimo; Erdreich-Epstein, Anat; Moats, Rex A.

    2016-01-01

    Medulloblastomas are the most common malignant pediatric brain tumor and have been divided into four major molecular subgroups. Animal models that mimic the principal molecular aberrations of these subgroups will be important tools for preclinical studies and allow greater understanding of medulloblastoma biology. We report a new transgenic model of medulloblastoma that possesses a unique combination of desirable characteristics including, among others, the ability to incorporate multiple and variable genes of choice and to produce bioluminescent tumors from a limited number of somatic cells within a normal cellular environment. This model, termed BarTeL, utilizes a Barhl1 homeobox gene promoter to target expression of a bicistronic transgene encoding both the avian retroviral receptor TVA and an eGFP-Luciferase fusion protein to neonatal cerebellar granule neuron precursor (cGNP) cells, which are cells of origin for the sonic hedgehog (SHH) subgroup of human medulloblastomas. The Barhl1 promoter-driven transgene is expressed strongly in mammalian cGNPs and weakly or not at all in mature granule neurons. We efficiently induced bioluminescent medulloblastomas expressing eGFP-luciferase in BarTeL mice by infection of a limited number of somatic cGNPs with avian retroviral vectors encoding the active N-terminal fragment of SHH and a stabilized MYCN mutant. Detection and quantification of the increasing bioluminescence of growing tumors in young BarTeL mice was facilitated by the declining bioluminescence of their uninfected maturing cGNPs. Inclusion of eGFP in the transgene allowed enriched sorting of cGNPs from neonatal cerebella. Use of a single bicistronic avian vector simultaneously expressing both Shh and Mycn oncogenes increased the medulloblastoma incidence and aggressiveness compared to mixed virus infections. Bioluminescent tumors could also be produced by ex vivo transduction of neonatal BarTeL cerebellar cells by avian retroviruses and subsequent

  3. BarTeL, a Genetically Versatile, Bioluminescent and Granule Neuron Precursor-Targeted Mouse Model for Medulloblastoma.

    PubMed

    Shackleford, Gregory M; Shi, Xiang-He; Swanson, Kimberly S; Mahdi, Min Y; Gonzalez-Gomez, Ignacio; Asgharzadeh, Shahab; D'Apuzzo, Massimo; Erdreich-Epstein, Anat; Moats, Rex A

    2016-01-01

    Medulloblastomas are the most common malignant pediatric brain tumor and have been divided into four major molecular subgroups. Animal models that mimic the principal molecular aberrations of these subgroups will be important tools for preclinical studies and allow greater understanding of medulloblastoma biology. We report a new transgenic model of medulloblastoma that possesses a unique combination of desirable characteristics including, among others, the ability to incorporate multiple and variable genes of choice and to produce bioluminescent tumors from a limited number of somatic cells within a normal cellular environment. This model, termed BarTeL, utilizes a Barhl1 homeobox gene promoter to target expression of a bicistronic transgene encoding both the avian retroviral receptor TVA and an eGFP-Luciferase fusion protein to neonatal cerebellar granule neuron precursor (cGNP) cells, which are cells of origin for the sonic hedgehog (SHH) subgroup of human medulloblastomas. The Barhl1 promoter-driven transgene is expressed strongly in mammalian cGNPs and weakly or not at all in mature granule neurons. We efficiently induced bioluminescent medulloblastomas expressing eGFP-luciferase in BarTeL mice by infection of a limited number of somatic cGNPs with avian retroviral vectors encoding the active N-terminal fragment of SHH and a stabilized MYCN mutant. Detection and quantification of the increasing bioluminescence of growing tumors in young BarTeL mice was facilitated by the declining bioluminescence of their uninfected maturing cGNPs. Inclusion of eGFP in the transgene allowed enriched sorting of cGNPs from neonatal cerebella. Use of a single bicistronic avian vector simultaneously expressing both Shh and Mycn oncogenes increased the medulloblastoma incidence and aggressiveness compared to mixed virus infections. Bioluminescent tumors could also be produced by ex vivo transduction of neonatal BarTeL cerebellar cells by avian retroviruses and subsequent

  4. X-ray computed microtomography of sea ice - comment on "A review of air-ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow", by Bartels-Rausch et al. (2014)

    NASA Astrophysics Data System (ADS)

    Obbard, R. W.

    2015-05-01

    This comment addresses a statement made in "A review of air-ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow" by Bartels-Rausch et al. (2014). Here we rebut the assertion that X-ray computed microtomography of sea ice fails to reveal liquid brine inclusions, by discussing the phases present at the analysis temperature.

  5. X-ray computed microtomography of sea ice - comment on "A review of air-ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow" by Bartels-Rausch et al. (2014)

    NASA Astrophysics Data System (ADS)

    Obbard, R. W.

    2015-07-01

    This comment addresses a statement made in "A review of air-ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow" by Bartels-Rausch et al. (Atmos. Chem. Phys., 14, 1587-1633, doi:10.5194/acp-14-1587-2014, 2014). Here we rebut the assertion that X-ray computed microtomography of sea ice fails to reveal liquid brine inclusions by discussing the phases present at the analysis temperature.

  6. Planets in Space (Julius Bartels Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Glassmeier, Karl-Heinz

    2010-05-01

    Interplanetary space is not void, but filled with photons and energetic particle of solar origin as well as the fast stream solar wind plasma. Planets and other planetary bodies such as comets and asteroids need to interact with this interplanetary medium. Different types of interaction are known, dependent on the properties of the planetary body. The parameter space in which the interaction is described is mainly spanned by the magnetic field of the body, the density of its atmosphere, and the solar wind dynamic pressure. Using the concept of ternary triangles, different possible interaction scenarios will be described. As no active planetary scale experiments are possible only a few points in the interaction space can be visited right now. The discovery of exo-planets will allow exploring the parameter space further. Also, temporal changes of the terrestrial magnetic field strength and the resulting paleo-interaction situations will be discussed as they represent additional points in parameter space. Furthermore, the interaction between a planetary body and the interplanetary medium will not only modify the solar wind streaming past, but the body itself experiences changes. Planetary bodies are thus treated as embedded systems. As an example the impact of an external magnetic field on planetary dynamo action is discussed. Possible connections with the small observed magnetic field of Mercury are mentioned.

  7. Data-Based Mapping of Our Dynamical Magnetosphere (Julius Bartels Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Tsyganenko, Nikolai A.

    2013-04-01

    The geomagnetic field is a principal agent connecting our planet's ionosphere with thehighly variable interplanetary medium, incessantly disturbed by dynamical processesat the Sun. The Earth's magnetosphere serves as a giant storage reservoir of energy pumped in from the solar wind and intermittently spilled into the upperatmosphere during space storms. As the humankindgets more and more dependent on space technologies, it becomes increasingly important to be able to accurately map the distant geomagnetic field and predict its dynamicsusing data of upstream solar wind monitors. Two approaches to the problem have beensuccessfully pursued over last decades. The first one is to treat the solar wind asa flow of magnetized conducting fluid and to numerically solve first-principle equations,governing its interaction with the terrestrial magnetic dipole. Based on pure theory, that approachaddresses the question: "What the magnetosphere would look like and behaveunder assumption thatthe underlying approximations and techniques were universally accurate?" This lecturewill focus on the other, completely different approach, based on direct observations. Its essence is to develop an empirical description of the global geomagnetic field and its response to the solar wind driving by fitting model parameters to large multi-year sets of spacecraft data. Models of that kind seek to answer the question: "What can in situ measurements tell us about the global magnetospheric configuration and its storm-time dynamics, provided our approximations are realistic, flexible, and the data coverage is sufficiently dense and broad?" Five decades of spaceflight produced enormous amount of archived data anda number of empirical models have already been developed on that basis. Recent and ongoing multi-spacecraft missions keep pouring in new data and further expandthe huge and yet largely untapped resource of valuable information. The main goal of the data-based modeling is to extract the largest possible knowledge from the accumulated data, thus synergistically maximizing the output of present and past space experiments.

  8. Dysregulation of RNA Interference in Breast Cancer

    DTIC Science & Technology

    2007-07-01

    of microRNAs by stem-loop RT–PCR. Nucleic Acids Res 33: e179. Chen CZ, Li L, Lodish HF, Bartel DP. (2004). MicroRNAs modulate hematopoietic lineage...2005) Cell 122, 6–7 8. Chen, C. Z., Li, L., Lodish , H. F., and Bartel, D. P. (2004) Science 303, 83–86 9. Chen, C. Z. (2005) N. Engl. J. Med. 353

  9. Three-Dimensional near Infrared Imaging of Pathophysiological Changes within the Breast

    DTIC Science & Technology

    2007-03-01

    Ramanujam, G. Vishnoi, A. H. Hielscher , M. E. Rode, I. Forouzan and B. Chance, "Photon migration through fetal head in utero using continuous wave...14 12. A. H. Hielscher and S. Bartel, “Use of penalty terms in gradient-based iterative recon- struction schemes for optical tomography,” J. Biomed...after indocyanine green enhancement,” Proc. Nat. Acad. Sci. U.S.A. 97, 2767-2772 (2000). 15. A. H. Hielscher and S. Bartel, “Use of penalty terms in

  10. 77 FR 43350 - Draft Environmental Assessment and Proposed Habitat Conservation Plan for the San Diego Unified...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... San Diego Unified School District's Jonas Salk Elementary School Project in the City of San Diego, San... Elementary School Project in response to an application from the San Diego Unified School District (District... Elementary School'' in the subject line of the message. Fax: Attn: Jim Bartel, Field Supervisor, (760)...

  11. Proceedings of the Annual Penn Linguistics Colloquium (21st, Philadelphia, Pennsylvania, February 22-23, 1997). University of Pennsylvania Working Papers in Linguistics, Volume 4, Number 2.

    ERIC Educational Resources Information Center

    Dimitriadis, Alexis, Ed.; Siegel, Laura, Ed.; Surek-Clark, Clarissa, Ed.; Williams, Alexander, Ed.

    This issue contains the following articles: "The Pragmatics of Wh-Question Intonation in English" (Christine Bartels); "The Nature of Object Agreement in Hungarian" (Huba Bartos); "Voah Mei Daett Sei Deitsh: Developments in the Vowel System of Pennsylvania German" (David Bowie); "Event Time Properties"…

  12. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (82nd, New Orleans, Louisiana, August 3-8, 1999). Communication Technology and Policy.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    The Communication Technology and Policy section of the Proceedings contains the following 15 papers: "The Virtual Sphere: The Internet as a Public Sphere" (Zizi Papacharissi); "Toward a Typology of Internet Users and Online Privacy Concerns" (Kim Bartel Sheehan); "Blind Spots of the Communications Decency Act Debate: A…

  13. The Development of PIPA: An Integrated and Automated Pipeline for Genome-Wide Protein Function Annotation

    DTIC Science & Technology

    2008-01-25

    bacterial genome annotation. Nucleic Acids Res 2005/06/28 edition. 2005, 33(Web Server issue):W455-9. 14. Meyer F, Goesmann A, McHardy AC, Bartels D...GO.evi dence.shtml] 37. Jain AK Murthy MN, Flynn PJ: Data Clustering: A Review. ACM Computing Surveys 1999, 31(3):264-323. 38. Chenna R, Sugawara H

  14. Isogeometric Collocation: Cost Comparison with Galerkin Methods and Extension to Adaptive Hierarchical NURBS Discretizations (Preprint)

    DTIC Science & Technology

    2013-02-06

    levels, the ratio saturates to an asymptotic value acceptably “close” to its optimum reff=1.0. Second, we focus on the 2D advection benchmark discussed in...112] D. Forsey and R.H. Bartels. Hierarchical B-spline refinement. Computer Graphics (SIGGRAPH ’88 Proceedings), 22(4):205–212, 1988. [113] R. Kraft

  15. 77 FR 12361 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... Brown Eddie R. Del Angel George E. Gross Wayne Figroid Darrell E. Graumann Heidi J. Morse Ian D. Holbin... George R. Boutin Eugene P. Fournier Rudolph J. McPhearson Saint Marc Louis Edgar Daye Anthony Bartel... experience operating a CMV: Michael Meke-Eze David M. Krause Michael R. Morgan Alexander D. Avery Alan...

  16. Electrophysiological Measures of Regional Neural Interactive Coupling (Linear and Nonlinear Dependence Relationships Among Multiple Channel Electroencephalographic (EEG) Recordings),

    DTIC Science & Technology

    1980-01-01

    studies in dyslexia . In A.L. Benton and D. Pearl (Fs.), Dyslexia : An Appraisal of Current Knowledge. New York: Oxford University Press, 1978. 4...Electroencephalo- graphy and Clinical Neurophysio !. Oct., 67, 23(4):306-19. 6) Duffy, F.H., Denckla, M.B., Bartels, P.H., and Sandini, G. Dyslexia

  17. Delta Pi Epsilon National Conference. Book of Readings (Nashville, Tennessee, November 15-17, 2001).

    ERIC Educational Resources Information Center

    Delta Pi Epsilon Society, Little Rock, AR.

    This document contains 23 papers from a conference on promoting excellence in research and teaching for business. The following are among the papers included: "Alternative Licensure/Certification Assessment of State Specialists" (Marilyn Chalupa, Ginny Richerson, Nancy Groneman, Kimberlee Bartel, Randy L. Joyner, Dennis LaBonty);…

  18. Reflections

    ERIC Educational Resources Information Center

    Bartell, Carol A.

    2015-01-01

    From 1998-2000, Carol Bartell served as President of the California Council on the Education of Teachers. However, election to office in this organization is generally a six-year commitment, because an individual will serve for two years as President Elect, two years as President, and two more as Past President. In this article, she expresses that…

  19. 78 FR 2700 - First Trust Exchange-Traded Fund, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ...)(48) of the 1940 Act, and registered unit investment trusts that are within or outside the same group... FURTHER INFORMATION CONTACT: Jill Ehrlich, Senior Counsel, at (202) 551-6819, or David P. Bartels, Branch... registered open-end management investment companies and any series thereof that are part of the same group...

  20. 78 FR 30346 - Financial Investors Trust and Hanson McClain Strategic Advisors, Inc.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... (``UITs'') that are within and outside the same group of investment companies as the acquiring investment...: Courtney S. Thornton, Senior Counsel, at (202) 551-6812, or David P. Bartels, Branch Chief, at (202) 551... control with the Adviser and that is part of the same group of investment companies (as defined in...

  1. Proceedings of the Fiber Optics in the Nuclear Environment Symposium 25-27 March 1980. Volume II. Radiation Physics,

    DTIC Science & Technology

    1980-04-30

    emphasis on systems for transmitting nuclear device diagnostic data during, or shortly after, a nuclear explosion . This interest has required...Corp. A1rN: YCPT D. Bartel ATN: T. Neighbors ATTN: YCD E. Brininstool ATfI: ¥CD R. Spray Bell Telephone Labs ATTN: YCP H. Staubs ATTN: J. Fleming

  2. KSOS Final Report (Kernelized Secure Operating System).

    DTIC Science & Technology

    1981-08-01

    Wentworth, Denise E. M. Bartels, Mark Volden, Jeremy Holden, Nanette Harter and Susan L. Dahlberg. The Network area was managed by Norm Abramovitz...like to thank: Daniel J. Edwards (COTR, NSA), John Woodward (MITRE), Ken Shotting (NSA), Howie Weiss (NSA), Grace Nibaldi (MITRE), Susan Rajunas (MITRE

  3. Evolution in a Test Tube: Exploring the Structure and Function of RNA Probes

    DTIC Science & Technology

    2008-05-02

    Bartel, D.P. and Szostak, J.W. (1993) Isolation of New Ribozymes from a Large Pool of Random Sequences. Science, New Series 261, 1141-1418. 24...Szostak, J.W. (1993) Isolation of New Ribozymes from a Large Pool of Random Sequences. Science, New Series 261, 1141-1418. Chen, Ying; Carlini

  4. Enhancing Adherence to a Problem Solving Model for Middle-School Pre-Referral Teams: A Performance Feedback and Checklist Approach

    ERIC Educational Resources Information Center

    Bartels, Susan M.; Mortensen, Bruce P.

    2006-01-01

    Performance feedback and checklists were used to improve the degree to which middle-school teams adhered to elements of systematic problem solving as described in the Instructional Consultation literature (Bartels & Mortenson, 2002; Rosenfield, 1987). Direct observations of problem-solving meetings were conducted to determine levels of adherence…

  5. Multilingualism in an EFL Practicum: Increasing Student Teachers' Pedagogical Knowledge

    ERIC Educational Resources Information Center

    Olivero, María Matilde

    2015-01-01

    Research in second language teacher education has demonstrated that novice teachers have difficulty in using their pedagogical knowledge, which partly results from a heavy focus on theory offered in teacher training programs (e.g., Bartels, 2005, 2009; Tarone & Allwright, 2005). In order to better equip student teachers with the knowledge…

  6. Exceptional Children Research Review.

    ERIC Educational Resources Information Center

    Johnson, G. Orville, Ed.; Blank, Harriett D., Ed.

    Research reviews are presented for eight areas of exceptionality and for administration. Included are the following reports: 16 on the gifted compiled by Edward C. Frierson; 46 on the mentally retarded reviewed by Howard H. Spicker and Nettie R. Bartel; 20 on the visually impaired presented by William J. Tisdall; 44 on the hearing impaired…

  7. Fulbright-Hays Seminars Abroad Program, 1992. China: Tradition and Transformation (Curriculum Projects).

    ERIC Educational Resources Information Center

    National Committee on United States-China Relations, New York, NY.

    This collection of papers is from a seminar on China includes the following papers: "Women in China: A Curriculum Unit" (Mary Ann Backiel); "Education in Mainland China" (Deanna D. Bartels; Felicia C. Eppley); "From the Great Wall to the Bamboo Curtain: China The Asian Giant An Integrated Interdisciplinary Unit for Sixth…

  8. Using RNA Interference to Reveal Genetic Vulnerabilities in Human Cancer Cells

    DTIC Science & Technology

    2005-07-01

    Luo, B., Heard, A.D. & Lodish , H.F. Small interfering RNA production by enzymatic engineering of DNA (SPEED). Proc Natl Acad Sci U S A 101, 5494-9...suppressors identifies REST. Cell 121, 837-48 (2005). 44. Chen, C.Z., Li, L., Lodish , H.F. & Bartel, D.P. MicroRNAs modulate hematopoietic lineage

  9. Proceedings of the Second Annual Conference GeoComputation 97, University of Otago, Dunedin, New Zealand, 26-29 August 1997

    DTIC Science & Technology

    1997-08-29

    this development has been to allow this dimensional with each band taking up a two dimensional feature to be used as an image analyzer.As once the ex...landscape evolu- tion, there are numerous processes acting over a wide step is used which is dependant upon the erosion rates. This allows the representation ...analysis is represented using rules Bartell, S.M. 1996. Ecological / environmental risk assess- to help make it more visible (through the rule network

  10. Linear Sweep Voltammetry of Adsorbed Neutral Red.

    DTIC Science & Technology

    1982-05-01

    showed that neutral red undergoes a potentiometrically reversible two-electron reduction to the leuco dye and established approximate acidity constants for...both the dye and the leuco dye from equilibrium potential measurements. More recently, Bartels [3,43 estimated the acid dissociation constant of...and the total dye concentration on the equilibrium potential of the dye - leuco dye couple, Nikolskii and coworkers [5-73 derived precise values for

  11. Investigation into the Distribution of Ballast Water Tracers in Coastal Waters

    DTIC Science & Technology

    2009-11-01

    Detection Diagnostic tests were performed to identify outliers due to sample contamination or analytical error, providing standardized criteria for...2.3.2.2 Outlier Detection Diagnostic tests were performed to identify outliers due to contamination or analytical error, using a standardized...3629. Stabenau, E.R., Zepp, R.G., Bartels, E. and Zika , R.G., 2004. Role of the seagrass Thalassia testudinum as a source of chromophoric dissolved

  12. High Speed Heuristics for Real-Time Personnel Assignment Models

    DTIC Science & Technology

    1994-01-26

    Minimum Norm Problems Over Transportation Polytopes, Linear Algebra and its Applications, Vol. 31, pp. 103-118, 1980. [2] Beck, P., L. Lasdon and M...Analysis, 13, 145-154, 1976. [5] R.H. Bartels, " A penalty linear programming method using reduced- 0 gradient basis-exchange techniques", Linear Algebra ...1992. [8] Wets, R.J.B. and C. Witzgall, "Algorithms for frames and lineality spaces of cones," Journal of Research of the National Bureau of

  13. Glutamate Receptor Aptamers and ALS

    DTIC Science & Technology

    2008-01-01

    that the evolutionary conversion of a ribozyme (RNA) to a deoxribozyme (DNA) of the same function can be accomplished but only with some critical...the role of neutrality in adaptation. Proc Natl Acad Sci U S A 93, 397-401. 40. Schultes, E. A., and Bartel, D. P. (2000) One sequence, two ribozymes ...implications for the emergence of new ribozyme folds. Science 289, 448-452. 41. Mandal, M., and Breaker, R. R. (2004) Gene regulation by

  14. Glutamate Receptor Aptamers and ALS

    DTIC Science & Technology

    2009-01-01

    that the evolutionary conversion of a ribozyme (RNA) to a deoxribozyme (DNA) of the same function can be accomplished but only with some critical...2006) Conversion of a ribozyme to a deoxyribozyme through in vitro evolution. Chem Biol. 13, 329-338. 18. Schultes, E. A., and Bartel, D. P. (2000...One sequence, two ribozymes : implications for the emergence of new ribozyme folds. Science 289, 448-452. 19. Wilkinson, K. A., Merino, E. J., and

  15. Periodic variation in the geomagnetic activity - A study based on the Ap index

    NASA Technical Reports Server (NTRS)

    De Gonzalez, Alicia L. C.; Gonzalez, Walter D.; Dutra, Severino L. G.; Tsurutani, Bruce T.

    1993-01-01

    The monthly and daily samples of the Ap index for the interval from 1932 through 1982 were studied using the power spectrum technique. Results obtained for Bartel's period (about 27 days), the semiannual period, the dual-peak solar cycle distribution of geomagnetic storms, and certain other medium-scale periodicities are examined in detail. In addition, results on the cumulative occurrence number of storms per decade as a function of the Ap and Dst indices for the storm are presented.

  16. Generating High Modulus Fibers by Nanoparticle Incorporation with Potential to Introduce Multifunctionality

    DTIC Science & Technology

    2008-12-07

    hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of...Papers published in peer- reviewed journals (N/A for none) J. Xu, J. W. Bartels, D. A. Bohnsack, M. E. Mackay and K. L. Wooley, "Hierarchical Inorganic

  17. An Examination of Brazil and the United States as Potential Partners in a Joint Supersonic Military Fighter Aircraft Codevelopment and Production Program.

    DTIC Science & Technology

    1986-09-01

    Brazilian-American Chamber of Commerce Mr. Frank J. Devine, Executive Director Embraer, Empresa Brasileira De Aeronautica Mr. Salo Roth Vice President...Sales & Marketing , North America Mr. W. Bartels Program Manager For advice and help in writing the thesis Lieutanant Colonel Robert D. Materna, USAF...3.2.5 Current Market ........................... . 41 3.2.6 Future Prospects ........................... 44 3.2.7 Summary

  18. The Definition and Ray-Tracing of B-Spline Objects in a Combinatorial Solid Geometric Modeling System

    DTIC Science & Technology

    2013-04-01

    October 1983) . 2. R. F . Riesenfeld, E. Cohen, T . Lyche and C. deBoor, "A Practical Guide to Splines," Com- puter Graphics and Image Processing, New...8. M . A . J. Sweeny, R. H. Bartels, "Ray Tracing Free-Form B-spline Surfaces," IEEE Com- puter Graphics (February 1986). 9. John W. Peterson, "Ray...Geometric Desgin 1(1) (1984) . 13. J. M . Snyder, A H. Barr, "Ray Tracing Complex Models Containing Surface Tessellations," Computer Graphics (Proceedings

  19. Identification, Characterization and Clinical Development of the New Generation of Breast Cancer Susceptibility Alleles

    DTIC Science & Technology

    2007-03-01

    5d. PROJECT NUMBER Nazneen Rahman M.D. Ph.D. 5e. TASK NUMBER E -Mail: nazneen.rahman@icr.ac.uk 5f. WORK UNIT NUMBER 7. PERFORMING...Oldenburg R, Hollestelle A, Houben M, Crepin E , van Veghel-Plandsoen M, Elstrodt F, van Duijn C, Bartels C, Meijers C, Schutte M, McGuffog L, Thompson D...Collaboration (UK), Douglas F Easton2, Michael R Stratton1,5 & Nazneen Rahman1 We screened individuals from 443 familial breast cancer pedigrees and 521

  20. On the Proper Calculation of Electrostatic Interactions in Solid-Supported Bilayer Systems

    DTIC Science & Technology

    2011-01-01

    Shinozaki, K. Varadarajan, and K. Schulten, J. Comput. Phys. 151(1), 283 (1999). 24A. D. MacKerell , D. Bashford, M. Bellott, R. L. Dunbrack, J. D...1983). 26P. E. M. Lopes, V. Murashov, M. Tazi, E. Demchuk, and A. D. MacKerell , J. Phys. Chem. B 110(6), 2782 (2006). 27J. P. Ryckaert, G. Ciccotti... Mackerell , L. Nilsson, R. J. Petrella, B. Roux, Y. Won, G. Archontis, C. Bartels, S. Boresch, A. Caflisch, L. Caves, Q. Cui, A. R. Dinner, M. Feig, S

  1. Climbing Darwin's ladder

    NASA Technical Reports Server (NTRS)

    Joyce, G. F.; Miller, S. L. (Principal Investigator)

    1993-01-01

    The work of Bartel and Szostak, in which RNA molecules were selected to enhance the ability to catalyze a reaction similar to a step in protein-catalyzed RNA replication, is discussed. An important aspect of this experiment was the ability to reach a high level of functional organization in ten evolutionary steps. Further steps necessary to obtain an RNA enzyme with RNA replicase activity include performing the reaction with mononucleoside 5'-triphosphates, generalizing the reaction to include a variety of sequences without loss of template-dependent specificity, and overcoming template self-structure that could prevent some regions from being copied efficiently.

  2. Spectral Modulation by Rotational Wave Packets

    NASA Astrophysics Data System (ADS)

    Baertschy, Mark; Hartinger, Klaus

    2005-05-01

    Periodic rephasing of molecular rotational wave packets can create rapid fluctuations in the optical properties of a molecular gas which can be used to manipulate the temporal phase and spectral content of ultrashort light pulses. We have demonstrated spectral control of a time-delayed ultrafast probe pulse propagating through the rotational wave packet prepared by a pump laser pulse. The spectrum of the probe pulse can be either broadened or compressed, depending on the relative sign of the temporal phase modulation and the initial chirp of the probe pulse. Adjustment of the spectral phase at the output of the interaction region allows controlled temporal pulse streching^1 and compression^2. The degree to which the spectrum of an ultrafast pulse can be modified depends on the strength and shape of the rotational wavepacket. We are studying the optimization of the rotational wave packet excitation with complex, shaped pump laser pulses for the purpose of optimizing probe pulse spectra modulation. ^1 Klaus Hartinger and Randy A. Bartels, Opt. Lett., submitted (2005). ^2 R.A. Bartels, T.C. Weinacht, N. Wagner, M. Baertschy, Chris H. Greene, M.M. Murnane, and H.C. Kapteyn , Phys. Rev. Lett., 88, 013903 (2002). This work was supported by the NSF.

  3. Electron diffraction analysis for the molecules with degenerate large amplitude motions: Intramolecular dynamics in arsenic pentafluoride

    NASA Astrophysics Data System (ADS)

    Kochikov, Igor V.; Kovtun, Dmitry M.; Tarasov, Yury I.

    2017-03-01

    There exists a noticeable disagreement in the difference of axial and equatorial bond lengths in D3h symmetry arsenic and phosphorus pentafluorides between the GED data and high level quantum chemical results. In order to resolve this disagreement, a new structural analysis of the original experiment of (Clippard & Bartell, Inorg. Chem., 9 (1970) 805-811) was undertaken on the basis of modern approach incorporating spectroscopic evidence and quantum chemical information and allowing for intramolecular large-amplitude motion. The results of the analysis prove the internal insufficiency of the experimental material in the description of the accurate positions of the peaks on the radial distribution function. Additional experimental investigation of pentahalide molecules, especially at high temperatures, is of interest.

  4. A NOVEL MUTATION IN NPR2 GENE IN A PATIENT WITH ACROMESOMELIC DYSPLASIA, MAROTEAUX TYPE.

    PubMed

    Sag, S Ozemri; Gorukmez, O; Topak, A; Gorukmez, O; Ture, M; Sahinturk, S; Gulten, T; Yakut, T

    2015-01-01

    Acromesomelic dysplasia, Maroteaux type (AMDM) is a rare autosomal recessive disease characterized by disproportionate shortening of skeletal elements, predominantly affecting the middle segments (forearms and forelegs) and distal segments (hands and feet) of appendicular skeleton. Furthermore it is related to axial skeleton and leads to wedging of vertebral bodies, with shorter dorsal margins than the ventral margins. Bartels et al. defined mutations in NPR2 gene, encoding natriuretic peptide receptor B (NPR-B), underlying Acromesomelic dysplasia, type Maroteaux. We present here molecular and clinical findings of a case with AMDM. In a patient, a novel homozygous mutation c.1435C>T p.R479X in exon 7 of NPR2 gene was found. Further testing confirmed the heterozygous carrier status of the parents. Our findings expand the spectrum of causative mutations in AMDM.

  5. Coronal holes and high-speed wind streams

    NASA Technical Reports Server (NTRS)

    Zirker, J. B.

    1977-01-01

    Coronal holes, regions of unusually low density and low temperature in the solar corona, are identified as Bartel's M regions, i.e., sources of high-speed wind streams that produce recurrent geomagnetic variations. Throughout the Skylab period the polar caps of the sun were coronal holes, and at lower latitudes the most persistent and recurrent holes were equatorial extensions of the polar caps. The holes rotated 'rigidly' at the equatorial synodic rate. They formed in regions of unipolar photospheric magnetic field, and their internal magnetic fields diverged rapidly with increasing distance from the sun. The geometry of the magnetic field in the inner corona seems to control both the physical properties of the holes and the global distribution of high-speed wind streams in the heliosphere. Phenomenological models for the birth and decay of coronal holes have been proposed.

  6. Helicity evolution at small-x

    DOE PAGES

    Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.

    2016-01-13

    We construct small-x evolution equations which can be used to calculate quark and anti-quark helicity TMDs and PDFs, along with the g1 structure function. These evolution equations resum powers of αs ln2(1/x) in the polarization-dependent evolution along with the powers of αs ln(1/x) in the unpolarized evolution which includes saturation efects. The equations are written in an operator form in terms of polarization-dependent Wilson line-like operators. While the equations do not close in general, they become closed and self-contained systems of non-linear equations in the large-Nc and large-Nc & Nf limits. As a cross-check, in the ladder approximation, our equationsmore » map onto the same ladder limit of the infrared evolution equations for g1 structure function derived previously by Bartels, Ermolaev and Ryskin.« less

  7. Aquatic tardigrades in the Great Smoky Mountains National Park, North Carolina and Tennessee, U.S.A., with the description of a new species of Thulinius (Tardigrada, Isohypsibiidae).

    PubMed

    Bertolani, Roberto; Bartels, Paul J; Guidetti, Roberto; Cesari, Michele; Nelson, Diane R

    2014-02-05

    As part of the All Taxa Biodiversity Inventory (http://www.dlia.org), an extensive survey of tardigrades has been conducted in the Great Smoky Mountains National Park (GSMNP) in Tennessee and North Carolina, U.S.A., by Bartels and Nelson. Freshwater tardigrades include three species in the aquatic genus Thulinius (Eutardigrada, Isohypsibiidae). A new species, Thulinius romanoi, described from stream sediment, is distinguished from all other congeners by having a sculptured cuticle. In addition, the presence of Thulinius augusti (Murray, 1907) was verified by combined morphological and molecular analysis, and nine specimens of a third species, Thulinius cf. saltursus, were also found. Thulinius augusti is a new record for the United States. Thulinius saltursus (Schuster, Toftner & Grigarick, 1978) was previously recorded in California and Ohio, but our specimens vary slightly in morphology. The list of tardigrades from streams in the GSMNP was updated to a total of 44 species, 22 of which were predominantly or exclusively aquatic.

  8. Care Burden and Self-Efficacy Levels of Family Caregivers of Elderly People in Turkey.

    PubMed

    Unver, Vesile; Basak, Tulay; Tosun, Nuran; Aslan, Ozlem; Akbayrak, Nalan

    2016-01-01

    The aim of this research was to determine the level of burden and self-efficacy among family caregivers of elderly people in Turkey. This study is descriptive and cross-sectional. A total of 658 family caregivers of elderly people were included in the study. The data were collected with a caregiver's characteristics form, elderly people's characteristics form, the Zarit Burden Interview, the self-efficacy scale, and the Barthell Index. Data were analyzed using SPSS 16.0 program. What are care burden and self-efficacy levels of the caregivers? Is there a relationship between care burden and self-efficacy levels of the caregivers with variables such as age, duration of care, sex, status of education, type of relationship, and status of employment that belong to the caregiver? Is there a relationship between care burden and self-efficacy levels of the caregivers with variables such as age and Bartell Index that belong to the elderly? The caregiver burden score was 38.65 ± 13.73, which indicates a moderate level of burden. The self-efficacy score was 29.31 ± 6.09, which is in the low range of self-efficacy. There were statistically significant differences between the caregiver burden score and the sex of caregivers, status of education, type of relationship, and the elderly person's score on the Bartell Index (P < .05). The relationship between the employment status of caregivers (P = .01), the age of the elderly (P = .01), and the caregivers' score on the self-efficacy scale (P < .05) was found to be statistically significant. Study revealed that the majority of the caregivers experienced moderate levels of care burden and low levels of self-efficacy. These results will provide beneficial information for nurses to provide the holistic nursing care.

  9. The Relationship between Parent-Child Conflict and Adolescent Antisocial Behavior: Confirming Shared Environmental Mediation

    PubMed Central

    Klahr, Ashlea M.; Rueter, Martha A.; McGue, Matt; Iacono, William G.; Burt, S. Alexandra

    2011-01-01

    Prior studies have indicated that the relationship between0020parent-child conflict and adolescent antisocial behavior is at least partially shared environmental in origin. However, all available research on this topic (to our knowledge) relies exclusively on parent and/or adolescent informant-reports, both of which are subject to various forms of rater bias. As the presence of significant shared environmental effects has often been attributed to rater bias in the past (Baker, Jacobsen, Raine, Lozano, & Bezdjian, 2007; Bartels et al., 2004; Bartels et al., 2003; Hewitt, Silberg, Neale, & Eaves, 1992), it would be important to confirm that findings of shared environmental mediation persist when even examining (presumably more objective) observer-ratings of these constructs. The current study thus examined the origins of the relationship between parent-child conflict and adolescent acting-out behavior, as measured using both observer-ratings and various informant-reports. Participants included 1,199 adopted and non-adopted adolescents in 610 families from the Sibling Interaction and Behavior Study (SIBS). Results indicated that parent-child conflict consistently predicts acting-out behavior in adopted adolescents, and moreover, that this association is equivalent to that in biologically-related adolescents. Most importantly, these findings did not vary across parent- and adolescent-reported or observer-ratings of parent-child conflict and acting-out behavior. Such findings argue strongly against rater bias as a primary explanation of shared environmental mediation of the association between parent-child conflict and adolescent antisocial behavior. PMID:21484334

  10. Prospective evaluation of rapid antigen tests for diagnosis of respiratory syncytial virus and human metapneumovirus infections.

    PubMed

    Aslanzadeh, Jaber; Zheng, Xiaotian; Li, Haijing; Tetreault, Janice; Ratkiewicz, Irene; Meng, Shufang; Hamilton, Pamela; Tang, Yi-Wei

    2008-05-01

    Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements.

  11. Prospective Evaluation of Rapid Antigen Tests for Diagnosis of Respiratory Syncytial Virus and Human Metapneumovirus Infections▿

    PubMed Central

    Aslanzadeh, Jaber; Zheng, Xiaotian; Li, Haijing; Tetreault, Janice; Ratkiewicz, Irene; Meng, Shufang; Hamilton, Pamela; Tang, Yi-Wei

    2008-01-01

    Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements. PMID:18337386

  12. Dst Prediction from CIR Events During 2008 Using Synthesized Signals Derived From SOHO, STEREO, and ACE Observations

    NASA Astrophysics Data System (ADS)

    Spencer, E. A.; Andriyas, T.; Mays, M. L.; Sojka, J. J.

    2011-12-01

    Observations from SOHO, STEREO, and ACE during the declining phase of the deep solar minimum in 2008 are analyzed in order to synthesize signals of the IMF Bz, solar wind velocity vx, and solar wind proton density Np at 1 AU. These synthesized signals are used as a substitute for ACE measurements to represent solar wind forcing due to coronal hole driven CIR events occuring during multiple Bartel rotations (BR 2381 - BR 2393). The signals drive a low order physics based model of the magnetosphere called WINDMI, one of whose outputs is the ground based measurement of the Dst index. Estimating the arrival of CIR events for future rotations using ACE and SOHO data during BR 2381 produced what we referred to as an uncalibrated yearly prediction. We proceeded to generate a video calibrated (VC) estimate of the arrival times of CIR events in addition to information from BR 2381 using SOHO and STEREO images of the Sun in order to produce a simulated 3.5 day ahead prediction of possible geomagnetic activity. The time of arrival of CIR events is taken to be the travel time of compressions as seen in a non-inertial frame according to a radial solar wind speed of 500 km/s and a distance of 1 AU. We found that we were able to predict the timing of CIR induced geomagnetic activity quite accurately by using the expected recurrence of the events through multiple Bartel rotations, and further improve it through SOHO and STEREO coronal hole sightings made 3.5 days before every event. The uncertainty in the IMF Bz led to predictions of levels of geomagnetic activity on an ensemble basis, yielding a distribution of different possible Dst signatures.

  13. Forecasting the Dst index during corotating interaction region events using synthesized solar wind parameters

    NASA Astrophysics Data System (ADS)

    Andriyas, T.; Spencer, E.; Raj, A.; Sojka, J.; Mays, M. L.

    2012-03-01

    Observations from SOHO, STEREO, and ACE during the declining phase of the solar cycle toward the deep minimum in 2008 are analyzed to establish the timing of corotating interaction region (CIR) activity. This analysis is then employed to synthesize signals of the z component of the interplanetary magnetic field (IMF) Bz, solar wind radial velocity vx, and solar wind proton density Np at 1 AU. The synthesized signals are used as a substitute for ACE measurements to represent solar wind forcing due to coronal hole driven CIR events occurring during multiple Bartel rotations (BR 2381 to BR 2393). The signals drive a low-order physics-based model of the magnetosphere called WINDMI, one of whose outputs is the ground-based measurement of the Dst index. Estimating the arrival of CIR events for future rotations using ACE and SOHO data during BR 2381 produced what we refer to as an uncalibrated yearly forecast. We next generated a video-calibrated estimate of the arrival times of CIR events in addition to information from BR 2381 using SOHO and STEREO images of the Sun in order to produce a simulated 3.5 day ahead forecast of possible geomagnetic activity. The time of arrival of CIR events is taken to be the travel time of density compressions as seen in a noninertial frame according to a radial solar wind speed of 500 km/s and a distance of 1 AU. We were able to forecast the timing of CIR-induced geomagnetic activity to within 12 h for 17 out of 28 events by using the expected recurrence of the events through multiple Bartel rotations together with SOHO and STEREO coronal hole sightings made 3.5 days before every event. The uncertainty in the IMF Bz led to a forecast of levels of geomagnetic activity on an ensemble basis, yielding a distribution of different possible Dst signatures. We used a 10-sample ensemble and a 50-sample ensemble to obtain typical representations of geomagnetic activity. Depending on the periodicity and intensity of fluctuations in Bz, we obtained

  14. Genetic counselor perceptions of genetic counseling session goals: a validation study of the reciprocal-engagement model.

    PubMed

    Hartmann, Julianne E; Veach, Patricia McCarthy; MacFarlane, Ian M; LeRoy, Bonnie S

    2015-04-01

    Although some researchers have attempted to define genetic counseling practice goals, no study has obtained consensus about the goals from a large sample of genetic counselors. The Reciprocal-Engagement Model (REM; McCarthy Veach, Bartels & LeRoy, 2007) articulates 17 goals of genetic counseling practice. The present study investigated whether these goals could be generalized as a model of practice, as determined by a larger group of clinical genetic counselors. Accordingly, 194 genetic counselors were surveyed regarding their opinions about the importance of each goal and their perceptions of how frequently they achieve each goal. Mean importance ratings suggest they viewed every goal as important. Factor analysis of the 17 goals yielded four factors: Understanding and Appreciation, Support and Guidance, Facilitative Decision-Making, and Patient-Centered Education. Patient-Centered Education and Facilitative Decision-Making goals received the highest mean importance ratings. Mean frequency ratings were consistently lower than importance ratings, suggesting genetic counseling goals may be difficult to achieve and/or not applicable in all situations. A number of respondents provided comments about the REM goals that offer insight into factors related to implementing the goals in clinical practice. This study presents preliminary evidence concerning the validity of the goals component of the REM.

  15. A molecular dynamics study of water nucleation using the TIP4P/2005 model

    NASA Astrophysics Data System (ADS)

    Pérez, Alejandro; Rubio, Angel

    2011-12-01

    Extensive molecular dynamics simulations were conducted using the TIP4P/2005 water model of Abascal and Vega [J. Chem. Phys. 123, 234505 (2005)] to investigate its condensation from supersaturated vapor to liquid at 330 K. The mean first passage time method [J. Wedekind, R. Strey, and D. Reguera, J. Chem. Phys. 126, 134103 (2007); L. S. Bartell and D. T. Wu, 125, 194503 (2006)] was used to analyze the influence of finite size effects, thermostats, and charged species on the nucleation dynamics. We find that the Nosé-Hoover thermostat and the one proposed by Bussi et al. [J. Chem. Phys. 126, 014101 (2007)] give essentially the same averages. We identify the maximum thermostat coupling time to guarantee proper thermostating for these simulations. The presence of charged species has a dramatic impact on the dynamics, inducing a marked change towards a pure growth regime, which highlights the importance of ions in the formation of liquid droplets in the atmosphere. It was found a small but noticeable sign preference at intermediate cluster sizes (between 5 and 30 water molecules) corresponding mostly to the formation of the second solvation shell around the ion. The TIP4P/2005 water model predicts that anions induce faster formation of water clusters than cations of the same magnitude of charge.

  16. A method for analyzing the non-stationary nucleation and overall transition kinetics: A case of water

    NASA Astrophysics Data System (ADS)

    Mokshin, Anatolii V.; Galimzyanov, Bulat N.

    2014-01-01

    We present the statistical method as a direct extension of the mean first-passage time concept to the analysis of molecular dynamics simulation data of a phase transformation. According to the method, the mean first-passage time trajectories for the first (i = 1) as well as for the subsequent (i = 2, 3, 4,…) nucleation events should be extracted that allows one to calculate the time-dependent nucleation rate, the critical value of the order parameter (the critical size), the waiting times for the nucleation events, and the growth law of the nuclei - i.e., all the terms, which are usually necessary to characterize the overall transition kinetics. There are no restrictions in the application of the method by the specific thermodynamic regions; and the nucleation rate parameters are extracted according to their basic definitions. The method differs from the Wedekind-Bartell scheme and its modification [A. V. Mokshin and B. N. Galimzyanov, J. Phys. Chem. B 116, 11959 (2012)], where the passage-times for the first (largest) nucleus are evaluated only and where the average waiting time for the first nucleation event is accessible instead of the true steady-state nucleation time scale. We demonstrate an efficiency of the method by its application to the analysis of the vapor-to-liquid transition kinetics in water at the different temperatures. The nucleation rate/time characteristics and the droplet growth parameters are computed on the basis of the coarse-grained molecular dynamics simulation data.

  17. Explicit simulation of a midlatitude Mesoscale Convective System

    SciTech Connect

    Alexander, G.D.; Cotton, W.R.

    1996-04-01

    We have explicitly simulated the mesoscale convective system (MCS) observed on 23-24 June 1985 during PRE-STORM, the Preliminary Regional Experiment for the Stormscale Operational and Research and Meterology Program. Stensrud and Maddox (1988), Johnson and Bartels (1992), and Bernstein and Johnson (1994) are among the researchers who have investigated various aspects of this MCS event. We have performed this MCS simulation (and a similar one of a tropical MCS; Alexander and Cotton 1994) in the spirit of the Global Energy and Water Cycle Experiment Cloud Systems Study (GCSS), in which cloud-resolving models are used to assist in the formulation and testing of cloud parameterization schemes for larger-scale models. In this paper, we describe (1) the nature of our 23-24 June MCS dimulation and (2) our efforts to date in using our explicit MCS simulations to assist in the development of a GCM parameterization for mesoscale flow branches. The paper is organized as follows. First, we discuss the synoptic situation surrounding the 23-24 June PRE-STORM MCS followed by a discussion of the model setup and results of our simulation. We then discuss the use of our MCS simulation. We then discuss the use of our MCS simulations in developing a GCM parameterization for mesoscale flow branches and summarize our results.

  18. The six-point remainder function to all loop orders in the multi-Regge limit

    NASA Astrophysics Data System (ADS)

    Pennington, Jeffrey

    2013-01-01

    We present an all-orders formula for the six-point amplitude of planar maximally supersymmetric {N}=4 Yang-Mills theory in the leading-logarithmic approximation of multi-Regge kinematics. In the MHV helicity configuration, our results agree with an integral formula of Lipatov and Prygarin through at least 14 loops. A differential equation linking the MHV and NMHV helicity configurations has a natural action in the space of functions relevant to this problem — the single-valued harmonic polylogarithms introduced by Brown. These functions depend on a single complex variable and its conjugate, w and w * , which are quadratically related to the original kinematic variables. We investigate the all-orders formula in the near-collinear limit, which is approached as |w| → 0. Up to power-suppressed terms, the resulting expansion may be organized by powers of log |w|. The leading term of this expansion agrees with the all-orders double-leading-logarithmic approximation of Bartels, Lipatov, and Prygarin. The explicit form for the sub-leading powers of log |w| is given in terms of modified Bessel functions.

  19. Geomagnetic activity during 10 - 11 solar cycles that has been observed by old Russian observatories.

    NASA Astrophysics Data System (ADS)

    Seredyn, Tomasz; Wysokinski, Arkadiusz; Kobylinski, Zbigniew; Bialy, Jerzy

    2016-07-01

    A good knowledge of solar-terrestrial relations during past solar activity cycles could give the appropriate tools for a correct space weather forecast. The paper focuses on the analysis of the historical collections of the ground based magnetic observations and their operational indices from the period of two sunspot solar cycles 10 - 11, period 1856 - 1878 (Bartels rotations 324 - 635). We use hourly observations of H and D geomagnetic field components registered at Russian stations: St. Petersburg - Pavlovsk, Barnaul, Ekaterinburg, Nertshinsk, Sitka, and compare them to the data obtained from the Helsinki observatory. We compare directly these records and also calculated from the data of the every above mentioned station IHV indices introduced by Svalgaard (2003), which have been used for further comparisons in epochs of assumed different polarity of the heliospheric magnetic field. We used also local index C9 derived by Zosimovich (1981) from St. Petersburg - Pavlovsk data. Solar activity is represented by sunspot numbers. The correlative and continuous wavelet analyses are applied for estimation of the correctness of records from different magnetic stations. We have specially regard to magnetic storms in the investigated period and the special Carrington event of 1-2 Sep 1859. Generally studied magnetic time series correctly show variability of the geomagnetic activity. Geomagnetic activity presents some delay in relation to solar one as it is seen especially during descending and minimum phase of the even 11-year cycle. This pattern looks similarly in the case of 16 - 17 solar cycles.

  20. A survey of genetic counselors' strategies for addressing ethical and professional challenges in practice.

    PubMed

    Bower, Matthew A; Veach, Patricia McCarthy; Bartels, Dianne M; LeRoy, Bonnie S

    2002-06-01

    There is limited research about ethical and professional dilemmas that genetic counselors encounter in their practice and their strategies for addressing them. In this study, 454 genetic counselors rated the frequency with which they encounter each of 16 ethical/professional challenges identified and categorized previously (McCarthy Veach P., Bartels DM, LeRoy BS (2001) J Genet Couns 10(2):97-119). Over 40% indicated these issues occurred frequently: patient emotions, diversity, financial constraints, uncertainty, and colleague error. Two hundred and fifty-five respondents provided personal anecdotes describing exceptionally challenging situations and recommended strategies for addressing them. Most of their anecdotes involved informed consent, value conflicts, confidentiality, colleague error, withholding information, and resource allocation. The most frequently recommended strategies were further discussion with patients, consultation with other professionals, and referral to other health sources. Thirty-five respondents were unable to/did not offer strategies. Respondent demographics were not related to frequency of issues, type of anecdote, or recommended strategies. Practice, policy, and research implications are discussed.

  1. Temporal Variation of the Rotation of the Solar Mean Magnetic Field

    NASA Astrophysics Data System (ADS)

    Xie, J. L.; Shi, X. J.; Xu, J. C.

    2017-04-01

    Based on continuous wavelet transformation analysis, the daily solar mean magnetic field (SMMF) from 1975 May 16 to 2014 July 31 is analyzed to reveal its rotational behavior. Both the recurrent plot in Bartels form and the continuous wavelet transformation analysis show the existence of rotational modulation in the variation of the daily SMMF. The dependence of the rotational cycle lengths on solar cycle phase is also studied, which indicates that the yearly mean rotational cycle lengths generally seem to be longer during the rising phase of solar cycles and shorter during the declining phase. The mean rotational cycle length for the rising phase of all of the solar cycles in the considered time is 28.28 ± 0.67 days, while for the declining phase it is 27.32 ± 0.64 days. The difference of the mean rotational cycle lengths between the rising phase and the declining phase is 0.96 days. The periodicity analysis, through the use of an auto-correlation function, indicates that the rotational cycle lengths have a significant period of about 10.1 years. Furthermore, the cross-correlation analysis indicates that there exists a phase difference between the rotational cycle lengths and solar activity.

  2. Helicity evolution at small-x

    SciTech Connect

    Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.

    2016-01-13

    We construct small-x evolution equations which can be used to calculate quark and anti-quark helicity TMDs and PDFs, along with the g1 structure function. These evolution equations resum powers of αs ln2(1/x) in the polarization-dependent evolution along with the powers of αs ln(1/x) in the unpolarized evolution which includes saturation efects. The equations are written in an operator form in terms of polarization-dependent Wilson line-like operators. While the equations do not close in general, they become closed and self-contained systems of non-linear equations in the large-Nc and large-Nc & Nf limits. As a cross-check, in the ladder approximation, our equations map onto the same ladder limit of the infrared evolution equations for g1 structure function derived previously by Bartels, Ermolaev and Ryskin.

  3. Lateral hopping and desorption of a single CO molecule on a Cu(110) surface induced by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Ueba, H.; Ootsuka, Y.

    2013-05-01

    Lateral hopping and desorption of a single CO molecule on a Cu(110) surface [Bartels , ScienceSCIEAS0036-807510.1126/science.1099770 305, 648 (2004)] induced by femtosecond laser pulses are studied using an indirect heat-transfer model. In addition to a direct heating of the reaction coordinate (RC) mode [frustrated translation (FT) mode for hopping and center-of-mass (CM) mode for desorption] by laser-generated hot electrons in the substrate, we consider an indirect heating of the RC mode through intermode coupling between the frustrated rotation (FR) mode and the RC mode. We calculate the transient behavior of the effective temperature of the FT and the CM modes, and of the normalized reaction yield. The experimental result of a ratio of the hopping yield along and across a row on a Cu(110) surface is nicely calculated. Although no information is available for the attempt frequency in a form of the Arrhenius equation for thermally activated reactions, it is predicted under which condition the desorption rate becomes in the same order of magnitude as the hopping rate, although the barrier height for desorption is much higher than for hopping. The present analysis highlights the role of excitation of the FR mode in reactions of a CO molecule as has been confirmed in the real-time observation [Backus , ScienceSCIEAS0036-807510.1126/science.1120693 310, 1790 (2005)].

  4. Radio Telescopes Reveal Youngest Stellar Corpse

    NASA Astrophysics Data System (ADS)

    2004-06-01

    Astronomers using a global combination of radio telescopes to study a stellar explosion some 30 million light-years from Earth have likely discovered either the youngest black hole or the youngest neutron star known in the Universe. Their discovery also marks the first time that a black hole or neutron star has been found associated with a supernova that has been seen to explode since the invention of the telescope nearly 400 years ago. M51 An artist's impression of Supernova 1986J. The newly discovered nebula around the black hole or neutron star in the center is shown in blue, and is in the center of the expanding, fragmented shell of material thrown off in the supernova explosion, which is shown in red. CREDIT: Norbert Bartel and Michael F. Bietenholz, York University; Artist: G. Arguner (Click on image for larger version) Image Files Artist's Conception (above image, 836K) Galaxy and Supernova (47K) A VLA image (left) of the galaxy NGC 891, showing the bright supernova explosion below the galaxy's center. At right, a closer view of the supernova, made with a global array of radio telescopes. CREDIT: Miguel A. Perez-Torres, Antxon Alberdi and Lucas Lara, Instituto de Astrofisica de Andalucia - CSIC, Spain, Jon Marcaide and Jose C. Guirado, Universidad de Valencia, Spain Franco Mantovani, IRA-CNR, Italy, Eduardo Ros, MPIfR, Germany, and Kurt W. Weiler, Naval Research Laboratory, USA Multi-Frequency Closeup View (201K) Blue and white area shows the nebula surrounding the black hole or neutron star lurking in the center of the supernova. This nebula is apparent at a higher radio frequency (15 GHz). The red and also the contours show the distorted, expanding shell of material thrown off in the supernova explosion. This shell is seen at a lower radio frequency (5 GHz). CREDIT: Michael F. Bietenholz and Norbert Bartel, York University, Michael Rupen, NRAO, NRAO/AUI/NSF A supernova is the explosion of a massive star after it exhausts its supply of nuclear fuel and

  5. Twenty-Seven-Day Variation of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Sabbah, I.

    2007-09-01

    Neutron monitor data observed at Climax (CL) and Huancayo/Haleakala (HU/HAL) have been used to calculate the amplitude A of the 27-day variation of galactic cosmic rays (CRs). The median primary rigidity of response, R m, for these detectors encompasses the range 18 ≤ R m≤46 GV and the threshold rigidity R 0 covers the range 2.97≤ R 0≤12.9 GV. The daily average values of CR counts have been harmonically analyzed for each Bartels solar rotation (SR) during the period 1953 2001. The amplitude of the 27-day CR variation is cross-correlated to solar activity as measured by the sunspot number R, the interplanetary magnetic field (IMF) strength B, the z-component B z of the IMF vector, and the tilt angle ψ of the heliospheric current sheet (HCS). It is anticorrelated to the solar coronal hole area (CHA) index as well as to the solar wind speed V. The wind speed V leads the amplitude by 24 SRs. The amplitude of the 27-day CR variation is better correlated to each of the these parameters during positive solar polarity ( A>0) than during negative solar polarity ( A<0) periods. The CR modulation differs during A>0 from that during A<0 owing to the contribution of the z-component of the IMF. It differs during A 1>0 (1971 1980) from that during A 2>0 (1992 2001) owing to solar wind speed.

  6. Reciprocal Space Mapping of Macromolecular Crystals in the Laboratory

    NASA Technical Reports Server (NTRS)

    Snell, Edward H.; Boggon, T. J.; Fewster, P. F.; Siddons, D. P.; Stojanof, V.; Pusey, M. L.

    1998-01-01

    The technique of reciprocal space mapping applied to the physical measurement of macromolecular crystals will be described. This technique uses a triple axis diffractometer setup whereby the monochromator is the first crystal, the sample is the second and the third crystal (of the same material as the monochromator) analyzes the diffracted beam. The geometry is such that it is possible to separate mosaic volume effects from lattice strain effects. The deconvolution of the instrument parameters will also be addressed. Results from measurements at Brookhaven National Synchrotron Radiation Source carried out on microgravity and ground-grown crystals will be presented. The required beam characteristics for reciprocal space mapping are also ideal for topographic studies and the first topographs ever recorded from microgravity protein crystal samples will be shown. We are now working on a system which will enable reciprocal space mapping, mosaicity and topography studies to be carried out in the home laboratory. This system uses a rotating anode X-ray source to provide an intense beam then a Bartels double crystal, four reflection monochromator to provide the spectral and geometric beam conditioning necessary such that the instrument characteristics do not mask the measurement. This is coupled to a high precision diffractometer and sensitive detector. Commissioning data and first results from the system will be presented.

  7. Effect of nonsphericity of scattering centers on light transport in turbid media

    NASA Astrophysics Data System (ADS)

    Mourant, Judith R.; Aida, Toru; Coburn, Leslie; Ramachandran, Janak

    2004-07-01

    The scattering centers in cells are not spheres, however, in most modeling of light transport, the scattering centers are assumed to be spherical. For example, in Monte Carlo simulations a Mie or Henyey-Greenstein phase function is often used. It is known that an elliptical particle will have a different phase function than a spherical particle. In particular there are differences in the phase functions for scattering polarized light. To examine how these changes in phase function affect light transport in tissue, we have developed a Monte Carlo code for light transport that uses elliptical scatterers. The phase functions are calculated using a T-matrix code and the propagation of polarized photons is performed in a manner analagous to that used by Bartel and Hielscher. Our initial results indicate that for narrow particle distributions the difference in shape can cause large differences in the intensity and polarization properties of the diffusely reflected light. For a mixture of particle sizes, however, there is a much smaller difference in the properties of the diffusely scattered light. Results are presented for both narrow and broad distributions of scatter sizes relevant to tissue.

  8. Reversing subdivision rules: local linear conditions and observations on inner products

    NASA Astrophysics Data System (ADS)

    Bartels, Richard H.; Samavati, Faramarz F.

    2000-07-01

    In a previous work (Samavati and Bartels, Comput. Graphics Forum 18 (1998) 97-119) we investigated how to reverse subdivision rules using global least-squares fitting. This led to multiresolution structures that could be viewed as semiorthogonal wavelet systems whose inner product was that for finite-dimensional Cartesian vector space. We produced simple and sparse reconstruction filters, but had to appeal to matrix factorization to obtain an efficient, exact decomposition. We also made some observations on how the inner product that defines the semiorthogonality influences the sparsity of the reconstruction filters. In this work we carry the investigation further by studying biorthogonal systems based upon subdivision rules and local least-squares fitting problems that reverse the subdivision. We are able to produce multiresolution structures for some common univariate subdivision rules that have both sparse reconstruction and decomposition filters. Three will be presented here - for quadratic and cubic B-spline subdivision and for the four-point interpolatory subdivision of Dyn et al. We observe that each biorthogonal system we produce can be interpreted as a semiorthogonal system with an inner product induced on the multiresolution that is quite different from that normally used. Some examples of the use of this approach on images, curves, and surfaces are given.

  9. Helicity evolution at small x : Flavor singlet and nonsinglet observables

    NASA Astrophysics Data System (ADS)

    Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.

    2017-01-01

    We extend our earlier results for the quark helicity evolution at small x [J. High Energy Phys. 01 (2016) 072, 10.1007/JHEP01(2016)072] to derive the small-x asymptotics of the flavor singlet and flavor nonsinglet quark helicity TMDs and PDFs and of the g1 structure function. In the flavor singlet case we rederive the evolution equations obtained in our previous paper on the subject [J. High Energy Phys. 01 (2016) 072, 10.1007/JHEP01(2016)072], performing additional cross-checks of our results. In the flavor nonsinglet case we construct new small-x evolution equations by employing the large-Nc limit. All evolution equations resum double-logarithmic powers of αsln2(1 /x ) in the polarization-dependent evolution along with the single-logarithmic powers of αsln (1 /x ) in the unpolarized evolution which includes saturation effects. We solve the linearized flavor nonsinglet equation analytically, obtaining an intercept which agrees with the one calculated earlier by Bartels, Ermolaev and Ryskin [Z. Phys. C 70, 273 (1996)] using the infrared evolution equations. Our numerical solution of the linearized large-Nc evolution equations for the flavor singlet case is presented in the accompanying Letter [Phys. Rev. Lett. 118, 052001 (2017), 10.1103/PhysRevLett.118.052001] and is further discussed here.

  10. Development of a toolbox of organic synthetic reactions that can be induced on individual molecules by STM

    SciTech Connect

    Ludwig Bartels

    2003-09-25

    OAK B262 Final Report DOE Grant No.: DE-FG03-01ER15263 ''Development of a toolbox of organic synthetic reactions that can be induced on individual molecules by STM'' Abstract Bommisetty V. Rao, Ki-Young Kwon, Robert Perry, Luke Nysen, Gregory Pavin, Qibin Zhang, Casey Dugger and Ludwig Bartels University of California at Riverside, Pierce Hall, Riverside, CA92521, email: Ludwig.Bartels@ucr.edu The key scientific objective of this project is the development of a set of reliable techniques for the addressal of specific bonds of individual molecules in order to assemble functional molecules on a metal surface at single-atom precision. Success in this direction will open up a conceptually novel route to single molecule chemistry, which can provide its products at any desired surface location without involving any lithographic steps at all. In the course of this project a number of halo-substituted aryls and alkyls where investigated with special concern to two properties: clean deposition of the reactants from the gas phase on metallic surfaces and STM-based addressability of individual substituents of them. In order to prevent contamination of the sample by deposition of solvent residue, a special depositions source was developed that uses a skimmed molecular beam. Exemplary substances studied were 1,3-iodobromobenzene (IBB), 3 bromopropionitrile (BPN) and 4,4'-dibromobiphenyl (DBB). In STM-induced reactions, IBB shows concerted activation of both halogens, which does not allow the individual addressal of one bond at a time. The concept of individual addressabilities of bonds in bi-substituted molecule was confirmed by use of BPN. This reactant is, however, strongly bound to the substrate and, hence, not very suitable for the assembly of larger aggregates, even if the nitrile group could be activated. We found individual activation of one of the bromines of DBB. This molecule lies flat on the surface and it is a promising candidate for the assembly of larger molecular

  11. [Effect of antioxidant therapy on neurotrophins and processes of rehabilitation after stroke].

    PubMed

    Karakulova, Yu V; Selyanina, N V; Zhelnin, A V; Filimonova, T A; Tsepilov, S V

    The aim of the research was to study the effect of the inclusion in the scheme cytoflavin patient care during the recovery period of ischemic stroke in the neuropsychological changes in the status and content of neurotrophins in serum. For this purpose we surveyed 52 patients who underwent a first ischemic stroke (29 women and 23 men) aged 52-74 years. Patients were divided into 2 groups: primary (25 patients) received in addition to basic therapy cytoflavin: intravenously at 20 ml per 400 ml of 5% glucose solution, 1 time a day for 10 days, then into 2 tablets 2 times a day for half an hour before food for a month, and the comparison group (27 patients) who received standard treatment. The control group consisted of 12 healthy people. In addition to standard clinical and laboratory tests were carried out a comprehensive neuropsychological study and evaluation of the data on the scale NIHSS, Bartell, Beck, Spielberger-Hanin, test «frontal dysfunction of the battery» and the Mini-Mental State Examination. Furthermore, determination carried neurotrophic factors: nerve growth factor (NGF) and brain-derived neurotrophic factor brain (BDNF). The study was conducted in the dynamics: before treatment and 2 months after treatment. Patients in the recovery period of the first ischemic stroke revealed moderate manifestations of neuropsychological disorders status and reduction of neurotrophic factors. Inclusion in cytoflavin scheme increased the efficiency of the treatment, which was manifested in a more pronounced when compared with the results of basic therapy, positive dynamics of neurological symptoms and improved cognitive function, accompanied by an increase in BDNF levels. The data on the efficacy and safety allow us to recommend its inclusion in the scheme of treatment of patients in the recovery period after the first carotid ischemic stroke.

  12. Electromagnetic Reciprocity.

    SciTech Connect

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories and now a

  13. Long periods (1 -10 mHz) geomagnetic pulsations variation with solar cycle in South Atlantic Magnetic Anomaly

    NASA Astrophysics Data System (ADS)

    Rigon Silva, Willian; Schuch, Nelson Jorge; Guimarães Dutra, Severino Luiz; Babulal Trivedi, Nalin; Claudir da Silva, Andirlei; Souza Savian, Fernando; Ronan Coelho Stekel, Tardelli; de Siqueira, Josemar; Espindola Antunes, Cassio

    The occurrence and intensity of the geomagnetic pulsations Pc-5 (2-7 mHz) and its relationship with the solar cycle in the South Atlantic Magnetic Anomaly -SAMA is presented. The study of geomagnetic pulsations is important to help the understanding of the physical processes that occurs in the magnetosphere region and help to predict geomagnetic storms. The fluxgate mag-netometers H, D and Z, three axis geomagnetic field data from the Southern Space Observatory -SSO/CRS/INPE -MCT, São Martinho da Serra (29.42° S, 53.87° W, 480m a.s.l.), RS, Brasil, a were analyzed and correlated with the solar wind parameters (speed, density and temperature) from the ACE and SOHO satellites. A digital filtering to enhance the 2-7 mHz geomagnetic pulsations was used. Five quiet days and five perturbed days in the solar minimum and in the solar maximum were selected for this analysis. The days were chosen based on the IAGA definition and on the Bartels Musical Diagrams (Kp index) for 2001 (solar maximum) and 2008 (solar minimum). The biggest Pc-5 amplitude averages differences between the H-component is 78,35 nT for the perturbed days and 1,60nT for the quiet days during the solar maximum. For perturbed days the average amplitude during the solar minimum is 8,32 nT, confirming a direct solar cycle influence in the geomagnetic pulsations intensity for long periods.

  14. [For the Introduction of a Conceptual Perspective in Mathematics: Dedekind, Noether, van der Waerden].

    PubMed

    Koreuber, Mechthild

    2015-09-01

    ,,She [Noether] then appeared as the creator of a new direction in algebra and became the leader, the most consistent and brilliant representative, of a particular mathematical doctrine - of all that is characterized by the term ‚Begriffliche Mathematik‘.“ The aim of this paper is to illuminate this "new direction", which can be characterized as a conceptual [begriffliche] perspective in mathematics, and to comprehend its roots and trace its establishment. Field, ring, ideal, the core concepts of this new direction in mathematical images of knowledge, were conceptualized by Richard Dedekind (1831-1916) within the scope of his number theory research and associated with an understanding of a formation of concepts as a "free creation of the human spirit". They thus stand for an abstract perspective of mathematics in their entirety, described as 'modern algebra' in the 1920s and 1930s, leading to an understanding of mathematics as structural sciences. The establishment of this approach to mathematics, which is based on "general mathematical concepts" [allgemein-mathematische Begriffe], was the success of a cultural movement whose most important protagonists included Emmy Noether (1882-1935) and her pupil Bartel L. van der Waerden (1903-1996). With the use of the term 'conceptual', a perspective is taken in the analysis which allows for developing connections between the thinking of Dedekind, the "working and conceptual methods" [Arbeits- und Auffassungsmethoden] of Noether as well as the methodological approach, represented through the thought space of the Noether School as presented under the term "conceptual world" [Begriffswelt] in the Moderne Algebra of van der Waerden. This essay thus makes a contribution to the history of the introduction of a structural perspective in mathematics, a perspective that is inseparable from the mathematical impact of Noether, her reception of the work of Dedekind and the creative strength of the Noether School.

  15. Nonlinearly Activated Neural Network for Solving Time-Varying Complex Sylvester Equation.

    PubMed

    Li, Shuai; Li, Yangming

    2013-10-28

    The Sylvester equation is often encountered in mathematics and control theory. For the general time-invariant Sylvester equation problem, which is defined in the domain of complex numbers, the Bartels-Stewart algorithm and its extensions are effective and widely used with an O(n³) time complexity. When applied to solving the time-varying Sylvester equation, the computation burden increases intensively with the decrease of sampling period and cannot satisfy continuous realtime calculation requirements. For the special case of the general Sylvester equation problem defined in the domain of real numbers, gradient-based recurrent neural networks are able to solve the time-varying Sylvester equation in real time, but there always exists an estimation error while a recently proposed recurrent neural network by Zhang et al [this type of neural network is called Zhang neural network (ZNN)] converges to the solution ideally. The advancements in complex-valued neural networks cast light to extend the existing real-valued ZNN for solving the time-varying real-valued Sylvester equation to its counterpart in the domain of complex numbers. In this paper, a complex-valued ZNN for solving the complex-valued Sylvester equation problem is investigated and the global convergence of the neural network is proven with the proposed nonlinear complex-valued activation functions. Moreover, a special type of activation function with a core function, called sign-bi-power function, is proven to enable the ZNN to converge in finite time, which further enhances its advantage in online processing. In this case, the upper bound of the convergence time is also derived analytically. Simulations are performed to evaluate and compare the performance of the neural network with different parameters and activation functions. Both theoretical analysis and numerical simulations validate the effectiveness of the proposed method.

  16. Experimental data comparing two coral grow-out methods in nursery-raised Acropora cervicornis

    USGS Publications Warehouse

    Kuffner, Ilsa B.; Bartels, Erich; Stathakopoulos, Anastasios; Enochs, Ian C.; Kolodziej, Graham; Toth, Lauren; Manzello, Derek P.

    2017-01-01

    Staghorn coral, Acropora cervicornis, is a threatened species and the primary focus of western Atlantic reef-restoration efforts to date. As part of the USGS Coral Reef Ecosystems Studies project (http://coastal.er.usgs.gov/crest/), we investigated skeletal characteristics of nursery-grown staghorn coral reared using two commonly used grow-out methods at Mote Tropical Research Laboratory’s offshore nursery. We compared linear extension, calcification rate, and skeletal density of nursery-raised A. cervicornis branches reared for six months either on blocks attached to substratum or hanging from monofilament line (on PVC “trees”) in the water column. We demonstrate that branches grown on the substratum had significantly higher skeletal density, measured using computerized tomography (CT), and lower linear extension rates compared to water-column fragments. Calcification rates determined with buoyant weighing were not statistically different between the two grow-out methods, but did vary among coral genotypes. Whereas skeletal density and extension rates were plastic traits that depended on environment, calcification rate was conserved. Our results show that the two rearing methods generate the same amount of calcium-carbonate skeleton but produce colonies with different skeletal characteristics, and suggest that genetically based variability in coral-calcification performance exists. The data resulting from this experiment are provided in this data release and are interpreted in Kuffner et al. (2017).Kuffner, I.B., E. Bartels, A. Stathakopoulos, I.C. Enochs, G. Kolodziej, L.T. Toth, and D.P. Manzello, 2017, Plasticity in skeletal characteristics of nursery-raised staghorn coral, Acropora cervicornis: Coral Reefs, in press.

  17. Reward and motivation systems: a brain mapping study of early-stage intense romantic love in Chinese participants.

    PubMed

    Xu, Xiaomeng; Aron, Arthur; Brown, Lucy; Cao, Guikang; Feng, Tingyong; Weng, Xuchu

    2011-02-01

    Early-stage romantic love has been studied previously in the United States and United Kingdom (Aron et al. [2005]: J Neurophysiol 94:327–337; Bartels and Zeki [2000]: Neuroreport 11:3829–3834; Ortigue et al. [2007]: J Cogn Neurosci 19:1218–1230), revealing activation in the reward and motivation systems of the brain. In this study, we asked what systems are activated for early-stage romantic love in Easterners, specifically Chinese participants? Are these activations affected by individual differences within a cultural context of Traditionality and Modernity? Also, are these brain activations correlated with later satisfaction in the relationship? In Beijing, we used the same procedure used by Aron et al. (Aron et al. [2005]: J Neurophysiol 94:327–337). The stimuli for 18 Chinese participants were a picture of the face of their beloved, the face of a familiar acquaintance, and a countback task. We found significant activations specific to the beloved in the reward and motivation systems, particularly, the ventral tegmental area and the caudate. The mid-orbitofrontal cortex and cerebellum were also activated, whereas amygdala, medial orbitofrontal, and medial accumbens activity were decreased relative to the familiar acquaintance. Self-reported Traditionality and Modernity scores were each positively correlated with activity in the nucleus accumbens, although in different regions and sides of the brain. Activity in the subgenual area and the superior frontal gyrus was associated with higher relationship happiness at 18-month follow-up. Our results show that midbrain dopamine-rich reward/motivation systems were activated by early-stage romantic love in Chinese participants, as found by other studies. Neural activity was associated with Traditionality and Modernity attitudes as well as with later relationship happiness for Chinese participants.

  18. Low LET radiolysis escape yields for reducing radicals and H2 in pressurized high temperature water

    NASA Astrophysics Data System (ADS)

    Sterniczuk, Marcin; Yakabuskie, Pamela A.; Wren, J. Clara; Jacob, Jasmine A.; Bartels, David M.

    2016-04-01

    Low Linear Energy Transfer (LET) radiolysis escape yields (G values) are reported for the sum (G(radH)+G(e-)aq) and for G(H2) in subcritical water up to 350 °C. The scavenger system 1-10 mM acetate/0.001 M hydroxide/0.00048 M N2O was used with simultaneous mass spectroscopic detection of H2 and N2 product. Temperature-dependent measurements were carried out with 2.5 MeV electrons from a van de Graaff accelerator, while room temperature calibration measurements were done with a 60Co gamma source. The concentrations and dose range were carefully chosen so that initial spur chemistry is not perturbed and the N2 product yield corresponds to those reducing radicals that escape recombination in pure water. In comparison with a recent review recommendation of Elliot and Bartels (AECL report 153-127160-450-001, 2009), the measured reducing radical yield is seven percent smaller at room temperature but in fairly good agreement above 150 °C. The H2 escape yield is in good agreement throughout the temperature range with several previous studies that used much larger radical scavenging rates. Previous analysis of earlier high temperature measurements of Gesc(radOH) is shown to be flawed, although the actual G values may be nearly correct. The methodology used in the present report greatly reduces the range of possible error and puts the high temperature escape yields for low-LET radiation on a much firmer quantitative foundation than was previously available.

  19. Evaluation of five methods for respiratory syncytial virus detection.

    PubMed Central

    Halstead, D C; Todd, S; Fritch, G

    1990-01-01

    A total of 117 nasal aspirates were cultured for respiratory syncytial virus (RSV) and tested for RSV antigen by a direct fluorescent-antibody (DFA) test (Bartels Immunodiagnostic Supplies, Inc., Bellevue, Wash.), the Directigen enzyme immunoassay (EIA; Becton Dickinson Microbiology Systems, Cockeysville, Md.), the TestPack EIA (Abbott Laboratories, North Chicago, Ill.), and RSV EIA (Abbott). Agreement of two of five methods or a positive RSV culture were required to validate a result. A total of 57 of 117 (48.7%) specimens were culture positive in HEp-2 cells, A549 cells, or both. A total of 5 of 117 (4.3%) additional specimens met the criteria of a positive specimen; i.e., 62 of 117 (53.0%) specimens were positive. Results obtained from 77 of 117 (65.8%) specimens were concordant for all five methods. The sensitivities, specificities, and positive and negative predictive values for the culture and DFA methods were 91.9, 100, 100, and 91.7% and 91.9, 96.4, 96.6, and 91.4%, respectively. The sensitivities, specificities, and positive and negative predictive values for the three EIA procedures, Directigen, TestPack, and RSV EIA, were 75.8, 80.0, 81.0, and 74.6%; 93.6, 100, 100, and 93.2%; and 71.0, 100, 100, and 75.3%, respectively. New self-contained EIA configurations and the DFA method offer attractive alternatives to the culture method. Technical simplicity, rapid turnaround time, performance, and cost must all be considered when selecting a system for RSV detection. PMID:2191003

  20. Adaptation and survival of plants in high stress habitats via fungal endophyte conferred stress tolerance

    USGS Publications Warehouse

    Rodriguez, Rusty J.; Woodward, Claire; Redman, Regina S.

    2010-01-01

    From the Arctic to the Antarctic, plants thrive in diverse habitats that impose different levels of adaptive pressures depending on the type and degree of biotic and abiotic stresses inherent to each habitat (Stevens, 1989). At any particular location, the abundance and distribution of individual plant species vary tremendously and is theorized to be based on the ability to tolerate a wide range of edaphic conditions and habitat-specific stresses (Pianka, 1966). The ability of individual plant species to thrive in diverse habitats is commonly referred to as phenotypic plasticity and is thought to involve adaptations based on changes in the plant genome (Givnish, 2002; Pan et al., 2006; Robe and Griffiths, 2000; Schurr et al., 2006). Habitats that impose high levels of abiotic stress are typically colonized with fewer plant species compared to habitats imposing low levels of stress. Moreover, high stress habitats have decreased levels of plant abundance compared to low stress habitats even though these habitats may occur in close proximity to one another (Perelman et al., 2007). This is particularly interesting because all plants are known to perceive, transmit signals, and respond to abiotic stresses such as drought, heat, and salinity (Bartels and Sunkar, 2005; Bohnert et al., 1995). Although there has been extensive research performed to determine the genetic, molecular, and physiological bases of how plants respond to and tolerate stress, the nature of plant adaptation to high stress habitats remains unresolved (Leone et al., 2003; Maggio et al., 2003; Tuberosa et al., 2003). However, recent evidence indicates that a ubiquitous aspect of plant biology (fungal symbiosis) is involved in the adaptation and survival of at least some plants in high stress habitats (Rodriguez et al., 2008).

  1. Impact of Exposure Uncertainty on the Association between Perfluorooctanoate and Preeclampsia in the C8 Health Project Population

    PubMed Central

    Avanasi, Raghavendhran; Shin, Hyeong-Moo; Vieira, Verónica M.; Savitz, David A.; Bartell, Scott M.

    2015-01-01

    Background Uncertainty in exposure estimates from models can result in exposure measurement error and can potentially affect the validity of epidemiological studies. We recently used a suite of environmental models and an integrated exposure and pharmacokinetic model to estimate individual perfluorooctanoate (PFOA) serum concentrations and assess the association with preeclampsia from 1990 through 2006 for the C8 Health Project participants. Objectives The aims of the current study are to evaluate impact of uncertainty in estimated PFOA drinking-water concentrations on estimated serum concentrations and their reported epidemiological association with preeclampsia. Methods For each individual public water district, we used Monte Carlo simulations to vary the year-by-year PFOA drinking-water concentration by randomly sampling from lognormal distributions for random error in the yearly public water district PFOA concentrations, systematic error specific to each water district, and global systematic error in the release assessment (using the estimated concentrations from the original fate and transport model as medians and a range of 2-, 5-, and 10-fold uncertainty). Results Uncertainty in PFOA water concentrations could cause major changes in estimated serum PFOA concentrations among participants. However, there is relatively little impact on the resulting epidemiological association in our simulations. The contribution of exposure uncertainty to the total uncertainty (including regression parameter variance) ranged from 5% to 31%, and bias was negligible. Conclusions We found that correlated exposure uncertainty can substantially change estimated PFOA serum concentrations, but results in only minor impacts on the epidemiological association between PFOA and preeclampsia. Citation Avanasi R, Shin HM, Vieira VM, Savitz DA, Bartell SM. 2016. Impact of exposure uncertainty on the association between perfluorooctanoate and preeclampsia in the C8 Health Project population

  2. Full configuration interaction computer simulation study of the thermodynamic and kinetic stability of hydrated dielectrons.

    PubMed

    Larsen, Ross E; Schwartz, Benjamin J

    2006-01-19

    The hydrated electron is a unique solvent-supported state comprised of an excess electron that is confined to a cavity by the surrounding water. Theoretical studies have suggested that two-electron solvent-supported states also can be formed; in particular, simulations indicate that two excess electrons could pair up and occupy a single cavity, forming a so-called hydrated dielectron. Although hydrated dielectrons have not been observed directly by experiment, their existence has been posited to explain the lack of an ionic strength effect in hydrated electron bimolecular annihilation [Schmidt, K. H.; Bartels, D. M. Chem. Phys. 1995, 190, 145]. To determine whether dielectrons may be created in the laboratory, we use thermodynamic integration (TI), combined with mixed quantum/classical molecular dynamics simulation, to examine the thermodynamic stability of hydrated electrons and dielectrons. For the dielectron calculations, we solve the two-electron quantum problem using full configuration interaction. Our results suggest that hydrated dielectrons are thermodynamically unstable relative to separated (single) hydrated electrons, although we also show that increasing the pressure could drive the equilibrium toward the formation of dielectrons. Because the simulations suggest that hydrated dielectrons are kinetically stable, we also examine a scenario for creating metstable, nonequilibrium populations of dielectrons, which involves the capture of a newly injected electron by a preexisting, equilibrated hydrated electron. These calculations, which allow for the full nonadiabatic relaxation of the injected electron, show that hydrated electrons may indeed act as trapping sites for unequilibrated electrons, so that capture may be a viable mechanism for creating dielectrons. We suggest possible experimental procedures to create such nonequilibrium hydrated dielectrons using either pulse radiolysis or ultrafast spectroscopic techniques.

  3. The relationship between parent-child conflict and adolescent antisocial behavior: confirming shared environmental mediation.

    PubMed

    Klahr, Ashlea M; Rueter, Martha A; McGue, Matt; Iacono, William G; Burt, S Alexandra

    2011-07-01

    Prior studies have indicated that the relationship between parent-child conflict and adolescent antisocial behavior is at least partially shared environmental in origin. However, all available research on this topic (to our knowledge) relies exclusively on parent and/or adolescent informant-reports, both of which are subject to various forms of rater bias. As the presence of significant shared environmental effects has often been attributed to rater bias in the past (Baker et al. Journal of Abnormal Psychology 16:219-235, 2007; Bartels et al. Journal of the American Academy of Child and Adolescent Psychiatry 42:1351-1359, 2003, Twin Research 7:162-175, 2004; Hewitt et al. Behavior Genetics 22:293-317, 1992), it would be important to confirm that findings of shared environmental mediation persist when even examining (presumably more objective) observer-ratings of these constructs. The current study thus examined the origins of the relationship between parent-child conflict and adolescent acting-out behavior, as measured using both observer-ratings and various informant-reports. Participants included 1,199 adopted and non-adopted adolescents in 610 families from the Sibling Interaction and Behavior Study (SIBS). Results indicated that parent-child conflict consistently predicts acting-out behavior in adopted adolescents, and moreover, that this association is equivalent to that in biologically-related adolescents. Most importantly, these findings did not vary across parent- and adolescent-reported or observer-ratings of parent-child conflict and acting-out behavior. Such findings argue strongly against rater bias as a primary explanation of shared environmental mediation of the association between parent-child conflict and adolescent antisocial behavior.

  4. Modeled Perfluorooctanoic Acid (PFOA) Exposure and Liver Function in a Mid-Ohio Valley Community

    PubMed Central

    Darrow, Lyndsey A.; Groth, Alyx C.; Winquist, Andrea; Shin, Hyeong-Moo; Bartell, Scott M.; Steenland, Kyle

    2016-01-01

    diagnosed liver disease. Citation: Darrow LA, Groth AC, Winquist A, Shin HM, Bartell SM, Steenland K. 2016. Modeled perfluorooctanoic acid (PFOA) exposure and liver function in a Mid-Ohio Valley community. Environ Health Perspect 124:1227–1233; http://dx.doi.org/10.1289/ehp.1510391 PMID:26978841

  5. Transgenic Mouse Model for Reducing Oxidative Damage in Bone

    NASA Technical Reports Server (NTRS)

    Schreurs, Ann-Sofie; Torres, S.; Truong, T.; Moyer, E. L.; Kumar, A.; Tahimic, Candice C. G.; Alwood, J. S.; Limoli, C. L.; Globus, R. K.

    2016-01-01

    Bone loss can occur due to many challenges such age, radiation, microgravity, and Reactive Oxygen Species (ROS) play a critical role in bone resorption by osteoclasts (Bartell et al. 2014). We hypothesize that suppression of excess ROS in skeletal cells, both osteoblasts and osteoclasts, regulates skeletal growth and remodeling. To test our hypothesis, we used transgenic mCAT mice which overexpress the human anti-oxidant catalase gene targeted to the mitochondria, the main site for endogenous ROS production. mCAT mice have a longer life-span than wildtype controls and have been used to study various age-related disorders. To stimulate remodeling, 16 week old mCAT mice or wildtype mice were exposed to treatment (hindlimb-unloading and total body-irradiation) or sham treatment conditions (control). Tissues were harvested 2 weeks later for skeletal analysis (microcomputed tomography), biochemical analysis (gene expression and oxidative damage measurements), and ex vivo bone marrow derived cell culture (osteoblastogenesis and osteoclastogenesis). mCAT mice expressed the transgene and displayed elevated catalase activity in skeletal tissue and marrow-derived osteoblasts and osteoclasts grown ex vivo. In addition, when challenged with treatment, bone tissues from wildtype mice showed elevated levels of malondialdehyde (MDA), indicating oxidative damage) whereas mCAT mice did not. Correlation analysis revealed that increased catalase activity significantly correlated with decreased MDA levels and that increased oxidative damage correlated with decreased percent bone volume (BVTV). In addition, ex-vivo cultured osteoblast colony growth correlated with catalase activity in the osteoblasts. Thus, we showed that these transgenic mice can be used as a model to study the relationship between markers of oxidative damage and skeletal properties. mCAT mice displayed reduced BVTV and trabecular number relative to wildtype mice, as well as increased structural model index in the

  6. A Long-term Ring Current Measure Created by Using the VMO MANGO Service Package

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.; King, T. A.

    2008-12-01

    A set of computational routines called MANGO (Magnetogram Analysis for the Network of Geomagnetic Observatories) is utilized to calculate a new measure of magnetic storm activity for the years 1932 to the near present. The MANGO routines are part of an effort to enhance data services available to users of the Heliophysics VxOs, specifically for the Virtual Magnetospheric Observatory (VMO). The community can utilize MANGO to derive value-added data products and images suitable for publication via the VMO web site. MANGO routines will be demonstrated through their application to study magnetic storms, a field of research that began in 1828 when von Humboldt launched an investigation of observations taken simultaneously from magnetic field stations spread around the Earth. The defining signature of magnetic storms is a worldwide decrease of the horizontal component of the magnetic field caused by fluctuations in the strength of the ring current. In the 1940's, Bartel pushed for deriving an index to measure the strength of magnetic storms. Progress intensified during the International Geophysical Year leading to the definition of the Dst index. The definitive Dst index is calculated at WDC-C2 for Geomagnetism in Kyoto by using a derivation scheme certified by Division V of IAGA. The Dst index time series spans the years 1957 to present with a cadence equal to 1-hr. The new data set we will present is a magnetic storm measure that is similar to the Dst index though it is calculated by using MANGO and a method that differs slightly from the official scheme. The MANGO data service package is based on a set of IDL routines that decompose ground magnetic field observations to isolate secular, diurnal, and disturbance variations of the magnetic field station-by-station. Each MANGO subroutine has been written in modular fashion to allow "plug and play"- style flexibility and each has been designed to account for failure modes and noisy data so that the programs will run to

  7. In-situ characterization of wettability and pore-scale displacements during two- and three-phase flow in natural porous media

    NASA Astrophysics Data System (ADS)

    Khishvand, M.; Alizadeh, A. H.; Piri, M.

    2016-11-01

    . Pore-scale fluid occupancy maps and the Bartell-Osterhoff constraint verify the above-mentioned findings.

  8. Attitudes to biotechnology: estimating the opinions of a better-informed public.

    PubMed

    Sturgis, Patrick; Cooper, Helen; Fife-Schaw, Chris

    2005-04-01

    (Bartels, 1996; Althaus, 1998; Sturgis, 2003). Controlling for a range of socio-demographic characteristics, we provide estimates of what collective and individual opinion would look like if everyone were as knowledgeable as the currently best-informed members of the general public on the knowledge domains in question. Our findings demonstrate that scientific knowledge does appear to have an important role in determining individual and group attitudes to genetic science. However, we find no support for a simple 'deficit model' of public understanding, as the nature of the relationship itself depends on the application of biotechnology in question and the social location of the individual.

  9. A Statewide Nested Case–Control Study of Preterm Birth and Air Pollution by Source and Composition: California, 2001–2008

    PubMed Central

    Laurent, Olivier; Hu, Jianlin; Li, Lianfa; Kleeman, Michael J.; Bartell, Scott M.; Cockburn, Myles; Escobedo, Loraine; Wu, Jun

    2016-01-01

    to both primary and secondary pollutants were associated with an increase in PTB. Citation: Laurent O, Hu J, Li L, Kleeman MJ, Bartell SM, Cockburn M, Escobedo L, Wu J. 2016. A statewide nested case–control study of preterm birth and air pollution by source and composition: California, 2001–2008. Environ Health Perspect 124:1479–1486; http://dx.doi.org/10.1289/ehp.1510133 PMID:26895492

  10. Solar active region display system

    NASA Astrophysics Data System (ADS)

    Golightly, M.; Raben, V.; Weyland, M.

    2003-04-01

    The Solar Active Region Display System (SARDS) is a client-server application that automatically collects a wide range of solar data and displays it in a format easy for users to assimilate and interpret. Users can rapidly identify active regions of interest or concern from color-coded indicators that visually summarize each region's size, magnetic configuration, recent growth history, and recent flare and CME production. The active region information can be overlaid onto solar maps, multiple solar images, and solar difference images in orthographic, Mercator or cylindrical equidistant projections. Near real-time graphs display the GOES soft and hard x-ray flux, flare events, and daily F10.7 value as a function of time; color-coded indicators show current trends in soft x-ray flux, flare temperature, daily F10.7 flux, and x-ray flare occurrence. Through a separate window up to 4 real-time or static graphs can simultaneously display values of KP, AP, daily F10.7 flux, GOES soft and hard x-ray flux, GOES >10 and >100 MeV proton flux, and Thule neutron monitor count rate. Climatologic displays use color-valued cells to show F10.7 and AP values as a function of Carrington/Bartel's rotation sequences - this format allows users to detect recurrent patterns in solar and geomagnetic activity as well as variations in activity levels over multiple solar cycles. Users can customize many of the display and graph features; all displays can be printed or copied to the system's clipboard for "pasting" into other applications. The system obtains and stores space weather data and images from sources such as the NOAA Space Environment Center, NOAA National Geophysical Data Center, the joint ESA/NASA SOHO spacecraft, and the Kitt Peak National Solar Observatory, and can be extended to include other data series and image sources. Data and images retrieved from the system's database are converted to XML and transported from a central server using HTTP and SOAP protocols, allowing

  11. EDITORIAL: Ice in the environment: connections to atmospheric chemistry Ice in the environment: connections to atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    McNeill, V. Faye; Hastings, Meredith G.

    2008-12-01

    understanding of the atmospheric chemistry of ice: the role of a quasi-liquid layer (QLL) or quasi-brine layer (QBL) at the ice surface. The studies presented here advance our understanding of the complex interactions of snow and ice with important reactive components in our atmosphere. It has become clear in recent years that the polar regions do not act as an ultimate sink for many compounds—the release of halogens and reactive nitrogen oxides from ice and snow are examples of this. Two notable implications arise from these findings (i) the impact of anthropogenic pollutants in our environment may extend further than we fully appreciate with current global atmospheric chemistry models and (ii) our interpretation of chemical records in ice cores requires that we fundamentally understand and quantify air-snow and air-ice interactions. Additionally, laboratory studies are elucidating the details of heterogeneous reactions that are prevalent on ice and snow surfaces throughout the troposphere, and we are poised to make significant strides in the near future quantifying these effects on regional and global scales. We look forward to continued progress in this field in the coming years, and we will continue to work to connect those conducting modeling, field and laboratory studies. Focus on Connections between Atmospheric Chemistry and Snow and Ice Contents HONO emissions from snow surfaces Harry Beine, Agustín J Colussi, Antonio Amoroso, Giulio Esposito, Mauro Montagnoli and Michael R Hoffmann Heterogeneous ozonation kinetics of phenanthrene at the air-ice interface T F Kahan and D J Donaldson Release of gas-phase halogens from sodium halide substrates: heterogeneous oxidation of frozen solutions and desiccated salts by hydroxyl radicals S J Sjostedt and J P D Abbatt Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature J P D Abbatt, T Bartels-Rausch, M Ullerstam and T J Ye Interaction of gaseous elemental mercury with snow surfaces

  12. Polarized Sources, Targets and Polarimetry

    NASA Astrophysics Data System (ADS)

    Ciullo, Guiseppe; Contalbrigo, Marco; Lenisa, P.

    2011-01-01

    Remarks on the history of workshops on "spin tools" / E. Steffens -- Polarized proton beams in RHIC / A. Zelenski -- The COSY/Julich polarized H[symbol] and D[symbol] ion source / O. Felden -- The new source of polarized ions for the JINR accelerator complex / V. V. Fimushkin -- Resonance effects in nuclear dichroism - an inexpensive source of tensor-polarized deuterons / H. Seyfarth -- Polarized electrons and positrons at the MESA accelerator / K. Aulenbacher -- Status report of the Darmstadt polarized electron injector / Y. Poltoratska -- The Mott polarimeter at MAMI / V. Tioukine -- Proton polarimetry at the relativistic heavy ion collider / Y. Makdisi -- Polarisation and polarimetry at HERA / B. Sobloher -- Polarisation measurement at the ILC with a Compton polarimeter / C. Bartels -- Time evolution of ground motion-dependent depolarisation at linear colliders / A. Hartin -- Electron beam polarimetry at low energies and its applications / R. Barday -- Polarized solid targets: recent progress and future prospects / C. D. Keith -- HD gas distillation and analysis for HD frozen spin targets / A. D'Angelo -- Electron spin resonance study of hydrogen and alkyl free radicals trapped in solid hydrogen aimed for dynamic nuclear polarization of solid HD / T. Kumada -- Change of ultrafast nuclear-spin polarization upon photoionization by a short laser pulse / T. Nakajima -- Radiation damage and recovery in polarized [symbol]NH[symbol] ammonia targets at Jefferson lab / J. D. Maxwell.Polarized solid proton target in low magnetic field and at high temperature / T. Uesaka -- Pulse structure dependence of the proton spin polarization rate / T. Kawahara -- Proton NMR in the large COMPASS [symbol]NH[symbol] target / J. Koivuniemi -- DNP with TEMPO and trityl radicals in deuterated polystyrene / L. Wang -- The CLIC electron and positron polarized sources / L. Rinolfi -- Status of high intensity polarized electron gun at MIT-Bates / E. Tsentalovich -- Target section for spin

  13. Preface

    NASA Astrophysics Data System (ADS)

    Gurvits, L. I.; Frey, S.; Rawlings, S.

    than 30 contributed papers from that symposium have been published recently in Baltic Astronomy (2005, Vol. 14, No. 3). This book contains a set of invited review presentations given at the symposium. They cover a range of scientific topics in extragalactic and galactic radio astronomy studies as well as recent developments in radio astronomy techniques aimed at the next generation radio astronomy facilities. On behalf of the organisers and participants of the symposium, we express our gratitude to the sponsors of the event and this publication: the European Astronomical Society, Hungarian Academy of Sciences, Eötvös Loránd University, Konkoly Observatory, Eötvös Loránd Physical Society, Netherlands Foundation for Research in Astronomy (ASTRON), Joint Institute for VLBI in Europe, Hungarian Scientific Research Fund, EC FP5 Infrastructure Cooperation Network RadioNET and EC FP6 Integrated Infrastructure Initiative RadioNet. We are grateful to the members of the Scientific Organising Committee of the Symposium. Ken Kellermann made very useful remarks on several papers. Ellen Bouton and Pat Smiley helped to include in this book several photos from the AUI-NRAO archive. Mark Bentum designed the cover picture of the book, visual components for which were kindly supplied by W.A. Baan, M.F. Bietenholz, R. Boomsma, R. Braun, N. Bartel, M.A. Garrett, J.M. van der Hulst, H.R. Klockner, NASA/WMAP Science Team, T.A. Oosterloo, M.P. Rupen, R. Sancisi, B. Stappers, R.G. Strom, D.A. Thilker, and R.A.M. Walterbos. Most of all, we are grateful to all the authors of this book for their efforts in the increasingly old-fashioned art of writing papers for a real “paper” publication as opposed to putting powerpoint files on a web site. We do hope that their nice work will be appreciated by the readers. Leonid Gurvits, Dwingeloo, The Netherlands Sándor Frey, Budapest, Hungary Steve Rawlings, Oxford, UK

  14. Possible relationship between changes in IMF, M7+ earthquakes and VEI index, during the transition between the solar minimum cycle 23 and the rise of solar cycle 24

    NASA Astrophysics Data System (ADS)

    Casati, Michele; Straser, Valentino

    2013-04-01

    Numerous scientific papers seem to suggest a possible influence of solar activity on geological dynamics (hypothesis triggers earthquakes or volcanic activity) on Earth. In the following study, all earthquakes around the globe with a magnitude greater than or equal to 7, from January 2010 to November 2012, were taken into account which corresponds to the appearance of the first sunspot of Solar Cycle SC24. The data was then compared with the graph that shows the variations of the interplanetary magnetic field (IMF). This second track is the result of a moving average equal to 27 (solar rotation of Bartel) starting from the daily values of the field, detected by the magnetometer on board the probe Advanced Composition Explorer (ACE). The analysis reveals a first major change in February 2010, when the IMF changes from 4.5 nT to about 5.8 nT . A second identical significant change is found in February 2011, when the IMF, went from 4.5 nT to about 5.8 nT. In March 2012, we have, the other way around, a third important change in the IMF, with later's dynamics registering a variation from 5.6 nT to about 6.8 nT. We find that the three most important seismic events of the last three years (M8.8 in Chile 27/02/2010; M9 in Japan on 11/03/2011, and M8.6 on 11/04/2012 in Sumatra) occurred at the same time or slightly after the peaks (Bmax) of increase in the magnetic field of the heliosphere "facing the Earth" were reached. The analysis also suggests further connections between earthquakes with M> 7 and when the peak (maximum value the IMF) were reached, recorded in other changes in the field in these three years. Like, for example, the earthquake of M7.5 in India of 12/06/2010, when the IMF increased from 4.5 nT to 5.2 nT, or the earthquake in Sumatra 25/10/2010, when the IMF went from 4.4 nT to 5.1 nT. The variation of the IMF, recorded in May 2011, from 4.7 nT to 5.9 nT, relates, for example, not only with the M7.6 earthquake in Kermadec (07/06/2011), but also with

  15. Integration of EEG source imaging and fMRI during continuous viewing of natural movies.

    PubMed

    Whittingstall, Kevin; Bartels, Andreas; Singh, Vanessa; Kwon, Soyoung; Logothetis, Nikos K

    2010-10-01

    estimate of the current density at every time point. We then carried out a correlation between the time series of visual contrast changes in the movie with that of EEG voxels. We found the most significant correlations in visual area V1, just as seen in previous fMRI studies (Bartels A, Zeki, S, Logothetis NK. Natural vision reveals regional specialization to local motion and to contrast-invariant, global flow in the human brain. Cereb Cortex 2008;18(3):705-717), but on the time scale of milliseconds rather than of seconds. To obtain an estimate of how the EEG signal relates to the BOLD signal, we calculated the IRF between the BOLD signal and the estimated current density in area V1. We found that this IRF was very similar to that observed using combined intracortical recordings and fMRI experiments in nonhuman primates. Taken together, these findings open a new approach to noninvasive mapping of the brain. It allows, firstly, the localization of feature-selective brain areas during natural viewing conditions with the temporal resolution of EEG. Secondly, it provides a tool to assess EEG/BOLD transfer functions during processing of more natural stimuli. This is especially useful in combined EEG/fMRI experiments, where one can now potentially study neural-hemodynamic relationships across the whole brain volume in a noninvasive manner.

  16. Physical Meaning of the Equinoctial Effect for Seasonal Variation of Geomagnetic Activity

    NASA Astrophysics Data System (ADS)

    Yoshida, A.

    2008-12-01

    The general tendency for magnetic disturbances to be more stormy at equinoxes than at solstices has been recognised for more than 150 years. To explain the seasonal variation three principal hypotheses have been proposed; the axial hypothesis (Cortie, 1912), the equinoctial hypothesis (Bartels, 1932; McIntosh, 1959), and the Russell and McPherron (RM) hypothesis (Russell and McPherron, 1973). The RM hypothesis, which is based on the recognition that the magnetic field in the solar equatorial plane tends to have the largest southward component in geocentric solar magnetospheric (GSM) coordinates in early April and October, has been largely accepted for many years. However, recent studies have confirmed that the RM effect accounts for only a subordinate proportion of the seasonal variation of geomagnetic activity, and that the larger part of the phenomenon is attributable to the equinoctial effect in which the angle between the solar wind flow and the dipole axis of the Earth plays an essential role (Cliver, Kamide and Ling, 2000; Cliver, Kamide, Ling and Yokoyama, 2001; O'Brien and McPherron, 2002). In this paper physical meaning of the equinoctial effect is investigated based on the data of three-hourly am index and solar wind parameters acquired by the ACE satellite. The am indices are well correlated with BsVxVx, where Bs is the southward component of the interplanetary magnetic field (IMF) and Vx is the solar wind velocity in the sun-earth direction. It is found, however, that the am - BsVxVx relation depends on the range of VxVx: The am in higher ranges of VxVx tends to be larger than am in lower ranges of VxVx for both equinoctial and solstitial epochs for the same value of BsVxVx. Using the data sets of the same VxVx range, it is shown that distribution of points in the am - BsVxVx diagram at the solstitial epochs overlaps with that at the equinoctial epochs and the average am values in each BsVxVx bin in solstitial epochs are almost equal to those in

  17. EDITORIAL: From reciprocal space to real space in surface science From reciprocal space to real space in surface science

    NASA Astrophysics Data System (ADS)

    Bartels, Ludwig; Ernst, Karl-Heinz

    2012-09-01

    Triest.let's finish—aus basta Some move atoms around to hear how they sound.Karl-Heinz Rieder, Erice, 6 April 1998 From reciprocal space to real space in surface science contents From reciprocal space to real space in surface scienceLudwig Bartels and Karl-Heinz Ernst Karl-Heinz Reider: the quiet pioneerGiorgio Benedek Scattering of CO and N2 molecules by a graphite surfaceJunepyo Oh, Takahiro Kondo, Keitaro Arakawa, Yoshihiko Saito, Junji Nakamura, W W Hayes and J R Manson Helium, neon and argon diffraction from Ru(0001)M Minniti, C Díaz, J L Fernández Cuñado, A Politano, D Maccariello, F Martín, D Farías and R Miranda Enhanced charge transfer in a monolayer of the organic charge transfer complex TTF-TNAP on Au(111)T R Umbach, I Fernandez-Torrente, J N Ladenthin, J I Pascual and K J Franke Extended pattern recognition scheme for self-learning kinetic Monte Carlo simulationsSyed Islamuddin Shah, Giridhar Nandipati, Abdelkader Kara and Talat S Rahman Acetylene on Cu(111): imaging a molecular surface arrangement with a constantly rearranging tipYeming Zhu, Jonathan Wyrick, Kamelia D Cohen, Katie Marie Magnone, Connor Holzke, Daniel Salib, Quan Ma, Dezheng Sun and Ludwig Bartels Coulomb attraction during the carpet growth mode of NaClFriederike Matthaei, Sarah Heidorn, Konrad Boom, Cord Bertram, Ali Safiei, Jörg Henzl and Karina Morgenstern Molecular self-assembly on an insulating surface: interplay between substrate templating and intermolecular interactionsMarkus Kittelmann, Philipp Rahe and Angelika Kühnle Vertical manipulation of native adatoms on the InAs(111)A surfaceJ Yang, C Nacci, J Martínez-Blanco, K Kanisawa and S Fölsch Charge transfer between isomer domains on n+-doped Si(111)-2 × 1: energetic stabilizationR M Feenstra, G Bussetti, B Bonanni, A Violante, C Goletti, P Chiaradia, M G Betti and C Mariani Probing the properties of metal-oxide interfaces: silica films on Mo and Ru supportsLeonid Lichtenstein, Markus Heyde, Stefan Ulrich, Niklas Nilius

  18. Supernova 1987A in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Kafatos, Minas; Michalitsianos, Andrew G.

    2006-11-01

    Foreword; Acknowledgements; Workshop participants; 1. Images and spectrograms of Sanduleak - 69º202, the SN 1987a progenitor N. R. Walborn; 2. The progenitor of SN 1987A G. Sonneborn; 3. Another supernova with a blue progenitor C. M. Gaskell and W. C. Keel; 4. Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory M. M. Phillips; 5. SN 1987A: observational results obtained at ESO I. J. Danziger, P. Bouchet, R. A. E. Fosbury, C. Gouiffes, L. B. Lucy, A. F. M. Moorwood, E. Oliva and F. Rufener; 6. Observations of SN 1987A at the South African Astronomical Observatory (SAAO) M. W. Feast; 7. Observations of SN 1987A at the Anglo-Australian Telescope W. J. Couch; 8. Linear polarimetric study of SN 1987A A. Clocchiatti, M. Méndez, O. Benvenuto, C. Feinstein, H. Marraco, B. García and N. Morrell; 9. Infrared spectroscopy of SN 1987A from the NASA Kuiper Airborne Observatory H. P. Larson, S. Drapatz, M. J. Mumma and H. A. Weaver; 10. Radio observations of SN 1987A N. Bartel et al.; 11. Ultraviolet observations of SN 1987A: clues to mass loss R. P. Kirshner; 12. On the energetics of SN 1987A N. Panagia; 13. On the nature and apparent uniqueness of SN 1987A A. V. Filippenko; 14. A comparison of the SN 1987A light curve with other type II supernovae, and the detectability of similar supernovae M. F. Schmitz and C. M. Gaskell; 15. P-Cygni features and photospheric velocities L. Bildsten and J. C. L. Wang; 16. The Neutrino burst from SN 1987A detected in the Mont Blanc LSD experiment M. Aglietta et al.; 17. Toward observational neutrino astrophysics M. Koshiba; 18. The discovery of neutrinos from SN 1987A with the IMB detector J. Matthews; 19. Peering into the abyss: the neutrinos from SN 1987A A. Burrows; 20. Phenomenological analysis of neutrino emission from SN 1987A J. N. Bahcall, D. N. Spergel and W. H. Press; 21. Mass determination of neutrinos H. Y. Chiu; 22. Neutrino transport in a type II supernova D. C. Ellison, P. M. Giovanoni

  19. Powerful Nearby Supernova Caught By Web

    NASA Astrophysics Data System (ADS)

    2008-09-01

    previously thought, but it also teaches us more about the tremendous upheavals that massive stars can undergo during their lifetime," said co-author Vikram Dwarkadas of the University of Chicago. SN 1996cr, at a distance of about 12 million light years, will be a compelling target for future work because it is nearby and so much brighter than a typical supernova. These results will appear in an upcoming issue of The Astrophysical Journal. Other co-authors on this paper include Niel Brandt (Penn State), Stefan Immler (NASA Goddard Space Flight Center), Norbert Bartel (York University, Canada), and Michael Bietenholz (York University and Hartebeesthoek Radio Observatory, South Africa). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

  20. NARRATIVE: A short history of my life in science A short history of my life in science

    NASA Astrophysics Data System (ADS)

    Manson, Joseph R.

    2010-08-01

    bicycle rides taken with these colleagues and many others through the streets of Göttingen and the surrounding countryside of Niedersachsen. The long series of visits to Göttingen were interrupted by three summers beginning in 1988 at the Institut für Grenzflachenforschung and Vakuumphysik at the Forschungszentrum Jülich in Germany working with George Comsa and his group. I had met Comsa in the late 1970s at a scientific meeting in France and we had continued our scientific correspondence ever since, which eventually led to the invitation to visit his lab for an extended stay. Among the very large range of surface-related experiments being carried out in the Comsa group were machines, operated by Bene Poelsema and Rudolf David and the then graduate students Klaus Kern and Peter Zeppenfeld, devoted to He atom scattering from metal and adsorbate-covered surfaces. Once again, it was a great privilege to carry out scientific research in such a stimulating environment. In 1998, with a three-month summer visit, I began a collaboration with Professor Karl-Heinz Rieder at the Institut für Experimentalphysik of the Freie Universität Berlin in Germany. Rieder was a pioneer in the field of surface scattering experiments using helium and other rare gas atomic beams as projectiles and after he moved to the Freie Universität from the IBM Zürich laboratories he continued this work as well as becoming a world leader in the field of single molecule manipulation on surfaces using scanning tunneling microscopy (STM). This collaboration resulted in visits to Berlin every summer through 2006 during which we collaborated on several projects involving both atom-surface scattering and STM. The work during this period included interesting collaborative work with many members of the Rieder group including Ludwig Bartels, Daniel Farías, Gerhard Meyer and Saw Hla. It was a great experience to be able to pursue science in such favorable surroundings, and to have, in addition, all the