WorldWideScience

Sample records for understanding complex matter

  1. Fundamental understanding of matter: an engineering viewpoint

    International Nuclear Information System (INIS)

    Cullingford, H.S.; Cort, G.E.

    1980-01-01

    Fundamental understanding of matter is a continuous process that should produce physical data for use by engineers and scientists in their work. Lack of fundamental property data in any engineering endeavor cannot be mitigated by theoretical work that is not confirmed by physical experiments. An engineering viewpoint will be presented to justify the need for understanding of matter. Examples will be given in the energy engineering field to outline the importance of further understanding of material and fluid properties and behavior. Cases will be cited to show the effects of various data bases in energy, mass, and momentum transfer. The status of fundamental data sources will be discussed in terms of data centers, new areas of engineering, and the progress in measurement techniques. Conclusions and recommendations will be outlined to improve the current situation faced by engineers in carrying out their work. 4 figures

  2. Neutron beams. Understanding and characterizing matter

    International Nuclear Information System (INIS)

    Pepy, G.

    2007-01-01

    This article treats of the numerous methods that use the undulatory properties of neutrons (their scattering in matter). Content: 1 - structure of crystallized matter: determination of a magnetic structure, hydrogen localization inside an alloy, 3D mapping of internal stresses inside materials, determination of the crystallographic structure, structure of a monocrystal by 4 circles diffraction; 2 - reflectometry, surface profiles: super-mirrors for neutron guides, giant magnetoresistance thin film devices; 3 - small angle scattering: protein and polyelectrolyte complexes, ropes integrity and microstructure, aggregates growth inside irradiated steels, microstructural evolution of defects inside race car engine pistons; 4 - dynamics: collective mode dynamics - three axis spectrometer, Mn Te magnons in thin film, scattering dynamics - quasi-elastic time-of-flight spectrometer, water diffusion inside cement. (J.S.)

  3. White matter abnormalities in tuberous sclerosis complex

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, P.D. [Sheffield Univ. (United Kingdom). Academic Dept. of Radiology; Bolton, P. [Cambridge Univ. (United Kingdom). Section of Developmental Psychiatry; Verity, C. [Addenbrooke`s NHS Trust, Cambridge (United Kingdom). Dept. of Paediatric Radiology

    1998-09-01

    The aim of this study was to investigate and describe the range of white matter abnormalities in children with tuberous sclerosis complex by means of MR imaging. Material and Methods: A retrospective cross-sectional study was performed on the basis of MR imaging findings in 20 cases of tuberous sclerosis complex in children aged 17 years or younger. Results: White matter abnormalities were present in 19/20 (95%) cases of tuberous sclerosis complex. These were most frequently (19/20 cases) found in relation to cortical tubers in the supratentorial compartment. White matter abnormalities related to tubers were found in the cerebellum in 3/20 (15%) cases. White matter abnormalities described as radial migration lines were found in relation to 5 tubers in 3 (15%) children. In 4/20 (20%) cases, white matter abnormalities were found that were not related to cortical tubers. These areas had the appearance of white matter cysts in 3 cases and infarction in the fourth. In the latter case there was a definable event in the clinical history, supporting the diagnosis of stroke. Conclusion: A range of white matter abnormalities were found by MR imaging in tuberous sclerosis complex, the commonest being gliosis and hypomyelination related to cortical tubers. Radial migration lines were seen infrequently in relation to cortical tubers and these are thought to represent heterotopic glia and neurons along the expected path of cortical migration. (orig.)

  4. Complexity analysis in particulate matter measurements

    Directory of Open Access Journals (Sweden)

    Luciano Telesca

    2011-09-01

    Full Text Available We investigated the complex temporal fluctuations of particulate matter data recorded in London area by using the Fisher-Shannon (FS information plane. In the FS plane the PM10 and PM2.5 data are aggregated in two different clusters, characterized by different degrees of order and organization. This results could be related to different sources of the particulate matter.

  5. Scalar dark matter: real vs complex

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hongyan; Zheng, Sibo [Department of Physics, Chongqing University,Chongqing 401331 (China)

    2017-03-27

    We update the parameter spaces for both a real and complex scalar dark matter via the Higgs portal. In the light of constraints arising from the LUX 2016 data, the latest Higgs invisible decay and the gamma ray spectrum, the dark matter resonant mass region is further restricted to a narrow window between 54.9−62.3 GeV in both cases, and its large mass region is excluded until 834 GeV and 3473 GeV for the real and complex scalar, respectively.

  6. Scalar dark matter: real vs complex

    International Nuclear Information System (INIS)

    Wu, Hongyan; Zheng, Sibo

    2017-01-01

    We update the parameter spaces for both a real and complex scalar dark matter via the Higgs portal. In the light of constraints arising from the LUX 2016 data, the latest Higgs invisible decay and the gamma ray spectrum, the dark matter resonant mass region is further restricted to a narrow window between 54.9−62.3 GeV in both cases, and its large mass region is excluded until 834 GeV and 3473 GeV for the real and complex scalar, respectively.

  7. Wet granular matter a truly complex fluid

    CERN Document Server

    Herminghaus, Stephan

    2013-01-01

    This is a monograph written for the young and advanced researcher who is entering the field of wet granular matter and keen to understand the basic physical principles governing this state of soft matter. It treats wet granulates as an instance of a ternary system, consisting of the grains, a primary, and a secondary fluid. After addressing wetting phenomena in general and outlining the basic facts on dry granular systems, a chapter on basic mechanisms and their effects is dedicated to every region of the ternary phase diagram. Effects of grain shape and roughness are considered as well. Rather than addressing engineering aspects such as existing books on this topic do, the book aims to provide a generalized framework suitable for those who want to understand these systems on a more fundamental basis. Readership: For the young and advanced researcher entering the field of wet granular matter.

  8. Understanding soft condensed matter via modeling and computation

    CERN Document Server

    Shi, An-Chang

    2011-01-01

    All living organisms consist of soft matter. For this reason alone, it is important to be able to understand and predict the structural and dynamical properties of soft materials such as polymers, surfactants, colloids, granular matter and liquids crystals. To achieve a better understanding of soft matter, three different approaches have to be integrated: experiment, theory and simulation. This book focuses on the third approach - but always in the context of the other two.

  9. Understanding Financial Statements. Financial Matters. Board Basics.

    Science.gov (United States)

    McCarthy, John H.; Turner, Robert M.

    1998-01-01

    This booklet for trustees of higher education institutions offers guidelines to help trustees understand the institution's financial statements. Individual sections describe the three major financial statements and cover topics such as: (1) standards of the Financial Accounting Standards Board; (2) the "statement of financial position,"…

  10. Parental Understanding of Tuberous Sclerosis Complex.

    Science.gov (United States)

    Samia, Pauline; Donald, Kirsten A; Schlegel, Birgit; Wilmshurst, Jo M

    2015-09-01

    Tuberous sclerosis complex is a genetic disorder with multisystem involvement that poses significant challenges to the affected child and family. Caregiver knowledge in the South African population has not previously been reported. A prospective study of the parents of 21 children with tuberous sclerosis complex was undertaken. Median parental age was 38 (interquartile range 34.5-45) years. Parents were randomly allocated to receive written information about the condition, or to receive verbal counseling already established in clinic. A significant difference (P = .001) was observed in the change in the mean knowledge scores for the parent group that received written information (34.2 at baseline, 51.7 at the second visit. This impact was higher in parents with an education level of at least grade 8 (P = .003). Parental understanding of tuberous sclerosis complex can be improved by provision of written information and should be routinely available in a readily understandable format. © The Author(s) 2014.

  11. Understanding Complex Construction Systems Through Modularity

    DEFF Research Database (Denmark)

    Jensen, Tor Clarke; Bekdik, Baris; Thuesen, Christian

    2014-01-01

    This paper develops a framework for understanding complexity in construction projects by combining theories of complexity management and modularization. The framework incorporates three dimensions of product, process, and organizational modularity with the case of gypsum wall elements. The analysis...... system, rather than a modular, although the industry forces modular organizational structures. This creates a high complexity degree caused by the non-alignment of building parts and organizations and the frequent swapping of modules....... finds that the main driver of complexity is the fragmentation of the design and production, which causes the production modules to construct and install new product types and variants for each project as the designers are swapped for every project. The many interfaces are characteristics of an integral...

  12. Evolution in students' understanding of thermal physics with increasing complexity

    Science.gov (United States)

    Langbeheim, Elon; Safran, Samuel A.; Livne, Shelly; Yerushalmi, Edit

    2013-12-01

    We analyze the development in students’ understanding of fundamental principles in the context of learning a current interdisciplinary research topic—soft matter—that was adapted to the level of high school students. The topic was introduced in a program for interested 11th grade high school students majoring in chemistry and/or physics, in an off-school setting. Soft matter was presented in a gradual increase in the degree of complexity of the phenomena as well as in the level of the quantitative analysis. We describe the evolution in students’ use of fundamental thermodynamics principles to reason about phase separation—a phenomenon that is ubiquitous in soft matter. In particular, we examine the impact of the use of free energy analysis, a common approach in soft matter, on the understanding of the fundamental principles of thermodynamics. The study used diagnostic questions and classroom observations to gauge the student’s learning. In order to gain insight on the aspects that shape the understanding of the basic principles, we focus on the responses and explanations of two case-study students who represent two trends of evolution in conceptual understanding in the group. We analyze changes in the two case studies’ management of conceptual resources used in their analysis of phase separation, and suggest how their prior knowledge and epistemological framing (a combination of their personal tendencies and their prior exposure to different learning styles) affect their conceptual evolution. Finally, we propose strategies to improve the instruction of these concepts.

  13. Matter-wave interferometry with complex nanoparticles

    International Nuclear Information System (INIS)

    Geyer, P.

    2015-01-01

    Quantum Mechanics is one of the most thoroughly tested theories in physics; however the quantum phenomena that appear on the microscopic scale are incompatible with the behavior of the macroscopic world. Whether the transition between quantum and classical behavior is virtual or real is still an open question. During my thesis I have built, together with my colleagues, a Talbot-Lau interferometer with light gratings that is capable of handling very large and complex particles. With this device it will be possible to test some of the hypotheses that postulate mechanisms for the quantum to classic transition. During my thesis I have designed the experimental setup using CAD and we assembled the apparatus. I have designed and implemented the data acquisition and experiment control software system MOPS (Molecular Optics Programming System). Furthermore, I have implemented and tested various particle sources for the experiment to bring neutral particles into the gas phase at a velocity and with a beam flux that meets the requirements of the experiment. The Optical Time-domain Interferometer for Matter-waves (OTIMA) is made up of 3 retro-reflected, ⁓7 ns short excimer laser pulses with a wavelength of 157.6 nm, i.e. a grating period of 78.8 nm. The purely optical and pulsed diffraction elements avoid all dispersive interactions that would reduce the interference contrast. Therefore, we expect a high fringe contrast even for large particles; under realistic conditions on earth this type of interferometer is conceptually capable of exploring the wave-particle duality with particles up to 106 amu or even beyond. During my PhD thesis we successfully showed interference for single-photon ionizable molecular clusters up to 2300 amu. Furthermore, we have demonstrated that single-photon fragmentation gratings enable interference experiments with a new class of weakly bound particles and provided interesting perspectives for biomolecules. (author) [de

  14. Dependency visualization for complex system understanding

    Energy Technology Data Exchange (ETDEWEB)

    Smart, J. Allison Cory [Univ. of California, Davis, CA (United States)

    1994-09-01

    With the volume of software in production use dramatically increasing, the importance of software maintenance has become strikingly apparent. Techniques now sought and developed for reverse engineering and design extraction and recovery. At present, numerous commercial products and research tools exist which are capable of visualizing a variety of programming languages and software constructs. The list of new tools and services continues to grow rapidly. Although the scope of the existing commercial and academic product set is quite broad, these tools still share a common underlying problem. The ability of each tool to visually organize object representations is increasingly impaired as the number of components and component dependencies within systems increases. Regardless of how objects are defined, complex ``spaghetti`` networks result in nearly all large system cases. While this problem is immediately apparent in modem systems analysis involving large software implementations, it is not new. As will be discussed in Chapter 2, related problems involving the theory of graphs were identified long ago. This important theoretical foundation provides a useful vehicle for representing and analyzing complex system structures. While the utility of directed graph based concepts in software tool design has been demonstrated in literature, these tools still lack the capabilities necessary for large system comprehension. This foundation must therefore be expanded with new organizational and visualization constructs necessary to meet this challenge. This dissertation addresses this need by constructing a conceptual model and a set of methods for interactively exploring, organizing, and understanding the structure of complex software systems.

  15. Evolution in students’ understanding of thermal physics with increasing complexity

    Directory of Open Access Journals (Sweden)

    Elon Langbeheim

    2013-11-01

    Full Text Available We analyze the development in students’ understanding of fundamental principles in the context of learning a current interdisciplinary research topic—soft matter—that was adapted to the level of high school students. The topic was introduced in a program for interested 11th grade high school students majoring in chemistry and/or physics, in an off-school setting. Soft matter was presented in a gradual increase in the degree of complexity of the phenomena as well as in the level of the quantitative analysis. We describe the evolution in students’ use of fundamental thermodynamics principles to reason about phase separation—a phenomenon that is ubiquitous in soft matter. In particular, we examine the impact of the use of free energy analysis, a common approach in soft matter, on the understanding of the fundamental principles of thermodynamics. The study used diagnostic questions and classroom observations to gauge the student’s learning. In order to gain insight on the aspects that shape the understanding of the basic principles, we focus on the responses and explanations of two case-study students who represent two trends of evolution in conceptual understanding in the group. We analyze changes in the two case studies’ management of conceptual resources used in their analysis of phase separation, and suggest how their prior knowledge and epistemological framing (a combination of their personal tendencies and their prior exposure to different learning styles affect their conceptual evolution. Finally, we propose strategies to improve the instruction of these concepts.

  16. In between matters, interfaces in complex oxides

    NARCIS (Netherlands)

    van Zalk, M.

    2009-01-01

    Complex oxides are emerging as a versatile class of materials, exhibiting a wide variety of properties. In recent years, it has become increasingly clear that the properties of complex-oxide interfaces can differ considerably from those of the bulk. This opens up the possibility of tuning and

  17. In Between Matters : Interfaces in Complex Oxides

    NARCIS (Netherlands)

    van Zalk, M.

    2009-01-01

    Complex oxides are emerging as a versatile class of materials, exhibiting a wide variety of properties. In recent years, it has become increasingly clear that the properties of complex-oxide interfaces can differ considerably from those of the bulk. This opens up the possibility of tuning and

  18. Complexities of Parental Understanding of Phenylketonuria

    Science.gov (United States)

    Sibinga, Maarten S.; Friedman, C. Jack

    1971-01-01

    Parental understanding of PKU, investigated through a questionnaire, was evaluated as to completeness and with respect to distortion. Education of parents was found to be unrelated to their understanding or tendency to distort. Effectiveness of the pediatrician's communication with parents is discussed. (Author/KW)

  19. Improved understanding of protein complex offers insight into DNA

    Science.gov (United States)

    Summer Science Writing Internship Improved understanding of protein complex offers insight into DNA clearer understanding of the origin recognition complex (ORC) - a protein complex that directs DNA replication - through its crystal structure offers new insight into fundamental mechanisms of DNA replication

  20. ICPP: Approach for Understanding Complexity of Plasma

    Science.gov (United States)

    Sato, Tetsuya

    2000-10-01

    In this talk I wish to present an IT system that could promote Science of Complexity. In order to deal with a seemingly `complex' phenomenon, which means `beyond analytical manipulation', computer simulation is a viable powerful tool. However, complexity implies a concept beyond the horizon of reductionism. Therefore, rather than simply solving a complex phenomenon for a given boundary condition, one must establish an intelligent way of attacking mutual evolution of a system and its environment. NIFS-TCSC has been developing a prototype system that consists of supercomputers, virtual reality devices and high-speed network system. Let us explain this by picking up a global atmospheric circulation group, global oceanic circulation group and local weather prediction group. Local weather prediction group predicts the local change of the weather such as the creation of cloud and rain in the near future under the global conditions obtained by the global atmospheric and ocean groups. The global groups run simulations by modifying the local heat source/sink evaluated by the local weather prediction and then obtain the global conditions in the next time step. By repeating such a feedback performance one can predict the mutual evolution of the local system and its environment. Mutual information exchanges among multiple groups are carried out instantaneously by the networked common virtual reality space in which 3-D global and local images of the atmospheric and oceanic circulation and the cloud and rain maps are arbitrarily manipulated by any of the groups and commonly viewed. The present networking system has a great advantage that any simulation groups can freely and arbitrarily change their alignment, so that mutual evolution of any stratum system can become tractable by utilizing this network system.

  1. Framework for understanding LENR processes, using conventional condensed matter physics

    International Nuclear Information System (INIS)

    Chubb, Scott R.

    2006-01-01

    Conventional condensed matter physics provides a unifying framework for understanding low-energy nuclear reactions (LENRs) in solids. In the paper, standard many-body physics techniques are used to illustrate this fact. Specifically, the paper shows that formally the theories by Schwinger, Hagelstein, and Chubb and Chubb (C and C), all can be related to a common set of equations, associated with reaction rate and energy transfer, through a standard many-body physics procedure (R-matrix theory). In each case, particular forms of coherence are used that, implicitly provide a mechanism for understanding how LENRs can proceed without. the emission of high-energy particles. In addition, additional ideas, associated with Conventional Condensed Matter physics, are used to extend the earlier ion band state (IBS) model by C and C. The general model clarifies the origin of coherent. processes that initiate LENRs, through the onset of ion conduction that can occur through ionic fluctuations in nano-scale crystals. In the case of PdD x , these fluctuations begin to occur as x → 1 in sub-lattice structures with characteristic dimensions of 60 nm. The resulting LENRs are triggered by the polarization between injected d's and electrons (immediately above the Fermi energy) that takes place in finite-size PdD crystals. During the prolonged charging of PdD x the applied, external electric field induces these fluctuations through a form of Zener tunneling that mimics the kind of tunneling, predicted by Zener, that is responsible for possible conduction (referred to as Zener-electric breakdown) in insulators. But because the fluctuations are ionic and they occur in PdD, nano-scale structures, a more appropriate characterization is Zener-ionic breakdown in nano-crystalline PdD. Using the underlying dynamics, it is possible to relate triggering times that are required for the initiation of the effect, to crystal size and externally applied fields. (authors)

  2. Framework for understanding LENR processes, using conventional condensed matter physics

    Energy Technology Data Exchange (ETDEWEB)

    Chubb, Scott R. [Research Systems Inc., 9822 Pebble Weigh Ct., Burke VA 22015-3378 (United States)

    2006-07-01

    Conventional condensed matter physics provides a unifying framework for understanding low-energy nuclear reactions (LENRs) in solids. In the paper, standard many-body physics techniques are used to illustrate this fact. Specifically, the paper shows that formally the theories by Schwinger, Hagelstein, and Chubb and Chubb (C and C), all can be related to a common set of equations, associated with reaction rate and energy transfer, through a standard many-body physics procedure (R-matrix theory). In each case, particular forms of coherence are used that, implicitly provide a mechanism for understanding how LENRs can proceed without. the emission of high-energy particles. In addition, additional ideas, associated with Conventional Condensed Matter physics, are used to extend the earlier ion band state (IBS) model by C and C. The general model clarifies the origin of coherent. processes that initiate LENRs, through the onset of ion conduction that can occur through ionic fluctuations in nano-scale crystals. In the case of PdD{sub x}, these fluctuations begin to occur as x {yields} 1 in sub-lattice structures with characteristic dimensions of 60 nm. The resulting LENRs are triggered by the polarization between injected d's and electrons (immediately above the Fermi energy) that takes place in finite-size PdD crystals. During the prolonged charging of PdD{sub x} the applied, external electric field induces these fluctuations through a form of Zener tunneling that mimics the kind of tunneling, predicted by Zener, that is responsible for possible conduction (referred to as Zener-electric breakdown) in insulators. But because the fluctuations are ionic and they occur in PdD, nano-scale structures, a more appropriate characterization is Zener-ionic breakdown in nano-crystalline PdD. Using the underlying dynamics, it is possible to relate triggering times that are required for the initiation of the effect, to crystal size and externally applied fields. (authors)

  3. Understanding Interdependency Through Complex Information Sharing

    Directory of Open Access Journals (Sweden)

    Fernando Rosas

    2016-01-01

    Full Text Available The interactions between three or more random variables are often nontrivial, poorly understood and, yet, are paramount for future advances in fields such as network information theory, neuroscience and genetics. In this work, we analyze these interactions as different modes of information sharing. Towards this end, and in contrast to most of the literature that focuses on analyzing the mutual information, we introduce an axiomatic framework for decomposing the joint entropy that characterizes the various ways in which random variables can share information. Our framework distinguishes between interdependencies where the information is shared redundantly and synergistic interdependencies where the sharing structure exists in the whole, but not between the parts. The key contribution of our approach is to focus on symmetric properties of this sharing, which do not depend on a specific point of view for differentiating roles between its components. We show that our axioms determine unique formulas for all of the terms of the proposed decomposition for systems of three variables in several cases of interest. Moreover, we show how these results can be applied to several network information theory problems, providing a more intuitive understanding of their fundamental limits.

  4. Complexation of lead by organic matter in Luanda Bay, Angola.

    Science.gov (United States)

    Leitão, Anabela; Santos, Ana Maria; Boaventura, Rui A R

    2015-10-01

    Speciation is defined as the distribution of an element among different chemical species. Although the relation between speciation and bioavailability is complex, the metal present as free hydrated ion, or as weak complexes able to dissociate, is usually more bioavailable than the metal incorporated in strong complexes or adsorbed on colloidal or particulate matter. Among the analytical techniques currently available, anodic stripping voltammetry (ASV) has been one of the most used in the identification and quantification of several heavy metal species in aquatic systems. This work concerns the speciation study of lead, in original (natural, non-filtered) and filtered water samples and in suspensions of particulate matter and sediments from Luanda Bay (Angola). Complexes of lead with organics were identified and quantified by differential pulse anodic stripping voltammetry technique. Each sample was progressively titrated with a Pb(II) standard solution until complete saturation of the organic ligands. After each addition of Pb(II), the intensity, potential and peak width of the voltammetric signal were measured. The results obtained in this work show that more than 95 % of the lead in the aquatic environment is bound in inert organic complexes, considering all samples from different sampling sites. In sediment samples, the lead is totally (100 %) complexed with ligands adsorbed on the particles surface. Two kinds of dominant lead complexes, very strong (logK >11) and strong to moderately strong (8< logK <11), were found, revealing the lead affinity for the stronger ligands.

  5. Ecosystemic Complexity Theory of Conflict: Understanding the Fog of Conflict

    Science.gov (United States)

    Brack, Greg; Lassiter, Pamela S.; Hill, Michele B.; Moore, Sarah A.

    2011-01-01

    Counselors often engage in conflict mediation in professional practice. A model for understanding the complex and subtle nature of conflict resolution is presented. The ecosystemic complexity theory of conflict is offered to assist practitioners in navigating the fog of conflict. Theoretical assumptions are discussed with implications for clinical…

  6. Understanding Learner Agency as a Complex Dynamic System

    Science.gov (United States)

    Mercer, Sarah

    2011-01-01

    This paper attempts to contribute to a fuller understanding of the nature of language learner agency by considering it as a complex dynamic system. The purpose of the study was to explore detailed situated data to examine to what extent it is feasible to view learner agency through the lens of complexity theory. Data were generated through a…

  7. A Chargeless Complex Vector Matter Field in Supersymmetric Scenario

    Directory of Open Access Journals (Sweden)

    L. P. Colatto

    2015-01-01

    Full Text Available We construct and study a formulation of a chargeless complex vector matter field in a supersymmetric framework. To this aim we combine two nochiral scalar superfields in order to take the vector component field to build the chargeless complex vector superpartner where the respective field strength transforms into matter fields by a global U1 gauge symmetry. For the aim of dealing with consistent terms without breaking the global U1 symmetry we imposes a choice to the complex combination revealing a kind of symmetry between the choices and eliminates the extra degrees of freedom which is consistent with the supersymmetry. As the usual case the mass supersymmetric sector contributes as a complement to dynamics of the model. We obtain the equations of motion of the Proca’s type field for the chiral spinor fields and for the scalar field on the mass-shell which show the same mass as expected. This work establishes the first steps to extend the analysis of charged massive vector field in a supersymmetric scenario.

  8. Thorium-particulate matter interaction. Thorium complexing capacity of oceanic particulate matter: Theory

    International Nuclear Information System (INIS)

    Hirose, Katsumi; Tanque, Eiichiro

    1994-01-01

    The interaction between thorium and oceanic particulate matter was examined experimentally by using chemical equilibrium techniques. Thorium reacts quantitatively with the organic binding site of Particulate Matter (PM) in 0.1 mol/L HCl solution by complexation, which is equilibrated within 34 h. According to mass balance analysis, thorium forms a 1:1 complex with the organic binding site in PM, whose conditional stability constant is 10 6.6 L/mol. The Th adsorption ability is present even in 6.9 mol/L HCl solution although the amount of Th adsorption decreases with increasing acidity in the solution. Interferences to Th adsorption by Fe(III) suggests that other metals cannot react with PM in more than 0.1 mol/L HCl solutions when concentrations of other metals are the same level of Th. The competitive reaction between Th and Fe(III) occurs in higher Fe concentrations, which means that the organic binding site is nonspecific for Th. A vertical profile of Th complexing capacity of PM in the western North Pacific is characterized; that is, the Th complexing capacity shows a surface maximum and decreases rapidly with depth

  9. Understanding complex urban systems multidisciplinary approaches to modeling

    CERN Document Server

    Gurr, Jens; Schmidt, J

    2014-01-01

    Understanding Complex Urban Systems takes as its point of departure the insight that the challenges of global urbanization and the complexity of urban systems cannot be understood – let alone ‘managed’ – by sectoral and disciplinary approaches alone. But while there has recently been significant progress in broadening and refining the methodologies for the quantitative modeling of complex urban systems, in deepening the theoretical understanding of cities as complex systems, or in illuminating the implications for urban planning, there is still a lack of well-founded conceptual thinking on the methodological foundations and the strategies of modeling urban complexity across the disciplines. Bringing together experts from the fields of urban and spatial planning, ecology, urban geography, real estate analysis, organizational cybernetics, stochastic optimization, and literary studies, as well as specialists in various systems approaches and in transdisciplinary methodologies of urban analysis, the volum...

  10. Understanding Music's Therapeutic Efficacy with Implications for Why Music Matters

    Science.gov (United States)

    Thram, Diane

    2015-01-01

    In this essay, I focus on how attention to music's therapeutic efficacy is important to the praxial music education philosophy espoused by Elliott and Silverman. I note, despite the use of the term praxis from Aristotle's philosophy dating back to antiquity, there is no mention in Music Matters 2 of what historical evidence tells us about how…

  11. Simple, complex and hyper-complex understanding - enhanced sensitivity in observation of information

    DEFF Research Database (Denmark)

    Bering Keiding, Tina

    for construction and analysis of empirical information. A quick overview on empirical research drawing on Luhmann reveals a diverse complex of analytical strategies and empirical methods. Despite differences between strategies and methods they have in common that understanding of uttered information is crucial...... in their production of empirically founded knowledge. However research generally seems to pay more attention to production of uttered information than to selection of understanding. The aim of this contribution is to sketch out a suggestion to how selection of understanding can be systematized in order to produce...... enhanced transparency in selection of understanding as well as enhanced sensitivity and definition in dept. The contribution suggest that we distinguish between three types of understanding; simple, complex and hyper-complex understanding. Simple understanding is the simultaneous selection of understanding...

  12. Mercury reduction and complexation by natural organic matter

    International Nuclear Information System (INIS)

    Gu, Baohua; Bian, Yongrong; Miller, Carrie L.; Dong, Wenming; Jiang, Xin; Liang, Liyuan

    2011-01-01

    Mercuric Hg(II) species form complexes with natural dissolved organic matter (DOM) such as humic acid (HA), and this binding is known to affect the chemical and biological transformation and cycling of mercury in aquatic environments. Dissolved elemental mercury, Hg(0), is also widely observed in sediments and water. However, reactions between Hg(0) and DOM have rarely been studied in anoxic environments. Here, under anoxic dark conditions we show strong interactions between reduced HA and Hg(0) through thiol-ligand induced oxidative complexation with an estimated binding capacity of about 3.5 umol Hg(0)/g HA and a partitioning coefficient greater than 10 6 mL/g. We further demonstrate that Hg(II) can be effectively reduced to Hg(0) in the presence of as little as 0.2 mg/L reduced HA, whereas production of purgeable Hg(0) is inhibited by complexation as HA concentration increases. This dual role played by DOM in the reduction and complexation of mercury is likely widespread in anoxic sediments and water and can be expected to significantly influence the mercury species transformations and biological uptake that leads to the formation of toxic methylmercury.

  13. How to make a complex story understandable. Communication on nitrogen

    International Nuclear Information System (INIS)

    Bleeker, A.; Hensen, A.; Erisman, J.W.

    2011-01-01

    Understanding is the first step towards solving the nitrogen problem. Various applications have been developed to gain insight in the complex interactions between the nitrogen cycle and the social-economic and environmental aspects. Experience has learned that many users have not only gained a clearer picture of the urgency and complexity of the problem; now they also have options for dealing with the nitrogen problem. [nl

  14. Physics understanding the properties of matter and energy

    CERN Document Server

    2015-01-01

    Without physics, modern life would not exist. Instead of electric light, we would read by the light of candles. We couldn''t build skyscrapers. We could not possibly bridge rivers, much less build a jet or interplanetary craft. Computers and smartphones would be unimaginable. Physics is concerned with the most fundamental aspects of matter and energy and how they interact to make the physical universe work. In accessible language and with explanatory graphics and visual aids, this book introduces readers to the science that is at the very center of all other sciences and essential to our very

  15. Understanding complex urban systems integrating multidisciplinary data in urban models

    CERN Document Server

    Gebetsroither-Geringer, Ernst; Atun, Funda; Werner, Liss

    2016-01-01

    This book is devoted to the modeling and understanding of complex urban systems. This second volume of Understanding Complex Urban Systems focuses on the challenges of the modeling tools, concerning, e.g., the quality and quantity of data and the selection of an appropriate modeling approach. It is meant to support urban decision-makers—including municipal politicians, spatial planners, and citizen groups—in choosing an appropriate modeling approach for their particular modeling requirements. The contributors to this volume are from different disciplines, but all share the same goal: optimizing the representation of complex urban systems. They present and discuss a variety of approaches for dealing with data-availability problems and finding appropriate modeling approaches—and not only in terms of computer modeling. The selection of articles featured in this volume reflect a broad variety of new and established modeling approaches such as: - An argument for using Big Data methods in conjunction with Age...

  16. Increasing process understanding by analyzing complex interactions in experimental data

    DEFF Research Database (Denmark)

    Naelapaa, Kaisa; Allesø, Morten; Kristensen, Henning Gjelstrup

    2009-01-01

    understanding of a coating process. It was possible to model the response, that is, the amount of drug released, using both mentioned techniques. However, the ANOVAmodel was difficult to interpret as several interactions between process parameters existed. In contrast to ANOVA, GEMANOVA is especially suited...... for modeling complex interactions and making easily understandable models of these. GEMANOVA modeling allowed a simple visualization of the entire experimental space. Furthermore, information was obtained on how relative changes in the settings of process parameters influence the film quality and thereby drug......There is a recognized need for new approaches to understand unit operations with pharmaceutical relevance. A method for analyzing complex interactions in experimental data is introduced. Higher-order interactions do exist between process parameters, which complicate the interpretation...

  17. Context Matters: Increasing Understanding with Interactive Clicker Case Studies

    Science.gov (United States)

    Lundeberg, Mary A.; Kang, Hosun; Wolter, Bjorn; delMas, Robert; Armstrong, Norris; Borsari, Bruno; Boury, Nancy; Brickman, Peggy; Hannam, Kristi; Heinz, Cheryl; Horvath, Thomas; Knabb, Maureen; Platt, Terry; Rice, Nancy; Rogers, Bill; Sharp, Joan; Ribbens, Eric; Maier, Kimberly S.; Deschryver, Mike; Hagley, Rodney; Goulet, Tamar; Herreid, Clyde F.

    2011-01-01

    Although interactive technology is presumed to increase student understanding in large classes, no previous research studies have empirically explored the effects of Clicker Cases on students' performance. A Clicker Case is a story (e.g., a problem someone is facing) that uses clickers (student response systems) to engage students in understanding…

  18. Understanding Cellular Respiration in Terms of Matter & Energy within Ecosystems

    Science.gov (United States)

    White, Joshua S.; Maskiewicz, April C.

    2014-01-01

    Using a design-based research approach, we developed a data-rich problem (DRP) set to improve student understanding of cellular respiration at the ecosystem level. The problem tasks engage students in data analysis to develop biological explanations. Several of the tasks and their implementation are described. Quantitative results suggest that…

  19. Framework for Understanding LENR Processes, Using Ordinary Condensed Matter Physics

    Science.gov (United States)

    Chubb, Scott

    2005-03-01

    As I have emphasizedootnotetextS.R. Chubb, Proc. ICCF10 (in press). Also, http://www.lenr-canr.org/acrobat/ChubbSRnutsandbol.pdf http://www.lenr-canr.org/acrobat/ChubbSRnutsandbol.pdf, S.R. Chubb, Trans. Amer. Nuc. Soc. 88 , 618 (2003)., in discussions of Low Energy Nuclear Reactions(LENRs), mainstream many-body physics ideas have been largely ignored. A key point is that in condensed matter, delocalized, wave-like effects can allow large amounts of momentum to be transferred instantly to distant locations, without any particular particle (or particles) acquiring high velocity through a Broken Gauge Symmetry. Explicit features in the electronic structure explain how this can occur^1 in finite size PdD crystals, with real boundaries. The essential physics^1 can be related to standard many-body techniquesootnotetextBurke,P.G. and K.A. Berrington, Atomic and Molecular Processes:an R matrix Approach (Bristol: IOP Publishing, 1993).. In the paper, I examine this relationship, the relationship of the theory^1 to other LENR theories, and the importance of certain features (for example, boundaries^1) that are not included in the other LENR theories.

  20. Towards a Molecular Understanding of the Fanconi Anemia Core Complex

    Directory of Open Access Journals (Sweden)

    Charlotte Hodson

    2012-01-01

    Full Text Available Fanconi Anemia (FA is a genetic disorder characterized by the inability of patient cells to repair DNA damage caused by interstrand crosslinking agents. There are currently 14 verified FA genes, where mutation of any single gene prevents repair of DNA interstrand crosslinks (ICLs. The accumulation of ICL damage results in genome instability and patients having a high predisposition to cancers. The key event of the FA pathway is dependent on an eight-protein core complex (CC, required for the monoubiquitination of each member of the FANCD2-FANCI complex. Interestingly, the majority of patient mutations reside in the CC. The molecular mechanisms underlying the requirement for such a large complex to carry out a monoubiquitination event remain a mystery. This paper documents the extensive efforts of researchers so far to understand the molecular roles of the CC proteins with regard to its main function in the FA pathway, the monoubiquitination of FANCD2 and FANCI.

  1. Towards a Molecular Understanding of the Fanconi Anemia Core Complex

    Science.gov (United States)

    Hodson, Charlotte; Walden, Helen

    2012-01-01

    Fanconi Anemia (FA) is a genetic disorder characterized by the inability of patient cells to repair DNA damage caused by interstrand crosslinking agents. There are currently 14 verified FA genes, where mutation of any single gene prevents repair of DNA interstrand crosslinks (ICLs). The accumulation of ICL damage results in genome instability and patients having a high predisposition to cancers. The key event of the FA pathway is dependent on an eight-protein core complex (CC), required for the monoubiquitination of each member of the FANCD2-FANCI complex. Interestingly, the majority of patient mutations reside in the CC. The molecular mechanisms underlying the requirement for such a large complex to carry out a monoubiquitination event remain a mystery. This paper documents the extensive efforts of researchers so far to understand the molecular roles of the CC proteins with regard to its main function in the FA pathway, the monoubiquitination of FANCD2 and FANCI. PMID:22675617

  2. Understanding of Leaf Development—the Science of Complexity

    Directory of Open Access Journals (Sweden)

    Robert Malinowski

    2013-06-01

    Full Text Available The leaf is the major organ involved in light perception and conversion of solar energy into organic carbon. In order to adapt to different natural habitats, plants have developed a variety of leaf forms, ranging from simple to compound, with various forms of dissection. Due to the enormous cellular complexity of leaves, understanding the mechanisms regulating development of these organs is difficult. In recent years there has been a dramatic increase in the use of technically advanced imaging techniques and computational modeling in studies of leaf development. Additionally, molecular tools for manipulation of morphogenesis were successfully used for in planta verification of developmental models. Results of these interdisciplinary studies show that global growth patterns influencing final leaf form are generated by cooperative action of genetic, biochemical, and biomechanical inputs. This review summarizes recent progress in integrative studies on leaf development and illustrates how intrinsic features of leaves (including their cellular complexity influence the choice of experimental approach.

  3. Disaster forensics understanding root cause and complex causality

    CERN Document Server

    2016-01-01

    This book aims to uncover the root causes of natural and man-made disasters by going beyond the typical reports and case studies conducted post-disaster. It opens the black box of disasters by presenting ‘forensic analysis approaches’ to disasters, thereby revealing the complex causality that characterizes them and explaining how and why hazards do, or do not, become disasters. This yields ‘systemic’ strategies for managing disasters. Recently the global threat landscape has seen the emergence of high impact, low probability events. Events like Hurricane Katrina, the Great Japan Earthquake and tsunami, Hurricane Sandy, Super Typhoon Haiyan, global terrorist activities have become the new norm. Extreme events challenge our understanding regarding the interdependencies and complexity of the disaster aetiology and are often referred to as Black Swans. Between 2002 and 2011, there were 4130 disasters recorded that resulted from natural hazards around the world. In these, 1,117,527 people perished and a mi...

  4. Complexity and simplification in understanding recruitment in benthic populations

    KAUST Repository

    Pineda, Jesús

    2008-11-13

    Research of complex systems and problems, entities with many dependencies, is often reductionist. The reductionist approach splits systems or problems into different components, and then addresses these components one by one. This approach has been used in the study of recruitment and population dynamics of marine benthic (bottom-dwelling) species. Another approach examines benthic population dynamics by looking at a small set of processes. This approach is statistical or model-oriented. Simplified approaches identify "macroecological" patterns or attempt to identify and model the essential, "first-order" elements of the system. The complexity of the recruitment and population dynamics problems stems from the number of processes that can potentially influence benthic populations, including (1) larval pool dynamics, (2) larval transport, (3) settlement, and (4) post-settlement biotic and abiotic processes, and larval production. Moreover, these processes are non-linear, some interact, and they may operate on disparate scales. This contribution discusses reductionist and simplified approaches to study benthic recruitment and population dynamics of bottom-dwelling marine invertebrates. We first address complexity in two processes known to influence recruitment, larval transport, and post-settlement survival to reproduction, and discuss the difficulty in understanding recruitment by looking at relevant processes individually and in isolation. We then address the simplified approach, which reduces the number of processes and makes the problem manageable. We discuss how simplifications and "broad-brush first-order approaches" may muddle our understanding of recruitment. Lack of empirical determination of the fundamental processes often results in mistaken inferences, and processes and parameters used in some models can bias our view of processes influencing recruitment. We conclude with a discussion on how to reconcile complex and simplified approaches. Although it

  5. Understanding Parkinson Disease: A Complex and Multifaceted Illness.

    Science.gov (United States)

    Gopalakrishna, Apoorva; Alexander, Sheila A

    2015-12-01

    Parkinson disease is an incredibly complex and multifaceted illness affecting millions of people in the United States. Parkinson disease is characterized by progressive dopaminergic neuronal dysfunction and loss, leading to debilitating motor, cognitive, and behavioral symptoms. Parkinson disease is an enigmatic illness that is still extensively researched today to search for a better understanding of the disease, develop therapeutic interventions to halt or slow progression of the disease, and optimize patient outcomes. This article aims to examine in detail the normal function of the basal ganglia and dopaminergic neurons in the central nervous system, the etiology and pathophysiology of Parkinson disease, related signs and symptoms, current treatment, and finally, the profound impact of understanding the disease on nursing care.

  6. Land, power and conflict in Afghanistan: seeking to understand complexity

    Directory of Open Access Journals (Sweden)

    Adam Pain

    2013-06-01

    Full Text Available This paper explores the diverse links between land and power under conditions of conflict in Afghanistan, taking into account the complexities of Afghan society. These complexities are structured around interconnecting informal institutions and personalised relationships, culturally specific, diverse and shifting patterns of social relations, and spatially specific patterns of land ownership inequalities. The paper draws on a decade of empirical fieldwork in Afghanistan and recent work on livelihood trajectories and the opium economy. An understanding of the evolution of land ownership and access issues needs to be associated with an appreciation of diverse and potentially contradictory long-term drivers of change in the rural economy. The first of these long-term drivers of change relates to the effects of conflict, not only on land but also of water access under conditions of an increasingly scarce water supply. The second driver relates both to the roles played by village elites and to the structural contrasts between villages located in the mountains and in the plains, with the latter displaying major inequalities in land ownership. The third driver relates to the declining economic role of land in rural livelihoods, given long-term agrarian change and falling farm sizes. An understanding of history is fundamental to explaining these phenomena. How such conflicts play out, and which social groups or individuals they involve, also depend to a large degree on spatial positioning.

  7. Neuroanthropological Understanding of Complex Cognition – Numerosity and Arithmetics

    Directory of Open Access Journals (Sweden)

    Zarja Mursic

    2013-10-01

    Full Text Available Humankind has a long evolutionary history. When we are trying to understand human complex cognition, it is as well important to look back to entire evolution. I will present the thesis that our biological predispositions and culture, together with natural and social environment, are tightly connected. During ontogenetically development we are shaped by various factors, and they enabled humans to develop some aspects of complex cognition, such as mathematics.In the beginning of the article I present the importance of natural and cultural evolution in other animals. In the following part, I briefly examine the field of mathematics – numerosity and arithmetic. Presentation of comparative animal studies, mainly made on primates, provides some interesting examples in animals’ abilities to separate between different quantities. From abilities for numerosity in animals I continue to neuroscientific studies of humans and our ability to solve simple arithmetic tasks. I also mention cross-cultural studies of arithmetic skills. In the final part of the text I present the field neuroanthropology as a possible new pillar of cognitive science. Finally, it is important to connect human evolution and development with animal cognition studies, but as well with cross-cultural studies in shaping of human ability for numerosity and arithmetic.

  8. Understanding the role of fast electrons in the heating of dense matter: experimental techniques and recent results

    International Nuclear Information System (INIS)

    Freeman, R.; Anderson, C.; Hill, J.M.; King, J.; Snavely, R.; Hatchett, S.; Key, M.; Koch, J.; MacKinnon, A.; Stephens, R.; Cowan, T.

    2003-01-01

    An intense laser impinging upon dense matter converts a large fraction of its energy into fast electrons. (Here we take 'fast' to mean electrons that are much more energetic than the normal Boltzmann-like distribution measured in the tens to hundreds of eV.) Upon transiting the interior of the dense matter, these electrons are responsible for isochoric heating of the material. Just how these electrons traverse the material, and various interfaces within the material, is a subject of substantial amounts of computation and theory, and recently, experiments. Here we outline the nature of the heating mechanisms, and the current level of understanding of the complex physical processes. In particular we discuss new experimental techniques to record essential features of this transport problem

  9. The Effect of Constructivist Science Teaching on 4th Grade Students' Understanding of Matter

    Science.gov (United States)

    Cakici, Yilmaz; Yavuz, Gulben

    2010-01-01

    In the last three decades, the constructivist approach has been the dominant ideology in the field of educational research. The aim of this study is to explore the effect of constructivist science teaching on the students' understanding about matter, and to compare the effectiveness of a constructivist approach over traditional teaching methods.…

  10. Students' Understanding of Conservation of Matter, Stoichiometry and Balancing Equations in Indonesia

    Science.gov (United States)

    Agung, Salamah; Schwartz, Marc S.

    2007-01-01

    This study examines Indonesian students' understanding of conservation of matter, balancing of equations and stoichiometry. Eight hundred and sixty-seven Grade 12 students from 22 schools across four different cities in two developed provinces in Indonesia participated in the study. Nineteen teachers also participated in order to validate the…

  11. The Effect of Logical Thinking and Two Cognitive Styles on Understanding the Structure of Matter: An Analysis with the Random Walk Method

    Science.gov (United States)

    Stamovlasis, Dimitrios; Tsitsipis, Georgios; Papageorgiou, George

    2010-01-01

    This work uses the concepts and tools of complexity theory to examine the effect of logical thinking and two cognitive styles, such as, the degree of field dependence/independence and the convergent/divergent thinking on students' understanding of the structure of matter. Students were categorized according to the model they adopted for the…

  12. Soft condensed matter: Polymers, complex fluids, and biomaterials

    International Nuclear Information System (INIS)

    Schaefer, D.

    1995-01-01

    Historians often characterize epochs through their dominant materials, clay, bronze, iron, and steel. From this perspective, the modern era is certainly the age of plastics. The progression from hard to soft materials suggests that the emerging era will be the age of open-quotes soft condensed matter.close quotes

  13. Spatial Reasoning and Understanding the Particulate Nature of Matter: A Middle School Perspective

    Science.gov (United States)

    Cole, Merryn L.

    This dissertation employed a mixed-methods approach to examine the relationship between spatial reasoning ability and understanding of chemistry content for both middle school students and their science teachers. Spatial reasoning has been linked to success in learning STEM subjects (Wai, Lubinski, & Benbow, 2009). Previous studies have shown a correlation between understanding of chemistry content and spatial reasoning ability (e.g., Pribyl & Bodner, 1987; Wu & Shah, 2003: Stieff, 2013), raising the importance of developing the spatial reasoning ability of both teachers and students. Few studies examine middle school students' or in-service middle school teachers' understanding of chemistry concepts or its relation to spatial reasoning ability. The first paper in this dissertation addresses the quantitative relationship between mental rotation, a type of spatial reasoning ability, and understanding a fundamental concept in chemistry, the particulate nature of matter. The data showed a significant, positive correlation between scores on the Purdue Spatial Visualization Test of Rotations (PSVT; Bodner & Guay, 1997) and the Particulate Nature of Matter Assessment (ParNoMA; Yezierski, 2003) for middle school students prior to and after chemistry instruction. A significant difference in spatial ability among students choosing different answer choices on ParNoMA questions was also found. The second paper examined the ways in which students of different spatial abilities talked about matter and chemicals differently. Students with higher spatial ability tended to provide more of an explanation, though not necessarily in an articulate matter. In contrast, lower spatial ability students tended to use any keywords that seemed relevant, but provided little or no explanation. The third paper examined the relationship between mental reasoning and understanding chemistry for middle school science teachers. Similar to their students, a significant, positive correlation between

  14. Cellular complexity in subcortical white matter: a distributed control circuit?

    Science.gov (United States)

    Colombo, Jorge A

    2018-03-01

    The subcortical white matter (SWM) has been traditionally considered as a site for passive-neutral-information transfer through cerebral cortex association and projection fibers. Yet, the presence of subcortical neuronal and glial "interstitial" cells expressing immunolabelled neurotransmitters/neuromodulators and synaptic vesicular proteins, and recent immunohistochemical and electrophysiological observations on the rat visual cortex as well as interactive regulation of myelinating processes support the possibility that SWM nests subcortical, regionally variable, distributed neuronal-glial circuits, that could influence information transfer. Their hypothetical involvement in regulating the timing and signal transfer probability at the SWM axonal components ought to be considered and experimentally analysed. Thus, the "interstitial" neuronal cells-associated with local glial cells-traditionally considered to be vestigial and functionally inert under normal conditions, they may well turn to be critical in regulating information transfer at the SWM.

  15. Complexation with dissolved organic matter and solubility control of heavy metals in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Lofts, S.; Tipping, E.; Riemsdijk, van W.H.

    2002-01-01

    The complexation of heavy metals with dissolved organic matter (DOM) in the environment influences the solubility and mobility of these metals. In this paper, we measured the complexation of Cu, Cd, Zn, Ni, and Pb with DOM in the soil solution at pH 3.7-6.1 using a Donnan membrane technique. The

  16. Characterization of Aluminum(III) Complexes in Coal Organic Matter

    Czech Academy of Sciences Publication Activity Database

    Straka, Pavel

    2016-01-01

    Roč. 7, č. 4 (2016), s. 378-394 ISSN 2156-8251 Institutional support: RVO:67985891 Keywords : aluminium * complex * 27Al MAS NMR * coal * lignite * altered coal Subject RIV: DD - Geochemistry http://www.scirp.org/journal/AJAC/

  17. Why "g" Matters: The Complexity of Everyday Life.

    Science.gov (United States)

    Gottfredson, Linda S.

    1997-01-01

    This article provides evidence that general intelligence ("g") has pervasive utility in work settings because it is essentially the ability to deal with cognitive complexity. Data from the National Adult Literacy Survey are used to show how higher levels of cognitive ability improve individuals' chances of dealing with the demands of…

  18. Organic matter linked radionuclide transport in Boom clay - Phenomenological understanding and abstraction to PA

    International Nuclear Information System (INIS)

    Maes, N.; Bruggeman, C.; Liu, D.J.; Salah, S.; Van Laer, L.; Wang, L.; Weetjens, E.; Govaerts, J.; Marivoet, J.; Brassinnes, S.

    2012-01-01

    Document available in extended abstract form only. In the frame of the Belgian research program on long term management of high-level and/or long-lived radioactive wastes coordinated by ONDRAF/NIRAS, plastic clays (i.e., Boom Clay and Ypresian clays) are investigated for their potential to host a deep geological disposal repository for radioactive waste because of, among others, their ability to significantly retard radionuclide releases to the biosphere. The Boom Clay is characterised by the presence of a relatively high amount of dissolved organic matter (DOM, humic substances) which show a strong interaction with a suite of radionuclides (RN) like lanthanides, actinides and transition metals. This interaction with DOM leads in general to an increased mobility of the radionuclide as the OM can act as a colloidal carrier for the radionuclide. Therefore, the quantification and the understanding of the underlying processes are needed for the demonstration of confidence in the host formation to act as a suitable barrier. However, this is not an easy task, given the multitude of processes involved: complexation/colloid formation, sorption, kinetics, filtration, -. In this presentation, we will provide an overview of the research work that leads to a straightforward reactive transport model capturing fairly well the experimental observations. The model can be considered as an intermediate model providing a good basis for further safety abstraction on the one hand and the way to a more detailed phenomenological understanding on the other hand. The research is focussed on the underlying processes that govern speciation, sorption and transport. These underlying processes are investigated in a bottom-up approach, from simple systems to more complex systems. Interpretation is done using thermodynamic based models. Whereas the contribution of Bruggeman et al. focusses mainly on (batch) sorption studies (of trivalent RN), this presentation will provide more details on the

  19. Power distribution in complex environmental negotiations: Does balance matter?

    Science.gov (United States)

    Burkardt, N.; Lamb, B.L.; Taylor, J.G.

    1997-01-01

    We studied six interagency negotiations covering Federal Energy Regulatory Commission (FERC) hydroelectric power licenses. Negotiations occurred between state and federal resource agencies and developers over project operations and natural resource mitigation. We postulated that a balance of power among parties was necessary for successful negotiations. We found a complex relationship between balanced power and success and conclude that a balance of power was associated with success in these negotiations. Power played a dynamic role in the bargaining and illuminates important considerations for regulatory design.

  20. Complexity Matters: On Gender Agreement in Heritage Scandinavian

    Science.gov (United States)

    Johannessen, Janne Bondi; Larsson, Ida

    2015-01-01

    This paper investigates aspects of the noun phrase from a Scandinavian heritage language perspective, with an emphasis on noun phrase-internal gender agreement and noun declension. Our results are somewhat surprising compared with earlier research: We find that noun phrase-internal agreement for the most part is rather stable. To the extent that we find attrition, it affects agreement in the noun phrase, but not the declension of the noun. We discuss whether this means that gender is lost and has been reduced to a pure declension class, or whether gender is retained. We argue that gender is actually retained in these heritage speakers. One argument for this is that the speakers who lack agreement in complex noun phrases, have agreement intact in simpler phrases. We have thus found that the complexity of the noun phrase is crucial for some speakers. However, among the heritage speakers we also find considerable inter-individual variation, and different speakers can have partly different systems. PMID:26733114

  1. Enacting understanding of inclusion in complex contexts: classroom ...

    African Journals Online (AJOL)

    Hennie

    2015-08-14

    Aug 14, 2015 ... Dan Tlale. Department of Inclusive Education, College of Education, University of South Africa, Pretoria, South Africa ..... challenges and teachers' understanding of inclusive ..... agency.org/sites/default/files/Profile-of-Inclusive-.

  2. Complexity and simplification in understanding recruitment in benthic populations

    KAUST Repository

    Pineda, Jesú s; Reyns, Nathalie B.; Starczak, Victoria R.

    2008-01-01

    reduces the number of processes and makes the problem manageable. We discuss how simplifications and "broad-brush first-order approaches" may muddle our understanding of recruitment. Lack of empirical determination of the fundamental processes often

  3. Matters of Scale: Sociology in and for a Complex World.

    Science.gov (United States)

    Pyyhtinen, Olli

    2017-08-01

    The article proposes that if sociology is to make sense of a world that is ever more complex and complicated, it is important to reconsider the scale(s) of our relations and actions. Instead of assuming a nested vertical hierarchy of the micro to macro binary, scale should be treated not only as multiple, but also as something produced and sustained in practice. Coming to grips with the complex world, we are living in also necessitates attending to the conduits and connections between various sites, fields, and terrains to which our lives are entangled. The article concludes with a note on the marginalization of sociology from public discussions, and it argues that it is possibly by attending to ambiguity and to the unfinished making of our contemporary world that sociology might have the most to give to discussions about the economy, about the future of humanity, and how to organize society. Cet article suggère que si la sociologie doit nous éclairer sur le sens d'un monde de plus en plus complexe, il est important de revoir l'échelle de nos relations et actions. Au lieu d'assumer une hiérarchie verticale de la dualité micro-macro, cette étendue doit être traitée non seulement comme multiple, mais aussi comme une chose produite et soutenue par la pratique. Pour faire face à la complexité du monde dans lequel nous vivons, il faut aussi de s'occuper des conduits et connections entre des sites divers, des champs, et des terrains dans lesquels nos vies se déroulent. Cet article conclut avec une note sur la marginalisation de la sociologie dans les discussions publiques ; et il défend l'idée que c'est possiblement en appréhendant l'ambiguïté et la construction incomplète de notre monde contemporain que la sociologie peut être la plus fructueuse en termes de discussions portant sur l'économie, le futur de l'humanité, et l'organisation de la société. © 2017 Canadian Sociological Association/La Société canadienne de sociologie.

  4. Understanding global health governance as a complex adaptive system.

    Science.gov (United States)

    Hill, Peter S

    2011-01-01

    The transition from international to global health reflects the rapid growth in the numbers and nature of stakeholders in health, as well as the constant change embodied in the process of globalisation itself. This paper argues that global health governance shares the characteristics of complex adaptive systems, with its multiple and diverse players, and their polyvalent and constantly evolving relationships, and rich and dynamic interactions. The sheer quantum of initiatives, the multiple networks through which stakeholders (re)configure their influence, the range of contexts in which development for health is played out - all compound the complexity of this system. This paper maps out the characteristics of complex adaptive systems as they apply to global health governance, linking them to developments in the past two decades, and the multiple responses to these changes. Examining global health governance through the frame of complexity theory offers insight into the current dynamics of governance, and while providing a framework for making meaning of the whole, opens up ways of accessing this complexity through local points of engagement.

  5. Understanding sustainability from an exergetic frame in complex adaptive systems

    International Nuclear Information System (INIS)

    Aguilar Hernandez, Glem Alonso

    2017-01-01

    The concept of sustainability was developed from thermodynamic properties applied to complex adaptive systems. The origins of the perception about sustainable development and limitation in its application to analyze the interaction between a system and its surroundings were described. The properties of a complex adaptive system were taken as basis to determine how a system can to be affected by the resources restriction and irreversibility of the processes. The complex adaptive system was understood using the first and second law of thermodynamics, generating a conceptual framework to define the sustainability of a system. The contributions developed by exergy were shown to analyze the sustainability of systems in an economic, social and environmental context [es

  6. Understanding dyadic promoter-stakeholder relations in complex projects

    Directory of Open Access Journals (Sweden)

    Janita Vos

    2016-01-01

    Full Text Available In this study, we propose a Bilateral Double Motive framework of stakeholder cooperation in complex projects. The framework analyses and explains dyadic promoter-stakeholder relationships at a micro level by acknowledging both transactional and relational motives. We demonstrate the framework’s usefulness by illustrating its explanatory power in two instances of cooperation and two of non-cooperation within two health information technology projects. The study contributes to project management theory through its combined focus on transactional and relational motives. Further, the study contributes to practice by providing a tool for planning and evaluating cooperation in health Information Technology projects and similar complex multi-stakeholder environments.

  7. Understanding Educational Change through the Lens of Complexity Science

    Science.gov (United States)

    Girtz, Suzann

    2009-01-01

    The purpose of this study was to investigate four attractor states in schools through the perceptions of formal leaders that engaged in and reflected upon school reform regarding the Millennial generation. The term attractor was used as a metaphor for a habitual pattern, gleaned from complexity science which informs of new ways in which to…

  8. Understanding Particulate Matter Dynamics in the San Joaquin Valley during DISCOVER-AQ, 2013

    Science.gov (United States)

    Prabhakar, G.; Zhang, X.; Kim, H.; Parworth, C.; Pusede, S. E.; Wooldridge, P. J.; Cohen, R. C.; Zhang, Q.; Cappa, C. D.

    2015-12-01

    Air quality in the California San Joaquin Valley (SJV) during winter continues to be the worst in the state, failing EPA's 24-hour standard for particulate matter. Despite our improved understanding of the sources of particulate matter (PM) in the valley, air-quality models are unable to predict PM concentrations accurately. We aim to characterize periods of high particulate matter concentrations in the San Joaquin Valley based on ground and airborne measurements of aerosols and gaseous pollutants, during the DISCOVER-AQ campaign, 2013. A highly instrumented aircraft flew across the SJV making three transects in a repeatable pattern, with vertical spirals over select locations. The aircraft measurements were complemented by ground measurements at these locations, with extensive chemically-speciated measurements at a ground "supersite" at Fresno. Hence, the campaign provided a comprehensive three-dimensional view of the particulate and gaseous pollutants around the valley. The vertical profiles over the different sites indicate significant variability in the concentrations and vertical distribution of PM around the valley, which are most likely driven by differences in the combined effects of emissions, chemistry and boundary layer dynamics at each site. The observations suggest that nighttime PM is dominated by surface emissions of PM from residential fuel combustion, while early morning PM is strongly influenced by mixing of low-level, above-surface, nitrate-rich layers formed from dark chemistry overnight to the surface.

  9. Understanding vaginal microbiome complexity from an ecological perspective

    Science.gov (United States)

    Hickey, Roxana J.; Zhou, Xia; Pierson, Jacob D.; Ravel, Jacques; Forney, Larry J.

    2012-01-01

    The various microbiota normally associated with the human body have an important influence on human development, physiology, immunity, and nutrition. This is certainly true for the vagina wherein communities of mutualistic bacteria constitute the first line of defense for the host by excluding invasive, nonindigenous organisms that may cause disease. In recent years much has been learned about the bacterial species composition of these communities and how they differ between individuals of different ages and ethnicities. A deeper understanding of their origins and the interrelationships of constituent species is needed to understand how and why they change over time or in response to changes in the host environment. Moreover, there are few unifying theories to explain the ecological dynamics of vaginal ecosystems as they respond to disturbances caused by menses and human activities such as intercourse, douching, and other habits and practices. This fundamental knowledge is needed to diagnose and assess risk to disease. Here we summarize what is known about the species composition, structure, and function of bacterial communities in the human vagina and the applicability of ecological models of community structure and function to understanding the dynamics of this and other ecosystems that comprise the human microbiome. PMID:22683415

  10. "Touching Triton": Building Student Understanding of Complex Disease Risk.

    Science.gov (United States)

    Loftin, Madelene; East, Kelly; Hott, Adam; Lamb, Neil

    2016-01-01

    Life science classrooms often emphasize the exception to the rule when it comes to teaching genetics, focusing heavily on rare single-gene and Mendelian traits. By contrast, the vast majority of human traits and diseases are caused by more complicated interactions between genetic and environmental factors. Research indicates that students have a deterministic view of genetics, generalize Mendelian inheritance patterns to all traits, and have unrealistic expectations of genetic technologies. The challenge lies in how to help students analyze complex disease risk with a lack of curriculum materials. Providing open access to both content resources and an engaging storyline can be achieved using a "serious game" model. "Touching Triton" was developed as a serious game in which students are asked to analyze data from a medical record, family history, and genomic report in order to develop an overall lifetime risk estimate of six common, complex diseases. Evaluation of student performance shows significant learning gains in key content areas along with a high level of engagement.

  11. Fusion in computer vision understanding complex visual content

    CERN Document Server

    Ionescu, Bogdan; Piatrik, Tomas

    2014-01-01

    This book presents a thorough overview of fusion in computer vision, from an interdisciplinary and multi-application viewpoint, describing successful approaches, evaluated in the context of international benchmarks that model realistic use cases. Features: examines late fusion approaches for concept recognition in images and videos; describes the interpretation of visual content by incorporating models of the human visual system with content understanding methods; investigates the fusion of multi-modal features of different semantic levels, as well as results of semantic concept detections, fo

  12. Quantifying ‘Causality’ in Complex Systems: Understanding Transfer Entropy

    Science.gov (United States)

    Abdul Razak, Fatimah; Jensen, Henrik Jeldtoft

    2014-01-01

    ‘Causal’ direction is of great importance when dealing with complex systems. Often big volumes of data in the form of time series are available and it is important to develop methods that can inform about possible causal connections between the different observables. Here we investigate the ability of the Transfer Entropy measure to identify causal relations embedded in emergent coherent correlations. We do this by firstly applying Transfer Entropy to an amended Ising model. In addition we use a simple Random Transition model to test the reliability of Transfer Entropy as a measure of ‘causal’ direction in the presence of stochastic fluctuations. In particular we systematically study the effect of the finite size of data sets. PMID:24955766

  13. Understanding Complex Human Ecosystems: The Case of Ecotourism on Bonaire

    Directory of Open Access Journals (Sweden)

    Thomas Abel

    2003-12-01

    Full Text Available It is suggested that ecotourism development on the island of Bonaire can be productively understood as a perturbation of a complex human ecosystem. Inputs associated with ecotourism have fueled transformations of the island ecology and sociocultural system. The results of this study indicate that Bonaire's social and economic hierarchy is approaching a new, stable systems state following a 50-yr transition begun by government and industry that stabilized with the appearance of ecotourism development and population growth. Ecotourism can be understood to have "filled in" the middle of the production hierarchy of Bonaire. Interpreted from this perspective, population growth has completed the transformation by expanding into production niches at smaller scales in the production hierarchy. Both a consequence and a cause, ecotourism has transformed the island's social structure and demography. The theory and methods applied in this case study of interdisciplinary research in the field of human ecosystems are also presented.

  14. Understanding implementation in complex public organizations – implication for practice

    Directory of Open Access Journals (Sweden)

    Gry Cecilie Høiland

    2016-10-01

    Full Text Available The effective implementation of politically initiated public service innovations to the front-lines of the public service organization, where the innovation is to be applied, is a challenge that both practitioners and researchers struggle to solve. We highlight the importance of analysing contextual factors at several levels of the implementation system, as well as the importance of considering how the practical everyday work situations of the front-line workers influence their application of the innovation in question. We illustrate this by exploring the implementation process of a specific work inclusion measure, looking at its wider context and some of its implementation outcomes at a specific public agency. The intention is to illustrate the significance of considering the contextual complexity influencing implementation work as a reminder for practitioners to take this into account in their planning and practices.

  15. From structure of the complex to understanding of the biology

    Energy Technology Data Exchange (ETDEWEB)

    Rossmann, Michael G., E-mail: mr@purdue.edu [Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 (United States); Arisaka, Fumio [Graduate School and School of Bioscience and Biotechnology, Tokyo Institute of Technology, 5249 Nagatsuta-cho, Yokohama 226-8501-B39 (Japan); Battisti, Anthony J.; Bowman, Valorie D.; Chipman, Paul R.; Fokine, Andrei; Hafenstein, Susan [Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 (United States); Kanamaru, Shuji [Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 (United States); Graduate School and School of Bioscience and Biotechnology, Tokyo Institute of Technology, 5249 Nagatsuta-cho, Yokohama 226-8501-B39 (Japan); Kostyuchenko, Victor A. [Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 (United States); Mesyanzhinov, Vadim V.; Shneider, Mikhail M. [Laboratory of Molecular Bioengineering, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya Street, Moscow, 117997 (Russian Federation); Morais, Marc C.; Leiman, Petr G. [Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 (United States); Palermo, Laura M.; Parrish, Colin R. [James A. Baker Institute, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (United States); Xiao, Chuan [Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054 (United States)

    2007-01-01

    The most extensive structural information on viruses relates to apparently icosahedral virions and is based on X-ray crystallography and on cryo-electron microscopy single-particle reconstructions. This paper concerns itself with the study of the macromolecular complexes that constitute viruses, using structural hybrid techniques. The most extensive structural information on viruses relates to apparently icosahedral virions and is based on X-ray crystallography and on cryo-electron microscopy (cryo-EM) single-particle reconstructions. Both techniques lean heavily on imposing icosahedral symmetry, thereby obscuring any deviation from the assumed symmetry. However, tailed bacteriophages have icosahedral or prolate icosahedral heads that have one obvious unique vertex where the genome can enter for DNA packaging and exit when infecting a host cell. The presence of the tail allows cryo-EM reconstructions in which the special vertex is used to orient the head in a unique manner. Some very large dsDNA icosahedral viruses also develop special vertices thought to be required for infecting host cells. Similarly, preliminary cryo-EM data for the small ssDNA canine parvovirus complexed with receptor suggests that these viruses, previously considered to be accurately icosahedral, might have some asymmetric properties that generate one preferred receptor-binding site on the viral surface. Comparisons are made between rhinoviruses that bind receptor molecules uniformly to all 60 equivalent binding sites, canine parvovirus, which appears to have a preferred receptor-binding site, and bacteriophage T4, which gains major biological advantages on account of its unique vertex and tail organelle.

  16. From structure of the complex to understanding of the biology

    International Nuclear Information System (INIS)

    Rossmann, Michael G.; Arisaka, Fumio; Battisti, Anthony J.; Bowman, Valorie D.; Chipman, Paul R.; Fokine, Andrei; Hafenstein, Susan; Kanamaru, Shuji; Kostyuchenko, Victor A.; Mesyanzhinov, Vadim V.; Shneider, Mikhail M.; Morais, Marc C.; Leiman, Petr G.; Palermo, Laura M.; Parrish, Colin R.; Xiao, Chuan

    2007-01-01

    The most extensive structural information on viruses relates to apparently icosahedral virions and is based on X-ray crystallography and on cryo-electron microscopy single-particle reconstructions. This paper concerns itself with the study of the macromolecular complexes that constitute viruses, using structural hybrid techniques. The most extensive structural information on viruses relates to apparently icosahedral virions and is based on X-ray crystallography and on cryo-electron microscopy (cryo-EM) single-particle reconstructions. Both techniques lean heavily on imposing icosahedral symmetry, thereby obscuring any deviation from the assumed symmetry. However, tailed bacteriophages have icosahedral or prolate icosahedral heads that have one obvious unique vertex where the genome can enter for DNA packaging and exit when infecting a host cell. The presence of the tail allows cryo-EM reconstructions in which the special vertex is used to orient the head in a unique manner. Some very large dsDNA icosahedral viruses also develop special vertices thought to be required for infecting host cells. Similarly, preliminary cryo-EM data for the small ssDNA canine parvovirus complexed with receptor suggests that these viruses, previously considered to be accurately icosahedral, might have some asymmetric properties that generate one preferred receptor-binding site on the viral surface. Comparisons are made between rhinoviruses that bind receptor molecules uniformly to all 60 equivalent binding sites, canine parvovirus, which appears to have a preferred receptor-binding site, and bacteriophage T4, which gains major biological advantages on account of its unique vertex and tail organelle

  17. A modeling process to understand complex system architectures

    Science.gov (United States)

    Robinson, Santiago Balestrini

    2009-12-01

    In recent decades, several tools have been developed by the armed forces, and their contractors, to test the capability of a force. These campaign level analysis tools, often times characterized as constructive simulations are generally expensive to create and execute, and at best they are extremely difficult to verify and validate. This central observation, that the analysts are relying more and more on constructive simulations to predict the performance of future networks of systems, leads to the two central objectives of this thesis: (1) to enable the quantitative comparison of architectures in terms of their ability to satisfy a capability without resorting to constructive simulations, and (2) when constructive simulations must be created, to quantitatively determine how to spend the modeling effort amongst the different system classes. The first objective led to Hypothesis A, the first main hypotheses, which states that by studying the relationships between the entities that compose an architecture, one can infer how well it will perform a given capability. The method used to test the hypothesis is based on two assumptions: (1) the capability can be defined as a cycle of functions, and that it (2) must be possible to estimate the probability that a function-based relationship occurs between any two types of entities. If these two requirements are met, then by creating random functional networks, different architectures can be compared in terms of their ability to satisfy a capability. In order to test this hypothesis, a novel process for creating representative functional networks of large-scale system architectures was developed. The process, named the Digraph Modeling for Architectures (DiMA), was tested by comparing its results to those of complex constructive simulations. Results indicate that if the inputs assigned to DiMA are correct (in the tests they were based on time-averaged data obtained from the ABM), DiMA is able to identify which of any two

  18. Thinking in complexity the complex dynamics of matter, mind, and mankind

    CERN Document Server

    Mainzer, Klaus

    1994-01-01

    The theory of nonlinear complex systems has become a successful and widely used problem-solving approach in the natural sciences - from laser physics, quantum chaos and meteorology to molecular modeling in chemistry and computer simulations of cell growth in biology In recent times it has been recognized that many of the social, ecological and political problems of mankind are also of a global, complex and nonlinear nature And one of the most exciting topics of present scientific and public interest is the idea that even the human mind is governed largely by the nonlinear dynamics of complex systems In this wide-ranging but concise treatment Prof Mainzer discusses, in nontechnical language, the common framework behind these endeavours Special emphasis is given to the evolution of new structures in natural and cultural systems and it is seen clearly how the new integrative approach of complexity theory can give new insights that were not available using traditional reductionistic methods

  19. Understanding Life : The Evolutionary Dynamics of Complexity and Semiosis

    Science.gov (United States)

    Loeckenhoff, Helmut K.

    2010-11-01

    Post-Renaissance sciences created different cultures. To establish an epistemological base, Physics were separated from the Mental domain. Consciousness was excluded from science. Life Sciences were left in between e.g. LaMettrie's `man—machine' (1748) and 'vitalism' [e.g. Bergson 4]. Causative thinking versus intuitive arguing limited strictly comprehensive concepts. First ethology established a potential shared base for science, proclaiming the `biology paradigm' in the middle of the 20th century. Initially procured by Cybernetics and Systems sciences, `constructivist' models prepared a new view on human perception and thus also of scientific `objectivity when introducing the `observer'. In sequel Computer sciences triggered the ICT revolution. In turn ICT helped to develop Chaos and Complexity sciences, Non-linear Mathematics and its spin-offs in the formal sciences [Spencer-Brown 49] as e.g. (proto-)logics. Models of life systems, as e.g. Anticipatory Systems, integrated epistemology with mathematics and Anticipatory Computing [Dubois 11, 12, 13, 14] connecting them with Semiotics. Seminal ideas laid in the turn of the 19th to the 20th century [J. v. Uexküll 53] detected the co-action and co-evolvement of environments and life systems. Bio-Semiotics ascribed purpose, intent and meaning as essential qualities of life. The concepts of Systems Biology and Qualitative Research enriched and develop also anthropologies and humanities. Brain research added models of (higher) consciousness. An avant-garde is contemplating a science including consciousness as one additional base. New insights from the extended qualitative approach led to re-conciliation of basic assumptions of scientific inquiry, creating the `epistemological turn'. Paradigmatically, resting on macro- micro- and recently on nano-biology, evolution biology sired fresh scripts of evolution [W. Wieser 60,61]. Its results tie to hypotheses describing the emergence of language, of the human mind and of

  20. The Effect of 7E Learning Model on Conceptual Understandings of Prospective Science Teachers on "de Broglie Matter Waves" Subject

    Science.gov (United States)

    Gorecek Baybars, Meryem; Kucukozer, Huseyin

    2018-01-01

    The object of this study is to determine the conceptual understanding that prospective Science teachers have relating "de Broglie: Matter waves" and to investigate the effect of the instruction performed, on the conceptual understanding. This study was performed at a state university located in the western part of Turkey, with the…

  1. Dark fluid: A complex scalar field to unify dark energy and dark matter

    International Nuclear Information System (INIS)

    Arbey, Alexandre

    2006-01-01

    In this article, we examine a model which proposes a common explanation for the presence of additional attractive gravitational effects - generally considered to be due to dark matter - in galaxies and in clusters, and for the presence of a repulsive effect at cosmological scales - generally taken as an indication of the presence of dark energy. We therefore consider the behavior of a so-called dark fluid based on a complex scalar field with a conserved U(1)-charge and associated to a specific potential, and show that it can at the same time account for dark matter in galaxies and in clusters, and agree with the cosmological observations and constraints on dark energy and dark matter

  2. Complexity in practice: understanding primary care as a complex adaptive system

    Directory of Open Access Journals (Sweden)

    Beverley Ellis

    2010-06-01

    Conclusions The results are real-world exemplars of the emergent properties of complex adaptive systems. Improving clinical governance in primary care requires both complex social interactions and underpinning informatics. The socio-technical lessons learned from this research should inform future management approaches.

  3. Understanding dissolved organic matter reactivity in a global context: tribute to Dr. George Aiken's many contributions

    Science.gov (United States)

    McKnight, Diane

    2017-04-01

    As Dr. George Aiken emphasized throughout his distinguished research career, the diversity of sources of dissolved organic material (DOM) is associated with a diversity of dissolved organic compounds with a range of chemistries and reactivities that are present in the natural environment. From a limnological perspective, dissolved organic matter (DOM) can originate from allochthonous sources on the landscape which drains into a lake, river, wetland, coastal region, or other aquatic ecosystem, or from autochthonous sources within the given aquatic ecosystem. In many landscapes, the precursor organic materials that contribute to the DOM of the associated aquatic ecosystem can be derived from diverse sources, e.g. terrestrial plants, plant litter, organic material in different soil horizons, and the products of microbial growth and decay. Yet, through his focus on the underlying chemical processes a clear, chemically robust foundation for understanding DOM reactivity has emerged from Aiken's research. These processes include the enhancement in solubility due to ionized carboxylic acid functional groups and the reactions of organic sulfur groups with mercury. This approach has advanced understand of carbon cycling in the lakes of the Mars-like barren landscapes of the McMurdo Dry Valleys in Antarctica and the rivers draining the warming tundra of the Arctic.

  4. Preliminary investigation of phosphorus adsorption onto two types of iron oxide-organic matter complexes.

    Science.gov (United States)

    Yan, Jinlong; Jiang, Tao; Yao, Ying; Lu, Song; Wang, Qilei; Wei, Shiqiang

    2016-04-01

    Iron oxide (FeO) coated by natural organic matter (NOM) is ubiquitous. The associations of minerals with organic matter (OM) significantly changes their surface properties and reactivity, and thus affect the environmental fate of pollutants, including nutrients (e.g., phosphorus (P)). In this study, ferrihydrite/goethite-humic acid (FH/GE-HA) complexes were prepared and their adsorption characteristics on P at various pH and ionic strength were investigated. The results indicated that the FeO-OM complexes showed a decreased P adsorption capacity in comparison with bare FeO. The maximum adsorption capacity (Qmax) decreased in the order of FH (22.17 mg/g)>FH-HA (5.43 mg/g)>GE (4.67 mg/g)>GE-HA (3.27 mg/g). After coating with HA, the amorphous FH-HA complex still showed higher P adsorption than the crystalline GE-HA complex. The decreased P adsorption observed might be attributed to changes of the FeO surface charges caused by OM association. The dependence of P adsorption on the specific surface area of adsorbents suggests that the FeO component in the complexes is still the main contributor for the adsorption surfaces. The P adsorptions on FeO-HA complexes decreased with increasing initial pH or decreasing initial ionic strength. A strong dependence of P adsorption on ionic strength and pH may demonstrate that outer-sphere complexes between the OM component on the surface and P possibly coexist with inner-sphere surface complexes between the FeO component and P. Therefore, previous over-emphasis on the contributions of original minerals to P immobilization possibly over-estimates the P loading capacity of soils, especially in humic-rich areas. Copyright © 2015. Published by Elsevier B.V.

  5. Advances in understanding gray matter pathology in multiple sclerosis: Are we ready to redefine disease pathogenesis?

    Directory of Open Access Journals (Sweden)

    Zivadinov Robert

    2012-03-01

    Full Text Available Abstract The purpose of this special issue in BMC Neurology is to summarize advances in our understanding of the pathological, immunological, imaging and clinical concepts of gray matter (GM pathology in patients with multiple sclerosis (MS. Review articles by Lucchinetti and Popescu, Walker and colleagues, Hulst and colleagues and Horakova and colleagues summarize important recent advances in understanding GM damage and its implications to MS pathogenesis. They also raise a number of important new questions and outline comprehensive approaches to addressing those questions in years to come. In the last decade, the use of immunohistochemistry staining methods and more advanced imaging techniques to detect GM lesions, like double inversion recovery, contributed to a surge of studies related to cortical and subcortical GM pathology in MS. It is becoming more apparent from recent biopsy studies that subpial cortical lesions in early MS are highly inflammatory. The mechanisms responsible for triggering meningeal inflammation in MS patients are not yet elucidated, and they should be further investigated in relation to their role in initiating and perpetuating the disease process. Determining the role of antigens, environmental and genetic factors in the pathogenesis of GM involvement in MS is critical. The early involvement of cortical and subcortical GM damage in MS is very intriguing and needs to be further studied. As established in numerous cross-sectional and longitudinal studies, GM damage is a better predictor of physical disability and cognitive impairment than WM damage. Monitoring the evolution of GM damage is becoming an important marker in predicting future disease course and response to therapy in MS patients.

  6. Limitations in Using Chemical Oxidative Potential to Understand Oxidative Stress from Particulate Matter

    Science.gov (United States)

    Chan, A. W. H.; Wang, S.; Wang, X.; Kohl, L.; Chow, C. W.

    2017-12-01

    Particulate matter (PM) in the atmosphere is known to cause adverse cardiorespiratory health effects. It has been suggested that the ability of PM to generate oxidative stress leads to a proinflammatory response. In this work, we study the biological relevance of using a chemical oxidative potential (OP) assay to evaluate proinflammatory response in airway epithelial cells. Here we study the OPs of laboratory secondary organic aerosol (SOA) and metal mixtures, ambient PM from India, ash from the 2016 Alberta wildfires, and diesel exhaust particles. We use SOA derived from naphthalene and from monoterpenes as model systems for SOA. We measure OP using the dithiothreitol (DTT) assay, and cytosolic reactive oxygen species (ROS) production in BEAS-2B cell culture was measured using CellROX assay. We found that both SOA and copper show high OPs individually, but the OP of the combined SOA/copper mixture, which is more atmospherically relevant, was lower than either of the individual OPs. The reduced activity is attributed to chelation between metals and organic compounds using proton nuclear magnetic resonance. There is reasonable association between DTT activity and cellular ROS production within each particle type, but weak association across different particle types, suggesting that particle composition plays an important role in distinguishing between antioxidant consumption and ROS production. Our results highlight that while oxidative potential is a useful metric of PM's ability to generate oxidative stress, the chemical composition and cellular environment should be considered in understanding health impacts of PM.

  7. Poly-functional description of metal complexation by natural organic matter: theory and practice

    International Nuclear Information System (INIS)

    Buffle, J.; Filella, M.; Altmann, R.S.

    1995-01-01

    The Differential Equilibrium Function (DEF) approach to metal complexation interpretation and prediction is compared to other models or approaches. The basic features of DEF are summarized, both from the experimental and theoretical points of view. The relation of DEF with key environmental concepts or parameters, in particular minor vs major complexing sites, the buffering intensity of natural organic matter (NOM), and their poly functional vs polyelectrolyte properties, is discussed. The relation between DEF and Freundlich isotherm is described quantitatively. The practical applications of DEF are discussed for (i) interpretation of metal complexation by NOM, and (ii) prediction of metal complexation by NOM. It is shown that DEF (i.e. sound extrapolation is possible with care). DEF cans be readily incorporated in metal species distribution codes (e.g. MINEQL). DEF is not equivalent to a molecular complexation model which describes complexation at each individual site; DEF gives a rigorous representation of complexation by NOM as a whole chemical system. (authors). 23 refs., 6 figs

  8. Towards understanding thermal history of the Universe through direct and indirect detection of dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Roszkowski, Leszek; Trojanowski, Sebastian [National Centre for Nuclear Research, Hoża 69, 00-681 Warsaw (Poland); Turzyński, Krzysztof, E-mail: leszek.roszkowski@ncbj.gov.pl, E-mail: sebastian.trojanowski@uci.edu, E-mail: Krzysztof-Jan.Turzynski@fuw.edu.pl [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland)

    2017-10-01

    We examine the question to what extent prospective detection of dark matter by direct and indirect- detection experiments could shed light on what fraction of dark matter was generated thermally via the freeze-out process in the early Universe. By simulating putative signals that could be seen in the near future and using them to reconstruct WIMP dark matter properties, we show that, in a model- independent approach this could only be achieved in a thin sliver of the parameter space. However, with additional theoretical input the hypothesis about the thermal freeze-out as the dominant mechanism for generating dark matter can potentially be verified. We illustrate this with two examples: an effective field theory of dark matter with a vector messenger and a higgsino or wino dark matter within the MSSM.

  9. Toward A Better Understanding of Perceived Complexity in Music: A Commentary on Eerola (2016

    Directory of Open Access Journals (Sweden)

    Elizabeth Hellmuth Margulis

    2016-07-01

    Full Text Available Eerola (2016 evaluates models of musical complexity based on expectancy violation and information theory. This commentary notes the deep relationship between these two phenomena, and argues for a more active partnership between computational and psychological approaches in understanding perceptions of musical complexity.

  10. Thermophilic anaerobes in arctic marine sediments induced to mineralize complex organic matter at high temperature

    DEFF Research Database (Denmark)

    Hubert, Casey; Arnosti, Carol; Brüchert, Volker

    2010-01-01

    Marine sediments harbour diverse populations of dormant thermophilic bacterial spores that become active in sediment incubation experiments at much higher than in situ temperature. This response was investigated in the presence of natural complex organic matter in sediments of two Arctic fjords......, as well as with the addition of freeze-dried Spirulina or individual high-molecular-weight polysaccharides. During 50°C incubation experiments, Arctic thermophiles catalysed extensive mineralization of the organic matter via extracellular enzymatic hydrolysis, fermentation and sulfate reduction. This high...... reactivity determined the extent of the thermophilic response. Fjord sediments with higher in situ SRR also supported higher SRR at 50°C. Amendment with Spirulina significantly increased volatile fatty acids production and SRR relative to unamended sediment in 50°C incubations. Spirulina amendment also...

  11. Understanding large multiprotein complexes: applying a multiple allosteric networks model to explain the function of the Mediator transcription complex.

    Science.gov (United States)

    Lewis, Brian A

    2010-01-15

    The regulation of transcription and of many other cellular processes involves large multi-subunit protein complexes. In the context of transcription, it is known that these complexes serve as regulatory platforms that connect activator DNA-binding proteins to a target promoter. However, there is still a lack of understanding regarding the function of these complexes. Why do multi-subunit complexes exist? What is the molecular basis of the function of their constituent subunits, and how are these subunits organized within a complex? What is the reason for physical connections between certain subunits and not others? In this article, I address these issues through a model of network allostery and its application to the eukaryotic RNA polymerase II Mediator transcription complex. The multiple allosteric networks model (MANM) suggests that protein complexes such as Mediator exist not only as physical but also as functional networks of interconnected proteins through which information is transferred from subunit to subunit by the propagation of an allosteric state known as conformational spread. Additionally, there are multiple distinct sub-networks within the Mediator complex that can be defined by their connections to different subunits; these sub-networks have discrete functions that are activated when specific subunits interact with other activator proteins.

  12. Facilitating Conceptual Change in Understanding State of Matter and Solubility Concepts by Using 5E Learning Cycle Model

    Science.gov (United States)

    Ceylan, Eren; Geban, Omer

    2009-01-01

    The main purpose of the study was to compare the effectiveness of 5E learning cycle model based instruction and traditionally designed chemistry instruction on 10th grade students' understanding of state of matter and solubility concepts. In this study, 119 tenth grade students from chemistry courses instructed by same teacher from an Anatolian…

  13. Students' Understanding of the Nature of Matter and Chemical Reactions--A Longitudinal Study of Conceptual Restructuring

    Science.gov (United States)

    Øyehaug, Anne Bergliot; Holt, Anne

    2013-01-01

    This longitudinal study aims to provide greater insight into how students' understanding of matter and chemical reactions develops over time and how their knowledge structures are restructured. Four case-study students in a Norwegian primary school were followed for two years from age 10-11 to age 12-13. Researchers were responsible for…

  14. The Effect of Recycling Education on High School Students' Conceptual Understanding about Ecology: A Study on Matter Cycle

    Science.gov (United States)

    Ugulu, Ilker; Yorek, Nurettin; Baslar, Suleyman

    2015-01-01

    The objective of this study is to analyze and determine whether a developed recycling education program would lead to a positive change in the conceptual understanding of ecological concepts associated with matter cycles by high school students. The research was conducted on 68 high school 10th grade students (47 female and 21 male students). The…

  15. "Very Good" Ratings in a Survey of Maternity Care: Kindness and Understanding Matter to Australian Women.

    Science.gov (United States)

    Todd, Angela L; Ampt, Amanda J; Roberts, Christine L

    2017-03-01

    Surveys have shown that women are highly satisfied with their maternity care. Their satisfaction has been associated with various demographic, personal, and care factors. Isolating the factors that most matter to women about their care can guide quality improvement efforts. This study aimed to identify the most significant factors associated with high ratings of care by women in the three maternity periods (antenatal, birth, and postnatal). A survey was sent to 2,048 women who gave birth at seven public hospitals in New South Wales, Australia, exploring their expectations of, and experiences with maternity care. Women's overall ratings of care for the antenatal, birth, and postnatal periods were analyzed, and a number of maternal characteristics and care factors examined as potential predictors of "Very good" ratings of care. Among 886 women with a completed survey, 65 percent assigned a "Very good" rating for antenatal care, 74 percent for birth care, 58 percent for postnatal care, and 44 percent for all three periods. One factor was strongly associated with care ratings in all three maternity periods: women who were "always or almost always" treated with kindness and understanding were 1.8-2.8 times more likely to rate their antenatal, birth, and postnatal care as "Very good." A limited number of other factors were significantly associated with high care ratings for one or two of the maternity periods. Women's perceptions about the quality of their interpersonal interactions with health caregivers have a significant bearing on women's views about their maternity care journey. © 2016 Wiley Periodicals, Inc.

  16. Rhetorical meta-language to promote the development of students' writing skills and subject matter understanding

    Science.gov (United States)

    Pelger, Susanne; Sigrell, Anders

    2016-01-01

    students' understanding of their subject matter.

  17. An enzyme complex increases in vitro dry matter digestibility of corn and wheat in pigs.

    Science.gov (United States)

    Park, Kyu Ree; Park, Chan Sol; Kim, Beob Gyun

    2016-01-01

    Two experiments were conducted to determine the effects of enzyme complex on in vitro dry matter (DM) digestibility for feed ingredients. The objective of experiment 1 was to screen feed ingredients that can be effective substrates for an enzyme complex, mainly consisted of β-pentosanase, β-glucanase and α-amylase, using in vitro digestibility methods. In experiment 1, the test ingredients were three grain sources (barley, corn and wheat) and six protein supplements (canola meal, copra expellers, cottonseed meal, distillers dried grains with solubles, palm kernel expellers and soybean meal). In vitro ileal and total tract digestibility (IVID and IVTTD, respectively) of DM for test ingredients were determined. In vitro digestibility methods consisted of two- or three-step procedure simulating in vivo digestion in the pig gastrointestinal tracts with or without enzyme complex. As the enzyme complex added, the IVID of DM for corn and wheat increased (p digestibility, corn grains were selected to determine the in vitro digestibility of the fractions (starch, germ, hull and gluten) that maximally respond to the enzyme complex in experiment 2. The IVID of DM for corn starch, germ and hull increased (p digestibility of corn and wheat, and the digestibility increments of corn are mainly attributed to the increased digestibility of corn starch.

  18. Turning the Star Trek Dream into Reality by Understanding Matter & Antimatter

    Science.gov (United States)

    Hansen, Norm

    2002-04-01

    People are going to learn all about matter and antimatter. Where matter and antimatter comes from. Where antimatter exists within our solar system. What the Periodic Table of Matter-AntiMatter Elements looks like. What each of the 109 antimatter element's nuclear, physical, and chemical characteristics are. How much energy is produced from matter and antimatter. And what needs to be done to turn the Star Trek Dream into Reality. The Milky Way Galaxy is composed of matter and antimatter. At the center of the galaxy, there are two black holes. One black hole is composed of matter; and the other is antimatter. The black holes are ejecting matter and antimatter into space forming a halo and spiral arms of matter & antimatter stars. The sun is one of the billions of stars that are composed of matter. There are a similar number of antimatter stars. Our Solar System contains the sun, earth, planets, and asteroids that are composed of matter, and comets that are composed of antimatter. When galactic antimatter enters our solar system, the antimatter is called comets. Astronomers have observed hundred of comets orbiting the sun and are finding new comets every year. During the last century, mass destruction has resulted when antimatter collided with Jupiter and Earth. How Humanity deals with the opportunities and dangers of antimatter will determine our destiny. Mankind has known about comets destructive power for thousands of years going back to the days of antiquity. Did comets have anything to do with the disappearance of Atlantis over twelve thousand years ago? We may never know; but is there a similar situation about to take place? Scientists have been studying antimatter by producing, storing, and colliding small quantities at national laboratories for several decades. Symmetry exists between matter and antimatter. Science and Technology provides unlimited opportunities to benefit humanity. Antimatter can be used, as a natural source of energy, to bring every country

  19. Distinct white matter integrity in glutamic acid decarboxylase and voltage-gated potassium channel-complex antibody-associated limbic encephalitis.

    Science.gov (United States)

    Wagner, Jan; Schoene-Bake, Jan-Christoph; Witt, Juri-Alexander; Helmstaedter, Christoph; Malter, Michael P; Stoecker, Winfried; Probst, Christian; Weber, Bernd; Elger, Christian E

    2016-03-01

    Autoantibodies against glutamic acid decarboxylase (GAD) and the voltage-gated potassium channel (VGKC) complex are associated with distinct subtypes of limbic encephalitis regarding clinical presentation, response to therapy, and outcome. The aim of this study was to investigate white matter changes in these two limbic encephalitis subtypes by means of diffusion tensor imaging (DTI). Diffusion data were obtained in 14 patients with GAD antibodies and 16 patients with VGKC-complex antibodies and compared with age- and gender-matched control groups. Voxelwise statistical analysis was carried out using tract-based spatial statistics. The results were furthermore compared with those of 15 patients with unilateral histologically confirmed hippocampal sclerosis and correlated with verbal and figural memory performance. We found widespread changes of fractional anisotropy and all diffusivity parameters in GAD-associated limbic encephalitis, whereas no changes were found in VGKC-complex-associated limbic encephalitis. The changes observed in the GAD group were even more extensive when compared against those of the hippocampal sclerosis group, although the disease duration was markedly shorter in patients with GAD antibodies. Correlation analysis revealed areas with a trend toward a negative correlation of diffusivity parameters with figural memory performance located mainly in the right temporal lobe in the GAD group as well. The present study provides further evidence that, depending on the associated antibody, limbic encephalitis features clearly distinct imaging characteristics by showing widespread white matter changes in GAD-associated limbic encephalitis and preserved white matter integrity in VGKC-complex-associated limbic encephalitis. Furthermore, our results contribute to a better understanding of the specific pathophysiologic properties in these two subforms of limbic encephalitis by revealing that patients with GAD antibodies show widespread affections of

  20. Tetra- and hexavalent uranium forms bidentate-mononuclear complexes with particulate organic matter in a naturally uranium-enriched peatland

    DEFF Research Database (Denmark)

    Mikutta, Christian; Langner, Peggy; Bargar, John R.

    2016-01-01

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work...... of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents...... the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI)....

  1. Copper toxicity and organic matter: Resiliency of watersheds in the Duluth Complex, Minnesota, USA

    Science.gov (United States)

    Piatak, Nadine; Seal, Robert; Jones, Perry M.; Woodruff, Laurel G.

    2015-01-01

    We estimated copper (Cu) toxicity in surface water with high dissolved organic matter (DOM) for unmined mineralized watersheds of the Duluth Complex using the Biotic Ligand Model (BLM), which evaluates the effect of DOM, cation competition for biologic binding sites, and metal speciation. A sediment-based BLM was used to estimate stream-sediment toxicity; this approach factors in the cumulative effects of multiple metals, incorporation of metals into less bioavailable sulfides, and complexation of metals with organic carbon. For surface water, the formation of Cu-DOM complexes significantly reduces the amount of Cu available to aquatic organisms. The protective effects of cations, such as calcium (Ca) and magnesium (Mg), competing with Cu to complex with the biotic ligand is likely not as important as DOM in water with high DOM and low hardness. Standard hardness-based water quality criteria (WQC) are probably inadequate for describing Cu toxicity in such waters and a BLM approach may yield more accurate results. Nevertheless, assumptions about relative proportions of humic acid (HA) and fulvic acid (FA) in DOM significantly influence BLM results; the higher the HA fraction, the higher calculated resiliency of the water to Cu toxicity. Another important factor is seasonal variation in water chemistry, with greater resiliency to Cu toxicity during low flow compared to high flow.Based on generally low total organic carbon and sulfur content, and equivalent metal ratios from total and weak partial extractions, much of the total metal concentration in clastic streambedsediments may be in bioavailable forms, sorbed on clays or hydroxide phases. However, organicrich fine-grained sediment in the numerous wetlands may sequester significant amount of metals, limiting their bioavailability. A high proportion of organic matter in waters and some sediments will play a key role in the resiliency of these watersheds to potential additional metal loads associated with future

  2. Why we need to see the dark matter to understand the dark energy

    OpenAIRE

    Kunz, Martin

    2007-01-01

    The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up some 20% of the total energy budget today, while the dark energy is responsible for about 75%. Here we show that these numbers are only robust for specific dark energy models and that in general we cannot measure the abundance of the dark constituents sepa...

  3. Mass the quest to understand matter from Greek atoms to quantum fields

    CERN Document Server

    Baggott, Jim

    2017-01-01

    Everything around us is made of 'stuff', from planets, to books, to our own bodies. Whatever it is, we call it matter or material substance. It is solid; it has mass. But what is matter, exactly? We are taught in school that matter is not continuous, but discrete. As a few of the philosophers of ancient Greece once speculated, nearly two and a half thousand years ago, matter comes in 'lumps', and science has relentlessly peeled away successive layers of matter to reveal its ultimate constituents. Surely, we can't keep doing this indefinitely. We imagine that we should eventually run up against some kind of ultimately fundamental, indivisible type of stuff, the building blocks from which everything in the Universe is made. The English physicist Paul Dirac called this 'the dream of philosophers'. But science has discovered that the foundations of our Universe are not as solid or as certain and dependable as we might have once imagined. They are instead built from ghosts and phantoms, of a peculiar quantum kind....

  4. Copper complexing ligands and organic matter characterization in the northern Adriatic Sea

    Science.gov (United States)

    Plavšić, Marta; Gašparović, Blaženka; Strmečki, Slađana; Vojvodić, Vjeročka; Tepić, Nataša

    2009-11-01

    The study on dissolved organic ligands capable to complex copper ions (L T), surface-active substances (SAS) and dissolved organic carbon (DOC) in the Northern Adriatic Sea station (ST 101) under the influence of Po River was conducted in period from 2006-2008. The acidity of surface-active organic material (Ac r) was followed as well. The results are compared to temperature and salinity distributions. On that way, the contribution of the different pools of ligands capable to complex Cu ions could be determined as well as the influence of aging and transformation of the organic matter. The L T values in the investigated period were in the range of 40-300 nmol l -1. The range of DOC values for surface and bottom samples were 0.84-1.87 mg l -1 and 0.80-1.30 mg l -1, respectively. Total SAS concentrations in the bottom layer were 0.045-0.098 mg l -1 in equiv. of Triton-X-100 while those in the surface layer were 0.050-0.143 mg l -1 in equiv. of Triton-X-100. The majority of organic ligands responsible for Cu binding in surface water originate from new phytoplankton production promoted by river borne nutrients. Older, transformed organic matter, possessing higher relative acidity, is the main contributor to the pool of organic ligands that bind copper in the bottom samples. It was estimated that ˜9% of DOC in surface samples and ˜12% of DOC in the bottom samples are present as ligands capable to complex copper ions.

  5. Understanding the physiology of complex congenital heart disease using cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    Kappanayil, Mahesh; Kannan, Rajesh; Kumar, Raman Krishna

    2011-01-01

    Complex congenital heart diseases are often associated with complex alterations in hemodynamics. Understanding these key hemodynamic changes is critical to making management decisions including surgery and postoperative management. Existing tools for imaging and hemodynamic assessment like echocardiography, computed tomography and cardiac catheterization have inherent limitations. Cardiac magnetic resonance imaging (MRI) is emerging as a powerful bouquet of tools that allow not only excellent imaging, but also a unique insight into hemodynamics. This article introduces the reader to cardiac MRI and its utility through the clinical example of a child with a complex congenital cyanotic heart disease

  6. The Co-Creation of Caring Student-Teacher Relationships: Does Teacher Understanding Matter?

    Science.gov (United States)

    Cooper, Kristy S.; Miness, Andrew

    2014-01-01

    This study explores the role of high school students' perceptions of teacher understanding in the development of caring student-teacher relationships. Whereas past research has embedded understanding as a facet of care, this research distinguishes between care and understanding to examine whether and how understanding is necessary for care.…

  7. Towards an understanding of dark matter: Precise gravitational lensing analysis complemented by robust photometric redshifts

    Science.gov (United States)

    Coe, Daniel Aaron

    The goal of thesis is to help scientists resolve one of the great mysteries of our time: the nature of Dark Matter. Dark Matter is currently believed to make up over 80% of the material in our universe, yet we have so far inferred but a few of its basic properties. Here we study the Dark Matter surrounding a galaxy cluster, Abell 1689, via the most direct method currently available--gravitational lensing. Abell 1689 is a "strong" gravitational lens, meaning it produces multiple images of more distant galaxies. The observed positions of these images can be measured very precisely and act as a blueprint allowing us to reconstruct the Dark Matter distribution of the lens. Until now, such mass models of Abell 1689 have reproduced the observed multiple images well but with significant positional offsets. Using a new method we develop here, we obtain a new mass model which perfectly reproduces the observed positions of 168 knots identified within 135 multiple images of 42 galaxies. An important ingredient to our mass model is the accurate measurement of distances to the lensed galaxies via their photometric redshifts. Here we develop tools which improve the accuracy of these measurements based on our study of the Hubble Ultra Deep Field, the only image yet taken to comparable depth as the magnified regions of Abell 1689. We present results both for objects in the Hubble Ultra Deep Field and for galaxies gravitationally lensed by Abell 1689. As part of this thesis, we also provide reviews of Dark Matter and Gravitational Lensing, including a chapter devoted to the mass profiles of Dark Matter halos realized in simulations. The original work presented here was performed primarily by myself under the guidance of Narciso Benítez and Holland Ford as a member of the Advanced Camera for Surveys GTO Science Team at Johns Hopkins University and the Instituto de Astrofisica de Andalucfa. My advisors served on my thesis committee along with Rick White, Gabor Domokos, and Steve

  8. Why we need to see the dark matter to understand the dark energy

    International Nuclear Information System (INIS)

    Kunz, M

    2008-01-01

    Abstract. The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up some 20% of the total energy budget today, while the dark energy is responsible for about 75%. Here we show that these numbers are only robust for specific dark energy models and that in general we cannot measure the abundance of the dark constituents separately without making strong assumptions

  9. Understanding the Fundamental Properties of Dark Matter and Dark Energy in Structure formation and Cosmology

    International Nuclear Information System (INIS)

    Ellis, Richard S.

    2008-01-01

    This program is concerned with developing and verifying the validity of observational methods for constraining the properties of dark matter and dark energy in the universe. Excellent progress has been made in comparing observational projects involving weak gravitational lensing using both ground and space-based instruments, in further constraining the nature of dark matter via precise measures of its distribution in clusters of galaxies using strong gravitational lensing, in demonstrating the possible limitations of using distant supernovae in future dark energy missions, and in investigating the requirement for ground-based surveys of baryonic acoustic oscillations.

  10. Understanding complexity in managing agro-pastoral dams ecosystem services in Northern Benin

    NARCIS (Netherlands)

    Kpera, G.N.

    2015-01-01

    Key words: conflict, water quality, crocodile, fish diversity, vegetable, watershed management, institutional changes, innovation system.

    Understanding complexity in managing agro-pastoral dams ecosystem services in Northern Benin

    Gnanki

  11. Hypothesis: the chaos and complexity theory may help our understanding of fibromyalgia and similar maladies.

    Science.gov (United States)

    Martinez-Lavin, Manuel; Infante, Oscar; Lerma, Claudia

    2008-02-01

    Modern clinicians are often frustrated by their inability to understand fibromyalgia and similar maladies since these illnesses cannot be explained by the prevailing linear-reductionist medical paradigm. This article proposes that new concepts derived from the Complexity Theory may help understand the pathogenesis of fibromyalgia, chronic fatigue syndrome, and Gulf War syndrome. This hypothesis is based on the recent recognition of chaos fractals and complex systems in human physiology. These nonlinear dynamics concepts offer a different perspective to the notion of homeostasis and disease. They propose that the essence of disease is dysfunction and not structural damage. Studies using novel nonlinear instruments have shown that fibromyalgia and similar maladies may be caused by the degraded performance of our main complex adaptive system. This dysfunction explains the multifaceted manifestations of these entities. To understand and alleviate the suffering associated with these complex illnesses, a paradigm shift from reductionism to holism based on the Complexity Theory is suggested. This shift perceives health as resilient adaptation and some chronic illnesses as rigid dysfunction.

  12. PARTICULATE MATTER AND HUMAN HEALTH: USING HUMAN STUDIES TO UNDERSTAND SUSCEPTIBILITY

    Science.gov (United States)

    The potential for experiencing adverse health effects from air pollution particulate matter (PM) exposure is an important public health issue. The World Health Organization has estimated that PM contributes to the deaths of 500,000 people world-wide each year. Epidemiologic stu...

  13. Understanding the diverse roles of soil organic matter in the cereal - Striga hermontica interaction

    NARCIS (Netherlands)

    Ayongwa, G.C.

    2011-01-01

    Keywords: Striga hermonthica, Sorghum bicolor, soil fertility, organic matter, N-mineralisation, farmers’ priority, production constraints, intensification.


    The problem of the parasitic weed striga (Striga hermonthica (Del.) Benth.) has worsened for African farmers, in conjunction

  14. A Novel Approach to Teaching and Understanding Transformations of Matter in Dynamic Earth Systems

    Science.gov (United States)

    Clark, Scott K.; Sibley, Duncan F.; Libarkin, Julie C.; Heidemann, Merle

    2009-01-01

    The need to engage K-12 and post-secondary students in considering the Earth as a dynamic system requires explicit discussion of system characteristics. Fundamentally, dynamic systems involve the movement and change of matter, often through processes that are difficult to see and comprehend. We introduce a novel instructional method, termed…

  15. Formation of mercury sulfide from Hg(II)−thiolate complexes in natural organic matter

    Science.gov (United States)

    Alain Manceau,; Cyprien Lemouchi,; Mironel Enescu,; Anne-Claire Gaillot,; Martine Lanson,; Valerie Magnin,; Pieter Glatzel,; Poulin, Brett; Ryan, Joseph N.; Aiken, George R.; Isabelle Gautier-Lunea,; Kathryn L. Nagy,

    2015-01-01

    Methylmercury is the environmental form of neurotoxic mercury that is biomagnified in the food chain. Methylation rates are reduced when the metal is sequestered in crystalline mercury sulfides or bound to thiol groups in macromolecular natural organic matter. Mercury sulfide minerals are known to nucleate in anoxic zones, by reaction of the thiol-bound mercury with biogenic sulfide, but not in oxic environments. We present experimental evidence that mercury sulfide forms from thiol-bound mercury alone in aqueous dark systems in contact with air. The maximum amount of nanoparticulate mercury sulfide relative to thiol-bound mercury obtained by reacting dissolved mercury and soil organic matter matches that detected in the organic horizon of a contaminated soil situated downstream from Oak Ridge, TN, in the United States. The nearly identical ratios of the two forms of mercury in field and experimental systems suggest a common reaction mechanism for nucleating the mineral. We identified a chemical reaction mechanism that is thermodynamically favorable in which thiol-bound mercury polymerizes to mercury–sulfur clusters. The clusters form by elimination of sulfur from the thiol complexes via breaking of mercury–sulfur bonds as in an alkylation reaction. Addition of sulfide is not required. This nucleation mechanism provides one explanation for how mercury may be immobilized, and eventually sequestered, in oxygenated surface environments.

  16. Context matters — the complex interplay between resistome genotypes and resistance phenotypes

    DEFF Research Database (Denmark)

    Dantas, Gautam; Sommer, Morten

    2012-01-01

    Application of metagenomic functional selections to study antibiotic resistance genes is revealing a highly diverse and complex network of genetic exchange between bacterial pathogens and environmental reservoirs, which likely contributes significantly to increasing resistance levels in pathogens...... the resistome genotype, and we highlight examples of genes and their hosts where this distinction becomes important in order to understand the relevance of environmental niches that contribute most to clinical problems associated with antibiotic resistance....

  17. Understanding the core-halo relation of quantum wave dark matter from 3D simulations.

    Science.gov (United States)

    Schive, Hsi-Yu; Liao, Ming-Hsuan; Woo, Tak-Pong; Wong, Shing-Kwong; Chiueh, Tzihong; Broadhurst, Tom; Hwang, W-Y Pauchy

    2014-12-31

    We examine the nonlinear structure of gravitationally collapsed objects that form in our simulations of wavelike cold dark matter, described by the Schrödinger-Poisson (SP) equation with a particle mass ∼10(-22)  eV. A distinct gravitationally self-bound solitonic core is found at the center of every halo, with a profile quite different from cores modeled in the warm or self-interacting dark matter scenarios. Furthermore, we show that each solitonic core is surrounded by an extended halo composed of large fluctuating dark matter granules which modulate the halo density on a scale comparable to the diameter of the solitonic core. The scaling symmetry of the SP equation and the uncertainty principle tightly relate the core mass to the halo specific energy, which, in the context of cosmological structure formation, leads to a simple scaling between core mass (Mc) and halo mass (Mh), Mc∝a(-1/2)Mh(1/3), where a is the cosmic scale factor. We verify this scaling relation by (i) examining the internal structure of a statistical sample of virialized halos that form in our 3D cosmological simulations and by (ii) merging multiple solitons to create individual virialized objects. Sufficient simulation resolution is achieved by adaptive mesh refinement and graphic processing units acceleration. From this scaling relation, present dwarf satellite galaxies are predicted to have kiloparsec-sized cores and a minimum mass of ∼10(8)M⊙, capable of solving the small-scale controversies in the cold dark matter model. Moreover, galaxies of 2×10(12)M⊙ at z=8 should have massive solitonic cores of ∼2×10(9)M⊙ within ∼60  pc. Such cores can provide a favorable local environment for funneling the gas that leads to the prompt formation of early stellar spheroids and quasars.

  18. Understanding the implementation of complex interventions in health care: the normalization process model

    Directory of Open Access Journals (Sweden)

    Rogers Anne

    2007-09-01

    Full Text Available Abstract Background The Normalization Process Model is a theoretical model that assists in explaining the processes by which complex interventions become routinely embedded in health care practice. It offers a framework for process evaluation and also for comparative studies of complex interventions. It focuses on the factors that promote or inhibit the routine embedding of complex interventions in health care practice. Methods A formal theory structure is used to define the model, and its internal causal relations and mechanisms. The model is broken down to show that it is consistent and adequate in generating accurate description, systematic explanation, and the production of rational knowledge claims about the workability and integration of complex interventions. Results The model explains the normalization of complex interventions by reference to four factors demonstrated to promote or inhibit the operationalization and embedding of complex interventions (interactional workability, relational integration, skill-set workability, and contextual integration. Conclusion The model is consistent and adequate. Repeated calls for theoretically sound process evaluations in randomized controlled trials of complex interventions, and policy-makers who call for a proper understanding of implementation processes, emphasize the value of conceptual tools like the Normalization Process Model.

  19. The Effect of 7E Learning Model on Conceptual Understandings of Prospective Science Teachers on 'de Broglie Matter Waves' Subject

    Directory of Open Access Journals (Sweden)

    Meryem Gorecek Baybars

    2018-04-01

    Full Text Available The object of this study is to determine the conceptual understanding that prospective Science teachers have relating "de Broglie: Matter waves" and to investigate the effect of the instruction performed, on the conceptual understanding. This study was performed at a state university located in the western part of Turkey, with the Faculty of Education-Science Teaching students (2nd year / 48 individual in the academic year of 2010-2011. The study was planned as a single group pretest-posttest design. A two-step question was used in the study, prior to and after the instruction. Lessons were conducted using the 7E learning model in the instruction process. When all these results are evaluated, it can be said that the conceptual understanding of the prospective teachers regarding "de Broglie; matter waves" has been taken place. In general, when all the sections are examined, it has been observed that the prospective teachers have more alternative concepts prior to the instruction and more scientific concepts after the instruction. In this process, besides instruction, the prospective teachers have not taken any place in a different application regarding the basic concepts of quantum physics. Therefore, it has been determined that the 7E learning model used in the research and the activities included in the 7E learning model are effective in conceptual understanding.

  20. An Approach to Understanding Complex Socio-Economic Impacts and Responses to Climate Disruption in the Chesapeake Bay Region

    Science.gov (United States)

    Schaefer, R. K.; Nix, M.; Ihde, A. G.; Paxton, L. J.; Weiss, M.; Simpkins, S.; Fountain, G. H.; APl GAIA Team

    2011-12-01

    In this paper we describe the application of a proven methodology for modeling the complex social and economic interactions of a system under stress to the regional issues that are tied to global climate disruption. Under the auspices of the GAIA project (http://gaia.jhuapl.edu), we have investigated simulating the complex interplay between climate, politics, society, industry, and the environment in the Chesapeake Bay Watershed and associated geographic areas of Maryland, Virginia, and Pennsylvania. This Chesapeake Bay simulation draws on interrelated geophysical and climate models to support decision-making analysis about the Bay. In addition to physical models, however, human activity is also incorporated via input and output calculations. For example, policy implications are modeled in relation to business activities surrounding fishing, farming, industry and manufacturing, land development, and tourism. This approach fosters collaboration among subject matter experts to advance a more complete understanding of the regional impacts of climate change. Simulated interactive competition, in which teams of experts are assigned conflicting objectives in a controlled environment, allow for subject exploration which avoids trivial solutions that neglect the possible responses of affected parties. Results include improved planning, the anticipation of areas of conflict or high risk, and the increased likelihood of developing mutually acceptable solutions.

  1. Toward an understanding of "Legacy P" - phosphorus sorption mechanisms in stream sediments as influenced by organic matter

    Science.gov (United States)

    Audette, Yuki; O'Halloran, Ivan P.; Nowell, Peter M.; Congreves, Katelyn; Voroney, R. Paul

    2017-04-01

    Water chemistry and phosphorus (P) forms were analyzed to determine the nature of legacy P in sediments of the West Holland River and the adjacent drainage canals of the Holland Marsh drainage system, located in southern Ontario, Canada. The river and canals route water from the intensively cropped muck polders of the Holland Marsh and drain Lake Simcoe. Sediment samples were characterized for mineralogy using X-ray diffraction techniques (XRD); total P (TP); and Ca, Fe, Mn, and Mg contents, as well as cation exchange capacity and organic matter (OM) content. Forms of sediment P in five depth sections (ranging from 0-15 cm depth) were characterized and quantified by sequential P fractionation chemistry. At all study sites, mobile P forms including organic P forms were found to be higher in surface sediments than in deeper sediments. The major P form within the sediments of the two canal sites, where the concentration of TP in the surface water was within the Ontario Provincial Water Quality Objectives (PWQO) of 0.03 mg P L-1, was Ca-bound P, indicating a low risk of soluble reactive P (SRP) release. A trace of apatite (a stable Ca-P mineral) was also detected in these sediments. Conversely, sediments collected from the West Holland River at sites located within the Holland Marsh exhibited a high risk of SRP release, and redox-sensitive P was the dominant P form in the sediment despite the surface water exhibiting higher concentration of Ca and alkaline pH. In addition, the concentrations of TP as measured in surface water samples taken from the site were 8 times greater than PWQO. In the sediments where the risk of SRP release was high, OM contents were also relatively high and traces of brushite (a labile Ca-P mineral) were detected. The formation of OM and cation complexes, such as OM-Fe complexes, may play an important role in regulating the fate of sediment-P forms through the adsorption of SRP. These OM-Fe complexes may inhibit the formation of more stable Ca

  2. Quantifying Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Quantifying Matter explains how scientists learned to measure matter and quantify some of its most fascinating and useful properties. It presents many of the most important intellectual achievements and technical developments that led to the scientific interpretation of substance. Complete with full-color photographs, this exciting new volume describes the basic characteristics and properties of matter. Chapters include:. -Exploring the Nature of Matter. -The Origin of Matter. -The Search for Substance. -Quantifying Matter During the Scientific Revolution. -Understanding Matter's Electromagnet

  3. Towards an understanding of feedbacks between plant productivity, acidity and dissolved organic matter

    Science.gov (United States)

    Rowe, Ed; Tipping, Ed; Davies, Jessica; Monteith, Don; Evans, Chris

    2014-05-01

    The recent origin of much dissolved organic carbon (DOC) (Tipping et al., 2010) implies that plant productivity is a major control on DOC fluxes. However, the flocculation, sorption and release of potentially-dissolved organic matter are governed by pH, and widespread increases in DOC concentrations observed in northern temperate freshwater systems seem to be primarily related to recovery from acidification (Monteith et al., 2007). We explore the relative importance of changes in productivity and pH using a model, MADOC, that incorporates both these effects (Rowe et al., 2014). The feedback whereby DOC affects pH is included. The model uses an annual timestep and relatively simple flow-routing, yet reproduces observed changes in DOC flux and pH in experimental (Evans et al., 2012) and survey data. However, the first version of the model probably over-estimated responses of plant productivity to nitrogen (N) deposition in upland semi-natural ecosystems. There is a strong case that plant productivity is an important regulator of DOC fluxes, and theoretical reasons for suspecting widespread productivity increases in recent years due not only to N deposition but to temperature and increased atmospheric CO2 concentrations. However, evidence that productivity has increased in upland semi-natural ecosystems is sparse, and few studies have assessed the major limitations to productivity in these habitats. In systems where phosphorus (P) limitation prevails, or which are co-limited, productivity responses to anthropogenic drivers will be limited. We present a revised version of the model that incorporates P cycling and appears to represent productivity responses to atmospheric N pollution more realistically. Over the long term, relatively small fluxes of nutrient elements into and out of ecosystems can profoundly affect productivity and the accumulation of organic matter. Dissolved organic N (DON) is less easily intercepted by plants and microbes than mineral N, and DON

  4. Investigating the capability to resolve complex white matter structures with high b-value diffusion magnetic resonance imaging on the MGH-USC Connectom scanner.

    Science.gov (United States)

    Fan, Qiuyun; Nummenmaa, Aapo; Witzel, Thomas; Zanzonico, Roberta; Keil, Boris; Cauley, Stephen; Polimeni, Jonathan R; Tisdall, Dylan; Van Dijk, Koene R A; Buckner, Randy L; Wedeen, Van J; Rosen, Bruce R; Wald, Lawrence L

    2014-11-01

    One of the major goals of the NIH Blueprint Human Connectome Project was to map and quantify the white matter connections in the brain using diffusion tractography. Given the prevalence of complex white matter structures, the capability of resolving local white matter geometries with multiple crossings in the diffusion magnetic resonance imaging (dMRI) data is critical. Increasing b-value has been suggested for delineation of the finer details of the orientation distribution function (ODF). Although increased gradient strength and duration increase sensitivity to highly restricted intra-axonal water, gradient strength limitations require longer echo times (TE) to accommodate the increased diffusion encoding times needed to achieve a higher b-value, exponentially lowering the signal-to-noise ratio of the acquisition. To mitigate this effect, the MGH-USC Connectom scanner was built with 300 mT/m gradients, which can significantly reduce the TE of high b-value diffusion imaging. Here we report comparisons performed across b-values based on q-ball ODF metrics to investigate whether high b-value diffusion imaging on the Connectom scanner can improve resolving complex white matter structures. The q-ball ODF features became sharper as the b-value increased, with increased power fraction in higher order spherical harmonic series of the ODF and increased peak heights relative to the overall size of the ODF. Crossing structures were detected in an increasingly larger fraction of white matter voxels and the spatial distribution of two-way and three-way crossing structures was largely consistent with known anatomy. Results indicate that dMRI with high diffusion encoding on the Connectom system is a promising tool to better characterize, and ultimately understand, the underlying structural organization and motifs in the human brain.

  5. MIGHT WE EVENTUALLY UNDERSTAND THE ORIGIN OF THE DARK MATTER VELOCITY ANISOTROPY?

    International Nuclear Information System (INIS)

    Hansen, Steen H.

    2009-01-01

    The density profile of simulated dark matter structures is fairly well-established, and several explanations for its characteristics have been put forward. In contrast, the radial variation of the velocity anisotropy has still not been explained. We suggest a very simple origin, based on the shapes of the velocity distribution functions, which are shown to differ between the radial and tangential directions. This allows us to derive a radial variation of the anisotropy profile which is in good agreement with both simulations and observations. One of the consequences of this suggestion is that the velocity anisotropy is entirely determined once the density profile is known. We demonstrate how this explains the origin of the γ-β relation, which is the connection between the slope of the density profile and the velocity anisotropy. These findings provide us with a powerful tool, which allows us to close the Jeans equations.

  6. The Effects of Visualizations on Linguistically Diverse Students' Understanding of Energy and Matter in Life Science

    Science.gov (United States)

    Ryoo, Kihyun; Bedell, Kristin

    2017-01-01

    Although extensive research has shown the educational value of different types of interactive visualizations on students' science learning in general, how such technologies can contribute to English learners' (ELs) understanding of complex scientific concepts has not been sufficiently explored to date. This mixed-methods study investigated how…

  7. Tackling complexities in understanding the social determinants of health: the contribution of ethnographic research.

    Science.gov (United States)

    Bandyopadhyay, Mridula

    2011-11-25

    The complexities inherent in understanding the social determinants of health are often not well-served by quantitative approaches. My aim is to show that well-designed and well-conducted ethnographic studies have an important contribution to make in this regard. Ethnographic research designs are a difficult but rigorous approach to research questions that require us to understand the complexity of people's social and cultural lives. I draw on an ethnographic study to describe the complexities of studying maternal health in a rural area in India. I then show how the lessons learnt in that setting and context can be applied to studies done in very different settings. I show how ethnographic research depends for rigour on a theoretical framework for sample selection; why immersion in the community under study, and rapport building with research participants, is important to ensure rich and meaningful data; and how flexible approaches to data collection lead to the gradual emergence of an analysis based on intense cross-referencing with community views and thus a conclusion that explains the similarities and differences observed. When using ethnographic research design it can be difficult to specify in advance the exact details of the study design. Researchers can encounter issues in the field that require them to change what they planned on doing. In rigorous ethnographic studies, the researcher in the field is the research instrument and needs to be well trained in the method. Ethnographic research is challenging, but nevertheless provides a rewarding way of researching complex health problems that require an understanding of the social and cultural determinants of health.

  8. Why Understanding Science Matters: The IES Research Guidelines as a Case in Point

    Science.gov (United States)

    Rudolph, John L.

    2014-01-01

    The author outlines the rise of a hard-science model advocated by the Institute for Education Sciences, including the application of research and development approaches to education following the Second World War, and describes the attraction of these hard-science approaches for education policymakers. He notes that in the face of complex and…

  9. Understanding Crew Decision-Making in the Presence of Complexity: A Flight Simulation Experiment

    Science.gov (United States)

    Young, Steven D.; Daniels, Taumi S.; Evans, Emory; deHaag, Maarten Uijt; Duan, Pengfei

    2013-01-01

    Crew decision making and response have long been leading causal and contributing factors associated with aircraft accidents. Further, it is anticipated that future aircraft and operational environments will increase exposure to risks related to these factors if proactive steps are not taken to account for ever-increasing complexity. A flight simulation study was designed to collect data to help in understanding how complexity can, or may, be manifest. More specifically, an experimental apparatus was constructed that allowed for manipulation of information complexity and uncertainty, while also manipulating operational complexity and uncertainty. Through these manipulations, and the aid of experienced airline pilots, several issues have been discovered, related most prominently to the influence of information content, quality, and management. Flight crews were immersed in an environment that included new operational complexities suggested for the future air transportation system as well as new technological complexities (e.g. electronic flight bags, expanded data link services, synthetic and enhanced vision systems, and interval management automation). In addition, a set of off-nominal situations were emulated. These included, for example, adverse weather conditions, traffic deviations, equipment failures, poor data quality, communication errors, and unexpected clearances, or changes to flight plans. Each situation was based on one or more reference events from past accidents or incidents, or on a similar case that had been used in previous developmental tests or studies. Over the course of the study, 10 twopilot airline crews participated, completing over 230 flights. Each flight consisted of an approach beginning at 10,000 ft. Based on the recorded data and pilot and research observations, preliminary results are presented regarding decision-making issues in the presence of the operational and technological complexities encountered during the flights.

  10. Prospective outcome of the influence of complexation by natural organic matter on enhanced or retarded transport of radionuclides: case of humic substances retention

    International Nuclear Information System (INIS)

    Reiller, P.

    2010-01-01

    This document takes a prospective stock of the natural organic matter influence on the possible effects on radionuclide migration, as well as a brief critical analysis of the literature data. A comparison with the retention of the 'simple' organic complexing agents is done in order to fix the limit of the 'simplistic' analogies done in the literature very often. It appears that the magnitude of the effects is function of the residence time in the medium, and of the possibilities for the organic complexes to be retained on the mineral surfaces. The contact time between radionuclides and the natural organic matter is also an influent parameter, as it influences part of the reversibility of this interaction vis-a-vis surface retention. Modelling of the metal-organic-surface systems is only satisfying up to now when accounting fractions of organic matter that are less susceptible to form colloidal aggregates, i.e., fulvic acids. These non-aggregated fractions could be considered as simple ligands in a first approximation. Conversely, when it comes to aggregated colloids of organic origin, i.e., humic acids, modelling are limited by the lack of theoretical understanding of their structure and of their evolution in response to geochemical condition variations, as ionic strength (harsh meteoric events), acidity or water composition (non-saturated water table). (author)

  11. Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Urbach, H.; Mader, I. [University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); Rauer, S.; Baumgartner, A. [University Medical Center Freiburg, Department of Neurology, Freiburg (Germany); Paus, S. [University Medical Center, Department of Neurology, Bonn (Germany); Wagner, J. [University Medical Center, Department of Epileptology, Bonn (Germany); Malter, M.P. [University of Cologne, Department of Neurology, Cologne (Germany); Pruess, H. [Charite - Universitaetsmedizin Berlin, Department of Neurology, Berlin (Germany); Lewerenz, J.; Kassubek, J. [Ulm University, Department of Neurology, Ulm (Germany); Hegen, H.; Auer, M.; Deisenhammer, F. [University Innsbruck, Department of Neurology, Innsbruck (Austria); Ufer, F. [University Medical Center, Department of Neurology, Hamburg (Germany); Bien, C.G. [Epilepsy Centre Bethel, Bielefeld-Bethel (Germany)

    2015-12-15

    Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE. Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type. SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005). SWMB is a newly described MRI sign rather specific for VGKC-LE. (orig.)

  12. Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis

    International Nuclear Information System (INIS)

    Urbach, H.; Mader, I.; Rauer, S.; Baumgartner, A.; Paus, S.; Wagner, J.; Malter, M.P.; Pruess, H.; Lewerenz, J.; Kassubek, J.; Hegen, H.; Auer, M.; Deisenhammer, F.; Ufer, F.; Bien, C.G.

    2015-01-01

    Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE. Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type. SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005). SWMB is a newly described MRI sign rather specific for VGKC-LE. (orig.)

  13. Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis.

    Science.gov (United States)

    Urbach, H; Rauer, S; Mader, I; Paus, S; Wagner, J; Malter, M P; Prüss, H; Lewerenz, J; Kassubek, J; Hegen, H; Auer, M; Deisenhammer, F; Ufer, F; Bien, C G; Baumgartner, A

    2015-12-01

    Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE. Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type. SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005). SWMB is a newly described MRI sign rather specific for VGKC-LE.

  14. On the Impact of Layout Quality to Understanding UML Diagrams: Size Matters

    DEFF Research Database (Denmark)

    Störrle, Harald

    2014-01-01

    Practical experience suggests that usage and understanding of UML diagrams is greatly affected by the quality of their layout. While existing research failed to provide conclusive evidence in support of this hypothesis, our own previous work provided substantial evidence to this effect. When...

  15. On improved understanding of plasma-chemical processes in complex low-temperature plasmas

    Science.gov (United States)

    Röpcke, Jürgen; Loffhagen, Detlef; von Wahl, Eric; Nave, Andy S. C.; Hamann, Stephan; van Helden, Jean-Piere H.; Lang, Norbert; Kersten, Holger

    2018-05-01

    Over the last years, chemical sensing using optical emission spectroscopy (OES) in the visible spectral range has been combined with methods of mid infrared laser absorption spectroscopy (MIR-LAS) in the molecular fingerprint region from 3 to 20 μm, which contains strong rotational-vibrational absorption bands of a large variety of gaseous species. This optical approach established powerful in situ diagnostic tools to study plasma-chemical processes of complex low-temperature plasmas. The methods of MIR-LAS enable to detect stable and transient molecular species in ground and excited states and to measure the concentrations and temperatures of reactive species in plasmas. Since kinetic processes are inherent to discharges ignited in molecular gases, high time resolution on sub-second timescales is frequently desired for fundamental studies as well as for process monitoring in applied research and industry. In addition to high sensitivity and good temporal resolution, the capacity for broad spectral coverage enabling multicomponent detection is further expanding the use of OES and MIR-LAS techniques. Based on selected examples, this paper reports on recent achievements in the understanding of complex low-temperature plasmas. Recently, a link with chemical modeling of the plasma has been provided, which is the ultimate objective for a better understanding of the chemical and reaction kinetic processes occurring in the plasma. Contribution to the Topical Issue "Fundamentals of Complex Plasmas", edited by Jürgen Meichsner, Michael Bonitz, Holger Fehske, Alexander Piel.

  16. Schedule Matters: Understanding the Relationship between Schedule Delays and Costs on Overruns

    Science.gov (United States)

    Majerowicz, Walt; Shinn, Stephen A.

    2016-01-01

    This paper examines the relationship between schedule delays and cost overruns on complex projects. It is generally accepted by many project practitioners that cost overruns are directly related to schedule delays. But what does "directly related to" actually mean? Some reasons or root causes for schedule delays and associated cost overruns are obvious, if only in hindsight. For example, unrealistic estimates, supply chain difficulties, insufficient schedule margin, technical problems, scope changes, or the occurrence of risk events can negatively impact schedule performance. Other factors driving schedule delays and cost overruns may be less obvious and more difficult to quantify. Examples of these less obvious factors include project complexity, flawed estimating assumptions, over-optimism, political factors, "black swan" events, or even poor leadership and communication. Indeed, is it even possible the schedule itself could be a source of delay and subsequent cost overrun? Through literature review, surveys of project practitioners, and the authors' own experience on NASA programs and projects, the authors will categorize and examine the various factors affecting the relationship between project schedule delays and cost growth. The authors will also propose some ideas for organizations to consider to help create an awareness of the factors which could cause or influence schedule delays and associated cost growth on complex projects.

  17. Evaluation of the production, composition and aluminum and iron complexation of algogenic organic matter

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Martin; Klouček, Ondřej; Pivokonská, Lenka

    2006-01-01

    Roč. 40, č. 16 (2006), s. 3045-3052 ISSN 0043-1354 R&D Projects: GA AV ČR KJB200600501 Institutional research plan: CEZ:AV0Z20600510 Keywords : affinity chromatography * algogenic organic matter * aluminum and iron coagulants * extracellular organic matter * molecular weight fractionation * intracellular organic matter Subject RIV: BK - Fluid Dynamics Impact factor: 2.459, year: 2006

  18. Mediation, moderation, and context: Understanding complex relations among cognition, affect, and health behaviour.

    Science.gov (United States)

    Kiviniemi, Marc T; Ellis, Erin M; Hall, Marissa G; Moss, Jennifer L; Lillie, Sarah E; Brewer, Noel T; Klein, William M P

    2018-01-01

    Researchers have historically treated cognition and affect as separate constructs in motivating health behaviour. We present a framework and empirical evidence for complex relations between cognition and affect in predicting health behaviour. Main Outcome, Design and Results: First, affect and cognition can mediate each other's relation to health behaviour. Second, affect and cognition can moderate the other's impact. Third, context can change the interplay of affect and cognition. Fourth, affect and cognition may be indelibly fused in some psychological constructs (e.g. worry, anticipated regret and reactance). These four propositions in our framework are not mutually exclusive. Examination of the types of complex relations described here can benefit theory development, empirical testing of theories and intervention design. Doing so will advance the understanding of mechanisms involved in regulation of health behaviours and the effectiveness of interventions to change health behaviours.

  19. Understanding valve program complexity in a refurbishment environment - learning from the past

    International Nuclear Information System (INIS)

    Roth, H.E.

    2012-01-01

    The complexity of Valve Program development, planning, execution and management in a refurbishment environment is an enormous undertaking requiring the proper coordination and integration of many moving parts. As such, lack of attention and understanding of this complexity has led to significant cost and schedule overruns in past refurbishment projects in the province. OPEX indicates the challenges in completing valve scope during refurbishments are related but not limited to; lack of detailed condition assessments, improper scope development, insignificant strategic approach to work task planning, scheduling and procurement, absence of contingency planning for common ‘as found’ conditions during execution, lack of proper training requirements, etc. In addition, past contracting strategies to employ numerous companies in collaboration to complete such a complex and specialized program, has resulted in further complications surrounding the management and integration of multiple quality programs and internal company processes. Finally, the aftermath of such fragmented projects results in an absolute closeout nightmare, often times taking years to locate, sift through and re-integrate pertinent information back into customer systems. Valve Program complexity cannot be understood by just anyone, only those that have lived through a refurbishment project and experienced the challenges mentioned above have the knowledge, skill, and ability to appreciate how to tactically apply past learning to realize future improvements. Furthermore, effective contractor-customer collaboration is crucial; true and in-depth knowledge and understanding of the customer quality programs, engineering and work management processes, configuration management requirements, and most importantly the imperative significance of nuclear safety, are all essential components to ensure overall alignment and program success. (author)

  20. Understanding valve program complexity in a refurbishment environment - learning from the past

    Energy Technology Data Exchange (ETDEWEB)

    Roth, H.E. [Babcock & Wilcox Canada Ltd., Cambridge, Ontario (Canada)

    2012-07-01

    The complexity of Valve Program development, planning, execution and management in a refurbishment environment is an enormous undertaking requiring the proper coordination and integration of many moving parts. As such, lack of attention and understanding of this complexity has led to significant cost and schedule overruns in past refurbishment projects in the province. OPEX indicates the challenges in completing valve scope during refurbishments are related but not limited to; lack of detailed condition assessments, improper scope development, insignificant strategic approach to work task planning, scheduling and procurement, absence of contingency planning for common ‘as found’ conditions during execution, lack of proper training requirements, etc. In addition, past contracting strategies to employ numerous companies in collaboration to complete such a complex and specialized program, has resulted in further complications surrounding the management and integration of multiple quality programs and internal company processes. Finally, the aftermath of such fragmented projects results in an absolute closeout nightmare, often times taking years to locate, sift through and re-integrate pertinent information back into customer systems. Valve Program complexity cannot be understood by just anyone, only those that have lived through a refurbishment project and experienced the challenges mentioned above have the knowledge, skill, and ability to appreciate how to tactically apply past learning to realize future improvements. Furthermore, effective contractor-customer collaboration is crucial; true and in-depth knowledge and understanding of the customer quality programs, engineering and work management processes, configuration management requirements, and most importantly the imperative significance of nuclear safety, are all essential components to ensure overall alignment and program success. (author)

  1. Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation

    International Nuclear Information System (INIS)

    Zalupski, Peter R.; Martin, Leigh R.; Nash, Ken; Nakamura, Yoshinobu; Yamamoto, Masahiko

    2009-01-01

    The ingenious combination of lactate and diethylenetriamine-N,N,N',N(double p rime),N(double p rime)-pentaacetic acid (DTPA) as an aqueous actinide-complexing medium forms the basis of the successful separation of americium and curium from lanthanides known as the TALSPEAK process. While numerous reports in the prior literature have focused on the optimization of this solvent extraction system, considerably less attention has been devoted to the understanding of the basic thermodynamic features of the complex fluids responsible for the separation. The available thermochemical information of both lactate and DTPA protonation and metal complexation reactions are representative of the behavior of these ions under idealized conditions. Our previous studies of medium effects on lactate protonation suggest that significant departures from the speciation predicted based on reported thermodynamic values should be expected in the TALSPEAK aqueous environment. Thermodynamic parameters describing the separation chemistry of this process thus require further examination at conditions significantly removed from conventional ideal systems commonly employed in fundamental solution chemistry. Such thermodynamic characterization is the key to predictive modelling of TALSPEAK. Improved understanding will, in principle, allow process technologists to more efficiently respond to off-normal conditions during large scale process operation. In this report, the results of calorimetric and potentiometric investigations of the effects of aqueous electrolytes on the thermodynamic parameters for lactate protonation and lactate complexation of americium and neodymium will be presented. Studies on the lactate protonation equilibrium will clearly illustrate distinct thermodynamic variations between strong electrolyte aqueous systems and buffered lactate environment.

  2. Towards a molecular level understanding of the sulfanilamide-soil organic matter-interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ashour A., E-mail: ashour.ahmed@uni-rostock.de [University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, D-18059 Rostock (Germany); Steinbeis GmbH & Co. KG für Technologietransfer, 70174 Stuttgart (Germany); University of Cairo, Faculty of Science, Department of Chemistry, 12613 Giza (Egypt); Thiele-Bruhn, Sören, E-mail: thiele@uni-trier.de [University of Trier, Soil Science, D-54286 Trier (Germany); Leinweber, Peter, E-mail: peter.leinweber@uni-rostock.de [Steinbeis GmbH & Co. KG für Technologietransfer, 70174 Stuttgart (Germany); University of Rostock, Soil Science, D-18051 Rostock (Germany); Kühn, Oliver, E-mail: oliver.kuehn@uni-rostock.de [University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, D-18059 Rostock (Germany)

    2016-07-15

    Sorption experiments of sulfanilamide (SAA) on well-characterized samples of soil size-fractions were combined with the modeling of SAA-soil-interaction via quantum chemical calculations. Freundlich unit capacities were determined in batch experiments and it was found that they increase with the soil organic matter (SOM) content according to the order fine silt > medium silt > clay > whole soil > coarse silt > sand. The calculated binding energies for mass-spectrometrically quantified sorption sites followed the order ionic species > peptides > carbohydrates > phenols and lignin monomers > lignin dimers > heterocyclic compounds > fatty acids > sterols > aromatic compounds > lipids, alkanes, and alkenes. SAA forms H-bonds through its polar centers with the polar SOM sorption sites. In contrast dispersion and π-π-interactions predominate the interaction of the SAA aromatic ring with the non-polar moieties of SOM. Moreover, the dipole moment, partial atomic charges, and molecular volume of the SOM sorption sites are the main physical properties controlling the SAA-SOM-interaction. Further, reasonable estimates of the Freundlich unit capacities from the calculated binding energies have been established. Consequently, we suggest using this approach in forthcoming studies to disclose the interactions of a wide range of organic pollutants with SOM. - Highlights: • Experiment and theory showed that SAA obeys a site-specific sorption on soil surfaces. • SAA-SOM-interaction increases by increasing polarity of SOM sorption site. • H-bonds, dispersion, and π-π-interactions were observed for SAA-SOM-interaction. • Dipole moment and atomic charges of SOM sorption sites control SAA-SOM-interaction. • The Freundlich unit capacities were estimated from the calculated binding energies. • The current SOM model is flexible to describe interactions of SOM with other pollutants.

  3. The Cryogenic Dark Matter Search: First 5-Tower Data and Improved Understanding of Ionization Collection

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Catherine N. [Case Western Reserve Univ., Cleveland, OH (United States)

    2010-01-01

    The Cryogenic Dark Matter Search (CDMS) is searching for Weakly Interacting Massive Particles (WIMPs) with cryogenic particle detectors. These detectors have the ability to discriminate between nuclear recoil candidate and electron recoil background events by collecting both phonon and ionization energy from recoils in the detector crystals. The CDMS-II experiment has completed analysis of the first data runs with 30 semiconductor detectors at the Soudan Underground Laboratory, resulting in a world leading WIMP-nucleon spin-independent cross section limit for WIMP masses above 44 GeV/c2. As CDMS aims to achieve greater WIMP sensitivity, it is necessary to increase the detector mass and discrimination between signal and background events. Incomplete ionization collection results in the largest background in the CDMS detectors as this causes electron recoil background interactions to appear as false candidate events. Two primary causes of incomplete ionization collection are surface and bulk trapping. Recent work has been focused on reducing surface trapping through the modification of fabrication methods for future detectors. Analyzing data taken with test devices has shown that hydrogen passivation of the amorphous silicon blocking layer worsens surface trapping. Additional data has shown that the iron-ion implantation used to lower the critical temperature of the tungsten transition-edge sensors causes a degradation of the ionization collection. Using selective implantation on future detectors may improve ionization collection for events near the phonon side detector surface. Bulk trapping is minimized by neutralizing ionized lattice impurities. Detector investigations at testing facilities and in situ at the experimental site have provided methods to optimize the neutralization process and monitor running conditions to maintain full ionization collection. This work details my contribution to the 5-tower data taking, monitoring, and analysis effort as

  4. Understanding complexities of synaptic transmission in medically intractable seizures: A paradigm of epilepsy research

    Directory of Open Access Journals (Sweden)

    Jyotirmoy Banerjee

    2013-01-01

    Full Text Available Investigating the changes associated with the development of epileptic state in humans is complex and requires a multidisciplinary approach. Understanding the intricacies of medically intractable epilepsy still remains a challenge for neurosurgeons across the world. A significant number of patients who has undergone resective brain surgery for epilepsy still continue to have seizures. The reason behind this therapy resistance still eludes us. Thus to develop a cure for the difficult to treat epilepsy, we need to comprehensively study epileptogenesis. Although various animal models are developed but none of them replicate the pathological conditions in humans. So the ideal way to understand epileptogenecity is to examine the tissue resected for the treatment of intractable epilepsy. Advanced imaging and electrical localization procedures are utilized to establish the epileptogenic zone in epilepsy patients. Further molecular and cytological studies are required for the microscopic analysis of brain samples collected from the epileptogenic focus. As alterations in inhibitory as well as excitatory synaptic transmission are key features of epilepsy, understanding the regulation of neurotransmission in the resected surgery zone is of immense importance. Here we summarize various modalities of in vitro slice analysis from the resected brain specimen to understand the changes in GABAergic and glutamatergic synaptic transmission in epileptogenic zone. We also review evidence pertaining to the proposed role of nicotinic receptors in abnormal synaptic transmission which is one of the major causes of epileptiform activity. Elucidation of current concepts in regulation of synaptic transmission will help develop therapies for epilepsy cases that cannot me managed pharmacologically.

  5. Using chemistry and microfluidics to understand the spatial dynamics of complex biological networks.

    Science.gov (United States)

    Kastrup, Christian J; Runyon, Matthew K; Lucchetta, Elena M; Price, Jessica M; Ismagilov, Rustem F

    2008-04-01

    Understanding the spatial dynamics of biochemical networks is both fundamentally important for understanding life at the systems level and also has practical implications for medicine, engineering, biology, and chemistry. Studies at the level of individual reactions provide essential information about the function, interactions, and localization of individual molecular species and reactions in a network. However, analyzing the spatial dynamics of complex biochemical networks at this level is difficult. Biochemical networks are nonequilibrium systems containing dozens to hundreds of reactions with nonlinear and time-dependent interactions, and these interactions are influenced by diffusion, flow, and the relative values of state-dependent kinetic parameters. To achieve an overall understanding of the spatial dynamics of a network and the global mechanisms that drive its function, networks must be analyzed as a whole, where all of the components and influential parameters of a network are simultaneously considered. Here, we describe chemical concepts and microfluidic tools developed for network-level investigations of the spatial dynamics of these networks. Modular approaches can be used to simplify these networks by separating them into modules, and simple experimental or computational models can be created by replacing each module with a single reaction. Microfluidics can be used to implement these models as well as to analyze and perturb the complex network itself with spatial control on the micrometer scale. We also describe the application of these network-level approaches to elucidate the mechanisms governing the spatial dynamics of two networkshemostasis (blood clotting) and early patterning of the Drosophila embryo. To investigate the dynamics of the complex network of hemostasis, we simplified the network by using a modular mechanism and created a chemical model based on this mechanism by using microfluidics. Then, we used the mechanism and the model to

  6. Understanding NaI(Tl) crystal background for dark matter searches

    Energy Technology Data Exchange (ETDEWEB)

    Adhikari, G.; Adhikari, P.; Kong, S.Y.; Oh, S.Y. [Sejong University, Department of Physics and Astronomy, Seoul (Korea, Republic of); Ha, C.; Jeon, E.J.; Kim, N.Y.; Lee, H.S.; Park, J.S.; Park, K.S. [Institute for Basic Science (IBS), Center for Underground Physics, Daejeon (Korea, Republic of); Kim, Y.D. [Institute for Basic Science (IBS), Center for Underground Physics, Daejeon (Korea, Republic of); Sejong University, Department of Physics and Astronomy, Seoul (Korea, Republic of)

    2017-07-15

    We have developed ultra-low-background NaI(Tl) crystals to reproduce the DAMA results with the ultimate goal of achieving purity levels that are comparable to or better than those of the DAMA/LIBRA crystals. Even though the achieved background level does not approach that of DAMA/LIBRA, it is crucial to have a quantitative understanding of the backgrounds. We have studied background simulations toward a deeper understanding of the backgrounds and developed background models for a 9.16-kg NaI(Tl) crystal used in the test arrangement. In this paper we describe the contributions of background sources quantitatively by performing Geant4 Monte Carlo simulations that are fitted to the measured data to quantify the unknown fractions of the background compositions. In the fitted results, the overall simulated background spectrum well describes the measured data with a 9.16-kg NaI(Tl) crystal and shows that the background sources are dominated by surface {sup 210}Pb and internal {sup 40}K in the 2-6-keV energy interval, which produce 2.4 counts/day/keV/kg (dru) and 0.5 dru, respectively. (orig.)

  7. Supramolecular chemistry: from molecular information towards self-organization and complex matter

    International Nuclear Information System (INIS)

    Lehn, Jean-Marie

    2004-01-01

    supramolecular polymers and liquid crystals, and provide an original approach to nanoscience and nanotechnology. In particular, the spontaneous but controlled generation of well-defined, functional supramolecular architectures of nanometric size through self-organization represents a means of performing programmed engineering and processing of nanomaterials. Supramolecular chemistry is intrinsically a dynamic chemistry, in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when a molecular entity contains covalent bonds that may form and break reversibly, so as to make possible a continuous change in constitution and structure by reorganization and exchange of building blocks. This behaviour defines a constitutional dynamic chemistry that allows self-organization by selection as well as by design at both the molecular and supramolecular levels. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization by selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation in a Darwinistic fashion. The merging of the features, information and programmability, dynamics and reversibility, constitution and structural diversity, points towards the emergence of adaptative and evolutionary chemistry. Together with the corresponding fields of physics and biology, it constitutes a science of informed matter, of organized, adaptative complex matter

  8. Energy landscape scheme for an intuitive understanding of complex domain dynamics in ferroelectric thin films.

    Science.gov (United States)

    Kim, Tae Heon; Yoon, Jong-Gul; Baek, Seung Hyub; Park, Woong-kyu; Yang, Sang Mo; Yup Jang, Seung; Min, Taeyuun; Chung, Jin-Seok; Eom, Chang-Beom; Noh, Tae Won

    2015-07-01

    Fundamental understanding of domain dynamics in ferroic materials has been a longstanding issue because of its relevance to many systems and to the design of nanoscale domain-wall devices. Despite many theoretical and experimental studies, a full understanding of domain dynamics still remains incomplete, partly due to complex interactions between domain-walls and disorder. We report domain-shape-preserving deterministic domain-wall motion, which directly confirms microscopic return point memory, by observing domain-wall breathing motion in ferroelectric BiFeO3 thin film using stroboscopic piezoresponse force microscopy. Spatial energy landscape that provides new insights into domain dynamics is also mapped based on the breathing motion of domain walls. The evolution of complex domain structure can be understood by the process of occupying the lowest available energy states of polarization in the energy landscape which is determined by defect-induced internal fields. Our result highlights a pathway for the novel design of ferroelectric domain-wall devices through the engineering of energy landscape using defect-induced internal fields such as flexoelectric fields.

  9. Energy landscape scheme for an intuitive understanding of complex domain dynamics in ferroelectric thin films

    Science.gov (United States)

    Heon Kim, Tae; Yoon, Jong-Gul; Hyub Baek, Seung; Park, Woong-Kyu; Mo Yang, Sang; Yup Jang, Seung; Min, Taeyuun; Chung, Jin-Seok; Eom, Chang-Beom; Won Noh, Tae

    2015-07-01

    Fundamental understanding of domain dynamics in ferroic materials has been a longstanding issue because of its relevance to many systems and to the design of nanoscale domain-wall devices. Despite many theoretical and experimental studies, a full understanding of domain dynamics still remains incomplete, partly due to complex interactions between domain-walls and disorder. We report domain-shape-preserving deterministic domain-wall motion, which directly confirms microscopic return point memory, by observing domain-wall breathing motion in ferroelectric BiFeO3 thin film using stroboscopic piezoresponse force microscopy. Spatial energy landscape that provides new insights into domain dynamics is also mapped based on the breathing motion of domain walls. The evolution of complex domain structure can be understood by the process of occupying the lowest available energy states of polarization in the energy landscape which is determined by defect-induced internal fields. Our result highlights a pathway for the novel design of ferroelectric domain-wall devices through the engineering of energy landscape using defect-induced internal fields such as flexoelectric fields.

  10. Getting angry matters: Going beyond perspective taking and empathic concern to understand bystanders' behavior in bullying.

    Science.gov (United States)

    Pozzoli, Tiziana; Gini, Gianluca; Thornberg, Robert

    2017-12-01

    The present study examined the relations between different empathic dimensions and bystanders' behavior in bullying. Specifically, the indirect effects of empathic concern and perspective taking via empathic anger on defending and passive bystanding were tested in a sample of Italian young adolescents (N = 398; M age  = 12 years, 3 months, 47.2% girls). Path analysis confirmed the direct and indirect effects, via empathic anger, of empathic concern and perspective taking on bystanders' behavior, with the exception of the direct association between perspective taking and passive bystanding that was not significant. Our findings suggest that considering empathic anger together with empathic concern and perspective taking could help researchers to better understand the links between empathic dispositions and bystanders' behavior in bullying. Copyright © 2017. Published by Elsevier Ltd.

  11. Simulation-based education: understanding the socio-cultural complexity of a surgical training 'boot camp'.

    Science.gov (United States)

    Cleland, Jennifer; Walker, Kenneth G; Gale, Michael; Nicol, Laura G

    2016-08-01

    The focus of simulation-based education (SBE) research has been limited to outcome and effectiveness studies. The effect of social and cultural influences on SBE is unclear and empirical work is lacking. Our objective in this study was to explore and understand the complexity of context and social factors at a surgical boot camp (BC). A rapid ethnographic study, employing the theoretical lenses of complexity and activity theory and Bourdieu's concept of 'capital', to better understand the socio-cultural influences acting upon, and during, two surgical BCs, and their implications for SBE. Over two 4-day BCs held in Scotland, UK, an observer and two preceptors conducted 81 hours of observations, 14 field interviews and 11 formal interviews with faculty members (n = 10, including the lead faculty member, session leaders and junior faculty members) and participants (n = 19 core surgical trainees and early-stage residents). Data collection and inductive analysis for emergent themes proceeded iteratively. This paper focuses on three analytical themes. First, the complexity of the surgical training system and wider health care education context, and how this influenced the development of the BC. Second, participants' views of the BC as a vehicle not just for learning skills but for gaining 'insider information' on how best to progress in surgical training. Finally, the explicit aim of faculty members to use the Scottish Surgical Bootcamp to welcome trainees and residents into the world of surgery, and how this occurred. To the best of our knowledge, this is the first empirical study of a surgical BC that takes a socio-cultural approach to exploring and understanding context, complexities, uncertainties and learning associated with one example of SBE. Our findings suggest that a BC is as much about social and cultural processes as it is about individual, cognitive and acquisitive learning. Acknowledging this explicitly will help those planning similar enterprises and

  12. Applying a complex adaptive system's understanding of health to primary care [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Johannes Bircher

    2016-09-01

    Full Text Available This paper explores the diagnostic and therapeutic potential of a new concept of health. Investigations into the nature of health have led to a new definition that explains health as a complex adaptive system (CAS and is based on five components (a-e. Humans like all biological creatures must satisfactorily respond to (a the demands of life. For this purpose they need (b a biologically given potential (BGP and (c a personally acquired potential (PAP. These properties of individuals are embedded within (d social and (e environmental determinants of health. Between these five components of health there are 10 complex interactions that justify viewing health as a CAS. In each patient, the current state of health as a CAS evolved from the past, will move forward to a new future, and has to be analyzed and treated as an autonomous whole. A diagnostic procedure is suggested as follows: together with the patient, the five components and 10 complex interactions are assessed. This may help patients to better understand their situations and to recognize possible next steps that may be useful in order to evolve toward better health by themselves. In this process mutual trust in the patient-physician interaction is critical. The described approach offers new possibilities for helping patients improve their health prospects.

  13. Understanding and quantifying cognitive complexity level in mathematical problem solving items

    Directory of Open Access Journals (Sweden)

    SUSAN E. EMBRETSON

    2008-09-01

    Full Text Available The linear logistic test model (LLTM; Fischer, 1973 has been applied to a wide variety of new tests. When the LLTM application involves item complexity variables that are both theoretically interesting and empirically supported, several advantages can result. These advantages include elaborating construct validity at the item level, defining variables for test design, predicting parameters of new items, item banking by sources of complexity and providing a basis for item design and item generation. However, despite the many advantages of applying LLTM to test items, it has been applied less often to understand the sources of complexity for large-scale operational test items. Instead, previously calibrated item parameters are modeled using regression techniques because raw item response data often cannot be made available. In the current study, both LLTM and regression modeling are applied to mathematical problem solving items from a widely used test. The findings from the two methods are compared and contrasted for their implications for continued development of ability and achievement tests based on mathematical problem solving items.

  14. The Crucible simulation: Behavioral simulation improves clinical leadership skills and understanding of complex health policy change.

    Science.gov (United States)

    Cohen, Daniel; Vlaev, Ivo; McMahon, Laurie; Harvey, Sarah; Mitchell, Andy; Borovoi, Leah; Darzi, Ara

    2017-05-11

    The Health and Social Care Act 2012 represents the most complex National Health Service reforms in history. High-quality clinical leadership is important for successful implementation of health service reform. However, little is known about the effectiveness of current leadership training. This study describes the use of a behavioral simulation to improve the knowledge and leadership of a cohort of medical doctors expected to take leadership roles in the National Health Service. A day-long behavioral simulation (The Crucible) was developed and run based on a fictitious but realistic health economy. Participants completed pre- and postsimulation questionnaires generating qualitative and quantitative data. Leadership skills, knowledge, and behavior change processes described by the "theory of planned behavior" were self-assessed pre- and postsimulation. Sixty-nine medical doctors attended. Participants deemed the simulation immersive and relevant. Significant improvements were shown in perceived knowledge, capability, attitudes, subjective norms, intentions, and leadership competency following the program. Nearly one third of participants reported that they had implemented knowledge and skills from the simulation into practice within 4 weeks. This study systematically demonstrates the effectiveness of behavioral simulation for clinical management training and understanding of health policy reform. Potential future uses and strategies for analysis are discussed. High-quality care requires understanding of health systems and strong leadership. Policymakers should consider the use of behavioral simulation to improve understanding of health service reform and development of leadership skills in clinicians, who readily adopt skills from simulation into everyday practice.

  15. Why understanding the impacts of the changing environment on river basin hydrology matters in Texas?

    Science.gov (United States)

    Gao, H.; Zhao, G.; Lee, K.; Zhang, S.; Shen, X.; Shao, M.; Nickelson, C.

    2017-12-01

    The State of Texas is prone to floods and droughts—both of which are expected to become more frequent, and more intensified, under a changing climate. This has a direct negative effect on agricultural productivity, which is a major revenue source for the state. Meanwhile, with the rapid population growth and economic development, the burden to Texas water resources is exacerbated by the ever increasing demands from users. From a hydrological processes perspective, the direct consequence of the increased impervious area due to urbanization is greater surface runoff and higher flood peaks. Although many reservoirs have been built during the past several decades to regulate river flows and increase water supply, the role of these reservoirs in the context of different future climate change and urbanization scenarios needs to be explored. Furthermore, phytoplankton productivity—an important indicator of coastal ecosystem health— is significantly affected by river discharge. The objective of this presentation is to reveal the importance of understanding the impacts of climate change, urbanization, and flow regulation on Texas river flows, water resources, and coastal water quality. Using state-of-the-art modeling and remote sensing techniques, we will showcase our results over representative Texas river basins and bay areas. A few examples include modeling peak flows in the San Antonio River Basin, evaluating water supply resilience under future drought and urbanization over the Dallas metropolitan area, projecting future crop yields from Texas agricultural lands, and monitoring and forecasting Chlorophyll-a concentrations over Galveston Bay. Results from these studies are expected to provide information relevant to decision making, both with regard to water resources management and to ecosystem protection.

  16. Memory Matters

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Memory Matters KidsHealth / For Kids / Memory Matters What's in ... of your complex and multitalented brain. What Is Memory? When an event happens, when you learn something, ...

  17. Computational Cellular Dynamics Based on the Chemical Master Equation: A Challenge for Understanding Complexity.

    Science.gov (United States)

    Liang, Jie; Qian, Hong

    2010-01-01

    Modern molecular biology has always been a great source of inspiration for computational science. Half a century ago, the challenge from understanding macromolecular dynamics has led the way for computations to be part of the tool set to study molecular biology. Twenty-five years ago, the demand from genome science has inspired an entire generation of computer scientists with an interest in discrete mathematics to join the field that is now called bioinformatics. In this paper, we shall lay out a new mathematical theory for dynamics of biochemical reaction systems in a small volume (i.e., mesoscopic) in terms of a stochastic, discrete-state continuous-time formulation, called the chemical master equation (CME). Similar to the wavefunction in quantum mechanics, the dynamically changing probability landscape associated with the state space provides a fundamental characterization of the biochemical reaction system. The stochastic trajectories of the dynamics are best known through the simulations using the Gillespie algorithm. In contrast to the Metropolis algorithm, this Monte Carlo sampling technique does not follow a process with detailed balance. We shall show several examples how CMEs are used to model cellular biochemical systems. We shall also illustrate the computational challenges involved: multiscale phenomena, the interplay between stochasticity and nonlinearity, and how macroscopic determinism arises from mesoscopic dynamics. We point out recent advances in computing solutions to the CME, including exact solution of the steady state landscape and stochastic differential equations that offer alternatives to the Gilespie algorithm. We argue that the CME is an ideal system from which one can learn to understand "complex behavior" and complexity theory, and from which important biological insight can be gained.

  18. Venom Resistance as a Model for Understanding the Molecular Basis of Complex Coevolutionary Adaptations.

    Science.gov (United States)

    Holding, Matthew L; Drabeck, Danielle H; Jansa, Sharon A; Gibbs, H Lisle

    2016-11-01

    SynopsisVenom and venom resistance are molecular phenotypes widely considered to have diversified through coevolution between predators and prey. However, while evolutionary and functional studies on venom have been extensive, little is known about the molecular basis, variation, and complexity of venom resistance. We review known mechanisms of venom resistance and relate these mechanisms to their predicted impact on coevolutionary dynamics with venomous enemies. We then describe two conceptual approaches which can be used to examine venom/resistance systems. At the intraspecific level, tests of local adaptation in venom and resistance phenotypes can identify the functional mechanisms governing the outcomes of coevolution. At deeper evolutionary timescales, the combination of phylogenetically informed analyses of protein evolution coupled with studies of protein function promise to elucidate the mode and tempo of evolutionary change on potentially coevolving genes. We highlight case studies that use each approach to extend our knowledge of these systems as well as address larger questions about coevolutionary dynamics. We argue that resistance and venom are phenotypic traits which hold exceptional promise for investigating the mechanisms, dynamics, and outcomes of coevolution at the molecular level. Furthermore, extending the understanding of single gene-for-gene interactions to the whole resistance and venom phenotypes may provide a model system for examining the molecular and evolutionary dynamics of complex multi-gene interactions. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  19. Understanding coral reefs as complex systems: degradation and prospects for recovery

    Directory of Open Access Journals (Sweden)

    Raymond T. Dizon

    2006-06-01

    Full Text Available The present century is witness to unprecedented levels of coral reef degradation worldwide. Current understanding based on traditional ideas is unlikely to capture adequately the dynamics of phenomena accompanying this trend. In this regard, the ideas of complexity are reviewed. Some applications to coral reefs as complex systems have already been discussed in the literature although further progress is warranted as the search for new and more effective management tools continues, and the direction towards more holistic, integrative and large scale approaches gains wider acceptance. We distinguish between the concepts of robustness and resilience in the face of disturbance, highlight the various mechanisms that foster these stability properties and provide some coral reef examples. We identify some of the driving forces behind succession that are critical for community assembly and possible reef recovery. Finally, we consider how self-organization arises out of apparently random and chaotic processes and interactions to exhibit certain regularities and patterns especially when moving up on the scale of space and/or time.

  20. Advances in the understanding of the BBSome complex structure and function

    Directory of Open Access Journals (Sweden)

    Hernandez-Hernandez V

    2015-10-01

    Full Text Available Victor Hernandez-Hernandez, Dagan JenkinsGenetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UKAbstract: Bardet–Biedl syndrome (BBS is an autosomal recessive condition characterized by important clinical features, including obesity, blindness, renal cystic disease, and intellectual disability. BBS is caused by mutations in >20 genes, a subset of which form the so-called BBSome. The BBSome is a complex that coats intracellular vesicles and interacts with key proteins, such as small GTPases, that regulate the trafficking of these vesicles to the base of cilia. Cilia are microtubular protusions present on the surface of most cells that are defective in a key group of disorders known as ciliopathies, of which BBS is one. BBSome components particularly localize to the basal body of cilia, and also centrosomes, where they interact with pericentriolar material proteins that regulate their function. The BBSome also facilitates the transport of key cargo within cilia by acting as an adaptor protein for intraflagellar transport complexes, and as such BBS mutations lead to a variety of functional defects in cilia in a tissue- and cell-type-specific manner. This might include defects in photoreceptor trafficking linked to the connecting cilium, abnormal hedgehog signaling within bone, and aberrant calcium signaling in response to fluid flow along renal tubules, although the precise mechanisms are still not completely understood. Taken together, the BBSome is an important complex that may be targeted for treatment of a variety of common and important disorders, and understanding the precise function of the BBSome will be essential to capitalize on this translationally.Keywords: retinitis pigmentosa GTPase regulator, polycystin, disrupted in schizophrenia 1, Hedgehog signaling, calcium signaling, photoreceptors

  1. Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi-Wei; Steele, T.G. [Department of Physics and Engineering Physics, University of Saskatchewan,116 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Hanif, T. [Department of Theoretical Physics, University of Dhaka,Dhaka-1000 (Bangladesh); Mann, R.B. [Department of Physics, University of Waterloo,Waterloo, ON, N2L 3G1 (Canada)

    2016-08-09

    We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model’s couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ≈0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F, which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

  2. Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

    Science.gov (United States)

    Wang, Zhi-Wei; Steele, T. G.; Hanif, T.; Mann, R. B.

    2016-08-01

    We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model's couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ ≈ 0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F , which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

  3. Understanding Student Cognition about Complex Earth System Processes Related to Climate Change

    Science.gov (United States)

    McNeal, K. S.; Libarkin, J.; Ledley, T. S.; Dutta, S.; Templeton, M. C.; Geroux, J.; Blakeney, G. A.

    2011-12-01

    The Earth's climate system includes complex behavior and interconnections with other Earth spheres that present challenges to student learning. To better understand these unique challenges, we have conducted experiments with high-school and introductory level college students to determine how information pertaining to the connections between the Earth's atmospheric system and the other Earth spheres (e.g., hydrosphere and cryosphere) are processed. Specifically, we include psychomotor tests (e.g., eye-tracking) and open-ended questionnaires in this research study, where participants were provided scientific images of the Earth (e.g., global precipitation and ocean and atmospheric currents), eye-tracked, and asked to provide causal or relational explanations about the viewed images. In addition, the students engaged in on-line modules (http://serc.carleton.edu/eslabs/climate/index.html) focused on Earth system science as training activities to address potential cognitive barriers. The developed modules included interactive media, hands-on lessons, links to outside resources, and formative assessment questions to promote a supportive and data-rich learning environment. Student eye movements were tracked during engagement with the materials to determine the role of perception and attention on understanding. Students also completed a conceptual questionnaire pre-post to determine if these on-line curriculum materials assisted in their development of connections between Earth's atmospheric system and the other Earth systems. The pre-post results of students' thinking about climate change concepts, as well as eye-tracking results, will be presented.

  4. Understanding the Complexities of Communicating Management Decisions on the Subsistence Use of Yukon River Salmon

    Science.gov (United States)

    Brooks, J. F.; Trainor, S.

    2017-12-01

    Over 20,000 residents in Alaska and Yukon Territory rely upon the Yukon River to provide them harvests of Pacific salmon each year. Salmon are a highly valued food resource and the practice of salmon fishing along the Yukon is deep rooted in local cultures and traditions. Potential future impacts of climate change on the health of Yukon River salmon stocks could be significant. Collaborative managerial processes which incorporate the viewpoints of subsistence stakeholders will be crucial in enabling communities and managerial institutions to adapt and manage these impacts. However, the massive extent of the Yukon River makes it difficult for communities rich with highly localized knowledge to situate themselves within a drainage-wide context of resource availability, and to fully understand the implications that management decisions may have for their harvest. Differences in salmon availability and abundance between the upper and lower Yukon, commercial vs. subsistence fishery interests, and enforcement of the international Pacific Salmon Treaty further complicate understanding and makes the topic of salmon as a subsistence resource a highly contentious issue. A map which synthesizes the presence and absence of Pacific salmon throughout the entire Yukon River drainage was requested by both subsistence fishers and natural resource managers in Alaska in order to help facilitate productive conversations about salmon management decisions. Interviews with Alaskan stakeholders with managerial, biological, and subsistence harvest backgrounds were carried out and a literature review was conducted in order to understand what such a map should and could accomplish. During the research process, numerous data gaps concerning the distribution of salmon along the Yukon River were discovered, and insights about the complexities involved in translating science when it is situated within a charged political, economic, and cultural context were revealed. Preliminary maps depicting

  5. Measuring spatial patterns in floodplains: A step towards understanding the complexity of floodplain ecosystems: Chapter 6

    Science.gov (United States)

    Scown, Murray W.; Thoms, Martin C.; DeJager, Nathan R.; Gilvear, David J.; Greenwood, Malcolm T.; Thoms, Martin C.; Wood, Paul J.

    2016-01-01

    Floodplains can be viewed as complex adaptive systems (Levin, 1998) because they are comprised of many different biophysical components, such as morphological features, soil groups and vegetation communities as well as being sites of key biogeochemical processing (Stanford et al., 2005). Interactions and feedbacks among the biophysical components often result in additional phenomena occuring over a range of scales, often in the absence of any controlling factors (sensu Hallet, 1990). This emergence of new biophysical features and rates of processing can lead to alternative stable states which feed back into floodplain adaptive cycles (cf. Hughes, 1997; Stanford et al., 2005). Interactions between different biophysical components, feedbacks, self emergence and scale are all key properties of complex adaptive systems (Levin, 1998; Phillips, 2003; Murray et al., 2014) and therefore will influence the manner in which we study and view spatial patterns. Measuring the spatial patterns of floodplain biophysical components is a prerequisite to examining and understanding these ecosystems as complex adaptive systems. Elucidating relationships between pattern and process, which are intrinsically linked within floodplains (Ward et al., 2002), is dependent upon an understanding of spatial pattern. This knowledge can help river scientists determine the major drivers, controllers and responses of floodplain structure and function, as well as the consequences of altering those drivers and controllers (Hughes and Cass, 1997; Whited et al., 2007). Interactions and feedbacks between physical, chemical and biological components of floodplain ecosystems create and maintain a structurally diverse and dynamic template (Stanford et al., 2005). This template influences subsequent interactions between components that consequently affect system trajectories within floodplains (sensu Bak et al., 1988). Constructing and evaluating models used to predict floodplain ecosystem responses to

  6. Bringing content understanding into usability testing in complex application domains—a case study in eHealth

    DEFF Research Database (Denmark)

    Andersen, Simon Bruntse; Rasmussen, Claire Kirchert; Frøkjær, Erik

    2017-01-01

    A usability evaluation technique, Cooperative Usability Testing with Questions of Understanding (CUT with QU) intended to illuminate users’ ability to understand the content information of an application is proposed. In complex application domains as for instance the eHealth domain, this issue...... of users’ content understanding is sometimes crucial, and thus should be carefully evaluated. Unfortunately, conventional usability evaluation techniques do not address challenges of content understanding. In a case study within eHealth, specifically the setting of a rehabilitation clinic involving...... the participation of four physiotherapists and four clients in a period of 3.5 months, it was demonstrated how CUT with QU can complement conventional usability testing and provide insight into users’ challenges with understanding of a new complex eHealth application. More experiments in other complex application...

  7. Soil organic matter dynamics and CO2 fluxes in relation to landscape scale processes: linking process understanding to regional scale carbon mass-balances

    Science.gov (United States)

    Van Oost, Kristof; Nadeu, Elisabet; Wiaux, François; Wang, Zhengang; Stevens, François; Vanclooster, Marnik; Tran, Anh; Bogaert, Patrick; Doetterl, Sebastian; Lambot, Sébastien; Van wesemael, Bas

    2014-05-01

    In this paper, we synthesize the main outcomes of a collaborative project (2009-2014) initiated at the UCL (Belgium). The main objective of the project was to increase our understanding of soil organic matter dynamics in complex landscapes and use this to improve predictions of regional scale soil carbon balances. In a first phase, the project characterized the emergent spatial variability in soil organic matter storage and key soil properties at the regional scale. Based on the integration of remote sensing, geomorphological and soil analysis techniques, we quantified the temporal and spatial variability of soil carbon stock and pool distribution at the local and regional scales. This work showed a linkage between lateral fluxes of C in relation with sediment transport and the spatial variation in carbon storage at multiple spatial scales. In a second phase, the project focused on characterizing key controlling factors and process interactions at the catena scale. In-situ experiments of soil CO2 respiration showed that the soil carbon response at the catena scale was spatially heterogeneous and was mainly controlled by the catenary variation of soil physical attributes (soil moisture, temperature, C quality). The hillslope scale characterization relied on advanced hydrogeophysical techniques such as GPR (Ground Penetrating Radar), EMI (Electromagnetic induction), ERT (Electrical Resistivity Tomography), and geophysical inversion and data mining tools. Finally, we report on the integration of these insights into a coupled and spatially explicit model and its application. Simulations showed that C stocks and redistribution of mass and energy fluxes are closely coupled, they induce structured spatial and temporal patterns with non negligible attached uncertainties. We discuss the main outcomes of these activities in relation to sink-source behavior and relevance of erosion processes for larger-scale C budgets.

  8. Influence of the competition of anions (hydroxides, carbonates) on the complexation of trivalent lanthanides by natural organic matter: case of humic substances

    International Nuclear Information System (INIS)

    Kouhail, Yasmine

    2016-01-01

    The aim of this study is to acquire and refine complexation data for understanding the fate of lanthanides in the environment where the concentrations of organic matter are highly variable. This study is focusing on both the description and understanding of the interactions between the europium(III) and a Suwannee River fulvic acid (SRFA) as a representative of humic substances (HS), and the influence of major anions present in natural waters, i.e. hydroxides and carbonates ions, in these interactions. To understand the ternary systems Eu-OH-SRFA and EU-CO_3-SRFA, Eu-SRFA and EU-CO_3 binary systems are first investigated by time-resolved luminescence spectroscopy (TRLS) for wide ranges of pH, ionic strength, Eu(III), SRFA and CO_3 concentrations. This study shows that the structures of humic substances are influenced by the presence of Eu(III). Interaction constants are determined for the Eu-SRFA binary system and are used for the understanding of the EU-CO_3-SRFA ternary system. EU-CO_3-SRF A ternary complexes are highlighted by SLRT, and an interaction constant has also been proposed in the frame of the NICA-Donnan model. Variations in size of EuSRFA complexes as a function of europium and SRFA concentrations are presented, and the impact of these variations on NICA-Donnan parameters is investigated. The results of this work are challenging modeling concepts of metal-HS interactions at various HS concentrations, in particular for the consideration of electrostatic effects. (author) [fr

  9. A Hypothesis for Using Pathway Genetic Load Analysis for Understanding Complex Outcomes in Bilirubin Encephalopathy

    Science.gov (United States)

    Riordan, Sean M.; Bittel, Douglas C.; Le Pichon, Jean-Baptiste; Gazzin, Silvia; Tiribelli, Claudio; Watchko, Jon F.; Wennberg, Richard P.; Shapiro, Steven M.

    2016-01-01

    Genetic-based susceptibility to bilirubin neurotoxicity and chronic bilirubin encephalopathy (kernicterus) is still poorly understood. Neonatal jaundice affects 60–80% of newborns, and considerable effort goes into preventing this relatively benign condition from escalating into the development of kernicterus making the incidence of this potentially devastating condition very rare in more developed countries. The current understanding of the genetic background of kernicterus is largely comprised of mutations related to alterations of bilirubin production, elimination, or both. Less is known about mutations that may predispose or protect against CNS bilirubin neurotoxicity. The lack of a monogenetic source for this risk of bilirubin neurotoxicity suggests that disease progression is dependent upon an overall decrease in the functionality of one or more essential genetically controlled metabolic pathways. In other words, a “load” is placed on key pathways in the form of multiple genetic variants that combine to create a vulnerable phenotype. The idea of epistatic interactions creating a pathway genetic load (PGL) that affects the response to a specific insult has been previously reported as a PGL score. We hypothesize that the PGL score can be used to investigate whether increased susceptibility to bilirubin-induced CNS damage in neonates is due to a mutational load being placed on key genetic pathways important to the central nervous system's response to bilirubin neurotoxicity. We propose a modification of the PGL score method that replaces the use of a canonical pathway with custom gene lists organized into three tiers with descending levels of evidence combined with the utilization of single nucleotide polymorphism (SNP) causality prediction methods. The PGL score has the potential to explain the genetic background of complex bilirubin induced neurological disorders (BIND) such as kernicterus and could be the key to understanding ranges of outcome severity

  10. Toward a better understanding of the complex geochemical processes governing subsurface contaminant transport

    International Nuclear Information System (INIS)

    Puls, R.W.

    1990-01-01

    Identification and understanding of the geochemical processes, including ion exchange, precipitation, organic partitioning, chemisorption, aqueous complexation, and colloidal stability and transport, controlling subsurface contamination is essential for making accurate predictions of the fate and transport of these constituents. Current approaches to quantify the effect of these processes primarily involve laboratory techniques, including the use of closed static systems (batch experiments) where small amounts of aquifer solids or minerals are contacted with an aqueous phase containing the components of interest for relatively short durations; and dynamic systems (column experiments) where a larger segment of the aquifer is investigated by analyzing the breakthrough profiles of reactive and non-reactive species. Both approaches are constrained by differences in scale, alteration of media during sample collection and use, and spatial variability. More field reactivity studies are needed to complement established laboratory approaches for the determination of retardation factors and scaling factors, corroboration of batch and column results, and validation of sampling techniques. These studies also serve to accentuate areas of geochemical process research where data deficiencies exist, such as the kinetics of adsorption-desorption, metal-organic-mineral interactions, and colloidal mobility. The advantages and disadvantages of the above approaches are discussed in the context of achieving a more completely integrated approach to geochemical transport experiments, with supportive data presented from selected studies. (Author) (16 refs., 4 figs., 2 tabs.)

  11. Complexities in Understanding Attentional Functioning among Children with Fetal Alcohol Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Kimberly eLane

    2014-03-01

    Full Text Available Parental reports of attention problems and clinical symptomatology of ADHD among children with fetal alcohol syndrome disorder (FASD were assessed in relation to performance on standardized subtests of attantional control/shifting and selective attention from the Test of Everyday Attention for Children (TEA-Ch; Manly et al., 1998. The participants included 14 children with FASD with a mean CA of 11.7 years and a mean MA of 9.7 years, and 14 typically developing (TD children with no reported history of prenatal exposure to alcohol or attention problems with a mean CA of 8.4 years and a mean MA of 9.6 years. The children with FASD were rated by their caregivers as having clinically significant attention difficulties for their developmental age. The reported symptomatology for the majority of the children with FASD were consistent with a diagnosis of ADHD, combined type, and only one child had a score within the average range. These reports are consistent with the finding here that the children with FASD demonstrated difficulties on the Creature Counting subtest of attentional control/shifting, but inconsistent with the finding that they outperformed the TD children on the Map Mission subtest of selective attention. These findings are considered within the context of the complexity in understanding attentional functioning among children with FASD and discrepancies across sources of information and components of attention.

  12. Understanding How to Support Family Caregivers of Seniors with Complex Needs

    Science.gov (United States)

    Charles, Lesley; Brémault-Phillips, Suzette; Parmar, Jasneet; Johnson, Melissa; Sacrey, Lori-Ann

    2017-01-01

    Purpose of the Study The purpose of this study was to describe the experiences and challenges of supporting family caregivers of seniors with complex needs and to outline support strategies and research priorities aimed at supporting them. Design and Methods A CIHR-funded, two-day conference entitled “Supporting Family Caregivers of Seniors: Improving Care and Caregiver Outcomes” was held. An integrated knowledge translation approach guided this planning conference. Day 1 included presentations of research evidence, followed by participant engagement Qualitative data was collected regarding facilitators, barriers/gaps, and recommendations for the provision of caregiver supports. Day 2 focused on determination of research priorities. Results Identified facilitators to the provision of caregiver support included accessibility of health-care and community-based resources, availability of well-intended health-care providers, and recognition of caregivers by the system. Barriers/gaps related to challenges with communication, access to information, knowledge of what is needed, system navigation, access to financial resources, and current policies. Recommendations regarding caregiver services and research revolved around assisting caregivers to self-identify and seek support, formalizing caregiver supports, centralizing resources, making system navigation available, and preparing the next generation for caregiving. Implication A better understanding of the needs of family caregivers and ways to support them is critical to seniors’ health services redesign. PMID:28690707

  13. Understanding Epistatic Interactions between Genes Targeted by Non-coding Regulatory Elements in Complex Diseases

    Directory of Open Access Journals (Sweden)

    Min Kyung Sung

    2014-12-01

    Full Text Available Genome-wide association studies have proven the highly polygenic architecture of complex diseases or traits; therefore, single-locus-based methods are usually unable to detect all involved loci, especially when individual loci exert small effects. Moreover, the majority of associated single-nucleotide polymorphisms resides in non-coding regions, making it difficult to understand their phenotypic contribution. In this work, we studied epistatic interactions associated with three common diseases using Korea Association Resource (KARE data: type 2 diabetes mellitus (DM, hypertension (HT, and coronary artery disease (CAD. We showed that epistatic single-nucleotide polymorphisms (SNPs were enriched in enhancers, as well as in DNase I footprints (the Encyclopedia of DNA Elements [ENCODE] Project Consortium 2012, which suggested that the disruption of the regulatory regions where transcription factors bind may be involved in the disease mechanism. Accordingly, to identify the genes affected by the SNPs, we employed whole-genome multiple-cell-type enhancer data which discovered using DNase I profiles and Cap Analysis Gene Expression (CAGE. Assigned genes were significantly enriched in known disease associated gene sets, which were explored based on the literature, suggesting that this approach is useful for detecting relevant affected genes. In our knowledge-based epistatic network, the three diseases share many associated genes and are also closely related with each other through many epistatic interactions. These findings elucidate the genetic basis of the close relationship between DM, HT, and CAD.

  14. Conciousness and Matter, A Complex Relationship: The Case of Sa¯mkhya

    Directory of Open Access Journals (Sweden)

    Juan Arnau

    2015-01-01

    Full Text Available The article focuses on the relationships (logic, metaphoric and epistemic between consciousness and matter in the sa-mkhya philosophy, one of the oldest systems of the Brahmanical tradition. After a brief introduction to the cosmology of the sa-mkhya, it discusses cosmogony and metaphysical pluralism of this current of thought using as primary sources the Sanskrit medieval commentaries on the Sa-mkhyaka-rika- by the medieval scholastic Va-caspati Mis´ra.

  15. Does song complexity matter in an intra-sexual context in common blackbirds

    DEFF Research Database (Denmark)

    Hesler, Nana; Sacher, Thomas; Coppack, Timothy

    Bird song is thought to be subject of both inter- and intra-sexual selection and song complexity a signal of male quality. One aspect of song complexity, repertoire size, correlates with estimates of male quality in several passerine species.  The Common Blackbird (Turdus merula) has a large repe...

  16. Graduate Social Work Education and Cognitive Complexity: Does Prior Experience Really Matter?

    Science.gov (United States)

    Simmons, Chris

    2014-01-01

    This study examined the extent to which age, education, and practice experience among social work graduate students (N = 184) predicted cognitive complexity, an essential aspect of critical thinking. In the regression analysis, education accounted for more of the variance associated with cognitive complexity than age and practice experience. When…

  17. Middle-School Teachers' Understanding and Teaching of the Engineering Design Process: A Look at Subject Matter and Pedagogical Content Knowledge

    Science.gov (United States)

    Hynes, Morgan M.

    2012-01-01

    This paper reports on research investigating six middle school teachers without engineering degrees as they taught an engineering unit on the engineering design process. Videotaped classroom sessions and teacher interviews were analyzed to understand the subject matter and pedagogical content knowledge the teachers used and developed as they…

  18. Does linear separability really matter? Complex visual search is explained by simple search

    Science.gov (United States)

    Vighneshvel, T.; Arun, S. P.

    2013-01-01

    Visual search in real life involves complex displays with a target among multiple types of distracters, but in the laboratory, it is often tested using simple displays with identical distracters. Can complex search be understood in terms of simple searches? This link may not be straightforward if complex search has emergent properties. One such property is linear separability, whereby search is hard when a target cannot be separated from its distracters using a single linear boundary. However, evidence in favor of linear separability is based on testing stimulus configurations in an external parametric space that need not be related to their true perceptual representation. We therefore set out to assess whether linear separability influences complex search at all. Our null hypothesis was that complex search performance depends only on classical factors such as target-distracter similarity and distracter homogeneity, which we measured using simple searches. Across three experiments involving a variety of artificial and natural objects, differences between linearly separable and nonseparable searches were explained using target-distracter similarity and distracter heterogeneity. Further, simple searches accurately predicted complex search regardless of linear separability (r = 0.91). Our results show that complex search is explained by simple search, refuting the widely held belief that linear separability influences visual search. PMID:24029822

  19. The Value of a Comparative Approach to Understand the Complex Interplay between Microbiota and Host Immunity

    Directory of Open Access Journals (Sweden)

    Norma M. Morella

    2017-09-01

    Full Text Available The eukaryote immune system evolved and continues to evolve within a microbial world, and as such is critically shaped by—and in some cases even reliant upon—the presence of host-associated microbial species. There are clear examples of adaptations that allow the host to simultaneously tolerate and/or promote growth of symbiotic microbiota while protecting itself against pathogens, but the relationship between immunity and the microbiome reaches far beyond simple recognition and includes complex cross talk between host and microbe as well as direct microbiome-mediated protection against pathogens. Here, we present a broad but brief overview of how the microbiome is controlled by and interacts with diverse immune systems, with the goal of identifying questions that can be better addressed by taking a comparative approach across plants and animals and different types of immunity. As two key examples of such an approach, we focus on data examining the importance of early exposure on microbiome tolerance and immune system development and function, and the importance of transmission among hosts in shaping the potential coevolution between, and long-term stability of, host–microbiome associations. Then, by comparing existing evidence across short-lived plants, mouse model systems and humans, and insects, we highlight areas of microbiome research that are strong in some systems and absent in others with the hope of guiding future research that will allow for broad-scale comparisons moving forward. We argue that such an approach will not only help with identification of generalities in host–microbiome–immune interactions but also improve our understanding of the role of the microbiome in host health.

  20. Theory and research in audiology education: understanding and representing complexity through informed methodological decisions.

    Science.gov (United States)

    Ng, Stella L

    2013-05-01

    The discipline of audiology has the opportunity to embark on research in education from an informed perspective, learning from professions that began this journey decades ago. The goal of this article is to position our discipline as a new member in the academic field of health professional education (HPE), with much to learn and contribute. In this article, I discuss the need for theory in informing HPE research. I also stress the importance of balancing our research goals by selecting appropriate methodologies for relevant research questions, to ensure that we respect the complexity of social processes inherent in HPE. Examples of relevant research questions are used to illustrate the need to consider alternative methodologies and to rethink the traditional hierarchy of evidence. I also provide an example of the thought processes and decisions that informed the design of an educational research study using a constructivist grounded theory methodology. As audiology enters the scholarly field of HPE, we need to arm ourselves with some of the knowledge and perspective that informs the field. Thus, we need to broaden our conceptions of what we consider to be appropriate styles of academic writing, relevant research questions, and valid evidence. Also, if we are to embark on qualitative inquiry into audiology education (or other audiology topics), we need to ensure that we conduct this research with an adequate understanding of the theories and methodologies informing such approaches. We must strive to conduct high quality, rigorous qualitative research more often than uninformed, generic qualitative research. These goals are imperative to the advancement of the theoretical landscape of audiology education and evolving the place of audiology in the field of HPE. American Academy of Audiology.

  1. Tetra- and hexavalent uranium forms bidentate-mononuclear complexes with particulate organic matter in a naturally uranium-enriched peatland

    International Nuclear Information System (INIS)

    Mikutta, Christian; Langner, Peggy; Bargar, John R.; Kretzschmar, Ruben

    2016-01-01

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7–6.6, E_h = –127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L_3-edge X-ray absorption spectroscopy. The soils contained 2.3–47.4 wt % organic C, 4.1–58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̄ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35–68% of total U (x̄ = 50%, n = 15). Shell-fit analyses of bulk U L_3-edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̄ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ~3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. As a result, our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).

  2. Tetra- and Hexavalent Uranium Forms Bidentate-Mononuclear Complexes with Particulate Organic Matter in a Naturally Uranium-Enriched Peatland.

    Science.gov (United States)

    Mikutta, Christian; Langner, Peggy; Bargar, John R; Kretzschmar, Ruben

    2016-10-04

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7-6.6, E h = -127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L 3 -edge X-ray absorption spectroscopy. The soils contained 2.3-47.4 wt % organic C, 4.1-58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̅ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35-68% of total U (x̅ = 50%, n = 15). Shell-fit analyses of bulk U L 3 -edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̅ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).

  3. Measuring the pollutant transport capacity of dissolved organic matter in complex matrixes

    DEFF Research Database (Denmark)

    Persson, L.; Alsberg, T.; Odham, G.

    2003-01-01

    Dissolved organic matter (DOM) facilitated transport in contaminated groundwater was investigated through the measurement of the binding capacity of landfill leachate DOM (Vejen, Denmark) towards two model pollutants (pyrene and phenanthrene). Three different methods for measuring binding capacity....... It was further concluded that DOM facilitated transport should be taken into account for non-ionic PAHs with lg K OW above 5, at DOM concentrations above 250 mg C/L. The total DOM concentration was found to be more important for the potential of facilitated transport than differences in the DOM binding capacity....

  4. Complex Parts, Complex Data: Why You Need to Understand What Radiation Single Event Testing Data Does and Doesn't Show and the Implications Thereof

    Science.gov (United States)

    LaBel, Kenneth A.; Berg, Melanie D.

    2015-01-01

    Electronic parts (integrated circuits) have grown in complexity such that determining all failure modes and risks from single particle event testing is impossible. In this presentation, the authors will present why this is so and provide some realism on what this means. Its all about understanding actual risks and not making assumptions.

  5. Bringing content understanding into usability testing in complex application domains—a case study in eHealth

    DEFF Research Database (Denmark)

    Andersen, Simon Bruntse; Rasmussen, Claire Kirchert; Frøkjær, Erik

    2017-01-01

    A usability evaluation technique, Cooperative Usability Testing with Questions of Understanding (CUT with QU) intended to illuminate users’ ability to understand the content information of an application is proposed. In complex application domains as for instance the eHealth domain, this issue...... the participation of four physiotherapists and four clients in a period of 3.5 months, it was demonstrated how CUT with QU can complement conventional usability testing and provide insight into users’ challenges with understanding of a new complex eHealth application. More experiments in other complex application...... domains involving different kinds of users and evaluators are needed before we can tell whether CUT with QU is an effective usability testing technique of wider applicability. Performing CUT with QU is very demanding by drawing heavily on the evaluators’ ability to respond effectively to openings...

  6. Impacting Early Childhood Teachers' Understanding of the Complexities of Place Value

    Science.gov (United States)

    Cady, Jo Ann; Hopkins, Theresa M.; Price, Jamie

    2014-01-01

    In order to help children gain a more robust understanding of place value, teachers must understand the connections and relationships among the related concepts as well as possess knowledge of how children learn early number concepts. Unfortunately, teachers' familiarity with the base-ten number system and/or lack of an understanding of…

  7. Does complexity matter? Meta-analysis of learner performance in artificial grammar tasks.

    Science.gov (United States)

    Schiff, Rachel; Katan, Pesia

    2014-01-01

    Complexity has been shown to affect performance on artificial grammar learning (AGL) tasks (categorization of test items as grammatical/ungrammatical according to the implicitly trained grammar rules). However, previously published AGL experiments did not utilize consistent measures to investigate the comprehensive effect of grammar complexity on task performance. The present study focused on computerizing Bollt and Jones's (2000) technique of calculating topological entropy (TE), a quantitative measure of AGL charts' complexity, with the aim of examining associations between grammar systems' TE and learners' AGL task performance. We surveyed the literature and identified 56 previous AGL experiments based on 10 different grammars that met the sampling criteria. Using the automated matrix-lift-action method, we assigned a TE value for each of these 10 previously used AGL systems and examined its correlation with learners' task performance. The meta-regression analysis showed a significant correlation, demonstrating that the complexity effect transcended the different settings and conditions in which the categorization task was performed. The results reinforced the importance of using this new automated tool to uniformly measure grammar systems' complexity when experimenting with and evaluating the findings of AGL studies.

  8. Managing product complexity: It`s just a matter of time

    Energy Technology Data Exchange (ETDEWEB)

    Hinckley, C.M.

    1998-06-01

    It has long been the goal of designers to identify a robust measure of product complexity to guide product decisions. Using Design for Assembly evaluations from over 225 assemblies and subassemblies, alternative measures of product complexity are identified and compared. Time is shown to be the most consistently predicted, useful, and fungible measure. The distribution of assembly times for a product can be modeled by Pareto`s law. This leads to a new, more effective product design guideline and a predictive tool that enables rapid and accurate prediction of assembly times for redesigned products without having to repeat DFMA analysis.

  9. From Solute, Fluidic and Particulate Precursors to Complex Organizations of Matter.

    Science.gov (United States)

    Rao, Ashit; Cölfen, Helmut

    2018-03-24

    The organization of matter from its constitutive units recruits intermediate states with distinctive degrees of self-association and molecular order. Existing as clusters, droplets, gels as well as amorphous and crystalline nanoparticles, these precursor forms have fundamental contributions towards the composition and structure of inorganic and organic architectures. In this personal account, we show that the transitions from atoms, molecules or ionic species to superstructures of higher order are intertwined with the interfaces and interactions of precursor and intermediate states. Structural organizations distributed across different length scales are explained by the multistep nature of nucleation and crystallization, which can be guided towards functional hybrid materials by the strategic application of additives, templates and reaction environments. Thus, the non-classical pathways for material formation and growth offer conceptual frameworks for elucidating, inducing and directing fascinating material organizations of biogenic and synthetic origins. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Improving biological understanding and complex trait prediction by integrating prior information in genomic feature models

    DEFF Research Database (Denmark)

    Edwards, Stefan McKinnon

    externally founded information, such as KEGG pathways, Gene Ontology gene sets, or genomic features, and estimate the joint contribution of the genetic variants within these sets to complex trait phenotypes. The analysis of complex trait phenotypes is hampered by the myriad of genes that control the trait...

  11. A review of human factors challenges of complex adaptive systems: discovering and understanding chaos in human performance.

    Science.gov (United States)

    Karwowski, Waldemar

    2012-12-01

    In this paper, the author explores a need for a greater understanding of the true nature of human-system interactions from the perspective of the theory of complex adaptive systems, including the essence of complexity, emergent properties of system behavior, nonlinear systems dynamics, and deterministic chaos. Human performance, more often than not, constitutes complex adaptive phenomena with emergent properties that exhibit nonlinear dynamical (chaotic) behaviors. The complexity challenges in the design and management of contemporary work systems, including service systems, are explored. Examples of selected applications of the concepts of nonlinear dynamics to the study of human physical performance are provided. Understanding and applications of the concepts of theory of complex adaptive and dynamical systems should significantly improve the effectiveness of human-centered design efforts of a large system of systems. Performance of many contemporary work systems and environments may be sensitive to the initial conditions and may exhibit dynamic nonlinear properties and chaotic system behaviors. Human-centered design of emergent human-system interactions requires application of the theories of nonlinear dynamics and complex adaptive system. The success of future human-systems integration efforts requires the fusion of paradigms, knowledge, design principles, and methodologies of human factors and ergonomics with those of the science of complex adaptive systems as well as modern systems engineering.

  12. Complexes of vanadyl and uranyl ions with the chelating groups of humic matter

    International Nuclear Information System (INIS)

    Goncalves, M.L.S.; Mota, A.M.

    1987-01-01

    The uranyl and vanadyl complexes formed with salicylic, phthalic and 3,4-dihydroxybenzoic acids have been studied by potentiometry in order to determine the stability constants of the Msub(m) Lsub(n) species formed in solution, and the constants for hydrolysis and polymeric complexes, at 25.0 0 , in 0.10, 0.40 and 0.70M sodium perchlorate. MINIQUAD was used in process the data to find the best models for the species in solution, and calculate the formation constants. The uranyl-salicylic acid sytem was also studied by spectrophotometry and the program SQUAD used to process the data obtained. The best models for these systems show that co-ordination of the uranyl ion by carboxylate groups is easier than for the vanadyl ion, whereas the vanadyl ion seems to form more stable complexes with phenolate groups. Both oxo-cations seem to tend to hydrolyse rather than form complexes when the L:M ratios are greater than unity. Although the change in the constants with ionic strength is small, the activity coefficients of the salicylate and phthalate species have been calculated at ionic strengths 0.40 and 0.70M, along with the interaction parameters with Na + , from the stability constants found for the species ML and H 2 L, according to the Bronsted-Guggenheim expression. (author)

  13. Understanding the Complexity of Temperature Dynamics in Xinjiang, China, from Multitemporal Scale and Spatial Perspectives

    Directory of Open Access Journals (Sweden)

    Jianhua Xu

    2013-01-01

    Full Text Available Based on the observed data from 51 meteorological stations during the period from 1958 to 2012 in Xinjiang, China, we investigated the complexity of temperature dynamics from the temporal and spatial perspectives by using a comprehensive approach including the correlation dimension (CD, classical statistics, and geostatistics. The main conclusions are as follows (1 The integer CD values indicate that the temperature dynamics are a complex and chaotic system, which is sensitive to the initial conditions. (2 The complexity of temperature dynamics decreases along with the increase of temporal scale. To describe the temperature dynamics, at least 3 independent variables are needed at daily scale, whereas at least 2 independent variables are needed at monthly, seasonal, and annual scales. (3 The spatial patterns of CD values at different temporal scales indicate that the complex temperature dynamics are derived from the complex landform.

  14. Understanding complex clinical reasoning in infectious diseases for improving clinical decision support design.

    Science.gov (United States)

    Islam, Roosan; Weir, Charlene R; Jones, Makoto; Del Fiol, Guilherme; Samore, Matthew H

    2015-11-30

    Clinical experts' cognitive mechanisms for managing complexity have implications for the design of future innovative healthcare systems. The purpose of the study is to examine the constituents of decision complexity and explore the cognitive strategies clinicians use to control and adapt to their information environment. We used Cognitive Task Analysis (CTA) methods to interview 10 Infectious Disease (ID) experts at the University of Utah and Salt Lake City Veterans Administration Medical Center. Participants were asked to recall a complex, critical and vivid antibiotic-prescribing incident using the Critical Decision Method (CDM), a type of Cognitive Task Analysis (CTA). Using the four iterations of the Critical Decision Method, questions were posed to fully explore the incident, focusing in depth on the clinical components underlying the complexity. Probes were included to assess cognitive and decision strategies used by participants. The following three themes emerged as the constituents of decision complexity experienced by the Infectious Diseases experts: 1) the overall clinical picture does not match the pattern, 2) a lack of comprehension of the situation and 3) dealing with social and emotional pressures such as fear and anxiety. All these factors contribute to decision complexity. These factors almost always occurred together, creating unexpected events and uncertainty in clinical reasoning. Five themes emerged in the analyses of how experts deal with the complexity. Expert clinicians frequently used 1) watchful waiting instead of over- prescribing antibiotics, engaged in 2) theory of mind to project and simulate other practitioners' perspectives, reduced very complex cases into simple 3) heuristics, employed 4) anticipatory thinking to plan and re-plan events and consulted with peers to share knowledge, solicit opinions and 5) seek help on patient cases. The cognitive strategies to deal with decision complexity found in this study have important

  15. Looking at the Complexity of Two Young Children's Understanding of Number

    Science.gov (United States)

    Thom, Jennifer S.; Pirie, Susan E. B.

    2006-01-01

    This paper presents a qualitative study that investigated two third-grade students' understanding of number. The children were videotaped while they worked to record everything they knew about the number, 72. Their artifacts and conversations were then analyzed using the Pirie-Kieren dynamical theory for the growth of mathematical understanding as…

  16. The Complexity in Defining Leadership: How Gifted Students' Backgrounds Influence Their Understanding of Effective Leadership

    Science.gov (United States)

    Jackson, Shawon; Sakuma, Satoe; DeVol, Purva

    2015-01-01

    There is no universally accepted definition of what it means to be an effective leader. Individuals understand leadership differently based on their own identities and lived experiences. The purpose of this investigation is to determine how one's ethnicity, class, and gender identities influence their understanding of effective leadership,…

  17. Rahman Prize Lecture: Lattice Boltzmann simulation of complex states of flowing matter

    Science.gov (United States)

    Succi, Sauro

    Over the last three decades, the Lattice Boltzmann (LB) method has gained a prominent role in the numerical simulation of complex flows across an impressively broad range of scales, from fully-developed turbulence in real-life geometries, to multiphase flows in micro-fluidic devices, all the way down to biopolymer translocation in nanopores and lately, even quark-gluon plasmas. After a brief introduction to the main ideas behind the LB method and its historical developments, we shall present a few selected applications to complex flow problems at various scales of motion. Finally, we shall discuss prospects for extreme-scale LB simulations of outstanding problems in the physics of fluids and its interfaces with material sciences and biology, such as the modelling of fluid turbulence, the optimal design of nanoporous gold catalysts and protein folding/aggregation in crowded environments.

  18. Advancing understanding of the fluvial export of organic matter through high-resolution profiling of dissolved organic carbon.

    Science.gov (United States)

    Waldron, S.; Drew, S.; Gilvear, D.; Murray, H.; Heal, K.

    2012-04-01

    Quantifying the natural variation (complexity) of a system remains an enduring scientific challenge in better understanding controls on surface water quality. This characterisation is needed in order to reveal controlling processes, such as dilution, and also to identify unusual load profiles. In trying to capture that natural variation we still rely largely on concentration time series (and associated export budgets) generated from manual spot sampling, or from samples collected by autosamplers - approaches which are unlikely to provide the high temporal resolution of parameter concentration required. Now however, advances in sensor technology are helping us address this challenge. Here we present detailed dissolved organic carbon (DOC) export profiles from a small upland river (9.4 km sq.), generated since June 2011 by semi-continuous logging of UV-vis absorption (200-750 nm, every 2.5 nm) every 30 minutes. Observed increases in the concentration of the DOC, [DOC], in freshwaters have prompted significant research to understand the cause and consequences of increased export: higher levels of DOC require additional water purification of potable sources; increased aquatic export may represent a reduction in terrestrial C-soil sequestration; changes in light penetration can affect the heterotrophic / autotrophic balance in surface waters and this has consequences for the food web structure; increased aquatic export may also result in increased carbon dioxide evasion. Additionally, C export is often linked to nutrient export: we have observed statistically significant stoichiometric relationships between DOC and soluble reactive phosphorus (SRP) concentrations, thus understanding better this parameters offers insight into export of other nutrient and the source of material from which these dissolved compounds are produced; this may be particulate. Our Scottish study site is interesting because there are multiple processes that can contribute to DOC and other nutrient

  19. On understanding creative language : The late positive complex and novel metaphor comprehension

    NARCIS (Netherlands)

    Rataj, Karolina; Przekoracka-Krawczyk, Anna; van der Lubbe, Rob H.J.

    2018-01-01

    Novel metaphoric sentences have repeatedly evoked larger N400 amplitudes than literal sentences, while investigations of the late positive complex (LPC) have brought inconsistent results, with reports of both increased and reduced amplitudes. In two experiments, we examined novel metaphor

  20. Understanding the Role of Context in the Interpretation of Complex Battlespace Intelligence

    National Research Council Canada - National Science Library

    Powell, Gerald M; Kokar, Mieczyslaw M; Matheus, Christopher J; Lorenz, David

    2006-01-01

    ... the information and identify critical enemy activities in a timely manner. What makes this information fusion problem particularly difficult is the strong contextual dependency of the interpretation of complex battlespace information...

  1. Understanding and Mitigating the Charging Behavior of Next Generation Complex and Active Spacecraft

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft that are fundamentally more complex and higher powered are necessary to expand our scientific missions and take commercial space endeavors to the next...

  2. Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Ian W.H., E-mail: Ian.Jarvis@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Bergvall, Christoffer, E-mail: Christoffer.Bergvall@anchem.su.se [Department of Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, SE-106 91 Stockholm (Sweden); Bottai, Matteo, E-mail: Matteo.Bottai@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Westerholm, Roger, E-mail: Roger.Westerholm@anchem.su.se [Department of Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, SE-106 91 Stockholm (Sweden); Stenius, Ulla, E-mail: Ulla.Stenius@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Dreij, Kristian, E-mail: Kristian.Dreij@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden)

    2013-02-01

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNA damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. -- Highlights: ► Benzo[a]pyrene (BP), dibenzo[a,l]pyrene (DBP) and air PM PAH extracts were compared. ► Binary mixture of BP and DBP induced a more than additive DNA damage response. ► Air PM PAH extracts were more potent than toxicity equivalency factor estimates. ► Larger PAHs (> 4 rings) contribute more to the genotoxicity of PAHs in air PM. ► Chk1 is a sensitive marker for persistent activation of DNA damage signaling from PAH mixtures.

  3. Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter

    International Nuclear Information System (INIS)

    Jarvis, Ian W.H.; Bergvall, Christoffer; Bottai, Matteo; Westerholm, Roger; Stenius, Ulla; Dreij, Kristian

    2013-01-01

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNA damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. -- Highlights: ► Benzo[a]pyrene (BP), dibenzo[a,l]pyrene (DBP) and air PM PAH extracts were compared. ► Binary mixture of BP and DBP induced a more than additive DNA damage response. ► Air PM PAH extracts were more potent than toxicity equivalency factor estimates. ► Larger PAHs (> 4 rings) contribute more to the genotoxicity of PAHs in air PM. ► Chk1 is a sensitive marker for persistent activation of DNA damage signaling from PAH mixtures.

  4. Measures of Morphological Complexity of Gray Matter on Magnetic Resonance Imaging for Control Age Grouping

    Directory of Open Access Journals (Sweden)

    Tuan D. Pham

    2015-12-01

    Full Text Available Current brain-age prediction methods using magnetic resonance imaging (MRI attempt to estimate the physiological brain age via some kind of machine learning of chronological brain age data to perform the classification task. Such a predictive approach imposes greater risk of either over-estimate or under-estimate, mainly due to limited training data. A new conceptual framework for more reliable MRI-based brain-age prediction is by systematic brain-age grouping via the implementation of the phylogenetic tree reconstruction and measures of information complexity. Experimental results carried out on a public MRI database suggest the feasibility of the proposed concept.

  5. Complex Indigenous Organic Matter Embedded in Apollo 17 Volcanic Black Glass Surface Deposits

    Science.gov (United States)

    Thomas-Keprta, Kathie L.; Clemett, S. J.; Ross, D. K.; Le, L.; Rahman, Z.; Gonzalez, C.; McKay, D. S.; Gibson, E. K.

    2013-01-01

    Papers presented at the first Lunar Science Conference [1] and those published in the subsequent Science Moon Issue [2] reported the C content of Apollo II soils, breccias, and igneous rocks as rang-ing from approx.50 to 250 parts per million (ppm). Later Fegley & Swindle [3] summarized the C content of bulk soils from all the Apollo missions as ranging from 2.5 (Apollo 15) to 280 ppm (Apollo 16) with an overall average of 124+/- 45 ppm. These values are unexpectedly low given that multiple processes should have contributed (and in some cases continue to contribute) to the lunar C inventory. These include exogenous accretion of cometary and asteroidal dust, solar wind implantation, and synthesis of C-bearing species during early lunar volcanism. We estimate the contribution of C from exogenous sources alone is approx.500 ppm, which is approx.4x greater than the reported average. While the assessm ent of indigenous organic matter (OM) in returned lunar samples was one of the primary scientific goals of the Apollo program, extensive analysis of Apollo samples yielded no evidence of any significant indigenous organic species. Furthermore, with such low concentrations of OM reported, the importance of discriminating indigenous OM from terrestrial contamination (e.g., lunar module exhaust, sample processing and handling) became a formidable task. After more than 40 years, with the exception of CH4 [5-7], the presence of indigenous lunar organics still remains a subject of considerable debate. We report for the first time the identification of arguably indigenous OM present within surface deposits of black glass grains collected on the rim of Shorty crater during the Apollo 17 mission by astronauts Eugene Cernan and Harrison Schmitt.

  6. Toxicity of silver nanoparticles in biological systems: Does the complexity of biological systems matter?

    Science.gov (United States)

    Vazquez-Muñoz, Roberto; Borrego, Belen; Juárez-Moreno, Karla; García-García, Maritza; Mota Morales, Josué D; Bogdanchikova, Nina; Huerta-Saquero, Alejandro

    2017-07-05

    Currently, nanomaterials are more frequently in our daily life, specifically in biomedicine, electronics, food, textiles and catalysis just to name a few. Although nanomaterials provide many benefits, recently their toxicity profiles have begun to be explored. In this work, the toxic effects of silver nanoparticles (35nm-average diameter and Polyvinyl-Pyrrolidone-coated) on biological systems of different levels of complexity was assessed in a comprehensive and comparatively way, through a variety of viability and toxicological assays. The studied organisms included viruses, bacteria, microalgae, fungi, animal and human cells (including cancer cell lines). It was found that biological systems of different taxonomical groups are inhibited at concentrations of silver nanoparticles within the same order of magnitude. Thus, the toxicity of nanomaterials on biological/living systems, constrained by their complexity, e.g. taxonomic groups, resulted contrary to the expected. The fact that cells and virus are inhibited with a concentration of silver nanoparticles within the same order of magnitude could be explained considering that silver nanoparticles affects very primitive cellular mechanisms by interacting with fundamental structures for cells and virus alike. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Ferrihydrite-associated organic matter (OM stimulates reduction by Shewanella oneidensis MR-1 and a complex microbial consortia

    Directory of Open Access Journals (Sweden)

    R. E. Cooper

    2017-11-01

    Full Text Available The formation of Fe(III oxides in natural environments occurs in the presence of natural organic matter (OM, resulting in the formation of OM–mineral complexes that form through adsorption or coprecipitation processes. Thus, microbial Fe(III reduction in natural environments most often occurs in the presence of OM–mineral complexes rather than pure Fe(III minerals. This study investigated to what extent does the content of adsorbed or coprecipitated OM on ferrihydrite influence the rate of Fe(III reduction by Shewanella oneidensis MR-1, a model Fe(III-reducing microorganism, in comparison to a microbial consortium extracted from the acidic, Fe-rich Schlöppnerbrunnen fen. We found that increased OM content led to increased rates of microbial Fe(III reduction by S. oneidensis MR-1 in contrast to earlier findings with the model organism Geobacter bremensis. Ferrihydrite–OM coprecipitates were reduced slightly faster than ferrihydrites with adsorbed OM. Surprisingly, the complex microbial consortia stimulated by a mixture of electrons donors (lactate, acetate, and glucose mimics S. oneidensis under the same experimental Fe(III-reducing conditions suggesting similar mechanisms of electron transfer whether or not the OM is adsorbed or coprecipitated to the mineral surfaces. We also followed potential shifts of the microbial community during the incubation via 16S rRNA gene sequence analyses to determine variations due to the presence of adsorbed or coprecipitated OM–ferrihydrite complexes in contrast to pure ferrihydrite. Community profile analyses showed no enrichment of typical model Fe(III-reducing bacteria, such as Shewanella or Geobacter sp., but an enrichment of fermenters (e.g., Enterobacteria during pure ferrihydrite incubations which are known to use Fe(III as an electron sink. Instead, OM–mineral complexes favored the enrichment of microbes including Desulfobacteria and Pelosinus sp., both of which can utilize lactate and

  8. Ferrihydrite-associated organic matter (OM) stimulates reduction by Shewanella oneidensis MR-1 and a complex microbial consortia

    Science.gov (United States)

    Cooper, Rebecca Elizabeth; Eusterhues, Karin; Wegner, Carl-Eric; Totsche, Kai Uwe; Küsel, Kirsten

    2017-11-01

    The formation of Fe(III) oxides in natural environments occurs in the presence of natural organic matter (OM), resulting in the formation of OM-mineral complexes that form through adsorption or coprecipitation processes. Thus, microbial Fe(III) reduction in natural environments most often occurs in the presence of OM-mineral complexes rather than pure Fe(III) minerals. This study investigated to what extent does the content of adsorbed or coprecipitated OM on ferrihydrite influence the rate of Fe(III) reduction by Shewanella oneidensis MR-1, a model Fe(III)-reducing microorganism, in comparison to a microbial consortium extracted from the acidic, Fe-rich Schlöppnerbrunnen fen. We found that increased OM content led to increased rates of microbial Fe(III) reduction by S. oneidensis MR-1 in contrast to earlier findings with the model organism Geobacter bremensis. Ferrihydrite-OM coprecipitates were reduced slightly faster than ferrihydrites with adsorbed OM. Surprisingly, the complex microbial consortia stimulated by a mixture of electrons donors (lactate, acetate, and glucose) mimics S. oneidensis under the same experimental Fe(III)-reducing conditions suggesting similar mechanisms of electron transfer whether or not the OM is adsorbed or coprecipitated to the mineral surfaces. We also followed potential shifts of the microbial community during the incubation via 16S rRNA gene sequence analyses to determine variations due to the presence of adsorbed or coprecipitated OM-ferrihydrite complexes in contrast to pure ferrihydrite. Community profile analyses showed no enrichment of typical model Fe(III)-reducing bacteria, such as Shewanella or Geobacter sp., but an enrichment of fermenters (e.g., Enterobacteria) during pure ferrihydrite incubations which are known to use Fe(III) as an electron sink. Instead, OM-mineral complexes favored the enrichment of microbes including Desulfobacteria and Pelosinus sp., both of which can utilize lactate and acetate as an electron

  9. Exploring the practicing-connections hypothesis: using gesture to support coordination of ideas in understanding a complex statistical concept.

    Science.gov (United States)

    Son, Ji Y; Ramos, Priscilla; DeWolf, Melissa; Loftus, William; Stigler, James W

    2018-01-01

    In this article, we begin to lay out a framework and approach for studying how students come to understand complex concepts in rich domains. Grounded in theories of embodied cognition, we advance the view that understanding of complex concepts requires students to practice, over time, the coordination of multiple concepts, and the connection of this system of concepts to situations in the world. Specifically, we explore the role that a teacher's gesture might play in supporting students' coordination of two concepts central to understanding in the domain of statistics: mean and standard deviation. In Study 1 we show that university students who have just taken a statistics course nevertheless have difficulty taking both mean and standard deviation into account when thinking about a statistical scenario. In Study 2 we show that presenting the same scenario with an accompanying gesture to represent variation significantly impacts students' interpretation of the scenario. Finally, in Study 3 we present evidence that instructional videos on the internet fail to leverage gesture as a means of facilitating understanding of complex concepts. Taken together, these studies illustrate an approach to translating current theories of cognition into principles that can guide instructional design.

  10. Why complexity matters: using ALMaSS for risk assessment of wildlife

    DEFF Research Database (Denmark)

    Topping, Christopher John

    with these system properties is agentbased modelling (ABM).ABMs are capable of integrating a range of drivers and actors in space and time and can represent detailed farming operations on a large scale, integrating these with realistic models of animal populations, and expressing each animal as an individual agent...... in time and space. All of these factors can affect the risk assessment. There is also another, difficult to observe, property of real systems, and that is the spatio-temporal dynamics associated with populations, climate, management, and ecology and behaviour, and the potential for feedback loops......-sink dynamics are emergent properties and do not need to be imposed.ALMaSS is one such model system and is used here to exemplify aspects of complexity in population-level risk assessment for terrestrial mammals, birds, and arthropods exposed to pesticides. Results are used to argue for greater realism...

  11. Referential Choices in a Collaborative Storytelling Task: Discourse Stages and Referential Complexity Matter.

    Science.gov (United States)

    Fossard, Marion; Achim, Amélie M; Rousier-Vercruyssen, Lucie; Gonzalez, Sylvia; Bureau, Alexandre; Champagne-Lavau, Maud

    2018-01-01

    During a narrative discourse, accessibility of the referents is rarely fixed once and for all. Rather, each referent varies in accessibility as the discourse unfolds, depending on the presence and prominence of the other referents. This leads the speaker to use various referential expressions to refer to the main protagonists of the story at different moments in the narrative. This study relies on a new, collaborative storytelling in sequence task designed to assess how speakers adjust their referential choices when they refer to different characters at specific discourse stages corresponding to the introduction, maintaining, or shift of the character in focus, in increasingly complex referential contexts. Referential complexity of the stories was manipulated through variations in the number of characters (1 vs. 2) and, for stories in which there were two characters, in their ambiguity in gender (different vs. same gender). Data were coded for the type of reference markers as well as the type of reference content (i.e., the extent of the information provided in the referential expression). Results showed that, beyond the expected effects of discourse stages on reference markers (more indefinite markers at the introduction stage, more pronouns at the maintaining stage, and more definite markers at the shift stage), the number of characters and their ambiguity in gender also modulated speakers' referential choices at specific discourse stages, For the maintaining stage, an effect of the number of characters was observed for the use of pronouns and of definite markers, with more pronouns when there was a single character, sometimes replaced by definite expressions when two characters were present in the story. For the shift stage, an effect of gender ambiguity was specifically noted for the reference content with more specific information provided in the referential expression when there was referential ambiguity. Reference content is an aspect of referential marking

  12. Referential Choices in a Collaborative Storytelling Task: Discourse Stages and Referential Complexity Matter

    Directory of Open Access Journals (Sweden)

    Marion Fossard

    2018-02-01

    Full Text Available During a narrative discourse, accessibility of the referents is rarely fixed once and for all. Rather, each referent varies in accessibility as the discourse unfolds, depending on the presence and prominence of the other referents. This leads the speaker to use various referential expressions to refer to the main protagonists of the story at different moments in the narrative. This study relies on a new, collaborative storytelling in sequence task designed to assess how speakers adjust their referential choices when they refer to different characters at specific discourse stages corresponding to the introduction, maintaining, or shift of the character in focus, in increasingly complex referential contexts. Referential complexity of the stories was manipulated through variations in the number of characters (1 vs. 2 and, for stories in which there were two characters, in their ambiguity in gender (different vs. same gender. Data were coded for the type of reference markers as well as the type of reference content (i.e., the extent of the information provided in the referential expression. Results showed that, beyond the expected effects of discourse stages on reference markers (more indefinite markers at the introduction stage, more pronouns at the maintaining stage, and more definite markers at the shift stage, the number of characters and their ambiguity in gender also modulated speakers' referential choices at specific discourse stages, For the maintaining stage, an effect of the number of characters was observed for the use of pronouns and of definite markers, with more pronouns when there was a single character, sometimes replaced by definite expressions when two characters were present in the story. For the shift stage, an effect of gender ambiguity was specifically noted for the reference content with more specific information provided in the referential expression when there was referential ambiguity. Reference content is an aspect of

  13. Exploring Different Types of Assessment Items to Measure Linguistically Diverse Students' Understanding of Energy and Matter in Chemistry

    Science.gov (United States)

    Ryoo, Kihyun; Toutkoushian, Emily; Bedell, Kristin

    2018-01-01

    Energy and matter are fundamental, yet challenging concepts in middle school chemistry due to their abstract, unobservable nature. Although it is important for science teachers to elicit a range of students' ideas to design and revise their instruction, capturing such varied ideas using traditional assessments consisting of multiple-choice items…

  14. Using multi-criteria analysis of simulation models to understand complex biological systems

    Science.gov (United States)

    Maureen C. Kennedy; E. David. Ford

    2011-01-01

    Scientists frequently use computer-simulation models to help solve complex biological problems. Typically, such models are highly integrated, they produce multiple outputs, and standard methods of model analysis are ill suited for evaluating them. We show how multi-criteria optimization with Pareto optimality allows for model outputs to be compared to multiple system...

  15. Understanding the Complex Dimensions of the Digital Divide: Lessons Learned in the Alaskan Arctic

    Science.gov (United States)

    Subramony, Deepak Prem

    2007-01-01

    An ethnographic case study of Inupiat Eskimo in the Alaskan Arctic has provided insights into the complex nature of the sociological issues surrounding equitable access to technology tools and skills, which are referred to as the digital divide. These people can overcome the digital divide if they get the basic ready access to hardware and…

  16. Understanding social behaviour with the help of complexity science (Invited article)

    NARCIS (Netherlands)

    Hemelrijk, C.K.

    2002-01-01

    In the study of complexity, a new kind of explanation has been developed for social behaviour. It shows how patterns of social behaviour can arise as a side-effect of the interaction of individuals with their social or physical environment (e.g. by self-organization). This development may influence

  17. Further Understanding of Complex Information Processing in Verbal Adolescents and Adults with Autism Spectrum Disorders

    Science.gov (United States)

    Williams, Diane L.; Minshew, Nancy J.; Goldstein, Gerald

    2015-01-01

    More than 20?years ago, Minshew and colleagues proposed the Complex Information Processing model of autism in which the impairment is characterized as a generalized deficit involving multiple modalities and cognitive domains that depend on distributed cortical systems responsible for higher order abilities. Subsequent behavioral work revealed a…

  18. Entropy: A Unifying Path for Understanding Complexity in Natural, Artificial and Social Systems

    Science.gov (United States)

    2011-07-01

    details can be seen. Figure 24 – Rank frequency functions of plays ( Shakespeare ) and books (Dickens) fitted by the generalizations of the...0-387-75888-6]. [4] Tsallis, C. (2009b). Introduction to Nonextensive Statistical Mechanics - Approaching a Complex World. (Springer, New York

  19. Understanding the Complex Processes in Developing Student Teachers' Knowledge about Grammar

    Science.gov (United States)

    Svalberg, Agneta M.-L.

    2015-01-01

    This article takes the view that grammar is driven by user choices and is therefore complex and dynamic. This has implications for the teaching of grammar in language teacher education and how teachers' cognitions about grammar, and hence their own grammar teaching, might change. In this small, interpretative study, the participants--students on…

  20. Towards a Better Understanding of Complex Disease: Identifying Endotypes of Childhood Asthma

    Science.gov (United States)

    Complex disease, where the diagnostic criteria cannot distinguish among differing etiologies, is often difficult to diagnose, treat and study due to the inability to classify individuals into suitable subtypes of the disease. Here, we aim to use and compare a combination of met...

  1. Complexity of Geometric Inductive Reasoning Tasks: Contribution to the Understanding of Fluid Intelligence.

    Science.gov (United States)

    Primi, Ricardo

    2002-01-01

    Created two geometric inductive reasoning matrix tests by manipulating four sources of complexity orthogonally. Results for 313 undergraduates show that fluid intelligence is most strongly associated with the part of the central executive component of working memory that is related to controlled attention processing and selective encoding. (SLD)

  2. Supporting Individuals with Autism Spectrum Disorder in Understanding and Coping with Complex Social Emotional Issues

    Science.gov (United States)

    Ahlers, Kaitlyn P.; Gabrielsen, Terisa P.; Lewis, Danielle; Brady, Anna M.; Litchford, April

    2017-01-01

    Core deficits in autism spectrum disorder (ASD) center around social communication and behavior. For those with ASD, these deficits complicate the task of learning how to cope with and manage complex social emotional issues. Although individuals with ASD may receive sufficient academic and basic behavioral support in school settings, supports for…

  3. The VULCAN Project: Toward a better understanding of the vulnerability of soil organic matter to climate change in permafrost ecosystems

    Science.gov (United States)

    Plaza, C.; Schuur, E.; Maestre, F. T.

    2015-12-01

    Despite much recent research, high uncertainty persists concerning the extent to which global warming influences the rate of permafrost soil organic matter loss and how this affects the functioning of permafrost ecosystems and the net transfer of C to the atmosphere. This uncertainty continues, at least in part, because the processes that protect soil organic matter from decomposition and stabilize fresh plant-derived organic materials entering the soil are largely unknown. The objective of the VULCAN (VULnerability of soil organic CArboN to climate change in permafrost and dryland ecosystems) project is to gain a deeper insight into these processes, especially at the molecular level, and to explore potential implications in terms of permafrost ecosystem functioning and feedback to climate change. We will capitalize on a globally unique ecosystem warming experiment in Alaska, the C in Permafrost Experimental Heating Research (CiPEHR) project, which is monitoring soil temperature and moisture, thaw depth, water table depth, plant productivity, phenology, and nutrient status, and soil CO2 and CH4 fluxes. Soil samples have been collected from the CiPEHR experiment from strategic depths, depending on thaw depth, and allow us to examine effects related to freeze/thaw, waterlogging, and organic matter relocation along the soil profile. We will use physical fractionation methods to separate soil organic matter pools characterized by different preservation mechanisms of aggregation and mineral interaction. We will determine organic C and total N content, transformation rates, turnovers, ages, and structural composition of soil organic matter fractions by elemental analysis, stable and radioactive isotope techniques, and nuclear magnetic resonance tools. Acknowledgements: This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 654132. Web site: http://vulcan.comule.com

  4. Complex Problem Solving in Radiologic Technology: Understanding the Roles of Experience, Reflective Judgment, and Workplace Culture

    Science.gov (United States)

    Yates, Jennifer L.

    2011-01-01

    The purpose of this research study was to explore the process of learning and development of problem solving skills in radiologic technologists. The researcher sought to understand the nature of difficult problems encountered in clinical practice, to identify specific learning practices leading to the development of professional expertise, and to…

  5. Techniques to better understand complex epikarst hydrogeology and contaminant transport in telogenetic karst settings

    Science.gov (United States)

    The movement of autogenic recharge through the shallow epikarstic zone in soil-mantled karst aquifers is important in understanding recharge areas and rates, groundwater storage, and contaminant transport processes. The groundwater flow in agricultural karst areas, such as Kentucky’s Pennyroyal Plat...

  6. Understanding social complexity within the wildland urban interface: A new species of human habitation? Environmental Management

    Science.gov (United States)

    Travis B. Paveglio; Pamela J. Jakes; Matthew S. Carroll; Daniel R. Williams

    2009-01-01

    The lack of knowledge regarding social diversity in the Wildland Urban Interface (WUI) or an in-depth understanding of the ways people living there interact to address common problems is concerning, perhaps even dangerous, given that community action is necessary for successful wildland fire preparedness and natural resource management activities. In this article, we...

  7. Contemporary Leadership Theories. Enhancing the Understanding of the Complexity, Subjectivity and Dynamic of Leadership

    DEFF Research Database (Denmark)

    Winkler, Ingo

    This book provides a comprehensive overview of basic theoretical approaches of today's leadership research. These approaches conceive leadership as an interactive and complex process. They stress the significance of the individual perception for developing and forming leadership relations....... Leadership is understood as product of complex social relationships embedded in the logic and dynamic of the social system. The book discusses theoretical approaches from top leadership journals, but also addresses various alternatives that are suitable to challenge mainstream leadership research....... It includes attributional and psychodynamic approaches, charismatic leadership theories, and theoretical approaches that define leader-member relations in terms of exchange relations leadership under symbolic and political perspectives, in the light of role theory and as process of social learning....

  8. Understanding the complexity of biopsychosocial factors in the public health epidemic of overweight and obesity

    OpenAIRE

    Rosenbaum, Diane L; White, Kamila S

    2016-01-01

    Obesity is a complex and multifaceted public health problem. This commentary reflects on a new theoretical model of obesity (i.e. Homeostatic Theory of Obesity proposed by Marks), and calls for additional research to examine biopsychosocial factors that may be of importance in developing interventions that promote long-term maintenance of weight loss and in developing obesity prevention programs. Furthermore, we discuss the role of socioeconomic factors in obesity and call for interdisciplina...

  9. Eating disorder emergencies: understanding the medical complexities of the hospitalized eating disordered patient.

    Science.gov (United States)

    Cartwright, Martina M

    2004-12-01

    Eating disorders are maladaptive eating behaviors that typically develop in adolescence and early adulthood. Psychiatric maladies and comorbid conditions, especially insulin-dependent diabetes mellitus, frequently co-exist with eating disorders. Serious medical complications affecting all organs and tissues can develop and result in numerous emergent hospitalizations. This article reviews the pathophysiologies of anorexia nervosa, bulimia nervosa, and orthorexia nervosa and discusses the complexities associated with the treatment of medical complications seen in these patients.

  10. Using mLearning and MOOCs to Understand Chaos, Emergence, and Complexity in Education

    Science.gov (United States)

    deWaard, Inge; Abajian, Sean; Gallagher, Michael Sean; Hogue, Rebecca; Keskin, Nilgun; Koutropoulos, Apostolos; Rodriguez, Osvaldo C.

    2011-01-01

    In this paper, we look at how the massive open online course (MOOC) format developed by connectivist researchers and enthusiasts can help analyze the complexity, emergence, and chaos at work in the field of education today. We do this through the prism of a MobiMOOC, a six-week course focusing on mLearning that ran from April to May 2011. MobiMOOC…

  11. Models for Understanding Student Thinking using Data from Complex Computerized Science Tasks

    OpenAIRE

    LaMar, Michelle

    2014-01-01

    The Next Generation Science Standards (NGSS Lead States, 2013) define performance targets which will require assessment tasks that can integrate discipline knowledge and cross-cutting ideas with the practices of science. Complex computerized tasks will likely play a large role in assessing these standards, but many questions remain about how best to make use of such tasks within a psychometric framework (National Research Council, 2014). This dissertation explores the use of a more extensive...

  12. Understanding and revisiting the most complex perovskite system via atomistic simulations

    Science.gov (United States)

    Yang, Yali; Xu, Bin; Xu, Changsong; Ren, Wei; Bellaiche, Laurent

    2018-05-01

    A first-principles-based effective Hamiltonian is developed and used, along with direct ab initio techniques, to investigate finite-temperature properties of the system commonly coined the most complex perovskite, that is NaNbO3. Such simulations successfully reproduce the existence of seven different phases in its phase diagram. The decomposition of the total energy of this effective Hamiltonian into different terms, altogether with the values of the parameters associated with these terms, also allow us to shed some light into puzzling features of such a compound. Examples include revealing the microscopic reasons of why R 3 c is its ground state and why it solely adopts in-phase tiltings at high temperatures versus complex nanotwins for intermediate temperatures. The results of the computations also call for a revisiting of the so-called P ,R , and S states, in the sense that an unexpected and previously overlooked inhomogeneous electrical polarization is numerically found in the P state while complex tiltings associated with the simultaneous condensation of several k points are predicted for the controversial R and S phases.

  13. Understanding the determinants of problem-solving behavior in a complex environment

    Science.gov (United States)

    Casner, Stephen A.

    1994-01-01

    It is often argued that problem-solving behavior in a complex environment is determined as much by the features of the environment as by the goals of the problem solver. This article explores a technique to determine the extent to which measured features of a complex environment influence problem-solving behavior observed within that environment. In this study, the technique is used to determine how complex flight deck and air traffic control environment influences the strategies used by airline pilots when controlling the flight path of a modern jetliner. Data collected aboard 16 commercial flights are used to measure selected features of the task environment. A record of the pilots' problem-solving behavior is analyzed to determine to what extent behavior is adapted to the environmental features that were measured. The results suggest that the measured features of the environment account for as much as half of the variability in the pilots' problem-solving behavior and provide estimates on the probable effects of each environmental feature.

  14. Douglas Hanahan: The daunting complexity of cancer: understanding the battlefield is a step towards winning the war

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The Inaugural Grace-CERN Lecture The daunting complexity of cancer: understanding the battlefield is a step towards winning the war  Douglas Hanahan, Ph.D. Director, Swiss Institute for Experimental Cancer Research (ISREC)  Professor of Molecular Oncology, School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL) Vice Director, Swiss Cancer Center Lausanne Synopsis (version francaise ci-dessous) Cancer is a disease with hundreds of variations, both in affected organs and in responses to different therapies.  Modern human cancer research is producing an avalanche of data about the distinctive genetic aberrations of its specific types, further accentuating the diversity and vast complexity of the disease. There is hope that elucidating its mechanisms will lead to more informed and more effective therapeutic strategies.  Understanding the enemy is paramount, and yet tumors arising in different organs can be so different as to de...

  15. Small angle scattering from soft matter-application to complex mixed systems

    International Nuclear Information System (INIS)

    Boue, F.; Cousin, F.; Gummel, J.; Carrot, G.; El Harrak, A.; Oberdisse, J.

    2007-01-01

    The advantage of small angle neutron scattering associated with isotopic labelling through deuteration is illustrated in the case of mixed systems, created by associating already well-known systems of characteristic structures; this is also important for applications. Our first mixed system associates charged polymer chains, polyelectrolyte (here polystyrene sulfonate, PSS), with oppositely charged particles, proteins (here lysozyme). Different fractions of deuterated water (D 2 O) mixed with normal water are used to match the scattering length density of the protein or of the polymer in non-deuterated or deuterated version. First, this allows us to separate the protein and the polymer signal: we can then distinguish a case where the structures of each species alone in water are hardly modified by mixing, except for interconnections yielding a gel, and a case inducing complete change into a structure common to both species, made of aggregated globules. Secondly, using, for counter-ions of the poly-ions, deuterated Tetramethylammonium, together with matching both protein and polymer, we establish unambiguously the counter-ion release into the solvent. Thirdly, matching only a fraction of polymer chains, the other being deuterated, we extrapolate at zero deuterated fraction their form factor and describe the chain conformation inside the complexes. Fourthly, we illustrate the possibilities of modelling the signal on a second example of mixed system: a nano-composite made of silica particles surrounded by polymer dispersed into a deuterated polymer matrix. Chains are then visible in such reinforced polymer system, in particular when it is submitted to elongation: we discuss a possible model for an ideal system, introducing the scattering contribution from deformed chains. (authors)

  16. Using a Design Science Perspective to Understand a Complex Design-Based Research Process

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2012-01-01

    The purpose of the paper is to demonstrate how a design science perspective can be used to describe and understand a set of related design-based research processes. We describe and analyze a case study in a manner that is inspired by design science. The case study involves the design of modeling......-based research processes. And we argue that a design science perspective may be useful for both researchers and practitioners....... tools and the redesign of an information service in a library. We use a set of guidelines from a design science perspective to organize the description and analysis of the case study. By doing this we demonstrate the usefulness of design science as an analytical tool for understanding related design...

  17. A Diagrammatic Approach to Understanding Complex Eco-Social Interactions in Kathmandu, Nepal

    Directory of Open Access Journals (Sweden)

    R. Cynthia. Neudoerffer

    2005-12-01

    Full Text Available As part of developing an international network of community-based ecosystem approaches to health, a project was undertaken in a densely populated and socio-economically diverse area of Kathmandu, Nepal. Drawing on hundreds of pages of narrative reports based on surveys, interviews, secondary data, and focus groups by trained Nepalese facilitators, the authors created systemic depictions of relationships between multiple stakeholder groups, ecosystem health, and human health. These were then combined to examine interactions among stakeholders, activities, concerns, perceived needs, and resource states (ecosystem health indicators. These qualitative models have provided useful heuristics for both community members and research scholars to understand the eco-social systems in which they live; many of the strategies developed by the communities and researchers to improve health intuitively drew on this systemic understanding. The diagrams enabled researchers and community participants to explicitly examine relationships and conflicts related to health and environmental issues in their community.

  18. Enacting understanding of inclusion in complex contexts: Classroom practices of South African teachers

    Directory of Open Access Journals (Sweden)

    Petra Engelbrecht

    2015-08-01

    Full Text Available While the practice of inclusive education has recently been widely embraced as an ideal model for education, the acceptance of inclusive education practices has not translated into reality in most mainstream classrooms. Despite the fact that education policies in South Africa stipulate that all learners should be provided with the opportunities to participate as far as possible in all classroom activities, the implementation of inclusive education is still hampered by a combination of a lack of resources and the attitudes and actions of the teachers in the classroom. The main purpose of this paper was to develop a deeper understanding of a group of South African teachers' personal understanding about barriers to learning and how their understanding relates to their consequent actions to implement inclusive education in their classrooms. A qualitative research approach placed within a cultural-historical and bio-ecological theoretical framework was used. The findings, in this paper, indicate that the way in which teachers understand a diversity of learning needs is based on the training that they initially received as teachers, which focused on a deficit, individualised approach to barriers to learning and development, as well as contextual challenges, and that both have direct and substantial effects on teachers' classroom practices. As a result, they engage in practices in their classrooms that are less inclusive, by creating dual learning opportunities that are not sufficiently made available for everyone, with the result that every learner is not able to participate fully as an accepted member of their peer group in all classroom activities.

  19. MURI: An Integrated Multi-Scale Approach for Understanding Ion Transport in Complex Heterogeneous Organic Materials

    Science.gov (United States)

    2017-09-30

    Thomas A. Witten,f Matthew W. Liberatore,a and Andrew M. Herring,a,* a Department of Chemical and Biological Engineering and bDepartment of Chemistry ...2) To fundamentally understand, with combined experimental and computational approaches, the interplay of chemistry , processing, and morphology on...Society, The International Society of Electrochemistry and The American Institute of Chemical Engineers to give oral and poster presentations. In

  20. What matters to infrequent customers: a pragmatic approach to understanding perceived value and intention to revisit trendy coffee caf?

    OpenAIRE

    Ting, Hiram; Thurasamy, Ramayah

    2016-01-01

    Notwithstanding the rise of trendy coffee caf?, little is done to investigate revisit intention towards the caf? in the context of developing markets. In particular, there is a lack of study which provides theoretical and practical explanation to the perceptions and behaviours of infrequent customers. Hence, the study aims to look into the subject matter by using the theory of reasoned action and social exchange theory as the underpinning basis. The framework proposed by Pine and Gilmore (Str...

  1. Emergent nested systems a theory of understanding and influencing complex systems as well as case studies in urban systems

    CERN Document Server

    Walloth, Christian

    2016-01-01

    This book presents a theory as well as methods to understand and to purposively influence complex systems. It suggests a theory of complex systems as nested systems, i. e. systems that enclose other systems and that are simultaneously enclosed by even other systems. According to the theory presented, each enclosing system emerges through time from the generative activities of the systems they enclose. Systems are nested and often emerge unplanned, and every system of high dynamics is enclosed by a system of slower dynamics. An understanding of systems with faster dynamics, which are always guided by systems of slower dynamics, opens up not only new ways to understanding systems, but also to effectively influence them. The aim and subject of this book is to lay out these thoughts and explain their relevance to the purposive development of complex systems, which are exemplified in case studies from an urban system. The interested reader, who is not required to be familiar with system-theoretical concepts or wit...

  2. The Affordable Care Act: a case study for understanding and applying complexity concepts to health care reform.

    Science.gov (United States)

    Larkin, D Justin; Swanson, R Chad; Fuller, Spencer; Cortese, Denis A

    2016-02-01

    The current health system in the United States is the result of a history of patchwork policy decisions and cultural assumptions that have led to persistent contradictions in practice, gaps in coverage, unsustainable costs, and inconsistent outcomes. In working toward a more efficient health system, understanding and applying complexity science concepts will allow for policy that better promotes desired outcomes and minimizes the effects of unintended consequences. This paper will consider three applied complexity science concepts in the context of the Patient Protection and Affordable Care Act (PPACA): developing a shared vision around reimbursement for value, creating an environment for emergence through simple rules, and embracing transformational leadership at all levels. Transforming the US health system, or any other health system, will be neither easy nor quick. Applying complexity concepts to health reform efforts, however, will facilitate long-term change in all levels, leading to health systems that are more effective, efficient, and equitable. © 2014 John Wiley & Sons, Ltd.

  3. Leveraging Understanding of Flow of Variable Complex Fluid to Design Better Absorbent Hygiene Products

    Science.gov (United States)

    Krautkramer, C.; Rend, R. R.

    2014-12-01

    Menstrual flow, which is a result of shedding of uterus endometrium, occurs periodically in sync with a women's hormonal cycle. Management of this flow while allowing women to pursue their normal daily lives is the purpose of many commercial products. Some of these products, e.g. feminine hygiene pads and tampons, utilize porous materials in achieving their goal. In this paper we will demonstrate different phenomena that have been observed in flow of menstrual fluid through these porous materials, share some of the advances made in experimental and analytical study of these phenomena, and also present some of the unsolved challenges and difficulties encountered while studying this kind of flow. Menstrual fluid is generally composed of four main components: blood plasma, blood cells, cervical mucus, and tissue debris. This non-homogeneous, multiphase fluid displays very complex rheological behavior, e. g., yield stress, thixotropy, and visco-elasticity, that varies throughout and between menstrual cycles and among women due to various factors. Flow rates are also highly variable during menstruation and across the population and the rheological properties of the fluid change during the flow into and through the product. In addition to these phenomena, changes to the structure of the porous medium within the product can also be seen due to fouling and/or swelling of the material. This paper will, also, share how the fluid components impact the flow and the consequences for computer simulation, the creation of a simulant fluid and testing methods, and for designing products that best meet consumer needs. We hope to bring to light the challenges of managing this complex flow to meet a basic need of women all over the world. An opportunity exists to apply learnings from research in other disciplines to improve the scientific knowledge related to the flow of this complex fluid through the porous medium that is a sanitary product.

  4. Understanding the Narratives Explaining the Ukrainian Crisis: Identity Divisions and Complex Diversity in Ukraine

    Directory of Open Access Journals (Sweden)

    Smoor Lodewijk

    2017-09-01

    Full Text Available The central argument of this paper is that radical and opposing interpretations of the Ukrainian conflict in politics and media should be studied as offspring of broader narratives. These narratives can be better understood by examining the national identity of Ukraine. Since Ukrainian national identity shows a high degree of diversity, it offers a rich source of arguments for any party wanting to give an interpretation of the present Ukrainian crisis. Narratives explaining the crisis often ignore this complex diversity or deliberately use elements from it to construct the ‘desired’ narrative.

  5. Ligand extraction of rare earth elements from aquifer sediments: Implications for rare earth element complexation with organic matter in natural waters

    Science.gov (United States)

    Tang, Jianwu; Johannesson, Karen H.

    2010-12-01

    The ability of organic matter as well as carbonate ions to extract rare earth elements (REEs) from sandy sediments of a Coastal Plain aquifer was investigated for unpurified organic matter from different sources (i.e., Mississippi River natural organic matter, Aldrich humic acid, Nordic aquatic fulvic acid, Suwannee River fulvic acid, and Suwannee River natural organic matter) and for extraction solutions containing weak (i.e., CH 3COO -) or strong (i.e., CO32-) ligands. The experimental results indicate that, in the absence of strong REE complexing ligands in solution, the amount of REEs released from the sand is small and the fractionation pattern of the released REEs appears to be controlled by the surface stability constants for REE sorption with Fe(III) oxides/oxyhydroxides. In the presence of strong solution complexing ligands, however, the amount and the fractionation pattern of the released REEs reflect the strength and variation of the stability constants of the dominant aqueous REE species across the REE series. The varying amount of REEs extracted by the different organic matter employed in the experiments indicates that organic matter from different sources has different complexing capacity for REEs. However, the fractionation pattern of REEs extracted by the various organic matter used in our experiments is remarkable consistent, being independent of the source and the concentration of organic matter used, as well as solution pH. Because natural aquifer sand and unpurified organic matter were used in our experiments, our experimental conditions are more broadly similar to natural systems than many previous laboratory experiments of REE-humic complexation that employed purified humic substances. Our results suggest that the REE loading effect on REE-humic complexation is negligible in natural waters as more abundant metal cations (e.g., Fe, Al) out-compete REEs for strong binding sites on organic matter. More specifically, our results indicate that REE

  6. Understanding characteristics in multivariate traffic flow time series from complex network structure

    Science.gov (United States)

    Yan, Ying; Zhang, Shen; Tang, Jinjun; Wang, Xiaofei

    2017-07-01

    Discovering dynamic characteristics in traffic flow is the significant step to design effective traffic managing and controlling strategy for relieving traffic congestion in urban cities. A new method based on complex network theory is proposed to study multivariate traffic flow time series. The data were collected from loop detectors on freeway during a year. In order to construct complex network from original traffic flow, a weighted Froenius norm is adopt to estimate similarity between multivariate time series, and Principal Component Analysis is implemented to determine the weights. We discuss how to select optimal critical threshold for networks at different hour in term of cumulative probability distribution of degree. Furthermore, two statistical properties of networks: normalized network structure entropy and cumulative probability of degree, are utilized to explore hourly variation in traffic flow. The results demonstrate these two statistical quantities express similar pattern to traffic flow parameters with morning and evening peak hours. Accordingly, we detect three traffic states: trough, peak and transitional hours, according to the correlation between two aforementioned properties. The classifying results of states can actually represent hourly fluctuation in traffic flow by analyzing annual average hourly values of traffic volume, occupancy and speed in corresponding hours.

  7. #consumingitall: Understanding The Complex Relationship Between Media Consumption And Eating Behaviors

    OpenAIRE

    Albert, Stephanie L.

    2017-01-01

    Adolescents spend almost nine hours a day engaging with media. As a result, they are confronted with large amounts of obesogenic content that shapes their understanding of what are normal and acceptable eating behaviors. Utilizing primary data collected from a sample of 4,838 low-income, racially and ethnically diverse middle school students in Los Angeles County, I studied the effects of different types of media use (i.e., social media, TV/movies/videos, gaming, music, Internet) on dietary p...

  8. Application for 3d Scene Understanding in Detecting Discharge of Domesticwaste Along Complex Urban Rivers

    Science.gov (United States)

    Ninsalam, Y.; Qin, R.; Rekittke, J.

    2016-06-01

    In our study we use 3D scene understanding to detect the discharge of domestic solid waste along an urban river. Solid waste found along the Ciliwung River in the neighbourhoods of Bukit Duri and Kampung Melayu may be attributed to households. This is in part due to inadequate municipal waste infrastructure and services which has caused those living along the river to rely upon it for waste disposal. However, there has been little research to understand the prevalence of household waste along the river. Our aim is to develop a methodology that deploys a low cost sensor to identify point source discharge of solid waste using image classification methods. To demonstrate this we describe the following five-step method: 1) a strip of GoPro images are captured photogrammetrically and processed for dense point cloud generation; 2) depth for each image is generated through a backward projection of the point clouds; 3) a supervised image classification method based on Random Forest classifier is applied on the view dependent red, green, blue and depth (RGB-D) data; 4) point discharge locations of solid waste can then be mapped by projecting the classified images to the 3D point clouds; 5) then the landscape elements are classified into five types, such as vegetation, human settlement, soil, water and solid waste. While this work is still ongoing, the initial results have demonstrated that it is possible to perform quantitative studies that may help reveal and estimate the amount of waste present along the river bank.

  9. Understanding the Complexities of Subnational Incentives in Supporting a National Market for Distributed Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Bush, B.; Doris, E.; Getman, D.

    2014-09-01

    Subnational policies pertaining to photovoltaic (PV) systems have increased in volume in recent years and federal incentives are set to be phased out over the next few. Understanding how subnational policies function within and across jurisdictions, thereby impacting PV market development, informs policy decision making. This report was developed for subnational policy-makers and researchers in order to aid the analysis on the function of PV system incentives within the emerging PV deployment market. The analysis presented is based on a 'logic engine,' a database tool using existing state, utility, and local incentives allowing users to see the interrelationships between PV system incentives and parameters, such as geographic location, technology specifications, and financial factors. Depending on how it is queried, the database can yield insights into which combinations of incentives are available and most advantageous to the PV system owner or developer under particular circumstances. This is useful both for individual system developers to identify the most advantageous incentive packages that they qualify for as well as for researchers and policymakers to better understand the patch work of incentives nationwide as well as how they drive the market.

  10. Food, health, and complexity: towards a conceptual understanding to guide collaborative public health action

    Directory of Open Access Journals (Sweden)

    Shannon E. Majowicz

    2016-06-01

    Full Text Available Abstract Background What we eat simultaneously impacts our exposure to pathogens, allergens, and contaminants, our nutritional status and body composition, our risks for and the progression of chronic diseases, and other outcomes. Furthermore, what we eat is influenced by a complex web of drivers, including culture, politics, economics, and our built and natural environments. To date, public health initiatives aimed at improving food-related population health outcomes have primarily been developed within ‘practice silos’, and the potential for complex interactions among such initiatives is not well understood. Therefore, our objective was to develop a conceptual model depicting how infectious foodborne illness, food insecurity, dietary contaminants, obesity, and food allergy can be linked via shared drivers, to illustrate potential complex interactions and support future collaboration across public health practice silos. Methods We developed the conceptual model by first conducting a systematic literature search to identify review articles containing schematics that depicted relationships between drivers and the issues of interest. Next, we synthesized drivers into a common model using a modified thematic synthesis approach that combined an inductive thematic analysis and mapping to synthesize findings. Results The literature search yielded 83 relevant references containing 101 schematics. The conceptual model contained 49 shared drivers and 227 interconnections. Each of the five issues was connected to all others. Obesity and food insecurity shared the most drivers (n = 28. Obesity shared several drivers with food allergy (n = 11, infectious foodborne illness (n = 7, and dietary contamination (n = 6. Food insecurity shared several drivers with infectious foodborne illness (n = 9 and dietary contamination (n = 9. Infectious foodborne illness shared drivers with dietary contamination (n = 8. Fewer drivers were

  11. Sorptive fractionation of organic matter and formation of organo-hydroxy-aluminum complexes during litter biodegradation in the presence of gibbsite

    Science.gov (United States)

    K. Heckman; A.S. Grandy; X. Gao; M. Keiluweit; K. Wickings; K. Carpenter; J. Chorover; C. Rasmussen

    2013-01-01

    Solid and aqueous phase Al species are recognized to affect organic matter (OM) stabilization in forest soils. However, little is known about the dynamics of formation, composition and dissolution of organo-Al hydroxide complexes in microbially-active soil systems, where plant litter is subject to microbial decomposition in close proximity to mineral weathering...

  12. APPLICATION FOR 3D SCENE UNDERSTANDING IN DETECTING DISCHARGE OF DOMESTICWASTE ALONG COMPLEX URBAN RIVERS

    Directory of Open Access Journals (Sweden)

    Y. Ninsalam

    2016-06-01

    Full Text Available In our study we use 3D scene understanding to detect the discharge of domestic solid waste along an urban river. Solid waste found along the Ciliwung River in the neighbourhoods of Bukit Duri and Kampung Melayu may be attributed to households. This is in part due to inadequate municipal waste infrastructure and services which has caused those living along the river to rely upon it for waste disposal. However, there has been little research to understand the prevalence of household waste along the river. Our aim is to develop a methodology that deploys a low cost sensor to identify point source discharge of solid waste using image classification methods. To demonstrate this we describe the following five-step method: 1 a strip of GoPro images are captured photogrammetrically and processed for dense point cloud generation; 2 depth for each image is generated through a backward projection of the point clouds; 3 a supervised image classification method based on Random Forest classifier is applied on the view dependent red, green, blue and depth (RGB-D data; 4 point discharge locations of solid waste can then be mapped by projecting the classified images to the 3D point clouds; 5 then the landscape elements are classified into five types, such as vegetation, human settlement, soil, water and solid waste. While this work is still ongoing, the initial results have demonstrated that it is possible to perform quantitative studies that may help reveal and estimate the amount of waste present along the river bank.

  13. Critical analysis of the data on complexation of lanthanides and actinides by natural organic matter: particular case of humic substances

    International Nuclear Information System (INIS)

    Reiller, P.

    2010-01-01

    This document proposes a critical analysis of the models that describe the actinides and lanthanides complexation by natural organic matter in general and by humic substances in particular. In order to better delimit the particular properties of these substances the most influent physical and chemical properties on complexation are recalled as a preamble. Models as well as data that has been used are reviewed, compiled, and eventually compared to independent data in order to identify (i) their application domain, (ii) the possible simplifications which permit to obtain operational models, (iii) the conditions in which simplifications cannot be ascertained yet, and (iv) the data or fields of knowledge which are still too uncertain. A comparison between the different models is proposed in order to adapt parameters from one model to another minimising the experimental acquisitions, or at least to focus on missing data. Usually, data on the complexation of free ions M z+ are reliable; as soon as hydrolysis, or competition with another ligand in general, in at stake data are much less reliable. Predictions from models are much more uncertain: formation of mixed complexes with hydroxide or carbonate anions is not univocal whatever the modelling strategy. Hints for transfer functions between models which are believed to be incompatible could be explored in order to justify necessary simplifications for using operational modelling. Influence on the solubility of oxides could be quantified, but it is difficult to clearly separate it from colloidal particles stabilisation. The account of the competition between cations by the models has also been tested. In view of the small number of available experimental data there still lie some uncertainties especially for the media that are close to neutrality and in the case of competition with magnesium, but overall in the case of the competition with aluminium and iron. The influence of redox activity of humic substances is also

  14. Dynamics of metal-humate complexation equilibria as revealed by isotope exchange studies - a matter of concentration and time

    Science.gov (United States)

    Lippold, Holger; Eidner, Sascha; Kumke, Michael U.; Lippmann-Pipke, Johanna

    2017-01-01

    Complexation with dissolved humic matter can be crucial in controlling the mobility of toxic or radioactive contaminant metals. For speciation and transport modelling, a dynamic equilibrium process is commonly assumed, where association and dissociation run permanently. This is, however, questionable in view of reported observations of a growing resistance to dissociation over time. In this study, the isotope exchange principle was employed to gain direct insight into the dynamics of the complexation equilibrium, including kinetic inertisation phenomena. Terbium(III), an analogue of trivalent actinides, was used as a representative of higher-valent metals. Isotherms of binding to (flocculated) humic acid, determined by means of 160Tb as a radiotracer, were found to be identical regardless of whether the radioisotope was introduced together with the bulk of stable 159Tb or subsequently after pre-equilibration for up to 3 months. Consequently, there is a permanent exchange of free and humic-bound Tb since all available binding sites are occupied in the plateau region of the isotherm. The existence of a dynamic equilibrium was thus evidenced. There was no indication of an inertisation under these experimental conditions. If the small amount of 160Tb was introduced prior to saturation with 159Tb, the expected partial desorption of 160Tb occurred at much lower rates than observed for the equilibration process in the reverse procedure. In addition, the rates decreased with time of pre-equilibration. Inertisation phenomena are thus confined to the stronger sites of humic molecules (occupied at low metal concentrations). Analysing the time-dependent course of isotope exchange according to first-order kinetics indicated that up to 3 years are needed to attain equilibrium. Since, however, metal-humic interaction remains reversible, exchange of metals between humic carriers and mineral surfaces cannot be neglected on the long time scale to be considered in predictive

  15. Boxes, Boosts, and Energy Duality: Understanding the Galactic-Center Gamma-Ray Excess through Dynamical Dark Matter

    CERN Document Server

    Boddy, Kimberly K.

    2017-03-28

    Many models currently exist which attempt to interpret the excess of gamma rays emanating from the Galactic Center in terms of annihilating or decaying dark matter. These models typically exhibit a variety of complicated cascade mechanisms for photon production, leading to a non-trivial kinematics which obscures the physics of the underlying dark sector. In this paper, by contrast, we observe that the spectrum of the gamma-ray excess may actually exhibit an intriguing "energy-duality" invariance under $E_\\gamma \\rightarrow E_\\ast^2/E_\\gamma$ for some $E_\\ast$. As we shall discuss, such an energy duality points back to a remarkably simple alternative kinematics which in turn is realized naturally within the Dynamical Dark Matter framework. Observation of this energy duality could therefore provide considerable information about the properties of the dark sector from which the Galactic-Center gamma-ray excess might arise, and highlights the importance of acquiring more complete data for the Galactic-Center exce...

  16. FuturICT: Participatory computing to understand and manage our complex world in a more sustainable and resilient way

    Science.gov (United States)

    Helbing, D.; Bishop, S.; Conte, R.; Lukowicz, P.; McCarthy, J. B.

    2012-11-01

    We have built particle accelerators to understand the forces that make up our physical world. Yet, we do not understand the principles underlying our strongly connected, techno-socio-economic systems. We have enabled ubiquitous Internet connectivity and instant, global information access. Yet we do not understand how it impacts our behavior and the evolution of society. To fill the knowledge gaps and keep up with the fast pace at which our world is changing, a Knowledge Accelerator must urgently be created. The financial crisis, international wars, global terror, the spreading of diseases and cyber-crime as well as demographic, technological and environmental change demonstrate that humanity is facing serious challenges. These problems cannot be solved within the traditional paradigms. Moving our attention from a component-oriented view of the world to an interaction-oriented view will allow us to understand the complex systems we have created and the emergent collective phenomena characterising them. This paradigm shift will enable new solutions to long-standing problems, very much as the shift from a geocentric to a heliocentric worldview has facilitated modern physics and the ability to launch satellites. The FuturICT flagship project will develop new science and technology to manage our future in a complex, strongly connected world. For this, it will combine the power of information and communication technology (ICT) with knowledge from the social and complexity sciences. ICT will provide the data to boost the social sciences into a new era. Complexity science will shed new light on the emergent phenomena in socially interactive systems, and the social sciences will provide a better understanding of the opportunities and risks of strongly networked systems, in particular future ICT systems. Hence, the envisaged FuturICT flagship will create new methods and instruments to tackle the challenges of the 21st century. FuturICT could indeed become one of the most

  17. Quantitative disease resistance: to better understand parasite-mediated selection on major histocompatibility complex.

    Science.gov (United States)

    Westerdahl, Helena; Asghar, Muhammad; Hasselquist, Dennis; Bensch, Staffan

    2012-02-07

    We outline a descriptive framework of how candidate alleles of the immune system associate with infectious diseases in natural populations of animals. Three kinds of alleles can be separated when both prevalence of infection and infection intensity are measured--qualitative disease resistance, quantitative disease resistance and susceptibility alleles. Our descriptive framework demonstrates why alleles for quantitative resistance and susceptibility cannot be separated based on prevalence data alone, but are distinguishable on infection intensity. We then present a case study to evaluate a previous finding of a positive association between prevalence of a severe avian malaria infection (GRW2, Plasmodium ashfordi) and a major histocompatibility complex (MHC) class I allele (B4b) in great reed warblers Acrocephalus arundinaceus. Using the same dataset, we find that individuals with allele B4b have lower GRW2 infection intensities than individuals without this allele. Therefore, allele B4b provides quantitative resistance rather than increasing susceptibility to infection. This implies that birds carrying B4b can mount an immune response that suppresses the acute-phase GRW2 infection, while birds without this allele cannot and may die. We argue that it is important to determine whether MHC alleles related to infections are advantageous (quantitative and qualitative resistance) or disadvantageous (susceptibility) to obtain a more complete picture of pathogen-mediated balancing selection.

  18. Animals on drugs: understanding the role of pharmaceutical companies in the animal-industrial complex.

    Science.gov (United States)

    Twine, Richard

    2013-12-01

    In this paper I revisit previous critiques that I have made of much, though by no means all, bioethical discourse. These pertain to faithfulness to dualistic ontology, a taken-for-granted normative anthropocentrism, and the exclusion of a consideration of how political economy shapes the conditions for bioethical discourse (Twine Medicine, Health Care and Philosophy 8(3):285-295, 2005; International Journal of Sociology of Agriculture and Food 16(3):1-18, 2007, 2010). Part of my argument around bioethical dualist ontology is to critique the assumption of a division between the "medical" (human) and "agricultural" (nonhuman) and to show various ways in which they are interrelated. I deepen this analysis with a focus on transnational pharmaceutical companies, with specific attention to their role in enhancing agricultural production through animal drug administration. I employ the topical case of antibiotics in order to speak to current debates in not only the interdisciplinary field of bioethics but also that of animal studies. More generally, the animal-industrial complex (Twine Journal for Critical Animal Studies 10(1):12-39, 2012) is underlined as a highly relevant bioethical object that deserves more conceptual and empirical attention.

  19. Mismatch repair proteins, meiosis, and mice: understanding the complexities of mammalian meiosis.

    Science.gov (United States)

    Svetlanov, Anton; Cohen, Paula E

    2004-05-15

    Mammalian meiosis differs from that seen in lower eukaryotes in several respects, not least of which is the added complexity of dealing with chromosomal interactions across a much larger genome (12 MB over 16 chromosome pairs in Saccharomyces cerevisiae compared to 2500 MB over 19 autosome pairs in Mus musculus). Thus, the recombination machinery, while being highly conserved through eukaryotes, has evolved to accommodate such issues to preserve genome integrity and to ensure propagation of the species. One group of highly conserved meiotic regulators is the DNA mismatch repair protein family that, as their name implies, were first identified as proteins that act to repair DNA mismatches that arise primarily during DNA replication. Their function in ensuring chromosomal integrity has also translated into a critical role for this family in meiotic recombination in most sexually reproducing organisms. In mice, targeted deletion of certain family members results in severe consequences for meiotic progression and infertility. This review will focus on the studies involving these mutant mouse models, with occasional comparison to the function of these proteins in other organisms.

  20. Continuity of care in mental health: understanding and measuring a complex phenomenon.

    Science.gov (United States)

    Burns, T; Catty, J; White, S; Clement, S; Ellis, G; Jones, I R; Lissouba, P; McLaren, S; Rose, D; Wykes, T

    2009-02-01

    Continuity of care is considered by patients and clinicians an essential feature of good quality care in long-term disorders, yet there is general agreement that it is a complex concept. Most policies emphasize it and encourage systems to promote it. Despite this, there is no accepted definition or measure against which to test policies or interventions designed to improve continuity. We aimed to operationalize a multi-axial model of continuity of care and to use factor analysis to determine its validity for severe mental illness. A multi-axial model of continuity of care comprising eight facets was operationalized for quantitative data collection from mental health service users using 32 variables. Of these variables, 22 were subsequently entered into a factor analysis as independent components, using data from a clinical population considered to require long-term consistent care. Factor analysis produced seven independent continuity factors accounting for 62.5% of the total variance. These factors, Experience and Relationship, Regularity, Meeting Needs, Consolidation, Managed Transitions, Care Coordination and Supported Living, were close but not identical to the original theoretical model. We confirmed that continuity of care is multi-factorial. Our seven factors are intuitively meaningful and appear to work in mental health. These factors should be used as a starting-point in research into the determinants and outcomes of continuity of care in long-term disorders.

  1. Understanding complexities in coupled dynamics of human-water and food security

    Science.gov (United States)

    Usmani, M.; Kondal, A.; Lin, L.; Colwell, R. R.; Jutla, A.

    2017-12-01

    Traditional premise of food security is associated with satisfying human hunger by providing sufficient calories to population. Water is the key variable associated with the growth of crops, which is then used as a metric of success for abundance of food across globe. The current framework often negates complex coupled interaction between availability of food nutrients and human well-being (such as productivity, work efficiency, low birth weight, physical and mental growth). Our analysis suggests that 1 in 3 humans suffer from malnutrition across the globe. In last five decades, most of the countries have a decreasing availability trend in at least one of the twenty-three essential food nutrients required for human well-being. We argue that food security can only be achieved if information on use of water for crops and consumption of food must include availability of nutrients for humans. Here, we propose a new concept of "consumptive nutrients" that include constant feedback mechanism between water-human and societal processes- essential for growth, distribution and consumption of food nutrients. Using Ethiopia as a signature rain-fed agricultural region, we will show how decreasing precipitation has led to an increase in crop productivity, but decreased availability of nutrients for humans. This in turn has destabilizing impact on overall regional economy. We will demonstrate why inclusion of nutrients must be a part of discussion for ensuring food security to human population.

  2. Nice to know you: Positive emotions, self-other overlap, and complex understanding in the formation of a new relationship.

    Science.gov (United States)

    Waugh, Christian E; Fredrickson, Barbara L

    2006-04-01

    Based on Fredrickson's ((1998). What good are positive emotions? Review of General Psychology, 2, 300-319.; (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56, 218-226) broaden-and-build theory and Aron and Aron's ((1986). Love as expansion of the self: Understanding attraction and satisfaction. New York: Hemisphere) self-expansion theory, it was hypothesized that positive emotions broaden people's feelings of self-other overlap in the beginning of a new relationship. In a prospective study of first-year college students, we found that, after 1 week in college, positive emotions predicted increased self-other overlap with new roommates, which in turn predicted a more complex understanding of the roommate. In addition, participants who experienced a high ratio of positive to negative emotions throughout the first month of college reported a greater increase in self-other overlap and complex understanding than participants with a low positivity ratio. Implications for the role of positive emotions in the formation of new relationships are discussed.

  3. Nice to know you: Positive emotions, self–other overlap, and complex understanding in the formation of a new relationship

    Science.gov (United States)

    WAUGH, CHRISTIAN E.; FREDRICKSON, BARBARA L.

    2007-01-01

    Based on Fredrickson's ((1998). What good are positive emotions? Review of General Psychology, 2, 300–319.; (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56, 218–226) broaden-and-build theory and Aron and Aron's ((1986). Love as expansion of the self: Understanding attraction and satisfaction. New York: Hemisphere) self-expansion theory, it was hypothesized that positive emotions broaden people's feelings of self–other overlap in the beginning of a new relationship. In a prospective study of first-year college students, we found that, after 1 week in college, positive emotions predicted increased self–other overlap with new roommates, which in turn predicted a more complex understanding of the roommate. In addition, participants who experienced a high ratio of positive to negative emotions throughout the first month of college reported a greater increase in self–other overlap and complex understanding than participants with a low positivity ratio. Implications for the role of positive emotions in the formation of new relationships are discussed. PMID:21691460

  4. Studying the complexity of change: toward an analytical framework for understanding deliberate social-ecological transformations

    Directory of Open Access Journals (Sweden)

    Michele-Lee Moore

    2014-12-01

    Full Text Available Faced with numerous seemingly intractable social and environmental challenges, many scholars and practitioners are increasingly interested in understanding how to actively engage and transform the existing systems holding such problems in place. Although a variety of analytical models have emerged in recent years, most emphasize either the social or ecological elements of such transformations rather than their coupled nature. To address this, first we have presented a definition of the core elements of a social-ecological system (SES that could potentially be altered in a transformation. Second, we drew on insights about transformation from three branches of literature focused on radical change, i.e., social movements, socio-technical transitions, and social innovation, and gave consideration to the similarities and differences with the current studies by resilience scholars. Drawing on these findings, we have proposed a framework that outlines the process and phases of transformative change in an SES. Future research will be able to utilize the framework as a tool for analyzing the alteration of social-ecological feedbacks, identifying critical barriers and leverage points and assessing the outcome of social-ecological transformations.

  5. Carbon-water Cycling in the Critical Zone: Understanding Ecosystem Process Variability Across Complex Terrain

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, Holly [Univ. of Colorado, Boulder, CO (United States); Brooks, Paul [Univ. of Utah, Salt Lake City, UT (United States); Univ. of Arizona, Tucson, AZ (United States)

    2016-06-16

    One of the largest knowledge gaps in environmental science is the ability to understand and predict how ecosystems will respond to future climate variability. The links between vegetation, hydrology, and climate that control carbon sequestration in plant biomass and soils remain poorly understood. Soil respiration is the second largest carbon flux of terrestrial ecosystems, yet there is no consensus on how respiration will change as water availability and temperature co-vary. To address this knowledge gap, we use the variation in soil development and topography across an elevation and climate gradient on the Front Range of Colorado to conduct a natural experiment that enables us to examine the co-evolution of soil carbon, vegetation, hydrology, and climate in an accessible field laboratory. The goal of this project is to further our ability to combine plant water availability, carbon flux and storage, and topographically driven hydrometrics into a watershed scale predictive model of carbon balance. We hypothesize: (i) landscape structure and hydrology are important controls on soil respiration as a result of spatial variability in both physical and biological drivers: (ii) variation in rates of soil respiration during the growing season is due to corresponding shifts in belowground carbon inputs from vegetation; and (iii) aboveground carbon storage (biomass) and species composition are directly correlated with soil moisture and therefore, can be directly related to subsurface drainage patterns.

  6. Improving the realism of white matter numerical phantoms: a step towards a better understanding of the influence of structural disorders in diffusion MRI

    Science.gov (United States)

    Ginsburger, Kévin; Poupon, Fabrice; Beaujoin, Justine; Estournet, Delphine; Matuschke, Felix; Mangin, Jean-François; Axer, Markus; Poupon, Cyril

    2018-02-01

    White matter is composed of irregularly packed axons leading to a structural disorder in the extra-axonal space. Diffusion MRI experiments using oscillating gradient spin echo sequences have shown that the diffusivity transverse to axons in this extra-axonal space is dependent on the frequency of the employed sequence. In this study, we observe the same frequency-dependence using 3D simulations of the diffusion process in disordered media. We design a novel white matter numerical phantom generation algorithm which constructs biomimicking geometric configurations with few design parameters, and enables to control the level of disorder of the generated phantoms. The influence of various geometrical parameters present in white matter, such as global angular dispersion, tortuosity, presence of Ranvier nodes, beading, on the extra-cellular perpendicular diffusivity frequency dependence was investigated by simulating the diffusion process in numerical phantoms of increasing complexity and fitting the resulting simulated diffusion MR signal attenuation with an adequate analytical model designed for trapezoidal OGSE sequences. This work suggests that angular dispersion and especially beading have non-negligible effects on this extracellular diffusion metrics that may be measured using standard OGSE DW-MRI clinical protocols.

  7. Complexity

    Indian Academy of Sciences (India)

    Rahul Pandit

    2008-10-31

    Oct 31, 2008 ... Centre for Condensed Matter Theory. Department of Physics. Indian Institute ... Interactions between a system's components are important role. ... Scale-free networks in, say, social networks or the world-wide web. ▻ A system ...

  8. Effects of Jigsaw Cooperative Learning and Animation Techniques on Students' Understanding of Chemical Bonding and Their Conceptions of the Particulate Nature of Matter

    Science.gov (United States)

    Karacop, Ataman; Doymus, Kemal

    2013-04-01

    The aim of this study was to determine the effect of jigsaw cooperative learning and computer animation techniques on academic achievements of first year university students attending classes in which the unit of chemical bonding is taught within the general chemistry course and these students' learning of the particulate nature of matter of this unit. The sample of this study consisted of 115 first-year science education students who attended the classes in which the unit of chemical bonding was taught in a university faculty of education during the 2009-2010 academic year. The data collection instruments used were the Test of Scientific Reasoning, the Purdue Spatial Visualization Test: Rotations, the Chemical Bonding Academic Achievement Test, and the Particulate Nature of Matter Test in Chemical Bonding (CbPNMT). The study was carried out in three different groups. One of the groups was randomly assigned to the jigsaw group, the second was assigned to the animation group (AG), and the third was assigned to the control group, in which the traditional teaching method was applied. The data obtained with the instruments were evaluated using descriptive statistics, one-way ANOVA, and MANCOVA. The results indicate that the teaching of chemical bonding via the animation and jigsaw techniques was more effective than the traditional teaching method in increasing academic achievement. In addition, according to findings from the CbPNMT, the students from the AG were more successful in terms of correct understanding of the particulate nature of matter.

  9. Navigating Special Education in Charter Schools Part I: Understanding Legal Roles and Responsibilities. Authorizing Matters. Issue Brief

    Science.gov (United States)

    Rhim, Lauren Morando

    2007-01-01

    Special education and related services are mandated by the federal Individuals with Disabilities Education Act (IDEA) and related state special education policies. Policies and procedures associated with implementing IDEA can be complex, cumbersome and time consuming. IDEA is founded on the notion that a free appropriate public education is a…

  10. Feasibility of using sodium chloride as a tracer for the characterization of the distribution of matter in complex multi-compartment 3D bioreactors for stem cell culture.

    Science.gov (United States)

    Gerlach, Jörg C; Witaschek, Tom; Strobel, Catrin; Brayfield, Candace A; Bornemann, Reinhard; Catapano, Gerardo; Zeilinger, Katrin

    2010-06-01

    The experimental characterization of the distribution of matter in complex multi-compartment three-dimensional membrane bioreactors for human cell culture is complicated by tracer interactions with the membranes and other bioreactor constituents. This is due to the fact that membranes with a high specific surface area often feature a hydrophobic chemical backbone that may adsorb tracers often used to this purpose, such as proteins and dyes. Membrane selectivity, and its worsening caused by protein adsorption, may also hinder tracer transfer across neighboring compartments, thus preventing effective characterization of the distribution of matter in the whole bioreactor. Tracer experiments with sodium chloride (NaCl) may overcome some of these limitations and be effectively used to characterize the distribution of matter in complex 3D multi-compartments membrane bioreactors for stem cell culture. NaCl freely permeates most used membranes, it does not adsorb on uncharged membranes, and its concentration may be accurately measured in terms of solution conductivity. In this preliminary study, the feasibility of complex multi-compartment membrane bioreactors was investigated with a NaCl concentration pulse challenge to characterize how their distribution of matter changes when they are operated under different conditions. In particular, bioreactors consisting of three different membrane types stacked on top of one another to form a 3D network were characterized under different feed conditions.

  11. When Statistical Literacy Really Matters: Understanding Published Information about the HIV/AIDS Epidemic in South Africa

    Science.gov (United States)

    Hobden, Sally

    2014-01-01

    Information on the HIV/AIDS epidemic in Southern Africa is often interpreted through a veil of secrecy and shame and, I argue, with flawed understanding of basic statistics. This research determined the levels of statistical literacy evident in 316 future Mathematical Literacy teachers' explanations of the median in the context of HIV/AIDS…

  12. Understanding TR binding to pMHC complexes: how does a TR scan many pMHC complexes yet preferentially bind to one.

    Directory of Open Access Journals (Sweden)

    Javed Mohammed Khan

    Full Text Available Understanding the basis of the binding of a T cell receptor (TR to the peptide-MHC (pMHC complex is essential due to the vital role it plays in adaptive immune response. We describe the use of computed binding (free energy (BE, TR paratope, pMHC epitope, molecular surface electrostatic potential (MSEP and calculated TR docking angle (θ to analyse 61 TR/pMHC crystallographic structures to comprehend TR/pMHC interaction. In doing so, we have successfully demonstrated a novel/rational approach for θ calculation, obtained a linear correlation between BE and θ without any "codon" or amino acid preference, provided an explanation for TR ability to scan many pMHC ligands yet specifically bind one, proposed a mechanism for pMHC recognition by TR leading to T cell activation and illustrated the importance of the peptide in determining TR specificity, challenging the "germline bias" theory.

  13. Why Society is a Complex Matter Meeting Twenty-first Century Challenges with a New Kind of Science

    CERN Document Server

    Ball, Philip

    2012-01-01

    Society is complicated. But this book argues that this does not place it beyond the reach of a science that can help to explain and perhaps even to predict social behaviour. As a system made up of many interacting agents – people, groups, institutions and governments, as well as physical and technological structures such as roads and computer networks – society can be regarded as a complex system. In recent years, scientists have made great progress in understanding how such complex systems operate, ranging from animal populations to earthquakes and weather. These systems show behaviours that cannot be predicted or intuited by focusing on the individual components, but which emerge spontaneously as a consequence of their interactions: they are said to be ‘self-organized’. Attempts to direct or manage such emergent properties generally reveal that ‘top-down’ approaches, which try to dictate a particular outcome, are ineffectual, and that what is needed instead is a ‘bottom-up’ approach that aim...

  14. Developing Seventh Grade Students' Understanding of Complex Environmental Problems with Systems Tools and Representations: a Quasi-experimental Study

    Science.gov (United States)

    Doganca Kucuk, Zerrin; Saysel, Ali Kerem

    2017-03-01

    A systems-based classroom intervention on environmental education was designed for seventh grade students; the results were evaluated to see its impact on the development of systems thinking skills and standard science achievement and whether the systems approach is a more effective way to teach environmental issues that are dynamic and complex. A quasi-experimental methodology was used to compare performances of the participants in various dimensions, including systems thinking skills, competence in dynamic environmental problem solving and success in science achievement tests. The same pre-, post- and delayed tests were used with both the comparison and experimental groups in the same public middle school in Istanbul. Classroom activities designed for the comparison group (N = 20) followed the directives of the Science and Technology Curriculum, while the experimental group (N = 22) covered the same subject matter through activities benefiting from systems tools and representations such as behaviour over time graphs, causal loop diagrams, stock-flow structures and hands-on dynamic modelling. After a one-month systems-based instruction, the experimental group demonstrated significantly better systems thinking and dynamic environmental problem solving skills. Achievement in dynamic problem solving was found to be relatively stable over time. However, standard science achievement did not improve at all. This paper focuses on the quantitative analysis of the results, the weaknesses of the curriculum and educational implications.

  15. Human development II: We Need an Integrated Theory for Matter, Life and Consciousness to Understand Life and Healing

    Directory of Open Access Journals (Sweden)

    Sören Ventegodt

    2006-01-01

    Full Text Available For almost a decade, we have experimented with supporting the philosophical development of severely ill patients to induce recovery and spontaneous healing. Recently, we have observed a new pattern of extremely rapid, spontaneous healing that apparently can facilitate even the spontaneous remission of cancer and the spontaneous recovery of mental diseases like schizophrenia and borderline schizophrenia. Our working hypothesis is that the accelerated healing is a function of the patient’s brain-mind and body-mind coming closer together due to the development of what we call “deep” cosmology. To understand and describe what happens at a biological level, we have suggested naming the process adult human metamorphosis, a possibility that is opened by the human genome showing full generic equipment for metamorphosis. To understand the mechanistic details in the complicated interaction between consciousness and biology, we need an adequate theory for biological information. In a series of papers, we propose what we call “holistic biology for holistic medicine”. We suggest that a relatively simple model based on interacting wholenesses instead of isolated parts can shed a new light on a number of difficult issues that we need to explain and understand in biology and medicine in order to understand and use metamorphosis in the holistic medical clinic. We aim to give a holistic theoretical interpretation of biological phenomena at large, morphogenesis, evolution, immune system regulation (self-nonself discrimination, brain function, consciousness, and health in particular. We start at the most fundamental problem: what is biological information at the subcellular, cellular, and supracellular levels if we presume that it is the same phenomenon on all levels (using Occam's razor, and how can this be described scientifically? The problems we address are all connected to the information flow in the functioning, living organism: function of the brain

  16. Human development II: we need an integrated theory for matter, life and consciousness to understand life and healing.

    Science.gov (United States)

    Ventegodt, Søren; Hermansen, Tyge Dahl; Nielsen, Maj Lyck; Clausen, Birgitte; Merrick, Joav

    2006-07-06

    For almost a decade, we have experimented with supporting the philosophical development of severely ill patients to induce recovery and spontaneous healing. Recently, we have observed a new pattern of extremely rapid, spontaneous healing that apparently can facilitate even the spontaneous remission of cancer and the spontaneous recovery of mental diseases like schizophrenia and borderline schizophrenia. Our working hypothesis is that the accelerated healing is a function of the patient's brain-mind and body-mind coming closer together due to the development of what we call "deep" cosmology. To understand and describe what happens at a biological level, we have suggested naming the process adult human metamorphosis, a possibility that is opened by the human genome showing full generic equipment for metamorphosis. To understand the mechanistic details in the complicated interaction between consciousness and biology, we need an adequate theory for biological information. In a series of papers, we propose what we call "holistic biology for holistic medicine". We suggest that a relatively simple model based on interacting wholenesses instead of isolated parts can shed a new light on a number of difficult issues that we need to explain and understand in biology and medicine in order to understand and use metamorphosis in the holistic medical clinic. We aim to give a holistic theoretical interpretation of biological phenomena at large, morphogenesis, evolution, immune system regulation (self-nonself discrimination), brain function, consciousness, and health in particular. We start at the most fundamental problem: what is biological information at the subcellular, cellular, and supracellular levels if we presume that it is the same phenomenon on all levels (using Occam's razor), and how can this be described scientifically? The problems we address are all connected to the information flow in the functioning, living organism: function of the brain and consciousness, the

  17. Tilts, dopants, vacancies and non-stoichiometry: Understanding and designing the properties of complex solid oxide perovskites from first principles

    Science.gov (United States)

    Bennett, Joseph W.

    Perovskite oxides of formula ABO3 have a wide range of structural, electrical and mechanical properties, making them vital materials for many applications, such as catalysis, ultrasound machines and communication devices. Perovskite solid solutions with high piezoelectric response, such as ferroelectrics, are of particular interest as they can be employed as sensors in SONAR devices. Ferroelectric materials are unique in that their chemical and electrical properties can be non-invasively and reversibly changed, by switching the bulk polarization. This makes ferroelectrics useful for applications in non-volatile random access memory (NVRAM) devices. Perovskite solid solutions with a lower piezoelectric response than ferroelectrics are important for communication technology, as they function well as electroceramic capacitors. Also of interest is how these materials act as a component in a solid oxide fuel cell, as they can function as an efficient source of energy. Altering the chemical composition of these solid oxide materials offers an opportunity to change the desired properties of the final ceramic, adding a degree of flexibility that is advantageous for a variety of applications. These solid oxides are complex, sometimes disordered systems that are a challenge to study experimentally. However, as it is their complexity which produces favorable properties, highly accurate modeling which captures the essential features of the disordered structure is necessary to explain the behavior of current materials and predict favorable compositions for new materials. Methodological improvements and faster computer speeds have made first-principles and atomistic calculations a viable tool for understanding these complex systems. Offering a combination of accuracy and computational speed, the density functional theory (DFT) approach can reveal details about the microscopic structure and interactions of complex systems. Using DFT and a combination of principles from both

  18. Understanding Spatially Complex Segmental and Branch Anatomy Using 3D Printing: Liver, Lung, Prostate, Coronary Arteries, and Circle of Willis.

    Science.gov (United States)

    Javan, Ramin; Herrin, Douglas; Tangestanipoor, Ardalan

    2016-09-01

    Three-dimensional (3D) manufacturing is shaping personalized medicine, in which radiologists can play a significant role, be it as consultants to surgeons for surgical planning or by creating powerful visual aids for communicating with patients, physicians, and trainees. This report illustrates the steps in development of custom 3D models that enhance the understanding of complex anatomy. We graphically designed 3D meshes or modified imported data from cross-sectional imaging to develop physical models targeted specifically for teaching complex segmental and branch anatomy. The 3D printing itself is easily accessible through online commercial services, and the models are made of polyamide or gypsum. Anatomic models of the liver, lungs, prostate, coronary arteries, and the Circle of Willis were created. These models have advantages that include customizable detail, relative low cost, full control of design focusing on subsegments, color-coding potential, and the utilization of cross-sectional imaging combined with graphic design. Radiologists have an opportunity to serve as leaders in medical education and clinical care with 3D printed models that provide beneficial interaction with patients, clinicians, and trainees across all specialties by proactively taking on the educator's role. Complex models can be developed to show normal anatomy or common pathology for medical educational purposes. There is a need for randomized trials, which radiologists can design, to demonstrate the utility and effectiveness of 3D printed models for teaching simple and complex anatomy, simulating interventions, measuring patient satisfaction, and improving clinical care. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  19. Functional speciation of metal-dissolved organic matter complexes by size exclusion chromatography coupled to inductively coupled plasma mass spectrometry and deconvolution analysis

    International Nuclear Information System (INIS)

    Laborda, Francisco; Ruiz-Begueria, Sergio; Bolea, Eduardo; Castillo, Juan R.

    2009-01-01

    High performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry (HP-SEC-ICP-MS), in combination with deconvolution analysis, has been used to obtain multielemental qualitative and quantitative information about the distributions of metal complexes with different forms of natural dissolved organic matter (DOM). High performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry chromatograms only provide continuous distributions of metals with respect to molecular masses, due to the high heterogeneity of dissolved organic matter, which consists of humic substances as well as biomolecules and other organic compounds. A functional speciation approach, based on the determination of the metals associated to different groups of homologous compounds, has been followed. Dissolved organic matter groups of homologous compounds are isolated from the aqueous samples under study and their high performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry elution profiles fitted to model Gaussian peaks, characterized by their respective retention times and peak widths. High performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry chromatograms of the samples are deconvoluted with respect to these model Gaussian peaks. This methodology has been applied to the characterization of metal-dissolved organic matter complexes in compost leachates. The most significant groups of homologous compounds involved in the complexation of metals in the compost leachates studied have been hydrophobic acids (humic and fulvic acids) and low molecular mass hydrophilic compounds. The environmental significance of these compounds is related to the higher biodegradability of the low molecular mass hydrophilic compounds and the lower mobility of humic acids. In general, the hydrophilic compounds accounted for the complexation of around 50% of the leached

  20. Applications of condensed matter understanding to medical tissues and disease progression: Elemental analysis and structural integrity of tissue scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D.A., E-mail: d.a.bradley@surrey.ac.u [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Farquharson, M.J. [Department of Radiography, School of Community and Health Sciences, City University, London (United Kingdom); Gundogdu, O. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Al-Ebraheem, Alia [Department of Radiography, School of Community and Health Sciences, City University, London (United Kingdom); Che Ismail, Elna [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Kaabar, W., E-mail: w.kaabar@surrey.ac.u [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Bunk, O. [Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Pfeiffer, F. [Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Falkenberg, G. [Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronensynchrotron DESY, Notkestr. 85, D-22603 Hamburg (Germany); Bailey, M. [Surrey Ion Beam Centre, Advanced Technology Institute, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2010-02-15

    The investigations reported herein link tissue structure and elemental presence with issues of environmental health and disease, exemplified by uptake and storage of potentially toxic elements in the body, the osteoarthritic condition and malignancy in the breast and other soft tissues. Focus is placed on application of state-of-the-art ionizing radiation techniques, including, micro-synchrotron X-ray fluorescence (mu-SXRF) and particle-induced X-ray emission/Rutherford backscattering mapping (mu-PIXE/RBS), coherent small-angle X-ray scattering (cSAXS) and X-ray phase-contrast imaging, providing information on elemental make-up, the large-scale organisation of collagen and anatomical features of moderate and low atomic number media. For the particular situations under investigation, use of such facilities is allowing information to be obtained at an unprecedented level of detail, yielding new understanding of the affected tissues and the progression of disease.

  1. Applications of condensed matter understanding to medical tissues and disease progression: Elemental analysis and structural integrity of tissue scaffolds

    International Nuclear Information System (INIS)

    Bradley, D.A.; Farquharson, M.J.; Gundogdu, O.; Al-Ebraheem, Alia; Che Ismail, Elna; Kaabar, W.; Bunk, O.; Pfeiffer, F.; Falkenberg, G.; Bailey, M.

    2010-01-01

    The investigations reported herein link tissue structure and elemental presence with issues of environmental health and disease, exemplified by uptake and storage of potentially toxic elements in the body, the osteoarthritic condition and malignancy in the breast and other soft tissues. Focus is placed on application of state-of-the-art ionizing radiation techniques, including, micro-synchrotron X-ray fluorescence (μ-SXRF) and particle-induced X-ray emission/Rutherford backscattering mapping (μ-PIXE/RBS), coherent small-angle X-ray scattering (cSAXS) and X-ray phase-contrast imaging, providing information on elemental make-up, the large-scale organisation of collagen and anatomical features of moderate and low atomic number media. For the particular situations under investigation, use of such facilities is allowing information to be obtained at an unprecedented level of detail, yielding new understanding of the affected tissues and the progression of disease.

  2. Effects of a wax organogel and alginate gel complex on holy basil (Ocimum sanctum) in vitro ruminal dry matter disappearance and gas production.

    Science.gov (United States)

    Templeman, James R; Rogers, Michael A; Cant, John P; McBride, Brian W; Osborne, Vern R

    2018-02-20

    The objectives of this study were to: (a) select an ideal organogel for the oil phase of a novel gel encapsulation technology, (b) optimize the formulation of an organogel and sodium alginate-based gel complex, and (c) examine the rumen protective ability of the gel by measuring 48-h in vitro ruminal dry matter disappearance and gas production from encapsulated dried and ground holy basil leaves. A rice-bran wax and canola oil organogel was selected for the oil phase of the gel complex as this combination had a 48-h dry matter disappearance of 6%, the lowest of all organogels analyzed. The gel complex was formulated by homogenizing the organogel with a sodium alginate solution to create a low-viscosity oil-in-water emulsion. Average dry matter disappearance of gel-encapsulated holy basil was 19%, compared to 42% for the free, unprotected holy basil. However, gel encapsulation of holy basil stimulated gas production. Specifically, gas production of encapsulated holy basil was four times higher than the treatment with holy basil added on top of the gel prior to incubation rather than encapsulated within the gel. Although the gel itself was highly degradable, it is speculated encapsulation thwarted holy basil's antimicrobial activity. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  3. The value of mechanistic biophysical information for systems-level understanding of complex biological processes such as cytokinesis.

    Science.gov (United States)

    Pollard, Thomas D

    2014-12-02

    This review illustrates the value of quantitative information including concentrations, kinetic constants and equilibrium constants in modeling and simulating complex biological processes. Although much has been learned about some biological systems without these parameter values, they greatly strengthen mechanistic accounts of dynamical systems. The analysis of muscle contraction is a classic example of the value of combining an inventory of the molecules, atomic structures of the molecules, kinetic constants for the reactions, reconstitutions with purified proteins and theoretical modeling to account for the contraction of whole muscles. A similar strategy is now being used to understand the mechanism of cytokinesis using fission yeast as a favorable model system. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. Topological Characteristics of the Hong Kong Stock Market: A Test-based P-threshold Approach to Understanding Network Complexity

    Science.gov (United States)

    Xu, Ronghua; Wong, Wing-Keung; Chen, Guanrong; Huang, Shuo

    2017-02-01

    In this paper, we analyze the relationship among stock networks by focusing on the statistically reliable connectivity between financial time series, which accurately reflects the underlying pure stock structure. To do so, we firstly filter out the effect of market index on the correlations between paired stocks, and then take a t-test based P-threshold approach to lessening the complexity of the stock network based on the P values. We demonstrate the superiority of its performance in understanding network complexity by examining the Hong Kong stock market. By comparing with other filtering methods, we find that the P-threshold approach extracts purely and significantly correlated stock pairs, which reflect the well-defined hierarchical structure of the market. In analyzing the dynamic stock networks with fixed-size moving windows, our results show that three global financial crises, covered by the long-range time series, can be distinguishingly indicated from the network topological and evolutionary perspectives. In addition, we find that the assortativity coefficient can manifest the financial crises and therefore can serve as a good indicator of the financial market development.

  5. Understanding the dynamics of the Seguro Popular de Salud policy implementation in Mexico from a complex adaptive systems perspective.

    Science.gov (United States)

    Nigenda, Gustavo; González-Robledo, Luz María; Juárez-Ramírez, Clara; Adam, Taghreed

    2016-05-13

    In 2003, Mexico's Seguro Popular de Salud (SPS), was launched as an innovative financial mechanism implemented to channel new funds to provide health insurance to 50 million Mexicans and to reduce systemic financial inequities. The objective of this article is to understand the complexity and dynamics that contributed to the adaptation of the policy in the implementation stage, how these changes occurred, and why, from a complex and adaptive systems perspective. A complex adaptive systems (CAS) framework was used to carry out a secondary analysis of data obtained from four SPS's implementation evaluations. We first identified key actors, their roles, incentives and power, and their responses to the policy and guidelines. We then developed a causal loop diagram to disentangle the feedback dynamics associated with the modifications of the policy implementation which we then analyzed using a CAS perspective. Implementation variations were identified in seven core design features during the first 10 years of implementation period, and in each case, the SPS's central coordination introduced modifications in response to the reactions of the different actors. We identified several CAS phenomena associated with these changes including phase transitions, network emergence, resistance to change, history dependence, and feedback loops. Our findings generate valuable lessons to policy implementation processes, especially those involving a monetary component, where the emergence of coping mechanisms and other CAS phenomena inevitably lead to modifications of policies and their interpretation by those who implement them. These include the difficulty of implementing strategies that aim to pool funds through solidarity among beneficiaries where the rich support the poor when there are no incentives for the rich to do so. Also, how resistance to change and history dependence can pose significant challenges to implementing changes, where the local actors use their significant power

  6. Ecosystem function in complex mountain terrain: Combining models and long-term observations to advance process-based understanding

    Science.gov (United States)

    Wieder, William R.; Knowles, John F.; Blanken, Peter D.; Swenson, Sean C.; Suding, Katharine N.

    2017-04-01

    Abiotic factors structure plant community composition and ecosystem function across many different spatial scales. Often, such variation is considered at regional or global scales, but here we ask whether ecosystem-scale simulations can be used to better understand landscape-level variation that might be particularly important in complex terrain, such as high-elevation mountains. We performed ecosystem-scale simulations by using the Community Land Model (CLM) version 4.5 to better understand how the increased length of growing seasons may impact carbon, water, and energy fluxes in an alpine tundra landscape. The model was forced with meteorological data and validated with observations from the Niwot Ridge Long Term Ecological Research Program site. Our results demonstrate that CLM is capable of reproducing the observed carbon, water, and energy fluxes for discrete vegetation patches across this heterogeneous ecosystem. We subsequently accelerated snowmelt and increased spring and summer air temperatures in order to simulate potential effects of climate change in this region. We found that vegetation communities that were characterized by different snow accumulation dynamics showed divergent biogeochemical responses to a longer growing season. Contrary to expectations, wet meadow ecosystems showed the strongest decreases in plant productivity under extended summer scenarios because of disruptions in hydrologic connectivity. These findings illustrate how Earth system models such as CLM can be used to generate testable hypotheses about the shifting nature of energy, water, and nutrient limitations across space and through time in heterogeneous landscapes; these hypotheses may ultimately guide further experimental work and model development.

  7. Science Outside the Lab: Helping Graduate Students in Science and Engineering Understand the Complexities of Science Policy.

    Science.gov (United States)

    Bernstein, Michael J; Reifschneider, Kiera; Bennett, Ira; Wetmore, Jameson M

    2017-06-01

    Helping scientists and engineers challenge received assumptions about how science, engineering, and society relate is a critical cornerstone for macroethics education. Scientific and engineering research are frequently framed as first steps of a value-free linear model that inexorably leads to societal benefit. Social studies of science and assessments of scientific and engineering research speak to the need for a more critical approach to the noble intentions underlying these assumptions. "Science Outside the Lab" is a program designed to help early-career scientists and engineers understand the complexities of science and engineering policy. Assessment of the program entailed a pre-, post-, and 1 year follow up survey to gauge student perspectives on relationships between science and society, as well as a pre-post concept map exercise to elicit student conceptualizations of science policy. Students leave Science Outside the Lab with greater humility about the role of scientific expertise in science and engineering policy; greater skepticism toward linear notions of scientific advances benefiting society; a deeper, more nuanced understanding of the actors involved in shaping science policy; and a continued appreciation of the contributions of science and engineering to society. The study presents an efficacious program that helps scientists and engineers make inroads into macroethical debates, reframe the ways in which they think about values of science and engineering in society, and more thoughtfully engage with critical mediators of science and society relationships: policy makers and policy processes.

  8. Understanding Magmatic Timescales and Magma Dynamics in Proterozoic Anorthosites: a Geochronological Investigation of the Kunene Complex (Angola)

    Science.gov (United States)

    Brower, A. M.; Corfu, F.; Bybee, G. M.; Lehmann, J.; Owen-Smith, T.

    2016-12-01

    The Kunene Anorthosite Complex, located in south west Angola, is one of the largest massif-type anorthosite intrusions on Earth, with an areal extent of at least 18 000 km2. Previous studies considered the Complex to consist of a series of coalesced plutons. However, the ages and relative emplacement sequence of these plutons are unknown. Understanding the relative timing of the pluton emplacement is crucial for understanding how these enigmatic magmas form and how they rise through the crust. Here we present new high precision U-Pb ID-TIMS ages (n=10) on zircons and baddeleyites for many of the coalesced plutons across the 300-km-long anorthositic complex. These new geochronological results reveal subtle variations in crystallization age between the coalesced plutons. There is no gradual age progression between plutons, but distinct groupings of ages (Fig.1). Age clusters of 1379.8 ± 2 Ma (n=5) occur north of the Red Granite NE-SW-striking intrusions, whereas in the south there is an older age grouping of 1390.4 ± 2.3 (n=3). Two additional ages of 1400.5 ± 1.3 in the centre and 1438.4 ± 1.1 Ma in the south east have been obtained. These results indicate that the Kunene anorthosites were emplaced over 60 Ma and may suggest long-lived magmatic systems and/or slowly ascending plutons. We also find a link between pluton composition and age. In general, leuconoritic domains are older than the leucotroctolitic domains. This may imply that the first pulses of magma received a greater degree of contamination, forcing the broadly basaltic magma to produce orthopyroxene as the main mafic phase. The later pulses receive less contamination as they ascend through the already partially melted crust, producing olivine as the mafic phase and deforming the older domains. This study reiterates the multiphase petrogenesis of Proterozoic anorthosites and sheds light on the assembly of crystal-rich magmas as they ascend through the crust.

  9. Implementing Health in All Policies - Time and Ideas Matter Too! Comment on "Understanding the Role of Public Administration in Implementing Action on the Social Determinants of Health and Health Inequities".

    Science.gov (United States)

    Clavier, Carole

    2016-06-20

    Carey and Friel suggest that we turn to knowledge developed in the field of public administration, especially new public governance, to better understand the process of implementing health in all policies (HiAP). In this commentary, I claim that theories from the policy studies bring a broader view of the policy process, complementary to that of new public governance. Drawing on the policy studies, I argue that time and ideas matter to HiAP implementation, alongside with interests and institutions. Implementing HiAP is a complex process considering that it requires the involvement and coordination of several policy sectors, each with their own interests, institutions and ideas about the policy. Understanding who are the actors involved from the various policy sectors concerned, what context they evolve in, but also how they own and frame the policy problem (ideas), and how this has changed over time, is crucial for those involved in HiAP implementation so that they can relate to and work together with actors from other policy sectors. © 2016 by Kerman University of Medical Sciences.

  10. Implementing Health in All Policies – Time and Ideas Matter Too!; Comment on “Understanding the Role of Public Administration in Implementing Action on the Social Determinants of Health and Health Inequities”

    Directory of Open Access Journals (Sweden)

    Carole Clavier

    2016-10-01

    Full Text Available Carey and Friel suggest that we turn to knowledge developed in the field of public administration, especially new public governance, to better understand the process of implementing health in all policies (HiAP. In this commentary, I claim that theories from the policy studies bring a broader view of the policy process, complementary to that of new public governance. Drawing on the policy studies, I argue that time and ideas matter to HiAP implementation, alongside with interests and institutions. Implementing HiAP is a complex process considering that it requires the involvement and coordination of several policy sectors, each with their own interests, institutions and ideas about the policy. Understanding who are the actors involved from the various policy sectors concerned, what context they evolve in, but also how they own and frame the policy problem (ideas, and how this has changed over time, is crucial for those involved in HiAP implementation so that they can relate to and work together with actors from other policy sectors.

  11. Understanding Litter Input Controls on Soil Organic Matter Turnover and Formation are Essential for Improving Carbon-Climate Feedback Predictions for Arctic, Tundra Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Wallenstein, Matthew [Colorado State Univ., Fort Collins, CO (United States)

    2017-12-05

    The Arctic region stored vast amounts of carbon (C) in soils over thousands of years because decomposition has been limited by cold, wet conditions. Arctic soils now contain roughly as much C that is contained in all other soils across the globe combined. However, climate warming could unlock this oil C as decomposition accelerates and permafrost thaws. In addition to temperature-driven acceleration of decomposition, several additional processes could either counteract or augment warming-induced SOM losses. For example, increased plant growth under a warmer climate will increase organic matter inputs to soils, which could fuel further soil decomposition by microbes, but will also increase the production of new SOM. Whether Arctic ecosystems store or release carbon in the future depends in part on the balance between these two counteracting processes. By differentiating SOM decomposition and formation and understanding the drivers of these processes, we will better understand how these systems function. We did not find evidence of priming under current conditions, defined as an increase in the decomposition of native SOM stocks. This suggests that decomposition is unlikely to be further accelerated through this mechanism. We did find that decomposition of native SOM did occur when nitrogen was added to these soils, suggesting that nitrogen limits decomposition in these systems. Our results highlight the resilience and extraordinary C storage capacity of these soils, and suggest shrub expansion may partially mitigate C losses from decomposition of old SOM as Arctic soils warm.

  12. The renewable energy industry in Massachussetts as a complex system: Developing a shared understanding for policy making

    Science.gov (United States)

    Jones, Charles A.

    A model-based field study was conducted to understand the mental models of participants in the photovoltaic industry in Massachusetts, with the purpose of understanding of how that industry works as a complex system. Mental models of industry participants are important, both as the holders of the best system information and as the critical actors in any policy solution. Experts from manufacturing, installation, development, policy, and advocacy sectors were interviewed. The knowledge they conveyed was expressed as a set system dynamics models; these models were characterized, compared, and combined in order to answer the following research questions: What are the mental models of participants? How widely are mental models shared among participants? What is the combined model of the system? How accurate are these models? Given these models, what policies would lead to success? The system described by informants is revealed as one of distributed and embedded agency---actors have the ability to take meaningful action, but that action and its effects are limited by the complexity of the system and by the actions of other actors. Both the growth of the industry and constraints on the growth occur through dynamic processes, many however outside local control. Mental models are shared in clusters of informants, with some differences between these groupings. Informants vary on the level of aggregation needed to express their descriptions and on the most important dynamic force. However, many processes are commonly perceived across informants, they perceive the same system trajectories, and the behavior of the simulation models constructed from their mental models was similar. A combined model was constructed which included a full range of potential feedback loops within an abstracted version of the described system. Testing for policy using the combined model reveals that the structures necessary for growth are present, as expected. Under several reasonable conditions

  13. Chemical imaging techniques for the analysis of complex mixtures: New application to the characterization of ritual matters on African wooden statuettes

    International Nuclear Information System (INIS)

    Mazel, Vincent; Richardin, Pascale; Touboul, David; Brunelle, Alain; Walter, Philippe; Laprevote, Olivier

    2006-01-01

    Chemical imaging techniques, based on the combination of microscopy and spectroscopy, are well suited to study both the composition and the spatial organization of heterogeneous complex mixtures of organic and mineral matter. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), followed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and Fourier transform infrared microscopy (FTIR microscopy) have been applied to non-destructive analysis of micro-samplings of ritual matters deposited on the surface of African wooden statuettes. With a very careful preparation, using ultramicrotomy on embedded samples, it was possible to perform successively all the measurements on a single fragment. Comparison and superposition of the different chemical images, obtained on a sample from a significant actual artefact, have allowed us to identify minerals (clays, quartz and calcium carbonate), proteins, starch, urate salts and lipids and to map their spatial distribution

  14. Magnetic resonance imaging and diffusion-weighted imaging of normal-appearing white matter in children and young adults with tuberous sclerosis complex

    International Nuclear Information System (INIS)

    Arulrajah, Sahayini; Ertan, Gulhan; Tekes, Aylin; Huisman, Thierry A.G.M.; Jordan, Lori; Khaykin, Elizabeth; Izbudak, Izlem

    2009-01-01

    Patients with tuberous sclerosis complex (TSC) frequently present with neurocognitive deficits which may be related to impaired white matter maturation. The purposes of our study were (a) to evaluate the white matter maturation in children and young adults with TSC by comparing the apparent diffusion coefficient (ADC) values of normal-appearing white matter (NAWM) with age-matched healthy controls and (b) to determine the association of NAWM-ADC values with the severity of neurological symptoms in TSC patients. Twenty-three TSC patients who underwent magnetic resonance imaging/diffusion-weighted imaging between January 2000 and January 2009 were studied. ADC values of NAWM were measured in the frontal, parietal, occipital lobes, and in the pons. ADC data were compared with age-matched normative data derived from healthy controls. Patients were neurologically scored by a pediatric neurologist. Two-sample t tests and linear regression were conducted using STATA software. ADC values of NAWM were higher in TSC patients compared with healthy controls; the increase, however, only reached statistical significance in the frontal white matter and pons in the age group between 96 and 144 months and in the right parietal and occipital white matter in the age group above 144 months. There was no significant change in neurological severity score per unit increase in ADC measurement. ADC values of NAWM appear increased in TSC patients. The abnormal ADC values suggest that myelination may be delayed/impaired in TSC patients, which could explain global neurocognitive deficits. Larger prospective studies, including diffusion tensor imaging, are necessary to validate our results. (orig.)

  15. Magnetic resonance imaging and diffusion-weighted imaging of normal-appearing white matter in children and young adults with tuberous sclerosis complex

    Energy Technology Data Exchange (ETDEWEB)

    Arulrajah, Sahayini; Ertan, Gulhan; Tekes, Aylin; Huisman, Thierry A.G.M. [Johns Hopkins Hospital, Division of Pediatric Radiology, Department of Radiology and Radiological Science, Baltimore, MD (United States); Jordan, Lori [Johns Hopkins School of Public Health, Division of Pediatric Neurology, Baltimore, MD (United States); Khaykin, Elizabeth [Johns Hopkins School of Public Health, Department of Mental Health, Baltimore, MD (United States); Izbudak, Izlem [Johns Hopkins Hospital, Division of Neuroradiology, Department of Radiology and Radiological Science, Baltimore, MD (United States)

    2009-11-15

    Patients with tuberous sclerosis complex (TSC) frequently present with neurocognitive deficits which may be related to impaired white matter maturation. The purposes of our study were (a) to evaluate the white matter maturation in children and young adults with TSC by comparing the apparent diffusion coefficient (ADC) values of normal-appearing white matter (NAWM) with age-matched healthy controls and (b) to determine the association of NAWM-ADC values with the severity of neurological symptoms in TSC patients. Twenty-three TSC patients who underwent magnetic resonance imaging/diffusion-weighted imaging between January 2000 and January 2009 were studied. ADC values of NAWM were measured in the frontal, parietal, occipital lobes, and in the pons. ADC data were compared with age-matched normative data derived from healthy controls. Patients were neurologically scored by a pediatric neurologist. Two-sample t tests and linear regression were conducted using STATA software. ADC values of NAWM were higher in TSC patients compared with healthy controls; the increase, however, only reached statistical significance in the frontal white matter and pons in the age group between 96 and 144 months and in the right parietal and occipital white matter in the age group above 144 months. There was no significant change in neurological severity score per unit increase in ADC measurement. ADC values of NAWM appear increased in TSC patients. The abnormal ADC values suggest that myelination may be delayed/impaired in TSC patients, which could explain global neurocognitive deficits. Larger prospective studies, including diffusion tensor imaging, are necessary to validate our results. (orig.)

  16. New understanding of the complex structure of knee menisci: implications for injury risk and repair potential for athletes.

    Science.gov (United States)

    Rattner, J B; Matyas, J R; Barclay, L; Holowaychuk, S; Sciore, P; Lo, I K Y; Shrive, N G; Frank, C B; Achari, Y; Hart, D A

    2011-08-01

    Menisci help maintain the structural integrity of the knee. However, the poor healing potential of the meniscus following a knee injury can not only end a career in sports but lead to osteoarthritis later in life. Complete understanding of meniscal structure is essential for evaluating its risk for injury and subsequent successful repair. This study used novel approaches to elucidate meniscal architecture. The radial and circumferential collagen fibrils in the meniscus were investigated using novel tissue-preparative techniques for light and electron microscopic studies. The results demonstrate a unique architecture based on differences in the packaging of the fundamental collagen fibrils. For radial arrays, the collagen fibrils are arranged in parallel into ∼10 μm bundles, which associate laterally to form flat sheets of varying dimensions that bifurcate and come together to form a honeycomb network within the body of the meniscus. In contrast, the circumferential arrays display a complex network of collagen fibrils arranged into ∼5 μm bundles. Interestingly, both types of architectural organization of collagen fibrils in meniscus are conserved across mammalian species and are age and sex independent. These findings imply that disruptions in meniscal architecture following an injury contribute to poor prognosis for functional repair. © 2010 John Wiley & Sons A/S.

  17. Simulation model 'methane' as a tool for effective biogas production during anaerobic conversion of complex organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Vavilin, V A; Vasiliev, V B; Ponomarev, A V; Rytow, S V [Russian Academy of Sciences, Moscow (Russian Federation). Water Problems Inst.

    1994-01-01

    A universal basic model of anaerobic conversion of complex organic material is suggested. The model can be used for investigating the start-up experiments for food industry wastewater. General results obtained in the model agreed with the experimental data. An explanation of a complex dynamic behaviour of the anaerobic system is suggested. (author)

  18. Toward a Simple Framework for Understanding the Influence of Litter Quality on Vertical and Horizontal Patterns of Soil Organic Matter Pools

    Science.gov (United States)

    Craig, M.; Phillips, R.

    2016-12-01

    Decades of research have revealed that plant litter quality fundamentally influences soil organic matter (SOM) properties. Yet we lack the predictive frameworks necessary to up-scale our understanding of these dynamics in biodiverse systems. Given that ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) plants are thought to differ in their litter quality, we ask whether this dichotomy represents a framework for understanding litter quality effects on SOM in temperate forests. To do this, we sampled soils from 250 spatially referenced locations within a 25-Ha plot where 28,000 trees had been georeferenced, and analyzed spatial patterns of plant and SOM properties. We then examined the extent to which the dominance of AM- versus EM-trees relates to 1) the quality of litter inputs to forest soils and 2) the horizontal and vertical distribution of SOM fractions. We found that leaf litters produced by EM-associated trees were generally of lower quality, having a lower concentration of soluble compounds and higher C:N. Concomitant with this, we observed higher soil C:N under EM trees. Interestingly, this reflected greater N storage in AM-dominated soils rather than greater C storage in EM-dominated soils. These patterns were driven by the storage of SOM in N-rich fractions in AM-dominated soils. Specifically, trees with high litter quality were associated with greater amounts of deep and mineral-associated SOM; pools that are generally considered stable. Our results support the recent contention that high-quality plant inputs should lead to the formation of stable SOM and suggest that the AM-EM framework may provide a way forward for representing litter quality effects on SOM in earth system models.

  19. Effects of molecular composition of natural organic matter on ferric iron complexation at circumneutral pH.

    Science.gov (United States)

    Fujii, Manabu; Imaoka, Akira; Yoshimura, Chihiro; Waite, T D

    2014-04-15

    Thermodynamic and kinetic parameters for ferric iron (Fe[III]) complexation by well-characterized humic substances (HS) from various origins were determined by a competitive ligand method with 5-sulfosalicylic acid at circumneutral pH (6.0-8.0) and an ionic strength of ∼0.06 M. The measured Fe binding properties including conditional stability constants and complexation capacities ranged over more than 2 orders of magnitude, depending on the origin and the particular operationally defined fraction of HS examined. Statistical comparison of the complexation parameters to a range of chemical properties of the HS indicated a strong positive correlation between Fe(III) complexation capacity and aromatic carbon content in the HS at all pHs examined. In contrast, the complexation capacity was determined to be up to a few orders of magnitude smaller than the concentration of carboxylic and phenolic groups present. Therefore, specific functional groups including those resident in the proximity of aromatic structures within the HS are likely preferable for Fe(III) coordination under the conditions examined. Overall, our results suggest that the concentration of dissolved Fe(III) complexes in natural waters is substantially influenced by variation in HS characteristics in addition to other well-known factors such as HS concentration and nature and concentration of competing cations present.

  20. A study of primary school teachers’ conceptual understanding on states of matter and their changes based on their job locations (case study at Ambon island in Moluccas-Indonesia)

    Science.gov (United States)

    Banawi, A.; Sopandi, W.; Kadarohman, A.; Solehuddin, M.

    2018-05-01

    The research aims to describe primary school teachers’ conceptual understandings about states of matter and their changes. The method was descriptive which involved 15 primary school teachers from three different school locations. They were from urban school (CS1), sub-urban school (CS2), and rular school (CS3) at Ambon Island on 2016/2017 academic year. The research instrument was a multiple-choice test combined with both essay and confidence level of their answers. The test was used to measure teachers’ understanding levels about states of matter and their changes. They were macroscopic, sub-microscopic and symbolic levels. Teachers’ understanding levels were classified into following categorization, they were understand, partly understand, misconception, and do not understand. The results show that primary school teachers’ conceptual understanding is varied based on their job locations and primary school teachers’ level understanding. Generally, primary school teachers’ conceptual understandings at sub-urban location (CS2) are better than those of both of urban (CS1) and rular locations (CS3). The results suggest that teachers need improvement to make better primary school teachers’ conceptual understanding. It can be on the job training and in service training activities. We also need a further research in order to investigate the program effectiveness.

  1. Underestimation of phosphorus fraction change in the supernatant after phosphorus adsorption onto iron oxides and iron oxide-natural organic matter complexes.

    Science.gov (United States)

    Yan, Jinlong; Jiang, Tao; Yao, Ying; Wang, Jun; Cai, Yuanli; Green, Nelson W; Wei, Shiqiang

    2017-05-01

    The phosphorus (P) fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid (HA) complexes were analyzed using the ultrafiltration method in this study. With an initial P concentration of 20mg/L (I=0.01mol/L and pH=7), it was shown that the colloid (1kDa-0.45μm) component of P accounted for 10.6%, 11.6%, 6.5%, and 4.0% of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite (FH), goethite (GE), ferrihydrite-humic acid complex (FH-HA), goethite-humic acid complex (GE-HA), respectively. The oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant. And colloidal adsorbent particles co-existing in the supernatant were another important reason for it. Additionally, dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant. Ultimately, we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P, even when considering other contaminants such as organic pollutants, heavy metal ions, and arsenate at the sediment/soil-water interface in the real environment. Copyright © 2016. Published by Elsevier B.V.

  2. Security matters : privacy in voting and fairness in digital exchange

    NARCIS (Netherlands)

    Jonker, H.L.

    2009-01-01

    Security matters. In the real world, there are various basic mechanisms that provide security. The digital counterparts of these basic mechanisms have been studied and are now well understood. Understanding of more complex security notions has yet to mature. This thesis studies two complex security

  3. Dark Matter Effective Theory

    DEFF Research Database (Denmark)

    Del Nobile, Eugenio; Sannino, Francesco

    2012-01-01

    We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff...... scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties....

  4. Understanding Energy

    Science.gov (United States)

    Menon, Deepika; Shelby, Blake; Mattingly, Christine

    2016-01-01

    "Energy" is a term often used in everyday language. Even young children associate energy with the food they eat, feeling tired after playing soccer, or when asked to turn the lights off to save light energy. However, they may not have the scientific conceptual understanding of energy at this age. Teaching energy and matter could be…

  5. FuturICT: Participatory computing to understand and manage our complex world in a more sustainable and resilient way

    OpenAIRE

    Helbing, D.; Bishop, S.; Conte, R.; Lukowicz, P.; McCarthy, J. B.

    2012-01-01

    We have built particle accelerators to understand the forces that make up our physical world. Yet, we do not understand the princi-ples underlying our strongly connected, techno-socio-economic systems. We have enabled ubiquitous Internet connectivity and instant, global information access. Yet we do not understand how it impacts our be-havior and the evolution of society. To fill the knowledge gaps and keep up with the fast pace at which our world is changing, a Knowledge Accelerator must urg...

  6. A stochastic model for the synthesis and degradation of natural organic matter. Part III: Modeling Cu(II) complexation

    Energy Technology Data Exchange (ETDEWEB)

    Cabaniss, Stephen E. [Department of Chemistry, University of New Mexico, Albuquerque, NM 87131 (United States)], E-mail: cabaniss@unm.edu; Maurice, Patricia A. [Department of Geology and Civil Engineering, University of Notre Dame (United States); Madey, Greg [Department of Computer Science, University of Notre Dame (United States)

    2007-08-15

    An agent-based biogeochemical model has been developed which begins with biochemical precursor molecules and simulates the transformation and degradation of natural organic matter (NOM). This manuscript presents an empirical quantitative structure activity relationship (QSAR) which uses the numbers of ligand groups, charge density and heteroatom density of a molecule to estimate Cu-binding affinity (K{sub Cu}{sup '}) at pH 7.0 and ionic strength 0.10 for the molecules in this model. Calibration of this QSAR on a set of 41 model compounds gives a root mean square error of 0.88 log units and r{sup 2} 0.93. Two simulated NOM assemblages, one beginning with small molecules (tannins, terpenoids, flavonoids) and one with biopolymers (protein, lignin), give markedly different distributions of logK{sub Cu}{sup '}. However, calculations based on these logK{sub Cu}{sup '} distributions agree qualitatively with published experimental Cu(II) titration data from river and lake NOM samples.

  7. Effects of Particulate Organic Matter Complexation and Photo-Irradiation on the Fate and Toxicity of Mercury(II) in Aqueous Systems

    Science.gov (United States)

    Gelfond, C. E.; Kocar, B. D.; Carrasquillo, A. J.

    2015-12-01

    This project investigates how interactions between mercury (Hg) and particulate organic matter (POM) affect the fate, transport, and toxicity of Hg in the environment. Previous studies have evaluated the coordination of dissolved organic matter (DOM) with Hg, but the coordination of POM with Hg has not been thoroughly addressed. Owing to a high density of reactive functional groups, POM will sorb appreciable quantities of Hg, resulting in a large pool of Hg susceptible to organic matter dependent transformations. Particulate organic carbon is also susceptible photolysis, hence chemical changes induced by irradiation by natural sunlight is also important. Further, photo-reduction of Hg(II) to elemental mercury in the presence of DOM has been observed, yet studies examining this process with Hg(II) complexed to POM are less exhaustive. Here, we illustrate that POM derived from fresh plant detritus is a powerful sorbent of Hg(II), and sorbent properties are altered during POM photolysis. Further, we examine redox transformations of Hg(II), and examine functional groups that contribute to mercury association with POM. Batch sorption isotherms of Hg to dark and irradiated POM from ground Phragmites australis ("common reed") were performed and data was collected using ICP-MS. Coordination of Hg to POM was lower in the irradiated samples, resulting from the decrease in Hg-associated (reduced) sulfur bearing functional groups as measured using X-ray adsorption near-edge spectroscopy (XANES) and extended x-ray adsorption fine structure (EXAFS). Further analysis of the dark and irradiated POM was performed using FT-IR microscopy and STXM to determine changes in distribution and alteration of functional groups responsible for Hg sorption to POM.

  8. Quality control considerations for size exclusion chromatography with online ICP-MS: a powerful tool for evaluating the size dependence of metal-organic matter complexation.

    Science.gov (United States)

    McKenzie, Erica R; Young, Thomas M

    2013-01-01

    Size exclusion chromatography (SEC), which separates molecules based on molecular volume, can be coupled with online inductively coupled plasma mass spectrometry (ICP-MS) to explore size-dependent metal-natural organic matter (NOM) complexation. To make effective use of this analytical dual detector system, the operator should be mindful of quality control measures. Al, Cr, Fe, Se, and Sn all exhibited columnless attenuation, which indicated unintended interactions with system components. Based on signal-to-noise ratio and peak reproducibility between duplicate analyses of environmental samples, consistent peak time and height were observed for Mg, Cl, Mn, Cu, Br, and Pb. Al, V, Fe, Co, Ni, Zn, Se, Cd, Sn, and Sb were less consistent overall, but produced consistent measurements in select samples. Ultrafiltering and centrifuging produced similar peak distributions, but glass fiber filtration produced more high molecular weight (MW) peaks. Storage in glass also produced more high MW peaks than did plastic bottles.

  9. Stability constants important to the understanding of plutonium in environmental waters, hydroxy and carbonate complexation of PuO2+

    International Nuclear Information System (INIS)

    Bennett, D.A.; Lawrence Berkeley Lab., CA

    1990-01-01

    The formation constants for the reactions PuO 2 + + H 2 O = PuO 2 (OH) + H + and PuO 2 + + CO 3 2 = PuO 2 (CO 3 ) - were determined in aqueous sodium perchlorate solutions by laser-induced photoacoustic spectroscopy. The molar absorptivity of the PuO 2 + band at 569 nm decreased with increasing hydroxide concentration. Similarly, spectral changes occurred between 540 and 580 nm as the carbonate concentration was increased. The absorption data were analyzed by the non-linear least-squares program SQUAD to yield complexation constants. Using the specific ion interaction theory, both complexation constants were extrapolated to zero ionic strength. These thermodynamic complexation constants were combined with the oxidation-reduction potentials of Pu to obtain Eh versus pH diagrams. 120 refs., 35 figs., 12 tabs

  10. What matters to infrequent customers: a pragmatic approach to understanding perceived value and intention to revisit trendy coffee café.

    Science.gov (United States)

    Ting, Hiram; Thurasamy, Ramayah

    2016-01-01

    Notwithstanding the rise of trendy coffee café, little is done to investigate revisit intention towards the café in the context of developing markets. In particular, there is a lack of study which provides theoretical and practical explanation to the perceptions and behaviours of infrequent customers. Hence, the study aims to look into the subject matter by using the theory of reasoned action and social exchange theory as the underpinning basis. The framework proposed by Pine and Gilmore (Strat Leadersh 28:18-23, 2000), which asserts the importance of product quality, service quality and experience quality in a progressive manner, is used to decompose perceived value in the model so as to determine their effects on intention to revisit the café. Given the importance to gain practical insights into revisit intention of infrequent customers, pragmatism stance is assumed. Explanatory sequential mixed-method design is thus adopted whereby qualitative approach is used to confirm and complement quantitative findings. Self-administered questionnaire-based survey is first administered before personal interview is carried out at various cafés. Partial least squares structural equation modelling and content analysis are appropriated successively. In the quantitative findings, although product quality, service quality and experience quality are found to have positive effect on perceived value and revisit intention towards trendy coffee café, experience quality is found to have the greater effect than the others among the infrequent customers. The qualitative findings not only confirm their importance, but most importantly explain the favourable impressions they have at trendy coffee café based on their last in-store experience. While product and service quality might not necessary stimulate them to revisit trendy coffee café, experience quality driven by purposes of visit would likely affect their intention to revisit. As retaining customers is of utmost importance to

  11. Sorptive fractionation of organic matter and formation of organo-hydroxy-aluminum complexes during litter biodegradation in the presence of gibbsite

    Science.gov (United States)

    Heckman, K.; Grandy, A. S.; Gao, X.; Keiluweit, M.; Wickings, K.; Carpenter, K.; Chorover, J.; Rasmussen, C.

    2013-11-01

    Solid and aqueous phase Al species are recognized to affect organic matter (OM) stabilization in forest soils. However, little is known about the dynamics of formation, composition and dissolution of organo-Al hydroxide complexes in microbially-active soil systems, where plant litter is subject to microbial decomposition in close proximity to mineral weathering reactions. We incubated gibbsite-quartz mineral mixtures in the presence of forest floor material inoculated with a native microbial consortium for periods of 5, 60 and 154 days. At each time step, samples were density separated into light (2.0 g cm-3) fractions. The light fraction was mainly comprised of particulate organic matter, while the intermediate and heavy density fractions contained moderate and large amounts of Al-minerals, respectively. Multi-method interrogation of the fractions indicated the intermediate and heavy fractions differed both in mineral structure and organic compound composition. X-ray diffraction analysis and SEM/EDS of the mineral component of the intermediate fractions indicated some alteration of the original gibbsite structure into less crystalline Al hydroxide and possibly proto-imogolite species, whereas alteration of the gibbsite structure was not evident in the heavy fraction. DRIFT, Py-GC/MS and STXM/NEXAFS results all showed that intermediate fractions were composed mostly of lignin-derived compounds, phenolics, and polysaccharides. Heavy fraction organics were dominated by polysaccharides, and were enriched in proteins, N-bearing compounds, and lipids. The source of organics appeared to differ between the intermediate and heavy fractions. Heavy fractions were enriched in 13C with lower C/N ratios relative to intermediate fractions, suggesting a microbial origin. The observed differential fractionation of organics among hydroxy-Al mineral types suggests that microbial activity superimposed with abiotic mineral-surface-mediated fractionation leads to strong density

  12. Complexities in understanding the role of compensation-related factors on recovery from whiplash-associated disorders : discussion paper 2

    NARCIS (Netherlands)

    Carroll, Linda J.; Connelly, Luke B.; Spearing, Natalie M.; Cote, Pierre; Buitenhuis, Jan; Kenardy, Justin

    2011-01-01

    Study Design. Focused discussion. Objective. To present some of the complexities in conducting research on the role of compensation and compensation-related factors in recovery from whiplash-associated disorders (WAD) and to suggest directions for future research. Summary of Background Data. There

  13. The development of second-order social cognition and its relation with complex language understanding and working memory

    NARCIS (Netherlands)

    Arslan, Burcu; Hohenberger, Annette; Verbrugge, Rineke

    2012-01-01

    In this study, the development of second-order social cognition and its possible relationship with language and memory were investigated. For this reason two second-order false belief tasks (FBT_2), a short term memory task (WST), a complex working memory task (LST), a linguistic perspective-taking

  14. Methodology to Model and Understand the Complexities of Social, Economic,and Governance Interactions for Regional Assessment in Kenya

    Science.gov (United States)

    2012-07-01

    narcotics trafficking in Mexico , complex commuter rail systems, and nuclear weapons proliferation. Systemigrams provide us with “a basis for systems...1997-1998. Not only did the flooding destroy bridges, roads, and crops, but it also created epidemics of cholera and malaria (CIA, 2011). In a large

  15. Using a Complexity-Based Perspective to Better Understand the Relationships among Mentoring, School Conflicts, and Novice Retention

    Science.gov (United States)

    Waterman, Sheryn Elaine Spencer

    2011-01-01

    In this study I used complexity-thinking, ecologically-based sustainable capacity-building, narrative methodology, and pragmatism to explore the relationships among mentoring, conflict, and novice retention. In order to explore these relationships, I constructed stories from my interviews with six mentor-novice dyads in a southeastern 9-12 high…

  16. Use of biological priors enhances understanding of genetic architecture and genomic prediction of complex traits within and between dairy cattle breeds

    DEFF Research Database (Denmark)

    Fang, Lingzhao; Sahana, Goutam; Ma, Peipei

    2017-01-01

    sequence variants in Holstein (HOL) and Jersey (JER) cattle were analysed. We first carried out a post-GWAS analysis in a HOL training population to assess the degree of enrichment of the association signals in the gene regions defined by each GO term. We then extended the genomic best linear unbiased......BACKGROUND: A better understanding of the genetic architecture underlying complex traits (e.g., the distribution of causal variants and their effects) may aid in the genomic prediction. Here, we hypothesized that the genomic variants of complex traits might be enriched in a subset of genomic...

  17. Using Memes and Memetic Processes to Explain Social and Conceptual Influences on Student Understanding about Complex Socio-Scientific Issues

    Science.gov (United States)

    Yoon, Susan

    2008-01-01

    This study investigated seventh grade learners' decision making about genetic engineering concepts and applications. A social network analyses supported by technology tracked changes in student understanding with a focus on social and conceptual influences. Results indicated that several social and conceptual mechanisms potentially affected how…

  18. Volume transmission and receptor-receptor interactions in heteroreceptor complexes: understanding the role of new concepts for brain communication

    Directory of Open Access Journals (Sweden)

    Kjell Fuxe

    2016-01-01

    Full Text Available The discovery of the central monoamine neurons not only demonstrated novel types of brain stem neurons forming global terminal networks all over the brain and the spinal cord, but also to a novel type of communication called volume transmission. It is a major mode of communication in the central nervous system that takes places in the extracellular fluid and the cerebral spinal fluid through diffusion and flow of molecules, like neurotransmitters and extracellular vesicles. The integration of synaptic and volume transmission takes place through allosteric receptor-receptor interactions in heteroreceptor complexes. These heterocomplexes represent major integrator centres in the plasma membrane and their protomers act as moonlighting proteins undergoing dynamic changes and their structure and function. In fact, we propose that the molecular bases of learning and memory can be based on the reorganization of multiples homo and heteroreceptor complexes into novel assembles in the post-junctional membranes of synapses.

  19. Contribution of Regional White Matter Integrity to Visuospatial Construction Accuracy, Organizational Strategy, and Memory for a Complex Figure in Abstinent Alcoholics.

    Science.gov (United States)

    Rosenbloom, Margaret J; Sassoon, Stephanie A; Pfefferbaum, Adolf; Sullivan, Edith V

    2009-12-01

    Visuospatial construction ability as used in drawing complex figures is commonly impaired in chronic alcoholics, but memory for such information can be enhanced by use of a holistic drawing strategy during encoding. We administered the Rey-Osterrieth Complex Figure Test (ROCFT) to 41 alcoholic and 38 control men and women and assessed the contribution of diffusion tensor imaging (DTI) measures of integrity of selected white matter tracts to ROCFT copy accuracy, copy strategy, and recall accuracy. Although alcoholics copied the figure less accurately than controls, a more holistic strategy at copy was associated with better recall in both groups. Greater radial diffusivity, reflecting compromised myelin integrity, in occipital forceps and external capsule was associated with poorer copy accuracy in both groups. Lower FA, reflecting compromised fiber microstructure in the inferior cingulate bundle, which links frontal and medial temporal episodic memory systems, was associated with piecemeal copy strategy and poorer immediate recall in the alcoholics. The correlations were generally modest and should be considered exploratory. To the extent that the inferior cingulate was relatively spared in alcoholics, it may have provided an alternative pathway to the compromised frontal system for successful copy strategy and, by extension, aided recall.

  20. Analyzing Learning about Conservation of Matter in Students while Adapting to the Needs of a School

    Science.gov (United States)

    Doucerain, Marina; Schwartz, Marc S.

    2010-01-01

    We probed the impact of two teaching strategies, "guided inquiry" and "argumentation," on students' conceptual understanding of the conservation of matter. Conservation of matter is a central concept in middle school science curriculum and a prerequisite upon which rests more complex constructs in chemistry. The results indicate that guided…

  1. Using a Virtual Tablet Machine to Improve Student Understanding of the Complex Processes Involved in Tablet Manufacturing.

    Science.gov (United States)

    Mattsson, Sofia; Sjöström, Hans-Erik; Englund, Claire

    2016-06-25

    Objective. To develop and implement a virtual tablet machine simulation to aid distance students' understanding of the processes involved in tablet production. Design. A tablet simulation was created enabling students to study the effects different parameters have on the properties of the tablet. Once results were generated, students interpreted and explained them on the basis of current theory. Assessment. The simulation was evaluated using written questionnaires and focus group interviews. Students appreciated the exercise and considered it to be motivational. Students commented that they found the simulation, together with the online seminar and the writing of the report, was beneficial for their learning process. Conclusion. According to students' perceptions, the use of the tablet simulation contributed to their understanding of the compaction process.

  2. Soft matter physics

    CERN Document Server

    Doi, Masao

    2013-01-01

    Soft matter (polymers, colloids, surfactants and liquid crystals) are an important class of materials in modern technology. They also form the basis of many future technologies, for example in medical and environmental applications. Soft matter shows complex behaviour between fluids and solids, and used to be a synonym of complex materials. Due to the developments of the past two decades, soft condensed matter can now be discussed on the same sound physical basis as solid condensedmatter. The purpose of this book is to provide an overview of soft matter for undergraduate and graduate students

  3. Nice to know you: Positive emotions, self–other overlap, and complex understanding in the formation of a new relationship

    OpenAIRE

    WAUGH, CHRISTIAN E.; FREDRICKSON, BARBARA L.

    2006-01-01

    Based on Fredrickson's ((1998). What good are positive emotions? Review of General Psychology, 2, 300–319.; (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56, 218–226) broaden-and-build theory and Aron and Aron's ((1986). Love as expansion of the self: Understanding attraction and satisfaction. New York: Hemisphere) self-expansion theory, it was hypothesized that positive emotions broaden people's feeling...

  4. Understanding Free Radicals: Isolating Active Thylakoid Membranes and Purifying the Cytochrome b6f Complex for Superoxide Generation Studies

    Directory of Open Access Journals (Sweden)

    Jason Stofleth

    2012-01-01

    Full Text Available All life persists in an environment that is rich in molecular oxygen. The production of oxygen free radicals, or superoxide, is a necessary consequence of the biogenesis of energy in cells. Both mitochondrial and photosynthetic electron transport chains have been found to produce superoxide associated with cell differentiation, proliferation, and cell death, thereby contributing to the effects of aging. Aerobic respiration in mitochondria consumes oxygen, whereas photosynthesis in chloroplasts or cyanobacteria produces oxygen. The increased concentration of molecular oxygen may serve to allow greater availability for the production of superoxide by cytochrome bc complexes in photosynthetic membranes compared to those of mitochondrial membranes. The isolation of well-coupled chloroplasts, containing the cytochrome b6f complex of oxygenic photosynthesis, is a vital initial step in the process of comparing the rate of production of superoxide to those of the homologous cytochrome bc1 complex of aerobic respiration. It is necessary to determine if the isolated chloroplasts have retained their oxygengenerating capability after isolation by an oxygen evolution assay with a Clark-type electrode. A necessary second step, which is the isolation of cytochrome b6f from spinach, has yet to be successfully performed. Oxygen measurements taken from chloroplasts in the presence of the uncoupler, NH4Cl, exhibited a rate of oxygen evolution over three times greater at 344 +/- 18 μmol O2/mg Chlorophyll a/hr than the rate of oxygen evolution without uncoupler at 109 +/- 29 μmol O2/mg Chlorophyll a/hr. These data demonstrate that the technique used to isolate spinach chloroplasts preserves their light-driven electron-transport activity, making them reliable for future superoxide assays.

  5. Complexities in understanding the role of compensation-related factors on recovery from whiplash-associated disorders: discussion paper 2.

    Science.gov (United States)

    Carroll, Linda J; Connelly, Luke B; Spearing, Natalie M; Côté, Pierre; Buitenhuis, Jan; Kenardy, Justin

    2011-12-01

    Focused discussion. To present some of the complexities in conducting research on the role of compensation and compensation-related factors in recovery from whiplash-associated disorders (WAD) and to suggest directions for future research. There is divergence of opinion, primary research findings, and systematic reviews on the role of compensation and/or compensation-related factors in WAD recovery. The topic of research of compensation/compensation-related factors was discussed at an international summit meeting of 21 researchers from diverse fields of scientific enquiry. This article summarizes the main points raised in that discussion. Traffic injury compensation is a complex sociopolitical construct, which varies widely across jurisdictions. This leads to conceptual and methodological challenges in conducting and interpreting research in this area. It is important that researchers and their audiences be clear about what aspect of the compensation system is being addressed, what compensation-related variables are being studied, and what social/economic environment the compensation system exists in. In addition, summit participants also recommended that nontraditional, sophisticated study designs and analysis strategies be employed to clarify the complex causal pathways and mechanisms of effects. Care must be taken by both researchers and their audiences not to overgeneralize or confuse different aspects of WAD compensation. In considering the role of compensation/compensation-related factors on WAD and WAD recovery, it is important to retain a broad-based conceptualization of the range of biological, psychological, social, and economic factors that combine and interact to define and determine how people recover from WAD.

  6. Regional molecular and cellular differences in the female rabbit Achilles tendon complex: potential implications for understanding responses to loading.

    Science.gov (United States)

    Huisman, Elise S; Andersson, Gustav; Scott, Alexander; Reno, Carol R; Hart, David A; Thornton, Gail M

    2014-05-01

    The aim of this study was: (i) to analyze the morphology and expression of extracellular matrix genes in six different regions of the Achilles tendon complex of intact normal rabbits; and (ii) to assess the effect of ovariohysterectomy (OVH) on the regional expression of these genes. Female New Zealand White rabbits were separated into two groups: (i) intact normal rabbits (n = 4); and (ii) OVH rabbits (n = 8). For each rabbit, the Achilles tendon complex was dissected into six regions: distal gastrocnemius (DG); distal flexor digitorum superficialis; proximal lateral gastrocnemius (PLG); proximal medial gastrocnemius; proximal flexor digitorum superficialis; and paratenon. For each of the regions, hematoxylin and eosin staining was performed for histological evaluation of intact normal rabbit tissues and mRNA levels for proteoglycans, collagens and genes associated with collagen regulation were assessed by real-time reverse transcription-quantitative polymerase chain reaction for both the intact normal and OVH rabbit tissues. The distal regions displayed a more fibrocartilaginous phenotype. For intact normal rabbits, aggrecan mRNA expression was higher in the distal regions of the Achilles tendon complex compared with the proximal regions. Collagen Type I and matrix metalloproteinase-2 expression levels were increased in the PLG compared to the DG in the intact normal rabbit tissues. The tendons from OVH rabbits had lower gene expressions for the proteoglycans aggrecan, biglycan, decorin and versican compared with the intact normal rabbits, although the regional differences of increased aggrecan expression in distal regions compared with proximal regions persisted. The tensile and compressive forces experienced in the examined regions may be related to the regional differences found in gene expression. The lower mRNA expression of the genes examined in the OVH group confirms a potential effect of systemic estrogen on tendon. © 2014 Anatomical Society.

  7. Molecular Studies of Complex Soil Organic Matter Interactions with Metal Ions and Mineral Surfaces using Classical Molecular Dynamics and Quantum Chemistry Methods

    Science.gov (United States)

    Andersen, A.; Govind, N.; Laskin, A.

    2017-12-01

    Mineral surfaces have been implicated as potential protectors of soil organic matter (SOM) against decomposition and ultimate mineralization to small molecules which can provide nutrients for plants and soil microbes and can also contribute to the Earth's elemental cycles. SOM is a complex mixture of organic molecules of biological origin at varying degrees of decomposition and can, itself, self-assemble in such a way as to expose some biomolecule types to biotic and abiotic attack while protecting other biomolecule types. The organization of SOM and SOM with mineral surfaces and solvated metal ions is driven by an interplay of van der Waals and electrostatic interactions leading to partitioning of hydrophilic (e.g. sugars) and hydrophobic (e.g., lipids) SOM components that can be bridged with amphiphilic molecules (e.g., proteins). Classical molecular dynamics simulations can shed light on assemblies of organic molecules alone or complexation with mineral surfaces. The role of chemical reactions is also an important consideration in potential chemical changes of the organic species such as oxidation/reduction, degradation, chemisorption to mineral surfaces, and complexation with solvated metal ions to form organometallic systems. For the study of chemical reactivity, quantum chemistry methods can be employed and combined with structural insight provided by classical MD simulations. Moreover, quantum chemistry can also simulate spectroscopic signatures based on chemical structure and is a valuable tool in interpreting spectra from, notably, x-ray absorption spectroscopy (XAS). In this presentation, we will discuss our classical MD and quantum chemistry findings on a model SOM system interacting with mineral surfaces and solvated metal ions.

  8. A Study of the Development in Fourth, Fifth and Sixth Grade Children of an Understanding of a Particulate Model of Matter.

    Science.gov (United States)

    Ward, Roger Woodmansee

    The study was designed to determine if chronological age is the main factor in a child's ability to develop a particulate concept of matter. Four demonstrations were organized which consisted of a graded series of particle mixing, gas diffusion, dissolving and smoke investigations. The individualized interviews with children were tape recorded. On…

  9. Participatory Ethnographic Evaluation and Research: Reflections on the Research Approach Used to Understand the Complexity of Maternal Health Issues in South Sudan.

    Science.gov (United States)

    Elmusharaf, Khalifa; Byrne, Elaine; Manandhar, Mary; Hemmings, Joanne; O'Donovan, Diarmuid

    2017-07-01

    Many methodological approaches have been used to understand cultural dimensions to maternal health issues. Although a well-designed quantitative survey with a representative sample can provide essential information on trends in behavior, it does not necessarily establish a contextualized understanding of the complexity in which different behaviors occur. This article addresses how contextualized data can be collected in a short time and under conditions in which participants in conflict-affected zones might not have established, or time to establish, trust with the researchers. The solution, the Participatory Ethnographic Evaluation and Research (PEER) approach, is illustrated through a study whereby South Sudanese marginalized women were trained to design research instruments, and collect and analyze qualitative data. PEER overcomes the problem that many ethnographic or participatory approaches face-the extensive time and resources required to develop trusting relationships with the community to understand the local context and the social networks they form.

  10. Avoiding genetic genocide: understanding good intentions and eugenics in the complex dialogue between the medical and disability communities.

    Science.gov (United States)

    Miller, Paul Steven; Levine, Rebecca Leah

    2013-02-01

    The relationship between the medical and disability communities is complex and is influenced by historical, social, and cultural factors. Although clinicians, health-care researchers, and people with disabilities all work from the standpoint of the best interest of disabled individuals, the notion of what actually is "best" is often understood quite differently among these constituencies. Eugenics campaigns, legal restrictions on reproductive and other freedoms, and prenatal testing recommendations predicated on the lesser worth of persons with disabilities have all contributed toward the historic trauma experienced by the disability community, particularly with respect to medical genetics. One premise of personalized medicine is that different individuals require different solutions. Disabled persons' experiences are a reminder that these solutions can be best realized by maintaining awareness and sensitivity in a complex ethical and moral terrain. Geneticists should recognize that their research may have implications for those with disabilities; they should recognize the impact of the historical trauma of the eugenics movement, and seek to involve people with disabilities in discussions about policies that affect them. Dialogue can be messy and uncomfortable, but it is the only way to avoid the mistakes of the past and to ensure a more equitable, and healthful, future.

  11. Know Your Client and Know Your Team: A Complexity Inspired Approach to Understanding Safe Transitions in Care

    Directory of Open Access Journals (Sweden)

    Deborah Tregunno

    2013-01-01

    Full Text Available Background. Transitions in care are one of the most important and challenging client safety issues in healthcare. This project was undertaken to gain insight into the practice setting realities for nurses and other health care providers as they manage increasingly complex care transitions across multiple settings. Methods. The Appreciative Inquiry approach was used to guide interviews with sixty-six healthcare providers from a variety of practice settings. Data was collected on participants’ experience of exceptional care transitions and opportunities for improving care transitions. Results. Nurses and other healthcare providers need to know three things to ensure safe care transitions: (1 know your client; (2 know your team on both sides of the transfer; and (3 know the resources your client needs and how to get them. Three themes describe successful care transitions, including flexible structures; independence and teamwork; and client and provider focus. Conclusion. Nurses often operate at the margins of acceptable performance, and flexibility with regulation and standards is often required in complex sociotechnical work like care transitions. Priority needs to be given to creating conditions where nurses and other healthcare providers are free to creatively engage and respond in ways that will optimize safe care transitions.

  12. Implementation of a school-based social and emotional learning intervention: understanding diffusion processes within complex systems.

    Science.gov (United States)

    Evans, Rhiannon; Murphy, Simon; Scourfield, Jonathan

    2015-07-01

    Sporadic and inconsistent implementation remains a significant challenge for social and emotional learning (SEL) interventions. This may be partly explained by the dearth of flexible, causative models that capture the multifarious determinants of implementation practices within complex systems. This paper draws upon Rogers (2003) Diffusion of Innovations Theory to explain the adoption, implementation and discontinuance of a SEL intervention. A pragmatic, formative process evaluation was conducted in alignment with phase 1 of the UK Medical Research Council's framework for Developing and Evaluating Complex Interventions. Employing case-study methodology, qualitative data were generated with four socio-economically and academically contrasting secondary schools in Wales implementing the Student Assistance Programme. Semi-structured interviews were conducted with 15 programme stakeholders. Data suggested that variation in implementation activity could be largely attributed to four key intervention reinvention points, which contributed to the transformation of the programme as it interacted with contextual features and individual needs. These reinvention points comprise the following: intervention training, which captures the process through which adopters acquire knowledge about a programme and delivery expertise; intervention assessment, which reflects adopters' evaluation of an intervention in relation to contextual needs; intervention clarification, which comprises the cascading of knowledge through an organisation in order to secure support in delivery; and intervention responsibility, which refers to the process of assigning accountability for sustainable delivery. Taken together, these points identify opportunities to predict and intervene with potential implementation problems. Further research would benefit from exploring additional reinvention activity.

  13. A model for understanding diagnostic imaging referrals and complex interaction processes within the bigger picture of a healthcare system

    International Nuclear Information System (INIS)

    Makanjee, Chandra R.; Bergh, Anne-Marie; Hoffmann, Willem A.

    2014-01-01

    Using experiences from the South African public healthcare system with limited resources, this review proposes a model that captures a holistic perspective of diagnostic imaging services embedded in a network of negotiated decision-making processes. Professional interdependency and interprofessional collaboration, cooperation and coordination are built around the central notion of integration in order to achieve a seamless transition through the continuum of various types of services needed to come to a diagnosis. Health-system role players interact with patients who enter the system from the perspective of their life-world. The distribution of diagnostic imaging services – within one setting or at multiple levels of care – demonstrates how fragments of information are filtered, interpreted and transformed at each point of care. The proposed model could contribute to alignment towards a common goal: services providing holistic quality of care within and beyond a complex healthcare system

  14. Using GeoVisual Analytics for understanding the distribution of complex movement patterns on the arterial roads

    DEFF Research Database (Denmark)

    Kveladze, Irma; Agerholm, Niels

    streets by igniting traffic rules. This will be studied on the basis of clusters of big unexplainable deviations from driving speed in FCD. The results will allow us to uncover meaningful patterns from complex traffic movements in populated areas, and provide some recommendations that are critical......Arterial roads have a particular operational significance and play a substantial role in the mobility and economic development of the modern society. They make up the majority of the road transport in urban and rural areas, and allow high-speed movement despite speed limitations and traffic...... controlling elements urban areas. In densely populated areas, where the presence of Vulnerable Road Users (VRU) is high, a high-speed movement is problematic from a road safety perspective, since many VRUs do crossroads by ignoring regardless of regulation and design limitations of the road network...

  15. A preliminary investigation of the applicability of surface complexation modeling to the understanding of transportation cask weeping

    International Nuclear Information System (INIS)

    Granstaff, V.E.; Chambers, W.B.; Doughty, D.H.

    1994-01-01

    A new application for surface complexation modeling is described. These models, which describe chemical equilibria among aqueous and adsorbed species, have typically been used for predicting groundwater transport of contaminants by modeling the natural adsorbents as various metal oxides. Our experiments suggest that this type of modeling can also explain stainless steel surface contamination and decontamination mechanisms. Stainless steel transportation casks, when submerged in a spent fuel storage pool at nuclear power stations, can become contaminated with radionuclides such as 137 Cs, 134 Cs, and 60 Co. Subsequent release or desorption of these contaminants under varying environmental conditions occasionally results in the phenomenon known as open-quotes cask weeping.close quotes We have postulated that contaminants in the storage pool adsorb onto the hydrous metal oxide surface of the passivated stainless steel and are subsequently released (by conversion from a fixed to a removable form) during transportation, due to varying environmental factors, such as humidity, road salt, dirt, and acid rain. It is well known that 304 stainless steel has a chromium enriched passive surface layer; thus its adsorption behavior should be similar to that of a mixed chromium/iron oxide. To help us interpret our studies of reversible binding of dissolved metals on stainless steel surfaces, we have studied the adsorption of Co +2 on Cr 2 O 3 . The data are interpreted using electrostatic surface complexation models. The FITEQL computer program was used to obtain the model binding constants and site densities from the experimental data. The MINTEQA2 computer speciation model was used, with the fitted constants, in an attempt to validate this approach

  16. Combined experimental and theoretical approach to understand the reactivity of a mononuclear Cu(II)-hydroperoxo complex in oxygenation reactions.

    Science.gov (United States)

    Kamachi, Takashi; Lee, Yong-Min; Nishimi, Tomonori; Cho, Jaeheung; Yoshizawa, Kazunari; Nam, Wonwoo

    2008-12-18

    A copper(II) complex bearing a pentadentate ligand, [Cu(II)(N4Py)(CF(3)SO(3))(2)] (1) (N4Py = N,N-bis(2-pyridylmethyl)bis(2-pyridyl)methylamine), was synthesized and characterized with various spectroscopic techniques and X-ray crystallography. A mononuclear Cu(II)-hydroperoxo complex, [Cu(II)(N4Py)(OOH)](+) (2), was then generated in the reaction of 1 and H(2)O(2) in the presence of base, and the reactivity of the intermediate was investigated in the oxidation of various substrates at -40 degrees C. In the reactivity studies, 2 showed a low oxidizing power such that 2 reacted only with triethylphosphine but not with other substrates such as thioanisole, benzyl alcohol, 1,4-cyclohexadiene, cyclohexene, and cyclohexane. In theoretical work, we have conducted density functional theory (DFT) calculations on the epoxidation of ethylene by 2 and a [Cu(III)(N4Py)(O)](+) intermediate (3) at the B3LYP level. The activation barrier is calculated to be 39.7 and 26.3 kcal/mol for distal and proximal oxygen attacks by 2, respectively. This result indicates that the direct ethylene epoxidation by 2 is not a plausible pathway, as we have observed in the experimental work. In contrast, the ethylene epoxidation by 3 is a downhill and low-barrier process. We also found that 2 cannot be a precursor to 3, since the homolytic cleavage of the O-O bond of 2 is very endothermic (i.e., 42 kcal/mol). On the basis of the experimental and theoretical results, we conclude that a mononuclear Cu(II)-hydroperoxo species bearing a pentadentate N5 ligand is a sluggish oxidant in oxygenation reactions.

  17. Understanding how the complex molecular architecture of mannan-degrading hydrolases contributes to plant cell wall degradation.

    Science.gov (United States)

    Zhang, Xiaoyang; Rogowski, Artur; Zhao, Lei; Hahn, Michael G; Avci, Utku; Knox, J Paul; Gilbert, Harry J

    2014-01-24

    Microbial degradation of plant cell walls is a central component of the carbon cycle and is of increasing importance in environmentally significant industries. Plant cell wall-degrading enzymes have a complex molecular architecture consisting of catalytic modules and, frequently, multiple non-catalytic carbohydrate binding modules (CBMs). It is currently unclear whether the specificities of the CBMs or the topology of the catalytic modules are the primary drivers for the specificity of these enzymes against plant cell walls. Here, we have evaluated the relationship between CBM specificity and their capacity to enhance the activity of GH5 and GH26 mannanases and CE2 esterases against intact plant cell walls. The data show that cellulose and mannan binding CBMs have the greatest impact on the removal of mannan from tobacco and Physcomitrella cell walls, respectively. Although the action of the GH5 mannanase was independent of the context of mannan in tobacco cell walls, a significant proportion of the polysaccharide was inaccessible to the GH26 enzyme. The recalcitrant mannan, however, was fully accessible to the GH26 mannanase appended to a cellulose binding CBM. Although CE2 esterases display similar specificities against acetylated substrates in vitro, only CjCE2C was active against acetylated mannan in Physcomitrella. Appending a mannan binding CBM27 to CjCE2C potentiated its activity against Physcomitrella walls, whereas a xylan binding CBM reduced the capacity of esterases to deacetylate xylan in tobacco walls. This work provides insight into the biological significance for the complex array of hydrolytic enzymes expressed by plant cell wall-degrading microorganisms.

  18. Formation of complexes between hematite nanoparticles and a non-conventional galactomannan gum. Toward a better understanding on interaction processes.

    Science.gov (United States)

    Busch, Verónica M; Loosli, Fréderic; Santagapita, Patricio R; Buera, M Pilar; Stoll, Serge

    2015-11-01

    The physicochemical characteristics of hematite nanoparticles related to their size, surface area and reactivity make them useful for many applications, as well as suitable models to study aggregation kinetics. For several applications (such as remediation of contaminated groundwater) it is crucial to maintain the stability of hematite nanoparticle suspensions in order to assure their arrival to the target place. The use of biopolymers has been proposed as a suitable environmentally friendly option to avoid nanoparticle aggregation and assure their stability. The aim of the present work was to investigate the formation of complexes between hematite nanoparticles and a non-conventional galactomannan (vinal gum--VG) obtained from Prosopis ruscifolia in order to promote hematite nanoparticle coating with a green biopolymer. Zeta potential and size of hematite nanoparticles, VG dispersions and the stability of their mixtures were investigated, as well as the influence of the biopolymer concentration and preparation method. DLS and nanoparticle tracking analysis techniques were used for determining the size and the zeta-potential of the suspensions. VG showed a polydispersed size distribution (300-475 nm Z-average diameter, 0.65 Pdi) and a negative zeta potential (between -1 and -12 mV for pH2 and 12, respectively). The aggregation of hematite nanoparticles (3.3 mg/L) was induced by the addition of VG at lower concentrations than 2mg/L (pH5.5). On the other hand, hematite nanoparticles were stabilized at concentrations of VG higher than 2 mg/L. Several phenomena between hematite nanoparticles and VG were involved: steric effects, electrostatic interactions, charge neutralization, charge inversion and polymer bridging. The process of complexation between hematite nanoparticles and the biopolymer was strongly influenced by the preparation protocols. It was concluded that the aggregation, dispersion, and stability of hematite nanoparticles depended on biopolymer

  19. Understanding strain transfer and basin evolution complexities in the Salton pull-apart basin near the Southern San Andreas Fault

    Science.gov (United States)

    Kell, A. M.; Sahakian, V. J.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.; Baskin, R. L.; Barth, M.; Hole, J. A.; Stock, J. M.; Fuis, G. S.

    2015-12-01

    Active source seismic data in the Salton Sea provide insight into the complexity of the pull-apart system development. Seismic reflection data combined with tomographic cross sections give constraints on the timing of basin development and strain partitioning between the two dominant dextral faults in the region; the Imperial fault to the southwest and the Southern San Andreas fault (SSAF) to the northeast. Deformation associated with this step-over appears young, having formed in the last 20-40 k.a. The complexity seen in the Salton Sea is similar to that seen in pull-apart basins worldwide. In the southern basin of the Salton Sea, a zone of transpression is noted near the southern termination of the San Andreas fault, though this stress regime quickly transitions to a region of transtension in the northern reaches of the sea. The evolution seen in the basin architecture is likely related to a transition of the SSAF dying to the north, and giving way to youthful segments of the Brawley seismic zone and Imperial fault. Stratigraphic signatures seen in seismic cross-sections also reveal a long-term component of slip to the southwest on a fault 1-2 km west of the northeastern Salton Sea shoreline. Numerous lines of evidence, including seismic reflection data, high-resolution bathymetry within the Salton Sea, and folding patterns in the Borrego Formation to the east of the sea support an assertion of a previously unmapped fault, the Salton Trough fault (STF), parallel to the SAF and just offshore within the Salton Sea. Seismic observations are seen consistently within two datasets of varying vertical resolutions, up to depths of 4-5 km, suggesting that this fault strand is much longer-lived than the evolution seen in the southern sub-basin. The existence of the STF unifies discrepancies between the onshore seismic studies and data collected within the sea. The STF likely serves as the current bounding fault to the active pull-apart system, as it aligns with the "rung

  20. Associations between speech understanding and auditory and visual tests of verbal working memory: effects of linguistic complexity, task, age, and hearing loss.

    Science.gov (United States)

    Smith, Sherri L; Pichora-Fuller, M Kathleen

    2015-01-01

    Listeners with hearing loss commonly report having difficulty understanding speech, particularly in noisy environments. Their difficulties could be due to auditory and cognitive processing problems. Performance on speech-in-noise tests has been correlated with reading working memory span (RWMS), a measure often chosen to avoid the effects of hearing loss. If the goal is to assess the cognitive consequences of listeners' auditory processing abilities, however, then listening working memory span (LWMS) could be a more informative measure. Some studies have examined the effects of different degrees and types of masking on working memory, but less is known about the demands placed on working memory depending on the linguistic complexity of the target speech or the task used to measure speech understanding in listeners with hearing loss. Compared to RWMS, LWMS measures using different speech targets and maskers may provide a more ecologically valid approach. To examine the contributions of RWMS and LWMS to speech understanding, we administered two working memory measures (a traditional RWMS measure and a new LWMS measure), and a battery of tests varying in the linguistic complexity of the speech materials, the presence of babble masking, and the task. Participants were a group of younger listeners with normal hearing and two groups of older listeners with hearing loss (n = 24 per group). There was a significant group difference and a wider range in performance on LWMS than on RWMS. There was a significant correlation between both working memory measures only for the oldest listeners with hearing loss. Notably, there were only few significant correlations among the working memory and speech understanding measures. These findings suggest that working memory measures reflect individual differences that are distinct from those tapped by these measures of speech understanding.

  1. Associations between speech understanding and auditory and visual tests of verbal working memory: effects of linguistic complexity, task, age, and hearing loss

    Science.gov (United States)

    Smith, Sherri L.; Pichora-Fuller, M. Kathleen

    2015-01-01

    Listeners with hearing loss commonly report having difficulty understanding speech, particularly in noisy environments. Their difficulties could be due to auditory and cognitive processing problems. Performance on speech-in-noise tests has been correlated with reading working memory span (RWMS), a measure often chosen to avoid the effects of hearing loss. If the goal is to assess the cognitive consequences of listeners’ auditory processing abilities, however, then listening working memory span (LWMS) could be a more informative measure. Some studies have examined the effects of different degrees and types of masking on working memory, but less is known about the demands placed on working memory depending on the linguistic complexity of the target speech or the task used to measure speech understanding in listeners with hearing loss. Compared to RWMS, LWMS measures using different speech targets and maskers may provide a more ecologically valid approach. To examine the contributions of RWMS and LWMS to speech understanding, we administered two working memory measures (a traditional RWMS measure and a new LWMS measure), and a battery of tests varying in the linguistic complexity of the speech materials, the presence of babble masking, and the task. Participants were a group of younger listeners with normal hearing and two groups of older listeners with hearing loss (n = 24 per group). There was a significant group difference and a wider range in performance on LWMS than on RWMS. There was a significant correlation between both working memory measures only for the oldest listeners with hearing loss. Notably, there were only few significant correlations among the working memory and speech understanding measures. These findings suggest that working memory measures reflect individual differences that are distinct from those tapped by these measures of speech understanding. PMID:26441769

  2. Understanding the complex determinants of height and adiposity in disadvantaged daycare preschoolers in Salvador, NE Brazil through structural equation modelling.

    Science.gov (United States)

    Lander, Rebecca L; Williams, Sheila M; Costa-Ribeiro, Hugo; Mattos, Angela P; Barreto, Danile L; Houghton, Lisa A; Bailey, Karl B; Lander, Alastair G; Gibson, Rosalind S

    2015-10-23

    Earlier we reported on growth and adiposity in a cross-sectional study of disadvantaged Brazilian preschoolers. Here we extend the work on these children, using structural equation modelling (SEM) to gather information on the complex relationships between the variables influencing height and adiposity. We hope this information will help improve the design and effectiveness of future interventions for preschoolers. In 376 preschoolers aged 3-6 years attending seven philanthropic daycares in Salvador, we used SEM to examine direct and indirect relationships among biological (sex, ethnicity, birth order, maternal height and weight), socio-economic, micronutrient (haemoglobin, serum selenium and zinc), and environmental (helminths, de-worming) variables on height and adiposity, as reflected by Z-scores for height-for-age (HAZ) and body mass index (BMIZ). Of the children, 11 % had HAZ  1. Of their mothers, 8 % had short stature, and 50 % were overweight or obese. Based on standardized regression coefficients, significant direct effects (p growth, helminth infection was a modifiable risk factor directly and indirectly affecting HAZ and BMIZ, respectively. Hence the WHO de-worming recommendation should include preschoolers living in at-risk environments as well as school-aged children.

  3. The Climate Change-Road Safety-Economy Nexus: A System Dynamics Approach to Understanding Complex Interdependencies

    Directory of Open Access Journals (Sweden)

    Mehdi Alirezaei

    2017-01-01

    Full Text Available Road accidents have the highest externality costs to society and to the economy, even when compared to the externality damages associated with air emissions and oil dependency. Road safety is one of the most complicated topics, which involves many interdependencies, and so, a sufficiently thorough analysis of roadway safety will require a novel system-based approach in which the associated feedback relationships and causal effects are given appropriate consideration. The factors affecting accident frequency and severity are highly dependent on economic parameters, environmental factors and weather conditions. In this study, we try to use a system dynamics modeling approach to model the climate change-road safety-economy nexus, thereby investigating the complex interactions among these important areas by tracking how they affect each other over time. For this purpose, five sub-models are developed to model each aspect of the overall nexus and to interact with each other to simulate the overall system. As a result, this comprehensive model can provide a platform for policy makers to test the effectiveness of different policy scenarios to reduce the negative consequences of traffic accidents and improve road safety.

  4. High-Velocity Cloud Complex H and Weaver's "Jet": Two candidate dwarf satellite galaxies for which dark matter halo models indicate distances of ~27 kpc and ~108 kpc

    Science.gov (United States)

    Simonson, S. Christian

    2018-04-01

    Two anomalous-velocity H I features, High-Velocity Cloud Complex H (HVC H) (Blitz et al. 1999), and Weaver's "jet" (Weaver 1974), appear to be good candidates for dwarf satellites. In this work they are modeled as H I disks in dark matter halos that move in 3D orbits in the combined time-dependent gravitational fields of the Milky Way and M31. As they orbit in the Local Group they develop tidal distortions and produce debris. The current l,b,V appearance of the tidal features as they approach the Milky Way indicate distances of 27 ± 9 kpc for HVC H and 108 ± 36 kpc for Weaver's "jet". As these are within the distances to known Milky Way satellites, finding stellar components would be of interest for the star formation history of the Milky Way. This work uses recent Hubble Space Telescope results on M31 (van der Marel et al. 2012) to calculate the center-of-mass (COM) locations and the dark matter mass distributions of the Milky-Way—M31 system since the Big Bang. Time-dependent COM orbits of the satellites have been computed in 3D, along with rings of test particles representing their disks. Tidal effects that develop on these rings have been compared with published 21-cm line data from Lockman (2003) and Simonson (1975). For HVC H at l = 130.5°, b = +1.5°, V = -200 km/s, the dark matter mass (in solar masses) is estimated as 5.2 ± 3.5E8. The previously estimated H I mass is 6.4E6, or 1.2% of the newly derived satellite mass. For Weaver's "jet", which covers 2° by 7° at l = 197.3°, b = +2.1°, V = -30 to -87 km/s, the dark matter mass is estimated as 1.8 ± 0.6E9. The H I mass is 1.8 ± 1.1E8, or 6% to 12% of the satellite mass. In the case of HVC H, owing to its disk angle of 45°, tidal debris is thrown upward. This would presumably contribute to a halo star stream. In the case of Weaver's "jet", the streamer represents accreting material for the disk. I am grateful to Leo Blitz for bringing Lockman's work on HVC H to my attention and for many helpful

  5. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  6. What Do Transgender Women’s Experiences Tell Us about Law? Towards an Understanding of Law as Legal Complex

    Directory of Open Access Journals (Sweden)

    Esen Ezgi Tascioglu

    2011-01-01

    Full Text Available Based on ethnographic study conducted in Istanbul, this thesis investigates the effects of law and legal operations on transgender women’s sex work and daily lives, and seeks to disentangle the multidimensional ways through which they and their conduct are governmentalized by law in Turkey. The first part of the thesis discusses the legal dynamics surrounding transgender sex work and delineates how transgender women are expulsed from regulated sex work by the interaction of the socially produced desire around their bodies and law. Led to work outside the regulated sex trade, transgender women navigate spaces which are regulated in an ambivalent manner yet which have the net effect of drawing transgender women into street sex work. The second part shows that these legal practices on sex work do not apply to all sex workers but to nearly all transgender women, depriving them from their most basic rights. Overall my analysis demonstrates that transgender women find themselves in a multitude of legal and institutional practices that are borne out of the interaction of their social contexts, their bodily performances and legal texts and their application, and that this is done through various regulatory agents. I argue that such an examination demonstrates law’s multiplicity and heterogeneity against the unitary and sovereigntist understandings of law which prevail in popular discourse as well as scholarly and activist thinking in Turkey and abroad. DOWNLOAD THIS PAPER FROM SSRN: http://ssrn.com/abstract=1730260

  7. Toward an analytical framework for understanding complex social-ecological systems when conducting environmental impact assessments in South Africa

    Directory of Open Access Journals (Sweden)

    Rebecca Bowd

    2015-03-01

    counterpoint to established approaches and could contribute to improving the quality of EIAs with respect to the complex SESs that characterize the developing world.

  8. Another dimension to metamorphic phase equilibria: the power of interactive movies for understanding complex phase diagram sections

    Science.gov (United States)

    Moulas, E.; Caddick, M. J.; Tisato, N.; Burg, J.-P.

    2012-04-01

    The investigation of metamorphic phase equilibria, using software packages that perform thermodynamic calculations, involves a series of important assumptions whose validity can often be questioned but are difficult to test. For example, potential influences of deformation on phase relations, and modification of effective reactant composition (X) at successive stages of equilibrium may both introduce significant uncertainty into phase diagram calculations. This is generally difficult to model with currently available techniques, and is typically not well quantified. We present here a method to investigate such phenomena along pre-defined Pressure-Temperature (P-T) paths, calculating local equilibrium via Gibbs energy minimization. An automated strategy to investigate complex changes in the effective equilibration composition has been developed. This demonstrates the consequences of specified X modification and, more importantly, permits automated calculation of X changes that are likely along the requested path if considering several specified processes. Here we describe calculations considering two such processes and show an additional example of a metamorphic texture that is difficult to model with current techniques. Firstly, we explore the assumption that although water saturation and bulk-rock equilibrium are generally considered to be valid assumptions in the calculation of phase equilibria, the saturation of thermodynamic components ignores mechanical effects that the fluid/melt phase can impose on the rock, which in turn can modify the effective equilibrium composition. Secondly, we examine how mass fractionation caused by porphyroblast growth at low temperatures or progressive melt extraction at high temperatures successively modifies X out of the plane of the initial diagram, complicating the process of determining best-fit P-T paths for natural samples. In particular, retrograde processes are poorly modeled without careful consideration of prograde

  9. The Complexities of Accessing Care and Treatment: Understanding Alcohol Use by Aboriginal Persons Living with HIV and AIDS

    Science.gov (United States)

    Masching, Renée; Dell, Colleen A.; Egan, John P.; McHugh, Nancy Gros-Louis; Lee, David; Prentice, Tracey; Storm, Lyanna; Thomas, Cliff; McGee, Amy; Dale-Harris, Hugh

    2016-01-01

    The role of alcohol in the transmission of HIV and access to health services for persons living with HIV/AIDS is relatively unexamined across the globe. Our team’s community-based, mixed methods study examined both of these questions from the perspectives of Aboriginal persons living in Canada with HIV/AIDS (APHA) and service providers (SP). A bilingual national survey was undertaken with APHAs and SPs and the findings were followed up on in peer interviews. A complex relationship was identified between alcohol use, perceptions of alcohol use and access to services. Nearly half of APHAs surveyed reported that alcohol played a role in their becoming HIV positive. APHAs and SPs differed in their assessment of the impact of alcohol in the lives of Aboriginal persons once diagnosed, with a far greater proportion of SPs identifying it as problematic. Both SPs and APHAs associated the misuse of alcohol with diminished health. Nearly half of the APHAs surveyed shared they had been told they were drinking by a SP when they were not, while over one-third reported ever being denied services because of drinking when in fact they were not. Both SPs and APHAs identified physical health and discrimination as key reasons. Notwithstanding these results that point to shortcomings in service provision, the data also reveal that most APHAs are recieving care in which their choices are respected and from providers they trust. The findings point to the need for a nuanced strategy to solidify the strengths and address the shortcomings in APHA’s service provision. PMID:27867443

  10. Media Matter

    Directory of Open Access Journals (Sweden)

    Holger Pötzsch

    2017-02-01

    Full Text Available The present contribution maps materialist advances in media studies. Based on the assumption that matter and materiality constitute significant aspects of communication processes and practices, I introduce four fields of inquiry - technology, political economy, ecology, and the body - and argue that these perspectives enable a more comprehensive understanding of the implications of contemporary technologically afforded forms of interaction. The article shows how each perspective can balance apologetic and apocalyptic approaches to the impact of in particular digital technologies, before it demonstrates the applicability of an integrated framework with reference to the techno-politics of NSA surveillance and the counter-practices of WikiLeaks.

  11. Play Matters

    DEFF Research Database (Denmark)

    Sicart (Vila), Miguel Angel

    ? In Play Matters, Miguel Sicart argues that to play is to be in the world; playing is a form of understanding what surrounds us and a way of engaging with others. Play goes beyond games; it is a mode of being human. We play games, but we also play with toys, on playgrounds, with technologies and design......, but not necessarily fun. Play can be dangerous, addictive, and destructive. Along the way, Sicart considers playfulness, the capacity to use play outside the context of play; toys, the materialization of play--instruments but also play pals; playgrounds, play spaces that enable all kinds of play; beauty...

  12. Understanding the addiction cycle: a complex biology with distinct contributions of genotype vs. sex at each stage.

    Science.gov (United States)

    Wilhelm, C J; Hashimoto, J G; Roberts, M L; Sonmez, M K; Wiren, K M

    2014-10-24

    Ethanol abuse can lead to addiction, brain damage and premature death. The cycle of alcohol addiction has been described as a composite consisting of three stages: intoxication, withdrawal and craving/abstinence. There is evidence for contributions of both genotype and sex to alcoholism, but an understanding of the biological underpinnings is limited. Utilizing both sexes of genetic animal models with highly divergent alcohol withdrawal severity, Withdrawal Seizure-Resistant (WSR) and Withdrawal Seizure-Prone (WSP) mice, the distinct contributions of genotype/phenotype and of sex during addiction stages on neuroadaptation were characterized. Transcriptional profiling was performed to identify expression changes as a consequence of chronic intoxication in the medial prefrontal cortex. Significant expression differences were identified on a single platform and tracked over a behaviorally relevant time course that covered each stage of alcohol addiction; i.e., after chronic intoxication, during peak withdrawal, and after a defined period of abstinence. Females were more sensitive to ethanol with higher fold expression differences. Bioinformatics showed a strong effect of sex on the data structure of expression profiles during chronic intoxication and at peak withdrawal irrespective of genetic background. However, during abstinence, differences were observed instead between the lines/phenotypes irrespective of sex. Confirmation of identified pathways showed distinct inflammatory signaling following intoxication at peak withdrawal, with a pro-inflammatory phenotype in females but overall suppression of immune signaling in males. Combined, these results suggest that each stage of the addiction cycle is influenced differentially by sex vs. genetic background and support the development of stage- and sex-specific therapies for alcohol withdrawal and the maintenance of sobriety. Published by Elsevier Ltd.

  13. Using an adaptive expertise lens to understand the quality of teachers' classroom implementation of computer-supported complex systems curricula in high school science

    Science.gov (United States)

    Yoon, Susan A.; Koehler-Yom, Jessica; Anderson, Emma; Lin, Joyce; Klopfer, Eric

    2015-05-01

    Background: This exploratory study is part of a larger-scale research project aimed at building theoretical and practical knowledge of complex systems in students and teachers with the goal of improving high school biology learning through professional development and a classroom intervention. Purpose: We propose a model of adaptive expertise to better understand teachers' classroom practices as they attempt to navigate myriad variables in the implementation of biology units that include working with computer simulations, and learning about and teaching through complex systems ideas. Sample: Research participants were three high school biology teachers, two females and one male, ranging in teaching experience from six to 16 years. Their teaching contexts also ranged in student achievement from 14-47% advanced science proficiency. Design and methods: We used a holistic multiple case study methodology and collected data during the 2011-2012 school year. Data sources include classroom observations, teacher and student surveys, and interviews. Data analyses and trustworthiness measures were conducted through qualitative mining of data sources and triangulation of findings. Results: We illustrate the characteristics of adaptive expertise of more or less successful teaching and learning when implementing complex systems curricula. We also demonstrate differences between case study teachers in terms of particular variables associated with adaptive expertise. Conclusions: This research contributes to scholarship on practices and professional development needed to better support teachers to teach through a complex systems pedagogical and curricular approach.

  14. The Holocene history of the North American Monsoon: 'known knowns' and 'known unknowns' in understanding its spatial and temporal complexity

    Science.gov (United States)

    Metcalfe, Sarah E.; Barron, John A.; Davies, Sarah J.

    2015-01-01

    Evidence for climatic change across the North American Monsoon (NAM) and adjacent areas is reviewed, drawing on continental and marine records and the application of climate models. Patterns of change at 12,000, 9000, 6000 and 4000 cal yr BP are presented to capture the nature of change from the Younger Dryas (YD) and through the mid-Holocene. At the YD, conditions were cooler overall, wetter in the north and drier in the south, while moving into the Holocene wetter conditions became established in the south and then spread north as the NAM strengthened. Until c. 8000 cal yr BP, the Laurentide Ice Sheet influenced precipitation in the north by pushing the Bermuda High further south. The peak extent of the NAM seems to have occurred around 6000 cal yr BP. 4000 cal yr BP marks the start of important changes across the NAM region, with drying in the north and the establishment of the clear differences between the summer-rain dominated south and central areas and the north, where winter rain is more important. This differentiation between south and north is crucial to understanding many climate responses across the NAM. This increasing variability is coincident with the declining influence of orbital forcing. 4000 cal yr BP also marks the onset of significant anthropogenic activity in many areas. For the last 2000 years, the focus is on higher temporal resolution change, with strong variations across the region. The Medieval Climate Anomaly (MCA) is characterised by centennial scale ‘megadrought’ across the southwest USA, associated with cooler tropical Pacific SSTs and persistent La Niña type conditions. Proxy data from southern Mexico, Central America and the Caribbean reveal generally wetter conditions, whereas records from the highlands of central Mexico and much of the Yucatan are typified by long -term drought. The Little Ice Age (LIA), in the north, was characterised by cooler, wetter winter conditions that have been linked with increased

  15. A more holistic understanding of soil organic matter pools of alpine and pre-alpine grassland soils in a changing climate

    Science.gov (United States)

    Garcia Franco, Noelia; Wiesmeier, Martin; Kiese, Ralf; Dannenmann, Michael; Wolf, Benjamin; Brandhuber, Robert; Beck, Robert; Kögel-Knabner, Ingrid

    2016-04-01

    In southern Germany, the alpine and pre-alpine grassland systems (> 1 Mio ha) provide an important economic value via fodder used for milk and meat production and grassland soils support environmental key functions (C and N storage, water retention, erosion control and biodiversity hot spot). In addition, these grassland soils constitute important regions for tourism and recreation. However, the different land use and management practices in this area introduce changes which are likely to accelerate due to climate change. The newly launched SUPSALPS project within the BonaRes Initiative of the German Ministry for Education and Research is focused on the development and evaluation of innovative grassland management strategies under climate change with an emphasis on soil functions, which are on the one hand environmental sustainable and on the other hand economically viable. Several field experiments of the project will be initialized in order to evaluate grassland soil functioning for a range of current and climate adapted management practices. A multi-factorial design combines ongoing and new plant-soil meso-/macrocosm and field studies at a multitude of existing long-term research sites along an elevation gradient in Bavaria. One of the specific objectives of the project is to improve our knowledge on the sensitivity of specific soil organic matter (SOM) fractions to climate change. Moreover, the project aims to determine the processes and mechanisms involved in the build-up and stabilization of C and N pools under different management practices. In order to derive sensitive SOM pools, a promising physical fractionation method was developed that enables the separation of five different SOM fractions by density, ultrasonication and sieving separation: fine particulate organic matter (fPOM), occluded particulate organic matter (oPOM>20μm and oPOM 20 μm; medium + fine silt and clay, management changes.

  16. Understanding the complex relationships among actors involved in the implementation of public-private mix (PPM) for TB control in India, using social theory.

    Science.gov (United States)

    Salve, Solomon; Harris, Kristine; Sheikh, Kabir; Porter, John D H

    2018-06-07

    Public Private Partnerships (PPP) are increasingly utilized as a public health strategy for strengthening health systems and have become a core component for the delivery of TB control services in India, as promoted through national policy. However, partnerships are complex systems that rely on relationships between a myriad of different actors with divergent agendas and backgrounds. Relationship is a crucial element of governance, and relationship building an important aspect of partnerships. To understand PPPs a multi-disciplinary perspective that draws on insights from social theory is needed. This paper demonstrates how social theory can aid the understanding of the complex relationships of actors involved in implementation of Public-Private Mix (PPM)-TB policy in India. Ethnographic research was conducted within a district in a Southern state of India over a 14 month period, combining participant observations, informal interactions and in-depth interviews with a wide range of respondents across public, private and non-government organisation (NGO) sectors. Drawing on the theoretical insights from Bourdieu's "theory of practice" this study explores the relationships between the different actors. The study found that programme managers, frontline TB workers, NGOs, and private practitioners all had a crucial role to play in TB partnerships. They were widely regarded as valued contributors with distinct social skills and capabilities within their organizations and professions. However, their potential contributions towards programme implementation tended to be unrecognized both at the top and bottom of the policy implementation chain. These actors constantly struggled for recognition and used different mechanisms to position themselves alongside other actors within the programme that further complicated the relationships between different actors. This paper demonstrates that applying social theory can enable a better understanding of the complex relationship

  17. Insight to structural subsite recognition in plant thiol protease-inhibitor complexes : Understanding the basis of differential inhibition and the role of water

    Directory of Open Access Journals (Sweden)

    Mukhopadhayay Bishnu P

    2001-09-01

    Full Text Available Abstract Background This work represents an extensive MD simulation / water-dynamics studies on a series of complexes of inhibitors (leupeptin, E-64, E-64-C, ZPACK and plant cysteine proteases (actinidin, caricain, chymopapain, calotropin DI of papain family to understand the various interactions, water binding mode, factors influencing it and the structural basis of differential inhibition. Results The tertiary structure of the enzyme-inhibitor complexes were built by visual interactive modeling and energy minimization followed by dynamic simulation of 120 ps in water environment. DASA study with and without the inhibitor revealed the potential subsite residues involved in inhibition. Though the interaction involving main chain atoms are similar, critical inspection of the complexes reveal significant differences in the side chain interactions in S2-P2 and S3-P3 pairs due to sequence differences in the equivalent positions of respective subsites leading to differential inhibition. Conclusion The key finding of the study is a conserved site of a water molecule near oxyanion hole of the enzyme active site, which is found in all the modeled complexes and in most crystal structures of papain family either native or complexed. Conserved water molecules at the ligand binding sites of these homologous proteins suggest the structural importance of the water, which changes the conventional definition of chemical geometry of inhibitor binding domain, its shape and complimentarity. The water mediated recognition of inhibitor to enzyme subsites (Pn...H2O....Sn of leupeptin acetyl oxygen to caricain, chymopapain and calotropinDI is an additional information and offer valuable insight to potent inhibitor design.

  18. It Doesn't Matter What Is in Their Hands: Understanding How Students Use Technology to Support, Enhance and Expand Their Learning in a Complex World

    Science.gov (United States)

    Bryant, Peter

    2017-01-01

    Perspectives on the use of technology in teaching and learning have been increasing polarised, with positions entrenched around the efficacy of using technology in lectures, the distractions assumed to arise from social media and the temporality and ephemerality of knowledge located outside the academy. This paper presents the preliminary…

  19. Use of biological priors enhances understanding of genetic architecture and genomic prediction of complex traits within and between dairy cattle breeds.

    Science.gov (United States)

    Fang, Lingzhao; Sahana, Goutam; Ma, Peipei; Su, Guosheng; Yu, Ying; Zhang, Shengli; Lund, Mogens Sandø; Sørensen, Peter

    2017-08-10

    A better understanding of the genetic architecture underlying complex traits (e.g., the distribution of causal variants and their effects) may aid in the genomic prediction. Here, we hypothesized that the genomic variants of complex traits might be enriched in a subset of genomic regions defined by genes grouped on the basis of "Gene Ontology" (GO), and that incorporating this independent biological information into genomic prediction models might improve their predictive ability. Four complex traits (i.e., milk, fat and protein yields, and mastitis) together with imputed sequence variants in Holstein (HOL) and Jersey (JER) cattle were analysed. We first carried out a post-GWAS analysis in a HOL training population to assess the degree of enrichment of the association signals in the gene regions defined by each GO term. We then extended the genomic best linear unbiased prediction model (GBLUP) to a genomic feature BLUP (GFBLUP) model, including an additional genomic effect quantifying the joint effect of a group of variants located in a genomic feature. The GBLUP model using a single random effect assumes that all genomic variants contribute to the genomic relationship equally, whereas GFBLUP attributes different weights to the individual genomic relationships in the prediction equation based on the estimated genomic parameters. Our results demonstrate that the immune-relevant GO terms were more associated with mastitis than milk production, and several biologically meaningful GO terms improved the prediction accuracy with GFBLUP for the four traits, as compared with GBLUP. The improvement of the genomic prediction between breeds (the average increase across the four traits was 0.161) was more apparent than that it was within the HOL (the average increase across the four traits was 0.020). Our genomic feature modelling approaches provide a framework to simultaneously explore the genetic architecture and genomic prediction of complex traits by taking advantage of

  20. Osteosarcoma models : understanding complex disease

    NARCIS (Netherlands)

    Mohseny, Alexander Behzad

    2012-01-01

    A mesenchymal stem cell (MSC) based osteosarcoma model was established. The model provided evidence for a MSC origin of osteosarcoma. Normal MSCs transformed spontaneously to osteosarcoma-like cells which was always accompanied by genomic instability and loss of the Cdkn2a locus. Accordingly loss of

  1. The quark matter

    International Nuclear Information System (INIS)

    Rho, Mannque.

    1980-04-01

    The present status of our understanding of the physics of hadronic (nuclear or neutron) matter under extreme conditions, in particular at high densities is discussed. This is a problem which challenges three disciplines of physics: nuclear physics, astrophysics and particle physics. It is generally believed that we now have a correct and perhaps ultimate theory of the strong interactions, namely quantum chromodynamics (QCD). The constituents of this theory are quarks and gluons, so highly dense matters should be describable in terms of these constituents alone. This is a question that addresses directly to the phenomenon of quark confinement, one of the least understood aspects in particle physics. For nuclear physics, the possibility of a phase change between nuclear matter and quark matter introduces entirely new degrees of freedom in the description of nuclei and will bring perhaps a deeper understanding of nuclear dynamics. In astrophysics, the properties of neutron stars will be properly understood only when the equation of state of 'neutron' matter at densities exceeding that of nuclear matter can be realiably calculated. Most fascinating is the possibility of quark stars existing in nature, not entirely an absurd idea. Finally the quark matter - nuclear matter phase transition must have occured in the early stage of universe when matter expanded from high temperature and density; this could be an essential ingredient in the big-bang cosmology

  2. First 5 tower WIMP-search results from the Cryogenic Dark Matter Search with improved understanding of neutron backgrounds and benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Hennings-Yeomans, Raul [Case Western Reserve Univ., Cleveland, OH (United States)

    2009-02-01

    Non-baryonic dark matter makes one quarter of the energy density of the Universe and is concentrated in the halos of galaxies, including the Milky Way. The Weakly Interacting Massive Particle (WIMP) is a dark matter candidate with a scattering cross section with an atomic nucleus of the order of the weak interaction and a mass comparable to that of an atomic nucleus. The Cryogenic Dark Matter Search (CDMS-II) experiment, using Ge and Si cryogenic particle detectors at the Soudan Underground Laboratory, aims to directly detect nuclear recoils from WIMP interactions. This thesis presents the first 5 tower WIMP-search results from CDMS-II, an estimate of the cosmogenic neutron backgrounds expected at the Soudan Underground Laboratory, and a proposal for a new measurement of high-energy neutrons underground to benchmark the Monte Carlo simulations. Based on the non-observation of WIMPs and using standard assumptions about the galactic halo [68], the 90% C.L. upper limit of the spin-independent WIMPnucleon cross section for the first 5 tower run is 6.6 × 10-44cm2 for a 60 GeV/c2 WIMP mass. A combined limit using all the data taken at Soudan results in an upper limit of 4.6×10-44cm2 at 90% C.L.for a 60 GeV/c2 WIMP mass. This new limit corresponds to a factor of ~3 improvement over any previous CDMS-II limit and a factor of ~2 above 60 GeV/c 2 better than any other WIMP search to date. This thesis presents an estimation, based on Monte Carlo simulations, of the nuclear recoils produced by cosmic-ray muons and their secondaries (at the Soudan site) for a 5 tower Ge and Si configuration as well as for a 7 supertower array. The results of the Monte Carlo are that CDMS-II should expect 0.06 ± 0.02+0.18 -0.02 /kgyear unvetoed single nuclear recoils in Ge for the 5 tower configuration, and 0.05 ± 0.01+0.15 -0.02 /kg-year for the 7 supertower configuration. The systematic error is based on the available

  3. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)

    2014-12-01

    There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.

  4. The MarsOrganiX experiment: Understanding the influence of the secondary X-Rays on the organic matter at Mars' near-surface.

    Science.gov (United States)

    Buch, A.; Szopa, C.; Freissinet, C.; Stalport, F.; Coscia, D.; Pavlov, A.; Gilbert, P.; Bonnet, J. Y.; Guerrini, V.; Navarro-Gonzalez, R.

    2017-12-01

    Mars may have harbored a prebiotic chemistry that could have led to the emergence of life. If such, traces of these could be preserved in the oldest (3.5 billion years and more) rocks at the surface of the planet. Because of the thin atmosphere of Mars and the absence of an active magnetic field, the harsh radiative environment at the near-surface consists of UV and X-ray radiation, galactic and solar cosmic rays (GCRs and SCRs), as well as secondary particles produced by the interaction of GCRs and SCRs with the atmosphere and soil (secondary X-rays). The majority of the X-rays at the martian surface are generated in the rocks by the penetrating GCR and SCR particles. The GCRs' secondary X-rays' absorbed dose, at the top centimeters of the surface of Mars, has been estimated at about 0.05 Gy per year. All these radiation (direct and indirect) are prone to induce extended degradation or transformation of organic matter that would be present at Mars' near-surface, down to the 3 m depth of the GCRs/SCRs penetration. The SAM experiment onboard Curiosity rover led to the first in situ detection of organic molecules in martian rocks and soils. Chlorobenzene was detected in Cumberland at a concentration of up to 300 parts per billion in weight. However, chlorobenzene was thought to be formed in the SAM oven, during the pyrolysis of the sample. Nevertheless, Cumberland sample has been exposed to GCRs and SCRs for about 80 million years, and thus, the undergone X-rays radiation may have processed the organic matter and chlorinated the organic molecules in presence of perchlorate. Therefore, this study aims at evaluating the possible precursor(s), that would lead to the formation of chlorobenzene (detected with SAM) when irradiated in presence of perchlorate. Using the PSICHE beam line at SOLEIL, a synchrotron facility in France, we studied the extend of degradation and transformation of two organic molecules of interest, a carboxylic acid (benzoic acid) and an amino acid

  5. Understanding the direction of the relationship between white matter hyperintensities of vascular origin, sleep quality, and chronic kidney disease-Results from the Atahualpa Project.

    Science.gov (United States)

    Del Brutto, Oscar H; Mera, Robertino M

    2018-02-01

    The burden of cerebral small vessel disease, sleep disorders, and chronic kidney disease is on the rise in remote rural settings. However, information on potential links between these conditions is limited. We aimed to assess the relationships between these conditions in community-dwelling older adults living in rural Ecuador. Atahualpa residents aged ≥60 years were offered a brain MRI. A venous blood sample was obtained for serum creatinine determination. Baseline interviews and procedures were directed to assess demographics, cardiovascular risk factors, and sleep quality. Using generalized structural equation modeling (GSEM), we assessed the associations between white matter hyperintensities (WMH) of vascular origin, sleep quality and kidney function, as well as the directions of the relationships between these variables. Of 423 candidates, 314 (74%) were enrolled. Moderate-to-severe WMH were noticed in 74 (24%) individuals, poor sleep quality in 101 (31%), and moderate-to-severe chronic kidney disease in 28 (9%). GSEM showed that the direction of the effect was from kidney function to WMH and from the latter to sleep quality. Of independent variables investigated, worse kidney function was associated with age, high glucose levels and male sex. WMH was associated with cholesterol blood levels, blood pressure, level of education and severe edentulism. Poor sleep quality was associated with poor physical activity. This population based study shows that chronic kidney disease is associated with increased severity of WMH, which, in turn, is associated with a poor sleep quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Organisation Matters

    DEFF Research Database (Denmark)

    Unphon, Hataichanok; Dittrich, Yvonne

    2008-01-01

    Our work aims at understanding the design rationale for product line architecture by focusing on the design of common data access modules for complex simulation software products. This paper presents empirical evidence of organisational and business domain aspects that influence the development...... of product line architecture. We suggest that the assessment of use-situation and his tory of organisational structure should be considered when creating product line architectures, especially for products that are tailored and used interactively....

  7. An observation on the quality of interfaces in order to understand the complexity and coherence of informal settlement: A study on Tamansari Kampung in Bandung

    Science.gov (United States)

    Sawira, S.; Rahman, T.

    2018-05-01

    Self-organized settlements are formed within the limited capacity of the inhabitants with or without the Government’s interventions. This pattern is mostly found in the informal settlements, where occupants are the planners who are guided by their needs, limited resources and vernacular knowledge about place making. Understanding the process of its development and transformation could be a way of unfolding the complexity it offers to a formal urban setting. To identify the patterns of adaptation process, a study of morphological elements (i.e. house form, streets) could be a possible way. A case study of an informal settlement (Kampung of Tamansari, Bandung in Indonesia) has been taken to dissect these elements. Two of important components of the study area: house forms and streets created the first layer of urban fabric. High population density demanded layers of needs and activities which eventually guided the multifunctional characteristics of streets and house forms. Thus, streets create dialogue with the complex built forms-often known as interface is the key element to understand the underneath order of Tamansari. Here interface can be divided into two categories depending on their scale – small and large. Small scale interfaces are comprised of small elements such as, extended platform, fence, steps, low height wall, blank wall and elements to set above, set forth, set over in house forms. These components help to create and define semipublic spaces in the settlement. These spaces could be visually and physically interactive or no interactive which result into active or inactive spaces respectively. Small scale interfaces are common features of the settlement, whereas large scale interfaces are placed at strategic locations and act as active spaces. Connecting bridges, open spaces and contours often create special dialogue within and beyond the study area. Interfaces cater diversity in the settlement by creating hierarchy of spaces. Sense of belonging

  8. Dark Matter

    Directory of Open Access Journals (Sweden)

    Einasto J.

    2011-06-01

    Full Text Available I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Dark matter is the dominant matter component in the Universe, thus properties of dark matter particles determine the structure of the cosmic web.

  9. Dark matter and its detection

    International Nuclear Information System (INIS)

    Bi Xiaojun; Qin Bo

    2011-01-01

    We first explain the concept of dark matter,then review the history of its discovery and the evidence of its existence. We describe our understanding of the nature of dark matter particles, the popular dark matter models,and why the weakly interacting massive particles (called WIMPs) are the most attractive candidates for dark matter. Then we introduce the three methods of dark matter detection: colliders, direct detection and indirect detection. Finally, we review the recent development of dark matter detection, including the new results from DAMA, CoGent, PAMELA, ATIC and Fermi. (authors)

  10. Understanding your cancer prognosis

    Science.gov (United States)

    ... about: Treatment Palliative care Personal matters such as finances Knowing what to expect may make it easier ... treatment. www.cancer.net/navigating-cancer-care/cancer-basics/understanding-statistics-used-guide-prognosis-and-evaluate-treatment . ...

  11. Solid Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Supported by a generous quantity of full-color illustrations and interesting sidebars, Solid Matter introduces the basic characteristics and properties of solid matter. It briefly describes the cosmic connection of the elements, leading readers through several key events in human pre-history that resulted in more advanced uses of matter in the solid state. Chapters include:. -Solid Matter: An Initial Perspective. -Physical Behavior of Matter. -The Gravity of Matter. -Fundamentals of Materials Science. -Rocks and Minerals. -Metals. -Building Materials. -Carbon Earth's Most Versatile Element. -S

  12. Conference Essay: Combat-Related Killings and Democratic Accountability: Towards an Understanding of the Cultural Capacities to Deal with Matters of War

    Directory of Open Access Journals (Sweden)

    Martina Kolanoski

    2015-04-01

    Full Text Available This report was written by the organizers of the workshop "Accounting for Combat-Related Killings," which took place at the Goethe University Frankfurt in July 2014. Scholars from Israel, the United Kingdom, the United States,, Canada, and Germany came together to present and discuss case studies on the discourse practices involved in accounting for combat-related killings in different national and transnational contexts. Intending to reflect on the methodological skills needed to analyze newly available process data, the workshop brought together scholars using different methodological approaches (here mainly ethnomethodology and critical discourse analysis. In regard to the global trend towards increasing numbers of so called permanent, asymmetric, small, and permanent wars, the report turns to concepts, methods, and empirical findings that foster understandings of the difficulties war generates at social, cultural and political levels as well as the manner in which these predicaments are negotiated, denied, or deflected. The report summarizes the workshop by presenting the papers in a specific order, beginning with accounting in combat, followed by tribunals of accounting, and finally the sedimentation of accounting in cultural representations. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1502239

  13. Light, Matter, and Geometry

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall

    Interaction of light and matter produces the appearance of materials. To deal with the immense complexity of nature, light and matter is modelled at a macroscopic level in computer graphics. This work is the first to provide the link between the microscopic physical theories of light and matter...... of a material and determine the contents of the material. The book is in four parts. Part I provides the link between microscopic and macroscopic theories of light. Part II describes how to use the properties of microscopic particles to compute the macroscopic properties of materials. Part III illustrates...

  14. Using the FLUKA Monte Carlo Code to Simulate the Interactions of Ionizing Radiation with Matter to Assist and Aid Our Understanding of Ground Based Accelerator Testing, Space Hardware Design, and Secondary Space Radiation Environments

    Science.gov (United States)

    Reddell, Brandon

    2015-01-01

    Designing hardware to operate in the space radiation environment is a very difficult and costly activity. Ground based particle accelerators can be used to test for exposure to the radiation environment, one species at a time, however, the actual space environment cannot be duplicated because of the range of energies and isotropic nature of space radiation. The FLUKA Monte Carlo code is an integrated physics package based at CERN that has been under development for the last 40+ years and includes the most up-to-date fundamental physics theory and particle physics data. This work presents an overview of FLUKA and how it has been used in conjunction with ground based radiation testing for NASA and improve our understanding of secondary particle environments resulting from the interaction of space radiation with matter.

  15. 'It's a matter of patient safety': understanding challenges in everyday clinical practice for achieving good care on the surgical ward - a qualitative study.

    Science.gov (United States)

    Jangland, Eva; Nyberg, Berit; Yngman-Uhlin, Pia

    2017-06-01

    Surgical care plays an important role in the acute hospital's delivery of safe, high-quality patient care. Although demands for effectiveness are high in surgical wards quality of care and patient safety must also be secured. It is therefore necessary to identify the challenges and barriers linked to quality of care and patient safety with a focus on this specific setting. To explore situations and processes that support or hinder good safe patient care on the surgical ward. This qualitative study was based on a strategic sample of 10 department and ward leaders in three hospitals and six surgical wards in Sweden. Repeated reflective interviews were analysed using systematic text condensation. Four themes described the leaders' view of a complex healthcare setting that demands effectiveness and efficiency in moving patients quickly through the healthcare system. Quality of care and patient safety were often hampered factors such as a shift of care level, with critically ill patients cared for without reorganisation of nurses' competencies on the surgical ward. There is a gap between what is described in written documents and what is or can be performed in clinical practice to achieve good care and safe care on the surgical ward. A shift in levels of care on the surgical ward without reallocation of the necessary competencies at the patient's bedside show consequences for quality of care and patient safety. This means that surgical wards should consider reviewing their organisation and implementing more advanced nursing roles in direct patient care on all shifts. The ethical issues and the moral stress on nurses who lack the resources and competence to deliver good care according to professional values need to be made more explicit as a part of the patient safety agenda in the surgical ward. © 2016 Nordic College of Caring Science.

  16. Speech Matters

    DEFF Research Database (Denmark)

    Hasse Jørgensen, Stina

    2011-01-01

    About Speech Matters - Katarina Gregos, the Greek curator's exhibition at the Danish Pavillion, the Venice Biannual 2011.......About Speech Matters - Katarina Gregos, the Greek curator's exhibition at the Danish Pavillion, the Venice Biannual 2011....

  17. Why participation matters for air quality studies: risk perceptions, understandings of air pollution and mobilization in a poor neighborhood in Nairobi, Kenya.

    Science.gov (United States)

    Ngo, N S; Kokoyo, S; Klopp, J

    2017-01-01

    With high urbanization rates, Sub-Saharan Africa is facing growing problems of poor air quality in its cities. We make a case for participatory approaches in air quality studies especially including those living in poor neighborhoods who may be particularly at risk from this trend. We used collaboration with a community based organization, interviews, focus group discussions and a community forum. We conducted a pilot study to assess health risk perceptions of air pollution for civic-minded residents in Mathare, an informal settlement in Nairobi, Kenya. Simultaneously, we involved Mathare residents in measuring levels of PM 2.5 and later presented these data at a community forum with the participants of the monitoring study and the focus group discussions. We found that participation in conducting and interpreting air quality studies helped residents improve their understanding of air pollution and also helped them develop responses to it. Initially, participants associated air pollution with a bad odor or discomfort rather than their health, but once the connection to health was made through participation, they sought more information about air quality data and its hazards. Some residents also came up with strategies for coping with their environment and its risks. These results point to the potential of including participation in air quality monitoring as a way to increase awareness and support local action to address it. Discussion and sharing of results at the local level as well as at a wider policy level will be critical for advocacy to improve air quality. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  18. Dynamics of Soft Matter

    CERN Document Server

    García Sakai, Victoria; Chen, Sow-Hsin

    2012-01-01

    Dynamics of Soft Matter: Neutron Applications provides an overview of neutron scattering techniques that measure temporal and spatial correlations simultaneously, at the microscopic and/or mesoscopic scale. These techniques offer answers to new questions arising at the interface of physics, chemistry, and biology. Knowledge of the dynamics at these levels is crucial to understanding the soft matter field, which includes colloids, polymers, membranes, biological macromolecules, foams, emulsions towards biological & biomimetic systems, and phenomena involving wetting, friction, adhesion, or micr

  19. Matter-antimatter Cosmology

    Science.gov (United States)

    Omnes, R.

    1973-01-01

    The possible existence of antimatter on a large scale in the universe is evaluated. As a starting point, an attempt was made to understand the origin of matter as being essentially analogous to the origin of backgound thermal radiation. Several theories and models are examined, with particular emphasis on nucleon-antinucleon interactions at intermediate energies. Data also cover annihilation interaction with the matter-antimatter boundary to produce the essential fluid motion known as coalesence.

  20. Dark Matter

    Indian Academy of Sciences (India)

    What You See Ain't What. You Got, Resonance, Vol.4,. No.9,1999. Dark Matter. 2. Dark Matter in the Universe. Bikram Phookun and Biman Nath. In Part 11 of this article we learnt that there are compelling evidences from dynamics of spiral galaxies, like our own, that there must be non-luminous matter in them. In this.

  1. Teaching Teaching & Understanding Understanding

    DEFF Research Database (Denmark)

    2006-01-01

    "Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

  2. Does it matter if clinicians recruiting for a trial don't understand what the trial is really about? Qualitative study of surgeons' experiences of participation in a pragmatic multi-centre RCT

    Directory of Open Access Journals (Sweden)

    Snowdon Claire

    2007-01-01

    design is not considered a design fault. We conclude that it does matter if clinicians do not understand the rationale for the trial if, as we have shown here, their perception of the trial aims and methods adversely affects who they recruit; if their views affect what the patients are told; and if they mistakenly view the results as unscientific, unreliable and ultimately irrelevant to their practice.

  3. Understanding physics

    CERN Document Server

    Cassidy, David; Rutherford, James

    2002-01-01

    Understanding Physics provides a thorough grounding in contemporary physics while placing physics into its social and historical context Based in large part on the highly respected Project Physics Course developed by two of the authors, it also integrates the results of recent pedagogical research The text thus - teaches about the basic phenomena in the physical world and the concepts developed to explain them - shows that science is a rational human endeavor with a long and continuing tradition, involving many different cultures and people - develops facility in critical thinking, reasoned argumentation, evaluation of evidence, mathematical modeling, and ethical values The treatment emphasizes not only what we know but also how we know it, why we believe it, and what effects that knowledge has - Why do we believe the Earth and planets revolve around the Sun? - Why do we believe that matter is made of atoms? - How do relativity theory and quantum mechanics alter our conception of Nature and in what ways do th...

  4. Understanding Maple

    CERN Document Server

    Thompson, Ian

    2016-01-01

    Maple is a powerful symbolic computation system that is widely used in universities around the world. This short introduction gives readers an insight into the rules that control how the system works, and how to understand, fix, and avoid common problems. Topics covered include algebra, calculus, linear algebra, graphics, programming, and procedures. Each chapter contains numerous illustrative examples, using mathematics that does not extend beyond first-year undergraduate material. Maple worksheets containing these examples are available for download from the author's personal website. The book is suitable for new users, but where advanced topics are central to understanding Maple they are tackled head-on. Many concepts which are absent from introductory books and manuals are described in detail. With this book, students, teachers and researchers will gain a solid understanding of Maple and how to use it to solve complex mathematical problems in a simple and efficient way.

  5. [Effect of Charge-Transfer Complex on Ultraviolet-Visible (UV-Vis) Absorption Property of Chromophoric Dissolved Organic Matter (CDOM) in Waters of Typical Water-Level Fluctuation Zones of the Three Gorges Reservoir Areas].

    Science.gov (United States)

    Jiang, Tao; Liang, Jian; Zhang, Mu-xue; Wang, Ding-yong; Wei, Shi-qiang; Lu, Song

    2016-02-15

    As an important fraction of dissolved organic matter (DOM), chromophoric dissolved organic matter (CDOM) plays a key role in decision of the optical properties and photogeochemistry of DOM, and further affects pollutant fate and global carbon cycle. These optical properties are ascribed to two chromophoric systems including superposition of individual chromophores and charge-transfer (CT) complexation between electron donor (e.g., phenols and indoles) and acceptor (e.g., quinones and other oxidized aromatics) in DOM structures. Thus in this study, based on the "double-chromophoric system" model, DOM samples from four typical water-level fluctuation zones of Three Gorges Reservoir (TGR) areas were selected, to investigate the effect and contribution of charge-transfer complex to ultraviolet-visible (UV-Vis) absorption property of CDOM. Using NaBH, reduction method, original featureless absorption curve was classified into two independent curves caused by individual chromophoric group, which were derived from a simple superposition of independent chromophore and charge-transfer complex, respectively. Also, the changes in curve properties and specific parameters before and after NaBH4 reduction were compared. The results showed that in all DOM samples from the four sites of TGR, more than 35% of absorption was attributed from CT complex. Shibaozhai of Zhongxian and Zhenxi of Fuling showed the highest proportion ( > 50%). It suggested that the role of CT complex in CDOM property could not be neglected. After removal of CT complex, absorption curve showed blue-shift and CDOM concentration [a (355)] decreased significantly. Meanwhile, because of deforming of bonds by reduction, DOM structures became more dispersive and the molecular size was decreased, resulting in the lower spectral slope (S) observed, which evidentially supported that the supermolecular association structure of DOM was self-assembled through CT complex. Meanwhile, deceasing hydrophobic components led

  6. Predicting Effects of Climate Change on Habitat Suitability of Red Spruce (Picea rubens Sarg. in the Southern Appalachian Mountains of the USA: Understanding Complex Systems Mechanisms through Modeling

    Directory of Open Access Journals (Sweden)

    Kyung Ah Koo

    2015-04-01

    Full Text Available Alpine, subalpine and boreal tree species, of low genetic diversity and adapted to low optimal temperatures, are vulnerable to the warming effects of global climate change. The accurate prediction of these species’ distributions in response to climate change is critical for effective planning and management. The goal of this research is to predict climate change effects on the distribution of red spruce (Picea rubens Sarg. in the Great Smoky Mountains National Park (GSMNP, eastern USA. Climate change is, however, conflated with other environmental factors, making its assessment a complex systems problem in which indirect effects are significant in causality. Predictions were made by linking a tree growth simulation model, red spruce growth model (ARIM.SIM, to a GIS spatial model, red spruce habitat model (ARIM.HAB. ARIM.SIM quantifies direct and indirect interactions between red spruce and its growth factors, revealing the latter to be dominant. ARIM.HAB spatially distributes the ARIM.SIM simulations under the assumption that greater growth reflects higher probabilities of presence. ARIM.HAB predicts the future habitat suitability of red spruce based on growth predictions of ARIM.SIM under climate change and three air pollution scenarios: 10% increase, no change and 10% decrease. Results show that suitable habitats shrink most when air pollution increases. Higher temperatures cause losses of most low-elevation habitats. Increased precipitation and air pollution produce acid rain, which causes loss of both low- and high-elevation habitats. The general prediction is that climate change will cause contraction of red spruce habitats at both lower and higher elevations in GSMNP, and the effects will be exacerbated by increased air pollution. These predictions provide valuable information for understanding potential impacts of global climate change on the spatiotemporal distribution of red spruce habitats in GSMNP.

  7. Dark matter universe.

    Science.gov (United States)

    Bahcall, Neta A

    2015-10-06

    Most of the mass in the universe is in the form of dark matter--a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations--from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is "cold" (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology--a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)--fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle.

  8. Dissociation kinetics of Fe(III)- and Al(III)-natural organic matter complexes at pH 6.0 and 8.0 and 25 °C

    Science.gov (United States)

    Jones, Adele M.; Pham, A. Ninh; Collins, Richard N.; Waite, T. David

    2009-05-01

    The rate at which iron- and aluminium-natural organic matter (NOM) complexes dissociate plays a critical role in the transport of these elements given the readiness with which they hydrolyse and precipitate. Despite this, there have only been a few reliable studies on the dissociation kinetics of these complexes suggesting half-times of some hours for the dissociation of Fe(III) and Al(III) from a strongly binding component of NOM. First-order dissociation rate constants are re-evaluated here at pH 6.0 and 8.0 and 25 °C using both cation exchange resin and competing ligand methods for Fe(III) and a cation exchange resin method only for Al(III) complexes. Both methods provide similar results at a particular pH with a two-ligand model accounting satisfactorily for the dissociation kinetics results obtained. For Fe(III), half-times on the order of 6-7 h were obtained for dissociation of the strong component and 4-5 min for dissociation of the weak component. For aluminium, the half-times were on the order of 1.5 h and 1-2 min for the strong and weak components, respectively. Overall, Fe(III) complexes with NOM are more stable than analogous complexes with Al(III), implying Fe(III) may be transported further from its source upon dilution and dispersion.

  9. D matter

    International Nuclear Information System (INIS)

    Shiu, Gary; Wang Liantao

    2004-01-01

    We study the properties and phenomenology of particlelike states originating from D branes whose spatial dimensions are all compactified. They are nonperturbative states in string theory and we refer to them as D matter. In contrast to other nonperturbative objects such as 't Hooft-Polyakov monopoles, D-matter states could have perturbative couplings among themselves and with ordinary matter. The lightest D particle (LDP) could be stable because it is the lightest state carrying certain (integer or discrete) quantum numbers. Depending on the string scale, they could be cold dark matter candidates with properties similar to that of WIMPs or wimpzillas. The spectrum of excited states of D matter exhibits an interesting pattern which could be distinguished from that of Kaluza-Klein modes, winding states, and string resonances. We speculate about possible signatures of D matter from ultrahigh energy cosmic rays and colliders

  10. Informationalising matter : systems understandings of the nanoscale.

    OpenAIRE

    Kearnes, M. B.

    2008-01-01

    Themes of mastery, domination and power are familiar to any scholar of modern technology. Science is commonly cast as enabling the technological control over both the natural and physical worlds. Indeed, Francis Bacon famously equated scientific knowledge with power itself—stating that ‘knowledge itself is a power’ (Bacon in Montagu 1825, 71). Bacon’s now ubiquitous phrase—commonly repeated as the banal ‘knowledge is power’—was an attempt to combat three heresies in scriptural interpretation ...

  11. Serving Up Vegetarian: A Matter of Understanding.

    Science.gov (United States)

    France, Cindy

    1997-01-01

    A food service manager at a resident camp discusses how she changed her attitude about vegetarianism and the strategies she used to create a vegetarian menu for staff and campers. She experimented with vegetarian recipes and allowed campers and staff their choice of menu options for each camp session. Includes information sources. (LP)

  12. Dark Matter

    International Nuclear Information System (INIS)

    Holt, S. S.; Bennett, C. L.

    1995-01-01

    These proceedings represent papers presented at the Astrophysics conference in Maryland, organized by NASA Goddard Space Flight Center and the University of Maryland. The topics covered included low mass stars as dark matter, dark matter in galaxies and clusters, cosmic microwave background anisotropy, cold and hot dark matter, and the large scale distribution and motions of galaxies. There were eighty five papers presented. Out of these, 10 have been abstracted for the Energy Science and Technology database

  13. The God Machine seeks the origin of the matter

    International Nuclear Information System (INIS)

    Martin, R.

    2015-01-01

    Under the green fields of the French-Swiss border, not far from the Alps and Lake Geneva, is hidden underground most strength Earth energy. The generated particles of low mass, subatomic, ue collide with each other in a huge circumference of 27 kilometers, the Large Hadron Collider (LHC English siglasen), an underground infrastructure that seeks to answer big questions of science: the origin of matter we know or dark matter and energy, which together occupy 95% of the universe and that we are not able to see or understand. They call it the 'god machine' and is the largest and most complex built in the world. (Author)

  14. Can a Healthcare "Lean Sweep" Deliver on What Matters to Patients? Comment on "Improving Wait Times to Care for Individuals with Multimorbidities and Complex Conditions Using Value Stream Mapping".

    Science.gov (United States)

    Verma, Jennifer Y; Amar, Claudia

    2015-07-28

    Disconnects and defects in care - such as duplication, poor integration between services or avoidable adverse events - are costly to the health system and potentially harmful to patients and families. For patients living with multiple chronic conditions, such disconnects can be particularly detrimental. Lean is an approach to optimizing value by reducing waste (eg, duplication and defects) and containing costs (eg, improving integration of services) as well as focusing on what matters to patients. Lean works particularly well to optimize existing processes and services. However, as the burden of chronic illness and frailty overtake episodic care needs, health systems require far greater complex, adaptive change. Such change ought to take into account outcomes in population health in addition to care experiences and costs (together, comprising the Triple Aim); and involve patients and families in co-designing new models of care that better address complex, longer-term health needs. © 2015 by Kerman University of Medical Sciences.

  15. Can a Healthcare “Lean Sweep” Deliver on What Matters to Patients?; Comment on “Improving Wait Times to Care for Individuals with Multimorbidities and Complex Conditions Using Value Stream Mapping”

    Directory of Open Access Journals (Sweden)

    Jennifer Y. Verma

    2015-11-01

    Full Text Available Disconnects and defects in care – such as duplication, poor integration between services or avoidable adverse events – are costly to the health system and potentially harmful to patients and families. For patients living with multiple chronic conditions, such disconnects can be particularly detrimental. Lean is an approach to optimizing value by reducing waste (eg, duplication and defects and containing costs (eg, improving integration of services as well as focusing on what matters to patients. Lean works particularly well to optimize existing processes and services. However, as the burden of chronic illness and frailty overtake episodic care needs, health systems require far greater complex, adaptive change. Such change ought to take into account outcomes in population health in addition to care experiences and costs (together, comprising the Triple Aim; and involve patients and families in co-designing new models of care that better address complex, longer-term health needs.

  16. Dark Matter

    International Nuclear Information System (INIS)

    Bashir, A.; Cotti, U.; De Leon, C. L.; Raya, A; Villasenor, L.

    2008-01-01

    One of the biggest scientific mysteries of our time resides in the identification of the particles that constitute a large fraction of the mass of our Universe, generically known as dark matter. We review the observations and the experimental data that imply the existence of dark matter. We briefly discuss the properties of the two best dark-matter candidate particles and the experimental techniques presently used to try to discover them. Finally, we mention a proposed project that has recently emerged within the Mexican community to look for dark matter

  17. Order and disorder in matter

    CERN Document Server

    Careri, Giorgio

    1984-01-01

    Order and Disorder in Matter offers a comprehensive and up-to-date view of structures and processes in matter, in terms of the evolving concepts of order and disorder. Particular emphasis is given to the recent evolution of these concepts and their relationship to the more complex systems in nature.

  18. Organic matters: investigating the sources, transport, and fate of organic matter in Fanno Creek, Oregon

    Science.gov (United States)

    Sobieszczyk, Steven; Keith, Mackenzie K.; Goldman, Jami H.; Rounds, Stewart A.

    2015-01-01

    The term organic matter refers to the remnants of all living material. This can include fallen leaves, yard waste, animal waste, downed timber, or the remains of any other plant and animal life. Organic matter is abundant both on land and in water. Investigating organic matter is necessary for understanding the fate and transport of carbon (a major constituent of organic matter).

  19. Dark matter universe

    Science.gov (United States)

    Bahcall, Neta A.

    2015-01-01

    Most of the mass in the universe is in the form of dark matter—a new type of nonbaryonic particle not yet detected in the laboratory or in other detection experiments. The evidence for the existence of dark matter through its gravitational impact is clear in astronomical observations—from the early observations of the large motions of galaxies in clusters and the motions of stars and gas in galaxies, to observations of the large-scale structure in the universe, gravitational lensing, and the cosmic microwave background. The extensive data consistently show the dominance of dark matter and quantify its amount and distribution, assuming general relativity is valid. The data inform us that the dark matter is nonbaryonic, is “cold” (i.e., moves nonrelativistically in the early universe), and interacts only weakly with matter other than by gravity. The current Lambda cold dark matter cosmology—a simple (but strange) flat cold dark matter model dominated by a cosmological constant Lambda, with only six basic parameters (including the density of matter and of baryons, the initial mass fluctuations amplitude and its scale dependence, and the age of the universe and of the first stars)—fits remarkably well all the accumulated data. However, what is the dark matter? This is one of the most fundamental open questions in cosmology and particle physics. Its existence requires an extension of our current understanding of particle physics or otherwise point to a modification of gravity on cosmological scales. The exploration and ultimate detection of dark matter are led by experiments for direct and indirect detection of this yet mysterious particle. PMID:26417091

  20. Comprehensive understanding of mole concept subject matter according to the tetrahedral chemistry education (empirical study on the first-year chemistry students of Technische Universität Dresden)

    Science.gov (United States)

    Prabowo, D. W.; Mulyani, S.; van Pée, K.-H.; Indriyanti, N. Y.

    2018-05-01

    This research aims to apprehend: (1) the shape of tetrahedral chemistry education which is called the future of chemistry education, (2) comprehensive understanding of chemistry first-year students of Technische Universität Dresden according to the chemistry education’s tetrahedral shape on mole concept subject matter. This research used quantitative and qualitative; paper and pencil test and interview. The former was conducted in the form of test containing objective test instrument. The results of this study are (1) learning based on tetrahedral shape of chemistry education put the chemical substance (macroscopic), symbolic representation (symbol), and its process (molecular) in the context of human beings (human element) by integrating content and context, without emphasis on one thing and weaken another, (2) first-year chemistry students of Technische Universität Dresden have comprehensively understood the mole concept associated with the context of everyday life, whereby students are able to find out macroscopic information from statements that are contextual to human life and then by using symbols and formulas are able to comprehend the molecular components as well as to interpret and analyse problems effectively.

  1. Distinctive EPR signals provide an understanding of the affinity of bis-(3-hydroxy-4-pyridinonato) copper(II) complexes for hydrophobic environments.

    Science.gov (United States)

    Rangel, Maria; Leite, Andreia; Silva, André M N; Moniz, Tânia; Nunes, Ana; Amorim, M João; Queirós, Carla; Cunha-Silva, Luís; Gameiro, Paula; Burgess, John

    2014-07-07

    In this work we report the synthesis and characterization of a set of 3-hydroxy-4-pyridinone copper(ii) complexes with variable lipophilicity. EPR spectroscopy was used to characterize the structure of copper(ii) complexes in solution, and as a tool to gain insight into solvent interactions. EPR spectra of solutions of the [CuL2] complexes recorded in different solvents reveal the presence of two copper species whose ratio depends on the nature of the solvent. Investigation of EPR spectra in the pure solvents methanol, dimethylsulfoxide, dichloromethane and their 50% (v/v) mixtures with toluene allowed the characterization of two types of copper signals (gzz = 2.30 and gzz = 2.26) whose spin-Hamiltonian parameters are consistent with solvated and non-solvated square-planar copper(ii) complexes. Regarding the potential biological application of ligands and complexes and to get insight into the partition properties in water-membrane interfaces, EPR spectra were also obtained in water-saturated octanol, an aqueous solution buffered at pH = 7.4 and liposome suspensions, for three compounds representative of different hydro-lipophilic balances. Analysis of the EPR spectra obtained in liposomes allowed establishment of the location of the complexes in the water and lipid phases. In view of the results of this work we put forward the use of EPR spectroscopy to assess the affinity of copper(ii) complexes for a hydrophobic environment and also to obtain indirect information about the lipophilicity of the ligands and similar EPR silent complexes.

  2. Gaseous Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    aseous Matter focuses on the many important discoveries that led to the scientific interpretation of matter in the gaseous state. This new, full-color resource describes the basic characteristics and properties of several important gases, including air, hydrogen, helium, oxygen, and nitrogen. The nature and scope of the science of fluids is discussed in great detail, highlighting the most important scientific principles upon which the field is based. Chapters include:. Gaseous Matter An Initial Perspective. Physical Characteristics of Gases. The Rise of the Science of Gases. Kinetic Theory of

  3. Colloquium: Toward living matter with colloidal particles

    Science.gov (United States)

    Zeravcic, Zorana; Manoharan, Vinothan N.; Brenner, Michael P.

    2017-07-01

    A fundamental unsolved problem is to understand the differences between inanimate matter and living matter. Although this question might be framed as philosophical, there are many fundamental and practical reasons to pursue the development of synthetic materials with the properties of living ones. There are three fundamental properties of living materials that we seek to reproduce: The ability to spontaneously assemble complex structures, the ability to self-replicate, and the ability to perform complex and coordinated reactions that enable transformations impossible to realize if a single structure acted alone. The conditions that are required for a synthetic material to have these properties are currently unknown. This Colloquium examines whether these phenomena could emerge by programming interactions between colloidal particles, an approach that bootstraps off of recent advances in DNA nanotechnology and in the mathematics of sphere packings. The argument is made that the essential properties of living matter could emerge from colloidal interactions that are specific—so that each particle can be programmed to bind or not bind to any other particle—and also time dependent—so that the binding strength between two particles could increase or decrease in time at a controlled rate. There is a small regime of interaction parameters that gives rise to colloidal particles with lifelike properties, including self-assembly, self-replication, and metabolism. The parameter range for these phenomena can be identified using a combinatorial search over the set of known sphere packings.

  4. Understanding the Southeast Asian haze

    Science.gov (United States)

    G, Karthik K. R.; Baikie, T.; T, Mohan Dass E.; Huang, Y. Z.; Guet, C.

    2017-08-01

    The Southeast Asian region had been subjected to a drastic reduction in air quality from the biomass burnings that occurred in 2013 and 2015. The smoke from the biomass burnings covered the entire region including Brunei, Indonesia, Malaysia, Singapore and Thailand, with haze particulate matter (PM) reducing the air quality to hazardous levels. Here we report a comprehensive size-composition-morphology characterization of the PM collected from an urban site in Singapore during the two haze events. The two haze events were a result of biomass burning and occurred in two different geographical source regions. We show the similarities and variations of particle size distribution during hazy and clear days during the two haze events. Sub-micron particles (method is used to determine the fractal dimensions of the PM, and the dimensionality varied for every classification from 1.79 to 1.88. We also report the complexities of particles and inconsistencies in the existing approaches to understand them.

  5. Processing of spatial and non-spatial information in rats with lesions of the medial and lateral entorhinal cortex: Environmental complexity matters.

    Science.gov (United States)

    Rodo, Christophe; Sargolini, Francesca; Save, Etienne

    2017-03-01

    The entorhinal-hippocampal circuitry has been suggested to play an important role in episodic memory but the contribution of the entorhinal cortex remains elusive. Predominant theories propose that the medial entorhinal cortex (MEC) processes spatial information whereas the lateral entorhinal cortex (LEC) processes non spatial information. A recent study using an object exploration task has suggested that the involvement of the MEC and LEC spatial and non-spatial information processing could be modulated by the amount of information to be processed, i.e. environmental complexity. To address this hypothesis we used an object exploration task in which rats with excitotoxic lesions of the MEC and LEC had to detect spatial and non-spatial novelty among a set of objects and we varied environmental complexity by decreasing the number of objects or amount of object diversity. Reducing diversity resulted in restored ability to process spatial and non-spatial information in MEC and LEC groups, respectively. Reducing the number of objects yielded restored ability to process non-spatial information in the LEC group but not the ability to process spatial information in the MEC group. The findings indicate that the MEC and LEC are not strictly necessary for spatial and non-spatial processing but that their involvement depends on the complexity of the information to be processed. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Dark matters

    International Nuclear Information System (INIS)

    Silk, Joseph

    2010-01-01

    One of the greatest mysteries in the cosmos is that it is mostly dark. That is, not only is the night sky dark, but also most of the matter and the energy in the universe is dark. For every atom visible in planets, stars and galaxies today there exists at least five or six times as much 'Dark Matter' in the universe. Astronomers and particle physicists today are seeking to unravel the nature of this mysterious but pervasive dark matter, which has profoundly influenced the formation of structure in the universe. Dark energy remains even more elusive, as we lack candidate fields that emerge from well established physics. I will describe various attempts to measure dark matter by direct and indirect means, and discuss the prospects for progress in unravelling dark energy.

  7. Dirac matter

    CERN Document Server

    Rivasseau, Vincent; Fuchs, Jean-Nöel

    2017-01-01

    This fifteenth volume of the Poincare Seminar Series, Dirac Matter, describes the surprising resurgence, as a low-energy effective theory of conducting electrons in many condensed matter systems, including graphene and topological insulators, of the famous equation originally invented by P.A.M. Dirac for relativistic quantum mechanics. In five highly pedagogical articles, as befits their origin in lectures to a broad scientific audience, this book explains why Dirac matters. Highlights include the detailed "Graphene and Relativistic Quantum Physics", written by the experimental pioneer, Philip Kim, and devoted to graphene, a form of carbon crystallized in a two-dimensional hexagonal lattice, from its discovery in 2004-2005 by the future Nobel prize winners Kostya Novoselov and Andre Geim to the so-called relativistic quantum Hall effect; the review entitled "Dirac Fermions in Condensed Matter and Beyond", written by two prominent theoreticians, Mark Goerbig and Gilles Montambaux, who consider many other mater...

  8. Understanding the Data Complexity continuum to reduce data management costs and increase data usability through partnerships with the National Centers for Environmental Information

    Science.gov (United States)

    Mesick, S.; Weathers, K. W.

    2017-12-01

    Data complexity can be seen as a continuum from complex to simple. The term data complexity refers to data collections that are disorganized, poorly documented, and generally do not follow best data management practices. Complex data collections are challenging and expensive to manage. Simplified collections readily support automated archival processes, enhanced discovery and data access, as well as production of services that make data easier to reuse. In this session, NOAA NCEI scientific data stewards will discuss the data complexity continuum. This talk will explore data simplification concepts, methods, and tools that data managers can employ which may offer more control over data management costs and processes, while achieving policy goals for open data access and ready reuse. Topics will include guidance for data managers on best allocation of limited data management resources; models for partnering with NCEI to accomplish shared data management goals; and will demonstrate through case studies the benefits of investing in documentation, accessibility, and services to increase data value and return on investment.

  9. In search of dark matter

    CERN Document Server

    Freeman, Kenneth C

    2006-01-01

    The dark matter problem is one of the most fundamental and profoundly difficult to solve problems in the history of science. Not knowing what makes up most of the known universe goes to the heart of our understanding of the Universe and our place in it. In Search of Dark Matter is the story of the emergence of the dark matter problem, from the initial erroneous ‘discovery’ of dark matter by Jan Oort to contemporary explanations for the nature of dark matter and its role in the origin and evolution of the Universe. Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.

  10. Resonant SIMP dark matter

    Directory of Open Access Journals (Sweden)

    Soo-Min Choi

    2016-07-01

    Full Text Available We consider a resonant SIMP dark matter in models with two singlet complex scalar fields charged under a local dark U(1D. After the U(1D is broken down to a Z5 discrete subgroup, the lighter scalar field becomes a SIMP dark matter which has the enhanced 3→2 annihilation cross section near the resonance of the heavier scalar field. Bounds on the SIMP self-scattering cross section and the relic density can be fulfilled at the same time for perturbative couplings of SIMP. A small gauge kinetic mixing between the SM hypercharge and dark gauge bosons can be used to make SIMP dark matter in kinetic equilibrium with the SM during freeze-out.

  11. Major Sources of Organic Matter in a Complex Coral Reef Lagoon: Identification from Isotopic Signatures (δ13C and δ15N.

    Directory of Open Access Journals (Sweden)

    Marine J Briand

    Full Text Available A wide investigation was conducted into the main organic matter (OM sources supporting coral reef trophic networks in the lagoon of New Caledonia. Sampling included different reef locations (fringing, intermediate and barrier reef, different associated ecosystems (mangroves and seagrass beds and rivers. In total, 30 taxa of macrophytes, plus pools of particulate and sedimentary OM (POM and SOM were sampled. Isotopic signatures (C and N of each OM sources was characterized and the composition of OM pools assessed. In addition, spatial and seasonal variations of reef OM sources were examined. Mangroves isotopic signatures were the most C-depleted (-30.17 ± 0.41 ‰ and seagrass signatures were the most C-enriched (-4.36 ± 0.72 ‰. Trichodesmium spp. had the most N-depleted signatures (-0.14 ± 0.03 ‰ whereas mangroves had the most N-enriched signatures (6.47 ± 0.41 ‰. The composition of POM and SOM varied along a coast-to-barrier reef gradient. River POM and marine POM contributed equally to coastal POM, whereas marine POM represented 90% of the POM on barrier reefs, compared to 10% river POM. The relative importance of river POM, marine POM and mangroves to the SOM pool decreased from fringing to barrier reefs. Conversely, the relative importance of seagrass, Trichodesmium spp. and macroalgae increased along this gradient. Overall, spatial fluctuations in POM and SOM were much greater than in primary producers. Seasonal fluctuations were low for all OM sources. Our results demonstrated that a large variety of OM sources sustain coral reefs, varying in their origin, composition and role and suggest that δ13C was a more useful fingerprint than δ15N in this endeavour. This study also suggested substantial OM exchanges and trophic connections between coral reefs and surrounding ecosystems. Finally, the importance of accounting for environmental characteristics at small temporal and spatial scales before drawing general patterns is

  12. Understanding the Effects of Team Cognition Associated with Complex Engineering Tasks: Dynamics of Shared Mental Models, Task-SMM, and Team-SMM

    Science.gov (United States)

    Lee, Miyoung; Johnson, Tristan E.

    2008-01-01

    This study investigates how shared mental models (SMMs) change over time in teams of students in a manufacturing engineering course. A complex ill-structured project was given to each team. The objective of the team project was to analyze, test, and propose ways to improve their given manufactured product. Shared mental models were measured in…

  13. Developing Seventh Grade Students' Understanding of Complex Environmental Problems with Systems Tools and Representations: A Quasi-Experimental Study

    Science.gov (United States)

    Doganca Kucuk, Zerrin; Saysel, Ali Kerem

    2018-01-01

    A systems-based classroom intervention on environmental education was designed for seventh grade students; the results were evaluated to see its impact on the development of systems thinking skills and standard science achievement and whether the systems approach is a more effective way to teach environmental issues that are dynamic and complex. A…

  14. The Nature of Conceptual Understanding in Biomedicine: The Deep Structure of Complex Ideas and the Development of Misconceptions. Technical Report No. 440.

    Science.gov (United States)

    Feltovich, Paul J.; And Others

    This report presents a general framework for studying the acquisition and cognitive representation of biomedical concepts and analyzing the nature and development of misconceptions. The central approach of the report is a selective and highly concentrated analysis of the true nature of clusters of complex concepts and the manner in which they are…

  15. Matter and memory

    CERN Document Server

    Bergson, Henri

    1991-01-01

    Since the end of the last century," Walter Benjamin wrote, "philosophy has made a series of attempts to lay hold of the 'true' experience as opposed to the kind that manifests itself in the standardized, denatured life of the civilized masses. It is customary to classify these efforts under the heading of a philosophy of life. Towering above this literature is Henri Bergson's early monumental work, Matter and Memory."Along with Husserl's Ideas and Heidegger's Being and Time, Bergson's work represents one of the great twentieth-century investigations into perception and memory, movement and time, matter and mind. Arguably Bergson's most significant book, Matter and Memory is essential to an understanding of his philosophy and its legacy.This new edition includes an annotated bibliography prepared by Bruno Paradis.Henri Bergson (1859-1941) was awarded the Nobel Prize in 1927. His works include Time and Free Will, An Introduction to Metaphysics, Creative Evolution, and The Creative Mind.

  16. Structure of matter an introductory course with problems and solutions

    CERN Document Server

    Rigamonti, Attilio

    2015-01-01

    This textbook, now in its third edition, provides a formative introduction to the structure of matter that will serve as a sound basis for students proceeding to more complex courses, thus bridging the gap between elementary physics and topics pertaining to research activities. The focus is deliberately limited to key concepts of atoms, molecules and solids, examining the basic structural aspects without paying detailed attention to the related properties. For many topics the aim has been to start from the beginning and to guide the reader to the threshold of advanced research. This edition includes four new chapters dealing with relevant phases of solid matter (magnetic, electric and superconductive) and the related phase transitions. The book is based on a mixture of theory and solved problems that are integrated into the formal presentation of the arguments. Readers will find it invaluable in enabling them to acquire basic knowledge in the wide and wonderful field of condensed matter and to understand how ...

  17. MASS-SAT: Matter-antimatter space spectrometer on satellite

    CERN Document Server

    Basini, G; Massimo Brancaccio, F; Ricci, M; Bocciolini, M; Spillantini, P; Wang, Y F; Bongiorno, F; de Pascale, M P; Morselli, A; Picozza, P; de Marzo, C; Erriquez, O; Barbiellini, G; Vacchi, A; Galeotti, P; Ballocchi, G; Simon, M; Carlson, P; Goret, P; Golden, R L

    The MASS-SAT Experiment (Matter-Antimatter Space Spectrometer on SATellite) presented here is conceived to search for an experimental answer to many open problems related to both Astrophysics and Physics, through the detection of positrons, antiprotons, nuclei and, overall, antinuclei if they exist. Among these problems there are the hypothesized presence of antigalaxies in the Universe (the matter-antimatter symmetry problem), the existence of black holes as possible antiproton sources (the Hawking effect), the existence of photinos as antiproton sources (related to the dark-matter problem), the understanding of the mechanism of cosmic-ray acceleration in the interstellar medium, the determination of the relative abundancies of isotopes in cosmic rays and many others. The choice of an orbit expecially appropriate for that (geostationary or polar orbit) as well as the choice of an apparatus composed only of solid-state detectors and permanent magnets (no gas and no liquid helium on board, avoiding complexity ...

  18. Complexity rating of abnormal events and operator performance

    International Nuclear Information System (INIS)

    Oeivind Braarud, Per

    1998-01-01

    The complexity of the work situation during abnormal situations is a major topic in a discussion of safety aspects of Nuclear Power plants. An understanding of complexity and its impact on operator performance in abnormal situations is important. One way to enhance understanding is to look at the dimensions that constitute complexity for NPP operators, and how those dimensions can be measured. A further step is to study how dimensions of complexity of the event are related to performance of operators. One aspect of complexity is the operator 's subjective experience of given difficulties of the event. Another related aspect of complexity is subject matter experts ratings of the complexity of the event. A definition and a measure of this part of complexity are being investigated at the OECD Halden Reactor Project in Norway. This paper focus on the results from a study of simulated scenarios carried out in the Halden Man-Machine Laboratory, which is a full scope PWR simulator. Six crews of two licensed operators each performed in 16 scenarios (simulated events). Before the experiment subject matter experts rated the complexity of the scenarios, using a Complexity Profiling Questionnaire. The Complexity Profiling Questionnaire contains eight previously identified dimensions associated with complexity. After completing the scenarios the operators received a questionnaire containing 39 questions about perceived complexity. This questionnaire was used for development of a measure of subjective complexity. The results from the study indicated that Process experts' rating of scenario complexity, using the Complexity Profiling Questionnaire, were able to predict crew performance quite well. The results further indicated that a measure of subjective complexity could be developed that was related to crew performance. Subjective complexity was found to be related to subjective work load. (author)

  19. Using ILD or ITD Cues for Sound Source Localization and Speech Understanding in a Complex Listening Environment by Listeners with Bilateral and with Hearing-Preservation Cochlear Implants

    Science.gov (United States)

    Loiselle, Louise H.; Dorman, Michael F.; Yost, William A.; Cook, Sarah J.; Gifford, Rene H.

    2016-01-01

    Purpose: To assess the role of interaural time differences and interaural level differences in (a) sound-source localization, and (b) speech understanding in a cocktail party listening environment for listeners with bilateral cochlear implants (CIs) and for listeners with hearing-preservation CIs. Methods: Eleven bilateral listeners with MED-EL…

  20. Understanding the Hydro-metathesis Reaction of 1-decene by Using Well-defined Silica Supported W, Mo, Ta Carbene/Carbyne Complexes

    KAUST Repository

    Saidi, Aya; Samantaray, Manoja; Tretiakov, Mykyta; Kavitake, Santosh Giridhar; Basset, Jean-Marie

    2017-01-01

    Direct conversion of 1-decene to petroleum range alkanes was obtained using hydro-metathesis reaction. To understand this reaction we employed three different well-defined single site catalysts precursors; [(≡Si-O-)W(CH3)5] 1, [(≡Si-O-)Mo(≡CtBu)(CH2

  1. Colloque S&T Symposium 2008: Understanding the Human Dimension in 21st Century Conflict/Warfare: The Complexities of Human-with-Human Relationships

    Science.gov (United States)

    2008-08-01

    intentionally left blank. DRDC Corporate TR [2008-004] v Executive summary Colloque S&T Symposium 2008: The Complexities of Human...mettaient en jeu notre capacité ou notre incapacité de déterminer le prochain choc radical et la manière dont la communauté y réagit. Il a aussi...iii Executive summary

  2. Remedial action of matrices contaminated by cobalt with supercritical CO_2: contribution to the understanding of the complex formation mechanisms and to the diphasic transfers

    International Nuclear Information System (INIS)

    Gervais, Florence

    2001-01-01

    Soils rehabilitation using supercritical CO_2 seems an interesting alternative way to existing techniques. No effluents are generated during the supercritical fluid extraction, which is the main advantage of this process. In order to be extracted by this techniques, metals or radionuclides have to be complexed by suitable chelating agents. Beta-diketones and dithiocarbamates (fluorinated or not) have been chosen. The first part of this work deals with chemical equilibria mechanisms study in an aqueous phase. Experiments show a very weak cobalt complexation kinetics with acetylacetone. Moreover, this complex exhibit a hydrophilic behaviour. On the other hand, cobalt and dithiocarbamate instantaneously from a chelate which is very hydrophobic. Mass transfer between extracting and aqueous phases (hexane and SC CO_2) are also investigated. Supercritical CO_2 seems to have a greater affinity towards fluorinated beta-diketones than hexane. This tendency is confirmed by in situ commercial chelates (fluorinates or not) solubility measurements using X-ray absorption spectroscopy. However, cobalt-beta-diketonates are hydrophilic because of their partial hydration. This kind of chelating agents is not suitable to cobalt supercritical fluid extraction from an aqueous phase. Inversely, distribution coefficients of hydrophobic dithiocarbamates are higher than beta-diketonates, whatever the extracting solvent is. Metals extraction from an aqueous matrix seems possible with these chelating agents. (author) [fr

  3. Dark matter and the equivalence principle

    Science.gov (United States)

    Frieman, Joshua A.; Gradwohl, Ben-Ami

    1993-01-01

    A survey is presented of the current understanding of dark matter invoked by astrophysical theory and cosmology. Einstein's equivalence principle asserts that local measurements cannot distinguish a system at rest in a gravitational field from one that is in uniform acceleration in empty space. Recent test-methods for the equivalence principle are presently discussed as bases for testing of dark matter scenarios involving the long-range forces between either baryonic or nonbaryonic dark matter and ordinary matter.

  4. Quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Csernai, L.; Kampert, K. H.

    1994-10-15

    Precisely one decade ago the GSI (Darmstadt)/LBL (Berkeley) Collaboration at the Berkeley Bevalac reported clear evidence for collective sidewards flow in high energy heavy ion collisions. This milestone observation clearly displayed the compression and heating up of nuclear matter, providing new insights into how the behaviour of nuclear matter changes under very different conditions. This year, evidence for azimuthally asymmetric transverse flow at ten times higher projectile energy (11 GeV per nucleon gold on gold collisions) was presented by the Brookhaven E877 collaboration at the recent European Research Conference on ''Physics of High Energy Heavy Ion Collisions'', held in Helsinki from 17-22 June.

  5. Small angle scattering from soft matter-application to complex mixed systems; Diffusion de neutrons aux petits angles par la matiere molle-application aux systemes mixtes

    Energy Technology Data Exchange (ETDEWEB)

    Boue, F.; Cousin, F.; Gummel, J.; Carrot, G.; El Harrak, A. [CEA Saclay, Lab. Leon Brillouin, CNRS, 91 - Gif-sur-Yvette (France); Oberdisse, J. [Montpellier-2 Univ., Lab. des Colloides, Verres et Nanomateriaux, UMR 5587, 34 (France)

    2007-09-15

    The advantage of small angle neutron scattering associated with isotopic labelling through deuteration is illustrated in the case of mixed systems, created by associating already well-known systems of characteristic structures; this is also important for applications. Our first mixed system associates charged polymer chains, polyelectrolyte (here polystyrene sulfonate, PSS), with oppositely charged particles, proteins (here lysozyme). Different fractions of deuterated water (D{sub 2}O) mixed with normal water are used to match the scattering length density of the protein or of the polymer in non-deuterated or deuterated version. First, this allows us to separate the protein and the polymer signal: we can then distinguish a case where the structures of each species alone in water are hardly modified by mixing, except for interconnections yielding a gel, and a case inducing complete change into a structure common to both species, made of aggregated globules. Secondly, using, for counter-ions of the poly-ions, deuterated Tetramethylammonium, together with matching both protein and polymer, we establish unambiguously the counter-ion release into the solvent. Thirdly, matching only a fraction of polymer chains, the other being deuterated, we extrapolate at zero deuterated fraction their form factor and describe the chain conformation inside the complexes. Fourthly, we illustrate the possibilities of modelling the signal on a second example of mixed system: a nano-composite made of silica particles surrounded by polymer dispersed into a deuterated polymer matrix. Chains are then visible in such reinforced polymer system, in particular when it is submitted to elongation: we discuss a possible model for an ideal system, introducing the scattering contribution from deformed chains. (authors)

  6. Dark Matter

    Indian Academy of Sciences (India)

    As if this was not enough, it turns out that if our knowledge of ... are thought to contain dark matter, although the evidences from them are the .... protons, electrons, neutrons ... ratio of protons to neutrons was close to unity then as they were in ...

  7. Quantum matter

    International Nuclear Information System (INIS)

    Buechler, Hans Peter; Calcarco, Tommaso; Dressel, Martin

    2008-01-01

    The following topics are dealt with: Artificial atoms and molecules, tailored from solids, fractional flux quanta, molecular magnets, controlled interaction in quantum gases, the theory of quantum correlations in mott matter, cold gases, and mesoscopic systems, Bose-Einstein condensates on the chip, on the route to the quantum computer, a quantum computer in diamond. (HSI)

  8. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces. E Arunan. Feature Article Volume 14 Issue 4 April 2009 pp 346-356 ...

  9. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule Matters - Dinitrogen. A G Samuelson J Jabadurai. Volume 16 Issue 12 ... Author Affiliations. A G Samuelson1 J Jabadurai1. Department of Inroganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  10. Interstellar matter

    International Nuclear Information System (INIS)

    Mezger, P.G.

    1978-01-01

    An overview of the formation of our galaxy is presented followed by a summary of recent work in star formation and related topics. Selected discussions are given on interstellar matter including absorption characteristics of dust, the fully ionised component of the ISM and the energy density of lyc-photons in the solar neighbourhood and the diffuse galactic IR radiation

  11. Dark Matter

    Indian Academy of Sciences (India)

    The study of gas clouds orbiting in the outer regions of spiral galaxies has revealed that their gravitational at- traction is much larger than the stars alone can provide. Over the last twenty years, astronomers have been forced to postulate the presence of large quantities of 'dark matter' to explain their observations. They are ...

  12. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Molecule Matters - A Chromium Compound with a Quintuple Bond. K C Kumara Swamy. Feature Article Volume 11 Issue 9 September 2006 pp 72-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Dark Matter

    International Nuclear Information System (INIS)

    Audouze, J.; Tran Thanh Van, J.

    1988-01-01

    The book begins with the papers devoted to the experimental search of signatures of the dark matter which governs the evolution of the Universe as a whole. A series of contributions describe the presently considered experimental techniques (cryogenic detectors, supraconducting detectors...). A real dialogue concerning these techniques has been instaured between particle physicists and astrophysicists. After the progress report of the particle physicists, the book provides the reader with an updated situation concerning the research in cosmology. The second part of the book is devoted to the analysis of the backgrounds at different energies such as the possible role of the cooling flows in the constitution of massive galactic halos. Any search of dark matter implies necessarily the analysis of the spatial distributions of the large scale structures of the Universe. This report is followed by a series of statistical analyses of these distributions. These analyses concern mainly universes filled up with cold dark matter. The last paper of this third part concerns the search of clustering in the spatial distribution of QSOs. The presence of dark matter should affect the solar neighborhood and related to the existence of galactic haloes. The contributions are devoted to the search of such local dark matter. Primordial nucleosynthesis provides a very powerful tool to set up quite constraining limitations on the overall baryonic density. Even if on takes into account the inhomogeneities in density possibly induced by the Quark-Hadron transition, this baryonic density should be much lower than the overall density deduced from the dynamical models of Universe or the inflationary theories

  14. Understanding the Hydro-metathesis Reaction of 1-decene by Using Well-defined Silica Supported W, Mo, Ta Carbene/Carbyne Complexes

    KAUST Repository

    Saidi, Aya

    2017-12-21

    Direct conversion of 1-decene to petroleum range alkanes was obtained using hydro-metathesis reaction. To understand this reaction we employed three different well-defined single site catalysts precursors; [(≡Si-O-)W(CH3)5] 1, [(≡Si-O-)Mo(≡CtBu)(CH2tBu)2] 2 and [(≡Si-O)Ta(=CHtBu)(CH2tBu)2] 3. We witnessed that in our conditions olefin metathesis/isomerization of 1-decene occurs much faster followed by reduction of the newly formed olefins rather than reduction of the 1-decene to decane, followed by metathesis of decane. We found that Mo-based catalyst favors 2+2 cycloaddition of 1-decene forming metallocarbene, followed by reduction of the newly formed olefins to alkanes. However, in the case of W and Ta-based catalysts, a rapid isomerization (migration) of the double bond followed by olefin metathesis and reduction of the newly formed olefins were observed. We witnessed that silica supported W catalyst precursor 1 and Mo catalyst precursor 2 are better catalysts for hydro-metathesis reaction with TONs of 818 and 808 than Ta-based catalyst 3 (TON of 334). This comparison of the catalysts provides us a better understanding that, if a catalyst is efficient in olefin metathesis reaction it would be a better catalyst for hydro-metathesis reaction.

  15. The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection.

    Science.gov (United States)

    Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

    2015-01-01

    The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity.

  16. The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection

    Science.gov (United States)

    Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

    2015-01-01

    The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity. PMID:26063964

  17. Mathematical models of granular matter

    CERN Document Server

    Mariano, Paolo; Giovine, Pasquale

    2008-01-01

    Granular matter displays a variety of peculiarities that distinguish it from other appearances studied in condensed matter physics and renders its overall mathematical modelling somewhat arduous. Prominent directions in the modelling granular flows are analyzed from various points of view. Foundational issues, numerical schemes and experimental results are discussed. The volume furnishes a rather complete overview of the current research trends in the mechanics of granular matter. Various chapters introduce the reader to different points of view and related techniques. New models describing granular bodies as complex bodies are presented. Results on the analysis of the inelastic Boltzmann equations are collected in different chapters. Gallavotti-Cohen symmetry is also discussed.

  18. Synthesis, Crystal Structures, Magnetic Properties, and Theoretical Investigation of a New Series of NiII-LnIII-WV Heterotrimetallics: Understanding the SMM Behavior of Mixed Polynuclear Complexes.

    Science.gov (United States)

    Vieru, Veacheslav; Pasatoiu, Traian D; Ungur, Liviu; Suturina, Elizaveta; Madalan, Augustin M; Duhayon, Carine; Sutter, Jean-Pascal; Andruh, Marius; Chibotaru, Liviu F

    2016-12-05

    The polynuclear compounds containing anisotropic metal ions often exhibit efficient barriers for blocking of magnetization at fairly arbitrary geometries. However, at variance with mononuclear complexes, which usually become single-molecule magnets (SMM) under the sole requirement of a highly axial crystal field at the metal ion, the factors influencing the SMM behavior in polynuclear complexes, especially, with weakly axial magnetic ions, still remain largely unrevealed. As an attempt to clarify these conditions, we present here the synthesis, crystal structures, magnetic behavior, and ab initio calculations for a new series of Ni II -Ln III -W V trimetallics, [(CN) 7 W(CN)Ni(H 2 O)(valpn)Ln(H 2 O) 4 ]·H 2 O (Ln = Y 1, Eu 2, Gd 3, Tb 4, Dy 5, Lu 6). The surprising finding is the absence of the magnetic blockage even for compounds involving strongly anisotropic Dy III and Tb III metal ions. This is well explained by ab initio calculations showing relatively large transversal components of the g-tensor in the ground exchange Kramers doublets of 1 and 4 and large intrinsic tunneling gaps in the ground exchange doublets of 3 and 5. In order to get more insight into this behavior, another series of earlier reported compounds with the same trinuclear [W V Ni II Ln III ] core structure, [(CN) 7 W(CN)Ni(dmf)(valdmpn)Ln(dmf) 4 ]·H 2 O (Ln = Gd III 7, Tb III 8a, Dy III 9, Ho III 10), [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Tb(dmf) 2.5 (H 2 O) 1.5 ]·H 2 O·0.5dmf 8b, and [(CN) 7 W(CN)Ni(H 2 O)(valdmpn)Er(dmf) 3 (H 2 O) 1 ]·H 2 O·0.5dmf 11, has been also investigated theoretically. In this series, only 8b exhibits SMM behavior which is confirmed by the present ab initio calculations. An important feature for the entire series is the strong ferromagnetic coupling between Ni(II) and W(V), which is due to an almost perfect trigonal dodecahedron geometry of the octacyano wolframate fragment. The reason why only 8b is an SMM is explained by positive zero-field splitting on the nickel

  19. Disposal Of Waste Matter

    International Nuclear Information System (INIS)

    Kim, Jeong Hyeon; Lee, Seung Mu

    1989-02-01

    This book deals with disposal of waste matter management of soiled waste matter in city with introduction, definition of waste matter, meaning of management of waste matter, management system of waste matter, current condition in the country, collect and transportation of waste matter disposal liquid waste matter, industrial waste matter like plastic, waste gas sludge, pulp and sulfuric acid, recycling technology of waste matter such as recycling system of Black clawson, Monroe and Rome.

  20. The Dark Matter of Biology.

    Science.gov (United States)

    Ross, Jennifer L

    2016-09-06

    The inside of the cell is full of important, yet invisible species of molecules and proteins that interact weakly but couple together to have huge and important effects in many biological processes. Such "dark matter" inside cells remains mostly hidden, because our tools were developed to investigate strongly interacting species and folded proteins. Example dark-matter species include intrinsically disordered proteins, posttranslational states, ion species, and rare, transient, and weak interactions undetectable by biochemical assays. The dark matter of biology is likely to have multiple, vital roles to regulate signaling, rates of reactions, water structure and viscosity, crowding, and other cellular activities. We need to create new tools to image, detect, and understand these dark-matter species if we are to truly understand fundamental physical principles of biology. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  1. Understanding the complex interplay of barriers to physical activity amongst black and minority ethnic groups in the United Kingdom: a qualitative synthesis using meta-ethnography.

    Science.gov (United States)

    Koshoedo, Sejlo A; Paul-Ebhohimhen, Virginia A; Jepson, Ruth G; Watson, Margaret C

    2015-07-12

    To conduct a meta-ethnographic analysis of qualitative studies to identify barriers to Black and Minority Ethnic (BME) individuals engaging in physical activity in the UK context. A qualitative synthesis using meta-ethnographic methods to synthesis studies of barriers to engaging in physical activity among BME groups in the UK. A comprehensive search strategy of multiple databases was employed to identify qualitative research studies published up to October 2012. The eleven searched databases included ASSIA, MEDLINE, EMBASE, CINAHL, Health Technology Assessment (HTA), NHS Scotland Library, Physical Activity Health Alliance (PAHA), PsyINFO, Social Services Abstract, Sport discuss and Web of Science. The Noblit and Hare's meta-ethnographic approach was undertaken to develop an inductive and interpretive form of knowledge synthesis. Fourteen papers met the inclusion criteria. The synthesis indicated that barriers to physical activity among BME individuals were influenced by four main concepts: perceptions; cultural expectations; personal barriers; and factors limiting access to facilities. BME individuals had different understandings of physical activity were influenced by migration history, experiences, cultural and health beliefs. This in turn may have a disempowering effect on BME individuals in terms of adopting or maintaining physical activity. These barriers to physical activity were explained at a higher conceptual level by a socio-ecological model. The social construct 'individual perception and understanding of physical activity' was particularly relevant to theoretical models and interventions. Interventions to promote engagement with physical activity need to address perceptions of this behaviour. The elicited concepts and contexts could be used to enhance the development of tailored effective health promotion interventions for BME individuals.

  2. Transport properties of dense matter

    International Nuclear Information System (INIS)

    Itoh, Naoki; Mitake, Shinichi; Iyetomi, Hiroshi; Ichimaru, Setsuo

    1983-01-01

    Transport coefficients, electrical and thermal conductivities in particular, are essential physical quantities for the theories of stellar structure. Since the discoveries of pulsars and X-ray stars, an accurate evaluation of the transport coefficients in the dense matter has become indispensable to the quantitative understanding of the observed neutron stars. The authors present improved calculations of the electrical and thermal conductivities of the dense matter in the liquid metal phase, appropriate to white dwarfs and neutron stars. (Auth.)

  3. Quark matter

    International Nuclear Information System (INIS)

    Csernai, L.; Kampert, K.H.

    1994-01-01

    Precisely one decade ago the GSI (Darmstadt)/LBL (Berkeley) Collaboration at the Berkeley Bevalac reported clear evidence for collective sidewards flow in high energy heavy ion collisions. This milestone observation clearly displayed the compression and heating up of nuclear matter, providing new insights into how the behaviour of nuclear matter changes under very different conditions. This year, evidence for azimuthally asymmetric transverse flow at ten times higher projectile energy (11 GeV per nucleon gold on gold collisions) was presented by the Brookhaven E877 collaboration at the recent European Research Conference on ''Physics of High Energy Heavy Ion Collisions'', held in Helsinki from 17-22 June

  4. Capturing prokaryotic dark matter genomes.

    Science.gov (United States)

    Gasc, Cyrielle; Ribière, Céline; Parisot, Nicolas; Beugnot, Réjane; Defois, Clémence; Petit-Biderre, Corinne; Boucher, Delphine; Peyretaillade, Eric; Peyret, Pierre

    2015-12-01

    Prokaryotes are the most diverse and abundant cellular life forms on Earth. Most of them, identified by indirect molecular approaches, belong to microbial dark matter. The advent of metagenomic and single-cell genomic approaches has highlighted the metabolic capabilities of numerous members of this dark matter through genome reconstruction. Thus, linking functions back to the species has revolutionized our understanding of how ecosystem function is sustained by the microbial world. This review will present discoveries acquired through the illumination of prokaryotic dark matter genomes by these innovative approaches. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  5. Understand Your Risk for Heart Failure

    Science.gov (United States)

    ... Heart.org Arrhythmia About Arrhythmia Why Arrhythmia Matters Understand Your Risk for Arrhythmia Symptoms, Diagnosis & Monitoring of ... Heart Defects The Impact of Congenital Heart Defects Understand Your Risk for Congenital Heart Defects Symptoms & Diagnosis ...

  6. Understanding the complexity of trans fatty acid reduction in the American diet: American Heart Association Trans Fat Conference 2006: report of the Trans Fat Conference Planning Group.

    Science.gov (United States)

    Eckel, Robert H; Borra, Susan; Lichtenstein, Alice H; Yin-Piazza, Shirley Y

    2007-04-24

    A 2-day forum was convened to discuss the current status and future implications of reducing trans fatty acids without increasing saturated fats in the food supply while maintaining functionality and consumer acceptance of packaged, processed, and prepared foods. Attendees represented the agriculture and oilseed industry and oil processing, food manufacturing, food service, government, food technology, and health and nutrition disciplines. Presentations included food science behind fatty acid technology, the health science of dietary fatty acids, alternatives to trans fatty acids, and the use of alternatives in food manufacturing and food service. The reduction of trans fatty acids in the food supply is a complex issue involving interdependent and interrelated stakeholders. Actions to reduce trans fatty acids need to carefully consider both intended and unintended consequences related to nutrition and public health. The unintended consequence of greatest concern is that fats and oils high in saturated fats, instead of the healthier unsaturated fats, might be used to replace fats and oils with trans fatty acids. Many different options of alternative oils and fats to replace trans fatty acids are available or in development. Decisions on the use of these alternatives need to consider availability, health effects, research and development investments, reformulated food quality and taste, supply-chain management, operational modifications, consumer acceptance, and cost. The conference demonstrated the value of collaboration between the food industry and health and nutrition professionals, and this conference model should be used to address other food development, processing, and/or technology issues.

  7. Ecological Understanding 2: Transformation--A Key to Ecological Understanding.

    Science.gov (United States)

    Carlsson, Britta

    2002-01-01

    Describes the structure and general features of the phenomenon of ecological understanding. Presents qualitatively different ways of experiencing cycling of matter and the flow of energy in the context of ecosystems. The idea of transformation is key to the development of ecological understanding. (Contains 17 references.) (Author/YDS)

  8. Soft Matter Characterization

    CERN Document Server

    Borsali, Redouane

    2008-01-01

    Progress in basic soft matter research is driven largely by the experimental techniques available. Much of the work is concerned with understanding them at the microscopic level, especially at the nanometer length scales that give soft matter studies a wide overlap with nanotechnology. This 2 volume reference work, split into 4 parts, presents detailed discussions of many of the major techniques commonly used as well as some of those in current development for studying and manipulating soft matter. The articles are intended to be accessible to the interdisciplinary audience (at the graduate student level and above) that is or will be engaged in soft matter studies or those in other disciplines who wish to view some of the research methods in this fascinating field. Part 1 contains articles with a largely (but, in most cases, not exclusively) theoretical content and/or that cover material relevant to more than one of the techniques covered in subsequent volumes. It includes an introductory chapter on some of t...

  9. The Complex Interplay between Chronic Inflammation, the Microbiome, and Cancer: Understanding Disease Progression and What We Can Do to Prevent It

    Directory of Open Access Journals (Sweden)

    Heather Armstrong

    2018-03-01

    Full Text Available Cancer is a multifaceted condition, in which a senescent cell begins dividing in an irregular manner due to various factors such as DNA damage, growth factors and inflammation. Inflammation is not typically discussed as carcinogenic; however, a significant percentage of cancers arise from chronic microbial infections and damage brought on by chronic inflammation. A hallmark cancer-inducing microbe is Helicobacter pylori and its causation of peptic ulcers and potentially gastric cancer. This review discusses the recent developments in understanding microbes in health and disease and their potential role in the progression of cancer. To date, microbes can be linked to almost every cancer, including colon, pancreatic, gastric, and even prostate. We discuss the known mechanisms by which these microbes can induce cancer growth and development and how inflammatory cells may contribute to cancer progression. We also discuss new treatments that target the chronic inflammatory conditions and their associated cancers, and the impact microbes have on treatment success. Finally, we examine common dietary misconceptions in relation to microbes and cancer and how to avoid getting caught up in the misinterpretation and over inflation of the results.

  10. Nuclear interactions and hadronic matter

    International Nuclear Information System (INIS)

    Petrovici, Mihai; Pop, Amalia; Stoicea, Gabriel; Berceanu, Ionela; Moisa, Dorin; Petris, Mariana; Simion, Victor; Aiftimiei, Cristina; Cruceru, Ilie; Ciobanu, Mircea; Catanescu, Vasile; Caragheorgheopol; Gheorghe

    2002-01-01

    The new generation of heavy ion accelerators and complex experimental devices, developed in the last two decades, give access to new information concerning the dynamics of nuclear collisions and allow to obtain and study in the laboratory the nuclear matter under extreme conditions of density and temperature. Of special interest is the intermediate energy region where the reactions are dominated by the competition between the mean field and nucleon-nucleon interaction. Fundamental aspects of nuclear reaction studies are probed at different instants of a nuclear collision. One can learn about the transport properties of nuclear matter in pure nucleonic regime and understand the modification of the nucleon-nucleon cross section due to various in-medium effects: density effects, effective mass, quantum effects, three-body interactions. With increasing energy, fast particle emission associated with direct nucleon-nucleon collisions in the first steps of the reaction come into play too. At higher energy, flow measurements are crucial tests of the influence of medium effects by probing the elastic part of the nucleon-nucleon collisions. On the other side, at higher incident energies, the characteristics of the nuclear equation of state (EoS) can be studied if local thermal and chemical equilibrium turns out to be established. Understanding of the properties of the nuclear matter in extreme conditions is a fundamental goal. The EoS is also an essential ingredient in the description of the massive stars leading to supernova explosion and neutron star formation. Experimental studies of such aspects needs experimental devices of high complexity which can detect and identify event by event all products coming out from heavy ion interactions at intermediate, relativistic and ultra-relativistic energies, having as complete as possible information on their mass, charge, velocity vector. CHIMERA and FOPI are such devices for intermediate and relativistic energy, respectively. Our

  11. Understanding the visual resource

    Science.gov (United States)

    Floyd L. Newby

    1971-01-01

    Understanding our visual resources involves a complex interweaving of motivation and cognitive recesses; but, more important, it requires that we understand and can identify those characteristics of a landscape that influence the image formation process. From research conducted in Florida, three major variables were identified that appear to have significant effect...

  12. Quantum simulations with photons and polaritons merging quantum optics with condensed matter physics

    CERN Document Server

    2017-01-01

    This book reviews progress towards quantum simulators based on photonic and hybrid light-matter systems, covering theoretical proposals and recent experimental work. Quantum simulators are specially designed quantum computers. Their main aim is to simulate and understand complex and inaccessible quantum many-body phenomena found or predicted in condensed matter physics, materials science and exotic quantum field theories. Applications will include the engineering of smart materials, robust optical or electronic circuits, deciphering quantum chemistry and even the design of drugs. Technological developments in the fields of interfacing light and matter, especially in many-body quantum optics, have motivated recent proposals for quantum simulators based on strongly correlated photons and polaritons generated in hybrid light-matter systems. The latter have complementary strengths to cold atom and ion based simulators and they can probe for example out of equilibrium phenomena in a natural driven-dissipative sett...

  13. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  14. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and

  15. Understanding the complexity of the Lévy-walk nature of human mobility with a multi-scale cost∕benefit model.

    Science.gov (United States)

    Scafetta, Nicola

    2011-12-01

    human mobility, that the proposed model predicts the statistical properties of human mobility below 1 km ranges, where people just walk. In the latter case, the threshold between zone 1 and zone 2 may be around 100-200 m and, perhaps, may have been evolutionary determined by the natural human high resolution visual range, which characterizes an area of interest where the benefits are assumed to be randomly and uniformly distributed. This rich and suggestive interpretation of human mobility may characterize other complex random walk phenomena that may also be described by a N-piece fit Pareto distributions with increasing integer exponents. This study also suggests that distribution functions used to fit experimental probability distributions must be carefully chosen for not improperly obscuring the physics underlying a phenomenon.

  16. Understanding the complexity of the Lévy-walk nature of human mobility with a multi-scale cost/benefit model

    Science.gov (United States)

    Scafetta, Nicola

    2011-12-01

    mobility, that the proposed model predicts the statistical properties of human mobility below 1 km ranges, where people just walk. In the latter case, the threshold between zone 1 and zone 2 may be around 100-200 m and, perhaps, may have been evolutionary determined by the natural human high resolution visual range, which characterizes an area of interest where the benefits are assumed to be randomly and uniformly distributed. This rich and suggestive interpretation of human mobility may characterize other complex random walk phenomena that may also be described by a N-piece fit Pareto distributions with increasing integer exponents. This study also suggests that distribution functions used to fit experimental probability distributions must be carefully chosen for not improperly obscuring the physics underlying a phenomenon.

  17. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    Ryu, C.; Boshier, M. G.

    2015-01-01

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

  18. Hydrogen Isotopes in Amino Acids and Soils Offer New Potential to Study Complex Processes

    Science.gov (United States)

    Fogel, M. L.; Newsome, S. D.; Williams, E. K.; Bradley, C. J.; Griffin, P.; Nakamoto, B. J.

    2016-12-01

    Hydrogen isotopes have been analyzed extensively in the earth and biogeosciences to trace water through various environmental systems. The majority of the measurements have been made on water in rocks and minerals (inorganic) or non-exchangeable H in lipids (organic), important biomarkers that represent a small fraction of the organic molecules synthesized by living organisms. Our lab has been investigating hydrogen isotopes in amino acids and complex soil organic matter, which have traditionally been thought to be too complex to interpret owing to complications from potentially exchangeable hydrogen. For the amino acids, we show how hydrogen in amino acids originates from two sources, food and water, and demonstrate that hydrogen isotopes can be routed directly between organisms. Amino acid hydrogen isotopes may unravel cycling in extremophiles in order to discover novel biochemical pathways central to the organism. For soil organic matter, recent approaches to understanding the origin of soil organic matter are pointing towards root exudates along with microbial biomass as the source, rather than aboveground leaf litter. Having an isotope tracer in very complex, potentially exchangeable organic matter can be handled with careful experimentation. Although no new instrumentation is being used per se, extension of classes of organic matter to isotope measurements has potential to open up new doors for understanding organic matter cycling on earth and in planetary materials.

  19. Optical engineering: understanding optical system by experiments

    Science.gov (United States)

    Scharf, Toralf

    2017-08-01

    Students have to be educated in theoretical and practical matters. Only one of them does not allow attacking complex problems in research, development, and management. After their study, students should be able to design, construct and analyze technical problems at highest levels of complexity. Who never experienced the difficulty of setting up measurements will not be able to understand, plan and manage such complex tasks in her/his future career. At EPFL a course was developed for bachelor education and is based on three pillars: concrete actions (enactive) to be done by the students, a synthesis of their work by writing a report (considered as the iconic part) and inputs from the teacher to generalize the findings and link it to a possible complete abstract description (symbolic). Intensive tutoring allowed an intermodal transfer between these categories. This EIS method originally introduced by Jerome Bruner for small children is particular well adapted for engineer education for which theoretical understanding often is not enough. The symbiosis of ex-cathedra lecture and practical work in a classroom-like situation presents an innovative step towards integrated learning that complements perfectly more abstract course principles like online courses.

  20. Cosmology and Dark Matter

    CERN Document Server

    Tkachev, Igor

    2017-01-01

    This lecture course covers cosmology from the particle physicist perspective. Therefore, the emphasis will be on the evidence for the new physics in cosmological and astrophysical data together with minimal theoretical frameworks needed to understand and appreciate the evidence. I review the case for non-baryonic dark matter and describe popular models which incorporate it. In parallel, the story of dark energy will be developed, which includes accelerated expansion of the Universe today, the Universe origin in the Big Bang, and support for the Inflationary theory in CMBR data.

  1. Marginal Matter

    Science.gov (United States)

    van Hecke, Martin

    2013-03-01

    All around us, things are falling apart. The foam on our cappuccinos appears solid, but gentle stirring irreversibly changes its shape. Skin, a biological fiber network, is firm when you pinch it, but soft under light touch. Sand mimics a solid when we walk on the beach but a liquid when we pour it out of our shoes. Crucially, a marginal point separates the rigid or jammed state from the mechanical vacuum (freely flowing) state - at their marginal points, soft materials are neither solid nor liquid. Here I will show how the marginal point gives birth to a third sector of soft matter physics: intrinsically nonlinear mechanics. I will illustrate this with shock waves in weakly compressed granular media, the nonlinear rheology of foams, and the nonlinear mechanics of weakly connected elastic networks.

  2. Particle dark matter: A multimessenger endeavour

    Science.gov (United States)

    Regis, M.

    2017-01-01

    The search for dark matter (DM) as a new, yet undiscovered, particle is explored through a complex host of different signals, from collider to direct and indirect searches. A special focus is dedicated to the latter ones, covering the full electromagnetic spectrum (from radio to gamma-rays), charged cosmic-rays and neutrinos. The expected DM signals are by definition faint, but the possibility to exploit a wide-field investigation offers promising prospects. In this brief review, I summarize the state-of-the-art in the search for particle DM signals, exploring some new ideas that are emerging in the effort of the scientific community to understand the elusive nature of DM.

  3. A Robust Analysis Method For Δ13c Signal Of Bulk Organic Matter In Speleothems

    Science.gov (United States)

    Bian, F.; Blyth, A. J.; Smith, C.; Baker, A.

    2017-12-01

    Speleothems preserve organic matter that is derived from both the surface soil and cave environments. This organic matter can be used to understand paleoclimate and paleoenvironments. However, a stable and quick micro-analysis method to measure the δ13C signals from speleothem organic matter separate from the total δ13C remains absent. And speleothem organic geochemistry is still relatively unexplored compared to inorganic geochemistry. In this research, for the organic matter analysis, bulk homogeneous power samples were obtained from one large stalagmite. These were dissolved by phosphoric acid to produce the aqueous solution. Then, the processed solution was degassed through a rotational vacuum concentrator. A liquid chromatograph was coupled to IRMS to control the oxidization and the measurement of analytes. This method is demonstrated to be robust for the analysis of speleothem d13C organic matter analysis under different preparation and instrumental settings, with the low standard deviation ( 0.2‰), and low sample consumption (<25 mg). Considering the complexity of cave environments, this method will be useful in further investigations the δ13C of entrapped organic matter and environmental controls in other climatic and ecological contexts, including the determination of whether vegetation or soil microbial activity is the dominant control on speleothem d13C of organic matter.

  4. Understanding the Etiology of Tuberous Sclerosis Complex

    Science.gov (United States)

    2011-07-01

    neurological symptoms (e.g. seizures), which are the most significant causes of disability and morbidity. Presently, there are no known cures for TSC and...diseases such as symptomatic epilepsy syndrome, fragile X syndrome, schizophrenia , and autism spectrum disorders (Orlova et al., 2010; Chu et al., 2009...hydramnios, megalencephaly, symptomatic epilepsy syndrome,  fragile X syndrome,  schizophrenia , and autism spectrum disorders  technical advance The

  5. Understanding the Complexity of a Rising China

    Science.gov (United States)

    2016-05-26

    tourism , shipping, and remittances from Hong Kong and other sources that resulted in overall current accounts surpluses of (US) $900 million and (US) $1.2... tourism and a surge in FDI. 95 Encyclopedia of the Nations, s.v. “China - Balance of Payments...Expenditures General Public Services Foreign Affairs National Defense Public Security Education Science and Technology Culture, Sport and Media Social Safety

  6. Understanding the Etiology of Tuberous Sclerosis Complex

    Science.gov (United States)

    2012-07-01

    catalog #4856), mouse anti-NeuN (1:500; Millipore), GFAP (1:100, DAKO) and DCX (1:500, Santa Cruz Biotechnology). Each staining was replicated in slices...Tramontin, A.D., Quinones-Hinojosa, A., Barbaro, N.M., Gupta, N., Kunwar, S., Lawton, M.T., McDermott, M.W., Parsa, A.T., Manuel -Garcia, V.J. et al

  7. Neuroscience-Enabled Complex Visual Scene Understanding

    Science.gov (United States)

    2012-04-12

    34, Rivista di Psicologia 49 (1): 7–30 • Kauppinen, Hannu. Seppanen, Tapio and Pietikainen, Matti. An Experimental Comparison of Autoregressive and...a Social Robot,“ IJCAI, pp. 1146-1151, 1999. [63] G. Heidemann, R. Rae, H. Bekel, I. Bax, and H. Ritter, ”Inte- grating Context-free and Context... social interaction. In Interna- tional Conference on Robotics, Automation, and Mecha- tronics (RAM 2006), Bangkok Thailand. Se, S., Lowe, D. G

  8. Understanding implementation and change in complex interventions

    DEFF Research Database (Denmark)

    Agergaard, Sine; Dankers, Silke; Munk, Mette

    2018-01-01

    and experiences of social inclusion in the PE context using a multi-method approach integrating quantitative and qualitative approaches. The multi-method approach allowed an integration of the findings with regard to the implementation as well as the effect of the intervention. First of all, standardized...... questionnaires provided a manipulation check of the delivery of the intervention, while qualitative observations and interviews identified the diversity in pupils’ reactions thereto. Secondly, quantitative findings on the effect of the intervention were related to qualitative findings pointing to ambiguities...

  9. Complex Networks

    CERN Document Server

    Evsukoff, Alexandre; González, Marta

    2013-01-01

    In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

  10. Matter in toy dynamical geometries

    NARCIS (Netherlands)

    Konopka, T.J.

    2009-01-01

    One of the objectives of theories describing quantum dynamical geometry is to compute expectation values of geometrical observables. The results of such computations can be affected by whether or not matter is taken into account. It is thus important to understand to what extent and to what effect

  11. The Particle Theory of Matter

    Science.gov (United States)

    Widick, Paul R.

    1969-01-01

    Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)

  12. Confinement and deconfinement of quarks in nuclear matter

    International Nuclear Information System (INIS)

    Baym, G.

    1982-01-01

    Nuclear matter at high baryon density or excitation energy is expected to undergo a transition to deconfined quark matter, a new state of matter, whose production and detection would be an exciting and basic advance in nuclear physics. These lectures summarize current understanding of quark matter and the deconfinement transition. Beginning with a review of elementary models of confinement, the basic properties of quark matter are described, estimates of the transition from hadronic to quark matter are made, and various ways one might see quark matter experimentally by production in nuclear collisions or in the form of metastable exotic nuclear objects are discussed. (author)

  13. Condensed Matter Nuclear Science

    Science.gov (United States)

    Biberian, Jean-Paul

    2006-02-01

    into characteristics of X-ray emission laser beams from solidstate cathode medium of high-current glow discharge / A. B. Karabut. Charged particles from Ti and Pd foils / L. Kowalski ... [et al.]. Cr-39 track detectors in cold fusion experiments: review and perspectives / A. S. Roussetski. Energetic particle shower in the vapor from electrolysis / R. A. Oriani and J. C. Fisher. Nuclear reactions produced in an operating electrolysis cell / R. A. Oriani and J. C. Fisher. Evidence of microscopic ball lightning in cold fusion experiments / E. H. Lewis. Neutron emission from D[symbol] gas in magnetic fields under low temperature / T. Mizuno ... [et al.]. Energetic charged particle emission from hydrogen-loaded Pd and Ti cathodes and its enhancement by He-4 implantation / A. G. Lipson ... [et al.]. H-D permeation. Observation of nuclear transmutation reactions induced by D[symbol] gas permeation through Pd complexes / Y. Iwamura ... [et al.]. Deuterium (hydrogen) flux permeating through palladium and condensed matter nuclear science / Q. M. Wei ... [et al.]. Triggering. Precursors and the fusion reactions in polarized Pd/D-D[symbol]O system: effect of an external electric field / S. Szpak, P. A. Mosier-Boss, and F. E. Gordon. Calorimetric and neutron diagnostics of liquids during laser irradiation / Yu. N. Bazhutov ... [et al.]. Anomalous neutron capture and plastic deformation of Cu and Pd cathodes during electrolysis in a weak thermalized neutron field: evidence of nuclei-lattice exchange / A. G. Lipson and G. H. Miley. H-D loading. An overview of experimental studies on H/Pd over-loading with thin Pd wires and different electrolytic solutions / A. Spallone ... [et al.] -- 3. Transmutations. Photon and particle emission, heat production, and surface transformation in Ni-H system / E. Campari ... [et al.]. Surface analysis of hydrogen-loaded nickel alloys / E. Campari ... [et al.]. Low-energy nuclear reactions and the leptonic monopole / G. Lochak and L. Urutskoev. Results

  14. Mirror dark matter and large scale structure

    International Nuclear Information System (INIS)

    Ignatiev, A.Yu.; Volkas, R.R.

    2003-01-01

    Mirror matter is a dark matter candidate. In this paper, we reexamine the linear regime of density perturbation growth in a universe containing mirror dark matter. Taking adiabatic scale-invariant perturbations as the input, we confirm that the resulting processed power spectrum is richer than for the more familiar cases of cold, warm and hot dark matter. The new features include a maximum at a certain scale λ max , collisional damping below a smaller characteristic scale λ S ' , with oscillatory perturbations between the two. These scales are functions of the fundamental parameters of the theory. In particular, they decrease for decreasing x, the ratio of the mirror plasma temperature to that of the ordinary. For x∼0.2, the scale λ max becomes galactic. Mirror dark matter therefore leads to bottom-up large scale structure formation, similar to conventional cold dark matter, for x(less-or-similar sign)0.2. Indeed, the smaller the value of x, the closer mirror dark matter resembles standard cold dark matter during the linear regime. The differences pertain to scales smaller than λ S ' in the linear regime, and generally in the nonlinear regime because mirror dark matter is chemically complex and to some extent dissipative. Lyman-α forest data and the early reionization epoch established by WMAP may hold the key to distinguishing mirror dark matter from WIMP-style cold dark matter

  15. Quantifying the degradation of organic matter in marine sediments: A review and synthesis

    Science.gov (United States)

    Arndt, Sandra; Jørgensen, B. B.; LaRowe, D. E.; Middelburg, J. J.; Pancost, R. D.; Regnier, P.

    2013-08-01

    Quantifying the rates of biogeochemical processes in marine sediments is essential for understanding global element cycles and climate change. Because organic matter degradation is the engine behind benthic dynamics, deciphering the impact that various forces have on this process is central to determining the evolution of the Earth system. Therefore, recent developments in the quantitative modeling of organic matter degradation in marine sediments are critically reviewed. The first part of the review synthesizes the main chemical, biological and physical factors that control organic matter degradation in sediments while the second part provides a general review of the mathematical formulations used to model these processes and the third part evaluates their application over different spatial and temporal scales. Key transport mechanisms in sedimentary environments are summarized and the mathematical formulation of the organic matter degradation rate law is described in detail. The roles of enzyme kinetics, bioenergetics, temperature and biomass growth in particular are highlighted. Alternative model approaches that quantify the degradation rate constant are also critically compared. In the third part of the review, the capability of different model approaches to extrapolate organic matter degradation rates over a broad range of temporal and spatial scales is assessed. In addition, the structure, functions and parameterization of more than 250 published models of organic matter degradation in marine sediments are analyzed. The large range of published model parameters illustrates the complex nature of organic matter dynamics, and, thus, the limited transferability of these parameters from one site to another. Compiled model parameters do not reveal a statistically significant correlation with single environmental characteristics such as water depth, deposition rate or organic matter flux. The lack of a generic framework that allows for model parameters to be

  16. Plasma dark matter direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, J.D.; Foot, R., E-mail: j.clarke5@pgrad.unimelb.edu.au, E-mail: rfoot@unimelb.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Victoria 3010 Australia (Australia)

    2016-01-01

    Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless 'dark photon' (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.

  17. Baryonic matter and beyond

    OpenAIRE

    Fukushima, Kenji

    2014-01-01

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  18. Strange matter in compact stars

    Science.gov (United States)

    Klähn, Thomas; Blaschke, David B.

    2018-02-01

    We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations) remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

  19. Strange matter in compact stars

    Directory of Open Access Journals (Sweden)

    Klähn Thomas

    2018-01-01

    Full Text Available We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

  20. Theory of electronic excitations: a complex story

    International Nuclear Information System (INIS)

    Reinig, L.

    2014-01-01

    The interaction of radiation with matter is a challenge for condensed matter physics. Indeed, it consists in understanding how a collective system of about 10 23 electrons reacts to a perturbation. The difficulty lays in the fact that the electrons are not independent and the correlations between electrons appear for instance in the complexity of the energy spectra of the electrons released in the photon-induced emission process. It is unrealistic to solve the multi-particle Schroedinger equation that describes the behaviour of 10 23 electrons, the challenge is to find adequate mathematical models and approximations that contains the physics we want to study. Feynman diagrams are used to interpret the equations more easily

  1. Halal Matters

    DEFF Research Database (Denmark)

    In today’s globalized world, halal (meaning ‘permissible’ or ‘lawful’) is about more than food. Politics, power and ethics all play a role in the halal industry in setting new standards for production, trade, consumption and regulation. The question of how modern halal markets are constituted...... is increasingly important and complex. Written from a unique interdisciplinary global perspective, this book demonstrates that as the market for halal products and services is expanding and standardizing, it is also fraught with political, social and economic contestation and difference. The discussion...

  2. Snow Matters

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Jensen, Martin Trandberg

    2018-01-01

    attribute of high altitude mountain destinations. Hitherto, researchers mostly engaged with snowclad landscapes as a backstage; trying to deconstruct the complex symbolism and representational qualities of this elusive substance. Despite snow being a strategically crucial condition for tourism in the Alps......This chapter explores the performative potential of snow for Alpine tourism, by drawing attention to its material and nonrepresentational significance for tourism practices. European imagination has been preoccupied with snow since medieval times and even today, snow features as the sine que non...

  3. New Approaches in Soil Organic Matter Fluorescence; A Solid Phase Fluorescence Approach

    Science.gov (United States)

    Bowman, M. M.; Sanclements, M.; McKnight, D. M.

    2017-12-01

    Fluorescence spectroscopy is a well-established technique to investigate the composition of organic matter in aquatic systems and is increasingly applied to soil organic matter (SOM). Current methods require that SOM be extracted into a liquid prior to analysis by fluorescence spectroscopy. Soil extractions introduce an additional layer of complexity as the composition of the organic matter dissolved into solution varies based upon the selected extractant. Water is one of the most commonly used extractant, but only extracts the water-soluble fraction of the SOM with the insoluble soil organic matter fluorescence remaining in the soil matrix. We propose the use of solid phase fluorescence on whole soils as a potential tool to look at the composition of organic matter without the extraction bias and gain a more complete understand of the potential for fluorescence as a tool in terrestrial studies. To date, the limited applications of solid phase fluorescence have ranged from food and agriculture to pharmaceutical with no clearly defined methods and limitations available. We are aware of no other studies that use solid phase fluorescence and thus no clear methods to look at SOM across a diverse set of soil types and ecosystems. With this new approach to fluorescence spectroscopy there are new challenges, such as blank correction, inner filter effect corrections, and sample preparation. This work outlines a novel method for analyzing soil organic matter using solid phase fluorescence across a wide range of soils collected from the National Ecological Observatory Network (NEON) eco-domains. This method has shown that organic matter content in soils must be diluted to 2% to reduce backscattering and oversaturation of the detector in forested soils. In mineral horizons (A) there is observed quenching of the humic-like organic matter, which is likely a result of organo-mineral complexation. Finally, we present preliminary comparisons between solid and liquid phase

  4. Managing Complexity

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  5. ADHESION EFFECTS WITHIN THE HARD MATTER – SOFT MATTER INTERFACE: MOLECULAR DYNAMICS

    Directory of Open Access Journals (Sweden)

    Alexey Tsukanov

    2016-12-01

    Full Text Available In the present study three soft matter – hard matter systems consisting of different nanomaterials and organic molecules were studied using the steered molecular dynamics approach in order to reveal regularities in the formation of organic-inorganic hybrids and the stability of multimolecular complexes, as well as to analyze the energy aspects of adhesion between bio-molecules and layered ceramics. The combined process free energy estimation (COPFEE procedure was used for quantitative and qualitative assessment of the considered heterogeneous systems. Interaction of anionic and cationic amino acids with the surface of a [Mg4Al2(OH122+ 2Cl–] layered double hydroxide (LDH nanosheet was considered. In both cases, strong adhesion was observed despite the opposite signs of electric charge. The free energy of the aspartic amino acid anion, which has two deprotonated carboxylic groups, was determined to be –45 kJ/mol for adsorption on the LDH surface. For the cationic arginine, with only one carboxylic group and a positive net charge, the energy of adsorption was –26 kJ/mol, which is twice higher than that of chloride anion adsorption on the same cationic nanosheet. This fact clearly demonstrates the capability of “soft matter” species to adjust themselves and fit into the surface, minimizing energy of the system. The adsorption of protonated histamine, having no carboxylic groups, on a boehmite nanosheet is also energetically favorable, but the depth of free energy well is quite small at 3.6 kJ/mol. In the adsorbed state the protonated amino-group of histamine plays the role of proton donor, while the hydroxyl oxygens of the layered hydroxide have the role of proton acceptor, which is unusual. The obtained results represent a small step towards further understanding of the adhesion effects within the hard matter – soft matter contact zone.

  6. Front Matter

    Directory of Open Access Journals (Sweden)

    HLRC Editor

    2016-08-01

    Full Text Available Higher Learning Research Communications (HLRC, ISSN: 2157-6254 [Online] is published collaboratively by Walden University (USA, Universidad Andrés Bello (Chile, Universidad Europea de Madrid (Spain and Istanbul Bilgi University (Turkey. Written communication to HLRC should be addressed to the office of the Executive Director at Laureate Education, Inc. 701 Brickell Ave Ste. 1700, Miami, FL 33131, USA. HLRC is designed for open access and online distribution through www.hlrcjournal.com. The views and statements expressed in this journal do not necessarily reflect the views of Laureate Education, Inc. or any of its affiliates (collectively “Laureate”. Laureate does not warrant the accuracy, reliability, currency or completeness of those views or statements and does not accept any legal liability arising from any reliance on the views, statements and subject matter of the journal. Acknowledgements The Guest Editors gratefully acknowledge the substantial contribution of the readers for the blind peer review of essays submitted for this special issue as exemplars of individuals from around the world who have come together in a collective endeavor for the common good: Robert Bringle (Indiana University Purdue University Indianapolis, US, Linda Buckley (University of the Pacific, US, Guillermo Calleja (Universidad Rey Juan Carlos, Spain, Eva Egron-Polak (International Association of Universities, France, Heather Friesen (Abu Dhabi University, UAE, Saran Gill (National University of Malaysia, Malaysia, Chester Haskell (higher education consultant, US, Kanokkarn Kaewnuch (National Institute for Development Administration, Thailand, Gil Latz (Indiana University Purdue University Indianapolis, US, Molly Lee (higher education consultant, Malaysia, Deane Neubauer (East-West Center at University of Hawaii, US, Susan Sutton (Bryn Mawr College, US, Francis Wambalaba (United States International University, Kenya, and Richard Winn (higher education

  7. Condensed matter analogues of cosmology

    Science.gov (United States)

    Kibble, Tom; Srivastava, Ajit

    2013-10-01

    It is always exciting when developments in one branch of physics turn out to have relevance in a quite different branch. It would be hard to find two branches farther apart in terms of energy scales than early-universe cosmology and low-temperature condensed matter physics. Nevertheless ideas about the formation of topological defects during rapid phase transitions that originated in the context of the very early universe have proved remarkably fruitful when applied to a variety of condensed matter systems. The mathematical frameworks for describing these systems can be very similar. This interconnection has led to a deeper understanding of the phenomena in condensed matter systems utilizing ideas from cosmology. At the same time, one can view these condensed matter analogues as providing, at least in a limited sense, experimental access to the phenomena of the early universe for which no direct probe is possible. As this special issue well illustrates, this remains a dynamic and exciting field. The basic idea is that when a system goes through a rapid symmetry-breaking phase transition from a symmetric phase into one with spontaneously broken symmetry, the order parameter may make different choices in different regions, creating domains that when they meet can trap defects. The scale of those domains, and hence the density of defects, is constrained by the rate at which the system goes through the transition and the speed with which order parameter information propagates. This is what has come to be known as the Kibble-Zurek mechanism. The resultant scaling laws have now been tested in a considerable variety of different systems. The earliest experiments illustrating the analogy between cosmology and condensed matter were in liquid crystals, in particular on the isotropic-to-nematic transition, primarily because it is very easy to induce the phase transition (typically at room temperature) and to image precisely what is going on. This field remains one of the

  8. Understanding the Attributes of Implementation Frameworks to Guide the Implementation of a Model of Community-based Integrated Health Care for Older Adults with Complex Chronic Conditions: A Metanarrative Review

    Directory of Open Access Journals (Sweden)

    Ann McKillop

    2017-06-01

    Full Text Available Introduction: Many studies have investigated the process of healthcare implementation to understand better how to bridge gaps between recommended practice, the needs and demands of healthcare consumers, and what they actually receive. However, in the implementation of integrated community-based and integrated health care, it is still not well known which approaches work best.  Methods: We conducted a systematic review and metanarrative synthesis of literature on implementation frameworks, theories and models in support of a research programme investigating CBPHC for older adults with chronic health problems. Results: Thirty-five reviews met our inclusion criteria and were appraised, summarised, and synthesised. Five metanarratives emerged 1 theoretical constructs; 2 multiple influencing factors; 3 development of new frameworks; 4 application of existing frameworks; and 5 effectiveness of interventions within frameworks/models. Four themes were generated that exposed the contradictions and synergies among the metanarratives. Person-centred care is fundamental to integrated CBPHC at all levels in the health care delivery system, yet many implementation theories and frameworks neglect this cornerstone.  Discussion: The research identified perspectives central to integrated CBPHC that were missing in the literature. Context played a key role in determining success and in how consumers and their families, providers, organisations and policy-makers stay connected to implementing the best care possible.  Conclusions: All phases of implementation of a new model of CBPHC call for collaborative partnerships with all stakeholders, the most important being the person receiving care in terms of what matters most to them.

  9. Using global sensitivity analysis to understand higher order interactions in complex models: an application of GSA on the Revised Universal Soil Loss Equation (RUSLE) to quantify model sensitivity and implications for ecosystem services management in Costa Rica

    Science.gov (United States)

    Fremier, A. K.; Estrada Carmona, N.; Harper, E.; DeClerck, F.

    2011-12-01

    Appropriate application of complex models to estimate system behavior requires understanding the influence of model structure and parameter estimates on model output. To date, most researchers perform local sensitivity analyses, rather than global, because of computational time and quantity of data produced. Local sensitivity analyses are limited in quantifying the higher order interactions among parameters, which could lead to incomplete analysis of model behavior. To address this concern, we performed a GSA on a commonly applied equation for soil loss - the Revised Universal Soil Loss Equation. USLE is an empirical model built on plot-scale data from the USA and the Revised version (RUSLE) includes improved equations for wider conditions, with 25 parameters grouped into six factors to estimate long-term plot and watershed scale soil loss. Despite RUSLE's widespread application, a complete sensitivity analysis has yet to be performed. In this research, we applied a GSA to plot and watershed scale data from the US and Costa Rica to parameterize the RUSLE in an effort to understand the relative importance of model factors and parameters across wide environmental space. We analyzed the GSA results using Random Forest, a statistical approach to evaluate parameter importance accounting for the higher order interactions, and used Classification and Regression Trees to show the dominant trends in complex interactions. In all GSA calculations the management of cover crops (C factor) ranks the highest among factors (compared to rain-runoff erosivity, topography, support practices, and soil erodibility). This is counter to previous sensitivity analyses where the topographic factor was determined to be the most important. The GSA finding is consistent across multiple model runs, including data from the US, Costa Rica, and a synthetic dataset of the widest theoretical space. The three most important parameters were: Mass density of live and dead roots found in the upper inch

  10. Hyperons in dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Dapo, Haris

    2009-01-28

    -body force with a density-dependent interaction. This density-dependent interaction is fitted to the saturation properties of nuclear matter and used together with the V{sub low} {sub k} potential. The study of in-medium properties with these interactions is accomplished with a combination of Fermi liquid theory and random phase approximation(RPA). The Fermi liquid theory is then used to obtain the strength of the particle-hole interactions. The medium's response to neutrinos is represented via changes of the polarization function in the random phase approximation. The properties of neutrinos in dense matter are studied in both, Hartree-Fock and random phase, approximation. To understand how the changes in the mediums response alter the behavior of neutrinos in dense matter, we calculate the neutrino cross section and the neutrino mean free path. The neutrinos interact with baryons and leptons through the weak interaction, hence we calculate these for both neutral and charged currents. (orig.)

  11. Hyperons in dense matter

    International Nuclear Information System (INIS)

    Dapo, Haris

    2009-01-01

    density-dependent interaction is fitted to the saturation properties of nuclear matter and used together with the V low k potential. The study of in-medium properties with these interactions is accomplished with a combination of Fermi liquid theory and random phase approximation(RPA). The Fermi liquid theory is then used to obtain the strength of the particle-hole interactions. The medium's response to neutrinos is represented via changes of the polarization function in the random phase approximation. The properties of neutrinos in dense matter are studied in both, Hartree-Fock and random phase, approximation. To understand how the changes in the mediums response alter the behavior of neutrinos in dense matter, we calculate the neutrino cross section and the neutrino mean free path. The neutrinos interact with baryons and leptons through the weak interaction, hence we calculate these for both neutral and charged currents. (orig.)

  12. Complex analysis

    CERN Document Server

    Freitag, Eberhard

    2005-01-01

    The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...

  13. Understanding Alzheimer's

    Science.gov (United States)

    ... Navigation Bar Home Current Issue Past Issues Understanding Alzheimer's Past Issues / Fall 2007 Table of Contents For ... and brain scans. No treatment so far stops Alzheimer's. However, for some in the disease's early and ...

  14. Understanding of the characteristics of the local newspapers providing media coverage on the matters of nuclear energy in the regions where nuclear facilities are located. Based on analysis of the media reports and interviews with journalists

    International Nuclear Information System (INIS)

    Tsuchida, Tatsuro; Kimura, Hiroshi

    2011-01-01

    Taking into consideration the influence of the media coverage, this research aims to analyze the characteristics of the local newspapers that cover diverse events relevant to nuclear energy in regional areas where nuclear facilities are located (hereinafter called the 'region'). According to the previous surveys, local residents in the region are more interested in the nuclear energy matters than those who live in urban areas. Plus, the local newspapers turn out to report more events of nuclear energy from a variety of angles. Through interviews with executives and journalists of the local newspaper companies in the regions, it is revealed that the local newspapers tend not to report news sensationally, but they would rather take a supportive stance toward the development in their regions. The interviewees hope that various activities of the nuclear industry will promote education, employment and cooperation among government, industry and academia. They also desire that the industry's activities will help to increase benefits in their regions. It appears that the interviewees' awareness reflects articles of the local newspapers. As a result of the surveys conducted for this research, it is considered that the journalists expect that their region will make particularly qualitative progress in the future. (author)

  15. Understanding the structure

    Science.gov (United States)

    David J. Nowak

    1994-01-01

    Urban forests are complex ecosystems created by the interaction of anthropogenic and natural processes. One key to better management of these systems is to understand urban forest structure and its relationship to forest functions. Through sampling and inventories, urban foresters often obtain structural information (e.g., numbers, location, size, and condition) on...

  16. Critique Matters

    DEFF Research Database (Denmark)

    Holck, Lotte; Muhr, Sara Louise

    to cross-cultural training offered to Danish officers on a pre-departure course as well as at a leadership seminar for the top-management team in Greenland Police. The paper demonstrates how critical-affirmative interventions of tempered radicalism might instigate small scale practitioner-relevant changes......Concerned with tackling central issues within organizational diversity such as power inequality, managerial control and domination, critical diversity research has a potential for real, substantive changes. Yet this potential is by and large untapped, as critical diversity researcher have...... a tradition for passive methods with the researcher standing on the ‘outside’ pointing to problematic organizational practices. Echoing Lewin’s (1946) assentation that ‘to understand a system, you have to try and change it’, this paper explores how intervention-based research can be a way to conduct...

  17. Urban tree effects on fine particulate matter and human health

    Science.gov (United States)

    David J. Nowak

    2014-01-01

    Overall, city trees reduce particulate matter and provide substantial health benefits; but under certain conditions, they can locally increase particulate matter concentrations. Urban foresters need to understand how trees affect particulate matter so they can select proper species and create appropriate designs to improve air quality. This article details trees'...

  18. Embodied Understanding

    Directory of Open Access Journals (Sweden)

    Mark Leonard Johnson

    2015-06-01

    Full Text Available Western culture has inherited a view of understanding as an intellectual cognitive operation of grasping of concepts and their relations. However, cognitive science research has shown that this received intellectualist conception is substantially out of touch with how humans actually make and experience meaning. The view emerging from the mind sciences recognizes that understanding is profoundly embodied, insofar as our conceptualization and reasoning recruit sensory, motor, and affective patterns and processes to structure our understanding of, and engagement with, our world. A psychologically realistic account of understanding must begin with the patterns of ongoing interaction between an organism and its physical and cultural environments and must include both our emotional responses to changes in our body and environment, and also the actions by which we continuously transform our experience. Consequently, embodied understanding is not merely a conceptual/propositional activity of thought, but rather constitutes our most basic way of being in, and engaging with, our surroundings in a deep visceral manner.

  19. Is old organic matter simple organic matter?

    Science.gov (United States)

    Nunan, Naoise; Lerch, Thomas; Pouteau, Valérie; Mora, Philippe; Changey, Fréderique; Kätterer, Thomas; Herrmann, Anke

    2016-04-01

    Bare fallow soils that have been deprived of fresh carbon inputs for prolonged periods contain mostly old, stable organic carbon. In order to shed light on the nature of this carbon, the functional diversity profiles (MicroResp™, Biolog™ and enzyme activity spectra) of the microbial communities of long-term barefallow soils were analysed and compared with those of the microbial communities from their cultivated counterparts. The study was based on the idea that microbial communities adapt to their environment and that therefore the catabolic and enzymatic profiles would reflect the type of substrates available to the microbial communities. The catabolic profiles suggested that the microbial communities in the long-term bare-fallow soil were exposed to a less diverse range of substrates and that these substrates tended to be of simpler molecular forms. Both the catabolic and enzyme activity profiles suggested that the microbial communities from the long-term bare-fallow soils were less adapted to using polymers. These results do not fit with the traditional view of old, stable carbon being composed of complex, recalcitrant polymers. An energetics analysis of the substrate use of the microbial communities for the different soils suggested that the microbial communities from the long-term bare-fallow soils were better adapted to using readily oxidizable,although energetically less rewarding, substrates. Microbial communities appear to adapt to the deprivation of fresh organic matter by using substrates that require little investment.

  20. Conducting compositions of matter

    Science.gov (United States)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.