Sample records for differences give rise

  1. No Company for Old Men: Adventures in Unemployment in "The Company Men"

    ERIC Educational Resources Information Center

    Beck, Bernard

    2011-01-01

    Cultural diversity is often attributed to groups in a society from a variety of cultural backgrounds. Assimilation then blends subcultures into a mainstream culture. However, history and circumstance give rise to new groups whose experiences and activities produce new diversity. Big events and big changes give rise to important differences between…

  2. Intrinsic Fabry-Perot optical fiber sensors and their multiplexing

    DOEpatents

    Wang, Anbo

    2007-12-11

    An intrinsic Fabry-Perot optical sensor includes a thin film sandwiched between two fiber ends. When light is launched into the fiber, two reflections are generated at the two fiber/thin film interfaces due to a difference in refractive indices between the fibers and the film, giving rise to the sensor output. In another embodiment, a portion of the cladding of a fiber is removed, creating two parallel surfaces. Part of the evanescent fields of light propagating in the fiber is reflected at each of the surfaces, giving rise to the sensor output. In a third embodiment, the refractive index of a small portion of a fiber is changed through exposure to a laser beam or other radiation. Interference between reflections at the ends of the small portion give rise to the sensor output. Multiple sensors along a single fiber are multiplexed using an optical time domain reflectometry method.

  3. 45 CFR 77.3 - Conditions that may give rise to remedial actions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Conditions that may give rise to remedial actions. 77.3 Section 77.3 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION REMEDIAL ACTIONS APPLICABLE TO LETTER OF CREDIT ADMINISTRATION § 77.3 Conditions that may give rise to...

  4. 40 CFR 80.80 - Penalties.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirement or prohibition of subpart D, E, or F of this part shall be liable to the United States for a civil... violation for each and every day such gasoline giving rise to such violations remains any place in the... giving rise to the violations and any mixture of gasolines that contains any of the gasoline giving rise...

  5. 45 CFR 77.3 - Conditions that may give rise to remedial actions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Conditions that may give rise to remedial actions. 77.3 Section 77.3 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION REMEDIAL ACTIONS APPLICABLE TO LETTER OF CREDIT ADMINISTRATION § 77.3 Conditions that may give rise to...

  6. Dynamics on Networks of Manifolds

    NASA Astrophysics Data System (ADS)

    DeVille, Lee; Lerman, Eugene

    2015-03-01

    We propose a precise definition of a continuous time dynamical system made up of interacting open subsystems. The interconnections of subsystems are coded by directed graphs. We prove that the appropriate maps of graphs called graph fibrations give rise to maps of dynamical systems. Consequently surjective graph fibrations give rise to invariant subsystems and injective graph fibrations give rise to projections of dynamical systems.

  7. Alternatives for Measuring the Unexplained Wage Gap.

    ERIC Educational Resources Information Center

    Toutkoushian, Robert K.; Hoffman, Emily P.

    2002-01-01

    Reviews several different methods that analysts can use to measure gender- and race-based pay differences for academic employees, and how they are interrelated. Discusses the advantages and disadvantages of each method, and shows how they can give rise to different estimates of pay disparity. (EV)

  8. Cell delamination in the mesencephalic neural fold and its implication for the origin of ectomesenchyme

    PubMed Central

    Lee, Raymond Teck Ho; Nagai, Hiroki; Nakaya, Yukiko; Sheng, Guojun; Trainor, Paul A.; Weston, James A.; Thiery, Jean Paul

    2013-01-01

    The neural crest is a transient structure unique to vertebrate embryos that gives rise to multiple lineages along the rostrocaudal axis. In cranial regions, neural crest cells are thought to differentiate into chondrocytes, osteocytes, pericytes and stromal cells, which are collectively termed ectomesenchyme derivatives, as well as pigment and neuronal derivatives. There is still no consensus as to whether the neural crest can be classified as a homogenous multipotent population of cells. This unresolved controversy has important implications for the formation of ectomesenchyme and for confirmation of whether the neural fold is compartmentalized into distinct domains, each with a different repertoire of derivatives. Here we report in mouse and chicken that cells in the neural fold delaminate over an extended period from different regions of the cranial neural fold to give rise to cells with distinct fates. Importantly, cells that give rise to ectomesenchyme undergo epithelial-mesenchymal transition from a lateral neural fold domain that does not express definitive neural markers, such as Sox1 and N-cadherin. Additionally, the inference that cells originating from the cranial neural ectoderm have a common origin and cell fate with trunk neural crest cells prompted us to revisit the issue of what defines the neural crest and the origin of the ectomesenchyme. PMID:24198279

  9. Design and Architecture of Collaborative Online Communities: A Quantitative Analysis

    ERIC Educational Resources Information Center

    Aviv, Reuven; Erlich, Zippy; Ravid, Gilad

    2004-01-01

    This paper considers four aspects of online communities. Design, mechanisms, architecture, and the constructed knowledge. We hypothesize that different designs of communities drive different mechanisms, which give rise to different architectures, which in turn result in different levels of collaborative knowledge construction. To test this chain…

  10. Sex Differences in the Brain.

    ERIC Educational Resources Information Center

    Kimura, Doreen

    1992-01-01

    Explores the neural and hormonal basis of human intellectual function that gives rise to sex differences in the brain. Discusses behavioral, neurological, endocrinological studies, and studies of the effects of hormones on brain functioning that show a relationship between cognitive variations and sex. (MCO)

  11. Electromagnetic response of dielectric nanostructures in liquid crystals

    NASA Astrophysics Data System (ADS)

    Amanaganti, S.; Chowdhury, D. R.; Ravnik, M.; Dontabhaktuni, J.

    2018-02-01

    Sub-wavelength periodic metallic nanostructures give rise to very interesting optical phenomena like effective refractive index, perfect absorption, cloaking, etc. However, such metallic structures result in high dissipative losses and hence dielectric nanostructures are being considered increasingly to be an efficient alternative to plasmonic materials. High refractive index (RI) dielectric nanostructures exhibit magnetic and electric resonances simultaneously giving rise to interesting properties like perfect magnetic mirrors, etc. In the present work, we study light-matter interaction of cubic dielectric structures made of very high refractive index material Te in air. We observe a distinct band-like structure in both transmission and reflection spectra resulting from the interaction between magnetic and electric dipolar modes. FDTD simulations using CST software are performed to analyse the different modes excited at the band frequencies. The medium when replaced with liquid crystal gives rise to asymmetry in the band structure emphasizing one of the dominant magnetic modes at resonance frequencies. This will help in achieving a greater control on the excitation of the predominant magnetic dipolar modes at resonance frequencies with applications as perfect magnetic mirrors.

  12. Taming contact line instability for pattern formation

    PubMed Central

    Deblais, A.; Harich, R.; Colin, A.; Kellay, H.

    2016-01-01

    Coating surfaces with different fluids is prone to instability producing inhomogeneous films and patterns. The contact line between the coating fluid and the surface to be coated is host to different instabilities, limiting the use of a variety of coating techniques. Here we take advantage of the instability of a receding contact line towards cusp and droplet formation to produce linear patterns of variable spacings. We stabilize the instability of the cusps towards droplet formation by using polymer solutions that inhibit this secondary instability and give rise to long slender cylindrical filaments. We vary the speed of deposition to change the spacing between these filaments. The combination of the two gives rise to linear patterns into which different colloidal particles can be embedded, long DNA molecules can be stretched and particles filtered by size. The technique is therefore suitable to prepare anisotropic structures with variable properties. PMID:27506626

  13. Taming contact line instability for pattern formation.

    PubMed

    Deblais, A; Harich, R; Colin, A; Kellay, H

    2016-08-10

    Coating surfaces with different fluids is prone to instability producing inhomogeneous films and patterns. The contact line between the coating fluid and the surface to be coated is host to different instabilities, limiting the use of a variety of coating techniques. Here we take advantage of the instability of a receding contact line towards cusp and droplet formation to produce linear patterns of variable spacings. We stabilize the instability of the cusps towards droplet formation by using polymer solutions that inhibit this secondary instability and give rise to long slender cylindrical filaments. We vary the speed of deposition to change the spacing between these filaments. The combination of the two gives rise to linear patterns into which different colloidal particles can be embedded, long DNA molecules can be stretched and particles filtered by size. The technique is therefore suitable to prepare anisotropic structures with variable properties.

  14. Fate tracing reveals hepatic stellate cells as dominant contributors to liver fibrosis independent of its aetiology

    NASA Astrophysics Data System (ADS)

    Mederacke, Ingmar; Hsu, Christine C.; Troeger, Juliane S.; Huebener, Peter; Mu, Xueru; Dapito, Dianne H.; Pradere, Jean-Philippe; Schwabe, Robert F.

    2013-11-01

    Although organ fibrosis causes significant morbidity and mortality in chronic diseases, the lack of detailed knowledge about specific cellular contributors mediating fibrogenesis hampers the design of effective antifibrotic therapies. Different cellular sources, including tissue-resident and bone marrow-derived fibroblasts, pericytes and epithelial cells, have been suggested to give rise to myofibroblasts, but their relative contributions remain controversial, with profound differences between organs and different diseases. Here we employ a novel Cre-transgenic mouse that marks 99% of hepatic stellate cells (HSCs), a liver-specific pericyte population, to demonstrate that HSCs give rise to 82-96% of myofibroblasts in models of toxic, cholestatic and fatty liver disease. Moreover, we exclude that HSCs function as facultative epithelial progenitor cells in the injured liver. On the basis these findings, HSCs should be considered the primary cellular target for antifibrotic therapies across all types of liver disease.

  15. Geometrical Solutions of Some Quadratic Equations with Non-Real Roots

    ERIC Educational Resources Information Center

    Pathak, H. K.; Grewal, A. S.

    2002-01-01

    This note gives geometrical/graphical methods of finding solutions of the quadratic equation ax[squared] + bx + c = 0, a [not equal to] 0, with non-real roots. Three different cases which give rise to non-real roots of the quadratic equation have been discussed. In case I a geometrical construction and its proof for finding the solutions of the…

  16. Targeting Cell Polarity Machinery to Exhaust Breast Cancer Stem Cells

    DTIC Science & Technology

    2017-10-01

    resemble normal stem cells, specifically in the ability to infinitely give rise to the bulk of a tumor as the “seed” of the cancer, account for cancer...infinitely give rise to the bulk of a tumor as the “seed” of the cancer, account for cancer initiation, progression, recurrence, and chemo...cell population that can infinitely give rise to the bulk of a tumor as the “seed” of the cancer, account for cancer initiation, progression, radio

  17. 26 CFR 1.381(c)(16)-1 - Obligations of distributor or transferor corporation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... obligation of a distributor or transferor corporation which gives rise to a liability after the date of... shall govern: (i) If the obligation gave rise to a liability before the date of distribution or transfer, see section 381(c)(4) and the regulations thereunder. (ii) If the obligation gives rise to a liability...

  18. Emergent properties of magnetic materials

    NASA Astrophysics Data System (ADS)

    Ratcliff, William Davis, II

    In Tolstoy's War and Peace, history is presented as a tapestry spun from the daily interactions of large numbers of individuals. Even if one understands individuals, it is very difficult to predict history. Similarly, the interactions of large numbers of electrons give rise to properties that one would not initially guess from their microscopic interactions. During the course of my dissertation, I have explored emergent phenomena in a number of contexts. In ZnCr2O4, geometric frustration gives rise to a plethora of equivalent ground states. From these, a lower dimensional set of collinear spins on hexagons are selected to form the building blocks of the lattice. In MgTi2O4, quantum spins dimerize and form a unique chiral ordering pattern on the spinel lattice. Descending into two dimensions, differences in size and charge give rise to an ordering between triangular layers of magnetic and nonmagnetic ions. This triangular lattice allows for the possibility of observing the RVB spin liquid state, or perhaps a valence bond crystal and initial measurements are promising. Also, on the spinel lattice, ionic ordering gives rise to one dimensional chains with their own interesting physics. Finally, in the SrCoxTi1-x O3, system we find that upon reduction, tiny clusters of Co metal precipitate out and chemical inhomogeneity on the microscale may determine much of the physics. This has relevance to a number of recent claims of room temperature ferromagnism in dilute magnetic systems. In all of these systems, complex behavior emerges from well understood microscopic behavior. For me, this is the fascination of strongly correlated electronic systems.

  19. A Hilbert Space Geometric Representation of Shared Awareness and Joint Decision Making

    ERIC Educational Resources Information Center

    Canan, Mustafa

    2017-01-01

    Two people in the same situation may ascribe very different meanings to their experiences. They will form different awareness, reacting differently to shared information. Various factors can give rise to this behavior. These factors include, but are not limited to, prior knowledge, training, biases, cultural factors, social factors, team vs.…

  20. Can nonstandard interactions jeopardize the hierarchy sensitivity of DUNE?

    NASA Astrophysics Data System (ADS)

    Deepthi, K. N.; Goswami, Srubabati; Nath, Newton

    2017-10-01

    We study the effect of nonstandard interactions (NSIs) on the propagation of neutrinos through the Earth's matter and how it affects the hierarchy sensitivity of the DUNE experiment. We emphasize the special case when the diagonal NSI parameter ɛe e=-1 , nullifying the standard matter effect. We show that if, in addition, C P violation is maximal then this gives rise to an exact intrinsic hierarchy degeneracy in the appearance channel, irrespective of the baseline and energy. Introduction of the off diagonal NSI parameter, ɛe τ, shifts the position of this degeneracy to a different ɛe e. Moreover the unknown magnitude and phases of the off diagonal NSI parameters can give rise to additional degeneracies. Overall, given the current model independent limits on NSI parameters, the hierarchy sensitivity of DUNE can get seriously impacted. However, a more precise knowledge of the NSI parameters, especially ɛe e, can give rise to an improved sensitivity. Alternatively, if a NSI exists in nature, and still DUNE shows hierarchy sensitivity, certain ranges of the NSI parameters can be excluded. Additionally, we briefly discuss the implications of ɛe e=-1 (in the Earth) on the Mikheyev-Smirnov-Wolfenstein effect in the Sun.

  1. Molecular tools for studying plant genetic diversity

    USDA-ARS?s Scientific Manuscript database

    The ubiquitous nature of DNA is a central theme for all biology. The nucleus of each cell that makes up an organism contains genomic DNA, which is the blueprint for life. The differential expression of genes within each cell gives rise to different tissues, organs and, ultimately, different organi...

  2. "Religion" in Educational Spaces: Knowing, Knowing Well, and Knowing Differently

    ERIC Educational Resources Information Center

    I'Anson, John; Jasper, Alison

    2011-01-01

    The focus of this article is how "religion", as a materially heterogeneous concept, becomes mobilized in different educational spaces, and the "kinds of knowing" to which this gives rise. Three "case studyish" illustrations are deployed in order to consider how religion and education produce kinds of knowing which…

  3. Crystal structure of ethyl (E)-2-cyano-3-(thio-phen-2-yl)acrylate: two conformers forming a discrete disorder.

    PubMed

    Castro Agudelo, Brian; Cárdenas, Juan C; Macías, Mario A; Ochoa-Puentes, Cristian; Sierra, Cesar A

    2017-09-01

    In the title compound, C 10 H 9 NO 2 S, all the non-H atoms, except for the ethyl fragment, lie nearly in the same plane. Despite the mol-ecular planarity, the ethyl fragment presents more than one conformation, giving rise to a discrete disorder, which was modelled with two different crystallographic sites for the eth-oxy O and eth-oxy α-C atoms, with occupancy values of 0.5. In the crystal, the three-dimensional array is mainly directed by C-H⋯(O,N) inter-actions, giving rise to inversion dimers with R 2 2 (10) and R 2 2 (14) motifs and infinite chains running along the [100] direction.

  4. Analysis of mutational changes at the HLA locus in single human sperm.

    PubMed

    Huang, M M; Erlich, H A; Goodman, M F; Arnheim, N

    1995-01-01

    Using a simple and efficient single sperm PCR and direct sequencing method, we screened for HLA-DPB1 gene mutations that may give rise to new alleles at this highly polymorphic locus. More than 800 single sperm were studied from a heterozygous individual whose two alleles carried 16 nucleotide sequence differences clustered in six polymorphic regions. A potential microgene conversion event was detected. Unrepaired heteroduplex DNA similar to that which gives rise to postmeiotic segregation events in yeast was observed in three cases. Control experiments also revealed unusual sperm from DPB1 homozygous individuals. The data may help explain allelic diversity in the MHC and suggest that a possible source of human mosaicism may be incomplete DNA mismatch repair during gametogenesis.

  5. IMPERVIOUS COVER AS A REGIONAL INDICATOR

    EPA Science Inventory

    Increases in impervious surface area in a watershed gives rise to changes in stream hydrology, stream channel morphology, increased pollutant runoff, and an increase in stream water temperature. These physical changes in the stream systems in turn give rise to impacts on stream ...

  6. Effect of different forms of fungal biopreparation for increasing quality of Picea obovata seedlings

    Treesearch

    T. I. Gromovykh; A. L. Malinovsky; T. A. Koryanova

    2002-01-01

    The current stage of societal development is characterized by ecological deterioration, with the application of chemicals for the prevention of pests and plant diseases giving rise to new problems in environmental protection.

  7. Does Grammatical Aspect Affect Motion Event Cognition? A Cross-Linguistic Comparison of English and Swedish Speakers

    ERIC Educational Resources Information Center

    Athanasopoulos, Panos; Bylund, Emanuel

    2013-01-01

    In this article, we explore whether cross-linguistic differences in grammatical aspect encoding may give rise to differences in memory and cognition. We compared native speakers of two languages that encode aspect differently (English and Swedish) in four tasks that examined verbal descriptions of stimuli, online triads matching, and memory-based…

  8. The Sequence of Study Changes What Information Is Attended to, Encoded, and Remembered during Category Learning

    ERIC Educational Resources Information Center

    Carvalho, Paulo F.; Goldstone, Robert L.

    2017-01-01

    The sequence of study influences how we learn. Previous research has identified different sequences as potentially beneficial for learning in different contexts and with different materials. Here we investigate the mechanisms involved in inductive category learning that give rise to these sequencing effects. Across 3 experiments we show evidence…

  9. Environmental values and their relationship to ecological services

    Treesearch

    Herbert W. Schroeder

    2011-01-01

    Natural environments give rise to value in diverse ways for different people and groups. In this paper, I present a conceptual scheme for how different kinds of value may arise from a natural environment. I use this scheme to illustrate the different ways in which people value natural environments and to clarify the relationship between environmental values and...

  10. 48 CFR 3.904 - Procedures for filing complaints.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... IMPROPER BUSINESS PRACTICES AND PERSONAL CONFLICTS OF INTEREST Whistleblower Protections for Contractor... substantial violation of law giving rise to the disclosure; (4) The nature of the disclosure giving rise to the discriminatory act; and (5) The specific nature and date of the reprisal. ...

  11. 2 CFR 1532.1600 - What definitions apply specifically to actions under this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., floating craft, location or site of operations that gives rise to a CAA or CWA conviction, and is a... transactions may be performed. If a site of operations giving rise to a CAA or CWA conviction contains or...

  12. Subtraction of Positive and Negative Numbers: The Difference and Completion Approaches with Chips

    ERIC Educational Resources Information Center

    Flores, Alfinio

    2008-01-01

    Diverse contexts such as "take away," comparison," and "completion" give rise to subtraction problems. The take-away interpretation of subtraction has been explored using two-colored chips to help students understand addition and subtraction of integers. This article illustrates how the difference and completion (or missing addend) interpretations…

  13. 13 CFR 114.102 - When, where and how do I present a claim?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Office nearest to the site of the action giving rise to the claim and within the same state as the site... Office nearest to the site of the action giving rise to the claim. (c) How. You must use an official form...

  14. Diffuse Scattering from Lead-Containing Ferroelectric Perovskite Oxides

    DOE PAGES

    Goossens, D. J.

    2013-01-01

    Ferroelectric materials rely on some type of non-centrosymmetric displacement correlations to give rise to a macroscopic polarisation. These displacements can show short-range order (SRO) that is reflective of the local chemistry, and so studying it reveals important information about how the structure gives rise to the technologically useful properties. A key means of exploring this SRO is diffuse scattering. Conventional structural studies use Bragg peak intensitiesto determine the average structure. In a single crystal diffuse scattering (SCDS) experiment, the coherent scattered intensity is measured at non-integer Miller indices, and can be used to examine the population of local configurations. Thismore » is because the diffuse scattering is sensitive to two-body averages, whereas the Bragg intensity gives single-body averages. This review outlines key results of SCDS studies on several materials and explores the similarities and differences in their diffuse scattering. Random strains are considered, as are models based on a phonon-like picture or a more local-chemistry oriented picture. Limitations of the technique are discussed.« less

  15. An evaluation of rise time characterization and prediction methods

    NASA Technical Reports Server (NTRS)

    Robinson, Leick D.

    1994-01-01

    One common method of extrapolating sonic boom waveforms from aircraft to ground is to calculate the nonlinear distortion, and then add a rise time to each shock by a simple empirical rule. One common rule is the '3 over P' rule which calculates the rise time in milliseconds as three divided by the shock amplitude in psf. This rule was compared with the results of ZEPHYRUS, a comprehensive algorithm which calculates sonic boom propagation and extrapolation with the combined effects of nonlinearity, attenuation, dispersion, geometric spreading, and refraction in a stratified atmosphere. It is shown there that the simple empirical rule considerably overestimates the rise time estimate. In addition, the empirical rule does not account for variations in the rise time due to humidity variation or propagation history. It is also demonstrated that the rise time is only an approximate indicator of perceived loudness. Three waveforms with identical characteristics (shock placement, amplitude, and rise time), but with different shock shapes, are shown to give different calculated loudness. This paper is based in part on work performed at the Applied Research Laboratories, the University of Texas at Austin, and supported by NASA Langley.

  16. 17 CFR 142.2 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... employee, provided that the conduct giving rise to the verdict, judgment or award was taken within the... the United States, as determined by the Commission. (b) The Commission may settle or compromise a... alleged conduct giving rise to the personal damage claim was taken within the scope of employment and that...

  17. 39 CFR 3010.61 - Contents of exigent requests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... discussion of the extraordinary or exceptional circumstance(s) giving rise to the request, and a complete... States; (5) A full discussion of why the requested increases are reasonable and equitable as among types... of the circumstances giving rise to the request, which should, if applicable, include a discussion of...

  18. 32 CFR 750.2 - Investigations: In general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... give rise to a claim against the United States shall include the following: This investigation has been... command where the incident giving rise to the claim is alleged to have happened is responsible for... result in a claim against or in favor of the United States shall be promptly and thoroughly investigated...

  19. 15 CFR 15.31 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... defendant in any civil suit in state or federal court, or other legal proceeding seeking damages against a... is rendered against such employee, provided that the conduct giving rise to the verdict, judgment or... available funds at any time provided the alleged conduct giving rise to the personal property claim was...

  20. 15 CFR 15.31 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... defendant in any civil suit in state or federal court, or other legal proceeding seeking damages against a... is rendered against such employee, provided that the conduct giving rise to the verdict, judgment or... available funds at any time provided the alleged conduct giving rise to the personal property claim was...

  1. 20 CFR 430.101 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... award which is rendered against any such employee, provided that the conduct giving rise to the verdict... indemnification is in the interest of the United States, as determined by the Commissioner, or his or her designee... employee by the payment of available funds, at any time, provided the alleged conduct giving rise to the...

  2. 7 CFR 1.501 - Policy on employee indemnification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... her employment, giving rise to a verdict, judgment, or other monetary award rendered against the... her discretion, that the conduct giving rise to such verdict, judgment, or award was taken within the... United States. (c) The Department of Agriculture may pay for the settlement or compromise of a personal...

  3. 17 CFR 142.2 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... employee, provided that the conduct giving rise to the verdict, judgment or award was taken within the... the United States, as determined by the Commission. (b) The Commission may settle or compromise a... alleged conduct giving rise to the personal damage claim was taken within the scope of employment and that...

  4. Using a Spreadsheet To Explore Melting, Dissolving and Phase Diagrams.

    ERIC Educational Resources Information Center

    Goodwin, Alan

    2002-01-01

    Compares phase diagrams relating to the solubilities and melting points of various substances in textbooks with those generated by a spreadsheet using data from the literature. Argues that differences between the diagrams give rise to new chemical insights. (Author/MM)

  5. Observation of Lyman-alpha emission in interplanetary space

    NASA Technical Reports Server (NTRS)

    Bertaux, J. L.; Blamont, J. E.

    1972-01-01

    The extraterrestrial Lyman-alpha emission was mapped by the OGO 5 satellite, when it was outside the geocorona. Three maps, obtained at different periods of the year, are presented and analyzed. The results suggest that at least half of the emission takes place in the solar system, and give strong support to the theory that in its motion toward the apex, the sun crosses neutral atomic hydrogen of interstellar origin, giving rise to an apparent interstellar wind.

  6. Sea level rise from the Greenland Ice Sheet during the Eemian interglacial: Review of previous work with focus on the surface mass balance

    NASA Astrophysics Data System (ADS)

    Plach, Andreas; Hestnes Nisancioglu, Kerim

    2016-04-01

    The contribution from the Greenland Ice Sheet (GIS) to the global sea level rise during the Eemian interglacial (about 125,000 year ago) was the focus of many studies in the past. A main reason for the interest in this period is the considerable warmer climate during the Eemian which is often seen as an equivalent for possible future climate conditions. Simulated sea level rise during the Eemian can therefore be used to better understand a possible future sea level rise. The most recent assessment report of the Intergovernmental Panel on Climate Change (IPCC AR5) gives an overview of several studies and discusses the possible implications for a future sea level rise. The report also reveals the big differences between these studies in terms of simulated GIS extent and corresponding sea level rise. The present study gives a more exhaustive review of previous work discussing sea level rise from the GIS during the Eemian interglacial. The smallest extents of the GIS simulated by various authors are shown and summarized. A focus is thereby given to the methods used to calculate the surface mass balance. A hypothesis of the present work is that the varying results of the previous studies can largely be explained due to the various methods used to calculate the surface mass balance. In addition, as a first step for future work, the surface mass balance of the GIS for a proxy-data derived forcing ("index method") and a direct forcing with a General Circulation Model (GCM) are shown and discussed.

  7. The NEO-FFI in Multiple Sclerosis: Internal Consistency, Factorial Validity, and Correspondence between Self and Informant Reports

    ERIC Educational Resources Information Center

    Schwartz, Eben S.; Chapman, Benjamin P.; Duberstein, Paul R.; Weinstock-Guttman, Bianca; Benedict, Ralph H. B.

    2011-01-01

    Personality assessment is a potentially important component of clinical and empirical work with neurological patients because (a) individual differences in personality may be associated with different neurological outcomes and (b) central nervous system changes may give rise to alteration in personality. For personality assessment to be useful to…

  8. Plant Tissue Culture Development and Biotechnology, Chapter 10: Molecular Tools for Studying Plant Genetic Diversity

    USDA-ARS?s Scientific Manuscript database

    The ubiquitous nature of DNA is a central theme for all biology. The nucleus of each cell that makes up an organism contains genomic DNA, which is the blueprint for life. The differential expression of genes within each cell gives rise to different tissues, organs and, ultimately, different organism...

  9. Women in Experiential Education Speak Out: An Anthology of Personal Stories across Cultures.

    ERIC Educational Resources Information Center

    Roberts, Nina S.; Winiarczyk, Ellen J.

    The collection of stories gives voice to the variety of women's experiences rising out of ethnicity, race, class, and generational differences as well as to the simple individual histories of women. Five women with a wide range of differences, including African American, Native American, and Japanese women, share their experiences in, and…

  10. Covariant hamiltonian spin dynamics in curved space-time

    NASA Astrophysics Data System (ADS)

    d'Ambrosi, G.; Satish Kumar, S.; van Holten, J. W.

    2015-04-01

    The dynamics of spinning particles in curved space-time is discussed, emphasizing the hamiltonian formulation. Different choices of hamiltonians allow for the description of different gravitating systems. We give full results for the simplest case with minimal hamiltonian, constructing constants of motion including spin. The analysis is illustrated by the example of motion in Schwarzschild space-time. We also discuss a non-minimal extension of the hamiltonian giving rise to a gravitational equivalent of the Stern-Gerlach force. We show that this extension respects a large class of known constants of motion for the minimal case.

  11. 22 CFR 207.01 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., provided that the conduct giving rise to the verdict, judgment or award was taken within the scope of his... States, as determined by the Administrator, or his or her designee, in his or her discretion. (b) A.I.D... funds, at any time, provided the alleged conduct giving rise to the personal damage claim was taken...

  12. 32 CFR 536.50 - Determination of damages-applicable law.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ACCOUNTS CLAIMS AGAINST THE UNITED STATES Investigation and Processing of Claims § 536.50 Determination of... giving rise to the claim occurred, including choice of law rules, is applicable. Therefore, the law of... claims accruing on or after September 1, 1995. The law of the place of the incident giving rise to the...

  13. 22 CFR 207.01 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., provided that the conduct giving rise to the verdict, judgment or award was taken within the scope of his... States, as determined by the Administrator, or his or her designee, in his or her discretion. (b) A.I.D... funds, at any time, provided the alleged conduct giving rise to the personal damage claim was taken...

  14. COMPLETE INHIBITION OF SPONTANEOUS ACTIVITY IN NEURONAL NETWORKS IN VITRO BY DELTAMETHRIN AND PERMETHRIN

    EPA Science Inventory

    Type I and II pyrethroid insecticides cause temporally distinct decreases in voltage-gated sodium channel (VGSC) inactivation rates that are proposed to underlie their characteristic differences in toxicity signs. How alterations in VGSC channel function give rise to the characte...

  15. Diagnosing Portuguese Students' Misconceptions about the Mineral Concept

    ERIC Educational Resources Information Center

    Monteiro, Antonio; Nobrega, Clevio; Abrantes, Isabel; Gomes, Celeste

    2012-01-01

    Educational researchers and teachers are well aware that misconceptions--erroneous ideas that differ from the scientifically accepted ones--are very common amongst students. Daily experiences, creative and perceptive thinking and science textbooks give rise to students' misconceptions which lead them to draw erroneous conclusions that become…

  16. 34 CFR 60.1 - What are the policies of the Department regarding indemnification?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., judgment, or other monetary award rendered against the employee if— (i) The conduct giving rise to the... (ii) The indemnification is in the interest of the United States, as determined by the Secretary. (2... giving rise to the personal damage claim occurred within the scope of employment; and (ii) The settlement...

  17. 2 CFR 1532.1600 - What definitions apply specifically to actions under this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., partnership, association, state, municipality, commission, or political subdivision of a state, or any..., floating craft, location or site of operations that gives rise to a CAA or CWA conviction, and is a... transactions may be performed. If a site of operations giving rise to a CAA or CWA conviction contains or...

  18. 78 FR 52594 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ... registered representative learns of the facts or circumstances giving rise to the event (i.e., the filing of the judgment or lien).\\4\\ \\4\\ See FINRA By-Laws, Article V, Section 2(c), which states that every... after learning of the facts or circumstances giving rise to the amendment. In connection with fee...

  19. Asset Prices and Trading Volume under Fixed Transactions Costs.

    ERIC Educational Resources Information Center

    Lo, Andrew W.; Mamaysky, Harry; Wang, Jiang

    2004-01-01

    We propose a dynamic equilibrium model of asset prices and trading volume when agents face fixed transactions costs. We show that even small fixed costs can give rise to large "no-trade" regions for each agent's optimal trading policy. The inability to trade more frequently reduces the agents' asset demand and in equilibrium gives rise to a…

  20. A novel first exon directs hormone-sensitive transcription of the pig prolactin receptor

    USDA-ARS?s Scientific Manuscript database

    Endocrine, paracrine, and autocrine prolactin (PRL) acts through its receptor (PRLR) to confer a wide range of biological functions, including its established role during lactation.We have identified a novel first exon of the porcine PRLR that gives rise to three different mRNA transcripts. Transcri...

  1. Early Detection of Markers for Synaesthesia in Childhood Populations

    ERIC Educational Resources Information Center

    Simner, Julia; Harrold, Jenny; Creed, Harriet; Monro, Louise; Foulkes, Louise

    2009-01-01

    We show that the neurological condition of synaesthesia--which causes fundamental differences in perception and cognition throughout a lifetime--is significantly represented within the childhood population, and that it manifests behavioural markers as young as age 6 years. Synaesthesia gives rise to a merging of cognitive and/or sensory functions…

  2. Mathematical background of Parrondo's paradox

    NASA Astrophysics Data System (ADS)

    Behrends, Ehrhard

    2004-05-01

    Parrondo's paradox states that there are losing gambling games which, when being combined stochastically or in a suitable deterministic way, give rise to winning games. Here we investigate the probabilistic background. We show how the properties of the equilibrium distributions of the Markov chains under consideration give rise to the paradoxical behavior, and we provide methods how to find the best a priori strategies.

  3. 26 CFR 1.6694-1 - Section 6694 penalties applicable to tax return preparers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... provides the tax advice with respect to the position giving rise to the understatement. This date will be... advice that is given with respect to events that have occurred at the time the advice is rendered and... a reasonable allocation of the lump sum fee between the tax advice giving rise to the penalty and...

  4. Complex numbers in chemometrics: examples from multivariate impedance measurements on lipid monolayers.

    PubMed

    Geladi, Paul; Nelson, Andrew; Lindholm-Sethson, Britta

    2007-07-09

    Electrical impedance gives multivariate complex number data as results. Two examples of multivariate electrical impedance data measured on lipid monolayers in different solutions give rise to matrices (16x50 and 38x50) of complex numbers. Multivariate data analysis by principal component analysis (PCA) or singular value decomposition (SVD) can be used for complex data and the necessary equations are given. The scores and loadings obtained are vectors of complex numbers. It is shown that the complex number PCA and SVD are better at concentrating information in a few components than the naïve juxtaposition method and that Argand diagrams can replace score and loading plots. Different concentrations of Magainin and Gramicidin A give different responses and also the role of the electrolyte medium can be studied. An interaction of Gramicidin A in the solution with the monolayer over time can be observed.

  5. The Ising model coupled to 2d orders

    NASA Astrophysics Data System (ADS)

    Glaser, Lisa

    2018-04-01

    In this article we make first steps in coupling matter to causal set theory in the path integral. We explore the case of the Ising model coupled to the 2d discrete Einstein Hilbert action, restricted to the 2d orders. We probe the phase diagram in terms of the Wick rotation parameter β and the Ising coupling j and find that the matter and the causal sets together give rise to an interesting phase structure. The couplings give rise to five different phases. The causal sets take on random or crystalline characteristics as described in Surya (2012 Class. Quantum Grav. 29 132001) and the Ising model can be correlated or uncorrelated on the random orders and correlated, uncorrelated or anti-correlated on the crystalline orders. We find that at least one new phase transition arises, in which the Ising spins push the causal set into the crystalline phase.

  6. Interconnect-free parallel logic circuits in a single mechanical resonator

    PubMed Central

    Mahboob, I.; Flurin, E.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

    2011-01-01

    In conventional computers, wiring between transistors is required to enable the execution of Boolean logic functions. This has resulted in processors in which billions of transistors are physically interconnected, which limits integration densities, gives rise to huge power consumption and restricts processing speeds. A method to eliminate wiring amongst transistors by condensing Boolean logic into a single active element is thus highly desirable. Here, we demonstrate a novel logic architecture using only a single electromechanical parametric resonator into which multiple channels of binary information are encoded as mechanical oscillations at different frequencies. The parametric resonator can mix these channels, resulting in new mechanical oscillation states that enable the construction of AND, OR and XOR logic gates as well as multibit logic circuits. Moreover, the mechanical logic gates and circuits can be executed simultaneously, giving rise to the prospect of a parallel logic processor in just a single mechanical resonator. PMID:21326230

  7. Interconnect-free parallel logic circuits in a single mechanical resonator.

    PubMed

    Mahboob, I; Flurin, E; Nishiguchi, K; Fujiwara, A; Yamaguchi, H

    2011-02-15

    In conventional computers, wiring between transistors is required to enable the execution of Boolean logic functions. This has resulted in processors in which billions of transistors are physically interconnected, which limits integration densities, gives rise to huge power consumption and restricts processing speeds. A method to eliminate wiring amongst transistors by condensing Boolean logic into a single active element is thus highly desirable. Here, we demonstrate a novel logic architecture using only a single electromechanical parametric resonator into which multiple channels of binary information are encoded as mechanical oscillations at different frequencies. The parametric resonator can mix these channels, resulting in new mechanical oscillation states that enable the construction of AND, OR and XOR logic gates as well as multibit logic circuits. Moreover, the mechanical logic gates and circuits can be executed simultaneously, giving rise to the prospect of a parallel logic processor in just a single mechanical resonator.

  8. A tale of two timescales: Mixing, mass generation, and phase transitions in the early universe

    NASA Astrophysics Data System (ADS)

    Dienes, Keith R.; Kost, Jeff; Thomas, Brooks

    2016-02-01

    Light scalar fields such as axions and string moduli can play an important role in early-universe cosmology. However, many factors can significantly impact their late-time cosmological abundances. For example, in cases where the potentials for these fields are generated dynamically—such as during cosmological mass-generating phase transitions—the duration of the time interval required for these potentials to fully develop can have significant repercussions. Likewise, in scenarios with multiple scalars, mixing amongst the fields can also give rise to an effective timescale that modifies the resulting late-time abundances. Previous studies have focused on the effects of either the first or the second timescale in isolation. In this paper, by contrast, we examine the new features that arise from the interplay between these two timescales when both mixing and time-dependent phase transitions are introduced together. First, we find that the effects of these timescales can conspire to alter not only the total late-time abundance of the system—often by many orders of magnitude—but also its distribution across the different fields. Second, we find that these effects can produce large parametric resonances which render the energy densities of the fields highly sensitive to the degree of mixing as well as the duration of the time interval over which the phase transition unfolds. Finally, we find that these effects can even give rise to a "reoverdamping" phenomenon which causes the total energy density of the system to behave in novel ways that differ from those exhibited by pure dark matter or vacuum energy. All of these features therefore give rise to new possibilities for early-universe phenomenology and cosmological evolution. They also highlight the importance of taking into account the time dependence associated with phase transitions in cosmological settings.

  9. A Context-Based Theory of Recency and Contiguity in Free Recall

    ERIC Educational Resources Information Center

    Sederberg, Per B.; Howard, Marc W.; Kahana, Michael J.

    2008-01-01

    The authors present a new model of free recall on the basis of M. W. Howard and M. J. Kahana's temporal context model and M. Usher and J. L. McClelland's leaky-accumulator decision model. In this model, contextual drift gives rise to both short-term and long-term recency effects, and contextual retrieval gives rise to short-term and long-term…

  10. The Cost of Concreteness: The Effect of Nonessential Information on Analogical Transfer

    ERIC Educational Resources Information Center

    Kaminski, Jennifer A.; Sloutsky, Vladimir M.; Heckler, Andrew F.

    2013-01-01

    Most theories of analogical transfer focus on similarities between the learning and transfer domains, where transfer is more likely between domains that share common surface features, similar elements, or common interpretations of structure. We suggest that characteristics of the learning instantiation alone can give rise to different levels of…

  11. Agents Pedagogical: Bootstrapping Reflexive Practice through the Psychological Resources of Self-Agency

    ERIC Educational Resources Information Center

    Maclellan, Effie

    2016-01-01

    Two different strands of evidence coalesce to give rise to the issue of concern in this paper. Firstly, proposals for educational reform assert that teacher-agency is necessary for "effective" reform. Indeed it is argued that it is agency which drives the construction/reconstruction of professional knowledge, to influence and transform…

  12. 77 FR 8127 - Foreign Tax Credit Splitting Events

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... (or periods) due to, for example, timing differences between the U.S. and foreign tax accounting rules... paid or accrued by the owner of a U.S. equity hybrid instrument with respect to payments or accruals on.... equity hybrid instrument in an amount equal to the payments or accruals giving rise to the split taxes...

  13. Development of Lexical and Syntactic Representations: The Acquisition of Symmetrical and Asymmetrical Verbs

    ERIC Educational Resources Information Center

    Gurcanli, Ozge

    2013-01-01

    This dissertation concerns the acquisition of the interaction between lexicosemantic properties of verbs and syntax, focusing on symmetrical and asymmetrical verbs in different syntactic structures. Based on linguistic evidence, it is shown that two conceptual categories, Mutuality and Number, interact to give rise to four event-types: Single…

  14. Plausible Reasoning in Tactical Planning.

    DTIC Science & Technology

    1987-04-01

    different contexts and tasks that give rise to mappings, and the set of issues and different resolutions to these issues that have been proposed in the...humans use in reasoning about the wo~ ld ( Polya , 1958; Collins, 1978a). Our work attempts to formalize the plausible inferences that frequently occur in...are interconnected by traces. Each hierarchy represents knowledge about a class of concepts arranged in a tree structure according to some viewpoint

  15. Nonlinear dynamics, chaos and complex cardiac arrhythmias

    NASA Technical Reports Server (NTRS)

    Glass, L.; Courtemanche, M.; Shrier, A.; Goldberger, A. L.

    1987-01-01

    Periodic stimulation of a nonlinear cardiac oscillator in vitro gives rise to complex dynamics that is well described by one-dimensional finite difference equations. As stimulation parameters are varied, a large number of different phase-locked and chaotic rhythms is observed. Similar rhythms can be observed in the intact human heart when there is interaction between two pacemaker sites. Simplified models are analyzed, which show some correspondence to clinical observations.

  16. Nanometer-Scale Force Detected Nuclear Magnetic Resonance Imaging

    DTIC Science & Technology

    2013-01-01

    different crystallographic orientation. Single crystal thin films should thus minimize the stray electric fields by reducing the number of grain ...from epitaxial Ag films, rather than polycrystalline Ag films. It is thought that grain boundaries in polycrystalline metal films give rise to stray...electric fields near the surface of the film. The electric fields are produced as a consequence of the work func- tion difference between grains of

  17. On the Implementation and Performance of Iterative Methods for Computational Electromagnetics

    DTIC Science & Technology

    1985-12-01

    based on F3 only if L is self-adjoint and positive definite in the sense of Griffel [651. Each of the above functionals gives rise to a different...New York: Wiley, 1960. [65] D. H. Griffel , Applied Functional Analysis. New York: Wiley, 1981. [661 R. Fletcher and C. M. Reeves, "Functional

  18. Student Ability to Distinguish between Superposition States and Mixed States in Quantum Mechanics

    ERIC Educational Resources Information Center

    Passante, Gina; Emigh, Paul J.; Shaffer, Peter S.

    2015-01-01

    Superposition gives rise to the probabilistic nature of quantum mechanics and is therefore one of the concepts at the heart of quantum mechanics. Although we have found that many students can successfully use the idea of superposition to calculate the probabilities of different measurement outcomes, they are often unable to identify the…

  19. The Structure of Human Memory. Technical Report No. 321.

    ERIC Educational Resources Information Center

    Brewer, William F.; Pani, John R.

    The four sections of this paper provide an analysis of the structure of human memory. The first section, intended to provide a clear example of personal memory, examines a hypothetical episode in the life of an undergraduate student, and shows how one episode can give rise to three different forms of memory: personal, semantic, and rote…

  20. Would You Like to Get along with Difficult People? Pick a Number

    ERIC Educational Resources Information Center

    Talley, Karen

    2005-01-01

    Working closely with others often gives rise to conflicts as each individual is driven by different and usually conflicting preoccupations and concerns. This article discusses the 3,000 year old 9-sided star-shaped paradigm known as Enneagram and how it is advantageous to early childhood professionals. This personality inventory purports that…

  1. Social Context as an Indirect Trigger in EFL Contexts: Issues and Solutions

    ERIC Educational Resources Information Center

    Gholami, Reza; Rahman, Sharifah Zainab Abd; Mustapha, Ghazali

    2012-01-01

    This paper investigates the value of the social context and its role in learning a second language in different contexts. Social context is believed to be able to influence attitude and motivation. It also provides learning opportunities which give rise to learner's outcomes. In fact, students acquire a language by using it in social interaction…

  2. The Information in Multiple Ratings

    ERIC Educational Resources Information Center

    Bock, R. Darrell; Brennan, Robert L.; Muraki, Eiji

    2002-01-01

    In assessment programs where scores are reported for individual examinees, it is desirable to have responses to performance exercises graded by more than one rater. If more than one item on each test form is so graded, it is also desirable that different raters grade the responses of any one examinee. This gives rise to sampling designs in which…

  3. Classification of basic facilities for high-rise residential: A survey from 100 housing scheme in Kajang area

    NASA Astrophysics Data System (ADS)

    Ani, Adi Irfan Che; Sairi, Ahmad; Tawil, Norngainy Mohd; Wahab, Siti Rashidah Hanum Abd; Razak, Muhd Zulhanif Abd

    2016-08-01

    High demand for housing and limited land in town area has increasing the provision of high-rise residential scheme. This type of housing has different owners but share the same land lot and common facilities. Thus, maintenance works of the buildings and common facilities must be well organized. The purpose of this paper is to identify and classify basic facilities for high-rise residential building hoping to improve the management of the scheme. The method adopted is a survey on 100 high-rise residential schemes that ranged from affordable housing to high cost housing by using a snowball sampling. The scope of this research is within Kajang area, which is rapidly developed with high-rise housing. The objective of the survey is to list out all facilities in every sample of the schemes. The result confirmed that pre-determined 11 classifications hold true and can provide the realistic classification for high-rise residential scheme. This paper proposed for redefinition of facilities provided to create a better management system and give a clear definition on the type of high-rise residential based on its facilities.

  4. Social Behavior in Medulloblastoma: Functional Analysis of Tumor-Supporting Glial Cells

    DTIC Science & Technology

    2015-10-01

    GNPs are unipotent and only give rise to granule neurons. However, using MADM, a mouse genetic mosaic model, we found that medulloblastoma contain...demonstrated that GNPs are unipotent and only give rise to granule neurons. However, using MADM, a mouse genetic mosaic model with lineage tracing capability...UVa Animal Care and Use Committee, and got the approval. We then submitted ACURO documents and IACUC approval by UVa to USAMRMC Office of Research

  5. System and method for trapping and measuring a charged particle in a liquid

    DOEpatents

    Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

    2013-07-23

    A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

  6. System and method for trapping and measuring a charged particle in a liquid

    DOEpatents

    Reed, Mark A; Krstic, Predrag S; Guan, Weihua; Zhao, Xiongce

    2012-10-23

    A system and method for trapping a charged particle is disclosed. A time-varying periodic multipole electric potential is generated in a trapping volume. A charged particle under the influence of the multipole electric field is confined to the trapping volume. A three electrode configuration giving rise to a 3D Paul trap and a four planar electrode configuration giving rise to a 2D Paul trap are disclosed.

  7. FGF signalling controls the specification of hair placode-derived SOX9 positive progenitors to Merkel cells.

    PubMed

    Nguyen, Minh Binh; Cohen, Idan; Kumar, Vinod; Xu, Zijian; Bar, Carmit; Dauber-Decker, Katherine L; Tsai, Pai-Chi; Marangoni, Pauline; Klein, Ophir D; Hsu, Ya-Chieh; Chen, Ting; Mikkola, Marja L; Ezhkova, Elena

    2018-06-13

    Merkel cells are innervated mechanosensory cells responsible for light-touch sensations. In murine dorsal skin, Merkel cells are located in touch domes and found in the epidermis around primary hairs. While it has been shown that Merkel cells are skin epithelial cells, the progenitor cell population that gives rise to these cells is unknown. Here, we show that during embryogenesis, SOX9-positive (+) cells inside hair follicles, which were previously known to give rise to hair follicle stem cells (HFSCs) and cells of the hair follicle lineage, can also give rise to Merkel Cells. Interestingly, while SOX9 is critical for HFSC specification, it is dispensable for Merkel cell formation. Conversely, FGFR2 is required for Merkel cell formation but is dispensable for HFSCs. Together, our studies uncover SOX9(+) cells as precursors of Merkel cells and show the requirement for FGFR2-mediated epithelial signalling in Merkel cell specification.

  8. The problem of the origin of primordial germ cells (PGCs) in vertebrates: historical review and a possible solution.

    PubMed

    Pilato, Giovanni; D'Urso, Vera; Viglianisi, Fabio; Sammartano, Francesca; Sabella, Giorgio; Lisi, Oscar

    2013-01-01

    A concise review of the articles about the origin of primordial germ cells (PGCs) in vertebrates is provided. Differences among various taxa concerning the origin of PGCs, not easily understandable on the base of traditional knowledge, are pointed out. All those differences can be explained taking into consideration the recent “theory of the endoderm as secondary layer”. That theory allows us to understand that those differences are only apparent, being related to modifications of stages of the consequent embryogeny, overall, to a different amount of yolk in the egg. Eggs very rich in yolk became meroblastic, and the portion of primordial ectomesenchyme destined to give rise to a part of the mesoderm and the PGCs separates early from the part destined to give rise to the rest of the mesoderm and to the digestive endoderm in order to form the vitelline hypoblast lamina. To this lamina, in contrast to the traditional interpretation, a mesodermal, not endodermal, origin must be attributed. With the misunderstanding regarding the origin of this lamina clarified, all the differences about the origin of PGCs disappears. Furthermore, in taxa where PGCs were considered to be of endodermal origin, they too have a mesodermal origin. Considering that a mesodermal origin of PGCs has been demonstrated in all sponges and cnidarians, as well, a unique, mesodermal origin of germinal cells in all pluricellular animals results.

  9. Charting the landscape of supercritical string theory.

    PubMed

    Hellerman, Simeon; Swanson, Ian

    2007-10-26

    Special solutions of string theory in supercritical dimensions can interpolate in time between theories with different numbers of spacetime dimensions and different amounts of world sheet supersymmetry. These solutions connect supercritical string theories to the more familiar string duality web in ten dimensions and provide a precise link between supersymmetric and purely bosonic string theories. Dimension quenching and c duality appear to be natural concepts in string theory, giving rise to large networks of interconnected theories.

  10. Acinar Cell Carcinoma of the Pancreas: Overview of Clinicopathologic Features and Insights into the Molecular Pathology.

    PubMed

    La Rosa, Stefano; Sessa, Fausto; Capella, Carlo

    2015-01-01

    Acinar cell carcinomas (ACCs) of the pancreas are rare pancreatic neoplasms accounting for about 1-2% of pancreatic tumors in adults and about 15% in pediatric subjects. They show different clinical symptoms at presentation, different morphological features, different outcomes, and different molecular alterations. This heterogeneous clinicopathological spectrum may give rise to difficulties in the clinical and pathological diagnosis with consequential therapeutic and prognostic implications. The molecular mechanisms involved in the onset and progression of ACCs are still not completely understood, although in recent years, several attempts have been made to clarify the molecular mechanisms involved in ACC biology. In this paper, we will review the main clinicopathological and molecular features of pancreatic ACCs of both adult and pediatric subjects to give the reader a comprehensive overview of this rare tumor type.

  11. Lanthanide complexes of azidophenacyl-DO3A as new synthons for click chemistry and the synthesis of heterometallic lanthanide arrays.

    PubMed

    Tropiano, Manuel; Kenwright, Alan M; Faulkner, Stephen

    2015-04-07

    Lanthanide complexes of azidophenacyl DO3A are effective substrates for click reactions with ethyne derivatives, giving rise to aryl triazole appended lanthanide complexes, in which the aryl triazole acts as an effective sensitising chromophore for lanthanide luminescence. They also undergo click chemistry with propargylDO3A derivatives, giving rise to heterometallic complexes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Leptogenesis from spin-gravity coupling following inflation.

    PubMed

    Mohanty, Subhendra; Prasanna, A R; Lambiase, G

    2006-02-24

    The energy levels of the left- and the right-handed neutrinos are split in the background of gravitational waves generated during inflation, which, in presence of lepton-number-violating interactions, gives rise to a net lepton asymmetry at equilibrium. Lepton number violation is achieved by the same dimension five operator which gives rise to neutrino masses after electroweak symmetry breaking. A net baryon asymmetry of the same magnitude can be generated from this lepton asymmetry by electroweak sphaleron processes.

  13. Control of the proportion of inner cells by asymmetric divisions and the ensuing resilience of cloned rabbit embryos

    PubMed Central

    Duranthon, Véronique

    2018-01-01

    ABSTRACT Mammalian embryo cloning by nuclear transfer has a low success rate. This is hypothesized to correlate with a high variability of early developmental steps that segregate outer cells, which are fated to extra-embryonic tissues, from inner cells, which give rise to the embryo proper. Exploring the cell lineage of wild-type embryos and clones, imaged in toto until hatching, highlights the respective contributions of cell proliferation, death and asymmetric divisions to phenotypic variability. Preferential cell death of inner cells in clones, probably pertaining to the epigenetic plasticity of the transferred nucleus, is identified as a major difference with effects on the proportion of inner cell. In wild type and clones, similar patterns of outer cell asymmetric divisions are shown to be essential to the robust proportion of inner cells observed in wild type. Asymmetric inner cell division, which is not described in mice, is identified as a regulator of the proportion of inner cells and likely gives rise to resilient clones. PMID:29567671

  14. Martensite Embryology

    NASA Astrophysics Data System (ADS)

    Reid, Andrew C. E.; Olson, Gregory B.

    2000-03-01

    Heterogeneous nucleation of martensite is modeled by examining the strain field of a dislocation array in a nonlinear, nonlocal continuum elastic matrix. The dislocations are modeled by including effects from atomic length scales, which control the dislocation Burger's vector, into a mesoscopic continuum model. The dislocation array models the heterogeneous nucleation source of the Olson/Cohen defect dissociation model, and depending on the potency can give rise to embryos of different character. High potency dislocations give rise to fully developed, classical pre-existing embryos, whereas low-potency dislocations result in the formation of highly nonclassical strain embryos. Heterogeneous nucleation theory is related to nucleation kinetics through the critical driving force for nucleation at a defect of a given potency. Recent stereological and calorimetric kinetic studies in thermoelastic TiNi alloys confirm that these materials exhibit the same form of defect potency distribution and resulting sample-size dependent Martensite start temperature, M_s, as nonthermoelastic FeNi systems. These results together point towards a broad theory of heterogeneous nucleation for both thermoelastic and nonthermoelastic martensites.

  15. Generation of structures formed by lens and retinal cells differentiating from embryonic stem cells.

    PubMed

    Hirano, Mariko; Yamamoto, Akitsugu; Yoshimura, Naoko; Tokunaga, Tomoyuki; Motohashi, Tsutomu; Ishizaki, Katsuhiko; Yoshida, Hisahiro; Okazaki, Kenji; Yamazaki, Hidetoshi; Hayashi, Shin-Ichi; Kunisada, Takahiro

    2003-12-01

    Embryonic stem cells have the potential to give rise to all cell lineages when introduced into the early embryo. They also give rise to a limited number of different cell types in vitro in specialized culture systems. In this study, we established a culture system in which a structure consisting of lens, neural retina, and pigmented retina was efficiently induced from embryonic stem cells. Refractile cell masses containing lens and neural retina were surrounded by retinal pigment epithelium layers and, thus, designated as eye-like structures. Developmental processes required for eye development appear to proceed in this culture system, because the formation of the eye-like structures depended on the expression of Pax6, a key transcription factor for eye development. The present culture system opens up the possibility of examining early stages of eye development and also of producing cells for use in cellular therapy for various diseases of the eye. Copyright 2003 Wiley-Liss, Inc.

  16. Glass transition of charged particles in two-dimensional confinement.

    PubMed

    Yazdi, Anoosheh; Heinen, Marco; Ivlev, Alexei; Löwen, Hartmut; Sperl, Matthias

    2015-05-01

    The glass transition of mesoscopic charged particles in two-dimensional confinement is studied by mode-coupling theory. We consider two types of effective interactions between the particles, corresponding to two different models for the distribution of surrounding ions that are integrated out in coarse-grained descriptions. In the first model, a planar monolayer of charged particles is immersed in an unbounded isotropic bath of ions, giving rise to an isotropically screened Debye-Hückel (Yukawa)-type effective interaction. The second, experimentally more relevant system is a monolayer of negatively charged particles that levitate atop a flat horizontal electrode, as frequently encountered in laboratory experiments with complex (dusty) plasmas. A steady plasma current toward the electrode gives rise to an anisotropic effective interaction potential between the particles, with an algebraically long-ranged in-plane decay. In a comprehensive parameter scan that covers the typical range of experimentally accessible plasma conditions, we calculate and compare the mode-coupling predictions for the glass transition in both kinds of systems.

  17. Cosmological density fluctuations produced by vacuum strings

    NASA Astrophysics Data System (ADS)

    Vilenkin, A.

    1981-04-01

    Consideration is given to the possible role of vacuum domain strings produced in the grand unification phase transition in the early universe in the generation of the density fluctuations giving rise to galaxies. The cosmological evolution of the strings formed in the grand unification phase transition is analyzed, with attention given to possible mechanisms for the damping out of oscillations produced by tension in convoluted strings and closed loops. The cosmological density fluctuations introduced by infinite strings and closed loops smaller than the horizon are then shown to be capable of giving rise to mass condensations on a scale of approximately 10 to the 9th solar masses at the time of the decoupling of radiation from matter, around which the galaxies condense. Differences between the present theory and that suggested by Zel'dovich (1980) are pointed out, and it is noted that string formation at the grand unification phase transition is possible only if the manifold of the degenerate vacua of the gauge theory is not simply connected.

  18. Generalized nucleation and looping model for epigenetic memory of histone modifications

    PubMed Central

    Erdel, Fabian; Greene, Eric C.

    2016-01-01

    Histone modifications can redistribute along the genome in a sequence-independent manner, giving rise to chromatin position effects and epigenetic memory. The underlying mechanisms shape the endogenous chromatin landscape and determine its response to ectopically targeted histone modifiers. Here, we simulate linear and looping-driven spreading of histone modifications and compare both models to recent experiments on histone methylation in fission yeast. We find that a generalized nucleation-and-looping mechanism describes key observations on engineered and endogenous methylation domains including intrinsic spatial confinement, independent regulation of domain size and memory, variegation in the absence of antagonists, and coexistence of short- and long-term memory at loci with weak and strong constitutive nucleation. These findings support a straightforward relationship between the biochemical properties of chromatin modifiers and the spatiotemporal modification pattern. The proposed mechanism gives rise to a phase diagram for cellular memory that may be generally applicable to explain epigenetic phenomena across different species. PMID:27382173

  19. The Research Laboratory of Electronics Progress Report Number 132: January 1-December 31, 1989

    DTIC Science & Technology

    1990-01-01

    between Binaural Hearing and Brainstem Auditory Evoked Potentials in Humans...fem- tosecond excitation pulses. This gives rise to the characteristic " beating " pattern which contains sum and difference frequencies. The "spike...vibrational modes whose through a simple optical network consisting simultaneous oscillations yield the " beating " of only two lenses, two gratings

  20. Computational Electromagnetics

    DTIC Science & Technology

    2011-02-20

    finite differences use the continuation method instead, and have been shown to lead to unconditionally stable numerics for a wide range of realistic PDE...best previous solvers were restricted to two-dimensional (range and height) refractive index variations. The numerical method we introduced...however, is such that even its solution on the basis of Rytov’s method gives rise to extremely high computational costs. We thus resort to

  1. Stem Cell, Regenerative Medicine and Cancer | Center for Cancer Research

    Cancer.gov

    Of the estimated trillion cells that build up our bodies, only a little number can self-renew and give rise to many different cell types. These unspecialized cells are called stem cells. Stem cell division and differentiation is fundamental to the development of the mature organism. Stem cells have recently attracted significant attention largely due to their potential medical

  2. All Tumor Cells Are Not Created Equal | Center for Cancer Research

    Cancer.gov

    Cell division is commonly thought of as a process whereby one cell gives rise to two identical daughter cells. However, rare cell divisions are asymmetric, generating daughter cells that may differ in size, developmental potential, or even DNA content. The ability of stem cells to undergo asymmetric division allows them to self-renew while simultaneously generate daughter

  3. Beam shaping with vectorial vortex beams under low numerical aperture illumination condition

    NASA Astrophysics Data System (ADS)

    Dai, Jianning; Zhan, Qiwen

    2008-08-01

    In this paper we propose and demonstrate a novel beam shaping method using vectorial vortex beam. A vectorial vortex beam is laser beam with polarization singularity in the beam cross section. This type of beams can be decomposed into two orthogonally polarized components. Each of the polarized components could have different vortex characteristics, and consequently, different intensity distribution when focused by lens. Beam shaping in the far field can be achieved by adjusting the relative weighing of these two components. As one example, we study the vectorial vortex that consists of a linearly polarized Gaussian component and a vortex component polarized orthogonally. When such a vectorial vortex beam is focus by low NA lens, the Gaussian component gives rise to a focal intensity distribution with a solid centre while the vortex component gives rise to a donut distribution with hollow dark center. The shape of the focus can be continuously varied by continuously adjusting the relative weight of the two components. Under appropriate conditions, flat top focusing can be obtained. We experimentally demonstrate the creation of such beams with a liquid crystal spatial light modulator. Flattop focus obtained by vectorial vortex beams with topological charge of +1 has been obtained.

  4. Modes of Interaction between Individuals Dominate the Topologies of Real World Networks

    PubMed Central

    Lee, Insuk; Kim, Eiru; Marcotte, Edward M.

    2015-01-01

    We find that the topologies of real world networks, such as those formed within human societies, by the Internet, or among cellular proteins, are dominated by the mode of the interactions considered among the individuals. Specifically, a major dichotomy in previously studied networks arises from modeling networks in terms of pairwise versus group tasks. The former often intrinsically give rise to scale-free, disassortative, hierarchical networks, whereas the latter often give rise to single- or broad-scale, assortative, nonhierarchical networks. These dependencies explain contrasting observations among previous topological analyses of real world complex systems. We also observe this trend in systems with natural hierarchies, in which alternate representations of the same networks, but which capture different levels of the hierarchy, manifest these signature topological differences. For example, in both the Internet and cellular proteomes, networks of lower-level system components (routers within domains or proteins within biological processes) are assortative and nonhierarchical, whereas networks of upper-level system components (internet domains or biological processes) are disassortative and hierarchical. Our results demonstrate that network topologies of complex systems must be interpreted in light of their hierarchical natures and interaction types. PMID:25793969

  5. Large-scale neural networks and the lateralization of motivation and emotion.

    PubMed

    Tops, Mattie; Quirin, Markus; Boksem, Maarten A S; Koole, Sander L

    2017-09-01

    Several lines of research in animals and humans converge on the distinction between two basic large-scale brain networks of self-regulation, giving rise to predictive and reactive control systems (PARCS). Predictive (internally-driven) and reactive (externally-guided) control are supported by dorsal versus ventral corticolimbic systems, respectively. Based on extant empirical evidence, we demonstrate how the PARCS produce frontal laterality effects in emotion and motivation. In addition, we explain how this framework gives rise to individual differences in appraising and coping with challenges. PARCS theory integrates separate fields of research, such as research on the motivational correlates of affect, EEG frontal alpha power asymmetry and implicit affective priming effects on cardiovascular indicators of effort during cognitive task performance. Across these different paradigms, converging evidence points to a qualitative motivational division between, on the one hand, angry and happy emotions, and, on the other hand, sad and fearful emotions. PARCS suggests that those two pairs of emotions are associated with predictive and reactive control, respectively. PARCS theory may thus generate important new insights on the motivational and emotional dynamics that drive autonomic and homeostatic control processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. On the Solutions of Two-Extended Principal Conformal Toda Theory

    NASA Astrophysics Data System (ADS)

    Chao, L.; Hou, B. Y.

    1994-02-01

    The solutions of the two-extended principal conformal Toda theory (2-EPCT theory, also called bosonic superconformal Toda theory) are constructed in two different ways: (1) Leznov-Saveliev algebraic analysis and (2) the associated chiral embedding surface. The first approach gives rise to the general solution in terms of appropriate matrix elements in different fundamental representations of the underlying Lie algebra, whilst the second one leads to a special solution in the form of Wronski determinants and their co-minors, and it gives an explicit geometrical interpretation of the WZNW → 2-EPCT reduction. The key points of both approaches are the chiral vectors derived recently by the authors, which constitute a closed exchange algebra of the theory.

  7. Jagged–Delta asymmetry in Notch signaling can give rise to a Sender/Receiver hybrid phenotype

    PubMed Central

    Boareto, Marcelo; Jolly, Mohit Kumar; Lu, Mingyang; Onuchic, José N.; Clementi, Cecilia; Ben-Jacob, Eshel

    2015-01-01

    Notch signaling pathway mediates cell-fate determination during embryonic development, wound healing, and tumorigenesis. This pathway is activated when the ligand Delta or the ligand Jagged of one cell interacts with the Notch receptor of its neighboring cell, releasing the Notch Intracellular Domain (NICD) that activates many downstream target genes. NICD affects ligand production asymmetrically––it represses Delta, but activates Jagged. Although the dynamical role of Notch–Jagged signaling remains elusive, it is widely recognized that Notch–Delta signaling behaves as an intercellular toggle switch, giving rise to two distinct fates that neighboring cells adopt––Sender (high ligand, low receptor) and Receiver (low ligand, high receptor). Here, we devise a specific theoretical framework that incorporates both Delta and Jagged in Notch signaling circuit to explore the functional role of Jagged in cell-fate determination. We find that the asymmetric effect of NICD renders the circuit to behave as a three-way switch, giving rise to an additional state––a hybrid Sender/Receiver (medium ligand, medium receptor). This phenotype allows neighboring cells to both send and receive signals, thereby attaining similar fates. We also show that due to the asymmetric effect of the glycosyltransferase Fringe, different outcomes are generated depending on which ligand is dominant: Delta-mediated signaling drives neighboring cells to have an opposite fate; Jagged-mediated signaling drives the cell to maintain a similar fate to that of its neighbor. We elucidate the role of Jagged in cell-fate determination and discuss its possible implications in understanding tumor–stroma cross-talk, which frequently entails Notch–Jagged communication. PMID:25605936

  8. Reconciling projections of the Antarctic contribution to sea level rise

    NASA Astrophysics Data System (ADS)

    Edwards, Tamsin; Holden, Philip; Edwards, Neil; Wernecke, Andreas

    2017-04-01

    Two recent studies of the Antarctic contribution to sea level rise this century had best estimates that differed by an order of magnitude (around 10 cm and 1 m by 2100). The first, Ritz et al. (2015), used a model calibrated with satellite data, giving a 5% probability of exceeding 30cm by 2100 for sea level rise due to Antarctic instability. The second, DeConto and Pollard (2016), used a model evaluated with reconstructions of palaeo-sea level. They did not estimate probabilities, but using a simple assumption here about the distribution shape gives up to a 5% chance of Antarctic contribution exceeding 2.3 m this century with total sea level rise approaching 3 m. If robust, this would have very substantial implications for global adaptation to climate change. How are we to make sense of this apparent inconsistency? How much is down to the data - does the past tell us we will face widespread and rapid Antarctic ice losses in the future? How much is due to the mechanism of rapid ice loss ('cliff failure') proposed in the latter paper, or other parameterisation choices in these low resolution models (GRISLI and PISM, respectively)? How much is due to choices made in the ensemble design and calibration? How do these projections compare with high resolution, grounding line resolving models such as BISICLES? Could we reduce the huge uncertainties in the palaeo-study? Emulation provides a powerful tool for understanding these questions and reconciling the projections. By describing the three numerical ice sheet models with statistical models, we can re-analyse the ensembles and re-do the calibrations under a common statistical framework. This reduces uncertainty in the PISM study because it allows massive sampling of the parameter space, which reduces the sensitivity to reconstructed palaeo-sea level values and also narrows the probability intervals because the simple assumption about distribution shape above is no longer needed. We present reconciled probabilistic projections for the Antarctic contribution to sea level rise from GRISLI, PISM and BISICLES this century, giving results that are meaningful and interpretable by decision-makers.

  9. ISS-flation

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

    Craig, Nathaniel J.; /SLAC /Stanford U., ITP

    2008-02-06

    Inflation may occur while rolling into the metastable supersymmetry-breaking vacuum of massive supersymmetric QCD. We explore the range of parameters in which slow-roll inflation and long-lived metastable supersymmetry breaking may be simultaneously realized. The end of slow-roll inflation in this context coincides with the spontaneous breaking of a global symmetry, which may give rise to significant curvature perturbations via inhomogeneous preheating. Such spontaneous symmetry breaking at the end of inflation may give rise to observable non-gaussianities, distinguishing this scenario from more conventional models of supersymmetric hybrid inflation.

  10. The Penrose dodecahedron and the Witting polytope are identical in CP3

    NASA Astrophysics Data System (ADS)

    Waegell, Mordecai; Aravind, P. K.

    2017-06-01

    The 40 states of a spin-3/2 particle used by Zimba and Penrose to prove the Kochen-Specker and Bell theorems are shown to be identical (i.e., unitarily equivalent) in CP3 to the 40 rays that follow from the vertices of the Witting polytope. The Witting polytope also gives rise to 120 rays in RP7 that give rise to well over a billion parity proofs of the Kochen-Specker theorem. The implications of these results are discussed.

  11. Neural Circuitry of Wakefulness and Sleep.

    PubMed

    Scammell, Thomas E; Arrigoni, Elda; Lipton, Jonathan O

    2017-02-22

    Sleep remains one of the most mysterious yet ubiquitous animal behaviors. We review current perspectives on the neural systems that regulate sleep/wake states in mammals and the circadian mechanisms that control their timing. We also outline key models for the regulation of rapid eye movement (REM) sleep and non-REM sleep, how mutual inhibition between specific pathways gives rise to these distinct states, and how dysfunction in these circuits can give rise to sleep disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Some special values of vertices of trees on the suborbital graphs

    NASA Astrophysics Data System (ADS)

    Deǧer, A. H.; Akbaba, Ü.

    2018-01-01

    In the present study, the action of a congruence subgroup of S L(2, Z) on ℚ ^ is examined. From this action and its properties, vertices of paths of minimal length on the suborbital graph Fu,N give rise to some special sequence values, that are alternate sequences such as identity, Fibonacci and Lucas sequences. These types of vertices also give rise to special continued fractions, hence from recurrence relations for continued fractions, values of these vertices and values of special sequences were associated.

  13. Approximate analytic expression for the Skyrmions crystal

    NASA Astrophysics Data System (ADS)

    Grandi, Nicolás; Sturla, Mauricio

    2018-01-01

    We find approximate solutions for the two-dimensional nonlinear Σ-model with Dzyalioshinkii-Moriya term, representing magnetic Skyrmions. They are built in an analytic form, by pasting different approximate solutions found in different regions of space. We verify that our construction reproduces the phenomenology known from numerical solutions and Monte Carlo simulations, giving rise to a Skyrmion lattice at an intermediate range of magnetic field, flanked by spiral and spin-polarized phases for low and high magnetic fields, respectively.

  14. Sustained currents in coupled diffusive systems

    NASA Astrophysics Data System (ADS)

    Larralde, Hernán; Sanders, David P.

    2014-08-01

    Coupling two diffusive systems may give rise to a nonequilibrium stationary state (NESS) with a non-trivial persistent, circulating current. We study a simple example that is exactly soluble, consisting of random walkers with different biases towards a reflecting boundary, modelling, for example, Brownian particles with different charge states in an electric field. We obtain analytical expressions for the concentrations and currents in the NESS for this model, and exhibit the main features of the system by numerical simulation.

  15. Tunneling spectroscopy of Majorana-Kondo devices

    NASA Astrophysics Data System (ADS)

    Eriksson, Erik; Nava, Andrea; Mora, Christophe; Egger, Reinhold

    2014-12-01

    We study the local density of states (LDOS) in systems of Luttinger-liquid nanowires connected to a common mesoscopic superconducting island, in which Majorana bound states give rise to different types of topological Kondo effects. We show that electron interactions enhance the low-energy LDOS in the leads close to the island, with unusual exponents due to Kondo physics that can be probed in tunneling experiments.

  16. Two-port active coupled microstrip antenna

    NASA Astrophysics Data System (ADS)

    Avitabile, G. F.; Maci, S.; Biffi Gentili, G.; Roselli, L.; Manes, G. F.

    1992-12-01

    A multilayer structure, based on a patch antenna coupled through a nonresonant slot to a pair of feeding microstrips is a versatile module which can be used as a radiating and resonating element in a number of different configurations. Direct connection to a low cost transistor in a feedback loop results in a very simple active antenna, as reported in the Letter. Different termination conditions at the four microstrip ports give rise to a number of alternative configurations for active generation/detection and multipatch arrays.

  17. STM/STS investigation of edge structure in epitaxial graphene

    NASA Astrophysics Data System (ADS)

    Ridene, M.; Girard, J. C.; Travers, L.; David, C.; Ouerghi, A.

    2012-08-01

    In this paper, we have used low temperature scanning tunneling microscopy and spectroscopy (LT-STM/STS) to study zigzag or armchair edges of epitaxial graphene on 6H-SiC (0001). The monolayer carbon structures exhibit occasionally one-dimensional ridge (1D) in close vicinity to step edge. This ridge exhibits different edges orientations in armchair-zigzag transition which give rise to different local density of states (LDOS) along this 1D structure. This ridge formation is likely explained by residual compressive in-plane stresses.

  18. Electronic structure and properties of unsubstituted rhodamine in different electron states

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

    Artyukhov, V.Ya.

    1988-04-01

    An analysis is given of the electron density distribution, dipole moment variation, and proton acceptor properties of unsubstituted rhodamine molecules in different electron states. It is shown that the electron density redistribution between the pyronine and benzoin parts of rhodamine may be large and strongly affect the molecular properties. In one of the electron transitions (S/sub 4/) producing the third absorption band the proton acceptor power markedly increases, giving rise to a protonated form under suitable conditions.

  19. Electronic structure and properties of unsubstituted rhodamine in different electron states

    NASA Astrophysics Data System (ADS)

    Artyukhov, V. Ya.

    1987-10-01

    An analysis is given of the electron density distribution, dipole moment variation, and proton acceptor properties of unsubstituted rhodamine molecules in different electron states. It is shown that the electron density redistribution between the pyronine and benzoin parts of rhodamine may be large and strongly affect the molecular properties. In one of the electron transitions (S4) producing the third absorption band the proton acceptor power markedly increases, giving rise to a protonated form under suitable conditions.

  20. Solvated molecular dynamics of LiCN isomerization: All-atom argon solvent versus a generalized Langevin bath.

    PubMed

    Junginger, Andrej; Garcia-Muller, Pablo L; Borondo, F; Benito, R M; Hernandez, Rigoberto

    2016-01-14

    The reaction rate rises and falls with increasing density or friction when a molecule is activated by collisions with the solvent particles. This so-called Kramers turnover has recently been observed in the isomerization reaction of LiCN in an argon bath. In this paper, we demonstrate by direct comparison with those results that a reduced-dimensional (generalized) Langevin description gives rise to similar reaction dynamics as the corresponding (computationally expensive) full molecular dynamics calculations. We show that the density distributions within the Langevin description are in direct agreement with the full molecular dynamics results and that the turnover in the reaction rates is reproduced qualitatively and quantitatively at different temperatures.

  1. Growth and development of cultured carrot cells and embryos under spaceflight conditions

    NASA Technical Reports Server (NTRS)

    Krikorian, A. D.; Dutcher, F. R.; Quinn, C. E.; Steward, F. C.

    1981-01-01

    Morphogenetically competent proembryonic cells and well-developed somatic embryos of carrot at two levels of organization were exposed for 18.5 days to a hypogravity environment aboard the Soviet Biosatellite Cosmos 1129. It was confirmed that cultured totipotent cells of carrot can give rise to embryos with well-developed roots and minimally developed shoots. It was also shown that the space hypogravity environment could support the further growth of already-organized, later somatic embryonic stages and give rise to fully developed embryo-plantlets with roots and shoots.

  2. Comparative reactivity of different types of stable cyclic and acyclic mono- and diamino carbenes with simple organic substrates.

    PubMed

    Martin, David; Canac, Yves; Lavallo, Vincent; Bertrand, Guy

    2014-04-02

    A series of stable carbenes, featuring a broad range of electronic properties, were reacted with simple organic substrates. The N,N-dimesityl imidazolylidene (NHC) does not react with isocyanides, whereas anti-Bredt di(amino)carbene (pyr-NHC), cyclic (alkyl)(amino)carbene (CAAC), acyclic di(amino)carbene (ADAC), and acyclic (alkyl)(amino)carbene (AAAC) give rise to the corresponding ketenimines. NHCs are known to promote the benzoin condensation, and we found that the CAAC, pyr-NHC, and ADAC react with benzaldehyde to give the ketone tautomer of the Breslow intermediate, whereas the AAAC first gives the corresponding epoxide and ultimately the Breslow intermediate, which can be isolated. Addition of excess benzaldehyde to the latter does not lead to benzoin but to a stable 1,3-dioxolane. Depending on the electronic properties of carbenes, different products are also obtained with methyl acrylate as a substrate. The critical role of the carbene electrophilicity on the outcome of reactions is discussed.

  3. Neither property right nor heroic gift, neither sacrifice nor aporia: the benefit of the theoretical lens of sharing in donation ethics.

    PubMed

    Zeiler, Kristin

    2014-05-01

    Two ethical frameworks have dominated the discussion of organ donation for long: that of property rights and that of gift-giving. However, recent years have seen a drastic rise in the number of philosophical analyses of the meaning of giving and generosity, which has been mirrored in ethical debates on organ donation and in critical sociological, anthropological and ethnological work on the gift metaphor in this context. In order to capture the flourishing of this field, this article distinguishes between four frameworks for thinking about bodily exchanges in medicine: those of property rights, heroic gift-giving, sacrifice, and gift-giving as aporia. These frameworks represent four different ways of making sense of donation of organs as well as tissue, gametes and blood, draw on different conceptions of the relations between the self and the other, and bring out different ethical issues as core ones. The article presents these frameworks, argues that all of them run into difficulties when trying to make sense of reciprocity and relational interdependence in donation, and shows how the three gift-giving frameworks (of heroism, sacrifice and aporia) hang together in a critical discussion about what is at stake in organ donation. It also presents and argues in favour of an alternative intercorporeal framework of giving-through-sharing that more thoroughly explicates the gift metaphor in the context of donation, and offers tools for making sense of relational dimensions of live and post mortem donations.

  4. Colony-Forming Progenitor Cells in the Postnatal Mouse Liver and Pancreas Give Rise to Morphologically Distinct Insulin-Expressing Colonies in 3D Cultures

    PubMed Central

    Jin, Liang; Feng, Tao; Chai, Jing; Ghazalli, Nadiah; Gao, Dan; Zerda, Ricardo; Li, Zhuo; Hsu, Jasper; Mahdavi, Alborz; Tirrell, David A.; Riggs, Arthur D.; Ku, Hsun Teresa

    2014-01-01

    In our previous studies, colony-forming progenitor cells isolated from murine embryonic stem cell-derived cultures were differentiated into morphologically distinct insulin-expressing colonies. These colonies were small and not light-reflective when observed by phase-contrast microscopy (therefore termed “Dark” colonies). A single progenitor cell capable of giving rise to a Dark colony was termed a Dark colony-forming unit (CFU-Dark). The goal of the current study was to test whether endogenous pancreas, and its developmentally related liver, harbored CFU-Dark. Here we show that dissociated single cells from liver and pancreas of one-week-old mice give rise to Dark colonies in methylcellulose-based semisolid culture media containing either Matrigel or laminin hydrogel (an artificial extracellular matrix protein). CFU-Dark comprise approximately 0.1% and 0.03% of the postnatal hepatic and pancreatic cells, respectively. Adult liver also contains CFU-Dark, but at a much lower frequency (~0.003%). Microfluidic qRT-PCR, immunostaining, and electron microscopy analyses of individually handpicked colonies reveal the expression of insulin in many, but not all, Dark colonies. Most pancreatic insulin-positive Dark colonies also express glucagon, whereas liver colonies do not. Liver CFU-Dark require Matrigel, but not laminin hydrogel, to become insulin-positive. In contrast, laminin hydrogel is sufficient to support the development of pancreatic Dark colonies that express insulin. Postnatal liver CFU-Dark display a cell surface marker CD133+CD49flowCD107blow phenotype, while pancreatic CFU-Dark are CD133-. Together, these results demonstrate that specific progenitor cells in the postnatal liver and pancreas are capable of developing into insulin-expressing colonies, but they differ in frequency, marker expression, and matrix protein requirements for growth. PMID:25148366

  5. Different morphologic formation patterns of dark patches in the black-spotted frog (Pelophylax nigromaculata) and the Asiatic toad (Bufo gargarizans).

    PubMed

    Guangming, Gan; Tao, Zhao; Chao, Li; Moyan, Zhao

    2017-01-01

    The black-spotted frog (Pelophylax nigromaculata) and Asiatic toad (Bufo gargarizans), two relatively distantly related species, live in different habitats with different adaptive dark patches. To explain the formation of dark patches, the distribution patterns of melanin granules were examined with light microscopy and transmission electron microscopy. Melanin granules were produced and gathered into the "cap" structures on top of the nuclei in most epidermal cells. The "cap" structures may play a role in forming the dorsal dark patches coupled with three-layer melanophores, which can give rise to three layers of interconnected melanin networks in the dorsal dermis in P. nigromaculata. Epidermal melanocytes are rare and do not have a definitive role in forming dorsal dark patches in either P. nigromaculata or B. gargarizans. In B. gargarizans, the dermal melanophores only give rise to a single-layered melanin network, which hardly results in dark patches in the dorsal skin. However, the dermal melanophores migrate twice and form into pseudostratified networks, leading to dark patch formation in the ventral skin in B. gargarizans. The melanin granules precisely coregulate dark patches in the dermis and/or epidermis in P. nigromaculata and B. gargarizans. The dark patch formation depends on melanin granules in the epidermis or/and dermis in P. nigromaculata and B. gargarizans.

  6. Temperature control and measurement with tunable femtosecond optical tweezers

    NASA Astrophysics Data System (ADS)

    Mondal, Dipankar; Goswami, Debabrata

    2016-09-01

    We present the effects of wavelength dependent temperature rise in a femtosecond optical tweezers. Our experiments involve the femtosecond trapping laser tunable from 740-820 nm at low power 25 mW to cause heating in the trapped volume within a homogeneous solution of sub micro-molar concentration of IR dye. The 780 nm high repetition rate laser acts as a resonant excitation source which helps to create the local heating effortlessly within the trapping volume. We have used both position autocorrelation and equipartion theorem to evaluate temperature at different wavelength having different absorption coefficient. Fixing the pulse width in the temporal domain gives constant bandwidth at spatial domain, which makes our system behave as a tunable temperature rise device with high precision. This observation leads us to calculate temperature as well as viscosity within the vicinity of the trapping zone. A mutual energy transfer occurs between the trapped bead and solvents that leads to transfer the thermal energy of solvents into the kinetic energy of the trap bead and vice-versa. Thus hot solvated molecules resulting from resonant and near resonant excitation of trapping wavelength can continuously dissipate heat to the trapped bead which will be reflected on frequency spectrum of Brownian noise exhibited by the bead. Temperature rise near the trapping zone can significantly change the viscosity of the medium. We observe temperature rise profile according to its Gaussian shaped absorption spectrum with different wavelength.

  7. On the origin of the electrostatic potential difference at a liquid-vacuum interface.

    PubMed

    Harder, Edward; Roux, Benoît

    2008-12-21

    The microscopic origin of the interface potential calculated from computer simulations is elucidated by considering a simple model of molecules near an interface. The model posits that molecules are isotropically oriented and their charge density is Gaussian distributed. Molecules that have a charge density that is more negative toward their interior tend to give rise to a negative interface potential relative to the gaseous phase, while charge densities more positive toward their interior give rise to a positive interface potential. The interface potential for the model is compared to the interface potential computed from molecular dynamics simulations of the nonpolar vacuum-methane system and the polar vacuum-water interface system. The computed vacuum-methane interface potential from a molecular dynamics simulation (-220 mV) is captured with quantitative precision by the model. For the vacuum-water interface system, the model predicts a potential of -400 mV compared to -510 mV, calculated from a molecular dynamics simulation. The physical implications of this isotropic contribution to the interface potential is examined using the example of ion solvation in liquid methane.

  8. Competition of tolerant strategies in the spatial public goods game

    NASA Astrophysics Data System (ADS)

    Szolnoki, Attila; Perc, Matjaž

    2016-08-01

    Tolerance implies enduring trying circumstances with a fair and objective attitude. To determine whether evolutionary advantages might be stemming from diverse levels of tolerance in a population, we study a spatial public goods game, where in addition to cooperators, defectors, and loners, tolerant players are also present. Depending on the number of defectors within a group, a tolerant player can either cooperate in or abstain from a particular instance of the game. We show that the diversity of tolerance can give rise to synergistic effects, wherein players with a different threshold in terms of the tolerated number of defectors in a group compete most effectively against defection and default abstinence. Such synergistic associations can stabilise states of full cooperation where otherwise defection would dominate. We observe complex pattern formation that gives rise to an intricate phase diagram, where invisible yet stable strategy alliances require outmost care lest they are overlooked. Our results highlight the delicate importance of diversity and tolerance for the provisioning of public goods, and they reveal fascinating subtleties of the spatiotemporal dynamics that is due to the competition of subsystem solutions in structured populations.

  9. Stationary and oscillatory bound states of dissipative solitons created by third-order dispersion

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Hidetsugu; Skryabin, Dmitry V.; Malomed, Boris A.

    2018-06-01

    We consider the model of fiber-laser cavities near the zero-dispersion point, based on the complex Ginzburg-Landau equation with the cubic-quintic nonlinearity, including the third-order dispersion (TOD) term. It is well known that this model supports stable dissipative solitons. We demonstrate that the same model gives rise to several families of robust bound states of the solitons, which exists only in the presence of the TOD. There are both stationary and dynamical bound states, with oscillating separation between the bound solitons. Stationary states are multistable, corresponding to different values of the separation. With the increase of the TOD coefficient, the bound state with the smallest separation gives rise the oscillatory state through the Hopf bifurcation. Further growth of TOD leads to a bifurcation transforming the oscillatory limit cycle into a strange attractor, which represents a chaotically oscillating dynamical bound state. Families of multistable three- and four-soliton complexes are found too, the ones with the smallest separation between the solitons again ending by a transition to oscillatory states through the Hopf bifurcation.

  10. Randomly chosen chaotic maps can give rise to nearly ordered behavior

    NASA Astrophysics Data System (ADS)

    Boyarsky, Abraham; Góra, Paweł; Islam, Md. Shafiqul

    2005-10-01

    Parrondo’s paradox [J.M.R. Parrondo, G.P. Harmer, D. Abbott, New paradoxical games based on Brownian ratchets, Phys. Rev. Lett. 85 (2000), 5226-5229] (see also [O.E. Percus, J.K. Percus, Can two wrongs make a right? Coin-tossing games and Parrondo’s paradox, Math. Intelligencer 24 (3) (2002) 68-72]) states that two losing gambling games when combined one after the other (either deterministically or randomly) can result in a winning game: that is, a losing game followed by a losing game = a winning game. Inspired by this paradox, a recent study [J. Almeida, D. Peralta-Salas, M. Romera, Can two chaotic systems give rise to order? Physica D 200 (2005) 124-132] asked an analogous question in discrete time dynamical system: can two chaotic systems give rise to order, namely can they be combined into another dynamical system which does not behave chaotically? Numerical evidence is provided in [J. Almeida, D. Peralta-Salas, M. Romera, Can two chaotic systems give rise to order? Physica D 200 (2005) 124-132] that two chaotic quadratic maps, when composed with each other, create a new dynamical system which has a stable period orbit. The question of what happens in the case of random composition of maps is posed in [J. Almeida, D. Peralta-Salas, M. Romera, Can two chaotic systems give rise to order? Physica D 200 (2005) 124-132] but left unanswered. In this note we present an example of a dynamical system where, at each iteration, a map is chosen in a probabilistic manner from a collection of chaotic maps. The resulting random map is proved to have an infinite absolutely continuous invariant measure (acim) with spikes at two points. From this we show that the dynamics behaves in a nearly ordered manner. When the foregoing maps are applied one after the other, deterministically as in [O.E. Percus, J.K. Percus, Can two wrongs make a right? Coin-tossing games and Parrondo’s paradox, Math. Intelligencer 24 (3) (2002) 68-72], the resulting composed map has a periodic orbit which is stable.

  11. All Tumor Cells Are Not Created Equal | Center for Cancer Research

    Cancer.gov

    Cell division is commonly thought of as a process whereby one cell gives rise to two identical daughter cells. However, rare cell divisions are asymmetric, generating daughter cells that may differ in size, developmental potential, or even DNA content. The ability of stem cells to undergo asymmetric division allows them to self-renew while simultaneously generate daughter cells committed to differentiating into specialized cell types.

  12. The kidney trade: or, the customer is always wrong.

    PubMed

    Brecher, B

    1990-09-01

    Much of the opinion scandalized by recent reports of kidneys being sold for transplant is significantly inconsistent. The sale of kidneys is not substantially different from practices espoused, and indeed endorsed, by many of those who condemn the former. Our moral concern, I suggest, needs to focus on the customer's actions rather than the seller's; and on the implications for larger questions of the considerations to which this gives rise.

  13. Parallel and convergent processing in grid cell, head-direction cell, boundary cell, and place cell networks

    PubMed Central

    Brandon, Mark P; Koenig, Julie; Leutgeb, Stefan

    2014-01-01

    The brain is able to construct internal representations that correspond to external spatial coordinates. Such brain maps of the external spatial topography may support a number of cognitive functions, including navigation and memory. The neuronal building block of brain maps are place cells, which are found throughout the hippocampus of rodents and, in a lower proportion, primates. Place cells typically fire in one or few restricted areas of space, and each area where a cell fires can range, along the dorsoventral axis of the hippocampus, from 30 cm to at least several meters. The sensory processing streams that give rise to hippocampal place cells are not fully understood, but substantial progress has been made in characterizing the entorhinal cortex, which is the gateway between neocortical areas and the hippocampus. Entorhinal neurons have diverse spatial firing characteristics, and the different entorhinal cell types converge in the hippocampus to give rise to a single, spatially modulated cell type—the place cell. We therefore suggest that parallel information processing in different classes of cells—as is typically observed at lower levels of sensory processing—continues up into higher level association cortices, including those that provide the inputs to hippocampus. WIREs Cogn Sci 2014, 5:207–219. doi: 10.1002/wcs.1272 PMID:24587849

  14. Microgenomic analysis reveals cell type-specific gene expression patterns between ray and fusiform initials within the cambial meristem of Populus.

    PubMed

    Goué, Nadia; Lesage-Descauses, Marie-Claude; Mellerowicz, Ewa J; Magel, Elisabeth; Label, Philippe; Sundberg, Björn

    2008-01-01

    The vascular cambium is the meristem in trees that produce wood. This meristem consists of two types of neighbouring initials: fusiform cambial cells (FCCs), which give rise to the axial cell system (i.e. fibres and vessel elements), and ray cambial cells (RCCs), which give rise to rays. There is little molecular information on the mechanisms whereby the differing characteristics of these neighbouring cells are maintained. A microgenomic approach was adopted in which the transcriptomes of FCCs and RCCs dissected out from the cambial meristem of poplar (Populus trichocarpa x Populus deltoïdes var. Boelare) were analysed, and a transcriptional database for these two cell types established. Photosynthesis genes were overrepresented in RCCs, providing molecular support for the presence of photosynthetic systems in rays. Genes that putatively encode transporters (vesicle, lipid and metal ion transporters and aquaporins) in RCCs were also identified. In addition, many cell wall-related genes showed cell type-specific expression patterns. Notably, genes involved in pectin metabolism and xyloglucan metabolism were overrepresented in RCCs and FCCs, respectively. The results demonstrate the use of microgenomics to reveal differences in biological processes in neighbouring meristematic cells, and to identify key genes involved in these processes.

  15. Fast Electrically Driven Capillary Rise Using Overdrive Voltage.

    PubMed

    Hong, Sung Jin; Hong, Jiwoo; Seo, Hee Won; Lee, Sang Joon; Chung, Sang Kug

    2015-12-29

    Enhancement of response speed (or reduction of response time) is crucial for the commercialization of devices based on electrowetting (EW), such as liquid lenses and reflective displays, and presents one of the main challenges in EW research studies. We demonstrate here that an overdrive EW actuation gives rise to a faster rise of a liquid column between parallel electrodes, compared to a DC EW actuation. Here, DC actuation is actually a simple applied step function, and overdrive is an applied step followed by reduction to a lower voltage. Transient behaviors and response time (i.e., the time required to reach the equilibrium height) of the rising liquid column are explored under different DC and overdrive EW actuations. When the liquid column rises up to a target height by means of an overdrive EW, the response time is reduced to as low as 1/6 of the response time using DC EW. We develop a theoretical model to simulate the EW-driven capillary rise by combining the kinetic equation of capillary flow (i.e., Lucas-Washburn equation) and the dynamic contact angle model considering contact line friction, contact angle hysteresis, contact angle saturation, and the EW effect. This theoretical model accurately predicts the outcome to within a ± 5% error in regard to the rising behaviors of the liquid column with a low viscosity, under both DC EW and overdrive actuation conditions, except for the early stage (

  16. Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance - A review.

    PubMed

    Saini, Ramesh Kumar; Keum, Young-Soo

    2018-06-15

    Linoleic acid (LA) (n-6) and α-linolenic acid (ALA) (n-3) are essential fatty acids (EFAs) as they cannot be synthesized by humans or other higher animals. In the human body, these fatty acids (FAs) give rise to arachidonic acid (ARA, n-6), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) that play key roles in regulating body homeostasis. Locally acting bioactive signaling lipids called eicosanoids derived from these FAs also regulate diverse homeostatic processes. In general, ARA gives rise to pro-inflammatory eicosanoids whereas EPA and DHA give rise to anti-inflammatory eicosanoids. Thus, a proportionally higher consumption of n-3 PUFAs can protect us against inflammatory diseases, cancer, cardiovascular diseases, and other chronic diseases. The present review summarizes major sources, intake, and global consumption of n-3 and n-6 PUFAs. Their metabolism to biosynthesize long-chain PUFAs and eicosanoids and their roles in brain metabolism, cardiovascular disease, obesity, cancer, and bone health are also discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Hard and soft acids and bases: structure and process.

    PubMed

    Reed, James L

    2012-07-05

    Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.

  18. Spontaneous emergence of catalytic cycles with colloidal spheres

    NASA Astrophysics Data System (ADS)

    Zeravcic, Zorana; Brenner, Michael P.

    2017-04-01

    Colloidal particles endowed with specific time-dependent interactions are a promising route for realizing artificial materials that have the properties of living ones. Previous work has demonstrated how this system can give rise to self-replication. Here, we introduce the process of colloidal catalysis, in which clusters of particles catalyze the creation of other clusters through templating reactions. Surprisingly, we find that simple templating rules generically lead to the production of huge numbers of clusters. The templating reactions among this sea of clusters give rise to an exponentially growing catalytic cycle, a specific realization of Dyson’s notion of an exponentially growing metabolism. We demonstrate this behavior with a fixed set of interactions between particles chosen to allow a catalysis of a specific six-particle cluster from a specific seven-particle cluster, yet giving rise to the catalytic production of a sea of clusters of sizes between 2 and 11 particles. The fact that an exponentially growing cycle emerges naturally from such a simple scheme demonstrates that the emergence of exponentially growing metabolisms could be simpler than previously imagined.

  19. Ant Species Differences Determined by Epistasis between Brood and Worker Genomes

    PubMed Central

    Linksvayer, Timothy A.

    2007-01-01

    Epistasis arising from physiological interactions between gene products often contributes to species differences, particularly those involved in reproductive isolation. In social organisms, phenotypes are influenced by the genotypes of multiple interacting individuals. In theory, social interactions can give rise to an additional type of epistasis between the genomes of social partners that can contribute to species differences. Using a full-factorial cross-fostering design with three species of closely related Temnothorax ants, I found that adult worker size was determined by an interaction between the genotypes of developing brood and care-giving workers, i.e. intergenomic epistasis. Such intergenomic social epistasis provides a strong signature of coevolution between social partners. These results demonstrate that just as physiologically interacting genes coevolve, diverge, and contribute to species differences, so do socially interacting genes. Coevolution and conflict between social partners, especially relatives such as parents and offspring, has long been recognized as having widespread evolutionary effects. This coevolutionary process may often result in coevolved socially-interacting gene complexes that contribute to species differences. PMID:17912371

  20. Calculation of Temperature Rise in Calorimetry.

    ERIC Educational Resources Information Center

    Canagaratna, Sebastian G.; Witt, Jerry

    1988-01-01

    Gives a simple but fuller account of the basis for accurately calculating temperature rise in calorimetry. Points out some misconceptions regarding these calculations. Describes two basic methods, the extrapolation to zero time and the equal area method. Discusses the theoretical basis of each and their underlying assumptions. (CW)

  1. Community Engagement for Collective Resilience: The Rising System

    DTIC Science & Technology

    2012-09-01

    the community. 3. Los Angeles Police Department The Los Angeles Police Department’s ( LAPD ) Counterterrorism...gives these residents a voice in the decision-making process for their neighborhood. 3. Los Angeles Police Department LAPD engagement regarding...Strategy ........................52 2. Philadelphia— The PhillyRising Collaborative ...............................53 3. Los

  2. 26 CFR 1.507-2 - Special rules; transfer to, or operation as, public charity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the seeking of advice by the transferee from, or the giving of advice by, any donor after the assets... willful repeated acts (or failures to act) or a willful and flagrant act (or failure to act) giving rise... apply to such a termination, a private foundation which makes such a termination is not required to give...

  3. 26 CFR 1.507-2 - Special rules; transfer to, or operation as, public charity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the seeking of advice by the transferee from, or the giving of advice by, any donor after the assets... willful repeated acts (or failures to act) or a willful and flagrant act (or failure to act) giving rise... apply to such a termination, a private foundation which makes such a termination is not required to give...

  4. 26 CFR 1.507-2T - Special rules; transfer to, or operation as, public charity (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... by the transferee from, or the giving of advice by, any donor after the assets have been transferred... failure to act) giving rise to liability for tax under chapter 42, may terminate its private foundation... is not required to give the notification described in section 507(a)(1). A private foundation that...

  5. 26 CFR 1.507-2T - Special rules; transfer to, or operation as, public charity (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... by the transferee from, or the giving of advice by, any donor after the assets have been transferred... failure to act) giving rise to liability for tax under chapter 42, may terminate its private foundation... is not required to give the notification described in section 507(a)(1). A private foundation that...

  6. U2AF1 mutations alter splice site recognition in hematological malignancies.

    PubMed

    Ilagan, Janine O; Ramakrishnan, Aravind; Hayes, Brian; Murphy, Michele E; Zebari, Ahmad S; Bradley, Philip; Bradley, Robert K

    2015-01-01

    Whole-exome sequencing studies have identified common mutations affecting genes encoding components of the RNA splicing machinery in hematological malignancies. Here, we sought to determine how mutations affecting the 3' splice site recognition factor U2AF1 alter its normal role in RNA splicing. We find that U2AF1 mutations influence the similarity of splicing programs in leukemias, but do not give rise to widespread splicing failure. U2AF1 mutations cause differential splicing of hundreds of genes, affecting biological pathways such as DNA methylation (DNMT3B), X chromosome inactivation (H2AFY), the DNA damage response (ATR, FANCA), and apoptosis (CASP8). We show that U2AF1 mutations alter the preferred 3' splice site motif in patients, in cell culture, and in vitro. Mutations affecting the first and second zinc fingers give rise to different alterations in splice site preference and largely distinct downstream splicing programs. These allele-specific effects are consistent with a computationally predicted model of U2AF1 in complex with RNA. Our findings suggest that U2AF1 mutations contribute to pathogenesis by causing quantitative changes in splicing that affect diverse cellular pathways, and give insight into the normal function of U2AF1's zinc finger domains. © 2015 Ilagan et al.; Published by Cold Spring Harbor Laboratory Press.

  7. Consistent compactification of double field theory on non-geometric flux backgrounds

    NASA Astrophysics Data System (ADS)

    Hassler, Falk; Lüst, Dieter

    2014-05-01

    In this paper, we construct non-trivial solutions to the 2 D-dimensional field equations of Double Field Theory (DFT) by using a consistent Scherk-Schwarz ansatz. The ansatz identifies 2( D - d) internal directions with a twist U M N which is directly connected to the covariant fluxes ABC . It exhibits 2( D - d) linear independent generalized Killing vectors K I J and gives rise to a gauged supergravity in d dimensions. We analyze the covariant fluxes and the corresponding gauged supergravity with a Minkowski vacuum. We calculate fluctuations around such vacua and show how they gives rise to massive scalars field and vectors field with a non-abelian gauge algebra. Because DFT is a background independent theory, these fields should directly correspond the string excitations in the corresponding background. For ( D - d) = 3 we perform a complete scan of all allowed covariant fluxes and find two different kinds of backgrounds: the single and the double elliptic case. The later is not T-dual to a geometric background and cannot be transformed to a geometric setting by a field redefinition either. While this background fulfills the strong constraint, it is still consistent with the Killing vectors depending on the coordinates and the winding coordinates, thereby giving a non-geometric patching. This background can therefore not be described in Supergravity or Generalized Geometry.

  8. Faddeev-Jackiw quantization of topological invariants: Euler and Pontryagin classes

    NASA Astrophysics Data System (ADS)

    Escalante, Alberto; Medel-Portugal, C.

    2018-04-01

    The symplectic analysis for the four dimensional Pontryagin and Euler invariants is performed within the Faddeev-Jackiw context. The Faddeev-Jackiw constraints and the generalized Faddeev-Jackiw brackets are reported; we show that in spite of the Pontryagin and Euler classes give rise the same equations of motion, its respective symplectic structures are different to each other. In addition, a quantum state that solves the Faddeev-Jackiw constraints is found, and we show that the quantum states for these invariants are different to each other. Finally, we present some remarks and conclusions.

  9. Finite Differences and Collocation Methods for the Solution of the Two Dimensional Heat Equation

    NASA Technical Reports Server (NTRS)

    Kouatchou, Jules

    1999-01-01

    In this paper we combine finite difference approximations (for spatial derivatives) and collocation techniques (for the time component) to numerically solve the two dimensional heat equation. We employ respectively a second-order and a fourth-order schemes for the spatial derivatives and the discretization method gives rise to a linear system of equations. We show that the matrix of the system is non-singular. Numerical experiments carried out on serial computers, show the unconditional stability of the proposed method and the high accuracy achieved by the fourth-order scheme.

  10. On the Nature of Earth-Mars Porkchop Plots

    NASA Technical Reports Server (NTRS)

    Woolley, Ryan C.; Whetsel, Charles W.

    2013-01-01

    Porkchop plots are a quick and convenient tool to help mission designers plan ballistic trajectories between two bodies. Parameter contours give rise to the familiar 'porkchop' shape. Each synodic period the pattern repeats, but not exactly, primarily due to differences in inclination and non-zero eccentricity. In this paper we examine the morphological features of Earth-to-Mars porkchop plots and the orbital characteristics that create them. These results are compared to idealistic and optimized transfers. Conclusions are drawn about 'good' opportunities versus 'bad' opportunities for different mission applications.

  11. Inversion of chalcogen defect levels in silicon - An MNDO study. [modified neglect of diatomic overlap

    NASA Technical Reports Server (NTRS)

    Singh, R. K.; Sahu, S. N.; Singh, V. A.; Corbett, J. W.

    1985-01-01

    MNDO (modified neglect of diatomic overlap) calculations have been carried out for substitutional oxygen and sulfur impurities in silicon. The calculations of the gap levels reveal a reversal of trend with atomic ionization energies in agreement with self-consistent Green function results, and analysis of the MNDO charge distribution supports the view that the electronegativity difference between oxygen and sulfur gives rise to this shallower energy level.

  12. Identification and Targeting of Candidate Pre-Existing Lurker Cells that Give Rise to Castration-Resistant Prostate Cancer

    DTIC Science & Technology

    2014-10-01

    carcinoma with different signaling pathways characteristic of each histo- logical pattern. eIF4E-driven protein translation pathway is el - evated in...and 4EBP1 ( Epitomics ); Histone H3, AKT, and p4EBP1 (Thr37/46); pErk1/ 2 (T202/Y204), pSTAT3 (Y705), Sox2, MTA1, Src, and pSrc (Y416) (Cell Signaling

  13. The kidney trade: or, the customer is always wrong.

    PubMed Central

    Brecher, B

    1990-01-01

    Much of the opinion scandalized by recent reports of kidneys being sold for transplant is significantly inconsistent. The sale of kidneys is not substantially different from practices espoused, and indeed endorsed, by many of those who condemn the former. Our moral concern, I suggest, needs to focus on the customer's actions rather than the seller's; and on the implications for larger questions of the considerations to which this gives rise. PMID:2231633

  14. Obtention of low oxidation states of copper from Cu 2+-Al 3+ layered double hydroxides containing organic sulfonates in the interlayer

    NASA Astrophysics Data System (ADS)

    Trujillano, Raquel; Holgado, María Jesús; Rives, Vicente

    2009-03-01

    A series of hydrotalcite-type compounds containing Cu(II) and Al(III) in the layers, and carbonate or different alkylsulfonates in the interlayer, have been prepared and studied. Calcination of these solids gives rise to formation of metallic copper and Cu 2+ and Cu + oxides or sulfates, depending on the calcination temperature and on the precise nature of the interlayer alkylsulfonate.

  15. Simultaneous Constraints on the Spectrum of the Extragalactic Background Light and the Intrinsic TeV Spectra of Markarian 421, Markarian 501, and H1426+428

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Krennrich, Frank

    2005-01-01

    Very high energy (~TeV) γ-rays from blazars are attenuated by photons from the extragalactic background light (EBL). Observations of blazars can therefore provide an ideal opportunity for determining the EBL intensity if their intrinsic spectrum is known. Conversely, knowledge of the EBL intensity can be used to determine the intrinsic blazar spectrum. Unfortunately, neither the EBL intensity nor the intrinsic blazar spectrum is known with high enough precision to accurately derive one quantity from the other. In this paper we use the most recent data on the EBL to construct 12 different realizations representing all possible permutations between EBL limits and the detections in the different wavelength regions. These realizations explore a significantly larger range of allowable EBL spectra than any previous studies. We show that these realizations can be used to explore the effects of the EBL on the inferred spectra of blazars. Concentrating on the two relatively nearby (z~0.03) blazars Mrk 421 and 501, we derive their intrinsic spectra and peak γ-ray energies for the different EBL realizations. Some EBL spectra give rise to ``unphysical'' intrinsic blazar spectra, characterized by an exponential rise at high TeV energies. We use the F-test to show that some of these exponential rises are statistically insignificant. Consequently, statements regarding the existence of an ``IR background-TeV γ-ray crisis'' are unfounded on the basis of our present knowledge of the EBL. EBL spectra that do give rise to unphysical blazar spectra are regarded as invalid realizations of the EBL. Those that do not thus define new constraints on the EBL spectrum and are used to derive new limits on the intensity and the peak γ-ray energy of these two blazars. In particular, we derive an upper limit of ~15 nW m-2 sr-1 on the 60 μm EBL intensity and find the peak energies of the Mrk 421 and Mrk 501 sources to be very similar, between 0.5-1.2 and 0.8-2.5 TeV, respectively. We also show that the intrinsic spectrum of Mrk 421 during a period of intense flaring activity has a peak energy that seems to shift to higher energies at higher flux states. For the most distant blazar H1426+428 (z=0.129), most EBL realizations give rise to spectra that peak between ~1 and 5 TeV, with some suggesting peaks below 400 GeV and above ~10 TeV. These results provide important constraints on the different particle acceleration mechanisms and the generation of the γ-ray emission. Finally, we also show that uncertainties in the absolute calibration of the γ-ray energies with atmospheric Cerenkov telescopes have an important impact on the intrinsic blazar spectra. These systematic uncertainties will be improved with the next generations of telescopes that will also cover a wider range of γ-ray energies, providing further insights into the intrinsic spectrum of TeV blazars.

  16. Particle in cell simulation of peaking switch for breakdown evaluation

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

    Umbarkar, Sachin B.; Bindu, S.; Mangalvedekar, H.A.

    2014-07-01

    Marx generator connected to peaking capacitor and peaking switch can generate Ultra-Wideband (UWB) radiation. A new peaking switch is designed for converting the existing nanosecond Marx generator to a UWB source. The paper explains the particle in cell (PIC) simulation for this peaking switch, using MAGIC 3D software. This peaking switch electrode is made up of copper tungsten material and is fixed inside the hermitically sealed derlin material. The switch can withstand a gas pressure up to 13.5 kg/cm{sup 2}. The lower electrode of the switch is connected to the last stage of the Marx generator. Initially Marx generator (withoutmore » peaking stage) in air; gives the output pulse with peak amplitude of 113.75 kV and pulse rise time of 25 ns. Thus, we design a new peaking switch to improve the rise time of output pulse and to pressurize this peaking switch separately (i.e. Marx and peaking switch is at different pressure). The PIC simulation gives the particle charge density, current density, E counter plot, emitted electron current, and particle energy along the axis of gap between electrodes. The charge injection and electric field dependence on ionic dissociation phenomenon are briefly analyzed using this simulation. The model is simulated with different gases (N{sub 2}, H{sub 2}, and Air) under different pressure (2 kg/cm{sup 2}, 5 kg/cm{sup 2}, 10 kg/cm{sup 2}). (author)« less

  17. The operational stability of a centrifugal compressor and its dependence on the characteristics of the subcomponents

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

    Hunziker, R.; Gyarmathy, G.

    1994-04-01

    A centrifugal compressor was tested with three different diffusers with circular-arc vanes. The vane inlet angle was varied from 15 to 30 deg. Detailed static wall pressure measurements show that the pressure field in the diffuser inlet is very sensitive to flow rate. The stability limit regularly occurred at the flow rate giving the maximum pressure rise for the overall stage. Mild surge arises as a dynamic instability of the compression system. The analysis of the pressure rise characteristic of each individual subcomponent (impeller, diffuser inlet, diffuser channel,...) reveals their contribution to the overall pressure rise. The diffuser channels playmore » an inherently destabilizing role while the impeller and the diffuser inlet are typically stabilizing. The stability limit was mainly determined by a change in the characteristic of the diffuser inlet. Further, the stability limit was found to be independent of the development of inducer-tip recirculation.« less

  18. Over my dead body: body donation and the rise in donor registrations in The Netherlands.

    PubMed

    Bolt, Sophie; Eisinga, Rob; Altena, Marga; Venbrux, Eric; Gerrits, Peter O

    In The Netherlands, the number of body donor registrations has been increasing for several years. Body donors are people who register at an anatomical institute to donate their entire body, after death, for scientific education and research. Although only 0.1% of the Dutch population is registered as a body donor, this is sufficient to realize the anatomical demand of about 650 bodies annually. Due to the recent rise of registrations many anatomical institutes have (temporarily) stopped registering new donors to prevent a surplus of bodies. Based on a large body donor survey (n=759) and in-depth anthropological interviews with 20 body donors, we try to give an explanation for the rising registration numbers. We argue that the choice for body donation in contemporary, individualized Dutch society is an autonomous way to give meaning and sense to life and death outside the framework of institutionalized religion.

  19. Baryogenesis in Lorentz-violating gravity theories

    NASA Astrophysics Data System (ADS)

    Sakstein, Jeremy; Solomon, Adam R.

    2017-10-01

    Lorentz-violating theories of gravity typically contain constrained vector fields. We show that the lowest-order coupling of such vectors to U (1)-symmetric scalars can naturally give rise to baryogenesis in a manner akin to the Affleck-Dine mechanism. We calculate the cosmology of this new mechanism, demonstrating that a net B - L can be generated in the early Universe, and that the resulting baryon-to-photon ratio matches that which is presently observed. We discuss constraints on the model using solar system and astrophysical tests of Lorentz violation in the gravity sector. Generic Lorentz-violating theories can give rise to the observed matter-antimatter asymmetry without violating any current bounds.

  20. Thermal waves or beam heating in the 1980, November 5 flare

    NASA Technical Reports Server (NTRS)

    Smith, Dean F.

    1986-01-01

    Observations of the temporal evolution of loop BC in soft X rays in the November 5, 1980 flare are reviewed. Calculations are performed to model this evolution. The most consistent interpretation involving a minimum account of energy is the following. Thermal heating near B gives rise to a conduction front which moves out along the loop uninhibited for about 27 s. Beam heating near C gives rise to a second conduction front which moves in the opposite direction and prevents any energy reaching C by thermal conduction from B. Thus both thermal waves and beam heating are required to explain the observed evolution.

  1. 33 CFR 25.113 - Contents of claim.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... identity of the department, agency, or activity whose act or omission gave rise to the claim; (2) The full... claimant shall also include residence address; (3) The date, time, and place of the incident giving rise to... claim; (6) A description of any property damage or loss, including the identity of the owner, if other...

  2. Mechanical Milk: An Essay on the Social History of Infant Formula.

    ERIC Educational Resources Information Center

    Schwab, Michael G.

    1996-01-01

    Describes how infant formula became an "icon of modernity" separating mothers from babies and causing health and social problems. Gives a 300-year social history of the rise in popularity of infant formula, covering aspects including the body as machine, rise of science and industrialization, formula and public health, the clean milk…

  3. 43 CFR 22.6 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., who is personally named as a defendant in any civil suit in state or federal court or an arbitration... rise to the verdict, judgment, or award was taken within the scope of his or her employment and that... conduct giving rise to the personal damage claim was taken within the employee's scope of employment and...

  4. 43 CFR 22.6 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., who is personally named as a defendant in any civil suit in state or federal court or an arbitration... rise to the verdict, judgment, or award was taken within the scope of his or her employment and that... conduct giving rise to the personal damage claim was taken within the employee's scope of employment and...

  5. Disentangling Quasar Nomenclature

    NASA Astrophysics Data System (ADS)

    Ross, Nicholas; Goulding, Andrew D.

    2015-01-01

    The terms Type 1, Type 2, Obscured, Unobscured, Compton-thin and Compton-thick are cemented naming conventions for describing AGN and QSOs. However, all too often, they are used interchangeably to describe seemingly similar/different entities, leading to confusion towards the physical mechanisms that give rise to them. Furthermore, as is often the case in scientific discovery, initial designations and acronyms become obsolete. In this poster, using data and new results from the SDSS, SDSS-III BOSS, Bootes, DEEP2 and WISE surveys, we present a comprehensive QSO Glossary giving clear definitions of numerous AGN terms and the physical interpretation behind them. We further elucidate to the physical nature of hot dust obscured galaxy population (``hot DOGs'') and the long-sought after high-z Type 2 QSO population.

  6. The Czechoslovak legal regulation of family relations affected by development in medicine.

    PubMed

    Dragonec, J

    1990-01-01

    Medicine has developed rapidly during the last decades. Transplantation, sex-change surgery in transsexual or heterosexual persons, interference in the process of reproduction of human species and procedures like lobotomy have remarkably expanded the possibilities of contemporary medicine. This, at the same time gives rise to unprecedented legal problems. A number of them have not yet been solved in many countries, though legislative solutions are sought. The road to their solution, however, is full of blind curves: no sooner does the law offer an answer to one problem than medicine demands the answer to another, brand new one. This is why knowledge of these problems' regulation in different countries might be of use. That article gives an outline of their regulation in Czechoslovakia.

  7. A numerical investigation of grain shape and crystallographic texture effects on the plastic strain localization in friction stir weld zones

    NASA Astrophysics Data System (ADS)

    Romanova, V.; Balokhonov, R.; Batukhtina, E.; Shakhidjanov, V.

    2015-10-01

    Crystal plasticity approaches were adopted to build models accounting for the microstructure and texture observed in different friction stir weld zones. To this end, a numerical investigation of crystallographic texture and grain shape effects on the plastic strain localization in a friction stir weld of an aluminum-base alloy was performed. The presence of texture was found to give rise to pronounced mesoscale plastic strain localization.

  8. When measured spin polarization is not spin polarization

    NASA Astrophysics Data System (ADS)

    Dowben, P. A.; Wu, Ning; Binek, Christian

    2011-05-01

    Spin polarization is an unusually ambiguous scientific idiom and, as such, is rarely well defined. A given experimental methodology may allow one to quantify a spin polarization but only in its particular context. As one might expect, these ambiguities sometimes give rise to inappropriate interpretations when comparing the spin polarizations determined through different methods. The spin polarization of CrO2 and Cr2O3 illustrate some of the complications which hinders comparisons of spin polarization values.

  9. Unique determination of "subatomic" contrast by imaging covalent backbonding.

    PubMed

    Sweetman, Adam; Rahe, Philipp; Moriarty, Philip

    2014-05-14

    The origin of so-called "subatomic" resolution in dynamic force microscopy has remained controversial since its first observation in 2000. A number of detailed experimental and theoretical studies have identified different possible physicochemical mechanisms potentially giving rise to subatomic contrast. In this study, for the first time we are able to assign the origin of a specific instance of subatomic contrast as being due to the back bonding of a surface atom in the tip-sample junction.

  10. Anomalous optogalvanic line shapes of argon metastable transitions in a hollow cathode lamp

    NASA Technical Reports Server (NTRS)

    Ruyten, W. M.

    1993-01-01

    Anomalous optogalvanic line shapes were observed in a commercial hollow cathode lamp containing argon buffer gas. Deviations from Gaussian line shapes were particularly strong for transitions originating from the 3P2 metastable level of argon. The anomalous line shapes can be described reasonably well by the assumption that two regions in the discharge are excited simultaneously, each giving rise to a purely Gaussian line shape, but with different polarities, amplitudes, and linewidths.

  11. Identification of functional differences in metabolic networks using comparative genomics and constraint-based models.

    PubMed

    Hamilton, Joshua J; Reed, Jennifer L

    2012-01-01

    Genome-scale network reconstructions are useful tools for understanding cellular metabolism, and comparisons of such reconstructions can provide insight into metabolic differences between organisms. Recent efforts toward comparing genome-scale models have focused primarily on aligning metabolic networks at the reaction level and then looking at differences and similarities in reaction and gene content. However, these reaction comparison approaches are time-consuming and do not identify the effect network differences have on the functional states of the network. We have developed a bilevel mixed-integer programming approach, CONGA, to identify functional differences between metabolic networks by comparing network reconstructions aligned at the gene level. We first identify orthologous genes across two reconstructions and then use CONGA to identify conditions under which differences in gene content give rise to differences in metabolic capabilities. By seeking genes whose deletion in one or both models disproportionately changes flux through a selected reaction (e.g., growth or by-product secretion) in one model over another, we are able to identify structural metabolic network differences enabling unique metabolic capabilities. Using CONGA, we explore functional differences between two metabolic reconstructions of Escherichia coli and identify a set of reactions responsible for chemical production differences between the two models. We also use this approach to aid in the development of a genome-scale model of Synechococcus sp. PCC 7002. Finally, we propose potential antimicrobial targets in Mycobacterium tuberculosis and Staphylococcus aureus based on differences in their metabolic capabilities. Through these examples, we demonstrate that a gene-centric approach to comparing metabolic networks allows for a rapid comparison of metabolic models at a functional level. Using CONGA, we can identify differences in reaction and gene content which give rise to different functional predictions. Because CONGA provides a general framework, it can be applied to find functional differences across models and biological systems beyond those presented here.

  12. Identification of Functional Differences in Metabolic Networks Using Comparative Genomics and Constraint-Based Models

    PubMed Central

    Hamilton, Joshua J.; Reed, Jennifer L.

    2012-01-01

    Genome-scale network reconstructions are useful tools for understanding cellular metabolism, and comparisons of such reconstructions can provide insight into metabolic differences between organisms. Recent efforts toward comparing genome-scale models have focused primarily on aligning metabolic networks at the reaction level and then looking at differences and similarities in reaction and gene content. However, these reaction comparison approaches are time-consuming and do not identify the effect network differences have on the functional states of the network. We have developed a bilevel mixed-integer programming approach, CONGA, to identify functional differences between metabolic networks by comparing network reconstructions aligned at the gene level. We first identify orthologous genes across two reconstructions and then use CONGA to identify conditions under which differences in gene content give rise to differences in metabolic capabilities. By seeking genes whose deletion in one or both models disproportionately changes flux through a selected reaction (e.g., growth or by-product secretion) in one model over another, we are able to identify structural metabolic network differences enabling unique metabolic capabilities. Using CONGA, we explore functional differences between two metabolic reconstructions of Escherichia coli and identify a set of reactions responsible for chemical production differences between the two models. We also use this approach to aid in the development of a genome-scale model of Synechococcus sp. PCC 7002. Finally, we propose potential antimicrobial targets in Mycobacterium tuberculosis and Staphylococcus aureus based on differences in their metabolic capabilities. Through these examples, we demonstrate that a gene-centric approach to comparing metabolic networks allows for a rapid comparison of metabolic models at a functional level. Using CONGA, we can identify differences in reaction and gene content which give rise to different functional predictions. Because CONGA provides a general framework, it can be applied to find functional differences across models and biological systems beyond those presented here. PMID:22666308

  13. [Neurological syndromes linked with the intake of plants and fungi containing a toxic component (I). Neurotoxic syndromes caused by the ingestion of plants, seeds and fruits].

    PubMed

    Carod-Artal, F J

    A wide range of plants, seeds and fruits used for nutritional and medicinal purposes can give rise to neurotoxic symptoms. We review the neurological pathology associated with the acute or chronic consumption of plants, seeds and fruits in human beings and in animals. Of the plants that can trigger acute neurotoxic syndromes in humans, some of the most notable include Mandragora officinalis, Datura stramonium, Conium maculatum (hemlock), Coriaria myrtifolia (redoul), Ricinus communis, Gloriosa superba, Catharanthus roseus, Karwinskia humboldtiana and Podophyllum pelatum. We also survey different neurological syndromes linked with the ingestion of vegetable foodstuffs that are rich in cyanogenic glycosides, Jamaican vomiting sickness caused by Blighia sapida, Parkinson dementia ALS of Guam island and exposition to Cycas circinalis, Guadeloupean parkinsonism and exposition to Annonaceae, konzo caused by ingestion of wild manioc and neurolathyrism from ingestion of Lathyrus sativus, the last two being models of motor neurone disease. Locoism is a chronic disease that develops in livestock feeding on plants belonging to Astragalus and Oxytropis sp., Sida carpinifolia and Ipomea carnea, which are rich in swainsonine, a toxin that inhibits the enzyme alpha mannosidase and induces a cerebellar syndrome. The ingestion of neurotoxic seeds, fruits and plants included in the diet and acute poisoning by certain plants can give rise to different neurological syndromes, some of which are irreversible.

  14. The two origins of hemocytes in Drosophila.

    PubMed

    Holz, Anne; Bossinger, Barbara; Strasser, Thomas; Janning, Wilfried; Klapper, Robert

    2003-10-01

    As in many other organisms, the blood of Drosophila consists of several types of hemocytes, which originate from the mesoderm. By lineage analyses of transplanted cells, we specified two separate anlagen that give rise to different populations of hemocytes: embryonic hemocytes and lymph gland hemocytes. The anlage of the embryonic hemocytes is restricted to a region within the head mesoderm between 70 and 80% egg length. In contrast to all other mesodermal cells, the cells of this anlage are already determined as hemocytes at the blastoderm stage. Unexpectedly, these hemocytes do not degenerate during late larval stages, but have the capacity to persist through metamorphosis and are still detectable in the adult fly. A second anlage, which gives rise to additional hemocytes at the onset of metamorphosis, is located within the thoracic mesoderm at 50 to 53% egg length. After transplantation within this region, clones were detected in the larval lymph glands. Labeled hemocytes are released by the lymph glands not before the late third larval instar. The anlage of these lymph gland-derived hemocytes is not determined at the blastoderm stage, as indicated by the overlap of clones with other tissues. Our analyses reveal that the hemocytes of pupae and adult flies consist of a mixture of embryonic hemocytes and lymph gland-derived hemocytes, originating from two distinct anlagen that are determined at different stages of development.

  15. Phononic Origins of Friction in Carbon Nanotube Oscillators.

    PubMed

    Prasad, Matukumilli V D; Bhattacharya, Baidurya

    2017-04-12

    Phononic coupling can have a significant role in friction between nanoscale surfaces. We find frictional dissipation per atom in carbon nanotube (CNT) oscillators to depend significantly on interface features such as contact area, commensurability, and by end-capping of the inner core. We perform large-scale phonon wavepacket MD simulations to study phonon coupling between a 250 nm long (10,10) outer tube and inner cores of four different geometries. Five different phonon polarizations known to have dominant roles in thermal transport are selected, and transmission coefficient plots for a range of phonon energies along with phonon scattering dynamics at specific energies are obtained. We find that the length of interface affects friction only through LA phonon scattering and has a significant nonlinear effect on total frictional force. Incommensurate contact does not always give rise to superlubricity: the net effect of two competing interaction mechanisms shown by longitudinal and transverse phonons decides the role of commensurability. Capping of the core has no effect on acoustic phonons but destroys the coherence of transverse optical phonons and creates diffusive scattering. In contrast, the twisting and radial breathing phonon modes have perfect transmission at all energies and can be deemed as the enablers of ultralow friction in CNT oscillators. Our work suggests that tuning of interface geometries can give rise to desirable friction properties in nanoscale devices.

  16. Projections of tsunami inundation area coupled with impacts of sea level rise in Banda Aceh, Indonesia

    NASA Astrophysics Data System (ADS)

    Tursina, Syamsidik, Kato, Shigeru

    2017-10-01

    In a long term, sea level rise is anticipated to give devastating effects on Banda Aceh, as one of the coastal cities in the northern tip of Sumatra. The growth of the population and buildings in the city has come to the stage where the coastal area is vulnerable to any coastal hazard. Some public facilities and settlements have been constructed and keep expanding in the future. According to TOPEX/POSEIDON satellite images, 7 mm/year the sea level has been risen between 1992 and 2015 in this area. It is estimated that in the next 100 years, there will be 700 mm additional sea level rise which will give a setback more over to a rather flat area around the coast. This research is aim at investigating the influence of sea level rise toward the tsunami inundation on the land area particularly the impacts on Banda Aceh city. Cornell Multigrid Coupled Tsunami Model (COMCOT) simulation numerically generated tsunami propagation. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Geological movement of the underwater fault was generated using Piatanesi and Lorito of 9.15 Mw 2004 multi-fault scenario. The inundation area produced by COMCOT revealed that the inundation area was expanded to several hundred meters from the shoreline. To investigate the impacts of tsunami wave on Banda Aceh, the inundation area were digitized and analyzed with Quantum GIS spatial tools. The Quantum GIS analyzed inundations area affected by the projected tsunami. It will give a new tsunami-prone coastal area map induced by sea level rise in 100 years.

  17. 26 CFR 301.7701-15 - Tax return preparer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... on advice that is given after events have occurred that represents less than 5 percent of the...) giving rise to the understatement is primarily attributable to the advice, the advice was substantially given before events occurred primarily to avoid treating the person giving the advice as a tax return...

  18. Anomalous compression behavior of ˜12 nm nanocrystalline TiO2

    NASA Astrophysics Data System (ADS)

    Wang, Qiming; Li, Shourui; Peng, Fang; Lei, Li; Hu, Qiwei; Wang, Pei; Nan, Xiaolong; Liu, Jing; Zhu, Wenjun; He, Duanwei

    2017-06-01

    When the grain size decreases, there inevitably exists a critical size (dc) where the contribution of surface atoms to the physical properties is competitive with that of the interior atoms, giving rise to a wide variety of new phenomena. The behavior of granular materials near dc is particularly interesting because of the crossover, a continuous transition from one type of mechanism to another. In situ high-pressure x-ray diffraction experiments showed that the compression curve of nanocrystalline anatase TiO2 with grain size near dc reached a platform after about 5%-6% of deformation under hydrostatic compression. Eventually, the unit cell volume of anatase expanded at ˜14-16 GPa. We propose that the anomalous compression behavior is attributed to the formation and thickening of the stiff high density amorphous shell under high pressure, giving rise to a great arching effect at the grain boundary at the nanolevel. This process results in a remarkable difference in stress between inside and outside of the shell, generating the illusions of the hardening and the negative compressibility. This study offers a new insight into the mechanical properties of nanomaterials under extreme conditions.

  19. From hydration repulsion to dry adhesion between asymmetric hydrophilic and hydrophobic surfaces

    PubMed Central

    Kanduč, Matej; Netz, Roland R.

    2015-01-01

    Using all-atom molecular dynamics (MD) simulations at constant water chemical potential in combination with basic theoretical arguments, we study hydration-induced interactions between two overall charge-neutral yet polar planar surfaces with different wetting properties. Whether the water film between the two surfaces becomes unstable below a threshold separation and cavitation gives rise to long-range attraction, depends on the sum of the two individual surface contact angles. Consequently, cavitation-induced attraction also occurs for a mildly hydrophilic surface interacting with a very hydrophobic surface. If both surfaces are very hydrophilic, hydration repulsion dominates at small separations and direct attractive force contribution can—if strong enough—give rise to wet adhesion in this case. In between the regimes of cavitation-induced attraction and hydration repulsion we find a narrow range of contact angle combinations where the surfaces adhere at contact in the absence of cavitation. This dry adhesion regime is driven by direct surface–surface interactions. We derive simple laws for the cavitation transition as well as for the transition between hydration repulsion and dry adhesion, which favorably compare with simulation results in a generic adhesion state diagram as a function of the two surface contact angles. PMID:26392526

  20. Connectivity disruption sparks explosive epidemic spreading.

    PubMed

    Böttcher, L; Woolley-Meza, O; Goles, E; Helbing, D; Herrmann, H J

    2016-04-01

    We investigate the spread of an infection or other malfunction of cascading nature when a system component can recover only if it remains reachable from a functioning central component. We consider the susceptible-infected-susceptible model, typical of mathematical epidemiology, on a network. Infection spreads from infected to healthy nodes, with the addition that infected nodes can only recover when they remain connected to a predefined central node, through a path that contains only healthy nodes. In this system, clusters of infected nodes will absorb their noninfected interior because no path exists between the central node and encapsulated nodes. This gives rise to the simultaneous infection of multiple nodes. Interestingly, the system converges to only one of two stationary states: either the whole population is healthy or it becomes completely infected. This simultaneous cluster infection can give rise to discontinuous jumps of different sizes in the number of failed nodes. Larger jumps emerge at lower infection rates. The network topology has an important effect on the nature of the transition: we observed hysteresis for networks with dominating local interactions. Our model shows how local spread can abruptly turn uncontrollable when it disrupts connectivity at a larger spatial scale.

  1. Symmetry breaking in nematic liquid crystals: analogy with cosmology and magnetism.

    PubMed

    Repnik, R; Ranjkesh, A; Simonka, V; Ambrozic, M; Bradac, Z; Kralj, S

    2013-10-09

    Universal behavior related to continuous symmetry breaking in nematic liquid crystals is studied using Brownian molecular dynamics. A three-dimensional lattice system of rod-like objects interacting via the Lebwohl-Lasher interaction is considered. We test the applicability of predictions originally derived in cosmology and magnetism. In the first part we focus on coarsening dynamics following the temperature driven isotropic-nematic phase transition for different quench rates. The behavior in the early coarsening regime supports predictions made originally by Kibble in cosmology. For fast enough quenches, symmetry breaking and causality give rise to a dense tangle of defects. When the degree of orientational ordering is large enough, well defined protodomains characterized by a single average domain length are formed. With time subcritical domains gradually vanish and supercritical domains grow with time, exhibiting a universal scaling law. In the second part of the paper we study the impact of random-field-type disorder on a range of ordering in the (symmetry broken) nematic phase. We demonstrate that short-range order is observed even for a minute concentration of impurities, giving rise to disorder in line with the Imry-Ma theorem prediction only for the appropriate history of systems.

  2. Super Memory Bros.: going from mirror patterns to concordant patterns via similarity enhancements.

    PubMed

    Ozubko, Jason D; Joordens, Steve

    2008-12-01

    When memory is contrasted for stimuli belonging to distinct stimulus classes, one of two patterns is observed: a mirror pattern, in which one stimulus gives rise to higher hits but lower false alarms (e.g., the frequency-based mirror effect) or a concordant pattern, in which one stimulus class gives rise both to higher hits and to higher false alarms (e.g., the pseudoword effect). On the basis of the dual-process account proposed by Joordens and Hockley (2000), we predict that mirror patterns occur when one stimulus class is more familiar and less distinctive than another, whereas concordant patterns occur when one stimulus class is more familiar than another. We tested these assumptions within a video game paradigm using novel stimuli that allow manipulations in terms of distinctiveness and familiarity (via similarity). When more distinctive, less familiar items are contrasted with less distinctive, more familiar items, a mirror pattern is observed. Systematically enhancing the familiarity of stimuli transforms the mirror pattern to a concordant pattern as predicted. Although our stimuli differ considerably from those used in examinations of the frequency-based mirror effect and the pseudoword effect, the implications of our findings with respect to those phenomena are also discussed.

  3. ATM-Dependent Phosphorylation of All Three Members of the MRN Complex: From Sensor to Adaptor.

    PubMed

    Lavin, Martin F; Kozlov, Sergei; Gatei, Magtouf; Kijas, Amanda W

    2015-10-23

    The recognition, signalling and repair of DNA double strand breaks (DSB) involves the participation of a multitude of proteins and post-translational events that ensure maintenance of genome integrity. Amongst the proteins involved are several which when mutated give rise to genetic disorders characterised by chromosomal abnormalities, cancer predisposition, neurodegeneration and other pathologies. ATM (mutated in ataxia-telangiectasia (A-T) and members of the Mre11/Rad50/Nbs1 (MRN complex) play key roles in this process. The MRN complex rapidly recognises and locates to DNA DSB where it acts to recruit and assist in ATM activation. ATM, in the company of several other DNA damage response proteins, in turn phosphorylates all three members of the MRN complex to initiate downstream signalling. While ATM has hundreds of substrates, members of the MRN complex play a pivotal role in mediating the downstream signalling events that give rise to cell cycle control, DNA repair and ultimately cell survival or apoptosis. Here we focus on the interplay between ATM and the MRN complex in initiating signaling of breaks and more specifically on the adaptor role of the MRN complex in mediating ATM signalling to downstream substrates to control different cellular processes.

  4. A Set of Regioselective O-Methyltransferases Gives Rise to the Complex Pattern of Methoxylated Flavones in Sweet Basil1[C][W][OA

    PubMed Central

    Berim, Anna; Hyatt, David C.; Gang, David R.

    2012-01-01

    Polymethoxylated flavonoids occur in a number of plant families, including the Lamiaceae. To date, the metabolic pathways giving rise to the diversity of these compounds have not been studied. Analysis of our expressed sequence tag database for four sweet basil (Ocimum basilicum) lines afforded identification of candidate flavonoid O-methyltransferase genes. Recombinant proteins displayed distinct substrate preferences and product specificities that can account for all detected 7-/6-/4′-methylated, 8-unsubstituted flavones. Their biochemical specialization revealed only certain metabolic routes to be highly favorable and therefore likely in vivo. Flavonoid O-methyltransferases catalyzing 4′- and 6-O-methylations shared high identity (approximately 90%), indicating that subtle sequence changes led to functional differentiation. Structure homology modeling suggested the involvement of several amino acid residues in defining the proteins’ stringent regioselectivities. The roles of these individual residues were confirmed by site-directed mutagenesis, revealing two discrete mechanisms as a basis for the switch between 6- and 4′-O-methylation of two different substrates. These findings delineate major pathways in a large segment of the flavone metabolic network and provide a foundation for its further elucidation. PMID:22923679

  5. Effects of Artificial Viscosity on the Accuracy of High-reynolds-number Kappa-epsilon Turbulence Model

    NASA Technical Reports Server (NTRS)

    Chitsomboon, Tawit

    1994-01-01

    Wall functions, as used in the typical high Reynolds number k-epsilon turbulence model, can be implemented in various ways. A least disruptive method (to the flow solver) is to directly solve for the flow variables at the grid point next to the wall while prescribing the values of k and epsilon. For the centrally-differenced finite-difference scheme employing artificial viscocity (AV) as a stabilizing mechanism, this methodology proved to be totally useless. This is because the AV gives rise to a large error at the wall due to too steep a velocity gradient resulting from the use of a coarse grid as required by the wall function methodology. This error can be eliminated simply by extrapolating velocities at the wall, instead of using the physical values of the no-slip velocities (i.e. the zero value). The applicability of the technique used in this paper is demonstrated by solving a flow over a flat plate and comparing the results with those of experiments. It was also observed that AV gives rise to a velocity overshoot (about 1 percent) near the edge of the boundary layer. This small velocity error, however, can yield as much as 10 percent error in the momentum thickness. A method which integrates the boundary layer up to only the edge of the boundary (instead of infinity) was proposed and demonstrated to give better results than the standard method.

  6. The first data on the innervation of the lophophore in the rhynchonelliform brachiopod Hemithiris psittacea: what is the ground pattern of the lophophore in lophophorates?

    PubMed

    Temereva, Elena N; Kuzmina, Tatyana V

    2017-07-31

    The nervous system in brachiopods has seldom been studied with modern methods. An understanding of lophophore innervation in adult brachiopods is useful for comparing the innervation of the same lophophore type among different brachiopods and can also help answer questions about the monophyly of the lophophorates. Although some brachiopods are studied with modern methods, rhynchonelliform brachiopods still require investigation. The current study used transmission electron microscopy, immunocytochemistry, and confocal laser scanning microscopy to investigate the nerve system of the lophophore and tentacles in the rhynchonelliform Hemithiris psittacea. Four longitudinal nerves pass along each brachium of the lophophore: the main, accessory, second accessory, and lower. The main brachial nerve extends at the base of the dorsal side of the brachial fold and gives rise to the cross nerves, passing through the extracellular matrix to the tentacles. Cross nerves skirt the accessory brachial nerve, branch, and penetrate into adjacent outer and inner tentacles, where they are referred to as the frontal tentacular nerves. The second accessory nerve passes along the base of the inner tentacles. This nerve consists of Ʊ-like parts, which repetitively skirt the frontal and lateral sides of the inner tentacle and the frontal sides of the outer tentacles. The second accessory nerve gives rise to the latero-frontal nerves of the inner and outer tentacles. The abfrontal nerves of the inner tentacles also originate from the second accessory nerve, whereas the abfrontal nerves of the outer tentacles originate from the lower brachial nerve. The lower brachial nerve extends along the outer side of the lophophore brachia and gives rise to the intertentacular nerves, which form a T-like branch and penetrate the adjacent outer tentacles where they are referred to as abfrontal nerves. The paired outer radial nerves start from the lower brachial nerve, extend into the second accessory nerve, and give rise to the lateroabfrontal tentacular nerves of the outer tentacles. The innervation of the lophophore in the rhynchonelliform Hemithiris psittacea differs from that in the inarticulate Lingula anatina in several ways. The accessory brachial nerve does not participate in the innervation of the tentacles in H. psittacea as it does in L. anatina. The second accessory nerve is present in H. psittacea but not in L. anatina. There are six tentacular nerves in the outer tentacles of H. psittacea but only four in all other brachiopods studied to date. The reduced contribution of the accessory brachial nerve to tentacle innervation may reflect the general pattern of reduction of the inner lophophoral nerve in both phoronids and brachiopods. Bryozoan lophophores, in contrast, have a weakened outer nerve and a strengthened inner nerve. Our results suggest that the ancestral lophophore of all lophophorates had a simple shape but many nerve elements.

  7. States' Budgets Reflect Rising Tax Collections

    ERIC Educational Resources Information Center

    Hoff, David J.

    2005-01-01

    Many state budgets are reaping the benefits of tax revenues that are rising faster than at any time since the economic slowdown ended. Overall tax collections by states rose by 11.7 percent in the first quarter of 2005, giving the legislatures extra cash to shore up school aid, increase teacher pay, and finance new initiatives such as full-day…

  8. Acute drug prescribing to children on chronic antiepilepsy therapy and the potential for adverse drug interactions in primary care

    PubMed Central

    Novak, Philipp H; Ekins-Daukes, Suzie; Simpson, Colin R; Milne, Robert M; Helms, Peter; McLay, James S

    2005-01-01

    Aims To investigate the extent of acute coprescribing in primary care to children on chronic antiepileptic therapy, which could give rise to potentially harmful drug–drug interactions. Design Acute coprescribing to children on chronic antiepileptic drug therapy in primary care was assessed in 178 324 children aged 0–17 years for the year 1 November 1999 to 31 October 2000. Computerized prescribing data were retrieved from 161 representative general practices in Scotland. Setting One hundred and sixty-one general practices throughout Scotland. Results During the study year 723 (0.41%) children chronically prescribed antiepileptic therapy were identified. Fourteen antiepileptic agents were prescribed, with carbamazepine, sodium valproate and lamotrigine accounting for 80% of the total. During the year children on chronic antiepileptic therapy were prescribed 4895 acute coprescriptions for 269 different medicines. The average number of acute coprescriptions for non-epileptic drug therapy were eight, 11, six, and six for the 0–1, 2–4, 5–11, and 12–17-year-olds, respectively. Of these acute coprescriptions 72 (1.5%) prescribed to 22 (3.0%) children were identified as a potential source of clinically serious interactions. The age-adjusted prevalence rates for potentially serious coprescribing were 86, 26, 22, and 33/1000 children chronically prescribed antiepileptic therapy in the 0–1, 2–4, 5–11, and 12–17-year-old age groups, respectively. The drugs most commonly coprescribed which could give rise to such interactions were antacids, erythromycin, ciprofloxacin, theophylline and the low-dose oral contraceptive. For 10 (45.5%0 of the 20 children identified at risk of a potentially clinically serious adverse drug interaction, the acute coprescription was prescribed off label because of age or specific contraindication/warning. Conclusions In primary care, 3.0% of children on chronic antiepileptic therapy are coprescribed therapeutic agents, which could give rise to clinically serious drug–drug interactions. PMID:15948936

  9. Transplantation of schistosome sporocysts between host snails: A video guide

    PubMed Central

    Mouahid, Gabriel; Rognon, Anne; de Carvalho Augusto, Ronaldo; Driguez, Patrick; Geyer, Kathy; Karinshak, Shannon; Luviano, Nelia; Mann, Victoria; Quack, Thomas; Rawlinson, Kate; Wendt, George; Grunau, Christoph; Moné, Hélène

    2018-01-01

    Schistosomiasis is an important parasitic disease, touching roughly 200 million people worldwide. The causative agents are different Schistosoma species. Schistosomes have a complex life cycle, with a freshwater snail as intermediate host. After infection, sporocysts develop inside the snail host and give rise to human dwelling larvae. We present here a detailed step-by-step video instruction in English, French, Spanish and Portuguese that shows how these sporocysts can be manipulated and transferred from one snail to another. This procedure provides a technical basis for different types of ex vivo modifications, such as those used in functional genomics studies. PMID:29487916

  10. An Algebraic Approach to the Evolution of Emittances upon Crossing the Linear Coupling Difference Resonance

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

    Gardner,C.

    One of the hallmarks of linear coupling is the resonant exchange of oscillation amplitude between the horizontal and vertical planes when the difference between the unperturbed tunes is close to an integer. The standard derivation of this phenomenon (known as the difference resonance) can be found, for example, in the classic papers of Guignard [1, 2]. One starts with an uncoupled lattice and adds a linear perturbation that couples the two planes. The equations of motion are expressed in hamiltonian form. As the difference between the unperturbed tunes approaches an integer, one finds that the perturbing terms in the hamiltonianmore » can be divided into terms that oscillate slowly and ones that oscillate rapidly. The rapidly oscillating terms are discarded or transformed to higher order with an appropriate canonical transformation. The resulting approximate hamiltonian gives equations of motion that clearly exhibit the exchange of oscillation amplitude between the two planes. If, instead of the hamiltonian, one is given the four-by-four matrix for one turn around a synchrotron, then one has the complete solution for the turn-by-turn (TBT) motion. However, the conditions for the phenomenon of amplitude exchange are not obvious from a casual inspection of the matrix. These conditions and those that give rise to the related sum resonance are identified in this report. The identification is made using the well known formalism of Edwards and Teng [3, 4, 5] and, in particular, the normalized coupling matrix of Sagan and Rubin [6]. The formulae obtained are general in that no particular hamiltonian or coupling elements are assumed. The only assumptions are that the one-turn matrix is symplectic and that it has distinct eigenvalues on the unit circle in the complex plane. Having identified the conditions of the one-turn matrix that give rise to the resonances, we focus on the difference resonance and apply the formulae to the evolution of the horizontal and vertical emittances of a beam distribution upon passing through the resonance. Exact and approximate expressions for the TBT evolution of the emittances are derived and applied to a number of examples.« less

  11. Non-plane-wave Hartree-Fock states and nuclear homework potentials

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

    Gutierrez, G.; Plastino, A.; de Llano, M.

    1979-12-01

    It is shown that non-plane-wave single-particle Hartree-Fock orbitals giving rise to a ''spin-density-wave-like'' structure give lower energy than plane waves beyond a certain relatively low density in both nuclear and neutron matter with homework pair potentials v/sub 1/ and v/sub 2/.

  12. New Technologies and Emerging Careers. Trends and Issues Alerts.

    ERIC Educational Resources Information Center

    Kerka, Sandra

    Technological innovations are giving rise to structural changes in the economy that are in turn creating profound changes in the nature of work and work organizations. Predicted changes are: traditional hierarchical organizations in the workplace will give way to network or weblike forms of organization; customary vertical divisions of labor will…

  13. Rain volume estimation over areas using satellite and radar data

    NASA Technical Reports Server (NTRS)

    Doneaud, Andre A.; Vonderhaar, T. H.; Johnson, L. R.; Laybe, P.; Reinke, D.

    1987-01-01

    The analysis of 18 convective clusters demonstrates that the extension of the Area-Time-Integral (ATI) technique to the use of satellite data is possible. The differences of the internal structures of the radar reflectivity features, and of the satellite features, give rise to differences in estimating rain volumes by delineating area; however, by focusing upon the area integrated over the lifetime of the storm, it is suggested that some of the errors produced by the differences in the cloud geometries as viewed by radar or satellite are minimized. The results are good and future developments should consider data from different climatic regions and should allow for implementation of the technique in a general circulation model.

  14. Dynamical analysis of tachyonic chameleon

    NASA Astrophysics Data System (ADS)

    Banijamali, Ali; Solbi, Milad

    2017-08-01

    In the present paper we investigate tachyonic chameleon scalar field and present the phase space analysis for four different combinations of the tachyonic potential V(φ ) and the coupling function f(φ ) of the chameleon field with matter. We find some stable solution in which accelerated expansion of the universe is satisfied. In one case where both f(φ ) and V(φ ) are exponential a scaling attractor was found that can give rise to the late-time acceleration of the universe and alleviate the coincidence problem.

  15. Boron neutron capture therapy for oral precancer: proof of principle in an experimental animal model

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

    A. Monti Hughes; ECC Pozzi; S. Thorp

    Field-cancerized tissue can give rise to second primary tumours, causing therapeutic failure. Boron neutron capture therapy (BNCT) is based on biological targeting and would serve to treat undetectable foci of malignant transformation. The aim of this study was to optimize BNCT for the integral treatment for oral cancer, with particular emphasis on the inhibitory effect on tumour development originating in precancerous conditions, and radiotoxicity of different BNCT protocols in a hamster cheek pouch oral precancer model.

  16. Effect of reversal of double-implantation schedule of boron in mercury cadmium telluride

    NASA Astrophysics Data System (ADS)

    Kumar, Rakesh; Dutt, M. B.; Nath, R.; Gopal, Vishnu; Khosla, Y. P.; Sharma, K. K.

    1992-02-01

    Radiation damage due to B+ ion implantation in p-type HgCdTe has been found to create Hg interstitials giving rise to n-type conversion. The implantation energies were kept at 50 and 100 keV with a dose of 1 X 1013 cm-2 each. The effect of implantation with ascending and descending orders of energies were found to be quite different from each other. Radiation enhanced diffusion is thought to be responsible for this anomaly.

  17. Mobilization and Defense Management Technical Reports Series. Long War Versus Short War: An Appraisal of Policy.

    DTIC Science & Technology

    1983-05-01

    based initially on tecnology and doctrine both World Wars had a different outoe for reasons of sustainability and national determination. Assuredly the...intensity of a future conflict gives rise to serious concern over our capability to mobilize, train, deploy and sustain the force. Emhasis on DOD...purpose of war as a "continuation of policy by other means, " 4 had as its main purpose the quick destruction of enemy fighting capability . "They must be

  18. Generalized monogamy relations of concurrence for N -qubit systems

    NASA Astrophysics Data System (ADS)

    Zhu, Xue-Na; Fei, Shao-Ming

    2015-12-01

    We present a different kind of monogamous relations based on concurrence and concurrence of assistance. For N -qubit systems A B C1...CN -2 , the monogamy relations satisfied by the concurrence of N -qubit pure states under the partition A B and C1...CN -2 , as well as under the partition A B C1 and C2...CN -2 , are established, which gives rise to a kind of restrictions on the entanglement distribution and trade off among the subsystems.

  19. Mosaic generalized neurofibromatosis 1: report of two cases.

    PubMed

    Hardin, Jori; Behm, Allan; Haber, Richard M

    2014-01-01

    We report two cases of mosaic generalized neurofibromatosis 1 (NF1) and review the history of the classification of segmental neurofibromatosis (SNF; Ricardi type NF-V). Somatic mutations giving rise to limited disease, such as segmental neurofibromatosis are manifestations of mosaicism. If the mutation occurs before tissue differentiation, the clinical phenotype will be generalized disease. Mutations that occur later in development give rise to disease that is confined to a single region. Segmental neurofibromatosis is caused by a somatic mutation of neurofibromatosis type 1, and should not be regarded as a distinct entity from neurofibromatosis 1. Cases previously referred to as unilateral or bilateral segmental neurofibromatosis are now best referred to as mosaic generalized or mosaic localized neurofibromatosis 1.

  20. Alpha effect of Alfv{acute e}n waves and current drive in reversed-field pinches

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

    Litwin, C.; Prager, S.C.

    Circularly polarized Alfv{acute e}n waves give rise to an {alpha}-dynamo effect that can be exploited to drive parallel current. In a {open_quotes}laminar{close_quotes} magnetic the effect is weak and does not give rise to significant currents for realistic parameters (e.g., in tokamaks). However, in reversed-field pinches (RFPs) in which magnetic field in the plasma core is stochastic, a significant enhancement of the {alpha} effect occurs. Estimates of this effect show that it may be a realistic method of current generation in the present-day RFP experiments and possibly also in future RFP-based fusion reactors. {copyright} {ital 1998 American Institute of Physics.}

  1. A context-based theory of recency and contiguity in free recall

    PubMed Central

    Sederberg, Per B.; Howard, Marc W.; Kahana, Michael J.

    2008-01-01

    We present a new model of free recall based on Howard and Kahana’s (2002) temporal context model and Usher and McClelland’s (2001) leaky-accumulator decision model. In this model, contextual drift gives rise to both short-term and long-term recency effects, and contextual retrieval gives rise to short-term and long-term contiguity effects, Recall decisions are controlled by a race between competitive leaky-accumulators. The model captures the dynamics of immediate, delayed, and continual distractor free recall, demonstrating that dissociations between short- and long-term recency can naturally arise from a model that uses an internal contextual state as the sole cue for retrieval across time scales. PMID:18954208

  2. Baryon number violation and novel canonical anti-commutation relations

    NASA Astrophysics Data System (ADS)

    Fujikawa, Kazuo; Tureanu, Anca

    2018-02-01

    The possible neutron-antineutron oscillation is described by an effective quadratic Lagrangian analogous to the BCS theory. It is shown that the conventional equal-time anti-commutation relations of the neutron variable n (t , x →) are modified by the baryon number violating terms. This is established by the Bjorken-Johnson-Low prescription and also by the canonical quantization combined with equations of motion. This novel canonical behavior can give rise to an important physical effect, which is illustrated by analyzing the Lagrangian that violates the baryon number but gives rise to the degenerate effective Majorana fermions and thus no neutron-antineutron oscillation. Technically, this model is neatly treated using a relativistic analogue of the Bogoliubov transformation.

  3. Capillary rise between planar surfaces

    NASA Astrophysics Data System (ADS)

    Bullard, Jeffrey W.; Garboczi, Edward J.

    2009-01-01

    Minimization of free energy is used to calculate the equilibrium vertical rise and meniscus shape of a liquid column between two closely spaced, parallel planar surfaces that are inert and immobile. States of minimum free energy are found using standard variational principles, which lead not only to an Euler-Lagrange differential equation for the meniscus shape and elevation, but also to the boundary conditions at the three-phase junction where the liquid meniscus intersects the solid walls. The analysis shows that the classical Young-Dupré equation for the thermodynamic contact angle is valid at the three-phase junction, as already shown for sessile drops with or without the influence of a gravitational field. Integration of the Euler-Lagrange equation shows that a generalized Laplace-Young (LY) equation first proposed by O’Brien, Craig, and Peyton [J. Colloid Interface Sci. 26, 500 (1968)] gives an exact prediction of the mean elevation of the meniscus at any wall separation, whereas the classical LY equation for the elevation of the midpoint of the meniscus is accurate only when the separation approaches zero or infinity. When both walls are identical, the meniscus is symmetric about the midpoint, and the midpoint elevation is a more traditional and convenient measure of capillary rise than the mean elevation. Therefore, for this symmetric system a different equation is fitted to numerical predictions of the midpoint elevation and is shown to give excellent agreement for contact angles between 15° and 160° and wall separations up to 30mm . When the walls have dissimilar surface properties, the meniscus generally assumes an asymmetric shape, and significant elevation of the liquid column can occur even when one of the walls has a contact angle significantly greater than 90°. The height of the capillary rise depends on the spacing between the walls and also on the difference in contact angles at the two surfaces. When the contact angle at one wall is greater than 90° but the contact angle at the other wall is less than 90°, the meniscus can have an inflection point separating a region of positive curvature from a region of negative curvature, the inflection point being pinned at zero height. However, this condition arises only when the spacing between the walls exceeds a threshold value that depends on the difference in contact angles.

  4. The Global Experience of Deployment of Energy-Efficient Technologies in High-Rise Construction

    NASA Astrophysics Data System (ADS)

    Potienko, Natalia D.; Kuznetsova, Anna A.; Solyakova, Darya N.; Klyueva, Yulia E.

    2018-03-01

    The objective of this research is to examine issues related to the increasing importance of energy-efficient technologies in high-rise construction. The aim of the paper is to investigate modern approaches to building design that involve implementation of various energy-saving technologies in diverse climates and at different structural levels, including the levels of urban development, functionality, planning, construction and engineering. The research methodology is based on the comprehensive analysis of the advanced global expertise in the design and construction of energy-efficient high-rise buildings, with the examination of their positive and negative features. The research also defines the basic principles of energy-efficient architecture. Besides, it draws parallels between the climate characteristics of countries that lead in the field of energy-efficient high-rise construction, on the one hand, and the climate in Russia, on the other, which makes it possible to use the vast experience of many countries, wholly or partially. The paper also gives an analytical review of the results arrived at by implementing energy efficiency principles into high-rise architecture. The study findings determine the impact of energy-efficient technologies on high-rise architecture and planning solutions. In conclusion, the research states that, apart from aesthetic and compositional interpretation of architectural forms, an architect nowadays has to address the task of finding a synthesis between technological and architectural solutions, which requires knowledge of advanced technologies. The study findings reveal that the implementation of modern energy-efficient technologies into high-rise construction is of immediate interest and is sure to bring long-term benefits.

  5. Extracellular regulation of VEGF: isoforms, proteolysis, and vascular patterning

    PubMed Central

    Vempati, Prakash; Popel, Aleksander S.; Mac Gabhann, Feilim

    2014-01-01

    The regulation of vascular endothelial growth factor A (VEGF) is critical to neovascularization in numerous tissues under physiological and pathological conditions. VEGF has multiple isoforms, created by alternative splicing or proteolytic cleavage, and characterized by different receptor-binding and matrix-binding properties. These isoforms are known to give rise to a spectrum of angiogenesis patterns marked by differences in branching, which has functional implications for tissues. In this review, we detail the extensive extracellular regulation of VEGF and the ability of VEGF to dictate the vascular phenotype. We explore the role of VEGF-releasing proteases and soluble carrier molecules on VEGF activity. While proteases such as MMP9 can ‘release’ matrix-bound VEGF and promote angiogenesis, for example as a key step in carcinogenesis, proteases can also suppress VEGF’s angiogenic effects. We explore what dictates pro- or anti-angiogenic behavior. We also seek to understand the phenomenon of VEGF gradient formation. Strong VEGF gradients are thought to be due to decreased rates of diffusion from reversible matrix binding, however theoretical studies show that this scenario cannot give rise to lasting VEGF gradients in vivo. We propose that gradients are formed through degradation of sequestered VEGF. Finally, we review how different aspects of the VEGF signal, such as its concentration, gradient, matrix-binding, and NRP1-binding can differentially affect angiogenesis. We explore how this allows VEGF to regulate the formation of vascular networks across a spectrum of high to low branching densities, and from normal to pathological angiogenesis. A better understanding of the control of angiogenesis is necessary to improve upon limitations of current angiogenic therapies. PMID:24332926

  6. Commitment of chondrogenic precursors of the avian scapula takes place after epithelial-mesenchymal transition of the dermomyotome

    PubMed Central

    2010-01-01

    Background Cells of the epithelially organised dermomyotome are traditionally believed to give rise to skeletal muscle and dermis. We have previously shown that the dermomyotome can undergo epithelial-mesenchymal transition (EMT) and give rise to chondrogenic cells, which go on to form the scapula blade in birds. At present we have little understanding regarding the issue of when the chondrogenic fate of dermomyotomal cells is determined. Using quail-chick grafting experiments, we investigated whether scapula precursor cells are committed to a chondrogenic fate while in an epithelial state or whether commitment is established after EMT. Results We show that the hypaxial dermomyotome, which normally forms the scapula, does not generate cartilaginous tissue after it is grafted to the epaxial domain. In contrast engraftment of the epaxial dermomyotome to the hypaxial domain gives rise to scapula-like cartilage. However, the hypaxial sub-ectodermal mesenchyme (SEM), which originates from the hypaxial dermomyotome after EMT, generates cartilaginous elements in the epaxial domain, whereas in reciprocal grafting experiments, the epaxial SEM cannot form cartilage in the hypaxial domain. Conclusions We suggest that the epithelial cells of the dermomyotome are not committed to the chondrogenic lineage. Commitment to this lineage occurs after it has undergone EMT to form the sub-ectodermal mesenchyme. PMID:20807426

  7. Neo-epitope Peptides as Biomarkers of Disease Progression for Muscular Dystrophies and Other Myopathies

    PubMed Central

    Arvanitidis, A.; Henriksen, K.; Karsdal, M.A.; Nedergaard, A.

    2016-01-01

    For several decades, serological biomarkers of neuromuscular diseases as dystrophies, myopathies and myositis have been limited to routine clinical biochemistry panels. Gauging the pathological progression is a prerequisite for proper treatment and therefore identifying accessible, easy to monitor biomarkers that can predict the disease progression would be an important advancement. Most muscle diseases involve accelerated muscle fiber degradation, inflammation, fatty tissue substitution and/or fibrosis. All these pathological traits have been shown to give rise to serological peptide biomarkers in other tissues, underlining the potential application of existing biomarkers of such traits in muscle disorders. A significant quantity of tissue is involved in these pathological mechanisms alongside with qualitative changes in protein turnover in myofibrillar, extra-cellular matrix and immunological cell protein fractions accompanied by alterations in body fluids. We propose that protein and peptides can leak out of the afflicted muscles and can be of use in diagnosis, prediction of pathology trajectory and treatment efficacy. Proteolytic cleavage systems are especially modulated during a range of muscle pathologies, thereby giving rise to peptides that are differentially released during disease manifestation. Therefore, we believe that pathology-specific post-translational modifications like cleavages can give rise to neoepitope peptides that may represent a promising class of peptides for discovery of biomarkers pertaining to neuromuscular diseases. PMID:27854226

  8. Elucidation of the EP defect in Diamond-Blackfan anemia by characterization and prospective isolation of human EPs.

    PubMed

    Iskander, Deena; Psaila, Bethan; Gerrard, Gareth; Chaidos, Aristeidis; En Foong, Hui; Harrington, Yvonne; Karnik, Leena C; Roberts, Irene; de la Fuente, Josu; Karadimitris, Anastasios

    2015-04-16

    Diamond-Blackfan anemia (DBA) is a disorder characterized by a selective defect in erythropoiesis. Delineation of the precise defect is hampered by a lack of markers that define cells giving rise to erythroid burst- and erythroid colony-forming unit (BFU-E and CFU-E) colonies, the clonogenic assays that quantify early and late erythroid progenitor (EEP and LEP) potential, respectively. By combining flow cytometry, cell-sorting, and single-cell clonogenic assays, we identified Lin(-)CD34(+)CD38(+)CD45RA(-)CD123(-)CD71(+)CD41a(-)CD105(-)CD36(-) bone marrow cells as EEP giving rise to BFU-E, and Lin(-)CD34(+/-)CD38(+)CD45RA(-)CD123(-)CD71(+)CD41a(-)CD105(+)CD36(+) cells as LEP giving rise to CFU-E, in a hierarchical fashion. We then applied these definitions to DBA and identified that, compared with controls, frequency, and clonogenicity of DBA, EEP and LEP are significantly decreased in transfusion-dependent but restored in corticosteroid-responsive patients. Thus, both quantitative and qualitative defects in erythroid progenitor (EP) contribute to defective erythropoiesis in DBA. Prospective isolation of defined EPs will facilitate more incisive study of normal and aberrant erythropoiesis. © 2015 by The American Society of Hematology.

  9. Wind velocity-change (gust rise) criteria for wind turbine design

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

    Cliff, W.C.; Fichtl, G.H.

    1978-07-01

    A closed-form equation is derived for root mean square (rms) value of velocity change (gust rise) that occurs over the swept area of wind turbine rotor systems and an equation for rms value of velocity change that occurs at a single point in space. These formulas confirm the intuitive assumption that a large system will encounter a less severe environment than a small system when both are placed at the same location. Assuming a normal probability density function for the velocity differences, an equation is given for calculating the expected number of velocity differences that will occur in 1 hrmore » and will be larger than an arbitrary value. A formula is presented that gives the expected number of velocity differences larger than an arbitrary value that will be encountered during the design life of a wind turbine. In addition, a method for calculating the largest velocity difference expected during the life of a turbine and a formula for estimating the risk of exceeding a given velocity difference during the life of the structure are given. The equations presented are based upon general atmospheric boundary-layer conditions and do not include information regarding events such as tornados, hurricanes, etc.« less

  10. Characterization of perovskite solar cells: Towards a reliable measurement protocol

    NASA Astrophysics Data System (ADS)

    Zimmermann, Eugen; Wong, Ka Kan; Müller, Michael; Hu, Hao; Ehrenreich, Philipp; Kohlstädt, Markus; Würfel, Uli; Mastroianni, Simone; Mathiazhagan, Gayathri; Hinsch, Andreas; Gujar, Tanaji P.; Thelakkat, Mukundan; Pfadler, Thomas; Schmidt-Mende, Lukas

    2016-09-01

    Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe "hysteretic" behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories.

  11. Task representation in individual and joint settings

    PubMed Central

    Prinz, Wolfgang

    2015-01-01

    This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding (TEC). This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions). On the other hand, stimulus and response code cooperate with each other (vertical interactions). Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task) and off-line implementation (i.e., setting the task). Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1) Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference; (2) The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference; and (3) Task sets for joint settings conflate intraindividual conflicts between responses (what), with interindividual conflicts between responding agents (whom). Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially). PMID:26029085

  12. Stem/progenitor cells derived from the cochlear sensory epithelium give rise to spheres with distinct morphologies and features.

    PubMed

    Diensthuber, Marc; Oshima, Kazuo; Heller, Stefan

    2009-06-01

    Nonmammalian vertebrates regenerate lost sensory hair cells by means of asymmetric division of supporting cells. Inner ear or lateral line supporting cells in birds, amphibians, and fish consequently serve as bona fide stem cells resulting in high regenerative capacity of hair cell-bearing organs. Hair cell regeneration does not happen in the mammalian cochlea, but cells with proliferative capacity can be isolated from the neonatal cochlea. These cells have the ability to form clonal floating colonies, so-called spheres, when cultured in nonadherent conditions. We noticed that the sphere population derived from mouse cochlear sensory epithelium cells was heterogeneous, consisting of morphologically distinct sphere types, hereby classified as solid, transitional, and hollow. Cochlear sensory epithelium-derived stem/progenitor cells initially give rise to small solid spheres, which subsequently transition into hollow spheres, a change that is accompanied by epithelial differentiation of the majority of sphere cells. Only solid spheres, and to a lesser extent, transitional spheres, appeared to harbor self-renewing stem cells, whereas hollow spheres could not be consistently propagated. Solid spheres contained significantly more rapidly cycling Pax-2-expressing presumptive otic progenitor cells than hollow spheres. Islet-1, which becomes upregulated in nascent sensory patches, was also more abundant in solid than in hollow spheres. Likewise, hair cell-like cells, characterized by the expression of multiple hair cell markers, differentiated in significantly higher numbers in cell populations derived from solid spheres. We conclude that cochlear sensory epithelium cell populations initially give rise to small solid spheres that have self-renewing capacity before they subsequently convert into hollow spheres, a process that is accompanied by loss of stemness and reduced ability to spontaneously give rise to hair cell-like cells. Solid spheres might, therefore, represent the most suitable sphere type for cell-based assays or animal model transplantation studies aimed at development of cell replacement therapies.

  13. [Methods of protein gradient determination for diagnostic use in the clinical laboratory].

    PubMed

    Schulz, D; Rothenhöfer, C

    1982-02-25

    Computed quotients of the concentrations of individual proteins in serum and in cerebrospinal fluid recorded in a semilogarithmic way against the hydrodynamic radius of the molecules may be connected and so give lineals, the positions of which are believed to estimate the actual function of the blood-brain-barrier (Felgenhauer et al. 1974; 1976). It is demonstrated by examinations of different samples of blood and cerebrospinal fluid, that both the described method and the simple measurement of total protein in cerebrospinal fluid are of the same power in their application to estimate the function of the blood-brain-barrier. However, the method introduced by Felgenhauer et al. enables to demonstrate immunoglobulins not having reached the cerebrospinal fluid by entering from the blood stream and so giving rise to diagnose a local humoral immune response within the central nervous system. In this way the method of Felgenhauer et al. gives advantages to the diagnostics of neurological diseases.

  14. Schema-based learning of adaptable and flexible prey-catching in anurans I. The basic architecture.

    PubMed

    Corbacho, Fernando; Nishikawa, Kiisa C; Weerasuriya, Ananda; Liaw, Jim-Shih; Arbib, Michael A

    2005-12-01

    A motor action often involves the coordination of several motor synergies and requires flexible adjustment of the ongoing execution based on feedback signals. To elucidate the neural mechanisms underlying the construction and selection of motor synergies, we study prey-capture in anurans. Experimental data demonstrate the intricate interaction between different motor synergies, including the interplay of their afferent feedback signals (Weerasuriya 1991; Anderson and Nishikawa 1996). Such data provide insights for the general issues concerning two-way information flow between sensory centers, motor circuits and periphery in motor coordination. We show how different afferent feedback signals about the status of the different components of the motor apparatus play a critical role in motor control as well as in learning. This paper, along with its companion paper, extend the model by Liaw et al. (1994) by integrating a number of different motor pattern generators, different types of afferent feedback, as well as the corresponding control structure within an adaptive framework we call Schema-Based Learning. We develop a model of the different MPGs involved in prey-catching as a vehicle to investigate the following questions: What are the characteristic features of the activity of a single muscle? How can these features be controlled by the premotor circuit? What are the strategies employed to generate and synchronize motor synergies? What is the role of afferent feedback in shaping the activity of a MPG? How can several MPGs share the same underlying circuitry and yet give rise to different motor patterns under different input conditions? In the companion paper we also extend the model by incorporating learning components that give rise to more flexible, adaptable and robust behaviors. To show these aspects we incorporate studies on experiments on lesions and the learning processes that allow the animal to recover its proper functioning.

  15. Mass and volume contributions to twentieth-century global sea level rise.

    PubMed

    Miller, Laury; Douglas, Bruce C

    2004-03-25

    The rate of twentieth-century global sea level rise and its causes are the subjects of intense controversy. Most direct estimates from tide gauges give 1.5-2.0 mm yr(-1), whereas indirect estimates based on the two processes responsible for global sea level rise, namely mass and volume change, fall far below this range. Estimates of the volume increase due to ocean warming give a rate of about 0.5 mm yr(-1) (ref. 8) and the rate due to mass increase, primarily from the melting of continental ice, is thought to be even smaller. Therefore, either the tide gauge estimates are too high, as has been suggested recently, or one (or both) of the mass and volume estimates is too low. Here we present an analysis of sea level measurements at tide gauges combined with observations of temperature and salinity in the Pacific and Atlantic oceans close to the gauges. We find that gauge-determined rates of sea level rise, which encompass both mass and volume changes, are two to three times higher than the rates due to volume change derived from temperature and salinity data. Our analysis supports earlier studies that put the twentieth-century rate in the 1.5-2.0 mm yr(-1) range, but more importantly it suggests that mass increase plays a larger role than ocean warming in twentieth-century global sea level rise.

  16. Brain size and limits to adult neurogenesis.

    PubMed

    Paredes, Mercedes F; Sorrells, Shawn F; Garcia-Verdugo, Jose M; Alvarez-Buylla, Arturo

    2016-02-15

    The walls of the cerebral ventricles in the developing embryo harbor the primary neural stem cells from which most neurons and glia derive. In many vertebrates, neurogenesis continues postnatally and into adulthood in this region. Adult neurogenesis at the ventricle has been most extensively studied in organisms with small brains, such as reptiles, birds, and rodents. In reptiles and birds, these progenitor cells give rise to young neurons that migrate into many regions of the forebrain. Neurogenesis in adult rodents is also relatively widespread along the lateral ventricles, but migration is largely restricted to the rostral migratory stream into the olfactory bulb. Recent work indicates that the wall of the lateral ventricle is highly regionalized, with progenitor cells giving rise to different types of neurons depending on their location. In species with larger brains, young neurons born in these spatially specified domains become dramatically separated from potential final destinations. Here we hypothesize that the increase in size and topographical complexity (e.g., intervening white matter tracts) in larger brains may severely limit the long-term contribution of new neurons born close to, or in, the ventricular wall. We compare the process of adult neuronal birth, migration, and integration across species with different brain sizes, and discuss how early regional specification of progenitor cells may interact with brain size and affect where and when new neurons are added. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

  17. The investigation of order–disorder transition process of ZSM-5 induced by spark plasma sintering

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

    Wang, Liang; Wang, Lianjun, E-mail: wanglj@dhu.edu.cn; Jiang, Wan

    2014-04-01

    Based on the amorphization of zeolites, an order–disorder transition method was used to prepare silica glass via Spark Plasma Sintering (SPS). In order to get a better understanding about the mechanism of amorphization induced by SPS, the intermediate products in this process were prepared and characterized by different characterization techniques. X-ray diffraction and High-energy synchrotron X-ray scattering show a gradual transformation from ordered crystal to glass. Local structural changes in glass network including Si–O bond length, O–Si–O bond angle, size of rings, coordination were detected by Infrared spectroscopy and {sup 29}Si magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. Topologically ordered,more » amorphous material with a different intermediate-range structure can be obtained by precise control of intermediate process which can be expected to optimize and design material. - Graphical abstract: Low-density, ordered zeolites collapse to the rigid amorphous glass through spark plasma sintering. The intermediate-range structure formed in the process of order–disorder transition may give rise to specific property. - Highlights: • Order–disorder transition process of ZSM-5 induced by spark plasma sintering was investigated using several methods including XRD, High-energy synchrotron X-ray scattering, SAXS, IR, NMR, ect. • Order–disorder transition induced by SPS was compared with TIA and PIA. • Three stages has been divided during the whole process. • The collapse temperature range which may give rise to intermediate-range structure has been located.« less

  18. Parallel and convergent processing in grid cell, head-direction cell, boundary cell, and place cell networks.

    PubMed

    Brandon, Mark P; Koenig, Julie; Leutgeb, Stefan

    2014-03-01

    The brain is able to construct internal representations that correspond to external spatial coordinates. Such brain maps of the external spatial topography may support a number of cognitive functions, including navigation and memory. The neuronal building block of brain maps are place cells, which are found throughout the hippocampus of rodents and, in a lower proportion, primates. Place cells typically fire in one or few restricted areas of space, and each area where a cell fires can range, along the dorsoventral axis of the hippocampus, from 30 cm to at least several meters. The sensory processing streams that give rise to hippocampal place cells are not fully understood, but substantial progress has been made in characterizing the entorhinal cortex, which is the gateway between neocortical areas and the hippocampus. Entorhinal neurons have diverse spatial firing characteristics, and the different entorhinal cell types converge in the hippocampus to give rise to a single, spatially modulated cell type-the place cell. We therefore suggest that parallel information processing in different classes of cells-as is typically observed at lower levels of sensory processing-continues up into higher level association cortices, including those that provide the inputs to hippocampus. WIREs Cogn Sci 2014, 5:207-219. doi: 10.1002/wcs.1272 Conflict of interest: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. © 2013 John Wiley & Sons, Ltd.

  19. Differential receptive field organizations give rise to nearly identical neural correlations across three parallel sensory maps in weakly electric fish

    PubMed Central

    2017-01-01

    Understanding how neural populations encode sensory information thereby leading to perception and behavior (i.e., the neural code) remains an important problem in neuroscience. When investigating the neural code, one must take into account the fact that neural activities are not independent but are actually correlated with one another. Such correlations are seen ubiquitously and have a strong impact on neural coding. Here we investigated how differences in the antagonistic center-surround receptive field (RF) organization across three parallel sensory maps influence correlations between the activities of electrosensory pyramidal neurons. Using a model based on known anatomical differences in receptive field center size and overlap, we initially predicted large differences in correlated activity across the maps. However, in vivo electrophysiological recordings showed that, contrary to modeling predictions, electrosensory pyramidal neurons across all three segments displayed nearly identical correlations. To explain this surprising result, we incorporated the effects of RF surround in our model. By systematically varying both the RF surround gain and size relative to that of the RF center, we found that multiple RF structures gave rise to similar levels of correlation. In particular, incorporating known physiological differences in RF structure between the three maps in our model gave rise to similar levels of correlation. Our results show that RF center overlap alone does not determine correlations which has important implications for understanding how RF structure influences correlated neural activity. PMID:28863136

  20. Fluxoids configurations in finite superconducting networks

    NASA Astrophysics Data System (ADS)

    Sharon, Omri J.; Haham, Noam; Shaulov, Avner A.; Yeshurun, Yosef

    2017-12-01

    Analysis of superconducting ladders consisting of rectangular loops, yields an Ising like expression for the total energy of the ladders as a function of the loops vorticities and the applied magnetic field. This expression shows that fluxoids can be treated as repulsively interacting objects driven towards the ladder center by the applied field. Distinctive repulsive interactions between fluxoids are obtained depending on the ratio l between the loops length and the common width of adjacent loops. A 'short range' and a 'long range' interactions obtained for l ≳ 1 and l ≪ 1, respectively, give rise to remarkably different fluxoid configurations. The different configurations of fluxoids in different types of ladders are illustrated by simulations.

  1. A Coupled Economic and Physical Model of Coastal Adaptation and Abandonment: Are human occupied coastlines a bubble waiting to burst?

    NASA Astrophysics Data System (ADS)

    McNamara, D.; Keeler, A.

    2011-12-01

    Policy discussions of adaptation by coastal residents to increasing rates of sea level rise and changing frequency of damaging storms have focused on community land use planning processes. This view neglects the role that market dynamics and climate change expectations play in the way coastal communities choose among risk mitigation options and manage land use decisions in an environment of escalating risks. We use a model coupling physical coastal processes with an agent-based model of behavior in real estate and mitigation markets to examine the interplay of climate-driven coastal hazards, collective mitigation decisions, and individual beliefs. The physical component model simulates barrier island processes that respond to both storms and slow scale dynamics associated with sea level rise. The economic component model is an agent-based model of economic behavior where agents are rational economic actors working off different assessments of future climate-driven events. Agents differentially update their beliefs based on a) how much emphasis they give to observed coastal changes and b) how much weight they give to scientific predictions. In essence, agents differ along a spectrum of how much they believe that the past is the best guide to the future and how quickly they react to new information. We use the coupled model to explore three questions of interest to coastal policy. First, how do the interplay of costal processes, beliefs, and mitigation choices affect the level and stability of real estate prices? Second, how does this interplay affect the incentives for community investments in shoreline protection? Third, how do expectations and reactions to observed events, as well as mitigation investments, affect the built environment in circumstances when climate risks reach very high levels? This last question relates to a key aspect of climate change adaptation on the coast - when does mitigation give way to abandonment as an optimal adaptation strategy? Results suggest that subjective expectations about climate risk and about the effectiveness of mitigation in high-risk environments are critical in determining when the market starts to reflect the possibility that property might no longer be inhabitable. Results will be presented that contrast the dynamics of abandonment over a range of sea level rise and storminess scenarios.

  2. Possible explanation of the atmospheric kinetic and potential energy spectra.

    PubMed

    Vallgren, Andreas; Deusebio, Enrico; Lindborg, Erik

    2011-12-23

    We hypothesize that the observed wave number spectra of kinetic and potential energy in the atmosphere can be explained by assuming that there are two related cascade processes emanating from the same large-scale energy source, a downscale cascade of potential enstrophy, giving rise to the k(-3) spectrum at synoptic scales and a downscale energy cascade giving rise to the k(-5/3) spectrum at mesoscales. The amount of energy which is going into the downscale energy cascade is determined by the rate of system rotation, with negligible energy going downscale in the limit of very fast rotation. We present a set of simulations of a system with strong rotation and stratification, supporting these hypotheses and showing good agreement with observations.

  3. Simple Emergent Power Spectra from Complex Inflationary Physics

    NASA Astrophysics Data System (ADS)

    Dias, Mafalda; Frazer, Jonathan; Marsh, M. C. David

    2016-09-01

    We construct ensembles of random scalar potentials for Nf-interacting scalar fields using nonequilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For Nf=O (few ), these heavily featured scalar potentials give rise to power spectra that are highly nonlinear, at odds with observations. For Nf≫1 , the superhorizon evolution of the perturbations is generically substantial, yet the power spectra simplify considerably and become more predictive, with most realizations being well approximated by a linear power spectrum. This provides proof of principle that complex inflationary physics can give rise to simple emergent power spectra. We explain how these results can be understood in terms of large Nf universality of random matrix theory.

  4. Simple Emergent Power Spectra from Complex Inflationary Physics.

    PubMed

    Dias, Mafalda; Frazer, Jonathan; Marsh, M C David

    2016-09-30

    We construct ensembles of random scalar potentials for N_{f}-interacting scalar fields using nonequilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For N_{f}=O(few), these heavily featured scalar potentials give rise to power spectra that are highly nonlinear, at odds with observations. For N_{f}≫1, the superhorizon evolution of the perturbations is generically substantial, yet the power spectra simplify considerably and become more predictive, with most realizations being well approximated by a linear power spectrum. This provides proof of principle that complex inflationary physics can give rise to simple emergent power spectra. We explain how these results can be understood in terms of large N_{f} universality of random matrix theory.

  5. Impact of active phase chemical composition and dispersity on catalytic behavior in PROX reaction

    NASA Astrophysics Data System (ADS)

    Cherkezova-Zheleva, Z.; Paneva, D.; Todorova, S.; Kolev, H.; Shopska, M.; Yordanova, I.; Mitov, I.

    2014-04-01

    Iron and iron-platinum catalysts supported on activated carbon have been successfully synthesized by wet impregnation method and low-temperature treatment in inert atmosphere. The content of the supported phases corresponds to 10 wt % Fe and 0.5 wt % Pt. Four catalytic samples were synthesized: Sample A—activated carbon impregnated with Fe nitrate; Sample B—activated carbon impregnated with Pt salt; Sample C—activated carbon impregnated consequently with Fe and Pt salts; Sample D—activated carbon impregnated simultaneously with Fe and Pt salts. The as-prepared materials were characterized by Mössbauer spectroscopy, X-ray diffraction, infrared and X-ray photoelectron spectroscopy. The spectra show that the activated carbon support and the preparation procedure give rise to the synthesis of isolated metal Pt ions and ultradispersed Fe and Pt oxide species. Probably the presence of different functional groups of activated carbon gives rise to registered very high dispersion of loaded species on support. The catalytic tests were carried out in PROX reaction. A lower activity of bimetallic Pt-Fe samples was explained with the increase in surface oxygen species as a result of predomination of iron oxide on the support leading to the increase in selectivity to the H2 oxidation. Partial agglomeration of supported iron oxide phase was registered after catalytic tests.

  6. Black holes in vector-tensor theories

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

    Heisenberg, Lavinia; Kase, Ryotaro; Tsujikawa, Shinji

    We study static and spherically symmetric black hole (BH) solutions in second-order generalized Proca theories with nonminimal vector field derivative couplings to the Ricci scalar, the Einstein tensor, and the double dual Riemann tensor. We find concrete Lagrangians which give rise to exact BH solutions by imposing two conditions of the two identical metric components and the constant norm of the vector field. These exact solutions are described by either Reissner-Nordström (RN), stealth Schwarzschild, or extremal RN solutions with a non-trivial longitudinal mode of the vector field. We then numerically construct BH solutions without imposing these conditions. For cubic andmore » quartic Lagrangians with power-law couplings which encompass vector Galileons as the specific cases, we show the existence of BH solutions with the difference between two non-trivial metric components. The quintic-order power-law couplings do not give rise to non-trivial BH solutions regular throughout the horizon exterior. The sixth-order and intrinsic vector-mode couplings can lead to BH solutions with a secondary hair. For all the solutions, the vector field is regular at least at the future or past horizon. The deviation from General Relativity induced by the Proca hair can be potentially tested by future measurements of gravitational waves in the nonlinear regime of gravity.« less

  7. Identification and characterization of secondary neural tube-derived embryonic neural stem cells in vitro.

    PubMed

    Shaker, Mohammed R; Kim, Joo Yeon; Kim, Hyun; Sun, Woong

    2015-05-15

    Secondary neurulation is an embryonic progress that gives rise to the secondary neural tube, the precursor of the lower spinal cord region. The secondary neural tube is derived from aggregated Sox2-expressing neural cells at the dorsal region of the tail bud, which eventually forms rosette or tube-like structures to give rise to neural tissues in the tail bud. We addressed whether the embryonic tail contains neural stem cells (NSCs), namely secondary NSCs (sNSCs), with the potential for self-renewal in vitro. Using in vitro neurosphere assays, neurospheres readily formed at the rosette and neural-tube levels, but less frequently at the tail bud tip level. Furthermore, we identified that sNSC-generated neurospheres were significantly smaller in size compared with cortical neurospheres. Interestingly, various cell cycle analyses revealed that this difference was not due to a reduction in the proliferation rate of NSCs, but rather the neuronal commitment of sNSCs, as sNSC-derived neurospheres contain more committed neuronal progenitor cells, even in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). These results suggest that the higher tendency for sNSCs to spontaneously differentiate into progenitor cells may explain the limited expansion of the secondary neural tube during embryonic development.

  8. ATM-Dependent Phosphorylation of All Three Members of the MRN Complex: From Sensor to Adaptor

    PubMed Central

    Lavin, Martin F.; Kozlov, Sergei; Gatei, Magtouf; Kijas, Amanda W.

    2015-01-01

    The recognition, signalling and repair of DNA double strand breaks (DSB) involves the participation of a multitude of proteins and post-translational events that ensure maintenance of genome integrity. Amongst the proteins involved are several which when mutated give rise to genetic disorders characterised by chromosomal abnormalities, cancer predisposition, neurodegeneration and other pathologies. ATM (mutated in ataxia-telangiectasia (A-T) and members of the Mre11/Rad50/Nbs1 (MRN complex) play key roles in this process. The MRN complex rapidly recognises and locates to DNA DSB where it acts to recruit and assist in ATM activation. ATM, in the company of several other DNA damage response proteins, in turn phosphorylates all three members of the MRN complex to initiate downstream signalling. While ATM has hundreds of substrates, members of the MRN complex play a pivotal role in mediating the downstream signalling events that give rise to cell cycle control, DNA repair and ultimately cell survival or apoptosis. Here we focus on the interplay between ATM and the MRN complex in initiating signaling of breaks and more specifically on the adaptor role of the MRN complex in mediating ATM signalling to downstream substrates to control different cellular processes. PMID:26512707

  9. Physiological Characterization of Vestibular Efferent Brainstem Neurons Using a Transgenic Mouse Model

    PubMed Central

    Leijon, Sara; Magnusson, Anna K.

    2014-01-01

    The functional role of efferent innervation of the vestibular end-organs in the inner ear remains elusive. This study provides the first physiological characterization of the cholinergic vestibular efferent (VE) neurons in the brainstem by utilizing a transgenic mouse model, expressing eGFP under a choline-acetyltransferase (ChAT)-locus spanning promoter in combination with targeted patch clamp recordings. The intrinsic electrical properties of the eGFP-positive VE neurons were compared to the properties of the lateral olivocochlear (LOC) brainstem neurons, which gives rise to efferent innervation of the cochlea. Both VE and the LOC neurons were marked by their negative resting membrane potential <−75 mV and their passive responses in the hyperpolarizing range. In contrast, the response properties of VE and LOC neurons differed significantly in the depolarizing range. When injected with positive currents, VE neurons fired action potentials faithfully to the onset of depolarization followed by sparse firing with long inter-spike intervals. This response gave rise to a low response gain. The LOC neurons, conversely, responded with a characteristic delayed tonic firing upon depolarizing stimuli, giving rise to higher response gain than the VE neurons. Depolarization triggered large TEA insensitive outward currents with fast inactivation kinetics, indicating A-type potassium currents, in both the inner ear-projecting neuronal types. Immunohistochemistry confirmed expression of Kv4.3 and 4.2 ion channel subunits in both the VE and LOC neurons. The difference in spiking responses to depolarization is related to a two-fold impact of these transient outward currents on somatic integration in the LOC neurons compared to in VE neurons. It is speculated that the physiological properties of the VE neurons might be compatible with a wide-spread control over motion and gravity sensation in the inner ear, providing likewise feed-back amplification of abrupt and strong phasic signals from the semi-circular canals and of tonic signals from the gravito-sensitive macular organs. PMID:24867596

  10. Collapse of a self-similar cylindrical scalar field with non-minimal coupling II: strong cosmic censorship

    NASA Astrophysics Data System (ADS)

    Condron, Eoin; Nolan, Brien C.

    2014-08-01

    We investigate self-similar scalar field solutions to the Einstein equations in whole cylinder symmetry. Imposing self-similarity on the spacetime gives rise to a set of single variable functions describing the metric. Furthermore, it is shown that the scalar field is dependent on a single unknown function of the same variable and that the scalar field potential has exponential form. The Einstein equations then take the form of a set of ODEs. Self-similarity also gives rise to a singularity at the scaling origin. We extend the work of Condron and Nolan (2014 Class. Quantum Grav. 31 015015), which determined the global structure of all solutions with a regular axis in the causal past of the singularity. We identified a class of solutions that evolves through the past null cone of the singularity. We give the global structure of these solutions and show that the singularity is censored in all cases.

  11. Mechanism of degradation of LH-RH and neurotensin by synaptosomal peptidases.

    PubMed

    McDermott, J R; Smith, A I; Dodd, P R; Hardy, J A; Edwardson, J A

    1983-01-01

    The products of degradation of LH-RH and neurotensin by synaptosomes isolated from rat hypothalamus and cortex have been identified. LH-RH is cleaved at Tyr5-Gly6 and Pro9-Gly10 giving rise to LH-RH (1-5), LH-RH (6-10) and LH-RH (1-9). Neurotensin is cleaved at Arg8-Arg9, Pro10-Tyr11 and Ile12-Leu13, giving neurotensin (1-8), neurotensin (1-10), neurotensin (1-12) and neurotensin (9-13) as major products. While most of the peptidase activity is localized in the cytoplasmic fraction, a small but significant proportion is membrane bound. For LH-RH, the specificity of the membrane-bound activity is similar to that in the cytosol fraction; for neurotensin, the membrane fraction preferentially gives rise to the (1-10) and (1-11) peptides. The most potent inhibitors of the LH-RH and neurotensin degrading enzymes in synaptosomes are heavy metal ions (mercury and copper), p-chloromercuribenzoate and 1,10 phenanthroline.

  12. Micromagnetic simulations of anisotropies in coupled and uncoupled ferromagnetic nanowire systems.

    PubMed

    Blachowicz, T; Ehrmann, A

    2013-01-01

    The influence of a variation of spatial relative orientations onto the coupling dynamics and subsequent magnetic anisotropies was modeled in ferromagnetic nanowires. The wires were analyzed in the most elementary configurations, thus, arranged in pairs perpendicular to each other, leading to one-dimensional (linear) and zero-dimensional (point-like) coupling. Different distances within each elementary pair of wires and between the pairs give rise to varying interactions between parallel and perpendicular wires, respectively. Simulated coercivities show an exchange of easy and hard axes for systems with different couplings. Additionally, two of the systems exhibit a unique switching behavior which can be utilized for developing new functionalities.

  13. Raman spectroscopy investigation and improved knowledge on industrial cation-exchange membranes involved in electrodialysis process

    NASA Astrophysics Data System (ADS)

    Chaouki, M.; Huguet, P.; Bribes, J.-L.

    1996-06-01

    Raman spectra of three specific, industrial, cation-exchange membranes (CEMs) have shown the existence of an extra vibrational band. The relative intensity of this band is different in each membrane spectrum recorded. Chlorosulfonation of polymeric ethylenetrifluoroethylene (ETFE) film grafted with polystyrene chains is used to obtain these CEMs involved in the electrodialysis process. A Raman study of the above reaction has been undertaken and has shown that non-sulfonated polystyrene rings give rise to this extra vibrational band. Different behavior of CEMs synthesized under similar conditions can be explained by a variable amount of non-sulfonated polystyrene rings contained in these materials.

  14. Chondroitin sulfates and their binding molecules in the central nervous system.

    PubMed

    Djerbal, L; Lortat-Jacob, H; Kwok, Jcf

    2017-06-01

    Chondroitin sulfate (CS) is the most abundant glycosaminoglycan (GAG) in the central nervous system (CNS) matrix. Its sulfation and epimerization patterns give rise to different forms of CS, which enables it to interact specifically and with a significant affinity with various signalling molecules in the matrix including growth factors, receptors and guidance molecules. These interactions control numerous biological and pathological processes, during development and in adulthood. In this review, we describe the specific interactions of different families of proteins involved in various physiological and cognitive mechanisms with CSs in CNS matrix. A better understanding of these interactions could promote a development of inhibitors to treat neurodegenerative diseases.

  15. Wavelength-dependent scattering in human eye with cataracts.

    PubMed

    Kelly-Pérez, Ismael; Méndez-Aguilar, Emilia M; Treviño-Palacios, Carlos G; Bruce, Neil C; Berriel-Valdos, Luis R; Al-Hohamedi, Haroun; Bende, Thomas

    2018-03-02

    The gradual process in which the crystalline lens is cloudy due to the appearance of elements giving rise to variations in the refractive index is known as cataract. Clinical assessment is usually complicated because it considers patient's perception, and individuals with similar development have different visual deficits. This work presents a model which considers the fluctuations in the refractive index as spherical particles produce measurable scatter radial profiles patterns on the retina. Measurements for 2 different wavelengths simultaneously provide information on particle size and a quantitative assessment by measurement of the fluctuations of the refractive index. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Mechanical tunability via hydrogen bonding in metal-organic frameworks with the perovskite architecture.

    PubMed

    Li, Wei; Thirumurugan, A; Barton, Phillip T; Lin, Zheshuai; Henke, Sebastian; Yeung, Hamish H-M; Wharmby, Michael T; Bithell, Erica G; Howard, Christopher J; Cheetham, Anthony K

    2014-06-04

    Two analogous metal-organic frameworks (MOFs) with the perovskite architecture, [C(NH2)3][Mn(HCOO)3] (1) and [(CH2)3NH2][Mn(HCOO)3] (2), exhibit significantly different mechanical properties. The marked difference is attributed to their distinct modes of hydrogen bonding between the A-site amine cation and the anionic framework. The stronger cross-linking hydrogen bonding in 1 gives rise to Young's moduli and hardnesses that are up to twice those in 2, while the thermal expansion is substantially smaller. This study presents clear evidence that the mechanical properties of MOF materials can be substantially tuned via hydrogen-bonding interactions.

  17. Sex and the singer: Gender categorization aspects of singing voice

    NASA Astrophysics Data System (ADS)

    Ternström, Sten

    2003-04-01

    The singing voice exhibits many systematic differences by gender and age. The physiological differences between the voice organs of males, females, and children are well known and give rise to several acoustic differences, including acoustic power, pitch range, and spectral distribution. Vocal artists often strive to widen their range of expression, and it is not uncommon for males to sing in a femalelike register, as in counter tenors and in some pop/rock genres. The opposite, however, is quite rare. While ambiguous or contradictory gender in speech is usually a social disadvantage, in singing it can be a desired effect. The physical differences in singing voice production between males and females are reviewed in detail. Some interesting borderline cases are examined from an acoustic standpoint.

  18. The rise of the regulatory state in health care: a comparative analysis of The Netherlands, England and Italy.

    PubMed

    Helderman, Jan-Kees; Bevan, Gwyn; France, George

    2012-01-01

    In a relatively short time, regulation has become a significant and distinct feature of how modern states wish to govern and steer their economy and society. Whereas the former 'dirigiste' state used to be closely related to public ownership (e.g. hospitals), planning (volume and capacity planning) and centralised administration (e.g. fixed prices and budgets), the new regulatory state relies mainly on the instrument of regulation to achieve its objectives. In this paper, we wish to relate the rise of the 'regulatory state' to the path-dependent trajectories and institutional legacies of discrete European health-care systems. For this purpose, we compared the Dutch corporatist social health insurance system, the strongly centralised National Health Service (NHS) of England and federal regionalised NHS system of Italy. Comparing these three different health-care systems suggests that it is indeed possible to identify a general trend towards the rise of the regulatory state in health care in the last two decades. However, although the three countries examined in this paper face similar problems of multilevel governance of networks of third-party payers and providers, each system also gives rise to its own distinct regulatory challenges. © Cambridge University Press 2012

  19. Heteroclinic switching between chimeras

    NASA Astrophysics Data System (ADS)

    Bick, Christian

    2018-05-01

    Functional oscillator networks, such as neuronal networks in the brain, exhibit switching between metastable states involving many oscillators. We give exact results how such global dynamics can arise in paradigmatic phase oscillator networks: Higher-order network interactions give rise to metastable chimeras—localized frequency synchrony patterns—which are joined by heteroclinic connections. Moreover, we illuminate the mechanisms that underly the switching dynamics in these experimentally accessible networks.

  20. Chimera patterns in two-dimensional networks of coupled neurons.

    PubMed

    Schmidt, Alexander; Kasimatis, Theodoros; Hizanidis, Johanne; Provata, Astero; Hövel, Philipp

    2017-03-01

    We discuss synchronization patterns in networks of FitzHugh-Nagumo and leaky integrate-and-fire oscillators coupled in a two-dimensional toroidal geometry. A common feature between the two models is the presence of fast and slow dynamics, a typical characteristic of neurons. Earlier studies have demonstrated that both models when coupled nonlocally in one-dimensional ring networks produce chimera states for a large range of parameter values. In this study, we give evidence of a plethora of two-dimensional chimera patterns of various shapes, including spots, rings, stripes, and grids, observed in both models, as well as additional patterns found mainly in the FitzHugh-Nagumo system. Both systems exhibit multistability: For the same parameter values, different initial conditions give rise to different dynamical states. Transitions occur between various patterns when the parameters (coupling range, coupling strength, refractory period, and coupling phase) are varied. Many patterns observed in the two models follow similar rules. For example, the diameter of the rings grows linearly with the coupling radius.

  1. Chimera patterns in two-dimensional networks of coupled neurons

    NASA Astrophysics Data System (ADS)

    Schmidt, Alexander; Kasimatis, Theodoros; Hizanidis, Johanne; Provata, Astero; Hövel, Philipp

    2017-03-01

    We discuss synchronization patterns in networks of FitzHugh-Nagumo and leaky integrate-and-fire oscillators coupled in a two-dimensional toroidal geometry. A common feature between the two models is the presence of fast and slow dynamics, a typical characteristic of neurons. Earlier studies have demonstrated that both models when coupled nonlocally in one-dimensional ring networks produce chimera states for a large range of parameter values. In this study, we give evidence of a plethora of two-dimensional chimera patterns of various shapes, including spots, rings, stripes, and grids, observed in both models, as well as additional patterns found mainly in the FitzHugh-Nagumo system. Both systems exhibit multistability: For the same parameter values, different initial conditions give rise to different dynamical states. Transitions occur between various patterns when the parameters (coupling range, coupling strength, refractory period, and coupling phase) are varied. Many patterns observed in the two models follow similar rules. For example, the diameter of the rings grows linearly with the coupling radius.

  2. Diversity within a Birdsong

    NASA Astrophysics Data System (ADS)

    Laje, Rodrigo; Mindlin, Gabriel B.

    2002-12-01

    We present a model for the activities of neural circuits in a nucleus found in the brains of songbirds: the robust nucleus of the archistriatum (RA). This is a fore brain song control nucleus responsible for the phasic and precise neural signals driving vocal and respiratory motor neurons during singing. Driving a physical model of the avian vocal organ with the signals generated by the neural model, we produce synthetic songs. This allows us to show that certain connectivity architectures in the RA give rise to a wide range of different vocalizations under simple excitatory instructions.

  3. Effect of a target on the stimulated emission of microsecond CO2-laser pulses

    NASA Astrophysics Data System (ADS)

    Baranov, V. Iu.; Dolgov, V. A.; Maliuta, D. D.; Mezhevov, V. S.; Semak, V. V.

    1987-12-01

    The paper reports a change in the pulse shape of a TEA CO2 laser with an unstable cavity under the interaction between the laser radiation and a metal surface in the presence of a breakdown plasma. It is shown that a continuous change in the phase difference between the wave reflected in the cavity and the principal cavity wave gives rise to changes in the pulse shape and the appearance of power fluctuations. The possible effect of these phenomena on the laser treatment of materials is considered.

  4. Alternative RNA splicing and cancer

    PubMed Central

    Liu, Sali; Cheng, Chonghui

    2015-01-01

    Alternative splicing of pre-messenger RNA (mRNA) is a fundamental mechanism by which a gene can give rise to multiple distinct mRNA transcripts, yielding protein isoforms with different, even opposing, functions. With the recognition that alternative splicing occurs in nearly all human genes, its relationship with cancer-associated pathways has emerged as a rapidly growing field. In this review, we summarize recent findings that have implicated the critical role of alternative splicing in cancer and discuss current understandings of the mechanisms underlying dysregulated alternative splicing in cancer cells. PMID:23765697

  5. Reply to Comment on X-ray resonant scattering studies of orbital and charge ordering in Pr[sub 1-x]Ca[sub x]MnO[sub 3].

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

    Zimmermann, M. V.; Grenier, S.; Nelson, C. S.

    2003-09-01

    The interpretation given in our recent x-ray scattering study of Pr{sub 1-x}Ca{sub x}MnO{sub 3} in terms of charge and orbital ordering is questioned in the preceding Comment by Garcia and Subias. They argue that anisotropy of the charge distribution induced by local distortions gives rise to the so-called charge order reflections. In this Reply we suggest that the two different pictures are reconcilable.

  6. Reflectivity of the gyroid biophotonic crystals in the ventral wing scales of the Green Hairstreak butterfly, Callophrys rubi.

    PubMed

    Michielsen, K; De Raedt, H; Stavenga, D G

    2010-05-06

    We present a comparison of the computer simulation data of gyroid nanostructures with optical measurements (reflectivity spectra and scattering diagrams) of ventral wing scales of the Green Hairstreak butterfly, Callophrys rubi. We demonstrate that the omnidirectional green colour arises from the gyroid cuticular structure grown in the domains of different orientation. We also show that this three-dimensional structure, operating as a biophotonic crystal, gives rise to various polarization effects. We briefly discuss the possible biological utility of the green coloration and polarization effects.

  7. Self-similar pyramidal structures and signal reconstruction

    NASA Astrophysics Data System (ADS)

    Benedetto, John J.; Leon, Manuel; Saliani, Sandra

    1998-03-01

    Pyramidal structures are defined which are locally a combination of low and highpass filtering. The structures are analogous to but different from wavelet packet structures. In particular, new frequency decompositions are obtained; and these decompositions can be parameterized to establish a correspondence with a large class of Cantor sets. Further correspondences are then established to relate such frequency decompositions with more general self- similarities. The role of the filters in defining these pyramidal structures gives rise to signal reconstruction algorithms, and these, in turn, are used in the analysis of speech data.

  8. Nonlinear fluctuations-induced rate equations for linear birth-death processes

    NASA Astrophysics Data System (ADS)

    Honkonen, J.

    2008-05-01

    The Fock-space approach to the solution of master equations for one-step Markov processes is reconsidered. It is shown that in birth-death processes with an absorbing state at the bottom of the occupation-number spectrum and occupation-number independent annihilation probability of occupation-number fluctuations give rise to rate equations drastically different from the polynomial form typical of birth-death processes. The fluctuation-induced rate equations with the characteristic exponential terms are derived for Mikhailov’s ecological model and Lanchester’s model of modern warfare.

  9. Local electronic effects and irradiation resistance in high-entropy alloys

    DOE PAGES

    Egami, Takeshi; Stocks, George Malcolm; Nicholson, Don; ...

    2015-08-14

    High-entropy alloys are multicomponent solid solutions in which various elements with different chemistries and sizes occupy the same crystallographic lattice sites. Thus, none of the atoms perfectly fit the lattice site, giving rise to considerable local lattice distortions and atomic-level stresses. These characteristics can be beneficial for performance under both radiation and in a high-temperature environment, making them attractive candidates as nuclear materials. We discuss electronic origin of the atomic-level stresses based upon first-principles calculations using a density functional theory approach.

  10. Combinatorial synthesis of bimetallic complexes with three halogeno bridges.

    PubMed

    Gauthier, Sébastien; Quebatte, Laurent; Scopelliti, Rosario; Severin, Kay

    2004-06-07

    Methods for the synthesis of bimetallic complexes in which two different metal fragments are connected by three chloro or bromo bridges are reported. The reactions are general, fast, and give rise to structurally defined products in quantitative yields. Therefore, they are ideally suited for generating a library of homo- and heterobimetallic complexes in a combinatorial fashion. This is of special interest for applications in homogeneous catalysis. Selected members of this library were synthesized and comprehensively characterized; single-crystal X-ray analyses were performed for 15 new bimetallic compounds.

  11. Estimating Vibrational Powers Of Parts In Fluid Machinery

    NASA Technical Reports Server (NTRS)

    Harvey, S. A.; Kwok, L. C.

    1995-01-01

    In new method of estimating vibrational power associated with component of fluid-machinery system, physics of flow through (or in vicinity of) component regarded as governing vibrations. Devised to generate scaling estimates for design of new parts of rocket engines (e.g., pumps, combustors, nozzles) but applicable to terrestrial pumps, turbines, and other machinery in which turbulent flows and vibrations caused by such flows are significant. Validity of method depends on assumption that fluid flows quasi-steadily and that flow gives rise to uncorrelated acoustic powers in different parts of pump.

  12. Magneto-optical spectra of transition metal dichalcogenides: A comparative study

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

    Ho, Yen-Hung; Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan; Chiu, Chih-Wei

    2014-12-01

    Following our previous work [Ho et al., Phys. Rev. B 89, 155316 (2014)], we systematically calculate the magneto-optical properties of various transition metal dichalcogenide monolayers. The intrinsic spin-orbit coupling gives rise to the spin-split electronic states, while a perpendicular magnetic field further induces a valley splitting. In magneto-optical spectra with linearly polarized light, spectral features are spin and valley-polarized. Compounds are different from one another in terms of transition energies and appearance of twin peaks. Our numerical results can serve as a guide for future experimental identification.

  13. Cultured Human Adipose Tissue Pericytes and Mesenchymal Stromal Cells Display a Very Similar Gene Expression Profile

    PubMed Central

    Malta, Tathiane Maistro; de Deus Wagatsuma, Virgínia Mara; Palma, Patrícia Viana Bonini; Araújo, Amélia Goes; Ribeiro Malmegrim, Kelen Cristina; Morato de Oliveira, Fábio; Panepucci, Rodrigo Alexandre; Silva, Wilson Araújo; Kashima Haddad, Simone; Covas, Dimas Tadeu

    2015-01-01

    Mesenchymal stromal cells (MSCs) are cultured cells that can give rise to mature mesenchymal cells under appropriate conditions and secrete a number of biologically relevant molecules that may play an important role in regenerative medicine. Evidence indicates that pericytes (PCs) correspond to mesenchymal stem cells in vivo and can give rise to MSCs when cultured, but a comparison between the gene expression profiles of cultured PCs (cPCs) and MSCs is lacking. We have devised a novel methodology to isolate PCs from human adipose tissue and compared cPCs to MSCs obtained through traditional methods. Freshly isolated PCs expressed CD34, CD140b, and CD271 on their surface, but not CD146. Both MSCs and cPCs were able to differentiate along mesenchymal pathways in vitro, displayed an essentially identical surface immunophenotype, and exhibited the ability to suppress CD3+ lymphocyte proliferation in vitro. Microarray expression data of cPCs and MSCs formed a single cluster among other cell types. Further analyses showed that the gene expression profiles of cPCs and MSCs are extremely similar, although MSCs differentially expressed endothelial cell (EC)-specific transcripts. These results confirm, using the power of transcriptomic analysis, that PCs give rise to MSCs and suggest that low levels of ECs may persist in MSC cultures established using traditional protocols. PMID:26192741

  14. Continuous diffraction of molecules and disordered molecular crystals

    PubMed Central

    Yefanov, Oleksandr M.; Ayyer, Kartik; White, Thomas A.; Barty, Anton; Morgan, Andrew; Mariani, Valerio; Oberthuer, Dominik; Pande, Kanupriya

    2017-01-01

    The intensities of far-field diffraction patterns of orientationally aligned molecules obey Wilson statistics, whether those molecules are in isolation (giving rise to a continuous diffraction pattern) or arranged in a crystal (giving rise to Bragg peaks). Ensembles of molecules in several orientations, but uncorrelated in position, give rise to the incoherent sum of the diffraction from those objects, modifying the statistics in a similar way as crystal twinning modifies the distribution of Bragg intensities. This situation arises in the continuous diffraction of laser-aligned molecules or translationally disordered molecular crystals. This paper develops the analysis of the intensity statistics of such continuous diffraction to obtain parameters such as scaling, beam coherence and the number of contributing independent object orientations. When measured, continuous molecular diffraction is generally weak and accompanied by a background that far exceeds the strength of the signal. Instead of just relying upon the smallest measured intensities or their mean value to guide the subtraction of the background, it is shown how all measured values can be utilized to estimate the background, noise and signal, by employing a modified ‘noisy Wilson’ distribution that explicitly includes the background. Parameters relating to the background and signal quantities can be estimated from the moments of the measured intensities. The analysis method is demonstrated on previously published continuous diffraction data measured from crystals of photosystem II [Ayyer et al. (2016 ▸), Nature, 530, 202–206]. PMID:28808434

  15. Intrinsic regenerative potential of murine cochlear supporting cells.

    PubMed

    Sinkkonen, Saku T; Chai, Renjie; Jan, Taha A; Hartman, Byron H; Laske, Roman D; Gahlen, Felix; Sinkkonen, Wera; Cheng, Alan G; Oshima, Kazuo; Heller, Stefan

    2011-01-01

    The lack of cochlear regenerative potential is the main cause for the permanence of hearing loss. Albeit quiescent in vivo, dissociated non-sensory cells from the neonatal cochlea proliferate and show ability to generate hair cell-like cells in vitro. Only a few non-sensory cell-derived colonies, however, give rise to hair cell-like cells, suggesting that sensory progenitor cells are a subpopulation of proliferating non-sensory cells. Here we purify from the neonatal mouse cochlea four different non-sensory cell populations by fluorescence-activated cell sorting (FACS). All four populations displayed proliferative potential, but only lesser epithelial ridge and supporting cells robustly gave rise to hair cell marker-positive cells. These results suggest that cochlear supporting cells and cells of the lesser epithelial ridge show robust potential to de-differentiate into prosensory cells that proliferate and undergo differentiation in similar fashion to native prosensory cells of the developing inner ear.

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

    Kahler, S. W., E-mail: stephen.kahler@kirtland.af.mil

    Prompt onsets and short rise times to peak intensities Ip have been noted in a few solar energetic (E > 10 MeV) particle (SEP) events from far behind (≥25°) the west limb. We discuss 15 archival and recent examples of these prompt events, giving their source longitudes, onset and rise times, and associated coronal mass ejection (CME) speeds. Their timescales and CME speeds are not exceptional in comparison with a larger set of SEP events from behind the west limb. A further statistical comparison of observed timescales of SEP events from behind the west limb with events similarly poorly magneticallymore » connected to the eastern hemisphere (EH) shows the longer timescales of the latter group. We interpret this result in terms of a difference between SEP production at parallel shocks on the eastern flanks of western backside events and at perpendicular shocks on the western flanks of EH events.« less

  17. GLI1+ progenitor cells in the adrenal capsule of the adult mouse give rise to heterotopic gonadal-like tissue.

    PubMed

    Dörner, Julia; Martinez Rodriguez, Verena; Ziegler, Ricarda; Röhrig, Theresa; Cochran, Rebecca S; Götz, Ronni M; Levin, Mark D; Pihlajoki, Marjut; Heikinheimo, Markku; Wilson, David B

    2017-02-05

    As certain strains of mice age, hyperplastic lesions resembling gonadal tissue accumulate beneath the adrenal capsule. Gonadectomy (GDX) accelerates this heterotopic differentiation, resulting in the formation of wedge-shaped adrenocortical neoplasms that produce sex steroids. Stem/progenitor cells that reside in the adrenal capsule and retain properties of the adrenogonadal primordium are thought to be the source of this heterotopic tissue. Here, we demonstrate that GLI1 + progenitors in the adrenal capsule give rise to gonadal-like cells that accumulate in the subcapsular region. A tamoxifen-inducible Cre driver (Gli1-creER T2 ) and two reporters (R26R-lacZ, R26R-confetti) were used to track the fate of GLI1 + cells in the adrenal glands of B6D2F2 mice, a strain that develops both GDX-induced adrenocortical neoplasms and age-dependent subcapsular cell hyperplasia. In gonadectomized B6D2F2 mice GLI1 + progenitors contributed to long-lived adrenal capsule cells and to adrenocortical neoplasms that expressed Gata4 and Foxl2, two prototypical gonadal markers. Pdgfra, a gene expressed in adrenocortical stromal cells, was upregulated in the GDX-induced neoplasms. In aged non-gonadectomized B6D2F2 mice GLI1 + progenitors gave rise to patches of subcapsular cell hyperplasia. Treatment with GANT61, a small-molecule GLI antagonist, attenuated the upregulation of gonadal-like markers (Gata4, Amhr2, Foxl2) in response to GDX. These findings support the premise that GLI1 + progenitor cells in the adrenal capsule of the adult mouse give rise to heterotopic tissue. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Charm and the rise of the pp-bar total cross section

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

    Jones, S.T.; Dash, J.W.

    We give a detailed description of the pp-bar forward amplitude through CERN SPS collider energies, using the flavored Pomeron model as an effective parametrization of nonperturbative QCD. We show that the rise in the total cross section between CERN ISR and SPS collider energies is consistent with the onset of charmed-particle production up to the level of a few millibarns, along with other processes, and in agreement with available data. In contrast with our estimates of charm production, perturbative QCD charm-production calculations are well below the data. We give estimates of the p-bar and K/sup +- / multiplicities at SPSmore » collider energies. We also present a simplified version of the flavoring model in order to facilitate comparisons between it and other parametrizations.« less

  19. Shocks and finite-time singularities in Hele-Shaw flow

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

    Teodorescu, Razvan; Wiegmann, P; Lee, S-y

    Hele-Shaw flow at vanishing surface tension is ill-defined. In finite time, the flow develops cusplike singularities. We show that the ill-defined problem admits a weak dispersive solution when singularities give rise to a graph of shock waves propagating in the viscous fluid. The graph of shocks grows and branches. Velocity and pressure jump across the shock. We formulate a few simple physical principles which single out the dispersive solution and interpret shocks as lines of decompressed fluid. We also formulate the dispersive solution in algebro-geometrical terms as an evolution of Krichever-Boutroux complex curve. We study in details the most genericmore » (2,3) cusp singularity which gives rise to an elementary branching event. This solution is self-similar and expressed in terms of elliptic functions.« less

  20. Coordination Dynamics in Cognitive Neuroscience

    PubMed Central

    Bressler, Steven L.; Kelso, J. A. Scott

    2016-01-01

    Many researchers and clinicians in cognitive neuroscience hold to a modular view of cognitive function in which the cerebral cortex operates by the activation of areas with circumscribed elementary cognitive functions. Yet an ongoing paradigm shift to a dynamic network perspective is underway. This new viewpoint treats cortical function as arising from the coordination dynamics within and between cortical regions. Cortical coordination dynamics arises due to the unidirectional influences imposed on a cortical area by inputs from other areas that project to it, combined with the projection reciprocity that characterizes cortical connectivity and gives rise to reentrant processing. As a result, cortical dynamics exhibits both segregative and integrative tendencies and gives rise to both cooperative and competitive relations within and between cortical areas that are hypothesized to underlie the emergence of cognition in brains. PMID:27695395

  1. A New Mechanism for Upper Crustal Fluid Flow Driven by Solitary Porosity Waves in Rigid Reactive Media?

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sumit

    2017-10-01

    The equations governing the interaction of viscous deformation with porous flow of fluids give rise to wave-like solutions. Such solutions have been explored in the context of melt and fluid flow in the mantle and crust at high temperatures, where ductile behavior occurs. Now it has been shown that the coupling of the kinetics of chemical reactions with fluid flow may give rise to similar solutions. This opens intriguing new possibilities. Porosity waves may arise in low-temperature regimes, and may become more accessible to observation, or they may remain mathematical curiosities because other modes of transport dominate in such settings. A number of possibilities, questions, and future courses of research have been opened up by Omlin et al. (2017).

  2. Flat bands in lattices with non-Hermitian coupling

    NASA Astrophysics Data System (ADS)

    Leykam, Daniel; Flach, Sergej; Chong, Y. D.

    2017-08-01

    We study non-Hermitian photonic lattices that exhibit competition between conservative and non-Hermitian (gain/loss) couplings. A bipartite sublattice symmetry enforces the existence of non-Hermitian flat bands, which are typically embedded in an auxiliary dispersive band and give rise to nondiffracting "compact localized states". Band crossings take the form of non-Hermitian degeneracies known as exceptional points. Excitations of the lattice can produce either diffracting or amplifying behaviors. If the non-Hermitian coupling is fine-tuned to generate an effective π flux, the lattice spectrum becomes completely flat, a non-Hermitian analog of Aharonov-Bohm caging in which the magnetic field is replaced by balanced gain and loss. When the effective flux is zero, the non-Hermitian band crossing points give rise to asymmetric diffraction and anomalous linear amplification.

  3. Germline epimutation in humans.

    PubMed

    Cropley, Jennifer E; Martin, David I K; Suter, Catherine M

    2008-12-01

    Epigenetic modifications provide all multicellular organisms with a system of gene regulation that allows clonally heritable yet reversible alterations in gene transcription. Errors in this complex system can give rise to abnormal gene silencing, termed 'epimutation'; importantly, this can occur in the absence of any underlying genetic defect. Epimutations are commonly somatic events, and are particularly prevalent in tumors, but we and others have shown that epimutation can also arise in the germline, giving rise to soma-wide transcriptional silencing of a gene. A germline epimutation can mimic the effect of an inactivating mutation, and in doing so, can phenocopy a genetic disease. In this article, we will review the recent findings with germline epimutation at the tumor suppressor gene MLH1, discuss the possible etiology of this phenomenon, and the implications of germline epimutation in humans.

  4. Possible relation of water structural relaxation to water anomalies

    PubMed Central

    Mallamace, Francesco; Corsaro, Carmelo; Stanley, H. Eugene

    2013-01-01

    The anomalous behavior of thermodynamic response functions is an unsolved problem in the physics of water. The mechanism that gives rise to the dramatic indefinite increase at low temperature in the heat capacity, the compressibility, and the coefficient of thermal expansion, is unknown. We explore this problem by analyzing both new and existing experimental data on the power spectrum S(Q, ω) of bulk and confined water at ambient pressure. When decreasing the temperature, we find that the liquid undergoes a structural transformation coinciding with the onset of an extended hydrogen bond network. This network onset seems to give rise to the marked viscoelastic behavior, consistent with the interesting possibility that the sound velocity and response functions of water depend upon both the frequency and wave vector. PMID:23483053

  5. High-Rise Buildings versus Outdoor Thermal Environment in Chongqing

    PubMed Central

    Lu, Jun; Chen, Jin-hua; Tang, Ying; Feng, Yuan; Wang, Jin-sha

    2007-01-01

    This paper gives a brief description of the over quick urbanization since Chongqing, one of the biggest cities in China, has been a municipality directly under the Central Government in 1997, excessive development and exceeding increase of high-rise buildings because of its special geographical position which finally leads to the worsening of the urban outdoor thermal environment. Then, this paper makes a bright balance to the field measurement and simulated results of the wind speed field, temperature field of one multifunctional high-rise building in Chongqing university located in the city center, and the contrasted results validate the correctness of CFD in the outdoor thermal environmental simulation, expose the disadvantages of high-rise buildings on the aspects of blocking the wind field, decreasing wind speed which results in accumulation of the air-conditioning heat revolving around and periscian region where sunshine can not rip into. Finally, in order to improve the urban outdoor thermal environment near the high-rise buildings especially for the angle of natural ventilation, this paper simulates the wind environment in different architectural compositions and architectural layouts by CFD, and the simulated results show that freestyle and tower buildings which can guarantee the wind speed and take the air-conditioning heat away are much suitable and reasonable for the special Chongqing geography. These conclusions can also be used as a reference in other mountain cities, especially for the one with a great number of populations. PMID:28903222

  6. ANALYSIS AND MODELING OF TWO FLARE LOOPS OBSERVED BY AIA AND EIS

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

    Li, Y.; Ding, M. D.; Qiu, J.

    2012-10-10

    We analyze and model an M1.0 flare observed by SDO/AIA and Hinode/EIS to investigate how flare loops are heated and evolve subsequently. The flare is composed of two distinctive loop systems observed in extreme ultraviolet (EUV) images. The UV 1600 A emission at the feet of these loops exhibits a rapid rise, followed by enhanced emission in different EUV channels observed by the Atmospheric Imaging Assembly (AIA) and the EUV Imaging Spectrometer (EIS). Such behavior is indicative of impulsive energy deposit and the subsequent response in overlying coronal loops that evolve through different temperatures. Using the method we recently developed,more » we infer empirical heating functions from the rapid rise of the UV light curves for the two loop systems, respectively, treating them as two big loops with cross-sectional area of 5'' by 5'', and compute the plasma evolution in the loops using the EBTEL model. We compute the synthetic EUV light curves, which, with the limitation of the model, reasonably agree with observed light curves obtained in multiple AIA channels and EIS lines: they show the same evolution trend and their magnitudes are comparable by within a factor of two. Furthermore, we also compare the computed mean enthalpy flow velocity with the Doppler shift measurements by EIS during the decay phase of the two loops. Our results suggest that the two different loops with different heating functions as inferred from their footpoint UV emission, combined with their different lengths as measured from imaging observations, give rise to different coronal plasma evolution patterns captured both in the model and in observations.« less

  7. Geoethics: IPCC disgraced by violation of observational facts and physical laws in their sea level scenario

    NASA Astrophysics Data System (ADS)

    Mörner, Nils-Axel

    2014-05-01

    Sea level may rise due to glacier melting, heat expansion of the oceanic water column, and redistribution of the waster masses - all these factors can be handled as to rates and amplitudes (provided one knows what one is talking about). In key areas over the entire Indian Ocean and in many Pacific Islands there are no traces of and sea level rise over the last 40-50 years. This is also the case for test-areas like Venice and the North Sea coasts. In the Kattegatt Sea one can fix the sea level factor to a maximum rise of 1.0-0.9 mm/year over the last century. The 204 tide gauges selected by NOAA for their global sea level monitoring provide a strong and sharp maximum (of 182 sites) in the range of 0.0-2.0 mm/yr. Satellite altimetry is said to give a rise of 3.2 mm/yr; this, however, is a value achieved after a quite subjective and surely erroneous "correction". The IPCC is talking about exceptionally much higher rates, and even worse are some "boy scouts" desperate try to launce real horror ratios. Physical laws set the frames of the rate and amount of ice melting, and so do records of events in the past (i.e. the geological records). During the Last Ice Age so much ice was accumulated on land, that the sea level dropped by about 120 m. When the process was reversed and ice melted under exceptionally strong climate forcing, sea level rose at a maximum rate of about 10 mm/yr (a meter per century). This can never happen under today's climate conditions. Even with IPCC's hypothetical scenarios, the true sea rise must be far less. When people like Rahmstorf (claiming 1 m or more by 2100) and Hansen (claiming a 4 m rise from 2080 to 2100) give their values, they exceed what is possible according to physical laws and accumulated geological knowledge. The expansion of the oceanic water column may reach amounts of sea level rise in the order of a few centimetres, at the most a decimetre. Old temperature measurements may record a temperature rise over the last 50 years in the order of 0.4o C. The improved ARGO measurements starting 2004 give virtually no change, however. The physically possible amount of expansion decreases, of course, with the decreasing water columns towards the coasts, and at the coasts it is zero (±0.0 mm). The redistribution of water masses in response to the Earth's rotation, surface current beat, wind stress, air pressure, etc. is an important factor. It gives local to regional changes, cancelled out on the global scale, however. From a geoethical point of view, it is of course quite blameworthy that IPCC excels in spreading these horror scenarios of a rapid, even accelerating, sea level rise. Besides, modern understanding of the planetary-solar-terrestrial interaction shows that we are now on our way into grand solar minimum with severely colder climate - that is just the opposite to IPCC's talk about an accelerating warming. In science we should debate - but we should not dictate (as IPCC insist upon), and it is here the perspectives of geoethics comes into the picture.

  8. Shelf-geometry response to changes in relative sea level on a mixed carbonate siliciclastic shelf in the Guyana Basin

    NASA Astrophysics Data System (ADS)

    Campbell, A. Ewan

    2005-04-01

    Differences in the shelf-margin geometry for various depositional regimes show how siliciclastic and carbonate margins respond differently to changes in accommodation space. During the Cenozoic, sequences of carbonate and siliciclastic sediment were deposited in the Guyana Basin on the passive continental margin of NE South America. Study of the sequence geometries reveal significantly different geometric responses to changes in relative sea level of intervals dominated by carbonates to intervals dominated by siliciclastics. Using the geometrical shelf break as a reference point, aggradation and progradation rates for the carbonate and siliciclastic depositional systems were measured. In siliciclastics, the lateral position of the margin remains roughly stationary with relative sea-level rises in the order of 30 m/My. At higher rates the margin retreats at lower rates it progrades. Carbonate margins remain stationary or slightly progradational even with relative sea-level rises of up to 100 m/My, the fastest rates observed in this study. This illustrates the strong tendency of carbonate platforms to stack their margins and keep up with relative rises in sea level, rather than gradually retreat landward as do siliciclastics. This observation may explain why carbonate platforms preferentially try to defend a margin prior to ultimate backstepping. The high aggradation potential of carbonate margins also gives onlap and downlap termination patterns on seismic profiles where carbonate platforms develop on sloping siliciclastic shelves. The resulting unconformities are a result of differences in sediment dispersal between the two systems and not necessarily from changes of relative sea level.

  9. The osteogenic capacity of biomimetic hierarchical micropore/nanorod-patterned Sr-HA coatings with different interrod spacings.

    PubMed

    Zhou, Jianhong; Li, Bo; Han, Yong; Zhao, Lingzhou

    2016-07-01

    Advanced titanium based bone implant with fast established, rigid and stable osseointegration is stringently needed in clinic. Here the hierarchical micropore/nanorod-patterned strontium doped hydroxyapatite (Ca9Sr1(PO4)6(OH)2, Sr1-HA) coatings (MNRs) with different interrod spacings varying from about 300 to 33nm were developed. MNRs showed dramatically differential biological performance closely related to the interrod spacing. Compared to micropore/nanogranule-patterned Sr1-HA coating (MNG), MNRs with an interrod spacing of larger than 137nm resulted in inhibited in vitro mesenchymal stem cell functions and in vivo osseointegration, while those of smaller than 96nm gave rise to dramatically enhanced the biological effect, especially those of mean 67nm displayed the best effect. The differential biological effect of MNRs was related to their modulation on the focal adhesion mediated mechanotransduction. These results suggest that MNRs with a mean interrod spacing of 67nm may give rise to an advanced implant of improved clinical performance. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Calcium ascorbate as a potential partial substitute for NaCl in dry fermented sausages: effect on colour, texture and hygienic quality at different concentrations.

    PubMed

    Gimeno, O; Astiasarán, I; Bello, J

    2001-01-01

    A control product (2.6% NaCl) and different treatments with reduced levels of salt (1, 2.3% NaCl; 2, 2.0% NaCl; 3, 1.7% NaCl; 4, 1.4% NaCl) and increased amounts of calcium ascorbate with an equivalent ionic strength to that of the control were assayed. The percentages of reduction of sodium content in relation to the control were 15, 24, 37 and 45% and the supply of calcium was 26, 33, 42 and 50% of the Recommended Dietary Allowance (RDAs established by NRC, US) for treatments 1, 2, 3 and 4, respectively. Partial substitution of NaCl by calcium ascorbate caused higher acidification related with the higher lactic acid bacteria development and probably with the presence of calcium. The instrumental measurement of colour gave rise to some significant differences especially with the highest amount of calcium ascorbate (treatment 4), giving rise to significant higher a* and b* values and lower L* values in relation to the control. Treatments 2, 3 and 4 lead to products with lower hardness and gumminess values than the control. No problems related to the hygienic quality were observed.

  11. Detection of Potential TNA and RNA Nucleoside Precursors in a Prebiotic Mixture by Pure Shift Diffusion-Ordered NMR Spectroscopy

    PubMed Central

    Islam, Saidul; Aguilar, Juan A; Powner, Matthew W; Nilsson, Mathias; Morris, Gareth A; Sutherland, John D

    2013-01-01

    In the context of prebiotic chemistry, one of the characteristics of mixed nitrogenous-oxygenous chemistry is its propensity to give rise to highly complex reaction mixtures. There is therefore an urgent need to develop improved spectroscopic techniques if onerous chromatographic separations are to be avoided. One potential avenue is the combination of pure shift methodology, in which NMR spectra are measured with greatly improved resolution by suppressing multiplet structure, with diffusion-ordered spectroscopy, in which NMR signals from different species are distinguished through their different rates of diffusion. Such a combination has the added advantage of working with intact mixtures, allowing analyses to be carried out without perturbing mixtures in which chemical entities are part of a network of reactions in equilibrium. As part of a systems chemistry approach towards investigating the self-assembly of potentially prebiotic small molecules, we have analysed the complex mixture arising from mixing glycolaldehyde and cyanamide, in a first application of pure shift DOSY NMR to the characterisation of a partially unknown reaction composition. The work presented illustrates the potential of pure shift DOSY to be applied to chemistries that give rise to mixtures of compounds in which the NMR signal resolution is poor. The direct formation of potential RNA and TNA nucleoside precursors, amongst other adducts, was observed. These preliminary observations may have implications for the potentially prebiotic assembly chemistry of pyrimidine threonucleotides, and therefore of TNA, by using recently reported chemistries that yield the activated pyridimidine ribonucleotides. PMID:23371787

  12. Precipitation of coherent Ni{sub 2}(Cr, W) superlattice in an Ni–Cr–W superalloy

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

    Gao, Xiangyu; Hu, Rui, E-mail: rhu@nwpu.edu.cn; Zhang, Tiebang

    2016-01-15

    It is demonstrated that a nanometer-sized Ni{sub 2}(Cr, W) superlattice with a Pt{sub 2}Mo-type structure can precipitate in an Ni–Cr–W alloy by means of a simple aging treatment at 550 °C. The dark-field image of short-range order domains has been found for the first time experimentally. The mechanism of short-range order to long-range order transformation has been revealed based on transmission electron microscopy result and static concentration waves theory and found to be continuous ordering. The randomness of the transformation of static concentration waves leads to equiprobable occurrence of the different variants. The transformation of short-range order to long-range ordermore » gives rise to the Pt{sub 2}Mo-type Ni{sub 2}(Cr, W) superlattice. The interfaces between Ni{sub 2}(Cr, W) and Ni-based matrix and the different variants of Ni{sub 2}(Cr, W) have been investigated by high resolution transmission electron microscopy. The results reveal that the interfaces between Ni{sub 2}(Cr, W) and surrounding matrix are coherent at the atomic scale. - Highlights: • The DF image of SRO cluster has been found for the first time experimentally. • The transformation of SRO to LRO gives rise to the Pt{sub 2}Mo-type Ni{sub 2}(Cr, W). • Variants of Ni{sub 2}(Cr, W) occur equiprobably. • The interfaces between Ni{sub 2}(Cr, W) and matrix are coherent at the atomic scale.« less

  13. 26 CFR 301.6111-2 - Confidential corporate tax shelters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... customary commercial practice (a transaction involving the acquisition, disposition, or restructuring of a... accounting purposes and as debt giving rise to allowable interest deductions for Federal income tax purposes...

  14. 26 CFR 301.6111-2 - Confidential corporate tax shelters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... customary commercial practice (a transaction involving the acquisition, disposition, or restructuring of a... accounting purposes and as debt giving rise to allowable interest deductions for Federal income tax purposes...

  15. 26 CFR 301.6111-2 - Confidential corporate tax shelters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... customary commercial practice (a transaction involving the acquisition, disposition, or restructuring of a... accounting purposes and as debt giving rise to allowable interest deductions for Federal income tax purposes...

  16. Current and efficiency of Brownian particles under oscillating forces in entropic barriers

    NASA Astrophysics Data System (ADS)

    Nutku, Ferhat; Aydιner, Ekrem

    2015-04-01

    In this study, considering the temporarily unbiased force and different forms of oscillating forces, we investigate the current and efficiency of Brownian particles in an entropic tube structure and present the numerically obtained results. We show that different force forms give rise to different current and efficiency profiles in different optimized parameter intervals. We find that an unbiased oscillating force and an unbiased temporal force lead to the current and efficiency, which are dependent on these parameters. We also observe that the current and efficiency caused by temporal and different oscillating forces have maximum and minimum values in different parameter intervals. We conclude that the current or efficiency can be controlled dynamically by adjusting the parameters of entropic barriers and applied force. Project supported by the Funds from Istanbul University (Grant No. 45662).

  17. Analysis of S2QA- charge recombination with the Arrhenius, Eyring and Marcus theories.

    PubMed

    Rantamäki, Susanne; Tyystjärvi, Esa

    2011-01-01

    The Q band of photosynthetic thermoluminescence, measured in the presence of a herbicide that blocks electron transfer from PSII, is associated with recombination of the S(2)Q(A)(-) charge pair. The same charge recombination reaction can be monitored with chlorophyll fluorescence. It has been shown that the recombination occurs via three competing routes of which one produces luminescence. In the present study, we measured the thermoluminescence Q band and the decay of chlorophyll fluorescence yield after a single turnover flash at different temperatures from spinach thylakoids. The data were analyzed using the commonly used Arrhenius theory, the Eyring rate theory and the Marcus theory of electron transfer. The fitting error was minimized for both thermoluminescence and fluorescence by adjusting the global, phenomenological constants obtained when the reaction rate theories were applied to the multi-step recombination reaction. For chlorophyll fluorescence, all three theories give decent fits. The peak position of the thermoluminescence Q band is correct by all theories but the form of the Q band is somewhat different in curves predicted by the three theories. The Eyring and Marcus theories give good fits for the decreasing part of the thermoluminescence curve and Marcus theory gives the closest fit for the rising part. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Feeding and Swallowing Disorders in Pediatric Neuromuscular Diseases: An Overview

    PubMed Central

    van den Engel-Hoek, Lenie; de Groot, Imelda J.M.; de Swart, Bert J.M.; Erasmus, Corrie E.

    2015-01-01

    Feeding and swallowing problems in infants and children have a great impact on health and wellbeing. The aim of this study was to provide an overview of recognized feeding and swallowing problems in different groups of children with neuromuscular diseases, based on relevant literature and expert opinion, and to propose recommendations for the assessment and treatment of these problems. Almost all pediatric neuromuscular diseases are accompanied by feeding and swallowing problems during the different phases of deglutition, problems that give rise to a wide variety of signs and symptoms, which emphasizes the importance of a comprehensive feeding and swallowing assessment by a speech and language therapist. PMID:27858755

  19. Coming to terms with fear

    PubMed Central

    LeDoux, Joseph E.

    2014-01-01

    The brain mechanisms of fear have been studied extensively using Pavlovian fear conditioning, a procedure that allows exploration of how the brain learns about and later detects and responds to threats. However, mechanisms that detect and respond to threats are not the same as those that give rise to conscious fear. This is an important distinction because symptoms based on conscious and nonconscious processes may be vulnerable to different predisposing factors and may also be treatable with different approaches in people who suffer from uncontrolled fear or anxiety. A conception of so-called fear conditioning in terms of circuits that operate nonconsciously, but that indirectly contribute to conscious fear, is proposed as way forward. PMID:24501122

  20. The Structure of the Elusive Simplest Dipeptide Gly-Gly.

    PubMed

    Cabezas, Carlos; Varela, Marcelino; Alonso, José L

    2017-06-01

    Among the hundreds of peptide compounds for which conformations have been determined by using different spectroscopic techniques, the structure of the simplest dipeptide glycylglycine (Gly-Gly) is conspicuously absent. Herein, for the first time, solid samples of Gly-Gly have been vaporized by laser ablation and three different structures have been revealed in a supersonic expansion by Fourier transform microwave spectroscopy. The intramolecular hydrogen bonding interactions that stabilize the observed forms have been established based on the 14 N nuclear quadrupole hyperfine structure. We have illustrated how conformer interconversion distorts the equilibrium conformational distribution, giving rise to missing conformers in the conformational landscape. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. [Origins of the coat, appearance of physicians of the Russian fleet in the first third of XVIII century].

    PubMed

    Danchenko, V G

    2011-05-01

    The article is devoted to the reconstruction of medical uniforms Russian navy first third of the 18th century. It can be assumed that doctors were in varying degrees, the senior officer's dress, but of course without the braid, although there are exceptions, which related to doctors willing to go to a more senior hypostasis. A number of documents of different structures gives rise to speak with a high probability that the doctors of different ranks, serving in the Marine units that had shaped dress that is largely consistent with their position in the hierarchy of ranks and received in the near future, its development.

  2. Simulation of Non-Abelian Braiding in Majorana Time Crystals

    NASA Astrophysics Data System (ADS)

    Bomantara, Raditya Weda; Gong, Jiangbin

    2018-06-01

    Discrete time crystals have attracted considerable theoretical and experimental studies but their potential applications have remained unexplored. A particular type of discrete time crystals, termed "Majorana time crystals," is found to emerge in a periodically driven superconducting wire accommodating two different species of topological edge modes. It is further shown that one can manipulate different Majorana edge modes separated in the time lattice, giving rise to an unforeseen scenario for topologically protected gate operations mimicking braiding. The proposed protocol can also generate a magic state that is important for universal quantum computation. This study thus advances the quantum control in discrete time crystals and reveals their great potential arising from their time-domain properties.

  3. Advances in colloidal manipulation and transport via hydrodynamic interactions.

    PubMed

    Martínez-Pedrero, F; Tierno, P

    2018-06-01

    In this review article, we highlight many recent advances in the field of micromanipulation of colloidal particles using hydrodynamic interactions (HIs), namely solvent mediated long-range interactions. At the micrsocale, the hydrodynamic laws are time reversible and the flow becomes laminar, features that allow precise manipulation and control of colloidal matter. We focus on different strategies where externally operated microstructures generate local flow fields that induce the advection and motion of the surrounding components. In addition, we review cases where the induced flow gives rise to hydrodynamic bound states that may synchronize during the process, a phenomenon essential in different systems such as those that exhibit self-assembly and swarming. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Consciousness and body image: lessons from phantom limbs, Capgras syndrome and pain asymbolia.

    PubMed Central

    Ramachandran, V S

    1998-01-01

    Words such as 'consciousness' and 'self' actually encompass a number of distinct phenomena that are loosely lumped together. The study of neurological syndromes allows us to explore the neural mechanisms that might underlie different aspects of self, such as body image and emotional responses to sensory stimuli, and perhaps even laughter and humour. Mapping the 'functional logic' of the many different attributes of human nature on to specific neural circuits in the brain offers the best hope of understanding how the activity of neurons gives rise to conscious experience. We consider three neurological syndromes (phantom limbs, Capgras delusion and pain asymbolia) to illustrate this idea. PMID:9854257

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

    Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possiblemore » effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.« less

  6. Effects of overlapping strings in pp collisions

    DOE PAGES

    Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif; ...

    2015-03-26

    In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possiblemore » effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.« less

  7. Computational and Experimental Study of the Transient Transport Phenomena in a Full-Scale Twin-Roll Continuous Casting Machine

    NASA Astrophysics Data System (ADS)

    Xu, Mianguang; Li, Zhongyang; Wang, Zhaohui; Zhu, Miaoyong

    2017-02-01

    To gain a fundamental understanding of the transient fluid flow in twin-roll continuous casting, the current paper applies both large eddy simulation (LES) and full-scale water modeling experiments to investigate the characteristics of the top free surface, stirring effect of the roll rotation, boundary layer fluctuations, and backflow stability. The results show that, the characteristics of the top free surface and the flow field in the wedge-shaped pool region are quite different with/without the consideration of the roll rotation. The roll rotation decreases the instantaneous fluctuation range of the top free surface, but increases its horizontal velocity. The stirring effect of the roll rotating makes the flow field more homogenous and there exists clear shear flow on the rotating roll surface. The vortex shedding induced by the Kármán Vortex Street from the submerged entry nozzle (SEN) causes the "velocity magnitude wave" and strongly influences the boundary layer stability and the backflow stability. The boundary layer fluctuations or the "velocity magnitude wave" induced by the vortex shedding could give rise to the internal porosity. In strip continuous casting process, the vortex shedding phenomenon indicates that the laminar flow can give rise to instability and that it should be made important in the design of the feeding system and the setting of the operating parameters.

  8. Wilsonian dark matter in string derived Z' model

    NASA Astrophysics Data System (ADS)

    Delle Rose, L.; Faraggi, A. E.; Marzo, C.; Rizos, J.

    2017-09-01

    The dark matter issue is among the most perplexing in contemporary physics. The problem is more enigmatic due to the wide range of possible solutions, ranging from the ultralight to the supermassive. String theory gives rise to plausible dark matter candidates due to the breaking of the non-Abelian grand unified theory (GUT) symmetries by Wilson lines. The physical spectrum then contains states that do not satisfy the quantization conditions of the unbroken GUT symmetry. Given that the Standard Model states are identified with broken GUT representations, and provided that any ensuing symmetry breakings are induced by components of GUT states, a remnant discrete symmetry remains that forbids the decay of the Wilsonian states. A class of such states are obtained in a heterotic-string-derived Z' model. The model exploits the spinor-vector duality symmetry, observed in the fermionic Z2×Z2 heterotic-string orbifolds, to generate a Z'∈E6 symmetry that may remain unbroken down to low energies. The E6 symmetry is broken at the string level with discrete Wilson lines. The Wilsonian dark matter candidates in the string-derived model are S O (10 ), and hence Standard Model, singlets and possess non-E6 U(1)Z' charges. Depending on the U(1)Z' breaking scale and the reheating temperature they give rise to different scenarios for the relic abundance, and are in accordance with the cosmological constraints.

  9. Novel forms of colloidal self-organization in temporally and spatially varying external fields: from low-density network-forming fluids to spincoated crystals

    NASA Astrophysics Data System (ADS)

    Yethiraj, Anand

    2010-03-01

    External fields affect self-organization in Brownian colloidal suspensions in many different ways [1]. High-frequency time varying a.c. electric fields can induce effectively quasi-static dipolar inter-particle interactions. While dipolar interactions can provide access to multiple open equilibrium crystal structures [2] whose origin is now reasonably well understood, they can also give rise to competing interactions on short and long length scales that produce unexpected low-density ordered phases [3]. Farther from equilibrium, competing external fields are active in colloid spincoating. Drying colloidal suspensions on a spinning substrate produces a ``perfect polycrystal'' - tiny polycrystalline domains that exhibit long-range inter-domain orientational order [4] with resultant spectacular optical effects that are decoupled from single-crystallinity. High-speed movies of drying crystals yield insights into mechanisms of structure formation. Phenomena arising from multiple spatially- and temporally-varying external fields can give rise to further control of order and disorder, with potential application as patterned (photonic and magnetic) materials. [4pt] [1] A. Yethiraj, Soft Matter 3, 1099 (2007). [2] A. Yethiraj, A. van Blaaderen, Nature 421, 513 (2003). [3] A.K. Agarwal, A. Yethiraj, Phys. Rev. Lett ,102, 198301 (2009). [4] C. Arcos, K. Kumar, W. Gonz'alez-Viñas, R. Sirera, K. Poduska, A. Yethiraj, Phys. Rev. E ,77, 050402(R) (2008).

  10. Sox2 marks epithelial competence to generate teeth in mammals and reptiles

    PubMed Central

    Juuri, Emma; Jussila, Maria; Seidel, Kerstin; Holmes, Scott; Wu, Ping; Richman, Joy; Heikinheimo, Kristiina; Chuong, Cheng-Ming; Arnold, Katrin; Hochedlinger, Konrad; Klein, Ophir; Michon, Frederic; Thesleff, Irma

    2013-01-01

    Tooth renewal is initiated from epithelium associated with existing teeth. The development of new teeth requires dental epithelial cells that have competence for tooth formation, but specific marker genes for these cells have not been identified. Here, we analyzed expression patterns of the transcription factor Sox2 in two different modes of successional tooth formation: tooth replacement and serial addition of primary teeth. We observed specific Sox2 expression in the dental lamina that gives rise to successional teeth in mammals with one round of tooth replacement as well as in reptiles with continuous tooth replacement. Sox2 was also expressed in the dental lamina during serial addition of mammalian molars, and genetic lineage tracing indicated that Sox2+ cells of the first molar give rise to the epithelial cell lineages of the second and third molars. Moreover, conditional deletion of Sox2 resulted in hyperplastic epithelium in the forming posterior molars. Our results indicate that the Sox2+ dental epithelium has competence for successional tooth formation and that Sox2 regulates the progenitor state of dental epithelial cells. The findings imply that the function of Sox2 has been conserved during evolution and that tooth replacement and serial addition of primary teeth represent variations of the same developmental process. The expression patterns of Sox2 support the hypothesis that dormant capacity for continuous tooth renewal exists in mammals. PMID:23462476

  11. Micromere lineages in the glossiphoniid leech Helobdella

    NASA Technical Reports Server (NTRS)

    Huang, Francoise Z.; Kang, Dongmin; Ramirez-Weber, Felipe-Andres; Bissen, Shirley T.; Weisblat, David A.

    2002-01-01

    In leech embryos, segmental mesoderm and ectoderm arise from teloblasts by lineages that are already relatively well characterized. Here, we present data concerning the early divisions and the definitive fate maps of the micromeres, a group of 25 small cells that arise during the modified spiral cleavage in leech (Helobdella robusta) and contribute to most of the nonsegmental tissues of the adult. Three noteworthy results of this work are as follows. (1) The c"' and dm' clones (3d and 3c in traditional nomenclature) give rise to a hitherto undescribed network of fibers that run from one end of the embryo to the other. (2) The clones of micromeres b" and b"' (2b and 3b in traditional nomenclature) die in normal development; the b" clone can be rescued to assume the normal c" fate if micromere c" or its clone are ablated in early development. (3) Two qualitative differences in micromere fates are seen between H. robusta (Sacramento) and another Helobdella sp. (Galt). First, in Helobdella sp. (Galt), the clone of micromere b" does not normally die, and contributes a subset of the cells arising exclusively from c" in H. robusta (Sacramento). Second, in Helobdella sp. (Galt), micromere c"' makes no definitive contribution, whereas micromere dm' gives rise to cells equivalent to those arising from c"' and dm' in H. robusta (Sacramento).

  12. An Adaptive Complex Network Model for Brain Functional Networks

    PubMed Central

    Gomez Portillo, Ignacio J.; Gleiser, Pablo M.

    2009-01-01

    Brain functional networks are graph representations of activity in the brain, where the vertices represent anatomical regions and the edges their functional connectivity. These networks present a robust small world topological structure, characterized by highly integrated modules connected sparsely by long range links. Recent studies showed that other topological properties such as the degree distribution and the presence (or absence) of a hierarchical structure are not robust, and show different intriguing behaviors. In order to understand the basic ingredients necessary for the emergence of these complex network structures we present an adaptive complex network model for human brain functional networks. The microscopic units of the model are dynamical nodes that represent active regions of the brain, whose interaction gives rise to complex network structures. The links between the nodes are chosen following an adaptive algorithm that establishes connections between dynamical elements with similar internal states. We show that the model is able to describe topological characteristics of human brain networks obtained from functional magnetic resonance imaging studies. In particular, when the dynamical rules of the model allow for integrated processing over the entire network scale-free non-hierarchical networks with well defined communities emerge. On the other hand, when the dynamical rules restrict the information to a local neighborhood, communities cluster together into larger ones, giving rise to a hierarchical structure, with a truncated power law degree distribution. PMID:19738902

  13. Cobalt(II) sheet-like systems based on diacetic ligands: from subtle structural variances to different magnetic behaviors.

    PubMed

    Fabelo, Oscar; Pasán, Jorge; Cañadillas-Delgado, Laura; Delgado, Fernando S; Lloret, Francesc; Julve, Miguel; Ruiz-Pérez, Catalina

    2009-07-06

    The preparation, X-ray crystallography, and magnetic investigation of the compounds [Co(H(2)O)(2)(phda)](n) (1), [Co(phda)](n) (2), and [Co(chda)](n) (3) [H(2)phda = 1,4-phenylenediacetic acid and H(2)chda = 1,1-cyclohexanediacetic acid] are described herein. The cobalt atoms in this series are six- (1) and four-coordinated (2 and 3) in distorted octahedral (CoO(6)) and tetrahedral (CoO(4)) environments. The structures of 1-3 consists of rectangular-grids which are built up by sheets of cobalt atoms linked through anti-syn carboxylate bridges, giving rise to either a three-dimensional structure across the phenyl ring (1 and 2) or to regularly stacked layers with the cyclohexyl groups acting as organic separators (3). The magnetic properties of 1-3 were investigated as a function of the temperature and the magnetic field. Ferromagnetic coupling between the six-coordinate cobalt(II) ions across the anti-syn carboxylate bridge occurs in 1 (J = +1.2 cm(-1)) whereas antiferromagnetic coupling among the tetrahedral cobalt(II) centers within the sheets is observed in 2 and 3 [J = -1.63 (2) and -1.70 cm(-1) (3)] together with a spin-canted structure in 3 giving rise a long-range magnetic ordering (T(c) = 7.5 K).

  14. 48 CFR 2452.209-71 - Limitation on future contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... give rise to potential organizational conflicts of interest as defined at FAR subpart 9.5. (b) The nature of the potential conflict of interest is [Contracting Officer insert description] (c) If the...

  15. The Handedness of the Universe.

    ERIC Educational Resources Information Center

    Hegstrom, Roger A.; Kondepudi, Dilip K.

    1990-01-01

    Discusses how handedness at one level may give rise to handedness at another. Presents examples from plants and animals, molecules, atoms, to elementary particles. Examines the chiral symmetry in life and when it starts. (YP)

  16. Genetics Home Reference: 3MC syndrome

    MedlinePlus

    ... pathway is thought to help direct the movement (migration) of cells during early development before birth to ... appears to be particularly important in directing the migration of neural crest cells, which give rise to ...

  17. 48 CFR 2009.570-9 - Waiver.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... contracting officer determines the need to seek a waiver for specific contract awards with the advice and... by a contractor whose interests give rise to a question of conflict of interest. (3) Contractual and...

  18. Ion acoustic wave assisted laser beat wave terahertz generation in a plasma channel

    NASA Astrophysics Data System (ADS)

    Tyagi, Yachna; Tripathi, Deepak; Walia, Keshav; Garg, Deepak

    2018-04-01

    Resonant excitation of terahertz (THz) radiation by non-linear mixing of two lasers in the presence of an electrostatic wave is investigated. The electrostatic wave assists in k matching and contributes to non-linear coupling. In this plasma channel, the electron plasma frequency becomes minimum on the axis. The beat frequency ponderomotive force imparts an oscillating velocity to the electrons. In the presence of an ion-acoustic wave, density perturbation due to the ion-acoustic wave couples with the oscillating velocity of the electrons and give rise to non-linear current that gives rise to an ion-acoustic wave frequency assisted THz radiation field. The normalized field amplitude of ion acoustic wave assisted THz varies inversely for ω/ωp . The field amplitude of ion acoustic wave assisted THz decreases as ω/ωp increases.

  19. Epitaxially stabilized iridium spinel oxide without cations in the tetrahedral site

    NASA Astrophysics Data System (ADS)

    Kuriyama, Hiromichi; Matsuno, Jobu; Niitaka, Seiji; Uchida, Masaya; Hashizume, Daisuke; Nakao, Aiko; Sugimoto, Kunihisa; Ohsumi, Hiroyuki; Takata, Masaki; Takagi, Hidenori

    2010-05-01

    Single-crystalline thin film of an iridium dioxide polymorph Ir2O4 has been fabricated by the pulsed laser deposition of LixIr2O4 precursor and the subsequent Li-deintercalation using soft chemistry. Ir2O4 crystallizes in a spinel (AB2O4) without A cations in the tetrahedral site, which is isostructural to λ-MnO2. Ir ions form a pyrochlore sublattice, which is known to give rise to a strong geometrical frustration. This Ir spinel was found to be a narrow gap insulator, in remarkable contrast to the metallic ground state of rutile-type IrO2. We argue that an interplay of a strong spin-orbit coupling and a Coulomb repulsion gives rise to an insulating ground state as in a layered perovskite Sr2IrO4.

  20. Unipotent, Atoh1+ progenitors maintain the Merkel cell population in embryonic and adult mice

    PubMed Central

    Wright, Margaret C.; Reed-Geaghan, Erin G.; Bolock, Alexa M.; Fujiyama, Tomoyuki; Hoshino, Mikio

    2015-01-01

    Resident progenitor cells in mammalian skin generate new cells as a part of tissue homeostasis. We sought to identify the progenitors of Merkel cells, a unique skin cell type that plays critical roles in mechanosensation. We found that some Atoh1-expressing cells in the hairy skin and whisker follicles are mitotically active at embryonic and postnatal ages. Genetic fate-mapping revealed that these Atoh1-expressing cells give rise solely to Merkel cells. Furthermore, selective ablation of Atoh1+ skin cells in adult mice led to a permanent reduction in Merkel cell numbers, demonstrating that other stem cell populations are incapable of producing Merkel cells. These data identify a novel, unipotent progenitor population in the skin that gives rise to Merkel cells both during development and adulthood. PMID:25624394

  1. Socioecological psychology.

    PubMed

    Oishi, Shigehiro

    2014-01-01

    Socioecological psychology investigates humans' cognitive, emotional, and behavioral adaption to physical, interpersonal, economic, and political environments. This article summarizes three types of socioecological psychology research: (a) association studies that link an aspect of social ecology (e.g., population density) with psychology (e.g., prosocial behavior), (b) process studies that clarify why there is an association between social ecology and psychology (e.g., residential mobility → anxiety → familiarity seeking), and (c) niche construction studies that illuminate how psychological states give rise to the creation and maintenance of a social ecology (e.g., familiarity seeking → dominance of national chain stores). Socioecological psychology attempts to bring the objectivist perspective to psychological science, investigating how objective social and physical environments, not just perception and construal of the environments, affect one's thinking, feeling, and behaviors, as well as how people's thinking, feeling, and behaviors give rise to social and built environments.

  2. Motion of spin label side chains in cellular retinol-binding protein: correlation with structure and nearest-neighbor interactions in an antiparallel beta-sheet.

    PubMed

    Lietzow, Michael A; Hubbell, Wayne L

    2004-03-23

    A goal in the development of site-directed spin labeling in proteins is to correlate the motion of a nitroxide side chain with local structure, interactions, and dynamics. Significant progress toward this goal has been made using alpha-helical proteins of known structure, and the present study is the first step in a similar exploration of a beta-sheet protein, cellular retinol-binding protein (CRBP). Nitroxide side chains were introduced along both interior and edge strands. At sites in interior strands, the side-chain motion is strongly influenced by interactions with side chains of neighboring strands, giving rise to a rich variety of dynamic modes (weakly ordered, strongly ordered, immobilized) and complex electron paramagnetic resonance spectra that are modulated by strand twist. The interactions giving rise to the dynamic modes are explored using mutagenesis, and the results demonstrate the particular importance of the non-hydrogen-bonded neighbor residue in giving rise to highly ordered states. Along edge strands of the beta-sheet, the motion of the side chain is simple and weakly ordered, resembling that at solvent-exposed surfaces of an alpha-helix. A simple working model is proposed that can account for the wide variety of dynamic modes encountered. Collectively, the results suggest that the nitroxide side chain is an effective probe of side-chain interactions, and that site-directed spin labeling should be a powerful means of monitoring conformational changes that involve changes in beta-sheet topology.

  3. Distinct populations of endoderm cells converge to generate the embryonic liver bud and ventral foregut tissues.

    PubMed

    Tremblay, Kimberly D; Zaret, Kenneth S

    2005-04-01

    The location and movement of mammalian gut tissue progenitors, prior to the expression of tissue-specific genes, has been unknown, but this knowledge is essential to identify transitions that lead to cell type specification. To address this, we used vital dyes to label exposed anterior endoderm cells of early somite stage mouse embryos, cultured the embryos into the tissue bud phase of development, and determined the tissue fate of the dye labeled cells. This approach was performed at three embryonic stages that are prior to, or coincident with, foregut tissue patterning (1-3 somites, 4-6 somites, and 7-10 somites). Short-term labeling experiments tracked the movement of tissue progenitor cells during foregut closure. Surprisingly, we found that two distinct types of endoderm-progenitor cells, lateral and medial, arising from three spatially separated embryonic domains, converge to generate the epithelial cells of the liver bud. Whereas the lateral endoderm-progenitors give rise to descendants that are constrained in tissue fate and position along the anterior-posterior axis of the gut, the medial gut endoderm-progenitors give rise to descendants that stream along the anterior-posterior axis at the ventral midline and contribute to multiple gut tissues. The fate map reveals extensive morphogenetic movement of progenitors prior to tissue specification, it permits a detailed analysis of endoderm tissue patterning, and it illustrates that diverse progenitor domains can give rise to individual tissue cell types.

  4. Small differences in amylopectin fine structure may explain large functional differences of starch.

    PubMed

    Bertoft, Eric; Annor, George A; Shen, Xinyu; Rumpagaporn, Pinthip; Seetharaman, Koushik; Hamaker, Bruce R

    2016-04-20

    Four amylose-free waxy rice starches were found to give rise to gels with clearly different morphology after storage for seven days at 4°C. The thermal and rheological properties of these gels were also different. This was remarkable in light of the subtle differences in the molecular structure of the amylopectin in the samples. Addition of iodine to the amylopectin samples suggested that not only external chains, but also the internal chains of amylopectin, could form helical inclusion complexes. It is suggested that these internal helical segments participate in the retrogradation of amylopectin, thereby stabilising the gels through double helical structures with external chains of adjacent molecules. Albeit few in number, such interactions appear to have important influences on starch functional properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Environment and Structure Influence in DNA Conduction

    NASA Technical Reports Server (NTRS)

    Adessi, C.; Walch, S.; Anantram, M. P.; Biegel, Bryan (Technical Monitor)

    2002-01-01

    Results for transmission through the poly(G) DNA molecule are presented. We show that (i) periodically arranged sodium counter-ions in close proximity to dry DNA gives rise to a new conduction channel and aperiodicity in the counter-ion sequence can lead to a significant reduction in conduction, (ii) modification of the rise of B-DNA induces a change in the width of the transmission window, and (iii) specifically designed sequences are predicted to show intrinsic resonant tunneling behavior.

  6. Human visual response to nuclear particle exposures

    NASA Technical Reports Server (NTRS)

    Tobias, C. A.; Budinger, T. F.; Lyman, J. T.

    1972-01-01

    Experiments with accelerated helium ions were performed in an effort to localize the site of initial radiation interactions in the eye that lead to light flash observations by astronauts during spaceflight. The character and efficiency of helium ion induction of visual sensations depended on the state of dark adaptation of the retina; also, the same events were seen with different efficiencies and details when particle flux density changed. It was concluded that fast particles cause interactions in the retina, particularly in the receptor layer, and thus give rise to the sensations of light flashes, streaks, and supernovae.

  7. Electronic and magnetic properties of epitaxial SrRh O 3 films

    DOE PAGES

    Nichols, John A.; Yuk, Simuck F.; Sohn, Changhee; ...

    2017-06-16

    The strong interplay of fundamental order parameters in complex oxides is known to give rise to exotic physical phenomena. The 4$d$ transition-metal oxide SrRh O 3 has generated much interest, but advances have been hindered by difficulties in preparing single-crystalline phases. Here we epitaxially stabilize high-quality single-crystalline SrRh O 3 films and investigate their structural, electronic, and magnetic properties. Lastly, we determine that their properties significantly differ from the paramagnetic metallic ground state that governs bulk samples and are strongly related to rotations of Rh O 6 octahedra.

  8. Constructing neutron stars with a gravitational Higgs mechanism

    NASA Astrophysics Data System (ADS)

    Franchini, Nicola; Coates, Andrew; Sotiriou, Thomas P.

    2018-03-01

    In scalar-tensor theories, spontaneous scalarization is a phase transition that can occur in ultradense environments such as neutron stars. The scalar field develops a nontrivial configuration once the stars exceeds a compactness threshold. We recently pointed out that, if the scalar exhibits some additional coupling to matter, it could give rise to significantly different microphysics in these environments. In this work we study, at the nonperturbative level, a toy model in which the photon is given a large mass when spontaneous scalarization occurs. Our results demonstrate clearly the effectiveness of spontaneous scalarization as a Higgs-like mechanism in neutron stars.

  9. Near-Threshold Ionization of Argon by Positron Impact

    NASA Astrophysics Data System (ADS)

    Babij, T. J.; Machacek, J. R.; Murtagh, D. J.; Buckman, S. J.; Sullivan, J. P.

    2018-03-01

    The direct single-ionization cross section for Ar by positron impact has been measured in the region above the first ionization threshold. These measurements are compared to semiclassical calculations which give rise to a power law variation of the cross section in the threshold region. The experimental results appear to be in disagreement with extensions to the Wannier theory applied to positron impact ionization, with a smaller exponent than that calculated by most previous works. In fact, in this work, we see no difference in threshold behavior between the positron and electron cases. Possible reasons for this discrepancy are discussed.

  10. Reflectivity of the gyroid biophotonic crystals in the ventral wing scales of the Green Hairstreak butterfly, Callophrys rubi

    PubMed Central

    Michielsen, K.; De Raedt, H.; Stavenga, D. G.

    2010-01-01

    We present a comparison of the computer simulation data of gyroid nanostructures with optical measurements (reflectivity spectra and scattering diagrams) of ventral wing scales of the Green Hairstreak butterfly, Callophrys rubi. We demonstrate that the omnidirectional green colour arises from the gyroid cuticular structure grown in the domains of different orientation. We also show that this three-dimensional structure, operating as a biophotonic crystal, gives rise to various polarization effects. We briefly discuss the possible biological utility of the green coloration and polarization effects. PMID:19828506

  11. Collision-induced stimulated photon echo generated at transition 0-1 on broad spectral line conditions

    NASA Astrophysics Data System (ADS)

    Rubtsova, N. N.; Gol'dort, V. G.; Ishchenko, V. N.; Khvorostov, E. B.; Kochubei, S. A.; Borisov, G. M.; Ledovskikh, D. V.; Reshetov, V. A.

    2018-04-01

    For the first time, the collision induced stimulated photon echo generated at transition 1S0 → 3 P1 of 174Yb (type 0-1) in the mixture of gases Yb  +  Xe was investigated in the presence of weak longitudinal magnetic field, with experimental parameters corresponding to broad spectral line conditions. Comparison of the experimental echo amplitude versus magnetic field strength dependence with the theoretical curve shows a very good agreement, giving rise to an improved estimate for the difference between alignment and orientation decay rates.

  12. Information processing occurs via critical avalanches in a model of the primary visual cortex

    NASA Astrophysics Data System (ADS)

    Bortolotto, G. S.; Girardi-Schappo, M.; Gonsalves, J. J.; Pinto, L. T.; Tragtenberg, M. H. R.

    2016-01-01

    We study a new biologically motivated model for the Macaque monkey primary visual cortex which presents power-law avalanches after a visual stimulus. The signal propagates through all the layers of the model via avalanches that depend on network structure and synaptic parameter. We identify four different avalanche profiles as a function of the excitatory postsynaptic potential. The avalanches follow a size-duration scaling relation and present critical exponents that match experiments. The structure of the network gives rise to a regime of two characteristic spatial scales, one of which vanishes in the thermodynamic limit.

  13. 48 CFR 2452.209-71 - Limitation on future contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... give rise to potential organizational conflicts of interest as defined at FAR subpart 9.5. (b) The... contractor, under the terms of this contract or through the performance of tasks pursuant to this contract...

  14. 33 CFR 25.503 - Proper claimants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... been an inhabitant of a foreign country at the time of the incident giving rise to the claim and must... country on a permanent basis may qualify as a proper claimant although organized under United States law...

  15. 22 CFR 213.28 - Execution of releases.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and execute a release on behalf of the United States. In the event a mutual release is not executed... all claims and causes of action against USAID and its officials related to the transaction giving rise...

  16. 22 CFR 213.28 - Execution of releases.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and execute a release on behalf of the United States. In the event a mutual release is not executed... all claims and causes of action against USAID and its officials related to the transaction giving rise...

  17. 33 CFR 25.503 - Proper claimants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... been an inhabitant of a foreign country at the time of the incident giving rise to the claim and must... country on a permanent basis may qualify as a proper claimant although organized under United States law...

  18. Research on the Reproductive Effects of Endocrine Disrupting Chemicals

    EPA Pesticide Factsheets

    Reproductive hormones exert their effects at many life stages. During embryo and fetus development in the womb, these hormones direct formation of sex organs and the cells that give rise to sperm and eggs.

  19. The Early Days of Polymer Science

    ERIC Educational Resources Information Center

    Mark, H.

    1973-01-01

    Summarizes research studies made early in this century in the fields of cellulose, starch, proteins, and rubber. Included is a description of factors which give rise to the concept of very long, chain-like molecules. (CC)

  20. 45 CFR 73.735-806 - Documentation and publication of opinions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and accurate documentation of the formal advice and guidance given. (b) From time to time, the..., deleting, as necessary, any personal identifiers or other information which may give rise to an unwarranted...

  1. 45 CFR 73.735-806 - Documentation and publication of opinions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and accurate documentation of the formal advice and guidance given. (b) From time to time, the..., deleting, as necessary, any personal identifiers or other information which may give rise to an unwarranted...

  2. 8 CFR 292.3 - Professional conduct for practitioners-Rules and procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... professional misconduct as to give rise to the clear conviction that the adjudicating official could not... protection of the public when the necessity for disclosing information outweighs the necessity for preserving...

  3. Cosmic string with a light massive neutrino

    NASA Technical Reports Server (NTRS)

    Albrecht, Andreas; Stebbins, Albert

    1992-01-01

    We have estimated the power spectra of density fluctuations produced by cosmic strings with neutrino hot dark matter (HDM). Normalizing at 8/h Mpc, we find that the spectrum has more power on small scales than HDM + inflation, less than cold dark matter (CDM) + inflation, and significantly less the CDM + strings. With HDM, large wakes give significant contribution to the power on the galaxy scale and may give rise to large sheets of galaxies.

  4. Monogamy relations of concurrence for any dimensional quantum systems

    NASA Astrophysics Data System (ADS)

    Zhu, Xue-Na; Li-Jost, Xianqing; Fei, Shao-Ming

    2017-11-01

    We study monogamy relations for arbitrary dimensional multipartite systems. Monogamy relations based on concurrence and concurrence of assistance for any dimensional m_1⊗ m_2⊗ \\cdots ⊗ mN quantum states are derived, which give rise to the restrictions on the entanglement distributions among the subsystems. Besides, we give the lower bound of concurrence for four-partite mixed states. The approach can be readily generalized to arbitrary multipartite systems.

  5. Wireless Sensor Network Optimization: Multi-Objective Paradigm.

    PubMed

    Iqbal, Muhammad; Naeem, Muhammad; Anpalagan, Alagan; Ahmed, Ashfaq; Azam, Muhammad

    2015-07-20

    Optimization problems relating to wireless sensor network planning, design, deployment and operation often give rise to multi-objective optimization formulations where multiple desirable objectives compete with each other and the decision maker has to select one of the tradeoff solutions. These multiple objectives may or may not conflict with each other. Keeping in view the nature of the application, the sensing scenario and input/output of the problem, the type of optimization problem changes. To address different nature of optimization problems relating to wireless sensor network design, deployment, operation, planing and placement, there exist a plethora of optimization solution types. We review and analyze different desirable objectives to show whether they conflict with each other, support each other or they are design dependent. We also present a generic multi-objective optimization problem relating to wireless sensor network which consists of input variables, required output, objectives and constraints. A list of constraints is also presented to give an overview of different constraints which are considered while formulating the optimization problems in wireless sensor networks. Keeping in view the multi facet coverage of this article relating to multi-objective optimization, this will open up new avenues of research in the area of multi-objective optimization relating to wireless sensor networks.

  6. 'Groping through the fog': a metasynthesis of women's experiences on VBAC (Vaginal birth after Caesarean section).

    PubMed

    Lundgren, Ingela; Begley, Cecily; Gross, Mechthild M; Bondas, Terese

    2012-08-21

    Vaginal birth after Caesarean section (VBAC) is a relevant question for a large number of women due to the internationally rising Caesarean section (CS) rate. There is a great deal of research based on quantitative studies but few qualitative studies about women's experiences. A metasynthesis based on the interpretative meta ethnography method was conducted. The inclusion criterion was peer-review qualitative articles from different disciplines about women's experiences of VBAC. Eleven articles were checked for quality, and eight articles were included in the synthesis. The included studies were from Australia (four), UK (three), and US (one), and studied women's experience in relation to different aspects of VBAC; decision-making whether to give birth vaginally, the influence of health professionals on decision-making, reason for trying a vaginal birth, experiences when choosing VBAC, experiences of giving birth vaginally, and giving birth with CS when preferring VBAC. The main results are presented with the metaphor groping through the fog; for the women the issue of VBAC is like being in a fog, where decision-making and information from the health care system and professionals, both during pregnancy and the birth, is unclear and contrasting. The results are further presented with four themes: 'to be involved in decision about mode of delivery is difficult but important,' 'vaginal birth has several positive aspects mainly described by women,' 'vaginal birth after CS is a risky project,' and 'own strong responsibility for giving birth vaginally'. In order to promote VBAC, more studies are needed from different maternity settings and countries about women's experiences. Women need evidence-based information not only about the risks involved but also positive aspects of VBAC.

  7. ‘Groping through the fog’: a metasynthesis of women's experiences on VBAC (Vaginal birth after Caesarean section)

    PubMed Central

    2012-01-01

    Background Vaginal birth after Caesarean section (VBAC) is a relevant question for a large number of women due to the internationally rising Caesarean section (CS) rate. There is a great deal of research based on quantitative studies but few qualitative studies about women's experiences. Method A metasynthesis based on the interpretative meta ethnography method was conducted. The inclusion criterion was peer-review qualitative articles from different disciplines about women's experiences of VBAC. Eleven articles were checked for quality, and eight articles were included in the synthesis. Results The included studies were from Australia (four), UK (three), and US (one), and studied women's experience in relation to different aspects of VBAC; decision-making whether to give birth vaginally, the influence of health professionals on decision-making, reason for trying a vaginal birth, experiences when choosing VBAC, experiences of giving birth vaginally, and giving birth with CS when preferring VBAC. The main results are presented with the metaphor groping through the fog; for the women the issue of VBAC is like being in a fog, where decision-making and information from the health care system and professionals, both during pregnancy and the birth, is unclear and contrasting. The results are further presented with four themes: ‘to be involved in decision about mode of delivery is difficult but important,’ ‘vaginal birth has several positive aspects mainly described by women,’ ‘vaginal birth after CS is a risky project,’ and ‘own strong responsibility for giving birth vaginally'. Conclusion In order to promote VBAC, more studies are needed from different maternity settings and countries about women's experiences. Women need evidence-based information not only about the risks involved but also positive aspects of VBAC. PMID:22909230

  8. The role of H-bond in the high-pressure chemistry of model molecules

    NASA Astrophysics Data System (ADS)

    Fanetti, Samuele; Citroni, Margherita; Dziubek, Kamil; Medre Nobrega, Marcelo; Bini, Roberto

    2018-03-01

    Pressure is an extraordinary tool to modify direction and strength of intermolecular interactions with important consequences on the chemical stability of molecular materials. The decrease of the distance among nearest neighbour molecules can give rise to reactive configurations reflecting the crystal arrangement and leading to association processes. In this context, the role of the H-bonds is very peculiar because their usual strengthening with rising pressure does not necessarily configure a decrease of the reaction activation energy but, on the contrary, can give rise to an anomalous stability of the system. In spite of this central role, the mechanisms by which a chemical reaction is favoured or prevented by H-bonding under high pressure conditions is a poorly explored field. Here we review a few studies where the chemical behaviour of simple molecular systems under static compression was related to the H-bonding evolution with pressure. These results are able to clarify a wealth of changes of the chemical and physical properties caused by the strengthening with pressure of the H-bonding network and provide additional tools to understand the mechanisms of high-pressure reactivity, a mandatory step to make these synthetic methods of potential interest for applicative purposes.

  9. Multicentric epidemiological study of Aspergillus fumigatus isolates by multilocus enzyme electrophoresis.

    PubMed Central

    Rodriguez, E; De Meeüs, T; Mallie, M; Renaud, F; Symoens, F; Mondon, P; Piens, M A; Lebeau, B; Viviani, M A; Grillot, R; Nolard, N; Chapuis, F; Tortorano, A M; Bastide, J M

    1996-01-01

    The genotypes of 63 isolates of Aspergillus fumigatus obtained from three hospitals in different geographical areas and of eight culture collection strains were determined by multilocus enzyme electrophoresis. Twelve of the 17 enzymatic loci studied were polymorphic, giving rise to 48 different electrophoretic types. The existence of fixed multilocus genotypes, significant heterozygote deficits and excesses at the different loci, and linkage disequilibria within subpopulations strongly suggests a clonal reproduction mode for A. fumigatus. Numerical analysis of the comparison and disposition of the different electrophoretic types demonstrates a significant genetic differentiation between the three sampling sites. However, no correlation could be found between geographical distances and genetic differentiation. On account of the multiple discriminatory markers, multilocus enzyme electrophoresis typing seems to be a very powerful tool for epidemiological and reproductive mode studies of A. fumigatus. PMID:8880520

  10. Nonequivalent lanthanide defects: Energy level modeling

    NASA Astrophysics Data System (ADS)

    Joos, Jonas J.; Poelman, Dirk; Smet, Philippe F.

    2016-11-01

    Empirical charge-state transition level schemes are popular tools to model the properties of lanthanide-doped materials and their construction has become standard practice. Typically, it is implicitly assumed that all lanthanide ions form isostructural defects. However, in practice, multiple nonequivalent defects related to the same lanthanide can occur or different lanthanides can even incorporate in different ways. The consequences of these complications on the impurity energy levels are discussed in this article. It seems that small structural differences around the lanthanide dopant can give rise to important spectral differences in its emission. These are not always clearly reproduced by the charge-state transition level schemes. Improvements to the existing procedure are suggested and applied to the lanthanide ions in the well-studied host crystals SrAl2O4, Sr2Si5N8 and SrGa2S4.

  11. 22 CFR 181.1 - Purpose and application.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... subject to review by another agency. (b) Pursuant to the key legal requirements of the Act—full and timely..., will not give rise to a cause of action, and will not affect any public or private rights established...

  12. 22 CFR 181.1 - Purpose and application.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... subject to review by another agency. (b) Pursuant to the key legal requirements of the Act—full and timely..., will not give rise to a cause of action, and will not affect any public or private rights established...

  13. 22 CFR 181.1 - Purpose and application.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... subject to review by another agency. (b) Pursuant to the key legal requirements of the Act—full and timely..., will not give rise to a cause of action, and will not affect any public or private rights established...

  14. 22 CFR 181.1 - Purpose and application.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... subject to review by another agency. (b) Pursuant to the key legal requirements of the Act—full and timely..., will not give rise to a cause of action, and will not affect any public or private rights established...

  15. Interactive Classroom Graphics--Simulating Non-Linear Arrhenius Plots.

    ERIC Educational Resources Information Center

    Ben-Zion, M.; Hoz, S.

    1980-01-01

    Describes two simulation programs using an interactive graphic display terminal that were developed for a course in physical organic chemistry. Demonstrates the energetic conditions that give rise to deviations from linearity in the Arrhenius equation. (CS)

  16. 29 CFR 1471.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... findings by Federal, State, or local bodies that determine factual and/or legal matters, constitutes... of the circumstances giving rise to a cause for suspension or from potential business relationships...

  17. 29 CFR 1471.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... findings by Federal, State, or local bodies that determine factual and/or legal matters, constitutes... of the circumstances giving rise to a cause for suspension or from potential business relationships...

  18. 41 CFR 105-68.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... findings by Federal, State, or local bodies that determine factual and/or legal matters, constitutes... of the circumstances giving rise to a cause for suspension or from potential business relationships...

  19. Gamma-ray astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W. (Editor); Trombka, J. I. (Editor)

    1973-01-01

    Conference papers on gamma ray astrophysics are summarized. Data cover the energy region from about 0.3 MeV to a few hundred GeV and theoretical models of production mechanisms that give rise to both galactic and extragalactic gamma rays.

  20. DELTAMETHRIN AND PERMETHRIN DECREASE SPONTANEOUS NETWORK ACTIVITY IN VITRO.

    EPA Science Inventory

    ABSTRACT BODY: Pyrethroid insecticides alter inactivation of voltage-sensitive sodium channels, an action that underlies their insecticidal and neurotoxicological properties. How alterations in sodium channel function give rise to the characteristic signs of pyrethroid intoxicati...

  1. A Bayesian explanation of the "Uncanny Valley" effect and related psychological phenomena

    NASA Astrophysics Data System (ADS)

    Moore, Roger K.

    2012-11-01

    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the `uncanny valley' effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions.

  2. Casimir forces between defects in one-dimensional quantum liquids

    NASA Astrophysics Data System (ADS)

    Recati, A.; Fuchs, J. N.; Peça, C. S.; Zwerger, W.

    2005-08-01

    We discuss the effective interactions between two localized perturbations in one-dimensional quantum liquids. For noninteracting fermions, the interactions exhibit Friedel oscillations, giving rise to a Ruderman-Kittel-Kasuya-Yosida-type interaction familiar from impurity spins in metals. In the interacting case, at low energies, a Luttinger-liquid description applies. In the case of repulsive fermions, the Friedel oscillations of the interacting system are replaced, at long distances, by a universal Casimir-type interaction which depends only on the sound velocity and decays inversely with the separation. The Casimir-type interaction between localized perturbations embedded in a fermionic environment gives rise to a long-range coupling between quantum dots in ultracold Fermi gases, opening an alternative to couple qubits with neutral atoms. We also briefly discuss the case of bosonic quantum liquids in which the interaction between weak impurities turns out to be short ranged, decaying exponentially on the scale of the healing length.

  3. Generalized transformations and coordinates for static spherically symmetric general relativity

    NASA Astrophysics Data System (ADS)

    Hill, James M.; O'Leary, Joseph

    2018-04-01

    We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington-Finkelstein transformation and the Kruskal-Szekeres coordinates.

  4. Sustainable development in an N-rich/n-poor world.

    PubMed

    Perrings, Charles; Kinzig, Ann; Halkos, George

    2014-11-01

    Sustainable development requires that per capita inclusive wealth-produced, human, and natural capital-does not decline over time. We investigate the impact of changes in nitrogen on inclusive wealth. There are two sides to the nitrogen problem. Excess use of nitrogen in some places gives rise to N-pollution, which can cause environmental damage. Insufficient replacement of nitrogen in other places gives rise to N-depletion, or loss of nutrient stocks. Neither is explicitly accounted for in current wealth measures, but both affect wealth. We calculate an index of net N-replacement, and investigate its relationship to wealth. In countries with low levels of relative N-loss, we find that the uncompensated loss of soil nitrogen in poorer countries is associated with declining rates of growth of inclusive per capita wealth. What is less intuitive is that increasing fertilizer application in both rich and poor countries can increase per capita inclusive wealth.

  5. On the merging rates of envelope-deprived components of binary systems which can give rise to supernova events

    NASA Astrophysics Data System (ADS)

    Tornambe, Amedeo

    1989-08-01

    Theoretical rates of mergings of envelope-deprived components of binary systems, which can give rise to supernova events are described. The effects of the various assumptions on the physical properties of the progenitor system and of its evolutionary behavior through common envelope phases are discussed. Four cases have been analyzed: CO-CO, He-CO, He-He double degenerate mergings and He star-CO dwarf merging. It is found that, above a critical efficiency of the common envelope action in system shrinkage, the rate of CO-CO mergings is not strongly sensitive to the efficiency. Below this critical value, no CO-CO systems will survive for times larger than a few Gyr. In contrast, He-CO dwarf systems will continue to merge at a reasonable rate up to 20 Gyr, and more, also under extreme conditions.

  6. The Increased Incidence of Thyrotoxicosis in Immigrants

    PubMed Central

    Spaulding, W. B.

    1963-01-01

    Evidence is presented that, in Toronto, hyperthyroidism is significantly more prevalent in immigrants than in native-born patients. In a series of 4000 outpatients only eight of 1854 native-born patients were thyrotoxic, whereas 33 of 2146 immigrants proved to be so (p < 0.001). There is little likelihood that a genetic or nutritional predisposition accounted for the findings, because the immigrants came from widely scattered parts of the world. Possibly, the immigrants were reluctant to seek medical attention for minor illnesses, thereby giving rise to an apparent but not real increase of thyrotoxicosis in the foreignborn. There was less mental illness diagnosed in the immigrants than in the nativeborn patients, a point against relating the thyroid overactivity to emotional stress. It is suggested that the adjustment of settling in a strange country may be physiologically disturbing in some unknown way and may give rise to an increased incidence of thyrotoxicosis in immigrants. PMID:13989936

  7. Cardiovascular Disease, Psychosocial Factors, and Genetics: The Case of Depression

    PubMed Central

    Mulle, Jennifer Gladys; Vaccarino, Viola

    2013-01-01

    Psychosocial factors are associated with cardiovascular disease, but little is known about the role of genetics in this relationship. Focusing on the well-studied phenotype of depression, current data show that there are shared genetic factors that may give rise to both depression and CVD, and these genetic risks appear to be modified by gender. This pleiotropic effect suggests that a single pathway, when perturbed, gives rise to the dual phenotypes of CVD and depression. The data also suggest that women contribute disproportionately to the depression-CVD comorbidity, and this unbalanced contribution is attributable, in part, to genetic factors. While the underlying biology behind this relationship is unclear, recent data support contributions from inflammatory or serotonergic pathways toward the comorbidity between CVD and depression. Even without knowledge of a specific mechanism, epidemiological observations offer new directions to explain the relationship between depression and CVD that have both research and clinical applications. PMID:23621965

  8. Immune mechanism: a 'double-edged sword'.

    PubMed

    Musa, Mustaffa

    2013-05-01

    Immunology has now developed into an independent discipline in medicine which covers not only germ infection which is related to immunity solely but also covers a lot of non-infectious diseases such as autoimmune disease, allergies, and others. Therefore, "The Immune Mechanism: "A Double-Edged Sword" means that the immune mechanism (consisted of antibody mediated mechanism and T cell mediated mechanism), just like one edge playing the role of giving benefit (immunity) as it destroys the agent of infection, and another one can be detrimental as it will cause tissue/cell damages and then give rise to immune diseases (immunopathology). Now, the prevalence of these immune diseases is on the rise and has become a new challenge to our country towards developed country in 2020. Therefore, we have to make ample preparation (laboratory facilities/services, main power, and research) from now on in order to face the problems and challenges.

  9. Lgr5 Identifies Progenitor Cells Capable of Taste Bud Regeneration after Injury.

    PubMed

    Takeda, Norifumi; Jain, Rajan; Li, Deqiang; Li, Li; Lu, Min Min; Epstein, Jonathan A

    2013-01-01

    Taste buds are composed of a variety of taste receptor cell types that develop from tongue epithelium and are regularly replenished under normal homeostatic conditions as well as after injury. The characteristics of cells that give rise to regenerating taste buds are poorly understood. Recent studies have suggested that Lgr5 (leucine-rich repeat-containing G-protein coupled receptor 5) identifies taste bud stem cells that contribute to homeostatic regeneration in adult circumvallate and foliate taste papillae, which are located in the posterior region of the tongue. Taste papillae in the adult anterior region of the tongue do not express Lgr5. Here, we confirm and extend these studies by demonstrating that Lgr5 cells give rise to both anterior and posterior taste buds during development, and are capable of regenerating posterior taste buds after injury induced by glossopharyngeal nerve transection.

  10. Constructing topological models by symmetrization: A projected entangled pair states study

    NASA Astrophysics Data System (ADS)

    Fernández-González, Carlos; Mong, Roger S. K.; Landon-Cardinal, Olivier; Pérez-García, David; Schuch, Norbert

    2016-10-01

    Symmetrization of topologically ordered wave functions is a powerful method for constructing new topological models. Here we study wave functions obtained by symmetrizing quantum double models of a group G in the projected entangled pair states (PEPS) formalism. We show that symmetrization naturally gives rise to a larger symmetry group G ˜ which is always non-Abelian. We prove that by symmetrizing on sufficiently large blocks, one can always construct wave functions in the same phase as the double model of G ˜. In order to understand the effect of symmetrization on smaller patches, we carry out numerical studies for the toric code model, where we find strong evidence that symmetrizing on individual spins gives rise to a critical model which is at the phase transitions of two inequivalent toric codes, obtained by anyon condensation from the double model of G ˜.

  11. A Bayesian explanation of the ‘Uncanny Valley’ effect and related psychological phenomena

    PubMed Central

    Moore, Roger K.

    2012-01-01

    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the ‘uncanny valley’ effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions. PMID:23162690

  12. Familial cancer syndromes and clusters.

    PubMed

    Birch, J M

    1994-07-01

    The study of rare families in which a variety of cancers occur, usually at an early age and with patterns consistent with a common hereditary mechanism, has contributed much to our understanding of the process of carcinogenesis. So far, genes identified as having a role in cancer predisposition in these families have also been important in the histogenesis of sporadic cancers. In the two most clearly defined cancer family syndromes, the Li-Fraumeni syndrome and Lynch syndrome II, the genes involved predispose to diverse but specific constellations of cancers. Genes associated with site-specific familial cancer clusters may also give rise to increased susceptibility to other cancers, and site-specific clusters may represent one end of a spectrum. A consistent feature of familial cancer syndromes is the variable expression within and between families. A challenge for the future will be to determine other factors which may interact with the principal genes involved, giving rise to this variability.

  13. Phase Transitions of the Polariton Condensate in 2D Dirac Materials

    NASA Astrophysics Data System (ADS)

    Lee, Ki Hoon; Lee, Changhee; Min, Hongki; Chung, Suk Bum

    2018-04-01

    For the quantum well in an optical microcavity, the interplay of the Coulomb interaction and the electron-photon (e -ph) coupling can lead to the hybridizations of the exciton and the cavity photon known as polaritons, which can form the Bose-Einstein condensate above a threshold density. Additional physics due to the nontrivial Berry phase comes into play when the quantum well consists of the gapped two-dimensional Dirac material such as the transition metal dichalcogenide MoS2 or WSe2 . Specifically, in forming the polariton, the e -ph coupling from the optical selection rule due to the Berry phase can compete against the Coulomb electron-electron (e -e ) interaction. We find that this competition gives rise to a rich phase diagram for the polariton condensate involving both topological and symmetry breaking phase transitions, with the former giving rise to the quantum anomalous Hall and the quantum spin Hall phases.

  14. Phase Transitions of the Polariton Condensate in 2D Dirac Materials.

    PubMed

    Lee, Ki Hoon; Lee, Changhee; Min, Hongki; Chung, Suk Bum

    2018-04-13

    For the quantum well in an optical microcavity, the interplay of the Coulomb interaction and the electron-photon (e-ph) coupling can lead to the hybridizations of the exciton and the cavity photon known as polaritons, which can form the Bose-Einstein condensate above a threshold density. Additional physics due to the nontrivial Berry phase comes into play when the quantum well consists of the gapped two-dimensional Dirac material such as the transition metal dichalcogenide MoS_{2} or WSe_{2}. Specifically, in forming the polariton, the e-ph coupling from the optical selection rule due to the Berry phase can compete against the Coulomb electron-electron (e-e) interaction. We find that this competition gives rise to a rich phase diagram for the polariton condensate involving both topological and symmetry breaking phase transitions, with the former giving rise to the quantum anomalous Hall and the quantum spin Hall phases.

  15. Apparatus for atmospheric pressure pin-to-hole spark discharge and uses thereof

    DOEpatents

    Dobrynin, Danil V.; Fridman, Alexander; Cho, Young I.; Fridman, Gregory; Friedman, Gennady

    2016-12-06

    Disclosed herein are atmospheric pressure pin-to-hole pulsed spark discharge devices and methods for creating plasma. The devices include a conduit for fluidically communicating a gas, a plasma, or both, therethrough, portion of the conduit capable of being connected to a gas supply, and a second portion of the conduit capable of emitting a plasma; a positive electrode comprising a sharp tip; and a ground plate electrode. Disclosed are methods for treating a skin ulcer using non-thermal plasma include flowing a gas through a cold spark discharge zone simultaneously with the creation of a pulsed spark discharge to give rise to a non-thermal plasma emitted from a conduit, the non-thermal plasma comprising NO; and contacting a skin ulcer with said non-thermal plasma for sufficient time and intensity to give rise to treatment of the skin ulcer.

  16. Searching for topological defect dark matter via nongravitational signatures.

    PubMed

    Stadnik, Y V; Flambaum, V V

    2014-10-10

    We propose schemes for the detection of topological defect dark matter using pulsars and other luminous extraterrestrial systems via nongravitational signatures. The dark matter field, which makes up a defect, may interact with standard model particles, including quarks and the photon, resulting in the alteration of their masses. When a topological defect passes through a pulsar, its mass, radius, and internal structure may be altered, resulting in a pulsar "quake." A topological defect may also function as a cosmic dielectric material with a distinctive frequency-dependent index of refraction, which would give rise to the time delay of a periodic extraterrestrial light or radio signal, and the dispersion of a light or radio source in a manner distinct to a gravitational lens. A topological defect passing through Earth may alter Earth's period of rotation and give rise to temporary nonzero electric dipole moments for an electron, proton, neutron, nuclei and atoms.

  17. Generalized transformations and coordinates for static spherically symmetric general relativity.

    PubMed

    Hill, James M; O'Leary, Joseph

    2018-04-01

    We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington-Finkelstein transformation and the Kruskal-Szekeres coordinates.

  18. Generalized transformations and coordinates for static spherically symmetric general relativity

    PubMed Central

    2018-01-01

    We examine a static, spherically symmetric solution of the empty space field equations of general relativity with a non-orthogonal line element which gives rise to an opportunity that does not occur in the standard derivations of the Schwarzschild solution. In these derivations, convenient coordinate transformations and dynamical assumptions inevitably lead to the Schwarzschild solution. By relaxing these conditions, a new solution possibility arises and the resulting formalism embraces the Schwarzschild solution as a special case. The new solution avoids the coordinate singularity associated with the Schwarzschild solution and is achieved by obtaining a more suitable coordinate chart. The solution embodies two arbitrary constants, one of which can be identified as the Newtonian gravitational potential using the weak field limit. The additional arbitrary constant gives rise to a situation that allows for generalizations of the Eddington–Finkelstein transformation and the Kruskal–Szekeres coordinates. PMID:29765624

  19. The emergence of overlapping scale-free genetic architecture in digital organisms.

    PubMed

    Gerlee, P; Lundh, T

    2008-01-01

    We have studied the evolution of genetic architecture in digital organisms and found that the gene overlap follows a scale-free distribution, which is commonly found in metabolic networks of many organisms. Our results show that the slope of the scale-free distribution depends on the mutation rate and that the gene development is driven by expansion of already existing genes, which is in direct correspondence to the preferential growth algorithm that gives rise to scale-free networks. To further validate our results we have constructed a simple model of gene development, which recapitulates the results from the evolutionary process and shows that the mutation rate affects the tendency of genes to cluster. In addition we could relate the slope of the scale-free distribution to the genetic complexity of the organisms and show that a high mutation rate gives rise to a more complex genetic architecture.

  20. Dual Control of Giant Field-like Spin Torque in Spin Filter Tunnel Junctions

    PubMed Central

    Tang, Y. -H.; Chu, F. -C.; Kioussis, Nicholas

    2015-01-01

    We predict a giant field-like spin torque, , in spin-filter (SF) barrier tunnel junctions in sharp contrast to existing junctions based on nonmagnetic passive barriers. We demonstrate that has linear bias behavior, is independent of the SF thickness, and has odd parity with respect to the SF’s exchange splitting. Thus, it can be selectively controlled via external bias or external magnetic field which gives rise to sign reversal of via magnetic field switching. The underlying mechanism is the interlayer exchange coupling between the noncollinear magnetizations of the SF and free ferromagnetic electrode via the nonmagnetic insulating (I) spacer giving rise to giant spin-dependent reflection at the SF/I interface. These findings suggest that the proposed field-like-spin-torque MRAM may provide promising dual functionalities for both ‘reading’ and ‘writing’ processes which require lower critical current densities and faster writing and reading speeds. PMID:26095146

  1. Mechanisms Underlying Development of Visual Maps and Receptive Fields

    PubMed Central

    Huberman, Andrew D.; Feller, Marla B.; Chapman, Barbara

    2008-01-01

    Patterns of synaptic connections in the visual system are remarkably precise. These connections dictate the receptive field properties of individual visual neurons and ultimately determine the quality of visual perception. Spontaneous neural activity is necessary for the development of various receptive field properties and visual feature maps. In recent years, attention has shifted to understanding the mechanisms by which spontaneous activity in the developing retina, lateral geniculate nucleus, and visual cortex instruct the axonal and dendritic refinements that give rise to orderly connections in the visual system. Axon guidance cues and a growing list of other molecules, including immune system factors, have also recently been implicated in visual circuit wiring. A major goal now is to determine how these molecules cooperate with spontaneous and visually evoked activity to give rise to the circuits underlying precise receptive field tuning and orderly visual maps. PMID:18558864

  2. Neural Global Pattern Similarity Underlies True and False Memories.

    PubMed

    Ye, Zhifang; Zhu, Bi; Zhuang, Liping; Lu, Zhonglin; Chen, Chuansheng; Xue, Gui

    2016-06-22

    The neural processes giving rise to human memory strength signals remain poorly understood. Inspired by formal computational models that posit a central role of global matching in memory strength, we tested a novel hypothesis that the strengths of both true and false memories arise from the global similarity of an item's neural activation pattern during retrieval to that of all the studied items during encoding (i.e., the encoding-retrieval neural global pattern similarity [ER-nGPS]). We revealed multiple ER-nGPS signals that carried distinct information and contributed differentially to true and false memories: Whereas the ER-nGPS in the parietal regions reflected semantic similarity and was scaled with the recognition strengths of both true and false memories, ER-nGPS in the visual cortex contributed solely to true memory. Moreover, ER-nGPS differences between the parietal and visual cortices were correlated with frontal monitoring processes. By combining computational and neuroimaging approaches, our results advance a mechanistic understanding of memory strength in recognition. What neural processes give rise to memory strength signals, and lead to our conscious feelings of familiarity? Using fMRI, we found that the memory strength of a given item depends not only on how it was encoded during learning, but also on the similarity of its neural representation with other studied items. The global neural matching signal, mainly in the parietal lobule, could account for the memory strengths of both studied and unstudied items. Interestingly, a different global matching signal, originated from the visual cortex, could distinguish true from false memories. The findings reveal multiple neural mechanisms underlying the memory strengths of events registered in the brain. Copyright © 2016 the authors 0270-6474/16/366792-11$15.00/0.

  3. Peripheral mechanisms for vocal production in birds - differences and similarities to human speech and singing.

    PubMed

    Riede, Tobias; Goller, Franz

    2010-10-01

    Song production in songbirds is a model system for studying learned vocal behavior. As in humans, bird phonation involves three main motor systems (respiration, vocal organ and vocal tract). The avian respiratory mechanism uses pressure regulation in air sacs to ventilate a rigid lung. In songbirds sound is generated with two independently controlled sound sources, which reside in a uniquely avian vocal organ, the syrinx. However, the physical sound generation mechanism in the syrinx shows strong analogies to that in the human larynx, such that both can be characterized as myoelastic-aerodynamic sound sources. Similarities include active adduction and abduction, oscillating tissue masses which modulate flow rate through the organ and a layered structure of the oscillating tissue masses giving rise to complex viscoelastic properties. Differences in the functional morphology of the sound producing system between birds and humans require specific motor control patterns. The songbird vocal apparatus is adapted for high speed, suggesting that temporal patterns and fast modulation of sound features are important in acoustic communication. Rapid respiratory patterns determine the coarse temporal structure of song and maintain gas exchange even during very long songs. The respiratory system also contributes to the fine control of airflow. Muscular control of the vocal organ regulates airflow and acoustic features. The upper vocal tract of birds filters the sounds generated in the syrinx, and filter properties are actively adjusted. Nonlinear source-filter interactions may also play a role. The unique morphology and biomechanical system for sound production in birds presents an interesting model for exploring parallels in control mechanisms that give rise to highly convergent physical patterns of sound generation. More comparative work should provide a rich source for our understanding of the evolution of complex sound producing systems. Copyright © 2009 Elsevier Inc. All rights reserved.

  4. Apparent Genetic Complexity Generated by Developmental Thresholds: The Apterous Locus in DROSOPHILA MELANOGASTER

    PubMed Central

    Stevens, Mary E.; Bryant, Peter J.

    1985-01-01

    Mutations at the apterous (ap) locus in Drosophila melanogaster give rise to three distinct phenotypes: aberrant wings, female sterility and precocious adult death. The wing phenotype includes five types of abnormality: blistering, deficiencies, duplications, high-order repetitions and transformation of structures. The mildest phenotype is seen with homozygous apblt animals which have either normal or slightly blistered wings. Most alleles produce, in the homozygote, a deficient wing in which part or all of the wing margin and wing blade is missing, but wing hinge and notum regions are normal. Animals hemizygous for each of 20 ap alleles, as well as apID/apXa heterozygotes, show duplication of parts of the notum associated with complete wing deficiency. Animals heterozygous for apc and the other tested ap alleles show repetitions of parts of the anterior wing margin, an engrailed-like transformation of posterior wing margin into anterior margin or both. Both apblt and apc show similar phenotypes in homozygotes and hemizygotes, yet both produce a less extreme phenotype than that of the other hemizygotes, suggesting that neither mutation causes loss of the entire ap+ function. The 15 alleles that cause precocious death and female sterility occur in six complementation groups based on complementation for these phenotypes. This supports the previous conclusion that the effects of apterous mutations on the wing do not correlate with their effects on viability and fertility. We propose an explanation for the effects of apterous mutations on the wing in which quantitative reductions in the activity of gene product give rise to qualitatively different phenotypes because of different threshold requirements of the ap+ function for critical events in wing disc development. PMID:3924726

  5. Colony variation of Helicobacter pylori: pathogenic potential is correlated to cell wall lipid composition.

    PubMed

    Bukholm, G; Tannaes, T; Nedenskov, P; Esbensen, Y; Grav, H J; Hovig, T; Ariansen, S; Guldvog, I

    1997-05-01

    Differences in expression of disease after infection with Helicobacter pylori have so far been connected with host factors and bacterial interstrain variation. In this study, spontaneous and ecology-mediated intrastrain variation was examined. Four clinical isolates of H. pylori were shown to give rise to two colony forms. Bacterial morphology was examined by electron microscopy. Bacterial fractions were examined for proteins using ion exchange chromatography and SDS-PAGE; for lipids using thin-layer chromatography, lipid anion-exchange chromatography, column chromatography on silica gel, 31P-NMR, gas chromatography and mass spectrometry. Bacterial in vitro invasiveness and adhesiveness were examined in two different systems, and urease and VacA toxin were assayed by Western blot analysis. H. pylori was shown to give rise to two colony forms: at normal pH the population was dominated by L colonies. One strain was chosen for further studies. Bacteria from L colonies retained VacA toxin and urease, did not invade or adhere to epithelial cells, and contained normal quantities of phosphatidylethanolamine. In a small frequency, spontaneous S colonies were formed. Bacteria from these colonies released VacA and urease, adhered to and invaded epithelial cells and contained increased amounts of lysophosphatidyl ethanolamine and phosphatidyl serine. After addition of HCl to the culture medium (pH6), almost only S colonies were formed. The results demonstrate that environmental factors, such as HCl, can change the bacterial cell wall, and thereby enhance expression of virulence factors of H. pylori in vitro. A similar in vivo variation would have implications for our understanding of the interaction between HCl secretion in the gastric mucosa and H. pylori in the development of peptic ulcer disease.

  6. Applications of pressure-sensitive dielectric elastomer sensors

    NASA Astrophysics Data System (ADS)

    Böse, Holger; Ocak, Deniz; Ehrlich, Johannes

    2016-04-01

    Dielectric elastomer sensors for the measurement of compression loads with high sensitivity are described. The basic design of the sensors exhibits two profiled surfaces between which an elastomer film is confined. All components of the sensor were prepared with silicone whose stiffness can be varied in a wide range. Depending on details of the sensor design, various effects contribute to the enhancement of the capacitance. The intermediate elastomer film is stretched upon compression and electrode layers on the elastomer profiles and in the elastomer film approach each other. Different designs of the pressure sensor give rise to very different sensor characteristics in terms of the dependence of electric capacitance on compression force. Due to their inherent flexibility, the pressure sensors can be used on compliant substrates such as seats or beds or on the human body. This gives rise to numerous possible applications. The contribution describes also some examples of possible sensor applications. A glove was equipped with various sensors positioned at the finger tips. When grabbing an object with the glove, the sensors can detect the gripping forces of the individual fingers with high sensitivity. In a demonstrator of the glove equipped with seven sensors, the capacitances representing the gripping forces are recorded on a display. In another application example, a lower limb prosthesis was equipped with a pressure sensor to detect the load on the remaining part of the leg and the load is displayed in terms of the measured capacitance. The benefit of such sensors is to detect an eventual overload in order to prevent possible pressure sores. A third example introduces a seat load sensor system based on four extended pressure sensor mats. The sensor system detects the load distribution of a person on the seat. The examples emphasize the high performance of the new pressure sensor technology.

  7. A mathematical model of breast cancer development, local treatment and recurrence.

    PubMed

    Enderling, Heiko; Chaplain, Mark A J; Anderson, Alexander R A; Vaidya, Jayant S

    2007-05-21

    Cancer development is a stepwise process through which normal somatic cells acquire mutations which enable them to escape their normal function in the tissue and become self-sufficient in survival. The number of mutations depends on the patient's age, genetic susceptibility and on the exposure of the patient to carcinogens throughout their life. It is believed that in every malignancy 4-6 crucial similar mutations have to occur on cancer-related genes. These genes are classified as oncogenes and tumour suppressor genes (TSGs) which gain or lose their function respectively, after they have received one mutative hit or both of their alleles have been knocked out. With the acquisition of each of the necessary mutations the transformed cell gains a selective advantage over normal cells, and the mutation will spread throughout the tissue via clonal expansion. We present a simplified model of this mutation and expansion process, in which we assume that the loss of two TSGs is sufficient to give rise to a cancer. Our mathematical model of the stepwise development of breast cancer verifies the idea that the normal mutation rate in genes is only sufficient to give rise to a tumour within a clinically observable time if a high number of breast stem cells and TSGs exist or genetic instability is involved as a driving force of the mutation pathway. Furthermore, our model shows that if a mutation occurred in stem cells pre-puberty, and formed a field of cells with this mutation through clonal formation of the breast, it is most likely that a tumour will arise from within this area. We then apply different treatment strategies, namely surgery and adjuvant external beam radiotherapy and targeted intraoperative radiotherapy (TARGIT) and use the model to identify different sources of local recurrence and analyse their prevention.

  8. High-Fat Diet Reduces the Formation of Butyrate, but Increases Succinate, Inflammation, Liver Fat and Cholesterol in Rats, while Dietary Fibre Counteracts These Effects

    PubMed Central

    Jakobsdottir, Greta; Xu, Jie; Molin, Göran; Ahrné, Siv; Nyman, Margareta

    2013-01-01

    Introduction Obesity is linked to type 2 diabetes and risk factors associated to the metabolic syndrome. Consumption of dietary fibres has been shown to have positive metabolic health effects, such as by increasing satiety, lowering blood glucose and cholesterol levels. These effects may be associated with short-chain fatty acids (SCFAs), particularly propionic and butyric acids, formed by microbial degradation of dietary fibres in colon, and by their capacity to reduce low-grade inflammation. Objective To investigate whether dietary fibres, giving rise to different SCFAs, would affect metabolic risk markers in low-fat and high-fat diets using a model with conventional rats for 2, 4 and 6 weeks. Material and Methods Conventional rats were administered low-fat or high-fat diets, for 2, 4 or 6 weeks, supplemented with fermentable dietary fibres, giving rise to different SCFA patterns (pectin – acetic acid; guar gum – propionic acid; or a mixture – butyric acid). At the end of each experimental period, liver fat, cholesterol and triglycerides, serum and caecal SCFAs, plasma cholesterol, and inflammatory cytokines were analysed. The caecal microbiota was analysed after 6 weeks. Results and Discussion Fermentable dietary fibre decreased weight gain, liver fat, cholesterol and triglyceride content, and changed the formation of SCFAs. The high-fat diet primarily reduced formation of SCFAs but, after a longer experimental period, the formation of propionic and acetic acids recovered. The concentration of succinic acid in the rats increased in high-fat diets with time, indicating harmful effect of high-fat consumption. The dietary fibre partly counteracted these harmful effects and reduced inflammation. Furthermore, the number of Bacteroides was higher with guar gum, while noticeably that of Akkermansia was highest with the fibre-free diet. PMID:24236183

  9. Is the gap between micro- and macroeconomic assessments in health care well understood? The case of vaccination and potential remedies

    PubMed Central

    Kotsopoulos, Nikolaos; Connolly, Mark P.

    2014-01-01

    Vaccination is an established intervention that reduces the burden and prevents the spread of infectious diseases. Investing in vaccination is known to offer a wide range of economic and intangible benefits that can potentiate gains for the individual and for society. The discipline of economics provides us with microeconomic and macroeconomic methods for evaluating the economic gains attributed to health status changes. However, the observed gap between micro and macro estimates attributed to health presents challenges to our understanding of health-related productivity changes and, consequently, economic benefits. The gap suggests that the manner in which health-related productive output is quantified in microeconomic models might not adequately reflect the broader economic benefit. We propose that there is a transitional domain that links the micro- and macroeconomic improvement attributed to health status changes. Currently available economic evaluation methods typically omit these consequences, however; they may be adjusted to integrate these transitional consequences. In practical terms, this may give rise to multipliers to apply toward indirect costs to account for the broader macroeconomic benefits linked to changes in health status. In addition, it is possible to consider that different medical conditions and health care interventions may pose different multiplying effects, suggesting that the manner in which resources are allocated within health services gives rise to variation in the amount of the micro–macro gap. An interesting way to move forward in integrating the micro- and macro-level assessment might be by integrating computable general equilibrium (CGE) models as part of the evaluation framework, as was recently performed for pandemic flu and malaria vaccination. PMID:27226842

  10. Is the gap between micro- and macroeconomic assessments in health care well understood? The case of vaccination and potential remedies.

    PubMed

    Kotsopoulos, Nikolaos; Connolly, Mark P

    2014-01-01

    Vaccination is an established intervention that reduces the burden and prevents the spread of infectious diseases. Investing in vaccination is known to offer a wide range of economic and intangible benefits that can potentiate gains for the individual and for society. The discipline of economics provides us with microeconomic and macroeconomic methods for evaluating the economic gains attributed to health status changes. However, the observed gap between micro and macro estimates attributed to health presents challenges to our understanding of health-related productivity changes and, consequently, economic benefits. The gap suggests that the manner in which health-related productive output is quantified in microeconomic models might not adequately reflect the broader economic benefit. We propose that there is a transitional domain that links the micro- and macroeconomic improvement attributed to health status changes. Currently available economic evaluation methods typically omit these consequences, however; they may be adjusted to integrate these transitional consequences. In practical terms, this may give rise to multipliers to apply toward indirect costs to account for the broader macroeconomic benefits linked to changes in health status. In addition, it is possible to consider that different medical conditions and health care interventions may pose different multiplying effects, suggesting that the manner in which resources are allocated within health services gives rise to variation in the amount of the micro-macro gap. An interesting way to move forward in integrating the micro- and macro-level assessment might be by integrating computable general equilibrium (CGE) models as part of the evaluation framework, as was recently performed for pandemic flu and malaria vaccination.

  11. Polarization curve measurements combined with potential probe sensing for determining current density distribution in vanadium redox-flow batteries

    NASA Astrophysics Data System (ADS)

    Becker, Maik; Bredemeyer, Niels; Tenhumberg, Nils; Turek, Thomas

    2016-03-01

    Potential probes are applied to vanadium redox-flow batteries for determination of effective felt resistance and current density distribution. During the measurement of polarization curves in 100 cm2 cells with different carbon felt compression rates, alternating potential steps at cell voltages between 0.6 V and 2.0 V are applied. Polarization curves are recorded at different flow rates and states of charge of the battery. Increasing compression rates lead to lower effective felt resistances and a more uniform resistance distribution. Low flow rates at high or low state of charge result in non-linear current density distribution with high gradients, while high flow rates give rise to a nearly linear behavior.

  12. Fabrication of photonic crystal microprisms based on artificial opals

    NASA Astrophysics Data System (ADS)

    Fenollosa, Roberto; Ibisate, Marta; Rubio, Silvia; Lopez, Ceferino; Meseguer, Francisco; Sanchez-Dehesa, Jose

    2002-04-01

    This paper reports a new method for faceting artificial opals based on micromanipulation techniques. By this means it was possible to fabricate an opal prism in a single domain with different faces: (111), (110) and (100), which were characterized by Scanning Electron Microscopy and Optical Reflectance Spectroscopy. Their spectra exhibit different characteristics depending on the orientation of the facet. While (111)-oriented face gives rise to a high Bragg reflection peak at about a/(lambda) equals 0.66 (where a is the lattice parameter), (110) and (100) faces show much less intense peaks corresponding to features in the band structure at a/(lambda) equals 1.12 and a/(lambda) equals 1.07 respectively. Peaks at higher energies have less obvious explanation.

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

    Tsvelik, A. M.; Yevtushenko, O. M.

    We study the low energy physics of a Kondo chain where electrons from a one-dimensional band interact with magnetic moments via an anisotropic exchange interaction. It is demonstrated that the anisotropy gives rise to two different phases which are separated by a quantum phase transition. In the phase with easy plane anisotropy, Z2 symmetry between sectors with different helicity of the electrons is broken. As a result, localization effects are suppressed and the dc transport acquires (partial) symmetry protection. This effect is similar to the protection of the edge transport in time-reversal invariant topological insulators. The phase with easy axismore » anisotropy corresponds to the Tomonaga-Luttinger liquid with a pronounced spin-charge separation. The slow charge density wave modes have no protection against localizatioin.« less

  14. In silico gene expression profiling in Cannabis sativa.

    PubMed

    Massimino, Luca

    2017-01-01

    The cannabis plant and its active ingredients (i.e., cannabinoids and terpenoids) have been socially stigmatized for half a century. Luckily, with more than 430,000 published scientific papers and about 600 ongoing and completed clinical trials, nowadays cannabis is employed for the treatment of many different medical conditions. Nevertheless, even if a large amount of high-throughput functional genomic data exists, most researchers feature a strong background in molecular biology but lack advanced bioinformatics skills. In this work, publicly available gene expression datasets have been analyzed giving rise to a total of 40,224 gene expression profiles taken from cannabis plant tissue at different developmental stages. The resource presented here will provide researchers with a starting point for future investigations with Cannabis sativa .

  15. Posttranscriptional (Re)programming of Cell Fate: Examples in Stem Cells, Progenitor, and Differentiated Cells.

    PubMed

    Kanellopoulou, Chrysi; Muljo, Stefan A

    2018-01-01

    How a single genome can give rise to many different transcriptomes and thus all the different cell lineages in the human body is a fundamental question in biology. While signaling pathways, transcription factors, and chromatin architecture, to name a few determinants, have been established to play critical roles, recently, there is a growing appreciation of the roles of non-coding RNAs and RNA-binding proteins in controlling cell fates posttranscriptionally. Thus, it is vital that these emerging players are also integrated into models of gene regulatory networks that underlie programs of cellular differentiation. Sometimes, we can leverage knowledge about such posttranscriptional circuits to reprogram patterns of gene expression in meaningful ways. Here, we review three examples from our work.

  16. Emergence of Soft Communities from Geometric Preferential Attachment

    PubMed Central

    Zuev, Konstantin; Boguñá, Marián; Bianconi, Ginestra; Krioukov, Dmitri

    2015-01-01

    All real networks are different, but many have some structural properties in common. There seems to be no consensus on what the most common properties are, but scale-free degree distributions, strong clustering, and community structure are frequently mentioned without question. Surprisingly, there exists no simple generative mechanism explaining all the three properties at once in growing networks. Here we show how latent network geometry coupled with preferential attachment of nodes to this geometry fills this gap. We call this mechanism geometric preferential attachment (GPA), and validate it against the Internet. GPA gives rise to soft communities that provide a different perspective on the community structure in networks. The connections between GPA and cosmological models, including inflation, are also discussed. PMID:25923110

  17. Jet impact on a soap film

    NASA Astrophysics Data System (ADS)

    Kirstetter, Geoffroy; Raufaste, Christophe; Celestini, Franck

    2012-09-01

    We experimentally investigate the impact of a liquid jet on a soap film. We observe that the jet never breaks the film and that two qualitatively different steady regimes may occur. The first one is a refractionlike behavior obtained at small incidence angles when the jet crosses the film and is deflected by the film-jet interaction. For larger incidence angles, the jet is absorbed by the film, giving rise to a new class of flows in which the jet undulates along the film with a characteristic wavelength. Besides its fundamental interest, this paper presents a different way to guide a micrometric flow of liquid in the inertial regime and to probe foam stability submitted to violent perturbations at the soap film scale.

  18. Jet impact on a soap film.

    PubMed

    Kirstetter, Geoffroy; Raufaste, Christophe; Celestini, Franck

    2012-09-01

    We experimentally investigate the impact of a liquid jet on a soap film. We observe that the jet never breaks the film and that two qualitatively different steady regimes may occur. The first one is a refractionlike behavior obtained at small incidence angles when the jet crosses the film and is deflected by the film-jet interaction. For larger incidence angles, the jet is absorbed by the film, giving rise to a new class of flows in which the jet undulates along the film with a characteristic wavelength. Besides its fundamental interest, this paper presents a different way to guide a micrometric flow of liquid in the inertial regime and to probe foam stability submitted to violent perturbations at the soap film scale.

  19. Attention Modulates Spatio-temporal Grouping

    PubMed Central

    Aydın, Murat; Herzog, Michael H.; Öğmen, Haluk

    2011-01-01

    Dynamic stimuli are ubiquitous in natural viewing conditions implying that grouping operations need to operate, not only in space, but also jointly in space and time. Moreover, in natural viewing, attention plays an important role in controlling how resources are allocated. We investigated how attention interacts with spatiotemporal perceptual grouping by using a bistable stimulus, called the Ternus-Pikler display. Ternus-Pikler displays can give rise to two different motion percepts, called Element Motion (EM) and Group Motion (GM), the former dominating at short Inter-Stimulus Intervals (ISIs) and the latter at long ISIs. Our results indicate that GM grouping requires more attentional resources than EM grouping. Different theoretical accounts of perceptual grouping and attention are discussed and evaluated in the light of the current results. PMID:21266181

  20. Quaternions, Torsion and the Physical Vacuum: Theories of M. Sachs and G. Shipov Compared

    NASA Astrophysics Data System (ADS)

    Cyganski, David; Page, William S.

    Of several developments of unified field theories in the spirit of Einstein's original objective of a fully geometric description of all classical fields as well as quantum mechanics, two are particularly noteworthy. The works of Mendel Sachs and Gennady Shipov stand apart as major life works comprising tens of papers, several monographs and decades of effort. Direct comparison of these theories is hampered however by differences in notation and conceptual view-point. Despite these differences, there are many parallels between the fundamental mathematical structures appearing in each. In this paper we discuss the main tenets of the two approaches and demonstrate that they both give rise to a factorization of the invariant interval of general relativity.

  1. Vibrational and vibronic coherences in the dynamics of the FMO complex

    NASA Astrophysics Data System (ADS)

    Liu, Xiaomeng; Kühn, Oliver

    2016-12-01

    The coupled exciton-vibrational dynamics of a seven site Frenkel exciton model of the Fenna-Matthews-Olson (FMO) complex is investigated using a Quantum Master Equation approach. Thereby, one vibrational mode per monomer is treated explicitly as being part of the relevant system. Emphasis is put on the comparison of this model with that of a purely excitonic relevant system. Further, the effects of two different approximations to the exciton-vibrational basis are investigated, namely the one- and two-particle description. Analysis of the vibronic and vibrational density matrix in the site basis points to the importance of on- and inter-site coherences for the exciton transfer. Here, one- and two-particle approximations give rise to qualitatively different results.

  2. Motility versus fluctuations in mixtures of self-motile and passive agents.

    PubMed

    Hinz, Denis F; Panchenko, Alexander; Kim, Tae-Yeon; Fried, Eliot

    2014-12-07

    Many biological systems consist of self-motile and passive agents both of which contribute to overall functionality. However, little is known about the properties of such mixtures. Here we formulate a model for mixtures of self-motile and passive agents and show that the model gives rise to three different dynamical phases: a disordered mesoturbulent phase, a polar flocking phase, and a vortical phase characterized by large-scale counter rotating vortices. We use numerical simulations to construct a phase diagram and compare the statistical properties of the different phases with observed features of self-motile bacterial suspensions. Our findings afford specific insights regarding the interaction of microorganisms and passive particles and provide novel strategic guidance for efficient technological realizations of artificial active matter.

  3. Talking about stigma towards mental health professionals with psychiatry trainees: a movie club approach.

    PubMed

    Kalra, Gurvinder

    2012-09-01

    Psychiatry as a discipline is often perceived as 'different' by other medical professionals as much as by a common man. This perception of 'difference' may give rise to stigma both towards mental illness and to mental health professionals. Mental health professionals are thus both recipients of stigma and agents who can de-stigmatize psychiatry. A psychiatry movie club approach can be a very useful learning experience to understand various aspects of this stigmatization process. This paper presents a brief account of such an endeavour in which the film Gothika (2003) was used to help psychiatry trainees talk about their experiences with stigma towards mental illness as well as their profession. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Effects of magnetic field strength in the discharge channel on the performance of a multi-cusped field thruster

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

    Hu, Peng; Liu, Hui; Gao, Yuanyuan

    The performance characteristics of a Multi-cusped Field Thruster depending on the magnetic field strength in the discharge channel were investigated. Four thrusters with different outer diameters of the magnet rings were designed to change the magnetic field strength in the discharge channel. It is found that increasing the magnetic field strength could restrain the radial cross-field electron current and decrease the radial width of main ionization region, which gives rise to the reduction of propellant utilization and thruster performance. The test results in different anode voltage conditions indicate that both the thrust and anode efficiency are higher for the weakermore » magnetic field in the discharge channel.« less

  5. Thermodynamics and emergent universe

    NASA Astrophysics Data System (ADS)

    Ghosh, Saumya; Gangopadhyay, Sunandan

    2017-05-01

    We show that in the isentropic scenario, the first-order thermodynamical particle creation model gives an emergent universe solution even when the chemical potential is nonzero. However, there exists no emergent universe scenario in the second-order non-equilibrium theory for the particle creation model. We then point out a correspondence between the particle creation model with barotropic equation of state and the equation of state giving rise to an emergent universe without particle creation in spatially flat FRW cosmology.

  6. Spacetimes with Killing tensors. [for Einstein-Maxwell fields with certain spinor indices

    NASA Technical Reports Server (NTRS)

    Hughston, L. P.; Sommers, P.

    1973-01-01

    The characteristics of the Killing equation and the Killing tensor are discussed. A conformal Killing tensor is of interest inasmuch as it gives rise to a quadratic first integral for null geodesic orbits. The Einstein-Maxwell equations are considered together with the Bianchi identity and the conformal Killing tensor. Two examples for the application of the considered relations are presented, giving attention to the charged Kerr solution and the charged C-metric.

  7. Multigenerational family structure in Japanese society: impacts on stress and health behaviors among women and men.

    PubMed

    Takeda, Yasuhisa; Kawachi, Ichiro; Yamagata, Zentaro; Hashimoto, Shuji; Matsumura, Yasuhiro; Oguri, Shigenori; Okayama, Akira

    2004-07-01

    Rapid population aging in Japan has led to rising demands for informal care giving. Traditionally, care giving for aging parents has fallen disproportionately on the shoulders of women living in multigenerational households. However, rising labor force participation by Japanese women, declining marriage and fertility rates, and women's changing expectations have combined to produce unprecedented strains on traditional multigenerational households where care giving to elders traditionally takes place. In this paper, we explored gender-specific relationships between family structure, stress and worries, and health behaviors, using linked data from two national surveys conducted in Japan: the 1995 Comprehensive Survey of the Living Conditions of People on Health and Welfare, and the 1995 National Nutrition Survey. We found that women in multigenerational households reported more care-giving worries, and also less future health and financial worries. Living with parents was associated with protective health behaviors (less smoking, less heavy drinking), but also more sedentary behavior among women, while men in "sandwich" families (i.e., living with both parents and children) reported heavier smoking. The association of family structure and health behavior was not mediated by worries. Living alone was associated with worse health for women. These findings suggest gender-specific patterns of worries and health behaviors that reflect both the health-protecting and health-damaging effects of living in multigenerational households. Copyright 2003 Elsevier Ltd.

  8. Charge transfer in photorefractive CdTe:Ge at different wavelengths

    NASA Astrophysics Data System (ADS)

    Shcherbin, K.; Odoulov, S.; Ramaz, F.; Farid, B.; Briat, B.; von Bardeleben, H. J.; Delaye, P.; Roosen, G.

    2001-10-01

    The charge transfer processes in photorefractive CdTe:Ge were modeled using the data of optical absorption, magnetic circular dichroism (MCD) and electron paramagnetic resonance (EPR) spectroscopies. Within the developed model the variations in the photorefractive properties of different CdTe:Ge samples are explained by differences in the relative concentrations of donor and trap centers. The existence of two different centers of comparable concentrations, each in two charge states, allows charge redistribution between them and gives rise to optical sensitization of some CdTe:Ge samples for photorefractive recording under an auxiliary illumination. In the present article we follow the proposal of pseudo-3D presentation of light-induced absorption to distinguish the main charge transfer processes at different excitation energies and explain the sensitization of CdTe:Ge for photorefractive recording at 1.06, 1.32 and 1.55 μm by light with appropriate wavelength.

  9. What makes the difference in perovskite titanates?

    NASA Astrophysics Data System (ADS)

    Bussmann-Holder, Annette; Roleder, Krystian; Ko, Jae-Hyeon

    2018-06-01

    We have investigated in detail the lattice dynamics of five different perovskite titanates ATiO3 (A = Ca, Sr, Ba, Pb, Eu) where the A sites are occupied by +2 ions. In spite of the largely ionic character of these ions, the properties of these compounds differ substantially. They range from order/disorder like, to displacive ferroelectric, quantum paraelectric, and antiferromagnetic. All compounds crystallize in the cubic structure at high temperature and undergo structural phase transitions to tetragonal symmetry, partly followed by further transitions to lower symmetries. Since the TiO6 moiety is the essential electronic and structural unit, the question arises, what makes the significant difference between them. It is shown that the lattice dynamics of these compounds are very different, and that mode-mode coupling effects give rise to many distinct properties. In addition, the oxygen ion nonlinear polarizability plays a key role since it dominates the anharmonicity of these perovskites and determines the structural instability.

  10. Pox neuro control of cell lineages that give rise to larval poly-innervated external sensory organs in Drosophila.

    PubMed

    Jiang, Yanrui; Boll, Werner; Noll, Markus

    2015-01-15

    The Pox neuro (Poxn) gene of Drosophila plays a crucial role in the development of poly-innervated external sensory (p-es) organs. However, how Poxn exerts this role has remained elusive. In this study, we have analyzed the cell lineages of all larval p-es organs, namely of the kölbchen, papilla 6, and hair 3. Surprisingly, these lineages are distinct from any previously reported cell lineages of sensory organs. Unlike the well-established lineage of mono-innervated external sensory (m-es) organs and a previously proposed model of the p-es lineage, we demonstrate that all wild-type p-es lineages exhibit the following features: the secondary precursor, pIIa, gives rise to all three support cells-socket, shaft, and sheath, whereas the other secondary precursor, pIIb, is neuronal and gives rise to all neurons. We further show that in one of the p-es lineages, that of papilla 6, one cell undergoes apoptosis. By contrast in Poxn null mutants, all p-es lineages have a reduced number of cells and their pattern of cell divisions is changed to that of an m-es organ, with the exception of a lineage in a minority of mutant kölbchen that retains a second bipolar neuron. Indeed, the role of Poxn in p-es lineages is consistent with the specification of the developmental potential of secondary precursors and the regulation of cell division but not apoptosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Malignant pericytes expressing GT198 give rise to tumor cells through angiogenesis.

    PubMed

    Zhang, Liyong; Wang, Yan; Rashid, Mohammad H; Liu, Min; Angara, Kartik; Mivechi, Nahid F; Maihle, Nita J; Arbab, Ali S; Ko, Lan

    2017-08-01

    Angiogenesis promotes tumor development. Understanding the crucial factors regulating tumor angiogenesis may reveal new therapeutic targets. Human GT198 ( PSMC3IP or Hop2) is an oncoprotein encoded by a DNA repair gene that is overexpressed in tumor stromal vasculature to stimulate the expression of angiogenic factors. Here we show that pericytes expressing GT198 give rise to tumor cells through angiogenesis. GT198 + pericytes and perivascular cells are commonly present in the stromal compartment of various human solid tumors and rodent xenograft tumor models. In human oral cancer, GT198 + pericytes proliferate into GT198 + tumor cells, which migrate into lymph nodes. Increased GT198 expression is associated with increased lymph node metastasis and decreased progression-free survival in oral cancer patients. In rat brain U-251 glioblastoma xenografts, GT198 + pericytes of human tumor origin encase endothelial cells of rat origin to form mosaic angiogenic blood vessels, and differentiate into pericyte-derived tumor cells. The net effect is continued production of glioblastoma tumor cells from malignant pericytes via angiogenesis. In addition, activation of GT198 induces the expression of VEGF and promotes tube formation in cultured U251 cells. Furthermore, vaccination using GT198 protein as an antigen in mouse xenograft of GL261 glioma delayed tumor growth and prolonged mouse survival. Together, these findings suggest that GT198-expressing malignant pericytes can give rise to tumor cells through angiogenesis, and serve as a potential source of cells for distant metastasis. Hence, the oncoprotein GT198 has the potential to be a new target in anti-angiogenic therapies in human cancer.

  12. Non-Condon equilibrium Fermi’s golden rule electronic transition rate constants via the linearized semiclassical method

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

    Sun, Xiang; Geva, Eitan

    2016-06-28

    In this paper, we test the accuracy of the linearized semiclassical (LSC) expression for the equilibrium Fermi’s golden rule rate constant for electronic transitions in the presence of non-Condon effects. We do so by performing a comparison with the exact quantum-mechanical result for a model where the donor and acceptor potential energy surfaces are parabolic and identical except for shifts in the equilibrium energy and geometry, and the coupling between them is linear in the nuclear coordinates. Since non-Condon effects may or may not give rise to conical intersections, both possibilities are examined by considering: (1) A modified Garg-Onuchic-Ambegaokar modelmore » for charge transfer in the condensed phase, where the donor-acceptor coupling is linear in the primary mode coordinate, and for which non-Condon effects do not give rise to a conical intersection; (2) the linear vibronic coupling model for electronic transitions in gas phase molecules, where non-Condon effects give rise to conical intersections. We also present a comprehensive comparison between the linearized semiclassical expression and a progression of more approximate expressions. The comparison is performed over a wide range of frictions and temperatures for model (1) and over a wide range of temperatures for model (2). The linearized semiclassical method is found to reproduce the exact quantum-mechanical result remarkably well for both models over the entire range of parameters under consideration. In contrast, more approximate expressions are observed to deviate considerably from the exact result in some regions of parameter space.« less

  13. Volcanic tremor masks its seismogenic source: Results from a study of noneruptive tremor recorded at Mount St. Helens, Washington

    USGS Publications Warehouse

    Denlinger, Roger P.; Moran, Seth C.

    2014-01-01

    On 2 October 2004, a significant noneruptive tremor episode occurred during the buildup to the 2004–2008 eruption of Mount St. Helens (Washington). This episode was remarkable both because no explosion followed, and because seismicity abruptly stopped following the episode. This sequence motivated us to consider a model for volcanic tremor that does not involve energetic gas release from magma but does involve movement of conduit magma through extension on its way toward the surface. We found that the tremor signal was composed entirely of Love and Rayleigh waves and that its spectral bandwidth increased and decreased with signal amplitude, with broader bandwidth signals containing both higher and lower frequencies. Our modeling results demonstrate that the forces giving rise to this tremor were largely normal to conduit walls, generating hybrid head waves along conduit walls that are coupled to internally reflected waves. Together these form a crucial part of conduit resonance, giving tremor wavefields that are largely a function of waveguide geometry and velocity. We find that the mechanism of tremor generation fundamentally masks the nature of the seismogenic source giving rise to resonance. Thus multiple models can be invoked to explain volcanic tremor, requiring that information from other sources (such as visual observations, geodesy, geology, and gas geochemistry) be used to constrain source models. With concurrent GPS and field data supporting rapid rise of magma, we infer that tremor resulted from drag of nearly solid magma along rough conduit walls as magma was forced toward the surface.

  14. Electrothermal vaporization of mineral acid solutions in inductively coupled plasma mass spectrometry: comparison with sample nebulization

    NASA Astrophysics Data System (ADS)

    Mora, Juan; Gras, Luis; van Veen, Eric H.; de Loos-Vollebregt, Margaretha T. C.

    1999-06-01

    The analytical behaviour of an electrothermal vaporization (ETV) device for the introduction of mineral acid solutions in inductively coupled plasma mass spectrometry (ICP-MS) was evaluated. Water, nitric acid, hydrochloric acid, perchloric acid and sulphuric acid in concentrations within the 0.05-1.0 mol l-1 range were studied. For all the acids tested, increasing the acid concentration increases the ion signal and deteriorates the precision. The magnitude of the signal enhancement depends on the analyte and on the acid considered. Acid solutions give rise to ion signals that are between 2 and 10 times higher than those with water. Among the acids tested, sulphuric acid provides the highest signals. The addition of palladium reduces matrix effects due to the acids and increases the signal in ETV ICP-MS. In comparison with conventional sample nebulization (CS), the ETV sample introduction system provides higher sensitivities (between 2 and 20 times higher) at the same acid concentration. The magnitude of this improvement is similar to that obtained with a microwave desolvation system (MWDS). The ETV sample introduction system gives rise to the lowest background signals from matrix-induced species. Due to this fact, the limits of detection (LODs) obtained for the isotopes affected by any interference are lower for ETV sample introduction than those obtained with the CS and the MWDS. For the isotopes that do not suffer from matrix-induced spectral interferences, the ETV gives rise to LODs higher than those obtained with the CS. For these isotopes the lowest LODs are obtained with MWDS.

  15. Trimethylamine and Trimethylamine N-Oxide, a Flavin-Containing Monooxygenase 3 (FMO3)-Mediated Host-Microbiome Metabolic Axis Implicated in Health and Disease

    PubMed Central

    Fennema, Diede; Phillips, Ian R.

    2016-01-01

    Flavin-containing monooxygenase 3 (FMO3) is known primarily as an enzyme involved in the metabolism of therapeutic drugs. On a daily basis, however, we are exposed to one of the most abundant substrates of the enzyme trimethylamine (TMA), which is released from various dietary components by the action of gut bacteria. FMO3 converts the odorous TMA to nonodorous TMA N-oxide (TMAO), which is excreted in urine. Impaired FMO3 activity gives rise to the inherited disorder primary trimethylaminuria (TMAU). Affected individuals cannot produce TMAO and, consequently, excrete large amounts of TMA. A dysbiosis in gut bacteria can give rise to secondary TMAU. Recently, there has been much interest in FMO3 and its catalytic product, TMAO, because TMAO has been implicated in various conditions affecting health, including cardiovascular disease, reverse cholesterol transport, and glucose and lipid homeostasis. In this review, we consider the dietary components that can give rise to TMA, the gut bacteria involved in the production of TMA from dietary precursors, the metabolic reactions by which bacteria produce and use TMA, and the enzymes that catalyze the reactions. Also included is information on bacteria that produce TMA in the oral cavity and vagina, two key microbiome niches that can influence health. Finally, we discuss the importance of the TMA/TMAO microbiome-host axis in health and disease, considering factors that affect bacterial production and host metabolism of TMA, the involvement of TMAO and FMO3 in disease, and the implications of the host-microbiome axis for management of TMAU. PMID:27190056

  16. Microfabrication of a spider-silk analogue through the liquid rope coiling instability

    NASA Astrophysics Data System (ADS)

    Gosselin, Frederick P.; Therriault, Daniel; Levesque, Martin

    2012-02-01

    Spider capture silk outperforms most synthetic materials in terms of specific toughness. We developed a technique to fabricate tough microstructured fibers inspired by the molecular structure of the spider silk protein. To fabricate microfibers (with diameter ˜30μm) with various mechanical properties, we yield the control of their exact geometry to the liquid rope coiling instability. This instability causes a thread of honey to wiggle as it buckles when hitting a surface. Similarly, we flow a filament of viscous polymer solution towards a substrate moving perpendicularly at a slower velocity than the filament flows. The filament buckles repetitively giving rise to periodic meanders and stitch patterns. As the solvent evaporates, the filament solidifies into a fiber with a geometry bestowed by the instability. Microtraction tests performed on fibers show interesting links between the mechanical properties and the instability patterns. Some coiling patterns give rise to high toughness due to the sacrificial bonds created when the viscous filament loops over itself and fuse. The sacrificial bonds in the microstructured fiber play an analogous role to that of the hydrogen bonds present in the molecular structure of the silk protein which give its toughness to spider silk.

  17. Probing Massive Star Cluster Formation with ALMA

    NASA Astrophysics Data System (ADS)

    Johnson, Kelsey

    2015-08-01

    Observationally constraining the physical conditions that give rise to massive star clusters has been a long-standing challenge. Now with the ALMA Observatory coming on-line, we can finally begin to probe the birth environments of massive clusters in a variety of galaxies with sufficient angular resolution. In this talk I will give an overview of ALMA observations of galaxies in which candidate proto-super star cluster molecular clouds have been identified. These new data probe the physical conditions that give rise to super star clusters, providing information on their densities, pressures, and temperatures. In particular, the observations indicate that these clouds may be subject to external pressures of P/k > 108 K cm-3, which is consistent with the prevalence of optically observed adolescent super star clusters in interacting galaxy systems and other high pressure environments. ALMA observations also enable an assessement of the molecular cloud chemical abundances in the regions surrounding super star clusters. Molecular clouds associated with existing super star clusters are strongly correlated with HCO+ emission, but appear to have relatively low ratio of CO/HCO+ emission compared to other clouds, indicating that the super star clusters are impacting the molecular abundances in their vicinity.

  18. Possible Connection of Geological Composition With Geomagnetic Field Change In Kopaonik Thrust Region

    NASA Astrophysics Data System (ADS)

    Popeskov, Mirjana; Cukavac, Milena; Lazovic, Caslav

    This paper should consider interpretation of geomagnetic field changes on the basis of possible connection with geological composition of deformation zone. Analysis of total magnetic field intensity data from 38 surveys, carried out in the period may 1980 ­ november 2001 in Kopaonik thrust region, central Serbia, reveals anomalous behaviour of local field changes in particular time intervals. These data give us possibility to observe geomagnetic changes in long period of time. This paper shall consider if and how different magnetizations of geological composition of array are in connection with anomalous geomagnetic field change. We shall consider how non-uniform geological structure or rocks with different magnetizations can effect geomagnetic observations and weather sharp contrast in rock magnetization between neighbour layers can give rise to larger changes in the geomagnetic total intensity than those for a uniform layer. For that purpose we are going to consider geological and tectonical map of Kopaonik region. We shall also consider map of vertical component of geomagnetic field because Kopaonik belongs to high magnetic anomaly zone. Corelation of geomagnetic and geological data is supposed to give us some answers to the question of origine of some anomalious geomagnetic changes in total intensity of geomagnetic field. It can also represent first step in corelationof geomagnetic field changes to other geophysical, seismological or geological data that can be couse of geomagnetic field change.

  19. Children's Exhaustive Readings of Questions

    ERIC Educational Resources Information Center

    Cremers, Alexandre; Tieu, Lyn; Chemla, Emmanuel

    2017-01-01

    Questions, just like plain declarative sentences, can give rise to multiple interpretations. As discussed by Spector & Egré (2015), among others, questions embedded under know are ambiguous between "weakly exhaustive" (WE), "intermediate exhaustive" (IE), and "strongly exhaustive" (SE) interpretations (for…

  20. A note on the Hyper-CR equation, and gauged N = 2 supergravity

    NASA Astrophysics Data System (ADS)

    Dunajski, Maciej; Gutowski, Jan; Sabra, Wafic

    2018-05-01

    We construct a new class of solutions to the dispersionless hyper-CR equation, and show how any solution to this equation gives rise to a supersymmetric Einstein-Maxwell cosmological space-time in (3 + 1)-dimensions.

  1. Cell biophysics: How to eat on the go

    NASA Astrophysics Data System (ADS)

    Levine, Herbert

    2016-12-01

    Dendritic cells use components of their cytoskeleton to both move and ingest pieces of infected cells. This competition for protein resources can give rise to a complex set of states that may be understood with an advection-diffusion model.

  2. Period changes in Centaurus X-3

    NASA Technical Reports Server (NTRS)

    Sparks, W. M.

    1975-01-01

    A number of mechanisms which can change the orbital period are applied to various models of Cen X-3. Only four models which give rise to feasible mechanisms are found. Possible observations which could distinguish between these models are suggested.

  3. Review of Diesel Odor and Toxic Vapor Emissions

    DOT National Transportation Integrated Search

    1981-05-01

    The purpose of the study was to attempt to assess the adequacy of the diesel engine exhaust chemical composition data base and instrumental analysis methods for the measurement of chemicals giving rise to sensory response, especially odor and irritat...

  4. 22 CFR 1006.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  5. 34 CFR 85.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., conviction, civil judgment, or other official findings by Federal, State, or local bodies that determine... protect the public interest either from the nature of the circumstances giving rise to a cause for...

  6. 22 CFR 208.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  7. 22 CFR 1508.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  8. 21 CFR 1404.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  9. 22 CFR 1508.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  10. 34 CFR 85.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., conviction, civil judgment, or other official findings by Federal, State, or local bodies that determine... protect the public interest either from the nature of the circumstances giving rise to a cause for...

  11. 21 CFR 1404.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  12. 29 CFR 98.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., conviction, civil judgment, or other official findings by Federal, State, or local bodies that determine... protect the public interest either from the nature of the circumstances giving rise to a cause for...

  13. 2 CFR 180.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  14. 22 CFR 1006.705 - What does the suspending official consider in issuing a suspension?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) An indictment, conviction, civil judgment, or other official findings by Federal, State, or local... immediate action to protect the public interest either from the nature of the circumstances giving rise to a...

  15. 10 CFR 1015.307 - Mutual releases of the debtor and the Government.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STATES Standards for the Compromise of Claims § 1015.307 Mutual releases of the debtor and the Government... action against the Government and its officials related to the transaction giving rise to the compromised...

  16. 10 CFR 1015.307 - Mutual releases of the debtor and the Government.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STATES Standards for the Compromise of Claims § 1015.307 Mutual releases of the debtor and the Government... action against the Government and its officials related to the transaction giving rise to the compromised...

  17. Reasoning About Security Models

    DTIC Science & Technology

    1987-01-01

    similaritiesthan “family resemblance”... Wittgenstein [1, $66-7] If a concept fundamental to a mighty science gives rise to difficulties,then it is...References L. Wittgenstein , Philosophical Investigations (translated by G. E. M. Anscombe), The Macmillan Company, New York, 1953. G. Frege, The

  18. The Evolution of Ecological Systems.

    ERIC Educational Resources Information Center

    May, Robert M.

    1978-01-01

    Discusses the coevaluation of species within ecosystems. This process gives rise to interesting patterns in the total number of species found in a given area, in their relative abundances, and in the overall structure of the local food web. (Author/MA)

  19. Noquitohedra

    ERIC Educational Resources Information Center

    Stephenson, Paul

    2010-01-01

    The ability of interlocking polygonal tiles, like those in the "Polydron Frameworks kit," to flex can give rise to polyhedra whose faces don't quite fit. In this article, the author discusses what happens with polyhedra whose faces don't quite fit. (Contains 2 notes.)

  20. The Adolescent Brain

    ERIC Educational Resources Information Center

    Casey, B. J.; Getz, Sarah; Galvan, Adriana

    2008-01-01

    Adolescence is a developmental period characterized by suboptimal decisions and actions that give rise to an increased incidence of unintentional injuries and violence, alcohol and drug abuse, unintended pregnancy and sexually transmitted diseases. Traditional neurobiological and cognitive explanations for adolescent behavior have failed to…

  1. Basement structures over Rio Grande Rise from gravity inversion

    NASA Astrophysics Data System (ADS)

    Constantino, Renata; Hackspacker, Peter Christian; Anderson de Souza, Iata; Sousa Lima Costa, Iago

    2017-04-01

    In this study, we show that from satellite-derived gravity field, bathymetry and sediment thicknesses, it is possible to give a 3-D model of the basement over oceanic areas, and for this purpose, we have chosen the Rio Grande Rise, in South Atlantic Ocean, to build a gravity-equivalent basement topography. The advantages of the method applied in this study are manifold: does not depend directly on reflection seismic data; can be applied quickly and with fewer costs for acquiring and interpreting the data; and as the main result, presents the physical surface below the sedimentary layer, which may be different from the acoustic basement. We evaluated the gravity effect of the sediments using the global sediment thickness model of NOAA, fitting a sediment compaction model to observed density values from Deep Sea Drilling Program (DSDP) reports. The Global Relief Model ETOPO1 and constraining data from seismic interpretation on crustal thickness are integrated in the gravity inversion procedure. The modeled Moho depth values vary between 6 to 27 km over the area, being thicker under the Rio Grande Rise and also in the direction of São Paulo Plateau. The inversion for the gravity-equivalent basement topography is applied for a gravity residual data, which is free from the gravity effect of sediments and from the gravity effect of the estimated Moho interface. A description of the basement depth over Rio Grande Rise area is unprecedented in the literature, however, our results could be compared to in situ data, provided by DSDP, and a small difference of only 9 m between our basement depth and leg 516 F was found. Our model shows a rift crossing the entire Rio Grande Rise deeper than previously presented in literature, with depths up to 5 km in the East Rio Grande Rise (ERGR) and deeper in the West Rio Grande Rise (WRGR), reaching 6.4 km. We find several short-wavelengths structures not present in the bathymetry data. Seamounts, guyots and fracture zones are much more clearly defined in the basement than in the bathymetric model. An interesting NS structure that goes from 34S and extends through de São Paulo Ridge is interpreted in the basement model, and we propose that this feature can be related to the South Atlantic opening, revealing an extinct spreading center.

  2. Forecasting the peak of the present solar activity cycle 24

    NASA Astrophysics Data System (ADS)

    Hamid, R. H.; Marzouk, B. A.

    2018-06-01

    Solar forecasting of the level of sun Activity is very important subject for all space programs. Most predictions are based on the physical conditions prevailing at or before the solar cycle minimum preceding the maximum in question. Our aim is to predict the maximum peak of cycle 24 using precursor techniques in particular those using spotless event, geomagnetic aamin. index and solar flux F10.7. Also prediction of exact date of the maximum (Tr) is taken in consideration. A study of variation over previous spotless event for cycles 7-23 and that for even cycles (8-22) are carried out for the prediction. Linear correlation between maximum of solar cycles (RM) and spotless event around the preceding minimum gives R24t = 88.4 with rise time Tr = 4.6 years. For the even cycles R24E = 77.9 with rise time Tr = 4.5 y's. Based on the average aamin. index for cycles (12-23), we estimate the expected amplitude for cycle 24 to be Raamin = 99.4 and 98.1 with time rise of Traamin = 4.04 & 4.3 years for both the total and even cycles in consecutive. The application of the data of solar flux F10.7 which cover only cycles (19-23) was taken in consideration and gives predicted maximum amplitude R24 10.7 = 126 with rise time Tr107 = 3.7 years, which are over estimation. Our result indicating to somewhat weaker of cycle 24 as compared to cycles 21-23.

  3. Implications of climate change for agricultural productivity in the early twenty-first century.

    PubMed

    Gornall, Jemma; Betts, Richard; Burke, Eleanor; Clark, Robin; Camp, Joanne; Willett, Kate; Wiltshire, Andrew

    2010-09-27

    This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty. Few global-scale assessments have been carried out, and these are limited in their ability to capture the uncertainty in climate projections, and omit potentially important aspects such as extreme events and changes in pests and diseases. There is a lack of clarity on how climate change impacts on drought are best quantified from an agricultural perspective, with different metrics giving very different impressions of future risk. The dependence of some regional agriculture on remote rainfall, snowmelt and glaciers adds to the complexity. Indirect impacts via sea-level rise, storms and diseases have not been quantified. Perhaps most seriously, there is high uncertainty in the extent to which the direct effects of CO(2) rise on plant physiology will interact with climate change in affecting productivity. At present, the aggregate impacts of climate change on global-scale agricultural productivity cannot be reliably quantified.

  4. Implications of climate change for agricultural productivity in the early twenty-first century

    PubMed Central

    Gornall, Jemma; Betts, Richard; Burke, Eleanor; Clark, Robin; Camp, Joanne; Willett, Kate; Wiltshire, Andrew

    2010-01-01

    This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty. Few global-scale assessments have been carried out, and these are limited in their ability to capture the uncertainty in climate projections, and omit potentially important aspects such as extreme events and changes in pests and diseases. There is a lack of clarity on how climate change impacts on drought are best quantified from an agricultural perspective, with different metrics giving very different impressions of future risk. The dependence of some regional agriculture on remote rainfall, snowmelt and glaciers adds to the complexity. Indirect impacts via sea-level rise, storms and diseases have not been quantified. Perhaps most seriously, there is high uncertainty in the extent to which the direct effects of CO2 rise on plant physiology will interact with climate change in affecting productivity. At present, the aggregate impacts of climate change on global-scale agricultural productivity cannot be reliably quantified. PMID:20713397

  5. More Than Words: The Role of Multiword Sequences in Language Learning and Use.

    PubMed

    Christiansen, Morten H; Arnon, Inbal

    2017-07-01

    The ability to convey our thoughts using an infinite number of linguistic expressions is one of the hallmarks of human language. Understanding the nature of the psychological mechanisms and representations that give rise to this unique productivity is a fundamental goal for the cognitive sciences. A long-standing hypothesis is that single words and rules form the basic building blocks of linguistic productivity, with multiword sequences being treated as units only in peripheral cases such as idioms. The new millennium, however, has seen a shift toward construing multiword linguistic units not as linguistic rarities, but as important building blocks for language acquisition and processing. This shift-which originated within theoretical approaches that emphasize language learning and use-has far-reaching implications for theories of language representation, processing, and acquisition. Incorporating multiword units as integral building blocks blurs the distinction between grammar and lexicon; calls for models of production and comprehension that can accommodate and give rise to the effect of multiword information on processing; and highlights the importance of such units to learning. In this special topic, we bring together cutting-edge work on multiword sequences in theoretical linguistics, first-language acquisition, psycholinguistics, computational modeling, and second-language learning to present a comprehensive overview of the prominence and importance of such units in language, their possible role in explaining differences between first- and second-language learning, and the challenges the combined findings pose for theories of language. Copyright © 2017 Cognitive Science Society, Inc.

  6. Osteoporosis and body composition.

    PubMed

    Crepaldi, G; Romanato, G; Tonin, P; Maggi, S

    2007-01-01

    The Epidemiologic Study on the Prevalence of Osteoporosis in Italy showed that the prevalence of osteoporosis among women and men aged 60 yr and over is 22.8% and 14.5%, respectively, giving rise to about 80,000 new fractures a yr. Sarcopenia is considered to be one of the main features of the aging process. It is characterized by a reduction in muscle mass and muscle strength, and affects women more than men. It is associated with a increased risk of fractures consequent upon a greater predisposition to falls, but also to the lack of bone remodeling due to reduced muscle mechanical strength. Muscle strength determines quality bone modifications such as density, strength, and microarchitecture. Variations in the ratios of cortical and muscle areas give rise to various types of osteoporosis, with different risks of fracture. Bone mineral density increases with body fat mass, and obesity has a protective effect against osteoporosis. This protective effect is explained by a combination of hormonal (peripheral aromatization of androgens to estrogens in adipose tissue) and mechanical factors (on weight-bearing bone sites), but the hormone leptin also probably mediates fat and bone mass. Serum leptin levels are closely related to body fat mass, and some findings suggest the peripheral effect of leptin, which exerts estrogenic effects, enhancing osteoblastic differentiation and inhibiting late adipocytic differentiation. The overall effect of leptin on bone results from a balance between negative central effects and positive direct peripheral effects, according to serum leptin levels.

  7. Predictions of the spontaneous symmetry-breaking theory for visual code completeness and spatial scaling in single-cell learning rules.

    PubMed

    Webber, C J

    2001-05-01

    This article shows analytically that single-cell learning rules that give rise to oriented and localized receptive fields, when their synaptic weights are randomly and independently initialized according to a plausible assumption of zero prior information, will generate visual codes that are invariant under two-dimensional translations, rotations, and scale magnifications, provided that the statistics of their training images are sufficiently invariant under these transformations. Such codes span different image locations, orientations, and size scales with equal economy. Thus, single-cell rules could account for the spatial scaling property of the cortical simple-cell code. This prediction is tested computationally by training with natural scenes; it is demonstrated that a single-cell learning rule can give rise to simple-cell receptive fields spanning the full range of orientations, image locations, and spatial frequencies (except at the extreme high and low frequencies at which the scale invariance of the statistics of digitally sampled images must ultimately break down, because of the image boundary and the finite pixel resolution). Thus, no constraint on completeness, or any other coupling between cells, is necessary to induce the visual code to span wide ranges of locations, orientations, and size scales. This prediction is made using the theory of spontaneous symmetry breaking, which we have previously shown can also explain the data-driven self-organization of a wide variety of transformation invariances in neurons' responses, such as the translation invariance of complex cell response.

  8. Major Chromosomal Rearrangements Distinguish Willow and Poplar After the Ancestral “Salicoid” Genome Duplication

    PubMed Central

    Hou, Jing; Ye, Ning; Dong, Zhongyuan; Lu, Mengzhu; Li, Laigeng; Yin, Tongming

    2016-01-01

    Populus (poplar) and Salix (willow) are sister genera in the Salicaceae family. In both lineages extant species are predominantly diploid. Genome analysis previously revealed that the two lineages originated from a common tetraploid ancestor. In this study, we conducted a syntenic comparison of the corresponding 19 chromosome members of the poplar and willow genomes. Our observations revealed that almost every chromosomal segment had a parallel paralogous segment elsewhere in the genomes, and the two lineages shared a similar syntenic pinwheel pattern for most of the chromosomes, which indicated that the two lineages diverged after the genome reorganization in the common progenitor. The pinwheel patterns showed distinct differences for two chromosome pairs in each lineage. Further analysis detected two major interchromosomal rearrangements that distinguished the karyotypes of willow and poplar. Chromosome I of willow was a conjunction of poplar chromosome XVI and the lower portion of poplar chromosome I, whereas willow chromosome XVI corresponded to the upper portion of poplar chromosome I. Scientists have suggested that Populus is evolutionarily more primitive than Salix. Therefore, we propose that, after the “salicoid” duplication event, fission and fusion of the ancestral chromosomes first give rise to the diploid progenitor of extant Populus species. During the evolutionary process, fission and fusion of poplar chromosomes I and XVI subsequently give rise to the progenitor of extant Salix species. This study contributes to an improved understanding of genome divergence after ancient genome duplication in closely related lineages of higher plants. PMID:27352946

  9. Use of contrast media in diagnostic imaging: medico-legal considerations.

    PubMed

    Pomara, C; Pascale, N; Maglietta, F; Neri, M; Riezzo, I; Turillazzi, E

    2015-09-01

    Contrast media (CM) are used in imaging techniques to enhance the differences between body tissues on images. The ideal contrast medium should achieve very high concentration in the tissues without producing any adverse effects. Unfortunately, this has not been possible so far and all CM have adverse effects. The increasing use of CM is likely to give rise to a wide range of pitfalls, including compliance with and appropriateness of indications for the use of CM themselves, the choice of the 'best' contrast agent, off-label use, evaluation of special populations of patients, and competence to tackle emergency scenarios following the administration of CM. Even more prominent, and potentially more important, is the issue of informed consent which brings with it a duty to inform patients awaiting the administration of CM with regard to the nature of the procedure, the existence of alternative procedures, the extent of the risks relating to the use of CM and, finally, the risks relating to refusal of the procedure. All these issues may give rise to concerns about liability for failure to offer adequate information to patients or to carefully evaluate and balance the potential risks and benefits of the procedure or, finally, for being unprepared in the event of adverse reactions to CM, especially when these are severe and life-threatening. Educational and training programmes for radiologists are likely to shape change in the medical liability environment in the coming years.

  10. Broad Absorption Lines in Qsos: Observations and Implications for Models.

    NASA Astrophysics Data System (ADS)

    Turnshek, David Alvin

    Spectroscopic observations of fourteen broad absorption line (BAL) QSOs are presented and analyzed. Other observations are summarized. The following major conclusions are reached. Broad absorption lines (BALs) are probably present in 3 to 10 percent of the spectra of moderate to high redshift QSOs. The BALs exhibit a variety of velocity structures, from seemingly smooth, continuous absorption to complexes of individual absorption lines. Outflow velocities up to 40,000 km s(' -1) are observed. The level of ionization is high. The minimum total absorption column densities are 10('20) to 10('22) cm('-2). The emission line properties of BAL QSOs appear to be different from those of non-BAL QSOs. For example, N V emission is generally stronger in BAL QSOs and the emission near C III} (lamda)1909 is generally broader in BAL QSOs. The distribution of multiplicities for isolated absorption troughs suggests that the large -scale spatial distribution of BAL clouds is non-random, possibly described by a disk geometry. The BAL clouds are incapable of accounting for all of the observed broad emission lines, particularly C III} (lamda)1909 and Mg II (lamda)2798. Therefore, if the BAL clouds give rise to observable emission, the generally adopted (optically thick, single component) model for the emission line region must be incorrect. Also, photoionization models, which utilize solar abundances and take the ionizing continuum to be a simple power law, are incapable of explaining the level of ionization in the BAL clouds. By considering the observed percentage of QSOs with BALs and resonance line scattering models, it is found that the absorption covering factor in BAL QSOs is between 3 and 20 percent. This suggests that possibly all, but not less than 15 percent, of the QSOs have BAL clouds associated with them. The amount of observable emission and polarization expected to be produced by the BAL clouds from resonance line scattering and collisional excitation is considered in detail. It seems likely that the BAL clouds contribute to the observed high ionization emission. A model worth exploring is one in which an inner, optically thick component gives rise to the low ionization emission, whereas an outer BAL cloud region gives rise to much of the high ionization emission.

  11. Hydridosiloxanes as precursors to ceramic products

    DOEpatents

    Blum, Yigal D.; Johnson, Sylvia M.; Gusman, Michael I.

    1997-01-01

    A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si--H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

  12. OBO-Protected Pyruvates as Reagents for the Synthesis of Functionalized Heteroaromatic Compounds.

    PubMed

    Alves Esteves, C Henrique; Koyioni, Maria; Christensen, Kirsten E; Smith, Peter D; Donohoe, Timothy J

    2018-06-15

    Pd-catalyzed α-arylation of methyl-OBO-ketone (OBO = 4-methyl-2,6,7-trioxabicyclo[2.2.2]octan-1-yl) gives rise to arylated OBO-protected pyruvates. By appropriate prefunctionalization of the aryl ring or by subsequent functionalization at the α-carbonyl position of the arylated OBO-ketones, useful diketo OBO-protected carboxylates can be generated. Cyclization, aromatization, and OBO deprotection of these intermediates, using two distinct routes, gives access to valuable α-acyl heteroaromatic compounds.

  13. Hydridosiloxanes as precursors to ceramic products

    DOEpatents

    Blum, Y.D.; Johnson, S.M.; Gusman, M.I.

    1997-06-03

    A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si-H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

  14. Thermostatted molecular dynamics: How to avoid the Toda demon hidden in Nose-Hoover dynamics

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

    Holian, B.L.; Voter, A.F.; Ravelo, R.

    The Nose-Hoover thermostat, which is often used in the hope of modifying molecular dynamics trajectories in order to achieve canonical-ensemble averages, has hidden in it a Toda ``demon,`` which can give rise to unwanted, noncanonical undulations in the instantaneous kinetic temperature. We show how these long-lived oscillations arise from insufficient coupling of the thermostat to the atoms, and give straightforward, practical procedures for avoiding this weak-coupling pathology in isothermal molecular dynamics simulations.

  15. Identification of the structure of the 3107 cm(-1) H-related defect in diamond.

    PubMed

    Goss, J P; Briddon, P R; Hill, V; Jones, R; Rayson, M J

    2014-04-09

    A prominent hydrogen-related infrared absorption peak seen in many types of diamonds at 3107 cm(-1) has been the subject of investigation for many years. It is present in natural type-Ia material and can be introduced by heat-treating synthetic or CVD diamond. Based upon the most recent experimental data, it is thought that the defect giving rise to this vibrational mode is vacancy-related and is likely to contain nitrogen. Using first-principles simulations we present a VN3H model for the originating centre that simultaneously satisfies the different experimental observations including the strain response.

  16. Concurrent growth of InSe wires and In2O3 tulip-like structures in the Au-catalytic vapour-liquid-solid process

    NASA Astrophysics Data System (ADS)

    Taurino, A.; Signore, M. A.

    2015-06-01

    In this work, the concurrent growth of InSe and In2O3 nanostructures, obtained by thermal evaporation of InSe powders on Au-covered Si substrates, has been investigated by scanning and transmission electron microscopy techniques. The vapour-solid and Au catalytic vapour-liquid-solid growth mechanisms, responsible of the simultaneous development of the two different types of nanostructures, i.e. InSe wires and In2O3 tulip-like structures respectively, are discussed in detail. The thermodynamic processes giving rise to the obtained morphologies and materials are explained.

  17. Varying electric charge in multiscale spacetimes

    NASA Astrophysics Data System (ADS)

    Calcagni, Gianluca; Magueijo, João; Fernández, David Rodríguez

    2014-01-01

    We derive the covariant equations of motion for Maxwell field theory and electrodynamics in multiscale spacetimes with weighted Laplacian. An effective spacetime-dependent electric charge of geometric origin naturally emerges from the theory, thus giving rise to a varying fine-structure constant. The theory is compared with other varying-coupling models, such as those with a varying electric charge or varying speed of light. The theory is also confronted with cosmological observations, which can place constraints on the characteristic scales in the multifractional measure. We note that the model considered here is fundamentally different from those previously proposed in the literature, either of the varying-e or varying-c persuasion.

  18. Quantum many-body dynamics of strongly interacting atom arrays

    NASA Astrophysics Data System (ADS)

    Bernien, Hannes; Keesling, Alexander; Levine, Harry; Schwartz, Sylvain; Omran, Ahmed; Anschuetz, Eric; Endres, Manuel; Vuletic, Vladan; Greiner, Markus; Lukin, Mikhail

    2017-04-01

    The coherent interaction between large numbers of particles gives rise to fascinating quantum many-body effects and lies at the center of quantum simulations and quantum information processing. The development of systems consisting of many, well-controlled particles with tunable interactions is an outstanding challenge. Here we present a new platform based on large, reconfigurable arrays of individually trapped atoms. Strong interactions between these atoms are enabled by exciting them to Rydberg states. This flexible approach allows access to vastly different regimes with interactions tunable over several orders of magnitude. We study the coherent many-body dynamics in varying array geometries and observe the formation of Rydberg crystals.

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

    Rorsman, F.; Bywater, M.; Knott, T.J.

    The human platelet-derived growth factor (PDGF) A-chain locus was characterized by restriction endonuclease analysis, and the nucleotide sequence of its exons was determined. Seven exons were identified, spanning approximately 22 kilobase pairs of genomic DNA. Alternative exon usage, identified by cDNA cloning, occurs in a human glioblastoma cell line and may give rise to two types of A-chain precursors with different C termini. The exon-intron arrangement was similar to that of the PDGF B-chain/sis locus and seemed to divide the precursor proteins into functional domains. Southern blot analysis of genomic DNA showed that a single PDGF A-chain gene was presentmore » in the human genome.« less

  20. The syndrome of myosclerosis1

    PubMed Central

    Bradley, W. G.; Hudgson, P.; Gardner-Medwin, D.; Walton, J. N.

    1973-01-01

    Three cases are described presenting with progressive contractures in whom the muscles felt firm and `woody' and a clinical diagnosis of myosclerosis was made in each case. A patient and his young sister were shown to be suffering from spinal muscular atrophy with superimposed, excessive proliferative activity of fibroblasts, and in these cases a beneficial effect of penicillamine was demonstrated. The third case with a clinical picture of myosclerosis was found on muscle biopsy to have extensive inflammatory infiltration of the connective tissue, and responded temporarily at least to high doses of corticosteroids. It is emphasized that several different disease entities can give rise to this clinical picture. Images PMID:4793163

  1. Pulsed laser diffusion of thin hole-barrier contacts in high purity germanium for gamma radiation detectors

    NASA Astrophysics Data System (ADS)

    Maggioni, G.; Carturan, S.; Raniero, W.; Riccetto, S.; Sgarbossa, F.; Boldrini, V.; Milazzo, R.; Napoli, D. R.; Scarpa, D.; Andrighetto, A.; Napolitani, E.; De Salvador, D.

    2018-03-01

    A new method for the formation of hole-barrier contacts in high purity germanium (HPGe) is described, which consists in the sputter deposition of a Sb film on HPGe, followed by Sb diffusion produced through laser annealing of the Ge surface in the melting regime. This process gives rise to a very thin ( ≤ 100 nm) n-doped layer, as determined by SIMS measurement, while preserving the defect-free morphology of HPGe surface. A small prototype of gamma ray detector with a Sb laser-diffused contact was produced and characterized, showing low leakage currents and good spectroscopy data with different gamma ray sources.

  2. FIBER AND INTEGRATED OPTICS. FIBER WAVEGUIDE DEVICES: Vector solitons in fiber waveguides with a random birefringence

    NASA Astrophysics Data System (ADS)

    Kivshar', Yu S.; Konotop, V. V.

    1990-12-01

    A study is made of the propagation of soliton pulses in single-mode fiber waveguides with a birefringence that gives rise to a nonlinear interaction between the polarizations and to a difference between their group velocities. It is shown that a vector soliton decays if a parameter representing the birefringence intensity exceeds a certain critical value. The case when the birefringence can be described by a random function is of special interest. It is demonstrated that fluctuations of the birefringence then split the vector solitons into separate polarizations and the characteristic distance governing such splitting is calculated analytically.

  3. Shot noise enhancement from non-equilibrium plasmons in Luttinger liquid junctions.

    PubMed

    Kim, Jaeuk U; Kinaret, Jari M; Choi, Mahn-Soo

    2005-06-29

    We consider a quantum wire double junction system with each wire segment described by a spinless Luttinger model, and study theoretically shot noise in this system in the sequential tunnelling regime. We find that the non-equilibrium plasmonic excitations in the central wire segment give rise to qualitatively different behaviour compared to the case with equilibrium plasmons. In particular, shot noise is greatly enhanced by them, and exceeds the Poisson limit. We show that the enhancement can be explained by the emergence of several current-carrying processes, and that the effect disappears if the channels effectively collapse to one because of fast plasmon relaxation processes, for example.

  4. On the use of Lagrangian variables in descriptions of unsteady boundary-layer separation

    NASA Technical Reports Server (NTRS)

    Cowley, Stephen J.; Vandommelen, Leon L.; Lam, Shui T.

    1990-01-01

    The Lagrangian description of unsteady boundary layer separation is reviewed from both analytical and numerical perspectives. It is explained in simple terms how particle distortion gives rise to unsteady separation, and why a theory centered on Lagrangian coordinates provides the clearest description of this phenomenon. Some of the more recent results for unsteady three dimensional compressible separation are included. The different forms of separation that can arise from symmetries are emphasized. A possible description of separation is also included when the detaching vorticity layer exits the classical boundary layer region, but still remains much closer to the surface than a typical body-lengthscale.

  5. Extreme fluctuations of active Brownian motion

    NASA Astrophysics Data System (ADS)

    Pietzonka, Patrick; Kleinbeck, Kevin; Seifert, Udo

    2016-05-01

    In active Brownian motion, an internal propulsion mechanism interacts with translational and rotational thermal noise and other internal fluctuations to produce directed motion. We derive the distribution of its extreme fluctuations and identify its universal properties using large deviation theory. The limits of slow and fast internal dynamics give rise to a kink-like and parabolic behavior of the corresponding rate functions, respectively. For dipolar Janus particles in two- and three-dimensions interacting with a field, we predict a novel symmetry akin to, but different from, the one related to entropy production. Measurements of these extreme fluctuations could thus be used to infer properties of the underlying, often hidden, network of states.

  6. Consistent Initial Conditions for the DNS of Compressible Turbulence

    NASA Technical Reports Server (NTRS)

    Ristorcelli, J. R.; Blaisdell, G. A.

    1996-01-01

    Relationships between diverse thermodynamic quantities appropriate to weakly compressible turbulence are derived. It is shown that for turbulence of a finite turbulent Mach number there is a finite element of compressibility. A methodology for generating initial conditions for the fluctuating pressure, density and dilatational velocity is given which is consistent with finite Mach number effects. Use of these initial conditions gives rise to a smooth development of the flow, in contrast to cases in which these fields are specified arbitrarily or set to zero. Comparisons of the effect of different types of initial conditions are made using direct numerical simulation of decaying isotropic turbulence.

  7. Refining of plant oils to chemicals by olefin metathesis.

    PubMed

    Chikkali, Samir; Mecking, Stefan

    2012-06-11

    Plant oils are attractive substrates for the chemical industry. Their scope for the production of chemicals can be expanded by sophisticated catalytic conversions. Olefin metathesis is an example, which also illustrates generic issues of "biorefining" to chemicals. Utilization on a large scale requires high catalyst activities, which influences the choice of the metathesis reaction. The mixture of different fatty acids composing a technical-grade plant oil substrate gives rise to a range of products. This decisively determines possible process schemes, and potentially provides novel chemicals and intermediates not employed to date. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A question of style: method, integrity and the meaning of proper science.

    PubMed

    Penders, Bart; Vos, Rein; Horstman, Klasien

    2009-09-01

    Controversies in science often centre on methodology and integrity; these are the gatekeepers of proper science. But what exactly defines proper science as proper is not universal, especially in collaborative fields of enquiry where different perspectives meet. These encounters often result in friction, yet may equally give rise to new perspectives on proper science. A tour of collaborative endeavours like structural biology and nutrigenomics highlights some of those frictions and the controversies that can result from the encounter of 'wet' and 'dry' science. Attuning scientists to the plurality of proper science may safeguard many a scientist's integrity from being questioned unjustly.

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

    Bissa, Shivangi; Naruka, Preeti; Bishnoi, Nidhi

    In the present study the dielectric optical response of various nanostructures of ZnO deposited on silica substrate has been studied using Maxwell-Garnett Effective Medium Theory. Using the volume filling factors for different nanostructures of ZnO the effective dielectric constant has been evaluated. The variation of this effective dielectric constant with the frequency of applied signal has been investigated. Moreover, the reflectance of the film, power absorption and variation of refractive index with frequency has been studied. The results obtained show that the quantum confinement effects in ZnO nano-structural films deposited on silica substrate give rise to distinct optical properties makingmore » it an ideal choice for high power THz generation.« less

  10. Shot noise enhancement from non-equilibrium plasmons in Luttinger liquid junctions

    NASA Astrophysics Data System (ADS)

    Kim, Jaeuk U.; Kinaret, Jari M.; Choi, Mahn-Soo

    2005-06-01

    We consider a quantum wire double junction system with each wire segment described by a spinless Luttinger model, and study theoretically shot noise in this system in the sequential tunnelling regime. We find that the non-equilibrium plasmonic excitations in the central wire segment give rise to qualitatively different behaviour compared to the case with equilibrium plasmons. In particular, shot noise is greatly enhanced by them, and exceeds the Poisson limit. We show that the enhancement can be explained by the emergence of several current-carrying processes, and that the effect disappears if the channels effectively collapse to one because of fast plasmon relaxation processes, for example.

  11. Sexually transmitted diseases and the mobility explosion

    PubMed Central

    Catterall, R. D.

    1975-01-01

    The very great increase in the tourist industry during the past 20 years is described. This has occurred at a time when there has been an unprecedented rise in the incidence of sexually transmitted diseases. Evidence is presented that there is a relationship between the number of tourists and other travellers and the prevalence of sexually transmitted diseases. Case histories from three different categories of tourist are described and the impact of tourism on the spread of disease is stressed. It is suggested that health authorities throughout the world should give further consideration to plans to meet the challenge of the mobility explosion. PMID:1243165

  12. Role construction and boundaries in interprofessional primary health care teams: a qualitative study.

    PubMed

    MacNaughton, Kate; Chreim, Samia; Bourgeault, Ivy Lynn

    2013-11-24

    The move towards enhancing teamwork and interprofessional collaboration in health care raises issues regarding the management of professional boundaries and the relationship among health care providers. This qualitative study explores how roles are constructed within interprofessional health care teams. It focuses on elucidating the different types of role boundaries, the influences on role construction and the implications for professionals and patients. A comparative case study was conducted to examine the dynamics of role construction on two interprofessional primary health care teams. The data collection included interviews and non-participant observation of team meetings. Thematic content analysis was used to code and analyze the data and a conceptual model was developed to represent the emergent findings. The findings indicate that role boundaries can be organized around interprofessional interactions (giving rise to autonomous or collaborative roles) as well as the distribution of tasks (giving rise to interchangeable or differentiated roles). Different influences on role construction were identified. They are categorized as structural (characteristics of the workplace), interpersonal (dynamics between team members such as trust and leadership) and individual dynamics (personal attributes). The implications of role construction were found to include professional satisfaction and more favourable wait times for patients. A model that integrates these different elements was developed. Based on the results of this study, we argue that autonomy may be an important element of interprofessional team functioning. Counter-intuitive as this may sound, we found that empowering team members to develop autonomy can enhance collaborative interactions. We also argue that while more interchangeable roles could help to lessen the workloads of team members, they could also increase the potential for power struggles because the roles of various professions would become less differentiated. We consider the conceptual and practical implications of our findings and we address the transferability of our model to other interprofessional teams.

  13. Role construction and boundaries in interprofessional primary health care teams: a qualitative study

    PubMed Central

    2013-01-01

    Background The move towards enhancing teamwork and interprofessional collaboration in health care raises issues regarding the management of professional boundaries and the relationship among health care providers. This qualitative study explores how roles are constructed within interprofessional health care teams. It focuses on elucidating the different types of role boundaries, the influences on role construction and the implications for professionals and patients. Methods A comparative case study was conducted to examine the dynamics of role construction on two interprofessional primary health care teams. The data collection included interviews and non-participant observation of team meetings. Thematic content analysis was used to code and analyze the data and a conceptual model was developed to represent the emergent findings. Results The findings indicate that role boundaries can be organized around interprofessional interactions (giving rise to autonomous or collaborative roles) as well as the distribution of tasks (giving rise to interchangeable or differentiated roles). Different influences on role construction were identified. They are categorized as structural (characteristics of the workplace), interpersonal (dynamics between team members such as trust and leadership) and individual dynamics (personal attributes). The implications of role construction were found to include professional satisfaction and more favourable wait times for patients. A model that integrates these different elements was developed. Conclusions Based on the results of this study, we argue that autonomy may be an important element of interprofessional team functioning. Counter-intuitive as this may sound, we found that empowering team members to develop autonomy can enhance collaborative interactions. We also argue that while more interchangeable roles could help to lessen the workloads of team members, they could also increase the potential for power struggles because the roles of various professions would become less differentiated. We consider the conceptual and practical implications of our findings and we address the transferability of our model to other interprofessional teams. PMID:24267663

  14. The challenge of using experimental infectivity data in risk assessment for Ebola virus: why ecology may be important.

    PubMed

    Gale, P; Simons, R R L; Horigan, V; Snary, E L; Fooks, A R; Drew, T W

    2016-01-01

    Analysis of published data shows that experimental passaging of Zaire ebolavirus (EBOV) in guinea pigs changes the risk of infection per plaque-forming unit (PFU), increasing infectivity to some species while decreasing infectivity to others. Thus, a PFU of monkey-adapted EBOV is 10(7) -fold more lethal to mice than a PFU adapted to guinea pigs. The first conclusion is that the infectivity of EBOV to humans may depend on the identity of the donor species itself and, on the basis of limited epidemiological data, the question is raised as to whether bat-adapted EBOV is less infectious to humans than nonhuman primate (NHP)-adapted EBOV. Wildlife species such as bats, duikers and NHPs are naturally infected by EBOV through different species giving rise to EBOV with different wildlife species-passage histories (heritages). Based on the ecology of these wildlife species, three broad 'types' of EBOV-infected bushmeat are postulated reflecting differences in the number of passages within a given species, and hence the degree of adaptation of the EBOV present. The second conclusion is that the prior species-transmission chain may affect the infectivity to humans per PFU for EBOV from individuals of the same species. This is supported by the finding that the related Marburg marburgvirus requires ten passages in mice to fully adapt. It is even possible that the evolutionary trajectory of EBOV could vary in individuals of the same species giving rise to variants which are more or less virulent to humans and that the probability of a given trajectory is related to the heritage. Overall the ecology of the donor species (e.g. dog or bushmeat species) at the level of the individual animal itself may determine the risk of infection per PFU to humans reflecting the heritage of the virus and may contribute to the sporadic nature of EBOV outbreaks. © 2015 Crown copyright. © 2015 Society for Applied Microbiology.

  15. 20 CFR 416.994 - How we will determine whether your disability continues or ends, disabled adults.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... or improved diagnostic or evaluative techniques your impairment(s) is not as disabling as it was... medical and other diagnostic or evaluative techniques have given, and will continue to give, rise to...

  16. 20 CFR 416.994 - How we will determine whether your disability continues or ends, disabled adults.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... or improved diagnostic or evaluative techniques your impairment(s) is not as disabling as it was... medical and other diagnostic or evaluative techniques have given, and will continue to give, rise to...

  17. 20 CFR 416.994 - How we will determine whether your disability continues or ends, disabled adults.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... or improved diagnostic or evaluative techniques your impairment(s) is not as disabling as it was... medical and other diagnostic or evaluative techniques have given, and will continue to give, rise to...

  18. 20 CFR 416.994 - How we will determine whether your disability continues or ends, disabled adults.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... or improved diagnostic or evaluative techniques your impairment(s) is not as disabling as it was... medical and other diagnostic or evaluative techniques have given, and will continue to give, rise to...

  19. 20 CFR 416.994 - How we will determine whether your disability continues or ends, disabled adults.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... or improved diagnostic or evaluative techniques your impairment(s) is not as disabling as it was... medical and other diagnostic or evaluative techniques have given, and will continue to give, rise to...

  20. 26 CFR 1.865-1 - Loss with respect to personal property other than stock.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... money or publicly traded property) shall be allocated to the class of gross income and, if necessary... loss subject to this paragraph (b)(2)) would give rise. (c) Exceptions—(1) Foreign currency and certain...

  1. 30 CFR 701.5 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., animal stocking requirements, scheduling of activities and design of sedimentation ponds in accordance... practice giving rise to the peril, would avoid exposure to the danger during the time necessary for... establishments. (g) Recreation. Land used for public or private leisure-time activities, including developed...

  2. 30 CFR 701.5 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., animal stocking requirements, scheduling of activities and design of sedimentation ponds in accordance... practice giving rise to the peril, would avoid exposure to the danger during the time necessary for... establishments. (g) Recreation. Land used for public or private leisure-time activities, including developed...

  3. 30 CFR 701.5 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., animal stocking requirements, scheduling of activities and design of sedimentation ponds in accordance... practice giving rise to the peril, would avoid exposure to the danger during the time necessary for... establishments. (g) Recreation. Land used for public or private leisure-time activities, including developed...

  4. 30 CFR 701.5 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., animal stocking requirements, scheduling of activities and design of sedimentation ponds in accordance... practice giving rise to the peril, would avoid exposure to the danger during the time necessary for... establishments. (g) Recreation. Land used for public or private leisure-time activities, including developed...

  5. 30 CFR 701.5 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., animal stocking requirements, scheduling of activities and design of sedimentation ponds in accordance... practice giving rise to the peril, would avoid exposure to the danger during the time necessary for... establishments. (g) Recreation. Land used for public or private leisure-time activities, including developed...

  6. TOOLS FOR COMPARATIVE ANALYSIS OF ALTERNATIVES: COMPETING OR COMPLEMENTARY PERSPECTIVES?

    EPA Science Inventory

    A third generation of environmental policymaking and risk management will increasingly impose environmental measures, which may give rise to analyzing countervailing risks. Therefore, a comprehensive analysis of these risks associated with the decision alternatives at hand will e...

  7. Green modes of transportation for Connecticut's mixed used developments.

    DOT National Transportation Integrated Search

    2011-02-01

    Says Connecticut Governor Jodi Rell, : I want to give rise to a culture of change, opportunity and reform at DOT. As an : institution DOT has simply become too bureaucratic, too inefficient and too single-minded in its : problem solving approach....

  8. A mutation in the neurofibromatosis type 2 tumor-suppressor gene, giving rise to widely different clinical phenotypes in two unrelated individuals

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

    Bourn, D.; Carter, S.A.; Goodship, J.

    The authors have sought mutations in the recently identified neurofibromatosis type 2 (NF2) tumor-suppressor gene in a large panel of NF2 patients, using PCR-based SSCP and heteroduplex analysis, followed by cloning and sequencing of appropriate PCR products. Two unrelated NF2 patients were found to have identical nonsense mutations caused by a C-to-T transition in a CpG dinucleotide that is a potential mutational hot spot in the NF2 tumor-suppressor gene. Unexpectedly, the two individuals had widely different clinical phenotypes, representing the severe Wishart and mild Gardner clinical subtypes. Analysis of DNA samples from different tissues of the mildly affected patient suggestsmore » that he is a somatic mosaic for the mutation. 26 refs., 3 figs.« less

  9. Field study on the epidemiology and pathogenicity of different isolates of bovine Ostertagia spp.

    PubMed

    Al Saqur, I; Armour, J; Bairden, K; Dunn, A M; Jennings, F W; Murray, M

    1982-11-01

    The epidemiological features of three different isolates of bovine Ostertagia spp under similar initial levels of larval challenge were compared in the field. Two of the isolates, consisting mainly of Ostertagia ostertagi, and a low proportion of Skrjabinagia lyrata conformed in epidemiological behaviour with those investigated by previous workers, though the worm burdens which established did not give rise to the expected clinical signs. The third isolate behaved in a different way, yielding very high faecal egg counts which were followed by high pasture larval counts, heavy worm burdens and severe clinical disease. This isolate, while consisting mainly of O ostertagi and a few S lyrata, also contained a proportion of O leptospicularis, and it is suggested that this species may influence the dynamics of the host-parasite relationship in bovine ostertagiasis.

  10. Effect of tip polarity on Kelvin probe force microscopy images of thin insulator CaF2 films on Si(111)

    NASA Astrophysics Data System (ADS)

    Yurtsever, Ayhan; Sugimoto, Yoshiaki; Fukumoto, Masaki; Abe, Masayuki; Morita, Seizo

    2012-08-01

    We investigate thin insulating CaF2 films on a Si (111) surface using a combination of noncontact atomic force microscopy (NC-AFM) and Kelvin probe force microscopy (KPFM). Atomic-scale NC-AFM and KPFM images are obtained in different imaging modes by employing two different tip polarities. The KPFM image contrast and the distance-dependent variation of the local contact potential difference (LCPD) give rise to a tip-polarity-dependent contrast inversion. Ca2+ cations had a higher LCPD contrast than F- anions for a positively terminated tip, while the LCPD provided by a negatively charged tip gave a higher contrast for F- anions. Thus, this result implies that it is essential to determine the tip apex polarity to correctly interpret LCPD signals acquired by KPFM.

  11. Influence of grain boundaries on the distribution of components in binary alloys

    NASA Astrophysics Data System (ADS)

    L'vov, P. E.; Svetukhin, V. V.

    2017-12-01

    Based on the free-energy density functional method (the Cahn-Hilliard equation), a phenomenological model that describes the influence of grain boundaries on the distribution of components in binary alloys has been developed. The model is built on the assumption of the difference between the interaction parameters of solid solution components in the bulk and at the grain boundary. The difference scheme based on the spectral method is proposed to solve the Cahn-Hilliard equation with interaction parameters depending on coordinates. Depending on the ratio between the interaction parameters in the bulk and at the grain boundary, temperature, and alloy composition, the model can give rise to different types of distribution of a dissolved component, namely, either depletion or enrichment of the grain-boundary area, preferential grainboundary precipitation, competitive precipitation in the bulk and at the grain boundary, etc.

  12. A method of estimating ground-water supplies based on discharge by plants and evaporation from soil: Results of investigations in Escalante Valley, Utah

    USGS Publications Warehouse

    White, W.N.

    1932-01-01

    Fluctuations of water levels in wells, if critically studied, may give much information as to the occurrence, movement, and quantity of available ground water. In some localities the ground-water level has been observed to decline during the day and to rise at night, the decline beginning at about the same hour every morning and the rise at about the same hour every night. This daily decline is due to the withdrawal of ground water from the zone of saturation by plants, and the rise at night is due to upward movement of water under slight artesian pressure from permeable beds of sand and gravel at some depth beneath the water table.

  13. A study of the dispersity of iron oxide and iron oxide-noble metal (Me = Pd, Pt) supported systems

    NASA Astrophysics Data System (ADS)

    Cherkezova-Zheleva, Z. P.; Shopska, M. G.; Krstić, J. B.; Jovanović, D. M.; Mitov, I. G.; Kadinov, G. B.

    2007-09-01

    Samples of one-(Fe) and two-component (Fe-Pd and Fe-Pt) catalysts were prepared by incipient wetness impregnation of four different supports: TiO2 (anatase), γ-Al2O3, activated carbon, and diatomite. The chosen synthesis conditions resulted in the formation of nanosized supported phases—iron oxide (in the one-component samples), or iron oxide-noble metal (in the two-component ones). Different agglomeration degrees of these phases were obtained as a result of thermal treatment. Ultradisperse size of the supported phase was maintained in some samples, while a process of partial agglomeration occurred in others, giving rise to nearly bidisperse (ultra-and highdisperse) supported particles. The different texture of the used supports and their chemical composition are the reasons for the different stability of the nanosized supported phases. The samples were tested as heterogeneous catalysts in total benzene oxidation reaction.

  14. Introduction to fatty acids and lipids.

    PubMed

    Burdge, Graham C; Calder, Philip C

    2015-01-01

    The purpose of this article is to describe the structure, function and metabolism of fatty acids and lipids that are of particular importance in the context of parenteral nutrition. Lipids are a heterogeneous group of molecules that share the common property of hydrophobicity. Lipids range in structure from simple short hydrocarbon chains to more complex molecules, including triacylglycerols, phospholipids and sterols and their esters. Lipids within each class may differ structurally. Fatty acids are common components of complex lipids, and these differ according to chain length and the presence, number and position of double bonds in the hydrocarbon chain. Structural variation among complex lipids and among fatty acids gives rise to functional differences that result in different impacts upon metabolism and upon cell and tissue responses. Fatty acids and complex lipids exhibit a variety of structural variations that influence their metabolism and their functional effects. © 2015 S. Karger AG, Basel.

  15. Transformation volume effect on the magnetic anisotropy of Ni-Mn-Ga thin films

    NASA Astrophysics Data System (ADS)

    L'vov, V. A.; Golub, V.; Salyuk, O.; Barandiarán, J. M.; Chernenko, V. A.

    2015-01-01

    Ni-Mn-Ga ferromagnetic shape memory films with similar thickness and chemical composition, deposited onto cold (with a subsequent annealing) and hot MgO(001) substrates exhibit different internal stress and structure giving rise to a different orientation of the magnetic easy axes. A quantitative theoretical analysis of the crystallographic and ferromagnetic resonance (FMR) data shows that the different anisotropies can be caused by the difference in sign between the transformation volume changes in these films, as influenced by the internal stresses. To explain FMR data, the magnetoelastic coupling term of fourth-order in the magnetic vector and linear in the strain tensor components, appearing in the Landau expansion for the free energy, is taken into account. The coefficient of the term, which couples the magnetic vector components with the volume change of the Ni-Mn-Ga alloy, was estimated to be equal to about 10 7 erg cm - 3 .

  16. Inulin-enriched dairy desserts: physicochemical and sensory aspects.

    PubMed

    González-Tomás, L; Bayarri, S; Costell, E

    2009-09-01

    The aim of this work was to study how adding inulin of different average chain lengths (long-chain, native, and short-chain inulin) at a concentration of 7.5% (wt/wt) would affect the physicochemical and sensory characteristics of starch-based dairy desserts formulated with either skim or whole milk. The results have shown that the effect of adding 7.5% inulin of different average chain length can give rise to products with different rheological behavior and different sensory characteristics. The skim milk sample with long-chain inulin and the whole milk sample without inulin showed similar flow behavior. Both samples were perceived to have the same creaminess and consistency intensity, but addition of long-chain inulin increased roughness intensity and, consequently, the sensory quality could be negatively affected. The information obtained may be of great interest in designing new products with nutritional and sensory characteristics that meet consumer demands.

  17. Periodical energy oscillation and pulse splitting in sinusoidal volume holographic grating.

    PubMed

    Yan, Xiaona; Gao, Lirun; Dai, Ye; Yang, Xihua; Chen, Yuanyuan; Ma, Guohong

    2014-07-28

    This paper presents dynamical diffraction properties of a femtosecond pulse in a sinusoidal volume holographic grating (VHG). By the modified coupled-wave equations of Kogelnik, we show that the diffraction of a femtosecond pulse on the VHG gives rise to periodical energy oscillation and pulse splitting. In the initial stage of diffraction, one diffracted pulse and one transmitted pulse emerge, and energy of the transmitted pulse periodically transfers to the diffracted pulse and vice versa. In the latter stage, both the diffracted and transmitted pulses split into two spatially separated pulses. One pair of transmitted and diffracted pulses propagates in the same direction and forms the output diffracted dual pulses of the VHG, and the other pair of pulses forms the output transmitted dual pulses. The pulse interval between each pair of dual pulses is in linearly proportional to the refractive index modulation and grating thickness. By the interference effect and group velocity difference we give explanations on the periodical energy oscillation and pulse splitting respectively.

  18. Reverse Genetics and High Throughput Sequencing Methodologies for Plant Functional Genomics

    PubMed Central

    Ben-Amar, Anis; Daldoul, Samia; Reustle, Götz M.; Krczal, Gabriele; Mliki, Ahmed

    2016-01-01

    In the post-genomic era, increasingly sophisticated genetic tools are being developed with the long-term goal of understanding how the coordinated activity of genes gives rise to a complex organism. With the advent of the next generation sequencing associated with effective computational approaches, wide variety of plant species have been fully sequenced giving a wealth of data sequence information on structure and organization of plant genomes. Since thousands of gene sequences are already known, recently developed functional genomics approaches provide powerful tools to analyze plant gene functions through various gene manipulation technologies. Integration of different omics platforms along with gene annotation and computational analysis may elucidate a complete view in a system biology level. Extensive investigations on reverse genetics methodologies were deployed for assigning biological function to a specific gene or gene product. We provide here an updated overview of these high throughout strategies highlighting recent advances in the knowledge of functional genomics in plants. PMID:28217003

  19. Comparison of Zirconium Phosphonate-Modified Surfaces for Immobilizing Phosphopeptides and Phosphate-Tagged Proteins.

    PubMed

    Forato, Florian; Liu, Hao; Benoit, Roland; Fayon, Franck; Charlier, Cathy; Fateh, Amina; Defontaine, Alain; Tellier, Charles; Talham, Daniel R; Queffélec, Clémence; Bujoli, Bruno

    2016-06-07

    Different routes for preparing zirconium phosphonate-modified surfaces for immobilizing biomolecular probes are compared. Two chemical-modification approaches were explored to form self-assembled monolayers on commercially available primary amine-functionalized slides, and the resulting surfaces were compared to well-characterized zirconium phosphonate monolayer-modified supports prepared using Langmuir-Blodgett methods. When using POCl3 as the amine phosphorylating agent followed by treatment with zirconyl chloride, the result was not a zirconium-phosphonate monolayer, as commonly assumed in the literature, but rather the process gives adsorbed zirconium oxide/hydroxide species and to a lower extent adsorbed zirconium phosphate and/or phosphonate. Reactions giving rise to these products were modeled in homogeneous-phase studies. Nevertheless, each of the three modified surfaces effectively immobilized phosphopeptides and phosphopeptide tags fused to an affinity protein. Unexpectedly, the zirconium oxide/hydroxide modified surface, formed by treating the amine-coated slides with POCl3/Zr(4+), afforded better immobilization of the peptides and proteins and efficient capture of their targets.

  20. Streamwater nitrate concentrations in six agricultural catchments in Scotland.

    PubMed

    Hooda, P S; Moynagh, M; Svoboda, I F; Thurlow, M; Stewart, M; Thomson, M; Anderson, H A

    1997-08-01

    The concentrations of nitrate-N (NO3-N) in catchment inputs and outputs have been compared and contrasted between 6 farm catchments in Scotland, 3 in the West and 3 in the North-East. Forms of intensive animal farming ranging between beef and dairy cattle, sheep and poultry give different sources for potential NO3-N leakage from the systems. While stream reaches bordered by intensive cereal production give rise to the largest inputs to surface waters, climatic influences result in the more-efficient use of fertilizer- and farm waste-N in the West, and an enhanced potential for N-loss to waters in the cooler North-East, regardless of the N-inputs being considerably lower in the latter region. Although the EC Nitrate Directive limit of 11.3 mg NO3-N 1(-1) was not exceeded, peak values occurring during summer baseflows and autumn soil rewetting were commonly larger than the 'target' maximum concentration of 5.65 mg NO3-N 1-1.

  1. [Air pollution due to the burning of thermoplastics II (author's transl)].

    PubMed

    van Grimbergen, M; Reybrouck, G; van de Voorde, H

    1975-03-01

    Following on from the first publication, (12) concerning the burning of plastics, another 13 chemical pure polymers were burnt in an electric oven to determine the level of solid and gaseous air pollution caused by their stackgases. All 13 polymers are highly combustible but require different burning temperatures (300-900 degrees C) in order to be burnt completely (i.e. without ashrest). With the exception of PMMA and PTFE, all plastics leave a very heavy tar- and soot deposit after burning. At the other end of the scale, burning at low temperature (300 degrees C) gives rise to high concentrations of alipathic aldehyds. The pH of the exhaust-gases, dissolved in water, is neutral to strong acid (PTFE), and will cause a severe corrosion. The nitrogen-containing polymers pollute by forming cyanides, nitrogenoxides and ammonia. PTFE gives off high concentrations of fluorid into the air. PMMA decomposes in its monomer methylmethacrylate and forms large amounts of aliphatic aldehyds. ABS and SBR cause a styrene pollution.

  2. Phase-space reaction network on a multisaddle energy landscape: HCN isomerization.

    PubMed

    Li, Chun-Biu; Matsunaga, Yasuhiro; Toda, Mikito; Komatsuzaki, Tamiki

    2005-11-08

    By using the HCN/CNH isomerization reaction as an illustrative vehicle of chemical reactions on multisaddle energy landscapes, we give explicit visualizations of molecular motions associated with a straight-through reaction tube in the phase space inside which all reactive trajectories pass from one basin to another, with eliminating recrossing trajectories in the configuration space. This visualization provides us with a chemical intuition of how chemical species "walk along" the reaction-rate slope in the multidimensional phase space compared with the intrinsic reaction path in the configuration space. The distinct nonergodic features in the two different HCN and CNH wells can be easily demonstrated by a section of Poincare surface of section in those potential minima, which predicts in a priori the pattern of trajectories residing in the potential well. We elucidate the global phase-space structure which gives rise to the non-Markovian dynamics or the dynamical correlation of sequential multisaddle chemical reactions. The phase-space structure relevant to the controllability of the product state in chemical reactions is also discussed.

  3. Viewing Saturn from the Plane

    NASA Image and Video Library

    2006-04-19

    This view of the ringed planet shows its tilt relative to the plane of its orbit around the Sun. The planet tilts nearly 27 degrees relative to the ecliptic plane giving rise to seasons in which the rings shadow each hemisphere in its respective winter

  4. Photophysics of C60 Colloids

    DTIC Science & Technology

    2012-11-28

    strong linear absorption giving rise to thermionic emission, resulting in avalanche ionization and thus, nanoplasmas that absorb and scatter the...point of water is reached before the sublimation point of carbon black. If nanoplasmas are the source of the nonlinear absorption seen in CBS-1, then

  5. 48 CFR 552.243-71 - Equitable Adjustments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (exclusive of employer's overhead, profit, and any labor cost burdens carried in employer's overhead rate... condition giving rise to entitlement to an equitable adjustment, including increases or decreases to... site, unless separately itemized); (2) Labor cost broken down by trade, employer, occupation, quantity...

  6. pH-directed self-assembling helical peptide conformation

    USDA-ARS?s Scientific Manuscript database

    The beta-sheet and alpha-helix peptide conformation are two of the most fundamentally ordered secondary structures found in proteins and peptides. They also give rise to self-assembling motifs that form macromolecular channels and nanostructures. Through design these conformations can yield enhance...

  7. Method for preparing 6-.beta.-halopenicillanic acids

    DOEpatents

    Hansen, Erik I.; Kran-Nielsen, Mogens P.; Von Daehne, Welf

    1989-01-01

    The present invention relates to a new and improved method for the preparation of a compound of the formula I ##STR1## in which R stands for halogen, giving rise to high yields of substantially pure 6.beta.-halopenicillanic acids, obtained in one step.

  8. Magnetized environs of a repeating radio burst

    NASA Astrophysics Data System (ADS)

    Metzger, Brian D.

    2018-03-01

    One of the astrophysical sources that gives rise to the mysterious transients known as fast radio bursts is embedded in a highly magnetized environment, such as the vicinity of an accreting massive black hole or the birth nebula of a highly magnetized neutron star.

  9. 78 FR 8390 - Procedures for the Handling of Retaliation Complaints Under the Employee Protection Provision of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... elapse between the time the employer learns of the seaman's intent to report and the time the report can... the adverse action took place shortly after protected activity, giving rise to the inference that it...

  10. Self-Confrontation of Teachers.

    ERIC Educational Resources Information Center

    Schmuck, Richard A.

    Simply presenting teachers with information about discrepancies between their ideal and their actual classroom performances does not, in itself, lead to constructive change. In part, this is because teachers confronted with such discrepancies experience dissonance which often gives rise to anxiety. This paper discusses the psychological processes…

  11. Transition of spiral calcium waves between multiple stable patterns can be triggered by a single calcium spark in a fire-diffuse-fire model

    PubMed Central

    Tang, Ai-Hui; Wang, Shi-Qiang

    2009-01-01

    Spiral patterns have been found in various nonequilibrium systems. The Ca2+-induced Ca2+ release system in single cardiac cells is unique for highly discrete reaction elements, each giving rise to a Ca2+ spark upon excitation. We imaged the spiral Ca2+ waves in isolated cardiac cells and numerically studied the effect of system excitability on spiral patterns using a two-dimensional fire-diffuse-fire model. We found that under certain conditions, the system was able to display multiple stable patterns of spiral waves, each exhibiting different periods and distinct routines of spiral tips. Transition between these different patterns could be triggered by an internal fluctuation in the form of a single Ca2+ spark. PMID:19792039

  12. Transition of spiral calcium waves between multiple stable patterns can be triggered by a single calcium spark in a fire-diffuse-fire model.

    PubMed

    Tang, Ai-Hui; Wang, Shi-Qiang

    2009-09-01

    Spiral patterns have been found in various nonequilibrium systems. The Ca(2+)-induced Ca(2+) release system in single cardiac cells is unique for highly discrete reaction elements, each giving rise to a Ca(2+) spark upon excitation. We imaged the spiral Ca(2+) waves in isolated cardiac cells and numerically studied the effect of system excitability on spiral patterns using a two-dimensional fire-diffuse-fire model. We found that under certain conditions, the system was able to display multiple stable patterns of spiral waves, each exhibiting different periods and distinct routines of spiral tips. Transition between these different patterns could be triggered by an internal fluctuation in the form of a single Ca(2+) spark.

  13. Asymmetric thin-shell wormholes

    NASA Astrophysics Data System (ADS)

    Forghani, S. Danial; Mazharimousavi, S. Habib; Halilsoy, Mustafa

    2018-06-01

    Spacetime wormholes in isotropic spacetimes are represented traditionally by embedding diagrams which were symmetric paraboloids. This mirror symmetry, however, can be broken by considering different sources on different sides of the throat. This gives rise to an asymmetric thin-shell wormhole, whose stability is studied here in the framework of the linear stability analysis. Having constructed a general formulation, using a variable equation of state and related junction conditions, the results are tested for some examples of diverse geometries such as the cosmic string, Schwarzschild, Reissner-Nordström and Minkowski spacetimes. Based on our chosen spacetimes as examples, our finding suggests that symmetry is an important factor to make a wormhole more stable. Furthermore, the parameter γ , which corresponds to the radius dependency of the pressure on the wormholes's throat, can affect the stability in a great extent.

  14. Quantum phase transition and protected ideal transport in a Kondo chain

    DOE PAGES

    Tsvelik, A. M.; Yevtushenko, O. M.

    2015-11-30

    We study the low energy physics of a Kondo chain where electrons from a one-dimensional band interact with magnetic moments via an anisotropic exchange interaction. It is demonstrated that the anisotropy gives rise to two different phases which are separated by a quantum phase transition. In the phase with easy plane anisotropy, Z2 symmetry between sectors with different helicity of the electrons is broken. As a result, localization effects are suppressed and the dc transport acquires (partial) symmetry protection. This effect is similar to the protection of the edge transport in time-reversal invariant topological insulators. The phase with easy axismore » anisotropy corresponds to the Tomonaga-Luttinger liquid with a pronounced spin-charge separation. The slow charge density wave modes have no protection against localizatioin.« less

  15. Topologically Nontrivial Magnon Bands in Artificial Square Spin Ices with Dzyaloshinskii-Moriya Interaction

    NASA Astrophysics Data System (ADS)

    Iacocca, Ezio; Heinonen, Olle

    2017-09-01

    Systems that exhibit topologically protected edge states are interesting both from a fundamental point of view as well as for potential applications, the latter because of the absence of backscattering and robustness to perturbations. It is desirable to be able to control and manipulate such edge states. Here, we show that artificial square ices can incorporate both features: an interfacial Dzyaloshinskii-Moriya interaction gives rise to topologically nontrivial magnon bands, and the equilibrium state of the spin ice is reconfigurable with different configurations having different magnon dispersions and topology. The topology is found to develop as odd-symmetry bulk and edge magnon bands approach each other so that constructive band inversion occurs in reciprocal space. Our results show that topologically protected bands are supported in square spin ices.

  16. High dielectric hyperbranched polyaniline materials.

    PubMed

    Yan, X Z; Goodson, T

    2006-08-03

    New organic materials for the purpose of high speed capacitor applications are discussed. The effect of the microcrystalline size dependence of different polyaniline polymeric systems on the dielectric constant is investigated. Two different methods are described for the preparation of the polyaniline dielectric materials. By sonication polymerization, the prepared polyaniline with a suggested hyperbranched structure showed much larger microcrystalline domains in comparison to the conventional linear polyaniline. Investigations of the dielectric constant and capacitance at a relatively high frequency (>100 kHz) suggested that the system with the larger microcrystalline domains (hyperbranched) gives rise to a larger dielectric constant. The mechanism of the increased dielectric response at higher frequencies is investigated by EPR spectroscopy, and these results suggest that delocalized polarons may provide a way to enhance the dielectric response at high frequency.

  17. [Quantitative relationships between various representatives of gastrointestinal microflora of experimental animals (rats) in normal conditions and after immunosuppression with imuran].

    PubMed

    Amanov, N A

    1983-06-01

    The influence of imuran (an analog of nitrogen ioprin) on the quantitative relationship between lactobacilli, bifidobacteria, bacteroids and aerobic autoflora in different sections of the gastrointestinal tract of white rats was studied under experimental conditions. On days 7-14-30 after the introduction of imuran into the gastrointestinal tract dysbacteriosis developed; it was characterized by a decrease in the number of lactobacilli and asporogenic anaerobic microflora and an increase in the number of aerobic microorganisms. By days 60-90 the content of aerobic microbes in all sections of the gastrointestinal tract was still elevated, while the rapid restoration of the number of bacteroids took place. Therefore, immunosuppression therapy with imuran may give rise to autoinfectious complications caused by different representatives of infective microflora.

  18. Low energy X-ray grating interferometry at the Brazilian Synchrotron

    NASA Astrophysics Data System (ADS)

    Koch, F. J.; O'Dowd, F. P.; Cardoso, M. B.; Da Silva, R. R.; Cavicchioli, M.; Ribeiro, S. J. L.; Schröter, T. J.; Faisal, A.; Meyer, P.; Kunka, D.; Mohr, J.

    2017-06-01

    Grating based X-ray differential phase contrast imaging has found a large variety of applications in the last decade. Different types of samples call for different imaging energies, and efforts have been made to establish the technique all over the spectrum used for conventional X-ray imaging. Here we present a two-grating interferometer working at 8.3 keV, implemented at the bending magnet source of the IMX beamline of the Brazilian Synchrotron Light Laboratory. The low design energy is made possible by gratings fabricated on polymer substrates, and makes the interferometer mainly suited to the investigation of light and thin samples. We investigate polymer microspheres filled with Fe2O3 nanoparticles, and find that these particles give rise to a significant visibility reduction due to small angle scattering.

  19. Wireless Sensor Network Optimization: Multi-Objective Paradigm

    PubMed Central

    Iqbal, Muhammad; Naeem, Muhammad; Anpalagan, Alagan; Ahmed, Ashfaq; Azam, Muhammad

    2015-01-01

    Optimization problems relating to wireless sensor network planning, design, deployment and operation often give rise to multi-objective optimization formulations where multiple desirable objectives compete with each other and the decision maker has to select one of the tradeoff solutions. These multiple objectives may or may not conflict with each other. Keeping in view the nature of the application, the sensing scenario and input/output of the problem, the type of optimization problem changes. To address different nature of optimization problems relating to wireless sensor network design, deployment, operation, planing and placement, there exist a plethora of optimization solution types. We review and analyze different desirable objectives to show whether they conflict with each other, support each other or they are design dependent. We also present a generic multi-objective optimization problem relating to wireless sensor network which consists of input variables, required output, objectives and constraints. A list of constraints is also presented to give an overview of different constraints which are considered while formulating the optimization problems in wireless sensor networks. Keeping in view the multi facet coverage of this article relating to multi-objective optimization, this will open up new avenues of research in the area of multi-objective optimization relating to wireless sensor networks. PMID:26205271

  20. Assessment of groundwater vulnerability using supervised committee to combine fuzzy logic models.

    PubMed

    Nadiri, Ata Allah; Gharekhani, Maryam; Khatibi, Rahman; Moghaddam, Asghar Asghari

    2017-03-01

    Vulnerability indices of an aquifer assessed by different fuzzy logic (FL) models often give rise to differing values with no theoretical or empirical basis to establish a validated baseline or to develop a comparison basis between the modeling results and baselines, if any. Therefore, this research presents a supervised committee fuzzy logic (SCFL) method, which uses artificial neural networks to overarch and combine a selection of FL models. The indices are expressed by the widely used DRASTIC framework, which include geological, hydrological, and hydrogeological parameters often subject to uncertainty. DRASTIC indices represent collectively intrinsic (or natural) vulnerability and give a sense of contaminants, such as nitrate-N, percolating to aquifers from the surface. The study area is an aquifer in Ardabil plain, the province of Ardabil, northwest Iran. Improvements on vulnerability indices are achieved by FL techniques, which comprise Sugeno fuzzy logic (SFL), Mamdani fuzzy logic (MFL), and Larsen fuzzy logic (LFL). As the correlation between estimated DRASTIC vulnerability index values and nitrate-N values is as low as 0.4, it is improved significantly by FL models (SFL, MFL, and LFL), which perform in similar ways but have differences. Their synergy is exploited by SCFL and uses the FL modeling results "conditioned" by nitrate-N values to raise their correlation to higher than 0.9.

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