Science.gov

Sample records for early diffractive physics

  1. QCD subgroup on diffractive and forward physics

    SciTech Connect

    Albrow, M.G.; Baker, W.; Bhatti, A.

    1996-10-01

    The goal is to understand the pomeron, and hence the behavior of total cross sections, elastic scattering and diffractive excitation, in terms of the underlying theory, QCD. A description of the basic ideas and phenomenology is followed by a discussion of hadron-hadron and electron-proton experiments. An appendix lists recommended diffractive-physics terms and definitions. 44 refs., 6 figs.

  2. QCD subgroup on diffractive and forward physics

    SciTech Connect

    Albrow, M.G.; Baker, W.; Bhatti, A.

    1997-09-01

    Over the last few years, there has been a resurgence of interest in small-x or diffractive physics. This has been due to the realization that perturbative QCD techniques may be applicable to what was previously thought of as a non-perturbative problem and to the opening up of new energy regimes at HERA and the Tevatron collider. The goal is to understand the pomeron, and hence the behavior of total cross sections, elastic scattering and diffractive excitation, in terms of the underlying theory, QCD. This paper is divided into experiments of hadron-hadron colliders and electron-proton colliders.

  3. Early physics results.

    PubMed

    Jenni, Peter

    2012-02-28

    For the past year, experiments at the Large Hadron Collider (LHC) have started exploring physics at the high-energy frontier. Thanks to the superb turn-on of the LHC, a rich harvest of initial physics results have already been obtained by the two general-purpose experiments A Toroidal LHC Apparatus (ATLAS) and the Compact Muon Solenoid (CMS), which are the subject of this report. The initial data have allowed a test, at the highest collision energies ever reached in a laboratory, of the Standard Model (SM) of elementary particles, and to make early searches Beyond the Standard Model (BSM). Significant results have already been obtained in the search for the Higgs boson, which would establish the postulated electro-weak symmetry breaking mechanism in the SM, as well as for BSM physics such as Supersymmetry (SUSY), heavy new particles, quark compositeness and others. The important, and successful, SM physics measurements are giving confidence that the experiments are in good shape for their journey into the uncharted territory of new physics anticipated at the LHC. PMID:22253245

  4. Diffraction Physics with ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Evdokimov, Sergey

    2015-06-01

    The ALICE experiment is equipped with a wide range of detectors providing excellent tracking and particle identification in the central region, as well as forward detectors with extended pseudorapidity coverage, which are well suited for studying diffractive processes. Cross section measurements of single and double diffractive processes performed by ALICE in pp collisions at √ {s} = 0.9, ; 2.76, ; 7 ; {textrm{TeV}} will be reported. Currently, ALICE is studying double-gap events in pp collisions at √ {s} = 7 ; {textrm{TeV}}, which give an insight into the central diffraction processes: current status and future perspectives will be discussed. The upgrade plans for diffraction studies, further extending the pseudorapidity acceptance of the ALICE setup for the forthcoming Run 2 of the LHC, will be outlined.

  5. Status of diffractive physics at D0 Run II

    SciTech Connect

    Strang, M.; /Texas U., Arlington

    2005-01-01

    The Forward Proton Detector (FPD) is a new sub-system of the D0 detector implemented for Run II at the Fermilab Tevatron which gives access to a wide range of diffractive scattering physics processes. This new detector is described and preliminary results from the diffractive program are presented.

  6. Diffraction and Forward Physics in ATLAS: results and perspectives

    NASA Astrophysics Data System (ADS)

    Bruschi, M.

    2015-03-01

    The present and future potential of ATLAS for diffraction and forward physics is presented. As recent results the rapidity gap cross section and elastic and total pp cross sections are reported. The upgrade project AFP is presented and it is shown how it will complement the ALFA acceptance for diffractive physics in measurements taken with β*=90 m LHC beam optics. Moreover, the AFP detector will guarantee good acceptance on diffractive events also during normal running conditions allowing to improve the ATLAS detector performances. If in addition, a high luminosity program will be feasible, AFP might be fundamental for potential discoveries with extra dimensions being one example.

  7. Physical Education in Early Childhood

    ERIC Educational Resources Information Center

    Stork, Steve; Sanders, Stephen W.

    2008-01-01

    This article examines the incidence and quality of physical activity instruction during early childhood. Although the positive effect of physical activity on the cognitive, social, and physical development of young children is generally acknowledged, there is little emphasis nationally on ensuring appropriate physical educational experiences…

  8. Physics issues in diffraction limited storage ring design

    NASA Astrophysics Data System (ADS)

    Fan, Wei; Bai, ZhengHe; Gao, WeiWei; Feng, GuangYao; Li, WeiMin; Wang, Lin; He, DuoHui

    2012-05-01

    Diffraction limited electron storage ring is considered a promising candidate for future light sources, whose main characteristics are higher brilliance, better transverse coherence and better stability. The challenge of diffraction limited storage ring design is how to achieve the ultra low beam emittance with acceptable nonlinear performance. Effective linear and nonlinear parameter optimization methods based on Artificial Intelligence were developed for the storage ring physical design. As an example of application, partial physical design of HALS (Hefei Advanced Light Source), which is a diffraction limited VUV and soft X-ray light source, was introduced. Severe emittance growth due to the Intra Beam Scattering effect, which is the main obstacle to achieve ultra low emittance, was estimated quantitatively and possible cures were discussed. It is inspiring that better performance of diffraction limited storage ring can be achieved in principle with careful parameter optimization.

  9. Recent forward physics and diffraction results from CMS

    NASA Astrophysics Data System (ADS)

    Veres, Gábor

    2016-07-01

    Recent CMS results on forward physics and diffraction are reviewed. The differential diffractive cross section is measured as a function of ξ = M2X/S in the region dominated by single dissociation (SD) and double dissociation (DD), where MX is the mass of one of the two final-state hadronic systems separated by the largest rapidity gap in the event. The total SD and DD cross sections are extracted. The observation of a hard color-singlet exchange process in events with a large rapidity gap between two leading jets (jet-gap-jet) is reported. The fraction of jet-gap-jet to all dijet events is measured as a function of the second leading jet transverse momentum and the size of the pseudorapidity gap. The measured fractions are compared with predictions as well as Tevatron data.

  10. Physical Science in Constructivist Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Kato, Tsuguhiko; Van Meeteren, Beth Dykstra

    2008-01-01

    Teachers at the Freeburg Early Childhood Program know that experimentation with physical science is of great interest to young children, and can begin as early as the age of 3. The constructivist teachers at this experimental school at the University of Northern Iowa worked for six years to develop a center-based approach to physical science with…

  11. Quantum Optics, Diffraction Theory, and Elementary Particle Physics

    ScienceCinema

    None

    2016-07-12

    Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

  12. Physical Fitness and the Early Childhood Curriculum

    ERIC Educational Resources Information Center

    Pica, Rae

    2006-01-01

    The state of children's fitness is the responsibility of all who are involved with children. As early childhood professionals, they have a duty to educate the whole (thinking, feeling, "moving") child. Moreover, teachers of preschoolers can be more realistic than parents in their assessment of children's physical inactivity levels, and preschool…

  13. Diffractive Physics with ALICE at the LHC: the control of quantum collisions

    NASA Astrophysics Data System (ADS)

    Herrera Corral, G.

    2015-06-01

    We report on the status of the construction and installation of a new detector in the forward region of the ALICE experiment at the LHC. This detector will allow the study of processes with gaps at larger rapidity than those presently covered. A setup of two stations called AD (stands for ALICE Diffractive) on the right and on the left of the interaction point enhances significantly the efficiency to study diffractive physics and photon induced processes.

  14. Particle physics in the very early universe

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1981-01-01

    Events in the very early big bang universe in which elementary particle physics effects may have been dominant are discussed, with attention to the generation of a net baryon number by way of grand unification theory, and emphasis on the possible role of massive neutrinos in increasing current understanding of various cosmological properties and of the constraints placed on neutrino properties by cosmology. It is noted that when grand unification theories are used to describe very early universe interactions, an initially baryon-symmetrical universe can evolve a net baryon excess of 10 to the -9th to 10 to the -11th per photon, given reasonable parameters. If neutrinos have mass, the bulk of the mass of the universe may be in the form of leptons, implying that the form of matter most familiar to physical science may not be the dominant form of matter in the universe.

  15. Early Spacelab physics and astronomy missions

    NASA Technical Reports Server (NTRS)

    Chapman, R. D.

    1976-01-01

    Some of the scientific problems which will be investigated during the early Spacelab physics and astronomy missions are reviewed. The Solar Terrestrial Programs will include the Solar Physics Spacelab Payloads (SPSP) and the Atmospheres, Magnetospheres and Plasmas in Space (AMPS) missions. These missions will study the sun as a star and the influence of solar phenomena on the earth, including sun-solar wind interface, the nature of the solar flares, etc. The Astrophysics Spacelab Payloads (ASP) programs are divided into the Ultraviolet-Optical Astronomy and the High Energy Astrophysics areas. The themes of astrophysics Spacelab investigations will cover the nature of the universe, the fate of matter and the life cycles of stars. The paper discusses various scientific experiments and instruments to be used in the early Spacelab missions.

  16. The early development of neutron diffraction: science in the wings of the Manhattan Project

    SciTech Connect

    Mason, T. E. Gawne, T. J.; Nagler, S. E.; Nestor, M. B.; Carpenter, J. M.

    2013-01-01

    Early neutron diffraction experiments performed in 1944 using the first nuclear reactors are described. Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan’s group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool.

  17. Uniform diffracted fields from a perfectly conducting cylindrical reflector with modified theory of physical optics.

    PubMed

    Yalçın, Uğur; Sarnık, Mücahit

    2013-01-01

    The uniform diffracted fields are calculated on PEC cylindrical reflector by Modified Theory of Physical Optics (MTPO). It is aimed to convert the noncontinuous solution to a continuous solution by finding a uniform equation which does not contain any expression converging to 0 in the denominator part. Three axioms of MTPO theory are used to construct the integral equations for the perfectly electrically conducting surface application. The "edge-point" technique is used to find the diffracted field, and uniform solution is to be found via "detour parameter(s)." Finally, the obtained results are to be compared with the nonuniform ones, numerically. PMID:23766679

  18. Diffraction and forward physics results of the ATLAS experiment from the Run I

    SciTech Connect

    Taševský, Marek

    2015-04-10

    Various aspects of forward physics have been studied by the ATLAS collaboration using data from Run I at the LHC. In this text, main results of four published analyses are summarized, all based on data from proton-proton collisions at √(s)=7 TeV collected in 2010 or 2011. Two analyses deal with the diffractive signature, one based on single-sided events, the other on large rapidity gaps in soft events. In addition, a recent measurement of the total pp cross section using the ALFA subdetector and a recent study of higher-order QCD effects using a jet veto are discussed.

  19. A study of swing-curve physics in diffraction-based overlay

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Kaustuve; den Boef, Arie; Storms, Greet; van Heijst, Joost; Noot, Marc; An, Kevin; Park, Noh-Kyoung; Jeon, Se-Ra; Oh, Nang-Lyeom; McNamara, Elliott; van de Mast, Frank; Oh, SeungHwa; Lee, Seung Yoon; Hwang, Chan; Lee, Kuntack

    2016-03-01

    With the increase of process complexity in advanced nodes, the requirements of process robustness in overlay metrology continues to tighten. Especially with the introduction of newer materials in the film-stack along with typical stack variations (thickness, optical properties, profile asymmetry etc.), the signal formation physics in diffraction-based overlay (DBO) becomes an important aspect to apply in overlay metrology target and recipe selection. In order to address the signal formation physics, an effort is made towards studying the swing-curve phenomena through wavelength and polarizations on production stacks using simulations as well as experimental technique using DBO. The results provide a wealth of information on target and recipe selection for robustness. Details from simulation and measurements will be reported in this technical publication.

  20. Setting the Stage for Lifetime Physical Activity in Early Childhood

    ERIC Educational Resources Information Center

    Schneider, Holly; Lounsbery, Monica

    2008-01-01

    The purpose of this article is to provide a rationale and suggestions for emphasizing health-related physical education in preschool settings. In order to accomplish this, it will examine what is currently known about early childhood physical activity, as well as the existing professional preparation and accreditation standards for early childhood…

  1. Promoting Physical Activity during Early Childhood

    ERIC Educational Resources Information Center

    Vidoni, Carla; Ignico, Arlene

    2011-01-01

    The prevalence of obesity in children and adolescents from low-income families in the USA has become a significant concern over the last 20 years. One of the major contributors to this problem is the lack of physical activity. The purpose of this paper is to describe initiatives designed to: (1) engage young children in physical activity during…

  2. In-situ early-age hydration study of sulfobelite cements by synchrotron powder diffraction

    SciTech Connect

    Álvarez-Pinazo, G.; Cuesta, A.; García-Maté, M.; Santacruz, I.; Losilla, E.R.; Fauth, F.; Aranda, M.A.G.; De la Torre, A.G.

    2014-02-15

    Eco-friendly belite calcium sulfoaluminate (BCSA) cement hydration behavior is not yet well understood. Here, we report an in-situ synchrotron X-ray powder diffraction study for the first hours of hydration of BCSA cements. Rietveld quantitative phase analysis has been used to establish the degree of reaction (α). The hydration of a mixture of ye'elimite and gypsum revealed that ettringite formation (α ∼ 70% at 50 h) is limited by ye'elimite dissolution. Two laboratory-prepared BCSA cements were also studied: non-active-BCSA and active-BCSA cements, with β- and α′{sub H}-belite as main phases, respectively. Ye'elimite, in the non-active-BCSA system, dissolves at higher pace (α ∼ 25% at 1 h) than in the active-BCSA one (α ∼ 10% at 1 h), with differences in the crystallization of ettringite (α ∼ 30% and α ∼ 5%, respectively). This behavior has strongly affected subsequent belite and ferrite reactivities, yielding stratlingite and other layered phases in non-active-BCSA. The dissolution and crystallization processes are reported and discussed in detail. -- Highlights: •Belite calcium sulfoaluminate cements early hydration mechanism has been determined. •Belite hydration strongly depends on availability of aluminum hydroxide. •Orthorhombic ye’elimite dissolved at a higher pace than cubic one. •Ye’elimite larger reaction degree yields stratlingite formation by belite reaction. •Rietveld method quantified gypsum, anhydrite and bassanite dissolution rates.

  3. Early Childhood Services: Physical Resources Guide.

    ERIC Educational Resources Information Center

    Alberta Dept. of Education, Edmonton.

    Introduced by a parable on the value of children's play, this guidebook includes a list of 10 developmental functions of play, a discussion of matters for consideration in selecting and organizing equipment and facilities for early childhood programs, and a description of indoor and outdoor program resources for children's activities. Various…

  4. Physical conditions on the early Earth

    PubMed Central

    Lunine, Jonathan I

    2006-01-01

    The formation of the Earth as a planet was a large stochastic process in which the rapid assembly of asteroidal-to-Mars-sized bodies was followed by a more extended period of growth through collisions of these objects, facilitated by the gravitational perturbations associated with Jupiter. The Earth's inventory of water and organic molecules may have come from diverse sources, not more than 10% roughly from comets, the rest from asteroidal precursors to chondritic bodies and possibly objects near Earth's orbit for which no representative class of meteorites exists today in laboratory collections. The final assembly of the Earth included a catastrophic impact with a Mars-sized body, ejecting mantle and crustal material to form the Moon, and also devolatilizing part of the Earth. A magma ocean and steam atmosphere (possibly with silica vapour) existed briefly in this period, but terrestrial surface waters were below the critical point within 100 million years after Earth's formation, and liquid water existed continuously on the surface within a few hundred million years. Organic material delivered by comets and asteroids would have survived, in part, this violent early period, but frequent impacts of remaining debris probably prevented the continuous habitability of the Earth for one to several hundred million years. Planetary analogues to or records of this early time when life began include Io (heat flow), Titan (organic chemistry) and Venus (remnant early granites). PMID:17008213

  5. Early Career Experiences of Physical Education Teachers in Urban Schools

    ERIC Educational Resources Information Center

    Flory, Sara B.

    2015-01-01

    The purpose of this study was to examine the early career experiences of three physical education (PE) teachers who taught in urban charter schools. Using cultural relevance theory, three early career PE teachers were observed and interviewed for approximately six weeks each. Data were analyzed using constant comparison. Two major themes emerged…

  6. Early physics and astronomy. A historical introduction.

    NASA Astrophysics Data System (ADS)

    Pedersen, O.

    This book (first published in 1974) is an introductory exposition of the development of the physical and astronomical notions of the universe. It covers the period from Greek Antiquity to the Copernican revolution and the Renaissance, half of the text being devoted to Mediaeval Science within both the Aristotelian and the Archimedean traditions. It has a extensive bibliography classifying much of the secondary literature on the subject, and also a sixty page dictionary of all the scientists and philosophers mentioned in the text.

  7. Physical Identification of Binary System of Gliclazide-Hydrophilic Polymers Using X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Rachmawati, H.; Yatinasari, Faizatun, Syarie, S. A.

    2008-03-01

    The formation of binary system in pharmaceutical solid state is aimed to improve the physicochemical characteristics of active compound, such as its solubility. To identify the physical change of the binary system including crystallinity or particle morphology, there are many methods can be applied. In present report, we study the physical interaction of the binary system of gliclazide and hydrophilic polymers. In this binary system, gliclazide was either dispersed or mixed with polyvinyl pirrolidone (PVP K30) or polyethylene glycol (PEG 6000). The dispersion system of gliclazide in the polymeric carriers was prepared by solvation-evaporation method, using dichloromethane/methylene chloride as an organic solvent. The physical characterization of both dispersed and mixed of gliclazide was studied using X-ray diffraction at interval 6-50 °/2θ. As a comparison, the same procedure was performed for pure gliclazide. To confirm the diffractogram of this binary system, Fourier Transform Infrared (FT-IR) spectroscopy was carried out as well. Both diffarctogram and FT-IR spectra revealed that there was no new compound formed in the solid dispersion system of gliclazide:PEG 6000 and gliclazide:PVP K30. In contrast, the solubility as well as the dissolution rate of gliclazide in the presence of both hydrophilic polymers was increased as compared to pure gliclazide. We conclude therefore that solvatation followed by evaporation of gliclazide in the presence of either PEG 6000 or PVP K30 did not alter its crystalline characteristic. The improved of gliclazide solubility in the binary system might due to other mechanism such as increased in the wettability and the hydrophylicity effect of the polymers.

  8. Early Childhood Educators' Experience of an Alternative Physical Education Model

    ERIC Educational Resources Information Center

    Tsangaridou, Niki; Genethliou, Nicholas

    2016-01-01

    Alternative instructional and curricular models are regarded as more comprehensive and suitable approaches to providing quality physical education (Kulinna 2008; Lund and Tannehill 2010; McKenzie and Kahan 2008; Metzler 2011; Quay and Peters 2008). The purpose of this study was to describe the impact of the Early Steps Physical Education…

  9. The early development of neutron diffraction: science in the wings of the Manhattan Project.

    PubMed

    Mason, T E; Gawne, T J; Nagler, S E; Nestor, M B; Carpenter, J M

    2013-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan's group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool.

  10. The early development of neutron diffraction: Science in the wings of the Manhattan Project

    SciTech Connect

    Mason, Thom; Gawne, Timothy J; Nagler, Stephen E; Nestor, Margaret Boone {Bonnie}; Carpenter, John M

    2012-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurements of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst, and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor.

  11. The early development of neutron diffraction: science in the wings of the Manhattan Project

    PubMed Central

    Mason, T. E.; Gawne, T. J.; Nagler, S. E.; Nestor, M. B.; Carpenter, J. M.

    2013-01-01

    Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly focused on the development of the atomic bomb, groups working at Oak Ridge and Chicago carried out key measurements and recognized the future utility of neutron diffraction quite independent of its contributions to the measurement of nuclear cross sections. Ernest O. Wollan, Lyle B. Borst and Walter H. Zinn were all able to observe neutron diffraction in 1944 using the X-10 graphite reactor and the CP-3 heavy water reactor. Subsequent work by Wollan and Clifford G. Shull, who joined Wollan’s group at Oak Ridge in 1946, laid the foundations for widespread application of neutron diffraction as an important research tool. PMID:23250059

  12. Early Childhood Selected Bibliographies Series. Number 1, Physical.

    ERIC Educational Resources Information Center

    ERIC Clearinghouse on Early Childhood Education, Champaign, IL.

    This is the first in a series of six annotated bibliographies. It has as its general subject the physical aspects of early childhood education and includes three subdivisions: genetics, sensory-motor processes, and growth. Each of the 15 abstracts included has been classified by general and specific subject, by focus of study, and alphabetically…

  13. Service Delivery Complexities: Early Intervention for Children with Physical Disabilities

    ERIC Educational Resources Information Center

    Ziviani, Jenny; Darlington, Yvonne; Feeney, Rachel; Rodger, Sylvia; Watter, Pauline

    2013-01-01

    Early intervention (EI) for children with physical disabilities is advocated as a means of enhancing child outcomes and family functioning. The issues confronted by service providers in delivering this support have received relatively little attention. The purpose of this study was to gain an understanding of the experiences of frontline EI staff…

  14. Sports, Physical Activity and Recreation in Early American History.

    ERIC Educational Resources Information Center

    Ballou, Ralph B.

    Sports and physical recreation activities have been part of American life since the days of the early settlers. Although the settlers were faced with problems of survival, accounts of life in the colonies in the 1600's carry mention of bowling in the streets, play with bows and arrows, and ice skating. Other activities to gain popularity before…

  15. Trajectories of Physical Discipline: Early Childhood Antecedents and Developmental Outcomes

    PubMed Central

    Lansford, Jennifer E.; Criss, Michael M.; Dodge, Kenneth A.; Shaw, Daniel S.; Pettit, Gregory S.; Bates, John E.

    2009-01-01

    This study examined childhood antecedents and developmental outcomes associated with trajectories of mild and harsh parental physical discipline. Interview, questionnaire, and observational data were available from 499 children followed from age 5 to 16 and from 258 children in an independent sample followed from age 5 to 15. Analyses indicated distinct physical discipline trajectory groups that varied in frequency of physical discipline and rate of change. In both samples, family ecological disadvantage differentiated the trajectory groups; in the first sample, early child externalizing also differentiated the groups. Controlling for early childhood externalizing, the minimal/ceasing trajectory groups were associated with the lowest levels of subsequent adolescent antisocial behavior in both samples and with parent-adolescent positive relationship quality in the second sample. PMID:19765007

  16. Extra early physical contact and aspects of the early mother-infant relationship.

    PubMed

    Taylor, P M; Taylor, F H; Campbell, S B; Maloni, J A; Cannon, M

    1985-01-01

    We tested the hypothesis that extra early physical contact between mother and infant enhances aspects of their early relationship. Healthy, middle-class mothers and their healthy, firstborn, singleton infants delivered vaginally at full-term were randomly assigned to receive either regular contact (RC; N = 39) or extra early physical contact (EC; N = 39) following delivery. RC infants remained in cribs beside their mothers' beds, while EC infants and mothers had a mean of 46 min of physical contact in the recovery room. There was no difference between EC and RC subjects for the following outcome measures: amount of time mothers chose to have infants with them during the postpartum hospital stay; quality of mother-infant interaction at two days and one month; concern mothers expressed for the infant at one month; mothers' perception of their postpartum adjustment; mothers' perception of the infant at two days and one month, and of the infant's temperament at eight months; and extent of mothers' assisting with and soothing the child during a physical examination at 13 months. EC children cried significantly less during the examination at 13 months. These findings do not support the hypothesis that extra early physical contact between mother and infant enhances their relationship.

  17. Early resident-to-resident physics education in diagnostic radiology.

    PubMed

    Kansagra, Akash P

    2014-01-01

    The revised ABR board certification process has updated the method by which diagnostic radiology residents are evaluated for competency in clinical radiologic physics. In this work, the author reports the successful design and implementation of a resident-taught physics course consisting of 5 weekly, hour-long lectures intended for incoming first-year radiology residents in their first month of training. To the author's knowledge, this is the first description of a course designed to provide a very early framework for ongoing physics education throughout residency without increasing the didactic burden on faculty members. Twenty-six first-year residents spanning 2 academic years took the course and reported subjective improvement in their knowledge (90%) and interest (75%) in imaging physics and a high level of satisfaction with the use of senior residents as physics educators. Based on the success of this course and the minimal resources required for implementation, this work may serve as a blueprint for other radiology residency programs seeking to develop revised physics curricula.

  18. Diffraction pattern intensity measurements in the introductory college physics laboratory using microcomputers

    NASA Astrophysics Data System (ADS)

    Soundranayagam, R.; Ramayya, A. V.; Cleeman, L.; Riecken, Mark; Fuson, Nelson; Springer, John

    1983-10-01

    Measurement of the intensity variations in a single slit diffraction pattern formed by a laser beam is made by means of a photoresistor detector interfaced with an Apple II-plus microcomputer through the paddle (game controller) connection. The computer programs, written in BASIC and assembly language, enable the student to (1) determine quantitatively the intensity of the maxima and minima; (2) see the intensity pattern as the data is acquired; (3) obtain a hard copy of the intensity plot observed on the screen monitor; and (4) compare the experimental and theoretical intensity patterns.

  19. Tracking of physical activity and fitness during the early years.

    PubMed

    Caldwell, Hilary A T; Proudfoot, Nicole A; King-Dowling, Sara; Di Cristofaro, Natascja A; Cairney, John; Timmons, Brian W

    2016-05-01

    The early years are characterized by rapid physical growth and the development of behaviours such as physical activity. The objectives of this study were to assess the 12-month changes in and the tracking of physical activity and fitness in 400 preschoolers (201 boys, 4.5 ± 0.9 years of age). Physical activity data, expressed as minutes per day and as the percentage of time spent at various intensities while wearing an accelerometer, were collected in 3-s epochs for 7 days. Short-term muscle power, assessed with a 10-s modified Wingate Anaerobic Test, was expressed as absolute (W) and relative (W/kg) peak power (PP) and mean power (MP). Aerobic fitness, assessed with the Bruce Protocol progressive treadmill test, was expressed as maximal treadmill time and heart rate recovery (HRR). Light physical activity decreased by 3.2 min/day (p < 0.05), whereas vigorous physical activity increased by 3.7 min/day (p < 0.001), from year 1 to year 2. Physical activity exhibited moderate tracking on the basis of Spearman correlations (r = 0.45-0.59, p < 0.001) and fair tracking on the basis of κ statistics (κ = 0.26-0.38). PP and MP increased from year 1 (PP, 94.1 ± 37.3 W; MP, 84.1 ± 30.9 W) to year 2 (PP, 125.6 ± 36.2 W; MP, 112.3 ± 32.2 W) (p < 0.001) and tracked moderately to substantially (PP, r = 0.89, κ = 0.61; MP, r = 0.86, κ = 0.56). Time to exhaustion on the treadmill increased from 9.4 ± 2.3 min to 11.8 ± 2.3 min (p < 0.001) and tracked strongly (r = 0.82, κ = 0.56). HRR was unchanged at 65 ± 14 beats/min (p = 0.297) and tracked fairly (r = 0.52, κ = 0.23). The findings indicate that fitness tracks better than physical activity over a 12-month period during the early years. PMID:27045869

  20. Physical Mechanisms of Pattern Formation in the Early Chick Embryo

    NASA Astrophysics Data System (ADS)

    Balter, Ariel; Glazier, James; Zaitlen, Benji; Chaplain, Mark; Weijer, Cornelis

    2007-03-01

    Gastrulation marks a critical step in early embryogenesis when the first recognizable patterns are laid down. Although the genome maintains ultimate responsibility for this pattern formation, it cannot actually control the organization of individual cells. The robustness of embryogenic pattern formation suggests that a few simple, physical mechanisms are unleashed and that self-organization results. We perform numerical simulations of early chick gastrulation using an agent based method in which individual cells interact via a handful of behaviors including adhesivity, secretion and chemotaxis. Through these simulations we have identified certain behaviors as being important for various stages and morphological events. For instance, experimental results on primitive streak formation are best reproduced by a model in which the Kohler's Sickle secretes a chemo repellant for streak tip cells, and cell polarization appears to be important for initiating polonaise motion during streak elongation.

  1. X-Ray Diffraction of Intermetallic Compounds: A Physical Chemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Varberg, Thomas D.; Skakuj, Kacper

    2015-01-01

    Here we describe an experiment for the undergraduate physical chemistry laboratory in which students synthesize the intermetallic compounds AlNi and AlNi3 and study them by X-ray diffractometry. The compounds are synthesized in a simple one-step reaction occurring in the solid state. Powder X-ray diffractograms are recorded for the two compounds…

  2. BOOK REVIEW: The Physics of the Early Universe

    NASA Astrophysics Data System (ADS)

    Scott, Douglas

    2007-11-01

    The physics of the very small and the very large were successfully brought together in the 1980s through the idea of 'the universe as a particle accelerator'. The manifesto of this new campaign was laid out in the book 'The Early Universe' by Kolb and Turner in 1990. For at least the next decade that book was to be found on the shelves of every theorist (and many experimentalists) who professed an interest in this topic. But science marches on, and the last 10 15 years has seen an explosion in our understanding of the physics of the very earliest times and the very largest scales. Experimentally our world-view has changed utterly, through exquisitely precise measurements of the cosmic microwave background, galaxy clustering and supernova distances, with a refinement of the basic inflationary big bang paradigm into the new 'standard cosmological model'. And in tandem with these changes has been the development of new theoretical ideas, particularly involving dark energy and connections between string/brane theory and cosmology. So what is the new book for the shelves of today's cohort of young Rockys and Mikes? Despite a recent number of promising-sounding cosmology books, there is nothing at the advanced level which is broad enough to be a general introduction to the 'early universe' topic. Perhaps the best of the bunch is 'The Physics of the Early Universe', edited by E Papantonopoulos as part of Springer's series 'Lecture notes in physics'. This is a set of 9 review articles given as part of a 2003 summer school on Syros Island, Greece. Although far from perfect, the core of this book provides a solid introduction to current research in early universe physics, which should be useful for PhD students or postdoctoral researchers who want the real thing. The book starts with a competent introduction by Kyriakos Tamvakis, serving essentially as a summary of where we were in Kolb and Turner's text. We have learned since then, however, that inflation is really all

  3. Illinois Early Learning Project Tip Sheets: Physical Development and Health.

    ERIC Educational Resources Information Center

    2003

    The Illinois Early Learning Project (IEL) is funded by the Illinois State Board of Education to provide information resources on early learning and training related to implementing the Illinois Early Learning Standards for parents and for early childhood personnel in all settings. The IEL tip sheets offer suggestions to parents and early childhood…

  4. The early fluidic and optical physics of cytometry.

    PubMed

    Watson, J V

    1999-02-15

    All forms of cytometry, depend on the basic laws of physics, including those of fluidics, optics, and electronics, most of which were established centuries ago. Flow cytometry depends critically on the fluidics presenting each individual cell with precision to the sensing volume. This is intersected by a high-intensity light source, and light scattering and fluorescence from suitably stained constituents in each cell are captured by the light-collecting optics and measured. The works and observations of Bernoulli and Euler in the 18th century, Reynolds in the 19th century, and Crosland-Taylor in the 20th century in the field of fluid dynamics laid the foundations for hydrodynamic focussing, which is the primary prerequisite for presenting individual cells to the sensing volume. In addition, electrostatic cell sorters must have the ability to generate stable droplet formation in the jet-stream issuing from the flow chamber nozzle. The origins here can be traced to work carried out in the early to mid-19th century by Savart, Magnus, and Thomson. Flow, image, and confocal cytometry are all dependent on the laws of optics, including those of reflection and refraction as well as numerous other optical principles. The observations and works of Socrates, Ptolemy, Snel, and Descartes between about BC 370 and 1637 were of seminal importance in developing the laws of reflection and refraction. In the mid-17th century Hooke illustrated the power of magnifying glasses and microscopy in his Micrographia and Newton was responsible for explaining colours in the spectrum. Huygens, toward the end of the 17th century, put forward the concept of point source light propagation contributing to a wave front. Finally, Thomas Young, early in the 19th century, established the wave form of light from interference patterns. Most people will be familiar with some of these discoveries and the investigators who carried out the work; some people will be familiar with all of these. However, very

  5. The early fluidic and optical physics of cytometry.

    PubMed

    Watson, J V

    1999-02-15

    All forms of cytometry, depend on the basic laws of physics, including those of fluidics, optics, and electronics, most of which were established centuries ago. Flow cytometry depends critically on the fluidics presenting each individual cell with precision to the sensing volume. This is intersected by a high-intensity light source, and light scattering and fluorescence from suitably stained constituents in each cell are captured by the light-collecting optics and measured. The works and observations of Bernoulli and Euler in the 18th century, Reynolds in the 19th century, and Crosland-Taylor in the 20th century in the field of fluid dynamics laid the foundations for hydrodynamic focussing, which is the primary prerequisite for presenting individual cells to the sensing volume. In addition, electrostatic cell sorters must have the ability to generate stable droplet formation in the jet-stream issuing from the flow chamber nozzle. The origins here can be traced to work carried out in the early to mid-19th century by Savart, Magnus, and Thomson. Flow, image, and confocal cytometry are all dependent on the laws of optics, including those of reflection and refraction as well as numerous other optical principles. The observations and works of Socrates, Ptolemy, Snel, and Descartes between about BC 370 and 1637 were of seminal importance in developing the laws of reflection and refraction. In the mid-17th century Hooke illustrated the power of magnifying glasses and microscopy in his Micrographia and Newton was responsible for explaining colours in the spectrum. Huygens, toward the end of the 17th century, put forward the concept of point source light propagation contributing to a wave front. Finally, Thomas Young, early in the 19th century, established the wave form of light from interference patterns. Most people will be familiar with some of these discoveries and the investigators who carried out the work; some people will be familiar with all of these. However, very

  6. Move to Learn, Learn to Move: Prioritizing Physical Activity in Early Childhood Education Programming

    ERIC Educational Resources Information Center

    Lu, Chunlei; Montague, Brandi

    2016-01-01

    The global childhood trend towards obesity and unhealthy lifestyles is a growing concern. Childcare settings have been identified as the most influential factors for children's physical activity, and physical activity habits are better formed and maintained if started in early childhood. As a result, early childhood education environments are in…

  7. Affordances for Risk-Taking and Physical Activity in Australian Early Childhood Education Settings

    ERIC Educational Resources Information Center

    Little, Helen; Sweller, Naomi

    2015-01-01

    Motor competence and physical activity (PA) patterns are established during the early childhood years. Early childhood education (ECE) settings are an important context for children's engagement in physically active play. This paper reports the findings from an online survey examining resources, spaces and affordances for PA and risk-taking in…

  8. An Experimental Test of Parenting Practices as a Mediator of Early Childhood Physical Aggression

    ERIC Educational Resources Information Center

    Brotman, Laurie Miller; O'Neal, Colleen R.; Huang, Keng-Yen; Gouley, Kathleen Kiely; Rosenfelt, Amanda; Shrout, Patrick E.

    2009-01-01

    Background: Parenting practices predict early childhood physical aggression. Preventive interventions that alter parenting practices and aggression during early childhood provide the opportunity to test causal models of early childhood psychopathology. Although there have been several informative preventive intervention studies that test mediation…

  9. Promoting Professional Development for Physical Therapists in Early Intervention

    ERIC Educational Resources Information Center

    Catalino, Tricia; Chiarello, Lisa A.; Long, Toby; Weaver, Priscilla

    2015-01-01

    Early intervention service providers are expected to form cohesive teams to build the capacity of a family to promote their child's development. Given the differences in personnel preparation across disciplines of service providers, the Early Childhood Personnel Center is creating integrated and comprehensive professional development models for…

  10. The Early Careers of Physics Bachelors. AIP Report.

    ERIC Educational Resources Information Center

    Ivie, Rachel; Stowe, Katie

    This report focuses on graduates in physics who did not earn any degrees after their bachelor's degree and who are not primarily students. The report is based on data from a sample of physics bachelors between December 1998 and the summer of 1999. About 1,200 respondents, out of a potential 2,400, supplied the information. At 5 to 8 years after…

  11. Fibre Diffraction Analysis of Skin Offers a Very Early and Extremely Accurate Diagnostic Test for Prostate Cancer

    DOE PAGESBeta

    James, Veronica J.; O’Malley Ford, Judith M.

    2014-01-01

    Double blind analysis of a batch of thirty skin tissue samples from potential prostate cancer sufferers correctly identified all “control” patients, patients with high and low grade prostate cancers, the presence of benign prostate hyperplasia (BPH), perineural invasions, and the one lymphatic invasion. Identification was by analysis of fibre diffraction patterns interpreted using a schema developed from observations in nine previous studies. The method, schema, and specific experiment results are reported in this paper, with some implications then drawn.

  12. A short note on physical properties to irradiated nuclear fuel by means of X-ray diffraction and neutron scattering techniques

    NASA Astrophysics Data System (ADS)

    Abdullah, Yusof; Husain, Hishamuddin; Hak, Cik Rohaida Che; Alias, Nor Hayati; Yusof, Mohd Reusmaazran; Kasim, Norasiah Ab; Zali, Nurazila Mat; Mohamed, Abdul Aziz

    2015-04-01

    For nuclear reactor applications, understanding the evolution of the fuel materials microstructure during irradiation are of great importance. This paper reviews the physical properties of irradiated nuclear fuel analysis which are considered to be of most importance in determining the performance behavior of fuel. X-rays diffraction was recognize as important tool to investigate the phase identification while neutron scattering analyses the interaction between uranium and other materials and also investigation of the defect structure.

  13. The Early Universe and High-Energy Physics.

    ERIC Educational Resources Information Center

    Schramm, David N.

    1983-01-01

    Many properties of new particle field theories can only be tested by comparing their predictions about the physical conditions immediately after the big bang with what can be reconstructed about this event from astronomical data. Facts/questions about big bang, unified field theories, and universe epochs/mass are among the topics discussed. (JN)

  14. Locating Quality Physical Education in Early Years Pedagogy

    ERIC Educational Resources Information Center

    Marsden, Elizabeth; Weston, Carrie

    2007-01-01

    Government Ministers, health care professionals and sporting organisations throughout the UK are presently engaged in the promotion of extending the length of time each school child spends participating in quality physical education. Agendas may differ from a crackdown on obesity and sedentary lifestyles to basking in reflected glory of British…

  15. Soil and Rock Physical Properties at the Mars Exploration Rover Landing Sites: Early Returns

    NASA Technical Reports Server (NTRS)

    Ming, D. W.; Anderson, R. C.; Arvidson, R. E.; Bell, J. F., III; Biesiadecki, J.; Christensen, P. H.; Gorevan, S. P.; Ehlmann, B. L.; Guinness, E. A.; Graff, T. G.

    2004-01-01

    The purpose of this paper is to report the 'early returns' on the physical properties of soil units and rocks at the MER landing sites. Because we are still very early in the mission at Meridiani Planum, results from the Gusev Crater Landing Site are emphasized here.

  16. Recommended Practices for Promoting Physical Activity in Early Childhood Education Settings

    ERIC Educational Resources Information Center

    Wright, Paul M.; Stork, Steve

    2013-01-01

    Although the importance of physical development as an integrated part of early childhood education is well understood, many early childhood teachers lack the specific background and training in this area. To fill this gap, this article presents a framework of recommended practices and a corresponding assessment tool. The Head Start Body Start…

  17. The Influences of Pre-Professional Socialization on Early Career Physical Educators

    ERIC Educational Resources Information Center

    Flory, Sara B.; McCaughtry, Nate

    2014-01-01

    The purpose of this study was to examine how three PE teachers' personal biographies before their formal teacher education programs influenced their early careers in urban schools. Using occupational socialization theory and cultural relevance theory, we conducted in-depth interviews and observed early career physical education teachers who…

  18. Nuclear and particle physics in the early universe

    NASA Technical Reports Server (NTRS)

    Schramm, D. N.

    1981-01-01

    Basic principles and implications of Big Bang cosmology are reviewed, noting the physical evidence of a previous universe temperature of 10,000 K and theoretical arguments such as grand unification decoupling indicating a primal temperature of 10 to the 15th eV. The Planck time of 10 to the -43rd sec after the Big Bang is set as the limit before which gravity was quantized and nothing is known. Gauge theories of elementary particle physics are reviewed for successful predictions of similarity in weak and electromagnetic interactions and quantum chromodynamic predictions for strong interactions. The large number of photons in the universe relative to the baryons is considered and the grand unified theories are cited as showing the existence of baryon nonconservation as an explanation. Further attention is given to quark-hadron phase transition, the decoupling for the weak interaction and relic neutrinos, and Big Bang nucleosynthesis.

  19. Comparison between ray-tracing and physical optics for the computation of light absorption in capillaries--the influence of diffraction and interference.

    PubMed

    Qin, Yuan; Michalowski, Andreas; Weber, Rudolf; Yang, Sen; Graf, Thomas; Ni, Xiaowu

    2012-11-19

    Ray-tracing is the commonly used technique to calculate the absorption of light in laser deep-penetration welding or drilling. Since new lasers with high brilliance enable small capillaries with high aspect ratios, diffraction might become important. To examine the applicability of the ray-tracing method, we studied the total absorptance and the absorbed intensity of polarized beams in several capillary geometries. The ray-tracing results are compared with more sophisticated simulations based on physical optics. The comparison shows that the simple ray-tracing is applicable to calculate the total absorptance in triangular grooves and in conical capillaries but not in rectangular grooves. To calculate the distribution of the absorbed intensity ray-tracing fails due to the neglected interference, diffraction, and the effects of beam propagation in the capillaries with sub-wavelength diameter. If diffraction is avoided e.g. with beams smaller than the entrance pupil of the capillary or with very shallow capillaries, the distribution of the absorbed intensity calculated by ray-tracing corresponds to the local average of the interference pattern found by physical optics.

  20. Embedding Physical Activity and Nutrition in Early Care and Education Programs

    ERIC Educational Resources Information Center

    Deiner, Penny Low; Qiu, Wei

    2007-01-01

    The infant and toddler years provide a window of opportunity to establish healthy habits as part of daily routines and activities that prevent childhood obesity. Early care and education programs have the opportunity to make a significant impact on physical development when they promote healthy eating and physical activity in their daily routines.…

  1. An Empirical Investigation of the Dimensionality of the Physical Literacy Environment in Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Dynia, Jaclyn M.; Schachter, Rachel E.; Piasta, Shayne B.; Justice, Laura M.; O'Connell, Ann A.; Yeager Pelatti, Christina

    2016-01-01

    This study investigated the dimensionality of the physical literacy environment of early childhood education classrooms. Data on the classroom physical literacy environment were collected from 245 classrooms using the Classroom Literacy Observation Profile. A combination of confirmatory and exploratory factor analysis was used to identify five…

  2. Pilot-Testing CATCH Early Childhood: A Preschool-Based Healthy Nutrition and Physical Activity Program

    ERIC Educational Resources Information Center

    Sharma, Shreela; Chuang, Ru-Jye; Hedberg, Ann Marie

    2011-01-01

    Background: The literature on theoretically-based programs targeting healthy nutrition and physical activity in preschools is scarce. Purpose: To pilot test CATCH Early Childhood (CEC), a preschool-based nutrition and physical activity program among children ages three to five in Head Start. Methods: The study was conducted in two Head Start…

  3. Concerns of Preservice Physical Education Teachers Participating in an Early Field Experience

    ERIC Educational Resources Information Center

    Young, Shawna

    2012-01-01

    The purpose of this study was to examine the frequency of concerns by type (self, task, and impact) of preservice physical education teachers participating in an early field experience. Participants (n = 52) taught three physical education lessons in a junior high school. Following each teaching episode, participants wrote concerns in their…

  4. Early and current physical activity: relationship with intima-media thickness and metabolic variables in adulthood

    PubMed Central

    Lima, Manoel C. S.; Barbosa, Maurício F.; Diniz, Tiego A.; Codogno, Jamile S.; Freitas, Ismael F.; Fernandes, Rômulo A.

    2014-01-01

    Background: It is unclear whether early physical activity has a greater influence on intima-media thickness and metabolic variables than current physical activity. Objective: To analyze the relationship between current and early physical activity, metabolic variables, and intima-media thickness measures in adults. Method: The sample was composed of 55 healthy subjects of both sexes (33 men and 22 women). Total body fat and trunk fat were estimated by dual-energy X-ray absorptiometry. Carotid and femoral intima-media thickness were measured using a Doppler ultrasound device. A 12-hour fasting blood sample collection was taken (fasting glucose and lipid profile). Early physical activity was assessed through face-to-face interview, and the current physical activity was assessed by pedometer (Digi-Walker Yamax, SW200), which was used for a period of seven days. Results: Current physical activity was negatively related to total cholesterol (rho=-0.31), while early physical activity was negatively related to triglycerides (rho=-0.42), total cholesterol (rho=-0.28), very low density lipoprotein (rho=-0.44), and carotid intima-media thickness (rho=-0.50). In the multivariate model, subjects engaged in sports activities during early life had lower values of very low density lipoprotein (b=-8.74 [b=-16.1; -1.47]) and carotid intima-media thickness (b=-0.17 [95%CI: -0.28; -0.05]). Conclusion: Early 95%CI physical activity has a significant influence on carotid intima-media thickness, regardless of the current physical activity. PMID:25372009

  5. Modeling and Reality in Early Twentieth-Century Physics

    NASA Astrophysics Data System (ADS)

    Seth, Suman

    2011-04-01

    Towards the end of 1913, Arnold Sommerfeld, Professor of theoretical physics at Munich University, sent a letter of congratulations to a young Niels Bohr. The Dane's now-classic trilogy of papers, which coupled Rutherford's conception of the atom with a ``planetary'' configuration of electrons, had just appeared. Sommerfeld saw the calculation of the Rydberg constant as a singular triumph and immediately spotted an opportunity to try to explain the Zeeman effect. Yet he also sounded a note of caution, confessing that he remained ``somewhat skeptical'' of atomic models in general. In this, of course, he was hardly alone. Bohr's atom was a particularly egregious example of a peculiar model, one requiring what even its creator considered ``horrid assumptions.'' Nonetheless, success bred conviction. Expanding upon Bohr's original ideas, Sommerfeld soon produced the so-called ``Bohr-Sommerfeld quantization conditions,'' using them to calculate a myriad of results. Experimental evidence, Sommerfeld argued in 1915, showed that quantised electron-paths ``correspond exactly to reality'' and possess ``real existence.'' This kind of realism would not, of course, last long. In 1925, Werner Heisenberg (earlier a student of Sommerfeld's) made scepticism about the details of the Bohr model into a methodological dictum, one later enshrined in the ``Copenhagen interpretation'' of quantum mechanics. This paper uses Sommerfeld's work from the turn of the twentieth century to the mid-1920s as a window onto a landscape involving multiple contestations over the legitimacy of atomic modelling. The surprise that greeted Heisenberg's and others' phenomenological insistences, we will see, can only be understood with reference to what should be considered a ``realist interlude'' in the history of twentieth century atomic physics, one inspired by the astonishing successes of Rutherford's and Bohr's imaginings.

  6. The environment and physics of the early solar system

    NASA Astrophysics Data System (ADS)

    Salmeron, Raquel

    2012-03-01

    Astronomical observations and modelling suggest that stars assemble out of the gas and dust collected in the cores of vast clouds in interstellar space. These cores gravitationally attract more material from the surrounding cloud, until enough mass is concentrated to trigger their gravitational collapse. The result of this process is a growing object (a protostar), slowly fed by a flattened disc of material (aprotostellar disc) that encircles it. These discs are the analogues of the early solar system, and potential sites of current planet formation. Provided that disc material can shed its excess angular momentum, matter will flow onto the central object, and it is believed that this is how stars typically gain most of their mass. Although this basic paradigm appears solid, many aspects of this process remain unexplained. The mechanisms responsible for this transport of angular momentum are not well understood. The most promising are turbulent motions driven by the magnetorotational instability, and large-scale outflows accelerated from the disc surfaces. Both processes are driven by magnetic fields and are, in turn, likely to strongly affect the structure, evolution and planet-forming processes in the disc. The low ionisation of the material, however, may prevent the magnetic field from driving these processes in some regions of the disc. On the other hand, a record of the formation process of our own solar system is preserved in primitive meteorites, the "building blocks" of the solar nebula. Preserved in the samples are a variety of objects that have experienced very high temperatures (1700-2000 K), evidence that could imply a hot ambient temperature in the solar nebula. In contrast, the preservation of presolar grains in meteorites, geochemical evidence for a poorly mixed nebula, and astrophysical observations of forming stars suggest a cool protoplanetary disc, where temperatures are too low to produce this thermal processing. The coexistence of hot and cold

  7. Early Childhood Policy Focus: Healthy Eating and Physical Activity. Early Childhood Highlights. Volume 2, Issue 3

    ERIC Educational Resources Information Center

    Murphey, David; Mackintosh, Bonnie; McCoy-Roth, Marci

    2011-01-01

    The importance of good nutrition and exercise is well known, and parents have long worried about their children's diets and envied their high energy levels. Like so many life style habits, patterns of nutrition and exercise behaviors are typically established in early childhood. Poor diet and lack of exercise contribute to obesity, which has been…

  8. Early developments: Particle physics aspects of cosmic rays

    NASA Astrophysics Data System (ADS)

    Grupen, Claus

    2014-01-01

    Cosmic rays is the birthplace of elementary particle physics. The 1936 Nobel prize was shared between Victor Hess and Carl Anderson. Anderson discovered the positron in a cloud chamber. The positron was predicted by Dirac several years earlier. In subsequent cloud chamber investigations Anderson and Neddermeyer saw the muon, which for some time was considered to be a candidate for the Yukawa particle responsible for nuclear binding. Measurements with nuclear emulsions by Lattes, Powell, Occhialini and Muirhead clarified the situation by the discovery of the charged pions in cosmic rays. The cloud chamber continued to be a powerful instrument in cosmic ray studies. Rochester and Butler found V's, which turned out to be shortlived neutral kaons decaying into a pair of charged pions. Also Λ's, Σ's, and Ξ's were found in cosmic rays. But after that accelerators and storage rings took over. The unexpected renaissance of cosmic rays started with the search for solar neutrinos and the observation of the supernova 1987A. Cosmic ray neutrino results were best explained by the assumption of neutrino oscillations opening a view beyond the standard model of elementary particles. After 100 years of cosmic ray research we are again at the beginning of a new era, and cosmic rays may contribute to solve the many open questions, like dark matter and dark energy, by providing energies well beyond those of accelerators.

  9. Capitalizing on the Teachable Moment: Osteoarthritis Physical Activity and Exercise Net for Improving Physical Activity in Early Knee Osteoarthritis

    PubMed Central

    Lineker, Sydney; Cibere, Jolanda; Crooks, Valorie A; Jones, Catherine A; Kopec, Jacek A; Lear, Scott A; Pencharz, James; Rhodes, Ryan E; Esdaile, John M

    2013-01-01

    with OA tend to be more motivated to adopt an active lifestyle (ie, at the early stage of OA). Our approach, which consisted of the identification of early knee OA followed immediately by an online intervention that directly targets physical inactivity, can be easily implemented across communities. Conclusions Our online intervention directly targets physical inactivity at a time when the joint damage tends to be mild. If OPEN is found to be effective in changing long-term physical activity behaviors, it opens further opportunities to promote early diagnosis and to implement lifestyle interventions. Trial Registration Clinicaltrial.gov: NCT01608282; http://clinicaltrials.gov/ct2/show/NCT01608282 (Archived by WebCite at http://www.webcitation.org/6G7sBBayI) PMID:23659903

  10. Overcoming the diffraction limit in wave physics using a time-reversal mirror and a novel acoustic sink.

    PubMed

    de Rosny, J; Fink, M

    2002-09-16

    In recent years, time-reversal (TR) mirrors have been developed that create TR waves for ultrasonic transient fields propagating through complex media. A TR wave back propagates and refocuses exactly at its initial source. However, because of diffraction, even if the source is pointlike the wave refocuses on a spot size that cannot be smaller than half a wavelength. Here, by using a TR interpretation of this limit, we show that this latter limitation can be overcome if the source is replaced by its TR image. This new device acts as an acoustic sink that absorbs the TR wave. Here we report the first experimental result obtained with an acoustic sink where a focal spot size of less than 1/14th of one wavelength is recorded.

  11. A Longitudinal Examination of the Influence of Maturation on Physical Self-Perceptions and the Relationship with Physical Activity in Early Adolescent Girls

    ERIC Educational Resources Information Center

    Knowles, Ann-Marie; Niven, Ailsa G.; Fawkner, Samantha G.; Henretty, Joan M.

    2009-01-01

    This longitudinal study investigated the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls (N = 150; mean age = 12.79 plus or minus 0.31). Physical characteristics were measured and participants completed the Physical Activity Questionnaire for Children, the Children and…

  12. The relationship between self-perception of physical attractiveness and sexual bullying in early adolescence.

    PubMed

    Cunningham, Nancy J; Taylor, Matthew; Whitten, Michael E; Hardesty, Patrick H; Eder, Katheryn; DeLaney, Nancy

    2010-01-01

    The relationship between self-perception of physical attractiveness and four measures of sexual bullying behavior (victimization, perpetration, having friends who sexually bully, and observation of sexual bullying among peers at school) was examined in a sample of 396 middle school age students. Students who perceived themselves to be more physically attractive than their peers reported sexually bullying others more, being sexually bullied by others more, observing more sexual bullying, and having more friends who sexually bully others than did students who perceived themselves as average looking. In addition, males who perceived themselves to be less physically attractive than their peers reported being victimized more and reported observing more sexual bullying in the school environment. These findings highlight the importance of physical attractiveness in the early initiation of sexual harassment. Implications for future research and interventions with early adolescents are discussed. PMID:20623494

  13. Early Physical Rehabilitation in the ICU: A Review for the Neurohospitalist

    PubMed Central

    Mendez-Tellez, Pedro A.; Nusr, Rasha; Feldman, Dorianne; Needham, Dale M.

    2012-01-01

    Advances in critical care have resulted in improved intensive care unit (ICU) mortality. However, improved ICU survival has resulted in a growing number of ICU survivors living with long-term sequelae of critical illness, such as impaired physical function and quality of life (QOL). In addition to critical illness, prolonged bed rest and immobility may lead to severe physical deconditioning and loss of muscle mass and muscle weakness. ICU-acquired weakness is associated with increased duration of mechanical ventilation and weaning, longer ICU and hospital stay, and increased mortality. These physical impairments may last for years after ICU discharge. Early Physical Medicine and Rehabilitation (PM&R) interventions in the ICU may attenuate or prevent the weakness and physical impairments occurring during critical illness. This article reviews the evidence regarding safety, feasibility, barriers, and benefits of early PM&R interventions in ICU patients and discusses the limited existing data on early PM&R in the neurological ICU and future directions for early PM&R in the ICU. PMID:23983871

  14. The interaction between early-life body size and physical activity on risk of breast cancer

    PubMed Central

    Oh, Hannah; Boeke, Caroline E.; Tamimi, Rulla M.; Smith-Warner, Stephanie A.; Wang, Molin; Willett, Walter C.; Eliassen, A. Heather

    2014-01-01

    While early-life body leanness is associated with increased breast cancer risk, early-life physical activity may protect against breast cancer. We examined whether the excess risk among lean girls is modified by their levels of prior, concurrent, or future physical activity. We conducted an analysis among 74,723 women in the Nurses’ Health Study II (follow-up 1997–2011). Participants recalled their body size at ages 5, 10, and 20 years in 1989 using a 9-level pictogram (level 1: most lean). In 1997, they reported adolescent levels of physical activity (ages 12–13 and 14–17 years). Cox proportional hazards models estimated the overall association of body size with breast cancer risk and assessed interactions of adolescent physical activity with body size at three different age periods (5–10, 10–20, and 20 years), adjusting for early-life and adult risk factors for breast cancer. Regardless of levels of adolescent physical activity, early-life body leanness (level 1–2 vs. 4.5+) was significantly associated with higher breast cancer risk. The association was slightly attenuated among those who were active (60+ MET-hr/wk) during adolescence compared to those who were inactive (<30 MET-hr/wk) (body size at ages 5–10 years: hazard ratio=1.37, 95% confidence interval=1.04–1.81 vs. 1.66, 1.29–2.12), but the interaction was not significant (p=0.72). The results were similar for body size at three different age periods. Being lean during early life is a risk factor for breast cancer among both inactive and active girls. Adolescent physical activity did not significantly modify the association, although some interaction cannot be excluded. PMID:25335465

  15. A Qualitative Analysis of Individual Interest in Middle School Physical Education: Perspectives of Early-Adolescents

    ERIC Educational Resources Information Center

    Garn, Alex C.; Cothran, Donetta J.; Jenkins, Jayne M.

    2011-01-01

    Background: Past research has revealed the positive impact that interest development can have on achievement outcomes with early-adolescents in physical education (PE). Interest is considered a psychological state of engaging and willingness to reengage in specific content that develops over time; however, little work to date has examined interest…

  16. Incorporating Early Chinese Scientific Ideas into the Teaching of School Physics.

    ERIC Educational Resources Information Center

    Tao, P. K.

    1998-01-01

    Describes an initiative to develop and incorporate early Chinese scientific ideas into the teaching of physics in Hong Kong schools. Provides the background and rationale for the development and gives as an illustration an account of some of the scientific ideas included. Ideas include the Chinese magic mirror, force and motion, and atomic theory.…

  17. Sixty Minutes of Physical Activity per Day Included within Preschool Academic Lessons Improves Early Literacy

    ERIC Educational Resources Information Center

    Kirk, Stacie M.; Kirk, Erik P.

    2016-01-01

    Background: The effects of increases in physical activity (PA) on early literacy skills in preschool children are not known. Methods: Fifty-four African-American preschool children from a low socioeconomic urban Head Start participated over 8 months. A 2-group, quasi-experimental design was used with one preschool site participating in the PA…

  18. Psychosocial Correlates of Physical and Sedentary Activities of Early Adolescent Youth

    ERIC Educational Resources Information Center

    Rusby, Julie C.; Westling, Erika; Crowley, Ryann; Light, John M.

    2014-01-01

    This study examines physical and sedentary activities of early adolescent boys and girls using Ecological Momentary Assessment (EMA), a method that can link mood and behaviors in specific social situations. Twenty-seven assessments were collected across 7 days from 82 participating adolescents, three times in seventh grade and one time in eighth…

  19. Health and Physical Development in Early Childhood Programs: Recommendations for Programs and Their Evaluation.

    ERIC Educational Resources Information Center

    Love, John M.

    One concern frequently cited regarding early childhood programs is that methods for assessing some of their more important objectives are inadequate or nonexistent. This paper addresses this concern in the areas of health, safety, nutrition, dental health, and physical development during the preschool years. An organizing framework for classifying…

  20. Environmental Influences on Preschoolers' Physical Activity Levels in Various Early-Learning Facilities

    ERIC Educational Resources Information Center

    Vanderloo, Leigh M.; Tucker, Patricia; Johnson, Andrew M.; Burke, Shauna M.; Irwin, Jennifer D.

    2015-01-01

    Purpose: This study aimed to: (a) compare the physical activity (PA) levels (i.e., moderate-to-vigorous PA [MVPA] and total PA [TPA]) of preschoolers in 3 different early-learning environments (center-based childcare, home-based childcare, and full-day kindergarten [FDK]); and (b) assess which characteristics (e.g., play equipment, policies, etc.)…

  1. Exposure to Childhood Sexual and Physical Abuse and Adjustment in Early Adulthood

    ERIC Educational Resources Information Center

    Fergusson, David M.; Boden, Joseph M.; Horwood, L. John

    2008-01-01

    Objective: This research examined linkages between exposure to childhood sexual abuse (CSA) and childhood physical punishment/abuse (CPA) and mental health issues in early adulthood. Method: The investigation analyzed data from a birth cohort of over 1,000 New Zealand young adults studied to the age of 25. Results: Exposure to CSA and CPA was…

  2. Birth order and physical fitness in early adulthood: evidence from Swedish military conscription data.

    PubMed

    Barclay, Kieron; Myrskylä, Mikko

    2014-12-01

    Physical fitness at young adult ages is an important determinant of physical health, cognitive ability, and mortality. However, few studies have addressed the relationship between early life conditions and physical fitness in adulthood. An important potential factor influencing physical fitness is birth order, which prior studies associate with several early- and later-life outcomes such as height and mortality. This is the first study to analyse the association between birth order and physical fitness in late adolescence. We use military conscription data on 218,873 Swedish males born between 1965 and 1977. Physical fitness is measured by a test of maximal working capacity, a measure of cardiovascular fitness closely related to V02max. We use linear regression with sibling fixed effects, meaning a within-family comparison, to eliminate the confounding influence of unobserved factors that vary between siblings. To understand the mechanism we further analyse whether the association between birth order and physical fitness varies by sibship size, parental socioeconomic status, birth cohort or length of the birth interval. We find a strong, negative and monotonic relationship between birth order and physical fitness. For example, third-born children have a maximal working capacity approximately 0.1 (p < 0.000) standard deviations lower than first-born children. The association exists both in small (3 or less children) and large families (4 or more children), in high and low socioeconomic status families, and amongst cohorts born in the 1960s and the 1970s. While in the whole population the birth order effect does not depend on the length of the birth intervals, in two-child families a longer birth interval strengthens the advantage of the first-born. Our results illustrate the importance of birth order for physical fitness, and suggest that the first-born advantage already arises in late adolescence. PMID:25462615

  3. Early and extraordinary peaks in physical performance come with a longevity cost.

    PubMed

    van de Vijver, Paul L; van Bodegom, David; Westendorp, Rudi G J

    2016-08-01

    Life history theory postulates a trade-off between development and maintenance. This trade-off is observed when comparing life histories of different animal species. In humans, however, it is debated if variation in longevity is explained by differences in developmental traits. Observational studies found a trade-off between early and high fecundity and longevity in women. Development encompasses more than fecundity and also concerns growth and physical performance. Here, we show a life history trade-off between early and above average physical performance and longevity in male Olympic athletes. Athletes who peaked at an earlier age showed 17-percent increased mortality rates (95% CI 8-26% per SD, p≤0.001) and athletes who ranked higher showed 11-percent increased mortality rates (95% CI 1-22% per SD, p=0.025). Male athletes who had both an early and extraordinary peak performance suffered a 4.7-year longevity cost. (95% CI 2.1-7.5 years, p=0.001). This is the first time a life history trade-off between physical performance and longevity has been found in humans. This finding deepens our understanding of early developmental influences on the variation of longevity in humans. PMID:27540872

  4. Early and extraordinary peaks in physical performance come with a longevity cost

    PubMed Central

    van de Vijver, Paul L; van Bodegom, David; Westendorp, Rudi GJ

    2016-01-01

    Life history theory postulates a trade-off between development and maintenance. This trade-off is observed when comparing life histories of different animal species. In humans, however, it is debated if variation in longevity is explained by differences in developmental traits. Observational studies found a trade-off between early and high fecundity and longevity in women. Development encompasses more than fecundity and also concerns growth and physical performance. Here, we show a life history trade-off between early and above average physical performance and longevity in male Olympic athletes. Athletes who peaked at an earlier age showed 17-percent increased mortality rates (95% CI 8-26% per SD, p<0.001) and athletes who ranked higher showed 11-percent increased mortality rates (95% CI 1-22% per SD, p=0.025). Male athletes who had both an early and extraordinary peak performance suffered a 4.7-year longevity cost. (95% CI 2.1-7.5 years, p=0.001). This is the first time a life history trade-off between physical performance and longevity has been found in humans. This finding deepens our understanding of early developmental influences on the variation of longevity in humans. PMID:27540872

  5. Early age hydration and pozzolanic reaction in natural zeolite blended cements: Reaction kinetics and products by in situ synchrotron X-ray powder diffraction

    SciTech Connect

    Snellings, R.; Mertens, G.; Cizer, O.; Elsen, J.

    2010-12-15

    The in situ early-age hydration and pozzolanic reaction in cements blended with natural zeolites were investigated by time-resolved synchrotron X-ray powder diffraction with Rietveld quantitative phase analysis. Chabazite and Na-, K-, and Ca-exchanged clinoptilolite materials were mixed with Portland cement in a 3:7 weight ratio and hydrated in situ at 40 {sup o}C. The evolution of phase contents showed that the addition of natural zeolites accelerates the onset of C{sub 3}S hydration and precipitation of CH and AFt. Kinetic analysis of the consumption of C{sub 3}S indicates that the enveloping C-S-H layer is thinner and/or less dense in the presence of alkali-exchanged clinoptilolite pozzolans. The zeolite pozzolanic activity is interpreted to depend on the zeolite exchangeable cation content and on the crystallinity. The addition of natural zeolites alters the structural evolution of the C-S-H product. Longer silicate chains and a lower C/S ratio are deduced from the evolution of the C-S-H b-cell parameter.

  6. The Early Years of Indirect Drive Development for High Energy Density Physics Experiments at AWE

    NASA Astrophysics Data System (ADS)

    Thomas, Brian

    2016-10-01

    The importance of laser driven indirect drive for high energy density physics experiments was recognised at A WE in 1971. The two beam 1TW HELEN laser was procured to work in this area and experiments with this system began in 1980. Early experiments in hohlraum coupling and performance scaling with both l.06μm and 0.53μm will be described together with experiments specifically designed to confirm the understanding of radiation wave propagation, hohlraum heating and hohlraum plasma filling. The use of indirect drive for early experiments to study spherical and cylindrical implosions, opacity, EOS, mix and planar radiation hydrodynamics experiments will also be described.

  7. Early Sexual Intercourse: Prospective Associations with Adolescents Physical Activity and Screen Time

    PubMed Central

    Wijtzes, Anne; van de Bongardt, Daphne; van de Looij-Jansen, Petra; Bannink, Rienke; Raat, Hein

    2016-01-01

    Objectives To assess the prospective associations of physical activity behaviors and screen time with early sexual intercourse initiation (i.e., before 15 years) in a large sample of adolescents. Methods We used two waves of data from the Rotterdam Youth Monitor, a longitudinal study conducted in the Netherlands. The analysis sample consisted of 2,141 adolescents aged 12 to 14 years (mean age at baseline = 12.2 years, SD = 0.43). Physical activity (e.g., sports outside school), screen time (e.g., computer use), and early sexual intercourse initiation were assessed by means of self-report questionnaires. Logistic regression models were tested to assess the associations of physical activity behaviors and screen time (separately and simultaneously) with early sexual intercourse initiation, controlling for confounders (i.e., socio-demographics and substance use). Interaction effects with gender were tested to assess whether these associations differed significantly between boys and girls. Results The only physical activity behavior that was a significant predictor of early sexual intercourse initiation was sports club membership. Adolescent boys and girls who were members of a sports club) were more likely to have had early sex (OR = 2.17; 95% CI = 1.33, 3.56. Significant gender interaction effects indicated that boys who watched TV ≥2 hours/day (OR = 2.00; 95% CI = 1.08, 3.68) and girls who used the computer ≥2 hours/day (OR = 3.92; 95% CI = 1.76, 8.69) were also significantly more likely to have engaged in early sex. Conclusion These findings have implications for professionals in general pediatric healthcare, sexual health educators, policy makers, and parents, who should be aware of these possible prospective links between sports club membership, TV watching (for boys), and computer use (for girls), and early sexual intercourse initiation. However, continued research on determinants of adolescents’ early sexual initiation is needed to further contribute to

  8. Early Life Stress and Physical and Psychosocial Functioning in Late Adulthood

    PubMed Central

    Alastalo, Hanna; von Bonsdorff, Mikaela B.; Räikkönen, Katri; Pesonen, Anu-Katriina; Osmond, Clive; Barker, David J. P.; Heinonen, Kati; Kajantie, Eero; Eriksson, Johan G.

    2013-01-01

    Background Severe stress experienced in early life may have long-term effects on adult physiological and psychological health and well-being. We studied physical and psychosocial functioning in late adulthood in subjects separated temporarily from their parents in childhood during World War II. Methods The 1803 participants belong to the Helsinki Birth Cohort Study, born 1934–44. Of them, 267 (14.8%) had been evacuated abroad in childhood during WWII and the remaining subjects served as controls. Physical and psychosocial functioning was assessed with the Short Form 36 scale (SF-36) between 2001 and 2004. A test for trends was based on linear regression. All analyses were adjusted for age at clinical examination, social class in childhood and adulthood, smoking, alcohol intake, physical activity, body mass index, cardiovascular disease and diabetes. Results Physical functioning in late adulthood was lower among the separated men compared to non-separated men (b = −0.40, 95% confidence interval [95% CI]: −0.71 to −0.08). Those men separated in school age (>7 years) and who were separated for a duration over 2 years had the highest risk for lower physical functioning (b = −0.89, 95% CI: −1.58 to −0.20) and (b = −0.65, 95% CI: −1.25 to −0.05), respectively). Men separated for a duration over 2 years also had lower psychosocial functioning (b = −0.70, 95% CI: −1.35 to −0.06). These differences in physical and psychosocial functioning were not observed among women. Conclusion Early life stress may increase the risk for impaired physical functioning in late adulthood among men. Timing and duration of the separation influenced the physical and psychosocial functioning in late adulthood. PMID:23861956

  9. Views of Adolescent Female Youth on Physical Activity During Early Adolescence

    PubMed Central

    Yungblut, Hope E.; Schinke, Robert J.; McGannon, Kerry R.

    2012-01-01

    Early adolescence is a time when a transition away from sport and physical activity participation is at its highest level among female youth (Hedstrom & Gould, 2004). This has led to the identification of barriers and facilitators of physical activity participation for adolescent females. Consequently there have been calls to overcome barriers and augment facilitators via the creation of gender-relevant programming. Despite these calls and efforts, a gender disparity remains, and a detailed understanding of how girls experience and interpret physical activity within the context of their lives is still lacking. The current project aimed to gain further insight into the foregoing using tenets of Interpretive Phenomenology to further understand the lived physical activity experiences of females during early adolescence, delineating their barriers to participation and the factors enabling participation. Five themes were identified and made into vignettes to facilitate understanding from adolescent females' perspectives: friends or don't know anyone, good or not good enough, fun or not fun; good feeling or gross; and peer support or peer pressure. The physical activity promotion implications for female youth are discussed within the context of these themes. Key points Please provide 3-5 bullet points of the study. Inductive qualitative methodologies can encourage the much-needed voice of female youth in sport and physical activity research. Vignettes serve, not only as a method to illustrate data, but also as a medium to teach contextually relevant information to participants and sport science service providers. The barriers and solutions to female youth engagement in physical activity are best understood through the perspectives of the intended participant. Female youth can serve as central informants in the development and analysis of research projects relating to female youth physical activity. PMID:24149121

  10. Temperament, Parenting, and South Korean Early Adolescents' Physical Aggression: A Five-Wave Longitudinal Analysis

    ERIC Educational Resources Information Center

    Lee, Julie

    2014-01-01

    Objective: This study examined the growth pattern in physical aggression over a five-year period among South Korean early adolescents and the effects of temperament (anger/frustration and emotion regulation) and parenting (harsh parenting and parental monitoring) on early adolescents' physical aggression. Design: A five-year longitudinal…

  11. A longitudinal examination of the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls.

    PubMed

    Knowles, Ann-Marie; Niven, Ailsa G; Fawkner, Samantha G; Henretty, Joan M

    2009-06-01

    This longitudinal study investigated the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls (N=150; mean age=12.79+/-0.31). Physical characteristics were measured and participants completed the Physical Activity Questionnaire for Children, the Children and Youth Physical Self-Perception Profile and the Pubertal Development Scale on two occasions 12 months apart. The results demonstrated a decrease in overall physical activity levels over 12 months which was not influenced by maturational status or physical characteristics. Additional analysis indicated that physical self-perceptions partially accounted for the explained variance in physical activity change, with physical condition being an important individual predictor of physical activity. Further analysis indicated that body mass was an important individual predictor of changes in perceptions of body attractiveness and physical self-worth. At this age maturation has a limited influence on the physical activity behaviours of early adolescent girls and although the variance in physical activity was partly accounted for by physical self-perceptions, this was a relatively small contribution and other factors related to this drop in physical activity need to be considered longitudinally. PMID:18692232

  12. Physical activity, sedentary behaviour and energy balance in the preschool child: opportunities for early obesity prevention.

    PubMed

    Reilly, John J

    2008-08-01

    Prevalence of obesity in preschool children has increased dramatically in recent years. The preschool years (age 3-6 years) have been regarded as critical for the programming of energy balance, via the concept of early 'adiposity rebound'. Children who undergo early adiposity rebound are at increased risk of later obesity. Recent evidence suggests that associations between timing of adiposity rebound and later obesity may not reflect programming, but might denote that 'obesogenic' growth trajectories are often established by the preschool period. Studies of objectively-measured physical activity and sedentary behaviour in preschool children show that levels of physical activity are typically low and sedentary behaviour high. The review of evidence presented here is supportive of the hypothesis that physical activity is protective against obesity in the preschool period, and that sedentary behaviour, particularly television viewing, is obesogenic. Definitive evidence on dose-response relationships between physical activity, sedentary behaviour and obesity remain unclear. Dose-response evidence could be obtained fairly readily by intervention and longitudinal observational studies that use accelerometry in preschool children. The generalisability of much of the evidence base is limited and there is a need for research on the influence of physical activity and sedentary behaviour in the preschool years in the aetiology of obesity in the developing world.

  13. Effects of Online Self-Regulation Activities on Physical Activity Among Pregnant and Early Postpartum Women.

    PubMed

    Kim, Hye Kyung; Niederdeppe, Jeff; Graham, Meredith; Olson, Christine; Gay, Geri

    2015-01-01

    Physical and psychological changes that occur during pregnancy present a unique challenge for women's physical activity. Using a theory-based prospective design, this study examines the effects of pregnant women's (a) physical activity cognitions (self-efficacy, outcome expectancy, and safety beliefs) and (b) online self-regulation activities (goal-setting and self-monitoring) on subsequent changes in their physical activity intentions and behavior during pregnancy and immediately postpartum. The authors used data from three panel surveys administered to pregnant women enrolled in a web-based intervention to promote healthy pregnancy and postpartum weight, as well as log data on their use of self-regulatory features on the intervention website. Perceived self-efficacy and perceived safety of physical activity in pregnancy enhanced subsequent intentions to be physically active. Repeated goal-setting and monitoring of those goals helped to maintain positive intentions during pregnancy, but only repeated self-monitoring transferred positive intentions into actual behavior. Theoretically, this study offers a better understanding of the roles of self-regulation activities in the processes of goal-striving. The authors also discuss practical implications for encouraging physical activity among pregnant and early postpartum women.

  14. Effects of Online Self-Regulation Activitieson Physical Activity among Pregnant and Early Postpartum Women

    PubMed Central

    Niederdeppe, Jeff; Graham, Meredith; Olson, Christine; Gay, Geri

    2015-01-01

    Physical and psychological changes that occur during pregnancy present a unique challenge for women’s physical activity. Using a theory-based prospective design, this study examines effects of pregnant women’s (1) physical activity cognitions (self-efficacy, outcome expectancy, and safety beliefs) and (2) online self-regulation activities (goal-setting and self-monitoring) on subsequent changes in their physical activity intentions and behavior during pregnancy and immediately postpartum. We used data from three panel surveys administered to pregnant women enrolled in a web-based intervention to promote healthy pregnancy and postpartum weight, as well as log data on their use of self-regulatory features on the intervention website. Perceived self-efficacy and perceived safety of physical activity in pregnancy enhanced subsequent intentions to be physically active. Repeated goal-setting and monitoring of those goals helped to maintain positive intentions during pregnancy, but only repeated self-monitoring transferred positive intentions into actual behavior. Theoretically, this study offers a better understanding of the roles of self-regulation activities in the processes of goal-striving. We also discuss practical implications for encouraging physical activity among pregnant and early postpartum women. PMID:26132887

  15. The Scaffolded Mind: Higher mental processes are grounded in early experience of the physical world.

    PubMed

    Williams, Lawrence E; Huang, Julie Y; Bargh, John A

    2009-12-01

    It has long been a staple of psychological theory that early life experiences significantly shape the adult's understanding of and reactions to the social world. Here we consider how early concept development along with evolved motives operating early in life can come to exert a passive, unconscious influence on the human adult's higher-order goal pursuits, judgments, and actions. In particular, we focus on concepts and goal structures specialized for interacting with the physical environment (e.g., distance cues, temperature, cleanliness, and self-protection), which emerge early and automatically as a natural part of human development and evolution. It is proposed that via the process of scaffolding, these early sensorimotor experiences serve as the foundation for the later development of more abstract concepts and goals. Experiments using priming methodologies reveal the extent to which these early concepts serve as the analogical basis for more abstract psychological concepts, such that we come easily and naturally to speak of close relationships, warm personalities, moral purity, and psychological pain. Taken together, this research demonstrates the extent to which such foundational concepts are capable of influencing people's information processing, affective judgments, and goal pursuit, oftentimes outside of their intention or awareness.

  16. The Scaffolded Mind: Higher mental processes are grounded in early experience of the physical world

    PubMed Central

    Williams, Lawrence E.; Huang, Julie Y.; Bargh, John A.

    2009-01-01

    It has long been a staple of psychological theory that early life experiences significantly shape the adult's understanding of and reactions to the social world. Here we consider how early concept development along with evolved motives operating early in life can come to exert a passive, unconscious influence on the human adult's higher-order goal pursuits, judgments, and actions. In particular, we focus on concepts and goal structures specialized for interacting with the physical environment (e.g., distance cues, temperature, cleanliness, and self-protection), which emerge early and automatically as a natural part of human development and evolution. It is proposed that via the process of scaffolding, these early sensorimotor experiences serve as the foundation for the later development of more abstract concepts and goals. Experiments using priming methodologies reveal the extent to which these early concepts serve as the analogical basis for more abstract psychological concepts, such that we come easily and naturally to speak of close relationships, warm personalities, moral purity, and psychological pain. Taken together, this research demonstrates the extent to which such foundational concepts are capable of influencing people's information processing, affective judgments, and goal pursuit, oftentimes outside of their intention or awareness. PMID:20046813

  17. The Scaffolded Mind: Higher mental processes are grounded in early experience of the physical world.

    PubMed

    Williams, Lawrence E; Huang, Julie Y; Bargh, John A

    2009-12-01

    It has long been a staple of psychological theory that early life experiences significantly shape the adult's understanding of and reactions to the social world. Here we consider how early concept development along with evolved motives operating early in life can come to exert a passive, unconscious influence on the human adult's higher-order goal pursuits, judgments, and actions. In particular, we focus on concepts and goal structures specialized for interacting with the physical environment (e.g., distance cues, temperature, cleanliness, and self-protection), which emerge early and automatically as a natural part of human development and evolution. It is proposed that via the process of scaffolding, these early sensorimotor experiences serve as the foundation for the later development of more abstract concepts and goals. Experiments using priming methodologies reveal the extent to which these early concepts serve as the analogical basis for more abstract psychological concepts, such that we come easily and naturally to speak of close relationships, warm personalities, moral purity, and psychological pain. Taken together, this research demonstrates the extent to which such foundational concepts are capable of influencing people's information processing, affective judgments, and goal pursuit, oftentimes outside of their intention or awareness. PMID:20046813

  18. First measurements at LHC: early hadronic physics (soft + QCD) with ALICE, ATLAS, CMS, TOTEM and LHCb

    NASA Astrophysics Data System (ADS)

    Revol, Jean-Pierre

    2008-03-01

    Some hadronic physics topics that can be studied by the various LHC experiments during the LHC commissioning period are presented. An educated guess of the LHC commissioning scenario is used, based on the assumption that during commissioning up to the highest energy (14 TeV) some data will be collected at 900 GeV. The importance of the first data samples, in particular a sample representing only a few hours of collisions at 900 GeV, in terms of early physics, is discussed in the framework of non-perturbative QCD, the issue of parton overlap. Some aspects of the strong interaction, in terms of early jet measurements, baryon production, as well as the production of charm and beauty quarks, are also briefly mentioned.

  19. Effects of early menarche on physical and psychosocial health problems in adolescent girls and adult women

    PubMed Central

    2016-01-01

    The menarcheal age of Korean women has been rapidly decreasing for the last 50 years, and the average menarcheal age of women born in the 1990s is approaching 12.6 years. In addition, interest in early puberty has been increasing recently owing to the rapid increase in precocious puberty. Generally, out of concern for short stature and early menarche, idiopathic central precocious puberty in female adolescents is treated with gonadotropin-releasing hormone analogs. Studies to date have described the association between early menarche and psychosocial problems such as delinquency and risky sexual behavior, as well as physical health problems such as obesity, diabetes, cardiovascular diseases, and breast cancer throughout the lifespan of women. However, the pathophysiological mechanism underlying this association has not been clarified thus far. In this article, we review and discuss the existing literature to describe the current understanding of the effects of early menarche on the physical and psychosocial health of adolescent girls and adult women. PMID:27721839

  20. Electron Backscatter Diffraction (EBSD) Analysis and U-Pb Geochronology of the Oldest Lunar Zircon: Constraining Early Lunar Differentiation and Dating Impact-Related Deformation

    NASA Technical Reports Server (NTRS)

    Timms, Nick; Nemchin, Alexander; Grange, Marion; Reddy, Steve; Pidgeon, Bob; Geisler, Thorsten; Meyer, Chuck

    2009-01-01

    The evolution of the early moon was dominated by two processes (i) crystallization of the Lunar Magma Ocean (LMO) and differentiation of potassium-rare earth element-phosphorous-rich residual magma reservoir referred to as KREEP, and (ii) an intense meteorite bombardment referred to as lunar cataclysm . The exact timing of these processes is disputed, and resolution relies on collection and interpretation of precise age data. This study examines the microstructure and geochronology of zircon from lunar impact breccias collected during the Apollo 17 mission. A large zircon clast within lunar breccia 72215,195 shows sector zoning in optical microscopy, cathodoluminescence (CL) imaging and Raman mapping, and indicates that it was a relict fragment of a much larger magmatic grain. Sensitive high resolution ion microprobe (SHRIMP) U-Pb analysis of the zircon shows that U and Th concentration correlate with sector zoning, with darkest CL domains corresponding with high-U and Th (approx.150 and approx.100 ppm respectively), and the brightest-CL sectors containing approx.30-50 ppm U and approx.10-20 ppm Th. This indicates that variations in optical CL and Raman properties correspond to differential accumulation of alpha-radiation damage in each sector. Electron backscatter diffraction (EBSD) mapping shows that the quality of electron backscatter patterns (band contrast) varies with sector zoning, with the poorest quality patterns obtained from high-U and Th, dark-CL zones. EBSD mapping also reveals a deformation microstructure that is cryptic in optical, CL and Raman imaging. Two orthogonal sets of straight discrete and gradational low-angle boundaries accommodate approx.12 misorientation across the grain. The deformation bands are parallel to the crystallographic {a}-planes of the zircon, have misorientation axes parallel to the c-axis, and are geometrically consistent with formation by dislocation creep associated with <100>{010} slip. The deformation bands are unlike

  1. News Almost dry but never dull: ASE 2014 EuroPhysicsFun shows physics to Europe Institute of Physics for Africa (IOPfA) South Sudan Report October 2013 Celebrating the centenary of x-ray diffraction The Niels Bohr Institute—an EPS Historical Site Nordic Research Symposium on Science Education (NFSUN) 2014: inquiry-based science education in technology-rich environments Physics World Cup 2013

    NASA Astrophysics Data System (ADS)

    2014-03-01

    Almost dry but never dull: ASE 2014 EuroPhysicsFun shows physics to Europe Institute of Physics for Africa (IOPfA) South Sudan Report October 2013 Celebrating the centenary of x-ray diffraction The Niels Bohr Institute—an EPS Historical Site Nordic Research Symposium on Science Education (NFSUN) 2014: inquiry-based science education in technology-rich environments Physics World Cup 2013

  2. American Influence on Chinese Physics Study in the Early Twentieth Century

    NASA Astrophysics Data System (ADS)

    Hu, Danian

    2016-01-01

    To save China from the perils she faced in the early twentieth century, the majority of the Chinese seemed to agree that it was necessary to strengthen the country by developing shiye or industry and commerce. For this purpose, they overhauled China's education system and sent a large number of students to study overseas. Many of them enrolled in American colleges, sponsored either by governmental grants or by private funds. As American physics advanced rapidly during the early twentieth century, Chinese physicists studying in top US institutions received first-class professional training. They later went on to become a main driving force in Chinese physics development. The study-in-America programs were apparently more successful than other study-overseas programs. Among other factors, the historical lessons learned from the aborted Chinese Educational Mission in the 1870s, the prevalent and long-time presence of American mission schools in China, and stable public and private funding contributed to their success. American-trained Chinese physicists not only advanced physics study in China but also played leading roles in the development of Chinese science and technology during the twentieth century. This fertile and far-reaching American influence has been embedded in all their accomplishments.

  3. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    NASA Astrophysics Data System (ADS)

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2015-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8 to 415 μm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 data sets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-2012 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38-69,264 km2). An unrealistically low computed effective density (mass SSC/volumetric SSC) of 1.24 g/mL (95% confidence interval: 1.05-1.45 g/mL) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over two orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/mL (range: 2.56-2.87 g/mL, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  4. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    USGS Publications Warehouse

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2014-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 datasets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-12 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38 – 69,264 km2). An unrealistically low computed effective density (mass SSC / volumetric SSC) of 1.24 g/ml (95% confidence interval: 1.05-1.45 g/ml) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over 2 orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/ml (range: 2.56-2.87 g/ml, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  5. A Geophysical and Archaeological Analysis of Early Formative Physical Environments at Los Naranjos, Honduras

    NASA Astrophysics Data System (ADS)

    Tchakirides, T. F.; Brown, L. D.; Henderson, J. S.; Joyce, R. A.

    2006-12-01

    During the summer of 2003, ground-penetrating radar (GPR) and magnetometry data were acquired at the archaeological site of Los Naranjos, Honduras, one of the earliest archaeological sites in Mesoamerica with monumental architecture and sculpture and one of the easternmost sites in which Olmec artifacts have been recovered. The site was occupied continuously from the Early Formative to the Early Postclassic Periods, with large-scale monumental earthen platform construction occurring during much of its occupation. Geophysical surveys were undertaken in the open plaza areas in the Principal Group, where some of the largest platforms were constructed early in the history of the site. GPR data were collected with 50, 100, 200, and 250 MHz antennae in both 2-dimensional grids and linear profiles, with penetration in excess of 5 meters in some locations. Magnetometry data collection provided a much greater areal coverage of the site, but both methods covered both apparent archaeological and geological features. In some cases, correlation between the geophysical methods is strong, especially when integrated with archaeological information. Interpretation of the geophysical data, combined with analysis of cultural material from archaeological excavations, are helping to understand how the construction and significant expansion of large earthen platform mounds altered the Early Formative physical environment in dramatic ways, both reflecting and intensifying social differentiation and concentration of political power and generating both intended and unintended consequences.

  6. Research on Early Warning of Chinese Food Safety Based on Social Physics

    NASA Astrophysics Data System (ADS)

    Ma, Yonghuan; Niu, Wenyuan; Li, Qianqian

    Based on social physics, this paper designs the index system of food safety, builds early warning model of food safety, calculates the degree of food safety, and assesses the state of early warning of 2007 in China. The result shows the degree of food safety is near 0.7 in securer state, belonging to slight emergency. It is much lower in eastern areas of developed regions, belonging to insecure state in the mass. That the food safety is ensured in major grain producing areas, Inner Mongolia, Ningxia and Xinjiang is the prerequisite of realizing the food safety of China. The result also shows four significant indices, grain production capacity, grain circulation order, grain demand and grain supply, which are important indicatio to control food safety.

  7. Early physical and motor development of mouse offspring exposed to valproic acid throughout intrauterine development.

    PubMed

    Podgorac, Jelena; Pešić, Vesna; Pavković, Željko; Martać, Ljiljana; Kanazir, Selma; Filipović, Ljupka; Sekulić, Slobodan

    2016-09-15

    Clinical research has identified developmental delay and physical malformations in children prenatally exposed to the antiepileptic drug (AED) valproic acid (VPA). However, the early signs of neurodevelopmental deficits, their evolution during postnatal development and growth, and the dose effects of VPA are not well understood. The present study aimed to examine the influence of maternal exposure to a wide dose range (50, 100, 200 and 400mg/kg/day) of VPA during breeding and gestation on early physical and neuromotor development in mice offspring. Body weight gain, eye opening, the surface righting reflex (SRR) and tail suspension test (TST) were examined in the offspring at postnatal days 5, 10 and 15. We observed that: (1) all tested doses of VPA reduced the body weight of the offspring and the timing of eye opening; (2) offspring exposed to VPA displayed immature forms of righting and required more time to complete the SRR; (3) latency for the first immobilization in the TST is shorter in offspring exposed to higher doses of VPA; however, mice in all groups exposed to VPA exhibited atypical changes in this parameter during the examined period of maturation; (4) irregularities in swinging and curling activities were observed in animals exposed to higher doses of VPA. This study points to delayed somatic development and postponed maturation of the motor system in all of the offspring prenatally exposed to VPA, with stronger effects observed at higher doses. The results implicate that the strategy of continuous monitoring of general health and achievements in motor milestones during the early postnatal development in prenatally VPA-exposed offspring, irrespectively of the dose applied, could help to recognize early developmental irregularities.

  8. Predicting Early Adolescents' Academic Achievement, Social Competence, and Physical Health from Parenting, Ego Resilience, and Engagement Coping

    ERIC Educational Resources Information Center

    Swanson, Jodi; Valiente, Carlos; Lemery-Chalfant, Kathryn; O'Brien, T. Caitlin

    2011-01-01

    This study examined ego resilience and engagement coping as mediators of the relationships between supportive and controlling parenting practices and early adolescents' academic achievement, social competence, and physical health. Participants were 240 predominantly Mexican American early adolescents, their parents, and their teachers. There were…

  9. Early maternal and paternal bonding, childhood physical abuse and adult psychopathic personality

    PubMed Central

    Gao, Y.; Raine, A.; Chan, F.; Venables, P. H.; Mednick, S. A.

    2013-01-01

    Background A significant gap in the literature on risk factors for psychopathy is the relative lack of research on parental bonding. Method This study examines the cross-sectional relationship between maternal and paternal bonding, childhood physical abuse and psychopathic personality at age 28 years in a community sample of 333 males and females. It also assesses prospectively whether children separated from their parents in the first 3 years of life are more likely to have a psychopathic-like personality 25 years later. Results Hierarchical regression analyses indicated that: (1) poor parental bonding (lack of maternal care and low paternal overprotection) and childhood physical abuse were both associated with a psychopathic personality; (2) parental bonding was significantly associated with psychopathic personality after taking into account sex, social adversity, ethnicity and abuse; (3) those separated from parents in the first 3 years of life were particularly characterized by low parental bonding and a psychopathic personality in adulthood; and (4) the deviant behavior factor of psychopathy was more related to lack of maternal care whereas the emotional detachment factor was related to both lack of maternal care and paternal overprotection. Conclusions Findings draw attention to the importance of different components of early bonding in relation to adult psychopathy, and may have potential implications for early intervention and prevention of psychopathy. PMID:20441692

  10. Motor and functional recovery after neck dissection: comparison of two early physical rehabilitation programmes.

    PubMed

    Baggi, F; Santoro, L; Grosso, E; Zanetti, C; Bonacossa, E; Sandrin, F; Massaro, M A; Tradati, N; Simoncini, M C

    2014-08-01

    The aim of this prospective, single-centre, non-randomized explorative study is to comparatively assess two-month results of two early rehabilitation programmes in patients receiving neck dissection for head and neck cancer, with the hypothesis that those not receiving therapist-assisted physiotherapy would take an active role in their own rehabilitation to enhance outcomes. At the European Institute of Oncology, Milan (Italy), 97 patients were registered during the pre-hospitalization period and divided into an Autonomous group (living distant from the hospital) and a Physio group (living near). As expected, only 50 patients (25 per group) completed the study. Both groups received a Physical Therapy Brochure with instructions on to how to perform exercises at home. Home physical exercises started five days after surgery and continued for two months. The Autonomous group received a pre-surgery instruction session; the Physio group attended four once-weekly therapist-guided physiotherapy sessions. Two months after surgery, arm mobility and pain had recovered to pre-operative levels. Most endpoints, including the main composite, did not differ between groups. Although longer-follow-up is necessary, early physiotherapy seems to be effective in maintaining arm mobility and reducing pain, even in patients empowered to do exercises autonomously.

  11. Early motor skill competence as a mediator of child and adult physical activity

    PubMed Central

    Loprinzi, Paul D.; Davis, Robert E.; Fu, Yang-Chieh

    2015-01-01

    Objective: In order to effectively promote physical activity (PA) during childhood, and across the lifespan, a better understanding of the role of early motor skill development on child and adult PA is needed. Methods: Here, we propose a conceptual model delineating the hypothesized influence of motor skill development on child and adult PA, while providing an overview of the current empirical research related to this model. Results: There is consistent and emerging evidence showing that adequate motor skill competence, particularly locomotor and gross motor skills, is associated with increased PA levels during the preschool, child, and adolescent years, with early motor skill development also influencing enjoyment of PA as well as long-term PA and motor skill performance. The physical education setting appears to be a well-suited environment for motor skill development. Conclusion: Employing appropriate strategies to target motor skill development across the childhood years is of paramount interest in helping shape children's PA behavior, their experiences related to PA, as well as maintain their PA. PMID:26844157

  12. Bridging Empirical and Physical Approaches for Landslide Monitoring and Early Warning

    NASA Technical Reports Server (NTRS)

    Kirschbaum, Dalia; Peters-Lidard, Christa; Adler, Robert; Kumar, Sujay; Harrison, Ken

    2011-01-01

    Rainfall-triggered landslides typically occur and are evaluated at local scales, using slope-stability models to calculate coincident changes in driving and resisting forces at the hillslope level in order to anticipate slope failures. Over larger areas, detailed high resolution landslide modeling is often infeasible due to difficulties in quantifying the complex interaction between rainfall infiltration and surface materials as well as the dearth of available in situ soil and rainfall estimates and accurate landslide validation data. This presentation will discuss how satellite precipitation and surface information can be applied within a landslide hazard assessment framework to improve landslide monitoring and early warning by considering two disparate approaches to landslide hazard assessment: an empirical landslide forecasting algorithm and a physical slope-stability model. The goal of this research is to advance near real-time landslide hazard assessment and early warning at larger spatial scales. This is done by employing high resolution surface and precipitation information within a probabilistic framework to provide more physically-based grounding to empirical landslide triggering thresholds. The empirical landslide forecasting tool, running in near real-time at http://trmm.nasa.gov, considers potential landslide activity at the global scale and relies on Tropical Rainfall Measuring Mission (TRMM) precipitation data and surface products to provide a near real-time picture of where landslides may be triggered. The physical approach considers how rainfall infiltration on a hillslope affects the in situ hydro-mechanical processes that may lead to slope failure. Evaluation of these empirical and physical approaches are performed within the Land Information System (LIS), a high performance land surface model processing and data assimilation system developed within the Hydrological Sciences Branch at NASA's Goddard Space Flight Center. LIS provides the

  13. Effects of Perinatal HIV Infection and Early Institutional Rearing on Physical and Cognitive Development of Children in Ukraine

    ERIC Educational Resources Information Center

    Dobrova-Krol, Natasha A.; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie

    2010-01-01

    To study the effects of perinatal HIV-1 infection and early institutional rearing on the physical and cognitive development of children, 64 Ukrainian uninfected and HIV-infected institutionalized and family-reared children were examined (mean age = 50.9 months). Both HIV infection and institutional care were related to delays in physical and…

  14. Immersion francaise precoce: Education physique 1-7 (Early French Immersion: Physical Education for Grades 1-7).

    ERIC Educational Resources Information Center

    Burt, Andy; And Others

    This curriculum guide for physical education is intended for use in grades 1-7 in the early French immersion program. It is a translation of the regular physical education program and a compilation of references and supplementary teaching material. It is noted that because of the comparative lack of references in French, much of the reference…

  15. Early reduction in toe flexor strength is associated with physical activity in elderly men

    PubMed Central

    Suwa, Masataka; Imoto, Takayuki; Kida, Akira; Yokochi, Takashi

    2016-01-01

    [Purpose] To compare the toe flexor, hand grip and knee extensor strengths of young and elderly men, and to examine the association between toe flexor strength and physical activity or inactivity levels. [Subjects and Methods] Young (n=155, 18–23 years) and elderly (n=60, 65–88 years) men participated in this study. Toe flexor, hand grip, and knee extensor strength were measured. Physical activity (time spent standing/walking per day) and inactivity (time spent sitting per day) were assessed using a self-administered questionnaire. [Results] Toe flexor, hand grip, and knee extensor strength of the elderly men were significantly lower than those of the young men. Standing/walking and sitting times of the elderly men were lower than those of the young men. Toe flexor strength correlated with hand grip and knee extensor strength in both groups. In elderly men, toe flexor strength correlated with standing/walking time. In comparison to the young men’s mean values, toe flexor strength was significantly lower than knee extensor and hand grip strength in the elderly group. [Conclusion] The results suggest that age-related reduction in toe flexor strength is greater than those of hand grip and knee extensor strengths. An early loss of toe flexor strength is likely associated with reduced physical activity in elderly men. PMID:27313353

  16. Maternal prenatal smoking, parental antisocial behavior, and early childhood physical aggression.

    PubMed

    Huijbregts, Stephan C J; Séguin, Jean R; Zoccolillo, Mark; Boivin, Michel; Tremblay, Richard E

    2008-01-01

    This study investigated joint effects of maternal prenatal smoking and parental history of antisocial behavior on physical aggression between ages 17 and 42 months in a population sample of children born in Québec (N = 1,745). An analysis of variance (ANOVA) showed significant main effects of maternal prenatal smoking and a significant interaction between maternal prenatal smoking and mother's history of antisocial behavior in the prediction of children's probability to display high and rising physical aggression. The interaction indicated that the effects of heavy smoking during pregnancy (> or =10 cigarettes/day) were greater when the mother also had a serious history of antisocial behavior. The effects remained significant after the introduction of control variables (e.g., hostile-reactive parenting, family functioning, parental separation/divorce, family income, and maternal education). Another significant interaction not accounted for by control variables was observed for maternal prenatal smoking and family income, indicating more serious effects of maternal prenatal smoking under relatively low-income, conditions. Both interactions indicate critical adversities that, in combination with maternal prenatal smoking, have supra-additive effects on (the development of) physical aggression during early childhood. These findings may have implications for the selection of intervention targets and strategies. PMID:18423088

  17. Continuity and Change in Social and Physical Aggression from Middle Childhood through Early Adolescence

    PubMed Central

    Underwood, Marion K.; Beron, Kurt J.; Rosen, Lisa H.

    2009-01-01

    For a sample followed from age 9–13 (N=281), this investigation examined developmental trajectories for social and physical aggression as measured by teacher ratings. Trajectories for both forms of aggression were estimated first separately, then jointly. Mean levels of both social and physical aggression decreased over time for the overall sample, but with high variability of individual trajectories. Subgroups followed high trajectories for both social and physical aggression. Joint estimation yielded six trajectories: low stable, low increasers, medium increasers, medium desisters, high desisters, and high increasers. Membership in the high increaser group was predicted by male gender, unmarried parents, African American ethnicity, and maternal authoritarian and permissive parenting. Permissive parenting also predicted membership in the medium increaser group. This is one of the first studies to examine social aggression longitudinally across this developmental period. Though the results challenge the claim that social aggression is at its peak in early adolescence, the findings emphasize the importance of considering different developmental trajectories in trying to understand origins and outcomes of aggression. PMID:19685551

  18. Physical aggression, spreading of rumors, and social prominence in early adolescence: reciprocal effects supporting gender similarities?

    PubMed

    Juvonen, Jaana; Wang, Yueyan; Espinoza, Guadalupe

    2013-12-01

    There is a robust association between aggression and social prominence by early adolescence, yet findings regarding the direction of influence remain inconclusive in light of gender differences across various forms of aggressive behaviors. The current study examined whether physical aggression and spreading of rumors, as two gender-typed aggressive behaviors that differ in overt displays of power, promote and/or maintain socially prominent status for girls and boys during non-transitional grades in middle school. Peer nominations were used to assess physical aggression, spreading of rumors, and "cool" reputation (social prominence) during three time points between the spring of seventh grade and spring of eighth grade. Participants included 1,895 (54 % female) ethnically diverse youth: 47 % Latino, 22 % African-American, 11 % Asian, 10 % White and 10 % Other/Mixed ethnic background. Cross-lagged path analyses were conducted to test the directionality of the effects, and gender moderation was assessed by relying on multi-group analyses. The analyses revealed mainly reciprocal associations for each form of aggression, suggesting that boys, as well as girls, can both gain and maintain their status by spreading rumors about their peers, just as they do by physically fighting and pushing others in urban middle schools. The implications of the findings for interventions are discussed.

  19. Early reduction in toe flexor strength is associated with physical activity in elderly men.

    PubMed

    Suwa, Masataka; Imoto, Takayuki; Kida, Akira; Yokochi, Takashi

    2016-05-01

    [Purpose] To compare the toe flexor, hand grip and knee extensor strengths of young and elderly men, and to examine the association between toe flexor strength and physical activity or inactivity levels. [Subjects and Methods] Young (n=155, 18-23 years) and elderly (n=60, 65-88 years) men participated in this study. Toe flexor, hand grip, and knee extensor strength were measured. Physical activity (time spent standing/walking per day) and inactivity (time spent sitting per day) were assessed using a self-administered questionnaire. [Results] Toe flexor, hand grip, and knee extensor strength of the elderly men were significantly lower than those of the young men. Standing/walking and sitting times of the elderly men were lower than those of the young men. Toe flexor strength correlated with hand grip and knee extensor strength in both groups. In elderly men, toe flexor strength correlated with standing/walking time. In comparison to the young men's mean values, toe flexor strength was significantly lower than knee extensor and hand grip strength in the elderly group. [Conclusion] The results suggest that age-related reduction in toe flexor strength is greater than those of hand grip and knee extensor strengths. An early loss of toe flexor strength is likely associated with reduced physical activity in elderly men. PMID:27313353

  20. Application of radiation physics to improve dosimetry in early breast cancer radiotherapy

    SciTech Connect

    Donovan, Ellen Mary

    2005-07-15

    Radiotherapy for early breast cancer has been shown to be a highly effective treatment in a number of long term studies. The radiation dose uniformity of the current standard treatments is often poor, however, with dose variations across the breast much higher than those recommended in international guidelines. This work aimed to explore methods for improving this aspect of the radiation dosimetry of early breast cancer radiotherapy. An experimental method was validated by applying it to computed tomography data from 14 patients with a variety of breast shapes and sizes. The volume of the breast receiving the desired dose levels increased by a mean of 6.9% (range -0.8% to 15.9%) and this benefit was shown to increase with breast volume. The quality of reference images in the verification of treatments was improved by introducing differential filtering to the imaging beams on a radiotherapy simulator. The positive results from the first two studies were applied in a clinical trial (which used the experimental technique). The unique set of data from the trial was analyzed and confirmation of dosimetric improvement, and the increased benefit, for larger breasted women were found. In addition, an analysis of the position of high doses showed these occurred in the upper or lower third of the breast and affected 46% and 30% of patients, respectively, with standard treatment but only 1% of patients with the improved method. Other published methods for improving breast dosimetry were explored by building a simple physical model and carrying out a comparative planning study. The physical model was shown to be effective in predicting the dosimetric consequences of each method. The planning study showed that there was little difference between the methods generally but dosimetric improvement could be increased for larger breast volumes by an appropriate choice of technique. A final study explored how breathing control could be used to reduce cardiac doses in patients with

  1. Two-dimensional models of early-type fast rotating stars: new challenges in stellar physics

    NASA Astrophysics Data System (ADS)

    Rieutord, M.; Espinosa Lara, F.

    2013-12-01

    Two-dimensional models of rapidly rotating stars are already unavoidable for the interpretation of interferometric or asteroseismic data of this kind of stars. When combined with time evolution, they will allow the including of a more accurate physics for the computation of element transport and the determination of surface abundances. In addition, modeling the evolution of rotation will improve gyrochronology. Presently, two-dimensional ESTER models predict the structure and the large-scale flows (differential rotation and meridional circulation) of stars with mass larger than 1.7 M⊙ at any rotation rate. Main sequence evolution can be mimicked by varying the hydrogen content of the convective core. Models have been successfully tested on half a dozen of nearby fast rotating stars observed with optical or infra-red interferometers. They are now the right tool to investigate the oscillation spectrum of early-type fast rotators.

  2. Gravitational waves: A probe to the physics in the early universe

    NASA Astrophysics Data System (ADS)

    Huang, Qing-Guo

    2015-10-01

    Gravitational waves can escape from the big bang and can be taken as a probe to the physics, in particular the inflation, in the early universe. Planck scale is a fundamental scale for quantum theory of gravity. Requiring the excursion distance of inflaton in the field space during inflation yields an upper bound on the tensor-to-scalar ratio. For example, r < 7 × 10-4 for ns = 0.9645. In the typical inflationary scenario, we predict 1 - 2/N < ns < 1 and - 2/N2 < α s < 0 which are consistent with Planck data released in 2015 quite well. Subtracting the contribution of thermal dust measured by Planck, BICEP2 data implies r ≲ 0.08 which is the tightest bound on the tensor-to-scalar ratio from current experiments.

  3. The physics of a cell doublet: a minimal system to study early embryo morphogenesis

    NASA Astrophysics Data System (ADS)

    Turlier, Herve; Maitre, Jean-Leon; Hiiragi, Takashi; Nedelec, Francois

    2015-03-01

    In early embryos, the shape of cells is determined in part by the actomyosin cortex and in part by interactions with the surrounding environment. Cell-cell adhesion, in particular, is determinant for the overall embryo organization. This complex interplay between cell autonomous mechanical properties and cell-cell interactions can advantageously be analyzed in pairs of isolated cells. We study theoretically and experimentally shape changes in doublets of mouse embryo blastomeres. Simple scaling analysis and numerical simulations can predict the various configurations adopted by blastomere doublets over different stages of embryo development. Our study provides a simple and robust physical framework to understand and characterize quantitatively diverse morphogenetic events such as compaction, entosis and cell internalization.

  4. Dust Plate, Retina, Photograph: Imaging on Experimental Surfaces in Early Nineteenth-Century Physics.

    PubMed

    Ramalingam, Chitra

    2015-09-01

    This article explores the entangled histories of three imaging techniques in early nineteenth-century British physical science, techniques in which a dynamic event (such as a sound vibration or an electric spark) was made to leave behind a fixed trace on a sensitive surface. Three categories of "sensitive surface" are examined in turn: first, a metal plate covered in fine dust; second, the retina of the human eye; and finally, a surface covered with a light-sensitive chemical emulsion (a photographic plate). For physicists Michael Faraday and Charles Wheatstone, and photographic pioneer William Henry Fox Talbot, transient phenomena could be studied through careful observation and manipulation of the patterns wrought on these different surfaces, and through an understanding of how the imaging process unfolded through time. This exposes the often-ignored materiality and temporality of epistemic practices around nineteenth-century scientific images said to be "drawn by nature."

  5. Dust Plate, Retina, Photograph: Imaging on Experimental Surfaces in Early Nineteenth-Century Physics.

    PubMed

    Ramalingam, Chitra

    2015-09-01

    This article explores the entangled histories of three imaging techniques in early nineteenth-century British physical science, techniques in which a dynamic event (such as a sound vibration or an electric spark) was made to leave behind a fixed trace on a sensitive surface. Three categories of "sensitive surface" are examined in turn: first, a metal plate covered in fine dust; second, the retina of the human eye; and finally, a surface covered with a light-sensitive chemical emulsion (a photographic plate). For physicists Michael Faraday and Charles Wheatstone, and photographic pioneer William Henry Fox Talbot, transient phenomena could be studied through careful observation and manipulation of the patterns wrought on these different surfaces, and through an understanding of how the imaging process unfolded through time. This exposes the often-ignored materiality and temporality of epistemic practices around nineteenth-century scientific images said to be "drawn by nature." PMID:26256503

  6. Early intervention and child physical health: Evidence from a Dublin-based randomized controlled trial.

    PubMed

    Doyle, Orla; Fitzpatrick, Nick; Lovett, Judy; Rawdon, Caroline

    2015-12-01

    This article investigates the impact of an early intervention program, which experimentally modifies the parenting and home environment of disadvantaged families, on child physical health in the first 3 years of life. We recruited and randomized 233 (115 intervention, 118 control) pregnant women from a socioeconomically disadvantaged community in Dublin, Ireland into an intervention or control group. The treatment includes regular home visits commencing antenatally and an additional parenting course commencing at 2 years. Maternal reports of child health are assessed at 6, 12, 18, 24, and 36 months. Treatment effects are estimated using permutation testing to account for small sample size, inverse probability weighting to account for differential attrition, and both the stepdown procedure and an indices approach to account for multiple hypothesis testing. Following adjustment for multiple testing and attrition, we observe a positive and statistically significant main treatment effect for wheezing/asthma. The intervention group are 15.5 percentage points (pp) less likely to require medical attention for wheezing/asthma compared to the control group. Subgroup analysis reveals more statistically significant adjusted treatment effects for boys than girls regarding fewer health problems (d=0.63), accidents (23.9pp), and chest infections (22.8-37.9pp). Our results suggest that a community-based home visiting program may have favorable impacts on early health conditions.

  7. Radiometric analysis of diffraction

    NASA Astrophysics Data System (ADS)

    Castañeda, R.; Betancur, R.; Herrera, J.; Carrasquilla, J.

    2008-04-01

    A description of Fresnel and Fraunhofer diffraction of quasi-homogenous optical fields in any state of spatial coherence is presented, which clearly differs from the classical formalism. Instead of the propagation of the cross-spectral density from the diffracting aperture to the observation plane, the diffracting aperture is regarded as a planar quasi-homogeneous source, whose generalised radiance is carried by the spatial coherence wavelets, and the power distribution at the observation plane is expressed in terms of the generalised radiant intensity. It allows interpreting the negative values of the generalised radiance as "negative energies" emitted along specific directions and subjected to the achievement of the conservation law of energy. This interpretation is not evident in the classical formalism. Consequently, interference can be thought as resulting of energy transfer over a given wavefront, due to the addition of equal amounts of "positive" and "negative" energies, along specific directions, to the contributions provided by the individual radiators of the radiant source. In this sense, the radiant flux from the source, which is provided only by the individual contributions, is redistributed depending on the spatial coherence properties of the field. This redistribution characterises the diffraction phenomenon. It is also shown that the supports of the complex degree of spatial coherence near the aperture edge are vignetted by the edge. This feature is a cause for the generalised radiance providing "negative energies", and constitutes the actual effect of the edge on diffraction. The approach is validated by the close concordance between the numerical and the experimental results, which should be regarded as a proof of the physical existence of the spatial coherence wavelets.

  8. Early Adolescent Sexual Initiation and Physical/Psychological Symptoms: A Comparative Analysis of Five Nations

    PubMed Central

    Farhat, Tilda; Halpern, Carolyn Tucker; Godeau, Emmanuelle; Gabhainn, Saoirse Nic

    2010-01-01

    Although most people in developed countries experience sexual initiation during adolescence, little is known about inter-country variability in the psychosocial correlates of early initiation. Population-based samples of 15-year-olds (n = 6,111, 52% female) who participated in the Health Behaviors in School-Aged Children Study (Finland, Scotland, France and Poland, 1997/1998) or the National Longitudinal Study of Adolescent Health (United States, 1996) self-reported sexual intercourse experience and physical (headaches, trouble sleeping) or psychological (unhappiness, loneliness, sadness, moodiness) symptoms. Analyses were conducted stratified by gender. Sexual initiation prevalence and symptoms scores varied significantly across nations. In adjusted models, sexual initiation was not related to symptoms among boys in any nation, but significantly positively related to symptoms among girls in Poland and the US. Results support variability by gender and nation in the relationship between adolescents’ sexual initiation and physical/psychological symptoms. Empirically investigating specific features of national contexts that generate these differences should be explored further. PMID:20333456

  9. Psychosocial Correlates of Physical and Sedentary Activities of Early Adolescent Youth

    PubMed Central

    Rusby, Julie C.; Westling, Erika; Crowley, Ryann; Light, John M.

    2013-01-01

    This study examines physical and sedentary activities of early adolescent boys and girls using Ecological Momentary Assessment (EMA), a method that can link mood and behaviors in specific social situations. Twenty-seven assessments were collected across seven days from 82 participating adolescents, three times in seventh grade and one time in eighth grade. Assessments were completed during nonschool hours when youth had “free time.” Gender differences, longitudinal trends, and associations of physical activities (PA) and small screen recreation (SSR) with moods and peer presence are examined. Boys were engaged in PA more than girls. Patterns of PA differed by gender; boys significantly decreased PA from seventh to eighth grade, whereas girls had increased PA only during the spring. PA was associated with happier mood and was more likely to occur in the presence of peers. SSR significantly increased from seventh grade to eighth grade for both boys and girls. SSR occurred more when youth were alone, and was not associated with mood. Neither PA nor SSR were more likely to occur during weekdays or weekends. Implications for intervention efforts to increase PA in youth are discussed. PMID:23640122

  10. Diffraction techniques in engineering applications

    SciTech Connect

    Kozarczek, K.J.; Hubbard, C.R.; Watkins, T.R.; Wang, X.L.; Spooner, S.

    1995-12-31

    Diffraction techniques applied to crystalline materials provide quantitative information about the crystallographic structure and mechanical condition of the material. Those two characteristics influence the chemical, physical, and mechanical properties of a Component. A concerted application of x-ray and neutron diffraction allows one to comprehensively study the bulk and subsurface variations of such material characteristics as crystallographic texture, residual stress, and cold work. The Residual Stress User Center at the Oak Ridge National Laboratory offers academic and industrial researchers both neutron and x-ray diffraction capabilities. Recent examples of the application of work related to thin film, metal, ceramic and composite material technologies are presented.

  11. Possible underestimation by sports medicine of the effects of early physical exercise practice on the prevention of diseases in adulthood.

    PubMed

    Fernandes, Romulo Araujo; Coelho-E-Silva, Manuel Joao; Spiguel Lima, Manoel Carlos; Cayres, Suziane Ungari; Codogno, Jamile Sanches; Lira, Fabio Santos

    2015-01-01

    In modern society, combatting cardiovascular and metabolic diseases has been highlighted as an urgent global challenge. In recent decades, the scientific literature has identified that behavioral variables (e.g. smoking, unhealthy diet and physical inactivity) are related to the development of these outcomes and, therefore, preventive actions should focus on the promotion of physical exercise practice and a healthy diet, as well as combatting the smoking habit from an early age. The promotion of physical exercise in the general population has been suggested as a relevant goal by significant health organizations around the world. On the other hand, recent literature has indicated that physical exercise performed in early life prevents the development of diabetes mellitus, dyslipidemia and arterial hypertension during adulthood, although this protective effect seems to be independent of the physical activity performed during adulthood. Apparently, the interaction between physical exercise and human growth in early life constitutes an issue which is not completely understood by sports medicine. The aim of the present review was therefore to discuss recent evidence on the effects of physical exercise performed during childhood and adolescence on cardiovascular and metabolic outcomes in adulthood. PMID:25828743

  12. Physical Environmental Adversity and the Protective Role of Maternal Monitoring in Relation to Early Child Conduct Problems.

    PubMed

    Supplee, Lauren H; Unikel, Emily B; Shaw, Daniel S

    2007-01-01

    Research on the development of externalizing behaviors during early childhood has focused on child and parenting factors. Fewer studies have investigated effects of aversive features of the micro-level physical environment, such as overcrowding and chaos in the home, and the macro-level environment, such as neighborhood quality. This study extends research on physical environmental factors by examining their association with children's early externalizing behaviors, and exploring how maternal monitoring may serve as a protective factor in such contexts. 120 male toddlers at high risk for developing early externalizing behaviors were followed from ages 2 to 5 years. Direct longitudinal associations were found for micro-level environmental factors beginning at age 2 and for neighborhood risk beginning at age 3. Maternal monitoring served as a protective factor for child externalizing behaviors in the context of neighborhood risk. Implications for prevention research and the development of early externalizing behaviors are discussed.

  13. Mgat5 modulates the effect of early life stress on adult behavior and physical health in mice.

    PubMed

    Feldcamp, Laura; Doucet, Jean-Sebastien; Pawling, Judy; Fadel, Marc P; Fletcher, Paul J; Maunder, Robert; Dennis, James W; Wong, Albert H C

    2016-10-01

    Psychosocial adversity in early life increases the likelihood of mental and physical illness, but the underlying mechanisms are poorly understood. Mgat5 is an N-acetylglucosaminyltransferase in the Golgi pathway that remodels the N-glycans of glycoproteins at the cell surface. Mice lacking Mgat5 display conditional phenotypes in behaviour, immunity, metabolism, aging and cancer susceptibility. Here we investigated potential gene-environment interactions between Mgat5 and early life adversity on behaviour and physiological measures of physical health. Mgat5(-/-) mutant and Mgat5(+/+) wild-type C57Bl/6 littermates were subject to maternal separation or foster rearing as an early life stressor, in comparison to control mice reared normally. We found an interaction between Mgat5 genotype and maternal rearing condition in which Mgat5(-/-) mice subjected to early life stress had lower glucose levels and higher bone density. Mgat5(-/-) genotype was also associated with less immobility in the forced swim test and greater sucrose consumption, consistent with a less depression-like phenotype. Cortical neuron dendrite spine density and branching was altered by Mgat5 deletion as well. In general, Mgat5 genotype affects both behaviour and physical outcomes in response to early life stress, suggesting some shared pathways for both in this model. These results provide a starting point for studying the mechanisms by which protein N-glycosylation mediates the effects of early life adversity. PMID:27329152

  14. Attention Problems Mediate the Association between Severity of Physical Abuse and Aggressive Behavior in a Sample of Maltreated Early Adolescents.

    PubMed

    Garrido, Edward F; Taussig, Heather N; Culhane, Sara E; Raviv, Tali

    2011-10-01

    Empirical evidence has accumulated documenting an association between childhood physical abuse and aggressive behavior. Relatively fewer studies have explored possible mediating mechanisms that may explain this association. The purpose of the current study was to examine whether caregiver- and youth-reported attention problems mediate the association between physical abuse severity and aggressive behavior. A sample of 240 maltreated early adolescents (ages 9-11) and their caregivers were interviewed within 14 months of being removed from the home. Results from multiple regression analyses indicated that caregiver- and youth-reported attention problems were partial mediators of the association between physical abuse severity and aggressive behavior. These associations were significant even after controlling for children's intellectual functioning, sex, age, and severity of other maltreatment types. Possible explanations for the detrimental impact of physical abuse on behavior are discussed, along with the implications of the current study's results for interventions aimed at reducing early adolescent aggressive behavior. PMID:21966081

  15. Physical Activity in Early and Modern Populations. Papers from the Annual Meeting of the American Academy of Physical Education (59th, Las Vegas, Nevada, April 11-13, 1987). No. 21.

    ERIC Educational Resources Information Center

    Malina, Robert M., Ed.; Eckert, Helen M., Ed.

    Eleven conference papers explore physical activity in ancient societies as well as human adaptation of physical activities in modern society. The following papers are included: (1) "Physical Activity in Early and Modern Populations: An Evolutionary View" (Robert M. Malina); (2) "How Active Were Early Populations? or Squeezing the Fossil Record"…

  16. Documenting the conversion from traditional to Studio Physics formats at the Colorado School of Mines: Process and early results

    NASA Astrophysics Data System (ADS)

    Kohl, Patrick B.; Kuo, H. Vincent; Ruskell, Todd G.

    2008-10-01

    The Colorado School of Mines (CSM) has taught its first-semester introductory physics course using a hybrid lecture/Studio Physics format for several years. Over the past year we have converted the second semester of our calculus-based introductory physics course (Physics II) to a Studio Physics format, starting from a traditional lecture-based format. In this paper, we document the early stages of this conversion in order to better understand which features succeed and which do not, and in order to develop a model for switching to Studio that keeps the time and resource investment manageable. We describe the recent history of the Physics II course and of Studio at Mines, discuss the PER-based improvements that we are implementing, and characterize our progress via several metrics, including pre/post Conceptual Survey of Electricity and Magnetism (CSEM) scores, Colorado Learning About Science Survey scores (CLASS), solicited student comments, failure rates, and exam scores.

  17. Friendship Network Characteristics Are Associated with Physical Activity and Sedentary Behavior in Early Adolescence

    PubMed Central

    Marks, Jennifer; de la Haye, Kayla; Barnett, Lisa M; Allender, Steven

    2015-01-01

    Introduction There is limited understanding of the association between peer social networks and physical activity (PA), sedentary and screen-related behaviors. This study reports on associations between personal network characteristics and these important health behaviors for early adolescents. Methods Participants were 310 students, aged 11–13 years, from fifteen randomly selected Victorian primary schools (43% response rate). PA and sedentary behaviors were collected via accelerometer and self-report questionnaire, and anthropometric measures via trained researchers. Participants nominated up to fifteen friends, and described the frequency of interaction and perceived activity intensity of these friends. Personal network predictors were examined using regression modelling for PA and sedentary/screen behavior. Results Perceived activity levels of friends, and friendships with very frequent interaction were associated with outside-of-school PA and/or sedentary/screen time. Differences according to sex were also observed in the association between network characteristics and PA and sedentary time. A higher number of friends and greater proportion of same sex friends were associated with boys engaging in more moderate-to-vigorous PA outside of school hours. PA intensity during school-day breaks was positively associated with having a greater proportion of friends who played sports for girls, and a greater proportion of male friends for boys. Conclusion Friendship network characteristics are associated with PA and sedentary/screen time in late childhood/early adolescence, and these associations differ by sex. The positive influence of very active peers may be a promising avenue to strengthen traditional interventions for the promotion of PA and reduction in screen time. PMID:26709924

  18. Husbands' and Wives' Marital Adjustment, Verbal Aggression, and Physical Aggression as Longitudinal Predictors of Physical Aggression in Early Marriage

    ERIC Educational Resources Information Center

    Schumacher, Julie A.; Leonard, Kenneth E.

    2005-01-01

    Marital adjustment, verbal aggression, and physical aggression have long been associated in the marital literature, but the nature of their associations remains unclear. In this study, the authors examined these 3 constructs as risk factors for physical aggression during the first 2 years of marriage in 634 couples recruited as they applied for…

  19. Potentially Missing Physics of the Early Universe: Nonlinear Vacuum Polarization in Intense Blackbody Radiation

    SciTech Connect

    Wu, S Q; Hartemann, F V

    2010-04-13

    The standard Big Bang universe model is mainly based on linear interactions, except during exotic periods such as inflation. The purpose of the present proposal is to explore the effects, if any, of vacuum polarization in the very high energy density environment of the early universe. These conditions can be found today in astrophysical settings and may also be emulated in the laboratory using high intensity advanced lasers. Shortly after the Big Bang, there once existed a time when the energy density of the universe corresponded to a temperature in the range 10{sup 8} - 10{sup 9} K, sufficient to cause vacuum polarization effects. During this period, the nonlinear vacuum polarization may have had significant modifications on the propagation of radiation. Thus the thermal spectrum of the early universe may have been starkly non-Planckian. Measurements of the cosmic microwave background today show a spectrum relatively close to an ideal blackbody. Could the early universe have shown spectral deviations due to nonlinear vacuum effects? If so, is it possible to detect traces of those relic photons in the universe today? Found in galactic environments, compact objects such as blazars and magnetars can possess astronomically large energy densities that far exceed anything that can be created in the laboratory. Their field strengths are known to reach energy levels comparable to or surpassing the energy corresponding to the Schwinger critical field E {approx} 10{sup 18} V/m. Nonlinear vacuum effects become prominent under these conditions and have garnered much interest from the astronomical and theoretical physics communities. The effects of a nonlinear vacuum may be of crucial importance for our understanding of these objects. At energies of the order of the electron rest mass, the most important interactions are described by quantum electrodynamics (QED). It is predicted that nonlinear photon-photon interactions will occur at energies approaching the Schwinger

  20. Early MIMD experience with a plasma physics simulation program on the CRAY X-MP

    SciTech Connect

    Rhoades, C.E. Jr.

    1986-02-01

    This paper describes some early experience with converting a plasma physics simulation program to the CRAY X-MP, a current multiple instruction, multiple data (MIMD) computer consisting of two processors with architecture similar to that of the CRAY-1. The computer program used in this study is an all Fortran version of SELF, a two species, one space, two velocity, electromagnetic, Newtonian, particle in cell, plasma simulation code. The approach to converting SELF to use both processors of the CRAY X-MP is described in some detail. The resulting multiprocessor version of SELF is nearly a factor of two faster in real time than the single processor version. The multiprocessor version obtains 58.2+-.1 seconds of central processor time in 30+-.5 seconds of real time. For comparison, the CRAY-1 execution time if 74.5 seconds. For SELF, which is mostly scalar coding, the CRAY X-MP is about 2.5 times faster overall than the CRAY-1.

  1. Parent and Peer Predictors of Physical Dating Violence Perpetration in Early Adolescence: Tests of Moderation and Gender Differences

    ERIC Educational Resources Information Center

    Miller, Shari; Gorman-Smith, Deborah; Sullivan, Terri; Orpinas, Pamela; Simon, Thomas R.

    2009-01-01

    This study examined parenting and peer predictors of physical dating violence perpetration during early adolescence and tested moderation among these predictors and gender. Participants were 2,824 ethnically diverse sixth-grade students with a recent boyfriend/girlfriend who was part of a multisite, longitudinal investigation of the development…

  2. A Comparison of Student Knowledge between Traditional and Blended Instruction in a Physical Education in Early Childhood Course

    ERIC Educational Resources Information Center

    Giannousi, Maria; Vernadakis, Nikolaos; Derri, Vassiliki; Antoniou, Panagiotis; Kioumourtzoglou, Efthimis

    2014-01-01

    Blended learning model combines different advantages of face to face education and e-learning to ensure an effective learning environment for students. The purpose of this study was to investigate the impact of traditional and blended instruction, in students' knowledge in a Physical Education in Early Childhood course. For the purpose of…

  3. Physical Environmental Adversity and the Protective Role of Maternal Monitoring in Relation to Early Child Conduct Problems

    ERIC Educational Resources Information Center

    Supplee, Lauren H.; Unikel, Emily B.; Shaw, Daniel S.

    2007-01-01

    Research on the development of externalizing behaviors during early childhood has focused on child and parenting factors. Fewer studies have investigated effects of aversive features of the micro-level physical environment, such as overcrowding and chaos in the home, and the macro-level environment, such as neighborhood quality. This study extends…

  4. Body Size at Birth, Physical Development and Cognitive Outcomes in Early Childhood: Evidence from the Longitudinal Survey of Australian Children

    ERIC Educational Resources Information Center

    Ulker, Aydogan

    2016-01-01

    Using a rich sample created from the Longitudinal Survey of Australian Children, we investigate the extent to which the relationship between body size at birth and early childhood cognitive skills is mediated by physical development indicators. Consistent with existing evidence from other countries, we find a significant relationship between body…

  5. Behavioral Activation as an Early Intervention for Posttraumatic Stress Disorder and Depression among Physically Injured Trauma Survivors

    ERIC Educational Resources Information Center

    Wagner, Amy W.; Zatzick, Douglas F.; Ghesquiere, Angela; Jurkovich, Gregory J.

    2007-01-01

    This paper describes an adaptation of behavioral activation (BA) for the early intervention of posttraumatic stress disorder (PTSD) and depression among physically injured survivors of traumatic injury, and presents pilot data on a small randomized effectiveness trial (N = 8). The application of BA to PTSD is based on the theory that increases in…

  6. Music and Physical Play: What Can We Learn from Early Childhood Teachers in Kenya?

    ERIC Educational Resources Information Center

    Freshwater, Amy; Sherwood, Elizabeth; Mbugua, Esther

    2008-01-01

    Sharing classroom practices across international borders can add new dimensions to teaching methods, no matter where one calls home. With this idea in mind, the authors (two U.S. early childhood teacher educators and a Kenyan-born U.S. early childhood teacher) have corresponded for several years through e-mail with a small group of early childhood…

  7. The prompt-early afterglow connection in gamma-ray bursts: implications for the early afterglow physics

    NASA Astrophysics Data System (ADS)

    Hascoët, R.; Daigne, F.; Mochkovitch, R.

    2014-07-01

    The early X-ray afterglow of gamma-ray bursts revealed by Swift carried many surprises. Following an initial steep decay the light curve often exhibits a plateau phase that can last up to several 104 s, with in addition the presence of flares in 50 per cent of the cases. We focus in this paper on the plateau phase whose origin remains highly debated. We confront several newly discovered correlations between prompt and afterglow quantities (isotropic emitted energy in gamma-rays, luminosity and duration of the plateau) to several models proposed for the origin of plateaus in order to check if they can account for these observed correlations. We first show that the scenario of plateau formation by energy injection into the forward shock leads to an efficiency crisis for the prompt phase and therefore study two possible alternatives: the first one still takes place within the framework of the standard forward shock model but allows for a variation of the microphysics parameters to reduce the radiative efficiency at early times; in the second scenario the early afterglow results from a long-lived reverse shock. Its shape then depends on the distribution of energy as a function of Lorentz factor in the ejecta. In both cases, we first present simple analytical estimates of the plateau luminosity and duration and then compute detailed light curves. In the two considered scenarios we find that plateaus following the observed correlations can be obtained under the condition that specific additional ingredients are included. In the forward shock scenario, the preferred model supposes a wind external medium and a microphysics parameter ɛe that first varies as n-ξ (n being the external density), with ξ ˜ 1 to get a flat plateau, before staying constant below a critical density n0. To produce a plateau in the reverse shock scenario the ejecta must contain a tail of low Lorentz factor with a peak of energy deposition at Γ ≳ 10.

  8. Simulation of blast-induced early-time intracranial wave physics leading to traumatic brain injury.

    PubMed

    Taylor, Paul A; Ford, Corey C

    2009-06-01

    The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm3 voxels) five material model of the human head was created by segmentation of color cryosections from the Visible Human Female data set. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior, and lateral directions. Three-dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric stress within the first 2 ms of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 ms time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early-time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI. PMID:19449961

  9. Study of the physical properties of a mesogenic mixture showing induced smectic A(d) phase by refractive index, density and x-ray diffraction measurements.

    PubMed

    Roy, P D; Prasad, A; Das, M K

    2009-02-18

    The binary mixture of 4-n-pentyl phenyl 4-n'-hexyloxy benzoate (ME6O.5) and p-cyanophenyl trans-4-pentyl cyclohexane carboxylate (CPPCC) shows the presence of an induced smectic A(d) phase in a certain concentration range 0.03diffraction measurements are reported here. In general, the change in birefringence is continuous at the smectic A(d) to nematic phase transition for mixtures with x>0.33, whereas there is a discontinuity in these values for mixtures with x<0.33, consistent with the density and transition entropy measurements done on this system. The orientational order parameter, measured from x-ray diffraction studies, are somewhat smaller than those obtained from refractive index measurement in the induced smectic phase for all the mixtures. In the smectic phase, the OOP values initially increases with molar concentration up to x = 0.24 and then decreases showing a broad minima around x = 0.4. The variation of layer thickness in the induced smectic phase with composition has been explained by assuming the formation of homo- and heterodimers. We conclude that the possible packing of molecules in the induced smectic A(d) phase stabilizes the layers but increases the orientational free volume, consistent with the lower orientational order parameter.

  10. Implementing a Physical Activity Curriculum into the School Day: Helping Early Childhood Teachers Meet the Challenge

    ERIC Educational Resources Information Center

    Breslin, Casey Marie; Morton, Jane R.; Rudisill, Mary E.

    2008-01-01

    In Fall 2006, North Carolina kindergarten teachers were charged with the task of meeting the NASPE guidelines for providing daily physical activity to their kindergarten students. In turn, the teachers researched resources and consulted experts to design and develop a developmentally appropriate physical activity and physical play environment for…

  11. Comparing physical activity and sedentary time among overweight and nonoverweight preschoolers enrolled in early learning programs: a cross-sectional study.

    PubMed

    Tucker, Patricia; Maltby, Alana M; Burke, Shauna M; Vanderloo, Leigh M; Irwin, Jennifer D

    2016-09-01

    Establishing appropriate physical activity and sedentary behaviours during early childhood is important to ensure children accrue the many associated health benefits. While physical activity levels have been reported as low within early learning programs, little research has explored the physical activity and sedentary time of Canadian preschoolers classified as overweight within these facilities. The purpose of this study was to compare objectively measured physical activity and sedentary time among preschoolers classified as overweight and nonoverweight in early learning programs. Direct assessment of physical activity and sedentary time of 216 preschool-aged children was collected via Actical accelerometers during early learning hours, while body mass index percentile was calculated based on preschoolers' objectively measured height and weight. Results of three 3-way ANOVAs suggest that rates of moderate to vigorous physical activity, total physical activity, and sedentary time (p > 0.05) did not significantly differ based on weight status, sex, and type of early learning facility. This study is one of few that has examined differences in overweight and nonoverweight preschoolers' sedentary time, and adds to the limited research exploring physical activity levels among overweight and nonoverweight preschoolers during early learning hours. Given the high rates of sedentary time reported, programming within early learning facilities is necessary to support preschoolers, regardless of weight status, to achieve increased physical activity levels and decreased sedentary time. PMID:27532225

  12. Electronically- and crystal-structure-driven magnetic structures and physical properties of RScSb (R = rare earth) compounds. A neutron diffraction, magnetization and heat capacity study

    SciTech Connect

    Ritter, C; Dhar, S K; Kulkarni, R; Provino, A; Paudyal, Durga; Manfrinetti, Pietro; Gschneidner, Karl A

    2014-08-14

    The synthesis of the new equiatomic RScSb ( R = La-Nd, Sm, Gd-Tm, Lu, Y) compounds has been recently reported. These rare earth compounds crystallize in two different crystal structures, adopting the CeScSi-type ( I 4/ mmm) for the lighter R (La-Nd, Sm) and the CeFeSi-type (P4 /nmm) structure for the heavier R ( R = Gd-Tm, Lu, Y). Here we report the results of neutron diffraction, magnetization and heat capacity measurements on some of these compounds ( R = Ce, Pr, Nd, Gd and Tb). Band structure calculations have also been performed on CeScSb and GdScGe (CeScSi-type), and on GdScSb and TbScSb (CeFeSi-type) to compare and understand the exchange interactions in CeScSi and CeFeSi structure types. The neutron diffraction investigation shows that all five compounds order magnetically, with the highest transition temperature of 66 K in TbScSb and the lowest of about 9 K in CeScSb. The magnetic ground state is simple ferromagnetic (τ = [0 0 0]) in CeScSb, as well in NdScSb for 32 >T > 22 K. Below 22 K a second magnetic transition, with propagation vector τ = [¼ ¼ 0], appears in NdScSb. PrScSb has a magnetic structure within, determined by mostly ferromagnetic interactions and antiferromagnetic alignment of the Pr-sites connected through the I-centering ( τ = [1 0 0]). A cycloidal spiral structure with a temperature dependent propagation vector τ = [δ δ ½] is found in TbScSb. The results of magnetization and heat capacity lend support to the main conclusions derived from neutron diffraction. As inferred from a sharp peak in magnetization, GdScSb orders antiferromagnetically at 56 K. First principles calculations show lateral shift of spin split bands towards lower energy from the Fermi level as the CeScSi-type structure changes to the CeFeSi-type structure. This rigid shift may force the system to transform from exchange split ferromagnetic state to the antiferromagnetic state in RScSb compounds (as seen for example in GdScSb and TbScSb) and is proposed to

  13. Slurry Consistency and In-situ Synchrotron X-ray Diffraction during the Early Hydration of Portland Cements with Calcium Chloride

    SciTech Connect

    Jupe, A.C.; Wilkinson, A.P.; Luke, K.; Funkhouser, G.P.

    2008-07-08

    Class A and H oil well cements are compared at 25 and 50 C with 0%, 1%, 2%, and 4% CaCl{sub 2}. Up to 4% CaCl{sub 2} accelerated Class A thickening, but 4% led to slower thickening than 2% for Class H. C{sub 3}S hydration in the two cements responded differently to CaCl{sub 2}. CaCl{sub 2} always accelerated aluminate hydration. For Class A, CaCl{sub 2} accelerated early Ca(OH){sub 2} precipitation, but sometimes reduced the amount at longer times. This may be coupled to C-S-H gel composition changes. For Class H, Ca(OH){sub 2} precipitation changes nonlinearly with CaCl{sub 2} concentration. Ettringite to monosulfate conversion and Friedel's salt formation were sometimes seen.

  14. Inquiry with Laser Printer Diffraction Gratings

    ERIC Educational Resources Information Center

    Van Hook, Stephen J.

    2007-01-01

    The pages of "The Physics Teacher" have featured several clever designs for homemade diffraction gratings using a variety of materials--cloth, lithographic film, wire, compact discs, parts of aerosol spray cans, and pseudoliquids and pseudosolids. A different and inexpensive method I use to make low-resolution diffraction gratings takes advantage…

  15. Mathematics, Experiments, and Theoretical Physics: The Early Days of the Sommerfeld School

    NASA Astrophysics Data System (ADS)

    Eckert, Michael

    1999-10-01

    The names of his students read like a Who's Who of the pioneers in modern physics Peter Debye, Peter Paul Ewald, Wolfgang Pauli, Werner Heisenberg, Hans A. Bethe - to name only the most prominent. In retrospect, the success of Sommerfeld's school of modern theoretical physics tends to overshadow its less glorious beginnings. A century ago, theoretical physics was not yet considered as a distinct discipline. In this article I emphasize more the haphazard beginnings than the later achievements of Sommerfeld's school, which mirrored the state of theoretical physics before it became an independent discipline.

  16. Physical activity status of academic professors during their early career transition: an application of the theory of planned behavior.

    PubMed

    Kirk, Megan A; Rhodes, Ryan E

    2012-01-01

    Life-transitions (e.g. parenthood) have been linked to physical inactivity, yet the topic requires further exploration. In this study, we evaluated changes in the physical activity (PA) of adults during their early career transition using retrospective analysis and the theory of planned behavior. Recruitment from January to March 2010 yielded a random sample of 267 assistant professors, ages 25-44, employed within the last five years. Repeated measures analysis of variance (RM ANOVA) concluded that PA declined across the transition (d = 0.36-0.43) and was further attenuated by marriage, work hours, and parenthood status. Discriminant function analysis (DFA) identified specific behavioral and control correlates about PA enjoyment, limited time, inconsistent schedule, work demands, and job pressures to distinguish between those who remained active from those who did not across the transition. PA interventions administered prior to career transitions may be needed to prevent physical inactivity.

  17. Physical activity status of academic professors during their early career transition: an application of the theory of planned behavior.

    PubMed

    Kirk, Megan A; Rhodes, Ryan E

    2012-01-01

    Life-transitions (e.g. parenthood) have been linked to physical inactivity, yet the topic requires further exploration. In this study, we evaluated changes in the physical activity (PA) of adults during their early career transition using retrospective analysis and the theory of planned behavior. Recruitment from January to March 2010 yielded a random sample of 267 assistant professors, ages 25-44, employed within the last five years. Repeated measures analysis of variance (RM ANOVA) concluded that PA declined across the transition (d = 0.36-0.43) and was further attenuated by marriage, work hours, and parenthood status. Discriminant function analysis (DFA) identified specific behavioral and control correlates about PA enjoyment, limited time, inconsistent schedule, work demands, and job pressures to distinguish between those who remained active from those who did not across the transition. PA interventions administered prior to career transitions may be needed to prevent physical inactivity. PMID:22348598

  18. Early Childcare and Physical Aggression: Differentiating Social Selection and Social Causation

    ERIC Educational Resources Information Center

    Borge, Anne I. H.; Rutter, Michael; Cote, Sylvana; Tremblay, Richard E.

    2004-01-01

    Background: Some research findings have suggested that group day-care may be associated with an increased risk for physical aggression. Methods: Cross-sectional maternal questionnaire data from a representative sample of 3431 Canadian 2- to 3-year-olds were used to compare rates of physical aggression shown by children looked after by their own…

  19. Does Built Environment Matter to Early Adolescents' Physical Activity?

    ERIC Educational Resources Information Center

    Lin, Jen-Jia; Ting, Tzu-Cheng

    2014-01-01

    This study examined the relationship of built environments to physical activity among adolescents aged 12 to 14 years old. The study sample included 269 junior high school students studying in Nangang District, Taipei, Taiwan. Sample physical activity data were obtained by surveying adolescents using a self-administered short version of the…

  20. Diffraction by m-bonacci gratings

    NASA Astrophysics Data System (ADS)

    Monsoriu, Juan A.; Giménez, Marcos H.; Furlan, Walter D.; Barreiro, Juan C.; Saavedra, Genaro

    2015-11-01

    We present a simple diffraction experiment with m-bonacci gratings as a new interesting generalization of the Fibonacci ones. Diffraction by these non-conventional structures is proposed as a motivational strategy to introduce students to basic research activities. The Fraunhofer diffraction patterns are obtained with the standard equipment present in most undergraduate physics labs and are compared with those obtained with regular periodic gratings. We show that m-bonacci gratings produce discrete Fraunhofer patterns characterized by a set of diffraction peaks which positions are related to the concept of a generalized golden mean. A very good agreement is obtained between experimental and numerical results and the students’ feedback is discussed.

  1. X-Ray Diffraction.

    ERIC Educational Resources Information Center

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  2. An exploration of Early Childhood Education students’ knowledge and preparation to facilitate physical activity for preschoolers: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Early childhood educators play an important role in influencing preschoolers’ physical activity levels. The current study sought to explore Early Childhood Education (ECE) students’ physical activity-related knowledge and educational experience during their formal training in Ontario. Methods A total of 1,113 ECE students from 20 Ontario Colleges completed the study survey (online or on paper), which examined students’ physical activity course content; awareness of physical activity guidelines; understanding of health-related benefits of physical activity; self-efficacy to facilitate physical activity for preschoolers; self-reported physical activity levels; as well as physical activity-related resource needs. Descriptive statistics and independent samples t-tests were used to analyze the quantitative findings. Results Survey results identified that 72.1% of ECE students had not completed any physical activity/physical education specific courses, while only 28.7% were familiar with, and 2.0% accurately reported, the Canadian Physical Activity Guidelines for the Early Years. Only 10.5% of ECE students reported personal physical activity behaviors consistent with national recommendations for adults (150 minutes/week). ECE students’ mean overall task self-efficacy to facilitate physical activity was 7.37 (SD = 1.64). Self-efficacy was significantly higher (p < .05) when students had taken one or more courses devoted to physical activity/physical education, as well as when students engaged in sufficient physical activity to meet the national guidelines for adults (p < .05). Conclusions The results indicate that the current ECE college curriculum represents an excellent opportunity to provide future childcare providers with enriched physical activity-related training and support, such as physical activity guidelines, workshops, and new ideas for activities. Emphasizing the health benefits of physical activity for adults might be important

  3. Electromagnetic diffraction by plane reflection diffraction gratings

    NASA Technical Reports Server (NTRS)

    Bocker, R. P.; Marathay, A. S.

    1972-01-01

    A plane wave theory was developed to study electromagnetic diffraction by plane reflection diffraction gratings of infinite extent. A computer program was written to calculate the energy distribution in the various orders of diffraction for the cases when the electric or magnetic field vectors are parallel to the grating grooves. Within the region of validity of this theory, results were in excellent agreement with those in the literature. Energy conservation checks were also made to determine the region of validity of the plane wave theory. The computer program was flexible enough to analyze any grating profile that could be described by a single value function f(x). Within the region of validity the program could be used with confidence. The computer program was used to investigate the polarization and blaze properties of the diffraction grating.

  4. Grounding Early Intervention: Physical Therapy Cannot Just Be About Motor Skills Anymore

    PubMed Central

    Harbourne, Regina T.; Dusing, Stacey C.; McCoy, Sarah Westcott

    2013-01-01

    This perspective article provides support for 4 interrelated tenets: grounded perceptual-motor experience within cultural and social contexts forms cognition; exploration through early behaviors, such as object interaction, sitting, and locomotion, broadly facilitates development; infants and children with limited exploration are at risk for global developmental impairments; and early interventions targeting exploratory behaviors may be feasible and effective at advancing a range of abilities across developmental domains and time. These tenets emphasize that through the promotion of early perceptual-motor behaviors, broader, more global developmental advancements can be facilitated and future delays can be minimized across domains for infants and children with special needs. Researchers, educators, and clinicians should build on these tenets to further demonstrate the effectiveness of targeted early interventions. The goals of these interventions should be not only to advance targeted perceptual-motor skills in the moment but also to more broadly advance future abilities and meet the early intervention goal of maximizing children's learning potential. PMID:23001524

  5. Anomalous Diffraction in Crystallographic Phase Evaluation

    PubMed Central

    Hendrickson, Wayne A.

    2014-01-01

    X-ray diffraction patterns from crystals of biological macromolecules contain sufficient information to define atomic structures, but atomic positions are inextricable without having electron-density images. Diffraction measurements provide amplitudes, but the computation of electron density also requires phases for the diffracted waves. The resonance phenomenon known as anomalous scattering offers a powerful solution to this phase problem. Exploiting scattering resonances from diverse elements, the methods of multiwavelength anomalous diffraction (MAD) and single-wavelength anomalous diffraction (SAD) now predominate for de novo determinations of atomic-level biological structures. This review describes the physical underpinnings of anomalous diffraction methods, the evolution of these methods to their current maturity, the elements, procedures and instrumentation used for effective implementation, and the realm of applications. PMID:24726017

  6. Dichroic Coherent Diffractive Imaging

    NASA Astrophysics Data System (ADS)

    Tripathi, Ashish

    Understanding electronic structure at nanometer resolution is crucial to understanding physics such as phase separation and emergent behavior in correlated electron materials. Nondestructive probes which have the ability to see beyond surfaces on nanometer length and sub-picosecond time scales can greatly enhance our understanding of these systems and will impact development of future technologies, such as magnetic storage. Polarized x-rays are an appealing choice of probe due to their penetrating power, elemental and magnetic specificity, and high spatial resolution. The resolution of traditional x-ray microscopy is limited by the nanometer precision required to fabricate x-ray optics. In this thesis, a novel approach to lensless imaging of an extended magnetic nanostructure is presented. We demonstrate this approach by imaging ferrimagnetic "maze" domains in a Gd/Fe multilayer with perpendicular anisotropy. A series of dichroic coherent diffraction patterns, ptychographically recorded, are numerically inverted using non-convex and non-linear optimization theory, and we follow the magnetic domain configuration evolution through part of its magnetization hysteresis loop by applying an external magnetic field. Unlike holographic methods, it does not require a reference wave or precision optics, and so is a far simpler experiment. In addition, it enables the imaging of samples with arbitrarily large spatial dimensions, at a spatial resolution limited solely by the coherent x-ray flux and wavelength. It can readily be extended to other non-magnetic systems that exhibit circular or linear dichroism. This approach is scalable to imaging with diffraction-limited resolution, a prospect rapidly becoming a reality in view of the new generation of phenomenally brilliant x-ray sources.

  7. An assemblage of science and home. The gendered lifestyle of Svante Arrhenius and early twentieth-century physical chemistry.

    PubMed

    Bergwik, Staffan

    2014-06-01

    This essay explores the gendered lifestyle of early twentieth-century physics and chemistry and shows how that way of life was produced through linking science and home. In 1905, the Swedish physical chemist Svante Arrhenius married Maja Johansson and established a scientific household at the Nobel Institute for Physical Chemistry in Stockholm. He created a productive context for research in which ideas about marriage and family were pivotal. He also socialized in similar scientific sites abroad. This essay displays how scholars in the international community circulated the gendered lifestyle through frequent travel and by reproducing gendered behavior. Everywhere, husbands and wives were expected to perform distinct duties. Shared performances created loyalties across national divides. The essay thus situates the physical sciences at the turn of the twentieth century in a bourgeois gender ideology. Moreover, it argues that the gendered lifestyle was not external to knowledge making but, rather, foundational to laboratory life. A legitimate and culturally intelligible lifestyle produced the trust and support needed for collaboration. In addition, it enabled access to prestigious facilities for Svante Arrhenius, ultimately securing his position in international physical chemistry. PMID:25154133

  8. Industrial applications of neutron diffraction

    SciTech Connect

    Felcher, G.P.

    1989-01-01

    Neutron diffraction (or, to be more general, neutron scattering) is a most versatile and universal tool, which has been widely employed to probe the structure, the dynamics and the magnetism of condensed matter. Traditionally used for fundamental research in solid state physics, this technique more recently has been applied to problems of immediate industrial interest, as illustrated in examples covering the main fields of endeavour. 14 refs., 14 figs.

  9. Physical and Sexual Abuse and Early-Onset Bipolar Disorder in Youths Receiving Outpatient Services: Frequent, but Not Specific

    PubMed Central

    Youngstrom, Eric A.; Martinez, Maria; KogosYoungstrom, Jennifer; Scovil, Kelly; Ross, Jody; Feeny, Norah C.; Findling, Robert L.

    2014-01-01

    The objective of this study was to determine if physical and sexual abuse showed relationships to early-onset bipolar spectrum disorders (BPSD) consistent with findings from adult retrospective data. Participants (N=829, M= 10.9 years old ±3.4 SD, 60 % male, 69 % African American, and 18 % with BPSD), primarily from a low socio-economic status, presented to an urban community mental health center and a university research center. Physical abuse was reported in 21 %, sexual abuse in 20 %, and both physical and sexual abuse in 11 % of youths with BPSD. For youths without BPSD, physical abuse was reported in 16 %, sexual abuse in 15 %, and both physical and sexual abuse in 5 % of youths. Among youth with BPSD, physical abuse was significantly associated with a worse global family environment, more severe depressive and manic symptoms, a greater number of sub-threshold manic/hypomanic symptoms, a greater likelihood of suicidality, a greater likelihood of being diagnosed with PTSD, and more self-reports of alcohol or drug use. Among youth with BPSD, sexual abuse was significantly associated with a worse global family environment, more severe manic symptoms, a greater number of sub-threshold manic/hypomanic symptoms, greater mood swings, more frequent episodes, more reports of past hospitalizations, and a greater number of current and past comorbid Axis I diagnoses. These findings suggest that if physical and/or sexual abuse is reported, clinicians should note that abuse appears to be related to increased severity of symptoms, substance use, greater co-morbidity, suicidality, and a worse family environment. PMID:25118660

  10. Physical and sexual abuse and early-onset bipolar disorder in youths receiving outpatient services: frequent, but not specific.

    PubMed

    Du Rocher Schudlich, Tina; Youngstrom, Eric A; Martinez, Maria; KogosYoungstrom, Jennifer; Scovil, Kelly; Ross, Jody; Feeny, Norah C; Findling, Robert L

    2015-04-01

    The objective of this study was to determine if physical and sexual abuse showed relationships to early-onset bipolar spectrum disorders (BPSD) consistent with findings from adult retrospective data. Participants (N = 829, M = 10.9 years old ± 3.4 SD, 60% male, 69% African American, and 18% with BPSD), primarily from a low socio-economic status, presented to an urban community mental health center and a university research center. Physical abuse was reported in 21%, sexual abuse in 20%, and both physical and sexual abuse in 11% of youths with BPSD. For youths without BPSD, physical abuse was reported in 16%, sexual abuse in 15%, and both physical and sexual abuse in 5% of youths. Among youth with BPSD, physical abuse was significantly associated with a worse global family environment, more severe depressive and manic symptoms, a greater number of sub-threshold manic/hypomanic symptoms, a greater likelihood of suicidality, a greater likelihood of being diagnosed with PTSD, and more self-reports of alcohol or drug use. Among youth with BPSD, sexual abuse was significantly associated with a worse global family environment, more severe manic symptoms, a greater number of sub-threshold manic/hypomanic symptoms, greater mood swings, more frequent episodes, more reports of past hospitalizations, and a greater number of current and past comorbid Axis I diagnoses. These findings suggest that if physical and/or sexual abuse is reported, clinicians should note that abuse appears to be related to increased severity of symptoms, substance use, greater co-morbidity, suicidality, and a worse family environment.

  11. A Strategy for Embedding Functional Motor and Early Numeracy Skill Instruction into Physical Education Activities

    ERIC Educational Resources Information Center

    Whinnery, Stacie B.; Whinnery, Keith W.; Eddins, Daisy

    2016-01-01

    This article addresses the challenges educators face when attempting to find a balance between both functional and academic skill instruction for students with severe, multiple disabilities including motor impairments. The authors describe a strategy that employs embedded instruction of early numeracy and functional motor skills during physical…

  12. Physical Activity, Self-Regulation, and Early Academic Achievement in Preschool Children

    ERIC Educational Resources Information Center

    Becker, Derek R.; McClelland, Megan M.; Loprinzi, Paul; Trost, Stewart G.

    2014-01-01

    Research Findings: The present study investigated whether active play during recess was associated with self-regulation and academic achievement in a prekindergarten sample. A total of 51 children in classes containing approximately half Head Start children were assessed on self-regulation, active play, and early academic achievement. Path…

  13. Early Adolescent Sexual Initiation and Physical/Psychological Symptoms: A Comparative Analysis of Five Nations

    ERIC Educational Resources Information Center

    Madkour, Aubrey Spriggs; Farhat, Tilda; Halpern, Carolyn Tucker; Godeau, Emmanuelle; Nic Gabhainn, Saoirse

    2010-01-01

    Although most people in developed countries experience sexual initiation during adolescence, little is known about inter-country variability in the psychosocial correlates of early initiation. Population-based samples of 15-year-olds (n = 6,111, 52% female) who participated in the Health Behaviors in School-Aged Children Study (Finland, Scotland,…

  14. Different Neurocognitive Functions Regulating Physical Aggression and Hyperactivity in Early Childhood

    ERIC Educational Resources Information Center

    Seguin, Jean R.; Parent, Sophie; Tremblay, Richard E.; Zelazo, Philip David

    2009-01-01

    Background: There are strong parallels between early childhood and adolescent behavior problems. However, we do not know if behavioral symptoms associate with neurocognitive processes in very young children as they do in older children. Methods: We studied a population-based birth cohort of children (N = 1,950) whose developmental trajectories of…

  15. Physical Growth and Maturation Following Early Severe Institutional Deprivation: Do They Mediate Specific Psychopathological Effects?

    ERIC Educational Resources Information Center

    Sonuga-Barke, Edmund J.; Schlotz, Wolff; Rutter, Michael

    2010-01-01

    The authors' previous work and the data reported in the preceding chapters of this monograph provide conclusive evidence of the persistent nature of the negative impact of early severe deprivation. Institutional deprivation, despite the good outcomes for many, was often associated with substantial impairment and disorder across a wide range of…

  16. "Intensive Mothering" in the Early Years: The Cultivation and Consolidation of (Physical) Capital

    ERIC Educational Resources Information Center

    Stirrup, Julie; Duncombe, Rebecca; Sandford, Rachel

    2015-01-01

    Growing pressure on parents to equip their children with the skills required for future success, coupled with an increased focus on providing quality learning experiences in the early years, has contributed to an upsurge in the enrolment of young children in formal (often privatised) activities. Moreover, in response to growing societal concerns…

  17. Psychosocial Correlates of Physical Dating Violence Victimization among Latino Early Adolescents

    ERIC Educational Resources Information Center

    Yan, Fang A.; Howard, Donna E.; Beck, Kenneth H.; Shattuck, Teresa; Hallmark-Kerr, Melissa

    2010-01-01

    This study examined the association between dating violence victimization and psychosocial risk and protective factors among Latino early adolescents. An anonymous, cross-sectional, self-reported survey was administered to a convenience sample of Latino youth (n = 322) aged 11 to 13 residing in suburban Washington, D.C. The dependent variable was…

  18. PROPOSED WATER QUALITY SURVEILLANCE NETWORK USING PHYSICAL, CHEMICAL AND BIOLOGICAL EARLY WARNING SYSTEMS (CBEWS)

    EPA Science Inventory

    The Homeland Protection Act of 2002 specifically calls for the investigation and use of Early Warning Systems (EWS) for water security reasons. The EWS is a screening tool for detecting changes in source water and distribution system water quality. A suite of time-relevant biol...

  19. PROPOSED WATER QUALITY SURVEILLANCE NETWORK USING PHYSICAL, CHEMICAL AND BIOLOGICAL EARLY WARNING SYSTEMS (BEWS)

    EPA Science Inventory

    The Homeland Protection Act of 2002 specifically calls for the investigation and use of Early Warning Systems (EWS) for water security reasons. The EWS is a screening tool for detecting changes in source water and distribution system water quality. A suite of time-relevant biol...

  20. Early postnatal nutrition determines adult physical activity and energy expenditure in female mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Decades of research in rodent models has shown that early postnatal overnutrition induces excess adiposity and other components of metabolic syndrome that persist into adulthood. The specific biologic mechanisms explaining the persistence of these effects, however, remain unknown. On postnatal day 1...

  1. Physical Activity Promotes Academic Achievement and a Healthy Lifestyle when Incorporated into Early Childhood Education

    ERIC Educational Resources Information Center

    Abadie, Ben R.; Brown, Stanley P.

    2010-01-01

    The detrimental effects of physical inactivity within children have enormous personal health consequences. These health conditions have the potential to impact the economic vitality of society as a whole. Studies have indicated that inactive children are far more likely to suffer from obesity, type II diabetes, and hypertension than their…

  2. Stepping toward Physical Activity Requirements: Integrating Pedometers into Early Childhood Settings

    ERIC Educational Resources Information Center

    Robinson, Leah E.; Wadsworth, Danielle D.

    2010-01-01

    Physical activity is an essential component for lifelong wellness and the quality of life. Over the past years, childhood obesity has dramatically increased. Data supports that young children are adopting sedentary behaviors within and outside of school hours that may contribute to obesity and other health-related diseases. This paper provides…

  3. Early Childhood Teachers' and Staff Members' Perceptions of Nutrition and Physical Activity Practices for Preschoolers

    ERIC Educational Resources Information Center

    Derscheid, Linda E.; Umoren, Josephine; Kim, So-Yeun; Henry, Beverly W.; Zittel, Lauriece L.

    2010-01-01

    Child care teachers and staff are important influences on preschoolers' nutrition and physical activity habits, and their views may be influenced by education level, years of field experience, and program involvement. For the 360 participants surveyed, responses on 5 of 18 survey items significantly differed by education level (e.g., less…

  4. Psychosocial Influences on Physical, Verbal, and Indirect Bullying Among Japanese Early Adolescents

    ERIC Educational Resources Information Center

    Ando, Mikayo; Asakura, Takashi; Simons-Morton, Bruce

    2005-01-01

    Although bullying among Japanese youth is a current major concern, psychosocial influences on bullying are not fully understood. The purpose of this study was to identify the psychosocial factors associated with physical, verbal, and indirect bullying among Japanese adolescents. Junior high school students between seventh and ninth grade (N =…

  5. The Role of Physical Contact and Association in Early Contamination Sensitivity.

    ERIC Educational Resources Information Center

    Springer, Ken; Belk, Amy

    1994-01-01

    Children were asked whether someone would get sick from drinking juice placed near a bug. Some preschoolers and most seven- and eight-year olds recognized the need for physical contact with the bug to make the juice noxious, whereas some believed the mere presence of a contaminant made it noxious. Thus, associational contamination sometimes plays…

  6. Role of Physical Evaluation in the Early Identification of Axial Spondyloarthritis: A Research Proposal

    PubMed Central

    Castro, Marcelo P; Stebbings, Simon M; Milosavljevic, Stephan; Bussey, Melanie D

    2015-01-01

    The aim of this study was to present a rationale to explore the use of clinical tests for the sacroiliac joints to detect early axial spondyloarthritis (SpA) and to suggest a protocol to validate these clinical tests. Based on the European Guidelines for Diagnosis and Treatments of Pelvic Girdle Pain, we propose a set of six clinical tests to identify the likely presence of inflammation in the sacroiliac joints associated with early axial SpA. As magnetic resonance imaging (MRI) is the current gold standard used to identify inflammation in the sacroiliac joints, the results of the proposed set of clinical tests are compared with those from the MRI examinations. We hypothesize that specific clinical tests, which combine pain provocation and functional tests, for assessing the sacroiliac joints will help to identify early active inflammation at the sacroiliac joints in axial SpA. If such tests prove to be sensitive and specific, they could add further value to the diagnostic classification criteria for axial SpA. PMID:26448694

  7. Physical activity in young children and their parents–An Early STOPP Sweden–China comparison study

    PubMed Central

    Johansson, Elin; Mei, Hong; Xiu, Lijuan; Svensson, Viktoria; Xiong, Yueling; Marcus, Claude; Zhang, Jianduan; Hagströmer, Maria

    2016-01-01

    Understanding about socio-cultural differences in physical activity in children with high and low risk for obesity can help tailor intervention programs in different settings. This study aimed to compare objectively measured physical activity in two-year-olds and their parents, living in Stockholm, Sweden, and Wuhan, China. Data from Early STOPP was used. Children and parents wore an accelerometer in connection with the child’s second birthday. Weekly and hourly patterns were examined. Correlation between child and parental physical activity was assessed. Data on 146 Swedish and 79 Chinese children and their parents was available. Children, mothers and fathers in Stockholm were significantly more active than their counterparts in Wuhan (children; 2989 (SD 702) vs. 1997 (SD 899) counts per minute (CPM), mothers 2625 (SD 752) vs. 2042 (SD 821) CPM; fathers 2233 (SD 749) vs. 1588 (SD 754) CPM). Activity levels were similar over a week for children and parents within both countries. No parental-child correlations, except for a paternal-son correlation in Stockholm, were found. Children, mothers and fathers in Stockholm are more active compared with their counterparts in Wuhan. Interventions to increase physical activity needs to take cultural aspects into account, also when targeting very young children. PMID:27404563

  8. Physical activity in young children and their parents-An Early STOPP Sweden-China comparison study.

    PubMed

    Johansson, Elin; Mei, Hong; Xiu, Lijuan; Svensson, Viktoria; Xiong, Yueling; Marcus, Claude; Zhang, Jianduan; Hagströmer, Maria

    2016-01-01

    Understanding about socio-cultural differences in physical activity in children with high and low risk for obesity can help tailor intervention programs in different settings. This study aimed to compare objectively measured physical activity in two-year-olds and their parents, living in Stockholm, Sweden, and Wuhan, China. Data from Early STOPP was used. Children and parents wore an accelerometer in connection with the child's second birthday. Weekly and hourly patterns were examined. Correlation between child and parental physical activity was assessed. Data on 146 Swedish and 79 Chinese children and their parents was available. Children, mothers and fathers in Stockholm were significantly more active than their counterparts in Wuhan (children; 2989 (SD 702) vs. 1997 (SD 899) counts per minute (CPM), mothers 2625 (SD 752) vs. 2042 (SD 821) CPM; fathers 2233 (SD 749) vs. 1588 (SD 754) CPM). Activity levels were similar over a week for children and parents within both countries. No parental-child correlations, except for a paternal-son correlation in Stockholm, were found. Children, mothers and fathers in Stockholm are more active compared with their counterparts in Wuhan. Interventions to increase physical activity needs to take cultural aspects into account, also when targeting very young children. PMID:27404563

  9. Parent and Peer Predictors of Physical Dating Violence Perpetration in Early Adolescence: Tests of Moderation and Gender Differences

    PubMed Central

    Miller, Shari; Gorman-Smith, Deborah; Sullivan, Terri; Orpinas, Pamela; Simon, Thomas R.

    2013-01-01

    This study examined parenting and peer predictors of physical dating violence perpetration during early adolescence and tested moderation among these predictors and gender. Participants were 2,824 ethnically diverse sixth-grade students with a recent boyfriend/girlfriend who was part of a multisite, longitudinal investigation of the development and prevention of violence among middle school students. Those students who reported having a boyfriend/girlfriend reported significantly more drug use and delinquent activity and were more likely to be male. Twenty-nine percent of youth with a boyfriend/girlfriend reported perpetrating physical aggression against their boyfriend/girlfriend. Parenting and peer variables were significant predictors of physical dating violence. However, gender moderated the association between parenting practices and physical dating violence, with parental monitoring inversely linked to dating violence for boys and parent support for nonaggression inversely linked to dating violence for girls. Parent support for aggression also moderated the association between peer deviancy and reported perpetration. Finally, gender moderated the interaction between peer deviancy and parent support for nonaggressive solutions. PMID:20183640

  10. Phonons from neutron powder diffraction

    SciTech Connect

    Dimitrov, D.A.; Louca, D.; Roeder, H. )

    1999-09-01

    The spherically averaged structure function S([vert bar][bold q][vert bar]) obtained from pulsed neutron powder diffraction contains both elastic and inelastic scattering via an integral over energy. The Fourier transformation of S([vert bar][bold q][vert bar]) to real space, as is done in the pair density function (PDF) analysis, regularizes the data, i.e., it accentuates the diffuse scattering. We present a technique which enables the extraction of off-center ([vert bar][bold q][vert bar][ne]0) phonon information from powder diffraction experiments by comparing the experimental PDF with theoretical calculations based on standard interatomic potentials and the crystal symmetry. This procedure [dynamics from powder diffraction] has been [ital successfully] implemented as demonstrated here for two systems, a simple metal fcc Ni and an ionic crystal CaF[sub 2]. Although computationally intensive, this data analysis allows for a phonon based modeling of the PDF, and additionally provides off-center phonon information from neutron powder diffraction. [copyright] [ital 1999] [ital The American Physical Society

  11. Hard Diffraction at CDF

    SciTech Connect

    Melese, P.; CDF Collaboration

    1997-06-01

    We present results on diffractive production of hard processes in {anti p}p collisions at {radical}s = 1.8 TeV at the Tevatron using the CDF detector. The signatures used to identify diffractive events are the forward rapidity gap and/or the detection of a recoil antiproton with high forward momentum. We have observed diffractive W- boson, dijet, and heavy quark production. We also present results on double-pomeron production of dijets.

  12. Victimization from Mental and Physical Bullying and Substance Use in Early Adolescence

    PubMed Central

    Tharp-Taylor, Shannah; Haviland, Amelia; D'Amico, Elizabeth J.

    2009-01-01

    Logistic regression analyses were used to assess the association between victimization from mental and physical bullying and use of alcohol, cigarettes, marijuana, and inhalants among middle school students. Self-report data were analyzed from 926 ethnically diverse sixth through eighth grade students (43% white, 26% Latino, 7% Asian American/Pacific Islander, 3% African American, 14% mixed ethnic origin, and 5% “other”) ages 11 – 14 years from southern California. Substance use was collected at two time points (fall 2004 and spring 2005) during an academic year. Models were run for each substance separately. Results supported an association between victimization from bullying and substance use. Youths who experienced each type of bullying (mental or physical) separately or in combination were more likely to report use of each substance in spring 2005. This finding held after controlling for gender, grade level, ethnicity and substance use in fall 2004. PMID:19398162

  13. Characterization of proteins by powder diffraction.

    SciTech Connect

    Von Dreele, R.; X-Ray Science Division

    2009-01-01

    A simulation of a protein powder diffraction pattern was stunning in the apparent amount of information that was seen. A subsequent experiment on metmyoglobin gave a powder diffraction pattern that showed very little sample broadening; the peak widths were essentially limited by the instrument resolution. The challenge is to make use of this in protein structure analysis. This talk will recall some of those early experiments and data analyses as well as an overview of current progress and future possibilities.

  14. Safeguards-by-Design: Early Integration of Physical Protection and Safeguardability into Design of Nuclear Facilities

    SciTech Connect

    T. Bjornard; R. Bean; S. DeMuth; P. Durst; M. Ehinger; M. Golay; D. Hebditch; J. Hockert; J. Morgan

    2009-09-01

    The application of a Safeguards-by-Design (SBD) process for new nuclear facilities has the potential to minimize proliferation and security risks as the use of nuclear energy expands worldwide. This paper defines a generic SBD process and its incorporation from early design phases into existing design / construction processes and develops a framework that can guide its institutionalization. SBD could be a basis for a new international norm and standard process for nuclear facility design. This work is part of the U.S. DOE’s Next Generation Safeguards Initiative (NGSI), and is jointly sponsored by the Offices of Non-proliferation and Nuclear Energy.

  15. Emission line gas in early-type galaxies: Kinematics and physical conditions

    NASA Technical Reports Server (NTRS)

    Deustua, S. E.; Koratkar, A. P.; Macalpine, G.

    1993-01-01

    Recent studies have found line emission gas in nearby early-type galaxies, but the properties of the emission-line gas in these 'normal' galaxies remain enigmatic. In terms of activity in the nucleus, these LINER-like galaxies form an important link between giant H 2 region galaxies and low-luminosity Seyferts. Despite their large numbers and evolutionary significance, we do not know whether these galaxies form a homogeneous class of objects; nor do we know how the distribution and kinematics of the line emission gas are affected by the host galaxy's environment or by the properties of the central engine, if present. To address these issues we are conducting a magnitude and volume limited survey of nearby early-type galaxies at Lick Observatory and the Michigan-Dartmouth-MIT Observatory. We have selected approximately 100 galaxies from radio catalogs. A large sample is necessary because while studies of individual 'LINERS' have led to a certain understanding of the phenomenon, these studies have not provided a global framework. Here we present results from our first run of medium resolution (approximately 5 A FWHM) spectroscopy. Kinematic data and line ratios determined along the major and minor axes of 6 galaxies are discussed. The information gleaned from spectroscopic data, when combined with data at other wavelengths, will enable a thorough investigation into the nature of low luminosity nuclear activity.

  16. CONSTRAINING GAMMA-RAY BURST EMISSION PHYSICS WITH EXTENSIVE EARLY-TIME, MULTIBAND FOLLOW-UP

    SciTech Connect

    Cucchiara, A.; Cenko, S. B.; Bloom, J. S.; Morgan, A.; Perley, D. A.; Li, W.; Butler, N. R.; Filippenko, A. V.; Melandri, A.; Kobayashi, S.; Smith, R. J.; Mundell, C. G.; Steele, I. A.; Hora, J. L.; Da Silva, R. L.; Prochaska, J. X.; Worseck, G.; Fumagalli, M.; Cobb, B.; and others

    2011-12-20

    Understanding the origin and diversity of emission processes responsible for gamma-ray bursts (GRBs) remains a pressing challenge. While prompt and contemporaneous panchromatic observations have the potential to test predictions of the internal-external shock model, extensive multiband imaging has been conducted for only a few GRBs. We present rich, early-time, multiband data sets for two Swift events, GRB 110205A and GRB 110213A. The former shows optical emission since the early stages of the prompt phase, followed by the steep rising in flux up to {approx}1000 s after the burst (t{sup -{alpha}} with {alpha} = -6.13 {+-} 0.75). We discuss this feature in the context of the reverse-shock scenario and interpret the following single power-law decay as being forward-shock dominated. Polarization measurements, obtained with the RINGO2 instrument mounted on the Liverpool Telescope, also provide hints on the nature of the emitting ejecta. The latter event, instead, displays a very peculiar optical to near-infrared light curve, with two achromatic peaks. In this case, while the first peak is probably due to the onset of the afterglow, we interpret the second peak to be produced by newly injected material, signifying a late-time activity of the central engine.

  17. Childhood Disadvantage and Health Problems in Middle and Later Life: Early Imprints on Physical Health?

    PubMed Central

    Ferraro, Kenneth F.; Schafer, Markus H.; Wilkinson, Lindsay R.

    2016-01-01

    Drawing from cumulative inequality theory, we examine the relationship between childhood disadvantage and health problems in adulthood. Using two waves of data from Midlife Development in the United States, we investigate whether childhood disadvantage is associated with adult disadvantage, including fewer social resources, and the effect of lifelong disadvantage on health problems measured at the baseline survey and a 10-year follow-up. Findings reveal that childhood socioeconomic disadvantage and frequent abuse by parents are generally associated with fewer adult social resources and more lifestyle risks. Health problems, in turn, are affected by childhood disadvantage and by lifestyle risks, especially smoking and obesity. Not only was early disadvantage related to health problems at the baseline survey, but childhood socioeconomic disadvantage and frequent abuse also were related to the development of new health problems at the follow-up survey. These findings reveal the imprint of early disadvantage on health decades later and suggest greater attention to resources, even during midlife, can interrupt the chain of risks. PMID:27445413

  18. Not all stressors are equal: early social enrichment favors resilience to social but not physical stress in male mice.

    PubMed

    Branchi, Igor; Santarelli, Sara; D'Andrea, Ivana; Alleva, Enrico

    2013-03-01

    Early experiences profoundly affect the adult coping response to stress and, consequently, adult vulnerability to psychopathologies triggered by stressing conditions, such as major depression. Though studies in animal models have demonstrated that individuals reared in different conditions are differently vulnerable to a stressor of a specific quality, no information is available as to whether such vulnerability differs when facing stressors of different qualities. To this purpose, we reared C57BL/6 male mice either in standard laboratory rearing condition (SN) or in Communal Nest (CN) condition, the latter consisting of a single nest where three mothers keep their pups together and share care-giving behavior until weaning. We scored the amount of interactions with the mother and with peers and found that CN is a form of social enrichment because both these components are significantly increased. At adulthood, we exposed SN and CN mice, for 4 weeks, to either a physical (forced swim) or a social stress (social instability). Immediately before, at week 1 and at week 4 of the stress procedure, corticosterone levels and the hedonic profile were measured. The results show that CN mice are more resilient to social stress than SN mice since they displayed no anhedonia and lower corticosterone levels. By contrast, both experimental groups were similarly vulnerable to physical stress. Overall, our results show that, in male mice, the adult vulnerability to stress changes according to the quality of the stressor, as a function of early experiences. In addition, the stressor to which CN mice are resilient is qualitatively similar to the stimuli they have experienced early on, both concerning the social domain.

  19. Physics.

    ERIC Educational Resources Information Center

    Bromley, D. Allan

    1980-01-01

    The author presents the argument that the past few years, in terms of new discoveries, insights, and questions raised, have been among the most productive in the history of physics. Selected for discussion are some of the most important new developments in physics research. (Author/SA)

  20. Genetic and physical mapping of the earliness per se locus Eps-A (m) 1 in Triticum monococcum identifies EARLY FLOWERING 3 (ELF3) as a candidate gene.

    PubMed

    Alvarez, M A; Tranquilli, G; Lewis, S; Kippes, N; Dubcovsky, J

    2016-07-01

    Wheat cultivars exposed to optimal photoperiod and vernalization treatments still exhibit differences in flowering time, referred to as earliness per se (Eps). We previously identified the Eps-A (m) 1 locus from Triticum monococcum and showed that the allele from cultivated accession DV92 significantly delays heading time and increases the number of spikelets per spike relative to the allele from wild accession G3116. Here, we expanded a high-density genetic and physical map of the Eps-A (m) 1 region and identified the wheat ortholog of circadian clock regulator EARLY FLOWERING 3 (ELF3) as a candidate gene. No differences in ELF3 transcript levels were found between near-isogenic lines carrying the DV92 and G3116 Eps-A (m) 1 alleles, but the encoded ELF3 proteins differed in four amino acids. These differences were associated with altered transcription profiles of PIF-like, PPD1, and FT1, which are known downstream targets of ELF3. Tetraploid wheat lines with combined truncation mutations in the A- and B-genome copies of ELF3 flowered earlier and had less spikelets per spike than the wild-type control under short- and long-day conditions. Both effects were stronger in a photoperiod-sensitive than in a reduced photoperiod-sensitive background, indicating a significant epistatic interaction between PPD1 and ELF3 (P < 0.0001). By contrast, the introgression of the T. monococcum chromosome segment carrying the Eps-A (m) 1 allele from DV92 into durum wheat delayed flowering and increased the number of spikelets per spike. Taken together, the above results support the hypothesis that ELF3 is Eps-A (m) 1. The ELF3 alleles identified here provide additional tools to modulate reproductive development in wheat.

  1. Methanol: the Swiss army knife of star formation. Physical properties of early stages of high mass star formation.

    NASA Astrophysics Data System (ADS)

    Leurini, Silvia; Schilke, Peter; Wyrowski, Friedrich; Menten, Karl

    Despite the major observational effort carried out in the last years by several authors (e.g. Molinari et al. 1996, Sridharan et al. 2002, Beuther et al. 2002), little is known about the initial phases of evolution of high-mass stars and their physics. A powerful diagnostic tool to investigate the early evolutionary sequence of high-mass stars is found in the analysis of their molecular spectra, which can be seen as fingerprints of a molecular cloud, as they carry the information on its chemistry, and therefore on its history, on its physical conditions and on its dynamics and kinematics. Often, symmetric rotors such as NH3 are used to probe a cloud's kinetic temperature (Walmsley & Ungerechts 1983, Danby et al. 1988), while linear molecules, e.g. CS, are used to determine its density (e.g. Snell et al. 1984, Beuther et al. 2002). However, different spatial distributions of the tracers (caused by their different chemistry) may complicate the picture, (see, e.g. Tafalla et al. 2002) as they often trace physically different and spatially non-coexisting gas components. It is thus desirable to trace all relevant physical parameters with a single molecule. Studies on slightly asymmetric rotors (H2CO: Mundy et al. 1987, Mangum & Wootten 1993; CH3OH: Leurini et al. 2004) reveal that these molecules can be used as diagnostic tools of both parameters, since slightly asymmetric molecules allow determinations of spatial density and often share a strong sensitivity to kinetic temperature with symmetric rotors. Leurini et al. 2004 have discussed the tracing properties of CH3OH, reaching the conclusion that CH3OH is indeed very useful as a prob of physical conditions in star forming regions in all mass regimes, since it has a very reach spectrum of transitions spread throughout all the centimeter, millimeter and submillimeter spectral windows. Moreover it is ubiquitously found in different regimes of star formation, from quiescent, cold (T ~ 10 K), dark clouds (Friberg et al

  2. Individual and social network predictors of physical bullying: a longitudinal study of Taiwanese early adolescents.

    PubMed

    Wei, Hsi-Sheng; Lee, Wonjae

    2014-01-01

    This study followed 125 7th-grade students in Taiwan for the entire school year and analyzed the individual and social network factors predicting their involvement in physical bullying over 5 waves of data. Using self-reports of bullying experiences, 20 classroom-level networks of bullying and friendship were constructed for 4 classrooms and 5 temporal points, from which 4 individual-level network measures were calculated. They included bully and victim centrality, popularity, and embeddedness in friendship networks. A series of mixed models for repeated measures were constructed to predict students' bully and victim centrality in bullying network at time t + 1. Compared to girls, boys were more likely to be both the bullies and victims. Lower self-esteem and higher family economic status contributed to victim centrality. Having parents married and living together predicted lower bully centrality. Higher educational level of parents predicted lower victim and bully centrality. Regarding the social network factors, students' bully centrality at t positively predicted their bully centrality at t + 1, whereas victim centrality predicted their subsequent victim centrality. Interaction effects between friendship network and bullying network were observed. Embeddedness in friendship network reduced victim centrality at t + 1 except for those students with low victim centrality at t. For those with high victim centrality at t, popularity increased their risk of physical victimization over time. Implications for research and practice are discussed.

  3. Size counts: evolutionary perspectives on physical activity and body size from early hominids to modern humans.

    PubMed

    Leonard, William R

    2010-11-01

    This paper examines the evolutionary origins of human dietary and activity patterns, and their implications for understanding modern health problems. Humans have evolved distinctive nutritional characteristics associated the high metabolic costs of our large brains. The evolution of larger hominid brain size necessitated the adoption of foraging strategies that both provided high quality foods, and required larger ranges and activity budgets. Over time, human subsistence strategies have become ever more efficient in obtaining energy with minimal time and effort. Today, populations of the industrialized world live in environments characterized by low levels of energy expenditure and abundant food supplies contributing to growing rates of obesity. Analyses of trends in dietary intake and body weight in the US over the last 50 years indicate that the dramatic rise in obesity cannot be explained solely by increased energy consumption. Rather, declines in activity are also important. Further, we find that recent recommendations on physical activity have the potential to bring daily energy expenditure levels of industrialized societies surprisingly close to those observed among subsistence-level populations. These findings highlight the importance of physical activity in promoting nutritional health and show the utility of evolutionary approaches for developing public health recommendations.

  4. Individual and social network predictors of physical bullying: a longitudinal study of Taiwanese early adolescents.

    PubMed

    Wei, Hsi-Sheng; Lee, Wonjae

    2014-01-01

    This study followed 125 7th-grade students in Taiwan for the entire school year and analyzed the individual and social network factors predicting their involvement in physical bullying over 5 waves of data. Using self-reports of bullying experiences, 20 classroom-level networks of bullying and friendship were constructed for 4 classrooms and 5 temporal points, from which 4 individual-level network measures were calculated. They included bully and victim centrality, popularity, and embeddedness in friendship networks. A series of mixed models for repeated measures were constructed to predict students' bully and victim centrality in bullying network at time t + 1. Compared to girls, boys were more likely to be both the bullies and victims. Lower self-esteem and higher family economic status contributed to victim centrality. Having parents married and living together predicted lower bully centrality. Higher educational level of parents predicted lower victim and bully centrality. Regarding the social network factors, students' bully centrality at t positively predicted their bully centrality at t + 1, whereas victim centrality predicted their subsequent victim centrality. Interaction effects between friendship network and bullying network were observed. Embeddedness in friendship network reduced victim centrality at t + 1 except for those students with low victim centrality at t. For those with high victim centrality at t, popularity increased their risk of physical victimization over time. Implications for research and practice are discussed. PMID:25199395

  5. A Conceptual Framework for Organizational Readiness to Implement Nutrition and Physical Activity Programs in Early Childhood Education Settings

    PubMed Central

    Upadhyaya, Mudita; Schober, Daniel J.; Byrd-Williams, Courtney

    2014-01-01

    Across multiple sectors, organizational readiness predicts the success of program implementation. However, the factors influencing readiness of early childhood education (ECE) organizations for implementation of new nutrition and physical activity programs is poorly understood. This study presents a new conceptual framework to measure organizational readiness to implement nutrition and physical activity programs in ECE centers serving children aged 0 to 5 years. The framework was validated for consensus on relevance and generalizability by conducting focus groups; the participants were managers (16 directors and 2 assistant directors) of ECE centers. The framework theorizes that it is necessary to have “collective readiness,” which takes into account such factors as resources, organizational operations, work culture, and the collective attitudes, motivation, beliefs, and intentions of ECE staff. Results of the focus groups demonstrated consensus on the relevance of proposed constructs across ECE settings. Including readiness measures during program planning and evaluation could inform implementation of ECE programs targeting nutrition and physical activity behaviors. PMID:25357258

  6. From Student of Physics to Historian of Science: T.S. Kuhn's Education and Early Career, 1940-1958

    NASA Astrophysics Data System (ADS)

    Hufbauer, Karl

    2012-12-01

    I first show that Kuhn came to have doubts about physics soon after entering college but did not make up his mind to leave the discipline until 1947-1948 when a close association with Harvard's President James B. Conant convinced him of the desirability of an alternative career in the history of science. I go on to maintain that it was realistic for Kuhn to prepare for such a career in essentially autodidactic ways both because he enjoyed Conant's patronage and because he could expect that his credentials in physics would be an asset in this relatively young interdisciplinary specialty. I then suggest that it was through his work as a teacher, researcher, and journeyman gatekeeper in the history of science that Kuhn gradually came to identify with the field. Finally, I argue that his training in physics, his teaching of general-education courses, and his hopes of influencing current philosophy of science helped shape his early practice as a historian of science. By way of epilogue, I briefly consider Kuhn's path from his tenuring at Berkeley in 1958 to the appearance of The Structure of Scientific Revolutions in 1962.

  7. Phononic crystal diffraction gratings

    NASA Astrophysics Data System (ADS)

    Moiseyenko, Rayisa P.; Herbison, Sarah; Declercq, Nico F.; Laude, Vincent

    2012-02-01

    When a phononic crystal is interrogated by an external source of acoustic waves, there is necessarily a phenomenon of diffraction occurring on the external enclosing surfaces. Indeed, these external surfaces are periodic and the resulting acoustic diffraction grating has a periodicity that depends on the orientation of the phononic crystal. This work presents a combined experimental and theoretical study on the diffraction of bulk ultrasonic waves on the external surfaces of a 2D phononic crystal that consists of a triangular lattice of steel rods in a water matrix. The results of transmission experiments are compared with theoretical band structures obtained with the finite-element method. Angular spectrograms (showing frequency as a function of angle) determined from diffraction experiments are then compared with finite-element simulations of diffraction occurring on the surfaces of the crystal. The experimental results show that the diffraction that occurs on its external surfaces is highly frequency-dependent and has a definite relation with the Bloch modes of the phononic crystal. In particular, a strong influence of the presence of bandgaps and deaf bands on the diffraction efficiency is found. This observation opens perspectives for the design of efficient phononic crystal diffraction gratings.

  8. Novel Aspects of Hard Diffraction in QCD

    SciTech Connect

    Brodsky, Stanley J.; /SLAC

    2005-12-14

    Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, and nuclear shadowing and antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency.

  9. [Psychosocial effects of the onset of menopause and physical symptoms in early postmenopause].

    PubMed

    Baum, E

    1990-06-01

    57 women were studied who were GMP patients, whose spontaneous menopause had occurred 6 to 36 months ago and who did not take any sexual hormones. Purpose of the study was to determine psychosocial influences on the time of onset of the menopause and on climacteric complaints. It was found that the overall impairment by hot flushes and pain in the limbs during this phase of life was largely independent of the studied parameters. With regard to the time of onset of the menopause there was a trend to an linear relationship between the factor "social dependence" and the age at which menopause occurred, as well as a link between that age and period intervals 5 years before cessation of menstrual bleeding. An enhanced tendency to exhaustion representing a nonspecific menopause syndrome was found particularly often in women who were highly "socially dependent". There was no relationship between climacteric complaints on the one hand and, on the other hand, experiences of loss, social stress and relief factors, partnership relations, experiences of menarche, menstruation and menopause as well as basic feeling tone; however, a depressive tone, as defined by the Giessen test, was clearly predominant in the examined population. It is concluded from these results that flushes in the early postmenopausal phase are mostly a biological phenomenon, whereas vegetative concomitant complaints are markedly dependent on psychosocial factors that correspond to a typically "feminine" role enactment as postulated by social convention. PMID:2381999

  10. Parametric Powder Diffraction

    NASA Astrophysics Data System (ADS)

    David, William I. F.; Evans, John S. O.

    The rapidity with which powder diffraction data may be collected, not only at neutron and X-ray synchrotron facilities but also in the laboratory, means that the collection of a single diffraction pattern is now the exception rather than the rule. Many experiments involve the collection of hundreds and perhaps many thousands of datasets where a parameter such as temperature or pressure is varied or where time is the variable and life-cycle, synthesis or decomposition processes are monitored or three-dimensional space is scanned and the three-dimensional internal structure of an object is elucidated. In this paper, the origins of parametric diffraction are discussed and the techniques and challenges of parametric powder diffraction analysis are presented. The first parametric measurements were performed around 50 years ago with the development of a modified Guinier camera but it was the automation afforded by neutron diffraction combined with increases in computer speed and memory that established parametric diffraction on a strong footing initially at the ILL, Grenoble in France. The theoretical parameterisation of quantities such as lattice constants and atomic displacement parameters will be discussed and selected examples of parametric diffraction over the past 20 years will be reviewed that highlight the power of the technique.

  11. Mothers' marital history and the physical and mental health of young adults: an investigation over the early life course.

    PubMed

    Wickrama, Kandauda K A S; Lee, Tae Kyoung; O'Neal, Catherine Walker

    2013-12-01

    Using survey data from 12,424 adolescents and their mothers over 13 years in the nationally representative National Longitudinal Study of Adolescent Health, the purpose of this study was to examine a life course model exploring the pathways linking mothers' marital history (identified as latent classes) and young adult health outcomes. During young adulthood (Wave 4), respondents ranged in age from 19 to 32. The results demonstrated unique long-term influences of stressful marital history typologies of mothers (prior to 1995) on the physical and mental health of young adults (2008) with reference to consistently married mothers after controlling for health status in 2001. These influences operated through family processes (economic pressure and parental rejection) and adolescent psychosocial adjustment (self-esteem, academic performance, and delinquent behavior). Our findings show that vulnerable groups of youth, in terms of mothers' marital history, can be identified early for appropriate intervention efforts. PMID:24215951

  12. Mothers' marital history and the physical and mental health of young adults: an investigation over the early life course.

    PubMed

    Wickrama, Kandauda K A S; Lee, Tae Kyoung; O'Neal, Catherine Walker

    2013-12-01

    Using survey data from 12,424 adolescents and their mothers over 13 years in the nationally representative National Longitudinal Study of Adolescent Health, the purpose of this study was to examine a life course model exploring the pathways linking mothers' marital history (identified as latent classes) and young adult health outcomes. During young adulthood (Wave 4), respondents ranged in age from 19 to 32. The results demonstrated unique long-term influences of stressful marital history typologies of mothers (prior to 1995) on the physical and mental health of young adults (2008) with reference to consistently married mothers after controlling for health status in 2001. These influences operated through family processes (economic pressure and parental rejection) and adolescent psychosocial adjustment (self-esteem, academic performance, and delinquent behavior). Our findings show that vulnerable groups of youth, in terms of mothers' marital history, can be identified early for appropriate intervention efforts.

  13. Early Detection of Physical Activity for People With Type 1 Diabetes Mellitus

    PubMed Central

    Dasanayake, Isuru S.; Bevier, Wendy C.; Castorino, Kristin; Pinsker, Jordan E.; Seborg, Dale E.; Doyle, Francis J.; Dassau, Eyal

    2015-01-01

    Background: Early detection of exercise in individuals with type 1 diabetes mellitus (T1DM) may allow changes in therapy to prevent hypoglycemia. Currently there is limited experience with automated methods that detect the onset and end of exercise in this population. We sought to develop a novel method to quickly and reliably detect the onset and end of exercise in these individuals before significant changes in blood glucose (BG) occur. Methods: Sixteen adults with T1DM were studied as outpatients using a diary, accelerometer, heart rate monitor, and continuous glucose monitor for 2 days. These data were used to develop a principal component analysis based exercise detection method. Subjects also performed 60 and 30 minute exercise sessions at 30% and 50% predicted heart rate reserve (HRR), respectively. The detection method was applied to the exercise sessions to determine how quickly the detection of start and end of exercise occurred relative to change in BG. Results: Mild 30% HRR and moderate 50% HRR exercise onset was identified in 6 ± 3 and 5 ± 2 (mean ± SD) minutes, while completion was detected in 3 ± 8 and 6 ± 5 minutes, respectively. BG change from start of exercise to detection time was 1 ± 6 and −1 ± 3 mg/dL, and, from the end of exercise to detection time was 6 ± 4 and −17 ± 13 mg/dL, respectively, for the 2 exercise sessions. False positive and negative ratios were 4 ± 2% and 21 ± 22%. Conclusions: The novel method for exercise detection identified the onset and end of exercise in approximately 5 minutes, with an average BG change of only −6 mg/dL. PMID:26134831

  14. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, Michael D.; Britten, Jerald A.; Nguyen, Hoang T.; Boyd, Robert; Shore, Bruce W.

    1999-01-01

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described.

  15. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, M.D.; Britten, J.A.; Nguyen, H.T.; Boyd, R.; Shore, B.W.

    1999-05-25

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described. 7 figs.

  16. Children’s Physic: Medical Perceptions and Treatment of Sick Children in Early Modern England, c. 1580–1720

    PubMed Central

    Newton, Hannah

    2015-01-01

    Summary Historians of medicine, childhood and paediatrics have often assumed that early modern doctors neither treated children, nor adapted their medicines to suit the peculiar temperaments of the young. Through an examination of medical textbooks and doctors’ casebooks, this article refutes these assumptions. It argues that medical authors and practising doctors regularly treated children, and were careful to tailor their remedies to complement the distinctive constitutions of children. Thus, this article proposes that a concept of ‘children’s physic’ existed in early modern England. This term refers to the notion that children were physiologically distinct, requiring special medical care. Children’s physic was rooted in the ancient traditions of Hippocratic and Galenic medicine: it was the child’s humoral make-up that underpinned all medical ideas about children’s bodies, minds, diseases and treatments. Children abounded in the humour blood, which made them humid and weak, and in need of medicines of a particularly gentle nature. PMID:26306061

  17. Design Principles for resilient cyber-physical Early Warning Systems - Challenges, Experiences, Design Patterns, and Best Practices

    NASA Astrophysics Data System (ADS)

    Gensch, S.; Wächter, J.; Schnor, B.

    2014-12-01

    Early warning systems (EWS) are safety-critical IT-infrastructures that serve the purpose of potentially saving lives or assets by observing real-world phenomena and issuing timely warning products to authorities and communities. An EWS consists of sensors, communication networks, data centers, simulation platforms, and dissemination channels. The components of this cyber-physical system may all be affected by both natural hazards and malfunctions of components alike. Resilience engineering so far has mostly been applied to safety-critical systems and processes in transportation (aviation, automobile), construction and medicine. Early warning systems need equivalent techniques to compensate for failures, and furthermore means to adapt to changing threats, emerging technology and research findings. We present threats and pitfalls from our experiences with the German and Indonesian tsunami early warning system, as well as architectural, technological and organizational concepts employed that can enhance an EWS' resilience. The current EWS is comprised of a multi-type sensor data upstream part, different processing and analysis engines, a decision support system, and various warning dissemination channels. Each subsystem requires a set of approaches towards ensuring stable functionality across system layer boundaries, including also institutional borders. Not only must services be available, but also produce correct results. Most sensors are distributed components with restricted resources, communication channels and power supply. An example for successful resilience engineering is the power capacity based functional management for buoy and tide gauge stations. We discuss various fault-models like cause and effect models on linear pathways, interaction of multiple events, complex and non-linear interaction of assumedly reliable subsystems and fault tolerance means implemented to tackle these threats.

  18. Physics

    NASA Astrophysics Data System (ADS)

    Campbell, Norman Robert

    2013-03-01

    Preface; Introduction; Part I. The Propositions of Science: 1. The subject matter of science; 2. The nature of laws; 3. The nature of laws (contd); 4. The discovery and proof of laws; 5. The explanation of laws; 6. Theories; 7. Chance and probability; 8. The meaning of science; 9. Science and philosophy; Part II. Measurement: 10. Fundamental measurement; 11. Physical number; 12. Fractional and negative magnitudes; 13. Numerical laws and derived magnitudes; 14. Units and dimensions; 15. The uses of dimensions; 16. Errors of measurement; methodical errors; 17. Errors of measurement; errors of consistency and the adjustment of observations; 18. Mathematical physics; Appendix; Index.

  19. Fraunhofer Diffraction and Polarization.

    ERIC Educational Resources Information Center

    Fortin, E.

    1979-01-01

    Describes an experiment for the intermediate undergraduate optics laboratory designed to illustrate simultaneously some aspects of the phenomena of diffraction; interference, coherence, apodization, the Fresnel-Arago law; as well as of the interrelations between these concepts. (HM)

  20. Fresnel Coherent Diffractive Imaging

    NASA Astrophysics Data System (ADS)

    Williams, G. J.; Quiney, H. M.; Dhal, B. B.; Tran, C. Q.; Nugent, K. A.; Peele, A. G.; Paterson, D.; de Jonge, M. D.

    2006-07-01

    We present an x-ray coherent diffractive imaging experiment utilizing a nonplanar incident wave and demonstrate success by reconstructing a nonperiodic gold sample at 24 nm resolution. Favorable effects of the curved beam illumination are identified.

  1. Multigap Diffraction at LHC

    SciTech Connect

    Goulianos, Konstantin

    2005-10-06

    The large rapidity interval available at the Large Hadron Collider (LHC) offers an arena in which the QCD aspects of diffraction may be explored in an environment free of gap survival complications using events with multiple rapidity gaps.

  2. Reflective diffraction grating

    DOEpatents

    Lamartine, Bruce C.

    2003-06-24

    Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

  3. Hypocholesterolemic effect of physically refined rice bran oil: studies of cholesterol metabolism and early atherosclerosis in hypercholesterolemic hamsters.

    PubMed

    Ausman, Lynne M; Rong, Ni; Nicolosi, Robert J

    2005-09-01

    Physically refined rice bran oil containing 2-4% nontriglyceride components as compared to other vegetable oils appears to be associated with lipid lowering and antiinflammatory properties in several rodent, primate and human models. These experiments were designed to investigate possible mechanisms for the hypocholesterolemic effect of the physically refined rice bran oil and to examine its effect on aortic fatty streak formation. In the first experiment, 30 hamsters were fed, for 8 weeks, chow-based diets plus 0.03% added cholesterol and 5% (wt/wt) coconut, canola, or physically refined rice bran oil (COCO, CANOLA or PRBO animal groups, respectively). Both plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly reduced in PRBO but not in CANOLA relative to COCO. PRBO also showed a significant 15-17% reduction in cholesterol absorption and significant 30% increase in neutral sterol (NS) excretion with no effect on bile acid (BA) excretion. Both CANOLA and PRBO showed a significant 300-500% increase in intestinal 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and significant (>25%) decrease in hepatic HMG-CoA reductase activities with respect to COCO. In a second experiment, 36 hamsters were fed chow-based diets with 0.05% added cholesterol, 10% coconut oil and 4% additional COCO, CANOLA or PRBO. Relative to COCO and CANOLA, plasma TC and LDL-C were significantly reduced in PRBO. Early atherosclerosis (fatty streak formation) was significantly reduced (48%) only in PRBO, relative to the other two. These results suggest that the lipid lowering found in PRBO is associated with decreased cholesterol absorption, but not hepatic cholesterol synthesis, and that the decrease in fatty streak formation with this oil may be associated with its nontriglyceride components not present in the other two diets.

  4. Complementary and Alternative Medicine Use Was Associated with Higher Perceived Physical and Mental Functioning in Early Systemic Sclerosis

    PubMed Central

    Hunnicutt, Sonya E.; Grady, James; McNearney, Terry A.

    2008-01-01

    Objective This study assessed the use of complementary and alternative medicine (CAM) therapies in patients with early systemic sclerosis (scleroderma, SSc). Methods At the annual visit, SSc patients enrolled in the Genetics versus Environment in Scleroderma Outcomes Study (GENISOS) were queried about their use of CAM therapies and intended symptom target, including herbal or nutriceutical therapy, acupuncture, transcutaneous electrical neural stimulation (TENS) and mind-body therapy (relaxation, meditative, imagery). The CAM user SSc patients were compared to matched non-CAM users over two years for database results of demographic, clinical and health-related quality of life SF-36 questionnaires by analysis of covariance. Results 25% of the university GENISOS group were CAM users: age: 54 years; female: 89%; diffuse cutaneous involvement: 47%; total skin score: 13.5; Medsger severity index: 5.8. Over 70% used ≥1 CAM therapies for over 1 year, independent of health insurance. Symptoms targeted included arthritis/arthralgia, pain, GI dysmotility and fatigue. CAM users had significantly higher mean mental component summary (MCS) scores on SF-36 at Baseline and Year 2, (49 and 49.9), compared to non-CAM users (42 and 40.2, respectively, p<0.01). At Year 2, the CAM user group had significantly higher scores of SF-36 domains physical component score, role-physical, bodily pain and vitality, whereas scores declined in the non-CAM user group. Conclusion In SSc, 70% of those in the CAM user group reported a long-term commitment to CAM therapies. Higher perceived mental functioning in CAM users might reflect more self-motivation to manage symptoms and subsequently, promote practices that result in higher perceived physical functioning. PMID:18602619

  5. "If I Had to Do It, Then I Would": Understanding Early Middle School Students' Perceptions of Physics and Physics-Related Careers by Gender

    ERIC Educational Resources Information Center

    Dare, Emily A.; Roehrig, Gillian H.

    2016-01-01

    This study examined the perceptions of 6th grade middle school students regarding physics and physics-related careers. The overarching goal of this work was to understand similarities and differences between girls' and boys' perceptions surrounding physics and physics-related careers as part of a long-term effort to increase female interest and…

  6. Knee pain during activities of daily living and its relationship with physical activity in patients with early and severe knee osteoarthritis.

    PubMed

    Fukutani, Naoto; Iijima, Hirotaka; Aoyama, Tomoki; Yamamoto, Yuko; Hiraoka, Masakazu; Miyanobu, Kazuyuki; Jinnouchi, Masashi; Kaneda, Eishi; Tsuboyama, Tadao; Matsuda, Shuichi

    2016-09-01

    This study aimed to investigate whether knee pain during various activities of daily living (ADLs) is associated with physical activity in patients with early and severe knee osteoarthritis (OA). We hypothesized that the painful ADLs associated with decreased physical activity differ according to disease severity. This cross-sectional study enrolled 270 patients with medial knee OA, assigned to either the early (Kellgren Lawrence [K/L] grade 1-2) or the severe group (K/L grade 3-4). Physical activity was assessed using a pedometer. Knee pain during six ADLs (waking up in the morning, walking on a flat surface, ascending stairs, etc.) was evaluated using a questionnaire. We performed multiple regression and quantile regression analysis to investigate whether knee pain during each ADL was associated with physical activity. In the early group, the more knee pain they experienced while ascending stairs, the lower their physical activity was (75th regression coefficient = -1033.70, P = 0.018). In the severe group, the more knee pain they experienced while walking on a flat surface or bending to the floor or standing up, the lower their physical activity was (unstandardized coefficients = -1850.87, P = 0.026; unstandardized coefficients = -2640.35, P = 0.010). Knee pain while ascending stairs and while walking on a flat surface or bending to the floor or standing up was a probable limiting factor for physical activity in early and severe knee OA, respectively. These findings suggested that a reduction in task-specific knee pain according to disease severity could improve physical activity levels. PMID:27041381

  7. Knee pain during activities of daily living and its relationship with physical activity in patients with early and severe knee osteoarthritis.

    PubMed

    Fukutani, Naoto; Iijima, Hirotaka; Aoyama, Tomoki; Yamamoto, Yuko; Hiraoka, Masakazu; Miyanobu, Kazuyuki; Jinnouchi, Masashi; Kaneda, Eishi; Tsuboyama, Tadao; Matsuda, Shuichi

    2016-09-01

    This study aimed to investigate whether knee pain during various activities of daily living (ADLs) is associated with physical activity in patients with early and severe knee osteoarthritis (OA). We hypothesized that the painful ADLs associated with decreased physical activity differ according to disease severity. This cross-sectional study enrolled 270 patients with medial knee OA, assigned to either the early (Kellgren Lawrence [K/L] grade 1-2) or the severe group (K/L grade 3-4). Physical activity was assessed using a pedometer. Knee pain during six ADLs (waking up in the morning, walking on a flat surface, ascending stairs, etc.) was evaluated using a questionnaire. We performed multiple regression and quantile regression analysis to investigate whether knee pain during each ADL was associated with physical activity. In the early group, the more knee pain they experienced while ascending stairs, the lower their physical activity was (75th regression coefficient = -1033.70, P = 0.018). In the severe group, the more knee pain they experienced while walking on a flat surface or bending to the floor or standing up, the lower their physical activity was (unstandardized coefficients = -1850.87, P = 0.026; unstandardized coefficients = -2640.35, P = 0.010). Knee pain while ascending stairs and while walking on a flat surface or bending to the floor or standing up was a probable limiting factor for physical activity in early and severe knee OA, respectively. These findings suggested that a reduction in task-specific knee pain according to disease severity could improve physical activity levels.

  8. Multipath analysis diffraction calculations

    NASA Technical Reports Server (NTRS)

    Statham, Richard B.

    1996-01-01

    This report describes extensions of the Kirchhoff diffraction equation to higher edge terms and discusses their suitability to model diffraction multipath effects of a small satellite structure. When receiving signals, at a satellite, from the Global Positioning System (GPS), reflected signals from the satellite structure result in multipath errors in the determination of the satellite position. Multipath error can be caused by diffraction of the reflected signals and a method of calculating this diffraction is required when using a facet model of the satellite. Several aspects of the Kirchhoff equation are discussed and numerical examples, in the near and far fields, are shown. The vector form of the extended Kirchhoff equation, by adding the Larmor-Tedone and Kottler edge terms, is given as a mathematical model in an appendix. The Kirchhoff equation was investigated as being easily implemented and of good accuracy in the basic form, especially in phase determination. The basic Kirchhoff can be extended for higher accuracy if desired. A brief discussion of the method of moments and the geometric theory of diffraction is included, but seems to offer no clear advantage in implementation over the Kirchhoff for facet models.

  9. Diffraction by nanocrystals II.

    PubMed

    Chen, Joe P J; Millane, Rick P

    2014-08-01

    Nanocrystals with more than one molecule in the unit cell will generally crystallize with incomplete unit cells on the crystal surface. Previous results show that the ensemble-averaged diffraction by such crystals consists of a usual Bragg component and two other Bragg-like components due to the incomplete unit cells. Using an intrinsic flexibility in the definition of the incomplete-unit-cell part of a crystal, the problem is formulated such that the magnitude of the Bragg-like components is minimized, which leads to a simpler and more useful interpretation of the diffraction. Simulations show the nature of the relative magnitudes of the diffraction components in different regions of reciprocal space and the effect of crystal faceting. PMID:25121528

  10. Physics.

    PubMed

    Bromley, D A

    1980-07-01

    From massive quarks deep in the hearts of atomic nuclei to the catastrophic collapse of giant stars in the farthest reaches of the universe, from the partial realization of Einstein's dream of a unified theory of the forces of nature to the most practical applications in technology, medicine, and throughout contemporary society, physics continues to have a profound impact on man's view of the universe and on the quality of life. The author argues that the past few years, in terms of new discoveries, new insight-and the new questions-have been among the most productive in the history of the field and puts into context his selection of some of the most important new developments in this fundamental science.

  11. Unaccompanied refugee minors' early life narratives of physical abuse from caregivers and teachers in their home countries.

    PubMed

    Skårdalsmo Bjørgo, Envor M; Jensen, Tine K

    2015-10-01

    The early life narratives of 34 unaccompanied refugee minors, especially their reports of interpersonal violence, were analyzed using Interpretative Phenomenological Analysis (IPA). The youth originated from eight countries, with Afghanistan, Eritrea, and Sri Lanka being the most frequent origins, and they arrived to Norway before the age of 15. Four of these youth were girls. The physical violence took place at home and/or at school and could be extremely harsh. Approximately half of the youth expressed some type of ambivalence toward the perpetrator. In analyzing how the youth understood the reasons for violence two categories of internal and three categories of external attributions were found. Several of the youth blamed their own behavior for the abuse, although such internal attributions were frequently combined with external attributions. Some different patterns of attributions emerged between home and school violence. Most of the youth placed the blame for school violence on their own behavior or that violence was part of normal school discipline. For violence at home there was a tendency to place more blame on the perpetrator (mostly fathers). Possible long-term consequences of the experiences and the different attributional styles as well as implications of the findings are discussed. Professionals should assess refugee children for interpersonal violence experiences as well as for other experiences in their home country. PMID:26307532

  12. Mathematical Assessment of Physical and Chemical Processes from the middle B to the early F Type Main Sequence Stars

    NASA Astrophysics Data System (ADS)

    Yuce, Kutluay; Adelman, Saul J.

    2016-07-01

    The middle B to the early F main sequence stars are thought to have some of the most quiet atmospheres. In this part of the HR diagram we find stars with atmospheres in radiative equilibrium. They lack the convective circulations of the middle F and cooler stars and the massive stellar winds of hotter stars. Diffusion theory requires the Chemically Peculiar stars to have relatively quiet atmospheres and if there are no magnetic fields they should lack abundance spots. If we look at stars evolving off the Main Sequence in this part of the HR diagram, we see that the evolutionary paths of stars of different mass do not cross. So if we compare stars with the same effective temperature and surface gravity, we are studying stars of the same luminosity and mass. By comparing their elemental abundances, we might be able to identify physical processes which cause their abundances to be different. In this work we begin with stars whose effective temperatures and surface gravities are similar, and which has been analyzed by us using spectra obtained from the Dominion Astrophysical Observatory.

  13. The Differential Impacts of Early Physical and Sexual Abuse and Internalizing Problems on Daytime Cortisol Rhythm in School-Aged Children

    ERIC Educational Resources Information Center

    Cicchetti, Dante; Rogosch, Fred A.; Gunnar, Megan R.; Toth, Sheree L.

    2010-01-01

    The impact of early physical and sexual abuse (EPA/SA) occurring in the first 5 years of life was investigated in relation to depressive and internalizing symptomatology and diurnal cortisol regulation. In a summer camp context, school-aged maltreated (n = 265) and nonmaltreated (n = 288) children provided morning and late afternoon saliva samples…

  14. The Role of Occupational Therapists and Physical Therapists in Elementary School System Early Intervening Services and Response to Intervention: A Case Report

    ERIC Educational Resources Information Center

    Reeder, Deborah L.; Arnold, Sandra H.; Jeffries, Lynn M.; McEwen, Irene R.

    2011-01-01

    The Individuals with Disabilities Improvement Act and No Child Left Behind Act broadened the roles of occupational therapists (OTs) and physical therapists (PTs) to include therapist participation in early intervening services including response to intervention (RTI). This case report describes one school district's inclusion of OT and PT in the…

  15. Exploring Daily Physical Activity and Nutrition Patterns in Early Learning Settings: Snapshots of Young Children in Head Start, Primary, and After-School Settings

    ERIC Educational Resources Information Center

    Stegelin, Dolores A.; Anderson, Denise; Kemper, Karen; Wagner, Jennifer; Evans, Katharine

    2014-01-01

    The purpose of this research project was to gain a greater understanding of daily routines of 4-7 year olds regarding physical activity and nutrition practices in typical early learning environments. The settings selected for this observational study included Head Start, primary, and after-school learning environments in a city in the southeast.…

  16. Calculating cellulose diffraction patterns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although powder diffraction of cellulose is a common experiment, the patterns are not widely understood. The theory is mathematical, there are numerous different crystal forms, and the conventions are not standardized. Experience with IR spectroscopy is not directly transferable. An awful error, tha...

  17. Diffraction with wavefront curvature

    NASA Astrophysics Data System (ADS)

    Nugent, K. A.; Peele, A. G.; Quiney, H. M.; Chapman, H. N.

    2005-05-01

    Modern X-ray optics can produce a focused synchrotron beam with curvature on a scale comparable to that of an isolated biomolecule or to the lattice spacing of a biomolecular crystal. It is demonstrated that diffraction of phase-curved beams from such systems allows unique and robust phase recovery.

  18. DIFFRACTION FROM MODEL CRYSTALS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although calculating X-ray diffraction patterns from atomic coordinates of a crystal structure is a widely available capability, calculation from non-periodic arrays of atoms has not been widely applied to cellulose. Non-periodic arrays result from modeling studies that, even though started with at...

  19. Diffract, then destroy

    NASA Astrophysics Data System (ADS)

    Ball, Philip

    2016-09-01

    A new implementation of X-ray diffraction using free-electron lasers can take snapshots of biological molecules that are inaccessible via X-ray crystallography. As Philip Ball reports, the technique can even be used to create stop-motion films of dynamic molecular processes

  20. Exploring direct and indirect influences of physical work environment on job satisfaction for early-career registered nurses employed in hospitals.

    PubMed

    Djukic, Maja; Kovner, Christine T; Brewer, Carol S; Fatehi, Farida; Greene, William H

    2014-08-01

    We explored direct and indirect influences of physical work environment on job satisfaction in a nationally representative sample of 1,141 early-career registered nurses. In the fully specified model, physical work environment had a non-significant direct effect on job satisfaction. The path analysis used to test multiple indirect effects showed that physical work environment had a positive indirect effect (p < .05) on job satisfaction through ten variables: negative affectivity, variety, workgroup cohesion, nurse-physician relations, quantitative workload, organizational constraints, distributive justice, promotional opportunity, local and non-local job opportunities. The findings make important contributions to the understanding of the relationship between physical work environment and job satisfaction. The results can inform health care leaders' insight about how physical work environment influences nurses' job satisfaction. PMID:24985551

  1. Exploring direct and indirect influences of physical work environment on job satisfaction for early-career registered nurses employed in hospitals.

    PubMed

    Djukic, Maja; Kovner, Christine T; Brewer, Carol S; Fatehi, Farida; Greene, William H

    2014-08-01

    We explored direct and indirect influences of physical work environment on job satisfaction in a nationally representative sample of 1,141 early-career registered nurses. In the fully specified model, physical work environment had a non-significant direct effect on job satisfaction. The path analysis used to test multiple indirect effects showed that physical work environment had a positive indirect effect (p < .05) on job satisfaction through ten variables: negative affectivity, variety, workgroup cohesion, nurse-physician relations, quantitative workload, organizational constraints, distributive justice, promotional opportunity, local and non-local job opportunities. The findings make important contributions to the understanding of the relationship between physical work environment and job satisfaction. The results can inform health care leaders' insight about how physical work environment influences nurses' job satisfaction.

  2. Modeling and simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

    SciTech Connect

    Ford, Corey C.; Taylor, Paul Allen

    2008-02-01

    The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm{sup 3} voxels), 5 material model of the human head was created by segmentation of color cryosections from the Visible Human Female dataset. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior and lateral directions. Three dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric (shear) stress within the first 2 milliseconds of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 msec time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.

  3. Colored Diffraction Catastrophes

    NASA Astrophysics Data System (ADS)

    Berry, M. V.; Klein, S.

    1996-03-01

    On fine scales, caustics produced with white light show vividly colored diffraction fringes. For caustics described by the elementary catastrophes of singularity theory, the colors are characteristic of the type of singularity. We study the diffraction colors of the fold and cusp catastrophes. The colors can be simulated computationally as the superposition of monochromatic patterns for different wavelengths. Far from the caustic, where the luminosity contrast is negligible, the fringe colors persist; an asymptotic theory explains why. Experiments with caustics produced by refraction through irregular bathroom-window glass show good agreement with theory. Colored fringes near the cusp reveal fine lines that are not present in any of the monochromatic components; these lines are explained in terms of partial decoherence between rays with widely differing path differences.

  4. Colored diffraction catastrophes.

    PubMed Central

    Berry, M V; Klein, S

    1996-01-01

    On fine scales, caustics produced with white light show vividly colored diffraction fringes. For caustics described by the elementary catastrophes of singularity theory, the colors are characteristic of the type of singularity. We study the diffraction colors of the fold and cusp catastrophes. The colors can be simulated computationally as the superposition of monochromatic patterns for different wavelengths. Far from the caustic, where the luminosity contrast is negligible, the fringe colors persist; an asymptotic theory explains why. Experiments with caustics produced by refraction through irregular bathroom-window glass show good agreement with theory. Colored fringes near the cusp reveal fine lines that are not present in any of the monochromatic components; these lines are explained in terms of partial decoherence between rays with widely differing path differences. Images Fig. 1 Fig. 2 Fig. 3 Fig. 6 Fig. 8 Fig. 9 Fig. 10 PMID:11607642

  5. Physical Activity, Physical Self-Concept, and Health-Related Quality of Life of Extreme Early and Late Maturing Adolescent Girls

    ERIC Educational Resources Information Center

    Cumming, Sean P.; Sherar, Lauren B.; Smart, Joanna E. Hunter; Rodrigues, Aristides M. M.; Standage, Martyn; Gillison, Fiona B.; Malina, Robert M.

    2012-01-01

    In this study we tested for differences in physical activity (PA), physical self-concept, and health-related quality of life (HRQoL) between the least and most biologically mature adolescent females within their respective chronological and academic year groups. A total of 222 British female adolescents aged 10 to 14 years (X[bar] age = 12.7…

  6. Multiple wavelength diffractive imaging

    NASA Astrophysics Data System (ADS)

    Chen, Bo; Dilanian, Ruben A.; Teichmann, Sven; Abbey, Brian; Peele, Andrew G.; Williams, Garth J.; Hannaford, Peter; van Dao, Lap; Quiney, Harry M.; Nugent, Keith A.

    2009-02-01

    We demonstrate coherent diffraction imaging using multiple harmonics from a high-harmonic generation source. An algorithm is presented that builds the known incident spectrum into the reconstruction procedure with the result that the useable flux is increased by more than an order of magnitude. Excellent images are obtained with a resolution of (165±5)nm and compare very well with images from a scanning electron microscope.

  7. SINGLE CRYSTAL NEUTRON DIFFRACTION.

    SciTech Connect

    KOETZLE,T.F.

    2001-03-13

    Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

  8. Polychromatic diffraction contrast tomography

    SciTech Connect

    King, A.; Reischig, P.; Adrien, J.; Peetermans, S.; Ludwig, W.

    2014-11-15

    This tutorial review introduces the use of polychromatic radiation for 3D grain mapping using X-ray diffraction contrast tomography. The objective is to produce a 3D map of the grain shapes and orientations within a bulk, millimeter-sized polycrystalline sample. The use of polychromatic radiation enables the standard synchrotron X-ray technique to be applied in a wider range of contexts: 1) Using laboratory X-ray sources allows a much wider application of the diffraction contrast tomography technique. 2) Neutron sources allow large samples, or samples containing high Z elements to be studied. 3) Applied to synchrotron sources, smaller samples may be treated, or faster measurements may be possible. Challenges and particularities in the data acquisition and processing, and the limitations of the different variants, are discussed. - Highlights: • We present a tutorial review of polychromatic diffraction contrast tomography techniques. • The use of polychromatic radiation allows the standard synchrotron DCT technique to be extended to a range of other sources. • The characteristics and limitations of all variants of the techniques are derived, discussed and compared. • Examples using laboratory X-ray and cold neutron radiation are presented. • Suggestions for the future development of these techniques are presented.

  9. Analysis of North Carolina Community College Early Childhood Education Coursework on Nutrition, Health, and Physical Activity. Early Childhood Professional Development Report, Volume 1, Number 1

    ERIC Educational Resources Information Center

    Dunst, Carl J.; Raab, Melinda; Hamby, Deborah W.; Long, Anna Lauren

    2015-01-01

    The results from a content analysis of coursework required and offered at the 58 North Carolina Community Colleges to obtain an Associate in Applied Sciences Degree in early childhood education are described. The analyses were conducted to determine the likelihood that the courses could include content knowledge or practice on 12 infant and child…

  10. The effects of early prevention programs for families with young children at risk for physical child abuse and neglect: a meta-analysis.

    PubMed

    Geeraert, Liesl; Van den Noortgate, Wim; Grietens, Hans; Onghena, Patrick

    2004-08-01

    In this article, a meta-analysis is presented on 40 evaluation studies of early prevention programs for families with young children at risk for physical child abuse and neglect with mostly nonrandomized designs. The main aim of all programs was to prevent physical child abuse and neglect by providing early family support. For the meta-analysis, a multilevel approach was used. A significant overall positive effect was found, pointing to the potential usefulness of these programs. The study demonstrated a significant decrease in the manifestation of abusive and neglectful acts and a significant risk reduction in factors such as child functioning, parent-child interaction, parent functioning, family functioning, and context characteristics. PMID:15245680

  11. The Differential Impacts of Early Physical and Sexual Abuse and Internalizing Problems on Daytime Cortisol Rhythm in School-Aged Children

    PubMed Central

    Cicchetti, Dante; Rogosch, Fred A.; Gunnar, Megan R.; Toth, Sheree L.

    2009-01-01

    The impact of early physical and sexual abuse (EPA/SA) occurring in the first five years of life was investigated in relation to depressive and internalizing symptomatology and diurnal cortisol regulation. In a summer camp context, school-aged maltreated (n = 265) and nonmaltreated (n = 288) children provided morning and late afternoon saliva samples on five consecutive days. Child self-report and adult observer reports of child internalizing and depressive symptoms were obtained. Children experiencing EPA/SA and high depressive or internalizing symptoms uniquely exhibited an attenuated diurnal decrease in cortisol, indicative of neuroendocrine dysregulation. These results were specific to EPA/SA, rather than later onset physical or sexual abuse or early occurring neglect or emotional maltreatment. PMID:20331666

  12. Diffraction of a Laser Beam.

    ERIC Educational Resources Information Center

    Jodoin, Ronald E.

    1979-01-01

    Investigates the effect of the nonuniform irradiance across a laser beam on diffraction of the beam, specifically the Fraunhofer diffraction of a laser beam with a Gaussian irradiance profile as it passes through a circular aperture. (GA)

  13. Aberrations of diffracted wave fields. II. Diffraction gratings.

    PubMed

    Mahajan, V N

    2000-12-01

    The Rayleigh-Sommerfeld theory is applied to diffraction of a spherical wave by a grating. The grating equation is obtained from the aberration-free diffraction pattern, and its aberrations are shown to be the same as the conventional aberrations obtained by using Fermat's principle. These aberrations are shown to be not associated with the diffraction process. Moreover, it is shown that the irradiance distribution of a certain diffraction order is the Fraunhofer diffraction pattern of the grating aperture as a whole aberrated by the aberration of that order. PMID:11140481

  14. Recent diffractive results from HERA

    NASA Astrophysics Data System (ADS)

    Valkárová, Alice

    2016-07-01

    The diffractive dijet cross sections for photoproduction and deep inelastic scattering were studied and compared with theoretical NLO QCD predictions. The results of exclusive dijet production were compared to predictions from models which are based on different assumptions about the nature of diffractive exchange. Isolated prompt photons in diffractive photoproduction produced inclusively or together with a jet were studied for the first time.

  15. Spectral diffraction efficiency characterization of broadband diffractive optical elements.

    SciTech Connect

    Choi, Junoh; Cruz-Cabrera, Alvaro Augusto; Tanbakuchi, Anthony

    2013-03-01

    Diffractive optical elements, with their thin profile and unique dispersion properties, have been studied and utilized in a number of optical systems, often yielding smaller and lighter systems. Despite the interest in and study of diffractive elements, the application has been limited to narrow spectral bands. This is due to the etch depths, which are optimized for optical path differences of only a single wavelength, consequently leading to rapid decline in efficiency as the working wavelength shifts away from the design wavelength. Various broadband diffractive design methodologies have recently been developed that improve spectral diffraction efficiency and expand the working bandwidth of diffractive elements. We have developed diffraction efficiency models and utilized the models to design, fabricate, and test two such extended bandwidth diffractive designs.

  16. Non Specular Diffractive Optics

    NASA Astrophysics Data System (ADS)

    Wang, Yunjin; Overcash, Dan; Morawice, Pawel; Yin, Ming; Datta, Timir

    2009-11-01

    Geometrically decorated two-dimensional (2D) discrete surfaces can be more effective than conventional smooth reflectors in managing wave radiation. Constructive non-specular wave scattering permits the scattering angle to be other than twice that of incidence and can result in gross violations of the law of reflection. A wide range of novel reflective behaviors ensues; including the phenomenon of negative reflection were energy transport remains on the same side of the normal. Also, at a critical incidence coherent superposition can force both the transmitted and reflected waves to graze the scattering surface thus synergistically reinforcing the diffractive process in a behavior reminiscent of critical internal reflection of ray optics. We experimentally demonstrate the concept with measurements on a one-dimensionally periodic system (grating) where the scattering angle is shown to be an inverse circular function of a function that depends on the diffractive index and the two angles. Excellent agreement is found between experimental data and theory. A preliminary report on our observations will be discussed.

  17. Keyhole coherent diffractive imaging

    NASA Astrophysics Data System (ADS)

    Abbey, Brian; Nugent, Keith A.; Williams, Garth J.; Clark, Jesse N.; Peele, Andrew G.; Pfeifer, Mark A.; de Jonge, Martin; McNulty, Ian

    2008-05-01

    The availability of third-generation synchrotrons and ultimately X-ray free-electron lasers is driving the development of many new methods of microscopy. Among these techniques, coherent diffractive imaging (CDI) is one of the most promising, offering nanometre-scale imaging of non-crystallographic samples. Image reconstruction from a single diffraction pattern has hitherto been possible only for small, isolated samples, presenting a fundamental limitation on the CDI method. Here we report on a form of imaging we term `keyhole' CDI, which can reconstruct objects of arbitrary size. We demonstrate the technique using visible light and X-rays, with the latter producing images of part of an extended object with a detector-limited resolution of better than 20nm. Combining the improved resolution of modern X-ray optics with the wavelength-limited resolution of CDI, the method paves the way for detailed imaging of a single quantum dot or of a small virus within a complex host environment.

  18. Trends in brain oxygenation during mental and physical exercise measured using near-infrared spectroscopy (NIRS): potential for early detection of Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Allen, Monica S.; Allen, Jeffery W.; Mikkilineni, Shweta; Liu, Hanli

    2005-04-01

    Motivation: Early diagnosis of Alzheimer's disease (AD) is crucial because symptoms respond best to available treatments in the initial stages of the disease. Recent studies have shown that marked changes in brain oxygenation during mental and physical tasks can be used for noninvasive functional brain imaging to detect Alzheimer"s disease. The goal of our study is to explore the possibility of using near infrared spectroscopy (NIRS) and mapping (NIRM) as a diagnostic tool for AD before the onset of significant morphological changes in the brain. Methods: A 16-channel NIRS brain imager was used to noninvasively measure spatial and temporal changes in cerebral hemodynamics induced during verbal fluency task and physical activity. The experiments involved healthy subjects (n = 10) in the age range of 25+/-5 years. The NIRS signals were taken from the subjects' prefrontal cortex during the activities. Results and Conclusion: Trends of oxygenated and deoxygenated hemoglobin in the prefrontal cortex of the brain were observed. During the mental stimulation, the subjects showed significant increase in oxygenated hemoglobin [HbO2] with a simultaneous decrease in deoxygenated hemoglobin [Hb]. However, physical exercise caused a rise in levels of HbO2 with small variations in Hb. This study basically demonstrates that NIRM taken from the prefrontal cortex of the human brain is sensitive to both mental and physical tasks and holds potential to serve as a diagnostic means for early detection of Alzheimer's disease.

  19. Short-term lower-body plyometric training improves whole body BMC, bone metabolic markers, and physical fitness in early pubertal male basketball players.

    PubMed

    Zribi, Anis; Zouch, Mohamed; Chaari, Hamada; Bouajina, Elyes; Ben Nasr, Hela; Zaouali, Monia; Tabka, Zouhair

    2014-02-01

    The effects of a 9-week lower-body plyometric training program on bone mass, bone markers and physical fitness was examined in 51 early pubertal male basketball players divided randomly into a plyometric group (PG: 25 participants) and a control group (CG: 26 participants). Areal bone mineral density (aBMD), bone mineral content (BMC), and bone area (BA) in the whole body, L2-L4 vertebrae, and in total hip, serum levels of osteocalcin (Oc) and C-terminal telopeptide fragment of Type I collagen (CTx), jump, sprint and power abilities were assessed at baseline and 9 weeks. Group comparisons were done by independent student's t-test between means and analyses of (ANOVA) and covariance (ANCOVA), adjusting for baseline values. PG experienced a significant increase in Oc (p < .01) and all physical fitness except for the 5-jump test. However, there was no improvement in aBMD, BMC and BA in any measured site, except in whole body BMC of the PG. A positive correlation was observed between percentage increase (Δ%) of physical fitness and those of (Oc) for the PG. In summary, biweekly sessions of lower body plyometric training program were successful for improving whole body BMC, bone formation marker (Oc) and physical fitness in early pubertal male basketball players.

  20. Hard diffraction in Pythia 8

    NASA Astrophysics Data System (ADS)

    Overgaard Rasmussen, Christine

    2016-07-01

    We present an overview of the options for diffraction implemented in the general-purpose event generator Pythia 8 [1]. We review the existing model for soft diffraction and present a new model for hard diffraction. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the diffractive cross section into a Pomeron flux and a Pomeron PDF, with several choices for both implemented in Pythia 8. The model of hard diffraction is implemented as a part of the multiparton interactions (MPI) framework, thus introducing a dynamical gap survival probability that explicitly breaks factorisation.

  1. Friendship conflict and the development of generalized physical aggression in the early school years: a genetically informed study of potential moderators.

    PubMed

    Salvas, Marie-Claude; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Tremblay, Richard E; Boivin, Michel

    2014-06-01

    Several authors consider high and frequent conflicts between friends during childhood as a serious risk for subsequent conduct problems such as generalized physical aggression toward others (e.g., Kupersmidt, Burchinal, & Patterson, 1995; Sebanc, 2003). Although it seems logical to assume that friendship conflict could have some negative consequences on children's behaviors, some scholars have suggested that a certain amount of conflict between friends may actually promote social adjustment (e.g., Laursen & Pursell, 2009). The aim of this study was to investigate the role of friendship conflict in regard to the development of generalized physical aggression toward others in the early school years (i.e., from kindergarten to Grade 1), as well as the moderating role of relational (i.e., shared positive affect and dyadic conflict resolution skills) and personal (i.e., children's sex and genetic liability for aggression) characteristics in this context. The sample included 745 twins assessed through teacher, peer, child, and friend ratings in kindergarten and Grade 1. Friendship conflict in kindergarten was linearly related to an increase in boys' but not girls' generalized physical aggression. However, shared positive affect and conflict resolution skills mitigated the prospective associations between friendship conflict and generalized physical aggression. These results were independent of children's sex, genetic risk for physical aggression, and initial levels of generalized physical aggression in kindergarten. Fostering a positive relationship between friends at school entry may buffer against the risk associated with experiencing friendship conflict. PMID:24684716

  2. Friendship conflict and the development of generalized physical aggression in the early school years: a genetically informed study of potential moderators.

    PubMed

    Salvas, Marie-Claude; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Tremblay, Richard E; Boivin, Michel

    2014-06-01

    Several authors consider high and frequent conflicts between friends during childhood as a serious risk for subsequent conduct problems such as generalized physical aggression toward others (e.g., Kupersmidt, Burchinal, & Patterson, 1995; Sebanc, 2003). Although it seems logical to assume that friendship conflict could have some negative consequences on children's behaviors, some scholars have suggested that a certain amount of conflict between friends may actually promote social adjustment (e.g., Laursen & Pursell, 2009). The aim of this study was to investigate the role of friendship conflict in regard to the development of generalized physical aggression toward others in the early school years (i.e., from kindergarten to Grade 1), as well as the moderating role of relational (i.e., shared positive affect and dyadic conflict resolution skills) and personal (i.e., children's sex and genetic liability for aggression) characteristics in this context. The sample included 745 twins assessed through teacher, peer, child, and friend ratings in kindergarten and Grade 1. Friendship conflict in kindergarten was linearly related to an increase in boys' but not girls' generalized physical aggression. However, shared positive affect and conflict resolution skills mitigated the prospective associations between friendship conflict and generalized physical aggression. These results were independent of children's sex, genetic risk for physical aggression, and initial levels of generalized physical aggression in kindergarten. Fostering a positive relationship between friends at school entry may buffer against the risk associated with experiencing friendship conflict.

  3. The Early Childhood Aggression Curve: Development of Physical Aggression in 10- to 50-Month-Old Children

    ERIC Educational Resources Information Center

    Alink, Lenneke R. A.; Mesman, Judi; van Zeijl, Jantien; Stolk, Mirjam N.; Juffer, Femmie; Koot, Hans M.; Bakermans-Kranenburg, Marian J.; van I Jzendoorn, Marinus H.

    2006-01-01

    This study examines the prevalence, stability, and development of physical aggression, as reported by mothers and fathers, in a sample of children initially recruited at 12, 24, and 36 months (N=2,253) and in a subsample followed up 1 year later (n=271) in a cross-sequential design. Physical aggression occurred in 12-month-olds, but significantly…

  4. Mothers' Perceived Physical Health during Early and Middle Childhood: Relations with Child Developmental Delay and Behavior Problems

    ERIC Educational Resources Information Center

    Eisenhower, Abbey; Blacher, Jan; Baker, Bruce L.

    2013-01-01

    The self-perceived physical health of mothers raising children with developmental delay (DD; N = 116) or typical development (TD; N = 129) was examined across child ages 3-9 years, revealing three main findings. First, mothers of children with DD experienced poorer self-rated physical health than mothers of children with TD at each age. Latent…

  5. Conference on Early Mars: Geologic and Hydrologic Evolution, Physical and Chemical Environments, and the Implications for Life

    NASA Technical Reports Server (NTRS)

    Clifford, S. M. (Editor); Treiman, A. H. (Editor); Newsom, H. E. (Editor); Farmer, J. D. (Editor)

    1997-01-01

    Topics considered include: Geology alteration and life in an extreme environment; developing a chemical code to identify magnetic biominerals; effect of impacts on early Martin geologic evolution; spectroscopic identification of minerals in Hematite-bearing soils and sediments; exopaleontology and the search for a Fossil record on Mars; geochemical evolution of the crust of Mars; geological evolution of the early earth;solar-wind-induced erosion of the Mars atmosphere. Also included geological evolution of the crust of Mars.

  6. Phase shifting diffraction interferometer

    DOEpatents

    Sommargren, G.E.

    1996-08-29

    An interferometer which has the capability of measuring optical elements and systems with an accuracy of {lambda}/1000 where {lambda} is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about {lambda}/50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms. 8 figs.

  7. Phase shifting diffraction interferometer

    DOEpatents

    Sommargren, Gary E.

    1996-01-01

    An interferometer which has the capability of measuring optical elements and systems with an accuracy of .lambda./1000 where .lambda. is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about .lambda./50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms.

  8. Multilayer diffraction grating

    DOEpatents

    Barbee, T.W. Jr.

    1990-04-10

    This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages. 2 figs.

  9. Multilayer diffraction grating

    DOEpatents

    Barbee, Jr., Troy W.

    1990-01-01

    This invention is for a reflection diffraction grating that functions at X-ray to VUV wavelengths and at normal angles of incidence. The novel grating is comprised of a laminar grating of period D with flat-topped grating bars. A multiplicity of layered synthetic microstructures, of period d and comprised of alternating flat layers of two different materials, are disposed on the tops of the grating bars of the laminar grating. In another embodiment of the grating, a second multiplicity of layered synthetic microstructures are also disposed on the flat faces, of the base of the grating, between the bars. D is in the approximate range from 3,000 to 50,000 Angstroms, but d is in the approximate range from 10 to 400 Angstroms. The laminar grating and the layered microstructures cooperatively interact to provide many novel and beneficial instrumentational advantages.

  10. A policy-driven multifaceted approach for early childhood physical fitness promotion: impacts on body composition and physical fitness in young Chinese children

    PubMed Central

    2014-01-01

    Background The prevalence of obesity increased while certain measures of physical fitness deteriorated in preschool children in China over the past decade. This study tested the effectiveness of a multifaceted intervention that integrated childcare center, families, and community to promote healthy growth and physical fitness in preschool Chinese children. Methods This 12-month study was conducted using a quasi-experimental pretest/posttest design with comparison group. The participants were 357 children (mean age = 4.5 year) enrolled in three grade levels in two childcare centers in Beijing, China. The intervention included: 1) childcare center intervention (physical activity policy changes, teacher training, physical education curriculum and food services training), 2) family intervention (parent education, internet website for support, and family events), and 3) community intervention (playground renovation and community health promotion events). The study outcome measures included body composition (percent body fat, fat mass, and muscle mass), Body Mass Index (BMI) and BMI z-score and physical fitness scores in 20-meter agility run (20M-AR), broad jump for distance (BJ), timed 10-jumps, tennis ball throwing (TBT), sit and reach (SR), balance beam walk (BBW), 20-meter crawl (20M-C)), 30-meter sprint (30M-S)) from a norm referenced test. Measures of process evaluation included monitoring of children’s physical activity (activity time and intensity) and food preparation records, and fidelity of intervention protocol implementation. Results Children in the intervention center significantly lowered their body fat percent (−1.2%, p < 0.0001), fat mass (−0.55 kg, p <0.0001), and body weight (0.36 kg, p <0.02) and increased muscle mass (0.48 kg, p <0.0001), compared to children in the control center. They also improved all measures of physical fitness except timed 10-jumps (20M-AR: −0.74 seconds, p < 0.0001; BJ: 8.09 cm, p < 0.0001; TBT: 0

  11. Circadian rhythm and the influence of physical activity on circulating surfactant protein D in early and long-standing rheumatoid arthritis.

    PubMed

    Christensen, A F; Hoegh, S V; Lottenburger, T; Holmskov, U; Tornoe, I; Hørslev-Petersen, K; Sørensen, G L; Junker, P

    2011-12-01

    Surfactant protein D (SP-D) belongs to the collectin family and has pro-and anti-inflammatory capacities depending on its oligomerization. Previously, circulating SP-D was shown to be decreased in early rheumatoid arthritis (RA) and negatively correlated to disease activity. This study aimed at assessing the diurnal rhythmicity and the influence of physical activity on circulating SP-D in patients with RA at different stages compared with healthy individuals. Patients with early RA (ERA) with disease duration <6 months and with long-standing RA (LRA) with disease duration 5-15 years were included in two sub-studies. Healthy individuals served as controls. Diurnal variation: blood samples were collected every 3 h from 7 a.m to 10 p.m and the following morning. Physical activity: blood sampling was done before and after standardized physical challenge. SP-D was measured by ELISA. SP-D exhibited diurnal variation in healthy controls (n = 15) and in patients with ERA (n = 9) and LRA (n = 9) with peak values at 10 a.m. and nadir in the evening (controls: P < 0.001, ERA: P = 0.004 and LRA: P = 0.009). Three hours after cessation of physical activity, SP-D decreased below pre-exercise levels in both ERA (n = 10), LRA (n = 10) and controls (n = 13) (ERA: P < 0.001, LRA: P < 0.001 and controls: P = 0.005). In patients with RA, the decline was already observed 1 h post-exercise. Circulating SP-D exhibits diurnal variation both in patients with RA at different stages and in healthy controls. SP-D in serum decreases following physical activity in health and RA disease. This study underscores the need of standardized blood sampling conditions in future studies on SP-D.

  12. A femtosecond electron diffraction system

    NASA Astrophysics Data System (ADS)

    Zhao, Baosheng; Zhang, Jie; Tian, Jinshou; Wang, Junfeng; Wu, Jianjun; Liu, Yunquan; Liu, Hulin

    2007-01-01

    The femtosecond electron diffraction (FED) is a unique method for the study of the changes of complex molecular structures, and has been specifically applied in the investigations of transient-optics, opto-physics, crystallography, and other fields. The FED system designed by the present group, consists of a 35nm Ag photocathode evaporated on an ultraviolet glass, an anode with a 0.1mm aperture, two pairs of deflection plate for the deflection of electron beams in X and Y directions, and the Y deflection plate can be used as a scanning plate while measuring the pulse width of electron beams, the double MCPs detector for the enhancing and detecting of electron image. The magnetic lens was used for the focusing of the electron beams, and the focal length is 125mm. The distance between the object(the photocathode) and the image(the sample) is 503mm, and the size of electron beams is smaller than 17microns after focusing, the convergence angle is of -0.075~0.075°, and the temporal resolution is better than 350fs.

  13. X-Ray Diffraction on NIF

    SciTech Connect

    Eggert, J H; Wark, J

    2012-02-15

    The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.

  14. Results on hard diffractive production

    SciTech Connect

    Goulianos, K.

    1995-07-01

    The results of experiments at hadron colliders probing the structure of the pomeron through hard diffraction are reviewed. Some results on deep inelastic diffractive scattering obtained a HERA are also discussed and placed in perspective. By using a properly normalized pomeron flux factor in single diffraction dissociation, as dictated by unitarity, the pomeron emerges as a combination of valence quark and gluon color singlets in a ratio suggested by asymptopia.

  15. Neighborhood Poverty Impacts Children's Physical Health and Well-Being over Time: Evidence from the Early Development Instrument

    ERIC Educational Resources Information Center

    Cushon, Jennifer A.; Vu, Lan T. H.; Janzen, Bonnie L.; Muhajarine, Nazeem

    2011-01-01

    Research Findings: The purpose of this study was to investigate how neighborhoods and neighborhood socioeconomic disadvantage impact school readiness over time. School readiness was measured using the Early Development Instrument (EDI) for 3 populations of kindergartners in 2001, 2003, and 2005 in Saskatoon, Saskatchewan, Canada. EDI results…

  16. Study of optical Laue diffraction

    SciTech Connect

    Chakravarthy, Giridhar E-mail: aloksharan@email.com; Allam, Srinivasa Rao E-mail: aloksharan@email.com; Satyanarayana, S. V. M. E-mail: aloksharan@email.com; Sharan, Alok E-mail: aloksharan@email.com

    2014-10-15

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known.

  17. Electrically-programmable diffraction grating

    DOEpatents

    Ricco, Antonio J.; Butler, Michael A.; Sinclair, Michael B.; Senturia, Stephen D.

    1998-01-01

    An electrically-programmable diffraction grating. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers).

  18. CDF experimental results on diffraction

    SciTech Connect

    Gallinaro, Michele; /Rockefeller U.

    2009-04-01

    Experimental results on diffraction from the Fermilab Tevatron collider obtained by the CDF experiment are reviewed and compared. We report on the diffractive structure function obtained from dijet production in the range 0 < Q{sup 2} < 10,000 GeV{sup 2}, and on the |t| distribution in the region 0 < |t| < 1 GeV{sup 2} for both soft and hard diffractive events up to Q{sup 2} {approx} 4,500 GeV{sup 2}. Results on single diffractive W/Z production, forward jets, and central exclusive production of both dijets and diphotons are also presented.

  19. History of ``NANO''-Scale VERY EARLY Solid-State (and Liquid-State) Physics/Chemistry/Metallurgy/ Ceramics; Interstitial-Alloys Carbides/Nitrides/Borides/...Powders and Cermets, Rock Shocks, ...

    NASA Astrophysics Data System (ADS)

    Maiden, Colin; Siegel, Edward

    History of ``NANO'': Siegel-Matsubara-Vest-Gregson[Mtls. Sci. and Eng. 8, 6, 323(`71); Physica Status Solidi (a)11,45(`72)] VERY EARLY carbides/nitrides/borides powders/cermets solid-state physics/chemistry/metallurgy/ ceramics FIRST-EVER EXPERIMENTAL NANO-physics/chemistry[1968 ->Physica Status Solidi (a)11,45(`72); and EARLY NANO-``physics''/NANO-``chemistry'' THEORY(after: Kubo(`62)-Matsubara(`60s-`70s)-Fulde (`65) [ref.: Sugano[Microcluster-Physics, Springer('82 `98)

  20. Physics Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Demonstrations, procedures, games, teaching suggestions and information on a variety of physics topics are presented, including hydraulic rams, units and formulae, static electric motors, a computer graphics program, diffraction, adaptation of a basic meter, photoelasticity, photo-diodes, radioactive decay, and analog-digital conversions. (DC)

  1. DoE Early Career Research Program: Final Report: Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics

    SciTech Connect

    Farbin, Amir

    2015-07-15

    This is the final report of for DoE Early Career Research Program Grant Titled "Model-Independent Dark-Matter Searches at the ATLAS Experiment and Applications of Many-core Computing to High Energy Physics".

  2. Teacher-Child Relationship, Parenting, and Growth in Likelihood and Severity of Physical Aggression in the Early School Years

    ERIC Educational Resources Information Center

    Runions, Kevin C.; Vitaro, Fank; Cross, Donna; Shaw, Thérèse; Hall, Margaret

    2014-01-01

    This investigation used two-part growth modeling and cross-lagged panel analysis to examine the predictive function of parenting and teacher-child relationship on the likelihood of children showing problems with parent-rated physical aggression, and on the severity of problems, for 374 children followed from prekindergarten and first grade.…

  3. The Children's Learning Center: A Study of a Self-Manipulative Physical Environment on Early Childhood Learning.

    ERIC Educational Resources Information Center

    Studio of Environmental Technology, Providence, RI.

    The Children's Learning Center in Providence, Rhode Island, is a prototypical teaching/learning environment for preschool children aged 3-5. The center represents the first prototypical application of the Multi-Activity Zones for Education (MAZE) system. This study attempts to demonstrate and test the physical and operational performances of the…

  4. Associations of Maternal Prenatal Smoking with Early Childhood Physical Aggression, Hyperactivity-Impulsivity, and Their Co-Occurrence

    ERIC Educational Resources Information Center

    Huijbregts, Stephan C. J.; Seguin, Jean R.; Zoccolillo, Mark; Boivin, Michel; Tremblay, Richard E.

    2007-01-01

    This study investigated associations between maternal prenatal smoking and physical aggression (PA), hyperactivity-impulsivity (HI) and co-occurring PA and HI between ages 17 and 42 months in a population sample of children born in Quebec (Canada) in 1997/1998 (N=1745). Trajectory model estimation showed three distinct developmental patterns for…

  5. Naturally Occurring Changes in Time Spent Watching Television Are Inversely Related to Frequency of Physical Activity during Early Adolescence

    ERIC Educational Resources Information Center

    Motl, Robert W.; McAuley, Edward; Birnbaum, Amanda S.; Lytle, Leslie A.

    2006-01-01

    In this longitudinal study, we examined the relationship between changes in time spent watching television and playing video games with frequency of leisure-time physical activity across a 2-year period among adolescent boys and girls (N=4594). Latent growth modelling indicated that a decrease in time spent watching television was associated with…

  6. Attention Problems Mediate the Association between Severity of Physical Abuse and Aggressive Behavior in a Sample of Maltreated Early Adolescents

    ERIC Educational Resources Information Center

    Garrido, Edward F.; Taussig, Heather N.; Culhane, Sara E.; Raviv, Tali

    2011-01-01

    Empirical evidence has accumulated documenting an association between childhood physical abuse and aggressive behavior. Relatively fewer studies have explored possible mediating mechanisms that may explain this association. The purpose of the current study was to examine whether caregiver- and youth-reported attention problems mediate the…

  7. Socialization of Physical and Social Aggression in Early Adolescents' Peer Groups: High-Status Peers, Individual Status, and Gender

    ERIC Educational Resources Information Center

    Shi, Bing; Xie, Hongling

    2012-01-01

    The influence of high-status peers on a target individual's physical and manipulative social aggression in peer groups was examined in a diverse sample of seventh-grade students. A total of 245 individual members belonging to 65 groups were included in analyses. Aggression was assessed by peer and victim nominations in the fall and spring…

  8. The Quantitative and Qualitative Analysis of Cohorts' Early Enrollment in Physics: concurrent with enrollment in mathematics, biology and chemistry

    NASA Astrophysics Data System (ADS)

    Lynch, Robert Bruce Rodes

    Cohorts of 48 entering biological science majors was recruited in the fall of 2007 and again in 2008 and 2009 for the Interdisciplinary Science Experience (ISE). These ISE students enrolled in their own sections of standard courses of physics, chemistry, and biology. In these courses average ISE student out-performed their non-cohort peers by up to a full letter grade. A qualitative analysis of ISE student interviews illuminates the student experience and shows how the ISE students perceived themselves to be different than their non-cohort peers. Quantitative modeling of student performance shows that higher grades are correlated with multiple factors. These factors includes admissions characteristics such as high school GPA, and SAT scores, as well as demographic information. These trends support and elaborate on the selection narratives told by participants. Additionally the quantitative model found that higher student performance is predicted by structural aspects of the ISE program, specifically the timing of course, enrolling as a freshmen in many of their courses, and the sequencing of physics and chemistry courses. There is a statistically significant benefit to student performance in general and organic chemistry courses associated with completing the first quarter of the Physics for Bio-Science majors prior to enrollment. Further the combination of quantitative and qualitative data suggest that there is a epistemological transfer of problem solving skills and outlook from the physics to the chemistry courses.

  9. Maternal versus Paternal Physical and Emotional Abuse, Affect Regulation and Risk for Depression from Adolescence to Early Adulthood

    ERIC Educational Resources Information Center

    Moretti, Marlene M.; Craig, Stephanie G.

    2013-01-01

    Objective: Current research has established that depression is a common outcome of child abuse. The current study extends previous research by examining the relationship between parental emotional and physical abuse and adolescents' depressive symptoms using a prospective longitudinal design. We anticipated that this relationship would be mediated…

  10. Is There an Association of Physical Activity with Brain Volume, Behavior, and Day-to-day Functioning? A Cross Sectional Design in Prodromal and Early Huntington Disease

    PubMed Central

    Wallace, McKenzie; Downing, Nancy; Lourens, Spencer; Mills, James; Kim, Ji-in; Long, Jeffrey; Paulsen, Jane; PREDICT-HD Investigators and Coordinators of the Huntington Study Group

    2016-01-01

    Background: Huntington disease (HD) is a genetic neurodegenerative disease leading to progressive motor, cognitive, and behavioral decline. Subtle changes in these domains are detectable up to 15 years before a definitive motor diagnosis is made. This period, called prodromal HD, provides an opportunity to examine lifestyle behaviors that may impact disease progression. Theoretical Framework: Physical activity relates to decreased rates of brain atrophy and improved cognitive and day-to-day functioning in Alzheimer disease and healthy aging populations. Previous research has yielded mixed results regarding the impact of physical activity on disease progression in HD and paid little attention to the prodromal phase. Methods: We conducted analyses of associations among current physical activity level, current and retrospective rate of change for hippocampus and striatum volume, and cognitive, motor, and day-to-day functioning variables. Participants were 48 gene-expanded cases with prodromal and early-diagnosed HD and 27 nongene-expanded control participants. Participants wore Fitbit Ultra activity monitors for three days and completed the self-reported International Physical Activity Questionnaire (IPAQ). Hippocampal and striatal white matter volumes were measured using magnetic resonance imaging. Cognitive tests included the Stroop Color and Word Test, and the Symbol Digit Modalities Test (SDMT). Motor function was assessed using the Unified Huntington’s Disease Rating Scale total motor score (TMS). Day-to-day functioning was measured using the World Health Organization Disability Assessment Schedule (WHODAS) version 2.0. Results: Higher Fitbit activity scores were significantly related to better scores on the SDMT and WHODAS in case participants but not in controls. Fitbit activity scores tracked better with TMS scores in the group as a whole, though the association did not reach statistical significance in the case participants. Higher Fitbit activity scores

  11. Ultrasonic diffraction of Bessel light beams in uniaxial gyrotropic crystals

    NASA Astrophysics Data System (ADS)

    Belyi, V. N.; Kulak, G. V.; Krokh, G. V.; Ropot, P. I.; Shakin, O. V.

    2016-09-01

    Specific features of the acousto-optic diffraction of Bessel light beams propagating in the vicinity of the optical axis of a uniaxial gyrotropic crystal have been investigated. The dependences of the diffraction efficiency on the acousto-optic interaction length, ultrasound power, and polarization state of the incident Bessel light beam have been analyzed using the coupled-wave equations and the overlap-integral method. It is shown that polarization-independent diffraction of Bessel light beams is observed in paratellurite crystals, when the Bragg diffraction efficiency is independent of the polarization state of the incident beam. The physical reason for this diffraction has been established (both theoretically and experimentally) to be simultaneous implementation of two processes of anisotropic scattering, at which the Bragg synchronism conditions are satisfied for orthogonal polarized Bessel beams with elliptical polarization.

  12. Catastrophic shifts in ecosystems: spatial early warnings and management procedures (Inspired in the physics of phase transitions)

    NASA Astrophysics Data System (ADS)

    Fort, H.; Mazzeo, N.; Scheffer, M.; van Nes, E.

    2010-09-01

    Ecosystems are complex systems which can respond to gradual changes of their conditions by a sudden shift to a contrasting regime or alternative stable state (ASS). Predicting such critical points before they are reached is extremely difficult and providing early warnings is fundamental to design management protocols for ecosystems. Here we study different spatial versions of popular ecological models which are known to exhibit ASS. The spatial heterogeneity is introduced by a local parameter varying from cell to cell in a regular lattice. Transport of biomass among cells occurs by simple diffusion. We investigate whether different quantities from statistical mechanics -like the variance, the two-point correlation function and the patchiness-may serve as early warnings of catastrophic phase transitions between the ASS. In particular, we find that the patch-size distribution follows a power law when the system is close to the catastrophic transition. We also provide links between spatial and temporal indicators and analyze how the interplay between diffusion and spatial heterogeneity may affect the earliness of each of the observables. Finally, we comment on similarities and differences between these catastrophic shifts and paradigmatic thermodynamic phase transitions like the liquid-vapor change of state for a fluid like water.

  13. Computer Simulation of Diffraction Patterns.

    ERIC Educational Resources Information Center

    Dodd, N. A.

    1983-01-01

    Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

  14. Ptychographic Fresnel coherent diffractive imaging

    NASA Astrophysics Data System (ADS)

    Vine, D. J.; Williams, G. J.; Abbey, B.; Pfeifer, M. A.; Clark, J. N.; de Jonge, M. D.; McNulty, I.; Peele, A. G.; Nugent, K. A.

    2009-12-01

    This paper reports improved reconstruction of complex wave fields from extended objects. The combination of ptychography with Fresnel diffractive imaging results in better reconstructions with fewer iterations required to convergence than either method considered separately. The method is applied to retrieve the projected thickness of a gold microstructure and comparative results using ptychography and Fresnel diffractive imaging are presented.

  15. Color Perception with Diffraction Gratings.

    ERIC Educational Resources Information Center

    Kruglak, Haym; Campbell, Don

    1983-01-01

    Describes an experiment enabling students to apply concept of diffraction, determine limits of their color perception, learn how to measure wavelength with a simple apparatus, observe continuous and line spectra, and associate colors with corresponding wavelengths. The homemade diffraction-grating spectrometer used is easily constructed. (JN)

  16. The effects of plasma physics target shrapnel and debris plumes arising from early operations of the Orion laser

    NASA Astrophysics Data System (ADS)

    Andrew, J.; Egan, D.; Miller, S.; Pearce, A.; Penman, R.; Scott, D.

    2014-10-01

    When lasers are used to produce high temperature, high density plasmas from solid targets it is inevitable that the targets are turned into a variety of products [gas, liquid, solid, sub-atomic particles and electromagnetic radiation] that are distributed around the surfaces of the vacuum chamber used to field such experiments. These by products are produced in plumes of debris and shrapnel that depend on the irradiation conditions, target materials and target geometry. We have monitored the distribution of such plumes by witness plates and used microscopy, photography and spectrophotometry to determine the physical state of material in the plumes and the spatial distribution from various target geometries. The impact of this material on the operations of laser optics and plasma physics diagnostics is discussed.

  17. Detection of nonthermal melting by ultrafast X-ray diffraction.

    PubMed

    Siders, C W; Cavalleri, A; Sokolowski-Tinten, K; Tóth, C; Guo, T; Kammler, M; Horn von Hoegen, M; Wilson, K R; von der Linde, D; Barty, C P

    1999-11-12

    Using ultrafast, time-resolved, 1.54 angstrom x-ray diffraction, thermal and ultrafast nonthermal melting of germanium, involving passage through nonequilibrium extreme states of matter, was observed. Such ultrafast, optical-pump, x-ray diffraction probe measurements provide a way to study many other transient processes in physics, chemistry, and biology, including direct observation of the atomic motion by which many solid-state processes and chemical and biochemical reactions take place.

  18. Multiple early victimization experiences as a pathway to explain physical health disparities among sexual minority and heterosexual individuals.

    PubMed

    Andersen, Judith P; Zou, Christopher; Blosnich, John

    2015-05-01

    Prior research shows that health disparities exist between sexual minority and heterosexual individuals. We extend the literature by testing if the higher prevalence of childhood victimization experienced by sexual minority individuals accounts for lifetime health disparities. Heterosexual (n = 422) and sexual minority (n = 681) participants were recruited on-line in North America. Respondents completed surveys about their childhood victimization experiences (i.e., maltreatment by adults and peer victimization) and lifetime physician-diagnosed physical health conditions. Results showed that sexual minority individuals experienced higher prevalence of childhood victimization and lifetime physical health problems than heterosexuals. Mediation analyses indicated that maltreatment by adults and peer bullying explained the health disparities between sexual minority individuals and heterosexuals. This study is the first to show that multiple childhood victimization experiences may be one pathway to explain lifetime physical health disparities. Intervention programs reducing the perpetration of violence against sexual minority individuals are critical to reduce health care needs related to victimization experiences. PMID:25864147

  19. Fresnel diffraction and fractal patterns from polygonal apertures.

    PubMed

    Huang, J G; Christian, J M; McDonald, G S

    2006-11-01

    Two compact analytical descriptions of Fresnel diffraction patterns from polygonal apertures under uniform illumination are detailed. In particular, a simple expression for the diffracted field from constituent edges is derived. These results have fundamental importance as well as specific applications, and they promise new physical insights into diffraction-related phenomena. The usefulness of the formulations is illuminated in the context of a virtual source theory that accounts for two transverse dimensions. This application permits calculation of fractal unstable-resonator modes of arbitrary order and unprecedented accuracy. PMID:17047703

  20. A survey of interstellar neutral potassium. I - Abundances and physical conditions in clouds toward 188 early-type stars

    NASA Technical Reports Server (NTRS)

    Chaffee, F. H., Jr.; White, R. E.

    1982-01-01

    Observations of interstellar absorption in the resonance doublet 7664, 7698 A of neutral potassium toward 188 early-type stars at a spectral resolution of 8 km/s are reported. The 7664 A line is successfully separated from nearly coincident telluric O2 absorption for all but a few of the 165 stars for which K I absorption is detected, making possible an abundance analysis by the doublet ratio method. The relationships between the potassium abundances and other atomic abundances, the abundance of molecular hydrogen, and interstellar reddening are investigated.

  1. Diffraction of walking droplets

    NASA Astrophysics Data System (ADS)

    Harris, Daniel M.; Pucci, Giuseppe; Bush, John W. M.

    2014-11-01

    We present results from our revisitation of the experiment of a walking droplet passing through a single slit, originally investigated by Couder & Fort (PRL, 2006). On each passage, the walker's trajectory is deviated as a result of the spatial confinement of its guiding wave. We explore the role of the droplet size and the bath's vibration amplitude on both the dynamics and statistics. We find the behavior to be remarkably sensitive to these control parameters. A complex physical picture emerges. The authors gratefully acknowledge the financial support of the NSF through Grant CMMI-1333242, DMH through the NSF Graduate Research Fellowship Program, and GP through the Programma Operativo Regionale (POR) Calabria - FSE 2007/2013.

  2. Photoinduced diffraction in polymer waveguides.

    PubMed

    Andrews, J H; Singer, K D

    1993-11-20

    We report on techniques for measuring photoinduced diffraction in prism-coupled slab polymer waveguides. Diffraction effects resulting from photochromic gratings in slab waveguides of Disperse Red 1 dye in polymethylmethacrylate were studied. Optical damage in the form of diffractive mode conversion was observed when we coupled in light with a wavelength slightly longer than the absorption edge of Disperse Red 1 dye. Slowly growing satellite beams in the outcoupled light were attributed to anisotropic scattering between the lowest-order TE mode and the lowest-order TM mode caused by self-diffraction from a grating produced through the photochromic effect. We have also investigated the effect of mode-coupling changes on the determination of diffraction efficiency and sensitivity in waveguide experiments. Diffraction efficiencies predicted by measurements of the modulation depth in the guide are found to overstate the actual diffraction efficiencies that could be observed in this geometry. Techniques for overc ming this limitation and for improving estimates of the energy density and interaction length in the guide are noted.

  3. Electromagnetic diffraction efficiencies for plane reflection diffraction gratings

    NASA Technical Reports Server (NTRS)

    Marathay, A. S.; Shrode, T. E.

    1973-01-01

    Results are presented of research activities on holographic grating research. A large portion of this work was performed using rigorous vector diffraction theory, therefore, the necessary theory has been included in this report. The diffraction efficiency studies were continued using programs based on a rigorous theory. The simultaneous occurrence of high diffraction efficiencies and the phenomenon of double Wood's anomalies is demonstrated along with a graphic method for determining the necessary grating parameters. Also, an analytical solution for a grating profile that is perfectly blazed is obtained. The performance of the perfectly blazed grating profile is shown to be significantly better than grating profiles previously studied. Finally, a proposed method is described for the analysis of coarse echelle gratings using rigorous vector diffraction that is currently being developed.

  4. Science and miscegenation in the early twentieth century: Edgard Roquette-Pinto's debates and controversies with US physical anthropology.

    PubMed

    Souza, Vanderlei Sebastião de

    2016-01-01

    The article analyzes Brazilian anthropologist Edgard Roquette-Pinto's participation in the international debate that involved the field of physical anthropology and discussions on miscegenation in the first decades of the twentieth century. Special focus is on his readings and interpretations of a group of US anthropologists and eugenicists and his controversies with them, including Charles Davenport, Madison Grant, and Franz Boas. The article explores the various ways in which Roquette-Pinto interpreted and incorporated their ideas and how his anthropological interpretations took on new meanings when they moved beyond Brazil's borders. PMID:27438731

  5. N.G. Basov and early works on semiconductor lasers at P.N. Lebedev Physics Institute

    SciTech Connect

    Eliseev, P G

    2012-12-31

    A survey is presented of works on creation and investigation of semiconductor lasers during 1957 - 1977 at the P.N. Lebedev Physics Institute. Many of these works were initiated by N.G. Basov, starting from pre-laser time, when N.G. Basov and his coworkers formulated principal conditions of creation of lasers on interband transitions in semiconductors. Main directions of further works were diode lasers based on various materials and structures, their characteristics of output power, high-speed operation and reliability. (special issue devoted to the 90th anniversary of n.g. basov)

  6. Science and miscegenation in the early twentieth century: Edgard Roquette-Pinto's debates and controversies with US physical anthropology.

    PubMed

    Souza, Vanderlei Sebastião de

    2016-01-01

    The article analyzes Brazilian anthropologist Edgard Roquette-Pinto's participation in the international debate that involved the field of physical anthropology and discussions on miscegenation in the first decades of the twentieth century. Special focus is on his readings and interpretations of a group of US anthropologists and eugenicists and his controversies with them, including Charles Davenport, Madison Grant, and Franz Boas. The article explores the various ways in which Roquette-Pinto interpreted and incorporated their ideas and how his anthropological interpretations took on new meanings when they moved beyond Brazil's borders.

  7. Diffraction effects in freeform optics

    NASA Astrophysics Data System (ADS)

    Ricketts, Melissa N.; Winston, Roland; Oliker, Vladimir

    2015-08-01

    Freeform optics is a relatively new field; it uses the methods necessary to describe surfaces lacking symmetry, and/or surfaces that create non-symmetrical irradiance distributions. The Supporting Quadrics Method (SQM) developed by Oliker is a superb for generating any desired irradiance distribution. The SQM uses an envelope of quadrics to create prescribed irradiance distributions. These optical systems are tested in ray trace software, where diffraction effects are not taken into account. It is important to understand the diffraction effects present in an optic, when moving from the ray trace stage to the prototype stage. Here we study the diffraction effects of Supporting Quadrics Method.

  8. Diffractive optics in adverse environments

    NASA Technical Reports Server (NTRS)

    Behrmann, Gregory P.

    1993-01-01

    An investigation at the Army Research Laboratory is in progress to characterize DOE performance in mil-spec environments. One of the most significant environmental influences is temperature. An analysis of a diffractive lens is presented in which optical performance is described as a function of temperature. In particular, we review the thermal dependence of focal length and diffraction efficiency. It is shown that the change in these parameters is independent of lens shape and relates only to material properties. Thermalized hybrid refractive/diffractive designs are discussed.

  9. Patterns of Leisure-Time Physical Activity Participation in a British Birth Cohort at Early Old Age

    PubMed Central

    Martin, Kathryn R.; Cooper, Rachel; Harris, Tamara B.; Brage, Soren; Hardy, Rebecca; Kuh, Diana

    2014-01-01

    Using data from a nationally representative British birth cohort we characterized the type and diversity of leisure-time physical activity that 2,188 participants (age 60–64 years) engaged in throughout the year by gender and obesity. Participants most commonly reported walking (71%), swimming (33%), floor exercises (24%) and cycling (15%). Sixty-two percent of participants reported ≥2 activities in the past year and 40% reported diversity on a regular basis. Regular engagement in different types of activity (cardio-respiratory, balance/flexibility and strength) was reported by 67%, 19% and 11% of participants, respectively. We found gender differences, as well as differences by obesity status, in the activities reported, the levels of activity diversity and activity type. Non-obese participants had greater activity diversity, and more often reported activities beneficial for cardio-respiratory health and balance/flexibility than obese participants. These findings may be used to inform the development of trials of physical activity interventions targeting older adults, and those older adults with high body mass index. PMID:24911018

  10. Coherent diffractive imaging using focused beams

    NASA Astrophysics Data System (ADS)

    Nugent, Keith A.; Peele, Andrew G.; Quiney, Harry M.

    2005-08-01

    It is well-known that the loss of phase information at detection means that a diffraction pattern may be consistent with a multitude of physically different structures. This paper shows that it is possible to perform unique structural determination in the absence of a-priori information using x-ray fields with phase curvature. We argue that significant phase curvature is already available using modern x-ray optics and we demonstrate an algorithm that allows the phase to be recovered uniquely and reliably.

  11. Electrically-programmable diffraction grating

    DOEpatents

    Ricco, A.J.; Butler, M.A.; Sinclair, M.B.; Senturia, S.D.

    1998-05-26

    An electrically-programmable diffraction grating is disclosed. The programmable grating includes a substrate having a plurality of electrodes formed thereon and a moveable grating element above each of the electrodes. The grating elements are electrostatically programmable to form a diffraction grating for diffracting an incident beam of light as it is reflected from the upper surfaces of the grating elements. The programmable diffraction grating, formed by a micromachining process, has applications for optical information processing (e.g. optical correlators and computers), for multiplexing and demultiplexing a plurality of light beams of different wavelengths (e.g. for optical fiber communications), and for forming spectrometers (e.g. correlation and scanning spectrometers). 14 figs.

  12. Femtosecond single-electron diffraction

    PubMed Central

    Lahme, S.; Kealhofer, C.; Krausz, F.; Baum, P.

    2014-01-01

    Ultrafast electron diffraction allows the tracking of atomic motion in real time, but space charge effects within dense electron packets are a problem for temporal resolution. Here, we report on time-resolved pump-probe diffraction using femtosecond single-electron pulses that are free from intra-pulse Coulomb interactions over the entire trajectory from the source to the detector. Sufficient average electron current is achieved at repetition rates of hundreds of kHz. Thermal load on the sample is avoided by minimizing the pump-probe area and by maximizing heat diffusion. Time-resolved diffraction from fibrous graphite polycrystals reveals coherent acoustic phonons in a nanometer-thick grain ensemble with a signal-to-noise level comparable to conventional multi-electron experiments. These results demonstrate the feasibility of pump-probe diffraction in the single-electron regime, where simulations indicate compressibility of the pulses down to few-femtosecond and attosecond duration. PMID:26798778

  13. Diffraction by random Ronchi gratings.

    PubMed

    Torcal-Milla, Francisco Jose; Sanchez-Brea, Luis Miguel

    2016-08-01

    In this work, we obtain analytical expressions for the near-and far-field diffraction of random Ronchi diffraction gratings where the slits of the grating are randomly displaced around their periodical positions. We theoretically show that the effect of randomness in the position of the slits of the grating produces a decrease of the contrast and even disappearance of the self-images for high randomness level at the near field. On the other hand, it cancels high-order harmonics in far field, resulting in only a few central diffraction orders. Numerical simulations by means of the Rayleigh-Sommerfeld diffraction formula are performed in order to corroborate the analytical results. These results are of interest for industrial and technological applications where manufacture errors need to be considered.

  14. Diffraction by random Ronchi gratings.

    PubMed

    Torcal-Milla, Francisco Jose; Sanchez-Brea, Luis Miguel

    2016-08-01

    In this work, we obtain analytical expressions for the near-and far-field diffraction of random Ronchi diffraction gratings where the slits of the grating are randomly displaced around their periodical positions. We theoretically show that the effect of randomness in the position of the slits of the grating produces a decrease of the contrast and even disappearance of the self-images for high randomness level at the near field. On the other hand, it cancels high-order harmonics in far field, resulting in only a few central diffraction orders. Numerical simulations by means of the Rayleigh-Sommerfeld diffraction formula are performed in order to corroborate the analytical results. These results are of interest for industrial and technological applications where manufacture errors need to be considered. PMID:27505363

  15. Evaluation design of New York City's regulations on nutrition, physical activity, and screen time in early child care centers.

    PubMed

    Breck, Andrew; Goodman, Ken; Dunn, Lillian; Stephens, Robert L; Dawkins, Nicola; Dixon, Beth; Jernigan, Jan; Kakietek, Jakub; Lesesne, Catherine; Lessard, Laura; Nonas, Cathy; O'Dell, Sarah Abood; Osuji, Thearis A; Bronson, Bernice; Xu, Ye; Kettel Khan, Laura

    2014-01-01

    This article describes the multi-method cross-sectional design used to evaluate New York City Department of Health and Mental Hygiene's regulations of nutrition, physical activity, and screen time for children aged 3 years or older in licensed group child care centers. The Center Evaluation Component collected data from a stratified random sample of 176 licensed group child care centers in New York City. Compliance with the regulations was measured through a review of center records, a facility inventory, and interviews of center directors, lead teachers, and food service staff. The Classroom Evaluation Component included an observational and biometric study of a sample of approximately 1,400 children aged 3 or 4 years attending 110 child care centers and was designed to complement the center component at the classroom and child level. The study methodology detailed in this paper may aid researchers in designing policy evaluation studies that can inform other jurisdictions considering similar policies. PMID:25321635

  16. New CDF results on diffraction

    SciTech Connect

    Mesropian, Christina; /Rockefeller U.

    2006-12-01

    We report new diffraction results obtained by the CDF collaboration in proton-antiproton collisions at the Fermilab Tevatron collider at {radical}s=1.96 TeV. The first experimental evidence of exclusive dijet and diphoton production is presented. The exclusive results are discussed in context of the exclusive Higgs production at LHC. We also present the measurement of the Q{sup 2} and t dependence of the diffractive structure function.

  17. Estimating the Size of Onion Epidermal Cells from Diffraction Patterns

    NASA Astrophysics Data System (ADS)

    Groff, Jeffrey R.

    2012-10-01

    Bioscience and premedical profession students are a major demographic served by introductory physics courses at many colleges and universities. Exposing these students to biological applications of physical principles will help them to appreciate physics as a useful tool for their future professions. Here I describe an experiment suitable for introductory physics where principles of wave optics are applied to probe the size of onion epidermal cells. The epidermis tissue is composed of cells of relatively uniform size and shape (Fig. 1) so the tissue acts like a one-dimensional transmission diffraction grating. The diffraction patterns generated when a laser beam passes through the tissue (Fig. 2) are analyzed and an estimate of the average width of individual onion epidermal cells is calculated. The results are compared to direct measurements taken using a light microscope. The use of microscopes and plant-cell tissue slides creates opportunities for cross-discipline collaboration between physics and biology instructors.

  18. Teller Medal Lecture IFSA2001: Problems and solutions in the design and analysis of early laser driven high energy density and ICF target physics experiments (IFSA 2001)

    NASA Astrophysics Data System (ADS)

    Rosen, Mordecai D.

    2016-10-01

    The high energy density (HED) and inertial confinement fusion (ICF) physics community relies on increasingly sophisticated high power laser driven experiments to advance the field. We review early work in the design and analysis of such experiments, and discuss the problems encountered. By finding solutions to those problems we put the field on firmer ground, allowing the community to develop it to the exciting stage it is in today. Specific examples include: drive and preheat in complex hohlraum geometries with the complicating effects of sample motion; and issues in the successful design of laboratory soft x-ray lasers and in the invention of methods to reduce the required optical laser driver energy by several orders of magnitude.

  19. Teller Medal Lecture IFSA2001: Problems and Solutions in the Design and Analysis of Early Laser Driven High Energy Density and ICF Target Physics Experiments

    SciTech Connect

    Rosen, M D

    2001-08-20

    The high energy density (HED) and inertial confinement fusion (ICF) physics community relies on increasingly sophisticated high power laser driven experiments to advance the field. We review early work in the design and analysis of such experiments, and discuss the problems encountered. By finding solutions to those problems we put the field on firmer ground, allowing the community to develop it to the exciting stage it is in today. Specific examples include: drive and preheat in complex hohlraum geometries with the complicating effects of sample motion; and issues in the successful design of laboratory soft x-ray lasers and in the invention of methods to reduce the required optical laser driver energy by several orders of magnitude.

  20. Cross-national comparison of prenatal methamphetamine exposure on infant and early child physical growth: a natural experiment.

    PubMed

    Abar, Beau; LaGasse, Linda L; Wouldes, Trecia; Derauf, Chris; Newman, Elana; Shah, Rizwan; Smith, Lynne M; Arria, Amelia M; Huestis, Marilyn A; DellaGrotta, Sheri; Dansereau, Lynne M; Wilcox, Tara; Neal, Charles R; Lester, Barry M

    2014-10-01

    The current study seeks to compare the effects of prenatal methamphetamine exposure (PME) on infant and child physical growth between the USA and New Zealand (NZ). This cross-national comparison provides a unique opportunity to examine the potential impact of services provided to drug using mothers on child health. The longitudinal Infant Development, Environment and Lifestyle study of PME from birth to 36 months was conducted in the USA and NZ. The US cohort included 204 children with PME and 212 non-PME matched comparisons (NPME); the NZ cohort included 108 children with PME and 115 NPME matched comparisons. Latent growth curve models were used to examine effects of PME, country of origin, and the country × PME interaction on growth in length/height and weight. In regard to length/height, PME and country of origin were associated with initial length and growth over time. There was also a significant interaction effect, such that children with PME in the USA were shorter at birth than children with PME in NZ after controlling for other prenatal exposures, infant set, socioeconomic status, and maternal height. In regard to weight, there was only an effect of country of origin. Effects of PME on infant and child growth were shown to differ across countries, with exposed children in NZ faring better than exposed children in the USA. Implications for prevention programs and public policy are discussed.

  1. On the representation of the diffracted field of Hermite-Gaussian modes in an alien basis and the young diffraction principle

    SciTech Connect

    Smirnov, V.N.; Strokovskii, G.A.

    1994-10-01

    An analytical form of expansion coefficients of a diffracted field for an arbitrary Hermite-Gaussian beam in an alien Hermite-Gaussian basis is obtained. A possible physical interpretation of the well-known Young phenomenological diffraction principle and experiments on diffraction of Hermite-Gaussian beams of the lowest types (n = 0 - 5) from half-plane are discussed. The case of nearly homogenous expansion corresponding to misalignment and mismatch of optical systems is also analyzed. 7 refs., 2 figs.

  2. Diffraction described by virtual particle momentum exchange: the "diffraction force"

    NASA Astrophysics Data System (ADS)

    Mobley, Michael J.

    2011-09-01

    Particle diffraction can be described by an ensemble of particle paths determined through a Fourier analysis of a scattering lattice where the momentum exchange probabilities are defined at the location of scattering, not the point of detection. This description is compatible with optical wave theories and quantum particle models and provides deeper insights to the nature of quantum uncertainty. In this paper the Rayleigh-Sommerfeld and Fresnel-Kirchoff theories are analyzed for diffraction by a narrow slit and a straight edge to demonstrate the dependence of particle scattering on the distance of virtual particle exchange. The quantized momentum exchange is defined by the Heisenberg uncertainty principle and is consistent with the formalism of QED. This exchange of momentum manifests the "diffraction force" that appears to be a universal construct as it applies to neutral and charged particles. This analysis indicates virtual particles might form an exchange channel that bridges the space of momentum exchange.

  3. Coherent grating x-ray diffraction (CGXD) and its applications

    SciTech Connect

    Shen, Q.

    1996-09-01

    We show that an x-ray interference phenomenon, coherent grating x-ray diffraction (CGXD), can be used to study lateral nanostructure arrays on crystal surfaces and interfaces. Compared to Fraunhofer grating diffraction of visible light, x-ray grating diffraction contains information not only about geometric profiles of the surface but also about the internal crystalline structures and lattice strain distributions in the grating features. The grating diffraction pattern can also be measured in a white-beam Laue method using highly collimated polychromatic synchrotron radiation, which provides a parallel data collection scheme and may be useful in {ital in} {ital situ} studies on evolution of nanostructure arrays. {copyright} {ital 1996 American Institute of Physics.}

  4. Electromagnetic diffraction efficiencies for plane reflection diffraction gratings

    NASA Technical Reports Server (NTRS)

    Marathay, A. S.; Shrode, T. E.

    1974-01-01

    The theory and computer programs, based on electromagnetic theory, for the analysis and design of echelle gratings were developed. The gratings are designed for instruments that operate in the ultraviolet portion of the spectrum. The theory was developed so that the resulting computer programs will be able to analyze deep (up to 30 wavelengths) gratings by including as many as 100 real or homogeneous diffraction orders. The program calculates the complex amplitude coefficient for each of the diffracted orders. A check on the numerical method used to solve the integral equations is provided by a conservation of energy calculation.

  5. Factors associated with early childhood education and care service implementation of healthy eating and physical activity policies and practices in Australia: a cross-sectional study.

    PubMed

    Wolfenden, Luke; Finch, Meghan; Nathan, Nicole; Weaver, Natasha; Wiggers, John; Yoong, Sze Lin; Jones, Jannah; Dodds, Pennie; Wyse, Rebecca; Sutherland, Rachel; Gillham, Karen

    2015-09-01

    Many early childhood education and care (ECEC) services fail to implement recommended policies and practices supportive of healthy eating and physical activity. The purpose of this study was to assess whether certain theoretically-based factors are associated with implementation of healthy eating and physical activity policies and practices in a sample of ECEC services. A cross-sectional survey was conducted with Service Managers of ECEC services. The survey assessed the operational characteristics, policy, and practice implementation, and 13 factors were suggested by Damschroder's Consolidated Framework for Implementation Research to impede or promote implementation. Logistic regression analyses found a significant association between implementation factor score and full implementation (OR 1.38; 95% CI 1.18-1.61; p = <0.01), indicating that for every one point increase in implementation score, ECEC services were 38 % more likely to be fully implementing the policies and practices. The findings highlight the opportunities for improving implementation of obesity prevention interventions in this setting by developing interventions that address such factors. PMID:26327938

  6. Forward light scattering for arbitrary sharp-edged convex crystals in Fraunhofer and anomalous diffraction approximations.

    PubMed

    Heffels, C; Heitzmann, D; Hirleman, E D; Scarlett, B

    1995-10-01

    Fraunhofer diffraction is a well-known physical model for describing forward light scattering from opaque particles much larger than the wavelength of the light. Analytical expressions exist for diffraction from circular- or rectangular-shaped apertures. An expression is derived for diffraction by apertures of a general polygonal shape. From this expression the exact solution for anomalous diffraction by arbitrary convex crystals is calculated. These expressions are useful in characterizing crystal size and shape, by laser diffraction instruments, when measured in a solution.

  7. Comparison of usual podiatric care and early physical therapy intervention for plantar heel pain: study protocol for a parallel-group randomized clinical trial

    PubMed Central

    2013-01-01

    Background A significant number of individuals suffer from plantar heel pain (PHP) and many go on to have chronic symptoms and continued disability. Persistence of symptoms adds to the economic burden of PHP and cost-effective solutions are needed. Currently, there is a wide variation in treatment, cost, and outcomes of care for PHP with limited information on the cost-effectiveness and comparisons of common treatment approaches. Two practice guidelines and recent evidence of effective physical therapy intervention are available to direct treatment but the timing and influence of physical therapy intervention in the multidisciplinary management of PHP is unclear. The purpose of this investigation is to compare the outcomes and costs associated with early physical therapy intervention (ePT) following initial presentation to podiatry versus usual podiatric care (uPOD) in individuals with PHP. Methods A parallel-group, block-randomized clinical trial will compare ePT and uPOD. Both groups will be seen initially by a podiatrist before allocation to a group that will receive physical therapy intervention consisting primarily of manual therapy, exercise, and modalities, or podiatric care consisting primarily of a stretching handout, medication, injections, and orthotics. Treatment in each group will be directed by practice guidelines and a procedural manual, yet the specific intervention for each participant will be selected by the treating provider. Between-group differences in the Foot and Ankle Ability Measure 6 months following the initial visit will be the primary outcome collected by an independent investigator. In addition, differences in the European Quality of Life – Five Dimensions, Numeric Pain Rating Scale, Global Rating of Change (GROC), health-related costs, and cost-effectiveness at 6 weeks, 6 months, and 1 year will be compared between groups. The association between successful outcomes based on GROC score and participant expectations of recovery

  8. The Growth of Thin Epitaxial Copper Films on Ruthenium (0001)and Oxygen-Precovered Ruthenium (0001) as studied by x-rayphotoelectron diffraction. University of California, Davis, Department of Physics, Ph.D. Thesis

    SciTech Connect

    Ruebush, Scott Daniel

    1997-06-01

    In the first part of this dissertation, the variation of mean emitter depths with direction for core photoelectron emission from single crystals, including the effects of both isotropic inelastic scattering and single and multiple elastic scattering was theoretically studied. The mean emitter depth was found to vary by as much as ±30% with direction. In the second part of this dissertation, x-ray photoelectron diffraction (XPD) was used to study the structure and growth mechanisms of Cu films grown on a clean and an oxygen-precovered Ru(OOO1) surface. Experimental Cu 2p3/2 (Ekin = 556 eV) and Ru 3d (Ekin = 1205 eV) intensities were measured for Cu coverages from submonolayer up to several monolayer (ML) on the clean Ru(OOO1) surface. In addition, the O 1s (Ekin = 958 eV) intensity was measured for Cu grown on oxygen precovered Ru(OOO1). These XPD intensities have been analyzed using single scattering cluster (SSC) and multiple scattering cluster (MSC) models. The first Cu layer has been found to grow pseudomorphically on the Ru(OOO1) surface in agreement with prior studies of the Cu/Ru(OOO 1) system. Thus, the initial growth is layer-by-layer. For higher coverages, XPD shows that the short-range structure of the Cu films is fcc Cu(l 11), but with significant interlayer relaxation (compared to bulk Cu(l 11)) that persists up to {ge}8 ML. When oxygen is preadsorbed on the Ru(OOO1) surface before Cu film growth (possibly to act as a surfactant promoting smoother growth), XPD shows that the first ~3 ML of Cu grow as 3-D islands. In addition, XPD shows that, during Cu growth, all of the oxygen "floats" on the CU surface, in contrast to prior studies which found that 30% of the oxygen remains at the Cu/Ru intetiace. XPD also indicates that the oxygen is highly disordered on the Cu overlayer surface. In thicker layers with oxygen prsent, the Cu grows as Cu(l 11) with equal occupations of two possible domains rotated by 1800 from each

  9. Single Photon diffraction and interference

    NASA Astrophysics Data System (ADS)

    Hodge, John

    2015-04-01

    A previous paper based on the Scalar Theory of Everything studied photon diffraction and interference (IntellectualArchive, Vol.1, No. 3, P. 20, Toronto, Canada July 2012. http://intellectualarchive.com/?link=item&id=597). Several photons were required in the experiment at the same time. Interference experiments with one photon in the experiment at a time also showed interference patterns. The previous paper with the Bohm Interpretation, models of the screen and mask, and the Transaction Interpretation of Quantum Mechanics were combined. The reverse wave required by the Transaction Interpretation was provided by a reflected plenum wave rather than a reverse time wave. The speed of the plenum wave was assumed to be much faster than the speed of photons/light. Using the assumptions of Fraunhofer diffraction resulted in the same equation for the photon distribution on a screen as the intensity pattern of the Fraunhofer diffraction. (http://myplace.frontier.com/ ~ jchodge/)

  10. Electron diffraction by plasmon waves

    NASA Astrophysics Data System (ADS)

    García de Abajo, F. J.; Barwick, B.; Carbone, F.

    2016-07-01

    An electron beam traversing a structured plasmonic field is shown to undergo diffraction with characteristic angular patterns of both elastic and inelastic outgoing electron components. In particular, a plasmonic grating (e.g., a standing wave formed by two counterpropagating plasmons in a thin film) produces diffraction orders of the same parity as the net number of exchanged plasmons. Large diffracted beam fractions are predicted to occur for realistic plasmon intensities in attainable geometries due to a combination of phase and amplitude changes locally imprinted on the passing electron wave. Our study opens vistas in the study of multiphoton exchanges between electron beams and evanescent optical fields with unexplored effects related to the transversal component of the electron wave function.

  11. Lensless reflective point diffraction interferometer.

    PubMed

    Zhu, Wenhua; Chen, Lei; Zheng, Donghui; Yang, Ying; Han, Zhigang; Li, Jinpeng

    2016-07-01

    A lensless reflective point diffraction interferometer (LRPDI) is proposed for dynamic wavefront measurement. The point diffraction interferometer is integrated on a small substrate with properly designed thin film, which is used for generating the interferogram with high carrier frequency at a CCD target. By lensless imaging, the complex amplitude at the CCD target can be propagated to the conjugated plane of the exit pupil of an incident wavefront, which not only avoids the edge diffraction in the interferogram, but also eliminates systematic error. The accuracy of LRPDI is demonstrated by simulation and experiment, and a precision better than 1/150 wavelength is achieved. The new design with lensless imaging processing is suitable for dynamic wavefront measurement. PMID:27409204

  12. Boundary diffraction wave integrals for diffraction modeling of external occulters.

    PubMed

    Cady, Eric

    2012-07-01

    An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional light into this region, and a challenge of modeling an occulter system is to accurately and quickly model these effects. We present a fast method for the calculation of electric fields following an occulter, based on the concept of the boundary diffraction wave: the 2D structure of the occulter is reduced to a 1D edge integral which directly incorporates the occulter shape, and which can be easily adjusted to include changes in occulter position and shape, as well as the effects of sources-such as exoplanets-which arrive off-axis to the occulter. The structure of a typical implementation of the algorithm is included. PMID:22772218

  13. Detonation diffraction through different geometries

    NASA Astrophysics Data System (ADS)

    Sorin, Rémy; Zitoun, Ratiba; Khasainov, Boris; Desbordes, Daniel

    2009-04-01

    We performed the study of the diffraction of a self-sustained detonation from a cylindrical tube (of inner diameter d) through different geometric configurations in order to characterise the transmission processes and to quantify the transmission criteria to the reception chamber. For the diffraction from a tube to the open space the transmission criteria is expressed by d c = k c · λ (with λ the detonation cell size and k c depending on the mixture and on the operture configuration, classically 13 for alkane mixtures with oxygen). The studied geometries are: (a) a sharp increase of diameter ( D/ d > 1) with and without a central obstacle in the diffracting section, (b) a conical divergent with a central obstacle in the diffracting section and (c) an inversed intermediate one end closed tube insuring a double reflection before a final diffraction between the initiator tube and the reception chamber. The results for case A show that the reinitiation process depends on the ratio d/ λ. For ratios below k c the re-ignition takes place at the receptor tube wall and at a fixed distance from the step, i.e. closely after the diffracted shock reflection shows a Mach stem configuration. For ratios below a limit ratio k lim (which depends on D/ d) the re-ignition distance increases with the decrease of d/λ. For both case A and B the introduction of a central obstacle (of blockage ratio BR = 0.5) at the exit of the initiator tube decreases the critical transmission ratio k c by 50%. The results in configuration C show that the re-ignition process depends both on d/ λ and the geometric conditions. Optimal configuration is found that provides the transmission through the two successive reflections (from d = 26 mm to D ch = 200 mm) at as small d/ λ as 2.2 whatever the intermediate diameter D is. This configuration provides a significant improvement in the detonation transmission conditions.

  14. Diffraction model for thermoreflectance data.

    PubMed

    Kureshi, S; Fabris, D; Tokairin, S; Cardenas, C V; Yang, C Y

    2015-06-10

    Thermoreflectance imaging provides the capability to map temperature spatially on the submicrometer scale by using a light source and CCD camera for data acquisition. The ability to achieve such spatial resolution and observe detailed features is influenced by optical diffraction. By combining diffraction from both the sample and substrate, a model is developed to determine the intensity of the thermoreflectance signal. This model takes into account the effective optical distance, sample width, wavelength, signal phase shift, and reflectance intensity, while showing qualitative and quantitative agreement with experimental thermoreflectance images from 1 and 10 μm wide gold lines at two wavelengths.

  15. High-pressure neutron diffraction

    SciTech Connect

    Xu, Hongwu

    2011-01-10

    This lecture will cover progress and prospect of applications of high-pressure neutron diffraction techniques to Earth and materials sciences. I will first introduce general high-pressure research topics and available in-situ high-pressure techniques. Then I'll talk about high-pressure neutron diffraction techniques using two types of pressure cells: fluid-driven and anvil-type cells. Lastly, I will give several case studies using these techniques, particularly, those on hydrogen-bearing materials and magnetic transitions.

  16. Diffraction encoded position measuring apparatus

    DOEpatents

    Tansey, R.J.

    1991-09-24

    When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a detector system can compare the phase of the zero order and higher order beams to obtain an indication of position. Multiple passes through the grating increase resolution for a given wavelength of a laser signal. The resolution can be improved further by using a smaller wavelength laser to generate the grating itself. Since the grating must only have a pitch sufficient to produce diffracted orders, inexpensive, ultraviolet wavelength lasers can be utilized and still obtain high resolution detection. 3 figures.

  17. Diffraction encoded position measuring apparatus

    DOEpatents

    Tansey, Richard J.

    1991-01-01

    When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a detector system can compare the phase of the zero order and higher order beams to obtain an indication of position. Multiple passes through the grating increase resolution for a given wavelength of a laser signal. The resolution can be improved further by using a smaller wavelength laser to generate the grating itself. Since the grating must only have a pitch sufficient to produce diffracted orders, inexpensive, ultraviolet wavelength lasers can be utilized and still obtain high resolution detection.

  18. Teaching diffraction with hands-on optical spectrometry

    NASA Astrophysics Data System (ADS)

    Fischer, Robert

    2012-09-01

    Although the observation of optical spectra is common practice in physics classes, students are usually limited to a passive, qualitative observation of nice colours. This paper discusses a diffraction-based spectrometer that allows students to take quantitative measurements of spectral bands. Students can build it within minutes from generic low-cost materials. The spectrometer’s simple, didactic design allows students to fully comprehend the underlying physical concepts and to engage in a discussion of measurement errors and uncertainties.

  19. Teaching Diffraction with Hands-On Optical Spectrometry

    ERIC Educational Resources Information Center

    Fischer, Robert

    2012-01-01

    Although the observation of optical spectra is common practice in physics classes, students are usually limited to a passive, qualitative observation of nice colours. This paper discusses a diffraction-based spectrometer that allows students to take quantitative measurements of spectral bands. Students can build it within minutes from generic…

  20. Six Classes of Diffraction-Based Optoelectronic Instruments

    NASA Technical Reports Server (NTRS)

    Spremo, Stevan; Fuhr, Peter; Schipper, John

    2003-01-01

    Six classes of diffraction-based optoelectronic instruments have been invented as means for wavelength-based processing of light. One family of anticipated applications lies in scientific instrumentation for studying chemical and physical reactions that affect and/or are affected differently by light of different wavelengths or different combinations of wavelengths. Another family of anticipated applications lies in optoelectronic communication systems.

  1. Optical Simulation of Debye-Scherrer Crystal Diffraction

    ERIC Educational Resources Information Center

    Logiurato, F.; Gratton, L. M.; Oss, S.

    2008-01-01

    In this paper we describe and discuss simple, inexpensive optical experiments used to simulate x-ray and electron diffraction according to the Debye-Scherrer theory. The experiment can be used to address, at the high school level, important subjects related to fundamental quantum and solid-state physics.

  2. Use of Justified Constraints in Coherent Diffractive Imaging

    SciTech Connect

    Kim, S.; McNulty, I.; Chen, Y. K.; Putkunz, C. T.; Dunand, D. C.

    2011-09-09

    We demonstrate the use of physically justified object constraints in x-ray Fresnel coherent diffractive imaging on a sample of nanoporous gold prepared by dealloying. Use of these constraints in the reconstruction algorithm enabled highly reliable imaging of the sample's shape and quantification of the 23- to 52-nm pore structure within it without use of a tight object support constraint.

  3. Rings Around the Sun and Moon: Coronae and Diffraction

    ERIC Educational Resources Information Center

    Cowley, Les; Laven, Philip; Vollmer, Michael

    2005-01-01

    Atmospheric optical effects can teach much about physics and especially optics. Coronae--coloured rings around the sun or moon--are large-scale consequences of diffraction, which is often thought of as only a small effect confined to the laboratory. We describe coronae, how they are formed and experiments that can be conducted on ones in the sky.…

  4. Diffraction by DNA, carbon nanotubes and other helical nanostructures

    NASA Astrophysics Data System (ADS)

    Lucas, Amand A.; Lambin, Philippe

    2005-05-01

    This review discusses the diffraction patterns of x-rays or electrons scattered by fibres of helical biological molecules and by carbon nanotubes (CNTs) from the unified point of view of the Fourier-Bessel transform of an atomic helix. This paper is intended for scientists who are not professional crystallographers. X-ray fibre diffraction patterns of Pauling's protein α-helix and of Crick and Pauling's protein coiled-coil are revisited. This is followed by a non-technical comparison between the historic x-ray diffraction patterns of the A and B conformations of DNA, which were crucial for the discovery of the double helix. The qualitative analysis of the diffraction images is supported by novel optical simulation experiments designed to pinpoint the gross structural informational content of the patterns. The spectacular helical structure of the tobacco mosaic virus determined by Rosalind Franklin and co-workers will then be described as an early example of the great power of x-ray crystallography in determining the structure of a large biomolecular edifice. After these mostly historical and didactic case studies, this paper will consider electron diffraction and transmission electron microscopy of CNTs of great current interest, focusing particularly on recent data obtained for single-wall, double-wall and scrolled nanotubes. Several points of convergence between the interpretations of the diffraction patterns of biological helices and CNTs will be emphasized.

  5. Fresnel Diffraction for CTR Microbunching

    SciTech Connect

    Tikhoplav, R.; Knyazik, A.; Rosenzweig, J. B.; Andonian, G.

    2009-01-22

    Laser beams of high intensities are routinely used for IFEL experiments. Such beams can potentially destroy microbunching diagnostic tools such as coherent transition radiation foils due to their low damage thresholds. Near-field Fresnel diffraction scheme for termination of CO{sub 2} laser beam has been experimentally studied and is presented in this paper. Novel THz camera was utilized for such study.

  6. Diffraction Plates for Classroom Demonstrations

    ERIC Educational Resources Information Center

    Hoover, Richard B.

    1969-01-01

    Describes the computer generation of random and regular arrays of apertures on photographic film and their applications for classroom demonstrations of the Fraunhofer patterns produced by simple and complex apertures, Babinet's principle, resolution according to the Rayleigh criterion, and many other aspects of diffraction. (LC)

  7. Hard diffraction and rapidity gaps

    SciTech Connect

    Albrow, M.G.

    1994-08-01

    I describe the evolution of experiments at hadron colliders on (a) high mass diffraction (b) double pomeron exchange, from the ISR through the Sp{bar p}S to the Tevatron. I emphasize an experimental approach to the question: ``What is the pomeron?``

  8. Mothers’ perceptions of the UK physical activity and sedentary behaviour guidelines for the early years (Start Active, Stay Active): a qualitative study

    PubMed Central

    Bentley, Georgina F; Jago, Russell; Turner, Katrina M

    2015-01-01

    Objectives Higher levels of physical activity (PA) during early childhood have been associated with improved health outcomes, whereas sedentary behaviour (SB) has been associated with poorer health outcomes in children. In 2011, the UK produced guidelines for PA and SB in children under 5 years. Mothers have been identified as key influences in young children's PA and SB. The aim of this study was to use in-depth interviews with mothers of preschool children to examine attitudes to the guidance. Design Qualitative study using one-to-one, semistructured interviews; Data were analysed thematically using a framework approach. Setting Mothers were recruited from preschools, nurseries, and mother and toddler groups located in four areas of varying socioeconomic status within Bristol, UK. Participants 24 mothers who were considered the main or joint carer for a preschool child who was at least 2 years of age but had not yet started formal schooling. Results Mothers are not aware of the UK PA and SB guidelines for the early years. They believe that their child achieves the guideline targets for PA and SB and therefore, they do not believe these quidelines are relevant to them. Mothers feel that an increase in PA and reduction in SB (especially screen-viewing) would cause stress for mothers. Mothers found defining and quantifying PA and SB in their preschool child problematic. Conclusions As mothers do not identify with the need to increase PA or reduce SB in their child, awareness of the guidelines alone is unlikely to initiate behaviour change. Information on how mothers can make a more accurate assessment of their preschool child's PA and SB levels, and information about the benefits of increased PA and reduced SB should be provided alongside the guideline targets. Clear messages need to be developed that reframe the guidelines into pragmatic and usable targets. PMID:26351186

  9. Prototyping an Early-warning System for Rainfall-triggered Landslides on a Regional Scale Using a Physically-based Model and Remote Sensing Datasets

    NASA Astrophysics Data System (ADS)

    Liao, Z.; Hong, Y.; Kirschbaum, D. B.; Fukuoka, H.; Sassa, K.; Karnawati, D.; Fathani, F.

    2010-12-01

    Recent advancements in the availability of remotely sensed datasets provide an opportunity to advance the predictability of rainfall-triggered landslides at larger spatial scales. An early-warning system based on a physical landslide model and remote sensing information is used to simulate the dynamical response of the soil water content to the spatiotemporal variability of rainfall in complex terrain. The system utilizes geomorphologic datasets including a 30-meter ASTER DEM, a 1-km downscaled FAO soil map, and satellite-based Tropical Rainfall Measuring Mission (TRMM) precipitation. The applied physical model SLIDE (SLope-Infiltration-Distributed Equilibrium) defines a direct relationship between a factor of safety and the rainfall depth on an infinite slope. This prototype model is applied to a case study in Honduras during Hurricane Mitch in 1998 and a secondary case of typhoon-induced shallow landslides over Java Island, Indonesia. In Honduras, two study areas were selected which cover approximately 1,200 square kilometers and where a high density of shallow landslides occurred. The results were quantitatively evaluated using landslide inventory data compiled by the United States Geological Survey (USGS) following Hurricane Mitch, and show a good agreement between the modeling results and observations. The success rate for accurately estimating slope failure locations reached as high as 78% and 75%, while the error indices were 35% and 49%, respectively for each of the two selected study areas. Advantages and limitations of this application are discussed with respect to future assessment and challenges of performing a slope-stability estimation using coarse data at 1200 square kilometers. In Indonesia, the system has been applied over the whole Java Island. The prototyped early-warning system has been enhanced by integration of a susceptibility mapping and a precipitation forecasting model (i.e. Weather Research Forecast). The performance has been evaluated

  10. Diffraction data analysis in the presence of radiation damage

    PubMed Central

    Borek, Dominika; Cymborowski, Marcin; Machius, Mischa; Minor, Wladek; Otwinowski, Zbyszek

    2010-01-01

    In macromolecular crystallography, the acquisition of a complete set of diffraction intensities typically involves a high cumulative dose of X-ray radiation. In the process of data acquisition, the irradiated crystal lattice undergoes a broad range of chemical and physical changes. These result in the gradual decay of diffraction intensities, accompanied by changes in the macroscopic organization of crystal lattice order and by localized changes in electron density that, owing to complex radiation chemistry, are specific for a particular macromolecule. The decay of diffraction intensities is a well defined physical process that is fully correctable during scaling and merging analysis and therefore, while limiting the amount of diffraction, it has no other impact on phasing procedures. Specific chemical changes, which are variable even between different crystal forms of the same macromolecule, are more difficult to predict, describe and correct in data. Appearing during the process of data collection, they result in gradual changes in structure factors and therefore have profound consequences in phasing procedures. Examples of various combinations of radiation-induced changes are presented and various considerations pertinent to the determination of the best strategies for handling diffraction data analysis in representative situations are discussed. PMID:20382996

  11. Very Early Prescient Experimental and Theoretical Nano/Microcluster-Scale-Physics Root-Cause Ultimate-Origins: History: EMET!!!/TRUTH!!!

    NASA Astrophysics Data System (ADS)

    Gregson, Victor; Kubo, Ryogiro; Siegel, Edward Carl-Ludwig

    2013-03-01

    Siegel[Phys.Stat.Sol.(a)11,45(72)] possibly first experimental nanoscale-physics/metallurgy/ceramics(VS CNRS Mdm.-Pres.resume-claims),following always-seminal Kubo[Phys. Lett.1,49(62);J.Phys.Soc.Jpn.:17,965(62); 21,1765(66); Comm.SS Phys.1,168 (68); J.Phys.Colloques,38,C2-69(77).]-Fulde[(1960s)]-Matsubara et. al.[(1960s]-Matsubara-Siegel[Intl.Conf.Lattice-Dym.(77);Statphys-13(77);ICMAO(77);Scripta Met.13,913(79)] as reviewed by Sugano[Microcluster-Physics(81)], very early experimental hardness/bulk-modului/shear-moduli versus/ connection to Dempsey[Phil.Mag. 8,86,285(63)] electrical-resistivity trends with cation-atomic-number of hot/cold-pressed ceramics versus Mott topological-disorder: Siegel: powders[Mtls.Sci.Eng.8,6 323(71);Phys.Stat.Sol.(a)11, 45(72) ;Semis, &Insuls.5:39,47,62 (79)] /glasses[J.Nonxline-Sols.40,453(80); NYAS Conf.Atomic & Molecular Glasses, Ann.NYAS(80); Ferroelectrics 34,1,127(81)]/ liquids[Phys.& Chem.Liqs.:4(4)(75);5(1)(76)] / slushes (!!!)/ blends /ferrofluids[Intl Conf. Ferrofluids, M. Zahn ed.(84)]/nanophysics of Goudschmidt [Interstitial-Alloys,(69)] transition-metalloids: carbides, nitrides, borides, hydrides, carbon [Phys.Stat.Sol.(a)11,45(72); Semis.&Insuls.5: 39,47,62(79)]) and proton-irradiated diamond Little[(1960s]-predicted hyper/superconducting polydiacetylene(???) quantum-wires [3rd World Cong.SC, Munich(92), Appl.-SC,1,10,1949(93); TWO OTHER PAPERS SPIKED BY ANL/DOE EDITORS!!! AS USUAL!!!: GOOGLE:

  12. Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

    NASA Astrophysics Data System (ADS)

    Kress, Bernard; Hejmadi, Vic

    2010-05-01

    When a new technology is integrated into industry commodity products and consumer electronic devices, and sold worldwide in retail stores, it is usually understood that this technology has then entered the realm of mainstream technology and therefore mainstream industry. Such a leap however does not come cheap, as it has a double edge sword effect: first it becomes democratized and thus massively developed by numerous companies for various applications, but also it becomes a commodity, and thus gets under tremendous pressure to cut down its production and integration costs while not sacrificing to performance. We will show, based on numerous examples extracted from recent industry history, that the field of Diffractive Optics is about to undergo such a major transformation. Such a move has many impacts on all facets of digital diffractive optics technology, from the optical design houses to the micro-optics foundries (for both mastering and volume replication), to the final product integrators or contract manufacturers. The main causes of such a transformation are, as they have been for many other technologies in industry, successive technological bubbles which have carried and lifted up diffractive optics technology within the last decades. These various technological bubbles have been triggered either by real industry needs or by virtual investment hype. Both of these causes will be discussed in the paper. The adjective ""digital"" in "digital diffractive optics" does not refer only, as it is done in digital electronics, to the digital functionality of the element (digital signal processing), but rather to the digital way they are designed (by a digital computer) and fabricated (as wafer level optics using digital masking techniques). However, we can still trace a very strong similarity between the emergence of micro-electronics from analog electronics half a century ago, and the emergence of digital optics from conventional optics today.

  13. Growing Larger Crystals for Neutron Diffraction

    NASA Technical Reports Server (NTRS)

    Pusey, Marc

    2003-01-01

    Obtaining crystals of suitable size and high quality has been a major bottleneck in macromolecular crystallography. With the advent of advanced X-ray sources and methods the question of size has rapidly dwindled, almost to the point where if one can see the crystal then it was big enough. Quality is another issue, and major national and commercial efforts were established to take advantage of the microgravity environment in an effort to obtain higher quality crystals. Studies of the macromolecule crystallization process were carried out in many labs in an effort to understand what affected the resultant crystal quality on Earth, and how microgravity improved the process. While technological improvements are resulting in a diminishing of the minimum crystal size required, neutron diffraction structural studies still require considerably larger crystals, by several orders of magnitude, than X-ray studies. From a crystal growth physics perspective there is no reason why these 'large' crystals cannot be obtained: the question is generally more one of supply than limitations mechanism. This talk will discuss our laboratory s current model for macromolecule crystal growth, with highlights pertaining to the growth of crystals suitable for neutron diffraction studies.

  14. Soft Classification of Diffractive Interactions at the LHC

    SciTech Connect

    Kuusela, Mikael; Malmi, Eric; Orava, Risto; Vatanen, Tommi

    2011-07-15

    Multivariate machine learning techniques provide an alternative to the rapidity gap method for event-by-event identification and classification of diffraction in hadron-hadron collisions. Traditionally, such methods assign each event exclusively to a single class producing classification errors in overlap regions of data space. As an alternative to this so called hard classification approach, we propose estimating posterior probabilities of each diffractive class and using these estimates to weigh event contributions to physical observables. It is shown with a Monte Carlo study that such a soft classification scheme is able to reproduce observables such as multiplicity distributions and relative event rates with a much higher accuracy than hard classification.

  15. New approaches to nonlinear diffractive field propagation.

    PubMed

    Christopher, P T; Parker, K J

    1991-07-01

    In many domains of acoustic field propagation, such as medical ultrasound imaging, lithotripsy shock treatment, and underwater sonar, a realistic calculation of beam patterns requires treatment of the effects of diffraction from finite sources. Also, the mechanisms of loss and nonlinear effects within the medium are typically nonnegligible. The combination of diffraction, attenuation, and nonlinear effects has been treated by a number of formulations and numerical techniques. A novel model that incrementally propagates the field of baffled planar sources with substeps that account for the physics of diffraction, attenuation, and nonlinearity is presented. The model accounts for the effect of refraction and reflection (but not multiple reflections) in the case of propagation through multiple, parallel layers of fluid medium. An implementation of the model for axis symmetric sources has been developed. In one substep of the implementation, a new discrete Hankel transform is used with spatial transform techniques to propagate the field over a short distance with diffraction and attenuation. In the other substep, the temporal frequency domain solution to Burgers' equation is implemented to account for the nonlinear accretion and depletion of harmonics. This approach yields a computationally efficient procedure for calculating beam patterns from a baffled planar, axially symmetric source under conditions ranging from quasilinear through shock. The model is not restricted by the usual parabolic wave approximation and the field's directionality is explicitly accounted for at each point. Useage of a harmonic-limiting scheme allows the model to propagate some previously intractable high-intensity nonlinear fields. Results of the model are shown to be in excellent agreement with measurements performed on the nonlinear field of an unfocused 2.25-MHz piston source, even in the near field where the established parabolic wave approximation model fails. Next, the model is used to

  16. Perturbation theory in electron diffraction

    NASA Astrophysics Data System (ADS)

    Bakken, L. N.; Marthinsen, K.; Hoeier, R.

    1992-12-01

    The Bloch-wave approach is used for discussing multiple inelastic electron scattering and higher-order perturbation theory in inelastic high-energy electron diffraction. In contrast to previous work, the present work describes three-dimensional diffraction so that higher-order Laue zone (HOLZ) effects are incorporated. Absorption is included and eigenvalues and eigenvectors are calculated from a structure matrix with the inclusion of an absorptive potential. Centrosymmetric as well as non-centrosymmetric crystal structures are allowed. An iteration method with a defined generalized propagation function for solving the inelastic coupling equations is described. It is shown that a similar iteration method with the same propagation function can be used for obtaining higher-order perturbation terms for the wave-function when a perturbation is added to the crystal potential. Finally, perturbation theory by matrix calculations when a general perturbation is added to the structure matrix is considered.

  17. Diffraction operators in paraxial approach

    NASA Astrophysics Data System (ADS)

    Lasso, William; Navas, Marianela; Añez, Liz; Urdaneta, Romer; Díaz, Leonardo; Torres, César O.

    2014-07-01

    Nowadays, research in the field of science education points to the creation of alternative ways of teaching contents encouraging the development of more elaborate reasoning, where a high degree of abstraction and generalization of scientific knowledge prevails. On that subject, this research shows a didactic alternative proposal for the construction of Fresnel and Fraunhoffer diffraction concepts applying the Fourier transform technique in the study of electromagnetic waves propagation in free space. Curvature transparency and Fourier sphere operators in paraxial approximation are used in order to make the usual laborious mathematical approach easier. The main result shows that the composition of optic metaxial operators results in the discovery of a simpler way out of the standard electromagnetic wave propagation in free space between a transmitter and a receptor separated from a given distance. This allows to state that the didactic proposal shown encourages the construction of Fresnel and Fraunhoffer diffraction concepts in a more effective and easier way than the traditional teaching.

  18. dxtbx: the diffraction experiment toolbox.

    PubMed

    Parkhurst, James M; Brewster, Aaron S; Fuentes-Montero, Luis; Waterman, David G; Hattne, Johan; Ashton, Alun W; Echols, Nathaniel; Evans, Gwyndaf; Sauter, Nicholas K; Winter, Graeme

    2014-08-01

    Data formats for recording X-ray diffraction data continue to evolve rapidly to accommodate new detector technologies developed in response to more intense light sources. Processing the data from single-crystal X-ray diffraction experiments therefore requires the ability to read, and correctly interpret, image data and metadata from a variety of instruments employing different experimental representations. Tools that have previously been developed to address this problem have been limited either by a lack of extensibility or by inconsistent treatment of image metadata. The dxtbx software package provides a consistent interface to both image data and experimental models, while supporting a completely generic user-extensible approach to reading the data files. The library is written in a mixture of C++ and Python and is distributed as part of the cctbx under an open-source licence at http://cctbx.sourceforge.net. PMID:25242914

  19. Phase Aberrations in Diffraction Microscopy

    SciTech Connect

    Marchesini, S; Chapman, H N; Barty, A; Howells, M R; Spence, J H; Cui, C; Weierstall, U; Minor, A M

    2005-09-29

    In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a lens the resolution is limited, in principle, only by the largest scattering angles recorded. However, the imaging task is shifted from the experiment to the computer, and the algorithm's ability to recover meaningful images in the presence of noise and limited prior knowledge may produce aberrations in the reconstructed image. We analyze the low order aberrations produced by our phase retrieval algorithms. We present two methods to improve the accuracy and stability of reconstructions.

  20. Diffraction Analysis of Solar Coronagraphs

    NASA Astrophysics Data System (ADS)

    Rabin, Douglas M.; gong, qian

    2016-05-01

    The design of a solar coronagraph is predicated on controlling diffracted and scattered light using principles dating back to Bernard Lyot in the 1930’s. The existence of many successful ground- and space-based coronagraphs testifies to our ability to apply these principles in specific cases, but it is difficult to explore a significant range of design parameters because the calculations are tricky and time-consuming. Indeed, scattered light is so design-specific that ad hoc analysis is unavoidable once guidelines from experience are used to create a first-guess system of baffles and low-scatter surfaces. Here we describe a combination of analytic and computational approaches that has the potential to explore coronagraph design space somewhat more systematically with respect to diffracted light.

  1. Neutron diffraction and Vitamin E

    NASA Astrophysics Data System (ADS)

    Harroun, T. A.

    2010-11-01

    It is generally accepted that neutron diffraction from model membrane systems is an effective biophysical technique for determining membrane structure. Here we describe an example of how deuterium labelling can elucidate the location of specific membrane soluble molecules, including a brief discussion of the technique itself. We show that deuterium labelled α-tocopherol sits upright in the bilayer, as might be expected, but at very different locations within the bilayer, depending on the degree of lipid chain unsaturation.

  2. Diffraction Techniques in Structural Biology

    PubMed Central

    Egli, Martin

    2010-01-01

    A detailed understanding of chemical and biological function and the mechanisms underlying the activities ultimately requires atomic-resolution structural data. Diffraction-based techniques such as single-crystal X-ray crystallography, electron microscopy and neutron diffraction are well established and have paved the road to the stunning successes of modern-day structural biology. The major advances achieved in the last 20 years in all aspects of structural research, including sample preparation, crystallization, the construction of synchrotron and spallation sources, phasing approaches and high-speed computing and visualization, now provide specialists and non-specialists alike with a steady flow of molecular images of unprecedented detail. The present chapter combines a general overview of diffraction methods with a step-by-step description of the process of a single-crystal X-ray structure determination experiment, from chemical synthesis or expression to phasing and refinement, analysis and quality control. For novices it may serve as a stepping-stone to more in-depth treatises of the individual topics. Readers relying on structural information for interpreting functional data may find it a useful consumer guide. PMID:20517991

  3. Monitoring model drug microencapsulation in PLGA scaffolds using X-ray powder diffraction

    PubMed Central

    Aina, Adeyinka; Gupta, Manish; Boukari, Yamina; Morris, Andrew; Billa, Nashiru; Doughty, Stephen

    2015-01-01

    The microencapsulation of three model drugs; metronidazole, paracetamol and sulphapyridine into Poly (dl-Lactide-Co-Glycolide) (PLGA) scaffolds were probed using X-ray Powder Diffraction (XRPD). Changes in the diffraction patterns of the PLGA scaffolds after encapsulation was suggestive of a chemical interaction between the pure drugs and the scaffolds and not a physical intermixture. PMID:27013917

  4. Modeling the field diffracted from photo mask at oblique incidence.

    PubMed

    Tawfik Elazhary, Tamer; Hisham Morshed, Ahmed; Khalil, Diaa

    2010-08-01

    In optical lithography, light diffracted from photo mask structures has been customarily assumed to be constant with the angle of incidence of the light illuminating the photo mask. As numerical aperture increases to unity and beyond, to cope with the continuous demand for shrinking integrated circuits, device dimensions, and densities, this approximation is no longer valid. In this paper we use the physical theory of diffraction to study, understand, and model the variation of light diffracted from photo mask structures of the order of the wavelength, with the angle of light incidence. We present a semianalytical model that is fast, accurate, and compatible with existing professional software in this domain. The accuracy of the model is studied using the finite-difference time-domain technique and is shown to be below 5% at the image plane, within angles of incidence between +/-20 degrees .

  5. Image processing for grazing incidence fast atom diffraction

    NASA Astrophysics Data System (ADS)

    Debiossac, Maxime; Roncin, Philippe

    2016-09-01

    Grazing incidence fast atom diffraction (GIFAD, or FAD) has developed as a surface sensitive technique. Compared with thermal energies helium diffraction (TEAS or HAS), GIFAD is less sensitive to thermal decoherence but also more demanding in terms of surface coherence, the mean distance between defects. Such high quality surfaces can be obtained from freshly cleaved crystals or in a molecular beam epitaxy (MBE) chamber where a GIFAD setup has been installed allowing in situ operation. Based on recent publications by Atkinson et al. (2014) and Debiossac et al. (2014), the paper describes in detail the basic steps needed to measure the relative intensities of the diffraction spots. Care is taken to outline the underlying physical assumptions.

  6. Resonance domain surface relief diffractive lens for the visible spectral region.

    PubMed

    Barlev, Omri; Golub, Michael A

    2013-03-01

    Early expectations for a role of diffractive lenses were dramatically lessened by their high order overlapping foci, low optical powers, and competing advances in refractive micro-optics. By bringing the Bragg properties of volume holograms to diffractive lenses we got rid of ghost diffractive orders and the critical trade-off between diffraction efficiency, number of phase levels, and spatial feature-size. Binary off-axis resonance domain diffractive lens with high numerical aperture of 0.16 was designed with analytical effective grating theory, fabricated by direct e-beam writing, etched in fused silica and experimentally investigated. More than 81% measured diffraction efficiency exceeds twice the limits of thin binary optics.

  7. Diffractive dijet and W production in CDF

    SciTech Connect

    Goulianos, K.

    1998-06-01

    Results on diffractive dijet and W-boson production from CDF are reviewed and compared with predictions based on factorization of the diffractive structure function of the proton measured in deep inelastic scattering at HERA.

  8. Diffractive optics: Design, fabrication, and applications

    NASA Technical Reports Server (NTRS)

    Morris, G. Michael

    1993-01-01

    The topics are presented in viewgraph form and include the following: features, applications, surface relief diffractive optics, optical data storage, waveguide lenses, diffractive lense imaging, phase grating synthesis, sub-wavelength structured surfaces, etc.

  9. High-pressure neutron diffraction studies at LANSCE

    NASA Astrophysics Data System (ADS)

    Zhao, Yusheng; Zhang, Jianzhong; Xu, Hongwu; Lokshin, Konstantin A.; He, Duanwei; Qian, Jiang; Pantea, Cristian; Daemen, Luke L.; Vogel, Sven C.; Ding, Yang; Xu, Jian

    2010-06-01

    The development of neutron diffraction under extreme pressure ( P) and temperature ( T) conditions is highly valuable to condensed matter physics, crystal chemistry, materials science, and earth and planetary sciences. We have incorporated a 500-ton press TAP-98 into the HiPPO diffractometer at the Los Alamos Neutron Science Center (LANSCE) to conduct in situ high- P- T neutron diffraction experiments. We have developed a large gem-crystal anvil cell, ZAP, to conduct neutron diffraction experiments at high P. The ZAP cell can be used to integrate multiple experimental techniques such as neutron diffraction, laser spectroscopy, and ultrasonic interferometery. More recently, we have developed high- P low- T gas/liquid cells in conjunction with neutron diffraction. These techniques enable in situ and real-time examination of gas uptake/release processes and allow accurate, time-dependent determination of changes in crystal structure and related reaction kinetics. We have successfully used these techniques to study the equations of state, structural phase transitions, and thermo-mechanical properties of metals, ceramics, and minerals. We have conducted researches on the formation/decomposition kinetics of methane, CO2 and hydrogen hydrate clathrates, and hydrogen/CO2 adsorption of inclusion compounds such as metal-organic frameworks (MOFs). The aim of our research is to accurately map out phase relations and determine structural parameters (lattice constants, atomic positions, atomic thermal parameters, bond lengths, bond angles, etc.) in the P- T- X space. We are developing further high- P- T technology with a new 2000-ton press, TAPLUS-2000, and a ZIA (Deformation-DIA type) cubic anvil package to routinely achieve pressures up to 20 GPa and temperatures up to 2000 K. The design of a dedicated high- P neutron beamline, LAPTRON, is also underway for simultaneous high- P- T neutron diffraction, ultrasonic, calorimetry, radiography, and tomography studies. Studies based

  10. 50 years of fiber diffraction.

    PubMed

    Holmes, Kenneth C

    2010-05-01

    In 1955 Ken Holmes started working on tobacco mosaic virus (TMV) as a research student with Rosalind Franklin at Birkbeck College, London. Afterward he spent 18months as a post doc with Don Caspar and Carolyn Cohen at the Children's Hospital, Boston where he continued the work on TMV and also showed that the core of the thick filament of byssus retractor muscle from mussels is made of two-stranded alpha-helical coiled-coils. Returning to England he joined Aaron Klug's group at the newly founded Laboratory of Molecular Biology in Cambridge. Besides continuing the TMV studies, which were aimed at calculating the three-dimensional density map of the virus, he collaborated with Pringle's group in Oxford to show that two conformation of the myosin cross-bridge could be identified in insect flight muscle. In 1968 he opened the biophysics department at the Max Planck Institute for Medical Research in Heidelberg, Germany. With Gerd Rosenbaum he initiated the use of synchrotron radiation as a source for X-ray diffraction. In his lab the TMV structure was pushed to 4A resolution and showed how the RNA binds to the protein. With his co-workers he solved the structure of g-actin as a crystalline complex and then solved the structure of the f-actin filament by orientating the g-actin structure so as to give the f-actin fiber diffraction pattern. He was also able to solve the structure of the complex of actin with tropomyosin from fiber diffraction. PMID:20079849

  11. Fiber optic diffraction grating maker

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1991-01-01

    A compact and portable diffraction grating maker comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate.

  12. Fiber optic diffraction grating maker

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1991-05-21

    A compact and portable diffraction grating maker is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate. 4 figures.

  13. Nonlinear ptychographic coherent diffractive imaging.

    PubMed

    Odstrcil, M; Baksh, P; Gawith, C; Vrcelj, R; Frey, J G; Brocklesby, W S

    2016-09-01

    Ptychographic Coherent diffractive imaging (PCDI) is a significant advance in imaging allowing the measurement of the full electric field at a sample without use of any imaging optics. So far it has been confined solely to imaging of linear optical responses. In this paper we show that because of the coherence-preserving nature of nonlinear optical interactions, PCDI can be generalised to nonlinear optical imaging. We demonstrate second harmonic generation PCDI, directly revealing phase information about the nonlinear coefficients, and showing the general applicability of PCDI to nonlinear interactions. PMID:27607631

  14. DIFFRACTION DISSOCIATION - 50 YEARS LATER.

    SciTech Connect

    WHITE, S.N.

    2005-04-27

    The field of Diffraction Dissociation, which is the subject of this workshop, began 50 years ago with the analysis of deuteron stripping in low energy collisions with nuclei. We return to the subject in a modern context- deuteron dissociation in {radical}s{sub NN} = 200 GeV d-Au collisions recorded during the 2003 RHIC run in the PHENIX experiment. At RHIC energy, d {yields} n+p proceeds predominantly (90%) through Electromagnetic Dissociation and the remaining fraction via the hadronic shadowing described by Glauber. Since the dissociation cross section has a small theoretical error we adopt this process to normalize other cross sections measured in RHIC.

  15. Twenty-meter space telescope based on diffractive Fresnel lens

    NASA Astrophysics Data System (ADS)

    Early, James T.; Hyde, Roderick; Baron, Richard L.

    2004-02-01

    Diffractive lenses offer two potential advantages for very large aperture space telescopes; very loose surface-figure tolerances and physical implementation as thin, flat optical elements. In order to actually realize these advantages one must be able to build large diffractive lenses with adequate optical precision and also to compactly stow the lens for launch and then fully deploy it in space. We will discuss the recent fabrication and assembly demonstration of a 5m glass diffractive Fresnel lens at LLNL. Optical performance data from smaller full telescopes with diffractive lens and corrective optics show diffraction limited performance with broad bandwidths. A systems design for a 20m space telescope will be presented. The primary optic can be rolled to fit inside of the standard fairings of the Delta IV vehicle. This configuration has a simple deployment and requires no orbital assembly. A twenty meter visible telescope could have a significant impact in conventional astronomy with eight times the resolution of Hubble and over sixty times the light gathering capacity. If the light scattering is made acceptable, this telescope could also be used in the search for terrestrial planets.

  16. Twenty Meter Space Telescope Based on Diffractive Fresnel Lens

    SciTech Connect

    Early, J; Hyde, R; Baron, R

    2003-06-26

    Diffractive lenses offer two potential advantages for very large aperture space telescopes; very loose surface-figure tolerances and physical implementation as thin, flat optical elements. In order to actually realize these advantages one must be able to build large diffractive lenses with adequate optical precision and also to compactly stow the lens for launch and then fully deploy it in space. We will discuss the recent fabrication and assembly demonstration of a 5m glass diffractive Fresnel lens at LLNL. Optical performance data from smaller full telescopes with diffractive lens and corrective optics show diffraction limited performance with broad bandwidths. A systems design for a 20m space telescope will be presented. The primary optic can be rolled to fit inside of the standard fairings of the Delta IV vehicle. This configuration has a simple deployment and requires no orbital assembly. A twenty meter visible telescope could have a significant impact in conventional astronomy with eight times the resolution of Hubble and over sixty times the light gathering capacity. If the light scattering is made acceptable, this telescope could also be used in the search for terrestrial planets.

  17. Diffraction Gratings for High-Intensity Laser Applications

    SciTech Connect

    Britten, J

    2008-01-23

    The scattering of light into wavelength-dependent discrete directions (orders) by a device exhibiting a periodic modulation of a physical attribute on a spatial scale similar to the wavelength of light has been the subject of study for over 200 years. Such a device is called a diffraction grating. Practical applications of diffraction gratings, mainly for spectroscopy, have been around for over 100 years. The importance of diffraction gratings in spectroscopy for the measurement of myriad properties of matter can hardly be overestimated. Since the advent of coherent light sources (lasers) in the 1960's, applications of diffraction gratings in spectroscopy have further exploded. Lasers have opened a vast application space for gratings, and apace, gratings have enabled entirely new classes of laser systems. Excellent reviews of the history, fundamental properties, applications and manufacturing techniques of diffraction gratings up to the time of their publication can be found in the books by Hutley (1) and more recently Loewen and Popov (2). The limited scope of this chapter can hardly do justice to such a comprehensive subject, so the focus here will be narrowly limited to characteristics required for gratings suitable for high-power laser applications, and methods to fabricate them. A particular area of emphasis will be on maximally-efficient large-aperture gratings for short-pulse laser generation.

  18. Diffraction-controlled backscattering threshold and application to Raman gap

    SciTech Connect

    Rose, Harvey A.; Mounaix, Philippe

    2011-04-15

    In most classic analytical models of linear stimulated scatter, light diffraction is omitted, a priori. However, modern laser optic typically includes a variant of the random phase plate [Y. Kato et al., Phys. Rev. Lett. 53, 1057 (1984)], resulting in diffraction limited laser intensity fluctuations - or localized speckles - which may result in explosive reflectivity growth as the average laser intensity approaches a critical value [H. A. Rose and D. F. DuBois, Phys. Rev. Lett. 72, 2883 (1994)]. Among the differences between stimulated Raman scatter (SRS) and stimulated Brillouin scatter is that the SRS scattered light diffracts more strongly than the laser light with increase of electron density. This weakens the tendency of the SRS light to closely follow the most amplified paths, diminishing gain. Let G{sub 0} be the one-dimensional power gain exponent of the stimulated scatter. In this paper we show that differential diffraction gives rise to an increase of G{sub 0} at the SRS physical threshold with increase of electron density up to a drastic disruption of SRS as electron density approaches one fourth of its critical value from below. For three wave interaction lengths not small compared to a speckle length, this is a physically robust Raman gap mechanism.

  19. Adaptability of laser diffraction measurement technique in soil physics methodology

    NASA Astrophysics Data System (ADS)

    Barna, Gyöngyi; Szabó, József; Rajkai, Kálmán; Bakacsi, Zsófia; Koós, Sándor; László, Péter; Hauk, Gabriella; Makó, András

    2016-04-01

    There are intentions all around the world to harmonize soils' particle size distribution (PSD) data by the laser diffractometer measurements (LDM) to that of the sedimentation techniques (pipette or hydrometer methods). Unfortunately, up to the applied methodology (e. g. type of pre-treatments, kind of dispersant etc.), PSDs of the sedimentation methods (due to different standards) are dissimilar and could be hardly harmonized with each other, as well. A need was arisen therefore to build up a database, containing PSD values measured by the pipette method according to the Hungarian standard (MSZ-08. 0205: 1978) and the LDM according to a widespread and widely used procedure. In our current publication the first results of statistical analysis of the new and growing PSD database are presented: 204 soil samples measured with pipette method and LDM (Malvern Mastersizer 2000, HydroG dispersion unit) were compared. Applying usual size limits at the LDM, clay fraction was highly under- and silt fraction was overestimated compared to the pipette method. Subsequently soil texture classes determined from the LDM measurements significantly differ from results of the pipette method. According to previous surveys and relating to each other the two dataset to optimizing, the clay/silt boundary at LDM was changed. Comparing the results of PSDs by pipette method to that of the LDM, in case of clay and silt fractions the modified size limits gave higher similarities. Extension of upper size limit of clay fraction from 0.002 to 0.0066 mm, and so change the lower size limit of silt fractions causes more easy comparability of pipette method and LDM. Higher correlations were found between clay content and water vapor adsorption, specific surface area in case of modified limit, as well. Texture classes were also found less dissimilar. The difference between the results of the two kind of PSD measurement methods could be further reduced knowing other routinely analyzed soil parameters (e.g. pH(H2O), organic carbon and calcium carbonate content).

  20. Undergraduate Experiment with Fractal Diffraction Gratings

    ERIC Educational Resources Information Center

    Monsoriu, Juan A.; Furlan, Walter D.; Pons, Amparo; Barreiro, Juan C.; Gimenez, Marcos H.

    2011-01-01

    We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics…

  1. Ultrafast electron diffraction from aligned molecules

    SciTech Connect

    Centurion, Martin

    2015-08-17

    The aim of this project was to record time-resolved electron diffraction patterns of aligned molecules and to reconstruct the 3D molecular structure. The molecules are aligned non-adiabatically using a femtosecond laser pulse. A femtosecond electron pulse then records a diffraction pattern while the molecules are aligned. The diffraction patterns are then be processed to obtain the molecular structure.

  2. Spectral partitioning in diffraction tomography

    SciTech Connect

    Lehman, S K; Chambers, D H; Candy, J V

    1999-06-14

    The scattering mechanism of diffraction tomography is described by the integral form of the Helmholtz equation. The goal of diffraction tomography is to invert this equation in order to reconstruct the object function from the measured scattered fields. During the forward propagation process, the spatial spectrum of the object under investigation is ''smeared,'' by a convolution in the spectral domain, across the propagating and evanescent regions of the received field. Hence, care must be taken in performing the reconstruction, as the object's spectral information has been moved into regions where it may be considered to be noise rather than useful information. This will reduce the quality and resolution of the reconstruction. We show haw the object's spectrum can be partitioned into resolvable and non-resolvable parts based upon the cutoff between the propagating and evanescent fields. Operating under the Born approximation, we develop a beam-forming on transmit approach to direct the energy into either the propagating or evanescent parts of the spectrum. In this manner, we may individually interrogate the propagating and evanescent regions of the object spectrum.

  3. Anomalous refraction, diffraction, and imaging in metamaterials

    NASA Astrophysics Data System (ADS)

    Paul, Thomas; Rockstuhl, Carsten; Menzel, Christoph; Lederer, Falk

    2009-03-01

    In the past several years, optical metamaterials (MMs) have attracted a considerable deal of interest because it may be anticipated that their properties can be shaped to an unprecedented extent relieving optics from some of its natural limitations. An inevitable first step toward this goal is the evaluation of the optical properties of specifically designed MMs. To date, apart from identifying chiral properties of very specific configurations, this is primarily done in retrieving an effective refractive index—mostly—only for normal incidence. On this basis suggestions for a perfect lens, exploiting this negative refractive index have been put forward by taking advantage of geometrical optics arguments. We show that this approach is pointless for realistic MMs. Instead we prove that the dispersion relation of normal modes in these MMs provides all the required information. Most of the relevant optical parameters, such as refraction and diffraction coefficients, can be derived from this relation. Imaging properties follow straightforwardly from that data. This general approach holds for any optical material, in particular, for all MMs in question. As an example, we apply it to the fishnet structure: one of the most prominent and best studied design approaches to date. We show that both refraction and diffraction properties are strongly spatially and temporally dispersive and they can even change sign. In detail, we study the effect of these peculiarities on imaging and refraction of finite beams. In particular, we discuss both the effect of the specific dispersion relation and the losses on the imaging properties. All our physical predictions are backed by rigorous numerical calculations and the agreement is almost perfect. Ultimately the main conclusion to be drawn is that a negative index of refraction is by no means a sufficient criterion to achieve negative refraction and/or perfect imaging.

  4. Transient x-ray diffraction and its application to materials science and x-ray optics

    SciTech Connect

    Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R.

    1997-12-01

    Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

  5. Active learning in optics and photonics: Fraunhofer diffraction

    NASA Astrophysics Data System (ADS)

    Ghalila, H.; Ben Lakhdar, Z.; Lahmar, S.; Dhouaidi, Z.; Majdi, Y.

    2014-07-01

    "Active Learning in Optics and Photonics" (ALOP), funded by UNESCO within its Physics Program framework with the support of ICTP (Abdus Salam International Centre for Theoretical Physics) and SPIE (Society of Photo-Optical Instrumentation Engineers), aimed to helps and promotes a friendly and interactive method in teaching optics using simple and inexpensive equipment. Many workshops were organized since 2005 the year when Z. BenLakhdar, whom is part of the creators of ALOP, proposed this project to STO (Société Tunisienne d'Optique). These workshops address several issues in optics, covering geometrical optics, wave optics, optical communication and they are dedicated to both teachers and students. We focus this lecture on Fraunhofer diffraction emphasizing the facility to achieve this mechanism in classroom, using small laser and operating a slit in a sheet of paper. We accompany this demonstration using mobile phone and numerical modeling to assist in the analysis of the diffraction pattern figure.

  6. Early history of neutron scattering at Oak Ridge

    SciTech Connect

    Wilkinson, M.K.

    1985-07-01

    Most of the early development of neutron scattering techniques utilizing reactor neutrons occurred at the Oak Ridge National Laboratory during the years immediately following World War II. C.G. Shull, E.O. Wollan, and their associates systematically established neutron diffraction as a quantitative research tool and then applied this technique to important problems in nuclear physics, chemical crystallography, and magnetism. This article briefly summarizes the very important research at ORNL during this period, which laid the foundation for the establishment of neutron scattering programs throughout the world. 47 refs., 10 figs.

  7. Near-field diffraction of chirped gratings.

    PubMed

    Sanchez-Brea, Luis Miguel; Torcal-Milla, Francisco Jose; Morlanes, Tomas

    2016-09-01

    In this Letter, we analyze the near-field diffraction pattern produced by chirped gratings. An intuitive analytical interpretation of the generated diffraction orders is proposed. Several interesting properties of the near-field diffraction pattern can be determined, such as the period of the fringes and its visibility. Diffraction orders present different widths and also, some of them present focusing properties. The width, location, and depth of focus of the converging diffraction orders are also determined. The analytical expressions are compared to numerical simulation and experimental results, showing a high agreement. PMID:27607980

  8. Diffractive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  9. Encapsulation process for diffraction gratings.

    PubMed

    Ratzsch, Stephan; Kley, Ernst-Bernhard; Tünnermann, Andreas; Szeghalmi, Adriana

    2015-07-13

    Encapsulation of grating structures facilitates an improvement of the optical functionality and/or adds mechanical stability to the fragile structure. Here, we introduce novel encapsulation process of nanoscale patterns based on atomic layer deposition and micro structuring. The overall size of the encapsulated structured surface area is only restricted by the size of the available microstructuring and coating devices; thus, overcoming inherent limitations of existing bonding processes concerning cleanliness, roughness, and curvature of the components. Finally, the process is demonstrated for a transmission grating. The encapsulated grating has 97.5% transmission efficiency in the -1st diffraction order for TM-polarized light, and is being limited by the experimental grating parameters as confirmed by rigorous coupled wave analysis.

  10. Exclusive, Hard Diffraction in QCD

    NASA Astrophysics Data System (ADS)

    Freund, Andreas

    1999-03-01

    In the first chapter we give an introduction to hard diffractive scattering in QCD to introduce basic concepts and terminology. In the second chapter we make predictions for the evolution of skewed parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA and solve the skewed GLAP evolution equations with a modified version of the CTEQ-package. In the third chapter, we discuss the algorithms used in the LO evolution program for skewed parton distributions in the DGLAP region, discuss the stability of the code and reproduce the LO diagonal evolution within less than 0.5% of the original CTEQ-code. In chapter 4, we show that factorization holds for the deeply virtual Compton scattering amplitude in QCD, up to power suppressed terms, to all orders in perturbation theory. In chapter 5, we demonstrate that perturbative QCD allows one to calculate the absolute cross section of diffractive, exclusive production of photons (DVCS) at large Q^2 at HERA, while the aligned jet model allows one to estimate the cross section for intermediate Q^2 ˜ 2 GeV^2. We find a significant DVCS counting rate for the current generation of experiments at HERA and a large azimuthal angle asymmetry for HERA kinematics. In the last chapter, we propose a new methodology of gaining shape fits to skewed parton distributions and, for the first time, to determine the ratio of the real to imaginary part of the DIS amplitude. We do this by using several recent fits to F_2(x,Q^2) to compute the asymmetry A for the combined DVCS and Bethe-Heitler cross section. In the appendix, we give an application of distributional methods as discussed abstractly in chapter 4.

  11. Variable focus crystal diffraction lens

    SciTech Connect

    Smither, R.K.

    1988-11-01

    A new method has been developed to control the shape of the surface of a diffracting crystal that will allow it to function as a variable focus crystal diffraction lens, for focusing photon beams from a synchrotron source. The new method uses thermal gradients in the crystal to control the shape of the surface of the crystal in two dimensions and allows one to generate both spherical and ellipsoidal surface shapes. In this work the thermal gradient was generated by core drilling two sets of cooling channels in a silicon crystal so that cooling or heating fluids could be circulated through the crystal at two different levels. The first set of channels is close to the surface of the crystal where the photon beam strikes it. The second set of channels is equal distant from the back surface. If a concave surface is desired, the fluid in the channels just below the surface exposed to the beam is cooler than the fluid circulating through the channels near the back surface. If a convex surface is desired, then the cooling fluid in the upper channels near the surface exposed to the incident photon beam, is warmer than the fluid in the lower channels. The focal length of the crystal lens is varied by varying the thermal gradient in the crystal. This approach can also be applied to the first crystal in a high power synchrotron beam line to eliminate the bowing and other thermal distortions of the crystal caused by the high heat load. 6 refs., 8 figs., 3 tabs.

  12. Future of Electron Scattering and Diffraction

    SciTech Connect

    Hall, Ernest; Stemmer, Susanne; Zheng, Haimei; Zhu, Yimei; Maracas, George

    2014-02-25

    The ability to correlate the atomic- and nanoscale-structure of condensed matter with physical properties (e.g., mechanical, electrical, catalytic, and optical) and functionality forms the core of many disciplines. Directing and controlling materials at the quantum-, atomic-, and molecular-levels creates enormous challenges and opportunities across a wide spectrum of critical technologies, including those involving the generation and use of energy. The workshop identified next generation electron scattering and diffraction instruments that are uniquely positioned to address these grand challenges. The workshop participants identified four key areas where the next generation of such instrumentation would have major impact: A – Multidimensional Visualization of Real Materials B – Atomic-scale Molecular Processes C – Photonic Control of Emergence in Quantum Materials D – Evolving Interfaces, Nucleation, and Mass Transport Real materials are comprised of complex three-dimensional arrangements of atoms and defects that directly determine their potential for energy applications. Understanding real materials requires new capabilities for three-dimensional atomic scale tomography and spectroscopy of atomic and electronic structures with unprecedented sensitivity, and with simultaneous spatial and energy resolution. Many molecules are able to selectively and efficiently convert sunlight into other forms of energy, like heat and electric current, or store it in altered chemical bonds. Understanding and controlling such process at the atomic scale require unprecedented time resolution. One of the grand challenges in condensed matter physics is to understand, and ultimately control, emergent phenomena in novel quantum materials that necessitate developing a new generation of instruments that probe the interplay among spin, charge, orbital, and lattice degrees of freedom with intrinsic time- and length-scale resolutions. Molecules and soft matter require imaging and

  13. Quantum Physics

    NASA Astrophysics Data System (ADS)

    Le Bellac, Michel

    2006-03-01

    Quantum physics allows us to understand the nature of the physical phenomena which govern the behavior of solids, semi-conductors, lasers, atoms, nuclei, subnuclear particles and light. In Quantum Physics, Le Bellac provides a thoroughly modern approach to this fundamental theory. Throughout the book, Le Bellac teaches the fundamentals of quantum physics using an original approach which relies primarily on an algebraic treatment and on the systematic use of symmetry principles. In addition to the standard topics such as one-dimensional potentials, angular momentum and scattering theory, the reader is introduced to more recent developments at an early stage. These include a detailed account of entangled states and their applications, the optical Bloch equations, the theory of laser cooling and of magneto-optical traps, vacuum Rabi oscillations, and an introduction to open quantum systems. This is a textbook for a modern course on quantum physics, written for advanced undergraduate and graduate students. Completely original and contemporary approach, using algebra and symmetry principles Introduces recent developments at an early stage, including many topics that cannot be found in standard textbooks. Contains 130 physically relevant exercises

  14. The Impact of Physical Maltreatment History on the Adolescent Mother-Infant Relationship: Mediating and Moderating Effects during the Transition to Early Parenthood

    ERIC Educational Resources Information Center

    Milan, Stephanie; Lewis, Jessica; Ethier, Kathleen; Kershaw, Trace; Ickovics, Jeannette R.

    2004-01-01

    Using attachment theory as a framework, this paper examines how pregnant adolescents' experiences of physical maltreatment during childhood influence the subsequent mother-infant relationship in 203 low-income adolescents followed from the 3rd trimester of pregnancy through the 1st year of parenthood. The relation between physical maltreatment…

  15. Applications of diffraction theory to aeroacoustics

    NASA Technical Reports Server (NTRS)

    Lansing, D. L.; Chen-Huei, L.; Norum, T. D.

    1979-01-01

    A review is given of the fundamentals of diffraction theory and the application of the theory to several problems of aircraft noise generation, propagation, and measurement. The general acoustic diffraction problem is defined and the governing equations set down. Diffraction phenomena are illustrated using the classical problem of the diffraction of a plane wave by a half-plane. Infinite series and geometric acoustic methods for solving diffraction problems are described. Four applications of diffraction theory are discussed: the selection of an appropriate shape for a microphone, the use of aircraft wings to shield the community from engine noise, the reflection of engine noise from an aircraft fuselage and the radiation of trailing edge noise.

  16. Hard diffraction with dynamic gap survival

    NASA Astrophysics Data System (ADS)

    Rasmussen, Christine O.; Sjöstrand, Torbjörn

    2016-02-01

    We present a new framework for the modelling of hard diffraction in pp and poverline{p} collisions. It starts from the the approach pioneered by Ingelman and Schlein, wherein the single diffractive cross section is factorized into a Pomeron flux and a Pomeron PDF. To this it adds a dynamically calculated rapidity gap survival factor, derived from the modelling of multiparton interactions. This factor is not relevant for diffraction in ep collisions, giving non-universality between HERA and Tevatron diffractive event rates. The model has been implemented in P ythia 8 and provides a complete description of the hadronic state associated with any hard single diffractive process. Comparisons with poverline{p} and pp data reveal improvement in the description of single diffractive events.

  17. Fraunhofer diffraction of light by human enamel.

    PubMed

    O'Brien, W J

    1988-02-01

    Fraunhofer diffraction patterns of human enamel samples were photographed with a helium-neon laser beam (lambda = 633 nm). The first-order diffraction angle was in reasonable agreement with a prediction based upon enamel prisms acting as a two-dimensional grating. These results support the hypothesis that enamel diffracts light because of the periodic structure of enamel prisms with interprismatic spaces, which act as slits.

  18. Twenty years of diffraction at the Tevatron

    SciTech Connect

    Goulianos, K.; /Rockefeller U.

    2005-10-01

    Results on diffractive particle interactions from the Fermilab Tevatron {bar p}p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held.

  19. Diffraction gratings used as identifying markers

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1991-03-26

    A finely detailed diffraction grating is applied to an object as an identifier or tag which is unambiguous, difficult to duplicate, or remove and transfer to another item, and can be read and compared with prior readings with relative ease. The exact pattern of the diffraction grating is mapped by diffraction moire techniques and recorded for comparison with future readings of the same grating. 7 figures.

  20. Aircraft noise propagation. [sound diffraction by wings

    NASA Technical Reports Server (NTRS)

    Hadden, W. J.; Pierce, A. D.

    1978-01-01

    Sound diffraction experiments conducted at NASA Langley Research Center to study the acoustical implications of the engine over wing configuration (noise-shielding by wing) and to provide a data base for assessing various theoretical approaches to the problem of aircraft noise reduction are described. Topics explored include the theory of sound diffraction around screens and wedges; the scattering of spherical waves by rectangular patches; plane wave diffraction by a wedge with finite impedence; and the effects of ambient flow and distribution sources.

  1. Coherent diffractive imaging and partial coherence

    NASA Astrophysics Data System (ADS)

    Williams, Garth J.; Quiney, Harry M.; Peele, Andrew G.; Nugent, Keith A.

    2007-03-01

    We formulate coherent diffractive imaging in the framework of partially spatially coherent diffraction. We find that the reconstruction can be critically dependent on the degree of coherence in the illuminating field and that even a small departure from full coherence may invalidate the conventional assumption that a mapping exists between an exit surface wave of finite support and a far field diffraction pattern. We demonstrate that the introduction of sufficient phase curvature in the illumination can overcome the adverse effects of partial coherence.

  2. Convex Diffraction Grating Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Chrisp, Michael P. (Inventor)

    1999-01-01

    A 1:1 Offner mirror system for imaging off-axis objects is modified by replacing a concave spherical primary mirror that is concentric with a convex secondary mirror with two concave spherical mirrors M1 and M2 of the same or different radii positioned with their respective distances d1 and d2 from a concentric convex spherical diffraction grating having its grooves parallel to the entrance slit of the spectrometer which replaces the convex secondary mirror. By adjusting their distances d1 and d2 and their respective angles of reflection alpha and beta, defined as the respective angles between their incident and reflected rays, all aberrations are corrected without the need to increase the spectrometer size for a given entrance slit size to reduce astigmatism, thus allowing the imaging spectrometer volume to be less for a given application than would be possible with conventional imaging spectrometers and still give excellent spatial and spectral imaging of the slit image spectra over the focal plane.

  3. What Phase Matters for Diffraction?

    NASA Astrophysics Data System (ADS)

    Jones, Eric; Bach, Roger; Batelaan, Herman

    2014-05-01

    Young's double-slit experiment for matter is often compared to that of optics. In rudimentary explanations of the locations of the diffraction maxima and minima far from the slits, paths are sometimes superimposed over waves drawn from the two slits to the detection screen, leading to a phase difference of Δϕ = 2 πΔL /λdB between paths. Despite the intuitive connection of the two kinds of wave phenomena, this approach can lead to a misunderstanding of the theory for matter waves. The Feynman path-integral formalism justifies the use of paths to determine the phase difference; however, the phase accumulated along single free-particle paths according to the formalism is not ϕ = 2 πL /λdB , even though the expression for the phase difference is correct. The resulting factor of 2 difference in the single path phase from the intuitive value arises from the particular treatment of time-dependence in interpreting the problem. The nature of this misunderstanding will be discussed, and a possible resolution proposed based on the quantum mechanical principle of indistinguishability: the time duration of all interfering paths must be equal. We gratefully acknowledge support from the NSF.

  4. Large aperture diffractive space telescope

    DOEpatents

    Hyde, Roderick A.

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  5. Diffractively corrected counter-rotating Risley prisms.

    PubMed

    Nie, Xin; Yang, Hongfang; Xue, Changxi

    2015-12-10

    Using the vector refraction equation and the vector diffraction equation, we obtain the expressions of the direction cosines of the refractive rays for the two wedge prisms, and the direction cosines of the diffractive rays for two wedge grisms, in which diffractive gratings were etched into the prism faces to correct the chromatic aberrations. A mathematical model between the two vector equations is proposed to compare the difference angle chromatic aberrations when the Risley prisms/grisms are rotating at different angles. We conclude that the use of diffractively corrected prisms offers a new method to correct chromatic aberrations in Risley prisms. PMID:26836873

  6. Broadband beam shaping with harmonic diffractive optics.

    PubMed

    Singh, Manisha; Tervo, Jani; Turunen, Jari

    2014-09-22

    We consider spatial shaping of broadband (either stationary or pulsed) spatially coherent light, comparing refractive, standard diffractive, and harmonic diffractive (modulo 2πM) elements. Considering frequency-integrated target profiles we show that, contrary to common belief, standard diffractive (M = 1) elements work reasonably well for, e.g., Gaussian femtosecond pulses and spatially coherent amplified-spontaneous-emission sources such as superluminescent diodes. It is also shown that harmonic elements with M ≥ 5 behave in essentially the same way as refractive elements and clearly outperform standard diffractive elements for highly broadband light.

  7. Results on hard diffraction from CDF

    SciTech Connect

    Goulianos, K.

    1997-05-01

    We present results from studies of hard diffractive processes in {anti p}p collisions at {radical}s=1.8 TeV at the Tevatron using the CDF detector. Diffractive events are identified by the characteristic signature of a rapidity gap and/or by detecting a recoil antiproton with high forward momentum. Reactions studied include the diffractive production of W-bosons and of two-jet (dijet) events, diffractive heavy quark production, and dijet production by double-pomeron exchange.

  8. Diffractive Imaging Using Partially Coherent X Rays

    NASA Astrophysics Data System (ADS)

    Whitehead, L. W.; Williams, G. J.; Quiney, H. M.; Vine, D. J.; Dilanian, R. A.; Flewett, S.; Nugent, K. A.; Peele, A. G.; Balaur, E.; McNulty, I.

    2009-12-01

    The measured spatial coherence characteristics of the illumination used in a diffractive imaging experiment are incorporated in an algorithm that reconstructs the complex transmission function of an object from experimental x-ray diffraction data using 1.4 keV x rays. Conventional coherent diffractive imaging, which assumes full spatial coherence, is a limiting case of our approach. Even in cases in which the deviation from full spatial coherence is small, we demonstrate a significant improvement in the quality of wave field reconstructions. Our formulation is applicable to x-ray and electron diffraction imaging techniques provided that the spatial coherence properties of the illumination are known or can be measured.

  9. Catastrophe optics of sharp-edge diffraction.

    PubMed

    Borghi, Riccardo

    2016-07-01

    A classical problem of diffraction theory, namely plane wave diffraction by sharp-edge apertures, is here reformulated from the viewpoint of the fairly new subject of catastrophe optics. On using purely geometrical arguments, properly embedded into a wave optics context, uniform analytical estimates of the diffracted wavefield at points close to fold caustics are obtained, within paraxial approximation, in terms of the Airy function and its first derivative. Diffraction from parabolic apertures is proposed to test reliability and accuracy of our theoretical predictions.

  10. Electron Diffraction Using Transmission Electron Microscopy

    PubMed Central

    Bendersky, Leonid A.; Gayle, Frank W.

    2001-01-01

    Electron diffraction via the transmission electron microscope is a powerful method for characterizing the structure of materials, including perfect crystals and defect structures. The advantages of electron diffraction over other methods, e.g., x-ray or neutron, arise from the extremely short wavelength (≈2 pm), the strong atomic scattering, and the ability to examine tiny volumes of matter (≈10 nm3). The NIST Materials Science and Engineering Laboratory has a history of discovery and characterization of new structures through electron diffraction, alone or in combination with other diffraction methods. This paper provides a survey of some of this work enabled through electron microscopy. PMID:27500060

  11. Broadband diffractive lens or imaging element

    DOEpatents

    Ceglio, Natale M.; Hawryluk, Andrew M.; London, Richard A.; Seppala, Lynn G.

    1991-01-01

    A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed.

  12. Broadband diffractive lens or imaging element

    DOEpatents

    Ceglio, Natale M.; Hawryluk, Andrew M.; London, Richard A.; Seppala, Lynn G.

    1993-01-01

    A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed. Thin film embodiments are described.

  13. Diffractively corrected counter-rotating Risley prisms.

    PubMed

    Nie, Xin; Yang, Hongfang; Xue, Changxi

    2015-12-10

    Using the vector refraction equation and the vector diffraction equation, we obtain the expressions of the direction cosines of the refractive rays for the two wedge prisms, and the direction cosines of the diffractive rays for two wedge grisms, in which diffractive gratings were etched into the prism faces to correct the chromatic aberrations. A mathematical model between the two vector equations is proposed to compare the difference angle chromatic aberrations when the Risley prisms/grisms are rotating at different angles. We conclude that the use of diffractively corrected prisms offers a new method to correct chromatic aberrations in Risley prisms.

  14. Broadband diffractive lens or imaging element

    DOEpatents

    Ceglio, N.M.; Hawryluk, A.M.; London, R.A.; Seppala, L.G.

    1993-10-26

    A broadband diffractive lens or imaging element produces a sharp focus and/or a high resolution image with broad bandwidth illuminating radiation. The diffractive lens is sectored or segmented into regions, each of which focuses or images a distinct narrowband of radiation but all of which have a common focal length. Alternatively, a serial stack of minus filters, each with a diffraction pattern which focuses or images a distinct narrowband of radiation but all of which have a common focal length, is used. The two approaches can be combined. Multifocal broadband diffractive elements can also be formed. Thin film embodiments are described. 21 figures.

  15. [Effect of the depth of myocardial infarction on the tolerance to physical exertion and hemodynamics in patients in the early rehabilitation period].

    PubMed

    Baĭdun, S

    1991-06-01

    Veloergometry (VEM) with determination of the threshold load power and indices of the hemodynamics in 135 patients with a varying depth of myocardial infarction (MI) with an uncomplicated course showed that the presence of asymptomatic coronary insufficiency limiting the tolerance to physical load does not allow to evaluate the physical state depending on the MI depth. Hemodynamic provision in loads and rest is determined by the functional state of the myocardium and does not always depend on the MI depth. VEM and determination of hemodynamic indices is of importance for revealing difference in the physical working capacity of patients with different MI depth, asymptomatic coronary insufficiency in patients with uncomplicated MI.

  16. General Reading on Early Adolescence.

    ERIC Educational Resources Information Center

    North Carolina Univ., Chapel Hill. Center for Early Adolescence.

    This brief resource list of books and articles on early adolescent physical, social, and intellectual development mentions materials relating to psychology, religion, employment, and parent participation. (BJD)

  17. Obesity, Physical Activity - Children.

    ERIC Educational Resources Information Center

    Gilliam, Thomas B.

    Childhood obesity starts at a very early age, and preventive measures taken early enough may retard the development of fat cells. It appears that physical activity plays an important role in reducing obesity. The activity program must start early, in preschool days. It is felt that screening children for obesity when they first enter school and…

  18. Exclusive, hard diffraction in QCD

    NASA Astrophysics Data System (ADS)

    Freund, Andreas

    In the first chapter we give an introduction to hard diffractive scattering in QCD to introduce basic concepts and terminology, thus setting the stage for the following chapters. In the second chapter we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the CTEQ-package and comment on the range of applicability of the LLA in the asymmetric regime. We show that the nondiagonal gluon distribution g(x1,x2,t,μ2) can be well approximated at small x by the conventional gluon density xG(x,μ2). In the third chapter, we discuss the algorithms used in the LO evolution program for nondiagonal parton distributions in the DGLAP region and discuss the stability of the code. Furthermore, we demonstrate that we can reproduce the case of the LO diagonal evolution within less than 0.5% of the original code as developed by the CTEQ-collaboration. In chapter 4, we show that factorization holds for the deeply virtual Compton scattering amplitude in QCD, up to power suppressed terms, to all orders in perturbation theory. Furthermore, we show that the virtuality of the produced photon does not influence the general theorem. In chapter 5, we demonstrate that perturbative QCD allows one to calculate the absolute cross section of diffractive exclusive production of photons at large Q2 at HERA, while the aligned jet model allows one to estimate the cross section for intermediate Q2~2GeV2. Furthermore, we find that the imaginary part of the amplitude for the production of real photons is larger than the imaginary part of the corresponding DIS amplitude, leading to predictions of a significant counting rate for the current generation of experiments at HERA. We also find a large azimuthal angle asymmetry in ep scattering for HERA kinematics which allows one to directly measure the real part of the DVCS amplitude and hence the

  19. Calculation of the diffraction efficiency on concave gratings based on Fresnel-Kirchhoff's diffraction formula.

    PubMed

    Huang, Yuanshen; Li, Ting; Xu, Banglian; Hong, Ruijin; Tao, Chunxian; Ling, Jinzhong; Li, Baicheng; Zhang, Dawei; Ni, Zhengji; Zhuang, Songlin

    2013-02-10

    Fraunhofer diffraction formula cannot be applied to calculate the diffraction wave energy distribution of concave gratings like plane gratings because their grooves are distributed on a concave spherical surface. In this paper, a method based on the Kirchhoff diffraction theory is proposed to calculate the diffraction efficiency on concave gratings by considering the curvature of the whole concave spherical surface. According to this approach, each groove surface is divided into several limited small planes, on which the Kirchhoff diffraction field distribution is calculated, and then the diffraction field of whole concave grating can be obtained by superimposition. Formulas to calculate the diffraction efficiency of Rowland-type and flat-field concave gratings are deduced from practical applications. Experimental results showed strong agreement with theoretical computations. With the proposed method, light energy can be optimized to the expected diffraction wave range while implementing aberration-corrected design of concave gratings, particularly for the concave blazed gratings.

  20. Characterization of the diffraction properties of quantum-dot-array diffraction grating

    SciTech Connect

    Wang Chuanke; Kuang Longyu; Wang Zhebin; Liu Shenye; Ding Yongkun; Cao Leifeng; Foerster, Eckhart; Wang Deqiang; Xie Changqing; Ye Tianchun

    2007-05-15

    A new dispersive element named as quantum-dot-array diffraction grating [L. F. Cao, China patent No. 200410081499 (August 10, 2004)] for visible light has been developed and characterized experimentally. A large number of quantum dots distributed on a substrate as sinusoidal function can be used to diffract x rays without higher-order diffraction. The experimental patterns show that the higher-order diffractions which inevitably exist in the spectrum recorded using traditional diffraction gratings can be eliminated effectively by this newly designed element. It indicates that quantum-dot-array diffraction grating could be an attractive alternative of presently used diffraction grating in soft x-ray spectroscopy application to get rid of the higher-order diffraction distortions.

  1. [Appearance of pathologic diastolic impedance wave during exercise test as a sign of physical exertion intolerance in patients in the early period of myocardial infarction].

    PubMed

    Al'khimovich, V M

    1988-07-01

    A review of the results of bicycle ergometry under continuous electrocardiographic monitoring and chest rheograms in 316 males of able age, including 115 patients with early myocardial infarction, demonstrated that inadequate hemodynamic support (transitory heart failure), emerging during exercise in 45.2% of patients with early myocardial infarction, was reflected in considerably increased diastolic wave amplitude. Since some of the patients exhibited no electrocardiographic ischemic changes at testing, the emergence of an abnormal diastolic impedance wave may serve as an objective indicator of stress intolerance.

  2. Diffraction profile synthesis applied to offset dual reflector antennas

    NASA Astrophysics Data System (ADS)

    Henderson, R. I.

    1985-05-01

    During the last 15 years, in work carried out at a research center, the physical optics method has been applied directly to the synthesis process itself. It is pointed out that the results of this method, known as Diffraction Profile Synthesis (DPS), are Cassegrain antennas with efficiencies superior to those of any ray optics design. Thus, the reflectors generated by this process realize the theoretical maximum efficiency for any given size of antenna. Attention is given to the diffraction profile synthesis, the extension of DPS, spherical wave expansions, the application to offset reflectors, the main reflector focussed field, the near-field feed pattern, reflector perturbations, profile smoothing, high efficiency offset Gregorian, the offset Gregorian with Hansen distribution, and the low sidelobe elliptical antenna.

  3. Fresnel coherent diffractive imaging: treatment and analysis of data

    NASA Astrophysics Data System (ADS)

    Williams, G. J.; Quiney, H. M.; Peele, A. G.; Nugent, K. A.

    2010-03-01

    Fresnel coherent diffractive imaging (FCDI) is a relatively recent addition to the suite of imaging tools available at third generation x-ray sources. It shares the strengths of other coherent diffractive techniques: resolution limits that are independent of focusing optics, single-plane measurement and high dose efficiency. The more challenging experimental geometry and detailed reconstruction algorithms of FCDI provide enhanced numerical stability and convergence properties to the iterative algorithms commonly used. Experimentally, a diverging beam is utilized, which facilitates sample alignment and allows the imaging of extended samples. We describe the underlying physics and assumptions that give rise to the FCDI iterative reconstruction algorithms, as well as their implications for the design of a successful FCDI experiment.

  4. White-Light Diffraction with a CD

    ERIC Educational Resources Information Center

    Ivanov, Dragia Trifonov; Nikolaev, Stefan

    2010-01-01

    Various wave optics experiments can be carried out using an ordinary compact disc. The CD is suitable for use as a diffraction grating. For instance, a standard CD (700 MB) has 625 lines/mm. In this article, the authors describe two white-light diffraction demonstrations for a large audience, realizable using a CD (as reflection or transmission…

  5. RENORM predictions of diffraction at LHC confirmed

    SciTech Connect

    Goulianos, Konstantin

    2015-04-10

    The RENORM model predictions of diffractive, total, and total-inelastic cross sections at the LHC are confirmed by recent measurements. The predictions of several other available models are discussed, highlighting their differences from RENORM, mainly arising from the way rapidity gap formation, low- and high-mass diffraction, unitarization, and hadronization are implemented.

  6. Electron Diffraction Experiments using Laser Plasma Electrons

    SciTech Connect

    Fill, E E; Trushin, S; Tommasini, R; Bruch, R

    2005-09-07

    We demonstrate that electrons emitted from a laser plasma can be used to generate diffraction patterns in reflection and transmission. The electrons are emitted in the direction of laser polarization with energies up to 100 keV. The broad electron energy spectrum makes possible the generation of a ''streaked'' diffraction pattern which allows recording fast processes in a single run.

  7. Diffraction experiments with infrared remote controls

    NASA Astrophysics Data System (ADS)

    Kuhn, Jochen; Vogt, Patrik

    2012-02-01

    In this paper we describe an experiment in which radiation emitted by an infrared remote control is passed through a diffraction grating. An image of the diffraction pattern is captured using a cell phone camera and then used to determine the wavelength of the radiation.

  8. An Improved Diffraction Grating Spectroscope Experiment.

    ERIC Educational Resources Information Center

    Scherzer, Robert

    1995-01-01

    Discusses problems associated with standard diffraction grating experiments involving a diffraction grating, a straight meter stick, and a slit. Describes the use of a new spectroscope to overcome these problems using a curved scale to simplify calculations and help students obtain results from simple and straightforward measurements, thus giving…

  9. CMS results on exclusive and diffractive production

    SciTech Connect

    Alves, Gilvan A.

    2015-04-10

    We present recent CMS measurements of diffractive and exclusive processes, using data collected at 7 TeV at the LHC. Measurements of soft single- and double-diffractive cross sections are presented, as well as measurements of photon-induced processes including studies of exclusive WW production via photon-photon exchange.

  10. Liquid-Crystal Point-Diffraction Interferometer

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.

    1996-01-01

    Liquid-crystal point-diffraction interferometer (LCPDI) invented to combine flexible control of liquid-crystal phase-shifts with robustness of point-diffraction interferometers. Produces interferograms indicative of shapes of wavefronts of laser beams having passed through or reflected from objects of interest. Interferograms combined in computers to produce phase maps describing wavefronts.

  11. Radiometric analysis of diffraction of quasi-homogenous optical fields

    NASA Astrophysics Data System (ADS)

    Castaneda, Roman; Carrasquilla, Juan; Herrera, Jorge

    2007-05-01

    A description of Fresnel and Fraunhofer diffraction of quasi-homogenous optical fields in any state of spatial coherence is presented, which clearly differs from the classical formalism. Instead of the propagation of the cross-spectral density from the diffracting aperture to the observation plane, the diffracting aperture is regarded as a planar quasi-homogeneous source, whose generalised radiance is carried by the spatial coherence wavelets, and the power distribution at the observation plane is expressed in terms of the generalised radiant intensity. It allows interpreting the negative values of the generalised radiance as "negative energies" emitted along specific directions and subjected to the achievement of the conservation law of energy. This interpretation is not evident in the classical formalism. Consequently, interference can be thought as resulting of energy transfer over a given wavefront, due to the addition of equal amounts of "positive" and "negative" energies, along specific directions, to the contributions provided by the individual radiators of the radiant source. In this sense, the radiant flux from the source, which is provided only by the individual contributions, is redistributed depending on the spatial coherence properties of the field. This redistribution characterises the diffraction phenomenon. It is also shown that the supports of the complex degree of spatial coherence near the aperture edge are vignetted by the edge. This feature is a cause for the generalised radiance providing "negative energies", and constitutes the actual effect of the edge on diffraction. The approach is validated by the close concordance between the numerical and the experimental results, which should be regarded as a proof of the physical existence of the spatial coherence wavelets.

  12. Fraunhofer diffraction by arbitrary-shaped obstacles.

    PubMed

    Malinka, Aleksey V; Zege, Eleonora P

    2009-08-01

    We consider Fraunhofer diffraction by an ensemble of large arbitrary-shaped screens that are randomly oriented in the plane of a wavefront and have edges of arbitrary shape. It is shown that far outside the main diffraction peak the differential scattering cross section behaves asymptotically as theta(-3), where theta is the diffraction angle. Moreover, the differential scattering cross section depends only on the length of the contours bordering the screens and does not depend on the shape of the obstacles. As both strictly forward and total diffraction cross sections are specified by obstacle area only, the differential cross section of size-distributed obstacles is expected to be nearly independent of obstacle shape over the entire region of the diffraction angles.

  13. Crystal structure refinement from electron diffraction data

    SciTech Connect

    Dudka, A. P. Avilov, A. S.; Lepeshov, G. G.

    2008-05-15

    A procedure of crystal structure refinement from electron diffraction data is described. The electron diffraction data on polycrystalline films are processed taking into account possible overlap of reflections and two-beam interaction. The diffraction from individual single crystals in an electron microscope equipped with a precession attachment is described using the Bloch-wave method, which takes into account multibeam scattering, and a special approach taking into consideration the specific features of the diffraction geometry in the precession technique. Investigations were performed on LiF, NaF, CaF{sub 2}, and Si crystals. A method for reducing experimental data, which allows joint electron and X-ray diffraction study, is proposed.

  14. Experimental results on diffraction at CDF

    SciTech Connect

    Gallinaro, Michele; /Rockefeller U. /Lisbon, LIFEP

    2010-09-01

    Diffractive events are studied by means of identification of one or more rapidity gaps and/or a leading antiproton. Measurements of soft and hard diffractive processes have been performed at the Tevatron p{bar p} collider and presented. We report on the diffractive structure function obtained from dijet production in the range 0 < Q{sup 2} < 10,000 GeV{sup 2}, and on the |t| distribution in the region 0 < |t| < 1 GeV{sup 2} for both soft and hard diffractive events up to Q{sup 2} {approx} 4,500 GeV{sup 2}. Results on single diffractive W/Z production, forward jets, and central exclusive production of both dijets and Z-bosons are also presented.

  15. Vector diffraction analysis of optical disk readout.

    PubMed

    Cheng, X; Jia, H; Xu, D

    2000-12-01

    The optical disk readout signals from ROM disks are presented by use of a rigorous three-dimensional vector diffraction method. The optical disk is modeled as a crossed metal grating without restriction on the form of the information marks, and the permittivity of the metal is taken into account. The diffracted field from the disk is obtained by means of decomposing the focused incident beam into a spectrum of plane waves and then calculating the diffracted plane waves for each respective incident component. The readout signal is obtained by integration of the energy-flux density of the diffracted field according to the detection scheme of the optical disk system. A typical digital versatile disk (DVD) system is applied with this theory, and the result is far from that of scalar diffraction theory. PMID:18354657

  16. Femtosecond diffractive imaging of biological cells

    NASA Astrophysics Data System (ADS)

    Marvin Seibert, M.; Boutet, Sébastien; Svenda, Martin; Ekeberg, Tomas; Maia, Filipe R. N. C.; Bogan, Michael J.; Tîmneanu, Nicusor; Barty, Anton; Hau-Riege, Stefan; Caleman, Carl; Frank, Matthias; Benner, Henry; Y Lee, Joanna; Marchesini, Stefano; Shaevitz, Joshua W.; Fletcher, Daniel A.; Bajt, Sasa; Andersson, Inger; Chapman, Henry N.; Hajdu, Janos

    2010-10-01

    In a flash diffraction experiment, a short and extremely intense x-ray pulse illuminates the sample to obtain a diffraction pattern before the onset of significant radiation damage. The over-sampled diffraction pattern permits phase retrieval by iterative phasing methods. Flash diffractive imaging was first demonstrated on an inorganic test object (Chapman et al 2006 Nat. Phys. 2 839-43). We report here experiments on biological systems where individual cells were imaged, using single, 10-15 fs soft x-ray pulses at 13.5 nm wavelength from the FLASH free-electron laser in Hamburg. Simulations show that the pulse heated the sample to about 160 000 K but not before an interpretable diffraction pattern could be obtained. The reconstructed projection images return the structures of the intact cells. The simulations suggest that the average displacement of ions and atoms in the hottest surface layers remained below 3 Å during the pulse.

  17. Genetic algorithm for chromaticity correction in diffraction limited storage rings

    NASA Astrophysics Data System (ADS)

    Ehrlichman, M. P.

    2016-04-01

    A multiobjective genetic algorithm is developed for optimizing nonlinearities in diffraction limited storage rings. This algorithm determines sextupole and octupole strengths for chromaticity correction that deliver optimized dynamic aperture and beam lifetime. The algorithm makes use of dominance constraints to breed desirable properties into the early generations. The momentum aperture is optimized indirectly by constraining the chromatic tune footprint and optimizing the off-energy dynamic aperture. The result is an effective and computationally efficient technique for correcting chromaticity in a storage ring while maintaining optimal dynamic aperture and beam lifetime.

  18. News and Views: New books to look out for; Prizes waiting for environmental physics essays; Meeting encourages early career scientists; A cosmological challenge

    NASA Astrophysics Data System (ADS)

    2008-12-01

    The RAS is pleased to announce the publication of the first book in its new publishing venture, the RAS Series. The UK Planetary Forum held its sixth Early Career Scientists' Meeting at University College London on 3 November 2008. 50 researchers attended, presenting and discussing their research, and making the contacts essential for future success. Katherine Joy, Vic Pearson and Caroline Smith report.

  19. Why Won't My Torch Work? Physics for 4 to 8 Year Olds. Australian Early Childhood Resource Booklets No. 1.

    ERIC Educational Resources Information Center

    Fleer, Marilyn

    Young children in Australia enter early childhood education settings eager to make sense of the world that surrounds them. Their interest in every day experiences is evident in the range of questions asked, many of which are scientific in nature. Intended as a resource for adults working with 4-to 8-year-old children, this booklet provides an…

  20. Early impact of the federally mandated Local Wellness Policy on physical activity in rural, low-income elementary schools in Colorado.

    PubMed

    Belansky, Elaine S; Cutforth, Nick; Delong, Erin; Ross, Courtney; Scarbro, Sharon; Gilbert, Lynn; Beatty, Bridget; Marshall, Julie A

    2009-01-01

    The What's Working project described the initial impact of the United States' federally mandated Local Wellness Policy in rural, low-income elementary schools located in Colorado. Before and after the Local Wellness Policy mandate went into effect, a survey about school features related to nutrition and physical activity was sent to a random sample of 45 rural elementary schools (i.e., schools located outside of urban areas), in which at least 40% of students qualified for free or reduced-cost lunch. Overall, opportunities for physical activity did not change after the policy went into effect: although time in physical education increased by 14 min per week (P=0.10), time for recess decreased by roughly 19 min per week (P=0.10). Policies supporting student participation in physical education and recess (an unstructured time during school hours when students are allowed to play outside) did not change. The researchers coded Local Wellness Policies and found them to have weak wording that produced minimal impact. Content analysis of key informant interviews suggested several barriers to the impact of the Local Wellness Policies: (1) competing pressures facing school districts, (2) lack of resources devoted to the Local Wellness Policy, (3) principals' lack of knowledge about the policy, and (4) lack of accountability mechanisms to ensure policy implementation. Financial resources and more effective communication about Local Wellness Policies among school districts and principals are needed to elevate the importance of and increase opportunities for physical activity in rural, low-income Colorado elementary schools.

  1. Design and Development of Binary Diffractive Germanium Lens by Thin Film Deposition

    NASA Astrophysics Data System (ADS)

    Alshami, M.; Wabby, A.; Mousselly, M. F.

    2015-11-01

    The design and development of infrared (λ: [8]-[12] μm) binary diffractive germanium lens (BDGL) by two - steps thin film deposition (Physical vapor deposition (PVD) technique) is presented. The optical design of the required elements using the optical design code Zemax, the design of the 4 steps binary surface and its required metallic masks using the programming language Delphi, the procedures of fabrication, and the measurement of the resulting profile, were presented. The comparison between the refractive/diffractive lenses by measuring the minimum resolvable temperature difference (MRTD) shows the advantages of binary diffractive surface.

  2. Remote Laser Diffraction Particle Size Distribution Analyzer

    SciTech Connect

    Batcheller, Thomas Aquinas; Huestis, Gary Michael; Bolton, Steven Michael

    2001-03-01

    In support of a radioactive slurry sampling and physical characterization task, an “off-the-shelf” laser diffraction (classical light scattering) particle size analyzer was utilized for remote particle size distribution (PSD) analysis. Spent nuclear fuel was previously reprocessed at the Idaho Nuclear Technology and Engineering Center (INTEC—formerly recognized as the Idaho Chemical Processing Plant) which is on DOE’s INEEL site. The acidic, radioactive aqueous raffinate streams from these processes were transferred to 300,000 gallon stainless steel storage vessels located in the INTEC Tank Farm area. Due to the transfer piping configuration in these vessels, complete removal of the liquid can not be achieved. Consequently, a “heel” slurry remains at the bottom of an “emptied” vessel. Particle size distribution characterization of the settled solids in this remaining heel slurry, as well as suspended solids in the tank liquid, is the goal of this remote PSD analyzer task. A Horiba Instruments Inc. Model LA-300 PSD analyzer, which has a 0.1 to 600 micron measurement range, was modified for remote application in a “hot cell” (gamma radiation) environment. This technology provides rapid and simple PSD analysis, especially down in the fine and microscopic particle size regime. Particle size analysis of these radioactive slurries down in this smaller range was not previously achievable—making this technology far superior than the traditional methods used. Successful acquisition of this data, in conjunction with other characterization analyses, provides important information that can be used in the myriad of potential radioactive waste management alternatives.

  3. Transmittance analysis of diffraction phase grating.

    PubMed

    Jing, Xufeng; Jin, Yunxia

    2011-03-20

    In order to accurately analyze and design the transmittance characteristic of a diffraction phase grating, the validity of both the scalar diffraction theory and the effective medium theory is quantitatively evaluated by the comparison of diffraction efficiencies predicted from both simplified theories to exact results calculated by the rigorous vector electromagnetic theory. The effect of surface profile parameters, including the normalized period, the normalized depth, and the fill factor for the precision of the simplified methods is determined at normal incidence. It is found that, in general, when the normalized period is more than four wavelengths of the incident light, the scalar diffraction theory is useful to estimate the transmittance of the phase grating. When the fill factor approaches 0.5, the error of the scalar method is minimized, and the scalar theory is accurate even at the grating period of two wavelengths. The transmittance characteristic as a function of the normalized period is strongly influenced by the grating duty cycle, but the diffraction performance on the normalized depth is independent of the fill factor of the grating. Additionally, the effective medium theory is accurate for evaluating the diffraction efficiency within an error of less than around 1% when no higher-order diffraction waves appear and only the zero-order waves exist. The precision of the effective medium theory for calculating transmittance properties as a function of the normalized period, the normalized groove depth, and the polarization state of incident light is insensitive to the fill factor of the phase grating. PMID:21460923

  4. Friendship Conflict and the Development of Generalized Physical Aggression in the Early School Years: A Genetically Informed Study of Potential Moderators

    ERIC Educational Resources Information Center

    Salvas, Marie-Claude; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Tremblay, Richard E.; Boivin, Michel

    2014-01-01

    Several authors consider high and frequent conflicts between friends during childhood as a serious risk for subsequent conduct problems such as generalized physical aggression toward others (e.g., Kupersmidt, Burchinal, & Patterson, 1995; Sebanc, 2003). Although it seems logical to assume that friendship conflict could have some negative…

  5. The Role of Service-Learning to Promote Early Childhood Physical Education while Examining Its Influence upon the Vocational Call to Teach

    ERIC Educational Resources Information Center

    Miller, Marybeth

    2012-01-01

    Background: The implementation of service-learning as a teaching and learning method has been well grounded in education, yet the discipline of physical education teacher education (PETE) has been slow to establish itself in this experiential learning paradigm. This study examined the role that service-learning plays in teacher candidates'…

  6. Early impact of the federally mandated Local Wellness Policy on physical activity in rural, low-income elementary schools in Colorado.

    PubMed

    Belansky, Elaine S; Cutforth, Nick; Delong, Erin; Ross, Courtney; Scarbro, Sharon; Gilbert, Lynn; Beatty, Bridget; Marshall, Julie A

    2009-01-01

    The What's Working project described the initial impact of the United States' federally mandated Local Wellness Policy in rural, low-income elementary schools located in Colorado. Before and after the Local Wellness Policy mandate went into effect, a survey about school features related to nutrition and physical activity was sent to a random sample of 45 rural elementary schools (i.e., schools located outside of urban areas), in which at least 40% of students qualified for free or reduced-cost lunch. Overall, opportunities for physical activity did not change after the policy went into effect: although time in physical education increased by 14 min per week (P=0.10), time for recess decreased by roughly 19 min per week (P=0.10). Policies supporting student participation in physical education and recess (an unstructured time during school hours when students are allowed to play outside) did not change. The researchers coded Local Wellness Policies and found them to have weak wording that produced minimal impact. Content analysis of key informant interviews suggested several barriers to the impact of the Local Wellness Policies: (1) competing pressures facing school districts, (2) lack of resources devoted to the Local Wellness Policy, (3) principals' lack of knowledge about the policy, and (4) lack of accountability mechanisms to ensure policy implementation. Financial resources and more effective communication about Local Wellness Policies among school districts and principals are needed to elevate the importance of and increase opportunities for physical activity in rural, low-income Colorado elementary schools. PMID:19190570

  7. Accelerometer data requirements for reliable estimation of habitual physical activity and sedentary time of children during the early years - a worked example following a stepped approach.

    PubMed

    Bingham, Daniel D; Costa, Silvia; Clemes, Stacy A; Routen, Ash C; Moore, Helen J; Barber, Sally E

    2016-10-01

    This study presents a worked example of a stepped process to reliably estimate the habitual physical activity and sedentary time of a sample of young children. A total of 299 children (2.9 ± 0.6 years) were recruited. Outcome variables were daily minutes of total physical activity, sedentary time, moderate to vigorous physical activity and proportional values of each variable. In total, 282 (94%) provided 3 h of accelerometer data on ≥1 day and were included in a 6-step process: Step-1: determine minimum wear-time; Step-2: process 7-day-data; Step-3: determine the inclusion of a weekend day; Step-4: examine day-to-day variability; Step-5: calculate single day intraclass correlation (ICC) (2,1); Step-6: calculate number of days required to reach reliability. Following the process the results were, Step-1: 6 h was estimated as minimum wear-time of a standard day. Step-2: 98 (32%) children had ≥6 h wear on 7 days. Step-3: no differences were found between weekdays and weekend days (P ≥ 0.05). Step-4: no differences were found between day-to-day variability (P ≥ 0.05). Step-5: single day ICC's (2,1) ranged from 0.48 (total physical activity and sedentary time) to 0.53 (proportion of moderate to vigorous physical activity). Step-6: to reach reliability (ICC = 0.7), 3 days were required for all outcomes. In conclusion following a 7 day wear protocol, ≥6 h on any 3 days was found to have acceptable reliability. The stepped-process offers researchers a method to derive sample-specific wear-time criterion.

  8. 3D printed diffractive terahertz lenses.

    PubMed

    Furlan, Walter D; Ferrando, Vicente; Monsoriu, Juan A; Zagrajek, Przemysław; Czerwińska, Elżbieta; Szustakowski, Mieczysław

    2016-04-15

    A 3D printer was used to realize custom-made diffractive THz lenses. After testing several materials, phase binary lenses with periodic and aperiodic radial profiles were designed and constructed in polyamide material to work at 0.625 THz. The nonconventional focusing properties of such lenses were assessed by computing and measuring their axial point spread function (PSF). Our results demonstrate that inexpensive 3D printed THz diffractive lenses can be reliably used in focusing and imaging THz systems. Diffractive THz lenses with unprecedented features, such as extended depth of focus or bifocalization, have been demonstrated. PMID:27082335

  9. A scattering approach to sea wave diffraction

    NASA Astrophysics Data System (ADS)

    Corradini, M. L.; Garbuglia, M.; Maponi, P.; Ruggeri, M.

    2016-06-01

    This paper intends to show a model for the diffraction of sea waves approaching an OWC device, which converts the sea waves motion into mechanical energy and then electrical energy. This is a preliminary study to the optimisation of the device, in fact the computation of sea waves diffraction around the device allows the estimation of the sea waves energy which enters into the device. The computation of the diffraction phenomenon is the result of a sea waves scattering problem, solved with an integral equation method.

  10. New diffractive results from the Tevatron

    SciTech Connect

    Gallinaro, Michele; /Rockefeller U.

    2005-05-01

    Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.

  11. Elementary amplitudes in the multiple diffraction theory reexamined

    SciTech Connect

    Martini, A.F.; Menon, M.J.; Thober, D.S.

    1996-08-01

    We show that, in the context of Glauber{close_quote}s multiple diffraction theory, the square of the correction factor introduced by Bourrely, Soffer, and Wu in a double-pole form factor parametrization, may be interpreted as an elementary (parton-parton) amplitude. The condition concerning the existence of a well-defined Fourier transform is demonstrated, and it is shown that the corresponding profile function comes from an ordinary transform (Bessel function) plus a generalized transform ({delta} distribution). Comparisons with a modified parametrization and results from a model-independent analysis are also presented and discussed. {copyright} {ital 1996 The American Physical Society.}

  12. What periodicities can be found in diffraction patterns of quasicrystals?

    PubMed

    Wolny, Janusz; Kozakowski, Bartlomiej; Kuczera, Pawel; Pytlik, Lucjan; Strzalka, Radoslaw

    2014-03-01

    The structure of quasicrystals is aperiodic. Their diffraction patterns, however, can be considered periodic. They are composed solely of series of peaks which exhibit a fully periodic arrangement in reciprocal space. Furthermore, the peak intensities in each series define the so-called `envelope function'. A Fourier transform of the envelope function gives an average unit cell, whose definition is based on the statistical distribution of atomic coordinates in physical space. If such a distribution is lifted to higher-dimensional space, it becomes the so-called atomic surface - the most fundamental feature of higher-dimensional analysis. PMID:24572319

  13. X-Ray Diffractive Optics

    NASA Technical Reports Server (NTRS)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  14. Mesoscale Diffractive Photonics in Geosciences

    NASA Astrophysics Data System (ADS)

    Minin, I. V.; Minin, O. V.

    2016-06-01

    The scattered light by various dielectric particles in atmosphere give information about the type of molecules and particles and their location, which are important to definition of propagation limitations through atmospheric and space weather variations, crisis communications, etc. Although these investigations explain far field properties of disturbed radiations, the solution of the physical problem requires simulations of the interactions in near-field. It has been shown that strongly localized EM field near the surface of single dielectric particle may be form by non-spherical and non-symmetrical mesoscale particles both as in transmitting as in reflection mode. It was also shown that the main lobe is narrower in case of 3 cube chain than single cube in far field, but there are many side-scattering lobes. It was mentioned that unique advantages provided by mesoscale dielectric photonic crystal based particles with three spatial dimensions of arbitrary shape allow developing a new types of micro/nano-probes with subwavelength resolution for ultra compact spectrometer-free sensor for on board a spacecraft or a plane.

  15. Identification of patterns in diffraction intensities affected by radiation exposure.

    PubMed

    Borek, Dominika; Dauter, Zbigniew; Otwinowski, Zbyszek

    2013-01-01

    In an X-ray diffraction experiment, the structure of molecules and the crystal lattice changes owing to chemical reactions and physical processes induced by the absorption of X-ray photons. These structural changes alter structure factors, affecting the scaling and merging of data collected at different absorbed doses. Many crystallographic procedures rely on the analysis of consistency between symmetry-equivalent reflections, so failure to account for the drift of their intensities hinders the structure solution and the interpretation of structural results. The building of a conceptual model of radiation-induced changes in macromolecular crystals is the first step in the process of correcting for radiation-induced inconsistencies in diffraction data. Here the complexity of radiation-induced changes in real and reciprocal space is analysed using matrix singular value decomposition applied to multiple complete datasets obtained from single crystals. The model consists of a resolution-dependent decay correction and a uniform-per-unique-reflection term modelling specific radiation-induced changes. This model is typically sufficient to explain radiation-induced effects observed in diffraction intensities. This analysis will guide the parameterization of the model, enabling its use in subsequent crystallographic calculations.

  16. Adjustable hybrid diffractive/refractive achromatic lens.

    PubMed

    Valley, Pouria; Savidis, Nickolaos; Schwiegerling, Jim; Dodge, Mohammad Reza; Peyman, Gholam; Peyghambarian, N

    2011-04-11

    We demonstrate a variable focal length achromatic lens that consists of a flat liquid crystal diffractive lens and a pressure-controlled fluidic refractive lens. The diffractive lens is composed of a flat binary Fresnel zone structure and a thin liquid crystal layer, producing high efficiency and millisecond switching times while applying a low ac voltage input. The focusing power of the diffractive lens is adjusted by electrically modifying the sub-zones and re-establishing phase wrapping points. The refractive lens includes a fluid chamber with a flat glass surface and an opposing elastic polydimethylsiloxane (PDMS) membrane surface. Inserting fluid volume through a pump system into the clear aperture region alters the membrane curvature and adjusts the refractive lens' focal position. Primary chromatic aberration is remarkably reduced through the coupling of the fluidic and diffractive lenses at selected focal lengths. Potential applications include miniature color imaging systems, medical and ophthalmic devices, or any design that utilizes variable focal length achromats.

  17. X-ray diffraction: instrumentation and applications.

    PubMed

    Bunaciu, Andrei A; Udriştioiu, Elena Gabriela; Aboul-Enein, Hassan Y

    2015-01-01

    X-ray diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of X-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the distribution of atoms within the lattice. Consequently, the X-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. This review summarizes the scientific trends associated with the rapid development of the technique of X-ray diffraction over the past five years pertaining to the fields of pharmaceuticals, forensic science, geological applications, microelectronics, and glass manufacturing, as well as in corrosion analysis.

  18. Diffraction-limited ultrabroadband terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Baillergeau, M.; Maussang, K.; Nirrengarten, T.; Palomo, J.; Li, L. H.; Linfield, E. H.; Davies, A. G.; Dhillon, S.; Tignon, J.; Mangeney, J.

    2016-05-01

    Diffraction is the ultimate limit at which details of objects can be resolved in conventional optical spectroscopy and imaging systems. In the THz spectral range, spectroscopy systems increasingly rely on ultra-broadband radiation (extending over more 5 octaves) making a great challenge to reach resolution limited by diffraction. Here, we propose an original easy-to-implement wavefront manipulation concept to achieve ultrabroadband THz spectroscopy system with diffraction-limited resolution. Applying this concept to a large-area photoconductive emitter, we demonstrate diffraction-limited ultra-broadband spectroscopy system up to 14.5 THz with a dynamic range of 103. The strong focusing of ultrabroadband THz radiation provided by our approach is essential for investigating single micrometer-scale objects such as graphene flakes or living cells, and besides for achieving intense ultra-broadband THz electric fields.

  19. New diffraction results from the Tevatron

    SciTech Connect

    Terashi, Koji; /Rockefeller U.

    2006-05-01

    We present new results from studies on diffractive dijet production and exclusive production of dijet and diphoton obtained by the CDF Collaboration in proton-antiproton collisions at the Fermilab Tevatron.

  20. Tension in the LHC diffractive data?

    SciTech Connect

    Gotsman, Errol

    2015-04-10

    I discuss the LHC diffractive data, and compare it to predicted energy behaviour of various models. I suggest that the so called 'tension' between the experimental results, maybe due to the different Monte Carlo programs used.

  1. Diffraction-limited ultrabroadband terahertz spectroscopy

    PubMed Central

    Baillergeau, M.; Maussang, K.; Nirrengarten, T.; Palomo, J.; Li, L. H.; Linfield, E. H.; Davies, A. G.; Dhillon, S.; Tignon, J.; Mangeney, J.

    2016-01-01

    Diffraction is the ultimate limit at which details of objects can be resolved in conventional optical spectroscopy and imaging systems. In the THz spectral range, spectroscopy systems increasingly rely on ultra-broadband radiation (extending over more 5 octaves) making a great challenge to reach resolution limited by diffraction. Here, we propose an original easy-to-implement wavefront manipulation concept to achieve ultrabroadband THz spectroscopy system with diffraction-limited resolution. Applying this concept to a large-area photoconductive emitter, we demonstrate diffraction-limited ultra-broadband spectroscopy system up to 14.5 THz with a dynamic range of 103. The strong focusing of ultrabroadband THz radiation provided by our approach is essential for investigating single micrometer-scale objects such as graphene flakes or living cells, and besides for achieving intense ultra-broadband THz electric fields. PMID:27142959

  2. Medium for polarization-sensitive diffraction gratings.

    PubMed

    Vretik, L O; Davidenko, N A; Davidenko, I I; Syromyatnikov, V G; Studzinsky, S L; Zagnij, V V

    2014-04-01

    New polymers applicable for optoelectronics are developed and investigated. The ability to form photoinduced anisotropy in the media based on the films of these polymers is demonstrated. The media can be used for recording of polarization-sensitive diffraction gratings.

  3. An Electronic Analog of the Diffraction Grating.

    ERIC Educational Resources Information Center

    MacLeod, A. M.

    1978-01-01

    Gives an outline description of electronic circuitry which is analogous to the optical diffraction grating or to crystals used in the Bragg reflection of X-rays or electron waves, and explains how to use it. (Author/GA)

  4. Inelastic diffraction and equivalence of states

    NASA Astrophysics Data System (ADS)

    Malecki, A.

    1991-09-01

    A new approach to diffraction, based on the concept of equivalent states, is applied to the inclusive inelastic scattering. Differences from the classical description of Good and Walker are pointed out.

  5. Scalar limitations of diffractive optical elements

    NASA Technical Reports Server (NTRS)

    Johnson, Eric G.; Hochmuth, Diane; Moharam, M. G.; Pommet, Drew

    1993-01-01

    In this paper, scalar limitations of diffractive optic components are investigated using coupled wave analyses. Results are presented for linear phase gratings and fanout devices. In addition, a parametric curve is given which correlates feature size with scalar performance.

  6. [Physical activity can influence the course of early arthritis. Both strength training and aerobic exercise provide pain relief and functional improvement].

    PubMed

    Roos, Ewa

    2002-11-01

    There is no causal treatment for osteoarthritis. Instead treatment is aimed at decreasing pain and improving function. The base of osteoarthritis treatment is education and exercise. Exercise, both aerobic exercise and muscular strength training, have positive effects on pain and function. The minimum recommendations of exercise are equivalent to the recommendations of physical activity to obtain or maintain a good general health. Acupuncture is a safe and effective treatment for osteoarthritis pain. However, function is not automatically improved when pain is relieved.

  7. Chronic physical illness in early life and risk of chronic widespread and regional pain at age 68: evidence from the 1946 British birth cohort.

    PubMed

    Muthuri, Stella G; Kuh, Diana; Bendayan, Rebecca; Macfarlane, Gary J; Cooper, Rachel

    2016-10-01

    This study aimed to examine the associations between serious illness in earlier life and risk of pain in old age using data from a large nationally representative British birth cohort, the Medical Research Council (MRC) National Survey of Health and Development (NSHD). Serious illness was defined as any experience of illness before age 25 requiring hospital admission of ≥28 days. Pain was self-reported at age 68, with chronic widespread pain (CWP) defined according to American College of Rheumatology criteria. Multinomial logistic regression was used to test associations of serious illness in early life with CWP, chronic regional pain (CRP), and other pain, with no pain as the referent category. Adjustment was made for sex, socioeconomic position, adult health status, health behaviours, and psychosocial factors. Of 2401 NSHD participants with complete data, 10.5% reported CWP (13.2% of women and 7.7% of men), 30.2% reported CRP, and 14.8% other pain. Compared with those with no history of serious illness, those who experienced serious illness in early life had a higher likelihood of CWP (relative risk ratio [RRR] = 1.62 [95% CI: 1.21-2.17]) and of CRP (RRR = 1.25 [95% CI: 1.01-1.54]) after adjusting for sex. In fully adjusted models, serious illness in early life remained associated with CWP (RRR = 1.43 [95% CI: 1.05-1.95]), but associations with CRP were attenuated (RRR = 1.19 [95% CI: 0.96-1.48]). There were no associations with other pain. These findings suggest that those who have experienced serious illness in earlier life may require more support than others to minimise their risk of CWP in later life.

  8. Chronic physical illness in early life and risk of chronic widespread and regional pain at age 68: evidence from the 1946 British birth cohort

    PubMed Central

    Muthuri, Stella G.; Kuh, Diana; Bendayan, Rebecca; Macfarlane, Gary J.; Cooper, Rachel

    2016-01-01

    Abstract This study aimed to examine the associations between serious illness in earlier life and risk of pain in old age using data from a large nationally representative British birth cohort, the Medical Research Council (MRC) National Survey of Health and Development (NSHD). Serious illness was defined as any experience of illness before age 25 requiring hospital admission of ≥28 days. Pain was self-reported at age 68, with chronic widespread pain (CWP) defined according to American College of Rheumatology criteria. Multinomial logistic regression was used to test associations of serious illness in early life with CWP, chronic regional pain (CRP), and other pain, with no pain as the referent category. Adjustment was made for sex, socioeconomic position, adult health status, health behaviours, and psychosocial factors. Of 2401 NSHD participants with complete data, 10.5% reported CWP (13.2% of women and 7.7% of men), 30.2% reported CRP, and 14.8% other pain. Compared with those with no history of serious illness, those who experienced serious illness in early life had a higher likelihood of CWP (relative risk ratio [RRR] = 1.62 [95% CI: 1.21-2.17]) and of CRP (RRR = 1.25 [95% CI: 1.01-1.54]) after adjusting for sex. In fully adjusted models, serious illness in early life remained associated with CWP (RRR = 1.43 [95% CI: 1.05-1.95]), but associations with CRP were attenuated (RRR = 1.19 [95% CI: 0.96-1.48]). There were no associations with other pain. These findings suggest that those who have experienced serious illness in earlier life may require more support than others to minimise their risk of CWP in later life. PMID:27547897

  9. Chronic physical illness in early life and risk of chronic widespread and regional pain at age 68: evidence from the 1946 British birth cohort.

    PubMed

    Muthuri, Stella G; Kuh, Diana; Bendayan, Rebecca; Macfarlane, Gary J; Cooper, Rachel

    2016-10-01

    This study aimed to examine the associations between serious illness in earlier life and risk of pain in old age using data from a large nationally representative British birth cohort, the Medical Research Council (MRC) National Survey of Health and Development (NSHD). Serious illness was defined as any experience of illness before age 25 requiring hospital admission of ≥28 days. Pain was self-reported at age 68, with chronic widespread pain (CWP) defined according to American College of Rheumatology criteria. Multinomial logistic regression was used to test associations of serious illness in early life with CWP, chronic regional pain (CRP), and other pain, with no pain as the referent category. Adjustment was made for sex, socioeconomic position, adult health status, health behaviours, and psychosocial factors. Of 2401 NSHD participants with complete data, 10.5% reported CWP (13.2% of women and 7.7% of men), 30.2% reported CRP, and 14.8% other pain. Compared with those with no history of serious illness, those who experienced serious illness in early life had a higher likelihood of CWP (relative risk ratio [RRR] = 1.62 [95% CI: 1.21-2.17]) and of CRP (RRR = 1.25 [95% CI: 1.01-1.54]) after adjusting for sex. In fully adjusted models, serious illness in early life remained associated with CWP (RRR = 1.43 [95% CI: 1.05-1.95]), but associations with CRP were attenuated (RRR = 1.19 [95% CI: 0.96-1.48]). There were no associations with other pain. These findings suggest that those who have experienced serious illness in earlier life may require more support than others to minimise their risk of CWP in later life. PMID:27547897

  10. Diffraction pattern of gratings with erosion

    NASA Astrophysics Data System (ADS)

    Olivares-Pérez, Arturo; Fuentes-Tapia, Israel

    2015-03-01

    We present a theoretical study of amplitude diffraction gratings using computer simulating, which consists of a random sampling of points on the image grating to determine the points to be plotted and the points to remove, to simulate erosion in amplitude on the grating. We show their behavior in the diffraction patterns and the induced noise by limiting the number of points that representing the image of the eroded gratings and their symmetry.

  11. Breakdown of QCD factorization in hard diffraction

    NASA Astrophysics Data System (ADS)

    Kopeliovich, B. Z.

    2016-07-01

    Factorization of short- and long-distance interactions is severely broken in hard diffractive hadronic collisions. Interaction with the spectator partons leads to an interplay between soft and hard scales, which results in a leading twist behavior of the cross section, on the contrary to the higher twist predicted by factorization. This feature is explicitly demonstrated for diffractive radiation of abelian (Drell-Yan, gauge bosons, Higgs) and non-abelian (heavy flavors) particles.

  12. Generalized phase diffraction gratings with tailored intensity.

    PubMed

    Albero, Jorge; Moreno, Ignacio; Davis, Jeffrey A; Cottrell, Don M; Sand, David

    2012-10-15

    We report the generation of continuous phase masks designed to generate a set of target diffraction orders with defined relative intensity weights. We apply a previously reported analytic calculation that requires resolving a single equation with a set of parameters defining the target diffraction orders. Then the same phase map is extended to other phase patterns such as vortex generating/sensing gratings. Results are demonstrated experimentally with a parallel-aligned spatial light modulator.

  13. Active diffraction gratings: Development and tests

    SciTech Connect

    Bonora, S.; Frassetto, F.; Poletto, L.; Zanchetta, E.; Della Giustina, G.; Brusatin, G.

    2012-12-15

    We present the realization and characterization of an active spherical diffraction grating with variable radius of curvature to be used in grazing-incidence monochromators. The device consists of a bimorph deformable mirror on the top of which a diffraction grating with laminar profile is realized by UV lithography. The experimental results show that the active grating can optimize the beam focalization of visible wavelengths through its rotation and focus accommodation.

  14. Active diffraction gratings: development and tests.

    PubMed

    Bonora, S; Frassetto, F; Zanchetta, E; Della Giustina, G; Brusatin, G; Poletto, L

    2012-12-01

    We present the realization and characterization of an active spherical diffraction grating with variable radius of curvature to be used in grazing-incidence monochromators. The device consists of a bimorph deformable mirror on the top of which a diffraction grating with laminar profile is realized by UV lithography. The experimental results show that the active grating can optimize the beam focalization of visible wavelengths through its rotation and focus accommodation.

  15. Three-dimensional micro-diffraction modeling.

    PubMed

    Castañeda, Román

    2014-03-20

    Squared elementary cells with correlated radiant point sources are presented as basic structures for characterizing the propagation of the field emitted by two-dimensional planar sources of any shape and in arbitrary state of spatial coherence. The field is transported on a finite expansion of nonparaxial modes, whose propagation in the micro-diffraction domain is discussed under both the diffraction and the interference conditions.

  16. FESDIF -- Finite Element Scalar Diffraction theory code

    SciTech Connect

    Kraus, H.G.

    1992-09-01

    This document describes the theory and use of a powerful scalar diffraction theory based computer code for calculation of intensity fields due to diffraction of optical waves by two-dimensional planar apertures and lenses. This code is called FESDIF (Finite Element Scalar Diffraction). It is based upon both Fraunhofer and Kirchhoff scalar diffraction theories. Simplified routines for circular apertures are included. However, the real power of the code comes from its basis in finite element methods. These methods allow the diffracting aperture to be virtually any geometric shape, including the various secondary aperture obstructions present in telescope systems. Aperture functions, with virtually any phase and amplitude variations, are allowed in the aperture openings. Step change aperture functions are accommodated. The incident waves are considered to be monochromatic. Plane waves, spherical waves, or Gaussian laser beams may be incident upon the apertures. Both area and line integral transformations were developed for the finite element based diffraction transformations. There is some loss of aperture function generality in the line integral transformations which are typically many times more computationally efficient than the area integral transformations when applicable to a particular problem.

  17. Early Childhood Special Music Education

    ERIC Educational Resources Information Center

    Darrow, Alice-Ann

    2011-01-01

    The process of early intervention is a critical component of Early Childhood Special Music Education. Early intervention is the process of providing services, education, and support to young children who have disabilities or to children who are at-risk of developing needs that may affect their physical, cognitive, or emotional development. The…

  18. X-ray dynamical diffraction from single crystals with arbitrary shape and strain field: A universal approach to modeling

    NASA Astrophysics Data System (ADS)

    Yan, Hanfei; Li, Li

    2014-01-01

    The effects of dynamical diffraction in single crystals engender many unique diffraction phenomena that cannot be interpreted by the kinematical-diffraction theory, yet knowledge of them is vital to resolving a vast variety of scientific problems ranging from crystal optics to strain measurements in crystalline specimens. Although the fundamental dynamical-diffraction theory was established decades ago, modeling it remains a challenge in a general case wherein the crystal has complex boundaries and mixed diffraction geometries (Bragg or Laue). Here, we propose a universal approach for modeling x-ray dynamical diffraction from a single crystal with arbitrary shape and strain field that is based on the integral representation of the Takagi-Taupin equations. Using it, we can construct the solution iteratively via a converging series, independent of the diffraction geometry. Moreover, the integral equations offer additional insights into the diffraction physics that are not readily apparent in its differential counterparts. To demonstrate this approach, we studied the dynamical diffraction from a slab of single crystal with both Bragg and Laue diffraction excited on the entrance boundaries, a problem that is difficult to model by other methods. We also explored the mirage effect caused by the presence of a linear strain field and compared it to the Eikonal theory. Lastly, we derived a dynamical-diffraction equation correlating the structural properties of a particle to its far-field Bragg-diffraction pattern, shedding light on how dynamical diffraction affects these kinematical-diffraction-based inverse techniques for reconstructing the shape and the strain field.

  19. Precision lens molding of asphero diffractive surfaces in chalcogenide materials

    NASA Astrophysics Data System (ADS)

    Nelson, J.; Scordato, M.; Schwertz, K.; Bagwell, J.

    2015-10-01

    Finished lens molding, and the similar process of precision lens molding, have long been practiced for high volume, accurate replication of optical surfaces on oxide glass. The physics surrounding these processes are well understood, and the processes are capable of producing high quality optics with great fidelity. However, several limitations exist due to properties inherent with oxide glasses. Tooling materials that can withstand the severe environmental conditions of oxide glass molding cannot easily be machined to produce complex geometries such as diffractive surfaces, lens arrays, and off axis features. Current machining technologies coupled with a limited selection of tool materials greatly limits the type of structures that can be molded into the finished optic. Tooling for chalcogenide glasses are not bound by these restrictions since the molding temperatures required are much lower than for oxide glasses. Innovations in tooling materials and manufacturing techniques have enabled the production of complex geometries to optical quality specifications and have demonstrated the viability of creating tools for molding diffractive surfaces, off axis features, datums, and arrays. Applications for optics having these features are found in automotive, defense, security, medical, and industrial domains. This paper will discuss results achieved in the study of various molding techniques for the formation of positive diffractive features on a concave spherical surface molded from As2Se3 chalcogenide glass. Examples and results of molding with tools having CTE match with the glass and non CTE match will be reviewed. The formation of stress within the glass during molding will be discussed, and methods of stress management will also be demonstrated and discussed. Results of process development methods and production of good diffractive surfaces will be shown.

  20. Phase-Shifting Liquid Crystal Point-Diffraction Interferometry

    NASA Technical Reports Server (NTRS)

    Griffin, DeVon W.; Marshall, Kenneth L.; Mercer, Carolyn R.

    2000-01-01

    Microgravity fluid physics experiments frequently measure concentration and temperature. Interferometers such as the Twyman Green illustrated have performed full-field measurement of these quantities. As with most such devices, this interferometer uses a reference path that is not common with the path through the test section. Recombination of the test and reference wavefronts produces interference fringes. Unfortunately, in order to obtain stable fringes, the alignment of both the test and reference paths must be maintained to within a fraction of the wavelength of the light being used for the measurement. Otherwise, the fringes will shift and may disappear. Because these interferometers are extremely sensitive to bumping, jarring and transmitted vibration, they are typically mounted on optical isolation tables. Schlieren deflectometers or the more recent Shack-Hartmann wavefront sensors also measure concentration and temperature in laboratory fluid flows. Ray optics describe the operation of both devices. In a schlieren system, an expanded, collimated beam passes through a test section where refractive index gradients deflect rays. A lens focuses the beam to a filter placed in the rear focal plane of the decollimating lens. In a quantitative color schlieren system, gradients in the index of refraction appear as colors in the field of view due to the action of the color filter. Since sensitivity is a function of the focal length of the decollimating lens, these systems are rather long and filter fabrication and calibration is rather difficult. A Shack-Hartmann wavefront sensor is an array of small lenslets. Typical diameters are on the order of a few hundred microns. Since these lenslets divide the test section into resolution elements, the spatial resolution can be no smaller than an individual lenslet. Such a device was recently used to perform high-speed tomography of heated air exiting a 1.27 cm diameter nozzle. While these wavefront sensors are very compact

  1. Overview Of Diffractive Optics At Honeywell

    NASA Astrophysics Data System (ADS)

    Cox, J. Allen

    1988-05-01

    Interest in holographic, or diffractive, optics has been rekindled in the last few years with demonstrated advances in three areas: computer-aided design (CAD) tools, VLSI lithographic and dry etching processes, and mathematical modeling of diffractive elements.1 The availability of CAD tools and electron-beam lithography led first to the emergence of computer-generated holography (CGH). CGH work at Honeywell was started and brought to maturity by Arnold2 in 1980-1983. However, because of the inherently low diffraction efficiency (-10%), lithographic CGHs have found a place in only a relatively few practical applications, such as testing diamond turned aspherics, and thus CGHs have not been widely accepted within industry. The first step in changing this situation came in the 1970s with numerical approaches to rigorously solve the vector field equations for diffraction from blazed gratings.3 The extensive numerical results from these models not only showed that high diffraction efficiencies are possible with etched surface profiles, but also indicated the sensitivity to various profile configurations and design parameters. Veldkamp et al.1,4'-'61 at MIT Lincoln Laboratories have taken the final step necessary to establish the practical feasibility of diffractive optics by using reactive ion etching techniques to produce the surface profiles prescribed by the numerical models and delineated by CGH lithographic masks. With this combined approach, they have demonstrated the feasibility of high-efficiency diffractive elements for a variety of diverse applications, such as the CO2 laser radar telescope,4 coherent beam addition of laser diode arrays,5 and on-axis, broadband, aspheric lens elements for infrared imagers.6 These elements are fabricated using well-established VLSI lithographic and dry etching techniques. Moreover, the ability to replicate each diffractive element provides the potential for high-volume, low-cost producibility. With this precedent, Honeywell

  2. Diffraction and interference--a standard teaching topic using non-standard diffracting objects

    NASA Astrophysics Data System (ADS)

    Gröber, S.; Vetter, M.; Eckert, B.; Jodl, H.-J.

    2014-01-01

    This topic--diffraction and interference--is a standard topic in teaching wave optics in schools and universities as well as in physics practical labs. The theoretical presentation needs some knowledge in mathematics; the final formula for the intensity pattern as a function of all parameters such as number of slits N, slit width b, slit distance d, wavelength λ of light used is not too complicated. The experimental setup is standard and well known. In our opinion the shortage comes here from the relatively poor quality of scattering objects produced by photolithography and by the small number of various objects in N, b and d. We on the contrary offer objects produced by electron beam lithography with much higher contrast and larger resolution. As a consequence, students are allowed to study not only positions of a few maxima and minima of the interference pattern, but determine relative intensities of maxima and minima with respect to central maximum, details around sub-maxima, band shape and bandwidth. In addition, we generated 150 objects with a variety in N, b and d and also offer five different wavelengths. Since these objects are hardly available and not so easy to copy we offer this experiment as a remotely controlled laboratory experiment which means the real experiment located in A can be used by everyone with his or her computer located in B via the Internet.

  3. A-DNA and B-DNA: Comparing Their Historical X-Ray Fiber Diffraction Images

    ERIC Educational Resources Information Center

    Lucas, Amand A.

    2008-01-01

    A-DNA and B-DNA are two secondary molecular conformations (among other allomorphs) that double-stranded DNA drawn into a fiber can assume, depending on the relative water content and other chemical parameters of the fiber. They were the first two forms to be observed by X-ray fiber diffraction in the early 1950s, respectively by Wilkins and…

  4. A UGO/EUTD Solution for the Scattering and Diffraction from Cubic Polynomial Strips

    NASA Technical Reports Server (NTRS)

    Constantinides, Evagoras D.; Marhefka, Ronald J.

    1993-01-01

    A uniform geometrical optics (UGO) and an extended uniform geometrical theory of diffraction (EUTD) solution is developed for the scattering and diffraction from perfectly conducting cubic polynomial strips. The new solution overcomes the difficulties of the classic GO/UTD solution near caustics and composite shadow boundaries. The approach for constructing the UGO/EUTD solution is based on a spatial domain physical optics (PO) radiation integral representation for the scattered field which is then reduced using a uniform asymptotic procedure. New uniform reflection, zero-curvature diffraction, and edge diffraction coefficients are derived and involve the ordinary and incomplete Airy integrals as canonical functions. Higher order effects such as double edge diffraction, edge-excited creeping waves, and whispering gallery modes are not examined in this work. The UGO/EUTD solution is very efficient and provides useful physical insight into the various scattering and diffraction processes. It is also universal in nature and can be used to effectively describe the scattered fields from flat, strictly concave or convex, and concave-convex boundaries containing edges. Its accuracy is confirmed via comparison with some reference moment method (MM) results.

  5. Searching for the developmental origins of sexual violence: examining the co-occurrence of physical aggression and sexual behaviors in early childhood.

    PubMed

    Lussier, Patrick; Healey, Jay

    2010-01-01

    While developmental perspectives on sexual violence have gained much interest in recent years, few empirical studies have been conducted to better understand its origins. This study attempts to fill this gap by examining the onset of physical aggression and normative sexual behaviors in preschoolers. This study is based on a sample of at-risk children (n = 100) recruited as part of the KD-BEAR project, an on-going longitudinal study conducted in Vancouver, British Columbia, Canada. Semi-structured interviews were completed with the primary caregiver and the child. The structural model examined showed a significant and important latent correlation between physical aggression and sexual behaviors across models tested, after controlling for child and familial characteristics. Furthermore, findings showed that male preschoolers coming from low income families having been referred for assessment and/or treatment for an externalizing spectrum disorder showed higher levels of both aggression and sexual behaviors. The implications of these findings are discussed in light of developmental models of sexual violence, and the secondary prevention of sexual violence at its earliest stages.

  6. Physical mapping of the major early-onset familial Alzheimer`s disease locus on chromosome 14 and analysis of candidate gene sequences

    SciTech Connect

    Tanzi, R.E.; Romano, D.M.; Crowley, A.C.

    1994-09-01

    Genetic studies of kindreds displaying evidence for familial AD (FAD) have led to the localization of gene defects responsible for this disorder on chromosomes 14, 19, and 21. A minor early-onset FAD gene on chromosome 21 has been identified to enode the amyloid precursor protein (APP), and the late-onset FAD susceptibility locus on chromosome 19 has been shown to be in linkage disequilibrium with the E4 allele of the APOE gene. Meanwhile, the locus responsible for the major form of early-onset FAD on chromosome 14q24 has not yet been identified. By recombinational analysis, we have refined the minimal candidate region containing the gene defect to approximately 3 megabases in 14q24. We will describe our laboratory`s progress on attempts to finely localize this locus, as well as test known candidate genes from this region for either inclusion in the minimal candidate region or the presence of pathogenic mutations. Candidate genes that have been tested so far include cFOS, heat shock protein 70 member (HSF2A), transforming growth factor beta (TGFB3), the trifunctional protein C1-THF synthase (MTHFD), bradykinin receptor (BR), and the E2k component of a-ketoglutarate dehydrogenase. HSP2A, E2k, MTHFD, and BR do not map to the current defined minimal candidate region; however, sequence analysis must be performed to confirm exclusion of these genes as true candidates. Meanwhile, no pathogenic mutations have yet been found in cFOS or TGFB3. We have also isolated a large number of novel transcribed sequences from the minimal candidate region in the form of {open_quotes}trapped exons{close_quotes} from cosmids identified by hybridization to select YAC clones; we are currently in the process of searching for pathogenic mutations in these exons in affected individuals from FAD families.

  7. Physical stratigraphy of Swift-Morrison and Kootenai-Colorado depositional sequences in the Late Jurassic-Early Cretaceous overfilled backarc and foreland basins, western Montana

    SciTech Connect

    Meyers, J.H. . Dept. of Geology); O'Malley, P.J. . Dept. of Geosciences)

    1993-04-01

    Late Jurassic-Early Cretaceous sedimentation in western Montana includes two depositional sequences. The older sequence (Swift-Morrison Formations) was deposited in the Sundance foreland basin and ensuing Morrison back-arc basin. The younger sequence (Kootenal Formation-Colorado Group) was deposited in the overfilled early Rocky Mountain foreland basin. Swift strata record coastal onlap and marine progradation over a dissected structural complex (Belt Island) and include a laterally restricted basal conglomerate (0--4 m-thick) representing estuarine paleovalley fill, and an overlying pervasive 16--25 m-thick upward-fining sandstone body dominated by tidal features. To the south, the sandstone body is conformably overlain by distal alluvial-fan and coastal-plain green mudstone, interbedded thin micritic limestone, and red mudstone of the lower and middle Morrison Formation. Morrison red mudstones contain thin sheet sandstones and sparse thick lenticular sandstones, representing northeastward dispersal of detritus in a mud-dominated distal alluvial fan. Northward, the Morrison thins and is mostly green and gray mudstone with thin interbedded sheet sandstone and rare intraformational-pebble-bearing ribbon sandstone. To the south, Kootenai rocks unconformably overlie the Morrison Formation and include a thick basal sandstone deposited in northeast-flowing truck rivers whose courses were controlled by subtle structural topography developed along reactivated basement faults. In the Great Falls area this sandstone (K1-Cutbank of Foster, 1992) may represent distributary channels in a prograding fluvial-dominated delta in the Sunburst sea. Overlying mudstones and thick nodular limestones (K2) represent alluvial-plain sedimentation and paleosol development. Thin shallow-marine sandstone (K3-Sunburst) caps the fluvial-deltaic sequence in the Great Falls area.

  8. State-of-the-art and problems of X-ray diffraction analysis of biomacromolecules

    SciTech Connect

    Andreeva, N. S.

    2006-12-15

    The state-of-the-art of X-ray diffraction studies of biomacromolecules is briefly characterized, and the challenge imposed by science is discussed. These studies are characterized by a wide scope and extensive use. This field of science is of great interest and is developed in many countries. The main purpose is to solve practical problems in medicine consisting in the design of drugs against various diseases. X-ray diffraction analysis of enzymes brought the pharmaceutical industry to a new level, thus allowing the rational design of drugs against formerly untreatable diseases. Modern X-ray diffraction studies of biomacromolecules laid the basis for a new science called structural biology. This method allows one to solve fundamental problems of physical chemistry for a new state of matter existing in living systems. Here, science poses numerous problems in analysis of X-ray diffraction data on biological macromolecules. Many of theses problems are in their infancy.

  9. Chemistry of Metal-organic Frameworks Monitored by Advanced X-ray Diffraction and Scattering Techniques.

    PubMed

    Mazaj, Matjaž; Kaučič, Venčeslav; Zabukovec Logar, Nataša

    2016-01-01

    The research on metal-organic frameworks (MOFs) experienced rapid progress in recent years due to their structure diversity and wide range of application opportunities. Continuous progress of X-ray and neutron diffraction methods enables more and more detailed insight into MOF's structural features and significantly contributes to the understanding of their chemistry. Improved instrumentation and data processing in high-resolution X-ray diffraction methods enables the determination of new complex MOF crystal structures in powdered form. By the use of neutron diffraction techniques, a lot of knowledge about the interaction of guest molecules with crystalline framework has been gained in the past few years. Moreover, in-situ time-resolved studies by various diffraction and scattering techniques provided comprehensive information about crystallization kinetics, crystal growth mechanism and structural dynamics triggered by external physical or chemical stimuli. The review emphasizes most relevant advanced structural studies of MOFs based on powder X-ray and neutron scattering. PMID:27640372

  10. Chemistry of Metal-organic Frameworks Monitored by Advanced X-ray Diffraction and Scattering Techniques.

    PubMed

    Mazaj, Matjaž; Kaučič, Venčeslav; Zabukovec Logar, Nataša

    2016-01-01

    The research on metal-organic frameworks (MOFs) experienced rapid progress in recent years due to their structure diversity and wide range of application opportunities. Continuous progress of X-ray and neutron diffraction methods enables more and more detailed insight into MOF's structural features and significantly contributes to the understanding of their chemistry. Improved instrumentation and data processing in high-resolution X-ray diffraction methods enables the determination of new complex MOF crystal structures in powdered form. By the use of neutron diffraction techniques, a lot of knowledge about the interaction of guest molecules with crystalline framework has been gained in the past few years. Moreover, in-situ time-resolved studies by various diffraction and scattering techniques provided comprehensive information about crystallization kinetics, crystal growth mechanism and structural dynamics triggered by external physical or chemical stimuli. The review emphasizes most relevant advanced structural studies of MOFs based on powder X-ray and neutron scattering.

  11. Fast diffraction computation algorithms based on FFT

    NASA Astrophysics Data System (ADS)

    Logofatu, Petre Catalin; Nascov, Victor; Apostol, Dan

    2010-11-01

    The discovery of the Fast Fourier transform (FFT) algorithm by Cooley and Tukey meant for diffraction computation what the invention of computers meant for computation in general. The computation time reduction is more significant for large input data, but generally FFT reduces the computation time with several orders of magnitude. This was the beginning of an entire revolution in optical signal processing and resulted in an abundance of fast algorithms for diffraction computation in a variety of situations. The property that allowed the creation of these fast algorithms is that, as it turns out, most diffraction formulae contain at their core one or more Fourier transforms which may be rapidly calculated using the FFT. The key in discovering a new fast algorithm is to reformulate the diffraction formulae so that to identify and isolate the Fourier transforms it contains. In this way, the fast scaled transformation, the fast Fresnel transformation and the fast Rayleigh-Sommerfeld transform were designed. Remarkable improvements were the generalization of the DFT to scaled DFT which allowed freedom to choose the dimensions of the output window for the Fraunhofer-Fourier and Fresnel diffraction, the mathematical concept of linearized convolution which thwarts the circular character of the discrete Fourier transform and allows the use of the FFT, and last but not least the linearized discrete scaled convolution, a new concept of which we claim priority.

  12. Surface diffusion studies by optical diffraction techniques

    SciTech Connect

    Xiao, X.D.

    1992-11-01

    The newly developed optical techniques have been combined with either second harmonic (SH) diffraction or linear diffraction off a monolayer adsorbate grating for surface diffusion measurement. Anisotropy of surface diffusion of CO on Ni(l10) was used as a demonstration for the second harmonic dim reaction method. The linear diffraction method, which possesses a much higher sensitivity than the SH diffraction method, was employed to study the effect of adsorbate-adsorbate interaction on CO diffusion on Ni(l10) surface. Results showed that only the short range direct CO-CO orbital overlapping interaction influences CO diffusion but not the long range dipole-dipole and CO-NI-CO interactions. Effects of impurities and defects on surface diffusion were further explored by using linear diffraction method on CO/Ni(110) system. It was found that a few percent S impurity can alter the CO diffusion barrier height to a much higher value through changing the Ni(110) surface. The point defects of Ni(l10) surface seem to speed up CO diffusion significantly. A mechanism with long jumps over multiple lattice distance initiated by CO filled vacancy is proposed to explain the observed defect effect.

  13. The Role of Adolescent Nutrition and Physical Activity in the Prediction of Verbal Intelligence during Early Adulthood: A Genetically Informed Analysis of Twin Pairs

    PubMed Central

    Jackson, Dylan B.; Beaver, Kevin M.

    2015-01-01

    A large body of research has revealed that nutrition and physical activity influence brain functioning at various stages of the life course. Nevertheless, very few studies have explored whether diet and exercise influence verbal intelligence as youth transition from adolescence into young adulthood. Even fewer studies have explored the link between these health behaviors and verbal intelligence while accounting for genetic and environmental factors that are shared between siblings. Employing data from the National Longitudinal Study of Adolescent Health, the current study uses a sample of same-sex twin pairs to test whether youth who engage in poorer fitness and nutritional practices are significantly more likely to exhibit reduced verbal intelligence during young adulthood. The results suggests that, independent of the effects of genetic and shared environmental factors, a number of nutritional and exercise factors during adolescence influence verbal intelligence during adulthood. Limitations are noted and suggestions for future research are outlined. PMID:25568969

  14. The role of adolescent nutrition and physical activity in the prediction of verbal intelligence during early adulthood: a genetically informed analysis of twin pairs.

    PubMed

    Jackson, Dylan B; Beaver, Kevin M

    2015-01-05

    A large body of research has revealed that nutrition and physical activity influence brain functioning at various stages of the life course. Nevertheless, very few studies have explored whether diet and exercise influence verbal intelligence as youth transition from adolescence into young adulthood. Even fewer studies have explored the link between these health behaviors and verbal intelligence while accounting for genetic and environmental factors that are shared between siblings. Employing data from the National Longitudinal Study of Adolescent Health, the current study uses a sample of same-sex twin pairs to test whether youth who engage in poorer fitness and nutritional practices are significantly more likely to exhibit reduced verbal intelligence during young adulthood. The results suggests that, independent of the effects of genetic and shared environmental factors, a number of nutritional and exercise factors during adolescence influence verbal intelligence during adulthood. Limitations are noted and suggestions for future research are outlined.

  15. The role of adolescent nutrition and physical activity in the prediction of verbal intelligence during early adulthood: a genetically informed analysis of twin pairs.

    PubMed

    Jackson, Dylan B; Beaver, Kevin M

    2015-01-01

    A large body of research has revealed that nutrition and physical activity influence brain functioning at various stages of the life course. Nevertheless, very few studies have explored whether diet and exercise influence verbal intelligence as youth transition from adolescence into young adulthood. Even fewer studies have explored the link between these health behaviors and verbal intelligence while accounting for genetic and environmental factors that are shared between siblings. Employing data from the National Longitudinal Study of Adolescent Health, the current study uses a sample of same-sex twin pairs to test whether youth who engage in poorer fitness and nutritional practices are significantly more likely to exhibit reduced verbal intelligence during young adulthood. The results suggests that, independent of the effects of genetic and shared environmental factors, a number of nutritional and exercise factors during adolescence influence verbal intelligence during adulthood. Limitations are noted and suggestions for future research are outlined. PMID:25568969

  16. Support for a special symposium to highlight the research of early career women physical chemists at the 2011 fall ACS nationall meeting, Aug 28-Sept

    SciTech Connect

    Geraldine Richmond

    2012-12-19

    The symposium was well attended during the 4-day symposium. The invited speakers were primarily women in early career stage (~4-8 years) with a few senior women and men as invited speakers or session chairs. Included in each day was a Poster Session for graduate students and a lunch in which the turn out was strong and the posters presented encouraged much of dialogue with the invited speakers, guests and others attending the ACS meeting and wanted to discuss the student’s research and meet with the speakers. Most all speakers and participants were very positive about the sessions and expressed that the funding to cover some expenses made it possible for them to attend the conference and the poster session luncheon. There was a total of 51 presenters, below are the speakers and their abstracts, in order presented:

  17. Diffraction of entangled particles by light gratings

    SciTech Connect

    Sancho, Pedro

    2015-04-15

    We analyze the diffraction regime of the Kapitza–Dirac effect for particles entangled in momentum. The detection patterns show two-particle interferences. In the single-mode case we identify a discontinuity in the set of joint detection probabilities, associated with the disconnected character of the space of non-separable states. For Gaussian multi-mode states we derive the diffraction patterns, providing an example of the dependence of the light–matter interaction on entanglement. When the particles are identical, we can explore the relation between exchange and entanglement effects. We find a complementary behavior between overlapping and Schmidt’s number. In particular, symmetric entanglement can cancel the exchange effects. - Highlights: • Kapitza–Dirac diffraction of entangled particles shows multiparticle interference. • There is a discontinuity in the set of joint detection patterns of entangled states. • We find a complementary behavior between overlapping and Schmidt’s number. • Symmetric entanglement can cancel the exchange effects.

  18. Adaptable Diffraction Gratings With Wavefront Transformation

    NASA Technical Reports Server (NTRS)

    Iazikov, Dmitri; Mossberg, Thomas W.; Greiner, Christoph M.

    2010-01-01

    Diffraction gratings are optical components with regular patterns of grooves, which angularly disperse incoming light by wavelength. Traditional diffraction gratings have static planar, concave, or convex surfaces. However, if they could be made so that they can change the surface curvature at will, then they would be able to focus on particular segments, self-calibrate, or perform fine adjustments. This innovation creates a diffraction grating on a deformable surface. This surface could be bent at will, resulting in a dynamic wavefront transformation. This allows for self-calibration, compensation for aberrations, enhancing image resolution in a particular area, or performing multiple scans using different wavelengths. A dynamic grating gives scientists a new ability to explore wavefronts from a variety of viewpoints.

  19. Data Exploration Toolkit for serial diffraction experiments

    DOE PAGESBeta

    Zeldin, Oliver B.; Brewster, Aaron S.; Hattne, Johan; Uervirojnangkoorn, Monarin; Lyubimov, Artem Y.; Zhou, Qiangjun; Zhao, Minglei; Weis, William I.; Sauter, Nicholas K.; Brunger, Axel T.

    2015-01-23

    Ultrafast diffraction at X-ray free-electron lasers (XFELs) has the potential to yield new insights into important biological systems that produce radiation-sensitive crystals. An unavoidable feature of the 'diffraction before destruction' nature of these experiments is that images are obtained from many distinct crystals and/or different regions of the same crystal. Combined with other sources of XFEL shot-to-shot variation, this introduces significant heterogeneity into the diffraction data, complicating processing and interpretation. To enable researchers to get the most from their collected data, a toolkit is presented that provides insights into the quality of, and the variation present in, serial crystallography datamore » sets. These tools operate on the unmerged, partial intensity integration results from many individual crystals, and can be used on two levels: firstly to guide the experimental strategy during data collection, and secondly to help users make informed choices during data processing.« less

  20. Beyond the diffraction limit via optical amplification.

    PubMed

    Kellerer, Aglaé N; Ribak, Erez N

    2016-07-15

    In a previous article [Astron. Astrophys.561, A118 (2014)], we suggested a method to overcome the diffraction limit behind a telescope. We discuss and extend recent numerical simulations and test whether it is indeed possible to use photon amplification to enhance the angular resolution of a telescope or a microscope beyond the diffraction limit. An essential addition is the proposal to select events with an above-average ratio of stimulated to spontaneous photons. The analysis shows that the diffraction limit of a telescope is surpassed by a factor of 10 for an amplifier gain of 200, if the analysis is restricted to a tenth of the incoming astronomical photons. A gain of 70 is sufficient with a hundredth of the photons. More simulations must be performed to account for the bunching of spontaneous photons. PMID:27420490