WorldWideScience

Sample records for subject matter general

  1. Changes in Dictionary Subject Matter

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2003-01-01

    The general content of the three editions of the Duden dictionary has undergone few changes. The most substantial changes are the addition of syllabification and the deletion of antonomy in respect of lemmata in the second and third editions. The concept of dictionary subject matter is questioned......, and it is argued that it is more appropriate to consider how the relationships between the classes of items interact with the function of the dictionary....

  2. Does Variation in the Extent of Generalized Trust, Individual Education and Extensiveness of Social Security Policies Matter for Maximization of Subjective Well-Being?

    Science.gov (United States)

    Valeeva, Rania F.

    2016-01-01

    In this paper, I examine whether generalized trust and education, as well as social security policies of welfare state institutions matter for cross-national differences in subjective well-being (SWB), because knowledge on this issue is still lacking. For this purpose I integrated the insights of two sociological theories: Social Function…

  3. Distinguishing medication-free subjects with unipolar disorder from subjects with bipolar disorder: state matters.

    Science.gov (United States)

    Rive, Maria M; Redlich, Ronny; Schmaal, Lianne; Marquand, André F; Dannlowski, Udo; Grotegerd, Dominik; Veltman, Dick J; Schene, Aart H; Ruhé, Henricus G

    2016-11-01

    Recent studies have indicated that pattern recognition techniques of functional magnetic resonance imaging (fMRI) data for individual classification may be valuable for distinguishing between major depressive disorder (MDD) and bipolar disorder (BD). Importantly, medication may have affected previous classification results as subjects with MDD and BD use different classes of medication. Furthermore, almost all studies have investigated only depressed subjects. Therefore, we focused on medication-free subjects. We additionally investigated whether classification would be mood state independent by including depressed and remitted subjects alike. We applied Gaussian process classifiers to investigate the discriminatory power of structural MRI (gray matter volumes of emotion regulation areas) and resting-state fMRI (resting-state networks implicated in mood disorders: default mode network [DMN], salience network [SN], and lateralized frontoparietal networks [FPNs]) in depressed (n=42) and remitted (n=49) medication-free subjects with MDD and BD. Depressed subjects with MDD and BD could be classified based on the gray matter volumes of emotion regulation areas as well as DMN functional connectivity with 69.1% prediction accuracy. Prediction accuracy using the FPNs and SN did not exceed chance level. It was not possible to discriminate between remitted subjects with MDD and BD. For the first time, we showed that medication-free subjects with MDD and BD can be differentiated based on structural MRI as well as resting-state functional connectivity. Importantly, the results indicated that research concerning diagnostic neuroimaging tools distinguishing between MDD and BD should consider mood state as only depressed subjects with MDD and BD could be correctly classified. Future studies, in larger samples are needed to investigate whether the results can be generalized to medication-naïve or first-episode subjects. © 2016 John Wiley & Sons A/S. Published by John Wiley

  4. Subject Matter Expert Workshop to Identify Cybersecurity ...

    Science.gov (United States)

    Report In recognition of the growing need to better address cyber risk and cyber management, the U.S. Environmental Protection Agency’s (EPA) National Homeland Security Research Center (NHSRC) held a Subject Matter Expert Workshop to Identify Cybersecurity Research Gaps and Needs of the Nation’s Water and Wastewater Systems Sector on March 30th and 31st, 2016, at the Ronald Reagan Building in Washington, D.C. The workshop was designed to create a forum for subject matter experts (SMEs) to exchange ideas and address important cybersecurity challenges facing the water sector.

  5. Teachers mathematical communication profile in explaining subject matter

    Science.gov (United States)

    Umami, Rohmatul; Budayasa, I. Ketut; Suwarsono, St.

    2017-12-01

    This study aimed to see a teachers mathematical communication profile in explaining a subject matter. It is a qualitative research. A high-school junior teacher (i.e., a teacher with 1- to 5-year experience) teaching mathematics at X-Social Class was selected as the subject of this study. The data was collected by observing the teachers mathematical communication in explaining a given material (i.e., the rule of sine) in class and an in-depth interview would be organized respectively. The result showed that the junior teacher explained the subject matter in systematic, complete, fluent, and centered manner. In this case, she began with reminding students on the previous material related to the current material to be learned, informing the current learning objectives, and finally delivering the subject matter. To support her explanation, the teacher also provided some related information, led the students attention into the given material by asking them particular related questions, and did not use any confusing terms. However, the study found that some of high-school teachers still used less appropriate language in explaining materials.

  6. Conditioning audience patronage using subject matters in ...

    African Journals Online (AJOL)

    Conditioning audience patronage using subject matters in Nollywood films: the example of 30 days in Atlanta. ... Abstract. Films are subject-based and when producers set out to communicate their viewpoints, some do it flamboyantly while others take the subtle path. Unlike live theatre before it, the possibility of a virile spiral ...

  7. Distinct white matter abnormalities in different idiopathic generalized epilepsy syndromes.

    Science.gov (United States)

    Liu, Min; Concha, Luis; Beaulieu, Christian; Gross, Donald W

    2011-12-01

    By definition idiopathic generalized epilepsy (IGE) is not associated with structural abnormalities on conventional magnetic resonance imaging (MRI). However, recent quantitative studies suggest white and gray matter alterations in IGE. The purpose of this study was to investigate whether there are white and/or gray matter structural differences between controls and two subsets of IGE, namely juvenile myoclonic epilepsy (JME) and IGE with generalized tonic-clonic seizures only (IGE-GTC). We assessed white matter integrity and gray matter volume using diffusion tensor tractography-based analysis of fractional anisotropy and voxel-based morphometry, respectively, in 25 patients with IGE, all of whom had experienced generalized tonic-clonic convulsions. Specifically, 15 patients with JME and 10 patients with IGE-GTC were compared to two groups of similarly matched controls separately. Correlations between total lifetime generalized tonic-clonic seizures and fractional anisotropy were investigated for both groups. Tractography revealed lower fractional anisotropy in specific tracts including the crus of the fornix, body of corpus callosum, uncinate fasciculi, superior longitudinal fasciculi, anterior limb of internal capsule, and corticospinal tracts in JME with respect to controls, whereas there were no fractional anisotropy differences in IGE-GTC. No correlation was found between fractional anisotropy and total lifetime generalized tonic-clonic seizures for either JME or IGE-GTC. Although false discovery rate-corrected voxel-based morphometry (VBM) showed no gray matter volume differences between patient and control groups, spatial extent cluster-corrected VBM analysis suggested a trend of gray matter volume reduction in frontal and central regions in both patient groups, more lateral in JME and more medial in IGE-GTC. The findings support the idea that the clinical syndromes of JME and IGE-GTC have unique anatomic substrates. The fact that the primary clinical

  8. Cortex Parcellation Associated Whole White Matter Parcellation in Individual Subjects

    Directory of Open Access Journals (Sweden)

    Patrick Schiffler

    2017-07-01

    Full Text Available The investigation of specific white matter areas is a growing field in neurological research and is typically achieved through the use of atlases. However, the definition of anatomically based regions remains challenging for the white matter and thus hinders region-specific analysis in individual subjects. In this article, we focus on creating a whole white matter parcellation method for individual subjects where these areas can be associated to cortex regions. This is done by combining cortex parcellation and fiber tracking data. By tracking fibers out of each cortex region and labeling the fibers according to their origin, we populate a candidate image. We then derive the white matter parcellation by classifying each white matter voxel according to the distribution of labels in the corresponding voxel from the candidate image. The parcellation of the white matter with the presented method is highly reliable and is not as dependent on registration as with white matter atlases. This method allows for the parcellation of the whole white matter into individual cortex region associated areas and, therefore, associates white matter alterations to cortex regions. In addition, we compare the results from the presented method to existing atlases. The areas generated by the presented method are not as sharply defined as the areas in most existing atlases; however, they are computed directly in the DWI space of the subject and, therefore, do not suffer from distortion caused by registration. The presented approach might be a promising tool for clinical and basic research to investigate modalities or system specific micro structural alterations of white matter areas in a quantitative manner.

  9. Transforming the Subject Matter: Examining the Intellectual Roots of Pedagogical Content Knowledge

    Science.gov (United States)

    Deng, Zongyi

    2007-01-01

    This article questions the basic assumptions of pedagogical content knowledge by analyzing the ideas of Jerome Bruner, Joseph Schwab, and John Dewey concerning transforming the subject matter. It argues that transforming the subject matter is not only a pedagogical but also a complex curricular task in terms of developing a school subject or a…

  10. Matter in general relativity

    Science.gov (United States)

    Ray, J. R.

    1982-01-01

    Two theories of matter in general relativity, the fluid theory and the kinetic theory, were studied. Results include: (1) a discussion of various methods of completing the fluid equations; (2) a method of constructing charged general relativistic solutions in kinetic theory; and (3) a proof and discussion of the incompatibility of perfect fluid solutions in anisotropic cosmologies. Interpretations of NASA gravitational experiments using the above mentioned results were started. Two papers were prepared for publications based on this work.

  11. students' perception of teacher's knowledge of subject matter

    African Journals Online (AJOL)

    ALEXANDER E. TIMOTHY

    COPYRIGHT© BACHUDO SCIENCE CO. ... students' perception of teachers' knowledge of subject matter as perceived by students on reading ... percent and above in English language (WAEC,. 2007). ... to the learners. ... mathematics.

  12. The most general cosmological dynamics for ELKO matter fields

    International Nuclear Information System (INIS)

    Fabbri, Luca

    2011-01-01

    Not long ago, the definition of eigenspinors of charge-conjugation belonging to a special Wigner class has lead to the unexpected theoretical discovery of a form of matter with spin 1/2 and mass dimension 1, called ELKO matter field; ELKO matter fields defined in flat spacetimes have been later extended to curved and twisted spacetimes, in order to include in their dynamics the coupling to gravitational fields possessing both metric and torsional degrees of freedom: the inclusion of non-commuting spinorial covariant derivatives allows for the introduction of more general dynamical terms influencing the behaviour of ELKO matter fields. In this Letter, we shall solve the theoretical problem of finding the most general dynamics for ELKO matter, and we will face the phenomenological issue concerning how the new dynamical terms may affect the behavior of ELKO matter; we will see that new effects will arise for which the very existence of ELKO matter will be endangered, due to the fact that ELKOs will turn incompatible with the cosmological principle. Thus we have that anisotropic universes must be taken into account if ELKOs are to be considered in their most general form.

  13. Age-related changes of diffusional anisotropy in the cerebral white matter in normal subjects

    International Nuclear Information System (INIS)

    Hanyu, Haruo; Asano, Tetsuichi; Ogawa, Kimikazu; Takasaki, Masaru; Shindo, Hiroaki; Kakizaki, Dai; Abe, Kimihiko

    1997-01-01

    To investigate age-related changes of diffusional anisotropy in the cerebral white matter, we performed diffusion-weighted MRI studies in 21 normal subjects aged 25 to 96 years. The anisotropic rations (ARs), defined as the apparent diffusion coefficients perpendicular to the nerve fibers to those parallel to the nerve fibers, were significantly higher in elderly than in young subjects in the anterior and posterior white matter surrounding the lateral ventricle. Moreover, significant correlation between age and AR was found in the anterior white matter. The ventricular index (VI) measured on MRI, as a quantitative indicator of brain atrophy, was significantly higher in elderly than younger subjects, and significantly correlated with AR in the anterior white matter. Multiple regression analysis demonstrated that the VI showed the highest correlation for AR. On the other hand, there was no significant correlations between ARs in the corpus callosum and age. These results suggest that morphological changes in the myelin and axon in the white matter occur in elderly normal subjects, probably due to neuronal loss with aging. (author)

  14. Medial frontal white and gray matter contributions to general intelligence.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Ohtani

    Full Text Available The medial orbitofrontal cortex (mOFC and rostral anterior cingulate cortex (rACC are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA, which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%-34% of the variance in IQ, in comparison to 11%-16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC, two gray matter regions of interests that are very close in physical proximity, and underscores the important independent contributions of variations in rACC gray matter volume and mOFC-rACC white matter connectivity to individual differences in general intelligence.

  15. Generalized calculus with applications to matter and forces

    CERN Document Server

    Campos, L M B C

    2014-01-01

    Combining mathematical theory, physical principles, and engineering problems, Generalized Calculus with Applications to Matter and Forces examines generalized functions, including the Heaviside unit jump and the Dirac unit impulse and its derivatives of all orders, in one and several dimensions. The text introduces the two main approaches to generalized functions: (1) as a nonuniform limit of a family of ordinary functions, and (2) as a functional over a set of test functions from which properties are inherited. The second approach is developed more extensively to encompass multidimensional generalized functions whose arguments are ordinary functions of several variables. As part of a series of books for engineers and scientists exploring advanced mathematics, Generalized Calculus with Applications to Matter and Forces presents generalized functions from an applied point of view, tackling problem classes such as: •Gauss and Stokes’ theorems in the differential geometry, tensor calculus, and theory of ...

  16. Beyond "Either-Or" Thinking: John Dewey and Confucius on Subject Matter and the Learner

    Science.gov (United States)

    Tan, Charlene

    2016-01-01

    This article compares the educational thought of John Dewey and Confucius on the nature of and relationship between subject matter and the learner. There is a common perception in the existing literature and discourse that Dewey advocates child- or learner-centred education whereas Confucius privileges subject matter via textual transmission.…

  17. 22 CFR 61.6 - Consultation with subject matter specialists.

    Science.gov (United States)

    2010-04-01

    ... FREE FLOW OF AUDIO-VISUAL MATERIALS § 61.6 Consultation with subject matter specialists. (a) The... assisting the Department in its determination of whether materials for which export certification or import authentication is sought contain widespread and gross misstatements of fact. (b) As necessary, the Department may...

  18. 12 CFR 791.6 - Subject matter of a meeting.

    Science.gov (United States)

    2010-01-01

    ....6 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING THE OPERATIONS OF THE... REGULATIONS; PUBLIC OBSERVATION OF NCUA BOARD MEETINGS Rules of NCUA Board Procedure § 791.6 Subject matter of... all Office Directors and President of the Central Liquidity Facility), and Regional Directors. [61 FR...

  19. Generalized Curvature-Matter Couplings in Modified Gravity

    Directory of Open Access Journals (Sweden)

    Tiberiu Harko

    2014-07-01

    Full Text Available In this work, we review a plethora of modified theories of gravity with generalized curvature-matter couplings. The explicit nonminimal couplings, for instance, between an arbitrary function of the scalar curvature R and the Lagrangian density of matter, induces a non-vanishing covariant derivative of the energy-momentum tensor, implying non-geodesic motion and, consequently, leads to the appearance of an extra force. Applied to the cosmological context, these curvature-matter couplings lead to interesting phenomenology, where one can obtain a unified description of the cosmological epochs. We also consider the possibility that the behavior of the galactic flat rotation curves can be explained in the framework of the curvature-matter coupling models, where the extra terms in the gravitational field equations modify the equations of motion of test particles and induce a supplementary gravitational interaction. In addition to this, these models are extremely useful for describing dark energy-dark matter interactions and for explaining the late-time cosmic acceleration.

  20. Experiential Learning of Electronics Subject Matter in Middle School Robotics Courses

    Science.gov (United States)

    Rihtaršic, David; Avsec, Stanislav; Kocijancic, Slavko

    2016-01-01

    The purpose of this paper is to investigate whether the experiential learning of electronics subject matter is effective in the middle school open learning of robotics. Electronics is often ignored in robotics courses. Since robotics courses are typically comprised of computer-related subjects, and mechanical and electrical engineering, these…

  1. Does tutor subject-matter expertise influence student achievement in ...

    African Journals Online (AJOL)

    Objective. To establish whether or not tutor subject-matter expertise influences student achievement in content-based examinations in the problem-based learning (PBL) curriculum at the University of Transkei (UNITRA) Medical School. Design. A retrospective study of MB ChB III student achievement in end-of-block ...

  2. Prospective Science Teachers' Subject-Matter Knowledge about Overflow Container

    Science.gov (United States)

    Ültay, Eser

    2016-01-01

    The purpose of this study was to determine prospective science teachers' subject-matter knowledge (SMK) about overflow container. This study was carried out in the form of a case study in spring term of the academic year of 2013-2014 with seven sophomore prospective science teachers who were studying at Elementary Science Teaching Department in…

  3. One Health in food safety and security education: Subject matter outline for a curricular framework.

    Science.gov (United States)

    Angelos, John A; Arens, Amanda L; Johnson, Heather A; Cadriel, Jessica L; Osburn, Bennie I

    2017-06-01

    Educating students in the range of subjects encompassing food safety and security as approached from a One Health perspective requires consideration of a variety of different disciplines and the interrelationships among disciplines. The Western Institute for Food Safety and Security developed a subject matter outline to accompany a previously published One Health in food safety and security curricular framework. The subject matter covered in this outline encompasses a variety of topics and disciplines related to food safety and security including effects of food production on the environment. This subject matter outline should help guide curriculum development and education in One Health in food safety and security and provides useful information for educators, researchers, students, and public policy-makers facing the inherent challenges of maintaining and/or developing safe and secure food supplies without destroying Earth's natural resources.

  4. One Health in food safety and security education: Subject matter outline for a curricular framework

    Directory of Open Access Journals (Sweden)

    John A. Angelos

    2017-06-01

    Full Text Available Educating students in the range of subjects encompassing food safety and security as approached from a One Health perspective requires consideration of a variety of different disciplines and the interrelationships among disciplines. The Western Institute for Food Safety and Security developed a subject matter outline to accompany a previously published One Health in food safety and security curricular framework. The subject matter covered in this outline encompasses a variety of topics and disciplines related to food safety and security including effects of food production on the environment. This subject matter outline should help guide curriculum development and education in One Health in food safety and security and provides useful information for educators, researchers, students, and public policy-makers facing the inherent challenges of maintaining and/or developing safe and secure food supplies without destroying Earth's natural resources.

  5. Thermodynamic laws for generalized f(R) gravity with curvature-matter coupling

    International Nuclear Information System (INIS)

    Wu Yabo; Zhao Yueyue; Cai Ronggen; Lu Jianbo; Lu Junwang; Gao Xiaojing

    2012-01-01

    The first law and the generalized second law (GSL) of thermodynamics for the generalized f(R) gravity with curvature-matter coupling are studied in the spatially homogeneous, isotropic FRW universe. The research results show that the field equations of the generalized f(R) gravity with curvature-matter coupling can be cast to the form of the first law of thermodynamics with the so-called the entropy production terms dS ¯ and the GSL can be given by considering the FRW universe filled only with ordinary matter enclosed by the dynamical apparent horizon with the Hawking temperature. Furthermore, as a concrete example, by utilizing the GSL the constraints on the gravitational model with f 1 (R)=R+αR l and f 2 (R)=R m are also discussed. It is worth noting these results given by us are quite general and can degenerate to the ones in Einstein's general relativity and pure f(R) gravity with non-coupling and non-minimal coupling as special cases. Comparing with the case of Einstein's general relativity, the appearance of the entropy production term dS ¯ in the first law of thermodynamics demonstrates that the horizon thermodynamics is non-equilibrium one for generalized f(R) gravity with curvature-matter coupling, which is consistent with the arguments given in Akbar and Cai (2007) [13] and Eling et al. (2006) [18].

  6. Problems Faced By Elementary School Second Grade English Subject Matter Teachers

    Directory of Open Access Journals (Sweden)

    Belgin Bal Incebacak

    2017-11-01

    Full Text Available The objective of thisstudy isto determine the problems experienced by subject matter teachers while instructing English lessons in the second grade of elementary school. What are the problemsfaced by English subject matter teachers when they instruct in 2nd grade lessons? In this research the descriptive modeling, which is one of the qualitative research methods, was employed. In accordance with this objective, we worked with 8 subject matter teachers from 5 different schoolsinAtakum and Ilkadim districtslocated in downtown Samsun, through easily accessible case sampling. The semi-structured “English Course Interview Form’’was applied to the teachers. In the study, descriptive survey model was employed, since it was aimed to reveal the current status of qualitative research methods.According to the results obtained from the research, the content was configured and presented under 5 themes. They were categorized as: 1. the problems experienced in classroom management, 2. the problems in physical and cognitive readiness, 3. the problems experienced in the learning and teacher process, 4. the problems seen in counseling, 5. the problems experienced in assessment and evaluation. In conclusion, the teachers stated that they had problems with managing the classroom, especially with the second grade students, whom are younger than others. It is observed that the change for teaching English at a younger age has been appropriate. Our teachersstated that they required in-service training so as to adapt to this aforementioned change.

  7. On indexes and subject matter of “global competitiveness”

    Directory of Open Access Journals (Sweden)

    A. V. Korotkov

    2017-01-01

    Full Text Available The aim of the research is to analyze the subject matter of a country’s competitiveness and to characterize statistical indexes of competitiveness known in the international practice from the perspective of a more elaborated theory of market competition. This aim follows from the identified problems. First, there are no generally accepted interpretation and joint understanding of competition and competitiveness at country level. Even the international organizations giving estimations of global competitiveness disagree on definitions of competitiveness. Secondly, there is no relation to the theory of market competition in the available source materials on competitiveness of the country without original methodology. Thirdly, well-known statistical indexes of global competitiveness do not have enough theoretical justification and differ in sets of factors. All this highlights the incompleteness of the methodology and methodological support of studying competitiveness at country level.Materials and methods. The research is based on the methodology of statistics, economic theory and marketing. The authors followed the basic principle of statistical methodology – requirement of continuous combination of qualitative and quantitative analysis, when the research begins and ends with qualitative analysis. A most important section of statistical methodology is widely used – construction of statistical indexes. In the course of the analysis, a method of statistical classifications is applied. A significant role in the present research is given to the method of generalizing and analogue method, realizing that related terms should mean similar and almost similar contents. Modeling of competition and competitiveness is widely used in the present research, which made it possible to develop a logical model of competition following from the competition theory.Results. Based on the definitions’ survey the analysis of the subject matter of global

  8. General calculation of the cross section for dark matter annihilations into two photons

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Cely, Camilo [Service de Physique Théorique, Université Libre de Bruxelles, Boulevard du Triomphe, CP225, 1050 Brussels (Belgium); Rivera, Andres, E-mail: Camilo.Alfredo.Garcia.Cely@ulb.ac.be, E-mail: afelipe.rivera@udea.edu.co [Instituto de Física, Universidad de Antioquia, Calle 70 No. 52-21, Medellín (Colombia)

    2017-03-01

    Assuming that the underlying model satisfies some general requirements such as renormalizability and CP conservation, we calculate the non-relativistic one-loop cross section for any self-conjugate dark matter particle annihilating into two photons. We accomplish this by carefully classifying all possible one-loop diagrams and, from them, reading off the dark matter interactions with the particles running in the loop. Our approach is general and leads to the same results found in the literature for popular dark matter candidates such as the neutralinos of the MSSM, minimal dark matter, inert Higgs and Kaluza-Klein dark matter.

  9. General calculation of the cross section for dark matter annihilations into two photons

    International Nuclear Information System (INIS)

    Garcia-Cely, Camilo; Rivera, Andres

    2017-01-01

    Assuming that the underlying model satisfies some general requirements such as renormalizability and CP conservation, we calculate the non-relativistic one-loop cross section for any self-conjugate dark matter particle annihilating into two photons. We accomplish this by carefully classifying all possible one-loop diagrams and, from them, reading off the dark matter interactions with the particles running in the loop. Our approach is general and leads to the same results found in the literature for popular dark matter candidates such as the neutralinos of the MSSM, minimal dark matter, inert Higgs and Kaluza-Klein dark matter.

  10. Small P Systems with Catalysts or Anti-Matter Simulating Generalized Register Machines and Generalized Counter Automata

    Directory of Open Access Journals (Sweden)

    Artiom Alhazov

    2015-11-01

    Full Text Available In this paper we focus on two weak forms of cooperation in P systems, namely, catalytic rules and matter/anti-matter annihilation rules. These variants of P systems both are computationally complete, while the corresponding rule complexity turns out to be of special interest. For establishing considerably small universal P systems in both cases, we found two suitable tools: generalized register machines and generalized counter automata. Depending on the features used in the different variants, we construct several small universal P systems.

  11. What Do Subject Matter Experts Have to Say about Participating in Education and Outreach?

    Science.gov (United States)

    Manning, Colleen; NASA's Universe of Learning Team

    2018-01-01

    NASA’s Universe of Learning partners wish to actively engage with Subject Matter Experts (scientists and engineers) throughout the design, development, and delivery of products, programs, and professional development. In order to ensure these engagement efforts aligned with the needs of Subject Matter Experts, the external evaluators conducted an online survey. The subject pool included the scientists and engineers employed at the partner organizations as well as other scientists and engineers affiliated with NASA’s Astrophysics missions and research programs. This presentation will describe scientists’/engineers’ interest in various types of education/outreach, their availability to participate in education/outreach, factors that would encourage their participation in education/outreach, and the preparation and support they have for participation in education/outreach.

  12. Generalized dynamics of soft-matter quasicrystals mathematical models and solutions

    CERN Document Server

    Fan, Tian-You

    2017-01-01

    The book systematically introduces the mathematical models and solutions of generalized hydrodynamics of soft-matter quasicrystals (SMQ). It provides methods for solving the initial-boundary value problems in these systems. The solutions obtained demonstrate the distribution, deformation and motion of the soft-matter quasicrystals, and determine the stress, velocity and displacement fields. The interactions between phonons, phasons and fluid phonons are discussed in some fundamental materials samples. Mathematical solutions for solid and soft-matter quasicrystals are compared, to help readers to better understand the featured properties of SMQ.

  13. Scientific and General Subject Classifications in the Digital World

    CERN Document Server

    De Robbio, Antonella; Marini, A

    2001-01-01

    In the present work we discuss opportunities, problems, tools and techniques encountered when interconnecting discipline-specific subject classifications, primarily organized as search devices in bibliographic databases, with general classifications originally devised for book shelving in public libraries. We first state the fundamental distinction between topical (or subject) classifications and object classifications. Then we trace the structural limitations that have constrained subject classifications since their library origins, and the devices that were used to overcome the gap with genuine knowledge representation. After recalling some general notions on structure, dynamics and interferences of subject classifications and of the objects they refer to, we sketch a synthetic overview on discipline-specific classifications in Mathematics, Computing and Physics, on one hand, and on general classifications on the other. In this setting we present The Scientific Classifications Page, which collects groups of...

  14. Diffusion tensor imaging identifies deficits in white matter microstructure in subjects with type 1 diabetes that correlate with reduced neurocognitive function.

    Science.gov (United States)

    Kodl, Christopher T; Franc, Daniel T; Rao, Jyothi P; Anderson, Fiona S; Thomas, William; Mueller, Bryon A; Lim, Kelvin O; Seaquist, Elizabeth R

    2008-11-01

    Long-standing type 1 diabetes is associated with deficits on neurocognitive testing that suggest central white matter dysfunction. This study investigated whether diffusion tensor imaging (DTI), a type of magnetic resonance imaging that measures white matter integrity quantitatively, could identify white matter microstructural deficits in patients with long-standing type 1 diabetes and whether these differences would be associated with deficits found by neurocognitive tests. Twenty-five subjects with type 1 diabetes for at least 15 years and 25 age- and sex-matched control subjects completed DTI on a 3.0 Tesla scanner and a battery of neurocognitive tests. Fractional anisotropy was calculated for the major white matter tracts of the brain. Diabetic subjects had significantly lower mean fractional anisotropy than control subjects in the posterior corona radiata and the optic radiation (P < 0.002). In type 1 diabetic subjects, reduced fractional anisotropy correlated with poorer performance on the copy portion of the Rey-Osterreith Complex Figure Drawing Test and the Grooved Peg Board Test, both of which are believed to assess white matter function. Reduced fractional anisotropy also correlated with duration of diabetes and increased A1C. A history of severe hypoglycemia did not correlate with fractional anisotropy. DTI can detect white matter microstructural deficits in subjects with long-standing type 1 diabetes. These deficits correlate with poorer performance on selected neurocognitive tests of white matter function.

  15. Neutron matter properties using generalized Skyrme force

    International Nuclear Information System (INIS)

    Mansour, H.M.M.; Ramadan, Kh.A.

    2002-01-01

    The generalized Skyrme potential is used to calculate the properties of neutron matter in the form of the Thomas–Fermi model. The binding energy per particle, spin symmetry energy, free energy, pressure, entropy, sound velocity and magnetic susceptibility are calculated as a function of density ρ. The results are comparable with those obtained by Friedman and Pandharipande, who used the Urbana v 14 potential plus an effective repulsive three-body force. (author)

  16. Primary teachers' subject matter knowledge: decimals

    Science.gov (United States)

    Ubuz, Behiye; Yayan, Betül

    2010-09-01

    The main objective of this study was to investigate primary teachers' subject matter knowledge in the domain of decimals and more elaborately to investigate their performance and difficulties in reading scale, ordering numbers, finding the nearest decimal and doing operations, such as addition and subtraction. The difficulties in these particular areas are analysed and suggestions are made regarding their causes. Further, factors that influence this knowledge were explored. The sample of the study was 63 primary teachers. A decimal concepts test including 18 tasks was administered and the total scores for the 63 primary teachers ranged from 3 to 18 with a mean and median of 12. Fifty per cent of the teachers were above the mean score. The detailed investigation of the responses revealed that the primary teachers faced similar difficulties that students and pre-service teachers faced. Discrepancy on teachers' knowledge revealed important differences based on educational level attained, but not the number of years of teaching experience and experience in teaching decimals. Some suggestions have been made regarding the implications for pre- and in-service teacher training.

  17. Commutative deformations of general relativity: nonlocality, causality, and dark matter

    Energy Technology Data Exchange (ETDEWEB)

    De Vegvar, P.G.N. [SWK Research, Bellingham, WA (United States)

    2017-01-15

    Hopf algebra methods are applied to study Drinfeld twists of (3+1)-diffeomorphisms and deformed general relativity on commutative manifolds. A classical nonlocality length scale is produced above which microcausality emerges. Matter fields are utilized to generate self-consistent Abelian Drinfeld twists in a background independent manner and their continuous and discrete symmetries are examined. There is negligible experimental effect on the standard model of particles. While baryonic twist producing matter would begin to behave acausally for rest masses above ∝1-10 TeV, other possibilities are viable dark matter candidates or a right-handed neutrino. First order deformed Maxwell equations are derived and yield immeasurably small cosmological dispersion and produce a propagation horizon only for photons at or above Planck energies. This model incorporates dark matter without any appeal to extra dimensions, supersymmetry, strings, grand unified theories, mirror worlds, or modifications of Newtonian dynamics. (orig.)

  18. 30 CFR 206.452 - Coal subject to royalties-general provisions.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Coal subject to royalties-general provisions... MINERALS REVENUE MANAGEMENT PRODUCT VALUATION Indian Coal § 206.452 Coal subject to royalties—general provisions. (a) All coal (except coal unavoidably lost as determined by BLM pursuant to 43 CFR group 3400...

  19. 30 CFR 206.253 - Coal subject to royalties-general provisions.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Coal subject to royalties-general provisions... MINERALS REVENUE MANAGEMENT PRODUCT VALUATION Federal Coal § 206.253 Coal subject to royalties—general provisions. (a) All coal (except coal unavoidably lost as determined by BLM under 43 CFR part 3400) from a...

  20. White Matter Injury and General Movements in High-Risk Preterm Infants.

    Science.gov (United States)

    Peyton, C; Yang, E; Msall, M E; Adde, L; Støen, R; Fjørtoft, T; Bos, A F; Einspieler, C; Zhou, Y; Schreiber, M D; Marks, J D; Drobyshevsky, A

    2017-01-01

    Very preterm infants (birth weight, cognitive and motor impairment, including cerebral palsy. These adverse neurodevelopmental outcomes are associated with white matter abnormalities on MR imaging at term-equivalent age. Cerebral palsy has been predicted by analysis of spontaneous movements in the infant termed "General Movement Assessment." The goal of this study was to determine the utility of General Movement Assessment in predicting adverse cognitive, language, and motor outcomes in very preterm infants and to identify brain imaging markers associated with both adverse outcomes and aberrant general movements. In this prospective study of 47 preterm infants of 24-30 weeks' gestation, brain MR imaging was performed at term-equivalent age. Infants underwent T1- and T2-weighted imaging for volumetric analysis and DTI. General movements were assessed at 10-15 weeks' postterm age, and neurodevelopmental outcomes were evaluated at 2 years by using the Bayley Scales of Infant and Toddler Development III. Nine infants had aberrant general movements and were more likely to have adverse neurodevelopmental outcomes, compared with infants with normal movements. In infants with aberrant movements, Tract-Based Spatial Statistics analysis identified significantly lower fractional anisotropy in widespread white matter tracts, including the corpus callosum, inferior longitudinal and fronto-occipital fasciculi, internal capsule, and optic radiation. The subset of infants having both aberrant movements and abnormal neurodevelopmental outcomes in cognitive, language, and motor skills had significantly lower fractional anisotropy in specific brain regions. Aberrant general movements at 10-15 weeks' postterm are associated with adverse neurodevelopmental outcomes and specific white matter microstructure abnormalities for cognitive, language, and motor delays. © 2017 by American Journal of Neuroradiology.

  1. Urban Extension: Aligning with the Needs of Urban Audiences Through Subject-Matter Centers

    Directory of Open Access Journals (Sweden)

    Brad Gaolach

    2017-06-01

    Full Text Available The educational program model is the principle approach Extension uses to deliver on its mission of “taking knowledge to the people.” However, with county-based faculty fully engaged in long-term program delivery, they may have little or no capacity to address emerging issues faced by urban communities. Urban governments often seek the research capacity of a university in addition to, or instead of, the traditional Extension programming model but sometimes turn first to other urban-serving universities. Washington State University Extension has addressed these challenges by establishing subject-matter centers. This article examines how subject-matter centers can add capacity to traditional Extension offices in order to be responsive to emerging local needs, suggesting models that other university Extension programs may use or adapt to their local communities. These models also foster more community engagement and articulate greater public value for the institution as a whole.

  2. Information processing speed mediates the relationship between white matter and general intelligence in schizophrenia.

    Science.gov (United States)

    Alloza, Clara; Cox, Simon R; Duff, Barbara; Semple, Scott I; Bastin, Mark E; Whalley, Heather C; Lawrie, Stephen M

    2016-08-30

    Several authors have proposed that schizophrenia is the result of impaired connectivity between specific brain regions rather than differences in local brain activity. White matter abnormalities have been suggested as the anatomical substrate for this dysconnectivity hypothesis. Information processing speed may act as a key cognitive resource facilitating higher order cognition by allowing multiple cognitive processes to be simultaneously available. However, there is a lack of established associations between these variables in schizophrenia. We hypothesised that the relationship between white matter and general intelligence would be mediated by processing speed. White matter water diffusion parameters were studied using Tract-based Spatial Statistics and computed within 46 regions-of-interest (ROI). Principal component analysis was conducted on these white matter ROI for fractional anisotropy (FA) and mean diffusivity, and on neurocognitive subtests to extract general factors of white mater structure (gFA, gMD), general intelligence (g) and processing speed (gspeed). There was a positive correlation between g and gFA (r= 0.67, p =0.001) that was partially and significantly mediated by gspeed (56.22% CI: 0.10-0.62). These findings suggest a plausible model of structure-function relations in schizophrenia, whereby white matter structure may provide a neuroanatomical substrate for general intelligence, which is partly supported by speed of information processing. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Generalized Liquid Crystals: Giant Fluctuations and the Vestigial Chiral Order of I , O , and T Matter

    Science.gov (United States)

    Liu, Ke; Nissinen, Jaakko; Slager, Robert-Jan; Wu, Kai; Zaanen, Jan

    2016-10-01

    The physics of nematic liquid crystals has been the subject of intensive research since the late 19th century. However, the focus of this pursuit has been centered around uniaxial and biaxial nematics associated with constituents bearing a D∞ h or D2 h symmetry, respectively. In view of general symmetries, however, these are singularly special since nematic order can in principle involve any point-group symmetry. Given the progress in tailoring nanoparticles with particular shapes and interactions, this vast family of "generalized nematics" might become accessible in the laboratory. Little is known because the order parameter theories associated with the highly symmetric point groups are remarkably complicated, involving tensor order parameters of high rank. Here, we show that the generic features of the statistical physics of such systems can be studied in a highly flexible and efficient fashion using a mathematical tool borrowed from high-energy physics: discrete non-Abelian gauge theory. Explicitly, we construct a family of lattice gauge models encapsulating nematic ordering of general three-dimensional point-group symmetries. We find that the most symmetrical generalized nematics are subjected to thermal fluctuations of unprecedented severity. As a result, novel forms of fluctuation phenomena become possible. In particular, we demonstrate that a vestigial phase carrying no more than chiral order becomes ubiquitous departing from high point-group symmetry chiral building blocks, such as I , O , and T symmetric matter.

  4. Developing a Democratic View of Academic Subject Matters: John Dewey, William Chandler Bagley, and Boyd Henry Bode

    Science.gov (United States)

    Watras, Joseph

    2012-01-01

    In the first half of the twentieth century, the ideal of democracy influenced the conceptions people had of the academic subject matters. A common criticism was that abstract academic subjects served aristocratic societies. Although most theorists considered the academic subjects to be important, they had differing views on the conception of…

  5. Being in a romantic relationship is associated with reduced gray matter density in striatum and increased subjective happiness

    Directory of Open Access Journals (Sweden)

    Hiroaki Kawamichi

    2016-11-01

    Full Text Available Romantic relationship, a widespread feature of human society, is one of the most influential factors in daily life. Although stimuli related to romantic love or being in a romantic relationship commonly result in enhancement of activation or functional connectivity of the reward system, including the striatum, the structure underlying romantic relationship-related regions remain unclear. Because individual experiences can alter gray matter within the adult human brain, we hypothesized that romantic relationship is associated with structural differences in the striatum related to the positive subjective experience of being in a romantic relationship. Because intimate romantic relationships contribute to perceived subjective happiness, this subjective enhancement of happiness might be accompanied by the experience of positive events related to being in a romantic relationship. To test this hypothesis and elucidate the structure involved, we compared subjective happiness, an indirect measure of the existence of positive experiences caused by being in a romantic relationship, of participants with or without romantic partners (N = 68. Furthermore, we also conducted a voxel-based morphometry (VBM study of the effects of being in a romantic relationship (N = 113. Being in a romantic relationship was associated with greater subjective happiness and reduced gray matter density within the right dorsal striatum. These results suggest that being in a romantic relationship enhances perceived subjective happiness via positive experiences. Furthermore, the observed reduction in gray matter density in the right dorsal striatum may reflect an increase in saliency of social reward within a romantic relationship. Thus, being in a romantic relationship is associated with positive experiences and a reduction of gray matter density in the right dorsal striatum, representing a modulation of social reward.

  6. Generalized Liquid Crystals: Giant Fluctuations and the Vestigial Chiral Order of I, O, and T Matter

    Directory of Open Access Journals (Sweden)

    Ke Liu (刘科 子竞

    2016-10-01

    Full Text Available The physics of nematic liquid crystals has been the subject of intensive research since the late 19th century. However, the focus of this pursuit has been centered around uniaxial and biaxial nematics associated with constituents bearing a D_{∞h} or D_{2h} symmetry, respectively. In view of general symmetries, however, these are singularly special since nematic order can in principle involve any point-group symmetry. Given the progress in tailoring nanoparticles with particular shapes and interactions, this vast family of “generalized nematics” might become accessible in the laboratory. Little is known because the order parameter theories associated with the highly symmetric point groups are remarkably complicated, involving tensor order parameters of high rank. Here, we show that the generic features of the statistical physics of such systems can be studied in a highly flexible and efficient fashion using a mathematical tool borrowed from high-energy physics: discrete non-Abelian gauge theory. Explicitly, we construct a family of lattice gauge models encapsulating nematic ordering of general three-dimensional point-group symmetries. We find that the most symmetrical generalized nematics are subjected to thermal fluctuations of unprecedented severity. As a result, novel forms of fluctuation phenomena become possible. In particular, we demonstrate that a vestigial phase carrying no more than chiral order becomes ubiquitous departing from high point-group symmetry chiral building blocks, such as I, O, and T symmetric matter.

  7. A generalized Bethe-Weizaecker mass formula for strange hadronic matter

    International Nuclear Information System (INIS)

    Dover, C.B.; Gal, A.

    1993-01-01

    We extend the Bethe- Weizsaecker nuclear mass formula to strange hadronic matter composed of nucleons, lambdas and cascade hyperons. The generalized formula contains several volume and symmetry terms constrained by phenomenologically determined Λ-nuclear, Ξ-nuclear and ΛΛ interaction parameters and by hyperon-hyperon (ΛΛ, ΛΞ, ΞΞ) interaction parameters suggested by one-boson-exchange models. We confirm that multi-Λ hypernuclei are generally unstable to ΛΛ→ΞN conversion. For strange hadronic matter we determine, as function of the baryon number A, the line of strong-interaction stability, along which a large strangeness fraction vertical stroke /Svertical stroke /A∝0.5-1.1 and a low charge fraction q/A< or ∼0.2 hold, and no fission occurs. The binding energy per baryon increases monotonically to its bulk limit, B/A→38 MeV, vertical stroke /Svertical stroke /A→ 1.1 and q/A→0 for the parameters adopted here assuming that the hyperon species saturate at densities similar to those of protons and neutrons in nuclei. Even in the extreme limit of vanishingly small hyperon-hyperon interaction strengths, strange hadronic matter with B/A→15 MeV, vertical stroke /Svertical stroke /A→0.7 and q/A→0 in the bulk limit should exist and our mass formula reproduces semi-quantitatively recent mean-field calculations which implicitly assumed weak hyperon-hyperon interactions. (orig.)

  8. A generalized Bethe-Weizsaecker mass formula for strange hadronic matter

    International Nuclear Information System (INIS)

    Dover, C.B.; Washington Univ., Seattle, WA; Gal, A.; Washington Univ., Seattle, WA

    1992-12-01

    The Bethe-Weizsaecker nuclear mass formula is extended to strange hadronic matter composed of nucleons, lambdas and cascade hyperons. The generalized formula contains several volume and symmetry terms constrained by phenomenologically determined λ-nuclear, ξ-nuclear and λλ interaction parameters and by hyperon-hyperon (λλ, λξ, ξξ) interaction parameters suggested by One-Boson-Exchange models. We find that hypernuclei are generally unstable to λλ → ξN conversion. For strange hadronic matter, as function of the baryon number A, the line of strong-interaction stability, along which a large strangeness fraction |S|/A ∼ 0.5 - 1.1 and a low charge fraction q/A approx-lt 0.2 hold, and no fission occurs, is determined. The binding energy per baryon increases monotonically to its bulk limit, B/A → 38 MeV, |S|/A → 1.1 and q/A → 0 for the parameters adopted here assuming that the hyperon species saturate at densities similar to those of protons and neutrons in nuclei. Even in the extreme limit of vanishingly small hyperon-hyperon interaction strengths, strange hadronic matter with B/A → 15 MeV, |S|/A → 0.7 and q/A → 0 in the bulk limit should exist; the mass formula reproduces semi-quantitatively recent mean-field calculations which implicitly assumed weak hyperon-hyperon interactions

  9. Analyzing Subject Disciplines of Knowledge Originality and Knowledge Generality for Library & Information Science

    Directory of Open Access Journals (Sweden)

    Mu-Hsuan Huang

    2007-12-01

    Full Text Available This study used bibliometric methods to analyze subject disciplines of knowledge originality and knowledge generality for Library and Information Science (LIS by using citing and cited documents from 1997 to 2006. We found that the major subject disciplines of knowledge originality and generality are still LIS, and computer science and LIS interact and influence each other closely. It is evident that number of subject disciplines of knowledge originality is higher than that of knowledge generality. The interdisciplinary characteristics of LIS are illustrated by variety areas of knowledge originality and knowledge generality. Because the number of received subject disciplines is higher than that of given subject disciplines, it suggests that LIS is an application-oriented research area. [Article content in Chinese

  10. Generalized thermodynamics of phase equilibria in scalar active matter

    Science.gov (United States)

    Solon, Alexandre P.; Stenhammar, Joakim; Cates, Michael E.; Kafri, Yariv; Tailleur, Julien

    2018-02-01

    Motility-induced phase separation (MIPS) arises generically in fluids of self-propelled particles when interactions lead to a kinetic slowdown at high densities. Starting from a continuum description of scalar active matter akin to a generalized Cahn-Hilliard equation, we give a general prescription for the mean densities of coexisting phases in flux-free steady states that amounts, at a hydrodynamics scale, to extremizing an effective free energy. We illustrate our approach on two well-known models: self-propelled particles interacting either through a density-dependent propulsion speed or via direct pairwise forces. Our theory accounts quantitatively for their phase diagrams, providing a unified description of MIPS.

  11. General aspects of the nucleon-nucleon interaction and nuclear matter properties

    Energy Technology Data Exchange (ETDEWEB)

    Plohl, Oliver

    2008-07-25

    The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

  12. General aspects of the nucleon-nucleon interaction and nuclear matter properties

    International Nuclear Information System (INIS)

    Plohl, Oliver

    2008-01-01

    The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are

  13. Influence of tutors' subject-matter expertise on student effort and achievement in problem-based learning

    NARCIS (Netherlands)

    H.G. Schmidt (Henk); A. van der Arend (Arie); J.H.C. Moust (Jos); I. Kokx (Irma); L. Boon (Louis)

    1993-01-01

    textabstractPurpose. To investigate the effects of tutors' subject-matter expertise on students' levels of academic achievement and study effort in a problem-based health sciences curriculum. Also, to study differences in turors' behaviors and the influences of these differences on students'

  14. {sup 1}H and {sup 31}P magnetic resonance spectroscopic imaging of white matter signal hyperintensity areas in elderly subjects

    Energy Technology Data Exchange (ETDEWEB)

    Constans, J M [Department of Veterans Affairs Medical Center and University of California Magnetic Resonance Unit, San Francisco, CA (United States); [California Univ., San Francisco, CA (United States). Dept. of Radiology; Meyerhoff, D J [Department of Veterans Affairs Medical Center and University of California Magnetic Resonance Unit, San Francisco, CA (United States); [California Univ., San Francisco, CA (United States). Dept. of Radiology; Norman, D [California Univ., San Francisco, CA (United States). Dept. of Radiology; Fein, G [Department of Veterans Affairs Psychiatry Service, University of California, San Francisco, California (United States); [University of California, San Francisco, CA (United States). Dept. of Psychiatry; Weiner, M W [Department of Veterans Affairs Medical Center and University of California Magnetic Resonance Unit, San Francisco, CA (United States); [California Univ., San Francisco, CA (United States). Dept. of Radiology; [California Univ., San Francisco, CA (United States). Dept. of Medicine; [DVA Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco, CA (United States)

    1995-11-01

    White matter signal hyperintensities (WMSH) are commonly seen on MRI of elderly subjects. The purpose of this study was to characterize metabolic changes in the white matter of elderly subjects with extensive WMSH. We used water-suppressed proton ({sup 1}H) magnetic resonance spectroscopic imaging (MRSI) to compare six subjects with extensive WMSH with eight age-matched elderly subjects with minimal or absent WMSH, and phosphorus ({sup 31}P) MRSI to compare nine subjects with extensive WMSH and seven age-matched elderly subjects without extensive WMSH. Relative to region-matched tissue in elderly controls, extensive WMSH were associated with increased signal from choline-containing metabolites, no significant change of signal from N-acetylaspartate, and a trend to a decreased phosphomonoester (PME) resonance. These findings suggest that WMSH may be associated with an alteration of brain myelin phospholipids in the absence of axonal damage. There were no differences in energy phosphates, consistent with lack of ongoing brain ischemia. Within the group with extensive WMSH, PME resonance measures were significantly lower in WMSH than in contralateral normal-appearing white matter. These results provide information on pathophysiology of WMSH and a basis for comparison with WMSH in Alzheimer`s disease, vascular dementia, multiple sclerosis, and other diseases. (orig.). With 4 figs., 4 tabs.

  15. Higgs exotic decays in general NMSSM with self-interacting dark matter

    Science.gov (United States)

    Wang, Wenyu; Zhang, Mengchao; Zhao, Jun

    2018-04-01

    Under current LHC and dark matter constraints, the general NMSSM can have self-interacting dark matter to explain the cosmological small structure. In this scenario, the dark matter is the light singlino-like neutralino (χ) which self-interacts through exchanging the light singlet-like scalars (h1,a1). These light scalars and neutralinos inevitably interact with the 125 GeV SM-like Higgs boson (hSM), which cause the Higgs exotic decays hSM → h1h1, a1a1, χχ. We first demonstrate the parameter space required by the explanation of the cosmological small structure and then display the Higgs exotic decays. We find that in such a parameter space the Higgs exotic decays can have branching ratios of a few percent, which should be accessible in the future e+e‑ colliders.

  16. Development Of Phisyics Learning Documents Based Student's Learning Style In The Matter Of Temperature And Heat Subjects Of Class X High School

    OpenAIRE

    Resty Noriwita, Indah Resty Noriwita Indah; Nasir, Muhammad Nasir Muhammad; Ma’aruf, Zuhdi Ma’aruf Zuhdi

    2015-01-01

    This study aims to produce a learning documents physicsbased learning styles of students in the matter of temperature and heat of class subjectS X SMA valid. The subjects were learning documents that consists of a lesson plan (RPP), worksheets (LKS), medium of learning and achievement test of cognitive, affective, process, and psychomotor. Data collection instrument in this study is an instrument validity device physics-based learning students' learning styles in the matter of temperature and...

  17. Do Subject Matter Knowledge, and Pedagogical Content Knowledge Constitute the Ideal Gas Law of Science Teaching?

    Science.gov (United States)

    Lederman, Norman G.; Gess-Newsome, Julie

    1992-01-01

    Describes Pedagogical Content Knowledge and focuses on the empirical research directly concerned with the relationship between science teachers' subject matter knowledge or structures and actual classroom practice. Concludes there is little evidence that a relationship exists. (PR)

  18. Incidental white-matter foci on MRI in ''healthy'' subjects: evidence of subtle cognitive dysfunction

    International Nuclear Information System (INIS)

    Baum, K.A.; Schulte, C.; Girke, W.; Reischies, F.M.; Felix, R.

    1996-01-01

    The clinical significance of incidental white-matter foci seen on MRI is controversial. Mainly using a computer-assisted neuropsychological test battery, we tested the hypothesis that there is a clinical correlate of these foci. We studied 41 individuals aged 45-65 years with no history of neurological or psychiatric disorder, in whom no indication of central nervous system abnormalities was found on standardised neurological examination. A computer-assisted neuropsychological test battery, with the advantage of precise measuring of both time and deviation (e. g. in position memory tests), and rating scales for emotional dysfunction were administered; selected soft neurological signs were assessed. In 16 subjects (39 %) MRI showed high-signal foci in the white matter on spin-echo sequences. White-matter foci not adjacent to the lateral ventricles were found to be related to performance on immediate visual memory/visuoperceptual skills, visuomotor tracking/psychomotor speed and, to a lesser degree, learning capacity and abstract and conceptual reasoning skills. Subtle cognitive dysfunction would appear to be a clinical correlate of punctate white-matter foci on MRI of otherwise ''healty'' individuals. (orig.). With 1 fig., 2 tabs

  19. General f(R and conformal inflation from minimal supergravity plus matter

    Directory of Open Access Journals (Sweden)

    Horatiu Nastase

    2016-02-01

    Full Text Available We embed general f(R inflationary models in minimal supergravity plus matter, a single chiral superfield Φ, with or without another superfield S, via a Jordan frame Einstein+scalar description. In particular, inflationary models like a generalized Starobinsky one are analyzed and constraints on them are found. We also embed the related models of conformal inflation, also described as Jordan frame Einstein+scalar models, in particular the conformal inflation from the Higgs model, and analyze the inflationary constraints on them.

  20. Insight on AV-45 binding in white and grey matter from histogram analysis: a study on early Alzheimer's disease patients and healthy subjects

    Science.gov (United States)

    Nemmi, Federico; Saint-Aubert, Laure; Adel, Djilali; Salabert, Anne-Sophie; Pariente, Jérémie; Barbeau, Emmanuel; Payoux, Pierre; Péran, Patrice

    2014-01-01

    Purpose AV-45 amyloid biomarker is known to show uptake in white matter in patients with Alzheimer’s disease (AD) but also in healthy population. This binding; thought to be of a non-specific lipophilic nature has not yet been investigated. The aim of this study was to determine the differential pattern of AV-45 binding in healthy and pathological populations in white matter. Methods We recruited 24 patients presenting with AD at early stage and 17 matched, healthy subjects. We used an optimized PET-MRI registration method and an approach based on intensity histogram using several indexes. We compared the results of the intensity histogram analyses with a more canonical approach based on target-to-cerebellum Standard Uptake Value (SUVr) in white and grey matters using MANOVA and discriminant analyses. A cluster analysis on white and grey matter histograms was also performed. Results White matter histogram analysis revealed significant differences between AD and healthy subjects, which were not revealed by SUVr analysis. However, white matter histograms was not decisive to discriminate groups, and indexes based on grey matter only showed better discriminative power than SUVr. The cluster analysis divided our sample in two clusters, showing different uptakes in grey but also in white matter. Conclusion These results demonstrate that AV-45 binding in white matter conveys subtle information not detectable using SUVr approach. Although it is not better than standard SUVr to discriminate AD patients from healthy subjects, this information could reveal white matter modifications. PMID:24573658

  1. Insight on AV-45 binding in white and grey matter from histogram analysis: a study on early Alzheimer's disease patients and healthy subjects

    International Nuclear Information System (INIS)

    Nemmi, Federico; Saint-Aubert, Laure; Peran, Patrice; Adel, Djilali; Salabert, Anne-Sophie; Payoux, Pierre; Pariente, Jeremie; Barbeau, Emmanuel J.

    2014-01-01

    AV-45 amyloid biomarker is known to show uptake in white matter in patients with Alzheimer's disease (AD), but also in the healthy population. This binding, thought to be of a non-specific lipophilic nature, has not yet been investigated. The aim of this study was to determine the differential pattern of AV-45 binding in white matter in healthy and pathological populations. We recruited 24 patients presenting with AD at an early stage and 17 matched, healthy subjects. We used an optimized positron emission tomography-magnetic resonance imaging (PET-MRI) registration method and an approach based on an intensity histogram using several indices. We compared the results of the intensity histogram analyses with a more canonical approach based on target-to-cerebellum Standard Uptake Value (SUVr) in white and grey matter using MANOVA and discriminant analyses. A cluster analysis on white and grey matter histograms was also performed. White matter histogram analysis revealed significant differences between AD and healthy subjects, which were not revealed by SUVr analysis. However, white matter histograms were not decisive to discriminate groups, and indices based on grey matter only showed better discriminative power than SUVr. The cluster analysis divided our sample into two clusters, showing different uptakes in grey, but also in white matter. These results demonstrate that AV-45 binding in white matter conveys subtle information not detectable using the SUVr approach. Although it is not more efficient than standard SUVr in discriminating AD patients from healthy subjects, this information could reveal white matter modifications. (orig.)

  2. Transferring and generalizing deep-learning-based neural encoding models across subjects.

    Science.gov (United States)

    Wen, Haiguang; Shi, Junxing; Chen, Wei; Liu, Zhongming

    2018-08-01

    Recent studies have shown the value of using deep learning models for mapping and characterizing how the brain represents and organizes information for natural vision. However, modeling the relationship between deep learning models and the brain (or encoding models), requires measuring cortical responses to large and diverse sets of natural visual stimuli from single subjects. This requirement limits prior studies to few subjects, making it difficult to generalize findings across subjects or for a population. In this study, we developed new methods to transfer and generalize encoding models across subjects. To train encoding models specific to a target subject, the models trained for other subjects were used as the prior models and were refined efficiently using Bayesian inference with a limited amount of data from the target subject. To train encoding models for a population, the models were progressively trained and updated with incremental data from different subjects. For the proof of principle, we applied these methods to functional magnetic resonance imaging (fMRI) data from three subjects watching tens of hours of naturalistic videos, while a deep residual neural network driven by image recognition was used to model visual cortical processing. Results demonstrate that the methods developed herein provide an efficient and effective strategy to establish both subject-specific and population-wide predictive models of cortical representations of high-dimensional and hierarchical visual features. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Glucose metabolism, gray matter structure, and memory decline in subjective memory impairment.

    Science.gov (United States)

    Scheef, Lukas; Spottke, Annika; Daerr, Moritz; Joe, Alexius; Striepens, Nadine; Kölsch, Heike; Popp, Julius; Daamen, Marcel; Gorris, Dominik; Heneka, Michael T; Boecker, Henning; Biersack, Hans J; Maier, Wolfgang; Schild, Hans H; Wagner, Michael; Jessen, Frank

    2012-09-25

    To identify biological evidence for Alzheimer disease (AD) in individuals with subjective memory impairment (SMI) and unimpaired cognitive performance and to investigate the longitudinal cognitive course in these subjects. [¹⁸F]fluoro-2-deoxyglucose PET (FDG-PET) and structural MRI were acquired in 31 subjects with SMI and 56 controls. Cognitive follow-up testing was performed (average follow-up time: 35 months). Differences in baseline brain imaging data and in memory decline were assessed between both groups. Associations of memory decline with brain imaging data were tested. The SMI group showed hypometabolism in the right precuneus and hypermetabolism in the right medial temporal lobe. Gray matter volume was reduced in the right hippocampus in the SMI group. At follow-up, subjects with SMI showed a poorer performance than controls on measures of episodic memory. Longitudinal memory decline in the SMI group was associated with reduced glucose metabolism in the right precuneus at baseline. The cross-sectional difference in 2 independent neuroimaging modalities indicates early AD pathology in SMI. The poorer memory performance at follow-up and the association of reduced longitudinal memory performance with hypometabolism in the precuneus at baseline support the concept of SMI as the earliest manifestation of AD.

  4. The Impact of Self-Perceived Subject Matter Knowledge on Pedagogical Decisions in EFL Grammar Teaching Practices

    Science.gov (United States)

    Sanchez, Hugo Santiago

    2014-01-01

    Recent developments in language teacher cognition research highlight the need to explore subject matter knowledge in relation to classroom practice. This study examines the impact of two foreign language teachers' knowledge about grammar upon their pedagogical decisions. The primary database consisted of classroom observations and post-lesson…

  5. Major Superficial White Matter Abnormalities in Huntington's Disease

    Science.gov (United States)

    Phillips, Owen R.; Joshi, Shantanu H.; Squitieri, Ferdinando; Sanchez-Castaneda, Cristina; Narr, Katherine; Shattuck, David W.; Caltagirone, Carlo; Sabatini, Umberto; Di Paola, Margherita

    2016-01-01

    Background: The late myelinating superficial white matter at the juncture of the cortical gray and white matter comprising the intracortical myelin and short-range association fibers has not received attention in Huntington's disease. It is an area of the brain that is late myelinating and is sensitive to both normal aging and neurodegenerative disease effects. Therefore, it may be sensitive to Huntington's disease processes. Methods: Structural MRI data from 25 Pre-symptomatic subjects, 24 Huntington's disease patients and 49 healthy controls was run through a cortical pattern-matching program. The surface corresponding to the white matter directly below the cortical gray matter was then extracted. Individual subject's Diffusion Tensor Imaging (DTI) data was aligned to their structural MRI data. Diffusivity values along the white matter surface were then sampled at each vertex point. DTI measures with high spatial resolution across the superficial white matter surface were then analyzed with the General Linear Model to test for the effects of disease. Results: There was an overall increase in the axial and radial diffusivity across much of the superficial white matter (p < 0.001) in Pre-symptomatic subjects compared to controls. In Huntington's disease patients increased diffusivity covered essentially the whole brain (p < 0.001). Changes are correlated with genotype (CAG repeat number) and disease burden (p < 0.001). Conclusions: This study showed broad abnormalities in superficial white matter even before symptoms are present in Huntington's disease. Since, the superficial white matter has a unique microstructure and function these abnormalities suggest it plays an important role in the disease. PMID:27242403

  6. Cross-sectional variations of white and grey matter in older hypertensive patients with subjective memory complaints

    Directory of Open Access Journals (Sweden)

    Ahmed Chetouani

    2018-01-01

    Altogether, our findings show that cross-sectional variations in overall white brain matter are linked to the metabolism of Alzheimer-like cortical areas and to cognitive performance in older hypertensive patients with only subjective memory complaints. Additional relationships with central BP strengthen the hypothesis of a contributing pathogenic role of hypertension.

  7. Lack of gender effects on gray matter volumes in adolescent generalized anxiety disorder.

    Science.gov (United States)

    Liao, Mei; Yang, Fan; Zhang, Yan; He, Zhong; Su, Linyan; Li, Lingjiang

    2014-02-01

    Previous epidemiological and clinical studies have reported gender differences in prevalence and clinical features of generalized anxiety disorder (GAD). Such gender differences in clinical phenomenology suggest that the underlying neural circuitry of GAD could also be different in males and females. This study aimed to explore the possible gender effect on gray matter volumes in adolescents with GAD. Twenty-six adolescent GAD patients and 25 healthy controls participated and underwent high-resolution structural magnetic resonance scans. Voxel-based morphometry (VBM) was used to investigate gray matter alterations. Our study revealed a significant diagnosis main effect in the right putamen, with larger gray matter volumes in GAD patients compared to healthy controls, and a significant gender main effect in the left precuneus/posterior cingulate cortex, with larger gray matter volumes in males compared to females. No gender-by-diagnosis interaction effect was found in this study. The relatively small sample size in this study might result in a lack of power to demonstrate gender effects on brain structure in GAD. The results suggested that there are differences in gray matter volumes between males and females, but gray matter volumes in GAD are not influenced by gender. © 2013 Published by Elsevier B.V.

  8. Reheating via a generalized nonminimal coupling of curvature to matter

    International Nuclear Information System (INIS)

    Bertolami, Orfeu; Frazao, Pedro; Paramos, Jorge

    2011-01-01

    In this work, one shows that a generalized nonminimal coupling between geometry and matter is compatible with Starobinsky inflation and leads to a successful process of preheating, a reheating scenario based on the production of massive particles via parametric resonance. The model naturally extends the usual preheating mechanism, which resorts to an ad hoc scalar curvature-dependent mass term for a scalar field χ, and also encompasses a previously studied preheating channel based upon a nonstandard kinetic term.

  9. "Non-cold" dark matter at small scales: a general approach

    Science.gov (United States)

    Murgia, R.; Merle, A.; Viel, M.; Totzauer, M.; Schneider, A.

    2017-11-01

    Structure formation at small cosmological scales provides an important frontier for dark matter (DM) research. Scenarios with small DM particle masses, large momenta or hidden interactions tend to suppress the gravitational clustering at small scales. The details of this suppression depend on the DM particle nature, allowing for a direct link between DM models and astrophysical observations. However, most of the astrophysical constraints obtained so far refer to a very specific shape of the power suppression, corresponding to thermal warm dark matter (WDM), i.e., candidates with a Fermi-Dirac or Bose-Einstein momentum distribution. In this work we introduce a new analytical fitting formula for the power spectrum, which is simple yet flexible enough to reproduce the clustering signal of large classes of non-thermal DM models, which are not at all adequately described by the oversimplified notion of WDM . We show that the formula is able to fully cover the parameter space of sterile neutrinos (whether resonantly produced or from particle decay), mixed cold and warm models, fuzzy dark matter, as well as other models suggested by effective theory of structure formation (ETHOS). Based on this fitting formula, we perform a large suite of N-body simulations and we extract important nonlinear statistics, such as the matter power spectrum and the halo mass function. Finally, we present first preliminary astrophysical constraints, based on linear theory, from both the number of Milky Way satellites and the Lyman-α forest. This paper is a first step towards a general and comprehensive modeling of small-scale departures from the standard cold DM model.

  10. 1 CFR 21.21 - General requirements: References.

    Science.gov (United States)

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false General requirements: References. 21.21 Section... to test methods or consensus standards produced by a Federal agency that have replaced or preempted private or voluntary test methods or consensus standards in a subject matter area. (5) The reference is to...

  11. Developing Pre-Service Teachers' Subject Matter Knowledge of Electromagnetism by Integrating Concept Maps and Collaborative Learning

    Science.gov (United States)

    Govender, Nadaraj

    2015-01-01

    This case study explored the development of two pre-service teachers' subject matter knowledge (SMK) of electromagnetism while integrating the use of concept maps (CM) and collaborative learning (CL) strategies. The study aimed at capturing how these pre-service teachers' SMK in electromagnetism was enhanced after having been taught SMK in a…

  12. Insight on AV-45 binding in white and grey matter from histogram analysis: a study on early Alzheimer's disease patients and healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    Nemmi, Federico; Saint-Aubert, Laure; Peran, Patrice [Inserm, Imagerie Cerebrale et Handicaps Neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse, Toulouse (France); Adel, Djilali; Salabert, Anne-Sophie; Payoux, Pierre [Inserm, Imagerie Cerebrale et Handicaps Neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse, Toulouse (France); Centre Hospitalier Universitaire de Toulouse, Service de Medecine Nucleaire, Pole Imagerie, Toulouse (France); Pariente, Jeremie [Inserm, Imagerie Cerebrale et Handicaps Neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques UMR 825, Centre Hospitalier Universitaire de Toulouse, Toulouse (France); Centre Hospitalier Universitaire de Toulouse, Service de Neurologie, Pole Neurosciences, Toulouse (France); Barbeau, Emmanuel J. [Centre Hospitalier Universitaire de Toulouse, Service de Neurologie, Pole Neurosciences, Toulouse (France); Universite de Toulouse, UPS, Centre de Recherche Cerveau et Cognition, CNRS, CerCo, Toulouse (France)

    2014-07-15

    AV-45 amyloid biomarker is known to show uptake in white matter in patients with Alzheimer's disease (AD), but also in the healthy population. This binding, thought to be of a non-specific lipophilic nature, has not yet been investigated. The aim of this study was to determine the differential pattern of AV-45 binding in white matter in healthy and pathological populations. We recruited 24 patients presenting with AD at an early stage and 17 matched, healthy subjects. We used an optimized positron emission tomography-magnetic resonance imaging (PET-MRI) registration method and an approach based on an intensity histogram using several indices. We compared the results of the intensity histogram analyses with a more canonical approach based on target-to-cerebellum Standard Uptake Value (SUVr) in white and grey matter using MANOVA and discriminant analyses. A cluster analysis on white and grey matter histograms was also performed. White matter histogram analysis revealed significant differences between AD and healthy subjects, which were not revealed by SUVr analysis. However, white matter histograms were not decisive to discriminate groups, and indices based on grey matter only showed better discriminative power than SUVr. The cluster analysis divided our sample into two clusters, showing different uptakes in grey, but also in white matter. These results demonstrate that AV-45 binding in white matter conveys subtle information not detectable using the SUVr approach. Although it is not more efficient than standard SUVr in discriminating AD patients from healthy subjects, this information could reveal white matter modifications. (orig.)

  13. Human subjects and experimental irradiation

    International Nuclear Information System (INIS)

    Rosen, R.

    1985-01-01

    In recent years the public has expressed concern about the use of human subjects in scientific research. Some professional institutions have adopted codes of practice to guide them in this matter. At the University of New South Wales, where human subjects are used in teaching and research programmes, a committee ensures that high ethical standards are maintained. As the volunteer subjects do not gain any benefit themselves from the procedures, their level of risk is kept low. One type of procedure in which risk is becoming quantifiable, is the irradiation of human subjects. To assist peer review groups, the ICRP, WHO and the National Health and Medical Research Council have enunciated principles which should be followed in the irradiation of human volunteer subjects. In general the role of the Committee is advisory to protect the rights of the investigator, the subject, and the institution. Some of the inherent problems are discussed

  14. Gray matter changes in subjects at high risk for developing psychosis and first-episode schizophrenia: a voxel-based structural MRI study

    Directory of Open Access Journals (Sweden)

    Kazue eNakamura

    2013-03-01

    Full Text Available Objectives: The aim of the present study was to use a voxel-based MRI method to investigate the neuroanatomical characteristics in subjects at high risk of developing psychosis compared with those of healthy controls and first-episode schizophrenia patients. Methods: This study included 14 subjects with at-risk mental state (ARMS, 34 patients with first-episode schizophrenia, and 51 healthy controls. We used voxel-based morphometry (VBM with the Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL tools to investigate the whole-brain difference in gray matter volume among the three groups. Results: Compared with the healthy controls, the schizophrenia patients showed significant gray matter reduction in the left anterior cingulate gyrus. There was no significant difference in the gray matter volume between the ARMS and other groups. Conclusion: The present study suggests that alteration of the anterior cingulate gyrus may be associated with development of frank psychosis. Further studies with a larger ARMS subjects would be required to examine the potential role of neuroimaging methods in the prediction of future transition into psychosis.

  15. White matter organization in cervical spinal cord relates differently to age and control of grip force in healthy subjects.

    Science.gov (United States)

    Lindberg, Påvel G; Feydy, Antoine; Maier, Marc A

    2010-03-17

    Diffusion tensor imaging (DTI) can be used to elucidate relations between CNS structure and function. We hypothesized that the degree of spinal white matter organization relates to the accuracy of control of grip force. Healthy subjects of different age were studied using DTI and visuomotor tracking of precision grip force. The latter is a prime component of manual dexterity. A regional analysis of spinal white matter [fractional anisotropy (FA)] across multiple cervical levels (C2-C3, C4-C5, and C6-C7) and in different regions of interest (left and right lateral or medial spinal cord) was performed. FA was highest at the C2-C3 level, higher on the right than the left side, and higher in the lateral than in the medial spinal cord (p level in the lateral spinal cord, in which the corticospinal tract innervates spinal circuitry controlling hand and digit muscles. FA of the medial spinal cord correlated consistently with age across all cervical levels, whereas FA of the lateral spinal cord did not. The results suggest (1) a functionally relevant specialization of lateral spinal cord white matter and (2) an increased sensitivity to age-related decline in medial spinal cord white matter in healthy subjects.

  16. Topology general & algebraic

    CERN Document Server

    Chatterjee, D

    2007-01-01

    About the Book: This book provides exposition of the subject both in its general and algebraic aspects. It deals with the notions of topological spaces, compactness, connectedness, completeness including metrizability and compactification, algebraic aspects of topological spaces through homotopy groups and homology groups. It begins with the basic notions of topological spaces but soon going beyond them reaches the domain of algebra through the notions of homotopy, homology and cohomology. How these approaches work in harmony is the subject matter of this book. The book finally arrives at the

  17. Subject Matter Specialists and Organizational Effectiveness of Krishi Vigyan Kendras of Tamil Nadu and Kerala

    Directory of Open Access Journals (Sweden)

    Bimal Puthuparambil Bashir

    2017-04-01

    Full Text Available The study was undertaken with the objective of determining the socio-personal characteristics of Subject Matter Specialists (SMS of Krishi Vigyan Kendra (KVK and their relationship with organizational effectiveness. Altogether 65 SMS’ from 12 KVKs across Tamil Nadu and Kerala were selected. The study has concluded that most of respondents were middle aged with more than half of them being female. Majority of them was married, had work experience of below five years and had attended three to five trainings. Most of the respondents had high level of job satisfaction team-work and one-fourth felt a medium to high job stress. More than half of the respondents felt medium level of work load. There was a positive and significant correlation at one per cent level between job satisfaction / team work and organizational effectiveness of KVKs whereas job stress had a negative and significant correlation at five per cent level. Hence it may be concluded that team work, job satisfaction and job stress play a significant role in improving the organizational effectiveness of KVK. More emphasis must be given for team building enhance the job satisfaction level and reduce the job stress among Subject Matter Specialists of KVKs.

  18. The Implementation of APIQ Creative Mathematics Game Method in the Subject Matter of Greatest Common Factor and Least Common Multiple in Elementary School

    Science.gov (United States)

    Rahman, Abdul; Saleh Ahmar, Ansari; Arifin, A. Nurani M.; Upu, Hamzah; Mulbar, Usman; Alimuddin; Arsyad, Nurdin; Ruslan; Rusli; Djadir; Sutamrin; Hamda; Minggi, Ilham; Awi; Zaki, Ahmad; Ahmad, Asdar; Ihsan, Hisyam

    2018-01-01

    One of causal factors for uninterested feeling of the students in learning mathematics is a monotonous learning method, like in traditional learning method. One of the ways for motivating students to learn mathematics is by implementing APIQ (Aritmetika Plus Intelegensi Quantum) creative mathematics game method. The purposes of this research are (1) to describe students’ responses toward the implementation of APIQ creative mathematics game method on the subject matter of Greatest Common Factor (GCF) and Least Common Multiple (LCM) and (2) to find out whether by implementing this method, the student’s learning completeness will improve or not. Based on the results of this research, it is shown that the responses of the students toward the implementation of APIQ creative mathematics game method in the subject matters of GCF and LCM were good. It is seen in the percentage of the responses were between 76-100%. (2) The implementation of APIQ creative mathematics game method on the subject matters of GCF and LCM improved the students’ learning.

  19. Subclinical Disease Burden as Assessed by Whole-Body MRI in Subjects With Prediabetes, Subjects With Diabetes, and Normal Control Subjects From the General Population: The KORA-MRI Study.

    Science.gov (United States)

    Bamberg, Fabian; Hetterich, Holger; Rospleszcz, Susanne; Lorbeer, Roberto; Auweter, Sigrid D; Schlett, Christopher L; Schafnitzel, Anina; Bayerl, Christian; Schindler, Andreas; Saam, Tobias; Müller-Peltzer, Katharina; Sommer, Wieland; Zitzelsberger, Tanja; Machann, Jürgen; Ingrisch, Michael; Selder, Sonja; Rathmann, Wolfgang; Heier, Margit; Linkohr, Birgit; Meisinger, Christa; Weber, Christian; Ertl-Wagner, Birgit; Massberg, Steffen; Reiser, Maximilian F; Peters, Annette

    2017-01-01

    Detailed pathophysiological manifestations of early disease in the context of prediabetes are poorly understood. This study aimed to evaluate the extent of early signs of metabolic and cardio-cerebrovascular complications affecting multiple organs in individuals with prediabetes. Subjects without a history of stroke, coronary artery disease, or peripheral artery disease were enrolled in a case-control study nested within the Cooperative Health Research in the Region of Augsburg (KORA) FF4 cohort and underwent comprehensive MRI assessment to characterize cerebral parameters (white matter lesions, microbleeds), cardiovascular parameters (carotid plaque, left ventricular function, and myocardial late gadolinium enhancement [LGE]), and metabolic parameters (hepatic proton-density fat fraction [PDFF] and subcutaneous and visceral abdominal fat). Among 400 subjects who underwent MRI, 103 subjects had prediabetes and 54 had established diabetes. Subjects with prediabetes had an increased risk for carotid plaque and adverse functional cardiac parameters, including reduced early diastolic filling rates as well as a higher prevalence of LGE compared with healthy control subjects. In addition, people with prediabetes had significantly elevated levels of PDFF and total and visceral fat. Thus, subjects with prediabetes show early signs of subclinical disease that include vascular, cardiac, and metabolic changes, as measured by whole-body MRI after adjusting for cardiometabolic risk factors. © 2017 by the American Diabetes Association.

  20. On general features of warm dark matter with reduced relativistic gas

    Science.gov (United States)

    Hipólito-Ricaldi, W. S.; vom Marttens, R. F.; Fabris, J. C.; Shapiro, I. L.; Casarini, L.

    2018-05-01

    Reduced relativistic gas (RRG) is a useful approach to describe the warm dark matter (WDM) or the warmness of baryonic matter in the approximation when the interaction between the particles is irrelevant. The use of Maxwell distribution leads to the complicated equation of state of the Jüttner model of relativistic ideal gas. The RRG enables one to reproduce the same physical situation but in a much simpler form. For this reason RRG can be a useful tool for the theories with some sort of a "new Physics". On the other hand, even without the qualitatively new physical implementations, the RRG can be useful to describe the general features of WDM in a model-independent way. In this sense one can see, in particular, to which extent the cosmological manifestations of WDM may be dependent on its Particle Physics background. In the present work RRG is used as a complementary approach to derive the main observational features for the WDM in a model-independent way. The only assumption concerns a non-negligible velocity v for dark matter particles which is parameterized by the warmness parameter b. The relatively high values of b ( b^2˜ 10^{-6}) erase the radiation (photons and neutrinos) dominated epoch and cause an early warm matter domination after inflation. Furthermore, RRG approach enables one to quantify the lack of power in linear matter spectrum at small scales and in particular, reproduces the relative transfer function commonly used in context of WDM with accuracy of ≲ 1%. A warmness with b^2≲ 10^{-6} (equivalent to v≲ 300 km/s) does not alter significantly the CMB power spectrum and is in agreement with the background observational tests.

  1. Dark matter and rotation curves of spiral galaxies

    Czech Academy of Sciences Publication Activity Database

    Křížek, Michal; Křížek, Filip; Somer, L.

    2016-01-01

    Roč. 25, April (2016), s. 64-77 ISSN 1313-2709 R&D Projects: GA MŠk(CZ) LG15052 Institutional support: RVO:67985840 ; RVO:61389005 Keywords : red dwarf * dark matter * spiral galaxy Subject RIV: BA - General Mathematics http://www.astro.bas.bg/AIJ/issues/n25/MKrizek.pdf

  2. Habitual sleep durations and subjective sleep quality predict white matter differences in the human brain

    Directory of Open Access Journals (Sweden)

    Sakh Khalsa

    2017-06-01

    Full Text Available Self-imposed short sleep durations are increasingly commonplace in society, and have considerable health and performance implications for individuals. Reduced sleep duration over multiple nights has similar behavioural effects to those observed following acute total sleep deprivation, suggesting that lack of sleep affects brain function cumulatively. A link between habitual sleep patterns and functional connectivity has previously been observed, and the effect of sleep duration on the brain's intrinsic functional architecture may provide a link between sleep status and cognition. However, it is currently not known whether differences in habitual sleep patterns across individuals are related to changes in the brain's white matter, which underlies structural connectivity. In the present study we use diffusion–weighted imaging and a group comparison application of tract based spatial statistics (TBSS to investigate changes to fractional anisotropy (FA and mean diffusivity (MD in relation to sleep duration and quality, hypothesising that white matter metrics would be positively associated with sleep duration and quality. Diffusion weighted imaging data was acquired from a final cohort of 33 (23–29 years, 10 female, mean 25.4 years participants. Sleep patterns were assessed for a 14 day period using wrist actigraphs and sleep diaries, and subjective sleep quality with the Pittsburgh Sleep Quality Index (PSQI. Median splits based on total sleep time and PSQI were used to create groups of shorter/longer and poorer/better sleepers, whose imaging data was compared using TBSS followed by post-hoc correlation analysis in regions identified as significantly different between the groups. There were significant positive correlations between sleep duration and FA in the left orbito-frontal region and the right superior corona radiata, and significant negative correlations between sleep duration and MD in right orbito-frontal white matter and the right

  3. Supervising and Controlling Unmanned Systems: A Multi-Phase Study with Subject Matter Experts.

    Science.gov (United States)

    Porat, Talya; Oron-Gilad, Tal; Rottem-Hovev, Michal; Silbiger, Jacob

    2016-01-01

    Proliferation in the use of Unmanned Aerial Systems (UASs) in civil and military operations has presented a multitude of human factors challenges; from how to bridge the gap between demand and availability of trained operators, to how to organize and present data in meaningful ways. Utilizing the Design Research Methodology (DRM), a series of closely related studies with subject matter experts (SMEs) demonstrate how the focus of research gradually shifted from "how many systems can a single operator control" to "how to distribute missions among operators and systems in an efficient way". The first set of studies aimed to explore the modal number, i.e., how many systems can a single operator supervise and control. It was found that an experienced operator can supervise up to 15 UASs efficiently using moderate levels of automation, and control (mission and payload management) up to three systems. Once this limit was reached, a single operator's performance was compared to a team controlling the same number of systems. In general, teams led to better performances. Hence, shifting design efforts toward developing tools that support teamwork environments of multiple operators with multiple UASs (MOMU). In MOMU settings, when the tasks are similar or when areas of interest overlap, one operator seems to have an advantage over a team who needs to collaborate and coordinate. However, in all other cases, a team was advantageous over a single operator. Other findings and implications, as well as future directions for research are discussed.

  4. Gray matter and white matter abnormalities in online game addiction

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Chuan-Bo, E-mail: send007@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); School of Neurosurgery, Anhui Medical University, 81 Meishang Road, Hefei, Anhui Province 230032 (China); Qian, Ruo-Bing, E-mail: rehomail@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China); Fu, Xian-Ming, E-mail: 506537677@qq.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China); Lin, Bin, E-mail: 274722758@qq.com [School of Neurosurgery, Anhui Medical University, 81 Meishang Road, Hefei, Anhui Province 230032 (China); Han, Xiao-Peng, E-mail: hanxiaopeng@163.com [Department of Psychology, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Niu, Chao-Shi, E-mail: niuchaoshi@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China); Wang, Ye-Han, E-mail: wangyehan@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China)

    2013-08-15

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA.

  5. Gray matter and white matter abnormalities in online game addiction

    International Nuclear Information System (INIS)

    Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

    2013-01-01

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA

  6. Gray matter and white matter abnormalities in online game addiction.

    Science.gov (United States)

    Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

    2013-08-01

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Supervising and Controlling Unmanned Systems: A Multi-Phase Study with Subject Matter Experts

    Science.gov (United States)

    Porat, Talya; Oron-Gilad, Tal; Rottem-Hovev, Michal; Silbiger, Jacob

    2016-01-01

    Proliferation in the use of Unmanned Aerial Systems (UASs) in civil and military operations has presented a multitude of human factors challenges; from how to bridge the gap between demand and availability of trained operators, to how to organize and present data in meaningful ways. Utilizing the Design Research Methodology (DRM), a series of closely related studies with subject matter experts (SMEs) demonstrate how the focus of research gradually shifted from “how many systems can a single operator control” to “how to distribute missions among operators and systems in an efficient way”. The first set of studies aimed to explore the modal number, i.e., how many systems can a single operator supervise and control. It was found that an experienced operator can supervise up to 15 UASs efficiently using moderate levels of automation, and control (mission and payload management) up to three systems. Once this limit was reached, a single operator's performance was compared to a team controlling the same number of systems. In general, teams led to better performances. Hence, shifting design efforts toward developing tools that support teamwork environments of multiple operators with multiple UASs (MOMU). In MOMU settings, when the tasks are similar or when areas of interest overlap, one operator seems to have an advantage over a team who needs to collaborate and coordinate. However, in all other cases, a team was advantageous over a single operator. Other findings and implications, as well as future directions for research are discussed. PMID:27252662

  8. Metabolic correlates of general cognitive function in nondemented elderly subjects: an FDG PET study

    International Nuclear Information System (INIS)

    Cho, Sang Soo; Kwak, Young Bin; Lee, Eun Ju; Ryu, Chang Hyung; Chey, Jean Yung; Kim, Sang Eun

    2004-01-01

    While many studies examined the neural correlates of individual cognitive functions, few made efforts to identify the neural networks associated with general cognitive function. General cognitive function decline in the elderly population is not infrequent. This study examined the brain areas associated with general cognitive function in the elderly subjects. Community-dwelling 116 elderly subjects without dementing illnesses (age, 71±5 y; 13 males and 103 females) participated. General cognitive ability was assessed with the Dementia Rating Scale (K-DRS), which is composed of five subtests of attention, initiation and perseveration, construction, conceptualization, and memory. The EVLT (Elderly Verbal Learning Test), a nine-word list learning test, was used for general memory assessment. Brain FDG PET scans were acquired in all subjects. Brain regions where metabolic levels are correlated with the total scores of K-DRS and EVLT were examined using SPM99. There was a significant positive correlation (P < 0.01 uncorrected, k=100) between the total score of K-DRS and glucose metabolism in the bilateral posterior cingulate gyri, bilateral inferior frontal gyri, left caudate, left inferior parietal lobule, right precuneus, bilateral unci, right parahippocampal gyrus, and right anterior cingulate gyrus. A significant positive correlation between the total score of EVLT and glucose metabolism was shown in the right precuneus, right posterior cingulate gyrus, left insula, bilateral inferior parietal lobules, left anterior cingulate gyrus, left caudate, right inferior frontal gyrus (P < 0.01 uncorrected, k=100). Our data showed the brain regions that are associated with general cognitive function in the elderly. Those regions may serve as the neural substrated of cognitive dysfunction associated with neurodegenerative and cerebrovascular diseases in elderly subjects

  9. Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

    International Nuclear Information System (INIS)

    Hirano, Shin'ichi; Nishi, Sakine; Kobayashi, Tsutomu

    2017-01-01

    We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

  10. Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Shin' ichi; Nishi, Sakine; Kobayashi, Tsutomu, E-mail: s.hirano@rikkyo.ac.jp, E-mail: sakine@rikkyo.ac.jp, E-mail: tsutomu@rikkyo.ac.jp [Department of Physics, Rikkyo University, Toshima, Tokyo 171-8501 (Japan)

    2017-07-01

    We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

  11. General neutralino NLSP with gravitino dark matter vs. big bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Hasenkamp, Jasper

    2009-08-15

    We study the scenario of gravitino dark matter with a general neutralino being the next-to-lightest supersymmetric particle (NLSP). Therefore, we compute analytically all 2- and 3-body decays of the neutralino NLSP to determine the lifetime and the electromagnetic and hadronic branching ratio of the neutralino decaying into the gravitino and Standard Model particles. We constrain the gravitino and neutralino NLSP mass via big bang nucleosynthesis and see how those bounds are relaxed for a Higgsino or a wino NLSP in comparison to the bino neutralino case. At neutralino masses >or similar 1 TeV, a wino NLSP is favoured, since it decays rapidly via a newly found 4-vertex. The Higgsino component becomes important, when resonant annihilation via heavy Higgses can occur. We provide the full analytic results for the decay widths and the complete set of Feynman rules necessary for these computations. This thesis closes any gap in the study of gravitino dark matter scenarios with neutralino NLSP coming from approximations in the calculation of the neutralino decay rates and its hadronic branching ratio. (orig.)

  12. General neutralino NLSP with gravitino dark matter vs. big bang nucleosynthesis

    International Nuclear Information System (INIS)

    Hasenkamp, Jasper

    2009-08-01

    We study the scenario of gravitino dark matter with a general neutralino being the next-to-lightest supersymmetric particle (NLSP). Therefore, we compute analytically all 2- and 3-body decays of the neutralino NLSP to determine the lifetime and the electromagnetic and hadronic branching ratio of the neutralino decaying into the gravitino and Standard Model particles. We constrain the gravitino and neutralino NLSP mass via big bang nucleosynthesis and see how those bounds are relaxed for a Higgsino or a wino NLSP in comparison to the bino neutralino case. At neutralino masses >or similar 1 TeV, a wino NLSP is favoured, since it decays rapidly via a newly found 4-vertex. The Higgsino component becomes important, when resonant annihilation via heavy Higgses can occur. We provide the full analytic results for the decay widths and the complete set of Feynman rules necessary for these computations. This thesis closes any gap in the study of gravitino dark matter scenarios with neutralino NLSP coming from approximations in the calculation of the neutralino decay rates and its hadronic branching ratio. (orig.)

  13. Interchange Instability and Transport in Matter-Antimatter Plasmas

    Science.gov (United States)

    Kendl, Alexander; Danler, Gregor; Wiesenberger, Matthias; Held, Markus

    2017-06-01

    Symmetric electron-positron plasmas in inhomogeneous magnetic fields are intrinsically subject to interchange instability and transport. Scaling relations for the propagation velocity of density perturbations relevant to transport in isothermal magnetically confined electron-positron plasmas are deduced, including damping effects when Debye lengths are large compared to Larmor radii. The relations are verified by nonlinear full-F gyrofluid computations. Results are analyzed with respect to planned magnetically confined electron-positron plasma experiments. The model is generalized to other matter-antimatter plasmas. Magnetized electron-positron-proton-antiproton plasmas are susceptible to interchange-driven local matter-antimatter separation, which can impede sustained laboratory magnetic confinement.

  14. Interchange Instability and Transport in Matter-Antimatter Plasmas.

    Science.gov (United States)

    Kendl, Alexander; Danler, Gregor; Wiesenberger, Matthias; Held, Markus

    2017-06-09

    Symmetric electron-positron plasmas in inhomogeneous magnetic fields are intrinsically subject to interchange instability and transport. Scaling relations for the propagation velocity of density perturbations relevant to transport in isothermal magnetically confined electron-positron plasmas are deduced, including damping effects when Debye lengths are large compared to Larmor radii. The relations are verified by nonlinear full-F gyrofluid computations. Results are analyzed with respect to planned magnetically confined electron-positron plasma experiments. The model is generalized to other matter-antimatter plasmas. Magnetized electron-positron-proton-antiproton plasmas are susceptible to interchange-driven local matter-antimatter separation, which can impede sustained laboratory magnetic confinement.

  15. Subjective or objective? What matters?

    Czech Academy of Sciences Publication Activity Database

    Sunega, Petr

    2014-01-01

    Roč. 1, č. 1 (2014), s. 35-43 ISSN 2336-2839 R&D Projects: GA ČR(CZ) GAP404/12/1446 Institutional support: RVO:68378025 Keywords : comparative housing policy * globalisation Subject RIV: AO - Sociology, Demography

  16. Generalizations of the subject-independent feature set for music-induced emotion recognition.

    Science.gov (United States)

    Lin, Yuan-Pin; Chen, Jyh-Horng; Duann, Jeng-Ren; Lin, Chin-Teng; Jung, Tzyy-Ping

    2011-01-01

    Electroencephalogram (EEG)-based emotion recognition has been an intensely growing field. Yet, how to achieve acceptable accuracy on a practical system with as fewer electrodes as possible is less concerned. This study evaluates a set of subject-independent features, based on differential power asymmetry of symmetric electrode pairs [1], with emphasis on its applicability to subject variability in music-induced emotion classification problem. Results of this study have evidently validated the feasibility of using subject-independent EEG features to classify four emotional states with acceptable accuracy in second-scale temporal resolution. These features could be generalized across subjects to detect emotion induced by music excerpts not limited to the music database that was used to derive the emotion-specific features.

  17. Average bit error probability of binary coherent signaling over generalized fading channels subject to additive generalized gaussian noise

    KAUST Repository

    Soury, Hamza

    2012-06-01

    This letter considers the average bit error probability of binary coherent signaling over flat fading channels subject to additive generalized Gaussian noise. More specifically, a generic closed form expression in terms of the Fox\\'s H function is offered for the extended generalized-K fading case. Simplifications for some special fading distributions such as generalized-K fading and Nakagami-m fading and special additive noise distributions such as Gaussian and Laplacian noise are then presented. Finally, the mathematical formalism is illustrated by some numerical examples verified by computer based simulations for a variety of fading and additive noise parameters. © 2012 IEEE.

  18. Generalized cardassian expansion: a model in which the universe is flat, matter dominated, and accelerating

    International Nuclear Information System (INIS)

    Freese, Katherine

    2003-01-01

    The Cardassian universe is a proposed modification to the Friedmann Robertson Walker equation (FRW) in which the universe is flat, matter dominated, and accelerating. In this presentation, we generalize the original Cardassian proposal to include additional variants on the FRW equation, specific examples are presented. In the ordinary FRW equation, the right hand side is a linear function of the energy density, H 2 ∼ ρ. Here, instead, the right hand side of the FRW equation is a different function of the energy density, H 2 ∼ g(ρ). This function returns to ordinary FRW at early times, but modifies the expansion at a late epoch of the universe. The only ingredients in this universe are matter and radiation: in particular, there is NO vacuum contribution. Currently the modification of the FRW equation is such that the universe accelerates; we call this period of acceleration the Cardassian era. The universe can be flat and yet consist of only matter and radiation, and still be compatible with observations. The energy density required to close the universe is much smaller than in a standard cosmology, so that matter can be sufficient to provide a flat geometry. The new term required may arise, e.g., as a consequence of our observable universe living as a 3-dimensional brane in a higher dimensional universe. The Cardassian model survives several observational tests, including the cosmic background radiation, the age of the universe, the Friedmann Robertson , and structure formation. As will be shown in future work, he predictions for observational tests of the generalized Cardassian models can be very different from generic quintessence models, whether the equation of state is constant or time dependent

  19. Subjective memory complaints in general practice predicts future dementia: a 4-year follow-up study

    DEFF Research Database (Denmark)

    Waldorff, Frans Boch; Vogel, Asmus Mejling; Siersma, Volkert Dirk

    2012-01-01

    Many older patients in general practice have subjective memory complaints (SMC); however, not all share this information with their general practitioner (GP). The association between SMC and future cognitive decline or dementia is not clear, especially in a general practice population. The aim...

  20. A more randomly organized grey matter network is associated with deteriorating language and global cognition in individuals with subjective cognitive decline.

    Science.gov (United States)

    Verfaillie, Sander C J; Slot, Rosalinde E R; Dicks, Ellen; Prins, Niels D; Overbeek, Jozefien M; Teunissen, Charlotte E; Scheltens, Philip; Barkhof, Frederik; van der Flier, Wiesje M; Tijms, Betty M

    2018-03-30

    Grey matter network disruptions in Alzheimer's disease (AD) are associated with worse cognitive impairment cross-sectionally. Our aim was to investigate whether indications of a more random network organization are associated with longitudinal decline in specific cognitive functions in individuals with subjective cognitive decline (SCD). We included 231 individuals with SCD who had annually repeated neuropsychological assessment (3 ± 1 years; n = 646 neuropsychological investigations) available from the Amsterdam Dementia Cohort (54% male, age: 63 ± 9, MMSE: 28 ± 2). Single-subject grey matter networks were extracted from baseline 3D-T1 MRI scans and we computed basic network (size, degree, connectivity density) and higher-order (path length, clustering, betweenness centrality, normalized path length [lambda] and normalized clustering [gamma]) parameters at whole brain and/or regional levels. We tested associations of network parameters with baseline and annual cognition (memory, attention, executive functioning, language composite scores, and global cognition [all domains with MMSE]) using linear mixed models, adjusted for age, sex, education, scanner and total gray matter volume. Lower network size was associated with steeper decline in language (β ± SE = 0.12 ± 0.05, p organized grey matter network was associated with a steeper decline of cognitive functioning, possibly indicating the start of cognitive impairment. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  1. Knot numbers used as labels for identifying subject matter of a khipu

    Directory of Open Access Journals (Sweden)

    Alberto Saez-Rodriguez

    2013-03-01

    Full Text Available This investigation presents a new way to look at the numerical khipu, a knotted-string recording device from Pachacamac (Peru, and the types of information it contains. In addition to celestial coordinates, khipu knots apparently pertain to an early form of double-entry accounting. This study hypothesizes that the khipu sample has the recording capacity needed to register double-entry-like accounts. After the identification of its subject matter, the khipu sample was studied in an attempt to ascertain whether the knot values could represent instructions from the Inca state administration to a local accounting center. The results indicate that the numerical information in the pairing quadrants (determined by the distribution of S- and Z-knots should be read from top to bottom along the full length of the string and can then provide certain complementary details regarding the projected corn stocks of the Inca stat

  2. 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…

  3. The Knowledge Base of Subject Matter Experts in Teaching: A Case Study of a Professional Scientist as a Beginning Teacher

    Science.gov (United States)

    Diezmann, Carmel M.; Watters, James J.

    2015-01-01

    One method of addressing the shortage of science and mathematics teachers is to train scientists and other science-related professionals to become teachers. Advocates argue that as discipline experts these career changers can relate the subject matter knowledge to various contexts and applications in teaching. In this paper, through interviews and…

  4. Generalizing a unified model of dark matter, dark energy, and inflation with a noncanonical kinetic term

    International Nuclear Information System (INIS)

    De-Santiago, Josue; Cervantes-Cota, Jorge L.

    2011-01-01

    We study a unification model for dark energy, dark matter, and inflation with a single scalar field with noncanonical kinetic term. In this model, the kinetic term of the Lagrangian accounts for the dark matter and dark energy, and at early epochs, a quadratic potential accounts for slow roll inflation. The present work is an extension to the work by Bose and Majumdar [Phys. Rev. D 79, 103517 (2009).] with a more general kinetic term that was proposed by Chimento in Phys. Rev. D 69, 123517 (2004). We demonstrate that the model is viable at the background and linear perturbation levels.

  5. Exploring the Relationship between Secondary Science Teachers' Subject Matter Knowledge and Knowledge of Student Conceptions While Teaching Evolution by Natural Selection

    Science.gov (United States)

    Lucero, Margaret M.; Petrosino, Anthony J.; Delgado, Cesar

    2017-01-01

    The fundamental scientific concept of evolution occurring by natural selection is home to many deeply held alternative conceptions and considered difficult to teach. Science teachers' subject matter knowledge (SMK) and the pedagogical content knowledge (PCK) component of knowledge of students' conceptions (KOSC) can be valuable resources for…

  6. Atrophy of gray and white matters in the brain during aging

    International Nuclear Information System (INIS)

    Takeda, Shumpei; Matsuzawa, Taiju; Ito, Hisao.

    1984-01-01

    We studied atrophy of gray and white matter during aging in 57 males and 44 females with no neurological disturbances using x-ray computed tomography. The ages ranged from 12 to 80 years. Brain atrophy was expressed as brain volume index: 100% x [(brain volume/cranial cavity volume) in individual subjects]/[(brain volume/cranial cavity volume) in normal subjects of 20-39 years]. Atrophy of gray and white matter volume was expressed as gray and white matter volume indices: 100% x (apparent gray or white matter volume index in individual subjects)/(apparent gray or white matter volume index in normal subjects whose brain volume index was greater than 98%), where apparent gray and white matter volume indices were expressed as 100% x [(gray or white matter volume/cranial cavity volume) in individual subjects]/[(gray or white matter volume/cranial cavity volume) in normal subjects of 20-39 years]. Both the gray and white matter volume indices changed proportionally to the brain volume index (p<0.001). As the brain atrophy advanced, the gray matter volume index decreased more than the white matter volume index (P<0.001). Decrease in the gray and white matter volume indices was statistically significant only in seventies (P<0.002 for gray matter, P<0.05 for white matter). (author)

  7. Developmental Dynamics of General and School-Subject-Specific Components of Academic Self-Concept, Academic Interest, and Academic Anxiety.

    Science.gov (United States)

    Gogol, Katarzyna; Brunner, Martin; Preckel, Franzis; Goetz, Thomas; Martin, Romain

    2016-01-01

    The present study investigated the developmental dynamics of general and subject-specific (i.e., mathematics, French, and German) components of students' academic self-concept, anxiety, and interest. To this end, the authors integrated three lines of research: (a) hierarchical and multidimensional approaches to the conceptualization of each construct, (b) longitudinal analyses of bottom-up and top-down developmental processes across hierarchical levels, and (c) developmental processes across subjects. The data stemmed from two longitudinal large-scale samples (N = 3498 and N = 3863) of students attending Grades 7 and 9 in Luxembourgish schools. Nested-factor models were applied to represent each construct at each grade level. The analyses demonstrated that several characteristics were shared across constructs. All constructs were multidimensional in nature with respect to the different subjects, showed a hierarchical organization with a general component at the apex of the hierarchy, and had a strong separation between the subject-specific components at both grade levels. Further, all constructs showed moderate differential stabilities at both the general (0.42 < r < 0.55) and subject-specific levels (0.45 < r < 0.73). Further, little evidence was found for top-down or bottom-up developmental processes. Rather, general and subject-specific components in Grade 9 proved to be primarily a function of the corresponding components in Grade 7. Finally, change in several subject-specific components could be explained by negative effects across subjects.

  8. Exact Symbol Error Probability of Square M-QAM Signaling over Generalized Fading Channels subject to Additive Generalized Gaussian Noise

    KAUST Repository

    Soury, Hamza

    2013-07-01

    This paper considers the average symbol error probability of square Quadrature Amplitude Modulation (QAM) coherent signaling over flat fading channels subject to additive generalized Gaussian noise. More specifically, a generic closedform expression in terms of the Fox H function and the bivariate Fox H function is offered for the extended generalized-K fading case. Simplifications for some special fading distributions such as generalized-K fading, Nakagami-m fading, and Rayleigh fading and special additive noise distributions such as Gaussian and Laplacian noise are then presented. Finally, the mathematical formalism is illustrated by some numerical examples verified by computer based simulations for a variety of fading and additive noise parameters.

  9. Physical and psychosocial prerequisites of functioning in relation to work ability and general subjective well-being among office workers.

    Science.gov (United States)

    Sjögren-Rönkä, Tuulikki; Ojanen, Markku T; Leskinen, Esko K; Tmustalampi, Sirpa; Mälkiä, Esko A

    2002-06-01

    The purpose of the study was to investigate the physical and psychological prerequisites of functioning, as well as the social environment at work and personal factors, in relation to work ability and general subjective well-being in a group of office workers. The study was a descriptive cross-sectional investigation, using path analysis, of office workers. The subjects comprised 88 volunteers, 24 men and 64 women, from the same workplace [mean age 45.7 (SD 8.6) years]. The independent variables were measured using psychosocial and physical questionnaires and physical measurements. The first dependent variable, work ability, was measured by a work ability index. The second dependent variable, general subjective well-being, was assessed by life satisfaction and meaning of life. The variables were structured according to a modified version of the International Classification of Functioning, Disability and Health. Forward flexion of the spine, intensity of musculoskeletal symptoms, self-confidence, and mental stress at work explained 58% of work ability and had indirect effects on general subjective well-being. Self-confidence, mood, and work ability had a direct effect on general subjective well-being. The model developed explained 68% of general subjective well-being. Age played a significant role in this study population. The prerequisites of physical functioning are important in maintaining work ability, particularly among aging workers, and psychological prerequisites of functioning are of even greater importance in maintaining general subjective well-being.

  10. Developmental Dynamics of General and School-Subject-Specific Components of Academic Self-Concept, Academic Interest, and Academic Anxiety

    Directory of Open Access Journals (Sweden)

    Katarzyna eGogol

    2016-03-01

    Full Text Available The present study investigated the developmental dynamics of general and subject-specific (i.e., mathematics, French, and German components of students’ academic self-concept, anxiety, and interest. To this end, the authors integrated three lines of research: (a hierarchical and multidimensional approaches to the conceptualization of each construct, (b longitudinal analyses of bottom-up and top-down developmental processes across hierarchical levels, and (c ipsative developmental processes across subjects. The data stemmed from two longitudinal large-scale samples (N = 3,498 and N = 3,863 of students attending Grades 7 and 9 in Luxembourgish schools. Nested-factor models were applied to represent each construct at each grade level. The analyses demonstrated that several characteristics were shared across constructs. All constructs were multidimensional in nature with respect to the different subjects, showed a hierarchical organization with a general component at the apex of the hierarchy, and had a strong separation between the subject-specific components at both grade levels. Further, all constructs showed moderate differential stabilities at both the general (.42 < r < .55 and subject-specific levels (.45 < r < .73. Further, little evidence was found for top-down or bottom-up developmental processes. Rather, general and subject-specific components in Grade 9 proved to be primarily a function of the corresponding components in Grade 7. Finally, change in several subject-specific components could be explained by negative, ipsative effects across subjects.

  11. Developmental Dynamics of General and School-Subject-Specific Components of Academic Self-Concept, Academic Interest, and Academic Anxiety

    Science.gov (United States)

    Gogol, Katarzyna; Brunner, Martin; Preckel, Franzis; Goetz, Thomas; Martin, Romain

    2016-01-01

    The present study investigated the developmental dynamics of general and subject-specific (i.e., mathematics, French, and German) components of students' academic self-concept, anxiety, and interest. To this end, the authors integrated three lines of research: (a) hierarchical and multidimensional approaches to the conceptualization of each construct, (b) longitudinal analyses of bottom-up and top-down developmental processes across hierarchical levels, and (c) developmental processes across subjects. The data stemmed from two longitudinal large-scale samples (N = 3498 and N = 3863) of students attending Grades 7 and 9 in Luxembourgish schools. Nested-factor models were applied to represent each construct at each grade level. The analyses demonstrated that several characteristics were shared across constructs. All constructs were multidimensional in nature with respect to the different subjects, showed a hierarchical organization with a general component at the apex of the hierarchy, and had a strong separation between the subject-specific components at both grade levels. Further, all constructs showed moderate differential stabilities at both the general (0.42 < r < 0.55) and subject-specific levels (0.45 < r < 0.73). Further, little evidence was found for top-down or bottom-up developmental processes. Rather, general and subject-specific components in Grade 9 proved to be primarily a function of the corresponding components in Grade 7. Finally, change in several subject-specific components could be explained by negative effects across subjects. PMID:27014162

  12. NASA’s Universe of Learning: Engaging Subject Matter Experts to Support Museum Alliance Science Briefings

    Science.gov (United States)

    Marcucci, Emma; Slivinski, Carolyn; Lawton, Brandon L.; Smith, Denise A.; Squires, Gordon K.; Biferno, Anya A.; Lestition, Kathleen; Cominsky, Lynn R.; Lee, Janice C.; Rivera, Thalia; Walker, Allyson; Spisak, Marilyn

    2018-06-01

    NASA's Universe of Learning creates and delivers science-driven, audience-driven resources and experiences designed to engage and immerse learners of all ages and backgrounds in exploring the universe for themselves. The project is a unique partnership between the Space Telescope Science Institute, Caltech/IPAC, Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, and Sonoma State University and is part of the NASA SMD Science Activation Collective. The NASA’s Universe of Learning projects pull on the expertise of subject matter experts (scientist and engineers) from across the broad range of NASA Astrophysics themes and missions. One such project, which draws strongly on the expertise of the community, is the NASA’s Universe of Learning Science Briefings, which is done in collaboration with the NASA Museum Alliance. This collaboration presents a monthly hour-long discussion on relevant NASA astrophysics topics or events to an audience composed largely of informal educators from informal learning environments. These professional learning opportunities use experts and resources within the astronomical community to support increased interest and engagement of the informal learning community in NASA Astrophysics-related concepts and events. Briefings are designed to create a foundation for this audience using (1) broad science themes, (2) special events, or (3) breaking science news. The NASA’s Universe of Learning team engages subject matter experts to be speakers and present their science at these briefings to provide a direct connection to NASA Astrophysics science and provide the audience an opportunity to interact directly with scientists and engineers involved in NASA missions. To maximize the usefulness of the Museum Alliance Science Briefings, each briefing highlights resources related to the science theme to support informal educators in incorporating science content into their venues and/or interactions with the public. During this

  13. A modified generalized Chaplygin gas as the unified dark matter-dark energy revisited

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xue-Mei, E-mail: xmd@pmo.ac.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing (China)

    2011-12-15

    A modified generalized Chaplygin gas (MGCG) is considered as the unified dark matter-dark energy revisited. The character of MGCG is endued with the dual role, which behaves as matter at early times and as a quiescence dark energy at late times. The equation of state for MGCG is p = -{alpha}{rho}/(1 + {alpha}) - {upsilon}(z){rho}{sup -{alpha}/(1 + {alpha})}, where {upsilon}(z) = -[{rho}0{sub c}(1 + z){sup 3}] {sup (1+{alpha})} (1 - {Omega}{sub 0B}){sup {alpha} {l_brace}{alpha}{Omega}0{sub DM} + {Omega}{sub 0DE} [{omega}{sub DE} + {alpha}(1 +{omega}{sub DE})](1 + z){sup 3}{omega}DE(1+{alpha}){r_brace}}. Some cosmological quantities, such as the densities of different components of the universe {Omega}{sub i} (i, respectively, denotes baryons, dark matter, and dark energy) and the deceleration parameter q, are obtained. The present deceleration parameter q{sub 0}, the transition redshift z{sub T}, and the redshift z{sub eq}, which describes the epoch when the densities in dark matter and dark energy are equal, are also calculated. To distinguish MGCG from others, we then apply the Statefinder diagnostic. Later on, the parameters ({alpha} and {omega}{sub DE}) of MGCG are constrained by combination of the sound speed c{sup 2}{sub s} , the age of the universe t{sub 0}, the growth factor m, and the bias parameter b. It yields {alpha} = -3.07{sup +5.66} {sub -4.98} x 10{sup -2} and {omega}{sub DE} = -1.05 {sup +0.06} {sub -0.11}. Through the analysis of the growth of density perturbations for MGCG, it is found that the energy will transfer from dark matter to dark energy which reach equal at z{sub e}{approx} 0.48 and the density fluctuations start deviating from the linear behavior at z {approx} 0.25 caused by the dominance of dark energy. (author)

  14. Contrast between white and grey matter: MRI appearance with ageing

    International Nuclear Information System (INIS)

    Magnaldi, S.; Ukmar, M.; Vasciaveo, A.; Longo, R.; Pozzi-Mucelli, R.S.

    1993-01-01

    MRI contrast between white and grey matter appears to be higher in young normal subjects than in older patients. The aim of the present study was to investigate the possible relationships between these changes in contrast and ageing. It consisted of two parts. In the first part we retrospectively evaluated 140 MRI brain examinations of healthy subjects, 20 per decade (age range 20-90 years), in whom the contrast was subjectively scored. In the second part we prospectively measured the actual T1, spin density (SD) and T2 values of white and grey matter in another 22 healthy subjects (age range 20-80 years). In the first group of subjects a progressive decrease in white/grey matter contrast was observed with ageing. In the second group of subjects the T1, SD and T2 values of white matter were always shorter than those of grey matter. There is a close relation among T1, SD and T2 values of white and grey matter with ageing. We suggest that there is a progressive loss of white/grey matter contrast with ageing. Such a phenomenon is possibly due to an increased water content in the white matter and the progressive neuronal loss in the grey matter that occurs with age. (orig.)

  15. A Case Study of Beginning Science Teachers' Subject Matter (SMK) and Pedagogical Content Knowledge (PCK) of Teaching Chemical Reaction in Turkey

    Science.gov (United States)

    Usak, Muhammet; Ozden, Mustafa; Eilks, Ingo

    2011-01-01

    This paper describes a case study focusing on the subject matter knowledge, pedagogical content knowledge, and beliefs about science teaching of student teachers in Turkey at the start of their university education. The topic of interest was that of teaching chemical reactions in secondary chemistry education. A written test was developed which…

  16. Extended ΛCDM: generalized non-minimal coupling for dark matter fluids

    International Nuclear Information System (INIS)

    Bettoni, Dario; Liberati, Stefano; Sindoni, Lorenzo

    2011-01-01

    In this paper we discuss a class of models that address the issue of explaining the gravitational dynamics at the galactic scale starting from a geometric point of view. Instead of claiming the existence of some hidden coupling between dark matter and baryons, or abandoning the existence of dark matter itself, we consider the possibility that dark matter and gravity have some non trivial interaction able to modify the dynamics at astrophysical scales. This interaction is implemented assuming that dark matter gets non-minimally coupled with gravity at suitably small scales and late times. After showing the predictions of the model in the Newtonian limit we also discuss the possible origin of it non-minimal coupling. This investigation seems to suggest that phenomenological mechanisms envisaged for the dark matter dynamics, such as the Bose-Einstein condensation of dark matter halos, could be connected to this class of models

  17. A Subject Matter Expert View of Curriculum Development.

    Science.gov (United States)

    Milazzo, M. P.; Anderson, R. B.; Edgar, L. A.; Gaither, T. A.; Vaughan, R. G.

    2017-12-01

    In 2015, NASA selected for funding the PLANETS project: Planetary Learning that Advances the Nexus of Engineering, Technology, and Science. The PLANETS partnership develops planetary science and engineering curricula for out of classroom time (OST) education settings. This partnership is between planetary science Subject Matter Experts (SMEs) at the US Geological Survey (USGS), curriculum developers at the Boston Museum of Science (MOS) Engineering is Everywhere (EiE), science and engineering teacher professional development experts at Northern Arizona University (NAU) Center for Science Teaching and Learning (CSTL), and OST teacher networks across the world. For the 2016 and 2017 Fiscal Years, our focus was on creating science material for two OST modules designed for middle school students. We have begun development of a third module for elementary school students. The first model teaches about the science and engineering of the availability of water in the Solar System, finding accessible water, evaluating it for quality, treating it for impurities, initial use, a cycle of greywater treatment and re-use, and final treatment of blackwater. This module is described in more detail in the abstract by L. Edgar et al., Water in the Solar System: The Development of Science Education Curriculum Focused on Planetary Exploration (233008) The second module involves the science and engineering of remote sensing in planetary exploration. This includes discussion and activities related to the electromagnetic spectrum, spectroscopy and various remote sensing systems and techniques. In these activities and discussions, we include observation and measurement techniques and tools as well as collection and use of specific data of interest to scientists. This module is described in more detail in the abstract by R. Anderson et al., Remote Sensing Mars Landing Sites: An Out-of-School Time Planetary Science Education Activity for Middle School Students (232683) The third module

  18. Pilates versus general exercise effectiveness on pain and functionality in non-specific chronic low back pain subjects.

    Science.gov (United States)

    Mostagi, Fernanda Queiroz Ribeiro Cerci; Dias, Josilainne Marcelino; Pereira, Ligia Maxwell; Obara, Karen; Mazuquin, Bruno Fles; Silva, Mariana Felipe; Silva, Monica Angelica Cardoso; de Campos, Renata Rosa; Barreto, Maria Simone Tavares; Nogueira, Jéssyca Fernandes; Lima, Tarcísio Brandão; Carregaro, Rodrigo Luiz; Cardoso, Jefferson Rosa

    2015-10-01

    Low back pain (LBP) is one of the most common causes of disability, and the Pilates method has been associated with improvements in symptoms. The purpose of this study was to assess the effectiveness of the Pilates method, when compared to general exercises, on pain and functionality after eight weeks (16 sessions, 2×/week) and a follow-up of three months, in subjects with non-specific chronic low back pain (NSCLBP). A randomised controlled trial composed of 22 subjects was proposed. Subjects were allocated into two groups: the Pilates group (PG) (n = 11) and the general exercise group (GEG) (n = 11). The PG protocol was based on the Pilates method and the GEG performed exercises to manage NSCLBP. There were no differences between the groups. When analysed over time, the GEG demonstrated improvements in functionality between baseline and the end of treatment (P = .02; Cohen'sd¯ = 0.34) and baseline and follow-up (P = .04; Cohen'sd¯ = 0.31). There were no differences between the Pilates and general exercises with regard to pain and functionality in NSCLBP subjects but general exercises were better than Pilates for increasing functionality and flexibility. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Dark matter annihilations into two light fermions and one gauge boson. General analysis and antiproton constraints

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Vogl, Stefan

    2011-12-01

    We study in this paper the scenario where the dark matter is constituted by Majo- rana particles which couple to a light Standard Model fermion and an extra scalar via a Yukawa coupling. In this scenario, the annihilation rate into the light fermions with the mediation of the scalar particle is strongly suppressed by the mass of the fermion. Nevertheless, the helicity suppression is lifted by the associated emission of a gauge boson, yielding annihilation rates which could be large enough to allow the indirect detection of the dark matter particles. We perform a general analysis of this scenario, calculating the annihilation cross section of the processes χχ → f anti fV when the dark matter particle is a SU(2) L singlet or doublet, f is a lepton or a quark, and V is a photon, a weak gauge boson or a gluon. We point out that the annihilation rate is particularly enhanced when the dark matter particle is degenerate in mass to the intermediate scalar particle, which is a scenario barely constrained by collider searches of exotic charged or colored particles. Lastly, we derive upper limits on the relevant cross sections from the non-observation of an excess in the cosmic antiproton-to-proton ratio measured by PAMELA. (orig.)

  20. Dark matter annihilations into two light fermions and one gauge boson. General analysis and antiproton constraints

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro; Vogl, Stefan [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2011-12-15

    We study in this paper the scenario where the dark matter is constituted by Majo- rana particles which couple to a light Standard Model fermion and an extra scalar via a Yukawa coupling. In this scenario, the annihilation rate into the light fermions with the mediation of the scalar particle is strongly suppressed by the mass of the fermion. Nevertheless, the helicity suppression is lifted by the associated emission of a gauge boson, yielding annihilation rates which could be large enough to allow the indirect detection of the dark matter particles. We perform a general analysis of this scenario, calculating the annihilation cross section of the processes {chi}{chi} {yields} f anti fV when the dark matter particle is a SU(2){sub L} singlet or doublet, f is a lepton or a quark, and V is a photon, a weak gauge boson or a gluon. We point out that the annihilation rate is particularly enhanced when the dark matter particle is degenerate in mass to the intermediate scalar particle, which is a scenario barely constrained by collider searches of exotic charged or colored particles. Lastly, we derive upper limits on the relevant cross sections from the non-observation of an excess in the cosmic antiproton-to-proton ratio measured by PAMELA. (orig.)

  1. Digital Literacy and Subject Matter Learning

    DEFF Research Database (Denmark)

    Levinsen, Karin; Sørensen, Birgitte Holm

    2015-01-01

    It is generally agreed that learners need to acquire digital literacy in order to be able to act as citizens, employees and entrepreneurs in an increasingly digitalized environment. It is also generally agreed that the educational system has to be responsible for educating towards digital literacy....... However, there is no shared conception of the scope and meaning of digital literacy. The overall picture shows two main approaches: The first aims at digital literacy in the sense of Buildung (general education) while the second addresses a wide range of specific skills and competences: From basic...... computer skills over multimodal analysis to social conventions for behavior in online environments. Consequently designs for teaching and learning that aim at learners acquiring digital literacy and the related learning objectives appear as weak defined. According to the Danish Ministry of Education Shared...

  2. Nonlocal gravity simulates dark matter

    OpenAIRE

    Hehl, Friedrich W.; Mashhoon, Bahram

    2009-01-01

    A nonlocal generalization of Einstein's theory of gravitation is constructed within the framework of the translational gauge theory of gravity. In the linear approximation, the nonlocal theory can be interpreted as linearized general relativity but in the presence of "dark matter" that can be simply expressed as an integral transform of matter. It is shown that this approach can accommodate the Tohline-Kuhn treatment of the astrophysical evidence for dark matter.

  3. Leadership in Diversity Organizations, and Immigrants' Organizational Commitment and Subjective General Health

    OpenAIRE

    Huynh, Victoria Tran

    2014-01-01

    The purpose of this paper is to examine leadership styles in managing cultural diversity from the LIDO-model at workplaces in Norway, and investigate the relationships between perceived leadership styles with immigrants’ organizational commitment and subjective general health through online survey. The leadership styles from the LIDO-model are diversity leadership, assimilation leadership, separation leadership, and laissez-faire leadership. The relationships were measured by t...

  4. Evaluation of dyspnoea in a sample of elderly subjects recruited from general practice

    DEFF Research Database (Denmark)

    Pedersen, F; Mehlsen, J; Raymond, I

    2007-01-01

    . Of 129 subjects with dyspnoea, 68 (53%) had signs of lung disease, 27 (21%) had heart disease, a total of 43 (33%) were obese, 20 (16%) were obese without other causes of dyspnoea and five (4%) had general physical deconditioning. Twelve per cent had none of the above-mentioned potential causes...

  5. Right Fronto-Subcortical White Matter Microstructure Predicts Cognitive Control Ability on the Go/No-go Task in a Community Sample.

    Science.gov (United States)

    Hinton, Kendra E; Lahey, Benjamin B; Villalta-Gil, Victoria; Boyd, Brian D; Yvernault, Benjamin C; Werts, Katherine B; Plassard, Andrew J; Applegate, Brooks; Woodward, Neil D; Landman, Bennett A; Zald, David H

    2018-01-01

    Go/no-go tasks are widely used to index cognitive control. This construct has been linked to white matter microstructure in a circuit connecting the right inferior frontal gyrus (IFG), subthalamic nucleus (STN), and pre-supplementary motor area. However, the specificity of this association has not been tested. A general factor of white matter has been identified that is related to processing speed. Given the strong processing speed component in successful performance on the go/no-go task, this general factor could contribute to task performance, but the general factor has often not been accounted for in past studies of cognitive control. Further, studies on cognitive control have generally employed small unrepresentative case-control designs. The present study examined the relationship between go/no-go performance and white matter microstructure in a large community sample of 378 subjects that included participants with a range of both clinical and subclinical nonpsychotic psychopathology. We found that white matter microstructure properties in the right IFG-STN tract significantly predicted task performance, and remained significant after controlling for dimensional psychopathology. The general factor of white matter only reached statistical significance when controlling for dimensional psychopathology. Although the IFG-STN and general factor tracts were highly correlated, when both were included in the model, only the IFG-STN remained a significant predictor of performance. Overall, these findings suggest that while a general factor of white matter can be identified in a young community sample, white matter microstructure properties in the right IFG-STN tract show a specific relationship to cognitive control. The findings highlight the importance of examining both specific and general correlates of cognition, especially in tasks with a speeded component.

  6. Matter bounce cosmology with a generalized single field: non-Gaussianity and an extended no-go theorem

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yu-Bin; Cai, Yi-Fu [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China); Quintin, Jerome [Department of Physics, McGill University, 3600 rue University, Montréal, QC, H3A 2T8 (Canada); Wang, Dong-Gang, E-mail: lyb2166@mail.ustc.edu.cn, E-mail: jquintin@physics.mcgill.ca, E-mail: wdgang@strw.leidenuniv.nl, E-mail: yifucai@ustc.edu.cn [Leiden Observatory, Leiden University, 2300 RA Leiden (Netherlands)

    2017-03-01

    We extend the matter bounce scenario to a more general theory in which the background dynamics and cosmological perturbations are generated by a k -essence scalar field with an arbitrary sound speed. When the sound speed is small, the curvature perturbation is enhanced, and the tensor-to-scalar ratio, which is excessively large in the original model, can be sufficiently suppressed to be consistent with observational bounds. Then, we study the primordial three-point correlation function generated during the matter-dominated contraction stage and find that it only depends on the sound speed parameter. Similar to the canonical case, the shape of the bispectrum is mainly dominated by a local form, though for some specific sound speed values a new shape emerges and the scaling behaviour changes. Meanwhile, a small sound speed also results in a large amplitude of non-Gaussianities, which is disfavored by current observations. As a result, it does not seem possible to suppress the tensor-to-scalar ratio without amplifying the production of non-Gaussianities beyond current observational constraints (and vice versa). This suggests an extension of the previously conjectured no-go theorem in single field nonsingular matter bounce cosmologies, which rules out a large class of models. However, the non-Gaussianity results remain as a distinguishable signature of matter bounce cosmology and have the potential to be detected by observations in the near future.

  7. Displacive phase transformations and generalized stacking faults

    Czech Academy of Sciences Publication Activity Database

    Paidar, Václav; Ostapovets, Andriy; Duparc, O. H.; Khalfallah, O.

    2012-01-01

    Roč. 122, č. 3 (2012), s. 490-492 ISSN 0587-4246. [International Symposium on Physics of Materials, ISPMA /12./. Praha, 04.09.2011-08.09.2011] R&D Projects: GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : ab-initio calculations * close-packed structures * generalized stacking faults * homogeneous deformation * lattice deformation * many-body potentials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.531, year: 2012

  8. Subject (of documents)

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2017-01-01

    This article presents and discuss the concept “subject” or subject matter (of documents) as it has been examined in library and information science (LIS) for more than 100 years. Different theoretical positions are outlined and it is found that the most important distinction is between document......-oriented views versus request-oriented views. The document-oriented view conceive subject as something inherent in documents, whereas the request-oriented view (or the policy based view) understand subject as an attribution made to documents in order to facilitate certain uses of them. Related concepts...

  9. Alterations in white matter volume and its correlation with clinical characteristics in patients with generalized anxiety disorder

    International Nuclear Information System (INIS)

    Moon, Chung-Man; Jeong, Gwang-Woo

    2015-01-01

    Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)

  10. Alterations in white matter volume and its correlation with clinical characteristics in patients with generalized anxiety disorder

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Chung-Man [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Jeong, Gwang-Woo [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Chonnam National University Medical School, Department of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2015-11-15

    Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)

  11. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

    Science.gov (United States)

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-01-01

    Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume. Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P prediabetic patients. PMID:27336893

  12. The effect of productive classroom talk and metacommunication on young children's oral communicative competence and subject matter knowledge: An intervention study in early childhood education

    NARCIS (Netherlands)

    van der Veen, C.; de Mey, J.R.P.B.; van Kruistum, C.J.; van Oers, B.

    The aim of the present study was to investigate the effect of productive classroom talk and metacommunication on the development of young children's oral communicative competence and subject matter knowledge. This study can be characterized as a quasi-experimental study with a

  13. Which effects of galaxy clusters can reduce the amount of dark matter

    Czech Academy of Sciences Publication Activity Database

    Křížek, Michal; Křížek, Filip; Somer, L.

    -, č. 21 (2014), s. 43-65 ISSN 1313-2709 R&D Projects: GA ČR GA14-02067S; GA MŠk EE2.3.20.0207 Institutional support: RVO:67985840 ; RVO:61389005 Keywords : dark matter * gravitational lensing * Virial Theorem Subject RIV: BA - General Mathematics; BG - Nuclear, Atomic and Molecular Physics, Colliders (UJF-V) http://www.astro.bas.bg/AIJ/issues/n21/MKrizek.pdf

  14. Background history and cosmic perturbations for a general system of self-conserved dynamical dark energy and matter

    International Nuclear Information System (INIS)

    Gómez-Valent, Adrià; Karimkhani, Elahe; Solà, Joan

    2015-01-01

    We determine the Hubble expansion and the general cosmic perturbation equations for a general system consisting of self-conserved matter, ρ m , and self-conserved dark energy (DE), ρ D . While at the background level the two components are non-interacting, they do interact at the perturbations level. We show that the coupled system of matter and DE perturbations can be transformed into a single, third order, matter perturbation equation, which reduces to the (derivative of the) standard one in the case that the DE is just a cosmological constant. As a nontrivial application we analyze a class of dynamical models whose DE density ρ D (H) consists of a constant term, C 0 , and a series of powers of the Hubble rate. These models were previously analyzed from the point of view of dynamical vacuum models, but here we treat them as self-conserved DE models with a dynamical equation of state. We fit them to the wealth of expansion history and linear structure formation data and compare their fit quality with that of the concordance ΛCDM model. Those with C 0 =0 include the so-called ''entropic-force'' and ''QCD-ghost'' DE models, as well as the pure linear model ρ D ∼H, all of which appear strongly disfavored. The models with C 0 ≠0 , in contrast, emerge as promising dynamical DE candidates whose phenomenological performance is highly competitive with the rigid Λ-term inherent to the ΛCDM

  15. Background history and cosmic perturbations for a general system of self-conserved dynamical dark energy and matter

    Energy Technology Data Exchange (ETDEWEB)

    Gómez-Valent, Adrià; Karimkhani, Elahe; Solà, Joan, E-mail: adriagova@ecm.ub.edu, E-mail: e.karimkhani91@basu.ac.ir, E-mail: sola@ecm.ub.edu [High Energy Physics Group, Dept. ECM, and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona, Av. Diagonal 647, E-08028 Barcelona, Catalonia (Spain)

    2015-12-01

    We determine the Hubble expansion and the general cosmic perturbation equations for a general system consisting of self-conserved matter, ρ{sub m}, and self-conserved dark energy (DE), ρ{sub D}. While at the background level the two components are non-interacting, they do interact at the perturbations level. We show that the coupled system of matter and DE perturbations can be transformed into a single, third order, matter perturbation equation, which reduces to the (derivative of the) standard one in the case that the DE is just a cosmological constant. As a nontrivial application we analyze a class of dynamical models whose DE density ρ{sub D}(H) consists of a constant term, C{sub 0}, and a series of powers of the Hubble rate. These models were previously analyzed from the point of view of dynamical vacuum models, but here we treat them as self-conserved DE models with a dynamical equation of state. We fit them to the wealth of expansion history and linear structure formation data and compare their fit quality with that of the concordance ΛCDM model. Those with C{sub 0}=0 include the so-called ''entropic-force'' and ''QCD-ghost'' DE models, as well as the pure linear model ρ{sub D}∼H, all of which appear strongly disfavored. The models with C{sub 0}≠0 , in contrast, emerge as promising dynamical DE candidates whose phenomenological performance is highly competitive with the rigid Λ-term inherent to the ΛCDM.

  16. A general theory for gauge-free lifting

    International Nuclear Information System (INIS)

    Morrison, P. J.

    2013-01-01

    A theory for lifting equations of motion for charged particle dynamics, subject to given electromagnetic like forces, up to a gauge-free system of coupled Hamiltonian Vlasov-Maxwell like equations is given. The theory provides very general expressions for the polarization and magnetization vector fields in terms of the particle dynamics description of matter. Thus, as is common in plasma physics, the particle dynamics replaces conventional constitutive relations for matter. Several examples are considered including the usual Vlasov-Maxwell theory, a guiding center kinetic theory, Vlasov-Maxwell theory with the inclusion of spin, and a Vlasov-Maxwell theory with the inclusion of Dirac's magnetic monopoles. All are shown to be Hamiltonian field theories and the Jacobi identity is proven directly.

  17. Aging of Holocaust Survivors: Discrepancies Between Subjective and General Health in the greater Tel Aviv Area.

    Science.gov (United States)

    Ohana, Irit; Golander, Hava; Barak, Yoram

    2018-04-01

    Aging has been associated with perceived lowering of health, especially in post-traumatic individuals. The effects may be more complex or even different for Holocaust survivors as they age due to their inherited resilience and life perspective. A cross-sectional study was conducted of Holocaust survivors and a matched comparison group recruited from the general Israeli population. All participants underwent a personal interview and completed the Cumulative Illness Rating Scale and a survey of subjective Likert-scale questions about perceived health. The study comprised 214 older adults: 107 Holocaust survivors and 107 comparison participants; 101 women and 113 men. The mean age for the participants was 80.7 ± 4.7 years (range 68-93). Holocaust survivors did not differ from comparison subjects in general health measures (mean 51.50 ± 3.06 vs. 52.27 ± 3.24, respectively). However, the Holocaust survivors' subjective health was significantly lower, F (2,211) = 4.18, P Holocaust survivors to achieve successful aging.

  18. 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....

  19. Geometrization of the electromagnetic field and dark matter

    International Nuclear Information System (INIS)

    Pestov, I.B.

    2005-01-01

    A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized electromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space-time which describes the interactions of spinor field with dark matter field

  20. Relative activity of cerebral subcortical gray matter in varying states of attention and awareness in normal subjects and patient studies

    International Nuclear Information System (INIS)

    Cooper, M.; Chen, C.T.; Levy, J.; Wagner, N.; Spire, J.P.; Jacobsen, J.; Meltzer, H.; Metz, J.; Beck, R.N.

    1985-01-01

    An important aspect of the study of brain function involves measurement of the relationships; between activities in the subcortical gray matter of the caudate and of the thalamus; and between these structures and functional cortical areas. The authors have studied these relationships in 22 subjects under different conditions of activation, sleep and sensory deprivation using a PET VI system and F-18-2DG to determine regional cerebral metabolism. Subject activating conditions were maintained throughout the period of equilibration of F-18-2DG and E.E.G.'s were monitored. Multiple tomographic slices of 1-2 million counts were obtained simultaneously with slice separation of 14mm and each plane parallel to the cantho-meatal line. In activated and non-activated awake conditions for normal subjects, left and right thalmus-to-caudate ratios were similar and greater than unity. This relationship was maintained in non-REM sleep, but was reversed and divergent in REM sleep and sensory deprivation; this was also evident in 3/4 narcoleptics awake and asleep in non-REM and REM and 2/3 schizophrenics and affective disorder, subjects. This approach appears to have potential for characterizating normal and disordered regional cerebral function

  1. Dark matter self-interactions from a general spin-0 mediator

    Energy Technology Data Exchange (ETDEWEB)

    Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Wild, Sebastian

    2017-04-15

    Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be consistent with having observable effects from dark matter self-interactions in astrophysical systems. For the case of a mediator with purely scalar couplings we point out the highly relevant impact of low-threshold direct detection experiments like CRESST-II, which essentially rule out the simplest realization of this model. These constraints can be significantly relaxed if the mediator has CP-violating couplings, but then the model faces strong constraints from CMB measurements, which can only be avoided in special regions of parameter space.

  2. Dark matter self-interactions from a general spin-0 mediator

    International Nuclear Information System (INIS)

    Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Wild, Sebastian

    2017-01-01

    Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be consistent with having observable effects from dark matter self-interactions in astrophysical systems. For the case of a mediator with purely scalar couplings we point out the highly relevant impact of low-threshold direct detection experiments like CRESST-II, which essentially rule out the simplest realization of this model. These constraints can be significantly relaxed if the mediator has CP-violating couplings, but then the model faces strong constraints from CMB measurements, which can only be avoided in special regions of parameter space.

  3. Dark matter self-interactions from a general spin-0 mediator

    Energy Technology Data Exchange (ETDEWEB)

    Kahlhoefer, Felix; Schmidt-Hoberg, Kai; Wild, Sebastian, E-mail: felix.kahlhoefer@desy.de, E-mail: kai.schmidt-hoberg@desy.de, E-mail: sebastian.wild@desy.de [DESY, Notkestraße 85, D-22607 Hamburg (Germany)

    2017-08-01

    Dark matter particles interacting via the exchange of very light spin-0 mediators can have large self-interaction rates and obtain their relic abundance from thermal freeze-out. At the same time, these models face strong bounds from direct and indirect probes of dark matter as well as a number of constraints on the properties of the mediator. We investigate whether these constraints can be consistent with having observable effects from dark matter self-interactions in astrophysical systems. For the case of a mediator with purely scalar couplings we point out the highly relevant impact of low-threshold direct detection experiments like CRESST-II, which essentially rule out the simplest realization of this model. These constraints can be significantly relaxed if the mediator has CP-violating couplings, but then the model faces strong constraints from CMB measurements, which can only be avoided in special regions of parameter space.

  4. White matter integrity in kleptomania: A pilot study

    Science.gov (United States)

    Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

    2007-01-01

    This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA than control subjects. Group differences remained significant when right and left frontal Trace and FA were analyzed. Groups did not differ significantly in posterior Trace or FA. Kleptomania may be associated with decreased white matter microstructural integrity in inferior frontal brain regions. PMID:16956753

  5. Geometrization of the Electromagnetic Field and Dark Matter

    CERN Document Server

    Pestov, I B

    2005-01-01

    A general concept of potential field is introduced. The potential field that one puts in correspondence with dark matter, has fundamental geometrical interpretation (parallel transport) and has intrinsically inherent local symmetry. The equations of dark matter field are derived that are invariant with respect to the local transformations. It is shown how to reduce these equations to the Maxwell equations. Thus, the dark matter field may be considered as generalized lectromagnetic field and a simple solution of the old problem is given to connect electromagnetic field with geometrical properties of the physical manifold itself. It is shown that gauge fixing renders generalized electromagnetic field effectively massive while the Maxwell electromagnetic field remains massless. To learn more about interactions between matter and dark matter on the microscopical level (and to recognize the fundamental role of internal symmetry) the general covariant Dirac equation is derived in the Minkowski space--time which des...

  6. Applications of General Systems Theory to the Development of an Adjustable Tutorial Software Machine.

    Science.gov (United States)

    Vos, Hans J.

    1994-01-01

    Describes the construction of a model of computer-assisted instruction using a qualitative block diagram based on general systems theory (GST) as a framework. Subject matter representation is discussed, and appendices include system variables and system equations of the GST model, as well as an example of developing flexible courseware. (Contains…

  7. The Place of Subject Matter Knowledge in Pedagogical Content Knowledge: A Case Study of South African Teachers Teaching the Amount of Substance and Chemical Equilibrium

    Science.gov (United States)

    Rollnick, Marissa; Bennett, Judith; Rhemtula, Mariam; Dharsey, Nadine; Ndlovu, Thandi

    2008-01-01

    This paper presents two South African case studies designed to explore the influence of subject matter knowledge on pedagogical content knowledge (PCK). In the first case study on teaching the mole in two township schools, the findings illustrate that the participant teachers favoured procedural approaches at the expense of conceptual…

  8. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

    OpenAIRE

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-01-01

    Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnet...

  9. Subjective discount rates in the general population and their predictive power for energy saving behavior

    International Nuclear Information System (INIS)

    Bruderer Enzler, Heidi; Diekmann, Andreas; Meyer, Reto

    2014-01-01

    Why do people sometimes refrain from saving energy even if it would pay off in monetary terms? Subjective discount rates present one possible explanation for this lack of foresight, but little is known about their level and reliability in the general population. With regard to behavior, persons with lower discount rates are expected to accept additional costs upfront more readily than those with higher discount rates. Based on a representative nation-wide study, the Swiss Environmental Survey 2007, and a follow-up survey, our analyses reveal that on average subjective discount rates are well above market interest rates and moderately stable over a time interval of four years. Income and education are negatively correlated with discount rates. Contrary to expectations, we did not find convincing support for an impact of discount rates on energy saving behavior. - Highlights: • Results of a large panel study in Switzerland. • Mean subjective discount rates in population are well above market interest rates. • Subjective discount rates are moderately stable over four years. • Theory suggests impact of subjective discount rates on energy saving behavior. • However, subjective discount rates do not contribute to explanation of energy saving behavior

  10. General relativistic razor-thin disks with magnetically polarized matter

    Science.gov (United States)

    Navarro-Noguera, Anamaría; Lora-Clavijo, F. D.; González, Guillermo A.

    2018-06-01

    The origin of magnetic fields in the universe still remains unknown and constitutes one of the most intriguing questions in astronomy and astrophysics. Their significance is enormous since they have a strong influence on many astrophysical phenomena. In regards of this motivation, theoretical models of galactic disks with sources of magnetic field may contribute to understand the physics behind them. Inspired by this, we present a new family of analytical models for thin disks composed by magnetized material. The solutions are axially symmetric, conformastatic and are obtained by solving the Einstein-Maxwell Field Equations for continuum media without the test field approximation, and assuming that the sources are razor-thin disk of magnetically polarized matter. We find analytical expressions for the surface energy density, the pressure, the polarization vector, the electromagnetic fields, the mass and the rotational velocity for circular orbits, for two particular solutions. In each case, the energy-momentum tensor agrees with the energy conditions and also the convergence of the mass for all the solutions is proved. Since the solutions are well-behaved, they may be used to model astrophysical thin disks, and also may contribute as initial data in numerical simulations. In addition, the process to obtain the solutions is described in detail, which may be used as a guide to find solutions with magnetized material in General Relativity.

  11. General analysis for experimental studies of time-reversal-violating effects in slow neutron propagation through polarized matter

    International Nuclear Information System (INIS)

    Lamoreaux, S.K.; Golub, R.

    1994-01-01

    A general technique is developed for the analysis of proposed experimental studies of possible P,T-violating effects in the neutron-nucleus interaction based on low-energy neutron transmission through polarized matter. The analysis is applied to proposed experimental schemes and we determine the levels at which the absolute neutron polarization, magnetic fields, and target polarization must be controlled in order for these experiments to obtain a given sensitivity to P,T-violating effects

  12. General U(1)xU(1) F-theory Compactifications and Beyond: Geometry of unHiggsings and novel Matter Structure

    CERN Document Server

    Cvetic, Mirjam; Piragua, Hernan; Taylor, Washington

    2015-01-01

    We construct the general form of an F-theory compactification with two U(1) factors based on a general elliptically fibered Calabi-Yau manifold with Mordell-Weil group of rank two. This construction produces broad classes of models with diverse matter spectra, including many that are not realized in earlier F-theory constructions with U(1)xU(1) gauge symmetry. Generic U(1)xU(1) models can be related to a Higgsed non-Abelian model with gauge group SU(2)xSU(2)xSU(3), SU(2)^3xSU(3), or a subgroup thereof. The nonlocal horizontal divisors of the Mordell-Weil group are replaced with local vertical divisors associated with the Cartan generators of non-Abelian gauge groups from Kodaira singularities. We give a global resolution of codimension two singularities of the Abelian model; we identify the full anomaly free matter content, and match it to the unHiggsed non-Abelian model. The non-Abelian Weierstrass model exhibits a new algebraic description of the singularities in the fibration that results in the first expl...

  13. Dark matter in the universe

    International Nuclear Information System (INIS)

    Kormendy, J.; Knapp, G.R.

    1987-01-01

    Until recently little more was known than that dark matter appears to exist; there was little systematic information about its properties. Only in the past several years was progress made to the point where dark matter density distributions can be measured. For example, with accurate rotation curves extending over large ranges in radius, decomposing the effects of visible and dark matter to measure dark matter density profiles can be tried. Some regularities in dark matter behaviour have already turned up. This volume includes review and invited papers, poster papers, and the two general discussions. (Auth.)

  14. Relativistic simulations of compact object mergers for nucleonic matter and strange quark matter

    International Nuclear Information System (INIS)

    Bauswein, Andreas Ottmar

    2010-01-01

    Under the assumption that the energy of the ground state of 3-flavor quark matter is lower than the one of nucleonic matter, the compact stellar remnants of supernova explosions are composed of this quark matter. Because of the appearance of strange quarks, such objects are called strange stars. Considering their observational features, strange stars are very similar to neutron stars made of nucleonic matter, and therefore observations cannot exclude the existence of strange stars. This thesis introduces a new method for simulating mergers of compact stars and black holes within a general relativistic framework. The main goal of the present work is the investigation of the question, whether the coalescence of two strange stars in a binary system yields observational signatures that allow one to distinguish them from colliding neutron stars. In this context the gravitational-wave signals are analyzed. It is found that in general the characteristic frequencies in the gravitational-wave spectra are higher for strange stars. Moreover, the amount of matter that becomes gravitationally unbound during the merging is determined. The detection of ejecta of strange star mergers as potential component of cosmic ray flux could serve as a proof of the existence of strange quark matter. (orig.)

  15. Relativistic simulations of compact object mergers for nucleonic matter and strange quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Bauswein, Andreas Ottmar

    2010-01-29

    Under the assumption that the energy of the ground state of 3-flavor quark matter is lower than the one of nucleonic matter, the compact stellar remnants of supernova explosions are composed of this quark matter. Because of the appearance of strange quarks, such objects are called strange stars. Considering their observational features, strange stars are very similar to neutron stars made of nucleonic matter, and therefore observations cannot exclude the existence of strange stars. This thesis introduces a new method for simulating mergers of compact stars and black holes within a general relativistic framework. The main goal of the present work is the investigation of the question, whether the coalescence of two strange stars in a binary system yields observational signatures that allow one to distinguish them from colliding neutron stars. In this context the gravitational-wave signals are analyzed. It is found that in general the characteristic frequencies in the gravitational-wave spectra are higher for strange stars. Moreover, the amount of matter that becomes gravitationally unbound during the merging is determined. The detection of ejecta of strange star mergers as potential component of cosmic ray flux could serve as a proof of the existence of strange quark matter. (orig.)

  16. White matter connectivity and Internet gaming disorder

    Science.gov (United States)

    Jeong, Bum Seok; Han, Doug Hyun; Kim, Sun Mi; Lee, Sang Won; Renshaw, Perry F.

    2017-01-01

    Internet use and on-line game play stimulate corticostriatal-limbic circuitry in both healthy subjects and subjects with Internet gaming disorder (IGD). We hypothesized that increased fractional anisotropy (FA) with decreased radial diffusivity (RD) would be observed in IGD subjects, compared with healthy control subjects, and that these white matter indices would be associated with clinical variables including duration of illness and executive function. We screened 181 male patients in order to recruit a large number (n = 58) of IGD subjects without psychiatric co-morbidity as well as 26 male healthy comparison subjects. Multiple diffusion-weighted images were acquired using a 3.0 Tesla magnetic resonance imaging scanner. Tract-based spatial statistics was applied to compare group differences in diffusion tensor imaging (DTI) metrics between IGD and healthy comparison subjects. IGD subjects had increased FA values within forceps minor, right anterior thalamic radiation, right corticospinal tract, right inferior longitudinal fasciculus, right cingulum to hippocampus and right inferior fronto-occipital fasciculus (IFOF) as well as parallel decreases in RD value within forceps minor, right anterior thalamic radiation and IFOF relative to healthy control subjects. In addition, the duration of illness in IGD subjects was positively correlated with the FA values (integrity of white matter fibers) and negatively correlated with RD scores (diffusivity of axonal density) of whole brain white matter. In IGD subjects without psychiatric co-morbidity, our DTI results suggest that increased myelination (increased FA and decreased RD values) in right-sided frontal fiber tracts may be the result of extended game play. PMID:25899390

  17. In vivo characterization of cortical and white matter neuroaxonal pathology in early multiple sclerosis.

    Science.gov (United States)

    Granberg, Tobias; Fan, Qiuyun; Treaba, Constantina Andrada; Ouellette, Russell; Herranz, Elena; Mangeat, Gabriel; Louapre, Céline; Cohen-Adad, Julien; Klawiter, Eric C; Sloane, Jacob A; Mainero, Caterina

    2017-11-01

    t-test). Cortical thickness did not differ significantly between multiple sclerosis subjects and controls. Higher orientation dispersion in the left primary motor-somatosensory cortex was associated with increased Expanded Disability Status Scale scores in surface-based general linear modelling (P < 0.05). Microstructural pathology was frequent in early multiple sclerosis, and present mainly focally in cortical lesions, whereas more diffusely in white matter. These results suggest early demyelination with loss of cells and/or cell volumes in cortical and white matter lesions, with additional axonal dispersion in white matter lesions. In the cortex, focal lesion changes might precede diffuse atrophy with cortical thinning. Findings in the normal-appearing white matter reveal early axonal pathology outside inflammatory demyelinating lesions. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Evidence for Functional Networks within the Human Brain's White Matter.

    Science.gov (United States)

    Peer, Michael; Nitzan, Mor; Bick, Atira S; Levin, Netta; Arzy, Shahar

    2017-07-05

    Investigation of the functional macro-scale organization of the human cortex is fundamental in modern neuroscience. Although numerous studies have identified networks of interacting functional modules in the gray-matter, limited research was directed to the functional organization of the white-matter. Recent studies have demonstrated that the white-matter exhibits blood oxygen level-dependent signal fluctuations similar to those of the gray-matter. Here we used these signal fluctuations to investigate whether the white-matter is organized as functional networks by applying a clustering analysis on resting-state functional MRI (RSfMRI) data from white-matter voxels, in 176 subjects (of both sexes). This analysis indicated the existence of 12 symmetrical white-matter functional networks, corresponding to combinations of white-matter tracts identified by diffusion tensor imaging. Six of the networks included interhemispheric commissural bridges traversing the corpus callosum. Signals in white-matter networks correlated with signals from functional gray-matter networks, providing missing knowledge on how these distributed networks communicate across large distances. These findings were replicated in an independent subject group and were corroborated by seed-based analysis in small groups and individual subjects. The identified white-matter functional atlases and analysis codes are available at http://mind.huji.ac.il/white-matter.aspx Our results demonstrate that the white-matter manifests an intrinsic functional organization as interacting networks of functional modules, similarly to the gray-matter, which can be investigated using RSfMRI. The discovery of functional networks within the white-matter may open new avenues of research in cognitive neuroscience and clinical neuropsychiatry. SIGNIFICANCE STATEMENT In recent years, functional MRI (fMRI) has revolutionized all fields of neuroscience, enabling identifications of functional modules and networks in the human

  19. Condensed matter physics

    CERN Document Server

    Isihara, A

    2007-01-01

    More than a graduate text and advanced research guide on condensed matter physics, this volume is useful to plasma physicists and polymer chemists, and their students. It emphasizes applications of statistical mechanics to a variety of systems in condensed matter physics rather than theoretical derivations of the principles of statistical mechanics and techniques. Isihara addresses a dozen different subjects in separate chapters, each designed to be directly accessible and used independently of previous chapters. Topics include simple liquids, electron systems and correlations, two-dimensional

  20. Incidence of lumbar spondylolysis in the general population in Japan based on multidetector computed tomography scans from two thousand subjects.

    Science.gov (United States)

    Sakai, Toshinori; Sairyo, Koichi; Takao, Shoichiro; Nishitani, Hiromu; Yasui, Natsuo

    2009-10-01

    Epidemiological analysis using CTs. To investigate the true incidence of lumbar spondylolysis in the general population in Japan. Although there have been several reports on the incidence of lumbar spondylolysis, they had some weakness. One of them concerns the subjects investigated, because the incidence of lumbar spondylolysis varies considerably, and some patients are asymptomatic. In addition, most of the past studies used plain radiograph films or skeletal investigation. Therefore, the past reported incidence may not correspond to that of the general population. We reviewed the computed tomography (CT) scans of 2000 subjects (age: 20-92 years) who had undergone abdominal and pelvic CT on a single multidetector CT scanner for reasons unrelated to low back pain. We reviewed them for spondylolysis, spondylolytic spondylolisthesis, and spina bifida occulta (SBO) in the lumbosacral region. The grade (I-IV) of spondylolisthesis was measured using midsagittal reconstructions. Lumbar spondylolysis was found in 117 subjects (5.9%). Their male-female ratio was 2:1. Multiple-level spondylolysis was found in 5 subjects (0.3%). Among these 117 subjects, there were 124 vertebrae with spondylolysis. Of them, 112 (90.3%) corresponded to L5, and 26 (21.0%) had unilateral spondylolysis.SBO was found in 154 subjects. Of them, 25 had spondylolysis (16.2%), whereas, in 1846 subjects without SBO, 92 had spondylolysis (5.0%). The incidence of spondylolysis among the patients with SBO was significantly higher than that in subjects without SBO (Odd ratio was 3.7-fold).Of 124 vertebrae with spondylolysis, 75 (60.5%) showed low-grade (Meyerding grade I or II) spondylolisthesis, and no subject presented high-grade spondylolisthesis. Spondylolisthesis was found in 74.5% of the subjects with bilateral spondylolysis, and in 7.7% of those with unilateral spondylolysis. The incidence of lumbar spondylolysis in the Japanese general population was 5.9% (males: 7.9%, females: 3.9%).

  1. General crystal in prebiotic context

    International Nuclear Information System (INIS)

    Simon, I.

    1993-09-01

    General crystal is an extension of the crystal concept to any form of matter which exhibit neighbour structure determination. This extension makes many results of solid state physics applicable to heterogeneous matter. Among other it includes the description of phase transition from random to unique structure. The advantage of the general crystal approach is demonstrated on globular protein, on of the most important macromolecules of life, which are capable to adopt unique 3D structure spontaneously, regardless of the heterogeneous character of their chemical structure and conformation. It is suggested that the use of general crystal concept may help to find candidates among heterogeneous matters capable to spontaneous self-organization in the same way as crystallization results in unique structure of homogeneous matter, and to apply some of the results of solid state physics to describe the phase transition and other behaviour of this matter. (author). 10 refs

  2. Dark matter and global symmetries

    Directory of Open Access Journals (Sweden)

    Yann Mambrini

    2016-09-01

    Full Text Available General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left–Right, Singlet Fermionic, Zee–Babu, 3-3-1 and Radiative See-Saw models. Assuming that (i global symmetries are broken at the Planck scale, that (ii the non-renormalizable operators mediating dark matter decay have O(1 couplings, that (iii the dark matter is a singlet field, and that (iv the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV–TeV, including the WIMP regime.

  3. The Specific Heat of Matter at Low Temperatures

    CERN Document Server

    Tari, A

    2003-01-01

    Recent discoveries of new materials and improvements in calorimetric techniques have given new impetus to the subject of specific heat. Nevertheless, there is a serious lack of literature on the subject. This invaluable book, which goes some way towards remedying that, is concerned mainly with the specific heat of matter at ordinary temperatures. It discusses the principles that underlie the theory of specific heat and considers a number of theoretical models in some detail. The subject matter ranges from traditional materials to those recently discovered - heavy fermion compounds, high temper

  4. Cosmological tests of general relativity

    International Nuclear Information System (INIS)

    Hut, P.

    1977-01-01

    It is stated that the general relativity theory could be tested on a cosmological scale by measuring the Hubble constant and the deceleration parameter, if, in addition, everything could be known about the matter filling the universe. If, on the other hand, nothing could be presupposed about the matter content of the universe general relativity could not be tested by measuring any number of time derivatives of the scale factor. But upon making the assumption of a universe filled with non-interacting mixture of non-relativistic matter and radiation general relativity can in principle be tested by measuring the first five derivatives of the scale factor. Some general relations are here presented using this assumption. (author)

  5. Sterile neutrino dark matter

    CERN Document Server

    Merle, Alexander

    2017-01-01

    This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.

  6. Cosmological constraints on the gravitational interactions of matter and dark matter

    International Nuclear Information System (INIS)

    Bai, Yang; Salvado, Jordi; Stefanek, Ben A.

    2015-01-01

    Although there is overwhelming evidence of dark matter from its gravitational interaction, we still do not know its precise gravitational interaction strength or whether it obeys the equivalence principle. Using the latest available cosmological data and working within the framework of ΛCDM, we first update the measurement of the multiplicative factor of cosmology-relevant Newton’s constant over the standard laboratory-based value and find that it is consistent with one. In general relativity, dark matter equivalence principle breaking can be mimicked by a long-range dark matter force mediated by an ultra light scalar field. Using the Planck three year data, we find that the dark matter “fifth-force” strength is constrained to be weaker than 10 −4 of the gravitational force. We also introduce a phenomenological, post-Newtonian two-fluid description to explicitly break the equivalence principle by introducing a difference between dark matter inertial and gravitational masses. Depending on the decoupling time of the dark matter and ordinary matter fluids, the ratio of the dark matter gravitational mass to inertial mass is constrained to be unity at the 10 −6 level

  7. Towards a generalized Landau theory of quasi-particles for hot dense matter

    International Nuclear Information System (INIS)

    Leermakers, R.

    1985-01-01

    In this thesis it is tried to construct a Landau quasi-particle theory for relativistic systems, using field-theoretical methods. It includes a perturbative calculation of the pressure of a quark-gluon plasma. It reports the existence of a hitherto unnoticed plasmon contribution of the order g 3 due to transverse quasi-gluons. A new and Lorentz covariant formulation of the Landau theory is being developed, for a general relativistic system. A detailed calculation is presented of the observables of a quantum electrodynamical (QED) plasma, in lowest orders of perturbation theory. A transverse plasmon effect is discovered, both analytically and numerically. In addition, the analysis shows quasi-electrons and positrons to be stable excitations at any temperature. This is proven in all orders of perturbation theory. Along with a Landau theory for quark-gluon matter, a linearized kinetic equation is derived for the singlet quark distribution function, with a collision term for soft encounters between quasi-quarks. (Auth.)

  8. The maximal-density mass function for primordial black hole dark matter

    Science.gov (United States)

    Lehmann, Benjamin V.; Profumo, Stefano; Yant, Jackson

    2018-04-01

    The advent of gravitational wave astronomy has rekindled interest in primordial black holes (PBH) as a dark matter candidate. As there are many different observational probes of the PBH density across different masses, constraints on PBH models are dependent on the functional form of the PBH mass function. This complicates general statements about the mass functions allowed by current data, and, in particular, about the maximum total density of PBH. Numerical studies suggest that some forms of extended mass functions face tighter constraints than monochromatic mass functions, but they do not preclude the existence of a functional form for which constraints are relaxed. We use analytical arguments to show that the mass function which maximizes the fraction of the matter density in PBH subject to all constraints is a finite linear combination of monochromatic mass functions. We explicitly compute the maximum fraction of dark matter in PBH for different combinations of current constraints, allowing for total freedom of the mass function. Our framework elucidates the dependence of the maximum PBH density on the form of observational constraints, and we discuss the implications of current and future constraints for the viability of the PBH dark matter paradigm.

  9. Generalized regression neural network (GRNN)-based approach for colored dissolved organic matter (CDOM) retrieval: case study of Connecticut River at Middle Haddam Station, USA.

    Science.gov (United States)

    Heddam, Salim

    2014-11-01

    The prediction of colored dissolved organic matter (CDOM) using artificial neural network approaches has received little attention in the past few decades. In this study, colored dissolved organic matter (CDOM) was modeled using generalized regression neural network (GRNN) and multiple linear regression (MLR) models as a function of Water temperature (TE), pH, specific conductance (SC), and turbidity (TU). Evaluation of the prediction accuracy of the models is based on the root mean square error (RMSE), mean absolute error (MAE), coefficient of correlation (CC), and Willmott's index of agreement (d). The results indicated that GRNN can be applied successfully for prediction of colored dissolved organic matter (CDOM).

  10. Girl Scouts and Subject Matter Experts: What’s the Connection?

    Science.gov (United States)

    Harman, Pamela; Girls Scouts of Northern California, Girl Scouts USA, Astronomical Society of the Pacifica, Univeristy of Arizona, and ARIES Scientific.

    2018-01-01

    Reaching for the Stars: NASA Science for Girl Scouts (Girl Scout Stars) fosters interaction between Girl Scouts and NASA Subject Matter Experts (SMEs), disseminates NASA STEM education-related resources, and engages Girl Scouts in NASA science and programs through space science badges and summer camps.A space science badge is in development for each of the six levels of Girl Scouts: Daisies, Grades K – 1; Brownies, Grades 2 -3; Juniors, Grades 4 -5; Cadettes, Grades 6 -8; Seniors, Grades 9 -10; and Ambassadors, Grades 11 -12. Indirectly, SMEs will reach tens of thousands of girls through the badges. SETI Institute SMEs Institute and SME Co-Is located at ARIES Scientific, Astronomical Society of the Pacific, University of Arizona, and Girl Scouts of Northern California developed and modified astronomy activities for the Girl Scouts USA badge writers to finesse into the Girl Scout formats. Revisions are reviewed by SMEs for accuracy. Each badge includes a step option that encourages girls to connect with SMEs, and recommendations for volunteers.A total of 127 girls from 31 states and the District of Columbia attendedTotal Eclipse Destination Camps at three locations. SMEs led activities and tours, inspiring girls to consider STEM careers. University of Arizona (U of A) SMEs lead Astronomy Camp for Volunteers, enabling volunteers to lead and inspire Girl Scouts in their respective Girl Scout Councils. A Destination Camp for Girl Scouts was also held at U of A. Girls experience authentic astronomy, learning how to collect and analyze data.Eleven teams comprised of two Girl Scouts, a volunteer or Council Staff, and an amateur astronomer attended Astronomy Club Camp, held at NASA GSFC. SMEs delivered science content. The girls will lead the formation of astronomy clubs in their councils, and will train their successors. SMEs will present and coach the clubs during monthly webinars.This presentation will highlight success and discuss lessons learned that are applicable

  11. Subjective happiness levels of staff working in provincial organization of general directorate of sport

    Directory of Open Access Journals (Sweden)

    Ömer YAZICI

    2016-03-01

    Full Text Available Aim: The purpose of this study was investigate to level of subjective happiness levels of staff who works in provincial organization of General Directorate of Sport. Material and Methods: The study group of the research consisted of 400 staff (164 female, 236 male who works in General Directorate of Sport’s İstanbul, Trabzon, Malatya and Tokat Youth Services and Sport provincial directorates. In the study as data collection tool; Subjective Happiness Scale (SHS which developed by Lyubomirsky & Lepper (1999 and adapted to Turkish by Akın and Satıcı (2011 was used. And also “personal data form” which created by the researchers was used. The data analyzed by descriptive statistics, T-test and Anova test. Also, Scheffe test was used to find out the significant differences of groups. Results: In accordance with t-test results obtained from the present study, there are significant differences with respect to variables such as marital status, income state and sport participation (p<0.05. Conclusion: As a result, it was determined that married staff is happier than single staff. Also, the staff who determined themselves in moderate income level is happier than the staff who determined themselves in lower income level.

  12. Compact bifluid hybrid stars: hadronic matter mixed with self-interacting fermionic asymmetric dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, Somnath; Basu, D.N. [HBNI, Variable Energy Cyclotron Centre, Kolkata (India); Atta, Debasis [HBNI, Variable Energy Cyclotron Centre, Kolkata (India); Government General Degree College, West Bengal (India); Imam, Kouser [HBNI, Variable Energy Cyclotron Centre, Kolkata (India); Aliah University, Department of Physics, Kolkata (India); Samanta, C. [Virginia Military Institute, Department of Physics and Astronomy, Lexington, VA (United States)

    2017-07-15

    The masses and radii of non-rotating and rotating configurations of pure hadronic stars mixed with self-interacting fermionic asymmetric dark matter are calculated within the two-fluid formalism of stellar structure equations in general relativity. The Equation of State (EoS) of nuclear matter is obtained from the density dependent M3Y effective nucleon-nucleon interaction. We consider the dark matter particle mass of 1 GeV. The EoS of self-interacting dark matter is taken from two-body repulsive interactions of the scale of strong interactions. We explore the conditions of equal and different rotational frequencies of nuclear matter and dark matter and find that the maximum mass of differentially rotating stars with self-interacting dark matter to be ∝1.94 M {sub CircleDot} with radius ∝10.4 km. (orig.)

  13. The interrelationship between subject matter and school gardens

    DEFF Research Database (Denmark)

    Christensen, Jacob Højgaard; Wistoft, Karen

    2018-01-01

    This article maps out existing research regarding the effectiveness of integrated teaching in school gardens, i.e. including the math, languages and science subjects with their related objectives and curricula in school garden teaching and vice versa. The article is based on a literature review...... that concludes that school gardens have a predominantly positive influence on students’ learning outcome. However, there are a few school garden programmes that have the same or even a less beneficial influence on students’ learning outcome than traditional teaching. Thus, school gardens do not have...... an unequivocally positive academic learning effect. The review extracts and discusses some of the factors that are consistently emphasized in the research literature as central to ensuring successful subject integration in school gardens. Taking these as a point of departure, it is concluded that developing...

  14. White matter integrity in kleptomania: A pilot study

    OpenAIRE

    Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

    2006-01-01

    This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA th...

  15. Neighborhood resolved fiber orientation distributions (NRFOD) in automatic labeling of white matter fiber pathways.

    Science.gov (United States)

    Ugurlu, Devran; Firat, Zeynep; Türe, Uğur; Unal, Gozde

    2018-05-01

    Accurate digital representation of major white matter bundles in the brain is an important goal in neuroscience image computing since the representations can be used for surgical planning, intra-patient longitudinal analysis and inter-subject population connectivity studies. Reconstructing desired fiber bundles generally involves manual selection of regions of interest by an expert, which is subject to user bias and fatigue, hence an automation is desirable. To that end, we first present a novel anatomical representation based on Neighborhood Resolved Fiber Orientation Distributions (NRFOD) along the fibers. The resolved fiber orientations are obtained by generalized q-sampling imaging (GQI) and a subsequent diffusion decomposition method. A fiber-to-fiber distance measure between the proposed fiber representations is then used in a density-based clustering framework to select the clusters corresponding to the major pathways of interest. In addition, neuroanatomical priors are utilized to constrain the set of candidate fibers before density-based clustering. The proposed fiber clustering approach is exemplified on automation of the reconstruction of the major fiber pathways in the brainstem: corticospinal tract (CST); medial lemniscus (ML); middle cerebellar peduncle (MCP); inferior cerebellar peduncle (ICP); superior cerebellar peduncle (SCP). Experimental results on Human Connectome Project (HCP)'s publicly available "WU-Minn 500 Subjects + MEG2 dataset" and expert evaluations demonstrate the potential of the proposed fiber clustering method in brainstem white matter structure analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Brain gray matter structural network in myotonic dystrophy type 1.

    Directory of Open Access Journals (Sweden)

    Atsuhiko Sugiyama

    Full Text Available This study aimed to investigate abnormalities in structural covariance network constructed from gray matter volume in myotonic dystrophy type 1 (DM1 patients by using graph theoretical analysis for further clarification of the underlying mechanisms of central nervous system involvement. Twenty-eight DM1 patients (4 childhood onset, 10 juvenile onset, 14 adult onset, excluding three cases from 31 consecutive patients who underwent magnetic resonance imaging in a certain period, and 28 age- and sex- matched healthy control subjects were included in this study. The normalized gray matter images of both groups were subjected to voxel based morphometry (VBM and Graph Analysis Toolbox for graph theoretical analysis. VBM revealed extensive gray matter atrophy in DM1 patients, including cortical and subcortical structures. On graph theoretical analysis, there were no significant differences between DM1 and control groups in terms of the global measures of connectivity. Betweenness centrality was increased in several regions including the left fusiform gyrus, whereas it was decreased in the right striatum. The absence of significant differences between the groups in global network measurements on graph theoretical analysis is consistent with the fact that the general cognitive function is preserved in DM1 patients. In DM1 patients, increased connectivity in the left fusiform gyrus and decreased connectivity in the right striatum might be associated with impairment in face perception and theory of mind, and schizotypal-paranoid personality traits, respectively.

  17. 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

  18. Macro Dark Matter

    CERN Document Server

    Jacobs, David M; Lynn, Bryan W.

    2015-01-01

    Dark matter is a vital component of the current best model of our universe, $\\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space; ho...

  19. Age-related cerebral white matter changes on computed tomography

    International Nuclear Information System (INIS)

    Fukuda, Hitoshi; Kobayashi, Shotai; Koide, Hiromi; Yamaguchi, Shuhei; Okada, Kazunori; Shimote, Kouichi; Tsunematsu, Tokugoro

    1989-01-01

    Changes of cerebral white matter on computed cranial tomography related to aging were studied in 70 subjects aged 30 to 94 years. The subjects had no histories of cerebrovascular accidents and no abnormalities in the central nervous system were shown by physical examinations and CT scans. We measured the average attenuation values (CT numbers) of each elliptical region (165 pixels, 0.39cm 2 ) in the bilateral thalamus and twelve areas of deep white matter. Multiple regression analysis was used to assess the effects of age, cranial size and cranial bone CT numbers on the brain CT numbers. We also studied the association between brain CT numbers and brain atrophy, hypertension, diabetes mellitus. CT numbers of frontal white matter surrounding anterior horns decreased with aging in 70 subjects aged 30 to 94 years. No significant correlation between age and brain CT numbers was found in any other region by multivariate analysis, because of the prominent effect of cranial bone CT numbers on brain CT numbers. Although no age-related changes of white matter CT numbers was found in 41 subjects aged 30 to 65 years, there were significant negative correlations between age and white matter CT numbers at all regions in 29 subjects aged 66 to 94 years. Brain atrophy was associated with brain CT numbers. No association was found for hypertension or diabetes mellitus. Brain CT numbers decreased with aging even in neurologically healthy persons in older age. Brain CT numbers also decreased as cerebral atrophy advanced. (author)

  20. Age-related cerebral white matter changes on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hitoshi; Kobayashi, Shotai; Koide, Hiromi; Yamaguchi, Shuhei; Okada, Kazunori; Shimote, Kouichi; Tsunematsu, Tokugoro

    1989-01-01

    Changes of cerebral white matter on computed cranial tomography related to aging were studied in 70 subjects aged 30 to 94 years. The subjects had no histories of cerebrovascular accidents and no abnormalities in the central nervous system were shown by physical examinations and CT scans. We measured the average attenuation values (CT numbers) of each elliptical region (165 pixels, 0.39cm/sup 2/) in the bilateral thalamus and twelve areas of deep white matter. Multiple regression analysis was used to assess the effects of age, cranial size and cranial bone CT numbers on the brain CT numbers. We also studied the association between brain CT numbers and brain atrophy, hypertension, diabetes mellitus. CT numbers of frontal white matter surrounding anterior horns decreased with aging in 70 subjects aged 30 to 94 years. No significant correlation between age and brain CT numbers was found in any other region by multivariate analysis, because of the prominent effect of cranial bone CT numbers on brain CT numbers. Although no age-related changes of white matter CT numbers was found in 41 subjects aged 30 to 65 years, there were significant negative correlations between age and white matter CT numbers at all regions in 29 subjects aged 66 to 94 years. Brain atrophy was associated with brain CT numbers. No association was found for hypertension or diabetes mellitus. Brain CT numbers decreased with aging even in neurologically healthy persons in older age. Brain CT numbers also decreased as cerebral atrophy advanced. (author).

  1. Phase transitions in nuclear matter

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1984-11-01

    The rather general circumstances under which a phase transition in hadronic matter at finite temperature to an abnormal phase in which baryon effective masses become small and in which copious baryon-antibaryon pairs appear is emphasized. A preview is also given of a soliton model of dense matter, in which at a density of about seven times nuclear density, matter ceases to be a color insulator and becomes increasingly color conducting. 22 references

  2. Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

    Directory of Open Access Journals (Sweden)

    Xue-mei Han

    2017-01-01

    Full Text Available We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe (superior frontal, middle frontal, precentral, and orbital gyri, right parietal lobe (postcentral and inferior parietal gyri, right temporal lobe (caudate nucleus, right occipital lobe (middle occipital gyrus, right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

  3. Comorbid subjective health complaints in patients with sciatica: a prospective study including comparison with the general population.

    Science.gov (United States)

    Grøvle, Lars; Haugen, Anne J; Ihlebaek, Camilla M; Keller, Anne; Natvig, Bård; Brox, Jens I; Grotle, Margreth

    2011-06-01

    Chronic nonspecific low back pain is accompanied by high rates of comorbid mental and physical conditions. The aims of this study were to investigate if patients with specific back pain, that is, sciatica caused by lumbar herniation, report higher rates of subjective health complaints (SHCs) than the general population and if there is an association between change in sciatica symptoms and change in SHCs over a 12-month period. A multicenter cohort study of 466 sciatica patients was conducted with follow-up at 3 months and 1 year. Comorbid SHCs were measured by 27 items of the SHC inventory. Odds ratios (ORs) for each SHC were calculated with comparison to a general population sample (n=928) by logistic regression. The SHC number was calculated by summing all complaints present. At baseline, the ORs for reporting SHCs for the sciatica patients were significantly elevated in 15 of the 27 items with a mean (S.D.) SHC number of 7.5 (4.4), compared to 5.2 (4.4) in the general population (Psciatica, the SHC number was reduced to normal levels. Among those with persisting or worsening sciatica, the number increased to a level almost double that of the general population. Compared to the general population, the prevalence of subjective health complaints in sciatica is increased. During follow-up, the number of health complaints increased in patients with persisting or worsening sciatica. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. White matter involvement in sporadic Creutzfeldt-Jakob disease.

    Science.gov (United States)

    Caverzasi, Eduardo; Mandelli, Maria Luisa; DeArmond, Stephen J; Hess, Christopher P; Vitali, Paolo; Papinutto, Nico; Oehler, Abby; Miller, Bruce L; Lobach, Irina V; Bastianello, Stefano; Geschwind, Michael D; Henry, Roland G

    2014-12-01

    Sporadic Creutzfeldt-Jakob disease is considered primarily a disease of grey matter, although the extent of white matter involvement has not been well described. We used diffusion tensor imaging to study the white matter in sporadic Creutzfeldt-Jakob disease compared to healthy control subjects and to correlated magnetic resonance imaging findings with histopathology. Twenty-six patients with sporadic Creutzfeldt-Jakob disease and nine age- and gender-matched healthy control subjects underwent volumetric T1-weighted and diffusion tensor imaging. Six patients had post-mortem brain analysis available for assessment of neuropathological findings associated with prion disease. Parcellation of the subcortical white matter was performed on 3D T1-weighted volumes using Freesurfer. Diffusion tensor imaging maps were calculated and transformed to the 3D-T1 space; the average value for each diffusion metric was calculated in the total white matter and in regional volumes of interest. Tract-based spatial statistics analysis was also performed to investigate the deeper white matter tracts. There was a significant reduction of mean (P=0.002), axial (P=0.0003) and radial (P=0.0134) diffusivities in the total white matter in sporadic Creutzfeldt-Jakob disease. Mean diffusivity was significantly lower in most white matter volumes of interest (PCreutzfeldt-Jakob disease. Mean diffusivity reduction reflected concomitant decrease of both axial and radial diffusivity, without appreciable changes in white matter anisotropy. Tract-based spatial statistics analysis showed significant reductions of mean diffusivity within the white matter of patients with sporadic Creutzfeldt-Jakob disease, mainly in the left hemisphere, with a strong trend (P=0.06) towards reduced mean diffusivity in most of the white matter bilaterally. In contrast, by visual assessment there was no white matter abnormality either on T2-weighted or diffusion-weighted images. Widespread reduction in white matter mean

  5. Substance use and regional gray matter volume in individuals at high risk of psychosis.

    Science.gov (United States)

    Stone, James M; Bhattacharyya, Sagnik; Barker, Gareth J; McGuire, Philip K

    2012-02-01

    Individuals with an at risk mental state (ARMS) are at greatly increased risk of developing a psychotic illness. Risk of transition to psychosis is associated with regionally reduced cortical gray matter volume. There has been considerable interest in the interaction between psychosis risk and substance use. In this study we investigate the relationship between alcohol, cannabis and nicotine use with gray matter volume in ARMS subjects and healthy volunteers. Twenty seven ARMS subjects and 27 healthy volunteers took part in the study. All subjects underwent volumetric MRI imaging. The relationship between regional gray matter volume and cannabis use, smoking, and alcohol use in controls and ARMS subjects was analysed using voxel-based morphometry. In any region where a significant relationship with drug was present, data were analysed to determine if there was any group difference in this relationship. Alcohol intake was inversely correlated with gray matter volume in cerebellum, cannabis intake was use was inversely correlated with gray matter volume in prefrontal cortex and tobacco intake was inversely correlated with gray matter volume in left temporal cortex. There were no significant interactions by group in any region. There is no evidence to support the hypothesis of increased susceptibility to harmful effects of drugs and alcohol on regional gray matter in ARMS subjects. However, alcohol, tobacco and cannabis at low to moderate intake may be associated with lower gray matter in both ARMS subjects and healthy volunteers-possibly representing low-level cortical damage or change in neural plasticity. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Features of the Subject Domain of Historical Psychology

    OpenAIRE

    V A Koltsova

    2008-01-01

    The known psychologist, the author of a number of important works on methodology of psychological science as a whole and historical psychology, in particular, considers pressing matters of the formation of historical psychology. Her attention is drawn to such matters, as the subject, structure and method of arising intersubject branch of knowledge - historical psychology.

  7. The matter Lagrangian and the energy-momentum tensor in modified gravity with nonminimal coupling between matter and geometry

    International Nuclear Information System (INIS)

    Harko, T.

    2010-01-01

    We show that in modified f(R) type gravity models with nonminimal coupling between matter and geometry, both the matter Lagrangian and the energy-momentum tensor are completely and uniquely determined by the form of the coupling. This result is obtained by using the variational formulation for the derivation of the equations of motion in the modified gravity models with geometry-matter coupling, and the Newtonian limit for a fluid obeying a barotropic equation of state. The corresponding energy-momentum tensor of the matter in modified gravity models with nonminimal coupling is more general than the usual general-relativistic energy-momentum tensor for perfect fluids, and it contains a supplementary, equation of state dependent term, which could be related to the elastic stresses in the body, or to other forms of internal energy. Therefore, the extra force induced by the coupling between matter and geometry never vanishes as a consequence of the thermodynamic properties of the system, or for a specific choice of the matter Lagrangian, and it is nonzero in the case of a fluid of dust particles.

  8. Dark matter search

    International Nuclear Information System (INIS)

    Bernabei, R.

    2003-01-01

    Some general arguments on the particle Dark Matter search are addressed. The WIMP direct detection technique is mainly considered and recent results obtained by exploiting the annual modulation signature are summarized. (author)

  9. Dark matter search

    Energy Technology Data Exchange (ETDEWEB)

    Bernabei, R [Dipto. di Fisica, Universita di Roma ' Tor Vergata' and INFN, sez. Roma2, Rome (Italy)

    2003-08-15

    Some general arguments on the particle Dark Matter search are addressed. The WIMP direct detection technique is mainly considered and recent results obtained by exploiting the annual modulation signature are summarized. (author)

  10. Topical subjects of nuclear energy

    International Nuclear Information System (INIS)

    1977-12-01

    The controversy as regards the introduction of nuclear energy to the energy supply of the Federal Republic of Germany has not subdued yet. However, the discussion has shifted from technical questions more to the field of political argumentation. In addition, questions concerning the back end cycle have come to the fore. The report at hand deals with the topical subjects of fuel reprocessing, ultimate storage of radioactive wastes, the impact of power plants in general and nuclear power plants in particular on the climate, safety and safeguard questions concerning nuclear facilities and fissionable materials, and with the properties and possibilities of plutonium. The authors tried to present technical know-how in an easy comprehensible way. Literature references enable the checking of facts and provide the possibility to deal in more detail with the matter. The seminar report is to give all those interested the opportunity to acquaint themselves with facts and know-how and to acquire knowledge on which to base a personal opinion. (orig.) [de

  11. The Professional Learning Experiences of Non-Mathematics Subject Specialist Teachers: A Descriptive Study

    OpenAIRE

    Ho Younghusband, Alice Christine

    2017-01-01

    Certified teachers in British Columbia (BC) schools can be assigned to teach secondary mathematics without having a major, minor, or formal background in mathematics. This is known as out-of-field teaching. These non-mathematics subject specialist teachers (NMSSTs) must learn or relearn the subject matter of mathematics to teach secondary mathematics. This study investigates what professional learning activities NMSSTs participate in to gain subject matter content knowledge in mathematics, wh...

  12. Gray Matter Concentration Abnormality in Brains of Narcolepsy Patients

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Eun Yeon; Tae, Woo Suk; Kim, Sung Tae; Hong, Seung Bong [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2009-12-15

    To investigate gray matter concentration changes in the brains of narcoleptic patients. Twenty-nine narcoleptic patient with cataplexy and 29 age and sex-matched normal subjects (mean age, 31 years old) underwent volumetric MRIs. The MRIs were spatially normalized to a standard T1 template and subdivided into gray matter, white matter, and cerebrospinal fluid (CSF). These segmented images were then smoothed using a 12-mm full width at half maximum (FWHM) isotropic Gaussian kernel. An optimized voxel-based morphometry protocol was used to analyze brain tissue concentrations using SPM2 (statistical parametric mapping). A one-way analysis of variance was applied to the concentration analysis of gray matter images. Narcoleptics with cataplexy showed reduced gray matter concentration in bilateral thalami, left gyrus rectus, bilateral frontopolar gyri, bilateral short insular gyri, bilateral superior frontal gyri, and right superior temporal and left inferior temporal gyri compared to normal subjects (uncorrected p < 0.001). Furthermore, small volume correction revealed gray matter concentration reduction in bilateral nuclei accumbens, hypothalami, and thalami (false discovery rate corrected p < 0.05). Gray matter concentration reductions were observed in brain regions related to excessive daytime sleepiness, cognition, attention, and memory in narcoleptics with cataplexy

  13. Gray Matter Concentration Abnormality in Brains of Narcolepsy Patients

    International Nuclear Information System (INIS)

    Joo, Eun Yeon; Tae, Woo Suk; Kim, Sung Tae; Hong, Seung Bong

    2009-01-01

    To investigate gray matter concentration changes in the brains of narcoleptic patients. Twenty-nine narcoleptic patient with cataplexy and 29 age and sex-matched normal subjects (mean age, 31 years old) underwent volumetric MRIs. The MRIs were spatially normalized to a standard T1 template and subdivided into gray matter, white matter, and cerebrospinal fluid (CSF). These segmented images were then smoothed using a 12-mm full width at half maximum (FWHM) isotropic Gaussian kernel. An optimized voxel-based morphometry protocol was used to analyze brain tissue concentrations using SPM2 (statistical parametric mapping). A one-way analysis of variance was applied to the concentration analysis of gray matter images. Narcoleptics with cataplexy showed reduced gray matter concentration in bilateral thalami, left gyrus rectus, bilateral frontopolar gyri, bilateral short insular gyri, bilateral superior frontal gyri, and right superior temporal and left inferior temporal gyri compared to normal subjects (uncorrected p < 0.001). Furthermore, small volume correction revealed gray matter concentration reduction in bilateral nuclei accumbens, hypothalami, and thalami (false discovery rate corrected p < 0.05). Gray matter concentration reductions were observed in brain regions related to excessive daytime sleepiness, cognition, attention, and memory in narcoleptics with cataplexy

  14. Subjective memory impairment in general practice : Short overview and design of a mixed methods study.

    Science.gov (United States)

    Pentzek, Michael; Leve, Verena; Leucht, Verena

    2017-05-01

    Public awareness for dementia is rising and patients with concerns about forgetfulness are not uncommon in general practice. For the general practitioner (GP) subjectively perceived memory impairment (SMI) also offers a chance to broach the issue of cognitive function with the patient. This may support GPs' patient-centered care in terms of a broader frailty concept. What is SMI (definition, operationalization, prevalence and burden)? Which conceptions and approaches do GPs have regarding SMI? Narrative overview of recent SMI criteria and results, selective utilization of results from a systematic literature search on GP dementia care, non-systematic search regarding SMI in general practice, deduction of a study design from the overview and development according to international standards. Studies revealed that approximately 60% of GP patients aged >74 reported a declining memory, every sixth person had concerns about this aspect and only relatively few seek medical advice. Concerns about SMI are considered a risk factor for future dementia. Specific general practice conceptions about SMI could not be identified in the literature. Using guidelines for mixed methods research, the design of an exploratory sequential mixed methods study is presented, which should reveal different attitudes of GPs towards SMI. Subjective memory impairment (SMI) is a common feature and troubles a considerable proportion of patients. Neuropsychiatric research is progressing, but for the transfer of the SMI concept into routine practice, involvement of GP research is necessary. A new study aims to make a contribution to this.

  15. 77 FR 269 - Matters Related to Patent Appeals

    Science.gov (United States)

    2012-01-04

    ... DEPARTMENT OF COMMERCE United States Patent and Trademark Office Matters Related to Patent Appeals ACTION: Proposed collection; comment request. SUMMARY: The United States Patent and Trademark Office... Matters Related to Patent Appeals comment'' in the subject line of the message. Mail: Susan K. Fawcett...

  16. Homothetic matter collineations of LRS Bianchi type I spacetimes

    Science.gov (United States)

    Hussain, Tahir; Rahim, Waqas

    2017-12-01

    A complete classification of locally rotationally symmetric (LRS) Bianchi type I spacetimes via homothetic matter collineations (HMCs) is presented. For non-degenerate energy-momentum tensor, a general form of the vector field generating HMCs is found, subject to some integrability conditions. Solving the integrability conditions in different cases, it is found that the LRS Bianchi type I spacetimes admit 6-, 7-, 8-, 10- or 11-dimensional Lie algebra of HMCs. When the energy-momentum tensor is degenerate, two cases give 6 and 11 HMCs, while the remaining cases produce infinite number of HMCs. Some LRS Bianchi type I metrics are provided admitting HMCs.

  17. Make dark matter charged again

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa; Scholtz, Jakub, E-mail: prateekagrawal@fas.harvard.edu, E-mail: fcyrraci@physics.harvard.edu, E-mail: randall@physics.harvard.edu, E-mail: jscholtz@physics.harvard.edu [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)

    2017-05-01

    We revisit constraints on dark matter that is charged under a U(1) gauge group in the dark sector, decoupled from Standard Model forces. We find that the strongest constraints in the literature are subject to a number of mitigating factors. For instance, the naive dark matter thermalization timescale in halos is corrected by saturation effects that slow down isotropization for modest ellipticities. The weakened bounds uncover interesting parameter space, making models with weak-scale charged dark matter viable, even with electromagnetic strength interaction. This also leads to the intriguing possibility that dark matter self-interactions within small dwarf galaxies are extremely large, a relatively unexplored regime in current simulations. Such strong interactions suppress heat transfer over scales larger than the dark matter mean free path, inducing a dynamical cutoff length scale above which the system appears to have only feeble interactions. These effects must be taken into account to assess the viability of darkly-charged dark matter. Future analyses and measurements should probe a promising region of parameter space for this model.

  18. Cigarette smoking is associated with reduced microstructural integrity of cerebral white matter.

    Science.gov (United States)

    Gons, Rob A R; van Norden, Anouk G W; de Laat, Karlijn F; van Oudheusden, Lucas J B; van Uden, Inge W M; Zwiers, Marcel P; Norris, David G; de Leeuw, Frank-Erik

    2011-07-01

    Cigarette smoking doubles the risk of dementia and Alzheimer's disease. Various pathophysiological pathways have been proposed to cause such a cognitive decline, but the exact mechanisms remain unclear. Smoking may affect the microstructural integrity of cerebral white matter. Diffusion tensor imaging is known to be sensitive for microstructural changes in cerebral white matter. We therefore cross-sectionally studied the relation between smoking behaviour (never, former, current) and diffusion tensor imaging parameters in both normal-appearing white matter and white matter lesions as well as the relation between smoking behaviour and cognitive performance. A structured questionnaire was used to ascertain the amount and duration of smoking in 503 subjects with small-vessel disease, aged between 50 and 85 years. Cognitive function was assessed with a neuropsychological test battery. All subjects underwent 1.5 Tesla magnetic resonance imaging. Using diffusion tensor imaging, fractional anisotropy and mean diffusivity were calculated in both normal-appearing white matter and white matter lesions. A history of smoking was associated with significant higher values of mean diffusivity in normal-appearing white matter and white matter lesions (P-trend for smoking status = 0.02) and with poorer cognitive functioning compared with those who never smoked. Associations with smoking and loss of structural integrity appeared to be strongest in normal-appearing white matter. Furthermore, the duration of smoking cessation was positively related to lower values of mean diffusivity and higher values of fractional anisotropy in normal-appearing white matter [β = -0.004 (95% confidence interval -0.007 to 0.000; P = 0.03) and β = 0.019 (95% confidence interval 0.001-0.038; P = 0.04)]. Fractional anisotropy and mean diffusivity values in normal-appearing white matter of subjects who had quit smoking for >20 years were comparable with subjects who had never smoked. These data suggest

  19. General informatics teaching with B-Learning teaching model

    Directory of Open Access Journals (Sweden)

    Nguyen The Dung

    2018-03-01

    Full Text Available Blended learning (B-learning, a combination of face-to-face teaching and E-learning-supported-teaching in an online course, and Information and Communication Technology (ICT tools have been studied in recent years. In addition, the use of this teaching model is effective in teaching and learning conditions in which some certain subjects are appropriate for the specific teaching context. As it has been a matter of concern of the universities in Vietnam today, deep studies related to this topic is crucial to be conducted. In this article, the process of developing online courses and organizing teaching for the General Informatics subject for first-year students at the Hue University of Education with B-learning teaching model will be presented. The combination of 60% face-to-face and 40% online learning.

  20. Mixed dark matter from technicolor

    DEFF Research Database (Denmark)

    Belyaev, Alexander; T. Frandsen, Mads; Sannino, Francesco

    2011-01-01

    We study natural composite cold dark matter candidates which are pseudo Nambu-Goldstone bosons (pNGB) in models of dynamical electroweak symmetry breaking. Some of these can have a significant thermal relic abundance, while others must be mainly asymmetric dark matter. By considering the thermal...... abundance alone we find a lower bound of MW on the pNGB mass when the (composite) Higgs is heavier than 115 GeV. Being pNGBs, the dark matter candidates are in general light enough to be produced at the LHC....

  1. Frontal white matter anisotropy and antidepressant remission in late-life depression.

    Directory of Open Access Journals (Sweden)

    Warren D Taylor

    2008-09-01

    Full Text Available Neuroanatomic features associated with antidepressant treatment outcomes in older depressed individuals are not well established. This study used diffusion tensor imaging to examine frontal white matter structure in depressed subjects undergoing a 12-week trial of sertraline. We hypothesized that remission would be associated with higher frontal anisotropy measures, and failure to remit with lower anisotropy.74 subjects with Major Depressive Disorder and age 60 years or older were enrolled in a twelve-week open-label trial of sertraline and completed clinical assessments and 1.5T magnetic resonance brain imaging. The apparent diffusion coefficient (ADC and fractional anisotropy (FA were measured in regions of interest placed in the white matter of the dorsolateral prefrontal cortex, anterior cingulate cortex, and corpus callosum. Differences in ADC and FA values between subjects who did and did not remit to treatment over the study period were assessed using generalized estimating equations, controlling for age, sex, medical comorbidity and baseline depression severity.Subjects who did not remit to sertraline exhibited higher FA values in the superior frontal gyri and anterior cingulate cortices bilaterally. There were no statistically significant associations between ADC measures and remission.Failure to remit to sertraline is associated with higher frontal FA values. Functional imaging studies demonstrate that depression is characterized by functional disconnection between frontal and limbic regions. Those individuals where this disconnection is related to structural changes as detected by DTI may be more likely to respond to antidepressants.ClinicalTrials.gov NCT00339066.

  2. 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.

  3. General relativity and dark matter

    International Nuclear Information System (INIS)

    Pestov, A.B.

    1993-01-01

    It is shown that from the first principles of General Relativity it follows that there exists a new type of interactions which are tightly connected with the gravitational interactions. New particles representing a new form of interactions do not interact electromagnetically, strongly and weakly with the known elementary particles. Physics of the new particles is defined by the Planck scales. (author.). 9 refs

  4. Selected Cardiovascular Risk Markers in Vegetarians and Subjects of General Population.

    Science.gov (United States)

    Valachovičová, Martina; Príbojová, Jana; Urbánek, Vladimír; Bírošová, Lucia

    2017-12-01

    Besides genetic factors there are environmental effects including nutritional habits which can influence the risk of age-related diseases. The aim of the study was to assess the age dependence of selected cardiovascular risk markers in two groups of subjects with different nutritional pattern. In 470 long-term vegetarians and 478 subjects of general population the following indicators were measured: total cholesterol, HDL-cholesterol, triacylglycerol, glucose, insulin concentrations, LDL-cholesterol, atherogenic index and insulin resistance IR(HOMA) were also calculated in studied subjects. Obtained data were evaluated according to age decades. Vegetarian vs. non-vegetarian concentrations of total cholesterol, LDL-cholesterol, insulin, and values of atherogenic index and IR(HOMA) were significantly reduced in all age decades. Vegetarian vs. non-vegetarian triacalglycerol concentrations were significantly reduced from 4th–7th decade. Vegetarian average decade values of all lipid parameters were in reference range. In non-vegetarian group, the risk average values of total cholesterol (>5.2 mmol/l) were found from 5th–7th decade, LDL-cholesterol (>3.3 mmol/l) in 7th decade and atherogenic index (>4) in 6th–7th decade. In vegetarians vs. non-vegetarians were noted the average decade values for total cholesterol ranging from 4.01–4.59 vs. 4.48–5.67 mmol/l, for triacylglycerols 1.00–1.33 vs. 1.13–1.74 mmol/l, for LDL-cholesterol 2.03–2.58 vs. 2.43–3.49 mmol/l, for atherogenic index 2.72–3.31 vs. 3.05–4.21 and for IR(HOMA) 0.99–1.15 vs. 1.15–1.84. Our data show significantly reduced mean age decade values of lipid and non-lipid cardiovascular risk markers in all adult vegetarians. Smaller changes of markers between decades compared to non-vegetarians document a protective effect of vegetarian nutrition in prevention of cardiovascular disease. Copyright© by the National Institute of Public Health, Prague 2017

  5. Questionnaire on Corporate Income Tax Subjects - Denmark

    DEFF Research Database (Denmark)

    Friis Hansen, Søren; Nielsen, Jacob Graff

    In terms of tax policy, tax harmonization or coordination of corporate taxation in the EU is usually considered from two complementary points of view: tax base and tax rate. These two perspectives structure the debate whether EU Member States, and more broadly States belonging to the same economic...... area, should harmonize or coordinate their policies in tax matters. However, little attention has been paid so far to a more basic question: who are corporate taxpayers? Are they defined in the same way over Europe? This may be explained by the fact that the vast majority of tax systems accept the same...... fundamental idea: while companies limited by shares and limited liability companies should be subject to corporate income tax (CIT), partnerships should be considered fully or partly transparent for tax purposes. This general statement is nevertheless an oversimplification of reality. Comparative law indeed...

  6. Inflatable Dark Matter.

    Science.gov (United States)

    Davoudiasl, Hooman; Hooper, Dan; McDermott, Samuel D

    2016-01-22

    We describe a general scenario, dubbed "inflatable dark matter," in which the density of dark matter particles can be reduced through a short period of late-time inflation in the early Universe. The overproduction of dark matter that is predicted within many, otherwise, well-motivated models of new physics can be elegantly remedied within this context. Thermal relics that would, otherwise, be disfavored can easily be accommodated within this class of scenarios, including dark matter candidates that are very heavy or very light. Furthermore, the nonthermal abundance of grand unified theory or Planck scale axions can be brought to acceptable levels without invoking anthropic tuning of initial conditions. A period of late-time inflation could have occurred over a wide range of scales from ∼MeV to the weak scale or above, and could have been triggered by physics within a hidden sector, with small but not necessarily negligible couplings to the standard model.

  7. A tale of three blind men on the proper subject matter of clinical science and practice: commentary on Plaud's behaviorism vs. Ilardi and Feldman's cognitive neuroscience.

    Science.gov (United States)

    Forsyth, J P; Kelly, M M

    2001-09-01

    Plaud (J Clin Psychol 57, 1089-1102, 1109-1111, 1119-1120) and Ilardi and Feldman (J Clin Psychol 57, 1067-1088, 1103-1107, 1113-1117, 1121-1124) argue for two very different approaches to clinical science and practice (i.e., behavior analysis and cognitive neuroscience, respectively). We comment on the assets and liabilities of both perspectives as presented and attempt to achieve some semblance of balance between the three protagonists embroiled in this current debate. The vision of clinical science we articulate is more ecumenical and evolutionary, rather than paradigmatic and revolutionary. As we see it, the problem clinical psychology faces is much larger than the authors let on; namely, how best to make clinical science meaningful and relevant to practitioners, consumers, the general public, and the behavioral health-care community. Clinical psychology's immediate internal problem is not pluralism with regard to subject matter, worldview, methodology, or school of thought, but pluralism in clinical psychologists' adherence to a scientific epistemology as the only legitimate form of clinical psychology. On this latter point, we still have a very long way to go. Copyright 2001 John Wiley & Sons, Inc.

  8. Entropy, matter, and cosmology.

    Science.gov (United States)

    Prigogine, I; Géhéniau, J

    1986-09-01

    The role of irreversible processes corresponding to creation of matter in general relativity is investigated. The use of Landau-Lifshitz pseudotensors together with conformal (Minkowski) coordinates suggests that this creation took place in the early universe at the stage of the variation of the conformal factor. The entropy production in this creation process is calculated. It is shown that these dissipative processes lead to the possibility of cosmological models that start from empty conditions and gradually build up matter and entropy. Gravitational entropy takes a simple meaning as associated to the entropy that is necessary to produce matter. This leads to an extension of the third law of thermodynamics, as now the zero point of entropy becomes the space-time structure out of which matter is generated. The theory can be put into a convenient form using a supplementary "C" field in Einstein's field equations. The role of the C field is to express the coupling between gravitation and matter leading to irreversible entropy production.

  9. Asymmetric condensed dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, Anthony; Diez-Tejedor, Alberto, E-mail: aguirre@scipp.ucsc.edu, E-mail: alberto.diez@fisica.ugto.mx [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA, 95064 (United States)

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  10. The pursuit of dark matter at colliders—an overview

    Science.gov (United States)

    Penning, Björn

    2018-06-01

    Dark matter is one of the main puzzles in fundamental physics and the goal of a diverse, multi-pronged research programme. Underground and astrophysical searches look for dark matter particles in the cosmos, either by interacting directly or by searching for dark matter annihilation. Particle colliders, in contrast, might produce dark matter in the laboratory and are able to probe most basic dark-matter–matter interactions. They are sensitive to low dark matter masses, provide complementary information at higher masses and are subject to different systematic uncertainties. Collider searches are therefore an important part of an inter-disciplinary dark matter search strategy. This article highlights the experimental and phenomenological development in collider dark matter searches of recent years and their connection with the wider field.

  11. 14 CFR 17.11 - Matters not subject to protest.

    Science.gov (United States)

    2010-01-01

    ... Acquisition: (a) FAA purchases from or through, state, local, and tribal governments and public authorities...) Other transactions which do not fall into the category of procurement contracts subject to the AMS. ...

  12. Interaction of relativistic elementary atoms with matter. I. General formulas

    International Nuclear Information System (INIS)

    Mrowczyn'ski, S.

    1987-01-01

    The problem of the interaction of relativistic elementary atoms (Coulomb bound states of elementary particles such as positronium, pionium, etc.) with matter is studied in the reference frame where the atom is initially at rest. An atom of matter is treated as a spinless structureless fast particle. The amplitudes of elementary-atom interaction are derived in the Born approximation under the assumption that a momentum transfer to the atom does not significantly exceed an inverse Bohr radius of the atom. The elementary-atom excitation and ionization processes are considered. The transitions where the spin projection of the atom component is reversed are also studied. In particular the matrix elements for para-ortho and ortho-para transitions are given. The spin structure of the amplitudes is discussed in detail. The sum rules, which allow the calculation of the cross sections summed over atom final states are found. Finally the formulas of the atom interaction cross sections are presented

  13. 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

  14. Sterile neutrino dark matter with supersymmetry

    Science.gov (United States)

    Shakya, Bibhushan; Wells, James D.

    2017-08-01

    Sterile neutrino dark matter, a popular alternative to the WIMP paradigm, has generally been studied in non-supersymmetric setups. If the underlying theory is supersymmetric, we find that several interesting and novel dark matter features can arise. In particular, in scenarios of freeze-in production of sterile neutrino dark matter, its superpartner, the sterile sneutrino, can play a crucial role in early Universe cosmology as the dominant source of cold, warm, or hot dark matter, or of a subdominant relativistic population of sterile neutrinos that can contribute to the effective number of relativistic degrees of freedom Neff during big bang nucleosynthesis.

  15. The dimensionality of between-person differences in white matter microstructure in old age.

    Science.gov (United States)

    Lövdén, Martin; Laukka, Erika Jonsson; Rieckmann, Anna; Kalpouzos, Grégoria; Li, Tie-Qiang; Jonsson, Tomas; Wahlund, Lars-Olof; Fratiglioni, Laura; Bäckman, Lars

    2013-06-01

    Between-person differences in white matter microstructure may partly generalize across the brain and partly play out differently for distinct tracts. We used diffusion-tensor imaging and structural equation modeling to investigate this issue in a sample of 260 adults aged 60-87 years. Mean fractional anisotropy and mean diffusivity of seven white matter tracts in each hemisphere were quantified. Results showed good fit of a model positing that individual differences in white matter microstructure are structured according to tracts. A general factor, although accounting for variance in the measures, did not adequately represent the individual differences. This indicates the presence of a substantial amount of tract-specific individual differences in white matter microstructure. In addition, individual differences are to a varying degree shared between tracts, indicating that general factors also affect white matter microstructure. Age-related differences in white matter microstructure were present for all tracts. Correlations among tract factors did not generally increase as a function of age, suggesting that aging is not a process with homogenous effects on white matter microstructure across the brain. These findings highlight the need for future research to examine whether relations between white matter microstructure and diverse outcomes are specific or general. Copyright © 2011 Wiley Periodicals, Inc.

  16. Galactic signatures of decaying dark matter

    International Nuclear Information System (INIS)

    Zhang, Le; Sigl, Guenter

    2009-05-01

    If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio surveys at 408 MHz, 1.42 GHz and 23 GHz, as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. (orig.)

  17. Galactic signatures of decaying dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Le; Sigl, Guenter [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-05-15

    If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio surveys at 408 MHz, 1.42 GHz and 23 GHz, as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. (orig.)

  18. The influence of discovery learning model application to the higher order thinking skills student of Srijaya Negara Senior High School Palembang on the animal kingdom subject matter

    Science.gov (United States)

    Riandari, F.; Susanti, R.; Suratmi

    2018-05-01

    This study aimed to find out the information in concerning the influence of discovery learning model application to the higher order thinking skills at the tenth grade students of Srijaya Negara senior high school Palembang on the animal kingdom subject matter. The research method used was pre-experimental with one-group pretest-posttest design. The researchconducted at Srijaya Negara senior high school Palembang academic year 2016/2017. The population sample of this research was tenth grade students of natural science 2. Purposive sampling techniquewas applied in this research. Data was collected by(1) the written test, consist of pretest to determine the initial ability and posttest to determine higher order thinking skills of students after learning by using discovery learning models. (2) Questionnaire sheet, aimed to investigate the response of the students during the learning process by using discovery learning models. The t-test result indicated there was significant increasement of higher order thinking skills students. Thus, it can be concluded that the application of discovery learning modelhad a significant effect and increased to higher order thinking skills students of Srijaya Negara senior high school Palembang on the animal kingdom subject matter.

  19. Interaction of radiation with matter

    CERN Document Server

    Nikjoo, Hooshang; Emfietzoglou, Dimitris

    2012-01-01

    Written for students approaching the subject for the first time, this text provides a solid grounding in the physics of the interactions of photons and particles with matter, which is the basis of radiological physics and radiation dosimetry. The authors first present the relevant atomic physics and then describe the interactions, emphasizing practical applications in health/medical physics and radiation biology. They cover such important topics as microdosimetry, interaction of photons with matter, electron energy loss, and dielectric response. Each chapter includes exercises and a summary.

  20. Limbic grey matter changes in early Parkinson's disease.

    Science.gov (United States)

    Li, Xingfeng; Xing, Yue; Schwarz, Stefan T; Auer, Dorothee P

    2017-05-02

    The purpose of this study was to investigate local and network-related changes of limbic grey matter in early Parkinson's disease (PD) and their inter-relation with non-motor symptom severity. We applied voxel-based morphometric methods in 538 T1 MRI images retrieved from the Parkinson's Progression Markers Initiative website. Grey matter densities and cross-sectional estimates of age-related grey matter change were compared between subjects with early PD (n = 366) and age-matched healthy controls (n = 172) within a regression model, and associations of grey matter density with symptoms were investigated. Structural brain networks were obtained using covariance analysis seeded in regions showing grey matter abnormalities in PD subject group. Patients displayed focally reduced grey matter density in the right amygdala, which was present from the earliest stages of the disease without further advance in mild-moderate disease stages. Right amygdala grey matter density showed negative correlation with autonomic dysfunction and positive with cognitive performance in patients, but no significant interrelations were found with anxiety scores. Patients with PD also demonstrated right amygdala structural disconnection with less structural connectivity of the right amygdala with the cerebellum and thalamus but increased covariance with bilateral temporal cortices compared with controls. Age-related grey matter change was also increased in PD preferentially in the limbic system. In conclusion, detailed brain morphometry in a large group of early PD highlights predominant limbic grey matter deficits with stronger age associations compared with controls and associated altered structural connectivity pattern. This provides in vivo evidence for early limbic grey matter pathology and structural network changes that may reflect extranigral disease spread in PD. Hum Brain Mapp, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2017 The

  1. A general holographic insulator/superconductor model with dark matter sector away from the probe limit

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Yan, E-mail: yanpengphy@163.com [School of Mathematical Sciences, Qufu Normal University, Qufu, Shandong 273165 (China); School of Mathematics and Computer Science, Shaanxi Sci-Tech University, Hanzhong, Shaanxi 723000 (China); Pan, Qiyuan, E-mail: panqiyuan@126.com [Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Liu, Yunqi, E-mail: liuyunqi@hust.edu.cn [School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2017-02-15

    We investigate holographic phase transitions with dark matter sector in the AdS soliton background away from the probe limit. In cases of weak backreaction, we find that the larger coupling parameter α makes the gap of condensation shallower and the critical chemical potential keeps as a constant. In contrast, for very heavy backreaction, the dark matter sector could affect the critical chemical potential and the order of phase transitions. We also find the jump of the holographic topological entanglement entropy corresponds to a first order transition between superconducting states in this model with dark matter sector. More importantly, for certain sets of parameters, we observe novel phenomenon of retrograde condensation. In a word, the dark matter sector provides richer physics in the phase structure and the holographic superconductor properties are helpful in understanding dark matter.

  2. A general holographic insulator/superconductor model with dark matter sector away from the probe limit

    International Nuclear Information System (INIS)

    Peng, Yan; Pan, Qiyuan; Liu, Yunqi

    2017-01-01

    We investigate holographic phase transitions with dark matter sector in the AdS soliton background away from the probe limit. In cases of weak backreaction, we find that the larger coupling parameter α makes the gap of condensation shallower and the critical chemical potential keeps as a constant. In contrast, for very heavy backreaction, the dark matter sector could affect the critical chemical potential and the order of phase transitions. We also find the jump of the holographic topological entanglement entropy corresponds to a first order transition between superconducting states in this model with dark matter sector. More importantly, for certain sets of parameters, we observe novel phenomenon of retrograde condensation. In a word, the dark matter sector provides richer physics in the phase structure and the holographic superconductor properties are helpful in understanding dark matter.

  3. A general holographic insulator/superconductor model with dark matter sector away from the probe limit

    Directory of Open Access Journals (Sweden)

    Yan Peng

    2017-02-01

    Full Text Available We investigate holographic phase transitions with dark matter sector in the AdS soliton background away from the probe limit. In cases of weak backreaction, we find that the larger coupling parameter α makes the gap of condensation shallower and the critical chemical potential keeps as a constant. In contrast, for very heavy backreaction, the dark matter sector could affect the critical chemical potential and the order of phase transitions. We also find the jump of the holographic topological entanglement entropy corresponds to a first order transition between superconducting states in this model with dark matter sector. More importantly, for certain sets of parameters, we observe novel phenomenon of retrograde condensation. In a word, the dark matter sector provides richer physics in the phase structure and the holographic superconductor properties are helpful in understanding dark matter.

  4. White matter hyperintensities and changes in white matter integrity in patients with Alzheimer's disease

    International Nuclear Information System (INIS)

    Wang, Liya; Mao, Hui; Goldstein, Felicia C.; Levey, Allan I.; Lah, James J.; Meltzer, Carolyn C.; Holder, Chad A.

    2011-01-01

    White matter hyperintensities (WMHs) are a risk factor for Alzheimer's disease (AD). This study investigated the relationship between WMHs and white matter changes in AD using diffusion tensor imaging (DTI) and the sensitivity of each DTI index in distinguishing AD with WMHs. Forty-four subjects with WMHs were included. Subjects were classified into three groups based on the Scheltens rating scale: 15 AD patients with mild WMHs, 12 AD patients with severe WMHs, and 17 controls with mild WMHs. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (D R ), and axial diffusivity (D A ) were analyzed using the region of interest and tract-based spatial statistics methods. Sensitivity and specificity of DTI indices in distinguishing AD groups from the controls were evaluated. AD patients with mild WMHs exhibited differences from control subjects in most DTI indices in the medial temporal and frontal areas; however, differences in DTI indices from AD patients with mild WMHs and AD patients with severe WMHs were found in the parietal and occipital areas. FA and D R were more sensitive measurements than MD and D A in differentiating AD patients from controls, while MD was a more sensitive measurement in distinguishing AD patients with severe WMHs from those with mild WMHs. WMHs may contribute to the white matter changes in AD brains, specifically in temporal and frontal areas. Changes in parietal and occipital lobes may be related to the severity of WMHs. D R may serve as an imaging marker of myelin deficits associated with AD. (orig.)

  5. S-Channel Dark Matter Simplified Models and Unitarity

    CERN Document Server

    Englert, Christoph; Spannowsky, Michael

    The ultraviolet structure of $s$-channel mediator dark matter simplified models at hadron colliders is considered. In terms of commonly studied $s$-channel mediator simplified models it is argued that at arbitrarily high energies the perturbative description of dark matter production in high energy scattering at hadron colliders will break down in a number of cases. This is analogous to the well documented breakdown of an EFT description of dark matter collider production. With this in mind, to diagnose whether or not the use of simplified models at the LHC is valid, perturbative unitarity of the scattering amplitude in the processes relevant to LHC dark matter searches is studied. The results are as one would expect: at the LHC and future proton colliders the simplified model descriptions of dark matter production are in general valid. As a result of the general discussion, a simple new class of previously unconsidered `Fermiophobic Scalar' simplified models is proposed, in which a scalar mediator couples to...

  6. Asymptotic safety of gravity with matter

    Science.gov (United States)

    Christiansen, Nicolai; Litim, Daniel F.; Pawlowski, Jan M.; Reichert, Manuel

    2018-05-01

    We study the asymptotic safety conjecture for quantum gravity in the presence of matter fields. A general line of reasoning is put forward explaining why gravitons dominate the high-energy behavior, largely independently of the matter fields as long as these remain sufficiently weakly coupled. Our considerations are put to work for gravity coupled to Yang-Mills theories with the help of the functional renormalization group. In an expansion about flat backgrounds, explicit results for beta functions, fixed points, universal exponents, and scaling solutions are given in systematic approximations exploiting running propagators, vertices, and background couplings. Invariably, we find that the gauge coupling becomes asymptotically free while the gravitational sector becomes asymptotically safe. The dependence on matter field multiplicities is weak. We also explain how the scheme dependence, which is more pronounced, can be handled without changing the physics. Our findings offer a new interpretation of many earlier results, which is explained in detail. The results generalize to theories with minimally coupled scalar and fermionic matter. Some implications for the ultraviolet closure of the Standard Model or its extensions are given.

  7. Dissipative neutrino oscillations in randomly fluctuating matter

    International Nuclear Information System (INIS)

    Benatti, F.; Floreanini, R.

    2005-01-01

    The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: It takes into account matter-induced, decoherence phenomena that go beyond the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect. A widely adopted density fluctuation pattern is found to be physically untenable: A more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis

  8. Dissipative neutrino oscillations in randomly fluctuating matter

    Science.gov (United States)

    Benatti, F.; Floreanini, R.

    2005-01-01

    The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: It takes into account matter-induced, decoherence phenomena that go beyond the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect. A widely adopted density fluctuation pattern is found to be physically untenable: A more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis.

  9. Cardiovascular risk factors in subjects with psoriasis

    DEFF Research Database (Denmark)

    Jensen, Peter; Thyssen, Jacob P; Zachariae, Claus

    2013-01-01

    Background Epidemiological data have established an association between cardiovascular disease and psoriasis. Only one general population study has so far compared prevalences of cardiovascular risk factors among subjects with psoriasis and control subjects. We aimed to determine the prevalence...... of cardiovascular risk factors in subjects with and without psoriasis in the general population. Methods During 2006-2008, a cross-sectional study was performed in the general population in Copenhagen, Denmark. A total of 3471 subjects participated in a general health examination that included assessment of current...... between subjects with and without psoriasis with regard to traditional cardiovascular risk factors. Conclusions Our results contrast with the hitherto-reported increased prevalence of metabolic syndrome in subjects with psoriasis in the general US population. However, our results agree with those of other...

  10. 32 CFR 776.66 - Bar admission and disciplinary matters.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Bar admission and disciplinary matters. 776.66... ADVOCATE GENERAL Rules of Professional Conduct § 776.66 Bar admission and disciplinary matters. (a) Bar admission and disciplinary matters. A covered attorney, in connection with any application for bar admission...

  11. X-rays in the eye of the general public

    International Nuclear Information System (INIS)

    Stegie, R.; Guenther, D.; Stender, K.H.

    1979-01-01

    For a pilot study, a random sample of 181 office personnel in steel companies were interviewed about their knowledge and feelings on X-rays and other forms of ionizing radiation. The general knowledge about the beneficial and detrimental aspects of X-rays was good, with education at school and news media reports being the main sources of information (70%). In general, the news media are considered to give objective and correct reports on this matter. 85% of the interviewed held ionizing radiation to be at least somewhat dangerous. Those with higher education (college/university) were significantly more vocal on the dangerous aspects. Concerning personal fear of X-rays, 30% were at least somewhat fearful. A significant correlation was found between statements on the dangerous aspects and subjective feelings of fear (anxiety). Interestingly, there was no correlation between general fearfulness (manifest anxiety) and fear of X-rays. (orig.) [de

  12. New insights on the matter-gravity coupling paradigm.

    Science.gov (United States)

    Delsate, Térence; Steinhoff, Jan

    2012-07-13

    The coupling between matter and gravity in general relativity is given by a proportionality relation between the stress tensor and the geometry. This is an oriented assumption driven by the fact that both the stress tensor and the Einstein tensor are divergenceless. However, general relativity is in essence a nonlinear theory, so there is no obvious reason why the coupling to matter should be linear. On another hand, modified theories of gravity usually affect the vacuum dynamics, yet keep the coupling to matter linear. In this Letter, we address the implications of consistent nonlinear gravity-matter coupling. The Eddington-inspired Born-Infeld theory recently introduced by Bañados and Ferreira provides an enlightening realization of such coupling modifications. We find that this theory coupled to a perfect fluid reduces to general relativity coupled to a nonlinearly modified perfect fluid, leading to an ambiguity between modified coupling and modified equation of state. We discuss observational consequences of this degeneracy and argue that such a completion of general relativity is viable from both an experimental and theoretical point of view through energy conditions, consistency, and singularity-avoidance perspectives. We use these results to discuss the impact of changing the coupling paradigm.

  13. General health assessment vs. job satisfaction : The relationship of indicators of subjective well-being with self-reported absenteeism

    NARCIS (Netherlands)

    Sczesny, S; Thau, S; Scesnzy, S.

    2004-01-01

    The present study was based on the assumption that people are motivated to gain or maintain their well-being. Being absent from work is conceptualized as a means to this end. We investigated which one of two indicators of subjective well-being - general health assessment versus job satisfaction - is

  14. The structural neural substrate of subjective happiness.

    Science.gov (United States)

    Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Kubota, Yasutaka; Sawada, Reiko; Yoshimura, Sayaka; Toichi, Motomi

    2015-11-20

    Happiness is a subjective experience that is an ultimate goal for humans. Psychological studies have shown that subjective happiness can be measured reliably and consists of emotional and cognitive components. However, the neural substrates of subjective happiness remain unclear. To investigate this issue, we used structural magnetic resonance imaging and questionnaires that assessed subjective happiness, the intensity of positive and negative emotional experiences, and purpose in life. We found a positive relationship between the subjective happiness score and gray matter volume in the right precuneus. Moreover, the same region showed an association with the combined positive and negative emotional intensity and purpose in life scores. Our findings suggest that the precuneus mediates subjective happiness by integrating the emotional and cognitive components of happiness.

  15. Probes for dark matter physics

    Science.gov (United States)

    Khlopov, Maxim Yu.

    The existence of cosmological dark matter is in the bedrock of the modern cosmology. The dark matter is assumed to be nonbaryonic and consists of new stable particles. Weakly Interacting Massive Particle (WIMP) miracle appeals to search for neutral stable weakly interacting particles in underground experiments by their nuclear recoil and at colliders by missing energy and momentum, which they carry out. However, the lack of WIMP effects in their direct underground searches and at colliders can appeal to other forms of dark matter candidates. These candidates may be weakly interacting slim particles, superweakly interacting particles, or composite dark matter, in which new particles are bound. Their existence should lead to cosmological effects that can find probes in the astrophysical data. However, if composite dark matter contains stable electrically charged leptons and quarks bound by ordinary Coulomb interaction in elusive dark atoms, these charged constituents of dark atoms can be the subject of direct experimental test at the colliders. The models, predicting stable particles with charge ‑ 2 without stable particles with charges + 1 and ‑ 1 can avoid severe constraints on anomalous isotopes of light elements and provide solution for the puzzles of dark matter searches. In such models, the excessive ‑ 2 charged particles are bound with primordial helium in O-helium atoms, maintaining specific nuclear-interacting form of the dark matter. The successful development of composite dark matter scenarios appeals for experimental search for doubly charged constituents of dark atoms, making experimental search for exotic stable double charged particles experimentum crucis for dark atoms of composite dark matter.

  16. Low episodic memory performance in cognitively normal elderly subjects is associated with increased posterior cingulate gray matter N-acetylaspartate: a 1H MRSI study at 7 Tesla.

    Science.gov (United States)

    Schreiner, Simon J; Kirchner, Thomas; Wyss, Michael; Van Bergen, Jiri M G; Quevenco, Frances C; Steininger, Stefanie C; Griffith, Erica Y; Meier, Irene; Michels, Lars; Gietl, Anton F; Leh, Sandra E; Brickman, Adam M; Hock, Christoph; Nitsch, Roger M; Pruessmann, Klaas P; Henning, Anke; Unschuld, Paul G

    2016-12-01

    Low episodic memory performance characterizes elderly subjects at increased risk for Alzheimer's disease (AD) and may reflect neuronal dysfunction within the posterior cingulate cortex and precuneus (PCP) region. To investigate a potential association between cerebral neurometabolism and low episodic memory in the absence of cognitive impairment, tissue-specific magnetic resonance spectroscopic imaging at ultrahigh field strength of 7 Tesla was used to investigate the PCP region in a healthy elderly study population (n = 30, age 70 ± 5.7 years, Mini-Mental State Examination 29.4 ± 4.1). The Verbal Learning and Memory Test (VLMT) was administered as part of a neuropsychological battery for assessment of episodic memory performance. Significant differences between PCP gray and white matter could be observed for glutamate-glutamine (p = 0.001), choline (p = 0.01), and myo-inositol (p = 0.02). Low Verbal Learning and Memory Test performance was associated with high N-acetylaspartate in PCP gray matter (p = 0.01) but not in PCP white matter. Our data suggest that subtle decreases in episodic memory performance in the elderly may be associated with increased levels of N-acetylaspartate as a reflection of increased mitochondrial energy capacity in PCP gray matter. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Gray matter network disruptions and amyloid beta in cognitively normal adults.

    Science.gov (United States)

    Tijms, Betty M; Kate, Mara Ten; Wink, Alle Meije; Visser, Pieter Jelle; Ecay, Mirian; Clerigue, Montserrat; Estanga, Ainara; Garcia Sebastian, Maite; Izagirre, Andrea; Villanua, Jorge; Martinez Lage, Pablo; van der Flier, Wiesje M; Scheltens, Philip; Sanz Arigita, Ernesto; Barkhof, Frederik

    2016-01-01

    Gray matter networks are disrupted in Alzheimer's disease (AD). It is unclear when these disruptions start during the development of AD. Amyloid beta 1-42 (Aβ42) is among the earliest changes in AD. We studied, in cognitively healthy adults, the relationship between Aβ42 levels in cerebrospinal fluid (CSF) and single-subject cortical gray matter network measures. Single-subject gray matter networks were extracted from structural magnetic resonance imaging scans in a sample of cognitively healthy adults (N = 185; age range 39-79, mini-mental state examination >25, N = 12 showed abnormal Aβ42 level and for 90 anatomical areas. Associations between continuous Aβ42 CSF levels and single-subject cortical gray matter network measures were tested. Smoothing splines were used to determine whether a linear or nonlinear relationship gave a better fit to the data. Lower Aβ42 CSF levels were linearly associated at whole brain level with lower connectivity density, and nonlinearly with lower clustering values and higher path length values, which is indicative of a less-efficient network organization. These relationships were specific to medial temporal areas, precuneus, and the middle frontal gyrus (all p levels can be related to gray matter networks disruptions. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Quark Matter May Not Be Strange.

    Science.gov (United States)

    Holdom, Bob; Ren, Jing; Zhang, Chen

    2018-06-01

    If quark matter is energetically favored over nuclear matter at zero temperature and pressure, then it has long been expected to take the form of strange quark matter (SQM), with comparable amounts of u, d, and s quarks. The possibility of quark matter with only u and d quarks (udQM) is usually dismissed because of the observed stability of ordinary nuclei. However, we find that udQM generally has lower bulk energy per baryon than normal nuclei and SQM. This emerges in a phenomenological model that describes the spectra of the lightest pseudoscalar and scalar meson nonets. Taking into account the finite size effects, udQM can be the ground state of baryonic matter only for baryon number A>A_{min} with A_{min}≳300. This ensures the stability of ordinary nuclei and points to a new form of stable matter just beyond the periodic table.

  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. 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.

  1. Cerebral Blood Flow during Rest Associates with General Intelligence and Creativity

    Science.gov (United States)

    Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Nagase, Tomomi; Nouchi, Rui; Kawashima, Ryuta

    2011-01-01

    Recently, much scientific attention has been focused on resting brain activity and its investigation through such methods as the analysis of functional connectivity during rest (the temporal correlation of brain activities in different regions). However, investigation of the magnitude of brain activity during rest has focused on the relative decrease of brain activity during a task, rather than on the absolute resting brain activity. It is thus necessary to investigate the association between cognitive factors and measures of absolute resting brain activity, such as cerebral blood flow (CBF), during rest (rest-CBF). In this study, we examined this association using multiple regression analyses. Rest-CBF was the dependent variable and the independent variables included two essential components of cognitive functions, psychometric general intelligence and creativity. CBF was measured using arterial spin labeling and there were three analyses for rest-CBF; namely mean gray matter rest-CBF, mean white matter rest-CBF, and regional rest-CBF. The results showed that mean gray and white matter rest-CBF were significantly and positively correlated with individual psychometric intelligence. Furthermore, mean white matter rest-CBF was significantly and positively correlated with creativity. After correcting the effect of mean gray matter rest-CBF the significant and positive correlation between regional rest-CBF in the perisylvian anatomical cluster that includes the left superior temporal gyrus and insula and individual psychometric intelligence was found. Also, regional rest-CBF in the precuneus was significantly and negatively correlated with individual creativity. Significance of these results of regional rest-CBF did not change when the effect of regional gray matter density was corrected. The findings showed mean and regional rest-CBF in healthy young subjects to be correlated with cognitive functions. The findings also suggest that, even in young cognitively intact

  2. Holographic duality in condensed matter physics

    CERN Document Server

    Zaanen, Jan; Sun, Ya-Wen; Schalm, Koenraad

    2015-01-01

    A pioneering treatise presenting how the new mathematical techniques of holographic duality unify seemingly unrelated fields of physics. This innovative development morphs quantum field theory, general relativity and the renormalisation group into a single computational framework and this book is the first to bring together a wide range of research in this rapidly developing field. Set within the context of condensed matter physics and using boxes highlighting the specific techniques required, it examines the holographic description of thermal properties of matter, Fermi liquids and superconductors, and hitherto unknown forms of macroscopically entangled quantum matter in terms of general relativity, stars and black holes. Showing that holographic duality can succeed where classic mathematical approaches fail, this text provides a thorough overview of this major breakthrough at the heart of modern physics. The inclusion of extensive introductory material using non-technical language and online Mathematica not...

  3. 'The body does matter': Women as embodied social subjects in Angela Carter's Nights at the Circus

    Directory of Open Access Journals (Sweden)

    Milosavljević Tatjana B.

    2017-01-01

    Full Text Available Postmodernism posed a crucial ontological challenge to reality, questioning what constitutes the real world, simultaneously interrogating the horizon of representation of this unstable reality in fiction. Feminism on the other hand equipped us with critical tools for interpreting the reality of being in the world in a gendered body, as well as with a conceptual apparatus for interpreting the manifold institutional and private oppressions of women's bodies that play out in women's daily lives and in the discourses that shape them, literary discourse being one of them. This paper argues that Angela Carter's 1984 novel Nights at the Circus, which is widely held as a postfeminist text due to its narrative commitment to transcending gender binaries, essentially uses the strategies of postmodern storytelling and characterization in order to explore women's embodied potentialities of agency i.e. their construction of subjectivity through body. We will argue that the hybrid magic realist narrative constructs Fevvers' body as a titillating postmodern performance, ontologically illusive and elusive, yet it grounds that same body in various socially effected predicaments and experiences that serve to show that even in the midst of a play of signifiers, in Patricia Waugh's words, 'the body does matter, at least to what has been the dominant perspective within British female fiction' (Waugh, 2006, p. 196. In other words, it may be argued that Carter's novel is invested in traditional second-wave feminist politics to the extent that it shows that a woman's body is an indispensable medium of being in the world with material consequences that bear on the formation of her subjectivity and possibility of agency, and through which she acts out her relationships to others and is acted upon.

  4. On uniform world models with matter and radiation

    International Nuclear Information System (INIS)

    Wojciulewitsch, E.

    1977-01-01

    Some properties of a universe containing matter with density and radiation with density have been investigated. The use of a density parameter for matter strongly suggests the use of an analogous parameter for radiation. Both parameters are associated with deceleration and their evolution in time can be calculated. The definition of a radiation density paramater allows for a generalization of the Stabell-Refsdal classification of uniform matter universes to universes containing both matter and radiation. In this paper no interaction between matter and radiation has been assumed. The effect of an interaction will be investigated in a future paper. (Author)

  5. Explanation of Rotation Curves in Galaxies and Clusters of them, by Generalization of Schwarzschild Metric and Combination with MOND, eliminating Dark Matter

    Science.gov (United States)

    Vossos, Spyridon; Vossos, Elias

    2017-12-01

    Schwarzschild Metric is the first and the most important solution of Einstein vacuum field equations. This is associated with Lorentz metric of flat spacetime and produces the relativistic potential (Φ) and the field strength (g) outside a spherically symmetric mass or a non-rotating black hole. It has many applications such as gravitational red shift, the precession of Mercury’s orbit, Shapiro time delay etc. However, it is inefficient to explain the rotation curves in large galaxies and clusters of them, causing the necessity for dark matter. On the other hand, Modified Newtonian Dynamics (MOND) has already explained these rotation curves in many cases, using suitable interpolating function (μ) in Milgrom’s Law. In this presentation, we initially produce a Generalized Schwarzschild potential and the corresponding Metric of spacetime, in order to be in accordance with any isotropic metric of flat spacetime (including Galilean Metric of spacetime which is associated with Galilean Transformation of spacetime). From this Generalized Schwarzschild potential (Φ), we calculate the corresponding field strength (g), which is associated with the interpolating function (μ). In this way, a new relativistic potential is obtained (let us call 2nd Generalized Schwarzschild potential) which describes the gravitational interaction at any distance and for any metric of flat spacetime. Thus, not only the necessity for Dark Matter is eliminated, but also MOND becomes a pure Relativistic Theory of Gravitational Interaction. Then, we pass to the case of flat spacetime with Lorentz metric (Minkowski space), because the experimental data have been extracted using the Relativistic Doppler Shift and the gravitational red shift of Classic Relativity (CR). Thus, we Explain the Rotation Curves in Galaxies (e.g. NGC 3198) and Clusters of them as well as the Solar system, eliminating Dark Matter. This relativistic potential and the corresponding metric of spacetime have been obtained

  6. Doppler effect on indirect detection of dark matter using dark matter only simulations

    Science.gov (United States)

    Powell, Devon; Laha, Ranjan; Ng, Kenny C. Y.; Abel, Tom

    2017-03-01

    Indirect detection of dark matter is a major avenue for discovery. However, baryonic backgrounds are diverse enough to mimic many possible signatures of dark matter. In this work, we study the newly proposed technique of dark matter velocity spectroscopy [E. G. Speckhard, K. C. Y. Ng, J. F. Beacom, and R. Laha, Phys. Rev. Lett. 116, 031301 (2016), 10.1103/PhysRevLett.116.031301]. The nonrotating dark matter halo and the Solar motion produce a distinct longitudinal dependence of the signal which is opposite in direction to that produced by baryons. Using collisionless dark matter only simulations of Milky Way like halos, we show that this new signature is robust and holds great promise. We develop mock observations by a high energy resolution x-ray spectrometer on a sounding rocket, the Micro-X experiment, to our test case, the 3.5 keV line. We show that by using six different pointings, Micro-X can exclude a constant line energy over various longitudes at ≥3 σ . The halo triaxiality is an important effect, and it will typically reduce the significance of this signal. We emphasize that this new smoking gun in motion signature of dark matter is general and is applicable to any dark matter candidate which produces a sharp photon feature in annihilation or decay.

  7. A fast iterative method for computing particle beams penetrating matter

    International Nuclear Information System (INIS)

    Boergers, C.

    1997-01-01

    Beams of microscopic particles penetrating matter are important in several fields. The application motivating our parameter choices in this paper is electron beam cancer therapy. Mathematically, a steady particle beam penetrating matter, or a configuration of several such beams, is modeled by a boundary value problem for a Boltzmann equation. Grid-based discretization of this problem leads to a system of algebraic equations. This system is typically very large because of the large number of independent variables in the Boltzmann equation (six if time independence is the only dimension-reducing assumption). If grid-based methods are to be practical at all, it is therefore necessary to develop fast solvers for the discretized problems. This is the subject of the present paper. For two-dimensional, mono-energetic, linear particle beam problems, we describe an iterative domain decomposition algorithm based on overlapping decompositions of the set of particle directions and computationally demonstrate its rapid, grid independent convergence. There appears to be no fundamental obstacle to generalizing the method to three-dimensional, energy dependent problems. 34 refs., 15 figs., 6 tabs

  8. Brain parenchymal density measurements by CT in demented subjects and normal controls

    International Nuclear Information System (INIS)

    Gado, M.; Danziger, W.L.; Chi, D.; Hughes, C.P.; Coben, L.A.

    1983-01-01

    Parachymal density measurements of 14 regions of gray and white matter from each cerebral hemisphere were made from CT scans of 25 subjects who had varying degrees of dementia as measured by a global Clinical Dementia Rating, and also from CT scans of 33 normal control subjects. There were few significant differences between the two groups in the mean density value for each of the regions examined, although several individual psychometric tests did correlate with density changes. Moreover, for six regions in the cerebral cortex, and for one region in the thalamus of each hemisphere, we found no significant correlation between the gray-white matter density difference and dementia. There was, however, a loss of the discriminability between the gray and white matter with an increase in the size of the ventricles. These findings may be attributed to the loss of white matter volume

  9. NASA's Universe of Learning: The Integral Role of Research Astronomers and Other Subject Matter Experts

    Science.gov (United States)

    Lee, Janice; Universe of Learning Team

    2018-01-01

    Astronomy seeks to understand the workings of the Universe on its largest scales, and to answer fundamental questions about the story of our origins. The science of astronomy thus naturally lends itself to informal education and public outreach activities, as it broadly captures the human imagination. There are at least three overall goals for investment of resources in Astronomy E/PO: to interest students in pursuing STEM education and careers; to develop Astronomy as context for teaching more basic physical and computer science in service of US National Education Goals; to help motivate continued public support of federally funded Astronomy research and technology development. Providing a full spectrum of opportunities for the public to learn about recent Astronomy discoveries is key to achieving these societal goals. Thus, the E/PO professional community must have an understanding of recent scientific/technological results, and engage with the researchers who are creating new knowledge to explicate that knowledge to the public. It stands to reason that researchers (or “subject matter experts, SMEs”) must be involved in and remain connected to the E/PO endeavor. In this talk, I will describe how research astronomers and other SMEs play an integral role in a full range of informal education programming developed by the NASA Universe of Learning collaboration, and opportunities to get involved.

  10. 48 CFR 4.801 - General.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false General. 4.801 Section 4.801 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Government Contract Files 4.801 General. (a) The head of each office performing contracting...

  11. White matter fibertracking in first-episode schizophrenia, schizoaffective patients and subjects at ultra-high risk of psychosis

    NARCIS (Netherlands)

    Peters, Bart D.; de Haan, Lieuwe; Dekker, Nienke; Blaas, Jorik; Becker, Hiske E.; Dingemans, Peter M.; Akkerman, Erik M.; Majoie, Charles B.; van Amelsvoort, Therèse; den Heeten, Gerard J.; Linszen, Don H.

    2008-01-01

    There is increasing evidence of white matter pathology in schizophrenia. The aim of this study was to examine whether white matter abnormalities found with diffusion tensor imaging (DTI) in previous schizophrenia studies are present in the early phase of the illness. DTI was performed at 3 T on 10

  12. Subjective time pressure: general or domain specific?

    Science.gov (United States)

    Kleiner, Sibyl

    2014-09-01

    Chronic time pressure has been identified as a pervasive societal problem, exacerbated by high demands of the labor market and the home. Yet time pressure has not been disaggregated and examined separately across home and work contexts, leaving many unanswered questions regarding the sources and potentially stressful consequences of time pressure. Using data collected in the United States General Social Survey waves 2002 and 2004, this study disaggregates time pressure into the domains of home and work, and asks whether considering time pressures within distinct work and home contexts reveals distinct predictors or associations with stress. Findings show that both predictors and stress associations differ across work and home pressures, revealing both methodological and theoretical implications for the study of time pressure and work and family life more generally. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Frontal and subcortical grey matter reductions in PTSD.

    Science.gov (United States)

    O'Doherty, Daniel C M; Tickell, Ashleigh; Ryder, Will; Chan, Charles; Hermens, Daniel F; Bennett, Maxwell R; Lagopoulos, Jim

    2017-08-30

    Post-traumatic stress disorder (PTSD) is characterised by a range of debilitating psychological, physical and cognitive symptoms. PTSD has been associated with grey matter atrophy in limbic and frontal cortical brain regions. However, previous studies have reported heterogeneous findings, with grey matter changes observed beyond limbic/frontal areas. Seventy-five adults were recruited from the community, 25 diagnosed with PTSD along with 25 healthy and 25 trauma exposed age and gender matched controls. Participants underwent clinical assessment and magnetic resonance imaging. The data-analyses method Voxel Based Morphometry (VBM) was used to estimate cortical grey matter volumes. When compared to both healthy and trauma exposed controls, PTSD subjects demonstrated decreased grey matter volumes within subcortical brain regions-including the hippocampus and amygdala-along with reductions in the anterior cingulate cortex, frontal medial cortex, middle frontal gyrus, superior frontal gyrus, paracingulate gyrus, and precuneus cortex. Significant negative correlations were found between total CAPS lifetime clinical scores/sub-scores and GM volume of both the PTSD and TC groups. GM volumes of the left rACC and right amygdala showed a significant negative correlation within PTSD diagnosed subjects. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  14. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    International Nuclear Information System (INIS)

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang

    2008-01-01

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD

  15. Natural Implementation of Neutralino Dark Matter

    CERN Document Server

    King, S F

    2006-01-01

    The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to ``supernatural dark matter'' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed ``well tempered neutralino'' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simu...

  16. Results on the gravity of quantum Fermi pressure of localized matter: A new test of general relativity

    International Nuclear Information System (INIS)

    Unnikrishnan, C.S.; Gillies, G.T.

    2006-01-01

    Recently Ehlers, Ozsvath, and Schucking discussed whether pressure contributes to active gravitational mass as required by general relativity. They pointed out that there is no experimental information on this available, though precision measurement of the gravitational constant should provide a test of this foundational aspect of gravity. We had used a similar argument earlier to test the contribution of leptons to the active gravitational mass. In this paper we use the result from the Zuerich gravitational constant experiment to provide the first adequate experimental input regarding the active gravitational mass of Fermi pressure. Apart from confirming the equality of the passive and active gravitational roles of the pressure term in general relativity within an accuracy of 5%, our results are consistent with the theoretical expectation of the cancellation of the gravity of pressure by the gravity of the surface tension of confined matter. This result on the active gravitational mass of the quantum zero-point Fermi pressure in the atomic nucleus is also interesting from the point of view of studying the interplay between quantum physics and classical gravity

  17. Weakening Gravity on Redshift-Survey Scales with Kinetic Matter Mixing

    CERN Document Server

    D'Amico, Guido; Mancarella, Michele; Vernizzi, Filippo

    2017-01-01

    We explore general scalar-tensor models in the presence of a kinetic mixing between matter and the scalar field, which we call Kinetic Matter Mixing. In the frame where gravity is de-mixed from the scalar this is due to disformal couplings of matter species to the gravitational sector, with disformal coefficients that depend on the gradient of the scalar field. In the frame where matter is minimally coupled, it originates from the so-called beyond Horndeski quadratic Lagrangian. We extend the Effective Theory of Interacting Dark Energy by allowing disformal coupling coefficients to depend on the gradient of the scalar field as well. In this very general approach, we derive the conditions to avoid ghost and gradient instabilities and we define Kinetic Matter Mixing independently of the frame metric used to described the action. We study its phenomenological consequences for a $\\Lambda$CDM background evolution, first analytically on small scales. Then, we compute the matter power spectrum and the angular spectr...

  18. An allometric scaling law between gray matter and white matter of cerebral cortex

    International Nuclear Information System (INIS)

    He Jihuan

    2006-01-01

    An allometric scaling relationship between cortical white and gray volumes is derived from a general model that describes brain's remarkable efficiency and prodigious communications between brain areas. The model assumes that (1) a cell's metabolic rate depends upon cell's surface; (2) the overall basal metabolic rates of brain areas depend upon their fractal structures; (3) differential brain areas have same basal metabolic rate at slow wave sleep. The obtained allometric exponent scaling white matter to gray matter is 1.2, which is very much close to Zhang and Sejnowski's observation data

  19. On the almost inconceivable misunderstandings concerning the subject of value-free social science.

    Science.gov (United States)

    Black, Donald

    2013-12-01

    A value judgment says what is good or bad, and value-free social science simply means social science free of value judgments. Yet many sociologists regard value-free social science as undesirable or impossible and readily make value judgments in the name of sociology. Often they display confusion about such matters as the meaning of value-free social science, value judgments internal and external to social science, value judgments as a subject of social science, the relevance of objectivity for value-free social science, and the difference between the human significance of social science and value-free social science. But why so many sociologists are so value-involved - and generally so unscientific - is sociologically understandable: The closest and most distant subjects attract the least scientific ideas. And during the past century sociologists have become increasingly close to their human subject. The debate about value-free social science is also part of an epistemological counterrevolution of humanists (including many sociologists) against the more scientific social scientists who invaded and threatened to expropriate the human subject during the past century. © London School of Economics and Political Science 2013.

  20. Silicon quantum dots: surface matters

    Czech Academy of Sciences Publication Activity Database

    Dohnalová, K.; Gregorkiewicz, T.; Kůsová, Kateřina

    2014-01-01

    Roč. 26, č. 17 (2014), 1-28 ISSN 0953-8984 R&D Projects: GA ČR GPP204/12/P235 Institutional support: RVO:68378271 Keywords : silicon quantum dots * quantum dot * surface chemistry * quantum confinement Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.346, year: 2014

  1. Culture confirmation of gonococcal infection by recall of subjects found to be positive by nucleic acid amplification tests in general practice

    DEFF Research Database (Denmark)

    Møller, Jens Kjølseth

    2010-01-01

    To evaluate a routine notification of general practitioners to recall nucleic acid amplification test (NAAT)-positive subjects for culture of Neisseria gonorrhoeae to confirm gonococcal infection in the community....

  2. Natural implementation of neutralino dark matter

    International Nuclear Information System (INIS)

    King, Steve F.; Roberts, Jonathan P.

    2006-01-01

    The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to 'supernatural dark matter' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed 'well tempered neutralino' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of 'supernatural dark matter' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains

  3. Natural implementation of neutralino dark matter

    Science.gov (United States)

    King, Steve F.; Roberts, Jonathan P.

    2006-09-01

    The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to ``supernatural dark matter'' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed ``well tempered neutralino'' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of ``supernatural dark matter'' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains.

  4. Antidopaminergic medication in healthy subjects provokes subjective and objective mental impairments tightly correlated with perturbation of biogenic monoamine metabolism and prolactin secretion

    Directory of Open Access Journals (Sweden)

    Veselinović T

    2018-04-01

    Full Text Available Tanja Veselinović,1,2 Ingo Vernaleken,1,2 Paul Cumming,3,4 Uwe Henning,5 Lina Winkler,1,2 Peter Kaleta,1,2 Michael Paulzen,1,2 Christian Luckhaus,6 Gerhard Gründer1,2,7 1Department of Psychiatry, Psychotherapy, and Psychosomatics, Faculty of Medicine, RWTH Aachen University, Aachen, 2Translational Brain Medicine, Jülich Aachen Research Alliance (JARA, Jülich, Germany; 3IHBI, School of Psychology and Counselling, Queensland University of Technology, 4QIMR Berghofer Institute, Brisbane, Australia; 5Neurobiochemical Research Unit, Department of Psychiatry, Heinrich Heine University, Düsseldorf, 6LWL University Hospital Bochum, Department of Psychiatry, Division of Cognitive Neuropsychiatry and Psychiatric Preventive Medicine, Ruhr University Bochum, Bochum, 7Department of Molecular Neuroimaging, Central Institute of Mental Health, Mannheim, Germany Objectives: Off-label prescription of antipsychotics to patients without psychotic symptoms has become a routine matter for many psychiatrists and also some general practitioners. Nonetheless, little is known about the possibly detrimental effects of antidopaminergic medications on general psychopathology, subjective mental state, or a possible association with physiological parameters in nonpsychotic individuals.Methods: In this randomized, single-blinded study, groups of healthy volunteers (n=18 received low doses of reserpine, aripiprazole, haloperidol, or placebo on 7 successive days. Relevant physiological parameters (plasma prolactin, concentrations of catecholamine metabolites in plasma, and 24-hour urine and each subject’s mental state (Positive and Negative Syndrome Scale, Hamilton Rating Scale for Depression, visual analogue scale, Beck Depression Inventory II were assessed at the start and end of the trial.Results: Of the three active treatments, only reserpine caused a significant increase in some plasma- and urine-catecholamine metabolites, but all three medications evoked objective

  5. Bromatological composition and dry matter digestibility of millet cultivars subjected to nitrogen doses

    Directory of Open Access Journals (Sweden)

    W.H.D. Buso

    2014-06-01

    Full Text Available The bromatological composition and in vitro dry matter digestibility of millet cultivars were assessed for different nitrogen doses and two sowing seasons in the Ceres municipality of Goiás state, Brazil. The treatments consisted of three millet cultivars (ADR-7010, ADR-500 and BRS-1501, four nitrogen (N doses (0, 50, 100 and 200kg ha-1 of N and two sowing seasons. Three replicates and a randomised block design with a 3 x 4 x 2 factorial scheme were used. Two cuttings were performed in each season when plants reached an average height of 0.70 cm. No significant interactions were observed between or among cultivars for N doses and dry matter (DM, crude protein (CP, neutral detergent fibre (NDF and acid detergent fibre (ADF contents. The DM, CP, NDF and ADF contents were significantly different between N doses. The DM and CP contents increased as the N dose increased to 100kg ha-1. The maximum DM and CP contents were 11.14 and 22.53%, respectively. The NDF and ADF contents were higher in the control treatment (60.11 and 30.01%, respectively. In addition, the lowest ADF and NDF concentrations occurred at an N dose of 50kg ha-1 (56.33 and 30.23%, respectively. The DM contents were higher for the February sowing, with an average of 10.59%. The highest CP and ADF contents were found for the December sowing (22.46 and 31.58%, respectively. No significant differences were found for millet cultivars, N doses or sowing seasons. A significant interaction was found between sowing season and millet cultivar. The BRS-1501 cultivar had a higher in vitro dry matter digestibility in the December/2010 sowing (73.88%.

  6. Constraints on hadronically decaying dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Tran, David [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy

    2012-05-15

    We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.

  7. Constraints on hadronically decaying dark matter

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Tran, David; Minnesota Univ., Minneapolis, MN

    2012-05-01

    We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.

  8. Frontal white matter hyperintensities, clasmatodendrosis and gliovascular abnormalities in ageing and post-stroke dementia.

    Science.gov (United States)

    Chen, Aiqing; Akinyemi, Rufus O; Hase, Yoshiki; Firbank, Michael J; Ndung'u, Michael N; Foster, Vincent; Craggs, Lucy J L; Washida, Kazuo; Okamoto, Yoko; Thomas, Alan J; Polvikoski, Tuomo M; Allan, Louise M; Oakley, Arthur E; O'Brien, John T; Horsburgh, Karen; Ihara, Masafumi; Kalaria, Raj N

    2016-01-01

    White matter hyperintensities as seen on brain T2-weighted magnetic resonance imaging are associated with varying degrees of cognitive dysfunction in stroke, cerebral small vessel disease and dementia. The pathophysiological mechanisms within the white matter accounting for cognitive dysfunction remain unclear. With the hypothesis that gliovascular interactions are impaired in subjects with high burdens of white matter hyperintensities, we performed clinicopathological studies in post-stroke survivors, who had exhibited greater frontal white matter hyperintensities volumes that predicted shorter time to dementia onset. Histopathological methods were used to identify substrates in the white matter that would distinguish post-stroke demented from post-stroke non-demented subjects. We focused on the reactive cell marker glial fibrillary acidic protein (GFAP) to study the incidence and location of clasmatodendrosis, a morphological attribute of irreversibly injured astrocytes. In contrast to normal appearing GFAP+ astrocytes, clasmatodendrocytes were swollen and had vacuolated cell bodies. Other markers such as aldehyde dehydrogenase 1 family, member L1 (ALDH1L1) showed cytoplasmic disintegration of the astrocytes. Total GFAP+ cells in both the frontal and temporal white matter were not greater in post-stroke demented versus post-stroke non-demented subjects. However, the percentage of clasmatodendrocytes was increased by >2-fold in subjects with post-stroke demented compared to post-stroke non-demented subjects (P = 0.026) and by 11-fold in older controls versus young controls (P < 0.023) in the frontal white matter. High ratios of clasmotodendrocytes to total astrocytes in the frontal white matter were consistent with lower Mini-Mental State Examination and the revised Cambridge Cognition Examination scores in post-stroke demented subjects. Double immunofluorescent staining showed aberrant co-localization of aquaporin 4 (AQP4) in retracted GFAP+ astrocytes with

  9. Late-time cosmological evolution of a general class of f(R, T) gravity with minimal curvature-matter coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shabani, Hamid [University of Sistan and Baluchestan, Physics Department, Faculty of Sciences, Zahedan (Iran, Islamic Republic of); Ziaie, Amir Hadi [Islamic Azad University, Department of Physics, Kahnooj Branch, Kerman (Iran, Islamic Republic of)

    2017-08-15

    In this work, we study the late-time cosmological solutions of f(R, T) = g(R) + h(-T) models assuming that the conservation of the energy-momentum tensor (EMT) is violated. We perform our analysis through constructing an autonomous dynamical system for the equations of motion. We study the stability properties of solutions via considering linear perturbations about the related equilibrium points. Moreover, we parameterize the Lagrangian by introducing the parameters m(r) and n(s). These parameters which are constructed out of the functions g(R) and h(-T) play the main role in finding the late-time behavior of the solutions. We find that there exist, in general, three classes of solutions; all models with n > 0 include a proper transition from a prolonged matter era to a de Sitter solution. Models with -0.5 < n < 0 and n{sup '} > 1, for at least a root of equation n(s) = s - 1, include an unphysical dark energy solution preceding an improper matter era. Finally, for n < -1/2 there is a transient accelerated expansion era with -1/2 < w{sup (eff)} < -1/3 before a de Sitter phase. For all cases, in order to have a long enough matter dominated epoch, the condition m{sup '} → 0{sup +} for r

  10. Generalized Noether symmetry in f(T) gravity

    International Nuclear Information System (INIS)

    Mohseni Sadjadi, H.

    2012-01-01

    We consider modified teleparallel gravity (f(T) gravity), as a framework to explain the present accelerated expansion of the universe. The matter component is assumed to be cold dark matter. To find the explicit form of the function f, we utilize generalized Noether theorem and use generalized vector fields as variational symmetries of the corresponding Lagrangian. We study the cosmological consequences of the obtained results.

  11. Weakening gravity on redshift-survey scales with kinetic matter mixing

    Energy Technology Data Exchange (ETDEWEB)

    D' Amico, Guido [Theoretical Physics Department, CERN, Geneva (Switzerland); Huang, Zhiqi [School of Physics and Astronomy, Sun Yat-Sen University, 135 Xingang Xi Road, 510275, Guangzhou (China); Mancarella, Michele; Vernizzi, Filippo [CEA, IPhT, CNRS, URA-2306, 91191 Gif-sur-Yvette cédex (France)

    2017-02-01

    We explore general scalar-tensor models in the presence of a kinetic mixing between matter and the scalar field, which we call Kinetic Matter Mixing. In the frame where gravity is de-mixed from the scalar this is due to disformal couplings of matter species to the gravitational sector, with disformal coefficients that depend on the gradient of the scalar field. In the frame where matter is minimally coupled, it originates from the so-called beyond Horndeski quadratic Lagrangian. We extend the Effective Theory of Interacting Dark Energy by allowing disformal coupling coefficients to depend on the gradient of the scalar field as well. In this very general approach, we derive the conditions to avoid ghost and gradient instabilities and we define Kinetic Matter Mixing independently of the frame metric used to described the action. We study its phenomenological consequences for a ΛCDM background evolution, first analytically on small scales. Then, we compute the matter power spectrum and the angular spectra of the CMB anisotropies and the CMB lensing potential, on all scales. We employ the public version of COOP, a numerical Einstein-Boltzmann solver that implements very general scalar-tensor modifications of gravity. Rather uniquely, Kinetic Matter Mixing weakens gravity on short scales, predicting a lower σ{sub 8} with respect to the ΛCDM case. We propose this as a possible solution to the tension between the CMB best-fit model and low-redshift observables.

  12. Genetic Schizophrenia Risk Variants Jointly Modulate Total Brain and White Matter Volume

    DEFF Research Database (Denmark)

    Terwisscha van Scheltinga, Afke F; Bakker, Steven C; van Haren, Neeltje E M

    2013-01-01

    with total brain volume (R(2)=.048, p=1.6×10(-4)) and white matter volume (R(2)=.051, p=8.6×10(-5)) equally in patients and control subjects. The number of (independent) SNPs that substantially influenced both disease risk and white matter (n=2020) was much smaller than the entire set of SNPs that modulated...... modulating schizophrenia and brain volume. METHODS: Odds ratios for genome-wide SNP data were calculated in the sample collected by the Psychiatric Genome-wide Association Study Consortium (8690 schizophrenia patients and 11,831 control subjects, excluding subjects from the present study). These were used...

  13. Kinematics in special and general relativity

    International Nuclear Information System (INIS)

    Woodside, R.W.M.

    1979-05-01

    This thesis investigates the problem of motion for extended bodies from the viewpoint of classical field theory, where the classical field is the body's energy-momentum or matter tensor. In special relativity a symmetric and divergence-free matter tensor combined with inertial frames is used to generate a kinematics for extended bodies. In general relativity the author suggests an analogous kinematics and applies it to the simplest non-trivial example of static, spherical stars, looking for special sets of vector fields whose matter currents are conserved. Such a set of ten vector fields defines a special frame, and integrals of the conserved matter currents define ten momenta whcih give the kinematics. Application of de Rham cohomology theory shows that the conserved matter currents for isolated bodies will have mechanical potentials which enable the momenta to be found from flux integrals evaluated in the vacuum region surrounding the body. These potentials contain the full Riemann curvature, allowing a body's general relativistic momenta to be determined by its vacuum graviational field

  14. Simplified models of mixed dark matter

    International Nuclear Information System (INIS)

    Cheung, Clifford; Sanford, David

    2014-01-01

    We explore simplified models of mixed dark matter (DM), defined here to be a stable relic composed of a singlet and an electroweak charged state. Our setup describes a broad spectrum of thermal DM candidates that can naturally accommodate the observed DM abundance but are subject to substantial constraints from current and upcoming direct detection experiments. We identify ''blind spots'' at which the DM-Higgs coupling is identically zero, thus nullifying direct detection constraints on spin independent scattering. Furthermore, we characterize the fine-tuning in mixing angles, i.e. well-tempering, required for thermal freeze-out to accommodate the observed abundance. Present and projected limits from LUX and XENON1T force many thermal relic models into blind spot tuning, well-tempering, or both. This simplified model framework generalizes bino-Higgsino DM in the MSSM, singlino-Higgsino DM in the NMSSM, and scalar DM candidates that appear in models of extended Higgs sectors

  15. Reduced time delay for gravitational waves with dark matter emulators

    International Nuclear Information System (INIS)

    Desai, S.; Kahya, E. O.; Woodard, R. P.

    2008-01-01

    We discuss the implications for gravitational wave detectors of a class of modified gravity theories which dispense with the need for dark matter. These models, which are known as dark matter emulators, have the property that weak gravitational waves couple to the metric that would follow from general relativity without dark matter whereas ordinary particles couple to a combination of the metric and other fields which reproduces the result of general relativity with dark matter. We show that there is an appreciable difference in the Shapiro delays of gravitational waves and photons or neutrinos from the same source, with the gravitational waves always arriving first. We compute the expected time lags for GRB 070201, for SN 1987a and for Sco-X1. We estimate the probable error by taking account of the uncertainty in position, and by using three different dark matter profiles

  16. Patterns of brain structural connectivity differentiate normal weight from overweight subjects

    Directory of Open Access Journals (Sweden)

    Arpana Gupta

    2015-01-01

    Conclusions: 1. An increased BMI (i.e., overweight subjects is associated with distinct changes in gray-matter and fiber density of the brain. 2. Classification algorithms based on white-matter connectivity involving regions of the reward and associated networks can identify specific targets for mechanistic studies and future drug development aimed at abnormal ingestive behavior and in overweight/obesity.

  17. Thermalizing Sterile Neutrino Dark Matter.

    Science.gov (United States)

    Hansen, Rasmus S L; Vogl, Stefan

    2017-12-22

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  18. Thermalizing Sterile Neutrino Dark Matter

    Science.gov (United States)

    Hansen, Rasmus S. L.; Vogl, Stefan

    2017-12-01

    Sterile neutrinos produced through oscillations are a well motivated dark matter candidate, but recent constraints from observations have ruled out most of the parameter space. We analyze the impact of new interactions on the evolution of keV sterile neutrino dark matter in the early Universe. Based on general considerations we find a mechanism which thermalizes the sterile neutrinos after an initial production by oscillations. The thermalization of sterile neutrinos is accompanied by dark entropy production which increases the yield of dark matter and leads to a lower characteristic momentum. This resolves the growing tensions with structure formation and x-ray observations and even revives simple nonresonant production as a viable way to produce sterile neutrino dark matter. We investigate the parameters required for the realization of the thermalization mechanism in a representative model and find that a simple estimate based on energy and entropy conservation describes the mechanism well.

  19. [Is health really the most important value? - Results of a representative survey of the German general population concerning the subjective meaning of health].

    Science.gov (United States)

    Hinz, A; Hübscher, U; Brähler, E; Berth, H

    2010-12-01

    The aim of this study was to investigate which meaning is attributed to health by the general population. Furthermore, the relationship between health satisfaction and health importance was also analysed. A sample of 4,808 representatively selected subjects from the general German population judged the importance and the satisfaction with several life domains, including health, using the questions on life satisfaction FLZ (M). Moreover, sociodemographic variables (sex, age, socioeconomic status) and psychological variables (self-esteem, resilience, anxiety and depression) were collected. Health is the most important life domain. The importance of health increases with increasing age. However, there are no sex differences and SES (socio-economic status) differences concerning the importance of health. Subjective satisfaction with health and health importance are only marginally correlated (r=0.08). High degrees of self-esteem and resilience are associated with a high importance of health. Anxiety and depression show only weak relationships to the importance of health. In the German general population health has a very high subjective significance. This is not only true for handicapped or ill people, but for all subsamples of the society. Therefore, a general plea for an understanding of the importance of health is not necessary, not even for subgroups. Preventive activity can be based on the general understanding of the meaning of health, but it should pursue specific health- related goals for target groups. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Polychlorinated biphenyl serum levels in subjects with hepatocellular carcinoma as compared with the general population

    Directory of Open Access Journals (Sweden)

    Claudia Zani

    2014-11-01

    Full Text Available Background. Polychlorinated biphenyls (PCBs have been recognized as human carcinogens and cause liver cancer in animal experimental studies. However, no study investigated their association with hepatocellular carcinoma (HCC so far.  This study aimed to evaluate the serum PCB concentration in HCC patients and in healthy subjects of the general population living in Brescia, North Italy, a highly industrialized area with heavy PCB environmental pollution due to the presence of a PCB producing factory. Methods. Lipid-adjusted PCB concentrations, computed as the sum of 24 congeners, were measured in the serum of 101 HCC patients and in 101 healthy subjects of the same age and gender.Results. Hepatitis B and C virus infection and history of heavy alcohol intake were found, alone and combined, in 87% of HCC patients. No difference was found in PCB serum concentration of HCC patients with and without, and according to, the major risk factors for liver disease. No significant difference was observed in serum total PCB concentration between HCC patients (median: 1081; range: 287.0-3182.0 ng/g lipid and healthy subjects (median: 1199.3; range: 225.7-22825 ng/g lipid. PCB congeners 118, 138, 153, 156, 180 and 194 were the only ones found over the detection limit in at least 30% of HCC patients. The serum level of PCB 118, but not that of other congeners, was higher in HCC patients than in healthy subjects.Conclusion. These findings  do not support the hypothesis that PCBs play an important role in HCC development, although a contribution by some specific congeners cannot be ruled out. 

  1. White matter abnormalities of microstructure and physiological noise in schizophrenia

    OpenAIRE

    Cheng, Hu; Newman, Sharlene D.; Kent, Jerillyn S.; Bolbecker, Amanda; Klaunig, Mallory J.; O'Donnell, Brian F.; Puce, Aina; Hetrick, William P.

    2015-01-01

    White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is ba...

  2. 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.

  3. Dark matter directional detection in non-relativistic effective theories

    International Nuclear Information System (INIS)

    Catena, Riccardo

    2015-01-01

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF 4 , CS 2 and 3 He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments

  4. Natural organic matter to enhance electrokinetic transport of PAH

    Energy Technology Data Exchange (ETDEWEB)

    Suer, P.; Joensson, S.; Allard, B. [Man-Technology-Environment Research Centre, Oerebro Univ. (Sweden)

    2001-07-01

    The remediation of contaminated soil can be enhanced with natural organic matter (NOM) as a complexing agent for pollutants. NOM has both hydrophobic and acidic properties, so that it is charged and thus subject to electroremediation. At the same time many contaminants have a high affinity for organic matter. Organic matter was produced in situ in an electric field or added in solute form. The resulting dissolved organic matter was transported towards the cathode, probably by cationic colloids. Produced dissolved organic matter included high molecular weight molecules near the cathode, at the site of pH buffering. Pyrene and phenanthrene were likewise transported towards the cathode. Movement was small but distinctive in 2-day experiments. Clay influence the soil/water distribution of the PAH but no effect on the total transport could be discerned. The presence of solid organic matter in the soil removed all PAH from the water phase, even though the concentration of organic matter in the water phase was high as well. (orig.)

  5. Single top quarks and dark matter

    Science.gov (United States)

    Pinna, Deborah; Zucchetta, Alberto; Buckley, Matthew R.; Canelli, Florencia

    2017-08-01

    Processes with dark matter interacting with the standard model fermions through new scalars or pseudoscalars with flavor-diagonal couplings proportional to fermion mass are well motivated theoretically, and provide a useful phenomenological model with which to interpret experimental results. Two modes of dark matter production from these models have been considered in the existing literature: pairs of dark matter produced through top quark loops with an associated monojet in the event, and pair production of dark matter with pairs of heavy flavored quarks (tops or bottoms). In this paper, we demonstrate that a third, previously overlooked channel yields a non-negligible contribution to LHC dark matter searches in these models. In spite of a generally lower production cross section at LHC when compared to the associated top-pair channel, non-flavor violating single top quark processes are kinematically favored and can significantly increase the sensitivity to these models. Including dark matter production in association with a single top quark through scalar or pseudoscalar mediators, the exclusion limit set by the LHC searches for dark matter can be improved by 30% up to a factor of two, depending on the mass assumed for the mediator particle.

  6. On physical scales of dark matter halos

    International Nuclear Information System (INIS)

    Zemp, Marcel

    2014-01-01

    It is common practice to describe formal size and mass scales of dark matter halos as spherical overdensities with respect to an evolving density threshold. Here, we critically investigate the evolutionary effects of several such commonly used definitions and compare them to the halo evolution within fixed physical scales as well as to the evolution of other intrinsic physical properties of dark matter halos. It is shown that, in general, the traditional way of characterizing sizes and masses of halos dramatically overpredicts the degree of evolution in the last 10 Gyr, especially for low-mass halos. This pseudo-evolution leads to the illusion of growth even though there are no major changes within fixed physical scales. Such formal size definitions also serve as proxies for the virialized region of a halo in the literature. In general, those spherical overdensity scales do not coincide with the virialized region. A physically more precise nomenclature would be to simply characterize them by their very definition instead of calling such formal size and mass definitions 'virial'. In general, we find a discrepancy between the evolution of the underlying physical structure of dark matter halos seen in cosmological structure formation simulations and pseudo-evolving formal virial quantities. We question the importance of the role of formal virial quantities currently ubiquitously used in descriptions, models, and relations that involve properties of dark matter structures. Concepts and relations based on pseudo-evolving formal virial quantities do not properly reflect the actual evolution of dark matter halos and lead to an inaccurate picture of the physical evolution of our universe.

  7. An Optimized Clustering Approach for Automated Detection of White Matter Lesions in MRI Brain Images

    Directory of Open Access Journals (Sweden)

    M. Anitha

    2012-04-01

    Full Text Available Settings White Matter lesions (WMLs are small areas of dead cells found in parts of the brain. In general, it is difficult for medical experts to accurately quantify the WMLs due to decreased contrast between White Matter (WM and Grey Matter (GM. The aim of this paper is to
    automatically detect the White Matter Lesions which is present in the brains of elderly people. WML detection process includes the following stages: 1. Image preprocessing, 2. Clustering (Fuzzy c-means clustering, Geostatistical Possibilistic clustering and Geostatistical Fuzzy clustering and 3.Optimization using Particle Swarm Optimization (PSO. The proposed system is tested on a database of 208 MRI images. GFCM yields high sensitivity of 89%, specificity of 94% and overall accuracy of 93% over FCM and GPC. The clustered brain images are then subjected to Particle Swarm Optimization (PSO. The optimized result obtained from GFCM-PSO provides sensitivity of 90%, specificity of 94% and accuracy of 95%. The detection results reveals that GFCM and GFCMPSO better localizes the large regions of lesions and gives less false positive rate when compared to GPC and GPC-PSO which captures the largest loads of WMLs only in the upper ventral horns of the brain.

  8. 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.

  9. Executive dysfunctions in migraine with and without aura: what is the role of white matter lesions?

    Science.gov (United States)

    Le Pira, Francesco; Reggio, Ester; Quattrocchi, Graziella; Sanfilippo, Cristina; Maci, Tiziana; Cavallaro, Tiziana; Zappia, Mario

    2014-01-01

    Executive dysfunctions and white matter lesions on magnetic resonance imaging have been reported in migraine. The aim of this study was to determine whether any correlation between these 2 variables exists. Forty-four subjects affected by migraine with or without aura were compared with 16 healthy subjects. A battery of neuropsychological tests assessing executive functions was administered to all subjects. Number and total volume of white matter lesions were assessed in the whole brain and in the frontal lobe. The performances of both groups of migraineurs, with and without aura, were significantly worse when compared with controls on Boston Scanning Test. Moreover, we found lower performances compared with controls respectively on Frontal Assessment Battery in patients with migraine with aura and on Controlled Oral Word Association Test in patients with migraine without aura. Nineteen patients (43.2%) and one control subject (6.2%) had white matter lesions. We did not find any significant correlation between white matter lesions load and neuropsychological performances. On the basis of our results, white matter lesions load on magnetic resonance imaging do not seem to contribute to neuropsychological performances deficit in migraineurs. © 2013 American Headache Society.

  10. Imperfect Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Mirzagholi, Leila; Vikman, Alexander, E-mail: l.mirzagholi@physik.uni-muenchen.de, E-mail: alexander.vikman@lmu.de [Arnold Sommerfeld Center for Theoretical Physics, Ludwig Maximilian University Munich, Theresienstr. 37, Munich, D-80333 Germany (Germany)

    2015-06-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

  11. Imperfect Dark Matter

    International Nuclear Information System (INIS)

    Mirzagholi, Leila; Vikman, Alexander

    2015-01-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models

  12. Imperfect Dark Matter

    Science.gov (United States)

    Mirzagholi, Leila; Vikman, Alexander

    2015-06-01

    We consider cosmology of the recently introduced mimetic matter with higher derivatives (HD). Without HD this system describes irrotational dust—Dark Matter (DM) as we see it on cosmologically large scales. DM particles correspond to the shift-charges—Noether charges of the shifts in the field space. Higher derivative corrections usually describe a deviation from the thermodynamical equilibrium in the relativistic hydrodynamics. Thus we show that mimetic matter with HD corresponds to an imperfect DM which: i) renormalises the Newton's constant in the Friedmann equations, ii) has zero pressure when there is no extra matter in the universe, iii) survives the inflationary expansion which puts the system on a dynamical attractor with a vanishing shift-charge, iv) perfectly tracks any external matter on this attractor, v) can become the main (and possibly the only) source of DM, provided the shift-symmetry in the HD terms is broken during some small time interval in the radiation domination époque. In the second part of the paper we present a hydrodynamical description of general anisotropic and inhomogeneous configurations of the system. This imperfect mimetic fluid has an energy flow in the field's rest frame. We find that in the Eckart and in the Landau-Lifshitz frames the mimetic fluid possesses nonvanishing vorticity appearing already at the first order in the HD. Thus, the structure formation and gravitational collapse should proceed in a rather different fashion from the simple irrotational DM models.

  13. Condensed matter studies by nuclear methods

    International Nuclear Information System (INIS)

    Krolas, K.; Tomala, K.

    1988-01-01

    The separate abstract was prepared for 1 of the papers in this volume. The remaining 13 papers dealing with the use but not with advances in the use of nuclear methods in studies of condensed matter, were considered outside the subject scope of INIS. (M.F.W.)

  14. Dark-matter QCD-axion searches.

    Science.gov (United States)

    Rosenberg, Leslie J

    2015-10-06

    In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments

  15. Invisible Higgs and Dark Matter

    DEFF Research Database (Denmark)

    Heikinheimo, Matti; Tuominen, Kimmo; Virkajärvi, Jussi Tuomas

    2012-01-01

    We investigate the possibility that a massive weakly interacting fermion simultaneously provides for a dominant component of the dark matter relic density and an invisible decay width of the Higgs boson at the LHC. As a concrete model realizing such dynamics we consider the minimal walking...... technicolor, although our results apply more generally. Taking into account the constraints from the electroweak precision measurements and current direct searches for dark matter particles, we find that such scenario is heavily constrained, and large portions of the parameter space are excluded....

  16. Subjective Cognitive Decline: Mapping Functional and Structural Brain Changes-A Combined Resting-State Functional and Structural MR Imaging Study.

    Science.gov (United States)

    Sun, Yu; Dai, Zhengjia; Li, Yuxia; Sheng, Can; Li, Hongyan; Wang, Xiaoni; Chen, Xiaodan; He, Yong; Han, Ying

    2016-10-01

    Purpose To determine whether individuals with subjective cognitive decline (SCD) exhibit functional and structural brain alterations by using resting-state functional and structural magnetic resonance (MR) imaging. Materials and Methods This study received institutional review board approval, and all participants gave informed consent. Resting-state functional MR imaging and structural MR imaging techniques were used to measure amplitude of low-frequency fluctuations (ALFF) and regional gray matter volume in 25 subjects with SCD (mean age, 65.52 years ± 6.12) and 61 control subjects (mean age, 64.11 years ± 8.59). Voxel-wise general linear model analyses were used to examine between-group differences in ALFF or in gray matter volume and to further determine the brain-behavioral relationship. Results Subjects with SCD exhibited higher ALFF values than did control subjects in the bilateral inferior parietal lobule (left: 0.44 ± 0.25 vs 0.27 ± 0.18, respectively; P = .0003; right: 1.46 ± 0.45 vs 1.10 ± 0.37, respectively; P = .0015), right inferior (0.45 ± 0.15 vs 0.37 ± 0.08, repectively; P = .0106) and middle (1.03 ± 0.32 vs 0.83 ± 0.20, respectively; P = .0008) occipital gyrus, right superior temporal gyrus (0.11 ± 0.07 vs 0.07 ± 0.04, respectively; P = .0016), and right cerebellum posterior lobe (0.51 ± 0.27 vs 0.39 ± 0.15, respectively; P = .0010). In the SCD group, significant correlations were found between Auditory Verbal Learning Test recognition scores and ALFF in the left inferior parietal lobe (r = -0.79, P Learning Test immediate recall scores and ALFF values in the right middle occipital gyrus (r = -0.64, P = .002). Nonsignificant group differences were found in gray matter volume (P > .05, corrected). Conclusion Individuals with SCD had altered spontaneous functional activity, suggesting that resting-state functional MR imaging may be a noninvasive method for characterizing SCD. (©) RSNA, 2016 Online supplemental material is available for

  17. 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

  18. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling

    Science.gov (United States)

    Li, Xiufeng; Sarkar, Subhendra N.; Purdy, David E.; Briggs, Richard W.

    2014-01-01

    To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values. PMID:24949416

  19. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling

    Directory of Open Access Journals (Sweden)

    Xiufeng Li

    2014-01-01

    Full Text Available To facilitate quantification of cerebellum cerebral blood flow (CBF, studies were performed to systematically optimize arterial spin labeling (ASL parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM and white matter (WM, and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values.

  20. Quantifying cerebellum grey matter and white matter perfusion using pulsed arterial spin labeling.

    Science.gov (United States)

    Li, Xiufeng; Sarkar, Subhendra N; Purdy, David E; Briggs, Richard W

    2014-01-01

    To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values.

  1. Dark matter seen as a Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Manzoni, Andre; Pires, Marcelo

    2011-01-01

    Full text: Astronomical observations of the stellar angular velocity in galaxies shows the general relativity theory, which considers that the usual matter changes the space-time, unable to describe the angular velocity to the peripheral stars. There are two possibilities to solve this problem, or the general relativity theory is not adequate to the phenomena or another type of matter must be considered in the composition of the galaxies. Many astrophysicists are in agreement considering another type of matter. This matter, called dark matter (DM), must interact very weakly with the barionic matter and, therefore, is invisible to direct observation. Some of them consider this dark matter made up of weakly interacting massive particles (WIMPs), which were not detected yet due to their very thin cross-section. A cloud of these particles is distributed around the galaxy under a low temperature and density. If we consider the cloud as a quantum gas, with the energies and the densities low enough to have binary interactions between particles, the gas can reach temperature condition to take a phase transition to the Bose-Einstein condensate where there are a constructive interference partner of these WIMPs. We performed an investigation about the dark matter being a Bose-Einstein condensate of WIMPs confined in itself gravitational potential. Taking the Thomas-Fermi approximation where the number of WIMPs is big enough to neglect the kinetic contribution in the total energy, we got the state equation of barotropic gas. Fitting this state equation with the data of rotational curves and density profiles taken from astronomical observations of galaxies, we estimated the mass and the scattering length of these WIMPs. (author)

  2. Use of Code-Switching in Multilingual Content Subject and Language Classrooms

    Science.gov (United States)

    Gwee, Susan; Saravanan, Vanithamani

    2018-01-01

    Research literature has shown that teachers code-switched to a language which is not the medium of instruction to help students understand subject matter and establish interpersonal relations with them. However, little is known about the extent to which teachers code-switch in content subject classrooms compared to language classrooms. Using…

  3. Testing alternative theories of dark matter with the CMB

    International Nuclear Information System (INIS)

    Li Baojiu; Barrow, John D.; Mota, David F.; Zhao, HongSheng

    2008-01-01

    We propose a method to study and constrain modified gravity theories for dark matter using CMB temperature anisotropies and polarization. We assume that the theories considered here have already passed the matter power-spectrum test of large-scale structure. With this requirement met, we show that a modified gravity theory can be specified by parametrizing the time evolution of its dark-matter density contrast, which is completely controlled by the dark-matter stress history. We calculate how the stress history with a given parametrization affects the CMB observables, and a qualitative discussion of the physical effects involved is supplemented with numerical examples. It is found that, in general, alternative gravity theories can be efficiently constrained by the CMB temperature and polarization spectra. There exist, however, special cases where modified gravity cannot be distinguished from the CDM model even by using both CMB and matter power spectrum observations, nor can they be efficiently restricted by other observables in perturbed cosmologies. Our results show how the stress properties of dark matter, which determine the evolutions of both density perturbations and the gravitational potential, can be effectively investigated using just the general conservation equations and without assuming any specific theoretical gravitational theory within a wide class.

  4. Introduction. Cosmology meets condensed matter.

    Science.gov (United States)

    Kibble, T W B; Pickett, G R

    2008-08-28

    At first sight, low-temperature condensed-matter physics and early Universe cosmology seem worlds apart. Yet, in the last few years a remarkable synergy has developed between the two. It has emerged that, in terms of their mathematical description, there are surprisingly close parallels between them. This interplay has been the subject of a very successful European Science Foundation (ESF) programme entitled COSLAB ('Cosmology in the Laboratory') that ran from 2001 to 2006, itself built on an earlier ESF network called TOPDEF ('Topological Defects: Non-equilibrium Field Theory in Particle Physics, Condensed Matter and Cosmology'). The articles presented in this issue of Philosophical Transactions A are based on talks given at the Royal Society Discussion Meeting 'Cosmology meets condensed matter', held on 28 and 29 January 2008. Many of the speakers had participated earlier in the COSLAB programme, but the strength of the field is illustrated by the presence also of quite a few new participants.

  5. The Problem of Subject Access to Visual Materials

    Directory of Open Access Journals (Sweden)

    Heather P. Jespersen

    2004-09-01

    Full Text Available This article discusses the problem of giving subject access to works of art. We survey both concept-based and content-based access by computers and by indexers/catalogers respectively, as well as issues of interoperability, database and indexer consistency, and cataloging standards. The authors, both of whom are trained art historians, question attempts to mystify fine art subject matter by the creation of clever library science systems that are executed by the naive. Only when trained art historians and knowledgeable catalogers are finally responsible for providing subject access to works of art, will true interoperability and consistency happen.

  6. Modified General Relativity and Cosmology

    Science.gov (United States)

    Abdel-Rahman, A.-M. M.

    1997-10-01

    Aspects of the modified general relativity theory of Rastall, Al-Rawaf and Taha are discussed in both the radiation- and matter-dominated flat cosmological models. A nucleosynthesis constraint on the theory's free parameter is obtained and the implication for the age of the Universe is discussed. The consistency of the modified matter- dominated model with the neoclassical cosmological tests is demonstrated.

  7. Molecular dynamics for dense matter

    International Nuclear Information System (INIS)

    Maruyama, Toshiki; Chiba, Satoshi; Watanabe, Gentaro

    2012-01-01

    We review a molecular dynamics method for nucleon many-body systems called quantum molecular dynamics (QMD), and our studies using this method. These studies address the structure and the dynamics of nuclear matter relevant to neutron star crusts, supernova cores, and heavy-ion collisions. A key advantage of QMD is that we can study dynamical processes of nucleon many-body systems without any assumptions about the nuclear structure. First, we focus on the inhomogeneous structures of low-density nuclear matter consisting not only of spherical nuclei but also of nuclear “pasta”, i.e., rod-like and slab-like nuclei. We show that pasta phases can appear in the ground and equilibrium states of nuclear matter without assuming nuclear shape. Next, we show our simulation of compression of nuclear matter which corresponds to the collapsing stage of supernovae. With the increase in density, a crystalline solid of spherical nuclei changes to a triangular lattice of rods by connecting neighboring nuclei. Finally, we discuss fragment formation in expanding nuclear matter. Our results suggest that a generally accepted scenario based on the liquid–gas phase transition is not plausible at lower temperatures. (author)

  8. Molecular dynamics for dense matter

    Science.gov (United States)

    Maruyama, Toshiki; Watanabe, Gentaro; Chiba, Satoshi

    2012-08-01

    We review a molecular dynamics method for nucleon many-body systems called quantum molecular dynamics (QMD), and our studies using this method. These studies address the structure and the dynamics of nuclear matter relevant to neutron star crusts, supernova cores, and heavy-ion collisions. A key advantage of QMD is that we can study dynamical processes of nucleon many-body systems without any assumptions about the nuclear structure. First, we focus on the inhomogeneous structures of low-density nuclear matter consisting not only of spherical nuclei but also of nuclear "pasta", i.e., rod-like and slab-like nuclei. We show that pasta phases can appear in the ground and equilibrium states of nuclear matter without assuming nuclear shape. Next, we show our simulation of compression of nuclear matter which corresponds to the collapsing stage of supernovae. With the increase in density, a crystalline solid of spherical nuclei changes to a triangular lattice of rods by connecting neighboring nuclei. Finally, we discuss fragment formation in expanding nuclear matter. Our results suggest that a generally accepted scenario based on the liquid-gas phase transition is not plausible at lower temperatures.

  9. Effect of curing methods, packaging and gamma irradiation on the weight loss and dry matter percent of garlic during curing and storage

    International Nuclear Information System (INIS)

    Mahmoud, A.A.; El-Oksh, I.I.; Farag, S.E.A.

    1988-01-01

    The Egyptian garlic plants, showed higher percent of weight loss at 17 or 27 days from curing compared to those of Chinese plants. The curing period of 17 days seemed satisfactory for the Egyptian cultivar, whereas, 27 days seemed to be enough for the Chinese garlic. No significant differences were observed between common and shaded curing methods in weight loss per cent. The Chinese garlic contained higher dry matter percentage than those of the Egyptian cultivar. Shaded cured plants of the two cultivars contained higher dry matter percent than those subjected to the common curing methods. Irradiation of garlic bulbs, shaded curing method and sack packaging decreased, in general the weight loss during storage in comparison with other treatments

  10. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    Energy Technology Data Exchange (ETDEWEB)

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang [Dept. of Bioengineering, Beijing Univ. of Aeronautics and Astronautics, Beijing (China)

    2008-02-15

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD.

  11. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    Energy Technology Data Exchange (ETDEWEB)

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang (Dept. of Bioengineering, Beijing Univ. of Aeronautics and Astronautics, Beijing (China))

    2008-02-15

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD

  12. Spectral properties of nuclear matter

    International Nuclear Information System (INIS)

    Bozek, P

    2006-01-01

    We review self-consistent spectral methods for nuclear matter calculations. The in-medium T-matrix approach is conserving and thermodynamically consistent. It gives both the global and the single-particle properties the system. The T-matrix approximation allows to address the pairing phenomenon in cold nuclear matter. A generalization of nuclear matter calculations to the super.uid phase is discussed and numerical results are presented for this case. The linear response of a correlated system going beyond the Hartree-Fock+ Random-Phase-Approximation (RPA) scheme is studied. The polarization is obtained by solving a consistent Bethe-Salpeter (BS) equation for the coupling of dressed nucleons to an external field. We find that multipair contributions are important for the spin(isospin) response when the interaction is spin(isospin) dependent

  13. Generalized Galilean algebras and Newtonian gravity

    Science.gov (United States)

    González, N.; Rubio, G.; Salgado, P.; Salgado, S.

    2016-04-01

    The non-relativistic versions of the generalized Poincaré algebras and generalized AdS-Lorentz algebras are obtained. These non-relativistic algebras are called, generalized Galilean algebras of type I and type II and denoted by GBn and GLn respectively. Using a generalized Inönü-Wigner contraction procedure we find that the generalized Galilean algebras of type I can be obtained from the generalized Galilean algebras type II. The S-expansion procedure allows us to find the GB5 algebra from the Newton Hooke algebra with central extension. The procedure developed in Ref. [1] allows us to show that the nonrelativistic limit of the five dimensional Einstein-Chern-Simons gravity is given by a modified version of the Poisson equation. The modification could be compatible with the effects of Dark Matter, which leads us to think that Dark Matter can be interpreted as a non-relativistic limit of Dark Energy.

  14. A White Paper on keV sterile neutrino Dark Matter

    Czech Academy of Sciences Publication Activity Database

    Adhikari, R.; Agostini, M.; Ky, N. A.; Araki, T.; Archidiacono, M.; Bahr, M.; Baur, J.; Dragoun, Otokar; Vénos, Drahoslav; Zuber, K.

    2017-01-01

    Roč. 2017, č. 1 (2017), č. článku 025. ISSN 1475-7516 R&D Projects: GA ČR(CZ) GAP203/12/1896 Institutional support: RVO:61389005 Keywords : cosmological neutrinos * dark matter experiments * dark matter theory * particle physics - cosmology connection Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 4.734, year: 2016

  15. α particles and the ''pasta'' phase in nuclear matter

    International Nuclear Information System (INIS)

    Avancini, S. S.; Barros, C. C. Jr.; Menezes, D. P.; Providencia, C.

    2010-01-01

    The effects of the α particles in nuclear matter at low densities are investigated within three different parametrizations of relativistic models at finite temperature. Both homogeneous and inhomogeneous matter (pasta phase) are described for neutral nuclear matter with fixed proton fractions and stellar matter subject to β equilibrium and trapped neutrinos. In homogeneous matter, α particles are present only at densities below 0.02 fm -3 and their presence decreases with increase of the temperature and, for a fixed temperature, the α particle fraction decreases for smaller proton fractions. A repulsive interaction is important to mimic the dissolution of the clusters in homogeneous matter. The effect of the α particles on the pasta structure is very small except close to the critical temperatures and/or proton fractions, when it may still predict a pasta phase while no pasta phase would occur in the absence of light clusters. It is shown that for densities above 0.01 fm 3 the α-particle fraction in the pasta phase is much larger than that in homogeneous matter.

  16. Hypertension and white matter lesions are independently associated with apathetic behavior in healthy elderly subjects. The Sefuri brain MRI study

    International Nuclear Information System (INIS)

    Yao, Hiroshi; Takashima, Yuki; Mori, Takahiro; Hashimoto, Manabu; Yuzuriha, Takefumi; Uchino, Akira; Miwa, Yoshikazu; Sasaguri, Toshiyuki

    2009-01-01

    Apathy is defined as a syndrome of primary loss of motivation not attributable to emotional distress, intellectual impairment or consciousness disturbance. The aim of our study was to investigate the effects of vascular risk factors and silent ischemic brain lesions on apathetic behavior of community-dwelling elderly subjects. Brain MRI and other medical examinations were performed on 222 non-demented community-dwelling elderly subjects (96 men and 126 women, average age 70.1 years). The apathy group was defined as the most apathetic quintile determined by Starkstein's apathy scale. Silent infarction, deep white matter lesions (DWMLs) and periventricular hyperintensities were detected in 12.2, 39.2 and 22.5%, respectively. Linear regression analysis (Pearson) revealed that the scores on the apathy scale correlated slightly but significantly with logarithmically transformed scores of the Modified Stroop Test (r=0.135, P=0.045), but not with the Mini-Mental State Examination. The apathy group tended to have more high blood pressure (141.6/82.6 vs. 136.1/79.6 mmHg), less prevalent hyperlipidemia (18 vs. 35%) and lower serum albumin. Multivariate analysis (the forward stepwise method of logistic analysis) revealed an independent correlation between the apathy and grade of DWMLs (odds ratio 1.826, 95% confidence interval (CI) 1.129-2.953 per grade) or diastolic blood pressure (DBP) (odds ratio 1.055, 95% CI 1.0 14-1.098 per mmHg) after adjusting for possible confounders. The mean apathy scale score in the DBP≥90 mmHg group was significantly lower (more apathetic) than that in the DBP<80 group (P=0.011, analysis of covariance). This study showed that hypertension and DWMLs are independently associated with apathy in healthy elderly subjects. (author)

  17. Dark matter influence on black objects thermodynamics

    Science.gov (United States)

    Rogatko, Marek; Wojnar, Aneta

    2018-05-01

    Physical process version of the first law of black hole thermodynamics in Einstein-Maxwell dark matter gravity was derived. The dark matter sector is mimicked by the additional U(1)-gauge field coupled to the ordinary Maxwell one. By considering any cross section of the black hole event horizon to the future of the bifurcation surface, the equilibrium state version of the first law of black hole mechanics was achieved. The considerations were generalized to the case of Einstein-Yang-Mills dark matter gravity theory. The main conclusion is that the influence of dark matter is crucial in the formation process of black objects. This fact may constitute the explanation of the recent observations of the enormous mass of the super luminous quasars formed in a relatively short time after Big Bang. We also pay attention to the compact binaries thermodynamics, when dark matter sector enters the game.

  18. A hypothesis concerning the nature of dark matter

    International Nuclear Information System (INIS)

    Paduroiu, Sinziana; Rusu, Mircea

    2004-01-01

    In this paper we briefly review the main observational facts that lead to the hypothesis of the so called 'dark matter' as a considerable part of the matter in the Universe that is not visible. The expansion rate of the universe, the birth of the galaxies and their rotation curves are some of the phenomena that can be explained by the existence of dark matter. Generally, there are two models for dark matter: the hot dark matter (HDM) model and the cold dark matter one (CDM). In this paper we will refer mainly to the cold dark matter model. Two different opinions regarding the nature of dark matter and its contribution to the total mass of the matter in the Universe due to a cosmological constant will be discussed. In the first part some particles candidates for dark matter like neutralino and axions will be considered and their prediction made by supersymmetry theory. In the second part different alternative models will be presented that imply singularities of the gravitational theory; inflationary models; and in particular one model that introduces a new expression in the gravitational potential as an attempt to explain the phenomena that made us believe in the existence of this kind of matter. (authors)

  19. Prescribing Behavior of General Practitioners : Competition Matters!

    NARCIS (Netherlands)

    Schaumans, C.B.C.

    2014-01-01

    Background: General Practitioners have limited means to compete. As quality is hard to observe by patients, GPs have incentives to signal quality by using instruments patients perceive as quality. Objectives: We investigate whether GPs exhibit different prescribing behavior (volume and value of

  20. That’s a matter for ALICE!

    CERN Multimedia

    Katarina Anthony

    2010-01-01

    ALICE has launched a new online newsletter to report on developments at the detector: ALICE Matters. The fortnightly newsletter will keep members of the collaboration – and a wider readership – up-to-date with the latest news from the detector.   Screenshot of the ALICE Matters website. The new ALICE Matters newsletter highlights the work of ALICE collaborators through news, interviews and feature articles. Published online every fortnight, it will report the latest developments from the experiment, providing information about operation and data taking, installation work during technical stops, and news from ALICE members. The newsletter is aimed at members of the collaboration, but as an online publication it is also open to the general public. “We often receive questions from people who follow our progress and are interested in what's happening at ALICE,” explains Despina Hatzifotiadou, ALICE Outreach Coordinator. “With ALICE Matters, we can n...

  1. Space-Time Geometry of Quark and Strange Quark Matter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We study quark and strange quark matter in the context of general relativity. For this purpose, we solve Einstein's field equations for quark and strange quark matter in spherical symmetric space-times. We analyze strange quark matter for the different equations of state (EOS) in the spherical symmetric space-times, thus we are able to obtain the space-time geometries of quark and strange quark matter. Also, we discuss die features of the obtained solutions. The obtained solutions are consistent with the results of Brookhaven Laboratory, i.e. the quark-gluon plasma has a vanishing shear (i.e. quark-gluon plasma is perfect).

  2. Matter-antimatter and matter-matter interactions at intermediate energies

    International Nuclear Information System (INIS)

    Santos, Antonio Carlos Fontes dos

    2002-01-01

    This article presents some of the recent experimental advances on the study on antimatter-matter and matter-matter interactions, and some of the subtle differences stimulated a great theoretical efforts for explanation of the results experimentally observed

  3. Role of baryons in unified dark matter models

    International Nuclear Information System (INIS)

    Beca, L.M.G.; Avelino, P.P.; Carvalho, J.P. de M.; Martins, C.J.A.P.

    2003-01-01

    We discuss the importance of including baryons in analyses of unified dark matter scenarios, focusing on toy models involving a generalized Chaplygin gas. We determine observational constraints on this unified dark matter scenario coming from large-scale structure, type Ia supernovae and CMB data showing how this component can bring about a different behavior from the classical cold dark matter model with a cosmological constant and thus motivate further studies of this type of models. We also speculate on interesting new features which are likely to be important on nonlinear scales in this context

  4. Substance use and regional gray matter volume in individuals at high risk of psychosis

    OpenAIRE

    Stone, James; Bhattacharyya, Sagnik; Barker, Gareth J; McGuire, Philip K; Bhattacharyya, Sagnik

    2012-01-01

    Individuals with an at risk mental state (ARMS) are at greatly increased risk of developing a psychotic illness. Risk of transition to psychosis is associated with regionally reduced cortical gray matter volume. There has been considerable interest in the interaction between psychosis risk and substance use. In this study we investigate the relationship between alcohol, cannabis and nicotine use with gray matter volume in ARMS subjects and healthy volunteers. Twenty seven ARMS subjects and 27...

  5. Direct and indirect detection of dissipative dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Fan, JiJi; Katz, Andrey; Shelton, Jessie, E-mail: jijifan1982@gmail.com, E-mail: katz.andrey@gmail.com, E-mail: jshelton137@gmail.com [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)

    2014-06-01

    We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints.

  6. Direct and indirect detection of dissipative dark matter

    International Nuclear Information System (INIS)

    Fan, JiJi; Katz, Andrey; Shelton, Jessie

    2014-01-01

    We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints

  7. 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

  8. Prescribing behavior of general practitioners : Competition matters!

    NARCIS (Netherlands)

    Schaumans, C.B.C.

    Background General Practitioners (GP) have limited means to compete. As quality is hard to observe by patients, GPs have incentives to signal quality by using instruments patients perceive as quality. Objectives I investigate whether GPs prescribe more units when confronted with more competition. As

  9. 28 CFR 0.28 - General functions.

    Science.gov (United States)

    2010-07-01

    ... Affairs § 0.28 General functions. The Office of Public Affairs is headed by a Director of Public Affairs who shall: (a) Handle matters pertaining to relations with the public generally. (b) Disseminate... 28 Judicial Administration 1 2010-07-01 2010-07-01 false General functions. 0.28 Section 0.28...

  10. Going to the Heart of the Matter

    Science.gov (United States)

    Todd, Sharon

    2011-01-01

    Written as a conversational response to Rosa Luxemburg, this piece discusses the importance of going to the heart of the matter for education, seen here in terms of the actual flesh and blood subjects who are at the centre of a pedagogy of transformation.

  11. Nucleon-nucleon correlations in dense nuclear matter

    International Nuclear Information System (INIS)

    Alm, T.

    1993-02-01

    In this thesis new results on the problematics of the formation of nucleon-nucleon correlations in nuclear matter could be presented. Starting from a general study of the two-particle problem in matter we studied the occurrence of a suprafluid phase (pair condensate of nucleons). The Gorkov decoupling by means of anomalous Green functions was generalized, so that also Cooper pairs with spin 1 (triplet pairing) can be described. A generalized gap equation resulted, which permits to determine the order parameters of the suprafluied phase in arbitrary channels of the nucleon-nucleon scattering states. This equation was solvd in the 1 S 0 -, in the 3 P 2 - 3 F 2 , and in the 3 S 1 - 3 D 1 channel under application of realistic nucleon-nucleon potentials. The behaviour of the resulting gap parameters in the single channels was studied as function of density and temperature. (orig.) [de

  12. Cosmic matter-antimatter asymmetry and gravitational force

    Science.gov (United States)

    Hsu, J. P.

    1980-01-01

    Cosmic matter-antimatter asymmetry due to the gravitational interaction alone is discussed, considering the gravitational coupling of fermion matter related to the Yang-Mills (1954) gauge symmetry with the unique generalization of the four-dimensional Poincare group. Attention is given to the case of weak static fields which determines the space-time metric where only large source terms are retained. In addition, considering lowest-order Feynman diagrams, there are presented gravitational potential energies between fermions, between antifermions, and between a fermion and an antifermion. It is concluded that the gravitational force between matter is different from that between antimatter; implications from this concerning the evolution of the universe are discussed.

  13. Playing Super Mario 64 increases hippocampal grey matter in older adults.

    Directory of Open Access Journals (Sweden)

    Greg L West

    Full Text Available Maintaining grey matter within the hippocampus is important for healthy cognition. Playing 3D-platform video games has previously been shown to promote grey matter in the hippocampus in younger adults. In the current study, we tested the impact of 3D-platform video game training (i.e., Super Mario 64 on grey matter in the hippocampus, cerebellum, and the dorsolateral prefrontal cortex (DLPFC of older adults. Older adults who were 55 to 75 years of age were randomized into three groups. The video game experimental group (VID; n = 8 engaged in a 3D-platform video game training over a period of 6 months. Additionally, an active control group took a series of self-directed, computerized music (piano lessons (MUS; n = 12, while a no-contact control group did not engage in any intervention (CON; n = 13. After training, a within-subject increase in grey matter within the hippocampus was significant only in the VID training group, replicating results observed in younger adults. Active control MUS training did, however, lead to a within-subject increase in the DLPFC, while both the VID and MUS training produced growth in the cerebellum. In contrast, the CON group displayed significant grey matter loss in the hippocampus, cerebellum and the DLPFC.

  14. Playing Super Mario 64 increases hippocampal grey matter in older adults.

    Science.gov (United States)

    West, Greg L; Zendel, Benjamin Rich; Konishi, Kyoko; Benady-Chorney, Jessica; Bohbot, Veronique D; Peretz, Isabelle; Belleville, Sylvie

    2017-01-01

    Maintaining grey matter within the hippocampus is important for healthy cognition. Playing 3D-platform video games has previously been shown to promote grey matter in the hippocampus in younger adults. In the current study, we tested the impact of 3D-platform video game training (i.e., Super Mario 64) on grey matter in the hippocampus, cerebellum, and the dorsolateral prefrontal cortex (DLPFC) of older adults. Older adults who were 55 to 75 years of age were randomized into three groups. The video game experimental group (VID; n = 8) engaged in a 3D-platform video game training over a period of 6 months. Additionally, an active control group took a series of self-directed, computerized music (piano) lessons (MUS; n = 12), while a no-contact control group did not engage in any intervention (CON; n = 13). After training, a within-subject increase in grey matter within the hippocampus was significant only in the VID training group, replicating results observed in younger adults. Active control MUS training did, however, lead to a within-subject increase in the DLPFC, while both the VID and MUS training produced growth in the cerebellum. In contrast, the CON group displayed significant grey matter loss in the hippocampus, cerebellum and the DLPFC.

  15. Algorithmic psychometrics and the scalable subject.

    Science.gov (United States)

    Stark, Luke

    2018-04-01

    Recent public controversies, ranging from the 2014 Facebook 'emotional contagion' study to psychographic data profiling by Cambridge Analytica in the 2016 American presidential election, Brexit referendum and elsewhere, signal watershed moments in which the intersecting trajectories of psychology and computer science have become matters of public concern. The entangled history of these two fields grounds the application of applied psychological techniques to digital technologies, and an investment in applying calculability to human subjectivity. Today, a quantifiable psychological subject position has been translated, via 'big data' sets and algorithmic analysis, into a model subject amenable to classification through digital media platforms. I term this position the 'scalable subject', arguing it has been shaped and made legible by algorithmic psychometrics - a broad set of affordances in digital platforms shaped by psychology and the behavioral sciences. In describing the contours of this 'scalable subject', this paper highlights the urgent need for renewed attention from STS scholars on the psy sciences, and on a computational politics attentive to psychology, emotional expression, and sociality via digital media.

  16. Matter and antimatter

    International Nuclear Information System (INIS)

    Schopper, H.

    1989-01-01

    For many years the physicist Herwig Schopper has been contributing in leading positions - either as director of DESY in Hamburg or as general director of CERN in Geneva - to the development of a fascinating field of modern physics. His book is the first comprehensive presentation of experimental particle physics for non-physicists. The search for the smallest constituents of matter, i.e. the exploration of the microcosmos, apart from the advance of the man into space belongs to the most exciting scientific-technical adventures of our century. Contrarily to the stars, atoms, atomic nuclei, and quarks cannot be seen. How objects are studied which are by thousands smaller than the smallest atomic nucleus? Can matter be decomposed in ever smaller constituents, or does there exist a limit? What is matter, and what is of consequence for the mysterious antimatter. Do the laws of the infinitely small also determine the development of the universe since its origin? Such and other questions - expressions of human curiosity - Schopper wants to answer with his generally understandable book. Thereby the 'machines' and the experiments of high-energy physics play a decicive role in the presentation. The author describes the development of the accelerators - in Europe, as well as in the Soviet Union, Japan, or in the USA -, and he shows, why for the investigation of the smallest immense experimental facilities - the 1989 finished LEP storage ring at CERN has a circumference of 27 kilometers - are necessary. Schopper explains how the 'machines' work and how the single experiments run. His book satisfies the curiosity of all those, who want to know more about the world of the quarks. (orig.) With 96 figs [de

  17. Self-interacting spin-2 dark matter

    Science.gov (United States)

    Chu, Xiaoyong; Garcia-Cely, Camilo

    2017-11-01

    Recent developments in bigravity allow one to construct consistent theories of interacting spin-2 particles that are free of ghosts. In this framework, we propose an elementary spin-2 dark matter candidate with a mass well below the TeV scale. We show that, in a certain regime where the interactions induced by the spin-2 fields do not lead to large departures from the predictions of general relativity, such a light dark matter particle typically self-interacts and undergoes self-annihilations via 3-to-2 processes. We discuss its production mechanisms and also identify the regions of the parameter space where self-interactions can alleviate the discrepancies at small scales between the predictions of the collisionless dark matter paradigm and cosmological N-body simulations.

  18. Gravitational closure of matter field equations

    Science.gov (United States)

    Düll, Maximilian; Schuller, Frederic P.; Stritzelberger, Nadine; Wolz, Florian

    2018-04-01

    The requirement that both the matter and the geometry of a spacetime canonically evolve together, starting and ending on shared Cauchy surfaces and independently of the intermediate foliation, leaves one with little choice for diffeomorphism-invariant gravitational dynamics that can equip the coefficients of a given system of matter field equations with causally compatible canonical dynamics. Concretely, we show how starting from any linear local matter field equations whose principal polynomial satisfies three physicality conditions, one may calculate coefficient functions which then enter an otherwise immutable set of countably many linear homogeneous partial differential equations. Any solution of these so-called gravitational closure equations then provides a Lagrangian density for any type of tensorial geometry that features ultralocally in the initially specified matter Lagrangian density. Thus the given system of matter field equations is indeed closed by the so obtained gravitational equations. In contrast to previous work, we build the theory on a suitable associated bundle encoding the canonical configuration degrees of freedom, which allows one to include necessary constraints on the geometry in practically tractable fashion. By virtue of the presented mechanism, one thus can practically calculate, rather than having to postulate, the gravitational theory that is required by specific matter field dynamics. For the special case of standard model matter one obtains general relativity.

  19. Modified gravity without dark matter

    NARCIS (Netherlands)

    Sanders, Robert; Papantonopoulos, L

    2007-01-01

    On an empirical level, the most successful alternative to dark matter in bound gravitational systems is the modified Newtonian dynamics, or MOND, proposed by Milgrom. Here I discuss the attempts to formulate MOND as a modification of General Relativity. I begin with a summary of the phenomenological

  20. Convexities move because they contain matter.

    Science.gov (United States)

    Barenholtz, Elan

    2010-09-22

    Figure-ground assignment to a contour is a fundamental stage in visual processing. The current paper introduces a novel, highly general dynamic cue to figure-ground assignment: "Convex Motion." Across six experiments, subjects showed a strong preference to assign figure and ground to a dynamically deforming contour such that the moving contour segment was convex rather than concave. Experiments 1 and 2 established the preference across two different kinds of deformational motion. Additional experiments determined that this preference was not due to fixation (Experiment 3) or attentional mechanisms (Experiment 4). Experiment 5 found a similar, but reduced bias for rigid-as opposed to deformational-motion, and Experiment 6 demonstrated that the phenomenon depends on the global motion of the effected contour. An explanation of this phenomenon is presented on the basis of typical natural deformational motion, which tends to involve convex contour projections that contain regions consisting of physical "matter," as opposed to concave contour indentations that contain empty space. These results highlight the fundamental relationship between figure and ground, perceived shape, and the inferred physical properties of an object.

  1. Non-pharmacological modulation of cerebral white matter organization

    DEFF Research Database (Denmark)

    Kristensen, Tina D; Mandl, Rene C W; Jepsen, Jens R M

    2018-01-01

    OBJECTIVE: Neuroplasticity is a well-described phenomenon, but effects of non-pharmacological interventions on white matter (WM) are unclear. Here we review associations between active non-pharmacological interventions and WM organization in healthy subjects and in psychiatric patients. METHOD...

  2. The research of condensed matter physics by using intense proton accelerator

    International Nuclear Information System (INIS)

    Endoh, Yasuo

    1990-01-01

    The present article covers the application of intense protons to basic condensed matter physics. Major recent neutron scattering activities in condensed matter physics are first outlined, emphasizing the fact that the contribution of accelerator base science has a tremendous impact on this basic science. Application of spallation neutrons to condensed matter physics is discussed in relation to such subjects as high energy (epithermal) excitations and small angle neutron scattering. Then the specific subject of high Tc superconductor is addressed, focusing on how neutrons as well as muons provide experimental results that serve significantly in exploring the mechanism of exotic high Tc superconductivity. Techniques for neutron polarization must be developed in the future. The neutron spin reflectivity ratio has been shown to be a sensitive probe of surface depth profile of magnetization. Another new method is neutron depolarization to probe bulk magnetic induction throughout a slab which neutrons pass through. (N.K.)

  3. 6d Conformal matter

    International Nuclear Information System (INIS)

    Zotto, Michele Del; Heckman, Jonathan J.; Tomasiello, Alessandro; Vafa, Cumrun

    2015-01-01

    A single M5-brane probing G, an ADE-type singularity, leads to a system which has G×G global symmetry and can be viewed as “bifundamental” (G,G) matter. For the A N series, this leads to the usual notion of bifundamental matter. For the other cases it corresponds to a strongly interacting (1,0) superconformal system in six dimensions. Similarly, an ADE singularity intersecting the Hořava-Witten wall leads to a superconformal matter system with E 8 ×G global symmetry. Using the F-theory realization of these theories, we elucidate the Coulomb/tensor branch of (G,G ′ ) conformal matter. This leads to the notion of fractionalization of an M5-brane on an ADE singularity as well as fractionalization of the intersection point of the ADE singularity with the Hořava-Witten wall. Partial Higgsing of these theories leads to new 6d SCFTs in the infrared, which we also characterize. This generalizes the class of (1,0) theories which can be perturbatively realized by suspended branes in IIA string theory. By reducing on a circle, we arrive at novel duals for 5d affine quiver theories. Introducing many M5-branes leads to large N gravity duals.

  4. Towards high-density matter with relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Nagamiya, Shoji.

    1990-04-01

    Recent progress in nucleus-nucleus collisions at BNL and CERN suggests a hint that the formation of high-density nuclear matter could be possible with relativistic heavy-ion beams. What is the maximum density that can be achieved by heavy-ion collisions? Are there data which show evidence or hints on the formation of high density matter? Why is the research of high-density interesting? How about the future possibilities on this subject? These points are discussed. (author)

  5. White matter structure and clinical characteristics of stroke patients: A diffusion tensor MRI study.

    Science.gov (United States)

    Ueda, Ryo; Yamada, Naoki; Kakuda, Wataru; Abo, Masahiro; Senoo, Atsushi

    2016-03-15

    Fractional anisotropy has been used in many studies that examined post-stroke changes in white matter. This study was performed to clarify cerebral white matter changes after stroke using generalized fractional anisotropy (GFA). White matter structure was visualized using diffusion tensor imaging in 72 patients with post-stroke arm paralysis. Exercise-related brain regions were examined in cerebral white matter using GFA. The relationship between GFA and clinical characteristics was examined. Overall, the mean GFA of the lesioned hemisphere was significantly lower than that of the non-lesioned hemisphere (PBrodmann area 5 of the non-lesioned hemisphere. Age correlated negatively with GFA in Brodmann areas 5 and 7 of the lesioned hemisphere. Though these results may be due to a decrease in the frequency of use of the paralyzed limb over time, GFA overall was significantly and negatively affected by the subject's age. The GFA values of patients with paralysis of the dominant hand were significantly different from those of patients with paralysis of the nondominant hand in Brodmann areas 4 and 6 of the non-lesioned hemisphere and Brodmann area 4 of the lesioned hemisphere (P<0.05). The stroke size and location were not associated with GFA differences. Differences between the GFA of the lesioned and non-lesioned hemispheres varied depending on the affected brain region, age at onset of paralysis, and paralysis of the dominant or non-dominant hand. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Ambient particulate matter as a risk factor for suicide.

    Science.gov (United States)

    Kim, Changsoo; Jung, Sang Hyuk; Kang, Dae Ryong; Kim, Hyeon Chang; Moon, Ki Tae; Hur, Nam Wook; Shin, Dong Chun; Suh, Il

    2010-09-01

    The authors assessed the relationship between exposure to ambient particulate matter and suicide in urban settings during a 1-year period. The association between particulate matter and suicide was determined using a time-stratified case-crossover approach in which subjects served as their own controls. All suicide cases (4,341) in 2004 that occurred in seven cities in the Republic of Korea were included. Hourly mean concentrations of particulate matter suicide risk associated with an interquartile range increase in particulate matter was determined by conditional logistic regression analysis after adjusting for national holidays and meteorological factors. Subgroup analysis was performed after stratification by underlying disease (cardiovascular disease, diabetes mellitus, chronic obstructive pulmonary disease, cancer, and psychiatric illness). The largest associations were a 9.0% increase (95% CI=2.4-16.1) and a 10.1% (95% CI=2.0-19.0) increase in suicide risk related to an interquartile range increase in particulate matter suicide) and particulate matter suicide), respectively. Among individuals with cardiovascular disease, a significant association between particulate matter suicide) and suicide was observed (18.9%; 95% CI=3.2-37.0). Conclusions: A transient increase in particulate matter was associated with increased suicide risk, especially for individuals with preexisting cardiovascular disease.

  7. White matter integrity as a predictor of response to treatment in first episode psychosis.

    Science.gov (United States)

    Reis Marques, Tiago; Taylor, Heather; Chaddock, Chris; Dell'acqua, Flavio; Handley, Rowena; Reinders, A A T Simone; Mondelli, Valeria; Bonaccorso, Stefania; Diforti, Marta; Simmons, Andrew; David, Anthony S; Murray, Robin M; Pariante, Carmine M; Kapur, Shitij; Dazzan, Paola

    2014-01-01

    The integrity of brain white matter connections is central to a patient's ability to respond to pharmacological interventions. This study tested this hypothesis using a specific measure of white matter integrity, and examining its relationship to treatment response using a prospective design in patients within their first episode of psychosis. Diffusion tensor imaging data were acquired in 63 patients with first episode psychosis and 52 healthy control subjects (baseline). Response was assessed after 12 weeks and patients were classified as responders or non-responders according to treatment outcome. At this second time-point, they also underwent a second diffusion tensor imaging scan. Tract-based spatial statistics were used to assess fractional anisotropy as a marker of white matter integrity. At baseline, non-responders showed lower fractional anisotropy than both responders and healthy control subjects (P psychosis. These data, together with earlier findings on cortical grey matter, suggest that grey and white matter integrity at the start of treatment is an important moderator of response to antipsychotics. These findings can inform patient stratification to anticipate care needs, and raise the possibility that antipsychotics may restore white matter integrity as part of the therapeutic response.

  8. Active Learning: 101 Strategies To Teach Any Subject.

    Science.gov (United States)

    Silberman, Mel

    This book contains specific, practical strategies that can be used for almost any subject matters to promote active learning. It brings together in one source a comprehensive collection of instructional strategies, with ways to get students to be active from the beginning through activities that build teamwork and get students thinking about the…

  9. The non-linear dynamics of vortices subjected to correlated and ...

    Indian Academy of Sciences (India)

    Understanding the dynamics of vortex matter subjected to random and .... The authors thank the support provided by a joint grant (USIF-funds) from the ... of Naval Research and the Department of Science and Technology, Government of India ...

  10. QUANTUM TRANSPORT-THEORY OF NUCLEAR-MATTER

    NARCIS (Netherlands)

    BOTERMANS, W; MALFLIET, R

    1990-01-01

    Quantum kinetic equations are derived using the Keldysh Green's function formalism to describe non-equilibrium processes in nuclear matter and nucleus-nucleus collisions. A general transport equation is proposed which includes energy spreading effects. We discuss a number of specific kinetic

  11. General Critical Properties of the Dynamics of Scientific Discovery

    Energy Technology Data Exchange (ETDEWEB)

    Bettencourt, L. M. A. (LANL); Kaiser, D. I. (MIT)

    2011-05-31

    Scientific fields are difficult to define and compare, yet there is a general sense that they undergo similar stages of development. From this point of view it becomes important to determine if these superficial similarities can be translated into a general framework that would quantify the general advent and subsequent dynamics of scientific ideas. Such a framework would have important practical applications of allowing us to compare fields that superficially may appear different, in terms of their subject matter, research techniques, typical collaboration size, etc. Particularh' important in a field's history is the moment at which conceptual and technical unification allows widespread exchange of ideas and collaboration, at which point networks of collaboration show the analog of a percolation phenomenon, developing a giant connected component containing most authors. Here we investigate the generality of this topological transition in the collaboration structure of scientific fields as they grow and become denser. We develop a general theoretical framework in which each scientific field is an instantiation of the same large-scale topological critical phenomenon. We consider whether the evidence from a variety of specific fields is consistent with this picture, and estimate critical exponents associated with the transition. We then discuss the generality of the phenomenon and to what extent we may expect other scientific fields — including very large ones — to follow the same dynamics.

  12. Principles of space-time-matter cosmology, particles and waves in five dimensions

    CERN Document Server

    Overduin, James

    2018-01-01

    This book is a summing up of the prospects for unification between relativity and particle physics based on the extension of Einstein's theory of General Relativity to five dimensions. This subject was first established by Paul Wesson in his previous best-seller, Space-Time-Matter, and discussed from a different perspective in Five-Dimensional Physics, both published by World Scientific in 1999 and 2006 respectively. This third book brings the field up to date and details many new developments and connections to particle theory and wave mechanics in particular. It was in largely finished form at the time of Paul Wesson's untimely death in 2015, and has been completed and expanded by his former student and longtime collaborator, James Overduin.

  13. Open problems in condensed matter physics, 1987

    International Nuclear Information System (INIS)

    Falicov, L.M.

    1988-08-01

    The 1970's and 1980's can be considered the third stage in the explosive development of condensed matter physics. After the very intensive research of the 1930's and 1940's, which followed the formulation of quantum mechanics, and the path-breaking activity of the 1950's and 1960's, the problems being faced now are much more complex and not always susceptible to simple modelling. The (subjectively) open problems discussed here are: high temperature superconductivity, its properties and the possible new mechanisms which lead to it; the integral and fractional quantum Hall effects; new forms of order in condensed-matter systems; the physics of disorder, especially the problem of spin glasses; the physics of complex anisotropic systems; the theoretical prediction of stable and metastable states of matter; the physics of highly correlated states (heavy fermions); the physics of artificially made structures, in particular heterostructures and highly metastable states of matter; the determination of the microscopic structure of surfaces; and chaos and highly nonlinear phnomena. 82 refs

  14. Dark matter as a ghost free conformal extension of Einstein theory

    International Nuclear Information System (INIS)

    Barvinsky, A.O.

    2014-01-01

    We discuss ghost free models of the recently suggested mimetic dark matter theory. This theory is shown to be a conformal extension of Einstein general relativity. Dark matter originates from gauging out its local Weyl invariance as an extra degree of freedom which describes a potential flow of the pressureless perfect fluid. For a positive energy density of this fluid the theory is free of ghost instabilities, which gives strong preference to stable configurations with a positive scalar curvature and trace of the matter stress tensor. Instabilities caused by caustics of the geodesic flow, inherent in this model, serve as a motivation for an alternative conformal extension of Einstein theory, based on the generalized Proca vector field. A potential part of this field modifies the inflationary stage in cosmology, whereas its rotational part at the post inflationary epoch might simulate rotating flows of dark matter

  15. Dark matter that can form dark stars

    International Nuclear Information System (INIS)

    Gondolo, Paolo; Huh, Ji-Haeng; Kim, Hyung Do; Scopel, Stefano

    2010-01-01

    The first stars to form in the Universe may be powered by the annihilation of weakly interacting dark matter particles. These so-called dark stars, if observed, may give us a clue about the nature of dark matter. Here we examine which models for particle dark matter satisfy the conditions for the formation of dark stars. We find that in general models with thermal dark matter lead to the formation of dark stars, with few notable exceptions: heavy neutralinos in the presence of coannihilations, annihilations that are resonant at dark matter freeze-out but not in dark stars, some models of neutrinophilic dark matter annihilating into neutrinos only and lighter than about 50 GeV. In particular, we find that a thermal DM candidate in standard Cosmology always forms a dark star as long as its mass is heavier than ≅ 50 GeV and the thermal average of its annihilation cross section is the same at the decoupling temperature and during the dark star formation, as for instance in the case of an annihilation cross section with a non-vanishing s-wave contribution

  16. Coherent radiation of photon by fast particles in exited matter

    International Nuclear Information System (INIS)

    Ryazanov, M.I.

    1981-01-01

    The review on the theory of coherent photon radiation by fast charged particle interaction with excited by external electromagnetic field atoms of matter is presented. The motive particle excites in the matter longitudinal electric oscillations (plasmons, longitudinal optical phonons, longitudinal excitons). Energy and momentum conservation laws in the course of quantum radiation in the matter by a charged particle are considered taking into account the energy-matter exchange. It follows from the conservation laws that for the processes investigated the quantum angle of escape is stiffly connected with its frequency. The cohe-- rent luminescence processes are considered as generalized Vavilov- Cherenkov radiation [ru

  17. Rippled cosmological dark matter from a damped oscillating Newton constant

    International Nuclear Information System (INIS)

    Davidson, Aharon

    2005-01-01

    Let the reciprocal Newton 'constant' be an apparently non-dynamical Brans-Dicke scalar field damped oscillating towards its general relativistic VEV. We show, without introducing additional matter fields or dust, that the corresponding cosmological evolution averagely resembles, in the Jordan frame, the familiar dark radiation → dark matter → dark energy domination sequence. The fingerprints of our theory are fine ripples, hopefully testable, in the FRW scale factor; they die away at the general relativity limit. The possibility that the Brans-Dicke scalar also serves as the inflaton is favourably examined

  18. arXiv New relations for graviton-matter amplitudes

    CERN Document Server

    Plefka, Jan

    We present new relations for scattering amplitudes of color ordered gluons, massive quarks and scalars minimally coupled to gravity. Tree-level amplitudes of arbitrary matter and gluon multiplicities involving one graviton are reduced to partial amplitudes in QCD or scalar QCD. The obtained relations are a direct generalization of the recently found Einstein-Yang-Mills relations. The proof of the new relation employs a simple diagrammatic argument trading the graviton-matter couplings to an `upgrade' of a gluon coupling with a color-kinematic replacement rule enforced. The use of the Melia-Johansson-Ochirov color basis is a key element of the reduction. We comment on the generalization to multiple gravitons in the single color trace case.

  19. Primordial Regular Black Holes: Thermodynamics and Dark Matter

    Directory of Open Access Journals (Sweden)

    José Antonio de Freitas Pacheco

    2018-05-01

    Full Text Available The possibility that dark matter particles could be constituted by extreme regular primordial black holes is discussed. Extreme black holes have zero surface temperature, and are not subjected to the Hawking evaporation process. Assuming that the common horizon radius of these black holes is fixed by the minimum distance that is derived from the Riemann invariant computed from loop quantum gravity, the masses of these non-singular stable black holes are of the order of the Planck mass. However, if they are formed just after inflation, during reheating, their initial masses are about six orders of magnitude higher. After a short period of growth by the accretion of relativistic matter, they evaporate until reaching the extreme solution. Only a fraction of 3.8 × 10−22 of relativistic matter is required to be converted into primordial black holes (PBHs in order to explain the present abundance of dark matter particles.

  20. Emission of Electromagnetic Waves through Medium of Matter Waves, Correlation between Wavelengths and Temperatures in Radiation Series of Hydrogen

    Czech Academy of Sciences Publication Activity Database

    Pekárek, Viktor

    2002-01-01

    Roč. 47, č. 2 (2002), s. 139-149 ISSN 0001-7043 Institutional research plan: CEZ:AV0Z2057903 Keywords : Matter waves * interference and surges of matter waves Subject RIV: BM - Solid Matter Physics ; Magnetism

  1. Characteristics of gray matter morphological change in Parkinson's disease patients with semantic abstract reasoning deficits.

    Science.gov (United States)

    Wang, Li; Nie, Kun; Zhao, Xin; Feng, Shujun; Xie, Sifen; He, Xuetao; Ma, Guixian; Wang, Limin; Huang, Zhiheng; Huang, Biao; Zhang, Yuhu; Wang, Lijuan

    2018-04-23

    Semantic abstract reasoning(SAR) is an important executive domain that is involved in semantic information processing and enables one to make sense of the attributes of objects, facts and concepts in the world. We sought to investigate whether Parkinson's disease subjects(PDs) have difficulty in SAR and to examine the associated pattern of gray matter morphological changes. Eighty-six PDs and 30 healthy controls were enrolled. PDs were grouped into PD subjects with Similarities preservation(PDSP, n = 62) and PD subjects with Similarities impairment(PDSI, n = 24)according to their performance on the Similarities subtest of the Wechsler Adult Intelligence Scale. Brain structural images were captured with a 3T MRI scanner. Surface-based investigation of cortical thickness and automated segmentation of deep gray matter were conducted using FreeSurfer software. PDs performed notably worse on the Similarities test than controls(F = 13.56, P < 0.001).In the PDSI group, cortical thinning associated with Similarities scores was found in the left superior frontal, left superior parietal and left rostral middle frontal regions. Notable atrophy of the bilateral hippocampi was observed, but only the right hippocampus volume was positively correlated with the Similarities scores of the PDSI group. PDs have difficulty in SAR, and this limitation may be associated with impaired conceptual abstraction and generalization along with semantic memory deficits. Cortical thinning in the left frontal and parietal regions and atrophy in the right hippocampus may explain these impairments among Chinese PDs. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Horizons in Matter:. Black Hole Hair Versus Null Big Bang

    Science.gov (United States)

    Bronnikov, K. A.; Zaslavskii, Oleg B.

    It is shown that only particular kinds of matter (in terms of the "radial" pressure-to-density ratio w) can coexist with Killing horizons in black hole or cosmological space-times. Thus, for arbitrary (not necessarily spherically symmetric) static black holes, admissible are vacuum matter (w = -1, i.e. the cosmological constant or its generalization with the same value of w) and matter with certain values of w between 0 and -1, in particular a gas of disordered cosmic strings (w = -1/3). If the cosmological evolution starts from a horizon (the so-called null big bang scenarios), this horizon can coexist with vacuum matter and certain kinds of phantom matter with w ≤ -3. It is concluded that normal matter in such scenarios is entirely created from vacuum.

  3. The Subjectivity of Participation

    DEFF Research Database (Denmark)

    Nissen, Morten

    of a community of social/youth workers in Copenhagen between 1987 and 2003, who developed a pedagogy through creating collectives and mobilizing young people as participants. The theoretical and practical traditions are combined in a unique methodology viewing research as a contentious modeling of prototypical......What is a 'we' – a collective – and how can we use such communal self-knowledge to help people? This book is about collectivity, participation, and subjectivity – and about the social theories that may help us understand these matters. It also seeks to learn from the innovative practices and ideas...

  4. White Matter Hyperintensity Volume and Cerebral Perfusion in Older Individuals with Hypertension Using Arterial Spin-Labeling

    NARCIS (Netherlands)

    van Dalen, J. W.; Mutsaerts, H. J. M. M.; Nederveen, A. J.; Vrenken, H.; Steenwijk, M. D.; Caan, M. W. A.; Majoie, C. B. L. M.; van Gool, W. A.; Richard, E.

    2016-01-01

    BACKGROUND AND PURPOSE: White matter hyperintensities of presumed vascular origin in elderly patients with hypertension may be part of a general cerebral perfusion deficit, involving not only the white matter hyperintensities but also the surrounding normal-appearing white matter and gray matter. We

  5. Revival of the unified dark energy-dark matter model?

    International Nuclear Information System (INIS)

    Bento, M.C.; Bertolami, O.; Sen, A.A.

    2004-01-01

    We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantomlike dark energy is excluded. Within this framework, we study structure formation and show that difficulties associated to unphysical oscillations or blowup in the matter power spectrum can be circumvented. Furthermore, we show that the dominance of dark energy is related to the time when energy density fluctuations start deviating from the linear δ∼a behavior

  6. Modified dark matter: Relating dark energy, dark matter and baryonic matter

    Science.gov (United States)

    Edmonds, Douglas; Farrah, Duncan; Minic, Djordje; Ng, Y. Jack; Takeuchi, Tatsu

    Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating universe with positive cosmological constant (Λ), such phenomenological considerations lead to the emergence of a critical acceleration parameter related to Λ. Such a critical acceleration is an effective phenomenological manifestation of MDM, and it is found in correlations between dark matter and baryonic matter in galaxy rotation curves. The resulting MDM mass profiles, which are sensitive to Λ, are consistent with observational data at both the galactic and cluster scales. In particular, the same critical acceleration appears both in the galactic and cluster data fits based on MDM. Furthermore, using some robust qualitative arguments, MDM appears to work well on cosmological scales, even though quantitative studies are still lacking. Finally, we comment on certain nonlocal aspects of the quanta of modified dark matter, which may lead to novel nonparticle phenomenology and which may explain why, so far, dark matter detection experiments have failed to detect dark matter particles.

  7. [A voxel-based morphometric analysis of brain gray matter in online game addicts].

    Science.gov (United States)

    Weng, Chuan-bo; Qian, Ruo-bing; Fu, Xian-ming; Lin, Bin; Ji, Xue-bing; Niu, Chao-shi; Wang, Ye-han

    2012-12-04

    To explore the possible brain mechanism of online game addiction (OGA) in terms of brain morphology through voxel-based morphometric (VBM) analysis. Seventeen subjects with OGA and 17 age- and gender-matched healthy controls (HC group) were recruited from Department of Psychology at our hospital during February-December 2011. The internet addiction scale (IAS) was used to measure the degree of OGA tendency. Magnetic resonance imaging (MRI) scans were performed to acquire 3-dimensional T1-weighted images. And FSL 4.1 software was employed to confirm regional gray matter volume changes. For the regions where OGA subjects showed significantly different gray matter volumes from the controls, the gray matter volumes of these areas were extracted, averaged and regressed against the scores of IAS. The OGA group had lower gray matter volume in left orbitofrontal cortex (OFC), left medial prefrontal cortex (mPFC), bilateral insula (INS), left posterior cingulate cortex (PCC) and left supplementary motor area (SMA). Gray matter volumes of left OFC and bilateral INS showed a negative correlation with the scores of IAS (r = -0.65, r = -0.78, P online game addicts and they may be correlated with the occurrence and maintenance of OGA.

  8. Particle dark matter - A theorist's perspective

    Indian Academy of Sciences (India)

    ture of the dark matter (DM) in the Universe, from the point of view of particle ... they must be electrically and (preferably) color neutral. .... in the general MssM and in two unification-based models: the constrained MssM ..... multi-TeV range.

  9. White Matter Hyperintensities on MRI in High-Altitude U-2 Pilots

    Science.gov (United States)

    2013-08-19

    SUBJECT TERMS MRI; white matter hyperintensities; hypobaric exposure; neurological decompression sickness 16. SECURITY CLASSIFICATION OF: 17...normal controls and did not increase with age in pilots, suggesting that hypobaric exposure produces white matter damage different from that occurring in...relapse we observed in 3 NDCS pilots after successful hyperbaric treatment (US Navy Treatment Table 6; 100% fraction of inspired oxygen; 2.8 atm absolute

  10. The Subject's Matter

    DEFF Research Database (Denmark)

    The body may be the object we know the best. It is the only object from which we constantly receive a flow of information through sight and touch; and it is the only object we can experience from the inside, through our proprioceptive, vestibular, and visceral senses. Yet there have been very few...

  11. Soil organic matter dynamics and the global carbon cycle

    International Nuclear Information System (INIS)

    Post, W.M.; Emanuel, W.R.; King, A.W.

    1992-01-01

    The large size and potentially long residence time of the soil organic matter pool make it an important component of the global carbon cycle. Net terrestrial primary production of about 60 Pg C·yr -1 is, over a several-year period of time, balanced by an equivalent flux of litter production and subsequent decomposition of detritus and soil organic matter. We will review many of the major factors that influence soil organic matter dynamics that need to be explicitly considered in development of global estimates of carbon turnover in the world's soils. We will also discuss current decomposition models that are general enough to be used to develop a representation of global soil organic matter dynamics

  12. Automatic generation of matter-of-opinion video documentaries

    NARCIS (Netherlands)

    Bocconi, S.; Nack, F.; Hardman, H.L.

    2008-01-01

    In this paper we describe a model for automatically generating video documentaries. This allows viewers to specify the subject and the point of view of the documentary to be generated. The domain is matter-of-opinion documentaries based on interviews. The model combines rhetorical presentation

  13. Automatic generation of matter-of-opinion video documentaries

    NARCIS (Netherlands)

    S. Bocconi; F.-M. Nack (Frank); L. Hardman (Lynda)

    2008-01-01

    textabstractIn this paper we describe a model for automatically generating video documentaries. This allows viewers to specify the subject and the point of view of the documentary to be generated. The domain is matter-of-opinion documentaries based on interviews. The model combines rhetorical

  14. OCCIPITAL SOURCES OF RESTING STATE ALPHA RHYTHMS ARE RELATED TO LOCAL GRAY MATTER DENSITY IN SUBJECTS WITH AMNESIC MILD COGNITIVE IMPAIRMENT AND ALZHEIMER’S DISEASE

    Science.gov (United States)

    Claudio, Babiloni; Claudio, Del Percio; Marina, Boccardi; Roberta, Lizio; Susanna, Lopez; Filippo, Carducci; Nicola, Marzano; Andrea, Soricelli; Raffaele, Ferri; Ivano, Triggiani Antonio; Annapaola, Prestia; Serenella, Salinari; Rasser Paul, E; Erol, Basar; Francesco, Famà; Flavio, Nobili; Görsev, Yener; Durusu, Emek-Savaş Derya; Gesualdo, Loreto; Ciro, Mundi; Thompson Paul, M; Rossini Paolo, M.; Frisoni Giovanni, B

    2014-01-01

    Occipital sources of resting state electroencephalographic (EEG) alpha rhythms are abnormal, at the group level, in patients with amnesic mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Here we evaluated the hypothesis that amplitude of these occipital sources is related to neurodegeneration in occipital lobe as measured by magnetic resonance imaging (MRI). Resting-state eyes-closed EEG rhythms were recorded in 45 healthy elderly (Nold), 100 MCI, and 90 AD subjects. Neurodegeneration of occipital lobe was indexed by weighted averages of gray matter density (GMD), estimated from structural MRIs. EEG rhythms of interest were alpha 1 (8–10.5 Hz) and alpha 2 (10.5–13 Hz). EEG cortical sources were estimated by low resolution brain electromagnetic tomography (LORETA). Results showed a positive correlation between occipital GMD and amplitude of occipital alpha 1 sources in Nold, MCI and AD subjects as a whole group (r=0.3, p=0.000004, N=235). Furthermore, there was a positive correlation between amplitude of occipital alpha 1 sources and cognitive status as revealed by Mini Mental State Evaluation (MMSE) score across all subjects (r=0.38, p=0.000001, N=235). Finally, amplitude of occipital alpha 1 sources allowed a moderate classification of individual Nold and AD subjects (sensitivity: 87.8%; specificity: 66.7%; area under the Receiver Operating Characteristic (ROC) curve: 0.81). These results suggest that the amplitude of occipital sources of resting state alpha rhythms is related to AD neurodegeneration in occipital lobe along pathological aging. PMID:25442118

  15. Grey Matter Abnormalities in Social Anxiety Disorder: Primary, Replication, and Specificity Studies

    Science.gov (United States)

    Talati, Ardesheer; Pantazatos, Spiro P.; Schneier, Franklin R.; Weissman, Myrna M; Hirsch, Joy

    2012-01-01

    Background Despite increasing evidence that neuroanatomical abnormalities underlie pathological anxiety, social anxiety disorder (SAD), although among the most common of anxiety disorders, has received little attention. Using Magnetic Resonance Imaging, we (1) examined grey matter (GM) differences between generalized SAD and healthy control groups; (2) retested the findings in an independent clinical sample; and (3) tested for specificity by contrasting the SAD group to a separate group of panic disorder (PD) subjects. Methods The primary SAD group (N=16) was required to meet DSM-IV criteria for SAD, with onset by age 30; controls (N=20) had no lifetime history of anxiety. The replication sample included 17 generalized SAD and 17 control subjects. The PD comparison group (N=16) was required to have no lifetime SAD. Images were acquired on a 1.5Tesla GE Signa MRI scanner using a 3D T1-weighted spoiled gradient recalled pulse sequence. Morphological differences were determined using voxel based morphometry, in SPM8. Results After adjusting for age, gender, and total intracranial volume, SAD (as compared to control) subjects had greater GM in the left parahippocampal and middle occipital, and bilateral supramarginal and angular cortices, and left cerebellum; and lower GM in bilateral temporal poles and left lateral orbitofrontal cortex. Cerebellar, parahippocampal, and temporal pole differences were observed in both samples, survived whole brain corrections, and were not observed in the PD group, pointing to relative specificity to SAD. Conclusions These findings parallel the functional literature on SAD, and suggest structural abnormalities underlying the functional disturbances. PMID:22748614

  16. Contenidos teóricos de las materias generales y especializadas en los planes de estudios de las diplomaturas de ciencias de la salud Theoretic contents of general and specialized subjects in core curricula of health sciences professions

    Directory of Open Access Journals (Sweden)

    José Antonio Arias Navalón

    2003-12-01

    Full Text Available Objetivo: Evaluar cuantitativamente los contenidos teóricos, generales y especializados, de los planes de estudios de las diplomaturas de ciencias de la salud en España. A partir de esos datos se harán algunas recomendaciones y se destacarán aspectos que podrían necesitar modificaciones. Diseño: Revisión sistemática. Emplazamiento y material de estudio: Planes de estudios de las diplomaturas de ciencias de la salud en España: Enfermería, Fisioterapia, Logopedia, Nutrición humana y dietética, Óptica y optometría, Podología y Terapia ocupacional. Mediciones: Número de horas teóricas dedicadas a materias troncales, detallando su carácter general o especializado. Resultados y conclusiones: En conjunto, los contenidos especializados y generales suponen, respectivamente, el 66,7 y el 33,3%. La mayoría de las carreras tienen más horas asignadas a materias especializadas. Los resultados oscilan entre la ausencia de materias troncales generales en las carreras de Óptica y optometría y de Logopedia y el 71,4% de carga lectiva de carácter general en la carrera de Terapia ocupacional. La carencia de conocimientos generales sobre la salud y la enfermedad puede tener consecuencias negativas en la práctica diaria y en las expectativas que tienen para hacer investigación los profesionales implicados.Objective: To assess general and specialized theoretic contents of core curricula of health professions in Spain, in order to make some recommendations to improve these curricula and to highlight some areas needing further modifications. Design: Systematic revision. Setting and study selection: Core curricula of health professions in Spain: Nursing, Physical therapy, Speech-language pathology, Nutrition and dietetics, Optometry, Podiatry and Occupational therapy. Measurements: Number of theoretic hours devoted to both general and specialized subjects. Results and conclusions: Overall, specialized and general contents are 66.7% and 33

  17. Self-energy dispersion effects on neutron matter superfluidity

    International Nuclear Information System (INIS)

    Zuo Wei

    2001-01-01

    The effects of the dispersion and ground state correlation of the single particle self-energy on neutron matter superfluidity have been investigated in the framework of the Extended Brueckner-Hartree-Fock and the generalized BCS approaches. A sizable reduction of the energy gap is found due to the energy dependence of the self-energy. And the inclusion of the ground state correlations in the self-energy suppresses further the neutron matter superfluidity

  18. Generalized modified gravity in large extra dimensions

    International Nuclear Information System (INIS)

    Aslan, Onder; Demir, Durmus A.

    2006-01-01

    We discuss effective interactions among brane matter induced by modifications of higher-dimensional Einstein gravity through the replacement of Einstein-Hilbert term with a generic function f(R,R AB R AB ,R ABCD R ABCD ) of the curvature tensors. We determine gravi-particle spectrum of the theory, and perform a comparative analysis of its predictions with those of the Einstein gravity within Arkani-Hamed-Dvali-Dimopoulos (ADD) setup. We find that this general higher-curvature quantum gravity theory contributes to scatterings among both massive and massless brane matter (in contrast to much simpler generalization of the Einstein gravity, f(R), which influences only the massive matter), and therefore, can be probed via various scattering processes at present and future colliders and directly confronted with the ADD expectations. In addition to collision processes which proceed with tree-level gravi-particle exchange, effective interactions among brane matter are found to exhibit a strong sensitivity to higher-curvature gravity via the gravi-particle loops. Furthermore, particle collisions with missing energy in their final states are found to be sensitive to additional gravi-particles not found in Einstein gravity. In general, road to a correct description of quantum gravity above Fermi energies depends crucially on if collider and other search methods end up with a negative or positive answer for the presence of higher-curvature gravitational interactions

  19. Planetary Exploration Education: As Seen From the Point of View of Subject Matter Experts

    Science.gov (United States)

    Milazzo, M. P.; Anderson, R. B.; Gaither, T. A.; Vaughan, R. G.

    2016-12-01

    Planetary Learning that Advances the Nexus of Engineering, Technology, and Science (PLANETS) was selected as one of 27 new projects to support the NASA Science Mission Directorate's Science Education Cooperative Agreement Notice. Our goal is to develop and disseminate out-of-school time (OST) curricular and related educator professional development modules that integrate planetary science, technology, and engineering. We are a partnership between planetary science Subject Matter Experts (SMEs), curriculum developers, science and engineering teacher professional development experts and OST teacher networks. The PLANETS team includes the Center for Science Teaching and Learning (CSTL) at Northern Arizona University (NAU); the U.S. Geological Survey (USGS) Astrogeology Science Center (Astrogeology), and the Boston Museum of Science (MOS). Here, we present the work and approach by the SMEs at Astrogeology. As part of this overarching project, we will create a model for improved integration of SMEs, curriculum developers, professional development experts, and educators. For the 2016 and 2017 Fiscal Years, our focus is on creating science material for two OST modules designed for middle school students. We will begin development of a third module for elementary school students in the latter part of FY2017. The first module focuses on water conservation and treatment as applied on Earth, the International Space Station, and at a fictional Mars base. This unit involves the science and engineering of finding accessible water, evaluating it for quality, treating it for impurities (i.e., dissolved and suspended), initial use, a cycle of greywater treatment and re-use, and final treatment of blackwater. The second module involves the science and engineering of remote sensing as it is related to Earth and planetary exploration. This includes discussion and activities related to the electromagnetic spectrum, spectroscopy and various remote sensing systems and techniques. In

  20. 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.

  1. Association between exercise habits and subcortical gray matter volumes in healthy elderly people: A population-based study in Japan.

    Science.gov (United States)

    Yamamoto, Mikie; Wada-Isoe, Kenji; Yamashita, Fumio; Nakashita, Satoko; Kishi, Masafumi; Tanaka, Kenichiro; Yamawaki, Mika; Nakashima, Kenji

    2017-06-01

    The relationship between exercise and subcortical gray matter volume is not well understood in the elderly population, although reports indicate that exercise may prevent cortical gray matter atrophy. To elucidate this association in the elderly, we measured subcortical gray matter volume and correlated this with volumes to exercise habits in a community-based cohort study in Japan. Subjects without mild cognitive impairment or dementia (n = 280, 35% male, mean age 73.1 ± 5.9 years) were evaluated using the Mini-Mental State Examination (MMSE), an exercise habit questionnaire, and brain magnetic resonance imaging. Subcortical gray matter volume was compared between groups based on the presence/absence of exercise habits. The MMSE was re-administered 3 years after the baseline examination. Ninety-one subjects (32.5%) reported exercise habits (exercise group), and 189 subjects (67.5%) reported no exercise habits (non-exercise group). Volumetric analysis revealed that the volumes in the exercise group were greater in the left hippocampus (p = 0.042) and bilateral nucleus accumbens (left, p = 0.047; right, p = 0.007) compared to those of the non-exercise group. Among the 195 subjects who received a follow-up MMSE examination, the normalized intra-cranial volumes of the left nucleus accumbens (p = 0.004) and right amygdala (p = 0.014)showed significant association with a decline in the follow-up MMSE score. Subjects with exercise habits show larger subcortical gray matter volumes than subjects without exercise habits in community-dwelling elderly subjects in Japan. Specifically, the volume of the nucleus accumbens correlates with both exercise habits and cognitive preservation.

  2. Incompressibility of asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Chen, Liewen; Cai, Baojun; Shen, Chun; Ko, Cheming; Xu, Jun; Li, Baoan

    2010-01-01

    Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility K sat (δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of K sat (δ) in powers of isospin asymmetry δ, i.e., K sat (δ) = K 0 + K sat,2 δ 2 + K sat,4 δ 4 + O(δ 6 ), the magnitude of the 4th-order K sat,4 parameter is generally small. The 2nd-order K sat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the K sat,2 can be expressed as K sat,2 = K sym – 6L – J 0 /K 0 L in terms of the slope parameter L and the curvature parameter K sym of the symmetry energy and the third-order derivative parameter J 0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J 0 contribution to K sat,2 generally cannot be neglected. Also, we have found a linear correlation between K sym and L as well as between J 0 /K 0 and K 0 . Using these correlations together with the empirical constraints on K 0 and L, the nuclear symmetry energy E sym (ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of K sat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)

  3. Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

    International Nuclear Information System (INIS)

    Wang Zhiqun; Guo Xiaojuan; Qi Zhigang; Yao Li; Li Kuncheng

    2010-01-01

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI). Materials and methods: We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions. Conclusion: Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.

  4. Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhiqun [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China); Guo Xiaojuan [College of Information Science and Technology, Beijing Normal University, 100875, Beijing (China); National Key Laboratory for Cognitive Neuroscience and Learning, Beijing Normal University, 100875, Beijing (China); Qi Zhigang [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China); Yao Li [College of Information Science and Technology, Beijing Normal University, 100875, Beijing (China); National Key Laboratory for Cognitive Neuroscience and Learning, Beijing Normal University, 100875, Beijing (China); Li Kuncheng, E-mail: likuncheng@xwh.ccmu.edu.c [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China)

    2010-08-15

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI). Materials and methods: We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions. Conclusion: Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.

  5. Building a better minimal supergravity: WIMP dark matter without flavor violation

    International Nuclear Information System (INIS)

    Craig, Nathaniel J.; Green, Daniel

    2009-01-01

    The appearance of a natural dark matter candidate, the neutralino, is among the principal successes of minimal supergravity (mSUGRA) and its descendents. In lieu of a suitable ultraviolet completion, however, theories of gravity-mediated supersymmetry breaking such as mSUGRA suffer from arbitrary degrees of flavor violation. Though theories of gauge-mediated supersymmetry breaking are free from such prohibitive flavor violation, they typically lack natural neutralino dark matter candidates. Yet this conventional dichotomy breaks down when the hidden sector is strongly coupled; in models of gauge-mediated supersymmetry breaking, the neutralino may be the lightest supersymmetric particle if the fields of the hidden sector possess large anomalous dimensions. In fact, general models of so-called 'sequestered' gauge mediation possess the full richness of neutralino dark matter found in mSUGRA without corresponding flavor problems. Here we explore generalized models of sequestered gauge mediation and the rich variety of neutralino dark matter they exhibit.

  6. Regional gray matter correlates of vocational interests.

    Science.gov (United States)

    Schroeder, David H; Haier, Richard J; Tang, Cheuk Ying

    2012-05-16

    Previous studies have identified brain areas related to cognitive abilities and personality, respectively. In this exploratory study, we extend the application of modern neuroimaging techniques to another area of individual differences, vocational interests, and relate the results to an earlier study of cognitive abilities salient for vocations. First, we examined the psychometric relationships between vocational interests and abilities in a large sample. The primary relationships between those domains were between Investigative (scientific) interests and general intelligence and between Realistic ("blue-collar") interests and spatial ability. Then, using MRI and voxel-based morphometry, we investigated the relationships between regional gray matter volume and vocational interests. Specific clusters of gray matter were found to be correlated with Investigative and Realistic interests. Overlap analyses indicated some common brain areas between the correlates of Investigative interests and general intelligence and between the correlates of Realistic interests and spatial ability. Two of six vocational-interest scales show substantial relationships with regional gray matter volume. The overlap between the brain correlates of these scales and cognitive-ability factors suggest there are relationships between individual differences in brain structure and vocations.

  7. Towards a thermodynamics of active matter.

    Science.gov (United States)

    Takatori, S C; Brady, J F

    2015-03-01

    Self-propulsion allows living systems to display self-organization and unusual phase behavior. Unlike passive systems in thermal equilibrium, active matter systems are not constrained by conventional thermodynamic laws. A question arises, however, as to what extent, if any, can concepts from classical thermodynamics be applied to nonequilibrium systems like active matter. Here we use the new swim pressure perspective to develop a simple theory for predicting phase separation in active matter. Using purely mechanical arguments we generate a phase diagram with a spinodal and critical point, and define a nonequilibrium chemical potential to interpret the "binodal." We provide a generalization of thermodynamic concepts like the free energy and temperature for nonequilibrium active systems. Our theory agrees with existing simulation data both qualitatively and quantitatively and may provide a framework for understanding and predicting the behavior of nonequilibrium active systems.

  8. Formal framework for a nonlocal generalization of Einstein's theory of gravitation

    International Nuclear Information System (INIS)

    Hehl, Friedrich W.; Mashhoon, Bahram

    2009-01-01

    The analogy between electrodynamics and the translational gauge theory of gravity is employed in this paper to develop an ansatz for a nonlocal generalization of Einstein's theory of gravitation. Working in the linear approximation, we show that the resulting nonlocal theory is equivalent to general relativity with 'dark matter'. The nature of the predicted dark matter, which is the manifestation of the nonlocal character of gravity in our model, is briefly discussed. It is demonstrated that this approach can provide a basis for the Tohline-Kuhn treatment of the astrophysical evidence for dark matter.

  9. Toward a minimum branching fraction for dark matter annihilation into electromagnetic final states

    International Nuclear Information System (INIS)

    Dent, James B.; Scherrer, Robert J.; Weiler, Thomas J.

    2008-01-01

    Observational limits on the high-energy neutrino background have been used to place general constraints on dark matter that annihilates only into standard model particles. Dark matter particles that annihilate into neutrinos will also inevitably branch into electromagnetic final states through higher-order tree and loop diagrams that give rise to charged leptons, and these charged particles can transfer their energy into photons via synchrotron radiation or inverse Compton scattering. In the context of effective field theory, we calculate the loop-induced branching ratio to charged leptons and show that it is generally quite large, typically > or approx. 1%, when the scale of the dark matter mass exceeds the electroweak scale, M W . For a branching fraction >or approx. 3%, the synchrotron radiation bounds on dark matter annihilation are currently stronger than the corresponding neutrino bounds in the interesting mass range from 100 GeV to 1 TeV. For dark matter masses below M W , our work provides a plausible framework for the construction of a model for 'neutrinos-only' dark matter annihilations.

  10. Grey matter changes of the pain matrix in patients with burning mouth syndrome.

    Science.gov (United States)

    Sinding, Charlotte; Gransjøen, Anne Mari; Schlumberger, Gina; Grushka, Miriam; Frasnelli, Johannes; Singh, Preet Bano

    2016-04-01

    Burning mouth syndrome (BMS) is characterized by a burning sensation in the mouth, usually in the absence of clinical and laboratory findings. Latest findings indicate that BMS could result from neuropathic trigeminal conditions. While many investigations have focused on the periphery, very few have examined possible central dysfunctions. To highlight changes of the central system of subjects with BMS, we analysed the grey matter concentration in 12 subjects using voxel-based morphometry. Data were compared with a control group (Ct). To better understand the brain mechanisms underlying BMS, the grey matter concentration of patients was also compared with those of dysgeusic patients (Dys). Dysgeusia is another oral dysfunction condition, characterized by a distorted sense of taste and accompanied by a reduced taste function. We found that a major part of the 'pain matrix' presented modifications of the grey matter concentration in subjects with BMS. Six regions out of eight were affected [anterior and posterior cingulate gyrus, lobules of the cerebellum, insula/frontal operculum, inferior temporal area, primary motor cortex, dorsolateral pre-frontal cortex (DLPFC)]. In the anterior cingulate gyrus, the lobules of the cerebellum, the inferior temporal lobe and the DLPFC, pain intensity correlated with grey matter concentration. Dys also presented changes in grey matter concentration but in different areas of the brain. Our results suggest that a deficiency in the control of pain could in part be a cause of BMS and that BMS and dysgeusia conditions are not linked to similar structural changes in the brain. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Late forming dark matter in theories of neutrino dark energy

    International Nuclear Information System (INIS)

    Das, Subinoy; Weiner, Neal

    2011-01-01

    We study the possibility of late forming dark matter, where a scalar field, previously trapped in a metastable state by thermal or finite density effects, goes through a phase transition near the era matter-radiation equality and begins to oscillate about its true minimum. Such a theory is motivated generally if the dark energy is of a similar form, but has not yet made the transition to dark matter, and, in particular, arises automatically in recently considered theories of neutrino dark energy. If such a field comprises the present dark matter, the matter power spectrum typically shows a sharp break at small, presently nonlinear scales, below which power is highly suppressed and previously contained acoustic oscillations. If, instead, such a field forms a subdominant component of the total dark matter, such acoustic oscillations may imprint themselves in the linear regime.

  12. Past and present of nuclear matter

    International Nuclear Information System (INIS)

    Ritter, H.G.

    1994-05-01

    The subject of nuclear matter is interesting for many fields of physics ranging from condensed matter to lattice QCD. Knowing its properties is important for our understanding of neutron stars, supernovae and cosmology. Experimentally, we have the most precise information on ground state nuclear matter from the mass formula and from the systematics of monopole vibrations. This gives us the ground state density, binding energy and the compression modulus k at ground state density. However, those methods can not be extended towards the regime we are most interested in, the regime of high density and high temperature. Additional information can be obtained from the observation of neutron stars and of supernova explosions. In both cases information is limited by the rare events that nature provides for us. High energy heavy ion collisions, on the other hand, allow us to perform controlled experiments in the laboratory. For a very short period in time we can create a system that lets us study nuclear matter properties. Density and temperature of the system depend on the mass of the colliding nuclei, on their energy and on the impact parameter. The system created in nuclear collisions has at best about 200 constituents not even close to infinite nuclear matter, and it lasts only for collision times of ∼ 10 -22 sec, not an ideal condition for establishing any kind of equilibrium. Extended size and thermal and chemical equilibrium, however, axe a priori conditions of nuclear matter. As a consequence we need realistic models that describe the collision dynamics and non-equilibrium effects in order to relate experimental observables to properties of nuclear matter. The study of high energy nuclear collisions started at the Bevalac. I will try to summarize the results from the Bevalac studies, the highlights of the continuing program, and extension to higher energies without claiming to be complete

  13. Model-independent constraints on dark matter annihilation in dwarf spheroidal galaxies

    OpenAIRE

    Boddy, Kimberly K.; Kumar, Jason; Marfatia, Danny; Sandick, Pearl

    2018-01-01

    We present a general, model-independent formalism for determining bounds on the production of photons in dwarf spheroidal galaxies via dark matter annihilation, applicable to any set of assumptions about dark matter particle physics or astrophysics. As an illustration, we analyze gamma-ray data from the Fermi Large Area Telescope to constrain a variety of nonstandard dark matter models, several of which have not previously been studied in the context of dwarf galaxy searches.

  14. Resource Letter HCMP-1: History of Condensed Matter Physics

    Science.gov (United States)

    Martin, Joseph D.

    2017-02-01

    This Resource Letter provides a guide to the literature on the history of condensed matter physics, including discussions of the development of the field and strategies for approaching its complicated historical trajectory. Following the presentation of general resources, journal articles and books are cited for the following topics: conceptual development; institutional and community structure; social, cultural, and political history; and connections between condensed matter physics and technology.

  15. Bivariate generalized Pareto distribution for extreme atmospheric particulate matter

    Science.gov (United States)

    Amin, Nor Azrita Mohd; Adam, Mohd Bakri; Ibrahim, Noor Akma; Aris, Ahmad Zaharin

    2015-02-01

    The high particulate matter (PM10) level is the prominent issue causing various impacts to human health and seriously affecting the economics. The asymptotic theory of extreme value is apply for analyzing the relation of extreme PM10 data from two nearby air quality monitoring stations. The series of daily maxima PM10 for Johor Bahru and Pasir Gudang stations are consider for year 2001 to 2010 databases. The 85% and 95% marginal quantile apply to determine the threshold values and hence construct the series of exceedances over the chosen threshold. The logistic, asymmetric logistic, negative logistic and asymmetric negative logistic models areconsidered as the dependence function to the joint distribution of a bivariate observation. Maximum likelihood estimation is employed for parameter estimations. The best fitted model is chosen based on the Akaike Information Criterion and the quantile plots. It is found that the asymmetric logistic model gives the best fitted model for bivariate extreme PM10 data and shows the weak dependence between two stations.

  16. Interacting dark matter disguised as warm dark matter

    International Nuclear Information System (INIS)

    Boehm, Celine; Riazuelo, Alain; Hansen, Steen H.; Schaeffer, Richard

    2002-01-01

    We explore some of the consequences of dark-matter-photon interactions on structure formation, focusing on the evolution of cosmological perturbations and performing both an analytical and a numerical study. We compute the cosmic microwave background anisotropies and matter power spectrum in this class of models. We find, as the main result, that when dark matter and photons are coupled, dark matter perturbations can experience a new damping regime in addition to the usual collisional Silk damping effect. Such dark matter particles (having quite large photon interactions) behave like cold dark matter or warm dark matter as far as the cosmic microwave background anisotropies or matter power spectrum are concerned, respectively. These dark-matter-photon interactions leave specific imprints at sufficiently small scales on both of these two spectra, which may allow us to put new constraints on the acceptable photon-dark-matter interactions. Under the conservative assumption that the abundance of 10 12 M · galaxies is correctly given by the cold dark matter, and without any knowledge of the abundance of smaller objects, we obtain the limit on the ratio of the dark-matter-photon cross section to the dark matter mass σ γ-DM /m DM -6 σ Th /(100 GeV)≅6x10 -33 cm 2 GeV -1

  17. Abnormalities in gray and white matter volumes associated with explicit memory dysfunction in patients with generalized anxiety disorder.

    Science.gov (United States)

    Moon, Chung-Man; Jeong, Gwang-Woo

    2017-03-01

    Background The neuroanatomical abnormalities associated with behavioral dysfunction on explicit memory in patients generalized anxiety disorder (GAD) have not yet been clearly identified. Purpose To investigate the regional gray matter (GM) and white matter (WM) volume alterations over the whole brain in patients with GAD, as well as the correlation between the brain structural abnormality and explicit memory dysfunction. Material and Methods Twenty patients with GAD and 20 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted magnetic resonance imaging (MRI). The participants performed the explicit memory tasks with the neutral and anxiety-inducing words. Results Patients with GAD showed significantly reduced GM volumes in the midbrain (MB), thalamus, hippocampus (Hip), insula, and superior temporal gyrus (STG); and reduced WM volumes in the MB, anterior limb of the internal capsule (ALIC), dorsolateral prefrontal cortex (DLPFC), and precentral gyrus (PrG). It is important to note that the GM volume of the Hip and the WM volume of the DLPFC were positively correlated with the recognition accuracy (%) in the explicit memory tasks with neutral and anxiety-inducing words, respectively. On the other hand, the WM volume of the PrG was negatively correlated with the reaction time in the same memory tasks. Conclusion This study demonstrated the regional volume changes on whole-brain GM and WM and the correlation between the brain structural alteration and explicit memory dysfunction in GAD patients. These findings would be helpful to understand the association between the brain structure abnormality and the functional deficit in the explicit memory in GAD.

  18. Short term (14 days) consumption of insoluble wheat bran fibre-containing breakfast cereals improves subjective digestive feelings, general wellbeing and bowel function in a dose dependent manner.

    Science.gov (United States)

    Lawton, Clare L; Walton, Jenny; Hoyland, Alexa; Howarth, Elaine; Allan, Peter; Chesters, David; Dye, Louise

    2013-04-22

    This study investigated whether increasing insoluble (predominantly wheat bran) fibre over 14 days improves subjective digestive feelings, general wellbeing and bowel function. A single centre, multi-site, open, within subjects design with a 14 day non-intervention (baseline) monitoring period followed by a 14 day fibre consumption (intervention) period was performed. 153 low fibre consumers (breakfast cereal containing at least 5.4 g fibre (3.5 g from wheat bran) for 14 days and completed a daily symptom diary. Significant improvements were demonstrated in subjective perception of bowel function (e.g., ease of defecation) and digestive feelings (bloating, constipation, feeling sluggish and digestive discomfort). Significant improvements were also found in subjective perception of general wellbeing (feeling less fat, more mentally alert, slim, happy and energetic whilst experiencing less stress, mental and physical tiredness, difficulty concentrating and fewer headaches). In general, improvements in study outcomes increased with increasing cereal/fibre consumption. However, consuming an additional minimum 5.4 g of fibre (3.5 g wheat bran) per day was shown to deliver measurable and significant benefits for digestive health, comfort and wellbeing. Encouraging consumption of relatively small amounts of wheat bran could also provide an effective method of increasing overall fibre consumption.

  19. Reduced binding of Pittsburgh Compound-B in areas of white matter hyperintensities

    Directory of Open Access Journals (Sweden)

    A.E. Goodheart

    2015-01-01

    Full Text Available The amyloid imaging agent, Pittsburgh Compound-B, binds with high affinity to β-amyloid (Aβ in the brain, and it is well established that PiB also shows non-specific retention in white matter (WM. However, little is known about retention of PiB in areas of white matter hyperintensities (WMH, abnormalities commonly seen in older adults. Further, it is hypothesized that WMH are related to both cognitive dysfunction and Aβ deposition. The goal of the present study was to explore PiB retention in both normal-appearing WM (NAWM and WMH in a group of elderly, cognitively normal individuals. In a group of cognitively normal elderly (n = 64; 86.5 ± 2.6 years two analyses were applied: (1 ROIs were placed over periventricular areas in which WMH caps are commonly seen on all subjects, regardless of WMH burden or size. (2 Subject-specific maps of NAWM and WMH were co-registered with the PiB-PET images and mean SUVR values were calculated in these NAWM and WMH maps. PiB retention was significantly reduced in the ROIs of subjects with high WMH compared to subjects with low WMH. Additionally, in subjects with high WMH, there was significantly lower PiB retention in subject-specific maps of WMH compared to NAWM, which was not observed in subjects with low WMH, likely because of the small size of WMH maps in this group. These data suggest that WM in areas of WMH binds PiB less effectively than does normal WM. Further exploration of this phenomenon may lead to insights about the molecular basis of the non-specific retention of amyloid tracers in white matter.

  20. Can An Amended Standard Model Account For Cold Dark Matter?

    International Nuclear Information System (INIS)

    Goldhaber, Maurice

    2004-01-01

    It is generally believed that one has to invoke theories beyond the Standard Model to account for cold dark matter particles. However, there may be undiscovered universal interactions that, if added to the Standard Model, would lead to new members of the three generations of elementary fermions that might be candidates for cold dark matter particles

  1. Invisible wombs: rethinking Paracelsus's concept of body and matter.

    Science.gov (United States)

    Daniel, Dane T

    2006-07-01

    Paracelsus's matter theory remains a puzzling subject, especially insofar as his division of matter and the human being is concerned. Paracelsus's early matter theory, as presented in perhaps his most significant chemical work, the Archidoxis, was influenced by John of Rupescissa and contained elements that the mature Paracelsus--greatly influenced by theological concerns and his own unique biblical exegesis--would abandon due to their nonconformity with scripture. The article stresses Paracelsus's interpretation of Genesis 2:7, and the author argues that the Paracelsus of the Astronomia Magna (1537-38)--somewhat echoing the theories in his so-called "meterological writings"--held that the cosmos and microcosm (man) consist of soul, sidereal body (also mortal spirit), elemental mortal matter (a combination of seeds and the tria prima of salt, sulfur, and mercury as produced in the four elemental mothers of air, earth, fire, and water), and eternal body (e.g. the resurrection body). The focus in this article is on mortal matter; Paracelsus's natural philosophy and theology become much more accessible when one understands this quadripartite division.

  2. Subject matter of the All-Union Coordination Conference. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Rudkevich, M.I.; Tselik, M.P.; Belkina, T.V.

    1984-06-01

    Conference on reviewing plans for new research and experimental design projects in the coking industry for 1984-85 took place on 13-17 June 1983. Participants represented the Ministry of Ferrous Metallurgy, Institute for the Chemistry of Coal and other research institutes, technical schools and coking plants. The titles of the more important papers delivered at the conference are given. Main directions in research and development, test results of new processes and technology, automation and mechanization in the industry, preparation of coal batches for coking, studies on coals from the eastern deposits, methods for evaluating blast furnace cokes, and other subject areas related to the coking and chemical industry were covered in the papers delivered at the conference. Altogether 179 on-going and new projects were discussed at the conference.

  3. On the track of dark matter

    International Nuclear Information System (INIS)

    Astier, P.; Pain, R.; Daninos, F.

    2008-01-01

    Physicists link dark matter to the acceleration of the universe expansion via a state equation that sets the ration between pressure and energy density of the dark matter component. 5 candidates to dark matter comply with this test. First, the cosmological constant, it might correspond to a homogenous fluid but not to vacuum energy as previously thought because its value would be far too big to match reality. Secondly, the quintessence, it means a new type of matter that does not interact with ordinary particles and does not collapse when submitted to gravity, it stays diffuse and fluctuates weakly even on very large distances. Thirdly, a modified version of general relativity theory that creates a new basic interaction that is negligible at the scale of the solar system but that affects the universe on cosmological scales. Fourthly, axions, in this theory there is no need for expansion acceleration since photons are likely to turn into axions and as a consequence remote objects appear to be farther than they really are. Fifth, inhomogeneous models, these models challenge the cosmological principle that states that in the universe matter is dispatched in a homogenous and isotropic way. According to these models the universe expansion is an illusion that results from a bad interpretation of experimental results. (A.C.)

  4. White matter hyperintensities and normal-appearing white matter integrity in the aging brain.

    Science.gov (United States)

    Maniega, Susana Muñoz; Valdés Hernández, Maria C; Clayden, Jonathan D; Royle, Natalie A; Murray, Catherine; Morris, Zoe; Aribisala, Benjamin S; Gow, Alan J; Starr, John M; Bastin, Mark E; Deary, Ian J; Wardlaw, Joanna M

    2015-02-01

    White matter hyperintensities (WMH) of presumed vascular origin are a common finding in brain magnetic resonance imaging of older individuals and contribute to cognitive and functional decline. It is unknown how WMH form, although white matter degeneration is characterized pathologically by demyelination, axonal loss, and rarefaction, often attributed to ischemia. Changes within normal-appearing white matter (NAWM) in subjects with WMH have also been reported but have not yet been fully characterized. Here, we describe the in vivo imaging signatures of both NAWM and WMH in a large group of community-dwelling older people of similar age using biomarkers derived from magnetic resonance imaging that collectively reflect white matter integrity, myelination, and brain water content. Fractional anisotropy (FA) and magnetization transfer ratio (MTR) were significantly lower, whereas mean diffusivity (MD) and longitudinal relaxation time (T1) were significantly higher, in WMH than NAWM (p curve, 0.982; 95% CI, 0.975-0.989). Furthermore, the level of deterioration of NAWM was strongly associated with the severity of WMH, with MD and T1 increasing and FA and MTR decreasing in NAWM with increasing WMH score, a relationship that was sustained regardless of distance from the WMH. These multimodal imaging data indicate that WMH have reduced structural integrity compared with surrounding NAWM, and MD provides the best discriminator between the 2 tissue classes even within the mild range of WMH severity, whereas FA, MTR, and T1 only start reflecting significant changes in tissue microstructure as WMH become more severe. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Deposition of Suspended Fine Particulate Matter in a Library

    Czech Academy of Sciences Publication Activity Database

    Smolík, Jiří; Mašková, Ludmila; Zíková, Naděžda; Ondráčková, Lucie; Ondráček, Jakub

    2013-01-01

    Roč. 1, 3 April (2013) ISSN 2050-7445 R&D Projects: GA MK DF11P01OVV020 Keywords : fine particulate matter * deposition * brownian diffusion Subject RIV: CF - Physical ; Theoretical Chemistry http://www.heritagesciencejournal.com/content/1/1/7

  6. Matter sources for a null big bang

    International Nuclear Information System (INIS)

    Bronnikov, K A; Zaslavskii, O B

    2008-01-01

    We consider the properties of stress-energy tensors compatible with a null big bang, i.e., cosmological evolution starting from a Killing horizon rather than a singularity. For Kantowski-Sachs cosmologies, it is shown that if matter satisfies the null energy condition, then (i) regular cosmological evolution can only start from a Killing horizon, (ii) matter is absent at the horizon and (iii) matter can only appear in the cosmological region due to interaction with vacuum. The latter is understood phenomenologically as a fluid whose stress tensor is insensitive to boosts in a particular direction. We also argue that matter is absent in a static region beyond the horizon. All this generalizes the observations recently obtained for a mixture of dust and a vacuum fluid. If, however, we admit the existence of phantom matter, its certain special kinds (with the parameter w ≤ -3) are consistent with a null big bang without interaction with vacuum (or without vacuum fluid at all). Then in the static region there is matter with w ≥ -1/3. Alternatively, the evolution can begin from a horizon in an infinitely remote past, leading to a scenario combining the features of a null big bang and an emergent universe

  7. White matter abnormalities in young males with antisocial personality disorder Evidence from voxel-based morphometry-diffeomorphic anatomical registration using exponentiated lie algebra analysis

    Institute of Scientific and Technical Information of China (English)

    Daxing Wu; Ying Zhao; Jian Liao; Huifang Yin; Wei Wang

    2011-01-01

    Voxel-based morphometry-diffeomorphic anatomical registration using exponentiated lie algebra analysis was used to investigate the structural characteristics of white matter in young males with antisocial personality disorder (APD) and healthy controls without APD. The results revealed that APD subjects, relative to healthy subjects, exhibited increased white matter volume in the bilateral prefrontal lobe, right insula, precentral gyrus, bilateral superior temporal gyrus, right postcentral gyrus, right inferior parietal lobule, right precuneus, right middle occipital lobe, right parahippocampal gyrus and bilateral cingulate, and decreased volume in the middle temporal cortex and right cerebellum. The white matter volume in the medial frontal gyrus was significantly correlated with antisocial type scores on the Personality Diagnostic Questionnaire in APD subjects. These experimental findings indicate that white matter abnormalities in several brain areas may contribute to antisocial behaviors in APD subjects.

  8. Dynamics of a magnetic monopole in matter

    International Nuclear Information System (INIS)

    Fayolle, David

    1999-07-01

    We study the dynamics of a slow (v/c ∼ 10 -4 ) Dirac magnetic monopole in matter. First, we show at macroscopic scale that the force exerted on a monopole is F vector = g(H vector - v vector x D vector), as if the monopole was not allowed to cross neither microscopic current loops nor microscopic electric dipoles. We interpret this result in terms of adiabatic monopole-atom interactions. Secondly, we generalized the macroscopic Maxwell's equations in 'dual symmetric' matter which contains monopoles and dyons, from which we deduce several properties such as the velocity of light, the behaviour under C, P and T transformation, and we generalize the energy-momentum tensor. These equations also apply when nucleons or electrons possess an electric dipole moment and we propose two experimental methods for detecting this electric dipole moment via its macroscopic polarization effects. (author)

  9. HISTORIOGRAPHY GENERAL, REGIONAL AND SPECIAL STUDIES OF JUDICIAL REFORM IN RUSSIA 1864

    Directory of Open Access Journals (Sweden)

    Sergei Evgenievich Strakhov

    2014-10-01

    Full Text Available In today's world, a crucial role is played by the judiciary. In the period lasting judicial reform, it is important to explore this institution not only at the present stage, but also to trace the history of its development, including - through analysis and synthesis of existing studies of the judiciary and judicial reforms.The purpose of this study - to explore the historiography of general, special and regional studies of judicial reform of1864 inRussia, to classify research on history and on the subject of the study.Scientific, theoretical and practical significance of the work lies in the fact that the study of this topic will summarize the significant weight of the studies of the judicial reform of 1864 and classified by facilitating orientation interested in individuals in the study subjects.The author uses historical, comparative, hermeneutical, mathematical methods, as well as general methods of scientific research.The author analyzes the historiography of general, special and regional studies of the judicial reform of1864 inRussia, introducing a classification of such studies in chronological order (pre-revolutionary, Soviet and modern stages and subject matter (common - affecting all aspects of judicial reform, special - dedicated to a particular aspect (legal agencies, prosecutors, legal, etc. and regional - dedicated to judicial reform, or some aspects of it in some regions of Russia.The results of this study are scientific and practical value, because they can be useful for teaching students - in industry disciplines "judiciary", "advocacy", "notary public", "public prosecutor's supervision" and general theoretical "History of State and Law," "History of the fatherland" ; in science - by picking up information about the historiography of the judicial reform, and in practice - said work can serve as a guide to research judicial reform, which may be useful to practitioners of judicial and investigative bodies, as well as - prosecutors

  10. General report

    International Nuclear Information System (INIS)

    Nicklisch, F.

    1984-01-01

    Growing complexity of technical matter has meant that technical expertise is called upon in more and more legal proceedings. The technical expert is, in general terms, the mediator between technology and the law, he is also entrusted with the task of pointing up the differences in approach and in the nature of authority in these two areas and thus paving the way for mutual understanding. The evaluation of the technical expert's opinion is one of the cardinal problems bound up with the role of the expert in legal procedure. After the presentation of the expert's opinion, the judge is supposed to possess so much specialised knowledge that he can assess the opinion itself in scientific and technical respects and put his finger on any errors the expert may have made. This problem can only be solved via an assessment opinion. First of all, the opinion can be assessed indirectly via evaluation of the credentials and the neutrality and independence of the expert. In direct terms, the opinion can be subjected to a certain - albeit restricted - scrutiny, whether it is generally convincing, as far as the layman is competent to judge. This interpretation alone makes it possible to classify and integrate legally the technical standards and regulations represent expert statements on the scientific and technical theorems based on the knowledge and experience gained in a given area. They are designed to reflect prevailing opinion among leading representatives of the profession and can thus themselves be regarded as expert opinions. As a rule, these opinions will have such weight that - other than in exceptional cases - they will not be invalidated in procedure by deviating opinions from individual experts. (orig./HSCH) [de

  11. On matter couplings in N=1 supergravities

    International Nuclear Information System (INIS)

    Galperin, A.; Ogievskiy, V.; Sokatchev, E.

    1983-01-01

    A flexible version of N=1 supergravity is proposed. It contains 28+28 fields and is an extension of the new minimal supergravity version. Matter couplings in various N=1 supergravity versions are discussed. The chiral densities are constructed for non-minimal and flexible versions. Therefore these versions admit a general R-non-invariant matter coupling as the minimal supergravity does. A modified Fayet-Iliopoulos type mechanism is conjectured which apparently can work in the non-minimal and flexible versions without R-symmetry of the superpotential unlike the minimal and new minimal ones

  12. Neutrino oscillation in the matter, in the context of tree families

    International Nuclear Information System (INIS)

    Bellandi, J.; Guzzo, M.M.

    1994-01-01

    From the equation of time evolution of three neutrino families system, in presence of matter, an analytical solution is derived for probability amplitude of transition between flavors. Particular cases, mixing between two families at constant matter density, and oscillations between three families in the vacuum, are obtained from the general solution

  13. Origin of heat-induced structural changes in dissolved organic matter

    Czech Academy of Sciences Publication Activity Database

    Drastík, M.; Novák, František; Kučerík, J.

    2013-01-01

    Roč. 90, č. 2 (2013), s. 789-795 ISSN 0045-6535 Institutional support: RVO:60077344 Keywords : dissolved organic matter * humic substances * hydration * hysteresis Subject RIV: DF - Soil Science Impact factor: 3.499, year: 2013

  14. General characteristics of the institute of bringing senior officials of the subjects of the Russian Federation to justice

    Directory of Open Access Journals (Sweden)

    Chepus A.V.

    2014-12-01

    Full Text Available The theoretical and practical aspects of the problem of bringing senior officials of the RF subjects to criminal liability are analyzed. Legal immunity as the most important feature of their legal status is considered. General characteristic of the liability of such senior officials in the context of the institute of state and law enforcement is provided. The current Russian legislation and judicial practice in this area are analyzed. Special attention is paid to the history of the issue of bringing senior officials to justice, on the example of the Federation Council member status. Basing on the other authors’ researches, the author proposes his own view on the issues of senior officials’ immunity. It’s suggested that in modern legal science the problems of the liability of senior officials of the RF regions aren’t given due attention. There’s no clear understanding of what should be the grounds of such liability, its procedures and application, the legal nature of its sanctions. The author substantiates the position that it’s not necessary to include the regional leaders or heads of executive authorities of the RF subjects in the list of persons having immunity from criminal or administrative prosecution. The arguments are the federal practice – the ministers of the RF Government don’t possess the immunity, and the recent practice – dismissal as a result of loss of confidence. The need to control the activities of the senior officials of the RF subjects and other persons holding the highest positions in the authorities of the RF subjects is substantiated.

  15. The Matter-Antimatter Asymmetry of the Universe

    Science.gov (United States)

    Stecker, F. W.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    I will give here an overview of the present observational and theoretical situation regarding the question of the matter-antimatter asymmetry of the universe and the related question of the existence of antimatter on a cosmological scale. I will also give a simple discussion of the role of CP (charge conjugation parity) violation in this subject.

  16. Strange-quark-matter stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-11-01

    We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 13 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to consist of individual hadrons. We conclude that it is implausible that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, is a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation if strange matter is stable at an energy density exceeding about 5.4 times that of nuclear matter. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 34 refs., 10 figs., 1 tab

  17. Incidental white matter lesions identified on magnetic resonance images of normal Japanese individuals; Correlation with age and hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Hirofumi; Kida, Yoshihisa; Tanaka, Takayuki; Iwakoshi, Takanori; Niwa, Masahiro; Kobayashi, Tatsuya [Komaki City Hospital, Hokkaido (Japan)

    1994-05-01

    Incidental white matter high-intensity lesions are frequently seen on T[sub 2]-weighted magnetic resonance (MR) images of the brain in older people. The incidence increases with advancing age or hypertension. Brain MR images of 59 normal individuals were examined to analyze this phenomenon. The total number of white matter high-intensity lesions correlated significantly with age (p=0.004) or systolic blood pressure (p=0.03). The 60- to 69-year-old group demonstrated a very close correlation of white matter lesions with systolic (p=0.02) and diastolic blood pressure (p=0.01), in contrast to the 50- to 59-year-old group. Hypertensive subjects in their 60s are thought to develop more white matter lesions than subjects in their 50s. (author).

  18. Coupled intertwiner dynamics: A toy model for coupling matter to spin foam models

    OpenAIRE

    Steinhaus, Sebastian

    2015-01-01

    The universal coupling of matter and gravity is one of the most important features of general relativity. In quantum gravity, in particular spin foams, matter couplings have been defined in the past, yet the mutual dynamics, in particular if matter and gravity are strongly coupled, are hardly explored, which is related to the definition of both matter and gravitational degrees of freedom on the discretisation. However extracting this mutual dynamics is crucial in testing the viability of the ...

  19. D-brane disformal coupling and thermal dark matter

    Science.gov (United States)

    Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

    2017-11-01

    Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.

  20. Shining LUX on isospin-violating dark matter beyond leading order

    DEFF Research Database (Denmark)

    Cirigliano, V.; Graesser, M. L.; Ovanesyan, G.

    2014-01-01

    Isospin-violating dark matter (IVDM) has been proposed as a viable scenario to reconcile conflicting positive and null results from direct detection dark matter experiments. We show that the lowest-order dark matter-nucleus scattering rate can receive large and nucleus-dependent corrections at next......-to-leading order (NLO) in the chiral expansion. The size of these corrections depends on the specific couplings of dark matter to quark flavors and gluons. In general the full NLO dark-matter-nucleus cross-section is not adequately described by just the zero-energy proton and neutron couplings. These statements...... are concretely illustrated in a scenario where the dark matter couples to quarks through scalar operators. We find the canonical IVDM scenario can reconcile the null XENON and LUX results and the recent CDMS-Si findings provided its couplings to second and third generation quarks either lie on a special line...

  1. Dissipative dark matter halos: The steady state solution

    Science.gov (United States)

    Foot, R.

    2018-02-01

    Dissipative dark matter, where dark matter particle properties closely resemble familiar baryonic matter, is considered. Mirror dark matter, which arises from an isomorphic hidden sector, is a specific and theoretically constrained scenario. Other possibilities include models with more generic hidden sectors that contain massless dark photons [unbroken U (1 ) gauge interactions]. Such dark matter not only features dissipative cooling processes but also is assumed to have nontrivial heating sourced by ordinary supernovae (facilitated by the kinetic mixing interaction). The dynamics of dissipative dark matter halos around rotationally supported galaxies, influenced by heating as well as cooling processes, can be modeled by fluid equations. For a sufficiently isolated galaxy with a stable star formation rate, the dissipative dark matter halos are expected to evolve to a steady state configuration which is in hydrostatic equilibrium and where heating and cooling rates locally balance. Here, we take into account the major cooling and heating processes, and numerically solve for the steady state solution under the assumptions of spherical symmetry, negligible dark magnetic fields, and that supernova sourced energy is transported to the halo via dark radiation. For the parameters considered, and assumptions made, we were unable to find a physically realistic solution for the constrained case of mirror dark matter halos. Halo cooling generally exceeds heating at realistic halo mass densities. This problem can be rectified in more generic dissipative dark matter models, and we discuss a specific example in some detail.

  2. Delay Discounting: Pigeon, Rat, Human – Does it Matter?

    Science.gov (United States)

    Vanderveldt, Ariana; Oliveira, Luís; Green, Leonard

    2016-01-01

    Delay discounting refers to the decrease in subjective value of an outcome as the time to its receipt increases. Across species and situations, animals discount delayed rewards, and their discounting is well-described by a hyperboloid function. The current review begins with a comparison of discounting models and the procedures used to assess delay discounting in nonhuman animals. We next discuss the generality of discounting, reviewing the effects of different variables on the degree of discounting delayed reinforcers by nonhuman animals. Despite the many similarities in discounting observed between human and nonhuman animals, several differences have been proposed (e.g., the magnitude effect; nonhuman animals discount over a matter of seconds whereas humans report willing to wait months, if not years before receiving a reward), raising the possibility of fundamental species differences in intertemporal choice. After evaluating these differences, we discuss delay discounting from an adaptationist perspective. The pervasiveness of discounting across species and situations suggests it is a fundamental process underlying decision making. PMID:26881899

  3. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H.; Skipper-Kallal, Laura M.; Jiang, Xiong; Harris-Love, Michelle L.; Zeng, Jinsheng

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor’s lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion–symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  4. Adiabatic instability in coupled dark energy/dark matter models

    International Nuclear Information System (INIS)

    Bean, Rachel; Flanagan, Eanna E.; Trodden, Mark

    2008-01-01

    We consider theories in which there exists a nontrivial coupling between the dark matter sector and the sector responsible for the acceleration of the Universe. Such theories can possess an adiabatic regime in which the quintessence field always sits at the minimum of its effective potential, which is set by the local dark matter density. We show that if the coupling strength is much larger than gravitational, then the adiabatic regime is always subject to an instability. The instability, which can also be thought of as a type of Jeans instability, is characterized by a negative sound speed squared of an effective coupled dark matter/dark energy fluid, and results in the exponential growth of small scale modes. We discuss the role of the instability in specific coupled cold dark matter and mass varying neutrino models of dark energy and clarify for these theories the regimes in which the instability can be evaded due to nonadiabaticity or weak coupling.

  5. On the spin saturation and thermal properties of nuclear matter

    International Nuclear Information System (INIS)

    Hassan, M.Y.M.; Ramadan, S.

    1983-12-01

    The binding energy and the incompressibility of nuclear matter with degree of spin saturation D is calculated using the Skyrme interaction and two forms of a velocity dependent effective potential. The effect of the degree of spin saturation D on the thermal properties of nuclear matter is also discussed. It is found that generally the pressure decreases with increasing D. (author)

  6. On couplings to matter in massive (bi-)gravity

    International Nuclear Information System (INIS)

    Rham, Claudia de; Ribeiro, Raquel H; Heisenberg, Lavinia

    2015-01-01

    We investigate the coupling to matter in ghost-free massive (bi-)gravity. When species in the matter sector couple covariantly to only one metric, we show that at one-loop these couplings do not spoil the special structure of the graviton potential. When the same species couples directly to both metrics we show that a ghost is present at the classical level and that loops destroy the special structure of the potential at an unacceptably low scale. We then propose a new ‘composite’ effective metric built out of both metrics. When matter fields couple covariantly to this effective metric, the would be Boulware–Deser (BD) ghost is absent in different representative limits. At one-loop such couplings do not detune the special structure of the potential. We conjecture that matter can couple covariantly to that effective metric in all generality without introducing any BD ghost below a cut-off scale parametrically larger than the strong coupling scale. We also discuss alternative couplings to matter where the kinetic and potential terms of the matter field couple to different metrics. In both cases we discuss preliminary implications for cosmology. (paper)

  7. Matter, dark matter, and anti-matter in search of the hidden universe

    CERN Document Server

    Mazure, Alain

    2012-01-01

    For over ten years, the dark side of the universe has been headline news. Detailed studies of the rotation of spiral galaxies, and 'mirages' created by clusters of galaxies bending the light from very remote objects, have convinced astronomers of the presence of large quantities of dark (unseen) matter in the cosmos. Moreover, in the 1990s, it was discovered that some four to five billion years ago the expansion of the universe entered a phase of acceleration. This implies the existence of dark energy. The nature of these 'dark; ingredients remains a mystery, but they seem to comprise about 95 percent of the matter/energy content of the universe. As for ordinary matter, although we are immersed in a sea of dark particles, including primordial neutrinos and photons from 'fossil' cosmological radiation, both we and our environment are made of ordinary, baryonic matter. Strangely, even if 15-20 percent of matter is baryonic matter, this represents only 4-5 percent of the total matter/energy content of the cosmos...

  8. Grey matter volume in adolescents with anorexia nervosa and associated eating disorder symptoms.

    Science.gov (United States)

    Martin Monzon, Beatriz; Henderson, Luke A; Madden, Sloane; Macefield, Vaughan G; Touyz, Stephen; Kohn, Michael R; Clarke, Simon; Foroughi, Nasim; Hay, Phillipa

    2017-10-01

    Anorexia nervosa (AN) is a mental health disorder of complex aetiology. Previous neuroimaging studies have found consistent global reductions in global grey matter volume of underweight girls with AN; however, differences in regional grey matter volumes are less consistent. The aims of this study were to investigate grey matter regional volumes of adolescent girls with AN before and after weight recovery and the relationship of any changes with clinical characteristics. We collected high-resolution T1-weighted images from 26 underweight girls with AN before weight gain and 20 healthy control volunteers. Clinical features were assessed using the Eating Disorder Examination Questionnaire. AN subjects displayed reduced grey matter volumes in the insula, amygdala, prefrontal, hippocampal and cingulate cortices and the precuneus, relative to healthy controls. In a subset of 10 AN subjects who were followed after weight recovery, grey matter volumes increased to near-control levels in the orbito- and medial prefrontal, insular, left hippocampal and mid- and posterior cingulate cortices and precuneus. The recovery of the right anterior thalamus and the left orbitofrontal cortex was correlated with improvements in eating concerns and shape concerns, respectively. However, large parts of the anterior cingulate cortex, caudate nuclei and right hippocampus did not display any grey matter recovery following a short-term of treatment. These results show that in adolescents with AN, some brain regions display marked recovery in grey matter volume following weight recovery, whereas others do not, considering grey mater recovery possibly linked to symptom improvement. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  9. Theories of Matter, Space and Time; Classical theories

    Science.gov (United States)

    Evans, N.; King, S. F.

    2017-12-01

    This book and its sequel ('Theories of Matter Space and Time: Quantum Theories') are taken from third and fourth year undergraduate Physics courses at Southampton University, UK. The aim of both books is to move beyond the initial courses in classical mechanics, special relativity, electromagnetism, and quantum theory to more sophisticated views of these subjects and their interdependence. The goal is to guide undergraduates through some of the trickier areas of theoretical physics with concise analysis while revealing the key elegance of each subject. The first chapter introduces the key areas of the principle of least action, an alternative treatment of Newtownian dynamics, that provides new understanding of conservation laws. In particular, it shows how the formalism evolved from Fermat's principle of least time in optics. The second introduces special relativity leading quickly to the need and form of four-vectors. It develops four-vectors for all kinematic variables and generalize Newton's second law to the relativistic environment; then returns to the principle of least action for a free relativistic particle. The third chapter presents a review of the integral and differential forms of Maxwell's equations before massaging them to four-vector form so that the Lorentz boost properties of electric and magnetic fields are transparent. Again, it then returns to the action principle to formulate minimal substitution for an electrically charged particle.

  10. 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

  11. The Symmetry, or Lack of it, Between Matter and Antimatter

    International Nuclear Information System (INIS)

    Quinn, Helen R

    2001-01-01

    The subject of antimatter and its relationship to matter began with Dirac, with the publication of his famous equation in 1928.[1] Today it remains an active area of particle physics. The dominant issue for a number of major experimental programs is to decipher the nature of the difference in the laws of physics for matter and for antimatter. This has been a central issue of my work in the past few years, and a recurring theme in earlier work. Hence when I was asked to review a subject of my choice for this conference, this was the obvious choice for me; a very different focus from any other talk here. (Also, it allows me along the way make reference to both pieces of work for which I was cited in my Dirac award, though neither is central to this story.) Given this opportunity, I decided to start with the early history of the subject, both in honor of Dirac and his essential role in it, and because it is fascinating to look back and see how understanding evolves

  12. 23 March 2015 - Tree planting ceremony Chemin Auguer, by His Holiness the XIIth Gyalwang Drukpa and CERN Director-General, on the occasion of the event Connecting Worlds: Science Meets Buddhism Great Minds, Great Matters.

    CERN Multimedia

    Brice, Maximilien

    2015-01-01

    23 March 2015 - Tree planting ceremony Chemin Auguer, by His Holiness the XIIth Gyalwang Drukpa and CERN Director-General, on the occasion of the event Connecting Worlds: Science Meets Buddhism Great Minds, Great Matters.

  13. Short Term (14 Days Consumption of Insoluble Wheat Bran Fibre-Containing Breakfast Cereals Improves Subjective Digestive Feelings, General Wellbeing and Bowel Function in a Dose Dependent Manner

    Directory of Open Access Journals (Sweden)

    Louise Dye

    2013-04-01

    Full Text Available This study investigated whether increasing insoluble (predominantly wheat bran fibre over 14 days improves subjective digestive feelings, general wellbeing and bowel function. A single centre, multi-site, open, within subjects design with a 14 day non-intervention (baseline monitoring period followed by a 14 day fibre consumption (intervention period was performed. 153 low fibre consumers (<15 g/day AOAC 985.29 completed a daily symptom diary for 14 days after which they consumed one bowl of ready-to-eat breakfast cereal containing at least 5.4 g fibre (3.5 g from wheat bran for 14 days and completed a daily symptom diary. Significant improvements were demonstrated in subjective perception of bowel function (e.g., ease of defecation and digestive feelings (bloating, constipation, feeling sluggish and digestive discomfort. Significant improvements were also found in subjective perception of general wellbeing (feeling less fat, more mentally alert, slim, happy and energetic whilst experiencing less stress, mental and physical tiredness, difficulty concentrating and fewer headaches. In general, improvements in study outcomes increased with increasing cereal/fibre consumption. However, consuming an additional minimum 5.4 g of fibre (3.5 g wheat bran per day was shown to deliver measurable and significant benefits for digestive health, comfort and wellbeing. Encouraging consumption of relatively small amounts of wheat bran could also provide an effective method of increasing overall fibre consumption.

  14. Short Term (14 Days) Consumption of Insoluble Wheat Bran Fibre-Containing Breakfast Cereals Improves Subjective Digestive Feelings, General Wellbeing and Bowel Function in a Dose Dependent Manner

    Science.gov (United States)

    Lawton, Clare L.; Walton, Jenny; Hoyland, Alexa; Howarth, Elaine; Allan, Peter; Chesters, David; Dye, Louise

    2013-01-01

    This study investigated whether increasing insoluble (predominantly wheat bran) fibre over 14 days improves subjective digestive feelings, general wellbeing and bowel function. A single centre, multi-site, open, within subjects design with a 14 day non-intervention (baseline) monitoring period followed by a 14 day fibre consumption (intervention) period was performed. 153 low fibre consumers (<15 g/day AOAC 985.29) completed a daily symptom diary for 14 days after which they consumed one bowl of ready-to-eat breakfast cereal containing at least 5.4 g fibre (3.5 g from wheat bran) for 14 days and completed a daily symptom diary. Significant improvements were demonstrated in subjective perception of bowel function (e.g., ease of defecation) and digestive feelings (bloating, constipation, feeling sluggish and digestive discomfort). Significant improvements were also found in subjective perception of general wellbeing (feeling less fat, more mentally alert, slim, happy and energetic whilst experiencing less stress, mental and physical tiredness, difficulty concentrating and fewer headaches). In general, improvements in study outcomes increased with increasing cereal/fibre consumption. However, consuming an additional minimum 5.4 g of fibre (3.5 g wheat bran) per day was shown to deliver measurable and significant benefits for digestive health, comfort and wellbeing. Encouraging consumption of relatively small amounts of wheat bran could also provide an effective method of increasing overall fibre consumption. PMID:23609776

  15. Matter and energy

    International Nuclear Information System (INIS)

    Rocha, A.F.G. da

    1976-01-01

    Rutherford's and Bhor's atomic models are presented, as well as the general configuration of the atom. In the study of energy, emphasis is given to its forms and unities, to equivalence between mass and energy and to the energy levels of the atom. Electrons and nuclear constituents, nuclear forces, stability and nuclear potential barrier are studied. The concepts of radioactive state, activity and nuclear decay are analysed, as well as nuclear reactions, fission, radioisotope production and cosmic rays. Interactions between radiation and matter are also analysed [pt

  16. Exposing asymmetric gray matter vulnerability in amyotrophic lateral sclerosis

    OpenAIRE

    Devine, Matthew S.; Pannek, Kerstin; Coulthard, Alan; McCombe, Pamela A.; Rose, Stephen E.; Henderson, Robert D.

    2015-01-01

    Limb weakness in amyotrophic lateral sclerosis (ALS) is typically asymmetric. Previous studies have identified an effect of limb dominance on onset and spread of weakness, however relative atrophy of dominant and non-dominant brain regions has not been investigated. Our objective was to use voxel-based morphometry (VBM) to explore gray matter (GM) asymmetry in ALS, in the context of limb dominance. 30 ALS subjects were matched with 17 healthy controls. All subjects were right-handed. Each und...

  17. Nanomedicine a soft matter perspective

    CERN Document Server

    Pan, Dipanjan

    2014-01-01

    This book provides a broad introduction to soft matters for nanomedicinal applications, with a deeper discussion of the individual modalities for molecular imaging. It includes a general introduction to the opportunities provided by this technology in chemistry, materials, biology and nanomedicine. It is designed and written with the perspective that anyone, with or without previous knowledge of nanotechnology, would benefit.

  18. Flooded Dark Matter and S level rise

    International Nuclear Information System (INIS)

    Randall, Lisa; Scholtz, Jakub; Unwin, James

    2016-01-01

    Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as “Maximum Baroqueness”. We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant

  19. Flooded Dark Matter and S level rise

    Energy Technology Data Exchange (ETDEWEB)

    Randall, Lisa; Scholtz, Jakub [Department of Physics, Harvard University,Cambridge, MA 02138 (United States); Unwin, James [Department of Physics, University of Illinois at Chicago,Chicago, IL 60607 (United States)

    2016-03-03

    Most dark matter models set the dark matter relic density by some interaction with Standard Model particles. Such models generally assume the existence of Standard Model particles early on, with the dark matter relic density a later consequence of those interactions. Perhaps a more compelling assumption is that dark matter is not part of the Standard Model sector and a population of dark matter too is generated at the end of inflation. This democratic assumption about initial conditions does not necessarily provide a natural value for the dark matter relic density, and furthermore superficially leads to too much entropy in the dark sector relative to ordinary matter. We address the latter issue by the late decay of heavy particles produced at early times, thereby associating the dark matter relic density with the lifetime of a long-lived state. This paper investigates what it would take for this scenario to be compatible with observations in what we call Flooded Dark Matter (FDM) models and discusses several interesting consequences. One is that dark matter can be very light and furthermore, light dark matter is in some sense the most natural scenario in FDM as it is compatible with larger couplings of the decaying particle. A related consequence is that the decay of the field with the smallest coupling and hence the longest lifetime dominates the entropy and possibly the matter content of the Universe, a principle we refer to as “Maximum Baroqueness”. We also demonstrate that the dark sector should be colder than the ordinary sector, relaxing the most stringent free-streaming constraints on light dark matter candidates. We will discuss the potential implications for the core-cusp problem in a follow-up paper. The FDM framework will furthermore have interesting baryogenesis implications. One possibility is that dark matter is like the baryon asymmetry and both are simultaneously diluted by a late entropy dump. Alternatively, FDM is compatible with an elegant

  20. 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.

  1. Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study.

    Science.gov (United States)

    Aydin, K; Ucar, A; Oguz, K K; Okur, O O; Agayev, A; Unal, Z; Yilmaz, S; Ozturk, C

    2007-01-01

    The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains.

  2. From basic processes to sensors: particle-matter interactions

    International Nuclear Information System (INIS)

    Laforge, Bertrand; Bourgeois, Christian

    2005-11-01

    This academic course aims at presenting and explaining techniques of detection of radiations displaying an energy higher that some tens of keV, such as those met in nuclear physics or in particle physics. In a first part, the author first analyses the operation of a biological sensor (the eye), and then presents some generalities about matter: Rutherford experiment, the atom, molecules and solids. The second part deals with interactions between radiations and matter. The author there addresses interactions of heavy charged particles (ionization with high or low energy transfer), interactions of electrons (ionization, Bremsstrahlung), multiple scattering and straggling, the Cherenkov effect, transition radiation, the interaction of γ radiations in matter (Compton effect, photoelectric effect), the interaction of neutrons in matter. Appendices address γ spectrometry, the radiation of a charged particle moving in a dielectric medium, and issues related to statistical fluctuations (distribution functions, fluctuation propagation, energy resolution, noises)

  3. Heavy spin-2 Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Babichev, Eugeny [Laboratoire de Physique Théorique, CNRS, Univ. Paris-Sud, Université Paris-Saclay,91405 Orsay (France); UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, GReCO,98bis boulevard Arago, F-75014 Paris (France); Marzola, Luca; Raidal, Martti [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Laboratory of Theoretical Physics, Institute of Physics, University of Tartu,Ravila 14c, 50411 Tartu (Estonia); Schmidt-May, Angnis [Institut für Theoretische Physik, Eidgenössische Technische Hochschule Zürich,Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland); Urban, Federico; Veermäe, Hardi [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Strauss, Mikael von [UPMC-CNRS, UMR7095, Institut d’Astrophysique de Paris, GReCO,98bis boulevard Arago, F-75014 Paris (France)

    2016-09-12

    We provide further details on a recent proposal addressing the nature of the dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by the presence of a heavy spin-2 particle. Massive spin-2 fields and their gravitational interactions are uniquely described by ghost-free bimetric theory, which is a minimal and natural extension of General Relativity. In this setup, the largeness of the physical Planck mass is naturally related to extremely weak couplings of the heavy spin-2 field to baryonic matter and therefore explains the absence of signals in experiments dedicated to Dark Matter searches. It also ensures the phenomenological viability of our model as we confirm by comparing it with cosmological and local tests of gravity. At the same time, the spin-2 field possesses standard gravitational interactions and it decays universally into all Standard Model fields but not into massless gravitons. Matching the measured DM abundance together with the requirement of stability constrains the spin-2 mass to be in the 1 to 100 TeV range.

  4. A general symplectic method for the response analysis of infinitely periodic structures subjected to random excitations

    Directory of Open Access Journals (Sweden)

    You-Wei Zhang

    Full Text Available A general symplectic method for the random response analysis of infinitely periodic structures subjected to stationary/non-stationary random excitations is developed using symplectic mathematics in conjunction with variable separation and the pseudo-excitation method (PEM. Starting from the equation of motion for a single loaded substructure, symplectic analysis is firstly used to eliminate the dependent degrees of the freedom through condensation. A Fourier expansion of the condensed equation of motion is then applied to separate the variables of time and wave number, thus enabling the necessary recurrence scheme to be developed. The random response is finally determined by implementing PEM. The proposed method is justified by comparison with results available in the literature and is then applied to a more complicated time-dependent coupled system.

  5. Analysis of condensed matter physics records in databases. Science and technology indicators in condensed matter physics

    International Nuclear Information System (INIS)

    Hillebrand, C.D.

    1999-05-01

    An analysis of the literature on Condensed Matter Physics, with particular emphasis on High Temperature Superconductors, was performed on the contents of the bibliographic database International Nuclear Information System (INIS). Quantitative data were obtained on various characteristics of the relevant INIS records such as subject categories, language and country of publication, publication types, etc. The analysis opens up the possibility for further studies, e.g. on international research co-operation and on publication patterns. (author)

  6. Solar-stellar astrophysics and dark matter

    International Nuclear Information System (INIS)

    Turck-Chièze, Sylvaine; Lopes, Ilídio

    2012-01-01

    In this review, we recall how stars contribute to the search for dark matter and the specific role of the Sun. We describe a more complete picture of the solar interior that emerges from neutrino detections, gravity and acoustic mode measurements of the Solar and Heliospheric Observatory (SOHO) satellite, becoming a reference for the most common stars in the Universe. The Sun is a unique star in that we can observe directly the effect of dark matter. The absence of a signature related to Weakly Interacting Massive Particles (WIMPs) in its core disfavors a WIMP mass range below 12GeV. We give arguments to continue this search on the Sun and other promising cases. We also examine another dark matter candidate, the sterile neutrino, and infer the limitations of the classical structural equations. Open questions on the young Sun, when planets formed, and on its present internal dynamics are finally discussed. Future directions are proposed for the next decade: a better description of the solar core, a generalization to stars coming from seismic missions and a better understanding of the dynamics of our galaxy which are all crucial keys for understanding dark matter.

  7. Evading direct dark matter detection in Higgs portal models

    Energy Technology Data Exchange (ETDEWEB)

    Arcadi, Giorgio [Max Planck Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Gross, Christian, E-mail: christian.gross@helsinki.fi [Department of Physics and Helsinki Institute of Physics, Gustaf Hällströmin katu 2, FI-00014 Helsinki (Finland); Lebedev, Oleg [Department of Physics and Helsinki Institute of Physics, Gustaf Hällströmin katu 2, FI-00014 Helsinki (Finland); Pokorski, Stefan [Institute of Theoretical Physics, University of Warsaw, Pasteura 5, PL-02-093 Warsaw (Poland); Toma, Takashi [Physik-Department T30d, Technische Universität München, James-Franck-Straße, D-85748 Garching (Germany)

    2017-06-10

    Many models of Higgs portal Dark Matter (DM) find themselves under pressure from increasingly tight direct detection constraints. In the framework of gauge field DM, we study how such bounds can be relaxed while retaining the thermal WIMP paradigm. When the hidden sector gauge symmetry is broken via the Higgs mechanism, the hidden sector generally contains unstable states which are lighter than dark matter. These states provide DM with an efficient annihilation channel. As a result, the DM relic abundance and the direct detection limits are controlled by different parameters, and the two can easily be reconciled. This simple setup realizes the idea of “secluded” dark matter naturally.

  8. Standard model Higgs boson-inflaton and dark matter

    International Nuclear Information System (INIS)

    Clark, T. E.; Liu Boyang; Love, S. T.; Veldhuis, T. ter

    2009-01-01

    The standard model Higgs boson can serve as the inflaton field of slow roll inflationary models provided it exhibits a large nonminimal coupling with the gravitational scalar curvature. The Higgs boson self interactions and its couplings with a standard model singlet scalar serving as the source of dark matter are then subject to cosmological constraints. These bounds, which can be more stringent than those arising from vacuum stability and perturbative triviality alone, still allow values for the Higgs boson mass which should be accessible at the LHC. As the Higgs boson coupling to the dark matter strengthens, lower values of the Higgs boson mass consistent with the cosmological data are allowed.

  9. 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

  10. Mirror matter as self-interacting dark matter

    International Nuclear Information System (INIS)

    Mohapatra, R.N.; Nussinov, S.; Teplitz, V.L.

    2002-01-01

    It has been argued that the observed core density profile of galaxies is inconsistent with having a dark matter particle that is collisionless and that alternative dark matter candidates which are self-interacting may explain observations better. One new class of self-interacting dark matter that has been proposed in the context of mirror universe models of particle physics is the mirror hydrogen atom, whose stability is guaranteed by the conservation of mirror baryon number. We show that the effective transport cross section for mirror hydrogen atoms has the right order of magnitude for solving the 'cuspy' halo problem. Furthermore, the suppression of dissipation effects for mirror atoms due to a higher mirror mass scale prevents the mirror halo matter from collapsing into a disk, strengthening the argument for mirror matter as galactic dark matter

  11. 76 FR 7479 - Office of the Ombudsman

    Science.gov (United States)

    2011-02-10

    ... facilitator or mediator is the essence of the Ombudsman's role and does not need further clarification. In... Ombudsman may further define what matters are subject to complaint. (b) Appeals.--(1) General. Any regulated.... The Ombudsman may further define what matters are subject to appeal. (3) Matters not subject to appeal...

  12. Segmentation of brain parenchymal regions into gray matter and white matter with Alzheimer's disease

    International Nuclear Information System (INIS)

    Tokunaga, Chiaki; Yoshiura, Takashi; Yamashita, Yasuo; Magome, Taiki; Honda, Hiroshi; Arimura, Hidetaka; Toyofuku, Fukai; Ohki, Masafumi

    2010-01-01

    It is very difficult and time consuming for neuroradiologists to estimate the degree of cerebral atrophy based on the volume of cortical regions etc. Our purpose of this study was to develop an automated segmentation of the brain parenchyma into gray and white matter regions with Alzheimer's disease (AD) in three-dimensional (3D) T1-weighted MR images. Our proposed method consisted of extraction of a brain parenchymal region based on a brain model matching and segmentation of the brain parenchyma into gray and white matter regions based on a fuzzy c-means (FCM) algorithm. We applied our proposed method to MR images of the whole brains obtained from 9 cases, including 4 clinically AD cases and 5 control cases. The mean volume percentage of a cortical region (41.7%) to a brain parenchymal region in AD patients was smaller than that (45.2%) in the control subjects (p=0.000462). (author)

  13. Structure formation constraints on Sommerfeld-enhanced dark matter annihilation

    International Nuclear Information System (INIS)

    Armendariz-Picon, Cristian; Neelakanta, Jayanth T.

    2012-01-01

    We study the growth of cosmic structure in a ΛCDM universe under the assumption that dark matter self-annihilates with an averaged cross section times relative velocity that grows with the scale factor, an increase known as Sommerfeld-enhancement. Such an evolution is expected in models in which a light force carrier in the dark sector enhances the annihilation cross section of dark matter particles, and has been invoked, for instance, to explain anomalies in cosmic ray spectra reported in the past. In order to make our results as general as possible, we assume that dark matter annihilates into a relativistic species that only interacts gravitationally with the standard model. This assumption also allows us to test whether the additional relativistic species mildly favored by cosmic-microwave background data could originate from dark matter annihilation. We do not find evidence for Sommerfeld-enhanced dark matter annihilation and derive the corresponding upper limits on the annihilation cross-section

  14. Interacting diffusive unified dark energy and dark matter from scalar fields

    Energy Technology Data Exchange (ETDEWEB)

    Benisty, David; Guendelman, E.I. [Ben Gurion University of the Negev, Department of Physics, Beersheba (Israel)

    2017-06-15

    Here we generalize ideas of unified dark matter-dark energy in the context of two measure theories and of dynamical space time theories. In two measure theories one uses metric independent volume elements and this allows one to construct unified dark matter-dark energy, where the cosmological constant appears as an integration constant associated with the equation of motion of the measure fields. The dynamical space-time theories generalize the two measure theories by introducing a vector field whose equation of motion guarantees the conservation of a certain Energy Momentum tensor, which may be related, but in general is not the same as the gravitational Energy Momentum tensor. We propose two formulations of this idea: (I) by demanding that this vector field be the gradient of a scalar, (II) by considering the dynamical space field appearing in another part of the action. Then the dynamical space time theory becomes a theory of Diffusive Unified dark energy and dark matter. These generalizations produce non-conserved energy momentum tensors instead of conserved energy momentum tensors which leads at the end to a formulation of interacting DE-DM dust models in the form of a diffusive type interacting Unified dark energy and dark matter scenario. We solved analytically the theories for perturbative solution and asymptotic solution, and we show that the ΛCDM is a fixed point of these theories at large times. Also a preliminary argument as regards the good behavior of the theory at the quantum level is proposed for both theories. (orig.)

  15. The MSW conversion of solar neutrinos and random matter density perturbations

    International Nuclear Information System (INIS)

    Nunokawa, H.; Rossi, A.; Valle, J.W.F.

    1997-01-01

    A generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile is presented. The study is focused on the effect of such matter perturbations upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active ν e → ν μ , τ as well as active-sterile ν e → conversion channels. The small mixing MSW solution is much more stable than the large mixing solution has been found. Future solar neutrino experiments, such as Borexino, could probe solar matter density noise at the few percent level

  16. White matter abnormalities of microstructure and physiological noise in schizophrenia.

    Science.gov (United States)

    Cheng, Hu; Newman, Sharlene D; Kent, Jerillyn S; Bolbecker, Amanda; Klaunig, Mallory J; O'Donnell, Brian F; Puce, Aina; Hetrick, William P

    2015-12-01

    White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is based on the hypothesis that signal fluctuation in white matter is associated with white matter functional activity. We examined the variance of the signal in resting state fMRI and found significant differences between individuals with schizophrenia and non-psychiatric controls specifically in white matter tissue. Controls showed higher temporal signal-to-noise ratios clustered in regions including temporal, frontal, and parietal lobes, cerebellum, corpus callosum, superior longitudinal fasciculus, and other major white matter tracts. These regions with higher temporal signal-to-noise ratio agree well with those showing higher metabolic activity reported by studies using PET. The results suggest that individuals with schizophrenia tend to have higher functional activity in white matter in certain brain regions relative to healthy controls. Despite some overlaps, the distinct regions for physiological noise are different from those for FA derived from diffusion tensor imaging, and therefore provide a unique angle to explore potential mechanisms to white matter abnormality.

  17. A simplified model of top-flavoured dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Kast, Simon; Blanke, Monika [Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

    2016-07-01

    We present the phenomenology of a new physics simplified model of top-flavoured dark matter. The dark matter particle is the lightest Dirac fermion of a new flavour-triplet coupling to the SM up-triplet via a new scalar mediator. The coupling is left general, following Dark Minimal Flavour Violation introduced in arXiv:1405.6709, and therefore is a new source of flavour violation. We study the impact of constraints from both flavour experiments, relic abundance and direct detection constraints, as well as collider bounds.

  18. Hypercharged dark matter and direct detection as a probe of reheating.

    Science.gov (United States)

    Feldstein, Brian; Ibe, Masahiro; Yanagida, Tsutomu T

    2014-03-14

    The lack of new physics at the LHC so far weakens the argument for TeV scale thermal dark matter. On the other hand, heavier, nonthermal dark matter is generally difficult to test experimentally. Here we consider the interesting and generic case of hypercharged dark matter, which can allow for heavy dark matter masses without spoiling testability. Planned direct detection experiments will be able to see a signal for masses up to an incredible 1010  GeV, and this can further serve to probe the reheating temperature up to about 109  GeV, as determined by the nonthermal dark matter relic abundance. The Z-mediated nature of the dark matter scattering may be determined in principle by comparing scattering rates on different detector nuclei, which in turn can reveal the dark matter mass. We will discuss the extent to which future experiments may be able to make such a determination.

  19. Einstein's Gravity and Dark Energy/Matter

    CERN Document Server

    Sarfatti, J

    2003-01-01

    Should Einstein's general relativity be quantized in the usual way even though it is not renormalizable the way the spin 1/2 lepto-quark - spin 1 gauge force boson local field theories are? Condensed matter theorists using P.W. Anderson's "More is different" approach, consistent with Andrei Sakharov's idea of "metric elasticity" with gravity emergent out of quantum electrodynamic zero point vacuum fluctuations, is the approach I take in this paper. The QED vacuum in globally-flat Minkowski space-time is unstable due to exchange of virtual photons between virtual electrons and positron "holes" near the -mc2 Fermi surface well inside the 2mc2 energy gap. This results in a non-perturbative emergence of both Einstein's gravity and a unified dark energy/dark matter w = -1 exotic vacuum zero point fluctuation field controlled by the local macro-quantum vacuum coherent field. The latter is a Bose-Einstein condensate of virtual off-mass-shell bound electron-positron pairs. The dark matter exotic vacuum phase with pos...

  20. Gravitational production of superheavy dark matter

    International Nuclear Information System (INIS)

    Chung, Daniel J. H.; Crotty, Patrick; Kolb, Edward W.; Riotto, Antonio

    2001-01-01

    The dark matter in the universe can be in the form of a superheavy matter species (wimpzilla). Several mechanisms have been proposed for the production of wimpzilla particles during or immediately following the inflationary epoch. Perhaps the most attractive mechanism is through gravitational particle production, where particles are produced simply as a result of the expansion of the universe. In this paper we present a detailed numerical calculation of wimpzilla gravitational production in hybrid-inflation models and natural-inflation models. Generalizing these findings, we also explore the dependence of the gravitational production mechanism on various models of inflation. We show that superheavy dark matter production seems to be robust, with Omega X h 2 ∼(M X /10 11 GeV) 2 (T RH /10 9 GeV), so long as M X I , where M X is the wimpzilla mass, T RH is the reheat temperature, and H I is the expansion rate of the universe during inflation

  1. The Subjective Well-Being Method of Valuation: An Application to General Health Status.

    Science.gov (United States)

    Brown, Timothy T

    2015-12-01

    To introduce the subjective well-being (SWB) method of valuation and provide an example by valuing health status. The SWB method allows monetary valuations to be performed in the absence of market relationships. Data are from the 1975-2010 General Social Survey. The value of health status is determined via the estimation of an implicit derivative based on a happiness equation. Two-stage least-squares was used to estimate happiness as a function of poor-to-fair health status, annual household income adjusted for household size, age, sex, race, marital status, education, year, and season. Poor-to-fair health status and annual household income are instrumented using a proxy for intelligence, a temporal version of the classic distance instrument, and the average health status of individuals who are demographically similar but geographically separated. Instrument validity is evaluated. Moving from good/excellent health to poor/fair health (1 year of lower health status) is equivalent to the loss of $41,654 of equivalized household income (2010 constant dollars) per annum, which is larger than median equivalized household income. The SWB method may be useful in making monetary valuations where fundamental market relationships are not present. © Health Research and Educational Trust.

  2. Conformal Gravity: Dark Matter and Dark Energy

    Directory of Open Access Journals (Sweden)

    Robert K. Nesbet

    2013-01-01

    Full Text Available This short review examines recent progress in understanding dark matter, dark energy, and galactic halos using theory that departs minimally from standard particle physics and cosmology. Strict conformal symmetry (local Weyl scaling covariance, postulated for all elementary massless fields, retains standard fermion and gauge boson theory but modifies Einstein–Hilbert general relativity and the Higgs scalar field model, with no new physical fields. Subgalactic phenomenology is retained. Without invoking dark matter, conformal gravity and a conformal Higgs model fit empirical data on galactic rotational velocities, galactic halos, and Hubble expansion including dark energy.

  3. Distinct optical chemistry of dissolved organic matter in urban pond ecosystems

    Czech Academy of Sciences Publication Activity Database

    McEnroe, N. A.; Williams, C. J.; Xenopoulos, M. A.; Porcal, Petr; Frost, P. C.

    2013-01-01

    Roč. 8, č. 11 (2013), e80334 E-ISSN 1932-6203 Institutional support: RVO:60077344 Keywords : dissolved organic matter * photodegradation * fluorescence * PARAFAC Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.534, year: 2013

  4. Microalbuminuria reflects a generalized transvascular albumin leakiness in clinically healthy subjects

    DEFF Research Database (Denmark)

    Jensen, J S; Borch-Johnsen, K; Jensen, G

    1995-01-01

    1. In epidemiological studies microalbuminuria, i.e. slightly elevated urinary albumin excretion rate, predicts increased atherosclerotic vascular morbidity and mortality. This study aimed to test the hypothesis that microalbuminuria in clinically healthy subjects is associated with a systemic...... transvascular albumin leakiness. In animal experiments the outflux of albumin and lipids to the arterial wall are highly correlated, and both are elevated in atherosclerosis. 2. All participants were recruited at random from a population-based epidemiological study, where the upper decile of urinary albumin...... excretion rate was 6.6 micrograms/min. Twenty-seven patients with persistent microalbuminuria (urinary albumin excretion rate 6.6-150 micrograms/min), and 56 age- and sex-matched control subjects with persistent normoalbuminuria (UAER

  5. Bulk viscosity in 2SC quark matter

    International Nuclear Information System (INIS)

    Alford, Mark G; Schmitt, Andreas

    2007-01-01

    The bulk viscosity of three-flavour colour-superconducting quark matter originating from the nonleptonic process u + s ↔ u + d is computed. It is assumed that up and down quarks form Cooper pairs while the strange quark remains unpaired (2SC phase). A general derivation of the rate of strangeness production is presented, involving contributions from a multitude of different subprocesses, including subprocesses that involve different numbers of gapped quarks as well as creation and annihilation of particles in the condensate. The rate is then used to compute the bulk viscosity as a function of the temperature, for an external oscillation frequency typical of a compact star r-mode. We find that, for temperatures far below the critical temperature T c for 2SC pairing, the bulk viscosity of colour-superconducting quark matter is suppressed relative to that of unpaired quark matter, but for T ∼> T c /30 the colour-superconducting quark matter has a higher bulk viscosity. This is potentially relevant for the suppression of r-mode instabilities early in the life of a compact star

  6. Objective and subjective evaluation of power plants and their non-radioactive emissions using the analytic hierarchy process

    International Nuclear Information System (INIS)

    Chatzimouratidis, Athanasios I.; Pilavachi, Petros A.

    2007-01-01

    Non-nuclear power plant emissions are of great concern to the public and to scientists alike. As energy demand tends to rise rapidly, especially in the developing countries, the negative effects to human health and to the environment from gaseous emissions together with hazardous particulate matter released by power plants can no longer be ignored. In this study, the impact of non-radioactive emissions is evaluated with the Analytic Hierarchy Process (AHP) by synthesizing objective and subjective criteria. There are five main emissions to be evaluated, non-methane volatile organic compounds (NMVOC), carbon dioxide equivalent (CO 2 -eq), nitrogen oxides (NO x ), sulphur dioxide (SO 2 ) and particulates or particulate matter (PM). Objective evaluation is achieved by expressing the impact of each emission released in monetary terms following generally accepted market rules, international agreements and protocols. That is, the Euro per kilogram of each emission exceeding a specific limit that should be paid as a penalty for environmental pollution and human health damage. Subjective assessment requires an intuitive expression of the percentage of damage to human health and to the ecosystem that each emission causes. Sensitivity analysis is then used in order to examine how change of input data affects final results. Finally, 10 main types of power plant are evaluated according to the level and kind of emissions they release. These types are coal/lignite, oil, natural gas turbine, natural gas combined cycle (NGCC), nuclear, hydro, wind, photovoltaic, biomass and geothermal

  7. Dose Matters: FDA's Guidance on Children's X-rays

    Science.gov (United States)

    ... Consumer Updates Dose Matters: FDA's Guidance on Children's X-rays Share Tweet Linkedin Pin it More sharing options ... exposure during medical procedures. The level of ionizing radiation from X-ray imaging is generally very low, but can ...

  8. Towards matter inflation in heterotic string theory

    International Nuclear Information System (INIS)

    Antusch, Stefan; Erdmenger, Johanna; Halter, Sebastian; Dutta, Koushik

    2011-02-01

    Recently, a class of inflation models in supergravity with gauge non-singlet matter fields as the inflaton has been proposed. It is based on a 'tribrid' structure in the superpotential and on a 'Heisenberg symmetry' for solving the η-problem. We suggest that a generalization of this model class may be suitable for realising inflation in heterotic orbifold compactifications, where the Heisenberg symmetry is a property of the tree-level Kaehler potential of untwisted matter fields. We discuss moduli stabilization in this setup and propose a mechanism to stabilize the modulus associated to the inflaton, which respects the symmetry in the large radius limit. Inflation ends via a waterfall phase transition, as in hybrid inflation. We give conditions which have to be satisfied for realising inflation along these lines in the matter sector of heterotic orbifolds. (orig.)

  9. Towards matter inflation in heterotic string theory

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan; Erdmenger, Johanna; Halter, Sebastian [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Dutta, Koushik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-02-15

    Recently, a class of inflation models in supergravity with gauge non-singlet matter fields as the inflaton has been proposed. It is based on a 'tribrid' structure in the superpotential and on a 'Heisenberg symmetry' for solving the {eta}-problem. We suggest that a generalization of this model class may be suitable for realising inflation in heterotic orbifold compactifications, where the Heisenberg symmetry is a property of the tree-level Kaehler potential of untwisted matter fields. We discuss moduli stabilization in this setup and propose a mechanism to stabilize the modulus associated to the inflaton, which respects the symmetry in the large radius limit. Inflation ends via a waterfall phase transition, as in hybrid inflation. We give conditions which have to be satisfied for realising inflation along these lines in the matter sector of heterotic orbifolds. (orig.)

  10. The Matter-Gravity Entanglement Hypothesis

    Science.gov (United States)

    Kay, Bernard S.

    2018-05-01

    I outline some of my work and results (some dating back to 1998, some more recent) on my matter-gravity entanglement hypothesis, according to which the entropy of a closed quantum gravitational system is equal to the system's matter-gravity entanglement entropy. The main arguments presented are: (1) that this hypothesis is capable of resolving what I call the second-law puzzle, i.e. the puzzle as to how the entropy increase of a closed system can be reconciled with the asssumption of unitary time-evolution; (2) that the black hole information loss puzzle may be regarded as a special case of this second law puzzle and that therefore the same resolution applies to it; (3) that the black hole thermal atmosphere puzzle (which I recall) can be resolved by adopting a radically different-from-usual description of quantum black hole equilibrium states, according to which they are total pure states, entangled between matter and gravity in such a way that the partial states of matter and gravity are each approximately thermal equilibrium states (at the Hawking temperature); (4) that the Susskind-Horowitz-Polchinski string-theoretic understanding of black hole entropy as the logarithm of the degeneracy of a long string (which is the weak string coupling limit of a black hole) cannot be quite correct but should be replaced by a modified understanding according to which it is the entanglement entropy between a long string and its stringy atmosphere, when in a total pure equilibrium state in a suitable box, which (in line with (3)) goes over, at strong-coupling, to a black hole in equilibrium with its thermal atmosphere. The modified understanding in (4) is based on a general result, which I also describe, which concerns the likely state of a quantum system when it is weakly coupled to an energy-bath and the total state is a random pure state with a given energy. This result generalizes Goldstein et al.'s `canonical typicality' result to systems which are not necessarily small.

  11. The Matter-Gravity Entanglement Hypothesis

    Science.gov (United States)

    Kay, Bernard S.

    2018-03-01

    I outline some of my work and results (some dating back to 1998, some more recent) on my matter-gravity entanglement hypothesis, according to which the entropy of a closed quantum gravitational system is equal to the system's matter-gravity entanglement entropy. The main arguments presented are: (1) that this hypothesis is capable of resolving what I call the second-law puzzle, i.e. the puzzle as to how the entropy increase of a closed system can be reconciled with the asssumption of unitary time-evolution; (2) that the black hole information loss puzzle may be regarded as a special case of this second law puzzle and that therefore the same resolution applies to it; (3) that the black hole thermal atmosphere puzzle (which I recall) can be resolved by adopting a radically different-from-usual description of quantum black hole equilibrium states, according to which they are total pure states, entangled between matter and gravity in such a way that the partial states of matter and gravity are each approximately thermal equilibrium states (at the Hawking temperature); (4) that the Susskind-Horowitz-Polchinski string-theoretic understanding of black hole entropy as the logarithm of the degeneracy of a long string (which is the weak string coupling limit of a black hole) cannot be quite correct but should be replaced by a modified understanding according to which it is the entanglement entropy between a long string and its stringy atmosphere, when in a total pure equilibrium state in a suitable box, which (in line with (3)) goes over, at strong-coupling, to a black hole in equilibrium with its thermal atmosphere. The modified understanding in (4) is based on a general result, which I also describe, which concerns the likely state of a quantum system when it is weakly coupled to an energy-bath and the total state is a random pure state with a given energy. This result generalizes Goldstein et al.'s `canonical typicality' result to systems which are not necessarily small.

  12. A galaxy lacking dark matter

    Science.gov (United States)

    van Dokkum, Pieter; Danieli, Shany; Cohen, Yotam; Merritt, Allison; Romanowsky, Aaron J.; Abraham, Roberto; Brodie, Jean; Conroy, Charlie; Lokhorst, Deborah; Mowla, Lamiya; O'Sullivan, Ewan; Zhang, Jielai

    2018-03-01

    Studies of galaxy surveys in the context of the cold dark matter paradigm have shown that the mass of the dark matter halo and the total stellar mass are coupled through a function that varies smoothly with mass. Their average ratio Mhalo/Mstars has a minimum of about 30 for galaxies with stellar masses near that of the Milky Way (approximately 5 × 1010 solar masses) and increases both towards lower masses and towards higher masses. The scatter in this relation is not well known; it is generally thought to be less than a factor of two for massive galaxies but much larger for dwarf galaxies. Here we report the radial velocities of ten luminous globular-cluster-like objects in the ultra-diffuse galaxy NGC1052–DF2, which has a stellar mass of approximately 2 × 108 solar masses. We infer that its velocity dispersion is less than 10.5 kilometres per second with 90 per cent confidence, and we determine from this that its total mass within a radius of 7.6 kiloparsecs is less than 3.4 × 108 solar masses. This implies that the ratio Mhalo/Mstars is of order unity (and consistent with zero), a factor of at least 400 lower than expected. NGC1052–DF2 demonstrates that dark matter is not always coupled with baryonic matter on galactic scales.

  13. Indirect detection of dark matter with γ rays.

    Science.gov (United States)

    Funk, Stefan

    2015-10-06

    The details of what constitutes the majority of the mass that makes up dark matter in the Universe remains one of the prime puzzles of cosmology and particle physics today-80 y after the first observational indications. Today, it is widely accepted that dark matter exists and that it is very likely composed of elementary particles, which are weakly interacting and massive [weakly interacting massive particles (WIMPs)]. As important as dark matter is in our understanding of cosmology, the detection of these particles has thus far been elusive. Their primary properties such as mass and interaction cross sections are still unknown. Indirect detection searches for the products of WIMP annihilation or decay. This is generally done through observations of γ-ray photons or cosmic rays. Instruments such as the Fermi large-area telescope, high-energy stereoscopic system, major atmospheric gamma-ray imaging Cherenkov, and very energetic radiation imaging telescope array, combined with the future Cherenkov telescope array, will provide important complementarity to other search techniques. Given the expected sensitivities of all search techniques, we are at a stage where the WIMP scenario is facing stringent tests, and it can be expected that WIMPs will be either be detected or the scenario will be so severely constrained that it will have to be rethought. In this sense, we are on the threshold of discovery. In this article, I will give a general overview of the current status and future expectations for indirect searches of dark matter (WIMP) particles.

  14. The Evaluation of the Outside Matter in Dictionary Reviews

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2009-01-01

    Reviewing dictionaries is part of the ongoing work in lexicography, and several lexi­cographers have discussed the process and guidelines for reviews published in academic journals. However, few have addressed the evaluation of the outside matter and, if so, only in a cursory way. This article...... examines the evaluation of the outside matter in reviews published in Lexikos with a view to proposing some general principles for reviewing outer texts in printed and electronic dictionaries. The study shows that reviewers define the review object differently, some excluding the outside matter altogether......, and that the way in which the outside matter is assessed differs within and between reviews. It is proposed that the separate sections of dictionaries should not only be examined independently but that their relationship to each other should also be evaluated so as to represent faithfully the lexicographic...

  15. STRANGE BARYONIC MATTER AND KAON CONDENSATION

    Czech Academy of Sciences Publication Activity Database

    Gazda, Daniel; Friedman, E.; Gal, A.; Mareš, Jiří

    2011-01-01

    Roč. 26, 3-4 (2011), s. 567-569 ISSN 0217-751X. [11th International Workshop on Meson Production, Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/09/1441 Institutional research plan: CEZ:AV0Z10480505 Keywords : (K)over-bar-nuclear bound states * strange baryonic matter * kaon condensation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.053, year: 2011

  16. Nuclear matter in all its states

    International Nuclear Information System (INIS)

    Bonche, P.; Cugnon, J.; Babinet, R.; Mathiot, J.F.; Van Hove, L.; Buenerd, M.; Galin, J.; Lemaire, M.C.; Meyer, J.

    1986-01-01

    This report includes the nine lectures which have been presented at the Joliot-Curie School of Nuclear Physics in 1985. The subjects covered are the following: thermodynamic description of excited nuclei; heavy ion reactions at high energy (theoretical approach); heavy ion reactions at high energy (experimental approach); relativistic nuclear physics and quark effects in nuclei; quark matter; nuclear compressibility and its experimental determinations; hot nuclei; anti p-nucleus interaction; geant resonances at finite temperature [fr

  17. 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

  18. 28 CFR 79.70 - Attorney General's delegation of authority.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Attorney General's delegation of... RADIATION EXPOSURE COMPENSATION ACT Procedures § 79.70 Attorney General's delegation of authority. (a) An... claim filed under the Act, and otherwise act on behalf of the Attorney General in all other matters...

  19. BCS-BEC crossover in dense relativistic matter: Collective excitations

    Czech Academy of Sciences Publication Activity Database

    Brauner, Tomáš

    2008-01-01

    Roč. 77, č. 9 (2008), 096006/1-096006/11 ISSN 1550-7998 R&D Projects: GA ČR GA202/06/0734 Institutional research plan: CEZ:AV0Z10480505 Keywords : quark matter * dynamical model * gross-neveu Subject RIV: BE - Theoretical Physics Impact factor: 5.050, year: 2008

  20. 28 CFR 600.2 - Alternatives available to the Attorney General.

    Science.gov (United States)

    2010-07-01

    ... GENERAL POWERS OF SPECIAL COUNSEL § 600.2 Alternatives available to the Attorney General. When matters are brought to the attention of the Attorney General that might warrant consideration of appointment of a Special Counsel, the Attorney General may: (a) Appoint a Special Counsel; (b) Direct that an initial...

  1. Possible constraints on SUSY-model parameters from direct dark matter search

    International Nuclear Information System (INIS)

    Bednyakov, V.A.; Kovalenko, S.G.

    1993-01-01

    We consider the SUSY-model neutralino as a dominant Dark Matter particle in the galactic halo and investigate some general issues of direct DM searches via elastic neutralino-nucleus scattering. On the basis of conventional assumptions about the nuclear and nucleon structure, without referring to a specific SUSY-model, we prove that it is impossible in principle to extract more than three constrains on fundamental SUSY-model parameters from the direct Dark Matter searches. Three types of Dark Matter detector probing different groups of parameters are recognized. 21 refs., 1 tab

  2. e-IQ and IQ knowledge mining for generalized LDA

    Science.gov (United States)

    Jenkins, Jeffrey; van Bergem, Rutger; Sweet, Charles; Vietsch, Eveline; Szu, Harold

    2015-05-01

    How can the human brain uncover patterns, associations and features in real-time, real-world data? There must be a general strategy used to transform raw signals into useful features, but representing this generalization in the context of our information extraction tool set is lacking. In contrast to Big Data (BD), Large Data Analysis (LDA) has become a reachable multi-disciplinary goal in recent years due in part to high performance computers and algorithm development, as well as the availability of large data sets. However, the experience of Machine Learning (ML) and information communities has not been generalized into an intuitive framework that is useful to researchers across disciplines. The data exploration phase of data mining is a prime example of this unspoken, ad-hoc nature of ML - the Computer Scientist works with a Subject Matter Expert (SME) to understand the data, and then build tools (i.e. classifiers, etc.) which can benefit the SME and the rest of the researchers in that field. We ask, why is there not a tool to represent information in a meaningful way to the researcher asking the question? Meaning is subjective and contextual across disciplines, so to ensure robustness, we draw examples from several disciplines and propose a generalized LDA framework for independent data understanding of heterogeneous sources which contribute to Knowledge Discovery in Databases (KDD). Then, we explore the concept of adaptive Information resolution through a 6W unsupervised learning methodology feedback system. In this paper, we will describe the general process of man-machine interaction in terms of an asymmetric directed graph theory (digging for embedded knowledge), and model the inverse machine-man feedback (digging for tacit knowledge) as an ANN unsupervised learning methodology. Finally, we propose a collective learning framework which utilizes a 6W semantic topology to organize heterogeneous knowledge and diffuse information to entities within a society in

  3. 39 CFR 3.4 - Matters reserved for decision by the Governors.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Matters reserved for decision by the Governors. 3... removal of the Postmaster General, 39 U.S.C. 202(c). (b) Appointment, term of service, and removal of the Deputy Postmaster General (by the Governors and the Postmaster General, 39 U.S.C. 202(d)); pay of the...

  4. Treatment options for subjective tinnitus: Self reports from a sample of general practitioners and ENT physicians within Europe and the USA

    Directory of Open Access Journals (Sweden)

    Hall Deborah A

    2011-11-01

    Full Text Available Abstract Background Tinnitus affects about 10-15% of the general population and risks for developing tinnitus are rising through increased exposure to leisure noise through listening to personal music players at high volume. The disorder has a considerable heterogeneity and so no single mechanism is likely to explain the presence of tinnitus in all those affected. As such there is no standardized management pathway nor singly effective treatment for the condition. Choice of clinical intervention is a multi-factorial decision based on many factors, including assessment of patient needs and the healthcare context. The present research surveyed clinicians working in six Westernized countries with the aims: a to establish the range of referral pathways, b to evaluate the typical treatment options for categories of subjective tinnitus defined as acute or chronic, and c to seek clinical opinion about levels of satisfaction with current standards of practice. Methods A structured online questionnaire was conducted with 712 physicians who reported seeing at least one tinnitus patients in the previous three months. They were 370 general practitioners (GPs and 365 ear-nose-throat specialists (ENTs from the US, Germany, UK, France, Italy and Spain. Results Our international comparison of health systems for tinnitus revealed that although the characteristics of tinnitus appeared broadly similar across countries, the patient's experience of clinical services differed widely. GPs and ENTs were always involved in referral and management to some degree, but multi-disciplinary teams engaged either neurology (Germany, Italy and Spain or audiology (UK and US professionals. For acute subjective tinnitus, pharmacological prescriptions were common, while audiological and psychological approaches were more typical for chronic subjective tinnitus; with several specific treatment options being highly country specific. All therapy options were associated with low levels

  5. The role of white matter lesions in cognitive impairment of vascular origin

    International Nuclear Information System (INIS)

    Kazakov, D.

    2003-01-01

    Abnormalities involving the cerebral white matter, in particular the centrum semiovale, are a subject of great current interest. Partly this is because modern neuroimaging methods detect white matter changes with increasing frequency in persons older than 60 years and also because these abnormalities may be associated with specific neuro behavioral deficits, including cognitive impairment. The significance of these changes, as well as their pathophysiological background is incompletely understood. The aim of this paper is to critically review the existing knowledge about the role of the white matter lesions, based on the critical analysis of over 100 publications (most appearing in the last decade). (author)

  6. Strong light-matter interaction in graphene - Invited talk

    DEFF Research Database (Denmark)

    Xiao, Sanshui

    Graphene has attracted lots of attention due to its remarkable electronic and optical properties, thus providing great promise in photonics and optoelectronics. However, the performance of these devices is generally limited by the weak light-matter interaction in graphene. The combination...

  7. The generalized second law of thermodynamics in generalized gravity theories

    International Nuclear Information System (INIS)

    Wu Shaofeng; Yang Guohong; Wang Bin; Zhang Pengming

    2008-01-01

    We investigate the generalized second law of thermodynamics (GSL) in generalized theories of gravity. We examine the total entropy evolution with time including the horizon entropy, the non-equilibrium entropy production, and the entropy of all matter, field and energy components. We derive a universal condition to protect the generalized second law and study its validity in different gravity theories. In Einstein gravity (even in the phantom-dominated universe with a Schwarzschild black hole), Lovelock gravity and braneworld gravity, we show that the condition to keep the GSL can always be satisfied. In f(R) gravity and scalar-tensor gravity, the condition to protect the GSL can also hold because the temperature should be positive, gravity is always attractive and the effective Newton constant should be an approximate constant satisfying the experimental bounds

  8. The power of general relativity

    International Nuclear Information System (INIS)

    Clifton, Timothy; Barrow, John D.

    2005-01-01

    We study the cosmological and weak-field properties of theories of gravity derived by extending general relativity by means of a Lagrangian proportional to R 1+δ . This scale-free extension reduces to general relativity when δ→0. In order to constrain generalizations of general relativity of this power class, we analyze the behavior of the perfect-fluid Friedmann universes and isolate the physically relevant models of zero curvature. A stable matter-dominated period of evolution requires δ>0 or δ -19 assuming that Mercury follows a timelike geodesic. The combination of these observational constraints leads to the overall bound 0≤δ -19 on theories of this type

  9. The Brans-Dicke gravity as a theory of dark matter

    International Nuclear Information System (INIS)

    Kim, Hongsu

    2010-01-01

    The pure Brans-Dicke (BD) gravity with or without the cosmological constant Λ has been taken as a model theory for dark matter. Indeed, there has been a consensus that unless one modifies either the standard theory of gravity, namely, general relativity, or the standard model for particle physics, or both, one can never achieve a satisfying understanding of the phenomena associated with dark matter and dark energy. Along this line, our dark matter model in this work can be thought of as an attempt to modify the gravity side alone in the simplest fashion to achieve the goal. Among others, it is demonstrated that our model theory can successfully predict the emergence of a dark matter halo-like configuration in terms of a self-gravitating spacetime solution to the BD field equations and reproduce the flattened rotation curve in this dark halo-like object in terms of the non-trivial energy density of the BD scalar field, which was absent in the context of general relativity, where Newton's constant is strictly a 'constant' having no dynamics. Our model theory, however, is not entirely without flaw, such as the prediction of relativistic jets in all types of galaxies, which actually is not the case.

  10. The interaction between dark energy and dark matter

    International Nuclear Information System (INIS)

    He Jianhua; Wang Bin

    2010-01-01

    In this review we first present a general formalism to study the growth of dark matter perturbations in the presence of interactions between dark matter(DM) and dark energy(DE). We also study the signature of such interaction on the temperature anisotropies of the large scale cosmic microwave background (CMB). We find that the effect of such interaction has significant signature on both the growth of dark matter structure and the late Integrated Sachs Wolfe effect(ISW). We further discuss the potential possibility to detect the coupling by cross-correlating CMB maps with tracers of the large scale structure. We finally confront this interacting model with WMAP 5-year data as well as other data sets. We find that in the 1σ range, the constrained coupling between dark sectors can solve the coincidence problem.

  11. Status of Suspended Particulate Matters Pollution at Traditional Markets in Makassar City

    Science.gov (United States)

    Suryani, Sri; Fahrunnisa

    2018-03-01

    Research on the status of suspended particulate matters pollution in four traditional markets located in Makassar city has been done. The purpose of this research is to know the air quality in the traditional market areas, especially caused by suspended particulate matters. The background of this research is because traders who trade in traditional markets generally peddle their goods along dusty roads and suspended particulate matters in dust can be inhaled when the vehicle passes. These suspended particulate matters pollutant can cause lung diseases. The results showed that the level of suspended particulate matters pollution fluctuates every year depending on the local wind speed, humidity, and temperature. Research results also showed the values were over the standard value according to the governor of South Sulawesi regulation.

  12. Matter couplings in Horava-Lifshitz theories and their cosmological applications

    International Nuclear Information System (INIS)

    Carloni, Sante; Elizalde, Emilio; Silva, Pedro J

    2011-01-01

    In this paper, the issue of how to introduce matter in Horava-Lifshitz theories of gravity is addressed. This is a key point in order to complete the proper definition of these theories and, more importantly, to study their possible phenomenological implications. As is well known, in Horava-Lifshitz gravity, the breakdown of Lorentz invariance invalidates the usual notion of minimally coupled matter. Two different approaches to bypass this problem are described here. One is based on a Kaluza-Klein reinterpretation of the 3+1 decomposition of the gravity degrees of freedom, which naturally leads to a definition of a U(1) gauge symmetry and, hence, to a new type of minimal coupling. The other approach relies on a midi-superspace formalism and the subsequent parametrization of the matter stress-energy tensor in terms of deep infrared variables. Using the last option, the phase space of Horava-Lifshitz cosmology in the presence of general matter couplings is studied. It is found, in particular, that the equation of state of the effective matter may be very different from the actual matter one, owing to the nonlinear interactions which exist between matter and gravity.

  13. Matter wave interferometry in the light of Schroedinger's wave mechanics

    International Nuclear Information System (INIS)

    1987-01-01

    This is a pre-conference abstracts collection for 67 oral presentations and posters, 62 of them are in INIS scope and are treated individually. The subject matters are interferometers (mainly neutron), interferometry experiments and the related interpretation - and epistemological problems of quantum theory. (qui)

  14. Soft matter food physics--the physics of food and cooking.

    Science.gov (United States)

    Vilgis, Thomas A

    2015-12-01

    This review discusses the (soft matter) physics of food. Although food is generally not considered as a typical model system for fundamental (soft matter) physics, a number of basic principles can be found in the interplay between the basic components of foods, water, oil/fat, proteins and carbohydrates. The review starts with the introduction and behavior of food-relevant molecules and discusses food-relevant properties and applications from their fundamental (multiscale) behavior. Typical food aspects from 'hard matter systems', such as chocolates or crystalline fats, to 'soft matter' in emulsions, dough, pasta and meat are covered and can be explained on a molecular basis. An important conclusion is the point that the macroscopic properties and the perception are defined by the molecular interplay on all length and time scales.

  15. CP violation and the matter-antimatter asymmetry of the Universe

    International Nuclear Information System (INIS)

    Hambye, T.

    2012-01-01

    In our everyday environment one observes only matter. That is quite a fortunate situation... Any sizeable presence of antimatter on Earth, from the enormous energy it would release through annihilation with matter, would prevent us talking about it. For the physicist this fact, at first sight obvious, is nevertheless a kind of surprise: antimatter, which is observed in cosmic rays, in radioactive decays of nuclei, which has been copiously produced and extensively studied in accelerators and which is nowadays currently used in hospitals, turns out to have pretty much the same properties as matter. Moreover, the fact that matter dominates appears to be a general property of our Universe: no evidence of large quantities of antimatter has been observed at any distance from us. Why would matter have taken the advantage on antimatter? In this short review we explain how, through a limited number of basic elements, one can find answers to this question. Matter and antimatter have, in fact, not exactly the same properties: from laboratory experiments CP conservation is known not to be a fundamental law of nature. (author)

  16. Chemical characterization and sources of personal exposure to fine particulate matter in the general population of Guangzhou, China

    Science.gov (United States)

    Chen, Xiao-Cui; Jahn, Heiko J.; Engling, Guenter; Ward, Tony J.; Kraemer, Alexander; Ho, Kin-Fai; Hung-Lam Yim, Steve; Chan, Chuen-Yu

    2017-04-01

    Fine particulate matter pollution severely deteriorates the environmental conditions and negatively impacts human health in the Chinese megacity Guangzhou. Concurrent ambient and personal measurements of fine particulate matter (PM2.5) were conducted in Guangzhou, China. Personal-to-ambient (P-C) relationships of PM2.5 chemical components were determined and sources of personal PM2.5 exposure were evaluated using principal component analysis along with a mixed-effects model. Water-soluble inorganic ions (mainly secondary inorganic ions) and anhydrosugars exhibited median personal-to-ambient (P/C) ratios < 1 accompanied by strong P-C correlations, indicating that these constituents in personal PM2.5 were significantly affected by ambient sources. Conversely, elemental carbon (EC) and calcium (Ca2+) showed median P/C ratios greater than unity, which indicated that among subjects who spent a great amount of time indoors, aside from particles of ambient origin, individual's total exposure to PM2.5 includes contributions of non-ambient exposure while indoors and outdoors (e.g., local traffic, indoor sources, personal activities). SO42- displayed very low coefficient of divergence (COD) values coupled with strong P-C correlations, implying a uniform distribution of SO42- in the urban area of Guangzhou. EC, Ca2+, and levoglucosan were otherwise heterogeneously distributed across individuals in different districts. Regional air pollution (50.4 ± 0.9%), traffic-related particles (8.6 ± 0.7%), dust-related particles (5.8 ± 0.7%), and biomass burning emissions (2.0 ± 0.2%) were moderate to high positive sources of personal PM2.5 exposure in Guangzhou. The observed positive and significant contribution of Ca2+ to personal PM2.5 exposure, highlighting indoor sources and/or personal activities, were driving factors determining personal exposure to dust-related particles. Considerable discrepancies (COD values ranging from 0.42 to 0.50) were shown between ambient

  17. Generalized pure Lovelock gravity

    Science.gov (United States)

    Concha, Patrick; Rodríguez, Evelyn

    2017-11-01

    We present a generalization of the n-dimensional (pure) Lovelock Gravity theory based on an enlarged Lorentz symmetry. In particular, we propose an alternative way to introduce a cosmological term. Interestingly, we show that the usual pure Lovelock gravity is recovered in a matter-free configuration. The five and six-dimensional cases are explicitly studied.

  18. The particulate matter dispersion studies from a local palm oil mill

    International Nuclear Information System (INIS)

    Abdullah, L.C.; Wong, L. L.; Amnorzahira, A.; Sa'ari, M.; Abdul Rashid, M. S.; Salmiaton Ali

    2006-01-01

    The appearance of industrial emissions and the degradation of scenic vistas are two characteristics of air pollution that humans object. Reduction in visibility suggests worsening pollution levels. The emissions from mobile source and stationary source are the major source of air pollutions contribution in Malaysia. Suspended particulate matter (SPM). The consequence of increasing the particulate concentrations, the particulate matter dissolves with vapour and grows into droplets when the humidity exceeds approximately 70% and causing opaque situation know as haze. This work focuses on the dispersion particulate matter from palm oil mill. The data obtained serves the purpose of modeling the transport of particulate matter for obtaining permits and prevention of significant deterioration (PSD) to the environment. Gaussian Plume Model from a point source, subject to various atmospheric conditions is used to calculate particulate matter concentration then display the distribution of plume dispersion using geographic information system (GIS). The calculated particulate matter concentration is evaluated using Transilient Matrice function. Atmospheric Stability, mixing height, wind direction, wind speed, natural and artificial features play an important role in dispersion process. High concentration area exhibits immediately under prevailing wind direction. (Author)

  19. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  20. Commission on Legal Matters

    CERN Multimedia

    Staff Association

    2016-01-01

    What is a commission within the Staff Association (SA)? A commission is a working group of the CERN Staff Council, led by a staff representative. The commission is composed mainly of staff representatives, but interested members of the SA can apply to participate in the work of a commission. What is the commission on legal matters? The commission on legal matters works on texts governing the employment conditions of staff (Employed Members of Personnel and Associated Members of Personnel). This covers legal documents such as the Staff Rules and Regulations, administrative and operational circulars, as well as any other document relating to employment conditions. How is the work organised in this commission? The revision process of the text is generally done along following lines: The HR department, and its legal experts, proposes new texts or modifications to existing texts. A schedule for the study of these texts is established each year and this calendar by the commission to plan its work. The new or modi...