Do you know DIS? a novel passive individual dosimeterd. Direct Ion Storage dosimeter DIS-1 officially approved in Switzerland

International Nuclear Information System (INIS)

Fiechtner, A.; Wernli, C.

2001-01-01

For individual monitoring film and TLD are the most often used types of dosimeters. On a smaller scale phosphate glasses and detectors based on optically stimulated luminescence (OSL) are also in use. As a new addition to the list of available personnel dosimeters the direct ion storage (DIS) system became legally approved for the first time in Switzerland. At the Paul Scherrer Institute (PSI) the RADOS dosimetry system DIS-1 is in official use since beginning of 2001. (orig.) [de

DisEpi: Compact Visualization as a Tool for Applied Epidemiological Research.

Science.gov (United States)

Benis, Arriel; Hoshen, Moshe

2017-01-01

Outcomes research and evidence-based medical practice is being positively impacted by proliferation of healthcare databases. Modern epidemiologic studies require complex data comprehension. A new tool, DisEpi, facilitates visual exploration of epidemiological data supporting Public Health Knowledge Discovery. It provides domain-experts a compact visualization of information at the population level. In this study, DisEpi is applied to Attention-Deficit/Hyperactivity Disorder (ADHD) patients within Clalit Health Services, analyzing the socio-demographic and ADHD filled prescription data between 2006 and 2016 of 1,605,800 children aged 6 to 17 years. DisEpi's goals facilitate the identification of (1) Links between attributes and/or events, (2) Changes in these relationships over time, and (3) Clusters of population attributes for similar trends. DisEpi combines hierarchical clustering graphics and a heatmap where color shades reflect disease time-trends. In the ADHD context, DisEpi allowed the domain-expert to visually analyze a snapshot summary of data mining results. Accordingly, the domain-expert was able to efficiently identify that: (1) Relatively younger children and particularly youngest children in class are treated more often, (2) Medication incidence increased between 2006 and 2011 but then stabilized, and (3) Progression rates of medication incidence is different for each of the 3 main discovered clusters (aka: profiles) of treated children. DisEpi delivered results similar to those previously published which used classical statistical approaches. DisEpi requires minimal preparation and fewer iterations, generating results in a user-friendly format for the domain-expert. DisEpi will be wrapped as a package containing the end-to-end discovery process. Optionally, it may provide automated annotation using calendar events (such as policy changes or media interests), which can improve discovery efficiency, interpretation, and policy implementation.

Intersectionality Dis/ability Research: How Dis/ability Research in Education Engages Intersectionality to Uncover the Multidimensional Construction of Dis/abled Experiences

Science.gov (United States)

Hernández-Saca, David I.; Gutmann Kahn, Laurie; Cannon, Mercedes A.

2018-01-01

The purpose of this chapter is to systematically review the research within the field of education that explicitly examined how various social constructions of identity intersect with dis/ability to qualitatively affect young adults' experiences by asking the following question: What are the key findings in education research focusing on youth and…

Physical entropy, information entropy and their evolution equations

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Inspired by the evolution equation of nonequilibrium statistical physics entropy and the concise statistical formula of the entropy production rate, we develop a theory of the dynamic information entropy and build a nonlinear evolution equation of the information entropy density changing in time and state variable space. Its mathematical form and physical meaning are similar to the evolution equation of the physical entropy: The time rate of change of information entropy density originates together from drift, diffusion and production. The concise statistical formula of information entropy production rate is similar to that of physical entropy also. Furthermore, we study the similarity and difference between physical entropy and information entropy and the possible unification of the two statistical entropies, and discuss the relationship among the principle of entropy increase, the principle of equilibrium maximum entropy and the principle of maximum information entropy as well as the connection between them and the entropy evolution equation.

DisVis: Visualizing Discussion Threads in Online Health Communities.

Science.gov (United States)

Nakikj, Drashko; Mamykina, Lena

2016-01-01

An increasing number of individuals turn to online health communities (OHC) for information, advice and support about their health condition or disease. As a result of users' active participation, these forums store overwhelming volumes of information, which can make access to this information challenging and frustrating. To help overcome this problem we designed a discussion visualization tool DisVis. DisVis includes features for overviewing, browsing and finding particular information in a discussion. In a between subjects study, we tested the impact of DisVis on individuals' ability to provide an overview of a discussion, find topics of interest and summarize opinions. The study showed that after using the tool, the accuracy of participants' answers increased by 68% (p-value = 0.023) while at the same time exhibiting trends for reducing the time to answer by 38% with no statistical significance (p-value = 0.082). Qualitative interviews showed general enthusiasm regarding tools for improving browsing and searching for information within discussion forums, suggested different usage scenarios, highlighted opportunities for improving the design of DisVis, and outlined new directions for visualizing user-generated content within OHCs.

Unitarized model of inclusive and diffractive DIS with Q2 evolution

International Nuclear Information System (INIS)

Armesto, Nestor; Salgado, Carlos A.; Tywoniuk, Konrad; Kaidalov, Alexei B.

2010-01-01

We discuss the interplay of low-x physics and QCD scaling violations by extending the unified approach describing inclusive structure functions and diffractive production in γ*p interactions proposed in previous papers to large values of Q 2 . We describe the procedure of extracting, from the nonperturbative model, initial conditions for the QCD evolution that respect unitarity. Assuming Regge factorization of the diffractive structure function, a similar procedure is proposed for the calculation of hard diffraction. The results are in good agreement with experimental data on the proton structure function F 2 and the most recent data on the reduced diffractive cross section, x P σ r D(3) . Predictions for both F 2 and F L are presented in a wide kinematical range and compared to calculations within high-energy QCD.

Adler Function, DIS sum rules and Crewther Relations

International Nuclear Information System (INIS)

Baikov, P.A.; Chetyrkin, K.G.; Kuehn, J.H.

2010-01-01

The current status of the Adler function and two closely related Deep Inelastic Scattering (DIS) sum rules, namely, the Bjorken sum rule for polarized DIS and the Gross-Llewellyn Smith sum rule are briefly reviewed. A new result is presented: an analytical calculation of the coefficient function of the latter sum rule in a generic gauge theory in order O(α s 4 ). It is demonstrated that the corresponding Crewther relation allows to fix two of three colour structures in the O(α s 4 ) contribution to the singlet part of the Adler function.

(Dis)organizing through imbrications of human and material agencies

DEFF Research Database (Denmark)

Tavella, Elena

and material agencies. However there is a lack of insight into how human and material agencies are imbricated during the emergence of (dis)order, and how different imbrications lead to (dis)order. This paper addresses this gap by presenting a content analysis of a book reporting the Battle of Stalingrad during...... World War II. Drawing on the theory of affordances, the author identifies how different materials were used by the German and Soviet armies to organize specific activities, and whether and how those activities led to order and/or disorder. The analysis suggests that soldiers used different materials...... to organize different activities within one and the same organizational context, which led to (dis)order. Whether order or disorder emerged was dependent on how human and material agencies were imbricated within the conduct of particular activities, and how they related to internal or external influencing...

On the production of clandestine dis/abled bodies

DEFF Research Database (Denmark)

Galis, Vasilis; Tzokas, Spyros; Tympas, Aristotle

paper makes a notice of this literature but moves on to discuss the co-production of technological borders and migrants with dis/abilities. In this case, dis/ability may be a cause or consequence of migration, and may become a barrier to both accessing protection and to entering a country. Nonetheless...... of policing technologies, repressive techniques and military technics. Instead, however, of staying at the technology of a fast patrolling boat with electronic eyes, we move on to show how exactly this EU electronic boat has clashed with a humble migrant floating device. We are interested...

3-dimensional interactive space (3DIS)

International Nuclear Information System (INIS)

Veitch, S.; Veitch, J.; West, S.J.

1991-01-01

This paper reports on the 3DIS security system which uses standard CCTV cameras to create 3-Dimensional detection zones around valuable assets within protected areas. An intrusion into a zone changes light values and triggers an alarm that is annunciated, while images from multiple cameras are recorded. 3DIS lowers nuisance alarm rates and provides superior automated surveillance capability. Performance is improved over 2-D systems because activity around, above or below the zone does to cause an alarm. Invisible 3-D zones protect assets as small as a pin or as large as a 747 jetliner. Detection zones are created by excising subspaces from the overlapping fields of view of two or more video cameras. Hundred of zones may co-exist, operating simultaneously. Intrusion into any 3-D zone will cause a coincidental change in light values, triggering an alarm specific to that space

Stellar Physics 2: Stellar Evolution and Stability

CERN Document Server

Bisnovatyi-Kogan, Gennady S

2011-01-01

"Stellar Physics" is a an outstanding book in the growing body of literature on star formation and evolution. Not only does the author, a leading expert in the field, very thoroughly present the current state of knowledge on stellar physics, but he handles with equal care the many problems that this field of research still faces. A bibliography with well over 1000 entries makes this book an unparalleled reference source. "Stellar Evolution and Stability" is the second of two volumes and can be read, as can the first volume "Fundamental Concepts and Stellar Equilibrium," as a largely independent work. It traces in great detail the evolution of protostars towards the main sequence and beyond this to the last stage of stellar evolution, with the corresponding vast range from white dwarfs to supernovae explosions, gamma-ray bursts and black hole formation. The book concludes with special chapters on the dynamical, thermal and pulsing stability of stars. This second edition is carefully updated in the areas of pre...

[(Dis)satisfaction with mental healthcare work: a study in Psychosocial Care Centers].

Science.gov (United States)

Guimarães, José Maria Ximenes; Jorge, Maria Salete Bessa; Assis, Marluce Maria Araújo

2011-04-01

The scope of this article is to analyze satisfaction in the workplace of mental healthcare professionals who serve in Psychosocial Care Centers (Caps). The research is of a qualitative nature and the data-collecting medium was semistructured interviews with 19 workers of three Caps in Fortaleza, in the Northern Brazilian State of Ceará. The treatment of the empirical material was based upon the analysis of content with an emphasis on the thematic bias. The results revealed the determinants of (dis)satisfaction present in the daily routine of these workers. The relationships established with the users were singled out as the main source of satisfaction, whereas the work and wage conditions were the main motives for dissatisfaction. In addition to these aspects, consequences of (dis)satisfaction at work in the private, social and organizational field of the workers' life in the Caps were revealed, mainly in physical and mental health. Lastly, they emphasized the urgent need for implementation - on the part of public administration - of strategies that seek to reduce the precariousness of healthcare work, especially in mental health, with a view to mitigating damages potentially caused by such work.

Evolution and non-equilibrium physics

DEFF Research Database (Denmark)

Becker, Nikolaj; Sibani, Paolo

2014-01-01

We argue that the stochastic dynamics of interacting agents which replicate, mutate and die constitutes a non-equilibrium physical process akin to aging in complex materials. Specifically, our study uses extensive computer simulations of the Tangled Nature Model (TNM) of biological evolution...

Exploring the diversity of conceptualizations of work (dis)ability: a scoping review of published definitions.

Science.gov (United States)

Lederer, Valérie; Loisel, Patrick; Rivard, Michèle; Champagne, François

2014-06-01

Researchers are confronted to numerous definitions of work ability/disability, influenced by their context of emergence, discipline, purpose, underlying paradigm and relationship to time. This study provides an in-depth analysis of the concept through a systematic scoping review and the development of an integrative concept map of work (dis)ability. The research questions are: How has work (dis)ability been conceptualized from the perspectives of research, practice, policy and industry in the published scientific literature? How has the conceptualization of work (dis)ability evolved over time? A search strategy was designed with a library scientist to retrieve scientific publications containing explicit definition(s) of work (dis)ability in leading-edge databases. The screening and the extraction of the definitions were achieved by duplicate assessment. The definitions were subject to a comparative analysis based on the grounded theory approach. In total, 423 abstracts were retrieved from the bibliographic databases. After removing duplicates, 280 unique records were screened for inclusion. A final set of 115 publications containing unique original conceptual definitions served as basis for analysis. The scientific literature does not reflect a shared, integrated vision of the exact nature and dimensions of work (dis)ability. However, except for a few definitions, there seems to be a consensus that work (dis)ability is a relational concept resulting from the interaction of multiple dimensions that influence each other through different ecological levels. The conceptualization of work (dis)ability also seems to have become more dynamic over time. The way work (dis)ability is defined has important implications for research, compensation and rehabilitation.

Why Do Smallholder Farmers Dis-adopt Conservation Agriculture? Insights from Malawi

Science.gov (United States)

Chinseu, Edna; Dougill, Andrew; Stringer, Lindsay

2017-04-01

International donors and advisory bodies, national governments and non-governmental organisations (NGOs) are all actively promoting conservation agriculture (CA) as a route to sustainable agricultural development, recognising the importance of agriculture to the national economy and livelihoods of rural communities. CA is anchored in 3 principles: i) minimum soil disturbance, ii) continuous soil cover and iii) crop associations. It is advocated on the basis of improving crop yields, income and/or profits; reducing production costs; and conserving soil and water. Despite huge investments made by CA proponents, many farmers only practice CA for a short time. They subsequently dis-adopt (abandon) the seemingly appropriate innovation and revert back to conventional tillage practices. While factors affecting the (initial) adoption of agricultural technologies have been studied extensively, dis-adoption has rarely been investigated. Improving our understanding of dis-adoption of seemingly appropriate and sustainable interventions is vital for long-term sustainable land management, food security and for ensuring sustained impacts of agricultural development project interventions more broadly. This research investigates why smallholder farmers abandon CA practices in Malawi by exploring farmers' experiences of CA and their implications in dis-adoption. A mixed methods approach was used, involving household questionnaire survey and focus group discussions with smallholder farmers. Findings reveal that reasons for dis-adoption are multi-dimensional and multi-layered. While CA proponents are marketing CA as a time saving, labour saving and yield improving technology, many farmers report contrary experiences. Findings also showed that farmers lacked ownership of CA projects and encountered various social challenges, which coupled with unfulfilled expectations, led to dis-adoption. In sub-Saharan Africa, this suggests that there is a need to: (1) market CA as a climate

Di-jet production and angular correlations in DIS at NLO

International Nuclear Information System (INIS)

Jaliflian-Marian, J.

2016-01-01

Angular correlations are a sensitive probe of the dynamics of QCD at high energy. In particular azimuthal angular correlations between two hadrons produced in Deeply Inelastic Scattering (DIS) of a virtual photon on a hadron or nucleus offer the best environment in which to investigate high gluon density (gluon saturation) effects expected to arise at small x. Here we give a progress report on our derivation of Next to Leading Order (NLO) corrections to di-jet (di-hadron) production in DIS. (author)

Physics results from polarized DIS

International Nuclear Information System (INIS)

Ramsey, G. P.

1998-01-01

We have extracted polarized nucleon distributions from recent data at CERN, SLAC and DESY. The flavor-dependent valence and sea quark spin distributions are determined for each experiment. We take into account possible differences in the up and down sea distributions, and assume that the strange sea contribution is suppressed by mass effects. Physics results determined from different experiments are compared, including higher order corrections

Physics results from polarized DIS.

Energy Technology Data Exchange (ETDEWEB)

Ramsey, G. P.

1998-03-23

We have extracted polarized nucleon distributions from recent data at CERN, SLAC and DESY. The flavor-dependent valence and sea quark spin distributions are determined for each experiment. We take into account possible differences in the up and down sea distributions, and assume that the strange sea contribution is suppressed by mass effects. Physics results determined from different experiments are compared, including higher order corrections.

Description of the evolution of nonconservative physics

International Nuclear Information System (INIS)

Fronteau, J.

1979-01-01

The objective of this paper is to outline some applications of nonconservative forces in physics, with particular reference to thermodynamics. After some generalities on particle optics, the author points out that the fundamental tool in this field, namely Liouville's theorem, has a much wider bearing than is currently believed, applicable indeed as it is to any dynamical system, conservative or not. The importance of the Jacobian of evolution, which governs the time evolution of the measure in the dynamical space studied, leads the author to justify the introduction of the concept of fine entropy associated to any particle of the system. He shows in fact how this notion allows us to build, on a dissipative basis (purely dissipative to begin with) a thermodynamical theory of evolutive phenomena. He insists on the necessity, for him, to consider the evolutive aspect of phenomena as primordial, with regards to the probabilistic aspect. A short incursion into Quantum Mechanics lays once again insistance on the necessity to study evolution whereever it appears. The author comes finally back to fine Thermodynamics and shows that it admits a relativistic covariant extension, compatible with macroscopic relativistic Thermodynamics. The connection between the physical ideas presented in this work and recent studies on strong nonconservative interactions is indicated in the Foreword

The physics of evolution

Science.gov (United States)

Eigen, Manfred

1988-12-01

The Darwinian concept of evolution through natural selection has been revised and put on a solid physical basis, in a form which applies to self-replicable macromolecules. Two new concepts are introduced: sequence space and quasi-species. Evolutionary change in the DNA- or RNA-sequence of a gene can be mapped as a trajectory in a sequence space of dimension ν, where ν corresponds to the number of changeable positions in the genomic sequence. Emphasis, however, is shifted from the single surviving wildtype, a single point in the sequence space, to the complex structure of the mutant distribution that constitutes the quasi-species. Selection is equivalent to an establishment of the quasi-species in a localized region of sequence space, subject to threshold conditions for the error rate and sequence length. Arrival of a new mutant may violate the local threshold condition and thereby lead to a displacement of the quasi-species into a different region of sequence space. This transformation is similar to a phase transition; the dynamical equations that describe the quase-species have been shown to be analogous to those of the two-dimensional Ising model of ferromagnetism. The occurrence of a selectively advantageous mutant is biased by the particulars of the quasi-species distribution, whose mutants are populated according to their fitness relative to that of the wild-type. Inasmuch as fitness regions are connected (like mountain ridges) the evolutionary trajectory is guided to regions of optimal fitness. Evolution experiments in test tubes confirm this modification of the simple chance and law nature of the Darwinian concept. The results of the theory can also be applied to the construction of a machine that provides optimal conditions for a rapid evolution of functionally active macromolecules. An introduction to the physics of molecular evolution by the author has appeared recently.1 Detailed studies of the kinetics and mechanisms of replication of RNA, the most

Final-state interaction in semi-inclusive DIS off nuclei

CERN Document Server

Ciofi degli Atti, C

2003-01-01

The Final-State Interaction (FSI) in Deep-Inelastic Scattering (DIS) of leptons off a nucleus A, due to the propagation of the struck nucleon debris and its hadronization in the nuclear environment is considered. The effective cross-section of such a partonic system with the nucleons of the medium and its time dependence are estimated, for different values of the Bjorken scaling variable, on the basis of a model which takes into account both the production of hadrons due to the breaking of the color string, which is formed after a quark is knocked out off a bound nucleon, as well as the production of hadrons originating from gluon radiation. It is shown that the interaction, the evolution and the hadronization of the partonic system in the nuclear environment can be thoroughly investigated by a new type of semi-inclusive process, denoted A(e,e'(A-1))X, in which the scattered lepton is detected in coincidence with a heavy nuclear fragment, namely a nucleus (A-1) in low energy and momentum states. As a matter o...

Dis3- and exosome subunit-responsive 3′ mRNA instability elements

International Nuclear Information System (INIS)

Kiss, Daniel L.; Hou, Dezhi; Gross, Robert H.; Andrulis, Erik D.

2012-01-01

Highlights: ► Successful use of a novel RNA-specific bioinformatic tool, RNA SCOPE. ► Identified novel 3′ UTR cis-acting element that destabilizes a reporter mRNA. ► Show exosome subunits are required for cis-acting element-mediated mRNA instability. ► Define precise sequence requirements of novel cis-acting element. ► Show that microarray-defined exosome subunit-regulated mRNAs have novel element. -- Abstract: Eukaryotic RNA turnover is regulated in part by the exosome, a nuclear and cytoplasmic complex of ribonucleases (RNases) and RNA-binding proteins. The major RNase of the complex is thought to be Dis3, a multi-functional 3′–5′ exoribonuclease and endoribonuclease. Although it is known that Dis3 and core exosome subunits are recruited to transcriptionally active genes and to messenger RNA (mRNA) substrates, this recruitment is thought to occur indirectly. We sought to discover cis-acting elements that recruit Dis3 or other exosome subunits. Using a bioinformatic tool called RNA SCOPE to screen the 3′ untranslated regions of up-regulated transcripts from our published Dis3 depletion-derived transcriptomic data set, we identified several motifs as candidate instability elements. Secondary screening using a luciferase reporter system revealed that one cassette—harboring four elements—destabilized the reporter transcript. RNAi-based depletion of Dis3, Rrp6, Rrp4, Rrp40, or Rrp46 diminished the efficacy of cassette-mediated destabilization. Truncation analysis of the cassette showed that two exosome subunit-sensitive elements (ESSEs) destabilized the reporter. Point-directed mutagenesis of ESSE abrogated the destabilization effect. An examination of the transcriptomic data from exosome subunit depletion-based microarrays revealed that mRNAs with ESSEs are found in every up-regulated mRNA data set but are underrepresented or missing from the down-regulated data sets. Taken together, our findings imply a potentially novel mechanism of m

Application of the Drilling Impact Study (DIS) to Forsmark groundwaters

International Nuclear Information System (INIS)

Gascoyne, Mel; Gurban, Ioana

2008-01-01

Characterisation of a geological formation as a repository for nuclear fuel waste requires deep drilling into the bedrock to gain an understanding of the geological structure, rock types, groundwater flow and the chemical composition of groundwater and the adjacent rock. The methods of characterisation from a hydrogeochemical point of view, might be affected by the various drilling activities and techniques for determining groundwater composition have been employed so that the composition can be corrected for these activities. SKB has developed and supported the Drilling Impact Study (DIS) project in which a tracer is used as an indicator of contamination to attempt to correct the groundwater composition for dilution or contamination by surface waters. The project began about five years ago with the intention of developing a routine method for determining the extent of contamination of borehole groundwater by drilling water. The main objectives of this work were: 1. Determine the extent of drilling water contamination in permeable zones in a test borehole on the Forsmark site. 2. Correct measured chemical compositions of the groundwaters based on contamination results. 3. Provide a workable methodology for routine correction of groundwater composition. 4. Apply the modified DIS model to suitable borehole zones at the Forsmark site in a systematic fashion 5. Determine uncertainties in DIS modelling. A memorandum was prepared by describing the characteristics of borehole KFM06 and its drilling history. Estimates were made of the amount of drilling water in permeable zones in the borehole and the various approaches to applying results of DIS were described and recommendations made, with an example calculation

Disability Critical Race Theory: Exploring the Intersectional Lineage, Emergence, and Potential Futures of DisCrit in Education

Science.gov (United States)

Annamma, Subini Ancy; Ferri, Beth A.; Connor, David J.

2018-01-01

In this review, we explore how intersectionality has been engaged with through the lens of disability critical race theory (DisCrit) to produce new knowledge. In this chapter, we (1) trace the intellectual lineage for developing DisCrit, (2) review the body of interdisciplinary scholarship incorporating DisCrit to date, and (3) propose the future…

Issues in leading particle and charm production in DIS at HERA

International Nuclear Information System (INIS)

Chekanov, S. V.

1999-01-01

A Monte Carlo simulation based on Ο(α s ) QCD matrix elements matched to parton showers shows that final-state hadrons in DIS can be used to tag events with a single (anti)quark recoiled against the proton. The method is particularly suited to study the mean charge of leading particles, which is sensitive to fragmentation and sea quark contribution to the proton structure function. They also discuss methods to study the charm production in DIS using the Breit frame

Dis-Equality: Exploring the Juxtaposition of Disability and Equality

Directory of Open Access Journals (Sweden)

Bronagh Byrne

2018-03-01

Full Text Available The (inequality issues facing disabled people are extensive and long-enduring. The way(s in which equality is conceptualised has important consequences for understandings of disability. The ambiguity of what I call dis-equality theory is two-fold; the apparent failure of mainstream equality theorising in, firstly, embracing disability concepts at all, and secondly, in fully incorporating the logistics of disability, particularly in relation to the social construction of such. Practices of institutional and more complex forms of discrimination are part of those deeper structures of domination and oppression which maintain disabled people in positions of disadvantage. Everyday practices, in the ‘ordinary order of things’ (Bourdieu, 2000, continue to be misrecognised as natural and taken for granted. This article critically explores the complexity of dis-equality theorising utilising a Bourdieusian lens which explicitly incorporates complex and subtle forms of discrimination, and by examining the UN Convention on the Rights of Persons with Disabilities’ approach to equality. I argue that the way forward for dis-equality theorising in today’s rights based era must be one that considers the nuances of the ‘rules of the game’ (Young, 1990 if it is to be effective in challenging the inequalities to which disabled people have long been subject.

A socio-cultural reframing of science and dis/ability in education: past problems, current concerns, and future possibilities

Science.gov (United States)

Connor, David J.; Valle, Jan W.

2015-12-01

In this article we assert the value of a socio-cultural reframing of science and dis/ability in education. We begin by problematizing current issues in education pertaining to the often-unquestioned concept of dis/ability and the impact that has upon research, theory, practice, and policy. As our topic is broad, we have chosen to focus upon four interconnected areas: (1) the historical mistrust of science and pseudo-science by people with dis/abilities; (2) the pervasive use of pseudo-science within the contemporary field of special education; (3) the use of dis/ability studies in education (DSE) to provide a contrast between a traditional positivist framing and a socio-cultural framing of dis/ability, and; (4) a brief exploration of what a DSE/socio-cultural grounding looks like for both schools and classroom teachers. In sum, our intention is to engage science educators to reject deficit-notions of dis/ability in favor of understanding it as part of human variation, and consider the personal and professional benefits of this shift.

[Estimation of cost-saving for reducing radioactive waste from nuclear medicine facilities by implementing decay in storage (DIS) in Japan].

Science.gov (United States)

Kida, Tetsuo; Hiraki, Hitoshi; Yamaguchi, Ichirou; Fujibuchi, Toshioh; Watanabe, Hiroshi

2012-01-01

DIS has not yet been implemented in Japan as of 2011. Therefore, even if risk was negligible, medical institutions have to entrust radioactive temporal waste disposal to Japan Radio Isotopes Association (JRIA) in the current situation. To decide whether DIS should be implemented in Japan or not, cost-saving effect of DIS was estimated by comparing the cost that nuclear medical facilities pay. By implementing DIS, the total annual cost for all nuclear medical facilities in Japan is estimated to be decreased to 30 million yen or less from 710 million yen. DIS would save 680 million yen (96%) per year.

Estimation of cost-saving for reducing radioactive waste from nuclear medicine facilities by implementing decay in storage (DIS) in Japan

International Nuclear Information System (INIS)

Kida, Tetsuo; Hiraki, Hitoshi; Yamaguchi, Ichirou; Fujibuchi, Toshioh; Watanabe, Hiroshi

2012-01-01

DIS has not yet been implemented in Japan as of 2011. Therefore, even if risk was negligible, medical institutions have to entrust radioactive temporal waste disposal to Japan Radio Isotopes Association (JRIA) in the current situation. To decide whether DIS should be implemented in Japan or not, cost-saving effect of DIS was estimated by comparing the cost that nuclear medical facilities pay. By implementing DIS, the total annual cost for all nuclear medical facilities in Japan is estimated to be decreased to 30 million yen or less from 710 million yen. DIS would save 680 million yen (96%) per year. (author)

Radiological accidents: methodologies of radio nuclides dis incorporation; Accidentes radiologicos: metodologias de desincorporacion de radionuclidos

Energy Technology Data Exchange (ETDEWEB)

Jimenez F, E. A. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Cortes, A., E-mail: lydia.paredes@inin.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

2014-08-15

Derived of the radioactive or nuclear material management, exists the risk that accidents can happen where people cases are presented with internal radioactive contamination, who will receive specialized medical care to accelerate the radioactive dis incorporation with the purpose of diminishing the absorbed dose and the associate biological effects. In this work treatments of radioactive dis incorporation were identified, in function of the radionuclide, radiation type, radioactive half life, biological half life, critical organ, ingestion duct and patient type. The factor time is decisive for the effectiveness of the selected treatment in the blockade stage (before the accident) or dis incorporation (after the accident); this factor is related with the radioactive and biological half lives. So to achieve dis incorporation efficiencies of more to 70%, the patient clinical treatment will begin before the first third of the biological half life of the radionuclide that generated the internal contamination. (Author)

The Microbial DNA Index System (MiDIS): A tool for microbial pathogen source identification

Energy Technology Data Exchange (ETDEWEB)

Velsko, S. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2010-08-09

The microbial DNA Index System (MiDIS) is a concept for a microbial forensic database and investigative decision support system that can be used to help investigators identify the sources of microbial agents that have been used in a criminal or terrorist incident. The heart of the proposed system is a rigorous method for calculating source probabilities by using certain fundamental sampling distributions associated with the propagation and mutation of microbes on disease transmission networks. This formalism has a close relationship to mitochondrial and Y-chromosomal human DNA forensics, and the proposed decision support system is somewhat analogous to the CODIS and SWGDAM mtDNA databases. The MiDIS concept does not involve the use of opportunistic collections of microbial isolates and phylogenetic tree building as a basis for inference. A staged approach can be used to build MiDIS as an enduring capability, beginning with a pilot demonstration program that must meet user expectations for performance and validation before evolving into a continuing effort. Because MiDIS requires input from a a broad array of expertise including outbreak surveillance, field microbial isolate collection, microbial genome sequencing, disease transmission networks, and laboratory mutation rate studies, it will be necessary to assemble a national multi-laboratory team to develop such a system. The MiDIS effort would lend direction and focus to the national microbial genetics research program for microbial forensics, and would provide an appropriate forensic framework for interfacing to future national and international disease surveillance efforts.

Polarized 3 parton production in inclusive DIS at small x

Energy Technology Data Exchange (ETDEWEB)

Ayala, Alejandro [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, Ciudad de México 04510 (Mexico); Centre for Theoretical and Mathematical Physics, and Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Hentschinski, Martin, E-mail: hentschinski@correo.nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, Ciudad de México 04510 (Mexico); Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Puebla 1152 (Mexico); Jalilian-Marian, Jamal [Department of Natural Sciences, Baruch College, CUNY, 17 Lexington Avenue, New York, NY 10010 (United States); CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016 (United States); Tejeda-Yeomans, Maria Elena [Departamento de Física, Universidad de Sonora, Boulevard Luis Encinas J. y Rosales, Colonia Centro, Hermosillo, Sonora 83000 (Mexico)

2016-10-10

Azimuthal angular correlations between produced hadrons/jets in high energy collisions are a sensitive probe of the dynamics of QCD at small x. Here we derive the triple differential cross section for inclusive production of 3 polarized partons in DIS at small x. The target proton or nucleus is described using the Color Glass Condensate (CGC) formalism. The resulting expressions are used to study azimuthal angular correlations between produced partons in order to probe the gluon structure of the target hadron or nucleus. Our analytic expressions can also be used to calculate the real part of the Next to Leading Order (NLO) corrections to di-hadron production in DIS by integrating out one of the three final state partons.

Polarized 3 parton production in inclusive DIS at small x

International Nuclear Information System (INIS)

Ayala, Alejandro; Hentschinski, Martin; Jalilian-Marian, Jamal; Tejeda-Yeomans, Maria Elena

2016-01-01

Azimuthal angular correlations between produced hadrons/jets in high energy collisions are a sensitive probe of the dynamics of QCD at small x. Here we derive the triple differential cross section for inclusive production of 3 polarized partons in DIS at small x. The target proton or nucleus is described using the Color Glass Condensate (CGC) formalism. The resulting expressions are used to study azimuthal angular correlations between produced partons in order to probe the gluon structure of the target hadron or nucleus. Our analytic expressions can also be used to calculate the real part of the Next to Leading Order (NLO) corrections to di-hadron production in DIS by integrating out one of the three final state partons.

Jet evolution in hot and cold QCD matter

Energy Technology Data Exchange (ETDEWEB)

Domdey, Svend Oliver

2010-07-23

In this thesis, we study the evolution of energetic partons in hot and cold QCD matter. In both cases, interactions with the medium lead to energy loss of the parton and its transverse momentum broadens. The propagation of partons in cold nuclear matter can be investigated experimentally in deep-inelastic scattering (DIS) on nuclei. We use the dipole model to calculate transverse momentum broadening in DIS on nuclei and compare to experimental data from HERMES. In hot matter, the evolution of the parton shower is strongly modified. To calculate this modification, we construct an additional scattering term in the QCD evolution equations which accounts for scattering of partons in the quark-gluon plasma. With this scattering term, we compute the modified gluon distribution in the shower at small momentum fractions. Furthermore, we calculate the modified fragmentation function of gluons into pions. The scattering term causes energy loss of the parton shower which leads to a suppression of hadrons with large transverse momentum. In the third part of this thesis, we study double dijet production in hadron collisions. This process contains information about the transverse parton distribution of hadrons. As main result, we find that double dijet production will allow for a study of the transverse growth of hadronic wave functions at the LHC. (orig.)

Prayer and the Registered Nurse (PRN): nurses' reports of ease and dis-ease with patient-initiated prayer request.

Science.gov (United States)

Minton, Mary E; Isaacson, Mary; Banik, Deborah

2016-09-01

To explore nurse comfort with patient-initiated prayer request scenarios. Spiritual care is fundamental to patient care evidenced by Joint Commission requirement of a spiritual assessment on a patient's hospital admission. Prayer is an assessment component. Patients may seek solace and support by requesting prayer from the bedside nurse, the nurse may lack confidence in responding. Absent in the literature are reports specific to nurses' comfort when patients initiate prayer requests. Cross-sectional mixed methods study. Data were collected in early 2014 from 134 nurses in the USA via an online survey using QuestionPro. The qualitative results reported here were collated by scenario and analysed using thematic analysis. The scenario responses revealed patterns of ease and dis-ease in response to patient requests for prayer. The pattern of ease of prayer with patients revealed three themes: open to voice of calm or silence; physical or spiritual; can I call the chaplain. For these nurses, prayer is a natural component of nursing care, as the majority of responses to all scenarios demonstrated an overwhelming ease in response and capacity to pray with patients on request. The pattern of dis-ease of prayer with patients distinguished two themes: cautious hesitancy and whose God. These nurses experienced dis-ease with the patient's request no matter the situation. Educators and administrators must nurture opportunities for students and nurses to learn about and engage in the reflective preparation needed to respond to patient prayer requests. © 2016 John Wiley & Sons Ltd.

Talking (and Not Talking) about Race, Social Class and Dis/Ability: Working Margin to Margin

Science.gov (United States)

Ferri, Beth A.; Connor, David J.

2014-01-01

In this article we examine some of the omnipresent yet unacknowledged discourses of social and economic disadvantage and dis/ability within schools in the US. First, we document ways that social class, race, and dis/ability function within schools to further disadvantage and exclude already marginalized students. Next, we show how particular ways…

Polarized 3 parton production in inclusive DIS at small x

Directory of Open Access Journals (Sweden)

Alejandro Ayala

2016-10-01

Full Text Available Azimuthal angular correlations between produced hadrons/jets in high energy collisions are a sensitive probe of the dynamics of QCD at small x. Here we derive the triple differential cross section for inclusive production of 3 polarized partons in DIS at small x. The target proton or nucleus is described using the Color Glass Condensate (CGC formalism. The resulting expressions are used to study azimuthal angular correlations between produced partons in order to probe the gluon structure of the target hadron or nucleus. Our analytic expressions can also be used to calculate the real part of the Next to Leading Order (NLO corrections to di-hadron production in DIS by integrating out one of the three final state partons.

Advancement in Watershed Modelling Using Dynamic Lateral and Longitudinal Sediment (Dis)connectivity Prediction

Science.gov (United States)

Mahoney, D. T.; al Aamery, N. M. H.; Fox, J.

2017-12-01

The authors find that sediment (dis)connectivity has seldom taken precedence within watershed models, and the present study advances this modeling framework and applies the modeling within a bedrock-controlled system. Sediment (dis)connectivity, defined as the detachment and transport of sediment from source to sink between geomorphic zones, is a major control on sediment transport. Given the availability of high resolution geospatial data, coupling sediment connectivity concepts within sediment prediction models offers an approach to simulate sediment sources and pathways within a watershed's sediment cascade. Bedrock controlled catchments are potentially unique due to the presence of rock outcrops causing longitudinal impedance to sediment transport pathways in turn impacting the longitudinal distribution of the energy gradient responsible for conveying sediment. Therefore, the authors were motivated by the need to formulate a sediment transport model that couples sediment (dis)connectivity knowledge to predict sediment flux for bedrock controlled catchments. A watershed-scale sediment transport model was formulated that incorporates sediment (dis)connectivity knowledge collected via field reconnaissance and predicts sediment flux through coupling with the Partheniades equation and sediment continuity model. Sediment (dis)connectivity was formulated by coupling probabilistic upland lateral connectivity prediction with instream longitudinal connectivity assessments via discretization of fluid and sediment pathways. Flux predictions from the upland lateral connectivity model served as an input to the instream longitudinal connectivity model. Disconnectivity in the instream model was simulated via the discretization of stream reaches due to barriers such as bedrock outcroppings and man-made check dams. The model was tested for a bedrock controlled catchment in Kentucky, USA for which extensive historic water and sediment flux data was available. Predicted sediment

Quark-antiquark production in DIS diffractive dissociation

International Nuclear Information System (INIS)

Bartels, J.; Lotter, H.; Wuesthoff, M.

1996-02-01

We calculate the cross section for the production of two jets with large transverse momenta k 2 in DIS diffractive dissociation for both transverse and longitudinally polarized photons. The scale which defines the hardness of the Pomeron is found to be k 2 (Q 2 +M 2 )/M 2 . We present analytic expressions and discuss numerical results relevant for the diffractive dissociation at HERA. (orig.)

Polarized DIS Structure Functions from Neural Networks

International Nuclear Information System (INIS)

Del Debbio, L.; Guffanti, A.; Piccione, A.

2007-01-01

We present a parametrization of polarized Deep-Inelastic-Scattering (DIS) structure functions based on Neural Networks. The parametrization provides a bias-free determination of the probability measure in the space of structure functions, which retains information on experimental errors and correlations. As an example we discuss the application of this method to the study of the structure function g 1 p (x,Q 2 )

Planning in All its (Dis)guises: Spheres of Government, Functional ...

African Journals Online (AJOL)

Planning in All its (Dis)guises: Spheres of Government, Functional Areas and ... Draft legislation such as the Spatial Planning and Land Use Management Bill ... of co-operative government where uncertainty and conflict exist is examined, ...

the organizing principle at the interface of biological (dis)order

Indian Academy of Sciences (India)

Complexity: the organizing principle at the interface of biological (dis)order ... in a quantifiable fashion, as the amount of information, an informatic template ... We propose that the complexity of living systems can be understood through two ...

Cyril Ponnamperuma Memorial. Trieste conference on chemical evolution, 4: Physics of the origin and evolution of life. Summaries

International Nuclear Information System (INIS)

1995-08-01

The document includes 19 summaries of papers presented at the Trieste Conference on Chemical Evolution, 4: Physics of the Origin and Evolution of Life (Cyril Ponnamperuma Memorial), Miramare, Trieste, 4-8 September 1995. The abstracts have been indexed individually. 3 refs, 1 fig

Performances of Student Activism: Sound, Silence, Gender, and Dis/ability

Science.gov (United States)

Pasque, Penny A.; Vargas, Juanita Gamez

2014-01-01

This chapter explores the various performances of activism by students through sound, silence, gender, and dis/ability and how these performances connect to social change efforts around issues such as human trafficking, homeless children, hunger, and children with varying abilities.

DIS - The Next Generation: A perspective for European Space Programmes

NARCIS (Netherlands)

Jense, G.J.; Kuijpers, N.H.L.

1996-01-01

During the past decade, requirements within the US defence community for simulation-based tools to support acquisition, planning, (team) training, and analysis, have resulted in a standard for distributed simulation known as DIS (Distributed Interactive Simulation). The potential advantages of

DIS - the next generation : a perspective for European space programmes

NARCIS (Netherlands)

Jense, Hans; Kuijpers, N.H.L.

1996-01-01

During the past decade, requirements within the US defence community for simulation-based tools to support acquisition, planning, (team) training, and analysis, have resulted in a standard for distributed simulation known as DIS (Distributed Interactive Simulation). The potential advantages of

ATLAS virtual visit features Al-Quds University, a Palestinian university with campuses in Abu Dis and al-Bireh.

CERN Multimedia

claudia marcelloni

2012-01-01

Mon, 02 Apr - 14:00 CET (15:00 local) ATLAS virtual visit features Al-Quds University, a Palestinian university with campuses in Abu Dis and al-Bireh. As part of the "Physics Without Frontiers" project, funded by ICTP, Al-Quds is hosting a one day particle physics masterclass. During the day the students are given an introduction to particle physics, the LHC and the ATLAS Experiment, before having the chance to analyse real LHC data. This virtual visit comprises of a live tour around the ATLAS control room and the opportunity to ask questions to the ATLAS physicists. Al-Quds Physics has active research in accelerators, biophysics, laser, nuclear & particle, plasma, and solid state. A new collaboration is underway Forschungszentrum Jülich in spintronics, bioelectronics Alquds Physics is involved in the regional synchrotron SESAME in Jordan. Members include nine states from the region and over 10 observers worldwide. SESAME was established a long the same philosophy behind building CERN.

Physics of stellar evolution and cosmology

International Nuclear Information System (INIS)

Goldberg, H.S.; Scadron, M.D.

1981-01-01

Astrophysical phenomena are examined on a fundamental level, stressing basic physical laws, in a textbook suitable for a one-semester intermediate course. The ideal gas law, the meaning of temperature, black-body radiation, discrete spectra, and the Doppler effect are introduced and used to study such features of the interstellar medium as 21-cm radiation, nebulae and dust, and the galactic magnetic field. The phases of stellar evolution are discussed, including stellar collapse, quasi-hydrostatic equilibrium, the main sequence, red giants, white dwarves, neutron stars, supernovae, pulsars, and black holes. Among the cosmological topics covered are the implications of Hubble's constant, the red-shift curve, the steady-state universe, the evolution of the big bang (thermal equilibrium, hadron era, lepton era, primordial nucleosynthesis, hydrogen recombination, galaxy formation, and the cosmic fireball), and the future (cold end or big crunch). 72 references

The Evolution of Software in High Energy Physics

International Nuclear Information System (INIS)

Brun, René

2012-01-01

The paper reviews the evolution of the software in High Energy Physics from the time of expensive mainframes to grids and clouds systems using thousands of multi-core processors. It focuses on the key parameters or events that have shaped the current software infrastructure.

Pion content of the nucleon in polarized semi-inclusive DIS

Energy Technology Data Exchange (ETDEWEB)

Melnitchouk, W. [Univ. of Regensburg (Germany); Thomas, A.W. [Univ. of Adelaide (Australia)

1994-04-01

An explicit pionic component of the nucleon may be identified by measuring polarized {Delta}{sup ++} fragments produced in deep-inelastic scattering (DIS) off polarized protons. The pion-exchange model predicts highly correlated polarizations of the {Delta}{sup ++} and target proton, in marked contrast with the competing diquark fragmentation process.

History and evolution of concepts in physics

CERN Document Server

Varvoglis, Harry

2014-01-01

Our understanding of nature, and in particular of physics and the laws governing it, has changed radically since the days of the ancient Greek natural philosophers. This book explains how and why these changes occurred, through landmark experiments as well as theories that - for their time - were revolutionary. The presentation covers Mechanics, Optics, Electromagnetism, Thermodynamics, Relativity Theory, Atomic Physics and Quantum Physics. The book places emphasis on ideas and on a qualitative presentation, rather than on mathematics and equations. Thus, although primarily addressed to those who are studying or have studied science, it can also be read by non-specialists. The author concludes with a discussion of the evolution and organization of universities, from ancient times until today, and of the organization and dissemination of knowledge through scientific publications and conferences.

Safety, efficacy, and intraoperative characteristics of DisCoVisc and Healon ophthalmic viscosurgical devices for cataract surgery

Directory of Open Access Journals (Sweden)

Modi SS

2011-09-01

Full Text Available Satish S Modi1, James A Davison2, Tom Walters3 1Seeta Eye Centers, Poughkeepsie, NY, USA; 2Wolfe Clinic, Marshalltown, IA, USA; 3Texas Eye Care, Austin, TX, USA Purpose: To evaluate the safety and efficacy of DisCoVisc ophthalmic viscosurgical device (OVD, Alcon Laboratories, Inc with respect to a comparator, Healon OVD (Advanced Medical Optics, Inc. Patients and methods: In this prospective study, patients with cataracts were randomized to an OVD, and then received phacoemulsification and injection of an intraocular lens. After each surgery, unmasked investigators completed subjective questionnaires about OVD characteristics during each stage of the procedure. Masked technicians evaluated objective safety parameters of intraocular pressure (IOP and endothelial cell density, with 90 days of follow-up. Results: The DisCoVisc OVD group (128 eyes and the Healon OVD group (121 eyes had statistically similar outcomes for IOP and for endothelial cell loss. Subjectively assessed viscosity was statistically different (P < 0.0001, with Healon OVD most often rated “cohesive” and DisCoVisc OVD most often rated “both dispersive and cohesive”. Workspace maintenance differed between groups (P < 0.0001, with workspace most frequently rated “full chamber maintained” when using DisCoVisc OVD and most frequently rated “workspace maintained” when using Healon OVD. “Flat” or “shallow” workspace ratings occurred only in the Healon OVD group. Conclusion: DisCoVisc OVD had both cohesive and dispersive properties, and was safe and effective for every stage of cataract surgery. Keywords: cataract, endothelial cell density, viscoelastic, phacoemulsification

A Socio-Cultural Reframing of Science and Dis/ability in Education: Past Problems, Current Concerns, and Future Possibilities

Science.gov (United States)

Connor, David J.; Valle, Jan W.

2015-01-01

In this article we assert the value of a socio-cultural reframing of science and dis/ability in education. We begin by problematizing current issues in education pertaining to the often-unquestioned concept of dis/ability and the impact that has upon research, theory, practice, and policy. As our topic is broad, we have chosen to focus upon four…

Network protocol changes can improve DisCom WAN performance : evaluating TCP modifications and SCTP in the ASC tri-lab environment.

Energy Technology Data Exchange (ETDEWEB)

Tolendino, Lawrence F.; Hu, Tan Chang

2005-06-01

The Advanced Simulation and Computing (ASC) Distance Computing (DisCom) Wide Area Network (WAN) is a high performance, long distance network environment that is based on the ubiquitous TCP/IP protocol set. However, the Transmission Control Protocol (TCP) and the algorithms that govern its operation were defined almost two decades ago for a network environment vastly different from the DisCom WAN. In this paper we explore and evaluate possible modifications to TCP that purport to improve TCP performance in environments like the DisCom WAN. We also examine a much newer protocol, SCTP (Stream Control Transmission Protocol) that claims to provide reliable network transport while also implementing multi-streaming, multi-homing capabilities that are appealing in the DisCom high performance network environment. We provide performance comparisons and recommendations for continued development that will lead to network communications protocol implementations capable of supporting the coming ASC Petaflop computing environments.

Short-range and long-range correlations in DIS at HERA

International Nuclear Information System (INIS)

Chekanov, S. V.; Zawiejski, L.

1999-01-01

Correlations in deep-inelastic scattering (DIS) at HERA are investigated in order to test perturbative QCD and quark fragmentation universality. Two-particle correlations at small angular separations are measured in the Breit frame and compared to e + e - collisions. Also presented are the correlations between the current and target regions of the Breit frame

Exonuclease hDIS3L2 specifies an exosome-independent 3'-5' degradation pathway of human cytoplasmic mRNA

DEFF Research Database (Denmark)

Lubas, Michal Szymon; Damgaard, Christian Kroun; Tomecki, Rafal

2013-01-01

Turnover of mRNA in the cytoplasm of human cells is thought to be redundantly conducted by the monomeric 5'-3' exoribonuclease hXRN1 and the 3'-5' exoribonucleolytic RNA exosome complex. However, in addition to the exosome-associated 3'-5' exonucleases hDIS3 and hDIS3L, the human genome encodes...

Gluon saturation: Survival probability for leading neutrons in DIS

International Nuclear Information System (INIS)

Levin, Eugene; Tapia, Sebastian

2012-01-01

In this paper we discuss the example of one rapidity gap process: the inclusive cross sections of the leading neutrons in deep inelastic scattering with protons (DIS). The equations for this process are proposed and solved, giving the example of theoretical calculation of the survival probability for one rapidity gap processes. It turns out that the value of the survival probability is small and it decreases with energy.

Scripted Curriculum: What Movies Teach about Dis/ability and Black Males

Science.gov (United States)

Agosto, Vonzell

2014-01-01

Background/Context: Tropes of dis/ability in the movies and master-narratives of Black males in education and society are typically treated in isolation. Furthermore, education research on Hollywood movies has typically focused on portrayals of schools, principals, and teachers even though education professionals are exposed to a broader range of…

Accuracy of inference on the physics of binary evolution from gravitational-wave observations

Science.gov (United States)

Barrett, Jim W.; Gaebel, Sebastian M.; Neijssel, Coenraad J.; Vigna-Gómez, Alejandro; Stevenson, Simon; Berry, Christopher P. L.; Farr, Will M.; Mandel, Ilya

2018-04-01

The properties of the population of merging binary black holes encode some of the uncertain physics underlying the evolution of massive stars in binaries. The binary black hole merger rate and chirp-mass distribution are being measured by ground-based gravitational-wave detectors. We consider isolated binary evolution, and explore how accurately the physical model can be constrained with such observations by applying the Fisher information matrix to the merging black hole population simulated with the rapid binary-population synthesis code COMPAS. We investigate variations in four COMPAS parameters: common-envelope efficiency, kick-velocity dispersion, and mass-loss rates during the luminous blue variable and Wolf-Rayet stellar-evolutionary phases. We find that ˜1000 observations would constrain these model parameters to a fractional accuracy of a few per cent. Given the empirically determined binary black hole merger rate, we can expect gravitational-wave observations alone to place strong constraints on the physics of stellar and binary evolution within a few years. Our approach can be extended to use other observational data sets; combining observations at different evolutionary stages will lead to a better understanding of stellar and binary physics.

Candidate Essential Genes in Burkholderia cenocepacia J2315 Identified by Genome-Wide TraDIS

KAUST Repository

Wong, Yee-Chin

2016-08-22

Burkholderia cenocepacia infection often leads to fatal cepacia syndrome in cystic fibrosis patients. However, antibiotic therapy rarely results in complete eradication of the pathogen due to its intrinsic resistance to many clinically available antibiotics. Recent attention has turned to the identification of essential genes as the proteins encoded by these genes may serve as potential targets for development of novel antimicrobials. In this study, we utilized TraDIS (Transposon Directed Insertion-site Sequencing) as a genome-wide screening tool to facilitate the identification of B. cenocepacia genes essential for its growth and viability. A transposon mutant pool consisting of approximately 500,000 mutants was successfully constructed, with more than 400,000 unique transposon insertion sites identified by computational analysis of TraDIS datasets. The saturated library allowed for the identification of 383 genes that were predicted to be essential in B. cenocepacia. We extended the application of TraDIS to identify conditionally essential genes required for in vitro growth and revealed an additional repertoire of 439 genes to be crucial for B. cenocepacia growth under nutrient-depleted conditions. The library of B. cenocepacia mutants can subsequently be subjected to various biologically related conditions to facilitate the discovery of genes involved in niche adaptation as well as pathogenicity and virulence.

Candidate Essential Genes in Burkholderia cenocepacia J2315 Identified by Genome-Wide TraDIS

KAUST Repository

Wong, Yee-Chin; Abd El Ghany, Moataz; Naeem, Raeece; Lee, Kok-Wei; Tan, Yung-Chie; Pain, Arnab; Nathan, Sheila

2016-01-01

Burkholderia cenocepacia infection often leads to fatal cepacia syndrome in cystic fibrosis patients. However, antibiotic therapy rarely results in complete eradication of the pathogen due to its intrinsic resistance to many clinically available antibiotics. Recent attention has turned to the identification of essential genes as the proteins encoded by these genes may serve as potential targets for development of novel antimicrobials. In this study, we utilized TraDIS (Transposon Directed Insertion-site Sequencing) as a genome-wide screening tool to facilitate the identification of B. cenocepacia genes essential for its growth and viability. A transposon mutant pool consisting of approximately 500,000 mutants was successfully constructed, with more than 400,000 unique transposon insertion sites identified by computational analysis of TraDIS datasets. The saturated library allowed for the identification of 383 genes that were predicted to be essential in B. cenocepacia. We extended the application of TraDIS to identify conditionally essential genes required for in vitro growth and revealed an additional repertoire of 439 genes to be crucial for B. cenocepacia growth under nutrient-depleted conditions. The library of B. cenocepacia mutants can subsequently be subjected to various biologically related conditions to facilitate the discovery of genes involved in niche adaptation as well as pathogenicity and virulence.

Candidate essential genes in Burkholderia cenocepacia J2315 identified by genome-wide TraDIS

Directory of Open Access Journals (Sweden)

Yee-Chin Wong

2016-08-01

Full Text Available Burkholderia cenocepacia infection often leads to fatal cepacia syndrome in cystic fibrosis patients. However, antibiotic therapy rarely results in complete eradication of the pathogen due to its intrinsic resistance to many clinically available antibiotics. Recent attention has turned to the identification of essential genes as the proteins encoded by these genes may serve as potential targets for development of novel antimicrobials. In this study, we utilized TraDIS (Transposon Directed Insertion-site Sequencing as a genome-wide screening tool to facilitate the identification of B. cenocepacia genes essential for its growth and viability. A transposon mutant pool consisting of approximately 500,000 mutants was successfully constructed, with more than 400,000 unique transposon insertion sites identified by computational analysis of TraDIS datasets. The saturated library allowed for the identification of 383 genes that were predicted to be essential in B. cenocepacia. We extended the application of TraDIS to identify conditionally essential genes required for in vitro growth and revealed an additional repertoire of 439 genes to be crucial for B. cenocepacia growth under nutrient-depleted conditions. The library of B. cenocepacia mutants can subsequently be subjected to various biologically related conditions to facilitate the discovery of genes involved in niche adaptation as well as pathogenicity and virulence.

DisA and c-di-AMP act at the intersection between DNA-damage response and stress homeostasis in exponentially growing Bacillus subtilis cells.

Science.gov (United States)

Gándara, Carolina; Alonso, Juan C

2015-03-01

Bacillus subtilis contains two vegetative diadenylate cyclases, DisA and CdaA, which produce cyclic di-AMP (c-di-AMP), and one phosphodiesterase, GdpP, that degrades it into a linear di-AMP. We report here that DisA and CdaA contribute to elicit repair of DNA damage generated by alkyl groups and H2O2, respectively, during vegetative growth. disA forms an operon with radA (also termed sms) that encodes a protein distantly related to RecA. Among different DNA damage agents tested, only methyl methane sulfonate (MMS) affected disA null strain viability, while radA showed sensitivity to all of them. A strain lacking both disA and radA was as sensitive to MMS as the most sensitive single parent (epistasis). Low c-di-AMP levels (e.g. by over-expressing GdpP) decreased the ability of cells to repair DNA damage caused by MMS and in less extent by H2O2, while high levels of c-di-AMP (absence of GdpP or expression of sporulation-specific diadenylate cyclase, CdaS) increased cell survival. Taken together, our results support the idea that c-di-AMP is a crucial signalling molecule involved in DNA repair with DisA and CdaA contributing to modulate different DNA damage responses during exponential growth. Copyright © 2015 Elsevier B.V. All rights reserved.

"Dis-able bodied" or "dis-able minded": stakeholders' return-to-work experiences compared between physical and mental health conditions.

Science.gov (United States)

Vossen, Emmie; Van Gestel, Nicolette; Van der Heijden, Beatrice I J M; Rouwette, Etiënne A J A

2017-05-01

This study aimed to explore if and why the return-to-work (RTW) experiences of various workplace stakeholders in the Netherlands and Denmark differ between physical and mental health conditions, and to understand the consequences of potentially different experiences for the RTW process in both health conditions. We studied 21 cases of long-term sickness absence, and held a total of 61 semi-structured interviews with the various actors involved in these cases. Physical cases were seen as "easy" and mental cases as "difficult" to manage, based on the visibility and predictability of health complaints. On this ground, assessing work ability and following required RTW actions were perceived as more urgent in mental than in physical cases. Despite these perceptions, in practice, the assessment of work ability seemed to impair the RTW process in mental cases (but not in physical ones), and the (non-)uptake of RTW actions appeared to have similar results in both mental and physical cases. With these outcomes, the effectiveness of a differential approach is questioned, and the relevance of a bidirectional dialog on work ability and a phased RTW plan is highlighted, regardless of the absence cause. Our study also demonstrates how policymakers need to strike a balance between obligatory and permissive legislation to better involve workplaces in RTW issues. Implications for rehabilitation Both physically and mentally sick-listed employees could benefit from a bidirectional dialog on work ability as well as from a phased RTW plan. A greater role for employers in the RTW process should be accompanied with a support for sick-listed employees, in both physical and mental sickness absence cases. Dutch and Danish RTW legislation could be improved by carefully balancing obligatory and permissive rules and regulations to involve workplaces in RTW matters.

The etiology of mathematical and reading (dis)ability covariation in a sample of Dutch twins.

Science.gov (United States)

Markowitz, Ezra M; Willemsen, Gonneke; Trumbetta, Susan L; van Beijsterveldt, Toos C E M; Boomsma, Dorret I

2005-12-01

The genetic etiology of mathematical and reading (dis)ability has been studied in a number of distinct samples, but the true nature of the relationship between the two remains unclear. Data from the Netherlands Twin Register was used to determine the etiology of the relationship between mathematical and reading (dis)ability in adolescent twins. Ratings of mathematical and reading problems were obtained from parents of over 1500 twin pairs. Results of bivariate structural equation modeling showed a genetic correlation around .60, which explained over 90% of the phenotypic correlation between mathematical and reading ability. The genetic model was the same for males and females.

Evolution viewed from physics, physiology and medicine.

Science.gov (United States)

Noble, Denis

2017-10-06

Stochasticity is harnessed by organisms to generate functionality. Randomness does not, therefore, necessarily imply lack of function or 'blind chance' at higher levels. In this respect, biology must resemble physics in generating order from disorder. This fact is contrary to Schrödinger's idea of biology generating phenotypic order from molecular- level order, which inspired the central dogma of molecular biology. The order originates at higher levels, which constrain the components at lower levels. We now know that this includes the genome, which is controlled by patterns of transcription factors and various epigenetic and reorganization mechanisms. These processes can occur in response to environmental stress, so that the genome becomes 'a highly sensitive organ of the cell' (McClintock). Organisms have evolved to be able to cope with many variations at the molecular level. Organisms also make use of physical processes in evolution and development when it is possible to arrive at functional development without the necessity to store all information in DNA sequences. This view of development and evolution differs radically from that of neo-Darwinism with its emphasis on blind chance as the origin of variation. Blind chance is necessary, but the origin of functional variation is not at the molecular level. These observations derive from and reinforce the principle of biological relativity, which holds that there is no privileged level of causation. They also have important implications for medical science.

Colour-singlet exchange and tests of models of diffractive DIS

International Nuclear Information System (INIS)

Williams, J.C.

2000-03-01

Diffractive deep-inelastic scattering events observed at the HERA electron-proton collider are interpreted as an interaction involving a virtual photon scattering off a colour-singlet state within the proton. Models which attempt to describe the colour-singlet exchanged in diffractive interactions range from the purely phenomenological Donnachie-Landshoff form factor approach to the QCD-motivated gluon-exchange models and the scalar-pomeron model. It is important to find ways to test these models. In this thesis colour-singlet exchange models of diffractive DIS are compared with cross section and structure function data from the H1 detector. H1 select diffractive data by requiring there to be a large angle between the forward proton direction and any other significant detector activity. This pseudo-rapidity gap cut extracts colour-singlet exchange events from the standard DIS data sample. For a wide range of the parameter space covered by the HERA experiments, however, the pseudo-rapidity gap cuts restrict the final-state phase space available for diffractive scattering. One consequence is that pseudo-rapidity gap cuts can be used to select diffractive events in which the colour-singlet only couples to off-shell partons. To leading order in the strong coupling constant, the diffractive final state consists of a quark-antiquark pair. Higher-order events include diffractive production of quark-antiquark-gluon states. In the region where pseudo-rapidity gap cuts restrict the accessible phase space, the cuts reject low transverse momentum quark-antiquark diffractive events. Pseudo-rapidity gap data selection cuts also allow selection of an enhanced 3-jet data sample. The structure function and transverse momentum distribution data can be described by either a two-gluon model or by the Donnachie-Landshoff model, both models requiring a significant contribution from quark-antiquark-gluon diffractive final states to fit the full kinematic range of the diffractive data

Functional requirements document for NASA/MSFC Earth Science and Applications Division: Data and information system (ESAD-DIS). Interoperability, 1992

Science.gov (United States)

Stephens, J. Briscoe; Grider, Gary W.

1992-01-01

These Earth Science and Applications Division-Data and Information System (ESAD-DIS) interoperability requirements are designed to quantify the Earth Science and Application Division's hardware and software requirements in terms of communications between personal and visualization workstation, and mainframe computers. The electronic mail requirements and local area network (LAN) requirements are addressed. These interoperability requirements are top-level requirements framed around defining the existing ESAD-DIS interoperability and projecting known near-term requirements for both operational support and for management planning. Detailed requirements will be submitted on a case-by-case basis. This document is also intended as an overview of ESAD-DIs interoperability for new-comers and management not familiar with these activities. It is intended as background documentation to support requests for resources and support requirements.

Measuring the (Dis) Satisfaction of the Employees in the Macedonian Companies

Science.gov (United States)

Mitreva, Elizabeta; Krivokapic, Zdravko; Taskov, Nako; Jovanovic, Jelena

2018-01-01

The (dis)satisfaction of the employees who create and realize activities is as much important as the satisfaction of the buyers. In this paper, we have presented the results from the research in the Macedonian companies concerning the capacity of the leadership to motivate the employees to do their job efficiently and to preserve their initiative…

Dis-harmony in European natural gas market(s). Discussion of standards and definitions

Energy Technology Data Exchange (ETDEWEB)

Karasz, Michael [The Energy House GmbH, Muenchen (Germany); Pustisek, Andrej [Hochschule fuer Technik, Stuttgart (Germany); Drasdo, Peter

2013-06-15

The European Union attempts to harmonise the European natural gas market(s). In general, this is supported on national levels. Nevertheless, such harmonisation is not yet fully accomplished: neither for the rules nor for the quality specifications nor for the physical quantities and their units. Even if the current economic impact of such dis-harmony is negligible, i.e. that market participants for the time being do not have to bear additional costs caused by the lack of harmonisation, participants in the commodity market are exposed to contractual risks. Potentially, this might lead to reduced competition and reduced liquidity of each single and the European internal market for natural gas. However, as the costs for a potential harmonisation of European gas markets are estimated to be significant, the dilemma is evident and the 'political' solution of the 'harmonisation problem' will necessarily deviate from the traders' one. (orig.)

Transformative social innovation and (dis)empowerment

DEFF Research Database (Denmark)

Avelino, Flor; Wittmayer, Julia; Pel, Bonno

2017-01-01

This article responds to increasing public and academic discourses on social innovation, which often rest on the assumption that social innovation can drive societal change and empower actors to deal with societal challenges and a retreating welfare state. In order to scrutinise this assumption......, this article proposes a set of concepts to study the dynamics of transformative social innovation and underlying processes of multi-actor (dis)empowerment. First, the concept of transformative social innovation is unpacked by proposing four foundational concepts to help distinguish between different pertinent...... ‘shades’ of change and innovation: 1) social innovation, (2) system innovation, (3) game-changers, and (4) narratives of change. These concepts, invoking insights from transitions studies and social innovations literature, are used to construct a conceptual account of how transformative social innovation...

School Choice or the Politics of Desperation? Black and Latinx Parents of Students with Dis/Abilities Selecting Charter Schools in Chicago

Science.gov (United States)

Waitoller, Federico R.; Super, Gia

2017-01-01

In this paper, we focus on the city of Chicago to examine how Black and Latinx parents of students with dis/abilities1 engage with school choice. Using analytical tools from grounded theory (Strauss & Corbin, 1990) and a theoretical lens informed by critical notions of space, race and dis/ability, we analyze interviews with parents of students…

A New Theoretical Approach to Postsecondary Student Disability: Disability-Diversity (Dis)Connect Model

Science.gov (United States)

Aquino, Katherine C.

2016-01-01

Disability is often viewed as an obstacle to postsecondary inclusion, but not a characteristic of student diversity. Additionally, current theoretical frameworks isolate disability from other student diversity characteristics. In response, a new conceptual framework, the Disability-Diversity (Dis)Connect Model (DDDM), was created to address…

Hydrogen induced dis-proportionation studies on Zr-Co-M (M=Ni, Fe, Ti) ternary alloys

International Nuclear Information System (INIS)

Jat, Ram Avtar; Pati, Subhasis; Parida, S.C.; Agarwal, Renu; Mukerjee, S.K.; Sastry, P.U.; Jayakrishnan, V.B.

2016-01-01

The intermetallic compound ZrCo is considered as a suitable material for storage, supply and recovery of hydrogen isotopes in International Thermonuclear Experimental Reactor (ITER). However, upon repeated hydriding-dehydriding cycles, the hydrogen storage capacity of ZrCo decreases, which is attributed to the disproportionate reaction ZrCo + H 2 ↔ ZrH 2 + ZrCo 2 . The reduction of hydrogen storage capacity of ZrCo is not desirable for its use in tritium facilities. In our previous studies, attempts were made to improve the durability of ZrCo against dis-proportionation by including a third element. The present study is aimed to investigate the hydrogen induced dis-proportionation of Zr-Co-M (M=Ni, Fe and Ti) ternary alloys under hydrogen delivery conditions

Darwin's legacy: why biology is not physics, or why evolution has not become a common sense.

Science.gov (United States)

Singh, Rama S

2011-10-01

Cosmology and evolution together have enabled us to look deep into the past and comprehend evolution-from the big bang to the cosmos, from molecules to humans. Here, I compare the nature of theories in biology and physics and ask why physical theories get accepted by the public without necessarily comprehending them but biological theories do not. Darwin's theory of natural selection, utterly simple in its premises but profound in its consequences, is not accepted widely. Organized religions, and creationists in particularly, have been the major critic of evolution, but not all opposition to evolution comes from organized religions. A great many people, between evolutionary biologists on one hand and creationists on the other, many academics included, who may not be logically opposed to evolution nevertheless do not accept it. This is because the process of and the evidence for evolution are invisible to a nonspecialist, or the theory may look too simple to explain complex traits to some, or because people compare evolution against God and find evolutionary explanations threatening to their beliefs. Considering how evolution affects our lives, including health and the environment to give just two examples, a basic course in evolution should become a required component of all our college and university educational systems.

Evolution of silicon sensor technology in particle physics

CERN Document Server

Hartmann, Frank

2017-01-01

This informative monograph describes the technological evolution of silicon detectors and their impact on high energy particle physics. The author here marshals his own first-hand experience in the development and also the realization of the DELPHI, CDF II and the CMS tracking detector. The basic principles of small strip- and pixel-detectors are presented and also the final large-scale applications. The Evolution of Silicon Detector Technology acquaints readers with the manifold challenges involving the design of sensors and pushing this technology to the limits. The expert will find critical information that is so far only available in various slide presentation scattered over the world wide web. This practical introduction of silicon sensor technology and its day to day life in the lab also offers many examples to illustrate problems and their solutions over several detector generations. The new edition gives a detailed overview of the silicon sensor technology used at the LHC, from basic principles to act...

Explaining Leibniz equivalence as difference of non-inertial appearances: Dis-solution of the Hole Argument and physical individuation of point-events

Science.gov (United States)

Lusanna, Luca; Pauri, Massimo

"The last remnant of physical objectivity of space-time" is disclosed in the case of a continuous family of spatially non-compact models of general relativity (GR). The physical individuation of point-events is furnished by the autonomous degrees of freedom of the gravitational field (viz., the Dirac observables) which represent-as it were-the ontic part of the metric field. The physical role of the epistemic part (viz. the gauge variables) is likewise clarified as embodying the unavoidable non-inertial aspects of GR. At the end the philosophical import of the Hole Argument is substantially weakened and in fact the Argument itself dissolved, while a specific four-dimensional holistic and structuralist view of space-time (called point-structuralism) emerges, including elements common to the tradition of both substantivalism and relationism. The observables of our models undergo real temporal change: this gives new evidence to the fact that statements like the frozen-time character of evolution, as other ontological claims about GR, are model dependent.

Influence of mathematical and physical background of drought indices on their complementarity and drought recognition ability

Science.gov (United States)

Frank, Anna; Armenski, Tanja; Gocic, Milan; Popov, Srdjan; Popovic, Ljiljana; Trajkovic, Slavisa

2017-09-01

The aim of this study is to test how effective and physically correct are the mathematical approaches of operational indices used by relevant National Agencies across the globe. To do so, the following indices were analysed Standardized Precipitation Index (SPI) -1, 3, 6, 12 and 24, Standardized Precipitation - Evapotranspiration Index (SPEI) - 1, 3, 6, 12 and 24, Effective Drought Index (EDI) and Index of Drying Efficiency of Air (IDEA). To make regions more comparable to each other and follow the spatial development of drought SPI index was advised by World Meteorological Organisation to be used widely by official meteorological services. The SPI and SPEI are used for Drought Early Warning in the USA, National Drought Mitigation Center and NASA, and in the EU by the European Drought Centre (EDC) and in the Balkan Region by National Meteorological Agencies. The EDI Index has wide application in Asia. In this paper four different issues were investigated: 1) how the mathematical method used in a drought indicator's computation influence drought indices' (DI) comparative analyses; 2) the sensitivity of the DIs on any change of the length of observational period; 3) similarities between the DIs time series; 4) and how accurate DIs are when compared to historical drought records. Results suggest that it is necessary to apply a few crucial changes in the Drought Monitoring and Early Warning Systems: 1) reconsider use of SPI and SPEI family indices as a measure of quality of other indices; and for Drought Early Recognition Programs 2) switch to DIs with a solid physical background, such as EDI; 3) Adopt solid physics for modelling drought processes and define the physical measure of drought, e.g. EDI and IDEA indices; 4) investigate further the IDEA index, which, supported by our study as well, is valuable for simulation of a drought process.

Links between galaxy evolution, morphology and internal physical processes

International Nuclear Information System (INIS)

Kraljic, Katarina

2014-01-01

This thesis aims at making the link between galaxy evolution, morphology and internal physical processes, namely star formation as the outcome of the turbulent multiphase interstellar medium, using the cosmological zoom-in simulations, simulations of isolated and merging galaxies, and the analytic model of star formation. In Chapter 1, I explain the motivation for this thesis and briefly review the necessary background related to galaxy formation and modeling with the use of numerical simulations. I first explore the evolution of the morphology of Milky-Way-mass galaxies in a suite of zoom-in cosmological simulations through the analysis of bars. I analyze the evolution of the fraction of bars with redshift, its dependence on the stellar mass and accretion history of individual galaxies. I show in particular, that the fraction of bars declines with increasing redshift, in agreement with the observations. This work also shows that the obtained results suggest that the bar formation epoch corresponds to the transition between an early 'violent' phase of spiral galaxies formation at z > 1, during which they are often disturbed by major mergers or multiple minor mergers as well as violent disk instabilities, and a late 'secular' phase at z [fr

The (Dis)Locative Effect of Noise: Globalisation, Disorientation and Noise in Marc Isaacs’ Lift

NARCIS (Netherlands)

Martin, N.

2016-01-01

This essay considers how thinking about noise can help us explore the relationship between disorientation and globalisation. It introduces the idea of the (dis)locative function of noise as a concept that enables the investigation of everyday disorientation. Such disorientation is encountered not as

DisGeNET-RDF: harnessing the innovative power of the Semantic Web to explore the genetic basis of diseases.

Science.gov (United States)

Queralt-Rosinach, Núria; Piñero, Janet; Bravo, Àlex; Sanz, Ferran; Furlong, Laura I

2016-07-15

DisGeNET-RDF makes available knowledge on the genetic basis of human diseases in the Semantic Web. Gene-disease associations (GDAs) and their provenance metadata are published as human-readable and machine-processable web resources. The information on GDAs included in DisGeNET-RDF is interlinked to other biomedical databases to support the development of bioinformatics approaches for translational research through evidence-based exploitation of a rich and fully interconnected linked open data. http://rdf.disgenet.org/ support@disgenet.org. © The Author 2016. Published by Oxford University Press.

MetSigDis: a manually curated resource for the metabolic signatures of diseases.

Science.gov (United States)

Cheng, Liang; Yang, Haixiu; Zhao, Hengqiang; Pei, Xiaoya; Shi, Hongbo; Sun, Jie; Zhang, Yunpeng; Wang, Zhenzhen; Zhou, Meng

2017-08-22

Complex diseases cannot be understood only on the basis of single gene, single mRNA transcript or single protein but the effect of their collaborations. The combination consequence in molecular level can be captured by the alterations of metabolites. With the rapidly developing of biomedical instruments and analytical platforms, a large number of metabolite signatures of complex diseases were identified and documented in the literature. Biologists' hardship in the face of this large amount of papers recorded metabolic signatures of experiments' results calls for an automated data repository. Therefore, we developed MetSigDis aiming to provide a comprehensive resource of metabolite alterations in various diseases. MetSigDis is freely available at http://www.bio-annotation.cn/MetSigDis/. By reviewing hundreds of publications, we collected 6849 curated relationships between 2420 metabolites and 129 diseases across eight species involving Homo sapiens and model organisms. All of these relationships were used in constructing a metabolite disease network (MDN). This network displayed scale-free characteristics according to the degree distribution (power-law distribution with R2 = 0.909), and the subnetwork of MDN for interesting diseases and their related metabolites can be visualized in the Web. The common alterations of metabolites reflect the metabolic similarity of diseases, which is measured using Jaccard index. We observed that metabolite-based similar diseases are inclined to share semantic associations of Disease Ontology. A human disease network was then built, where a node represents a disease, and an edge indicates similarity of pair-wise diseases. The network validated the observation that linked diseases based on metabolites should have more overlapped genes. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Collinear and TMD quark and gluon densities from parton branching solution of QCD evolution equations

Energy Technology Data Exchange (ETDEWEB)

Hautmann, F. [Rutherford Appleton Laboratory, Chilton (United Kingdom); Oxford Univ. (United Kingdom). Dept. of Theoretical Physics; Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysica; Jung, H.; Lelek, A.; Zlebcik, R. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Radescu, V. [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

2017-08-15

We study parton-branching solutions of QCD evolution equations and present a method to construct both collinear and transverse momentum dependent (TMD) parton densities from this approach. We work with next-to-leading-order (NLO) accuracy in the strong coupling. Using the unitarity picture in terms of resolvable and non-resolvable branchings, we analyze the role of the soft-gluon resolution scale in the evolution equations. For longitudinal momentum distributions, we find agreement of our numerical calculations with existing evolution programs at the level of better than 1 percent over a range of five orders of magnitude both in evolution scale and in longitudinal momentum fraction. We make predictions for the evolution of transverse momentum distributions. We perform fits to the high-precision deep inelastic scattering (DIS) structure function measurements, and we present a set of NLO TMD distributions based on the parton branching approach.

Intersectional harassment and deviant embodiment among Autistic adults: (dis)ability, gender and sexuality.

Science.gov (United States)

Barnett, Jessica Penwell

2017-11-01

Harassment scholarship increasingly attends to the intersectional nature of harassment and its function within systems of domination. However, little of this work includes disability. In-depth interviews with 24 adults on the autism spectrum in the USA demonstrate the intersections of gender, sexuality and (dis)ability in the construction of deviant embodiments as targets for harassment. These intersections also shape how participants made sense of these experiences of violence. Participants' disability characteristics were often read as gender or sexual variance, with harassers relying on sexist and heterosexist constructs to frighten, demean or humiliate them for disability characteristics. Participant experiences demonstrate the cisgender basis of 'able-bodied' identity as well as the 'able-bodied' basis of cisgender and heterosexual identities and experiences. The interdependency of gender, sexuality and (dis)ability embodiment point to how it is critical for scholars and activists to account for the role of gender and heterosexist harassment in ableist oppression and disability harassment in (hetero)sexist oppression, as well as the limits of current US law enforcement structures in providing redress for harassment.

ProDis-ContSHC: learning protein dissimilarity measures and hierarchical context coherently for protein-protein comparison in protein database retrieval.

Science.gov (United States)

Wang, Jingyan; Gao, Xin; Wang, Quanquan; Li, Yongping

2012-05-08

The need to retrieve or classify protein molecules using structure or sequence-based similarity measures underlies a wide range of biomedical applications. Traditional protein search methods rely on a pairwise dissimilarity/similarity measure for comparing a pair of proteins. This kind of pairwise measures suffer from the limitation of neglecting the distribution of other proteins and thus cannot satisfy the need for high accuracy of the retrieval systems. Recent work in the machine learning community has shown that exploiting the global structure of the database and learning the contextual dissimilarity/similarity measures can improve the retrieval performance significantly. However, most existing contextual dissimilarity/similarity learning algorithms work in an unsupervised manner, which does not utilize the information of the known class labels of proteins in the database. In this paper, we propose a novel protein-protein dissimilarity learning algorithm, ProDis-ContSHC. ProDis-ContSHC regularizes an existing dissimilarity measure dij by considering the contextual information of the proteins. The context of a protein is defined by its neighboring proteins. The basic idea is, for a pair of proteins (i, j), if their context N(i) and N(j) is similar to each other, the two proteins should also have a high similarity. We implement this idea by regularizing dij by a factor learned from the context N(i) and N(j).Moreover, we divide the context to hierarchial sub-context and get the contextual dissimilarity vector for each protein pair. Using the class label information of the proteins, we select the relevant (a pair of proteins that has the same class labels) and irrelevant (with different labels) protein pairs, and train an SVM model to distinguish between their contextual dissimilarity vectors. The SVM model is further used to learn a supervised regularizing factor. Finally, with the new Supervised learned Dissimilarity measure, we update the Protein Hierarchial

Wangai et al., Afr. J. Infect. Dis. (2011) 5(1): 1 - 6 SENSITIVITY OF ...

African Journals Online (AJOL)

AJTCAM

Wangai et al., Afr. J. Infect. Dis. (2011) 5(1): 1 - 6. 1. SENSITIVITY OF MICROSCOPY COMPARED TO MOLECULAR DIAGNOSIS OF P. FALCIPARUM: IMPLICATIONS ON MALARIA TREATMENT IN EPIDEMIC AREAS IN. KENYA. Laura Nyawira Wangai 1,2, Muriira Geoffrey Karau 3, Paul Nthakanio Njiruh 4, Omar Sabah 5 ...

Universal features of JIMWLK and BK evolution at small x

CERN Document Server

Rummukainen, K; Rummukainen, Kari; Weigert, Heribert

2004-01-01

In this paper we present the results of numerical studies of the JIMWLK and BK equations with a particular emphasis on the universal scaling properties and phase space structure involved. The results are valid for near zero impact parameter in DIS. We demonstrate IR safety due to the occurrence of a rapidity dependent saturation scale Q_s(\\tau). Within the set of initial conditions chosen both JIMWLK and BK equations show remarkable agreement. We point out the crucial importance of running coupling corrections to obtain consistency in the UV. Despite the scale breaking induced by the running coupling we find that evolution drives correlators towards an asymptotic form with near scaling properties. We discuss asymptotic features of the evolution, such as the \\tau- and A-dependence of Q_s away from the initial condition.

Apoptosis Triggers Specific, Rapid, and Global mRNA Decay with 3′ Uridylated Intermediates Degraded by DIS3L2

Directory of Open Access Journals (Sweden)

Marshall P. Thomas

2015-05-01

Full Text Available Apoptosis is a tightly coordinated cell death program that damages mitochondria, DNA, proteins, and membrane lipids. Little is known about the fate of RNA as cells die. Here, we show that mRNAs, but not noncoding RNAs, are rapidly and globally degraded during apoptosis. mRNA decay is triggered early in apoptosis, preceding membrane lipid scrambling, genomic DNA fragmentation, and apoptotic changes to translation initiation factors. mRNA decay depends on mitochondrial outer membrane permeabilization and is amplified by caspase activation. 3′ truncated mRNA decay intermediates with nontemplated uridylate-rich tails are generated during apoptosis. These tails are added by the terminal uridylyl transferases (TUTases ZCCHC6 and ZCCHC11, and the uridylated transcript intermediates are degraded by the 3′ to 5′ exonuclease DIS3L2. Knockdown of DIS3L2 or the TUTases inhibits apoptotic mRNA decay, translation arrest, and cell death, whereas DIS3L2 overexpression enhances cell death. Our results suggest that global mRNA decay is an overlooked hallmark of apoptosis.

ProDis-ContSHC: Learning protein dissimilarity measures and hierarchical context coherently for protein-protein comparison in protein database retrieval

KAUST Repository

Wang, Jim Jing-Yan

2012-05-08

Background: The need to retrieve or classify protein molecules using structure or sequence-based similarity measures underlies a wide range of biomedical applications. Traditional protein search methods rely on a pairwise dissimilarity/similarity measure for comparing a pair of proteins. This kind of pairwise measures suffer from the limitation of neglecting the distribution of other proteins and thus cannot satisfy the need for high accuracy of the retrieval systems. Recent work in the machine learning community has shown that exploiting the global structure of the database and learning the contextual dissimilarity/similarity measures can improve the retrieval performance significantly. However, most existing contextual dissimilarity/similarity learning algorithms work in an unsupervised manner, which does not utilize the information of the known class labels of proteins in the database.Results: In this paper, we propose a novel protein-protein dissimilarity learning algorithm, ProDis-ContSHC. ProDis-ContSHC regularizes an existing dissimilarity measure dij by considering the contextual information of the proteins. The context of a protein is defined by its neighboring proteins. The basic idea is, for a pair of proteins (i, j), if their context N (i) and N (j) is similar to each other, the two proteins should also have a high similarity. We implement this idea by regularizing dij by a factor learned from the context N (i) and N (j). Moreover, we divide the context to hierarchial sub-context and get the contextual dissimilarity vector for each protein pair. Using the class label information of the proteins, we select the relevant (a pair of proteins that has the same class labels) and irrelevant (with different labels) protein pairs, and train an SVM model to distinguish between their contextual dissimilarity vectors. The SVM model is further used to learn a supervised regularizing factor. Finally, with the new Supervised learned Dissimilarity measure, we update

Impact of varying physical activity levels on airway sensitivity and bronchodilation in healthy humans.

Science.gov (United States)

Smith, Joshua R; Kurti, Stephanie P; Johnson, Ariel M; Kolmer, Sarah A; Harms, Craig

2015-12-01

The purpose of this study was to determine if the amount of physical activity influences airway sensitivity and bronchodilation in healthy subjects across a range of physical activity levels. Thirty healthy subjects (age, 21.9 ± 2.6 years; 13 men/17 women) with normal pulmonary function reported to the laboratory on 2 separate occasions where they were randomized to breathe either hypertonic saline (HS) (nebulized hypertonic saline (25%) for 20 min) or HS followed by 5 deep inspirations (DIs), which has been reported to bronchodilate the airways. Pulmonary function tests (PFTs) were performed prior to both conditions and following the HS breathing or 5 DIs. Moderate to vigorous physical activity (MVPA) level was measured via accelerometer worn for 7 days. Following the HS breathing, forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) significantly decreased from baseline by -11.8% ± 8.4% and -9.3% ± 6.7%, respectively. A 2-segment linear model determined significant relationships between MVPA and percent change in FEV1 (r = 0.50) and FVC (r = 0.55). MVPA above ∼497 and ∼500 min/week for FEV1 and FVC, respectively, resulted in minor additional improvements (p > 0.05) in PFTs following the HS breathing. Following the DIs, FEV1 and FVC decreased (p 0.05) to MVPA. In conclusion, these data demonstrate that higher MVPA levels attenuated airway sensitivity but not bronchodilation in healthy subjects.

Controversial Embodiment: Sport, Masculinity, Dis/Ability

Directory of Open Access Journals (Sweden)

Marilena Parlati

2015-11-01

Full Text Available This essay is an attempt at investigating visible forms of complex, indeed controversial embodiment, with the specific intention of concentrating on the ways they interrogate delicate issues such as disability, masculinity and prosthetic sport performance. I intend to sound the shifting boundaries between dis-ability and super-ability as manifested in iconic figures such as Stelarc and, in other fields, Oscar Pistorius, whose unsteady position as privileged/disabled bladerunner seems to require – and indeed to gather – particularly intense scrutiny. I shall introduce a few contemporary discourses on corporeality and embodiment, which focus on the ‘troubling’ nature of auxiliary organs Freud refers to in the much contended paragraph I adopt as epigraph and guiding procedural light; I shall move from Butler and Giddens to Jean-Luc Nancy’s work on transplants and/as prostheses to include theoretical debates on disintegrating embodiment and disability studies, in order to proceed towards an analysis of the short-circuiting of allegedly secure practices of (masculine embodiment in sport culture and theory.

The etiology of mathematical and reading (dis)ability covariation in a sample of Dutch twins

NARCIS (Netherlands)

Markowitz, E.M.; Willemsen, A.H.M.; Trumbetta, S.L.; van Beijsterveldt, C.E.M.; Boomsma, D.I.

2005-01-01

The genetic etiology of mathematical and reading (dis)ability has been studied in a number of distinct samples, but the true nature of the relationship between the two remains unclear. Data from the Netherlands Twin Register was used to determine the etiology of the relationship between mathematical

Some Remarks on Methods of QCD Analysis of Polarized DIS Data

CERN Document Server

Leader, Elliot; Stamenov, Dimiter B

2009-01-01

The results on polarized parton densities (PDFs) obtained using different methods of QCD analysis of the present polarized DIS data are discussed. Their dependence on the method used in the analysis, accounting or not for the kinematic and dynamic 1/Q^2 corrections to spin structure function g_1, is demonstrated. It is pointed out that the precise data in the preasymptotic region require a more careful matching of the QCD predictions to the data in this region in order to determine the polarized PDFs correctly.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

I will review the progress made by the RHIC spin program, followed by the physics goals for the next few years. After that I will present a brief overview of a proposal to build a high intensity polarized electron/positron beam facility at BNL which would enable deep inelastic scattering (DIS) experiments to be pursued at BNL ...

First steps in eukaryogenesis: Physical phenomena in the origin and evolution of chromosome structure

International Nuclear Information System (INIS)

Chela Flores, J.

1995-01-01

Our present understanding of the origin and evolution of chromosomes differs considerably from current understanding of the origin and evolution of the cell itself. Chromosome origins have been less prominent in research, as the emphasis has not shifted so far appreciably from the phenomenon of primeval nucleic acid encapsulation to that of the origin of gene organization, expression, and regulation. In this work we discuss some reasons why preliminary steps in this direction are being taken. We have been led to examine properties that have contributed to raise the ancestral prokaryotic programmes to a level where we can appreciate in eukaryotes a clear departure from earlier themes in the evolution of the cell from the last common ancestor. We shift our point of view from evolution of cell morphology to the point of view of the genes. In particular, we focus attention on possible physical bases for the way transmission of information has evolved in eukaryotes, namely, the inactivation of whole chromosomes. The special case of inactivation of the X chromosome in mammals is discussed, paying particular attention to the physical process of the spread of X inactivation in monotremes (platypus and echidna.) When experimental data is unavailable some theoretical analysis is possible based on the idea that in certain cases collective phenomena in genetics, rather than chemical detail, are better correlates of complex chemical processes. (author). Abstract only

First steps in eukaryogenesis: Physical phenomena in the origin and evolution of chromosome structure

International Nuclear Information System (INIS)

Chela Flores, J.

1995-08-01

Our present understanding of the origin and evolution of chromosomes differs considerably from current understanding of the origin and evolution of the cell itself. Chromosome origins have been less prominent in research, as the emphasis has not shifted so far appreciably from the phenomenon of primeval nucleic acid encapsulation to that of the origin of gene organization, expression, and regulation. In this work we discuss some reasons why preliminary steps in this direction are being taken. We have been led to examine properties that have contributed to raise the ancestral prokaryotic programmes to a level where we can appreciate in eukaryotes a clear departure from earlier themes in the evolution of cell from the last common ancestor. We shift our point of view from evolution of cell morphology to the point of view of the genes. In particular we focus attention on possible physical bases for the way transmission of information has evolved in eukaryotes, namely, the inactivation of whole chromosomes. The special case of the inactivation of the X chromosome in mammals is discussed, paying particular attention to the physical process of the spread of X inactivation in monotremes (platypus and echidna). When experimental data is unavailable some theoretical analysis is possible based on the idea that in certain cases collective phenomena in genetics, rather than chemical detail, are better correlates of complex chemical processes. (author). 65 refs

Alimentary habits, physical activity, and Framingham global risk score in metabolic syndrome.

Science.gov (United States)

Soares, Thays Soliman; Piovesan, Carla Haas; Gustavo, Andréia da Silva; Macagnan, Fabrício Edler; Bodanese, Luiz Carlos; Feoli, Ana Maria Pandolfo

2014-04-01

Metabolic syndrome is a complex disorder represented by a set of cardiovascular risk factors. A healthy lifestyle is strongly related to improve Quality of Life and interfere positively in the control of risk factors presented in this condition. To evaluate the effect of a program of lifestyle modification on the Framingham General Cardiovascular Risk Profile in subjects diagnosed with metabolic syndrome. A sub-analysis study of a randomized clinical trial controlled blind that lasted three months. Participants were randomized into four groups: dietary intervention + placebo (DIP), dietary intervention + supplementation of omega 3 (fish oil 3 g/day) (DIS3), dietary intervention + placebo + physical activity (DIPE) and dietary intervention + physical activity + supplementation of omega 3 (DIS3PE). The general cardiovascular risk profile of each individual was calculated before and after the intervention. The study included 70 subjects. Evaluating the score between the pre and post intervention yielded a significant value (p study emphasizes the importance of lifestyle modification in the prevention and treatment of cardiovascular diseases.

An Overview of Thematic Evolution of Physical Therapy Research Area From 1951 to 2013

Directory of Open Access Journals (Sweden)

Jose A. Moral-Munoz

2018-03-01

Full Text Available Physical Therapy is a profession which development and conceptual framework have been performed in the twentieth century. One of the major challenges of Physical Therapy in the twenty-first century is to identify the intellectual basis of its scientific domain. The aim of the present paper is to analyze the evolution of Physical Therapy research throughout scientific literature published in Web of Science (WoS and Scopus databases. In order to perform the analysis, WoS and Scopus bibliographic databases were used to download all records. A set of journals with overall topics in Physical Therapy discipline with the largest history in the Journal Citation Report were selected: Physiotherapy, Physical Therapy, and Australian Journal of Physiotherapy/Journal of Physiotherapy. The bibliometric tool SciMAT was employed to perform a science mapping analysis in order to detect and visualize the research themes and their evolution across three periods: 1951–1984, 1985–2000, and 2001–2013. The analysis carried out shows that Physical Therapy research field is mainly divided into nine thematic areas: Middle-Aged People, Muscle Function Alterations and Recovery, Health Education, Gait and Biomechanics, Central Nervous System, Heart Rate and Exercise, Diagnosis, Low Back Pain, and Animals. In conclusion, Physical Therapy citations and production are primarily focused on two large thematic areas, diseases that involve middle-aged population and muscle function and its alterations. Results can be used to provide a historical perspective on research conducted in this emerging field and to provide a scientific evidence-based practice model on which future studies can be built.

Linear vs non-linear QCD evolution: from HERA data to LHC phenomenology

CERN Document Server

Albacete, J L; Quiroga-Arias, P; Rojo, J

2012-01-01

The very precise combined HERA data provides a testing ground in which the relevance of novel QCD regimes, other than the successful linear DGLAP evolution, in small-x inclusive DIS data can be ascertained. We present a study of the dependence of the AAMQS fits, based on the running coupling BK non-linear evolution equations (rcBK), on the fitted dataset. This allows for the identification of the kinematical region where rcBK accurately describes the data, and thus for the determination of its applicability boundary. We compare the rcBK results with NNLO DGLAP fits, obtained with the NNPDF methodology with analogous kinematical cuts. Further, we explore the impact on LHC phenomenology of applying stringent kinematical cuts to the low-x HERA data in a DGLAP fit.

[The nursing team and Maslow: (dis)satisfaction in the work].

Science.gov (United States)

Vitória Regis, Lorena Fagundes Ladeia; Porto, Isaura Setenta

2006-01-01

This text tries to understand the Nursing team and their (dis)satisfactions in the work. We consider the association with the theory of basic human needs of Abraham Maslow as a way to systemize and to comprehend the recurrent situations and the day-by-day Nursing issues. The necessities are structuralized hierarchically in physiological, security, social, auto-esteem and auto-accomplishment indicating the degree of satisfaction (from the disease to the fullness) of an individual or group. The advantage of this approach consists of being able to use the solid, depth and rich Maslow theory in concrete and particular situations of the Nursing team.

Thumbs Up for Refugees? : Influences of Online News Content and (Dis)Likes on Self-Reported Perceptions.

NARCIS (Netherlands)

Greijdanus, Hedy

2016-01-01

An extensive body of research on social validation indicates that people feel strengthened in their views and opinions when others agree with them. Notions of the extent of others' (dis)agreement can stem from conversations or other forms of interpersonal communication, but also from what one reads

Im/mobilities and dis/connectivities in medical globalisation: How global is Global Health?

Science.gov (United States)

Dilger, Hansjörg; Mattes, Dominik

2018-03-01

The interdisciplinary, politically contested field of Global Health has often been described as a consequence of, and response to, an intensification of the mobilities of, and connectivities between, people, pathogens, ideas, and infrastructure across national borders and large distances. However, such global mobilities and connectivities are not as omnidirectional and unpatterned as the rhetoric of many Global Health actors suggests. Instead, we argue that they are suffused by a plethora of institutional, national, and global political agendas, and substantially shaped by transnational and postcolonial power relations. Furthermore, the configurations that are typically subsumed under the category of Global Health represent only a minor part of the range of im/mobilities and dis/connectivities that are essential for understanding transformations of epidemiological patterns, health care infrastructures, and the responses to health-related challenges in a globalising world. In order to broaden such a limiting analytical perspective, we propose to expand the analytical focus in studying Global Health phenomena by paying close attention to the myriad ways in which particular im/mobilities and dis/connectivities constitute medicine and well-being in global and transnational settings. Pursuing a conceptual shift from studies of 'Global Health' to studying 'medical globalization' may carve out new analytical ground for such an endeavour.

Chains of (dis)trust : Exploring the underpinnings of knowledge-sharing and quality care across mental health services

NARCIS (Netherlands)

Brown, P.R.; Calnan, M.W.

Quality and safety in healthcare settings are underpinned by organisational cultures, which facilitate or impede the refinement, sharing and application of knowledge. Avoiding the use of the term culture as a residual category, we focus specifically on describing chains of (dis)trust, analysing

Egwuatu et al., Afr., J. Infect. Dis. (2017) 11 (1): 18-25 http://dx.doi ...

African Journals Online (AJOL)

PROF ADEWUNMI

Dis. (2017) 11 (1): 18-25 http://dx.doi.org/10.21010/ajid.v11i1.3. 18. EFFECT OF ... resistant isolates of Escherichia coli in HIV-infected adult patients in Lagos. .... Institute for Medical Research (NIMR), Yaba both in Nigeria. ..... with HIV/AIDS in Africa 2000. http://www.unaids.org/publications/documents/care/general/ ...

Evolution of microstructure, strain and physical properties in oxide nanocomposite films.

Science.gov (United States)

Chen, Aiping; Weigand, Marcus; Bi, Zhenxing; Zhang, Wenrui; Lü, Xuejie; Dowden, Paul; MacManus-Driscoll, Judith L; Wang, Haiyan; Jia, Quanxi

2014-06-24

We, using LSMO:ZnO nanocomposite films as a model system, have studied the effect of film thickness on the physical properties of nanocomposites. It shows that strain, microstructure, as well as magnetoresistance strongly rely on film thickness. The magnetotransport properties have been fitted by a modified parallel connection channel model, which is in agreement with the microstructure evolution as a function of film thickness in nanocomposite films on sapphire substrates. The strain analysis indicates that the variation of physical properties in nanocomposite films on LAO is dominated by strain effect. These results confirm the critical role of film thickness on microstructures, strain states, and functionalities. It further shows that one can use film thickness as a key parameter to design nanocomposites with optimum functionalities.

Diffractive D{sup *}-mesons production in DIS at HERA

Energy Technology Data Exchange (ETDEWEB)

Vinokurova, Svetlana

2010-05-15

This thesis presents a measurement of the cross sections for the production of the charmed mesons in diffractive deep inelastic positron-proton scattering (DIS) interactions of the type ep{yields}eXY, where the system X is separated from a low-mass system Y, by a large rapidity gap where no particles are observed. These diffractive processes can be explained as a result of the exchange of a strongly interacting colour singlet object between the final state particles. In this measurement data taken with the H1 detector in the years 1999-2000, corresponding to an integrated luminosity of L{sub int}=46.7 pb{sup -1} are used. Inclusive DIS events are selected in the kinematic range with the momentum transfer Q{sup 2} element of [2;100] GeV and inelasticity y{sub bj} element of [0.05;07]. The charm quark is tagged by requiring a D{sup *} meson decaying into the channel D{sup *}{yields}D{sup 0}{pi}{sub slow}{yields}K{pi}{pi}{sub slow} inside the central tracking system with transverse momenta p{sub t}(D{sup *})>2 GeV. The forward components of the H1 detector are used to select genuine diffractive events on the basis of the forward sub-detectors activity and of the presence a large rapidity gap in the final state hadrons. The visible charm production cross sections are measured in the diffractive kinematic range M{sub Y} < 1.6 GeV, vertical stroke t vertical stroke < 1 GeV{sup 2} and x{sub P} < 0.04 to be {sigma}(ep{yields}e{sup '}(D{sup *}X)Y)=249{+-}31(stat.){+-}30(sys) pb, where the first uncertainty is statistical and the second systematic. The shape of the differential distributions for diffractive D{sup *} production are well described by the collinear factorisation model which is implemented in the Monte Carlo simulation RAPGAP. (orig.)

Evolution in students' understanding of thermal physics with increasing complexity

Science.gov (United States)

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

2013-12-01

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

“Dis-able bodied” or “dis-able minded”: stakeholders’ return-to-work experiences compared between physical and mental health conditions

NARCIS (Netherlands)

Vossen, E.E.M.; Gestel, N.M. van; Heijden, B.I.J.M. van der; Rouwette, E.A.J.A.

2017-01-01

PURPOSE: This study aimed to explore if and why the return-to-work (RTW) experiences of various workplace stakeholders in the Netherlands and Denmark differ between physical and mental health conditions, and to understand the consequences of potentially different experiences for the RTW process in

Heterogeneous performances of conceptual dis/continuity: a dialectic reading of Brown and Kloser's article

Science.gov (United States)

Hwang, Sungwon; Kim, Mijung

2009-12-01

We review Brown and Kloser's article, "Conceptual continuity and the science of baseball: using informal science literacy to promote students science learning" from a Vygotskian cultural-historical and dialectic perspective. Brown and Kloser interpret interview data with student baseball players and claim that students' conceptual understanding articulated in vernacular genres involves continuities (similarities) with the canonical scientific explanations. In this commentary, we suggest that the authors' approach presupposes the dichotomy of the formal and the informal, which brings the authors' attention to continuity into the separation of cognition from language. We propose a Vygotskian approach that points out the problem of theorizing cognition (conceptual understanding) by depending on specific forms of representation (e.g., scientific terms). As alternative, we envision a Vygotskian cultural-historical approach to language, which considers different, irreducible modes of communication as an integrated whole and therefore allows theorizing cognition without dichotomizing it from the concrete ways by which human being communicates. We provide an exemplary analysis of a lecture talk in a university physics classroom and exemplify dialectic theories that explain the development of conceptual understanding. We discuss that this Vygotskian dialectic approach shows that people communicate scientific concepts through hybridization, which does not reproduce a genre self-identically; the continuity of conceptual understanding involves dis/continuity.

Forward gluon production in hadron-hadron scattering with Pomeron loops

International Nuclear Information System (INIS)

Iancu, E.

2006-01-01

We discuss new physical phenomena expected in particle production in hadron-hadron collisions at high energy, as a consequence of Pomerons loop effects in the evolution equations for the Color Glass Condensate. We focus on gluon production in asymmetric, 'dilute-dense', collisions: a dilute projectile scatters off a dense hadronic target, whose gluon distribution is highly evolved. This situation is representative for particle production in proton-proton collisions at forward rapidities (say, at LHC) and admits a dipole factorization similar to that of deep inelastic scattering (DIS). We show that at sufficiently large forward rapidities, where the Pomerons loop effects become important in the evolution of the target wavefunction, gluon production is dominated by 'black spots' (saturated gluon configurations) up to very large values of the transverse momentum, well above the average saturation momentum in the target. In this regime, the produced gluon spectrum exhibits diffusive scaling, so like DIS at sufficiently high energy. (authors)

Forward gluon production in hadron-hadron scattering with Pomeron loops

Energy Technology Data Exchange (ETDEWEB)

Iancu, E. [CEA Saclay, Service de Physique Th orique (DSM/SPhT), Unite de recherche associ e au CNRS (URA D2306), 91 - Gif-sur-Yvette (France). Direction des Sciences de la Matiere; Marquet, C.; Soyez, G. [CEA Saclay, Service de Physique Th orique (DSM/SPhT), Unite de recherche associ e au CNRS (URA D2306), 91 - Gif-sur-Yvette (France). Direction des Sciences de la Matiere; Liege Univ., Fundamental Theoretical Physics Group (Belgium)

2006-07-01

We discuss new physical phenomena expected in particle production in hadron-hadron collisions at high energy, as a consequence of Pomerons loop effects in the evolution equations for the Color Glass Condensate. We focus on gluon production in asymmetric, 'dilute-dense', collisions: a dilute projectile scatters off a dense hadronic target, whose gluon distribution is highly evolved. This situation is representative for particle production in proton-proton collisions at forward rapidities (say, at LHC) and admits a dipole factorization similar to that of deep inelastic scattering (DIS). We show that at sufficiently large forward rapidities, where the Pomerons loop effects become important in the evolution of the target wavefunction, gluon production is dominated by 'black spots' (saturated gluon configurations) up to very large values of the transverse momentum, well above the average saturation momentum in the target. In this regime, the produced gluon spectrum exhibits diffusive scaling, so like DIS at sufficiently high energy. (authors)

Amoral, im/moral and dis/loyal: Children's moral status in child welfare.

Science.gov (United States)

Knezevic, Zlatana

2017-11-01

This article is a discursive examination of children's status as knowledgeable moral agents within the Swedish child welfare system and in the widely used assessment framework BBIC. Departing from Fricker's concept of epistemic injustice, three discursive positions of children's moral status are identified: amoral, im/moral and dis/loyal. The findings show the undoubtedly moral child as largely missing and children's agency as diminished, deviant or rendered ambiguous. Epistemic injustice applies particularly to disadvantaged children with difficult experiences who run the risk of being othered, or positioned as reproducing or accommodating to the very same social problems they may be victimised by.

Gauge evolution of elementary particles physics during the last fifty years

International Nuclear Information System (INIS)

Khodjaev, L.Sh

2002-01-01

Gauge evolution of the elementary particle physics has been remarked by outstanding and exiting discoveries during the last fifty years of X X century. We review a new tendency in the development of the modern elementary particle physics. The phenomenological basis for the formulation of Standard Model has been reviewed. The Standard Model based on the fundamental postulates has been formulated. The concept of the fundamental symmetries has been introduced to look for not fundamental particles but fundamental symmetries. The Standard Model is renormalizable and therefore potentially consistent in all energy scales. The Standard Model in principle can describe the properties of the Universe beginning at 10 -43 sec. after Big Bang. In searching of more general theory obvious program is to searching the first of all global symmetries and then learn consequences connected with the localization of these global symmetries

Hybrid models for the simulation of microstructural evolution influenced by coupled, multiple physical processes

Energy Technology Data Exchange (ETDEWEB)

Tikare, Veena [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez-Rivera, Efrain [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Madison, Jonathan D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Holm, Elizabeth Ann [Carnegie Mellon Univ., Pittsburgh, PA (United States); Patterson, Burton R. [Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering; Homer, Eric R. [Brigham Young Univ., Provo, UT (United States). Dept. of Mechanical Engineering

2013-09-01

Most materials microstructural evolution processes progress with multiple processes occurring simultaneously. In this work, we have concentrated on the processes that are active in nuclear materials, in particular, nuclear fuels. These processes are coarsening, nucleation, differential diffusion, phase transformation, radiation-induced defect formation and swelling, often with temperature gradients present. All these couple and contribute to evolution that is unique to nuclear fuels and materials. Hybrid model that combines elements from the Potts Monte Carlo, phase-field models and others have been developed to address these multiple physical processes. These models are described and applied to several processes in this report. An important feature of the models developed are that they are coded as applications within SPPARKS, a Sandiadeveloped framework for simulation at the mesoscale of microstructural evolution processes by kinetic Monte Carlo methods. This makes these codes readily accessible and adaptable for future applications.

Thermal (dis)comfort experienced from physiological movements across indoor, transitional and outdoor spaces in Singapore: A pilot study

Science.gov (United States)

Li Heng, Su; Chow, Winston

2017-04-01

Human thermal comfort research is important as climate discomfort can adversely affect both health and work productivity in cities; however, such biometeorological work in low-latitude urban areas is still relatively unstudied hitherto. In the tropical metropolis of Singapore, a suite of policies have been implemented aimed at improving environmental sustainability via increasing car-free commutes and pedestrian movement during work/school journeys, with the consequence that individuals will likely have increased personal exposure through a variety of spaces (and climates) during typical daily activities. As such, research into exploring the thermal (dis)comfort experienced during pedestrian movements across these indoor, outdoor and transitional (semi-outdoor) spaces would yield interesting applied biometerological insights. This pilot study thus investigates how pedestrian thermal comfort varies spatially across a university campus, and how the physical intensity of pedestrian travel affects thermal comfort across these spaces. Over a 10-week period, we profiled six students for both their objective and subjective pedestrian thermal comfort during traverses across different spaces. Data were obtained through use of (a.) of a heat stress sensor, (b.) a fitness tracker, and (b.) a questionnaire survey to record traverse measurements of the microclimate, their physiological data, and their perceived microclimate comfort respectively. Measured climate and physiological data were used to derive commonly-used thermal comfort indices like wet-bulb globe temperature (WBGT) and physiological equivalent temperature (PET). Further, interviews were conducted with all six subjects at the end of the fieldwork period to ascertain details on individual acclimatization behavior and adaptation strategies. The results indicate that (a.) more than 50% of the microclimatic conditions within each indoor, semi-outdoor, and outdoor space exceeded heat stress thresholds of both PET and

DisArticle: a web server for SVM-based discrimination of articles on traditional medicine.

Science.gov (United States)

Kim, Sang-Kyun; Nam, SeJin; Kim, SangHyun

2017-01-28

Much research has been done in Northeast Asia to show the efficacy of traditional medicine. While MEDLINE contains many biomedical articles including those on traditional medicine, it does not categorize those articles by specific research area. The aim of this study was to provide a method that searches for articles only on traditional medicine in Northeast Asia, including traditional Chinese medicine, from among the articles in MEDLINE. This research established an SVM-based classifier model to identify articles on traditional medicine. The TAK + HM classifier, trained with the features of title, abstract, keywords, herbal data, and MeSH, has a precision of 0.954 and a recall of 0.902. In particular, the feature of herbal data significantly increased the performance of the classifier. By using the TAK + HM classifier, a total of about 108,000 articles were discriminated as articles on traditional medicine from among all articles in MEDLINE. We also built a web server called DisArticle ( http://informatics.kiom.re.kr/disarticle ), in which users can search for the articles and obtain statistical data. Because much evidence-based research on traditional medicine has been published in recent years, it has become necessary to search for articles on traditional medicine exclusively in literature databases. DisArticle can help users to search for and analyze the research trends in traditional medicine.

Evolution in students’ understanding of thermal physics with increasing complexity

Directory of Open Access Journals (Sweden)

Elon Langbeheim

2013-11-01

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

The relative importance of physical and biological energy in landscape evolution

Science.gov (United States)

Turowski, J. M.; Schwanghart, W.

2017-12-01

Landscapes are formed by the interplay of uplift and geomorphic processes, including interacting and competing physical and biological processes. For example, roots re-inforce soil and thereby stabilize hillslopes and the canopy cover of the forest may mediate the impact of precipitation. Furthermore, plants and animals act as geomorphic agents, directly altering landscape response and dynamics by their actions: tree roots may crack rocks, thus changing subsurface water flows and exposing fresh material for denudation; fungi excrete acids that accelerate rates of chemical weathering, and burrowing animals displace soil and rocks while digging holes for shelter or in search of food. Energetically, landscapes can be viewed as open systems in which topography stores potential energy above a base level. Tectonic processes add energy to the system by uplift and mechanically altering rock properties. Especially in unvegetated regions, erosion and transport by wind can be an important geomorphic process. Advection of atmospheric moisture in high altitudes provides potential energy that is converted by water fluxes through catchments. At the same time, the conversion of solar energy through atmospheric and biological processes drives primary production of living organisms. If we accept that biota influence geomorphic processes, then what is their energetic contribution to landscape evolution relative to physical processes? Using two case studies, we demonstrate that all components of energy input are negligible apart from biological production, quantified by net primary productivity (NPP) and potential energy conversion by water that is placed high up in the landscape as rainfall and leaves it as runoff. Assuming that the former is representative for biological energy and the latter for physical energy, we propose that the ratio of these two values can be used as a proxy for the relative importance of biological and physical processes in landscape evolution. All necessary

Thermodiffusion as a close-to-interface effect that matters in non-isothermal (dis)orderly protein aggregations

Energy Technology Data Exchange (ETDEWEB)

Gadomski, A., E-mail: agad@utp.edu.pl; Kruszewska, N., E-mail: nkruszewska@utp.edu.pl

2014-08-01

The goal of this discussion letter is to argue how and why an inherent nanoscale thermodiffusion (Soret-type) effect can be relevant in (dis)orderly protein aggregation. We propose a model in which the aggregation of proteins, in the presence of temperature gradient, is described in terms of Smoluchowski dynamics in the phase space of nuclei sizes. The Soret coefficient of the aggregation is proportional to the variations of the aggregation free energy over temperature. The free energy is related to the (interface) boundary condition of the system. When boundary condition is of equilibrium Gibbs–Thomson type, with a well-stated surface tension of the nucleus, to the system can be assigned a negative Soret effect. On the contrary, when a non-equilibrium perturbing (salting-out) term enters the boundary condition, a positive Soret effect may manifest. A zero-value Soret regime is expected to occur in between, yielding very soft (“fragile”) non-Kossel protein-type crystals. - Highlights: • Comprehension for non-isothermal formation of (dis)orderly protein aggregation. • Classification of temperature-sensitive morphologies in colloid-type aggregation. • Morphologies split into near-equilibrium and nonequilibrium structural outcomes. • Classification on mesoscopic nonequilibrium thermodynamics near local equilibrium.

VennDIS: a JavaFX-based Venn and Euler diagram software to generate publication quality figures.

Science.gov (United States)

Ignatchenko, Vladimir; Ignatchenko, Alexandr; Sinha, Ankit; Boutros, Paul C; Kislinger, Thomas

2015-04-01

Venn diagrams are graphical representations of the relationships among multiple sets of objects and are often used to illustrate similarities and differences among genomic and proteomic datasets. All currently existing tools for producing Venn diagrams evince one of two traits; they require expertise in specific statistical software packages (such as R), or lack the flexibility required to produce publication-quality figures. We describe a simple tool that addresses both shortcomings, Venn Diagram Interactive Software (VennDIS), a JavaFX-based solution for producing highly customizable, publication-quality Venn, and Euler diagrams of up to five sets. The strengths of VennDIS are its simple graphical user interface and its large array of customization options, including the ability to modify attributes such as font, style and position of the labels, background color, size of the circle/ellipse, and outline color. It is platform independent and provides real-time visualization of figure modifications. The created figures can be saved as XML files for future modification or exported as high-resolution images for direct use in publications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Capacitación a distancia (CapDis y el uso de plataformas virtuales. La experiencia del Centro Centroamericano de Población

Directory of Open Access Journals (Sweden)

Marín, Carmen

2006-01-01

Full Text Available Introducción.- Las NTIC abren nuevas posibilidades para la educación. Aprender en entornos mediados por NTIC supone flexibilidad en espacio y tiempo e interacción entre los participantes para el aprendizaje significativo. Las universidades al implementar ofertas formativas de carácter virtual deben reconsiderar sus modelos de enseñanza y de aprendizaje e iniciar procesos de análisis y revisión de las experiencias realizadas. El presente artículo pretende sistematizar el accionar del proyecto CapDis del Centro Centroamericano de Población (CCP al introducir el uso de las nuevas tecnologías de información y comunicación en la educación superior en la Universidad de Costa Rica (UCR.Métodos.- Se basa en un estudio de caso que aplica el método cualitativo mediante revisión documental y registro de eventos.Resultados.- En CapDis se identifican las siguientes etapas: I. Páginas web vinculadas; II. Páginas web integradas y III. Learning Management System. En las primeras dos etapas se dio soporte a los profesores y se asumió la mayor parte de las tareas de implementación y mantenimiento. Cuando se incorporó moodle.org, se facilitó la participación de más profesores quienes asumieron un rol más activo en CapDis. A marzo 2005, la comparación de metas y resultados evidencia que fueron superados los resultados esperados.Discusión.- El presente artículo se constituye en un insumo útil en la identificación de las dificultades, alcances y limitaciones de la incorporación de las NTIC en la docencia en educación superior en la Universidad de Costa Rica. Las etapas identificadas en CapDis han sido descritas en términos del alcance de los recursos NTIC puestos en práctica. Más allá de los aspectos tecnológicos y administrativos descritos, el proceso seguido por CapDis logró enriquecer la interacción de una modalidad asíncrona (diferida a una síncrona (inmediata, lo que abre la oportunidad de contribuir a una mejor comprensi

Factors Associated with Parent-Child (Dis)Agreement on Child Behavior and Parenting Problems in Chinese Immigrant Families

Science.gov (United States)

Fung, Joey J.; Lau, Anna S.

2010-01-01

We examined familial and cultural factors predicting parent-child (dis)agreement on child behavior and parenting problems. Immigrant Chinese parents (89.7% mothers; M age = 44.24 years) and their children (62 boys; 57.9%) between the ages of 9 and 17 years (M = 11.9 years, SD = 2.9) completed measures of parent punitive behavior and child…

The Taxonomy of Blue Amorphous Galaxies. II. Structure and Evolution

Science.gov (United States)

Marlowe, Amanda T.; Meurer, Gerhardt R.; Heckman, Timothy M.

1999-09-01

Dwarf galaxies play an important role in our understanding of galaxy formation and evolution, and starbursts are believed to affect the structure and evolution of dwarf galaxies strongly. We have therefore embarked on a systematic study of 12 of the nearest dwarf galaxies thought to be undergoing bursts of star formation. These were selected primarily by their morphological type (blue ``amorphous'' galaxies). We show that these blue amorphous galaxies are not physically distinguishable from dwarfs selected as starbursting by other methods, such as blue compact dwarfs (BCDs) and H II galaxies. All these classes exhibit surface brightness profiles that are exponential in the outer regions (r>~1.5re) but often have a predominantly central blue excess, suggesting a young burst in an older, redder galaxy. Typically, the starbursting ``cores'' are young (~107-108 yr) events compared to the older (~109-1010 yr) underlying galaxy (the ``envelope''). The ratio of the core to envelope in blue light ranges from essentially zero to about 2. These starbursts are therefore modest events involving only a few percent of the stellar mass. The envelopes have surface brightnesses that are much higher than typical dwarf irregular (dI) galaxies, so it is unlikely that there is a straightforward evolutionary relation between typical dIs and dwarf starburst galaxies. Instead we suggest that amorphous galaxies may repeatedly cycle through starburst and quiescent phases, corresponding to the galaxies with strong and weak/absent cores, respectively. Once amorphous galaxies use up the available gas (either through star formation or galactic winds) so that star formation is shut off, the faded remnants would strongly resemble dwarf elliptical galaxies. However, in the current cosmological epoch, this is evidently a slow process that is the aftermath of a series of many weak, recurring bursts. Present-day dE's must have experienced more rapid and intense evolution than this in the distant past.

Physics, Formation and Evolution of Rotating Stars

CERN Document Server

Maeder, André

2009-01-01

Rotation is ubiquitous at each step of stellar evolution, from star formation to the final stages, and it affects the course of evolution, the timescales and nucleosynthesis. Stellar rotation is also an essential prerequisite for the occurrence of Gamma-Ray Bursts. In this book the author thoroughly examines the basic mechanical and thermal effects of rotation, their influence on mass loss by stellar winds, the effects of differential rotation and its associated instabilities, the relation with magnetic fields and the evolution of the internal and surface rotation. Further, he discusses the numerous observational signatures of rotational effects obtained from spectroscopy and interferometric observations, as well as from chemical abundance determinations, helioseismology and asteroseismology, etc. On an introductory level, this book presents in a didactical way the basic concepts of stellar structure and evolution in "track 1" chapters. The other more specialized chapters form an advanced course on the gradua...

Ontology evolution in physics

OpenAIRE

Chan, Michael

2013-01-01

With the advent of reasoning problems in dynamic environments, there is an increasing need for automated reasoning systems to automatically adapt to unexpected changes in representations. In particular, the automation of the evolution of their ontologies needs to be enhanced without substantially sacrificing expressivity in the underlying representation. Revision of beliefs is not enough, as adding to or removing from beliefs does not change the underlying formal language. Gene...

Responses of soil physical and chemical properties to karst rocky desertification evolution in typical karst valley area

Science.gov (United States)

Chen, Fei; Zhou, Dequan; Bai, Xiaoyong; zeng, Cheng; Xiao, Jianyong; Qian, Qinghuan; Luo, Guangjie

2018-01-01

In order to reveal the differences of soil physical and chemical properties and their response mechanism to the evolution of KRD. The characteristics of soil physical and chemical properties of different grades of KRD were studied by field sampling method to research different types of KRD in the typical karst valley of southern China. Instead of using space of time, to explore the response and the mechanisms of the soil physical and chemical properties at the different evolution process. The results showed that: (1) There were significant differences in organic matter, pH, total nitrogen, total phosphorus, total potassium, sediment concentration, clay content and AWHC in different levels of KRD environment. However, these indicators are not with increasing desertification degree has been degraded, but improved after a first degradation trends; (2) The correlation analysis showed that soil organic matter, acid, alkali, total nitrogen, total phosphorus, total potassium and clay contents were significantly correlated with other physical and chemical factors. They are the key factors of soil physical and chemical properties, play a key role in improving soil physical and chemical properties and promoting nutrient cycling; (3) The principal component analysis showed that the cumulative contribution rate of organic matter, pH, total nitrogen, total phosphorus, total potassium and sediment concentration was 80.26%, which was the key index to evaluate rocky desertification degree based on soil physical and chemical properties. The results have important theoretical and practical significance for the protection and restoration of rocky desertification ecosystem in southwest China.

Excursions in fluvial (dis)continuity

Science.gov (United States)

Grant, Gordon E.; O'Connor, James E.; Safran, Elizabeth

2017-01-01

Lurking below the twin concepts of connectivity and disconnectivity are their first, and in some ways, richer cousins: continuity and discontinuity. In this paper we explore how continuity and discontinuity represent fundamental and complementary perspectives in fluvial geomorphology, and how these perspectives inform and underlie our conceptions of connectivity in landscapes and rivers. We examine the historical roots of continuum and discontinuum thinking, and how much of our understanding of geomorphology rests on contrasting views of continuity and discontinuity. By continuum thinking we refer to a conception of geomorphic processes as well as geomorphic features that are expressed along continuous gradients without abrupt changes, transitions, or thresholds. Balance of forces, graded streams, and hydraulic geometry are all examples of this perspective. The continuum view has played a prominent role in diverse disciplinary fields, including ecology, paleontology, and evolutionary biology, in large part because it allows us to treat complex phenomena as orderly progressions and invoke or assume equilibrium processes that introduce order and prediction into our sciences.In contrast the discontinuous view is a distinct though complementary conceptual framework that incorporates non-uniform, non-progressive, and non-equilibrium thinking into understanding geomorphic processes and landscapes. We distinguish and discuss examples of three different ways in which discontinuous thinking can be expressed: 1) discontinuous spatial arrangements or singular events; 2) specific process domains generally associated with thresholds, either intrinsic or extrinsic; and 3) physical dynamics or changes in state, again often threshold-linked. In moving beyond the continuous perspective, a fertile set of ideas comes into focus: thresholds, non-equilibrium states, heterogeneity, catastrophe. The range of phenomena that is thereby opened up to scientific exploration similarly expands

Higher order constraints on the Higgs production rate from fixed-target DIS data

International Nuclear Information System (INIS)

Alekhin, S.; Bluemlein, J.; Moch, S.

2011-01-01

The constraints of fixed-target DIS data in fits of parton distributions including QCD corrections to next-to-next-to leading order are studied. We point out a potential problem in the analysis of the NMC data which can lead to inconsistencies in the extracted value for α s (M Z ) and the gluon distribution at higher orders in QCD. The implications for predictions of rates for Standard Model Higgs boson production at hadron colliders are investigated. We conclude that the current range of excluded Higgs boson masses at the Tevatron appears to be much too large. (orig.)

History and Evolution of Concepts in Physics

Science.gov (United States)

Varvoglis, Harry

The history of any discipline is always based on written texts. In this way, to restrict ourselves to texts of Antiquity, the history of the Jewish people is based on the books of the Old Testament, the history of the Persian Wars on the books by Herodotus and the history of the Peloponnesian War on the books by Thucydides. Even the history of the Trojan War is based on Homer's written work, although this was based, in turn, on earlier oral traditions of the Greeks of Homer's time. This rule, of course, cannot find an exemption in the history of physics. This is the main reason why the history of physics, and hence the evolution of concepts in this science, necessarily starts from the ancient Greeks. It is certain that other people of historical times were also involved in scientific activities, such as the Babylonians, who developed astronomy, and the Egyptians, who developed geometry. But their aim was to solve practical problems of their everyday life and not to understand nature and its laws. The geometry of the ancient Egyptians was developed for the purpose of redistributing land after the annual flooding of Nile, while Babylonian astronomy was limited to the simple recording of astronomical observations, with a few surviving examples of predictions of future events. Instead, the interpretation of nature and its laws, in both these nations, was the responsibility of priests and kings. In other words, the interpretation of nature for them was not a result of rational thinking; it was based on truth by revelation. The "truth" was revealed to rulers, nobles and priests, and accepted, without questioning, by the rest of the people. This truth was closely related to the religion of each nation.

Generalized threshold resummation in inclusive DIS and semi-inclusive electron-positron annihilation

International Nuclear Information System (INIS)

Almasy, A.A.; Lo Presti, N.A.; Vogt, A.

2015-11-01

We present analytic all-order results for the highest three threshold logarithms of the space-like and time-like off-diagonal splitting functions and the corresponding coefficient functions for inclusive deep-inelastic scattering (DIS) and semi-inclusive e + e - annihilation. All these results, obtained through an order-by-order analysis of the structure of the corresponding unfactorized quantities in dimensional regularization, can be expressed in terms of the Bernoulli functions introduced by one of us and leading-logarithmic soft-gluon exponentials. The resulting numerical corrections are small for the splitting functions but large for the coefficient functions. In both cases more terms in the threshold expansion need to be determined in order to arrive at quantitatively reliable results.

Manifestations of classical physics in the quantum evolution of correlated spin states in pulsed NMR experiments.

Science.gov (United States)

Ligare, Martin

2016-05-01

Multiple-pulse NMR experiments are a powerful tool for the investigation of molecules with coupled nuclear spins. The product operator formalism provides a way to understand the quantum evolution of an ensemble of weakly coupled spins in such experiments using some of the more intuitive concepts of classical physics and semi-classical vector representations. In this paper I present a new way in which to interpret the quantum evolution of an ensemble of spins. I recast the quantum problem in terms of mixtures of pure states of two spins whose expectation values evolve identically to those of classical moments. Pictorial representations of these classically evolving states provide a way to calculate the time evolution of ensembles of weakly coupled spins without the full machinery of quantum mechanics, offering insight to anyone who understands precession of magnetic moments in magnetic fields.

Physical model of evolution of oxygen subsystem of PLZT-ceramics at neutron irradiation and annealing

CERN Document Server

Kulikov, D V; Trushin, Y V; Veber, K V; Khumer, K; Bitner, R; Shternberg, A R

2001-01-01

The physical model of evolution of the oxygen subsystem defects of the ferroelectric PLZT-ceramics by the neutron irradiation and isochrone annealing is proposed. The model accounts for the effect the lanthanum content on the material properties. The changes in the oxygen vacancies concentration, calculated by the proposed model, agree well with the polarization experimental behavior by the irradiated material annealing

Amoral, im/moral and dis/loyal: Children’s moral status in child welfare

Science.gov (United States)

Knezevic, Zlatana

2017-01-01

This article is a discursive examination of children’s status as knowledgeable moral agents within the Swedish child welfare system and in the widely used assessment framework BBIC. Departing from Fricker’s concept of epistemic injustice, three discursive positions of children’s moral status are identified: amoral, im/moral and dis/loyal. The findings show the undoubtedly moral child as largely missing and children’s agency as diminished, deviant or rendered ambiguous. Epistemic injustice applies particularly to disadvantaged children with difficult experiences who run the risk of being othered, or positioned as reproducing or accommodating to the very same social problems they may be victimised by. PMID:29187776

Benign multiple sclerosis: physical and cognitive impairment follow distinct evolutions.

Science.gov (United States)

Gajofatto, A; Turatti, M; Bianchi, M R; Forlivesi, S; Gobbin, F; Azzarà, A; Monaco, S; Benedetti, M D

2016-03-01

Benign multiple sclerosis (BMS) definitions rely on physical disability level but do not account sufficiently for cognitive impairment which, however, is not rare. To study the evolution of physical disability and cognitive performance of a group of patients with BMS followed at an University Hospital Multiple Sclerosis Center. A consecutive sample of 24 BMS cases (diagnosis according to 2005 McDonald's criteria, relapsing-remitting course, disease duration ≥ 10 years, and expanded disability status scale [EDSS] score ≤ 2.0) and 13 sex- and age-matched non-BMS patients differing from BMS cases for having EDSS score 2.5-5.5 were included. Main outcome measures were as follows: (i) baseline and 5-year follow-up cognitive impairment defined as failure of at least two tests of the administered neuropsychological battery; (ii) EDSS score worsening defined as confirmed increase ≥ 1 point (or 0.5 point if baseline EDSS score = 5.5). At inclusion, BMS subjects were 41 ± 8 years old and had median EDSS score 1.5 (range 0-2), while non-BMS patients were 46 ± 8 years old and had median EDSS score 3.0 (2.5-5.5). At baseline 16% of patients in both groups were cognitively impaired. After 5 years, EDSS score worsened in 8% of BMS and 46% of non-BMS patients (P = 0.008), while the proportion of cognitively impaired subjects increased to 25% in both groups. Patients with BMS had better physical disability outcome at 5 years compared to non-BMS cases. However, cognitive impairment frequency and decline over time appeared similar. Neuropsychological assessment is essential in patients with BMS given the distinct pathways followed by disease progression in cognitive and physical domains. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Evolution of Physical Activity Promotion.

Science.gov (United States)

Richards, Elizabeth Ann

2015-08-01

A physically active lifestyle has numerous physical and mental health benefits for patients of all ages. Despite these significant benefits, a majority of Americans do not meet current physical activity guidelines. Health care providers, especially nurses, play a vital role in physical activity promotion. Over the past several decades, exercise and physical activity guidelines have evolved from a focus on structured, vigorous exercise to a focus on moderate-intensity "lifestyle" physical activity. The author updates nurses on physical activity guidelines and provides tips for promoting physical activity, with a focus on lifestyle activities such as walking to work. This article also addresses new research findings on the importance of decreasing sedentary and sitting time, even in physically active people.

Sediment tracing in the upper Hunter catchment using elemental and mineralogical compositions: Implications for catchment-scale suspended sediment (dis)connectivity and management

Science.gov (United States)

Fryirs, Kirstie; Gore, Damian

2013-07-01

River bed colmation layers clog the interstices of gravel-bed rivers, impeding the vertical exchange of water and nutrients that drives ecosystem function in the hyporheic zone. In catchments where fine-grained sediment supply has increased since human disturbance, understanding sediment provenance and the (dis)connectivity of supply allows practitioners to target sediment source problems and treat them within catchment management plans. Release of alluvial fine-grained sediment from channel bank erosion since European settlement has resulted in the formation of a colmation layer along the upper Hunter River at Muswellbrook, eastern Australia. X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD) are used to determine the elemental and mineralogical signatures of colmation layer and floodplain sediment sources across this 4480 km2 catchment. This sediment tracing technique is used to construct a picture of how suspended sediment supply and (dis)connectivity operates in this catchment. In this system, the primary source areas are subcatchments in which sediments are stored largely in partly confined floodplain pockets, but from which sediment supply is unimpeded and directly connected to the receiving reach. Subcatchments in which alluvial sediment storage is significant — and which contain large, laterally unconfined valleys — are essentially 'switched off' or disconnected from the receiving reach. This is because large sediment sinks act to trap fine-grained sediment before it reaches the receiving reach, forming a buffer along the sediment conveyor belt. Given the age structure of floodplains in the receiving reach, this pattern of source area contributions and (dis)connectivity must have occurred throughout the Holocene.

Qualification diploma in radiological and medical physics. Evolution of the initial training of hospital physicists

International Nuclear Information System (INIS)

Hammadi, A.

2009-01-01

This series of slides presents: - the evolution of the radio-physicists training since its creation (history, 1995-2005 era, 2005-2009 changes); - the qualification diploma in radiological and medical physics (QDRMP - DQPRM in French) in figures (validating services, number of qualified people); - the QDRMP context and goals (strength needs, limited number of candidates); - the means implemented to reach the goals; - the perspectives (increase of students number, continuous training). (J.S.)

Evolution, Physics, and Cancer: Disrupting Traditional Approache

Science.gov (United States)

Austin, Robert

Physicists who were recruited to try and assist with the stubbornly constant mortality rates of cancer world-wide over the past 100 years have basically had the invitation withdrawn by the oncology community. The oncologists became annoyed with the independence of thought and the skepticism of some physicists with continuation of the present paradigm of the cancer genome as the rosette stone as the key to cancer. To quote a recent letter in Physics Today: ``Curing cancer is a complex biological problem to be solved by biologists''. Apparently our mission as minions is is to be high-level technicians. But I think that is wrong and will lead to continuation of the string of failures and deceptions foisted on the public at large by the Medical Industrial Complex, I think we really need to re-think cancer as a phenomena which is driven by evolution and may be desired by the organism and be a product of both the aging of the proteome and the genome. Further, searching for mutations (The Cancer Genome) may be completely the wrong direction, searching for protected genes may be as important as looking for mutated genes. I'll try to present the case that physicists should not have been kicked out of the Medical Industrial Complex that keeps the cancer business humming and profitable.

The Evolution of Physical Activity Promotion

OpenAIRE

Richards, Elizabeth

2015-01-01

Overview: A physically active lifestyle has numerous physical and mental health benefits for patients of all ages. Despite these significant benefits, a majority of Americans do not meet current physical activity guidelines. Health care providers, especially nurses, play a vital role in physical activity promotion. Over the past several decades, exercise and physical activity guidelines have evolved from a focus on structured, vigorous exercise to a focus on moderate-intensity “lifestyle” phy...

A Large Hadron Electron Collider at CERN, Physics, Machine, Detector

CERN Document Server

Adolphson, C

2011-01-01

The physics programme and the design are described of a new electron-hadron collider, the LHeC, in which electrons of $60$ to possibly $140$\\,GeV collide with LHC protons of $7000$\\,GeV. With an $ep$ design luminosity of about $10^{33}$\\,cm$^{-2}$s$^{-1}$, the Large Hadron Electron Collider exceeds the integrated luminosity collected at HERA by two orders of magnitude and the kinematic range by a factor of twenty in the four-momentum squared, $Q^2$, and in the inverse Bjorken $x$. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering (DIS) measurements. These are projected to solve a variety of fundamental questions in strong and electroweak interactions. The LHeC thus becomes the world's cleanest high resolution microscope, designed to continue the path of deep inelastic lepton-hadron scattering into unknown areas of physics and kinematics. The physics ...

Evolution operator equation: Integration with algebraic and finite difference methods. Applications to physical problems in classical and quantum mechanics and quantum field theory

Energy Technology Data Exchange (ETDEWEB)

Dattoli, Giuseppe; Torre, Amalia [ENEA, Centro Ricerche Frascati, Rome (Italy). Dipt. Innovazione; Ottaviani, Pier Luigi [ENEA, Centro Ricerche Bologna (Italy); Vasquez, Luis [Madris, Univ. Complutense (Spain). Dept. de Matemateca Aplicado

1997-10-01

The finite-difference based integration method for evolution-line equations is discussed in detail and framed within the general context of the evolution operator picture. Exact analytical methods are described to solve evolution-like equations in a quite general physical context. The numerical technique based on the factorization formulae of exponential operator is then illustrated and applied to the evolution-operator in both classical and quantum framework. Finally, the general view to the finite differencing schemes is provided, displaying the wide range of applications from the classical Newton equation of motion to the quantum field theory.

Alimentary Habits, Physical Activity, and Framingham Global Risk Score in Metabolic Syndrome

International Nuclear Information System (INIS)

Soares, Thays Soliman; Piovesan, Carla Haas; Gustavo, Andréia da Silva; Macagnan, Fabrício Edler; Bodanese, Luiz Carlos; Feoli, Ana Maria Pandolfo

2014-01-01

Metabolic syndrome is a complex disorder represented by a set of cardiovascular risk factors. A healthy lifestyle is strongly related to improve Quality of Life and interfere positively in the control of risk factors presented in this condition. To evaluate the effect of a program of lifestyle modification on the Framingham General Cardiovascular Risk Profile in subjects diagnosed with metabolic syndrome. A sub-analysis study of a randomized clinical trial controlled blind that lasted three months. Participants were randomized into four groups: dietary intervention + placebo (DIP), dietary intervention + supplementation of omega 3 (fish oil 3 g/day) (DIS3), dietary intervention + placebo + physical activity (DIPE) and dietary intervention + physical activity + supplementation of omega 3 (DIS3PE). The general cardiovascular risk profile of each individual was calculated before and after the intervention. The study included 70 subjects. Evaluating the score between the pre and post intervention yielded a significant value (p < 0.001). We obtained a reduction for intermediate risk in 25.7% of subjects. After intervention, there was a significant reduction (p < 0.01) on cardiovascular age, this being more significant in groups DIP (5.2%) and DIPE (5.3%). Proposed interventions produced beneficial effects for reducing cardiovascular risk score. This study emphasizes the importance of lifestyle modification in the prevention and treatment of cardiovascular diseases

Alimentary Habits, Physical Activity, and Framingham Global Risk Score in Metabolic Syndrome

Energy Technology Data Exchange (ETDEWEB)

Soares, Thays Soliman; Piovesan, Carla Haas; Gustavo, Andréia da Silva; Macagnan, Fabrício Edler; Bodanese, Luiz Carlos; Feoli, Ana Maria Pandolfo, E-mail: anamariafeoli@hotmail.com [Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil)

2014-04-15

Metabolic syndrome is a complex disorder represented by a set of cardiovascular risk factors. A healthy lifestyle is strongly related to improve Quality of Life and interfere positively in the control of risk factors presented in this condition. To evaluate the effect of a program of lifestyle modification on the Framingham General Cardiovascular Risk Profile in subjects diagnosed with metabolic syndrome. A sub-analysis study of a randomized clinical trial controlled blind that lasted three months. Participants were randomized into four groups: dietary intervention + placebo (DIP), dietary intervention + supplementation of omega 3 (fish oil 3 g/day) (DIS3), dietary intervention + placebo + physical activity (DIPE) and dietary intervention + physical activity + supplementation of omega 3 (DIS3PE). The general cardiovascular risk profile of each individual was calculated before and after the intervention. The study included 70 subjects. Evaluating the score between the pre and post intervention yielded a significant value (p < 0.001). We obtained a reduction for intermediate risk in 25.7% of subjects. After intervention, there was a significant reduction (p < 0.01) on cardiovascular age, this being more significant in groups DIP (5.2%) and DIPE (5.3%). Proposed interventions produced beneficial effects for reducing cardiovascular risk score. This study emphasizes the importance of lifestyle modification in the prevention and treatment of cardiovascular diseases.

Atomic physics

International Nuclear Information System (INIS)

Held, B.

1991-01-01

This general book describes the change from classical physics to quantum physics. The first part presents atom evolution since antiquity and introduces fundamental quantities and elements of relativity. Experiments which have contributed to the evolution of knowledge on matter are analyzed in the second part. Applications of wave mechanics to the study of matter properties are presented in the third part [fr

Geometric scaling behavior of the scattering amplitude for DIS with nuclei

Science.gov (United States)

Kormilitzin, Andrey; Levin, Eugene; Tapia, Sebastian

2011-12-01

The main question, that we answer in this paper, is whether the initial condition can influence on the geometric scaling behavior of the amplitude for DIS at high energy. We re-write the non-linear Balitsky-Kovchegov equation in the form which is useful for treating the interaction with nuclei. Using the simplified BFKL kernel, we find the analytical solution to this equation with the initial condition given by the McLerran-Venugopalan formula. This solution does not show the geometric scaling behavior of the amplitude deeply in the saturation region. On the other hand, the BFKL Pomeron calculus with the initial condition at x=1/mR given by the solution to Balitsky-Kovchegov equation, leads to the geometric scaling behavior. The McLerran-Venugopalan formula is the natural initial condition for the Color Glass Condensate (CGC) approach. Therefore, our result gives a possibility to check experimentally which approach: CGC or BFKL Pomeron calculus, is more satisfactory.

Geometric scaling behavior of the scattering amplitude for DIS with nuclei

International Nuclear Information System (INIS)

Kormilitzin, Andrey; Levin, Eugene; Tapia, Sebastian

2011-01-01

The main question, that we answer in this paper, is whether the initial condition can influence on the geometric scaling behavior of the amplitude for DIS at high energy. We re-write the non-linear Balitsky–Kovchegov equation in the form which is useful for treating the interaction with nuclei. Using the simplified BFKL kernel, we find the analytical solution to this equation with the initial condition given by the McLerran–Venugopalan formula. This solution does not show the geometric scaling behavior of the amplitude deeply in the saturation region. On the other hand, the BFKL Pomeron calculus with the initial condition at x A =1/mR A given by the solution to Balitsky–Kovchegov equation, leads to the geometric scaling behavior. The McLerran–Venugopalan formula is the natural initial condition for the Color Glass Condensate (CGC) approach. Therefore, our result gives a possibility to check experimentally which approach: CGC or BFKL Pomeron calculus, is more satisfactory.

Automating the Incremental Evolution of Controllers for Physical Robots.

Science.gov (United States)

Faíña, Andrés; Jacobsen, Lars Toft; Risi, Sebastian

2017-01-01

Evolutionary robotics is challenged with some key problems that must be solved, or at least mitigated extensively, before it can fulfill some of its promises to deliver highly autonomous and adaptive robots. The reality gap and the ability to transfer phenotypes from simulation to reality constitute one such problem. Another lies in the embodiment of the evolutionary processes, which links to the first, but focuses on how evolution can act on real agents and occur independently from simulation, that is, going from being, as Eiben, Kernbach, & Haasdijk [2012, p. 261] put it, "the evolution of things, rather than just the evolution of digital objects.…" The work presented here investigates how fully autonomous evolution of robot controllers can be realized in hardware, using an industrial robot and a marker-based computer vision system. In particular, this article presents an approach to automate the reconfiguration of the test environment and shows that it is possible, for the first time, to incrementally evolve a neural robot controller for different obstacle avoidance tasks with no human intervention. Importantly, the system offers a high level of robustness and precision that could potentially open up the range of problems amenable to embodied evolution.

On the energy dependence of DIS in the diffraction region of low x

Energy Technology Data Exchange (ETDEWEB)

Schildknecht, D. [Bielefeld, Univ., Fakultat fur Physik (Germany)

2005-07-01

The energy dependence of the virtual photoabsorption cross-section in deep inelastic scattering (DIS) at low x = Q{sup 2}/W{sup 2} < 0.1 may be described in terms of the saturation scale that in our approach depends on the energy, {lambda}{sup 2}{sub sat} = {lambda}{sup 2}{sub sat}(W{sup 2}). We briefly summarize our recent findings that allow us to predict the exponent C{sub 2} of {lambda}{sup 2}{sub sat}(W{sup 2}) {approx} (W{sup 2}){sup C{sub 2}} in agreement with the previous result obtained from fitting the experimental data. The exponent C{sub 2} depending on the relative magnitude of the longitudinal and transverse contribution to the structure function, direct measurements of the longitudinal part are urgently needed. (author)

Clinical applicability of nursing outcomes in the evolution of orthopedic patients with Impaired Physical Mobility.

Science.gov (United States)

da Silva, Marcos Barragan; Almeida, Miriam de Abreu; Panato, Bruna Paulsen; Siqueira, Ana Paula de Oliveira; da Silva, Mariana Palma; Reisderfer, Letícia

2015-01-01

to evaluate the clinical applicability of outcomes, according to the Nursing Outcomes Classification (NOC) in the evolution of orthopedic patients with Impaired Physical Mobility longitudinal study conducted in 2012 in a university hospital, with 21 patients undergoing Total Hip Arthroplasty, evaluated daily by pairs of trained data collectors. Data were collected using an instrument containing five Nursing Outcomes, 16 clinical indicators and a five point Likert scale, and statistically analyzed. The outcomes Body Positioning: self-initiated, Mobility, Knowledge: prescribed activity, and Fall Prevention Behavior presented significant increases in mean scores when comparing the first and final evaluations (p<0.001) and (p=0.035). the use of the NOC outcomes makes it possible to demonstrate the clinical progression of orthopedic patients with Impaired Physical Mobility, as well as its applicability in this context.

The x rescaling parameter' formula of the extended x rescaling model and the nuclear effect l-A DIS process

International Nuclear Information System (INIS)

Gao Yonghua; He Mingzhong; Duan Chungui

2003-01-01

The authors present an x rescaling parameters' formula for partons in the extended x rescaling model, where we have established the connection between the rescaling parameter and the mean binding energy. Using x rescaling parameters obtained by the x rescaling parameters' formula, we calculate the average nucleon structure function ratio of DIS process in l-A (Al, Ca, Pb) collision to l-C collision respectively. The result is in good agreement with experimental data

Stellar structure and evolution

International Nuclear Information System (INIS)

Kippernhahn, R.; Weigert, A.

1990-01-01

This book introduces the theory of the internal structure of stars and their evolution in time. It presents the basic physics of stellar interiors, methods for solving the underlying equations, and the most important results necessary for understanding the wide variety of stellar types and phenomena. The evolution of stars is discussed from their birth through normal evolution to possibly spectacular final stages. Chapters on stellar oscillations and rotation are included

Molybdenum and technetium cycle in the environment. Physical chemical evolution and mobility in soils and plants

International Nuclear Information System (INIS)

Saas, A.; Denardi, J.L.; Colle, C.; Quinault, J.M.

1980-01-01

Molybdenum 99 and technetium 99 from liquid discharges of base nuclear installations (reactors, reprocessing plants, UF 6 treatment, etc.) can reach the environment via irrigation waters and atmospheric deposits. The contribution to the soil by irrigation results in a physical-chemical transformation, the results of which, in the case of technetium 99, could be volatilization via microbes. The changes in the physical-chemical forms of technetium in different soils reveals the preponderant effect of the initial amount deposited. The determination of the rate of technetium and molybdenum assimilation shows a certain similarity in behaviour; yet the localization of these isotopes is not the same. The transfer of molybdenum and technetium via the root system is different in its intensity; this is mainly due to different physical-chemical forms. Finally, each isotope has an optimum assimilation threshold and a toxicity threshold. The study of the physical-chemical evolution and the mobility in the soil-plant-water table system of these two isotopes shows a new aspect with respect to certain transfer channels to the human being [fr

Sources and evolution of quantum physics

International Nuclear Information System (INIS)

Escoubes, B.

2005-01-01

The author has gathered in this book the founder articles of fundamental physics to illustrate the way how physics'ideas and concepts have emerged to form the modern physics we know today. The book is divided into 6 chapters: 1) from the Greek idea of matter to the discovery of radioactivity, 2) from relativity to quantification, 3) the devising of quantum mechanics, 4) from relativistic quantum mechanics to quantum field theory, 5) the great moments of particle physics, and 6) towards the great unification. 19 articles have been selected to illustrate the milestones of physics. Most are reproduced in full in their original texts. Among them we can find the article of Einstein about the existence of the photon, or the article of Pauli in which the exclusion principle is drafted or the article of Yukawa about the existence of the meson. The theoretical advances proposed in the articles are highlighted and put into perspective in discerning commentaries set in the different chapters. (A.C.)

Exponentiation of the Drell-Yan an cross section near partonic threshold in the DIS and MS-bar schemes

International Nuclear Information System (INIS)

Eynck, Tim Oliver; Laenen, Eric; Magnea, Lorenzo

2003-01-01

It has been observed that in the DIS scheme the refactorization of the Drell-Yan cross section leading to exponentiation of threshold logarithms can also be used to organize a class of constant terms, most of which arise from the ratio of the timelike Sudakov form factor to its spacelike counterpart. We extend this exponentiation to include all constant terms, and demonstrate how a similar organization may be achieved in the MS-bar scheme. We study the relevance of these exponentiations in a two-loop analysis. (author)

THE PROCESS OF SEPARATION AND INDIVIDUATION AS THE RISK FACTOR IN PSYCHOSOCIAL DEVELOPMENT OF PERSONS WITH PHYSICAL DISABILITIES

Directory of Open Access Journals (Sweden)

Simona OZHEK

2007-05-01

Full Text Available The process of separation and individuation is a developmental psychological process, which takes place at various phases of child development within his first three years of life. These phases include the Normal Autistic Phase, the Normal Symbiotic Phase, the Separation-Individuation Phase (with sub-phases Differentiation, Practicing and Rapprochement, On the Way to Object Con­stancy and the Final Separation and Psychological Birth of the Human Infant. Undisturbed transition through the developmental phases leads to the es­tablishment of psychological structure in the hu­man infant, which means that he reaches autonomy and independence, thus becoming an individual. For children which were born with physical dis­abilities and have their intellectual capacities pre­served (i.e. in cerebral palsy, muscular dystrophy etc., the fulfillment of this process is endangered, because their development was stuck at the Nor­mal Symbiotic Phase due to two types of factors. The first group represents factors of physical dis­ability (i.e. impossibility to move, obtain inde­pendent experiences and, consequently, the inabil­ity to detach from the Object, while the second group represents reactions to this hindrance (i.e. over-protection, which further thwarts attempts to detach from the Object.

Evolution: sympatric speciation the eusocial way

DEFF Research Database (Denmark)

Boomsma, Jacobus Jan; Nash, David Richard

2014-01-01

Sympatric speciation normally requires particular conditions of ecological niche differentiation. However, ant social parasites have been suspected to arise sympatrically, because (dis)loyalty to eusocial kin-structures induces disruptive selection for dispersal and inbreeding. A new study docume...

Quantum evolution life in the multiverse

CERN Document Server

McFadden, Johnjoe

2000-01-01

Quantum Evolution presents a revolutionary new scientific theory by asking: is there a force of will behind evolution? In his astonishing first book, Johnjoe McFadden shows that there is. 'McFadden's bold hypothesis that quantum physics plays a key role in the origin and evolution of life looks increasingly plausible. The weird behaviour of matter and information at the quantum level could be just what is needed to explain life's astonishing properties. If these ideas are right, they will transform our understanding of the relationship between physics and biology.' PAUL DAVIES In this brilliant debut, Johnjoe McFadden puts forward a theory of quantum evolution. He shows how living organisms have the ability to will themselves into action. Indeed, such an ability may be life's most fundamental attribute. This has radical implications. Evolution may not be random at all, as recent evolutionary theories have taught: rather, cells may, in certain circumstances, be able to choose to mutate particular genes that pr...

Witnessman: The software tool to design, analyse and assess a witness pack with respect to military and medical effects on an (UN)protected (DIS)mounted soldier

NARCIS (Netherlands)

Verhagen, Th.L.A.; Kemper, R.; Huisjes, H.; Knijnenburg, S.G.; Pronk, A.; Klink, M.H. van

2005-01-01

Witness packs are widely used to enable the characterization of fragments generated during ballistic experiments. To assess the effect of fragment impact on an exposed (dis)mounted soldier a follow-up Vulnerability/ Lethality (V/L) simulation is essential. The overall process is elaborative and time

Generalized Bell states map physical systems’ quantum evolution into a grammar for quantum information processing

Science.gov (United States)

Delgado, Francisco

2017-12-01

Quantum information processing should be generated through control of quantum evolution for physical systems being used as resources, such as superconducting circuits, spinspin couplings in ions and artificial anyons in electronic gases. They have a quantum dynamics which should be translated into more natural languages for quantum information processing. On this terrain, this language should let to establish manipulation operations on the associated quantum information states as classical information processing does. This work shows how a kind of processing operations can be settled and implemented for quantum states design and quantum processing for systems fulfilling a SU(2) reduction in their dynamics.

The Nietzsche’s “Error”, God is not Dead: the (dis enchantment of the world

Directory of Open Access Journals (Sweden)

Donizete Rodrigues

2017-10-01

Full Text Available From the Nietzsche’s emphasis that God is dead – basic principle of the secularization – and the concept of religion, from the substantivist and functionalist perspectives, this paper addresses the contribution of some authors, classical (Marx, Weber, Durkheim, Freud and modern (Eliade, Bourdieu, Habermas, Hervieu-Leger, Grace Davie, Heelas, in the important discussion of the (dis enchantment of the world. Another issue considered is the role of religion in the contemporary society, in the context of a “reenchanted” world, with significant changes in the “market of symbolic goods”, characterized by an individualization/privatization of faith, deterritorialization of the sacred space, religious pluralism (with new and diffused religious practices and by the phenomenon of Pentecostalism.

A physical map for the Amborella trichopoda genome sheds light on the evolution of angiosperm genome structure

OpenAIRE

Zuccolo, Andrea; Bowers, John E; Estill, James C; Xiong, Zhiyong; Luo, Meizhong; Sebastian, Aswathy; Goicoechea, Jos? Luis; Collura, Kristi; Yu, Yeisoo; Jiao, Yuannian; Duarte, Jill; Tang, Haibao; Ayyampalayam, Saravanaraj; Rounsley, Steve; Kudrna, Dave

2011-01-01

Background Recent phylogenetic analyses have identified Amborella trichopoda, an understory tree species endemic to the forests of New Caledonia, as sister to a clade including all other known flowering plant species. The Amborella genome is a unique reference for understanding the evolution of angiosperm genomes because it can serve as an outgroup to root comparative analyses. A physical map, BAC end sequences and sample shotgun sequences provide a first view of the 870 Mbp Amborella genome....

Mapping the evolution of scientific fields.

Science.gov (United States)

Herrera, Mark; Roberts, David C; Gulbahce, Natali

2010-05-04

Despite the apparent cross-disciplinary interactions among scientific fields, a formal description of their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society Physics and Astronomy Classification Scheme (PACS) numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using a community finding algorithm, and describe the time evolution of these fields over the course of 1985-2006. The communities we identify map to known scientific fields, and their age depends on their size and activity. We expect our approach to quantifying the evolution of ideas to be relevant for making predictions about the future of science and thus help to guide its development.

Cepheid evolution

International Nuclear Information System (INIS)

Becker, S.A.

1984-05-01

A review of the phases of stellar evolution relevant to Cepheid variables of both Types I and II is presented. Type I Cepheids arise as a result of normal post-main sequence evolutionary behavior of many stars in the intermediate to massive range of stellar masses. In contrast, Type II Cepheids generally originate from low-mass stars of low metalicity which are undergoing post core helium-burning evolution. Despite great progress in the past two decades, uncertainties still remain in such areas as how to best model convective overshoot, semiconvection, stellar atmospheres, rotation, and binary evolution as well as uncertainties in important physical parameters such as the nuclear reaction rates, opacity, and mass loss rates. The potential effect of these uncertainties on stellar evolution models is discussed. Finally, comparisons between theoretical predictions and observations of Cepheid variables are presented for a number of cases. The results of these comparisons show both areas of agreement and disagreement with the latter result providing incentive for further research

The Influence of (Dis)belief in Free Will on Immoral Behavior.

Science.gov (United States)

Caspar, Emilie A; Vuillaume, Laurène; Magalhães De Saldanha da Gama, Pedro A; Cleeremans, Axel

2017-01-01

One of the hallmarks of human existence is that we all hold beliefs that determine how we act. Amongst such beliefs, the idea that we are endowed with free will appears to be linked to prosocial behaviors, probably by enhancing the feeling of responsibility of individuals over their own actions. However, such effects appear to be more complex that one might have initially thought. Here, we aimed at exploring how induced disbeliefs in free will impact the sense of agency over the consequences of one's own actions in a paradigm that engages morality. To do so, we asked participants to choose to inflict or to refrain from inflicting an electric choc to another participant in exchange of a small financial benefit. Our results show that participants who were primed with a text defending neural determinism - the idea that humans are a mere bunch of neurons guided by their biology - administered fewer shocks and were less vindictive toward the other participant. Importantly, this finding only held for female participants. These results show the complex interaction between gender, (dis)beliefs in free will and moral behavior.

Are there laws of genome evolution?

Directory of Open Access Journals (Sweden)

Eugene V Koonin

2011-08-01

Full Text Available Research in quantitative evolutionary genomics and systems biology led to the discovery of several universal regularities connecting genomic and molecular phenomic variables. These universals include the log-normal distribution of the evolutionary rates of orthologous genes; the power law-like distributions of paralogous family size and node degree in various biological networks; the negative correlation between a gene's sequence evolution rate and expression level; and differential scaling of functional classes of genes with genome size. The universals of genome evolution can be accounted for by simple mathematical models similar to those used in statistical physics, such as the birth-death-innovation model. These models do not explicitly incorporate selection; therefore, the observed universal regularities do not appear to be shaped by selection but rather are emergent properties of gene ensembles. Although a complete physical theory of evolutionary biology is inconceivable, the universals of genome evolution might qualify as "laws of evolutionary genomics" in the same sense "law" is understood in modern physics.

A simple model for binary star evolution

International Nuclear Information System (INIS)

Whyte, C.A.; Eggleton, P.P.

1985-01-01

A simple model for calculating the evolution of binary stars is presented. Detailed stellar evolution calculations of stars undergoing mass and energy transfer at various rates are reported and used to identify the dominant physical processes which determine the type of evolution. These detailed calculations are used to calibrate the simple model and a comparison of calculations using the detailed stellar evolution equations and the simple model is made. Results of the evolution of a few binary systems are reported and compared with previously published calculations using normal stellar evolution programs. (author)

THE PSEUDO-EVOLUTION OF HALO MASS

International Nuclear Information System (INIS)

Diemer, Benedikt; Kravtsov, Andrey V.; More, Surhud

2013-01-01

A dark matter halo is commonly defined as a spherical overdensity of matter with respect to a reference density, such as the critical density or the mean matter density of the universe. Such definitions can lead to a spurious pseudo-evolution of halo mass simply due to redshift evolution of the reference density, even if its physical density profile remains constant over time. We estimate the amount of such pseudo-evolution of mass between z = 1 and 0 for halos identified in a large N-body simulation, and show that it accounts for almost the entire mass evolution of the majority of halos with M 200ρ-bar ≲ 10 12 h -1 M ☉ and can be a significant fraction of the apparent mass growth even for cluster-sized halos. We estimate the magnitude of the pseudo-evolution assuming that halo density profiles remain static in physical coordinates, and show that this simple model predicts the pseudo-evolution of halos identified in numerical simulations to good accuracy, albeit with significant scatter. We discuss the impact of pseudo-evolution on the evolution of the halo mass function and show that the non-evolution of the low-mass end of the halo mass function is the result of a fortuitous cancellation between pseudo-evolution and the absorption of small halos into larger hosts. We also show that the evolution of the low-mass end of the concentration-mass relation observed in simulations is almost entirely due to the pseudo-evolution of mass. Finally, we discuss the implications of our results for the interpretation of the evolution of various scaling relations between the observable properties of galaxies and galaxy clusters and their halo masses.

Automating the Incremental Evolution of Controllers for Physical Robots

DEFF Research Database (Denmark)

Faina, Andres; Jacobsen, Lars Toft; Risi, Sebastian

2017-01-01

the evolution of digital objects.…” The work presented here investigates how fully autonomous evolution of robot controllers can be realized in hardware, using an industrial robot and a marker-based computer vision system. In particular, this article presents an approach to automate the reconfiguration...... of the test environment and shows that it is possible, for the first time, to incrementally evolve a neural robot controller for different obstacle avoidance tasks with no human intervention. Importantly, the system offers a high level of robustness and precision that could potentially open up the range...

Weldon's Search for a Direct Proof of Natural Selection and the ...

Indian Academy of Sciences (India)

Plants under Domestication in 1868, there was considerable dis- agreement about whether natural selection could indeed work the. Keywords. Evolution, struggle for existence, natural selection, type, variations, heredity, biometrics, Mendelism. way Darwin had suggested and be the driving engine of adap- tive evolution.

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.

Modularity and Sparsity: Evolution of Neural Net Controllers in Physically Embodied Robots

Directory of Open Access Journals (Sweden)

Nicholas Livingston

2016-12-01

Full Text Available While modularity is thought to be central for the evolution of complexity and evolvability, it remains unclear how systems boot-strap themselves into modularity from random or fully integrated starting conditions. Clune et al. (2013 suggested that a positive correlation between sparsity and modularity is the prime cause of this transition. We sought to test the generality of this modularity-sparsity hypothesis by testing it for the first time in physically embodied robots. A population of ten Tadros — autonomous, surface-swimming robots propelled by a flapping tail — was used. Individuals varied only in the structure of their neural net control, a 2 x 6 x 2 network with recurrence in the hidden layer. Each of the 60 possible connections was coded in the genome, and could achieve one of three states: -1, 0, 1. Inputs were two light-dependent resistors and outputs were two motor control variables to the flapping tail, one for the frequency of the flapping and the other for the turning offset. Each Tadro was tested separately in a circular tank lit by a single overhead light source. Fitness was the amount of light gathered by a vertically oriented sensor that was disconnected from the controller net. Reproduction was asexual, with the top performer cloned and then all individuals entered into a roulette wheel selection process, with genomes mutated to create the offspring. The starting population of networks was randomly generated. Over ten generations, the population’s mean fitness increased two-fold. This evolution occurred in spite of an unintentional integer overflow problem in recurrent nodes in the hidden layer that caused outputs to oscillate. Our investigation of the oscillatory behavior showed that the mutual information of inputs and outputs was sufficient for the reactive behaviors observed. While we had predicted that both modularity and sparsity would follow the same trend as fitness, neither did so. Instead, selection gradients

Nonlinear evolution equations having a physical meaning

International Nuclear Information System (INIS)

Nakach, R.

1976-06-01

The non stationary self-similar solutions of the nonlinear evolution equations which can be solved by the inverse scattering method are studied. It turns out, as shown by means of several examples, that when the L linear operator associated with these equations, is of second order and only then, the self-similar solutions can be expressed in terms of the various Painleve's transcendents [fr

Asteroid families - Physical properties and evolution

International Nuclear Information System (INIS)

Chapman, C.R.; Paolicchi, P.; Zappala, V.; Binzel, R.P.; Bell, J.F.

1989-01-01

Asteroid families are considered to be fragments from collisional destruction of precursor bodies. However, results available on the inferred mineralogy, size distributions, and spins of family members do not confirm the expectations of the traditional model. Only a handful of nearly 100 proposed families, most of them populous, have distributions of inferred mineralogies consistent with simple cosmochemical models for parent bodies. It is suggested that most catastrophic collisions may not result in observable families, but rather in a spray of smaller particles, thus accounting for the small number of confirmed and consistent families, despite evidence for extensive collisional evolution of asteroids. 52 refs

Stellar Structure and Evolution

CERN Document Server

Kippenhahn, Rudolf; Weiss, Achim

2013-01-01

This long-awaited second edition of the classical textbook on Stellar Structure and Evolution by Kippenhahn and Weigert is a thoroughly revised version of the original text. Taking into account modern observational constraints as well as additional physical effects such as mass loss and diffusion, Achim Weiss and Rudolf Kippenhahn have succeeded in bringing the book up to the state-of-the-art with respect to both the presentation of stellar physics and the presentation and interpretation of current sophisticated stellar models. The well-received and proven pedagogical approach of the first edition has been retained. The book provides a comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The models developed to explain the stability, dynamics and evolution of the stars are presented and great care is taken to detail the various stages in a star’s life. Just as the first edition, which remained a standard work for more than 20 years after its...

International conference on the performance of engineered barriers. Physical and chemical properties, behaviour and evolution. Short abstracts

Energy Technology Data Exchange (ETDEWEB)

Schaefers, Annika; Fahland, Sandra (eds.)

2014-08-01

The volume includes the abstracts of the papers presented at the international conference on the performance of engineered barrier systems, their physical and chemical properties, behavior and evolution. The papers cover the topics bentonite buffers, radioactive waste repository safety, geophysical and geochemical property monitoring, repository sealing materials, thermo-hydro-mechanical characterization, gas injection tests, hydration and heating tests, clay-iron interaction experiments, water retention behavior, thermal stability of materials, numerical modeling studies, long-term simulations, thermo-hydrologic phenomena, uncertainty and sensitivity studies, probabilistic assessments, preliminary safety analyses of Gorleben.

Physical Properties and Evolution of the Eclipsing Binary System XZ Canis Minoris

Science.gov (United States)

Poochaum, R.; Komonjinda, S.; Soonthornthum, B.; Rattanasoon, S.

2010-07-01

This research aims to study the eclipse binary system so that its physical properties and evolution can be determined and used as an example to teach high school astronomy. The study of an eclipsing binary system XZ Canis Minoris (XZ CMi) was done at Sirindhorn Observatory, Chiang Mai University using a 0.5-meter reflecting telescope with CCD photometric system (2184×1417 pixel) in B V and R bands of UVB System. The data obtained were used to construct the light curve for each wavelength band and to compute the times of its light minima. New elements were derived using observations with linear to all available minima. As a result, linear ephemeris is HDJmin I = .578 808 948+/-0.000 000 121+2450 515.321 26+/-0.001 07 E, and the new orbital period of XZ CMi is 0.578 808 948+/-0.000 000 121 day. The values obtained were used with the previously published times of minima to get O-C curve of XZ CMi. The result revealed that the orbital period of XZ CMi is continuously decreased at a rate of 0.007 31+/-0.000 57 sec/year. This result indicates that the binary stars are moving closer continuously. From the O-C residuals, there is significant change to indicate the existence of the third body or magnetic activity cycle on the star. However, further analysis of the physical properties of XZ CMi is required.

Gravitational coupling to two-particle bound states and momentum conservation in deep inelastic scattering

International Nuclear Information System (INIS)

Batiz, Zoltan; Gross, Franz

2000-01-01

The momentum conservation sum rule for deep inelastic scattering (DIS) from composite particles is investigated using the general theory of relativity. For two (1+1)-dimensional examples, it is shown that covariant theories automatically satisy the DIS momentum conservation sum rule provided the bound state is covariantly normalized. Therefore, in these cases the two DIS sum rules for baryon conservation and momentum conservation are equivalent. (c) 2000 The American Physical Society

Metadata to Support Data Warehouse Evolution

Science.gov (United States)

Solodovnikova, Darja

The focus of this chapter is metadata necessary to support data warehouse evolution. We present the data warehouse framework that is able to track evolution process and adapt data warehouse schemata and data extraction, transformation, and loading (ETL) processes. We discuss the significant part of the framework, the metadata repository that stores information about the data warehouse, logical and physical schemata and their versions. We propose the physical implementation of multiversion data warehouse in a relational DBMS. For each modification of a data warehouse schema, we outline the changes that need to be made to the repository metadata and in the database.

Physical experiments and analysis on the generation and evolution of tsunami-induced turbulent coherent structures

Science.gov (United States)

Kalligeris, Nikos; Lynett, Patrick

2017-11-01

Numerous historical accounts describe the formation of ``whirpools'' inside ports and harbors during tsunami events, causing port operation disruptions. Videos from the Japan 2011 tsunami revealed complex nearshore flow patters, resulting from the interaction of tsunami-induced currents with the man-made coastline, and the generation of large eddies (or turbulent coherent structures) in numerous ports and harbors near the earthquake epicenter. The aim of this work is to study the generation and evolution of tsunami-induced turbulent coherent structures (TCS) in a well-controlled environment using realistic scaling. A physical configuration is created in the image of a port entrance at a scale of 1:27 and a small-amplitude, long period wave creates a transient flow through the asymmetric harbor channel. A separated region forms, which coupled with the transient flow, leads to the formation of a stable monopolar TCS. The surface flow is examined through mono- and stereo-PTV techniques to extract surface velocity vectors. Surface velocity maps and vortex flow profiles are used to study the experimental TCS generation and evolution, and characterize the TCS structure. Analytical tools are used to describe the TCS growth rate and kinetic energy decay. This work was funded by the National Science Foundation NEES Research program, with Award Number 1135026.

Small-x physics

Energy Technology Data Exchange (ETDEWEB)

Mueller, A.H. [Columbia Univ., New York, NY (United States). Dept. of Physics

1997-06-01

After a brief review of the kinematics of deep inelastic lepton-proton scattering, the parton model is described. Small-x behavior coming from DGLAP evolution and from BFKL evolution is discussed, and the two types of evolution are contrasted and compared. Then a more detailed discussion of BFKL dynamics is given. The phenomenology of small-x physics is discussed with an emphasis on ways in which BFKL dynamics may be discussed and measured. 45 refs., 12 figs.

Evolution Engines and Artificial Intelligence

Science.gov (United States)

Hemker, Andreas; Becks, Karl-Heinz

In the last years artificial intelligence has achieved great successes, mainly in the field of expert systems and neural networks. Nevertheless the road to truly intelligent systems is still obscured. Artificial intelligence systems with a broad range of cognitive abilities are not within sight. The limited competence of such systems (brittleness) is identified as a consequence of the top-down design process. The evolution principle of nature on the other hand shows an alternative and elegant way to build intelligent systems. We propose to take an evolution engine as the driving force for the bottom-up development of knowledge bases and for the optimization of the problem-solving process. A novel data analysis system for the high energy physics experiment DELPHI at CERN shows the practical relevance of this idea. The system is able to reconstruct the physical processes after the collision of particles by making use of the underlying standard model of elementary particle physics. The evolution engine acts as a global controller of a population of inference engines working on the reconstruction task. By implementing the system on the Connection Machine (Model CM-2) we use the full advantage of the inherent parallelization potential of the evolutionary approach.

Velocidad de crecimiento de grietas por corrosión bajo tensión en soldaduras disímiles

Directory of Open Access Journals (Sweden)

Fernández, María del Pilar

2000-02-01

Full Text Available Dissimilar welds, used to join different sections in light water reactors, are potentially susceptible to stress corrosion cracking (SCC in aqueous mediums characteristic of nuclear plants. However, the study of these welds has been limited to evaluating the weld material susceptibility in these mediums. Little scarce data are available on crack growth rates due, fundamentally, to inadequate testing techniques. In order to address this lack of information the crack growth rate at the interface of ferritic SA533B-1 alloy and alloy 1-82, in a dissimilar weld (SA533B-1/I-82/316L, was studied. Experiments were conducted in water at 288 °C, 8 ppm of O₂ and 1 μS/cm conductivity.

Las soldaduras disímiles, que son utilizadas para unir diferentes partes en los reactores de agua ligera, son potencialmente susceptibles de experimentar corrosión bajo tensión (SCC en los medios acuosos característicos de las plantas nucleares. Sin embargo, el estudio de estas soldaduras ha estado limitado a evaluar en dichos medios la susceptibilidad a SCC de los materiales que componen las mismas por separado, existiendo pocos datos de velocidad de crecimiento de grietas debido fundamentalmente a la falta de estandarización de este tipo de ensayos. En este trabajo se ha pretendido determinar la velocidad de crecimiento de grietas en la interfase formada por el acero ferrítico SA533B-1y la aleación I-82 dentro de la soldadura disímil compuesta por el acero SA533B-1/I-82/316L en unas condiciones de química del agua correspondientes a 8 ppm de O₂, una conductividad de 1 μS/cm y a una temperatura de 288 °C.

Particle physics and cosmology

International Nuclear Information System (INIS)

Kolb, E.W.

1986-10-01

This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs

Spatial distribution, luminosity function and cosmological evolution of quasars

International Nuclear Information System (INIS)

Mathez, G.

1981-01-01

The different ways of studying quasars statistics and evolution are reviewed. Attempt is given to deduce, from the observed evolution, some constraints on physical models of energy sources in quasars [fr

Hsp27 gene in Drosophila ananassae subgroup was split by a ...

Indian Academy of Sciences (India)

To investigate the molecular evolution of Hsp27 in the .... genetic evolution, as base composition bias is known to dis- tort determination of phylogenetic relationships in simulated datasets ... examined using unbiased tests with CONSEL (Shimodaira .... ACD is still unclear, however, mutations of a conserved argi- nine in the ...

Evolution of interstellar grains

International Nuclear Information System (INIS)

Greenberg, J.M.

1984-01-01

The principal aim of this chapter is to derive the properties of interstellar grains as a probe of local physical conditions and as a basis for predicting such properties as related to infrared emissivity and radiative transfer which can affect the evolution of dense clouds. The first sections will develop the criteria for grain models based directly on observations of gas and dust. A summary of the chemical evolution of grains and gas in diffuse and dense clouds follows. (author)

Chemical, physical, and optical evolution of biomass burning aerosols: a case study

Science.gov (United States)

Adler, G.; Flores, J. M.; Abo Riziq, A.; Borrmann, S.; Rudich, Y.

2011-02-01

In-situ chemical composition measurements of ambient aerosols have been used for characterizing the evolution of submicron aerosols from a large anthropogenic biomass burning (BB) event in Israel. A high resolution Time of Flight Aerosol Mass Spectrometer (HR-RES-TOF-AMS) was used to follow the chemical evolution of BB aerosols during a night-long, extensive nationwide wood burning event and during the following day. While these types of extensive BB events are not common in this region, burning of agricultural waste is a common practice. The aging process of the BB aerosols was followed through their chemical, physical and optical properties. Mass spectrometric analysis of the aerosol organic component showed that aerosol aging is characterized by shifting from less oxidized fresh BB aerosols to more oxidized aerosols. Evidence for aerosol aging during the day following the BB event was indicated by an increase in the organic mass, its oxidation state, the total aerosol concentration, and a shift in the modal particle diameter. The effective broadband refractive index (EBRI) was derived using a white light optical particle counter (WELAS). The average EBRI for a mixed population of aerosols dominated by open fires was m = 1.53(±0.03) + 0.07i(±0.03), during the smoldering phase of the fires we found the EBRI to be m = 1.54(±0.01) + 0.04i(±0.01) compared to m = 1.49(±0.01) + 0.02i(±0.01) of the aged aerosols during the following day. This change indicates a decrease in the overall aerosol absorption and scattering. Elevated levels of particulate Polycyclic Aromatic Hydrocarbons (PAHs) were detected during the entire event, which suggest possible implications for human health during such extensive event.

Methodology of radionuclides dis incorporation in people related to nuclear and radiological accidents

International Nuclear Information System (INIS)

Jimenez F, E. A.

2014-01-01

allow obtain a better result of the dis incorporation of the radioactive material. In this work, the attention is focused on the identification, classification and selection of the methodologies to accelerate the dis incorporation of radionuclides in people related to nuclear a radiological accidents, depending on the way of incorporation to the human body, the radionuclide, the radiotoxicity, the kind of radiation and its energy, the chemical compound, the half-life of the radioisotope, the target organ, the esteem of the absorbed dose, the characteristic of the accident, the clinical state of the patient and how long ago the accident happened. (Author)

Physical processes affecting the motion of small bodies in the solar system and their application to the evolution of meteor streams

International Nuclear Information System (INIS)

Williams, I.P.

1983-01-01

In addition to planetary perturbations, the small particles which make up a meteor stream are subject to outward radiation pressure and the Poynting-Robertson effect. New particles can also be generated in a stream through being released from the nucleus of a comet. The author summarises the main physical effects, discusses models for meteor stream evolution and gives a brief account of the observational data available. (Auth.)

Feminist Physics Education: Deconstructed Physics and Students' Multiple Subjectivities

Science.gov (United States)

Jammula, Diane Crenshaw

ameliorate differences in achievement, participation and feelings towards physics. Findings show how students (dis)connect with physics in both stereotypical and atypical ways; for example, one student drew from a classed identity to reject physics (e.g. "working was always in my DNA, but school is never really for me") and another student related his classed and gendered work as a mechanic to learn physics. Traditional aspects of the physics curriculum privileged discourse, performances, and epistemology associated with middle class white masculinity. The statement "I might nit pick it because I did it my way" is characteristic of competitive, assertive, self-interested discourse during problem presentations, taken up by male and female students. However, students engaged in other ways of doing physics that were personal, emotional, caring, inclusive and collaborative. A male student wrote, "Everyone is engaging and I feel that this class is like a family." Some students developed positive physics identities as they redefined physics: "When I experience physics on my own in anytime in a day or week, I feel like a physics person." Implications include interrogating beliefs about physics and students, and examining one's own practices such that the "smog of bias" (Kost-Smith, Pollock, & Finkelstein, 2010) may be demystified.

Correlation of electrical and physical properties of photoanode with hydrogen evolution in enzymatic photo-electrochemical cell

Energy Technology Data Exchange (ETDEWEB)

Bae, Sanghyun; Kang, Junwon [Department of Environmental Engineering, Yonsei University, 234 Maeji-ri, Hungub-myun, Wonju, Gangwon-do 220-710 (Korea); Shim, Eunjung [Department of Chemistry, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejeon 305-764 (Korea); Yoon, Jaekyung; Joo, Hyunku [Fossil Energy and Environment Research Department, Korea Institute of Energy Research, 71-2 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea)

2008-05-01

In this study, the electrical and physical properties, including the current density, open-circuit voltage, morphology and crystalline structure, of an anodized TiO{sub 2} electrode on a titanium foil are correlated with the hydrogen production rate in an enzymatic photo-electrochemical system. The effect of light intensity at ca. 74 and ca. 146 mW cm{sup -2} on the properties is also examined. Anodizing (20 V; bath temperature 5 C; anodizing time 45 min) and subsequent annealing (350-850 C for 5 h) of the Ti foils in an O{sub 2} atmosphere led to the formation of a tube-shaped, or a compact layered, TiO{sub 2} film on the Ti substrate depending on the annealing temperature. The annealing temperature has a similar effect on the properties of the sample and the hydrogen evolution rate. The generated electrical value, the chronoamperometry (CA), is +13 to -229 and +13 to -247 {mu}A for light intensities of ca. 74 and ca. 146 mW cm{sup -2}, while the corresponding open-circuit voltage (OCV) is in the range of -41 to -687 and -144 to 738 mV, respectively. In the absence of light (dark), the CA is 13-29 {mu}A and the OCV is +258 to -126 mW cm{sup -2}. The trend in the electrical properties for the different samples is well matched with the rate of hydrogen evolution. The samples with higher activities (450, 550, and 650 C) have similar X-ray diffraction (XRD) patterns, which clearly indicates that the samples showing the highest evolution rate are composed of both anatase and rutile, while those showing a lower evolution rate are made of either anatase or rutile. Increasing the intensity of the irradiated light causes a remarkable enhancement in the rate of hydrogen production from 71 to 153 {mu}mol h{sup -1} cm{sup -2}. (author)

Evolution algebras generated by Gibbs measures

International Nuclear Information System (INIS)

Rozikov, Utkir A.; Tian, Jianjun Paul

2009-03-01

In this article we study algebraic structures of function spaces defined by graphs and state spaces equipped with Gibbs measures by associating evolution algebras. We give a constructive description of associating evolution algebras to the function spaces (cell spaces) defined by graphs and state spaces and Gibbs measure μ. For finite graphs we find some evolution subalgebras and other useful properties of the algebras. We obtain a structure theorem for evolution algebras when graphs are finite and connected. We prove that for a fixed finite graph, the function spaces have a unique algebraic structure since all evolution algebras are isomorphic to each other for whichever Gibbs measures are assigned. When graphs are infinite graphs then our construction allows a natural introduction of thermodynamics in studying of several systems of biology, physics and mathematics by theory of evolution algebras. (author)

Leading order determination of the gluon polarisation from DIS events with high-$p_T$ hadron pairs

CERN Document Server

Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Antonov, A A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Burtin, E; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O.Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; jr., M.Finger; Fischer, H; Franco, C; von Hohenesche, N.du Fresne; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Hedicke, S; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Hoppner, Ch; d'Hose, N; Huber, S; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu.A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kunne, F.; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu.V; Moinester, M A; Morreale, A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J P; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nowak, W D; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S.; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Procureur, S L; Quaresma, M; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Rocco, E; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S.; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C.; Schluter, T; Schmidt, K; Schmitt, L; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O.Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Sznajder, P; Takekawa, S; Wolbeek, J.Ter; Tessaro, S; Tessarotto, F; Tkatchev, L G; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vlassov, N V; Wang, L; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhuravlev, N; Zvyagin, A

2013-01-01

We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam scattering off a polarised ^6LiD target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x_g. Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09 and a scale of mu^2 = 3~(GeV/c)^2.

Nonlinear evolution equations

CERN Document Server

Uraltseva, N N

1995-01-01

This collection focuses on nonlinear problems in partial differential equations. Most of the papers are based on lectures presented at the seminar on partial differential equations and mathematical physics at St. Petersburg University. Among the topics explored are the existence and properties of solutions of various classes of nonlinear evolution equations, nonlinear imbedding theorems, bifurcations of solutions, and equations of mathematical physics (Navier-Stokes type equations and the nonlinear Schrödinger equation). The book will be useful to researchers and graduate students working in p

Attractors for equations of mathematical physics

CERN Document Server

Chepyzhov, Vladimir V

2001-01-01

One of the major problems in the study of evolution equations of mathematical physics is the investigation of the behavior of the solutions to these equations when time is large or tends to infinity. The related important questions concern the stability of solutions or the character of the instability if a solution is unstable. In the last few decades, considerable progress in this area has been achieved in the study of autonomous evolution partial differential equations. For a number of basic evolution equations of mathematical physics, it was shown that the long time behavior of their soluti

Slowly switching between environments facilitates reverse evolution in small populations

Science.gov (United States)

Tan, Longzhi; Gore, Jeff

2011-03-01

The rate at which a physical process occurs usually changes the behavior of a system. In thermodynamics, the reversibility of a process generally increases when it occurs at an infinitely slow rate. In biological evolution, adaptations to a new environment may be reversed by evolution in the ancestral environment. Such fluctuating environments are ubiquitous in nature, although how the rate of switching affects reverse evolution is unknown. Here we use a computational approach to quantify evolutionary reversibility as a function of the rate of switching between two environments. For small population sizes, which travel on landscapes as random walkers, we find that both genotypic and phenotypic reverse evolution increase at slow switching rates. However, slow switching of environments decreases evolutionary reversibility for a greedy walker, corresponding to large populations (extensive clonal interference). We conclude that the impact of the switching rate for biological evolution is more complicated than other common physical processes, and that a quantitative approach may yield significant insight into reverse evolution.

Measurement of multiplicity and momentum spectra in the current fragmentation region of the Breit frame at HERA

International Nuclear Information System (INIS)

Derrick, M.; Krakauer, D.; Magill, S.

1995-01-01

Charged particle production has been measured in Deep Inelastic Scattering (DIS) events using the ZEUS detector over a large range of Q 2 from 10 to 1280 GeV 2 . The evolution with Q of the charged multiplicity and scaled momentum has been investigated in the current fragmentation region of the Breit frame. The data are used to study QCD coherence effects in DIS and are compared with corresponding e + e - data in order to test the universality of quark fragmentation. (orig.)

Modeling shoreface profile evolution

NARCIS (Netherlands)

Stive, M.J.F.; De Vriend, H.J.

1995-01-01

Current knowledge of hydro-, sediment and morpho-dynamics in the shoreface environment is insufficient to undertake shoreface-profile evolution modelling on the basis of first physical principles. We propose a simple, panel-type model to map observed behaviour. The internal dynamics are determined

Modelling shoreface profile evolution

NARCIS (Netherlands)

Stive, Marcel J.F.; de Vriend, Huib J.

1995-01-01

Current knowledge of hydro-, sediment and morpho-dynamics in the shoreface environment is insufficient to undertake shoreface-profile evolution modelling on the basis of first physical principles. We propose a simple, panel-type model to map observed behaviour. The internal dynamics are determined

The Energy Industry Profile of ISO/DIS 19115-1: Facilitating Discovery and Evaluation of, and Access to Distributed Information Resources

Science.gov (United States)

Hills, S. J.; Richard, S. M.; Doniger, A.; Danko, D. M.; Derenthal, L.; Energistics Metadata Work Group

2011-12-01

A diverse group of organizations representative of the international community involved in disciplines relevant to the upstream petroleum industry, - energy companies, - suppliers and publishers of information to the energy industry, - vendors of software applications used by the industry, - partner government and academic organizations, has engaged in the Energy Industry Metadata Standards Initiative. This Initiative envisions the use of standard metadata within the community to enable significant improvements in the efficiency with which users discover, evaluate, and access distributed information resources. The metadata standard needed to realize this vision is the initiative's primary deliverable. In addition to developing the metadata standard, the initiative is promoting its adoption to accelerate realization of the vision, and publishing metadata exemplars conformant with the standard. Implementation of the standard by community members, in the form of published metadata which document the information resources each organization manages, will allow use of tools requiring consistent metadata for efficient discovery and evaluation of, and access to, information resources. While metadata are expected to be widely accessible, access to associated information resources may be more constrained. The initiative is being conducting by Energistics' Metadata Work Group, in collaboration with the USGIN Project. Energistics is a global standards group in the oil and natural gas industry. The Work Group determined early in the initiative, based on input solicited from 40+ organizations and on an assessment of existing metadata standards, to develop the target metadata standard as a profile of a revised version of ISO 19115, formally the "Energy Industry Profile of ISO/DIS 19115-1 v1.0" (EIP). The Work Group is participating on the ISO/TC 211 project team responsible for the revision of ISO 19115, now ready for "Draft International Standard" (DIS) status. With ISO 19115 an

Evolution of White Dwarf Stars

OpenAIRE

L. G. Althaus

2001-01-01

This paper is aimed at presenting the main results we have obtained for the study of the evoution of white dwarf stars. The calculations are carried out by means of a detailed evolutionary code based on an updated physical description. In particular, we briefly discuss the results for the evolution of white dwarfs of different stellar masses and chemical composition, and the evolution of whit e dwarfs in the framework of a varying gravitational constant G scenario as well.

Chemical and physical drivers of the evolution of organic aerosols over forests

NARCIS (Netherlands)

Janssen, R.H.H.

2013-01-01

Diurnal evolution of organic aerosol over boreal and tropical forests

The first research question of this thesis is: how do local surface forcings and large-scale meteorological forcings shape the evolution of organic aerosol over the boreal and tropical forest? This

Concepts of particle physics

International Nuclear Information System (INIS)

Gottfried, K.; Weisskopf, V.F.

1984-01-01

This volume elucidates basic and well-established concepts of particle physics for the autodidact who is curious about recent developments in fundamental physics. Elementary quantum mechanics is a background must. Contents, abridged: The evolution of the particle concept before the advent of quantum mechanics. Nonrelativistic quantum mechanics and atomic physics. Relativistic quantum theory. Nuclear phenomena. Subnuclear phenomena. Index

Investigating ice cliff evolution and contribution to glacier mass-balance using a physically-based dynamic model

Science.gov (United States)

Buri, Pascal; Miles, Evan; Ragettli, Silvan; Brun, Fanny; Steiner, Jakob; Pellicciotti, Francesca

2016-04-01

Supraglacial cliffs are a surface feature typical of debris-covered glaciers, affecting surface evolution, glacier downwasting and mass balance by providing a direct ice-atmosphere interface. As a result, melt rates can be very high and ice cliffs may account for a significant portion of the total glacier mass loss. However, their contribution to glacier mass balance has rarely been quantified through physically-based models. Most cliff energy balance models are point scale models which calculate energy fluxes at individual cliff locations. Results from the only grid based model to date accurately reflect energy fluxes and cliff melt, but modelled backwasting patterns are in some cases unrealistic, as the distribution of melt rates would lead to progressive shallowing and disappearance of cliffs. Based on a unique multitemporal dataset of cliff topography and backwasting obtained from high-resolution terrestrial and aerial Structure-from-Motion analysis on Lirung Glacier in Nepal, it is apparent that cliffs exhibit a range of behaviours but most do not rapidly disappear. The patterns of evolution cannot be explained satisfactorily by atmospheric melt alone, and are moderated by the presence of supraglacial ponds at the base of cliffs and by cliff reburial with debris. Here, we document the distinct patterns of evolution including disappearance, growth and stability. We then use these observations to improve the grid-based energy balance model, implementing periodic updates of the cliff geometry resulting from modelled melt perpendicular to the ice surface. Based on a slope threshold, pixels can be reburied by debris or become debris-free. The effect of ponds are taken into account through enhanced melt rates in horizontal direction on pixels selected based on an algorithm considering distance to the water surface, slope and lake level. We use the dynamic model to first study the evolution of selected cliffs for which accurate, high resolution DEMs are available

Mathematical Analysis of Evolution, Information, and Complexity

CERN Document Server

Arendt, Wolfgang

2009-01-01

Mathematical Analysis of Evolution, Information, and Complexity deals with the analysis of evolution, information and complexity. The time evolution of systems or processes is a central question in science, this text covers a broad range of problems including diffusion processes, neuronal networks, quantum theory and cosmology. Bringing together a wide collection of research in mathematics, information theory, physics and other scientific and technical areas, this new title offers elementary and thus easily accessible introductions to the various fields of research addressed in the book.

H-theorem in quantum physics.

Science.gov (United States)

Lesovik, G B; Lebedev, A V; Sadovskyy, I A; Suslov, M V; Vinokur, V M

2016-09-12

Remarkable progress of quantum information theory (QIT) allowed to formulate mathematical theorems for conditions that data-transmitting or data-processing occurs with a non-negative entropy gain. However, relation of these results formulated in terms of entropy gain in quantum channels to temporal evolution of real physical systems is not thoroughly understood. Here we build on the mathematical formalism provided by QIT to formulate the quantum H-theorem in terms of physical observables. We discuss the manifestation of the second law of thermodynamics in quantum physics and uncover special situations where the second law can be violated. We further demonstrate that the typical evolution of energy-isolated quantum systems occurs with non-diminishing entropy.

On the evolution of stellar systems with a massive center

International Nuclear Information System (INIS)

Gurzadyan, V.G.; Kocharyan, A.A.

1986-01-01

The evolution of stellar systems with the massive center is investigated within the framework of dynamic system theory. Open dissipative systems, for which the Liouville theorem of the phase volume preservation is not implemented, are considered. Equations determining variation, in time, of main physical system parameters have been derived and studied. Results of the investigation show a principal possibility for determining the evolution path of stellar systems with the massive centers depending on physical parameters

Reactors physics. Bases of nuclear physics

International Nuclear Information System (INIS)

Diop, Ch.M.

2006-01-01

The aim of nuclear reactor physics is to quantify the relevant macroscopic data for the characterization of the neutronic state of a reactor core and to evaluate the effects of radiations (neutrons and gamma radiations) on organic matter and on inorganic materials. This first article presents the bases of nuclear physics in the context of nuclear reactors: 1 - reactor physics and nuclear physics; 2 - atomic nucleus - basic definitions: nucleus constituents, dimensions and mass of the atomic nucleus, mass defect, binding energy and stability of the nucleus, strong interaction, nuclear momentums of nucleons and nucleus; 3 - nucleus stability and radioactivity: equation of evolution with time - radioactive decay law; alpha decay, stability limit of spontaneous fission, beta decay, electronic capture, gamma emission, internal conversion, radioactivity, two-body problem and notion of radioactive equilibrium. (J.S.)

Interpreting Physics

CERN Document Server

MacKinnon, Edward

2012-01-01

This book is the first to offer a systematic account of the role of language in the development and interpretation of physics. An historical-conceptual analysis of the co-evolution of mathematical and physical concepts leads to the classical/quatum interface. Bohrian orthodoxy stresses the indispensability of classical concepts and the functional role of mathematics. This book analyses ways of extending, and then going beyond this orthodoxy orthodoxy. Finally, the book analyzes how a revised interpretation of physics impacts on basic philosophical issues: conceptual revolutions, realism, and r

Experiments on chemical and physical evolution of interstellar grain mantles

International Nuclear Information System (INIS)

Greenberg, J.M.

1984-01-01

The Astrophysical Laboratory at the University of Leiden is the first to succeed in simulating the essential conditions in interstellar space as they affect the evolution of interstellar grains. (author)

Disassembly and physical separation of electric/electronic components layered in printed circuit boards (PCB).

Science.gov (United States)

Lee, Jaeryeong; Kim, Youngjin; Lee, Jae-chun

2012-11-30

Although printed circuit boards (PCBs) contain various elements, only the major elements (i.e., those with content levels in wt% or over grade) of and precious metals (e.g., Ag, Au, and platinum groups) contained within PCBs can be recycled. To recover other elements from PCBs, the PCBs should be properly disassembled as the first step of the recycling process. The recovery of these other elements would be beneficial for efforts to conserve scarce resources, reuse electric/electronic components (EECs), and eliminate environmental problems. This paper examines the disassembly of EECs from wasted PCBs (WPCBs) and the physical separation of these EECs using a self-designed disassembling apparatus and a 3-step separation process of sieving, magnetic separation, and dense medium separation. The disassembling efficiencies were evaluated by using the ratio of grinding area (E(area)) and the weight ratio of the detached EECs (E(weight)). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (E(area)) and 98% (E(weight)) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5mm. Through a series of physical separations, most groups of the EECs (except for the diode, transistor, and IC chip groups) could be sorted at a relatively high separation efficiency of about 75% or more. To evaluate the separation efficiency with regard to the elemental composition, the distribution ratio (R(dis)) and the concentration ratio (R(conc)) were used. 15 elements could be separated with the highest R(dis) and R(conc) in the same separated division. This result implies that the recyclability of the elements is highly feasible, even though the initial content in EECs is lower than several tens of mg/kg. Copyright © 2012 Elsevier B.V. All rights reserved.

Angular correlations and high energy evolution

International Nuclear Information System (INIS)

Kovner, Alex; Lublinsky, Michael

2011-01-01

We address the question of to what extent JIMWLK evolution is capable of taking into account angular correlations in a high energy hadronic wave function. Our conclusion is that angular (and indeed other) correlations in the wave function cannot be reliably calculated without taking into account Pomeron loops in the evolution. As an example we study numerically the energy evolution of angular correlations between dipole scattering amplitudes in the framework of the large N c approximation to JIMWLK evolution (the 'projectile dipole model'). Target correlations are introduced via averaging over an (isotropic) ensemble of anisotropic initial conditions. We find that correlations disappear very quickly with rapidity even inside the saturation radius. This is in accordance with our physical picture of JIMWLK evolution. The actual correlations inside the saturation radius in the target QCD wave function, on the other hand, should remain sizable at any rapidity.

Direct view on the phase evolution in individual LiFePO4 nanoparticles during Li-ion battery cycling.

Science.gov (United States)

Zhang, Xiaoyu; van Hulzen, Martijn; Singh, Deepak P; Brownrigg, Alex; Wright, Jonathan P; van Dijk, Niels H; Wagemaker, Marnix

2015-09-23

Phase transitions in Li-ion electrode materials during (dis)charge are decisive for battery performance, limiting high-rate capabilities and playing a crucial role in the cycle life of Li-ion batteries. However, the difficulty to probe the phase nucleation and growth in individual grains is hindering fundamental understanding and progress. Here we use synchrotron microbeam diffraction to disclose the cycling rate-dependent phase transition mechanism within individual particles of LiFePO4, a key Li-ion electrode material. At low (dis)charge rates well-defined nanometer thin plate-shaped domains co-exist and transform much slower and concurrent as compared with the commonly assumed mosaic transformation mechanism. As the (dis)charge rate increases phase boundaries become diffuse speeding up the transformation rates of individual grains. Direct observation of the transformation of individual grains reveals that local current densities significantly differ from what has previously been assumed, giving new insights in the working of Li-ion battery electrodes and their potential improvements.

Channel-planform evolution in four rivers of Olympic National Park, Washington, U.S.A.: The roles of physical drivers and trophic cascades

Science.gov (United States)

East, Amy E.; Jenkins, Kurt J.; Happe, Patricia J.; Bountry, Jennifer A.; Beechie, Timothy J.; Mastin, Mark C.; Sankey, Joel B.; Randle, Timothy J.

2017-01-01

Identifying the relative contributions of physical and ecological processes to channel evolution remains a substantial challenge in fluvial geomorphology. We use a 74-year aerial photographic record of the Hoh, Queets, Quinault, and Elwha Rivers, Olympic National Park, Washington, U.S.A., to investigate whether physical or trophic-cascade-driven ecological factors—excessive elk impacts after wolves were extirpated a century ago—are the dominant controls on channel planform of these gravel-bed rivers. We find that channel width and braiding show strong relationships with recent flood history. All four rivers have widened significantly in recent decades, consistent with increased flood activity since the 1970s. Channel planform also reflects sediment-supply changes, evident from landslide response on the Elwha River. We surmise that the Hoh River, which shows a multi-decadal trend toward greater braiding, is adjusting to increased sediment supply associated with rapid glacial retreat. In this sediment-routing system with high connectivity, such climate-driven signals appear to propagate downstream without being buffered substantially by sediment storage. Legacy effects of anthropogenic modification likely also affect the Quinault River planform. We infer no correspondence between channel geomorphic evolution and elk abundance, suggesting that trophic-cascade effects in this setting are subsidiary to physical controls on channel morphology. Our findings differ from previous interpretations of Olympic National Park fluvial dynamics and contrast with the classic example of Yellowstone National Park, where legacy effects of elk overuse are apparent in channel morphology; we attribute these differences to hydrologic regime and large-wood availability.

Hidden Randomness between Fitness Landscapes Limits Reverse Evolution

Science.gov (United States)

Tan, Longzhi; Serene, Stephen; Xiao Chao, Hui; Gore, Jeff

2012-02-01

Natural populations must constantly adapt to the ever-changing environment. A fundamental question in evolutionary biology is whether adaptations can be reversed by returning the population to its ancestral environment. Traditionally, reverse evolution is defined as restoring an ancestral phenotype (physical characteristics such as body size), and the classic Dollo's Law has hypothesized the impossibility of reversing complex adaptations. However, this ``law'' remains ambiguous unless reverse evolution can be studied at the level of genotypes (the underlying genome sequence). We measured the fitness landscapes of a bacterial antibiotic-resistance gene and analyzed the reversibility of evolution as a global, statistical feature of the landscapes. In both experiments and simulations, we find that an adaptation's reversibility declines as the number of mutations it involves increases, suggesting a probabilistic form of Dollo's Law at the molecular level. We also show computationally that slowly switching between environments facilitates reverse evolution in small populations, where clonal interference is negligible or moderate. This is an analogy to thermodynamics, where the reversibility of a physical process is maximized when conditions are modified infinitely slowly.

Carbonate landscapes evolution: Insights from 36Cl

Science.gov (United States)

Godard, Vincent; Thomas, Franck; Ollivier, Vincent; Bellier, Olivier; Shabanian, Esmaeil; Miramont, Cécile; Fleury, Jules; Benedetti, Lucilla; Guillou, Valéry; Aster Team

2017-04-01

Carbonate landscapes cover a significant fraction of the Earth surface, but their long-term dynamics is still poorly understood. When comparing with the situation in areas underlain by quartz-rich lithologies, where the routine use of 10Be-derived denudation rates has delivered fundamental insights on landscape evolution processes, this knowledge gap is particularly notable. Recent advances in the measurement of 36Cl and better understanding of its production pathways has opened the way to the development of a similar physically-based and quantitative analysis of landscape evolution in carbonate settings. However, beyond these methodological considerations, we still face fundamental geomorphological open questions, as for example the assessment of the importance of congruent carbonate dissolution in long-wavelength topographic evolution. Such unresolved problems concerning the relative importance of physical and chemical weathering processes lead to question the applicability of standard slope-dependent Geomorphic Transport Laws in carbonate settings. These issues have been addressed studying the geomorphological evolution of selected limestone ranges in Provence, SE France, where 36Cl concentration measurements in bedrock and stream sediment samples allow constraining denudation over 10 ka time-scale. We first identify a significant denudation contrast between the summit surface and the flanks of the ranges, pointing to a substantial contribution of gravity-driven processes to the landscape evolution, in addition to dissolution. Furthermore, a detailed analysis of the relationships between hillslope morphology and hilltop denudation allow to identify a fundamental transition between two regimes: (1) a dynamics where hillslope evolution is controlled by linear diffusive downslope regolith transport; and, (2) a domain where denudation is limited by the rate at which physical and chemical weathering processes can produce clasts and lower the hilltop. Such an abrupt

Magneto–Thermal Evolution of Neutron Stars with Emphasis to ...

Indian Academy of Sciences (India)

The magnetic and thermal evolution of neutron stars is a very complex process with many non-linear interactions. For a decent understanding of neutron star physics, these evolutions cannot be considered isolated. A brief overview is presented, which describes the main magneto–thermal interactions that determine the fate ...

The Evolution of Research on Digital Education

Science.gov (United States)

Dillenbourg, Pierre

2016-01-01

How does AI&EdAIED today compare to 25 years ago? This paper addresses this evolution by identifying six trends. The trends are ongoing and will influence learning technologies going forward. First, the physicality of interactions and the physical space of the learner became genuine components of digital education. The frontier between the…

Physical, chemical, microbiological and sensorial behaviour evolution of non cooked pressed cheese paste while in refrigerated storage, made with red chilli powder, treated by heat or ionization

International Nuclear Information System (INIS)

Iben El Hadj Mohamed, A.

1998-01-01

The evolution of different physical, chemical, microbiological and sensorial characteristics of a Tunisian manufactured cheese made of non cooked pressed cheese paste with red chilli powder treated by heat, was measured while in refrigerated storage and compared to the one treated by ionization (author)

Cosmological evolution of the Higgs boson's vacuum expectation value

Energy Technology Data Exchange (ETDEWEB)

Calmet, Xavier [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)

2017-11-15

We point out that the expansion of the universe leads to a cosmological time evolution of the vacuum expectation of the Higgs boson. Within the standard model of particle physics, the cosmological time evolution of the vacuum expectation of the Higgs leads to a cosmological time evolution of the masses of the fermions and of the electroweak gauge bosons, while the scale of Quantum Chromodynamics (QCD) remains constant. Precise measurements of the cosmological time evolution of μ = m{sub e}/m{sub p}, where m{sub e} and m{sub p} are, respectively, the electron and proton mass (which is essentially determined by the QCD scale), therefore provide a test of the standard models of particle physics and of cosmology. This ratio can be measured using modern atomic clocks. (orig.)

Nobel Prize in Physics 2006

Indian Academy of Sciences (India)

Administrator

B ut every once in a w hile,these prizes are also given to team lead- ers w ho spearhead a large collaboration w hich .... saying that `the w hole universe is expanding' w ith dis- .... body form was a ¯rm prediction from big bang m odel, it w as im ...

Physics updates from HERMES

International Nuclear Information System (INIS)

Murray, Morgan J.

2013-01-01

The HERMES collaboration presents two sets of recent results: the first related to an extraction of the g 2 nucleon structure function determined for DIS on a polarised target and the second related to the measurement of asymmetries related to the deeply virtual Compton scattering process that can be used to discover information on generalised parton distributions and hence nucleon structure.

Physics updates from HERMES

Energy Technology Data Exchange (ETDEWEB)

Murray, Morgan J. [Rm. 514b, Dept. of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, Scotland (United Kingdom); Collaboration: HERMES Collaboration

2013-04-15

The HERMES collaboration presents two sets of recent results: the first related to an extraction of the g{sub 2} nucleon structure function determined for DIS on a polarised target and the second related to the measurement of asymmetries related to the deeply virtual Compton scattering process that can be used to discover information on generalised parton distributions and hence nucleon structure.

Adaptive evolution in ecological communities.

Directory of Open Access Journals (Sweden)

Martin M Turcotte

Full Text Available Understanding how natural selection drives evolution is a key challenge in evolutionary biology. Most studies of adaptation focus on how a single environmental factor, such as increased temperature, affects evolution within a single species. The biological relevance of these experiments is limited because nature is infinitely more complex. Most species are embedded within communities containing many species that interact with one another and the physical environment. To understand the evolutionary significance of such ecological complexity, experiments must test the evolutionary impact of interactions among multiple species during adaptation. Here we highlight an experiment that manipulates species composition and tracks evolutionary responses within each species, while testing for the mechanisms by which species interact and adapt to their environment. We also discuss limitations of previous studies of adaptive evolution and emphasize how an experimental evolution approach can circumvent such shortcomings. Understanding how community composition acts as a selective force will improve our ability to predict how species adapt to natural and human-induced environmental change.

TESTING MODELS OF MAGNETIC FIELD EVOLUTION OF NEUTRON STARS WITH THE STATISTICAL PROPERTIES OF THEIR SPIN EVOLUTIONS

International Nuclear Information System (INIS)

Zhang Shuangnan; Xie Yi

2012-01-01

We test models for the evolution of neutron star (NS) magnetic fields (B). Our model for the evolution of the NS spin is taken from an analysis of pulsar timing noise presented by Hobbs et al.. We first test the standard model of a pulsar's magnetosphere in which B does not change with time and magnetic dipole radiation is assumed to dominate the pulsar's spin-down. We find that this model fails to predict both the magnitudes and signs of the second derivatives of the spin frequencies (ν-double dot). We then construct a phenomenological model of the evolution of B, which contains a long-term decay (LTD) modulated by short-term oscillations; a pulsar's spin is thus modified by its B-evolution. We find that an exponential LTD is not favored by the observed statistical properties of ν-double dot for young pulsars and fails to explain the fact that ν-double dot is negative for roughly half of the old pulsars. A simple power-law LTD can explain all the observed statistical properties of ν-double dot. Finally, we discuss some physical implications of our results to models of the B-decay of NSs and suggest reliable determination of the true ages of many young NSs is needed, in order to constrain further the physical mechanisms of their B-decay. Our model can be further tested with the measured evolutions of ν-dot and ν-double dot for an individual pulsar; the decay index, oscillation amplitude, and period can also be determined this way for the pulsar.

Physics history. The physics in the 20 sup th century. Histoire de la physique. Tome 2: la physique au XXe siecle

Energy Technology Data Exchange (ETDEWEB)

Mathieu, J P

1991-01-01

This book proposes a synthesis of the physics evolution and of upsettings produced by the many discoveries in this century: Relativity theory, quantum mechanics, quantum statistics, thermodynamics, optics, electromagnetism, atomic physics, molecular physics, condensed matter physics, nuclear physics and high energy physics, information processing and computers. Many examples are illustrated.

Dihadron fragmentation function and its evolution

International Nuclear Information System (INIS)

Majumder, A.; Wang Xinnian

2004-01-01

Dihadron fragmentation functions and their evolution are studied in the process of e + e - annihilation. Under the collinear factorization approximation and facilitated by the cut-vertex technique, the two hadron inclusive cross section at leading order is shown to factorize into a short distance parton cross section and a long distance dihadron fragmentation function. We provide the definition of such a dihadron fragmentation function in terms of parton matrix elements and derive its Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation at leading log. The evolution equation for the nonsinglet quark fragmentation function is solved numerically with a simple ansatz for the initial condition and results are presented for cases of physical interest

Factorizing the time evolution operator

International Nuclear Information System (INIS)

Garcia Quijas, P C; Arevalo Aguilar, L M

2007-01-01

There is a widespread belief in the quantum physical community, and textbooks used to teach quantum mechanics, that it is a difficult task to apply the time evolution operator e itH-hat/h on an initial wavefunction. Because the Hamiltonian operator is, generally, the sum of two operators, then it is not possible to apply the time evolution operator on an initial wavefunction ψ(x, 0), for it implies using terms like (a-hat + b-hat). A possible solution is to factorize the time evolution operator and then apply successively the individual exponential operator on the initial wavefunction. However, the exponential operator does not directly factorize, i.e. e a-hat+b-hat ≠ e a-hat e b-hat . In this study we present a useful procedure for factorizing the time evolution operator when the argument of the exponential is a sum of two operators, which obey specific commutation relations. Then, we apply the exponential operator as an evolution operator for the case of elementary unidimensional potentials, like a particle subject to a constant force and a harmonic oscillator. Also, we discuss an apparent paradox concerning the time evolution operator and non-spreading wave packets addressed previously in the literature

Kinematic evolution of fold and thrust belts. Insights from experimental modeling

International Nuclear Information System (INIS)

Ueta, Keiichi

2011-01-01

Physical experiments were performed to gain a better understanding on the kinematic evolution of fold and thrust belts. The present study focuses on deformation of sedimentary cover caused by thrust and reverse movements along the basement fault. Our physical models comprise dry quartz sand representing brittle sedimentary rock and viscous silicone polymer representing overpressured mudstone. Computerized X-ray tomography was applied to the experiments to analyze the kinematic evolution of fold and thrust belts. In the sand models, the width of deformation zone above thrust was wider than that above reverse fault, because back thrust developed on the hanging wall of reverse fault. Within the physical models composed of dry sand and silicone polymer, minor folds and thrusts with minor displacement developed on the footwall of the major monoclinal flexure. These results compare well with the geometry and kinematic evolution of the fold and thrust belts in Japan. (author)

Nuclei at HERA and heavy ion physics

International Nuclear Information System (INIS)

Gavin, S.; Strikman, M.

1995-01-01

Copies of 16 viewgraph sets from a workshop held at Brookhaven National Laboratory, 17-18 November, 1995. Titles of talks: HERA: The Present; HERA: Potential with Nuclei; Review of Hadron-Lepton Nucleus Data; Fermilab E665: results in muon scattering; Interactions of Quarks and Gluons with Nuclear Matter; Rescattering in Nuclear Targets for Photoproduction and DIS; Structure Functions and Nuclear Effect at PHENIX; Probing Spin-Averaged and Spin-Dependent Parton Distributions Using the Solenoidal Tracker at RHIC (STAR); Jet Quenching in eA, pA, AA; Nuclear Gluon Shadowing via Continuum Lepton Pairs; What can we learn from HERA with a colliding heavy ion beam? The limiting curve of leading particles at infinite A; Coherent Production of Vector Mesons off Light Nuclei in DIS; A Model of High Parton Densities in PQCD; Gluon Production for Weizaecker-Williams Field in Nucleus-Nucleus Collisions; Summary Talk

Optimal evolution models for quantum tomography

International Nuclear Information System (INIS)

Czerwiński, Artur

2016-01-01

The research presented in this article concerns the stroboscopic approach to quantum tomography, which is an area of science where quantum physics and linear algebra overlap. In this article we introduce the algebraic structure of the parametric-dependent quantum channels for 2-level and 3-level systems such that the generator of evolution corresponding with the Kraus operators has no degenerate eigenvalues. In such cases the index of cyclicity of the generator is equal to 1, which physically means that there exists one observable the measurement of which performed a sufficient number of times at distinct instants provides enough data to reconstruct the initial density matrix and, consequently, the trajectory of the state. The necessary conditions for the parameters and relations between them are introduced. The results presented in this paper seem to have considerable potential applications in experiments due to the fact that one can perform quantum tomography by conducting only one kind of measurement. Therefore, the analyzed evolution models can be considered optimal in the context of quantum tomography. Finally, we introduce some remarks concerning optimal evolution models in the case of n-dimensional Hilbert space. (paper)

Evolution in bouncing quantum cosmology

International Nuclear Information System (INIS)

Mielczarek, Jakub; Piechocki, Włodzimierz

2012-01-01

We present the method of describing an evolution in quantum cosmology in the framework of the reduced phase space quantization of loop cosmology. We apply our method to the flat Friedmann-Robertson-Walker model coupled to a massless scalar field. We identify the physical quantum Hamiltonian that is positive-definite and generates globally a unitary evolution of the considered quantum system. We examine the properties of expectation values of physical observables in the process of the quantum big bounce transition. The dispersion of evolved observables is studied for the Gaussian state. Calculated relative fluctuations enable an examination of the semi-classicality conditions and possible occurrence of the cosmic forgetfulness. Preliminary estimations based on the cosmological data suggest that there was no cosmic amnesia. Presented results are analytical, and numerical computations are only used for the visualization purposes. Our method may be generalized to sophisticated cosmological models including the Bianchi-type universes. (paper)

Small-x resummation from HELL

Energy Technology Data Exchange (ETDEWEB)

Bonvini, Marco [University of Oxford, Rudolf Peierls Centre for Theoretical Physics, Oxford, England (United Kingdom); Marzani, Simone [University at Buffalo, The State University of New York, Buffalo, NY (United States); Peraro, Tiziano [The University of Edinburgh, Higgs Centre for Theoretical Physics, School of Physics and Astronomy, Edinburgh, Scotland (United Kingdom)

2016-11-15

Small-x logarithmic enhancements arising from high-energy gluon emissions affect both the evolution of collinearly-factorized parton densities and partonic coefficient functions. With the higher collider energy reached by the LHC, the prospect of a future high-energy collider, and the recent deep-inelastic scattering (DIS) results at small-x from HERA, providing phenomenological tools for performing small-x resummation has become of great relevance. In this paper we discuss a framework to perform small-x resummation for both parton evolution and partonic coefficient functions and we describe its implementation in a computer code named High-Energy Large Logarithms (HELL). We present resummed and matched results for the DGLAP splitting functions and, as a proof of principle, for the massless structure functions in DIS. Furthermore, we discuss the uncertainty from subleading terms on our results. (orig.)

The three-loop splitting functions in QCD. The helicity-dependent case

International Nuclear Information System (INIS)

Moch, S.; Vogt, A.

2014-09-01

We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting functions have been obtained by extending our previous all Mellin-N calculations to the structure function g 1 in electromagnetic deep-inelastic scattering (DIS). Their quark-gluon and gluon-gluon counterparts have been derived using third-order fixed-N calculations of structure functions in graviton-exchange DIS, relations to the unpolarized case and mathematical tools for systems of Diophantine equations. The NNLO corrections to the splitting functions are small outside the region of small momentum fractions x where they exhibit a large double-logarithmic enhancement, yet the corrections to the evolution of the parton densities can be unproblematic down to at least x∼10 -4 .

3D Imaging with Structured Illumination for Advanced Security Applications

Energy Technology Data Exchange (ETDEWEB)

Birch, Gabriel Carisle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dagel, Amber Lynn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kast, Brian A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Collin S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-09-01

Three-dimensional (3D) information in a physical security system is a highly useful dis- criminator. The two-dimensional data from an imaging systems fails to provide target dis- tance and three-dimensional motion vector, which can be used to reduce nuisance alarm rates and increase system effectiveness. However, 3D imaging devices designed primarily for use in physical security systems are uncommon. This report discusses an architecture favorable to physical security systems; an inexpensive snapshot 3D imaging system utilizing a simple illumination system. The method of acquiring 3D data, tests to understand illumination de- sign, and software modifications possible to maximize information gathering capability are discussed.

Nuclear physics

International Nuclear Information System (INIS)

Guzman B, O.; Vallejo M, J.I.; Cardenas C, H.F.

1989-01-01

A historical review of the evolution of the Nuclear Physics Section at the IAN is presented along the 30 years of existence of the Institute. Objectives, structure, programs and goal are historically examined. Present status of the section and its projection on national development is also analyzed

9. Biennial session of nuclear physics

International Nuclear Information System (INIS)

1987-03-01

As every two years the 9th biennial session of nuclear physics shall try to make a survey of the recent experimental developments as well as the evolution of the theoretical ideas in Nuclear Physics. Communications are indexed and analysed separately

Quantitative interface models for simulating microstructure evolution

International Nuclear Information System (INIS)

Zhu, J.Z.; Wang, T.; Zhou, S.H.; Liu, Z.K.; Chen, L.Q.

2004-01-01

To quantitatively simulate microstructural evolution in real systems, we investigated three different interface models: a sharp-interface model implemented by the software DICTRA and two diffuse-interface models which use either physical order parameters or artificial order parameters. A particular example is considered, the diffusion-controlled growth of a γ ' precipitate in a supersaturated γ matrix in Ni-Al binary alloys. All three models use the thermodynamic and kinetic parameters from the same databases. The temporal evolution profiles of composition from different models are shown to agree with each other. The focus is on examining the advantages and disadvantages of each model as applied to microstructure evolution in alloys

Mapping the evolution of scientific ideas

Energy Technology Data Exchange (ETDEWEB)

Roberts, David C [Los Alamos National Laboratory; Herrera, Mark [UNIV OF MARYLAND; Gulbahce, Natali [NORTHEASTERN UNIV

2008-01-01

The importance of interdisciplinary research is ever increasing as challenging world problems require expertise across diverse fields. Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific ideas and fields using a network-based analysis. We build a idea network consisting of American Physical Society Pacs numbers as nodes representing scientific concepts. Two Pacs numbers are linked in the network if there exist publications that reference them simultaneously. We locate scientific fields using an overlapping community finding algorithm and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. We find that the communities we find map to scientific fields, the lifetime of these fields strongly depends on their size, impact and activity, and longest living communities are least volatile. The described approach to quantify the evolution of ideas is expected to be relevant in making predictions about the future of science and how to guide its development.

Design of Introspective Circuits for Analysis of Cell-Level Dis-orientation in Self-Assembled Cellular Systems

Directory of Open Access Journals (Sweden)

Nicholas Jesse Macias

2016-02-01

Full Text Available This paper discusses a novel approach to managing complexity in a large self-assembled system, by employing the self-assembling components themselves to address the complexity. Challenges are discussed, including the question of how to deal with elements that are assembled in different orientations from each other, and a solution based on the idea of introspective circuits is described. A methodology for determining a single cell’s orientation from an adjacent cell is given. An algorithm is then described for using such re-oriented edge cells to determine orientation of more-interior cells, thus allowing re-orientation of an entire 2D region of cells. Test procedures are described, and results are presented to show better-than-linear time performance (O(sqrt(n. The significance of this work is discussed, not only in terms of managing arrays of dis-oriented cells, but more importantly as an example of the usefulness of local, distributed self-configuration to create and use introspective circuitry. Finally, future work is discussed, including extension to 3D collections of cells.

Semi-inclusive DIS Experiments Using Transversely Polarized Targets in Hall-A: Current Results and Future Plans

Directory of Open Access Journals (Sweden)

Allada Kalyan

2012-12-01

Full Text Available Measurement of single (SSA and double spin asymmetries (DSA in semiinclusive DIS reactions using polarized targets provide a powerful method to probe transverse momentum dependent parton distribution functions (TMDs. In particular, the experimentally measured SSA on nucleon targets can help in extracting the transversity and Sivers distribution functions of u and d-quarks. Similarly, the measured DSA are sensitive to the quark spin-orbital correlations, and provide an access to the TMD parton distribution function (g1T. A recent experiment conducted in Hall-A Jefferson Lab using transversely polarized 3He provide first such measurements on “effective” neutron target. The measurement was performed using 5.9 GeV beam from CEBAF and measured the target SSA/DSA in the SIDIS reaction 3He↑(e, e′π±X. The kinematical range, x = 0.19 ~ 0.34, at Q2 = 1.77 ~ 2.73 (GeV/c2, was focused on the valence quark region. The results from this measurement along with our plans for future high precision measurements in Hall-A are presented.

Managing risk and marginalizing identities: on the society-of-captives thesis and the harm of social dis-ease.

Science.gov (United States)

Arrigo, Bruce A

2013-06-01

This article develops the constitutive features of the society-of-captives thesis as suggested by Arrigo and Milovanovic, and Arrigo, Bersot, and Sellers. The relevance of this thesis is briefly explored in relation to the institutional and community-based treatment philosophies that currently inform the mental health and criminal justice systems. This exploration specifies how risk (being human and doing humanness differently) is managed symbolically, linguistically, materially, and culturally. The management of this risk extends to the kept as well as to their keepers, regulators, and watchers (i.e., the society of captives). This article calls for a new clinical praxis (being/doing a critical mindfulness) designed to overcome the totalizing madness (the harm of social dis-ease) that follows from managing risk fearfully and marginalizing identities desperately as reified recursively through society's captivity. The ethical underpinnings of this clinical praxis represent an emergent direction for undertaking correctional policy reform.

US nuclear physics funding

International Nuclear Information System (INIS)

Anon.

1992-01-01

Because of restrictions in the federal budget, US science spending is coming under close scrutiny, with strong implications for the evolution of the nation's physics research. Recently the Witherell subpanel of the Department of Energy's High Energy Physics Advisory Panel (HEPAP) submitted recommendations on how the US research scene could evolve pending commissioning of the SSC Superconducting Supercollider

Modeling aeolian dune and dune field evolution

Science.gov (United States)

Diniega, Serina

Aeolian sand dune morphologies and sizes are strongly connected to the environmental context and physical processes active since dune formation. As such, the patterns and measurable features found within dunes and dune fields can be interpreted as records of environmental conditions. Using mathematical models of dune and dune field evolution, it should be possible to quantitatively predict dune field dynamics from current conditions or to determine past field conditions based on present-day observations. In this dissertation, we focus on the construction and quantitative analysis of a continuum dune evolution model. We then apply this model towards interpretation of the formative history of terrestrial and martian dunes and dune fields. Our first aim is to identify the controls for the characteristic lengthscales seen in patterned dune fields. Variations in sand flux, binary dune interactions, and topography are evaluated with respect to evolution of individual dunes. Through the use of both quantitative and qualitative multiscale models, these results are then extended to determine the role such processes may play in (de)stabilization of the dune field. We find that sand flux variations and topography generally destabilize dune fields, while dune collisions can yield more similarly-sized dunes. We construct and apply a phenomenological macroscale dune evolution model to then quantitatively demonstrate how dune collisions cause a dune field to evolve into a set of uniformly-sized dunes. Our second goal is to investigate the influence of reversing winds and polar processes in relation to dune slope and morphology. Using numerical experiments, we investigate possible causes of distinctive morphologies seen in Antarctic and martian polar dunes. Finally, we discuss possible model extensions and needed observations that will enable the inclusion of more realistic physical environments in the dune and dune field evolution models. By elucidating the qualitative and

A differential evolution algorithm for tooth profile optimization with respect to balancing specific sliding coefficients of involute cylindrical spur and helical gears

Directory of Open Access Journals (Sweden)

Hammoudi Abderazek

2015-09-01

Full Text Available Profile shift has an immense effect on the sliding, load capacity, and stability of involute cylindrical gears. Available standards such as ISO/DIS 6336 and BS 436 DIN/3990 currently give the recommendation for the selection of profile shift coefficients. It is, however, very approximate and usually given in the form of implicit graphs or charts. In this article, the optimal selection values of profile shift coefficients for cylindrical involute spur and helical gears are described, using a differential evolution algorithm. The optimization procedure is developed specifically for exact balancing specific sliding coefficients at extremes of contact path and account for gear design constraints. The obtained results are compared with those of standards and research of other authors. They demonstrate the effectiveness and robustness of the applied method. A substantial improvement in balancing specific sliding coefficients is found in this work.

Anomalous evolution of Ar metastable density with electron density in high density Ar discharge

International Nuclear Information System (INIS)

Park, Min; Chang, Hong-Young; You, Shin-Jae; Kim, Jung-Hyung; Shin, Yong-Hyeon

2011-01-01

Recently, an anomalous evolution of argon metastable density with plasma discharge power (electron density) was reported [A. M. Daltrini, S. A. Moshkalev, T. J. Morgan, R. B. Piejak, and W. G. Graham, Appl. Phys. Lett. 92, 061504 (2008)]. Although the importance of the metastable atom and its density has been reported in a lot of literature, however, a basic physics behind the anomalous evolution of metastable density has not been clearly understood yet. In this study, we investigated a simple global model to elucidate the underlying physics of the anomalous evolution of argon metastable density with the electron density. On the basis of the proposed simple model, we reproduced the anomalous evolution of the metastable density and disclosed the detailed physics for the anomalous result. Drastic changes of dominant mechanisms for the population and depopulation processes of Ar metastable atoms with electron density, which take place even in relatively low electron density regime, is the clue to understand the result.

Linearized Flux Evolution (LiFE): A technique for rapidly adapting fluxes from full-physics radiative transfer models

Science.gov (United States)

Robinson, Tyler D.; Crisp, David

2018-05-01

Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate models require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, we describe a technique that uses an accurate full-physics radiative transfer model to generate a set of atmospheric radiative quantities which can be used to linearly adapt radiative flux profiles to changes in the atmospheric and surface state-the Linearized Flux Evolution (LiFE) approach. These radiative quantities describe how each model layer in a plane-parallel atmosphere reflects and transmits light, as well as how the layer generates diffuse radiation by thermal emission and by scattering light from the direct solar beam. By computing derivatives of these layer radiative properties with respect to dynamic elements of the atmospheric state, we can then efficiently adapt the flux profiles computed by the full-physics model to new atmospheric states. We validate the LiFE approach, and then apply this approach to Mars, Earth, and Venus, demonstrating the information contained in the layer radiative properties and their derivatives, as well as how the LiFE approach can be used to determine the thermal structure of radiative and radiative-convective equilibrium states in one-dimensional atmospheric models.

Asymptotic evolution of quantum Markov chains

Energy Technology Data Exchange (ETDEWEB)

Novotny, Jaroslav [FNSPE, CTU in Prague, 115 19 Praha 1 - Stare Mesto (Czech Republic); Alber, Gernot [Institut fuer Angewandte Physik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)

2012-07-01

The iterated quantum operations, so called quantum Markov chains, play an important role in various branches of physics. They constitute basis for many discrete models capable to explore fundamental physical problems, such as the approach to thermal equilibrium, or the asymptotic dynamics of macroscopic physical systems far from thermal equilibrium. On the other hand, in the more applied area of quantum technology they also describe general characteristic properties of quantum networks or they can describe different quantum protocols in the presence of decoherence. A particularly, an interesting aspect of these quantum Markov chains is their asymptotic dynamics and its characteristic features. We demonstrate there is always a vector subspace (typically low-dimensional) of so-called attractors on which the resulting superoperator governing the iterative time evolution of quantum states can be diagonalized and in which the asymptotic quantum dynamics takes place. As the main result interesting algebraic relations are presented for this set of attractors which allow to specify their dual basis and to determine them in a convenient way. Based on this general theory we show some generalizations concerning the theory of fixed points or asymptotic evolution of random quantum operations.

Star Formation Histories of Dwarf Irregular Galaxies

Science.gov (United States)

Skillman, Evan

1995-07-01

We propose to obtain deep WFPC2 `BVI' color-magnitude diagrams {CMDs} for the dwarf irregular {dI} Local Group galaxies GR 8, Leo A, Pegasus, and Sextans A. In addition to resolved stars, we will use star clusters, and especially any globulars, to probe the history of intense star formation. These data will allow us to map the Pop I and Pop II stellar components, and thereby construct the first detailed star formation histories for non-interacting dI galaxies. Our results will bear on a variety of astrophysical problems, including the evolution of small galaxies, distances in the Local Group, age-metallicity distributions in small galaxies, ages of dIs, and the physics of star formation. The four target galaxies are typical dI systems in terms of luminosity, gas content, and H II region abundance, and represent a range in current star forming activity. They are sufficiently near to allow us to reach to stars at M_V = 0, have 0.1 of the luminosity of the SMC and 0.25 of its oxygen abundance. Unlike the SMC, these dIs are not near giant galaxies. This project will allow the extension of our knowledge of stellar populations in star forming galaxies from the spirals in the Local Group down to its smallest members. We plan to take maximum advantage of the unique data which this project will provide. Our investigator team brings extensive and varied experience in studies of dwarf galaxies, stellar populations, imaging photometry, and stellar evolution to this project.

White dwarf evolution - Cradle-to-grave constraints via pulsation

Science.gov (United States)

Kawaler, Steven D.

1990-01-01

White dwarf evolution, particularly in the early phases, is not very strongly constrained by observation. Fortunately, white dwarfs undergo nonradial pulsation in three distinct regions of the H-R diagram. These pulsations provide accurate masses, surface compositional structure and rotation velocities, and help constrain other important physical properties. We demonstrate the application of the tools of stellar seismology to white dwarf evolution using the hot white dwarf star PG 1159-035 and the cool DAV (or ZZ Ceti) stars as examples. From pulsation studies, significant challenges to the theory of white dwarf evolution emerge.

The three-loop splitting functions in QCD: The helicity-dependent case

Directory of Open Access Journals (Sweden)

S. Moch

2014-12-01

Full Text Available We present the next-to-next-to-leading order (NNLO contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark–quark and gluon–quark splitting functions have been obtained by extending our previous all Mellin-N calculations to the structure function g1 in electromagnetic deep-inelastic scattering (DIS. Their quark–gluon and gluon–gluon counterparts have been derived using third-order fixed-N calculations of structure functions in graviton-exchange DIS, relations to the unpolarized case and mathematical tools for systems of Diophantine equations. The NNLO corrections to the splitting functions are small outside the region of small momentum fractions x where they exhibit a large double-logarithmic enhancement, yet the corrections to the evolution of the parton densities can be unproblematic down to at least x≈10−4.

Phase-space formalism: Operational calculus and solution of evolution equations in phase-space

International Nuclear Information System (INIS)

Dattoli, G.; Torre, A.

1995-05-01

Phase-space formulation of physical problems offers conceptual and practical advantages. A class of evolution type equations, describing the time behaviour of a physical system, using an operational formalism useful to handle time ordering problems has been described. The methods proposed generalize the algebraic ordering techniques developed to deal with the ordinary Schroedinger equation, and how they are taylored suited to treat evolution problems both in classical and quantum dynamics has been studied

GAMMA-RAY BURST AND STAR FORMATION RATES: THE PHYSICAL ORIGIN FOR THE REDSHIFT EVOLUTION OF THEIR RATIO

International Nuclear Information System (INIS)

Trenti, Michele; Perna, Rosalba; Tacchella, Sandro

2013-01-01

Gamma-ray bursts (GRBs) and galaxies at high redshift represent complementary probes of the star formation history of the universe. In fact, both the GRB rate and the galaxy luminosity density are connected to the underlying star formation. Here, we combine a star formation model for the evolution of the galaxy luminosity function from z = 0 to z = 10 with a metallicity-dependent efficiency for GRB formation to simultaneously predict the comoving GRB rate. Our model sheds light on the physical origin of the empirical relation often assumed between GRB rate and luminosity density-derived star formation rate: n-dot GRB (z)=ε(z)× ρ-dot * obs (z), with ε(z)∝(1 + z) 1.2 . At z ∼ ☉ ) ☉ ) > 0. Models with total suppression of GRB formation at log (Z/Z ☉ ) ∼> 0 are disfavored. At z ∼> 4, most of the star formation happens in low-metallicity hosts with nearly saturated efficiency of GRB production per unit stellar mass. However, at the same epoch, galaxy surveys miss an increasing fraction of the predicted luminosity density because of flux limits, driving an accelerated evolution of ε(z) compared to the empirical power-law fit from lower z. Our findings are consistent with the non-detections of GRB hosts in ultradeep imaging at z > 5, and point toward current galaxy surveys at z > 8 only observing the top 15%-20% of the total luminosity density

Is physics at the threshold of a new stage of evolution

International Nuclear Information System (INIS)

Rompe, R.; Treder, H.J.

1984-01-01

The paper reviews specific aspects of theoretical physics and mathematics, starting from Planck's thesis in 1908. Relativity theory; quantum mechanics; atomic physics; field theories, elementary particle physics; and mathematical physics, are all briefly discussed. (U.K.)

The Causality of Evolution on Different Fitness Landscapes

Science.gov (United States)

Vyawahare, Saurabh; Austin, Robert; Zhang, Qiucen; Kim, Hyunsung; Bestoso, John

2013-03-01

Evolution of antibiotic resistance is a growing problem. One major reason why most antibiotics fail is because of mutations on drug targets (e.g. essential enzymes). Sequencing of clinically resistant isolates have shown that multiple mutational-hotspots exist in coding regions, which could potentially prohibit the binding of drugs. However, it is not clear whether the appearance of each mutation is random or influenced by other factors. In this paper, we compare evolution of resistance to ciprofloxacin from two distinct but well characterized genetic backgrounds. By combining our recently developed evolution reactor and deep whole-genome sequencing, we show different alleles of σs factor lead to fixation of different mutations in gyrA gene that confer ciprofloxacin resistance to bacteria Escherichia coli. Such causality of evolution in different genes provides an opportunity to control the evolution of antibiotic resistance. Sponsored by the NCI/NIH Physical Sciences Oncology Centers

Design in nature how the constructal law governs evolution in biology, physics, technology, and social organization

CERN Document Server

Bejan, Adrian

2013-01-01

In this groundbreaking book, Adrian Bejan takes the recurring patterns in nature—trees, tributaries, air passages, neural networks, and lightning bolts—and reveals how a single principle of physics, the constructal law, accounts for the evolution of these and many other designs in our world. Everything—from biological life to inanimate systems—generates shape and structure and evolves in a sequence of ever-improving designs in order to facilitate flow. River basins, cardiovascular systems, and bolts of lightning are very efficient flow systems to move a current—of water, blood, or electricity. Likewise, the more complex architecture of animals evolve to cover greater distance per unit of useful energy, or increase their flow across the land. Such designs also appear in human organizations, like the hierarchical “flowcharts” or reporting structures in corporations and political bodies. All are governed by the same principle, known as the constructal law, and configure and reconfigure themselves...

Revisiting parton evolution and the large-x limit

International Nuclear Information System (INIS)

Dokshitzer, Yu.L.; Marchesini, G.; Salam, G.P.

2006-01-01

This remark is part of an ongoing project to simplify the structure of the multi-loop anomalous dimensions for parton distributions and fragmentation functions. It answers the call for a 'structural explanation' of a 'very suggestive' relation found by Moch, Vermaseren and Vogt in the context of the x->1 behaviour of three-loop DIS anomalous dimensions. It also highlights further structure that remains to be fully explained

Effective evolution equations from many-body quantum mechanics

International Nuclear Information System (INIS)

Benedikter, Niels Patriz

2014-01-01

Systems of interest in physics often consist of a very large number of interacting particles. In certain physical regimes, effective non-linear evolution equations are commonly used as an approximation for making predictions about the time-evolution of such systems. Important examples are Bose-Einstein condensates of dilute Bose gases and degenerate Fermi gases. While the effective equations are well-known in physics, a rigorous justification is very difficult. However, a rigorous derivation is essential to precisely understand the range and the limits of validity and the quality of the approximation. In this thesis, we prove that the time evolution of Bose-Einstein condensates in the Gross-Pitaevskii regime can be approximated by the time-dependent Gross-Pitaevskii equation, a cubic non-linear Schroedinger equation. We then turn to fermionic systems and prove that the evolution of a degenerate Fermi gas can be approximated by the time-dependent Hartree-Fock equation (TDHF) under certain assumptions on the semiclassical structure of the initial data. Finally, we extend the latter result to fermions with relativistic kinetic energy. All our results provide explicit bounds on the error as the number of particles becomes large. A crucial methodical insight on bosonic systems is that correlations can be modeled by Bogolyubov transformations. We construct initial data appropriate for the Gross-Pitaevskii regime using a Bogolyubov transformation acting on a coherent state, which amounts to studying squeezed coherent states. As a crucial insight for fermionic systems, we point out a semiclassical structure in states close to the ground state of fermions in a trap. As a convenient language for studying the dynamics of fermionic systems, we use particle-hole transformations.

Mapping the evolution of scientific ideas

Energy Technology Data Exchange (ETDEWEB)

Roberts, David [Los Alamos National Laboratory; Herrera, Mark [UNIV OF MARYLAND; Gulbahce, Natali [UNIV OF BOSTON

2009-01-01

Despite the apparent conceptual boundaries of scientific fields, a formal description for their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society PACS numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using Cfinder, an overlapping community finding algorithm, and describe the time evolution of these fields using a community evolution method over the course of 1985-2006. The communities we identify map to known scientific fields, and their age strongly depends on t.heir size, impact and activity. Our analysis further suggests that communities that redefine themselves by merging and creating new groups of ideas tend to have more fitness as measured by the impact per paper, and hence communities with a higher fitness tend to be short-lived. The described approach to quantify the evolution of ideas may be relevant in making predictions about the future of science and how to guide its development.

The physics of evolution and biodiversity: Old answers to new questions, and more...

Science.gov (United States)

Bar-Yam, Yaneer

2013-03-01

In recent years there has been a contentious battle among prominent biologists about the validity of Kin versus Group Selection as models of evolutionary biology. I will show that the controversy is widely misunderstood and is rooted in the mean field basis of RA Fisher's statistical treatment of population biology, which is the origin of the ``gene centered view''-kin selection and inclusive fitness-but is also often used in analysis of group selection. As in statistical physics, symmetry breaking and pattern formation, and their spatial realizations, result in breakdown of the mean field approximation and the widely believed mathematical 'proofs' of the universality of the gene centered view. Our simulation and analysis (http://necsi.edu/research/evoeco/) of the role of this breakdown in spatial ecology, biodiversity, speciation and altruism, suggest there is an entire field of new opportunities to explore in the implications for evolutionary theory. The difference between biodiversity of wildtype populations and narrowly homogeneous laboratory types manifest the self-consistency of theoretical assumptions and laboratory experiments performed under conditions in which the mean field approximation applies. In contrast, the highly diverse natural populations manifest the role of boundaries between types (hybrid zones), speciation by spontaneous clustering, and spatio-temporal dynamics in predator prey systems. Altruism arises in evolving populations due to the spontaneous dynamic group formation and the heritability of environmental conditions created by parents and experienced by offspring (niche construction with symmetry breaking), so that altruists are better able to survive over the long term than selfish variants. Many versions of the mean field approximation that are traditionally used eliminate these spatio-temporal processes, leading to false analytic conclusions about their impossibility. The traditional view of altruism influenced views also of

Pedestal evolution physics in low triangularity JET tokamak discharges with ITER-like wall

Science.gov (United States)

Bowman, C.; Dickinson, D.; Horvath, L.; Lunniss, A. E.; Wilson, H. R.; Cziegler, I.; Frassinetti, L.; Gibson, K.; Kirk, A.; Lipschultz, B.; Maggi, C. F.; Roach, C. M.; Saarelma, S.; Snyder, P. B.; Thornton, A.; Wynn, A.; Contributors, JET

2018-01-01

The pressure gradient of the high confinement pedestal region at the edge of tokamak plasmas rapidly collapses during plasma eruptions called edge localised modes (ELMs), and then re-builds over a longer time scale before the next ELM. The physics that controls the evolution of the JET pedestal between ELMs is analysed for 1.4 MA, 1.7 T, low triangularity, δ  =  0.2, discharges with the ITER-like wall, finding that the pressure gradient typically tracks the ideal magneto-hydrodynamic ballooning limit, consistent with a role for the kinetic ballooning mode. Furthermore, the pedestal width is often influenced by the region of plasma that has second stability access to the ballooning mode, which can explain its sometimes complex evolution between ELMs. A local gyrokinetic analysis of a second stable flux surface reveals stability to kinetic ballooning modes; global effects are expected to provide a destabilising mechanism and need to be retained in such second stable situations. As well as an electron-scale electron temperature gradient mode, ion scale instabilities associated with this flux surface include an electro-magnetic trapped electron branch and two electrostatic branches propagating in the ion direction, one with high radial wavenumber. In these second stability situations, the ELM is triggered by a peeling-ballooning mode; otherwise the pedestal is somewhat below the peeling-ballooning mode marginal stability boundary at ELM onset. In this latter situation, there is evidence that higher frequency ELMs are paced by an oscillation in the plasma, causing a crash in the pedestal before the peeling-ballooning boundary is reached. A model is proposed in which the oscillation is associated with hot plasma filaments that are pushed out towards the plasma edge by a ballooning mode, draining their free energy into the cooler plasma there, and then relaxing back to repeat the process. The results suggest that avoiding the oscillation and maximising the region

On Combining High and Low Q2 Information on the Polarized Parton Densities

International Nuclear Information System (INIS)

Leader, Elliot; Stamenov, Dimiter B.

2000-01-01

We draw attention to some problems in the combined use of high-Q 2 deep inelastic scattering (DIS) data and low-Q 2 hyperon β-decay data in the determination of the polarized parton densities. We explain why factorization schemes like the JET or AB schemes are the simplest in which to study the implications of the DIS parton densities for the physics of the low-Q 2 region. (author)

Formation and Evolution of Binary Asteroids

Science.gov (United States)

Walsh, K. J.; Jacobson, S. A.

Satellites of asteroids have been discovered in nearly every known small-body population, and a remarkable aspect of the known satellites is the diversity of their properties. They tell a story of vast differences in formation and evolution mechanisms that act as a function of size, distance from the Sun, and the properties of their nebular environment at the beginning of solar system history and their dynamical environment over the next 4.5 G.y. The mere existence of these systems provides a laboratory to study numerous types of physical processes acting on asteroids, and their dynamics provide a valuable probe of their physical properties otherwise possible only with spacecraft. Advances in understanding the formation and evolution of binary systems have been assisted by (1) the growing catalog of known systems, increasing from 33 to ~250 between the Merline et al. (2002) chapter in Asteroids III and now; (2) the detailed study and long-term monitoring of individual systems such as 1999 KW4 and 1996 FG3, (3) the discovery of new binary system morphologies and triple systems, (4) and the discovery of unbound systems that appear to be end-states of binary dynamical evolutionary paths. Specifically for small bodies (diameter smaller than 10 km), these observations and discoveries have motivated theoretical work finding that thermal forces can efficiently drive the rotational disruption of small asteroids. Long-term monitoring has allowed studies to constrain the system's dynamical evolution by the combination of tides, thermal forces, and rigid-body physics. The outliers and split pairs have pushed the theoretical work to explore a wide range of evolutionary end-states.

Skepping deur evolusie

Directory of Open Access Journals (Sweden)

P. A.J. Ryke

1987-03-01

Full Text Available Biblical Creation versus evolution has been an acrimonious issue for well over a century between religious conservatives, especially Protestant fundamentalists and those people who consider parts of the Bible - par­ticularly the Book of Genesis - to be allegorical and symbolic. During the nineteenth century the idea that the Bible gave a directly true ac­ count of the origins of the world was deeply affected by scientific dis­ coveries. The new sciences of geology, and later of astronomy, made it overwhelmingly probable that the physical world is of in fin ite ly greater age than the few thousand years contemplated by the biblical account. The science of biology developed an account of the evolution of the various species of living organisms. Early fundamentalism was savagely hostile to the theory of evolution. In the m id-twentieth century the strife over this question seemed to have died down; but in the seventies and eighties hostility to evolution flared up again, and theories of 'creationism' were deployed. Though creationism attempts to argue with scientific arguments against evolution, it is hardly to be doubted that the mainspring of its motivation lies in biblical fundamentalism: that is, people are creationists because they think that the theory of evolution contradicts scripture and that creationism agrees with it.

Evolution des paramètres biochimiques chez les chevaux de sport ...

African Journals Online (AJOL)

Evolution des paramètres biochimiques chez les chevaux de sport pendant un test d'effort. ... English Title: Evolution of biochemical parameters in sport horses subjected to a stress test. English Abstract. The study aimed ... The evaluation of the fitness of these racehorses is of great use in assessing the physical conditions.

White dwarf evolution - Cradle-to-grave constraints via pulsation

International Nuclear Information System (INIS)

Kawaler, S.D.

1990-01-01

White dwarf evolution, particularly in the early phases, is not very strongly constrained by observation. Fortunately, white dwarfs undergo nonradial pulsation in three distinct regions of the H-R diagram. These pulsations provide accurate masses, surface compositional structure and rotation velocities, and help constrain other important physical properties. We demonstrate the application of the tools of stellar seismology to white dwarf evolution using the hot white dwarf star PG 1159-035 and the cool DAV (or ZZ Ceti) stars as examples. From pulsation studies, significant challenges to the theory of white dwarf evolution emerge. 44 refs

Life on Mars? II. Physical restrictions

Science.gov (United States)

Mancinelli, R. L.; Banin, A.

1995-01-01

The primary physical factors important to life's evolution on a planet include its temperature, pressure and radiation regimes. Temperature and pressure regulate the presence and duration of liquid water on the surface of Mars. The prolonged presence of liquid water is essential for the evolution and sustained presence of life on a planet. It has been postulated that Mars has always been a cold dry planet; it has also been postulated that early mars possessed a dense atmosphere of CO2 (> or = 1 bar) and sufficient water to cut large channels across its surface. The degree to which either of these postulates is true correlates with the suitability of Mars for life's evolution. Although radiation can destroy living systems, the high fluxes of UV radiation on the martian surface do not necessarily stop the origin and early evolution of life. The probability for life to have arisen and evolved to a significant degree on Mars, based on the postulated ranges of early martian physical factors, is almost solely related to the probability of liquid water existing on the planet for at least hundreds of millions to billions of years.

Analytic treatment of nonlinear evolution equations using first ...

Indian Academy of Sciences (India)

1. — journal of. July 2012 physics pp. 3–17. Analytic treatment of nonlinear evolution ... Eskisehir Osmangazi University, Art-Science Faculty, Department of Mathematics, ... (2.2) is integrated where integration constants are considered zeros.

Reflections around "Deorum iniurias dis curae " (Tap. Ann. 1. 73: how can we interpret this sententia?

Directory of Open Access Journals (Sweden)

Jose Mambwini Kivuila‑Kiaku

2014-12-01

Full Text Available The study of the sententia "Deorum iniurias dis curae" of the Annals 1. 73, variously interpreted by specialists of Tacitus, dresses in a big importance in the understanding not only of political, philosophic and religious thought of Tacitus, but also its writing of the history the influence of the rhetoric of which is not to be any more demonstrated. At the same time as it returns on eternal question of the nature of the motives which, in the Tacitus’s Annals, justifies it resorts systematic by Tiberius of the lex maiestatis, the present article opens some tracks of the refletions on the main questions that some people settle on and around this sententia. One of these tracks consists in presenting this formula as an invitation or a kind of call to order of the historian towards the emperor not to confuse the ius, the right human being, and the fas, the divine justice, in other words to avoid the confusion between the ius humanum and the religio. In another context, this sententia can be considered warning on the way the imperial cult is exerced in Rome.http://dx.doi.org/10.14195/2183-1718_66_10

Quasi-Static Evolution, Catastrophe, and Failed Eruption of Solar Flux Ropes

Science.gov (United States)

2016-12-30

Ropes James Chen Beam Physics Branch Plasma Physics Division December 30, 2016 Approved for public release; distribution is unlimited. i REPORT...pressure gradient force combine to balance the major radial hoop force. The macroscopic forces on the flux ropes and onset conditions are quantified...Solar physics theory 67-4989-07 Quasi-Static Evolution, Catastrophe, and “Failed” Eruption of Solar Flux Ropes James Chen1 Plasma Physics Division

Recent results from low-x and forward physics at HERA

Energy Technology Data Exchange (ETDEWEB)

Goerlich, Lidia [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Collaboration: H1 Collaboration

2013-04-15

The production of forward jets in inclusive as well as diffractive deep inelastic scattering at HERA is studied with the H1 detector. For inclusive DIS events at low Q{sup 2} with a forward jet, produced close to the proton remnant, differential cross sections and normalised distributions are measured as a function of the azimuthal angle difference between the forward jet and the scattered positron. Results on dijet production cross sections are also presented for diffractive DIS events in which the final state proton is tagged in the H1 Forward Proton Spectrometer. Two topologies are investigated by either requiring the two jets being produced centrally or by requiring that one of the jets is going in the forward direction. The data are compared with NLO QCD predictions as well as leading order Monte Carlo models.

Towards a Universal Biology: Is the Origin and Evolution of Life Predictable?

Science.gov (United States)

Rothschild, Lynn J.

2017-01-01

The origin and evolution of life seems an unpredictable oddity, based on the quirks of contingency. Celebrated by the late Stephen Jay Gould in several books, "evolution by contingency" has all the adventure of a thriller, but lacks the predictive power of the physical sciences. Not necessarily so, replied Simon Conway Morris, for convergence reassures us that certain evolutionary responses are replicable. The outcome of this debate is critical to Astrobiology. How can we understand where we came from on Earth without prophesy? Further, we cannot design a rational strategy for the search for life elsewhere - or to understand what the future will hold for life on Earth and beyond - without extrapolating from pre-biotic chemistry and evolution. There are several indirect approaches to understanding, and thus describing, what life must be. These include philosophical approaches to defining life (is there even a satisfactory definition of life?), using what we know of physics, chemistry and life to imagine alternate scenarios, using different approaches that life takes as pseudoreplicates (e.g., ribosomal vs non-ribosomal protein synthesis), and experimental approaches to understand the art of the possible. Given that: (1) Life is a process based on physical components rather than simply an object; (2). Life is likely based on organic carbon and needs a solvent for chemistry, most likely water, and (3) Looking for convergence in terrestrial evolution we can predict certain tendencies, if not quite "laws", that provide predictive power. Biological history must obey the laws of physics and chemistry, the principles of natural selection, the constraints of an evolutionary past, genetics, and developmental biology. This amalgam creates a surprising amount of predictive power in the broad outline. Critical is the apparent prevalence of organic chemistry, and uniformity in the universe of the laws of chemistry and physics. Instructive is the widespread occurrence of

The MentDis_ICF65+study protocol: prevalence, 1-year incidence and symptom severity of mental disorders in the elderly and their relationship to impairment, functioning (ICF) and service utilisation

OpenAIRE

Andreas, Sylke; Haerter, Martin; Volkert, Jana; Hausberg, Maria; Sehner, Susanne; Wegscheider, Karl; Rabung, Sven; Ausin, Berta; Canuto, Alessandra; Da Ronch, Chiara; Grassi, Luigi; Hershkovitz, Yael; Lelliott, Paul; Munoz, Manuel; Quirk, Alan

2013-01-01

Background The EU currently lacks reliable data on the prevalence and incidence of mental disorders in older people. Despite the availability of several national and international epidemiological studies, the size and burden of mental disorders in the elderly remain unclear due to various reasons. Therefore, the aims of the MentDis_ICF65+ study are (1) to adapt existing assessment instruments, and (2) to collect data on the prevalence, the incidence, and the natural course and prognosis of me...

Measurement of the strong coupling constant αs with hadronic jets in deep inelastic scattering

International Nuclear Information System (INIS)

Gouzevitch, Maxime

2008-12-01

In this analysis we have used the production of hard jets in neutral-current DIS for the extraction of the strong coupling constant α s . The jets have been selected in the NC DIS events at large momentum transvers 150 2 2 within the limits of the detector acceptance -0.8 Lab T B >5. Three jet observables normalized to the total NC DIS cross section have been used: Inclusive jet multiplicity as well as the production rates of 2-jet and 3-jet events. The prediction of the renormalization-group equation for the evolution of the strong coupling constant has been successfully tested for two orders of magnitude between Q=2 QeV to Q=122 GeV. The better precision on α s (m Z ) has been obtained with the combination ob the three observables at Q 2 >150 GeV 2 : α s (m Z )=0.1180±0.0007(exp.) -0.0034 +0.0050 (th.)±0.0017 (pdf.).

A model of the microphysical evolution of a cloud

International Nuclear Information System (INIS)

Zinn, J.

1994-01-01

The earth's weather and climate are influenced strongly by phenomena associated with clouds. Therefore, a general circulation model (GCM) that models the evolution of weather and climate must include an accurate physical model of the clouds. This paper describes efforts to develop a suitable cloud model. It concentrates on the microphysical processes that determine the evolution of droplet and ice crystal size distributions, precipitation rates, total and condensed water content, and radiative extinction coefficients

The common extremalities in biology and physics maximum energy dissipation principle in chemistry, biology, physics and evolution

CERN Document Server

Moroz, Adam

2011-01-01

This book is the first unified systemic description of dissipative phenomena, taking place in biology, and non-dissipative (conservative) phenomena, which is more relevant to physics. Fully updated and revised, this new edition extends our understanding of nonlinear phenomena in biology and physics from the extreme / optimal perspective. The first book to provide understanding of physical phenomena from a biological perspective and biological phenomena from a physical perspective Discusses emerging fields and analysis Provides examples.

Universitality features in (pp), (e+e-), and deep inelastic scattering process

International Nuclear Information System (INIS)

Zichichi, A.

1985-01-01

This paper discusses the use of the correct variables in (pp), (e + e - ), and deep-inelastic scattering (DIS) processes which allow universality features to be established different ways of producing mulihadronic states. The experimental data where (pp) interactions are compared with (e + e - ) are shown. Extrapolations of collider physics are discussed and it is found that the leading effects must be subtracted and the correct variables have to be used if one wants to compare purely hadronic interactions with (e + e - ) and DIS. The new method of studying (pp) and (pp) collisions allows one to put on equal footing the multiparticle systems that are produced in purely hadronic interactions, in (e + e - ) annihilation, and in DIS processes

On the thermodynamics of multilevel evolution.

Science.gov (United States)

Tessera, Marc; Hoelzer, Guy A

2013-09-01

Biodiversity is hierarchically structured both phylogenetically and functionally. Phylogenetic hierarchy is understood as a product of branching organic evolution as described by Darwin. Ecosystem biologists understand some aspects of functional hierarchy, such as food web architecture, as a product of evolutionary ecology; but functional hierarchy extends to much lower scales of organization than those studied by ecologists. We argue that the more general use of the term "evolution" employed by physicists and applied to non-living systems connects directly to the narrow biological meaning. Physical evolution is best understood as a thermodynamic phenomenon, and this perspective comfortably includes all of biological evolution. We suggest four dynamical factors that build on each other in a hierarchical fashion and set the stage for the Darwinian evolution of biological systems: (1) the entropic erosion of structure; (2) the construction of dissipative systems; (3) the reproduction of growing systems and (4) the historical memory accrued to populations of reproductive agents by the acquisition of hereditary mechanisms. A particular level of evolution can underpin the emergence of higher levels, but evolutionary processes persist at each level in the hierarchy. We also argue that particular evolutionary processes can occur at any level of the hierarchy where they are not obstructed by material constraints. This theoretical framework provides an extensive basis for understanding natural selection as a multilevel process. The extensive literature on thermodynamics in turn provides an important advantage to this perspective on the evolution of higher levels of organization, such as the evolution of altruism that can accompany the emergence of social organization. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Galaxy formation and evolution

CERN Document Server

Mo, Houjun; White, Simon

2010-01-01

The rapidly expanding field of galaxy formation lies at the interface between astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual chapters explore the evolution of the Universe as a whole and its particle and radiation content; linear and nonlinear growth of cosmic structure; processes affecting the gaseous and dark matter components of galaxies and their stellar populations; the formation of spiral and elliptical galaxies; central supermassive black holes and the activity associated with them; galaxy interactions; and the intergalactic medium. Emphasizing both observational and theoretical aspects, this book provides a coherent introduction for astronomers, cosmologists, and astroparticle physicists to the broad range of science underlying the formation and evolution of galaxies.

Sherwood Washburn's New physical anthropology: rejecting the "religion of taxonomy".

Science.gov (United States)

Mikels-Carrasco, Jessica

2012-01-01

Many physical anthropologists and nearly all of those studying primatology today can trace their academic genealogy to Sherwood Larned Washburn. His New physical anthropology, fully articulated in a 1951 paper, proposed that the study of hominid evolution must link understandings of form, function, and behavior along with the environment in order most accurately to reconstruct the evolution of our ancestors. This shift of concentration from strictly analyzing fossil remains to what Washburn termed adaptive complexes challenged not only Washburn's predecessors, but also led Washburn to critique the very system of academia within which he worked. Collaboration across multiple disciplines, linking the four fields of anthropology in order to understand humans and application of our understandings of human evolution to the betterment of society, are the hallmarks of Washburnian anthropology. In this paper I will explore how Washburn's New physical anthropology led him to not only change the research direction in physical anthropology, but also to challenge the academia within which he worked. I will conclude by reflecting on the prospects of continuing to practice Washburnian Anthropology.

The structure and evolution of the Sun

CERN Document Server

Severino, Giuseppe

2017-01-01

This book equips the reader with a coherent understanding of the structure of the Sun and its evolution and provides all the knowledge required to construct a simplified model of the Sun. The early chapters cover key aspects of basic physics and describe the Sun’s size, mass, luminosity, and temperature. Using a semi-empirical approach, the structure of the present Sun is then modeled in detail, layer by layer, proceeding from the photosphere to the convection zone, radiation zone, and core. Finally, all stages of the Sun’s evolution, from its formation to the end of its life, are carefully explained. The book is primarily intended for university students taking the initial steps in moving from physics to astrophysics. It includes worked exercises and problems to illustrate the concepts discussed, as well as additional problems for independent study. With the aim of helping the reader as much as possible, most of the mathematics required to use the book are provided in the text.

Kaon electroproduction

Energy Technology Data Exchange (ETDEWEB)

Markowitz, P. [Univ. of Maryland, College Park (United States)

1994-04-01

The talk will focus on the physics which can be addressed by looking at semi-inclusive and exclusive channels in the DIS region. In particular, the author examines how this physics is reflected in the separated response functions.

Kaon electroproduction

International Nuclear Information System (INIS)

Markowitz, P.

1994-01-01

The talk will focus on the physics which can be addressed by looking at semi-inclusive and exclusive channels in the DIS region. In particular, the author examines how this physics is reflected in the separated response functions

The Origin and Evolution of Complex Enough Systems in Biology

OpenAIRE

Brändas, Erkki

2017-01-01

Recent criticisms of Neo-Darwinism are considered and disputed within the setting of recent advances in chemical physics. A related query, viz., the ontological thesis, that everything is physical, confronts a crucial test on the validity of reductionism as a fundamental approach to science.  While traditional ‘physicalism’ interprets evolution as a sequence of physical accidents governed by the second law of thermodynamics, the concepts of biology concern processes that owe their goal-direct...

Phase-field model and its numerical solution for coring and microstructure evolution studies in alloys

Science.gov (United States)

Turchi, Patrice E. A.; Fattebert, Jean-Luc; Dorr, Milo R.; Wickett, Michael E.; Belak, James F.

2011-03-01

We describe an algorithm for the numerical solution of a phase-field model (PFM) of microstructure evolution in alloys using physical parameters from thermodynamic (CALPHAD) and kinetic databases. The coupled system of PFM equations includes a local order parameter, a quaternion representation of local crystal orientation and a species composition parameter. Time evolution of microstructures and alloy composition is obtained using an implicit time integration of the system. Physical parameters in databases can be obtained either through experiment or first-principles calculations. Application to coring studies and microstructure evolution of Au-Ni will be presented. Prepared by LLNL under Contract DE-AC52-07NA27344

Time rescaling and pattern formation in biological evolution.

Science.gov (United States)

Igamberdiev, Abir U

2014-09-01

Biological evolution is analyzed as a process of continuous measurement in which biosystems interpret themselves in the environment resulting in changes of both. This leads to rescaling of internal time (heterochrony) followed by spatial reconstructions of morphology (heterotopy). The logical precondition of evolution is the incompleteness of biosystem's internal description, while the physical precondition is the uncertainty of quantum measurement. The process of evolution is based on perpetual changes in interpretation of information in the changing world. In this interpretation the external biospheric gradients are used for establishment of new features of organization. It is concluded that biological evolution involves the anticipatory epigenetic changes in the interpretation of genetic symbolism which cannot generally be forecasted but can provide canalization of structural transformations defined by the existing organization and leading to predictable patterns of form generation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Regge-like initial input and evolution of non-singlet structure ...

Indian Academy of Sciences (India)

Regge-like initial input and evolution of non-singlet structure functions from DGLAP equation up to next-next-to-leading order at low x and low Q. 2. NAYAN MANI NATH1,2,∗, MRINAL KUMAR DAS1 and JAYANTA KUMAR SARMA1. 1Department of Physics, Tezpur University, Tezpur 784 028, India. 2Department of Physics ...

Definition and evolution of quantum cellular automata with two qubits per cell

International Nuclear Information System (INIS)

Karafyllidis, Ioannis G.

2004-01-01

Studies of quantum computer implementations suggest cellular quantum computer architectures. These architectures can simulate the evolution of quantum cellular automata, which can possibly simulate both quantum and classical physical systems and processes. It is however known that except for the trivial case, unitary evolution of one-dimensional homogeneous quantum cellular automata with one qubit per cell is not possible. Quantum cellular automata that comprise two qubits per cell are defined and their evolution is studied using a quantum computer simulator. The evolution is unitary and its linearity manifests itself as a periodic structure in the probability distribution patterns

Dynamical parton distributions of the nucleon and very small-x physics

International Nuclear Information System (INIS)

Glueck, M.; Jimenez-Delgado, P.; Reya, E.

2008-01-01

Utilizing recent DIS measurements (F 2,L ) and data on dilepton and high-E T jet production we determine the dynamical parton distributions of the nucleon generated radiatively from valence-like positive input distributions at optimally chosen low resolution scales. These are compared with 'standard' distributions generated from positive input distributions at some fixed and higher resolution scale. It is shown that up to the next-to-leading order NLO(MS, DIS) of perturbative QCD considered in this paper, the uncertainties of the dynamical distributions are, as expected, smaller than those of their standard counterparts. This holds true in particular in the presently unexplored extremely small-x region relevant for evaluating ultrahigh energy cross sections in astrophysical applications. It is noted that our new dynamical distributions are compatible, within the presently determined uncertainties, with previously determined dynamical parton distributions. (orig.)

Conference on chemical evolution and the origin of life

International Nuclear Information System (INIS)

1992-10-01

This report contains 19 summaries of papers presented at the Conference on Chemical Evolution and the Origin of Life held at the International Centre for Theoretical Physics. A separate indexing is provided for each summary

High energy physics and cosmology

International Nuclear Information System (INIS)

Silk, J.I.

1991-01-01

This research will focus on the implications of recent theories and experiments in high energy physics of the evolution of the early universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including studies of the nature of dark matter and the signature of annihilations in the galactic halo, where the resulting γ-ray fluxes are potentially observable, and in stars, where stellar evolution may be affects. We will develop constraints on the inflationary predictions of scale-free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon, examining the observable imprint of primordial density fluctuations on the cosmic microwave background radiation in both flat and curved cosmological models, and implications for observations of large-scale galaxy clustering and structure formation theories. We will also study spectral distortions in the microwave background radiation that are produced by exotic particle decays in the very early universe. We expect such astrophysical considerations to provide fruitful insights both into high-energy particle physics and into possible cosmological for the early universe

Radiation physics as a new science discipline

International Nuclear Information System (INIS)

Sri Ram, K.

1987-01-01

After tracing the evolution of radiation physics teaching at the university level in U.S.A., the current status of teaching of radiation physics in Indian Universities is reviewed. It is noted that parts of radiation physics are taught in some Indian academic institutions. Only Madras University offers an M.Sc. programme in radiation physics. Its curriculum is critically examined and it is noted that more emphasis is required on practical and applied aspects of radiation physics. Closer interaction between academic and R and D institutions is required. (M.G.B.)

Quantitative Modeling of Landscape Evolution, Treatise on Geomorphology

NARCIS (Netherlands)

Temme, A.J.A.M.; Schoorl, J.M.; Claessens, L.F.G.; Veldkamp, A.; Shroder, F.S.

2013-01-01

This chapter reviews quantitative modeling of landscape evolution – which means that not just model studies but also modeling concepts are discussed. Quantitative modeling is contrasted with conceptual or physical modeling, and four categories of model studies are presented. Procedural studies focus

A stochastic approach to chemical evolution

International Nuclear Information System (INIS)

Copi, C.J.

1997-01-01

Observations of elemental abundances in the Galaxy have repeatedly shown an intrinsic scatter as a function of time and metallicity. The standard approach to chemical evolution does not attempt to address this scatter in abundances since only the mean evolution is followed. In this work, the scatter is addressed via a stochastic approach to solving chemical evolution models. Three simple chemical evolution scenarios are studied using this stochastic approach: a closed box model, an infall model, and an outflow model. These models are solved for the solar neighborhood in a Monte Carlo fashion. The evolutionary history of one particular region is determined randomly based on the star formation rate and the initial mass function. Following the evolution in an ensemble of such regions leads to the predicted spread in abundances expected, based solely on different evolutionary histories of otherwise identical regions. In this work, 13 isotopes are followed, including the light elements, the CNO elements, a few α-elements, and iron. It is found that the predicted spread in abundances for a 10 5 M circle-dot region is in good agreement with observations for the α-elements. For CN, the agreement is not as good, perhaps indicating the need for more physics input for low-mass stellar evolution. Similarly for the light elements, the predicted scatter is quite small, which is in contradiction to the observations of 3 He in HII regions. The models are tuned for the solar neighborhood so that good agreement with HII regions is not expected. This has important implications for low-mass stellar evolution and on using chemical evolution to determine the primordial light-element abundances in order to test big bang nucleosynthesis. copyright 1997 The American Astronomical Society

Modelling of surface evolution of rough surface on divertor target in fusion devices

International Nuclear Information System (INIS)

Dai, Shuyu; Liu, Shengguang; Sun, Jizhong; Kirschner, A.; Kawamura, G.; Tskhakaya, D.; Ding, Rui; Luo, Guangnan; Wang, Dezhen

2015-01-01

Highlights: • We study the surface evolution of rough surface on divertor target in fusion devices. • The effects of gyration motion and E × B drift affect 3D angular distribution. • A larger magnetic field angle leads to a reduced net eroded areal density. • The rough surface evolution affects the physical sputtering yield. - Abstract: The 3D Monte-Carlo code SURO has been used to study the surface evolution of rough surface on the divertor target in fusion devices. The edge plasma at divertor region is modelled by the SDPIC code and used as input data for SURO. Coupled with SDPIC, SURO can perform more sophisticated simulations to calculate the local angle and surface evolution of rough surface. The simulation results show that the incident direction of magnetic field, gyration and E × B force has a significant impact on 3D angular distribution of background plasma and accordingly on the erosion of rough surface. The net eroded areal density of rough surface is studied by varying the magnetic field angle with surface normal. The evolution of the microscopic morphology of rough surface can lead to a significant change in the physical sputtering yield

"(Dis)Empowered by What We See … ": Exploring the Use of Video-Stimulated Reflection in Physical Education Pedagogy and Practice

Science.gov (United States)

Mooney, Amanda; Hickey, Chris

2017-01-01

Reflexive accounts of physical education (PE) pedagogy and practice offer potential to reveal much about the intended and unintended learning, for both students and teachers, that can result from certain pedagogic encounters. Despite the promotion of reflective practice/s as a possible "panacea" for improved teaching and learning, there…

Arfiputri et al., Afr., J. Infect. Dis.

African Journals Online (AJOL)

Dharin Serebrina Arfiputri

2017-10-20

Oct 20, 2017 ... Diagnosis of VVC are from history taking, physical examination (Linhares et al, 2001; ... From the appearance of vaginal discharge usually minimal, ... (69.48%), and the rest are not yet married, divorce and widow, not yet.

Stellar evolution and the triple-α reactions

International Nuclear Information System (INIS)

Suda, Takuma

2014-01-01

Nuclear reaction rates play a crucial role in the evolution of stars. For low-mass stars, the triple-α reaction controls the helium burning stars in the red giant and asymptotic giant branch (AGB) phase. More importantly, the cross section of the triple-α reaction has a great impact on the helium ignition at the center of the electron degenerate helium core of red giants and on the helium shell flashes of AGB stars. It is to be noted that stellar evolution models are influenced not only by the value of the cross section, but also by the temperature dependence of the reaction rate. In this paper, I present the impact of the triple-α reaction rates on the evolution of low-mass metal-free stars and intermediate-mass AGB stars. According to the previous study, the constraint on the triple-α reaction rate is derived based on stellar evolution theory. It is found that the recent revisions of the rate proposed by nuclear physics calculations satisfy the condition for the ignition of the helium core flash in low-mass stars

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Optimum nuclear parton distributions are obtained by analysing available experimental data on electron and muon deep inelastic scattering (DIS). The distributions are given at 2 = 1 GeV2 with a number of parameters, which are determined by a 2 analysis of the data. Valencequark distributions are relatively well ...

Geometric origin of dynamically induced freezing of quantum evolution

International Nuclear Information System (INIS)

Matos-Abiague, A.; Berakdar, J.

2006-01-01

The phenomenon of dynamical, field-induced freezing of quantum evolution is discussed. It occurs when a time-dependent state is dynamically driven in such a way that the evolution of the corresponding wave function is effectively localized within a small region in the projective Hilbert space. As a consequence, the dynamics of the system is frozen and the expectation values of all physical observables hardly change with time. Necessary and sufficient conditions for inducing dynamical freezing are inferred from a general analysis of the geometry of quantum evolution. The relevance of the dynamical freezing for a sustainable in time, dynamical control is discussed and exemplified by a study of the coherent control of the kicked rotor motion

Solar Radiation as Driving Force In Early Evolution

Science.gov (United States)

Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

2002-01-01

Ultraviolet radiation (UVR) has provided an evolutionary challenge to life on Earth in that it is both an agent of mutation and as well as a selective force. Today surface fluxes of UVR vary diurnally, seasonally, etc. Still, the UVR flux was probably substantially higher during the early phases of evolution, suggesting that its role in evolution was even more prominent during this time. In this presentation, the creative role of UVR in evolution is discussed, specifically in connection with the role that UVR may have played in the evolution of early microbial ecosystems. The presentation will include discussions of the direct influence of UVR on such processes as photosynthesis and genetic damage, as well as the indirect influence of UVR as mediated through the production of reactive oxygen species. These biological effects of UVR will be viewed against the backdrop of the physical nature of the early Earth, surely a very different place then than now.

COSMIC EVOLUTION OF SIZE AND VELOCITY DISPERSION FOR EARLY-TYPE GALAXIES

International Nuclear Information System (INIS)

Fan, L.; Lapi, A.; Bressan, A.; De Zotti, G.; Danese, L.; Bernardi, M.

2010-01-01

Massive (stellar mass M * ∼> 3 x 10 10 M sun ), passively evolving galaxies at redshifts z ∼> 1 exhibit on average physical sizes smaller, by factors ∼3, than local early-type galaxies (ETGs) endowed with the same stellar mass. Small sizes are in fact expected on theoretical grounds, if dissipative collapse occurs. Recent results show that the size evolution at z ∼ 1, where both compact and already extended galaxies are observed and the scatter in size is remarkably larger than it is locally. The presence at high redshift of a significant number of ETGs with the same size as their local counterparts, as well as ETGs with quite small size (∼ H (z). We demonstrate that the projected mass of compact, high-redshift galaxies and that of local ETGs within the same physical radius, the nominal half-luminosity radius of high-redshift ETGs, differ substantially in that the high-redshift ETGs are on average significantly denser. This result suggests that the physical mechanism responsible for the size increase should also remove mass from central galaxy regions (r ∼ 1, we predict the local velocity dispersion distribution function. On comparing it to the observed one, we show that velocity dispersion evolution of massive ETGs is fully compatible with the observed average evolution in size at constant stellar mass. Less massive ETGs (with stellar masses M * ∼ 10 M sun ) are expected to evolve less both in size and in velocity dispersion, because their evolution is essentially determined by supernova feedback, which cannot yield winds as powerful as those triggered by quasars. The differential evolution is expected to leave imprints in the size versus luminosity/mass, velocity dispersion versus luminosity/mass, and central black hole mass versus velocity dispersion relationships, as observed in local ETGs.

Kopernik, Einstein and evolution of a logic structure of relativity principle

International Nuclear Information System (INIS)

Kruczek, W.

1986-01-01

This paper shown that the development of physics as a logic structure was begun by Mikolaj Kopernik. It was consequently presented that the whole period of physic evolution, since Kopernik times through Einstein and also later, was determined by the relativity principle. That principle in this primary version was used for scienific justification of heliocentric system. As a consequence it caused the development of research on the motion, the time and the space (Gallileo, Newton and others). The article presents successive stages of the evolution of those motions, explaining the difference between Einstein's and Poincare's interpretation of them. The methodologic background of Einstein's measuring procedures was also explained. 10 refs., 7 figs. (author)

On the physical realizability of quantum stochastic walks

Science.gov (United States)

Taketani, Bruno; Govia, Luke; Schuhmacher, Peter; Wilhelm, Frank

Quantum walks are a promising framework that can be used to both understand and implement quantum information processing tasks. The recently developed quantum stochastic walk combines the concepts of a quantum walk and a classical random walk through open system evolution of a quantum system, and have been shown to have applications in as far reaching fields as artificial intelligence. However, nature puts significant constraints on the kind of open system evolutions that can be realized in a physical experiment. In this work, we discuss the restrictions on the allowed open system evolution, and the physical assumptions underpinning them. We then introduce a way to circumvent some of these restrictions, and simulate a more general quantum stochastic walk on a quantum computer, using a technique we call quantum trajectories on a quantum computer. We finally describe a circuit QED approach to implement discrete time quantum stochastic walks.

Friction-induced nano-structural evolution of graphene as a lubrication additive

Science.gov (United States)

Zhao, Jun; Mao, Junyuan; Li, Yingru; He, Yongyong; Luo, Jianbin

2018-03-01

Graphene has attracted enormous attention in the field of lubrication based on its excellent physical and chemical properties. Although many studies have obtained thermally or chemically- exfoliated graphene and investigated their wide and important application, few studies have reported their physical nano-structural evolution under friction. In this study, we investigated the lubrication properties of graphene additives with different layer numbers and interlayer spacing by exfoliating. The additives with a higher degrees of exfoliation changed to ordering under friction, and had better lubrication properties, while that with a lower degrees exhibited obvious structural defects and high friction. Therefore, the original degrees of exfoliation plays a key role in the structural evolution of graphene and superior lubrication can be achieved through the physical nano-structure changing to ordering, even graphitization. Furthermore, the ordered tribofilm on the frictional interfaces was parallel to the sliding direction, meaning the highly exfoliated graphene indeed reaching slippage between its layers, which wasn't experimentally discovered in previous studies. This work provides a new understanding of the relationship between friction-induced nano-structural evolution and lubrication properties of graphene as a lubrication additive, and has great potential for the structural design of graphene as a lubrication additive.

Signalling, entanglement and quantum evolution beyond Cauchy horizons

International Nuclear Information System (INIS)

Yurtsever, Ulvi; Hockney, George

2005-01-01

Consider a bipartite entangled system, half of which falls through the event horizon of an evaporating black hole, while the other half remains coherently accessible to experiments in the exterior region. Beyond complete evaporation, the evolution of the quantum state past the Cauchy horizon cannot remain unitary, raising the questions: how can this evolution be described as a quantum map, and how is causality preserved? What are the possible effects of such non-standard quantum evolution maps on the behaviour of the entangled laboratory partner? More generally, the laws of quantum evolution under extreme conditions in remote regions (not just in evaporating black-hole interiors, but possibly near other naked singularities and regions of extreme spacetime structure) remain untested by observation, and might conceivably be non-unitary or even nonlinear, raising the same questions about the evolution of entangled states. The answers to these questions are subtle, and are linked in unexpected ways to the fundamental laws of quantum mechanics. We show that terrestrial experiments can be designed to probe and constrain exactly how the laws of quantum evolution might be altered, either by black-hole evaporation, or by other extreme processes in remote regions possibly governed by unknown physics

The Evolution of a Sharing Platform into a Sustainable Business

DEFF Research Database (Denmark)

Constantiou, Ioanna; Eaton, Ben; Tuunainen, Virpi Kristiina

2016-01-01

A number of sharing economy start-ups have taken both digital and physical product markets by storm. These start-ups operate on two-sided platforms and enable sharing of physical products or services based on physical assets. Interestingly, they are subject to both the dynamics of the digital world...... (i.e., network effects), and the constraints of the physical world (i.e., issues of accountability when physical property is destroyed). We investigate how Airbnb, a sharing platform, evolve into a sustainable business with an in-depth case analysis based on data retrieved from a number of blogs...... understanding of the evolution of sharing platforms into sustainable and competitive businesses....

Clay Caterpillars: A Tool for Ecology & Evolution Laboratories

Science.gov (United States)

Barber, Nicholas A.

2012-01-01

I present a framework for ecology and evolution laboratory exercises using artificial caterpillars made from modeling clay. Students generate and test hypotheses about predation rates on caterpillars that differ in appearance or "behavior" to understand how natural selection by predators shapes distribution and physical characteristics of…

New travelling wave solutions for nonlinear stochastic evolution

Indian Academy of Sciences (India)

The nonlinear stochastic evolution equations have a wide range of applications in physics, chemistry, biology, economics and finance from various points of view. In this paper, the (′/)-expansion method is implemented for obtaining new travelling wave solutions of the nonlinear (2 + 1)-dimensional stochastic ...

High and low dose-rate brachytherapy for cervical carcinoma

International Nuclear Information System (INIS)

Orton, C.G.

1998-01-01

For the brachytherapy component of the r[iation treatment of cervical carcinoma, high dose rate (HDR) is slowly replacing conventional low dose rate (LDR) due primarily to r[iation safety and other physical benefits attributed to the HDR modality. Many r[iation oncologists are reluctant to make this change because of perceived r[iobiological dis[vantages of HDR. However, in clinical practice HDR appears to be as effective as LDR but with a lower risk of late complications, as demonstrated by one randomized clinical trial and two comprehensive literature and practice surveys. The reason for this appears to be that the r[iobiological dis[vantages of HDR are outweighed by the physical [vantages. (orig.)

Atmospheric evolution on inhabited and lifeless worlds

CERN Document Server

Catling, David C

2017-01-01

As the search for Earth-like exoplanets gathers pace, in order to understand them, we need comprehensive theories for how planetary atmospheres form and evolve. Written by two well-known planetary scientists, this text explains the physical and chemical principles of atmospheric evolution and planetary atmospheres, in the context of how atmospheric composition and climate determine a planet's habitability. The authors survey our current understanding of the atmospheric evolution and climate on Earth, on other rocky planets within our Solar System, and on planets far beyond. Incorporating a rigorous mathematical treatment, they cover the concepts and equations governing a range of topics, including atmospheric chemistry, thermodynamics, radiative transfer, and atmospheric dynamics, and provide an integrated view of planetary atmospheres and their evolution. This interdisciplinary text is an invaluable one-stop resource for graduate-level students and researchers working across the fields of atmospheric science...

Evolution of oil droplets in a chemorobotic platform

Science.gov (United States)

Gutierrez, Juan Manuel Parrilla; Hinkley, Trevor; Taylor, James Ward; Yanev, Kliment; Cronin, Leroy

2014-12-01

Evolution, once the preserve of biology, has been widely emulated in software, while physically embodied systems that can evolve have been limited to electronic and robotic devices and have never been artificially implemented in populations of physically interacting chemical entities. Herein we present a liquid-handling robot built with the aim of investigating the properties of oil droplets as a function of composition via an automated evolutionary process. The robot makes the droplets by mixing four different compounds in different ratios and placing them in a Petri dish after which they are recorded using a camera and the behaviour of the droplets analysed using image recognition software to give a fitness value. In separate experiments, the fitness function discriminates based on movement, division and vibration over 21 cycles, giving successive fitness increases. Analysis and theoretical modelling of the data yields fitness landscapes analogous to the genotype-phenotype correlations found in biological evolution.

Imprint of galaxy formation and evolution on globular cluster properties

OpenAIRE

Bekki, Kenji

2006-01-01

We discuss the origin of physical properties of globular cluster systems (GCSs) in galaxies in terms of galaxy formation and evolution processes. Based on numerical simulations of dynamical evolution of GCSs in galaxies, we particularly discuss (1) the origin of radial density profiles of GCSs, (2) kinematics of GCSs in elliptical galaxies, (3) transformation from nucleated dwarf galaxies into GCs (e.g., omega Centauri), and (4) the origin of GCSs in the Large Magellanic Cloud (LMC).

Reviews Toy: Air swimmers Book: Their Arrows will Darken the Sun: The Evolution and Science of Ballistics Book: Physics Experiments for your Bag Book: Quantum Physics for Poets Equipment: SEP colour wheel kit Equipment: SEP colour mixing kit Software: USB DrDAQ App: iHandy Level Equipment: Photonics Explorer kit Web Watch

Science.gov (United States)

2012-01-01

WE RECOMMEND Air swimmers Helium balloon swims like a fish Their Arrows will Darken the Sun: The Evolution and Science of Ballistics Ballistics book hits the spot Physics Experiments for your Bag Handy experiments for your lessons Quantum Physics for Poets Book shows the economic importance of physics SEP colour wheel kit Wheels investigate colour theory SEP colour mixing kit Cheap colour mixing kit uses red, green and blue LEDs iHandy Level iPhone app superbly measures angles Photonics Explorer kit Free optics kit given to schools WORTH A LOOK DrDAQ DrDAQ software gets an upgrade WEB WATCH Websites show range of physics

Study on the dominant reaction path in nucleosynthesis during stellar evolution by means of the Monte Carlo method

International Nuclear Information System (INIS)

Yamamoto, K.; Hashizume, K.; Wada, T.; Ohta, M.; Suda, T.; Nishimura, T.; Fujimoto, M. Y.; Kato, K.; Aikawa, M.

2006-01-01

We propose a Monte Carlo method to study the reaction paths in nucleosynthesis during stellar evolution. Determination of reaction paths is important to obtain the physical picture of stellar evolution. The combination of network calculation and our method gives us a better understanding of physical picture. We apply our method to the case of the helium shell flash model in the extremely metal poor star

Dynamical evolution and disintegration of comets

Science.gov (United States)

Kresak, L.

Current concepts of the origin and evolution of comets are reviewed. The place of their formation from which they have been delivered into the Oort reservoir is still an open problem, but the region of the outermost planets appears most probable. The interplay of stellar and planetary perturbations can be traced by model computations which reveal both the general trends and the variety of individual evolutionary paths. The present structure of the system of comets is controlled by the dynamical evolution of its individual members, limited by their physical aging by disintegration. Where the lifetimes are short, as in the Jupiter family of short-period comets, an equilibrium between elimination and replenishment is established. The role of different destructive processes and the resulting survival times are discussed.

Observational constraints from models of close binary evolution

International Nuclear Information System (INIS)

Greve, J.P. de; Packet, W.

1984-01-01

The evolution of a system of 9 solar masses + 5.4 solar masses is computed from Zero Age Main Sequence through an early case B of mass exchange, up to the second phase of mass transfer after core helium burning. Both components are calculated simultaneously. The evolution is divided into several physically different phases. The characteristics of the models in each of these phases are transformed into corresponding 'observable' quantities. The outlook of the system for photometric observations is discussed, for an idealized case. The influence of the mass of the loser and the initial mass ratio is considered. (Auth.)

New way of demonstrating the competence of a laboratory measuring radionuclides - The international draft standard ISO/IEC DIS 17025

International Nuclear Information System (INIS)

Palsson, S.E.

1999-01-01

In recent years there has been increased interest, and even need, amongst laboratories performing measurements of radionuclides to obtain accreditation. It has been discussed how this could be achieved with maximum flexibility for the laboratories and with minimum effort. The issuing of a new draft international standard, the ISO/IEC DIS 17025, created speculations whether it could offer a new and better way for laboratories to obtain accreditation. It was decided within the NKS/BOK-1.1 project to explore possible options for obtaining accreditation and what possibilities the new standard could offer. The benefits of computerised document control systems were also explored. The results were reported at the 12th Annual Meeting of the Nordic Society for Radiation Protection, 23-27 August 1999. Since then the final version of the standard has been published. The voting will continue until November 16th 1999 and is not clear at present whether the standard will be accepted or not. The original version of this paper was updated to reflect these recent developments. (au)

Exploring New Physics Frontiers Through Numerical Relativity.

Science.gov (United States)

Cardoso, Vitor; Gualtieri, Leonardo; Herdeiro, Carlos; Sperhake, Ulrich

2015-01-01

The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology.

Quasistatic evolution of compact toroids

International Nuclear Information System (INIS)

Sgro, A.G.; Spencer, R.L.; Lilliequist, C.

1981-01-01

Some results are presented of simulations of the post formation evolution of compact toroids. The simulations were performed with a 1-1/2 D transport code. Such a code makes explicit use of the fact that the shapes of the flux surfaces in the plasma change much more slowly than do the profiles of the physical variables across the flux surfaces. Consequently, assuming that the thermodynamic variables are always equilibrated on a flux surface, one may calculate the time evolution of these profiles as a function of a single variable that labels the flux surfaces. Occasionally, during the calculation these profiles are used to invert the equilibrium equation to update the shapes of the flux surfaces. In turn, these shapes imply certain geometric cofficients, such as A = 2 >, which contain the geometric information required by the 1-D equations

Sociohistorical evolution of judo: introductory approaches

Directory of Open Access Journals (Sweden)

Orozimbo Cordeiro Júnior

2008-06-01

Full Text Available The sociohistorical evolution of judo provided by the research project Methodology for teaching judo from the critical–excelling stance is discussed in this article. The aim of the project was to establish a plan for systematizing judo as body culture constituent and scholastic knowledge of physical education. The ancillary pedagogical material is constituted by an introduction, objectives, contents, teaching methodology and evaluation system.

A physically based 3-D model of ice cliff evolution over debris-covered glaciers

Science.gov (United States)

Buri, Pascal; Miles, Evan S.; Steiner, Jakob F.; Immerzeel, Walter W.; Wagnon, Patrick; Pellicciotti, Francesca

2016-12-01

We use high-resolution digital elevation models (DEMs) from unmanned aerial vehicle (UAV) surveys to document the evolution of four ice cliffs on the debris-covered tongue of Lirung Glacier, Nepal, over one ablation season. Observations show that out of four cliffs, three different patterns of evolution emerge: (i) reclining cliffs that flatten during the ablation season; (ii) stable cliffs that maintain a self-similar geometry; and (iii) growing cliffs, expanding laterally. We use the insights from this unique data set to develop a 3-D model of cliff backwasting and evolution that is validated against observations and an independent data set of volume losses. The model includes ablation at the cliff surface driven by energy exchange with the atmosphere, reburial of cliff cells by surrounding debris, and the effect of adjacent ponds. The cliff geometry is updated monthly to account for the modifications induced by each of those processes. Model results indicate that a major factor affecting the survival of steep cliffs is the coupling with ponded water at its base, which prevents progressive flattening and possible disappearance of a cliff. The radial growth observed at one cliff is explained by higher receipts of longwave and shortwave radiation, calculated taking into account atmospheric fluxes, shading, and the emission of longwave radiation from debris surfaces. The model is a clear step forward compared to existing static approaches that calculate atmospheric melt over an invariant cliff geometry and can be used for long-term simulations of cliff evolution and to test existing hypotheses about cliffs' survival.

Quantitative Test of the Evolution of Geant4 Electron Backscattering Simulation

CERN Document Server

Basaglia, Tullio; Hoff, Gabriela; Kim, Chan Hyeong; Kim, Sung Hun; Pia, Maria Grazia; Saracco, Paolo

2016-01-01

Evolutions of Geant4 code have affected the simulation of electron backscattering with respect to previously published results. Their effects are quantified by analyzing the compatibility of the simulated electron backscattering fraction with a large collection of experimental data for a wide set of physics configuration options available in Geant4. Special emphasis is placed on two electron scattering implementations first released in Geant4 version 10.2: the Goudsmit-Saunderson multiple scattering model and a single Coulomb scattering model based on Mott cross section calculation. The new Goudsmit-Saunderson multiple scattering model appears to perform equally or less accurately than the model implemented in previous Geant4 versions, depending on the electron energy. The new Coulomb scattering model was flawed from a physics point of view, but computationally fast in Geant4 version 10.2; the physics correction released in Geant4 version 10.2p01 severely degrades its computational performance. Evolutions in ...

Evolution of physics examining 1940-2000 at Cambridge

Science.gov (United States)

Roberts, A.; Brown, L. M.

2001-07-01

Much controversy exists about the supposed changing examination standards. Emphasis has been placed on the standards of GCSE and A-level examinations. However, many large employers recruit graduates, and so university examination standards also deserve attention. Here, Cambridge University Part II (third year undergraduate) examinations in Physics are studied since 1940. Trends in prescriptiveness, choice of questions, and other variables were found.

Guide of good practices in medical physics - French Society of Medical Physics

International Nuclear Information System (INIS)

Rosenwald, Jean-Claude; Aventin, Christophe; Coste, Frederic; Francois, Pascal; Ginestet, Chantal; Perrin, Benedicte; Salvat, Cecile; Caselles, Olivier; Dedieu, Veronique; Dejean, Catherine; Batalla, Alain; Guillaume, Bonniaud; Le Du, Dominique; Lisbona, Albert; Marchesi, Vincent; Sarrazin, Thierry; Mazeron, Jean-Jacques; Lipinski, Francis; Vera, Pierre; Vermandel, Maximilien; Ducou le Pointe, Hubert; Vidal, Vincent; Henry, Cecile; Mazeau-Woynar, Valerie; Prot, Camille; Valero, Marc; Aubert, Bernard; Etard, Cecile; Jimonet, Christine; Roue, Amelie; Sage, Julie; Bardies, Manuel; Beauvais, Helene; Bey, Pierre; Costa, Andre; Desblancs, Claire; Eudaldo, Teresa; Farman, Bardia; Ferrand, Regis; Garcia, Robin; Giraud, Jean-Yves; Husson, Francois; Koulibaly, Malick; Carlan, Loic de; Manens, Jean-Pierre; Naudy, Suzanne; Noel, Alain; Pilette, Pierre; Verdun, Francis; Bouette, Aurelien; Breen, Stephen; Bridier, Andre; Chauvenet, Bruno; Chavaudra, Jean; Gardin, Isabelle; Herlevin, Karine

2012-01-01

After a presentation of the methodological approach used to write this book, the first chapter addresses the profession of medical physicist: medical physics in France (history, evolution of the profession, of the education and of regulation), legal framework (related to the medical use of ionizing radiations, legal texts directly concerning medical physics, regulations impacting the professional practice of medical physicists), scopes of intervention of the medical physicist (context, missions, dose management, image quality, quality management and safety, relationship with the patient, education, training and research, relationships with industry, cost management), operating conditions, and good professional practices. The second chapter addresses the principles of management of quality and safety: quality management in medical physics, safety management, quality and safety in health care facilities. The third part addresses good practices in medical physics: general principles of working methods, equipment management, participation to clinic activities

Information-theoretic metamodel of organizational evolution

Science.gov (United States)

Sepulveda, Alfredo

2011-12-01

Social organizations are abstractly modeled by holarchies---self-similar connected networks---and intelligent complex adaptive multiagent systems---large networks of autonomous reasoning agents interacting via scaled processes. However, little is known of how information shapes evolution in such organizations, a gap that can lead to misleading analytics. The research problem addressed in this study was the ineffective manner in which classical model-predict-control methods used in business analytics attempt to define organization evolution. The purpose of the study was to construct an effective metamodel for organization evolution based on a proposed complex adaptive structure---the info-holarchy. Theoretical foundations of this study were holarchies, complex adaptive systems, evolutionary theory, and quantum mechanics, among other recently developed physical and information theories. Research questions addressed how information evolution patterns gleamed from the study's inductive metamodel more aptly explained volatility in organization. In this study, a hybrid grounded theory based on abstract inductive extensions of information theories was utilized as the research methodology. An overarching heuristic metamodel was framed from the theoretical analysis of the properties of these extension theories and applied to business, neural, and computational entities. This metamodel resulted in the synthesis of a metaphor for, and generalization of organization evolution, serving as the recommended and appropriate analytical tool to view business dynamics for future applications. This study may manifest positive social change through a fundamental understanding of complexity in business from general information theories, resulting in more effective management.

Quanta - evolution - mind. An essay about nature, science, and reality; Quanten - Evolution - Geist. Eine Abhandlung ueber Natur, Wissenschaft und Wirklichkeit

Energy Technology Data Exchange (ETDEWEB)

Eidemueller, Dirk

2017-02-01

The first part gives a survey about the surprising properties of quantum physics and their most important interpretations. We contrast the new quantum-physical principles of the description of nature with those of classical physics. In the second part we perform in the framework of the reductionism debate an extensive analysis of the understanding of reality represented by the evolutionary theory of knowledge and subject this a critique by means of several central points. A special point of view lies hereby beside the results of quantum philosophy on the relation of physics, chemistry, and biology as well as on the body-soul problem. in the third part we deal with the mutual theories, which follow from the evolution theory and the quantum philosophy for our picture of world.

STATISTICAL ANALYSIS OF STELLAR EVOLUTION

OpenAIRE

van Dyk, DA; DeGennaro, S; Stein, N; Jefferys, WH; von Hippel, T

2009-01-01

Color-Magnitude Diagrams (CMDs) are plots that compare the magnitudes (luminosities) of stars in different wavelengths of light (colors). High nonlinear correlations among the mass, color, and surface temperature of newly formed stars induce a long narrow curved point cloud in a CMD known as the main sequence. Aging stars form new CMD groups of red giants and white dwarfs. The physical processes that govern this evolution can be described with mathematical models and explored using complex co...

Beyond the top of the volcano? A unified approach to electrocatalytic oxygen reduction and oxygen evolution

Czech Academy of Sciences Publication Activity Database

Busch, M.; Halck, N. B.; Kramm, U. I.; Siehrostami, S.; Krtil, Petr; Rossmeisl, J.

2016-01-01

Roč. 29, NOV 2016 (2016), s. 126-135 ISSN 2211-2855 Institutional support: RVO:61388955 Keywords : hydrogen evolution * catalytic-activity * Electrocatalysis * Oxygen reduction * Oxygen evolution * Volcano * Density functional theory Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 12.343, year: 2016

On the evolution of cluster scaling relations

International Nuclear Information System (INIS)

Diemer, Benedikt; Kravtsov, Andrey V.; More, Surhud

2013-01-01

Understanding the evolution of scaling relations between the observable properties of clusters and their total mass is key to realizing their potential as cosmological probes. In this study, we investigate whether the evolution of cluster scaling relations is affected by the spurious evolution of mass caused by the evolving reference density with respect to which halo masses are defined (pseudo-evolution). We use the relation between mass, M, and velocity dispersion, σ, as a test case, and show that the deviation from the M-σ relation of cluster-sized halos caused by pseudo-evolution is smaller than 10% for a wide range of mass definitions. The reason for this small impact is a tight relation between the velocity dispersion and mass profiles, σ(evolution, halos approximately preserve their M-σ relation. This result highlights the fact that tight scaling relations are the result of tight equilibrium relations between radial profiles of physical quantities. We find exceptions at very small and very large radii, where the profiles deviate from the relations they exhibit at intermediate radii. We discuss the implications of these results for other cluster scaling relations and argue that pseudo-evolution should have a small effect on most scaling relations, except for those that involve the stellar masses of galaxies. In particular, we show that the relation between stellar-mass fraction and total mass is affected by pseudo-evolution and is largely shaped by it for halo masses ≲ 10 14 M ☉ .

Galaxy evolution in dense environments: a concise HI perspective

NARCIS (Netherlands)

Verheijen, Marc A. W.; Diaferio, Antonaldo

2004-01-01

Observing the neutral hydrogen in galaxy clusters provides crucial insights in the physical processes that influence the evolution of gas-rich galaxies as they migrate from the lower-density filaments through the cluster outskirts into to the higher-density central regions. The morphology-density

Evolution of the human brain: design without a designer.

NARCIS (Netherlands)

Hofman, M.A.; Kaas, John

2017-01-01

The evolutionary expansion of the brain is among the most distinctive morphological features of mammals. During the past decades, considerable progress has been made in explaining brain evolution in terms of physical and adaptive principles. The objective of this chapter is to present current

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics. Jonu Lee. Articles written in Pramana – Journal of Physics. Volume 75 Issue 4 October 2010 pp 565-578 Research Articles. Travelling wave solutions for ( + 1)-dimensional nonlinear evolution equations · Jonu Lee Rathinasamy Sakthivel · More Details Abstract Fulltext PDF.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 83; Issue 4. Issue front cover thumbnail. Volume 83, Issue 4. October 2014, pages 457-632. pp 457-471 Research Articles. Solitary wave solutions to nonlinear evolution equations in mathematical physics · Anwar Ja'afar Mohamad Jawad M Mirzazadeh Anjan Biswas.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 77; Issue 6. Issue front cover thumbnail. Volume 77, Issue 6. December 2011, pages 1023-1203. pp 1023-1029. Application of the trial equation method for solving some nonlinear evolution equations arising in mathematical physics · Yusuf Gurefe Abdullah ...

SIGNUM: A Matlab, TIN-based landscape evolution model

Science.gov (United States)

Refice, A.; Giachetta, E.; Capolongo, D.

2012-08-01

Several numerical landscape evolution models (LEMs) have been developed to date, and many are available as open source codes. Most are written in efficient programming languages such as Fortran or C, but often require additional code efforts to plug in to more user-friendly data analysis and/or visualization tools to ease interpretation and scientific insight. In this paper, we present an effort to port a common core of accepted physical principles governing landscape evolution directly into a high-level language and data analysis environment such as Matlab. SIGNUM (acronym for Simple Integrated Geomorphological Numerical Model) is an independent and self-contained Matlab, TIN-based landscape evolution model, built to simulate topography development at various space and time scales. SIGNUM is presently capable of simulating hillslope processes such as linear and nonlinear diffusion, fluvial incision into bedrock, spatially varying surface uplift which can be used to simulate changes in base level, thrust and faulting, as well as effects of climate changes. Although based on accepted and well-known processes and algorithms in its present version, it is built with a modular structure, which allows to easily modify and upgrade the simulated physical processes to suite virtually any user needs. The code is conceived as an open-source project, and is thus an ideal tool for both research and didactic purposes, thanks to the high-level nature of the Matlab environment and its popularity among the scientific community. In this paper the simulation code is presented together with some simple examples of surface evolution, and guidelines for development of new modules and algorithms are proposed.

A Distributed Snow Evolution Modeling System (SnowModel)

Science.gov (United States)

Liston, G. E.; Elder, K.

2004-12-01

A spatially distributed snow-evolution modeling system (SnowModel) has been specifically designed to be applicable over a wide range of snow landscapes, climates, and conditions. To reach this goal, SnowModel is composed of four sub-models: MicroMet defines the meteorological forcing conditions, EnBal calculates surface energy exchanges, SnowMass simulates snow depth and water-equivalent evolution, and SnowTran-3D accounts for snow redistribution by wind. While other distributed snow models exist, SnowModel is unique in that it includes a well-tested blowing-snow sub-model (SnowTran-3D) for application in windy arctic, alpine, and prairie environments where snowdrifts are common. These environments comprise 68% of the seasonally snow-covered Northern Hemisphere land surface. SnowModel also accounts for snow processes occurring in forested environments (e.g., canopy interception related processes). SnowModel is designed to simulate snow-related physical processes occurring at spatial scales of 5-m and greater, and temporal scales of 1-hour and greater. These include: accumulation from precipitation; wind redistribution and sublimation; loading, unloading, and sublimation within forest canopies; snow-density evolution; and snowpack ripening and melt. To enhance its wide applicability, SnowModel includes the physical calculations required to simulate snow evolution within each of the global snow classes defined by Sturm et al. (1995), e.g., tundra, taiga, alpine, prairie, maritime, and ephemeral snow covers. The three, 25-km by 25-km, Cold Land Processes Experiment (CLPX) mesoscale study areas (MSAs: Fraser, North Park, and Rabbit Ears) are used as SnowModel simulation examples to highlight model strengths, weaknesses, and features in forested, semi-forested, alpine, and shrubland environments.

Evolution of clans in multiparticle production

International Nuclear Information System (INIS)

Zborovsky, I.

1994-01-01

An alternative interpretation of the development of the clan structure arising formally from the natural decomposition of the negative binomial multiplicity distribution is presented here. Our approach is based on stochastico-physical ideas of multiple production on the parton level. Specific differential-difference evolution equations have been proposed which besides the elementary processes involving the ingredients of QCD branching describe collective phenomena of clan's collapsing and clan's coherent disintegration. (orig.)

Rumors of transcendence in physics

International Nuclear Information System (INIS)

Pollard, W.G.

1984-01-01

There are several hints in physics of a domain of external reality transcendent to three-dimensional space and time. This paper calls attention to several of these intimations of a real world beyond the natural order. Examples are the complex state functions in configuration space of quantum mechanics, the singularity at the birth of the universe, the anthropic principle, the role of chance in evolution, and the unaccountable fruitfulness of mathematics for physics. None of these examples touch on the existence or activity of God, but they do suggest that external reality may be much richer than the natural world which it is the task of physics to describe

Physics division annual report 2006.

Energy Technology Data Exchange (ETDEWEB)

Glover, J.; Physics

2008-02-28

This report highlights the activities of the Physics Division of Argonne National Laboratory in 2006. The Division's programs include the operation as a national user facility of ATLAS, the Argonne Tandem Linear Accelerator System, research in nuclear structure and reactions, nuclear astrophysics, nuclear theory, investigations in medium-energy nuclear physics as well as research and development in accelerator technology. The mission of nuclear physics is to understand the origin, evolution and structure of baryonic matter in the universe--the core of matter, the fuel of stars, and the basic constituent of life itself. The Division's research focuses on innovative new ways to address this mission.

B physics at SLD

International Nuclear Information System (INIS)

Willocq, S.

1997-06-01

The authors review recent B physics results obtained in polarized e + e - interactions at the SLC by the SLD experiment. The excellent 3-D vertexing capabilities of SLD are exploited to extract precise B + and B d 0 lifetimes, as well as measurements of the time evolution of B d 0 - (anti B d 0 ) mixing

Dynamical evolution and disintegration of comets

International Nuclear Information System (INIS)

Kresak, L.

1982-01-01

Current concepts of the origin and evolution of comets are reviewed. The place of their formation from which they have been delivered into the Oort reservoir is still an open problem, but the region of the outermost planets appears most probable. The interplay of stellar and planetary perturbations can be traced by model computations which reveal both the general trends and the variety of individual evolutionary paths. The present structure of the system of comets is controlled by the dynamical evolution of its individual members limited by their physical aging by disintegration. Where the lifetimes are short, as in the Jupiter family of short-period comets, an equilibrium between elimination and replenishment is established. The role of different destructive processes and the resulting survival times are discussed. (Auth.)

Frost evolution in tailings

International Nuclear Information System (INIS)

1991-04-01

A review was carried out on the physical and thermal mechanisms of permafrost evaluation in soils and uranium tailings. The primary mechanism controlling permafrost evolution is conductive heat transfer with the latent heat of fusion of water being liberated as phase change occurs. Depending on the soil properties and freezing rate, pore water can be expelled from the frost front or pore water can migrate towards the frost front. Solute redistribution may occur as the frost front penetrates into the soil. The rate of frost penetration is a function of the thermal properties of the tailings and the climatic conditions. Computer modelling programmes capable of modelling permafrost evolution were reviewed. The GEOTHERM programme was selected as being the most appropriate for this study. The GEOTHERM programme uses the finite element method of thermal analysis. The ground surface temperature is determined by solving the energy balance equations a the ground surface. The GEOTHERM programme was used to simulate the permafrost evolution in the Key Lake Mine tailings located in north central Saskatchewan. The analyses indicated that the existing frozen zones in the tailing pond will eventually thaw if an average snow depth covers the tailings. Hundreds of years are required to thaw the tailings. If minimal snow cover is present the extent of the frozen zone in the tailings will increase

The basic physics of neutron scattering experiments

International Nuclear Information System (INIS)

Mezei, F.

1999-01-01

The basic physical principles behind the well-established but also developing practice of neutron scattering experiments are presented. A few examples are given either to illustrate the physical principles or to give an idea of the variety, importance or magnitude of various phenomena. The evolution of neutron scattering experimental techniques is investigated from a special aspect: the increasing capability of taking into account more and more important and sometimes decisive finer details by using more and more realistic mathematical models of the evolution of the neutrons from birth do death, eventually passing by the sample and being scattered more than one times. Working with such numerical 'virtual instruments' one will have to go far beyond notions like resolution function, convolution etc, and actually eliminate a large number of approximations currently in use. (K.A.)

Defect evolution in cosmology and condensed matter quantitative analysis with the velocity-dependent one-scale model

CERN Document Server

Martins, C J A P

2016-01-01

This book sheds new light on topological defects in widely differing systems, using the Velocity-Dependent One-Scale Model to better understand their evolution. Topological defects – cosmic strings, monopoles, domain walls or others - necessarily form at cosmological (and condensed matter) phase transitions. If they are stable and long-lived they will be fossil relics of higher-energy physics. Understanding their behaviour and consequences is a key part of any serious attempt to understand the universe, and this requires modelling their evolution. The velocity-dependent one-scale model is the only fully quantitative model of defect network evolution, and the canonical model in the field. This book provides a review of the model, explaining its physical content and describing its broad range of applicability.

A guide for good practices in medical physics - French Society of Medical Physics

International Nuclear Information System (INIS)

Rosenwald, Jean-Claude; Aventin, Christophe; Coste, Frederic; Francois, Pascal; Ginestet, Chantal; Perrin, Benedicte; Salvat, Cecile; Caselles, Olivier; Dedieu, Veronique; Dejean, Catherine; Batalla, Alain; Guillaume, Bonniaud; LeDu, Dominique; Lisbona, Albert; Marchesi, Vincent; Sarrazin, Thierry; Mazeron, Jean-Jacques; Lipinski, Francis; Vera, Pierre; Maximilien Vermandel; Ducou le Pointe, Hubert; Vidal, Vincent; Henry, Cecile; Mazeau-Woynar, Valerie; Prot, Camille; Valero, Marc; Aubert, Bernard; Etard, Cecile; Jimonet, Christine; Roue, Amelie; Sage, Julie; Bardies, Manuel; Beauvais, Helene; Bey, Pierre; Costa, Andre; Desblancs, Claire; Eudaldo, Teresa; Farman, Bardia; Ferrand, Regis; Garcia, Robin; Giraud, Jean-Yves; Husson, Francois; Koulibaly, Malick; Carlan, Loic de; Manens, Jean-Pierre; Naudy, Suzanne; Noel, Alain; Pilette, Pierre; Verdun, Francis

2012-12-01

After a presentation of the methodological approach used to write this book, the first chapter addresses the profession of medical physicist: medical physics in France (history, evolution of the profession, of the education and of regulation), legal framework (related to the medical use of ionizing radiations, legal texts directly concerning medical physics, regulations impacting the professional practice of medical physicists), scopes of intervention of the medical physicist (context, missions, dose management, image quality, quality management and safety, relationship with the patient, education, training and research, relationships with industry, cost management), operating conditions, and good professional practices. The second chapter addresses the principles of management of quality and safety: quality management in medical physics, safety management, quality and safety in health care facilities. The third part addresses good practices in medical physics: general principles of working methods, equipment management, participation to clinic activities

Evolution of interstellar dust in light of Herschel Space Observatory data

International Nuclear Information System (INIS)

Arab, Heddy

2012-01-01

Interstellar dust grains are nanometer to micrometer sized particles. Although a weak proportion of the total interstellar mass is at solid state, dust plays a fundamental role in the evolution of the interstellar medium (ISM) and of the galaxy itself. Grains can be observed in the UV and visible wavelength through extinction whereas their emission is in the infrared to submillimeter range. Astrophysical observations combined to numerical models and laboratory studies of dust analogs improve our comprehension of the nature and the physics of interstellar grains. For example, evidence of dust evolution in the interstellar medium are now numerous, even if the physical processes responsible of this evolution are still poorly understood. Understanding how grains evolve with physical conditions requires observations of various environments. Photodissociation regions (PDRs) are zones of the ISM where the radiation field and the local density vary on short spatial scales (∼10''- 20''). Moreover the many gas tracers offer the opportunity to constraint efficiently the physical conditions within PDRs. Past missions such as ISO and Spitzer allow to study the evolution of dust in the near-Infrared range. At longer wavelengths, where the emission is dominated by the grains at thermal equilibrium with the radiation, instruments rarely resolved the spatial emission in PDRs. PACS and SPIRE instruments onboard Herschel Space Observatory provide spectro-photometric data between 70 and 500 μm. Their high spatial resolution (from 5 to 35 arcmin) makes these observations ideal for the study of dust evolution in PDRs. We present here an analysis of Herschel observations of three PDRs: the Orion Bar, the Horsehead and NGC 7023 East, characterized by different physical conditions. By combining these data with shorter wavelength observations from Spitzer, we can study the dust emission spectrum from 3.6 to 500 μm at different positions within the PDR. Intensity profiles are extracted

Energy dependence of the Cronin effect from nonlinear QCD evolution

International Nuclear Information System (INIS)

Albacete, Javier L.; Armesto, Nestor; Salgado, Carlos A.; Wiedemann, Urs Achim; Kovner, Alex

2004-01-01

The nonlinear evolution of dense partonic systems has been suggested as a novel physics mechanism relevant for the dynamics of p-A and A-A collisions at collider energies. Here we study to what extent the description of Cronin enhancement in the framework of this nonlinear evolution is consistent with the recent observation in √(s)=200 GeV d-Au collisions at the Relativistic Heavy Ion Collider. We solve the Balitsky-Kovchegov evolution equation numerically for several initial conditions encoding Cronin enhancement. We find that the properly normalized nuclear gluon distribution is suppressed at all momenta relative to that of a single nucleon. For the resulting spectrum of produced gluons in p-A and A-A collisions, the nonlinear QCD evolution is unable to generate a Cronin-type enhancement, and it quickly erases any such enhancement which may be present at lower energies

Evolutionary Medicine and Future of Humanity: Will Evolution Have the Final Word?

Directory of Open Access Journals (Sweden)

Maciej Henneberg

2013-06-01

Full Text Available Evolutionary medicine in its classical form assumes that since cultural evolution is faster than biological evolution, ailments of modern people are a result of mismatch between adaptations to the past environments and current situations. A core principle is that we, humans, having evolved for millions of years in a specific natural environment (environment of evolutionary adaptation EEA are biologically adapted to this past environment and the ancient lifestyle. This adaptation to the past produces major mismatch of our bodies with the present, highly anthropic and thus “artificial” living conditions. This article provides two areas of possible future evolution, diet and physical activity levels which have been dramatically altered in industrialised societies. Consequently, micro-evolution is an on-going process.

BOOK REVIEW: Structures in the Universe by Exact Methods: Formation, Evolutions, Interactions (Cambridge Monographs on Mathematical Physics) Structures in the Universe by Exact Methods: Formation, Evolutions, Interactions (Cambridge Monographs on Mathematical Physics)

Science.gov (United States)

Coley, Alan

2010-05-01

Szekeres model) is studied regarding structure formation. I thought that the authors describe the advantages and drawbacks of the idealized exact solutions used in the physical modelling in a reasonable manner (although more concise conclusions might have been useful). The authors also address the formation of a galaxy with a central black hole, the formation and evolution of rich galactic clusters and voids and other structures, and the effects of radiation in the models. The most interesting application is presented in chapter 5; namely, the effects of inhomogeneities on observations such as the luminosity distance relation and the explanation of the observed dimming of distant SN Ia (which is usually interpreted within the standard FLRW model in terms of the existence of dark energy). The main conclusion of this work is that data can be reproduced within the LT model (via inhomogeneities in general relativity, but without introducing dark energy). In particular, a number of exact LT solutions were surveyed, and a full discussion of various models in the literature (and a critique of the various assumptions) is presented. In the next chapter the possible resolution of the horizon problem without inflation, in terms of shell crossing in a LT model, is discussed. This is perhaps the most controversial chapter of the book. In the final chapter 7, the influence of inhomogeneous structures in the path of a light ray (for both center and off-center observers in a special Szekeres Swiss cheese model) on the observed temperature distribution of the CMB is discussed. This is a very important topic, but only a heuristic and qualitative study is presented here; more work on the multipole moments of higher order would be necessary for a more comprehensive analysis.

New data libraries and physics data management tools

International Nuclear Information System (INIS)

Han, M; Kim, C H; Seo, H; Pia, M G; Saracco, P; Augelli, M; Hauf, S; Kuster, M; Moneta, L; Quintieri, L

2011-01-01

A number of physics data libraries for Monte Carlo simulation are reviewed. The development of a package for the management of physics data is described: its design, implementation and computational benchmarks. This package improves the data management tools originally developed for Geant4 electromagnetic physics models based on data libraries. The implementation exploits recent evolutions of the C++ libraries appearing in the C++0x draft, which are intended for inclusion in the next C++ ISO Standard. The new tools improve the computational performance of physics data management.

Evolution of massive stars with mass loss: surface abundances

International Nuclear Information System (INIS)

Greggio, L.

1984-01-01

The location of theoretical stellar models in the upper part of the Hertzsprung-Russell diagram depends on a variety of poorly understood physical processes which may occur during the evolution of massive stars. The comparison between theoretical predictions and observations of the surface chemical composition of these objects can help in understanding their evolution and to set more stringent limits to the mentioned parameters. To this end, evolutionary sequences corresponding to 20, 40 and 60 solar masses have been computed up to core He exhaustion, following in detail the abundance variations of CNO, Ne and Mg isotopes. (Auth.)

Impact of National Physical Activity and Health Guidelines and Documents on Research on Teaching K-12 Physical Education in U.S.A.

Science.gov (United States)

Li, Weidong; Xiang, Ping; Gao, Zan; Shen, Bo; Yin, Zhihua; Kong, Qingtao

2016-01-01

Purpose: This study examined the impact of published national physical activity (PA) and health guidelines, documents, and initiatives on the evolution of research on teaching K-12 physical education (PE) in U.S.A. from 1996 to October 2013. Methods: A total of 262 peer-reviewed, data-based journal articles meeting our inclusion and exclusion…

Transactional Infrastructure of the Economy: the Evolution of Concepts and Synthesis of Definitions

OpenAIRE

Maruschak Irina Valeryevna

2017-01-01

The overview of evolution of market infrastructure concepts is provided, the first concepts of institutional infrastructure are revealed in the paper. Evolutionarily developed narrowing of essence of infrastructure in connection with the priority analysis of its physical (material and technological) components is proved. It ignores the fact that transactional resources, being drivers (driving forces) of economic systems evolution, in turn evolve, becoming harder and harder, combining increase...

Physical Activity, Aging, and Physiological Function.

Science.gov (United States)

Harridge, Stephen D R; Lazarus, Norman R

2017-03-01

Human evolution suggests that the default position for health is to be physically active. Inactivity, by contrast, has serious negative effects on health across the lifespan. Therefore, only in physically active people can the inherent aging process proceed unaffected by disuse complications. In such individuals, although the relationship between age and physiological function remains complex, function is generally superior with health, well being, and the aging process optimized. ©2017 Int. Union Physiol. Sci./Am. Physiol. Soc.

Spatial evolution equation of wind wave growth

Institute of Scientific and Technical Information of China (English)

WANG; Wei; (王; 伟); SUN; Fu; (孙; 孚); DAI; Dejun; (戴德君)

2003-01-01

Based on the dynamic essence of air-sea interactions, a feedback type of spatial evolution equation is suggested to match reasonably the growing process of wind waves. This simple equation involving the dominant factors of wind wave growth is able to explain the transfer of energy from high to low frequencies without introducing the concept of nonlinear wave-wave interactions, and the results agree well with observations. The rate of wave height growth derived in this dissertation is applicable to both laboratory and open sea, which solidifies the physical basis of using laboratory experiments to investigate the generation of wind waves. Thus the proposed spatial evolution equation provides a new approach for the research on dynamic mechanism of air-sea interactions and wind wave prediction.

Evolution of Supernova Remnants

Science.gov (United States)

Arbutina, B.

2017-12-01

This book, both a monograph and a graduate textbook, is based on my original research and partly on the materials prepared earlier for the 2007 and 2008 IARS Astrophysics Summer School in Istanbul, AstroMundus course 'Supernovae and Their Remnants' that was held for the first time in 2011 at the Department of Astronomy, Faculty of Mathematics, University of Belgrade, and a graduate course 'Evolution of Supernova Remnants' that I teach at the aforementioned university. The first part Supernovae (introduction, thermonuclear supernovae, core-collapse supernovae) provides introductory information and explains the classification and physics of supernova explosions, while the second part Supernova remnants (introduction, shock waves, cosmic rays and particle acceleration, magnetic fields, synchrotron radiation, hydrodynamic and radio evolution of supernova remnants), which is the field I work in, is more detailed in scope i.e. technical/mathematical. Special attention is paid to details of mathematical derivations that often cannot be found in original works or available literature. Therefore, I believe it can be useful to both, graduate students and researchers interested in the field.

Unified model for vortex-string network evolution

International Nuclear Information System (INIS)

Martins, C.J.A.P.; Moore, J.N.; Shellard, E.P.S.

2004-01-01

We describe and numerically test the velocity-dependent one-scale string evolution model, a simple analytic approach describing a string network with the averaged correlation length and velocity. We show that it accurately reproduces the large-scale behavior (in particular the scaling laws) of numerical simulations of both Goto-Nambu and field theory string networks. We explicitly demonstrate the relation between the high-energy physics approach and the damped and nonrelativistic limits which are relevant for condensed matter physics. We also reproduce experimental results in this context and show that the vortex-string density is significantly reduced by loop production, an effect not included in the usual 'coarse-grained' approach

Time evolution as refining, coarse graining and entangling

International Nuclear Information System (INIS)

Dittrich, Bianca; Steinhaus, Sebastian

2014-01-01

We argue that refining, coarse graining and entangling operators can be obtained from time evolution operators. This applies in particular to geometric theories, such as spin foams. We point out that this provides a construction principle for the physical vacuum in quantum gravity theories and more generally allows construction of a (cylindrically) consistent continuum limit of the theory. (paper)

Time evolution as refining, coarse graining and entangling

Science.gov (United States)

Dittrich, Bianca; Steinhaus, Sebastian

2014-12-01

We argue that refining, coarse graining and entangling operators can be obtained from time evolution operators. This applies in particular to geometric theories, such as spin foams. We point out that this provides a construction principle for the physical vacuum in quantum gravity theories and more generally allows construction of a (cylindrically) consistent continuum limit of the theory.

The DarkStars code: a publicly available dark stellar evolution package

CERN Document Server

Scott, Pat; Fairbairn, Malcolm

2009-01-01

We announce the public release of the 'dark' stellar evolution code DarkStars. The code simultaneously solves the equations of WIMP capture and annihilation in a star with those of stellar evolution assuming approximate hydrostatic equilibrium. DarkStars includes the most extensive WIMP microphysics of any dark evolution code to date. The code employs detailed treatments of the capture process from a range of WIMP velocity distributions, as well as composite WIMP distribution and conductive energy transport schemes based on the WIMP mean-free path in the star. We give a brief description of the input physics and practical usage of the code, as well as examples of its application to dark stars at the Galactic centre.

Preface [11. Pacific Rim conference on stellar astrophysics: Physics and chemistry of the late stages of stellar evolution, Hong Kong (China), 14-17 December 2015

International Nuclear Information System (INIS)

Kwok, Sun; Leung, Kam Ching

2016-01-01

Stellar mass loss is now widely recognized to have a significant impact on stellar evolution. Mass loss on the asymptotic giant branch (AGB) allows stars with initial masses under 8 solar masses to avoid the fate of going supernovae. Over 95% of stars in our Galaxy will evolve through the planetary nebulae phase to end up as white dwarfs instead of neutron stars or black holes. Massive stars undergo mass loss both in the blue and red phases of evolution and create new classes of stars such as Wolf-Rayet stars and luminous blue variables. The circumstellar matter ejected by these mass loss processes becomes new laboratories to study the physical and chemical processes of interstellar matter. The interaction between different phases of mass loss (with variable mass loss rates, ejection speeds, and directions) leads to spectacular morphological transformation of the circumstellar nebulae. The circumstellar nebulae are also sites of molecular and solid-state synthesis. Close to 100 molecular species and a variety of solids, including minerals and complex organics, have been detected in circumstellar envelopes. Since the dynamical time scale of the ejection puts an upper limit on the chemical time scale, we are witnessing a rapid synthesis of chemical species in an extremely low-density environment, creating new challenges to our understanding of chemical reactions. Effects of mass loss are not limited to single stars. Mass loss by one component of a binary system allows mass transfer to occur at separations beyond the Roche Lobe limit. Accreted wind materials on the surface of a degenerate star can lead to periodic outbursts through H-shell burning. When both components are losing mass, we have interesting dynamical systems such as symbiotic novae. The theme of this conference is “Physics and Chemistry of the Late Stages of Stellar Evolution”. We try to bring together experts in different fields to exchange ideas in the hope of solving the many unsolved problems in

Chempy: A flexible chemical evolution model for abundance fitting. Do the Sun's abundances alone constrain chemical evolution models?

Science.gov (United States)

Rybizki, Jan; Just, Andreas; Rix, Hans-Walter

2017-09-01

Elemental abundances of stars are the result of the complex enrichment history of their galaxy. Interpretation of observed abundances requires flexible modeling tools to explore and quantify the information about Galactic chemical evolution (GCE) stored in such data. Here we present Chempy, a newly developed code for GCE modeling, representing a parametrized open one-zone model within a Bayesian framework. A Chempy model is specified by a set of five to ten parameters that describe the effective galaxy evolution along with the stellar and star-formation physics: for example, the star-formation history (SFH), the feedback efficiency, the stellar initial mass function (IMF), and the incidence of supernova of type Ia (SN Ia). Unlike established approaches, Chempy can sample the posterior probability distribution in the full model parameter space and test data-model matches for different nucleosynthetic yield sets. It is essentially a chemical evolution fitting tool. We straightforwardly extend Chempy to a multi-zone scheme. As an illustrative application, we show that interesting parameter constraints result from only the ages and elemental abundances of the Sun, Arcturus, and the present-day interstellar medium (ISM). For the first time, we use such information to infer the IMF parameter via GCE modeling, where we properly marginalize over nuisance parameters and account for different yield sets. We find that 11.6+ 2.1-1.6% of the IMF explodes as core-collapse supernova (CC-SN), compatible with Salpeter (1955, ApJ, 121, 161). We also constrain the incidence of SN Ia per 103M⊙ to 0.5-1.4. At the same time, this Chempy application shows persistent discrepancies between predicted and observed abundances for some elements, irrespective of the chosen yield set. These cannot be remedied by any variations of Chempy's parameters and could be an indication of missing nucleosynthetic channels. Chempy could be a powerful tool to confront predictions from stellar

Introduction to Particle Physics course

CERN Multimedia

CERN. Geneva HR-RFA

2006-01-01

These lectures are an introduction to the ideas of particle physics, aimed at students and teachers with little or on knowledge of the subject. They form a broad basis that will be developed in more detail by the subsequent lecturers in the school. These four lectures are meant to present an overview of particle physics based on its historical evolution over the past century. It will be shown how concepts have evolved following progress in instrumentation and in theoretical ideas, from atoms to the elementary particles and their interactions, as they are known today.

Evolution of sorption properties in large-scale concrete structures accounting for long-term physical-chemical concrete degradation - 59297

International Nuclear Information System (INIS)

Perko, Janez; Jacques, Diederik; Mallants, Dirk; Seetharam, Suresh

2012-01-01

Long-term safety of radioactive waste disposal facilities relies on the longevity of natural or engineered barriers designed to minimize the migration of contaminants from the facility into the environment. Especially near surface disposal facilities, such as planned by ONDRAF/NIRAS for the Dessel site in Belgium, long-term safety relies almost exclusively on the containment ability of the engineered barriers (EB) with concrete being the most important EB material used. Concrete is preferred over other materials mainly due to its favourable chemical properties resulting in a high chemical retention capacity, and owing to its good hydraulic isolation properties. However, due to the long time frames typically involved in safety assessment, the chemical, physical and mechanical properties of concrete evolve in time. The alterations in concrete mineralogy also cause changes in pH and sorption behaviour for many radionuclides during chemical degradation processes. Application of dynamic sorption of concrete requires an adequate knowledge of long-term concrete degradation processes, knowledge of the effect of changing mineralogy to sorption of radionuclides and knowledge of large-scale system behaviour over time. Moreover, when applied to safety assessment models, special attention is required to assure robustness and transparency of the implementation. The discussion in this paper focuses on the sorption properties of concrete; selection of data, rescaling issues and on the hypotheses used to build a robust and yet transparent dynamic model for large-scale concrete structures for assessing the long-term performance. In this paper we summarize the steps required for the appropriate use of sorption values for large-scale cementitious components accounting for long-term concrete degradation in safety assessment studies. Four steps were recognized through the safety assessment in the framework of the license application for the near-surface disposal facility in Dessel

The Evolution of Mindfulness-Based Physical Interventions in Breast Cancer Survivors

Directory of Open Access Journals (Sweden)

Daniela L. Stan

2012-01-01

Full Text Available Survivors of breast cancer are faced with a multitude of medical and psychological impairments during and after treatment and throughout their lifespan. Physical exercise has been shown to improve survival and recurrence in this population. Mind-body interventions combine a light-moderate intensity physical exercise with mindfulness, thus having the potential to improve both physical and psychological sequelae of breast cancer treatments. We conducted a review of mindfulness-based physical exercise interventions which included yoga, tai chi chuan, Pilates, and qigong, in breast cancer survivors. Among the mindfulness-based interventions, yoga was significantly more studied in this population as compared to tai chi chuan, Pilates, and qigong. The participants and the outcomes of the majority of the studies reviewed were heterogeneous, and the population included was generally not selected for symptoms. Yoga was shown to improve fatigue in a few methodologically strong studies, providing reasonable evidence for benefit in this population. Improvements were also seen in sleep, anxiety, depression, distress, quality of life, and postchemotherapy nausea and vomiting in the yoga studies. Tai chi chuan, Pilates, and qigong were not studied sufficiently in breast cancer survivors in order to be implemented in clinical practice.

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics. A G Wagh. Articles written in Pramana – Journal of Physics. Volume 71 Issue 4 October 2008 pp 877-885 Invited Papers. Small-angle neutron scattering study of structural evolution of different phases in protein solution · V K Aswal S Chodankar J Kohlbrecher R Vavrin A G ...

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics. S Chodankar. Articles written in Pramana – Journal of Physics. Volume 71 Issue 4 October 2008 pp 877-885 Invited Papers. Small-angle neutron scattering study of structural evolution of different phases in protein solution · V K Aswal S Chodankar J Kohlbrecher R Vavrin A G ...

Running coupling and pomeron loop effects on inclusive and diffractive DIS cross sections

Energy Technology Data Exchange (ETDEWEB)

Ducati, M.B. Gay [Universidade Federal do Rio Grande do Sul, Instituto de Fisica, Porto Alegre (Brazil); CERN, PH-TH, Geneva (Switzerland); Oliveira, E.G. de [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo (Brazil); Santana Amaral, J.T. de [Universidade Federal de Pelotas, Instituto de Fisica e Matematica, Pelotas (Brazil)

2012-11-15

Within the framework of a (1+1)-dimensional model which mimics high-energy QCD, we study the behavior of the cross sections for inclusive and diffractive deep inelastic {gamma} {sup *} h scattering cross sections. We analyze the cases of both fixed and running coupling within the mean-field approximation, in which the evolution of the scattering amplitude is described by the Balitsky-Kovchegov equation, and also through the pomeron loop equations, which include in the evolution the gluon number fluctuations. In the diffractive case, similarly to the inclusive one, suppression of the diffusive scaling, as a consequence of the inclusion of the running of the coupling, is observed. (orig.)

Running coupling and pomeron loop effects on inclusive and diffractive DIS cross sections

International Nuclear Information System (INIS)

Ducati, M.B. Gay; Oliveira, E.G. de; Santana Amaral, J.T. de

2012-01-01

Within the framework of a (1+1)-dimensional model which mimics high-energy QCD, we study the behavior of the cross sections for inclusive and diffractive deep inelastic γ * h scattering cross sections. We analyze the cases of both fixed and running coupling within the mean-field approximation, in which the evolution of the scattering amplitude is described by the Balitsky-Kovchegov equation, and also through the pomeron loop equations, which include in the evolution the gluon number fluctuations. In the diffractive case, similarly to the inclusive one, suppression of the diffusive scaling, as a consequence of the inclusion of the running of the coupling, is observed. (orig.)

Running coupling and pomeron loop effects on inclusive and diffractive DIS cross sections

CERN Document Server

Gay Ducati, M.B.; de Santana Amaral, J.T.

2012-01-01

Within the framework of a (1+1)--dimensional model which mimics high energy QCD, we study the behavior of the cross sections for inclusive and diffractive deep inelastic $\\gamma^*h$ scattering cross sections. We analyze the cases of both fixed and running coupling within the mean field approximation, in which the evolution of the scattering amplitude is described by the Balitsky-Kovchegov equation, and also through the pomeron loop equations, which include in the evolution the gluon number fluctuations. In the diffractive case, similarly to the inclusive one, the suppression of the diffusive scaling, as a consequence of the inclusion of the running of the coupling, is observed.

The E-volution of Preprints in the Scholarly Communication of Physicists and Astronomers.

Science.gov (United States)

Brown, Cecelia

2001-01-01

To learn how e-prints are cited, used, and accepted in the literature of physics and astronomy, the philosophies, policies, and practices of approximately 50 top-tier physics and astronomy journals regarding e-prints from the Los Alamos e-print archive were examined. Results provide a sense of the current impact of the evolution of e-prints on the…

Monitoring of computing resource use of active software releases at ATLAS

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00219183; The ATLAS collaboration

2017-01-01

The LHC is the world’s most powerful particle accelerator, colliding protons at centre of mass energy of 13 TeV. As the energy and frequency of collisions has grown in the search for new physics, so too has demand for computing resources needed for event reconstruction. We will report on the evolution of resource usage in terms of CPU and RAM in key ATLAS offline reconstruction workflows at the TierO at CERN and on the WLCG. Monitoring of workflows is achieved using the ATLAS PerfMon package, which is the standard ATLAS performance monitoring system running inside Athena jobs. Systematic daily monitoring has recently been expanded to include all workflows beginning at Monte Carlo generation through to end-user physics analysis, beyond that of event reconstruction. Moreover, the move to a multiprocessor mode in production jobs has facilitated the use of tools, such as “MemoryMonitor”, to measure the memory shared across processors in jobs. Resource consumption is broken down into software domains and dis...

Public outreach: (R)evolution by the lakeside

CERN Multimedia

2006-01-01

Why do the planets revolve around the Sun? Has genetic science shaken Darwin's theories to their foundations? Are viruses the champions of evolution? Is progress a form of tradition? On 8 and 9 July, Geneva's Science History Museum is inviting you to a Science Night on the theme of 'Evolution, revolution'. The Sixth Science Night will host some 60 stands and offer workshops for children, guided tours, exhibitions and shows. Anticipating the (r)evolutions from the LHC, CERN will also be taking part in the event. The future accelerator promises to deliver scientific advances and may even turn our understanding of the infinitesimally small on its head. However, the LHC has already led to technological breakthroughs. The Laboratory's stand will put a special emphasis on the part played by CERN in the computing revolution, from the Web to the Computing Grid. Computer animations will be used to explain these technologies which have spin-offs well beyond the field of particle physics that are of benefit to the whol...

The Impact of Modeling Assumptions in Galactic Chemical Evolution Models

Science.gov (United States)

Côté, Benoit; O'Shea, Brian W.; Ritter, Christian; Herwig, Falk; Venn, Kim A.

2017-02-01

We use the OMEGA galactic chemical evolution code to investigate how the assumptions used for the treatment of galactic inflows and outflows impact numerical predictions. The goal is to determine how our capacity to reproduce the chemical evolution trends of a galaxy is affected by the choice of implementation used to include those physical processes. In pursuit of this goal, we experiment with three different prescriptions for galactic inflows and outflows and use OMEGA within a Markov Chain Monte Carlo code to recover the set of input parameters that best reproduces the chemical evolution of nine elements in the dwarf spheroidal galaxy Sculptor. This provides a consistent framework for comparing the best-fit solutions generated by our different models. Despite their different degrees of intended physical realism, we found that all three prescriptions can reproduce in an almost identical way the stellar abundance trends observed in Sculptor. This result supports the similar conclusions originally claimed by Romano & Starkenburg for Sculptor. While the three models have the same capacity to fit the data, the best values recovered for the parameters controlling the number of SNe Ia and the strength of galactic outflows, are substantially different and in fact mutually exclusive from one model to another. For the purpose of understanding how a galaxy evolves, we conclude that only reproducing the evolution of a limited number of elements is insufficient and can lead to misleading conclusions. More elements or additional constraints such as the Galaxy’s star-formation efficiency and the gas fraction are needed in order to break the degeneracy between the different modeling assumptions. Our results show that the successes and failures of chemical evolution models are predominantly driven by the input stellar yields, rather than by the complexity of the Galaxy model itself. Simple models such as OMEGA are therefore sufficient to test and validate stellar yields. OMEGA

Stigma, discrimination, and sexual (dis)satisfaction among people living with HIV: results from the "AIDES et toi" survey.

Science.gov (United States)

Rojas Castro, D; Le Gall, J M; Andreo, C; Spire, B

2010-08-01

The effects of HIV-related stigma and discrimination have been studied in several areas, such as access to testing, quality of care quality, and access to work. Nevertheless, the effects of stigma and discrimination on the sexual life of people living with HIV/AIDS (PLWHA) have not been studied enough. AIDES, a French community-based organization, has developed a biannual survey which assesses several socioeconomical and psychosocial dimensions of the people in contact with this organization. A focus on the results concerning sexual (dis)satisfaction and the factors associated are presented here. A convenience sample of 521 HIV-positive men having sex with men, heterosexual men and women was analyzed. A logistic regression was performed to examine which factors were significantly associated with sexual dissatisfaction. Results showed that being older, not having a full-time job, not having a steady sexual partner, lower frequency of sexual intercourse, discrimination in the sexual relationship setting, and the perception of loneliness were independently associated with sexual dissatisfaction. A quality health approach must include the aspects linked to sexual life and sexual satisfaction. Given the potentially harmful effects that HIV-related stigma and discrimination have on PLWHA's well-being, more specific actions and advocacy in this direction should be developed and implemented.

Stochastic evolution of the Universe: A possible dynamical process ...

Indian Academy of Sciences (India)

C Sivakumar

2017-12-11

Dec 11, 2017 ... https://doi.org/10.1007/s12043-017-1491-z. Stochastic evolution of the Universe: A possible dynamical process leading to fractal structures. C SIVAKUMAR. Department of Physics, Maharaja's College, Ernakulam 682 011, India. E-mail: thrisivc@yahoo.com. MS received 6 July 2016; revised 26 June 2017; ...

Unitary evolution between pure and mixed states

International Nuclear Information System (INIS)

Reznik, B.

1996-01-01

We propose an extended quantum mechanical formalism that is based on a wave operator d, which is related to the ordinary density matrix via ρ=dd degree . This formalism allows a (generalized) unitary evolution between pure and mixed states. It also preserves much of the connection between symmetries and conservation laws. The new formalism is illustrated for the case of a two-level system. copyright 1996 The American Physical Society

Topological soliton solutions for some nonlinear evolution equations

Directory of Open Access Journals (Sweden)

Ahmet Bekir

2014-03-01

Full Text Available In this paper, the topological soliton solutions of nonlinear evolution equations are obtained by the solitary wave ansatz method. Under some parameter conditions, exact solitary wave solutions are obtained. Note that it is always useful and desirable to construct exact solutions especially soliton-type (dark, bright, kink, anti-kink, etc. envelope for the understanding of most nonlinear physical phenomena.

Quantum physics

International Nuclear Information System (INIS)

Basdevant, J.L.; Dalibart, J.

1997-01-01

This pedagogical book gives an initiation to the principles and practice of quantum mechanics. A large part is devoted to experimental facts and to their analysis: concrete facts, phenomena and applications related to fundamental physics, elementary particles, astrophysics, high-technology, semi-conductors, micro-electronics and lasers. The book is divided in 22 chapters dealing with: quantum phenomena, wave function and Schroedinger equation, physical units and measurements, energy quantification of some simple systems, Hilbert space, Dirac formalism and quantum mechanics postulates, two-state systems and ammonia Maser principle, bands theory and crystals conductibility, commutation of observables, Stern and Gerlach experiment, approximation methods, kinetic momentum in quantum mechanics, first description of atoms, 1/2 spin formalism and magnetic resonance, Lagrangian, Hamiltonian and Lorentz force in quantum mechanics, addition of kinetic momenta and fine and hyper-fine structure of atomic lines, identical particle systems and Pauli principle, qualitative physics and scale of size of some microscopic and macroscopic phenomena, systems evolution, collisions and cross sections, invariance and conservation laws, quantum mechanics and astrophysics, and historical aspects of quantum mechanics. (J.S.)

Evolution of the solar system - relations to physics and cosmology

International Nuclear Information System (INIS)

Treder, H.J.

1987-01-01

The Kantian cosmogony 'based on Newtonian principles' is founded on celestial mechanics, statistical mechanics, and atomistical thermodynamics. However, these fundamental physical laws are working in the given cosmos. (author)

Econophysics and physical economics

CERN Document Server

Richmond, Peter; Hutzler, Stefan

2013-01-01

An understanding of the behaviour of financial assets and the evolution of economies has never been as important as today. This book looks at these complex systems from the perspective of the physicist. So called 'econophysics' and its application to finance has made great strides in recent years. Less emphasis has been placed on the broader subject of macroeconomics and many economics students are still taught traditional neo-classical economics. The reader is given a general primer in statistical physics, probability theory, and use of correlation functions. Much of the mathematics that is developed is frequently no longer included in undergraduate physics courses. The statistical physics of Boltzmann and Gibbs is one of the oldest disciplines within physics and it can be argued that it was first applied to ensembles of molecules as opposed to being applied to social agents only by way of historical accident. The authors argue by analogy that the theory can be applied directly to economic systems comprising...

Shape evolution of a melting nonspherical particle

Science.gov (United States)

Kintea, Daniel M.; Hauk, Tobias; Roisman, Ilia V.; Tropea, Cameron

2015-09-01

In this study melting of irregular ice crystals was observed in an acoustic levitator. The evolution of the particle shape is captured using a high-speed video system. Several typical phenomena have been discovered: change of the particle shape, appearance of a capillary flow of the melted liquid on the particle surface leading to liquid collection at the particle midsection (where the interface curvature is smallest), and appearance of sharp cusps at the particle tips. No such phenomena can be observed during melting of spherical particles. An approximate theoretical model is developed which accounts for the main physical phenomena associated with melting of an irregular particle. The agreement between the theoretical predictions for the melting time, for the evolution of the particle shape, and the corresponding experimental data is rather good.

Three aspects of stellar evolution near the main sequence

International Nuclear Information System (INIS)

Morgan, J.C.

1979-05-01

Three problems of stellar evolution are considered: the gap in the HR diagram of M67, the evolutionary status of RS CVn binaries and the solar neutrino problem. The physical basis of the Eggleton stellar evolution computer program is described. The program was used to calculate a grid of evolutionary tracks for models with masses between 0.7 and 1.29 solar masses. The more massive stars considered here have expanding convective cores during their main sequence evolution. The isochrone of the old galactic cluster M67 has a gap at the top of its main sequence because of the rapid evolution of stars at hydrogen exhaustion. RS CVn binaries present a complex collection of observational phenomena although they appear to be detached binaries. Their evolutionary status has remained controversial because of their high space density. Here it is shown that a post main sequence interpretation is satisfactory. Models of the Sun with metal poor interiors have been proposed in an attempt to resolve the solar neutrino problem. Here the evolution of two such models is calculated in detail, including a gradual contamination of the surface convection zone to produce the observed metal abundance, giving fully consistent models of the Sun as it is observed. (author)

Physics in Vietnam

International Nuclear Information System (INIS)

Altarelli, Monica Pepe

1994-01-01

Vietnam is a country in rapid evolution, opening up communications with the rest of world and encouraging foreign investors. Although there is more ground to make up, the heady mixture of communism and free market they are aiming for is along the same lines as China. Jean Tran Thanh Van , who left Vietnam about forty years ago, judged that it was the right time to bring together Western and Vietnamese physicists. He promoted and organized the ''Rencontres du Vietnam'' on high energy physics and cosmology, which from December 13-18 brought together about one hundred physicists, half from Vietnam and half from abroad, in Hanoi for an intense programme to review the status of particle physics and its deep implications for cosmology

Physics in Vietnam

Energy Technology Data Exchange (ETDEWEB)

Altarelli, Monica Pepe

1994-03-15

Vietnam is a country in rapid evolution, opening up communications with the rest of world and encouraging foreign investors. Although there is more ground to make up, the heady mixture of communism and free market they are aiming for is along the same lines as China. Jean Tran Thanh Van , who left Vietnam about forty years ago, judged that it was the right time to bring together Western and Vietnamese physicists. He promoted and organized the ''Rencontres du Vietnam'' on high energy physics and cosmology, which from December 13-18 brought together about one hundred physicists, half from Vietnam and half from abroad, in Hanoi for an intense programme to review the status of particle physics and its deep implications for cosmology.

Evolution of galaxies

International Nuclear Information System (INIS)

Palous, J.

1987-01-01

The proceedings contain 87 papers divided into 8 chapters. The chapter Bipolar outflows and star formations contains papers on optical and infrared observations of young bipolar outflow objects and the theory thereof, and on observations of cometary nebulae. The chapter Masers and early stellar evolution discusses molecular masers and star forming regions. The following chapter contains papers on initial mass function and star formation rates in galaxies. The chapter Clusters and star formation contains data on OB associations and open star clusters, their development and observations, CO and H 2 in our galaxy, the four vector model of radio emission and an atlas of the wavelength dependence of ultraviolet extinction in the Galaxy. The most voluminous is the chapter Evolution of galaxies. It contains papers on the theories of the physical and chemodynamic development of galaxies of different types, rotation research and rotation velocities of galaxies and their arms, and on mathematical and laboratory models of morphological development. Chapter seven contains papers dealing with active extragalactic objects, quasars and active galactic nuclei. The last chapter discusses cosmological models, the theory of the inflationary universe, and presents an interpretation of the central void and X-ray background. (M.D.). 299 figs., 48 tabs., 1651 refs

Direct view on the phase evolution in individual LiFePO4 nanoparticles during Li-ion battery cycling

NARCIS (Netherlands)

Zhang, X.; Van Hulzen, M.; Singh, D.P.; Brownrigg, A.W.; Wright, J.P.; Van Dijk, N.H.; Wagemaker, M.

2015-01-01

Phase transitions in Li-ion electrode materials during (dis)charge are decisive for battery performance, limiting high-rate capabilities and playing a crucial role in the cycle life of Li-ion batteries. However, the difficulty to probe the phase nucleation and growth in individual grains is

Relations between the galactic evolution and the stellar evolution

International Nuclear Information System (INIS)

Audouze, J.

1984-01-01

After a quick definition of the galactic evolution and a summary of the basic ingredients (namely the abundances of the chemical elements observed in different astrophysical sites), the parameters directly related to the stellar evolution which govern the galactic evolution are outlined. They are the rates of star formation, the initial mass functions and the various nucleosynthetic yields. The 'classical' models of chemical evolution of galaxies are then briefly recalled. Finally, attention is drawn to three recent contributions concerning both the galactic evolution and the stellar evolution. They are (i) some prediction of the rate of star formation for low mass stars made from the planetary nebula abundance distribution (ii) the chemical evolution of C, O and Fe and (iii) the chemical evolution of the galactic interstellar medium. (Auth.)

Coherent states in quantum physics

CERN Document Server

Gazeau, Jean-Pierre

2009-01-01

This self-contained introduction discusses the evolution of the notion of coherent states, from the early works of Schrödinger to the most recent advances, including signal analysis. An integrated and modern approach to the utility of coherent states in many different branches of physics, it strikes a balance between mathematical and physical descriptions.Split into two parts, the first introduces readers to the most familiar coherent states, their origin, their construction, and their application and relevance to various selected domains of physics. Part II, mostly based on recent original results, is devoted to the question of quantization of various sets through coherent states, and shows the link to procedures in signal analysis. Title: Coherent States in Quantum Physics Print ISBN: 9783527407095 Author(s): Gazeau, Jean-Pierre eISBN: 9783527628292 Publisher: Wiley-VCH Dewey: 530.12 Publication Date: 23 Sep, 2009 Pages: 360 Category: Science, Science: Physics LCCN: Language: English Edition: N/A LCSH:

Cx43, ZO-1, alpha-catenin and beta-catenin in cataractous lens ...

Indian Academy of Sciences (India)

2012-10-17

Oct 17, 2012 ... physical association between neighboring cells and hold them together (Meng ..... radiation (Zigman et al. 1979), diabetes and vascular dis- .... JO 2003 Decreased caspase-3 activity in human lens epithelium from posterior ...

Structural evolution of a granular medium during simultaneous penetration

Science.gov (United States)

González-Gutiérrez, Jorge; Carreón, Yojana J. P.; Moctezuma, R. E.

2018-01-01

Typically, fluidized beds are granular systems composed of solid particles through which a fluid flows. They are relevant to a wide variety of disciplines such as physics, chemistry, engineering, among others. Generally, the fluidized beds are characterized by different flow regimes such as particulate, bubbling, slugging, turbulent, fast fluidization, and pneumatic conveying. Here, we report the experimental study of the structural evolution of a granular system due to simultaneous penetration of intruders in the presence of an upward airflow. We found that the granular medium evolves from the static state to the turbulent regime showing the coexistence of three regions in different flow regimes. Interestingly, the cooperative dynamic of intruders correlate with the formation of such regions. As a non-invasive method, we use lacunarity and fractal dimension to quantitatively describe the patterns arising within the system during the different stages of the penetration process. Finally, we found that our results would allow us to relate the evolution of the visual patterns appearing in the process with different physical properties of the system.

Measurement of the strong coupling constant {alpha}{sub s} with hadronic jets in deep inelastic scattering; Mesure de la constante de couplage forte {alpha}{sub s} avec les jets hadroniques en diffusion inelastique profonde

Energy Technology Data Exchange (ETDEWEB)

Gouzevitch, Maxime

2008-12-15

In this analysis we have used the production of hard jets in neutral-current DIS for the extraction of the strong coupling constant {alpha}{sub s}. The jets have been selected in the NC DIS events at large momentum transvers 1505. Three jet observables normalized to the total NC DIS cross section have been used: Inclusive jet multiplicity as well as the production rates of 2-jet and 3-jet events. The prediction of the renormalization-group equation for the evolution of the strong coupling constant has been successfully tested for two orders of magnitude between Q=2 QeV to Q=122 GeV. The better precision on {alpha}{sub s}(m{sub Z}) has been obtained with the combination ob the three observables at Q{sup 2}>150 GeV{sup 2}: {alpha}{sub s}(m{sub Z})=0.1180{+-}0.0007(exp.){sub -0.0034}{sup +0.0050}(th.){+-}0.0017(pdf.).

Long-run evolution of the global economy: 1. Physical basis

Science.gov (United States)

Garrett, Timothy J.

2014-04-01

Climate change is a two-way street during the Anthropocene: civilization depends upon a favorable climate at the same time that it modifies it. Yet studies that forecast economic growth employ fundamentally different equations and assumptions than those used to model Earth's physical, chemical, and biological processes. In the interest of establishing a common theoretical framework, this article treats humanity like any other physical process; that is, as an open, nonequilibrium thermodynamic system that sustains existing circulations and furthers its material growth through the consumption and dissipation of energy. The link of physical to economic quantities comes from a prior result that establishes a fixed relationship between rates of global energy consumption and a historical accumulation of global economic wealth. What follows are nonequilibrium prognostic expressions for how wealth, energy consumption, and the Gross World Product (GWP) grow with time. This paper shows that the key components that determine whether civilization "innovates" itself toward faster economic growth include energy reserve discovery, improvements to human and infrastructure longevity, and reductions in the amount of energy required to extract raw materials. Growth slows due to a combination of prior growth, energy reserve depletion, and a "fraying" of civilization networks due to natural disasters. Theoretical and numerical arguments suggest that when growth rates approach zero, civilization becomes fragile to such externalities as natural disasters, and the risk is for an accelerating collapse.

Establishing the Common Community Physics Package by Transitioning the GFS Physics to a Collaborative Software Framework

Science.gov (United States)

Xue, L.; Firl, G.; Zhang, M.; Jimenez, P. A.; Gill, D.; Carson, L.; Bernardet, L.; Brown, T.; Dudhia, J.; Nance, L. B.; Stark, D. R.

2017-12-01

The Global Model Test Bed (GMTB) has been established to support the evolution of atmospheric physical parameterizations in NCEP global modeling applications. To accelerate the transition to the Next Generation Global Prediction System (NGGPS), a collaborative model development framework known as the Common Community Physics Package (CCPP) is created within the GMTB to facilitate engagement from the broad community on physics experimentation and development. A key component to this Research to Operation (R2O) software framework is the Interoperable Physics Driver (IPD) that hooks the physics parameterizations from one end to the dynamical cores on the other end with minimum implementation effort. To initiate the CCPP, scientists and engineers from the GMTB separated and refactored the GFS physics. This exercise demonstrated the process of creating IPD-compliant code and can serve as an example for other physics schemes to do the same and be considered for inclusion into the CCPP. Further benefits to this process include run-time physics suite configuration and considerably reduced effort for testing modifications to physics suites through GMTB's physics test harness. The implementation will be described and the preliminary results will be presented at the conference.

On the Drell-Levy-Yan relation to O(α2s)

International Nuclear Information System (INIS)

Bluemlein, J.; Ravindran, V.; Neerven, W.L. van; Rijksuniversiteit Leiden

2000-03-01

We study the validity of a relation by Drell, Levy and Yan (DLY) connecting the deep inelastic structure (DIS) functions and the single-particle fragmentation functions in e + e - annihilation which are defined in the spacelike (q 2 2 > 0) regions respectively. Here q denotes the momentum of the virtual photon exchanged in the deep inelastic scattering process or the annihilation process. An extension of the DLY-relation, which originally was only derived in the scaling parton model, to all orders in QCD leads to a connection between the two evolution kernels determining the q 2 -dependence of the DIS structure functions and the fragmentation functions respectively. In relation to this we derive the transformation relations between the space-and time-like splitting functions up to next-to-leading order (NLO) and the coefficient functions up to NNLO both for unpolarized and polarized scattering. It is shown that the evolution kernels describing the combined singlet evolution for the structure functions F 2 (x, Q 2 ), F L (x, Q 2 ) where Q 2 = vertical stroke q 2 vertical stroke or F 2 (x, Q 2 ), ∂F 2 (x,Q 2 )/∂ln(Q 2 ) and the corresponding fragmentation functions satisfy the DLY relation up to next-to-leading order. We also comment on a relation proposed by Gribov and Lipatov. (orig.)

PHYSICS OF THE MIND

Directory of Open Access Journals (Sweden)

Leonid Perlovsky

2016-11-01

Full Text Available Is it possible to turn psychology into hard science? Physics of the mind follows the fundamental methodology of physics in all areas where physics have been developed. What is common among Newtonian mechanics, statistical physics, quantum physics, thermodynamics, theory of relativity, astrophysics... and a theory of superstrings? The common among all areas of physics is a methodology of physics discussed in the first few lines of the paper. Is physics of the mind possible? Is it possible to describe the mind based on the few first principles as physics does? The mind with its variabilities and uncertainties, the mind from perception and elementary cognition to emotions and abstract ideas, to high cognition. Is it possible to turn psychology and neuroscience into hard sciences? The paper discusses established first principles of the mind, their mathematical formulations, and a mathematical model of the mind derived from these first principles, mechanisms of concepts, emotions, instincts, behavior, language, cognition, intuitions, conscious and unconscious, abilities for symbols, functions of the beautiful and musical emotions in cognition and evolution. Some of the theoretical predictions have been experimentally confirmed. This research won national and international awards. In addition to summarizing existing results the paper describes new development theoretical and experimental. The paper discusses unsolved theoretical problems as well as experimental challenges for future research.

Physics of the Mind.

Science.gov (United States)

Perlovsky, Leonid I

2016-01-01

Is it possible to turn psychology into "hard science"? Physics of the mind follows the fundamental methodology of physics in all areas where physics have been developed. What is common among Newtonian mechanics, statistical physics, quantum physics, thermodynamics, theory of relativity, astrophysics… and a theory of superstrings? The common among all areas of physics is a methodology of physics discussed in the first few lines of the paper. Is physics of the mind possible? Is it possible to describe the mind based on the few first principles as physics does? The mind with its variabilities and uncertainties, the mind from perception and elementary cognition to emotions and abstract ideas, to high cognition. Is it possible to turn psychology and neuroscience into "hard" sciences? The paper discusses established first principles of the mind, their mathematical formulations, and a mathematical model of the mind derived from these first principles, mechanisms of concepts, emotions, instincts, behavior, language, cognition, intuitions, conscious and unconscious, abilities for symbols, functions of the beautiful and musical emotions in cognition and evolution. Some of the theoretical predictions have been experimentally confirmed. This research won national and international awards. In addition to summarizing existing results the paper describes new development theoretical and experimental. The paper discusses unsolved theoretical problems as well as experimental challenges for future research.

Pre-Big Bang, fundamental Physics and noncyclic cosmologies

Directory of Open Access Journals (Sweden)

Gonzalez-Mestres L.

2014-04-01

Full Text Available Detailed analyses of WMAP and Planck data can have significant implications for noncyclic pre-Big Bang approaches incorporating a new fundamental scale beyond the Planck scale and, potentially, new ultimate constituents of matter with unconventional basic properties as compared to standard particles. Cosmic-ray experiments at the highest energies can also yield relevant information. Hopefully, future studies will be able to deal with alternatives: i to standard physics for the structure of the physical vacuum, the nature of space-time, the validity of quantum field theory and conventional symmetries, the interpretation of string-like theories...; ii to standard cosmology concerning the origin and evolution of our Universe, unconventional solutions to the cosmological constant problem, the validity of inflationary scenarios, the need for dark matter and dark energy... Lorentz-like symmetries for the properties of matter can then be naturally stable space-time configurations resulting from more general primordial scenarios that incorporate physics beyond the Planck scale and describe the formation and evolution of the physical vacuum. A possible answer to the question of the origin of half-integer spins can be provided by a primordial spinorial space-time with two complex coordinates instead of the conventional four real ones, leading to a really new cosmology. We discuss basic questions and phenomenological topics concerning noncyclic pre-Big Bang cosmologies and potentially related physics.

Selected Topics in Light Front Field Theory and Applications to the High Energy Phenomena

Science.gov (United States)

Kundu, Rajen

1999-10-01

In this thesis, we have presented some of the aspects of light-front (LF) field theory through their successful application in the Deep Inelastic Scattering (DIS). We have developed a LFQCD Hamiltonian description of the DIS structure functions starting from Bjorken-Johnson-Low limit of virtual forward Compton scattering amplitude and using LF current commutators. We worked in the LF gauge A^+=0 and used the old-fashioned LFQCD perturbation theory in our calculations. The importance of our work are summarized below. Our approach shares the intution of parton model and addresses directly the structure functions, which are experimental objects, instead of its moments as in OPE method. Moreover, it can potentially incorporate the non-perturbative contents of the structure functions as we have demonstrated by introducing a new factorization scheme. In the context of nucleonic helicity structure, the well known gauge fixed LF helicity operator is shown to provide consistent physical information and helps us defining new relevant structure functions. The anomalous dimensions relevant for the Q^2-evolution of such structure functions are calculated. Our study is important in establishing the equivalance of LF field theory and the usual equal-time one through perturbative calculations of the dressed parton structure functions reproducing the well known results. Also the importance of Gallilean boost symmetry in understanding the correctness of any higher order calculation using (x^+)-ordered LFQCD perturbation theory are emphasized.

Relativistic heavy ion physics

International Nuclear Information System (INIS)

Hill, J.C.; Wohn, F.K.

1993-01-01

This is a progress report for the period May 1992 through April 1993. The first section, entitled ''Purpose and Trends, gives background on the recent trends in the research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled ''Physics Research Progress'', is divided into four parts: participation in the program to develop a large detector named PHENIX for the RHIC accelerator; joining E864 at the AGS accelerator and the role in that experiment; progress made in the study of electromagnetic dissociation highlight of this endeavor is an experiment carried out with the 197 Au beam from the AGS accelerator in April 1992; progress in completion of the nuclear structure studies. In the final section a list of publications, invited talks, and contributed talks is given

The Disciplinary and Pleasurable Spaces of Boys' PE--The Art of Distributions

Science.gov (United States)

Gerdin, Göran

2016-01-01

In taking heed of the so-called "spatial turn" in social theory this paper explores how the spatial intersects with boys' performances of gender and (dis)pleasures in school physical education (PE). In particular, the paper aims to contribute to our understanding of how the organisation and implementation of physical and social spaces in…

The universal lagrangian and the cosmic evolution

International Nuclear Information System (INIS)

El Tahir, A.

1984-08-01

By geometrizing Mach's Universe, we derive the most rational form of a Lagrangian which we, hence, call Universal. It contains both linear and nonlinear terms of the scalar curvature R, with constant coefficients which underlie a certain physical meaning. The metric derivable from this Lagrangian is believed to be far advanced from those derived from general relativity. A wave equation describing the overall evolution of the Universe is obtained and discussed. (author)

NATO Advanced Study Institute on Evolution from Cellular to Social Scales

CERN Document Server

Skjeltorp, Arne T

2008-01-01

Evolution is a critical challenge for many areas of science, technology and development of society. The book reviews general evolutionary facts such as origin of life and evolution of the genome and clues to evolution through simple systems. Emerging areas of science such as "systems biology" and "bio-complexity" are founded on the idea that phenomena need to be understood in the context of highly interactive processes operating at different levels and on different scales. This is where physics meets complexity in nature, and where we must begin to learn about complexity if we are to understand it. Similarly, there is an increasingly urgent need to understand and predict the evolutionary behavior of highly interacting man-made systems, in areas such as communications and transport, which permeate the modern world. The same applies to the evolution of human networks such as social, political and financial systems, where technology has tended to vastly increase both the complexity and speed of interaction, whic...

Computer models of vocal tract evolution: an overview and critique

NARCIS (Netherlands)

de Boer, B.; Fitch, W. T.

2010-01-01

Human speech has been investigated with computer models since the invention of digital computers, and models of the evolution of speech first appeared in the late 1960s and early 1970s. Speech science and computer models have a long shared history because speech is a physical signal and can be

Contextualizing physical literacy in the school environment: The challenges

Directory of Open Access Journals (Sweden)

Darla M. Castelli

2015-06-01

Full Text Available The intent of this paper is to conceptualize physical literacy in the school environment within the United States educational system. Evolution of physical literacy from both a general education and disciplinary focus is overviewed. The challenges of transitioning from a physically educated to a physically literate person as the primary learning outcome of physical education may inhibit progress. Five prioritized recommendations are made to assist teachers in overcoming such barriers: (a whole of school approach, (b effective, differentiated pedagogy, (c integration of technology for individualized tracking of progress, (d supportive school climate, and (e alignment of local efforts with national initiatives.

Biophysics of protein evolution and evolutionary protein biophysics

Science.gov (United States)

Sikosek, Tobias; Chan, Hue Sun

2014-01-01

The study of molecular evolution at the level of protein-coding genes often entails comparing large datasets of sequences to infer their evolutionary relationships. Despite the importance of a protein's structure and conformational dynamics to its function and thus its fitness, common phylogenetic methods embody minimal biophysical knowledge of proteins. To underscore the biophysical constraints on natural selection, we survey effects of protein mutations, highlighting the physical basis for marginal stability of natural globular proteins and how requirement for kinetic stability and avoidance of misfolding and misinteractions might have affected protein evolution. The biophysical underpinnings of these effects have been addressed by models with an explicit coarse-grained spatial representation of the polypeptide chain. Sequence–structure mappings based on such models are powerful conceptual tools that rationalize mutational robustness, evolvability, epistasis, promiscuous function performed by ‘hidden’ conformational states, resolution of adaptive conflicts and conformational switches in the evolution from one protein fold to another. Recently, protein biophysics has been applied to derive more accurate evolutionary accounts of sequence data. Methods have also been developed to exploit sequence-based evolutionary information to predict biophysical behaviours of proteins. The success of these approaches demonstrates a deep synergy between the fields of protein biophysics and protein evolution. PMID:25165599

Bluff evolution along coastal drumlins: Boston Harbor Islands, Massachusetts

Science.gov (United States)

Himmelstoss, E.A.; FitzGerald, D.M.; Rosen, P.S.; Allen, J.R.

2006-01-01

A series of partially drowned drumlins forms the backbone of the inner islands within Boston Harbor. The shoreline of these rounded glacial deposits is composed of actively retreating bluffs formed by continual wave attack. Comparisons of bluffs reveal variability in their height and lateral extent, as well as in the dominant mechanism causing their retreat. Two processes are responsible for bluff erosion and yield distinct bluff morphologies: (1) wave attack undercuts the bluff and causes episodic slumping, yielding planar bluff slopes, and (2) subaerial processes such as rainfall create irregular slopes characterized by rills and gullies. We propose a model of drumlin bluff evolution that is based on processes of erosion and physical characteristics such as bluff height, slope morphology, and the orientation of the bluff with respect to the long axis of the drumlin and its topographic crest. The four phases of drumlin bluff evolution consist of (1) initial formation of bluff, with retreat dominated by wave notching and slumping processes; (2) rill and gully development as bluff heights exceed 10 m and slumped sediment at bluff base inhibits wave attack; (3) return of wave notching and slumping as bluff heights decrease; and (4) final development of boulder retreat lag as last remnants of drumlin are eroded by wave action. These phases capture the important physical processes of drumlin evolution in Boston Harbor and could apply to other eroding coastal drumlin deposits.

Cytokinin delays dark-induced senescence in rice by maintaining the chlorophyll cycle and photosynthetic complexes.

Science.gov (United States)

Talla, Sai Krishna; Panigrahy, Madhusmita; Kappara, Saivishnupriya; Nirosha, P; Neelamraju, Sarla; Ramanan, Rajeshwari

2016-03-01

The phytohormone cytokinin (CK) is known to delay senescence in plants. We studied the effect of a CK analog, 6-benzyl adenine (BA), on rice leaves to understand the possible mechanism by which CK delays senescence in a drought- and heat-tolerant rice cultivar Nagina22 (N22) using dark-induced senescence (DIS) as a surrogate for natural senescence of leaves. Leaves of N22-H-dgl162, a stay-green mutant of N22, and BA-treated N22 showed retention of chlorophyll (Chl) pigments, maintenance of the Chl a/b ratio, and delay in reduction of both photochemical efficiency and rate of oxygen evolution during DIS. HPLC analysis showed accumulation of 7-hydroxymethyl chlorophyll (HmChl) during DIS, and the kinetics of its accumulation correlated with progression of senescence. Transcriptome analysis revealed that several plastid-localized genes, specifically those associated with photosystem II (PSII), showed higher transcript levels in BA-treated N22 and the stay-green mutant leaves compared with naturally senescing N22 leaves. Real-time PCR analyses showed that genes coding for enzymes associated with Chl a/b interconversion and proteins associated with light-harvesting complexes maintained higher transcript levels up to 72h of DIS following BA treatment. The pigment-protein complexes analyzed by green gel remained intact in both N22-H-dgl162 and BA-treated N22 leaves even after 96h of DIS. Thus, CK delays senescence by accumulation of HmChl and up-regulating genes in the Chl cycle, thereby maintaining the Chl a/b ratio. Also, CK treatment retains higher transcript levels of PSII-related genes, resulting in the stability of photosynthetic pigment complexes and functional stay-greenness in rice. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Evolution of parton densities beyond leading order

International Nuclear Information System (INIS)

Curci, G.; Petronzio, R.; Furmanski, W.

1980-01-01

We develop a technique, based explicitly on the factorization properties of mass singularities, which allows one to calculate the evolution of parton densities beyond leading order. We present the results for the evolution of hadronic structure functions as well as for parton fragmentation functions into hadrons. Within our scheme the predictions for a particular process are obtained by convoluting a universal parton density with a short-distance cross section specific to the process. As an application, we calculate the QCD predictions for the Q 2 dependence of deep inelastic lepton-hadron scattering and of one-particle inclusive e + e - annihilation cross sections. Our results for electroproduction agree with those obtained with the operator product expansion technique. Physical quantitites in scattering are related to the corresponding ones in annihilation by analytic continuation, whereas the Gribov-Lipatov relation is strongly violated. (orig.)

Cellular packing, mechanical stress and the evolution of multicellularity

Science.gov (United States)

Jacobeen, Shane; Pentz, Jennifer T.; Graba, Elyes C.; Brandys, Colin G.; Ratcliff, William C.; Yunker, Peter J.

2018-03-01

The evolution of multicellularity set the stage for sustained increases in organismal complexity1-5. However, a fundamental aspect of this transition remains largely unknown: how do simple clusters of cells evolve increased size when confronted by forces capable of breaking intracellular bonds? Here we show that multicellular snowflake yeast clusters6-8 fracture due to crowding-induced mechanical stress. Over seven weeks ( 291 generations) of daily selection for large size, snowflake clusters evolve to increase their radius 1.7-fold by reducing the accumulation of internal stress. During this period, cells within the clusters evolve to be more elongated, concomitant with a decrease in the cellular volume fraction of the clusters. The associated increase in free space reduces the internal stress caused by cellular growth, thus delaying fracture and increasing cluster size. This work demonstrates how readily natural selection finds simple, physical solutions to spatial constraints that limit the evolution of group size—a fundamental step in the evolution of multicellularity.

Approximate N3LO Higgs-boson production cross section using physical-kernel constraints

International Nuclear Information System (INIS)

Florian, D. de; Moch, S.; Hamburg Univ.; Vogt, A.

2014-08-01

The single-logarithmic enhancement of the physical kernel for Higgs production by gluon-gluon fusion in the heavy top-quark limit is employed to derive the leading so far unknown contributions, ln 5,4,3 (1-z), to the N 3 LO coefficient function in the threshold expansion. Also using knowledge from Higgs-exchange DIS to estimate the remaining terms not vanishing for z=m 2 H /s→1, these results are combined with the recently completed soft+virtual contributions to provide an uncertainty band for the complete N 3 LO correction. For the 2008 MSTW parton distributions these N 3 LO contributions increase the cross section at 14 TeV by (10±2)% and (3±2.5)% for the standard choices μ R =m H and μ R =m H /2 of the renormalization scale. The remaining uncertainty arising from the hard-scattering cross sections can be quantified as no more than 5%, which is smaller than that due to the strong coupling and the parton distributions.

The second evolution of ionic liquids: from solvents and separations to advanced materials--energetic examples from the ionic liquid cookbook.

Science.gov (United States)

Smiglak, Marcin; Metlen, Andreas; Rogers, Robin D

2007-11-01

In this Account of the small portion of the recent research in ionic liquids (ILs) by the Rogers Group, we fast forward through the first evolution of IL research, where ILs were studied for their unique set of physical properties and the resulting potential for tunable "green solvents", to the second evolution of ILs, where the tunability of the cation and anion independently offers almost unlimited access to targeted combinations of physical and chemical properties. This approach is demonstrated here with the field of energetic ionic liquids (EILs), which utilizes this design flexibility to find safe synthetic routes to ILs with high energy content and targeted physical properties.

Pre-main-sequence evolution of the sun

International Nuclear Information System (INIS)

Gough, D.

1980-01-01

The phase of solar evolution after the dynamical collapse is considered. The physics of the Kelvin-Helmholtz phase of gravitational collapse is described, attention being given to the early stages of the star when it was completely convective. It is noted that subsequently, a radiative core developed and evolution was controlled by the rate at which heat can diffuse through it by radiative transfer. Since the study of the Kelvin-Helmholtz contraction alone does not give enough information regarding the state of the sun when it first settled down to approximate hydrostatic equilibrium, other stars are studied, and information on the sun is obtained by analogy. Many young solar-type stars, such as the T Tauri stars, are not in the completely convective Hayashi (1961) phase hence it is proposed that the sun was completely mixed soon after its formation, which has some bearing on the sun's chemical structure. It is suggested that the surface of the sun was very nonuniform compared with the photosphere of today. The simple solar evolution model presented gives a good guide to the general way in which the sun contracted to the main sequence

Discovering local patterns of co - evolution: computational aspects and biological examples

Directory of Open Access Journals (Sweden)

Tuller Tamir

2010-01-01

Full Text Available Abstract Background Co-evolution is the process in which two (or more sets of orthologs exhibit a similar or correlative pattern of evolution. Co-evolution is a powerful way to learn about the functional interdependencies between sets of genes and cellular functions and to predict physical interactions. More generally, it can be used for answering fundamental questions about the evolution of biological systems. Orthologs that exhibit a strong signal of co-evolution in a certain part of the evolutionary tree may show a mild signal of co-evolution in other branches of the tree. The major reasons for this phenomenon are noise in the biological input, genes that gain or lose functions, and the fact that some measures of co-evolution relate to rare events such as positive selection. Previous publications in the field dealt with the problem of finding sets of genes that co-evolved along an entire underlying phylogenetic tree, without considering the fact that often co-evolution is local. Results In this work, we describe a new set of biological problems that are related to finding patterns of local co-evolution. We discuss their computational complexity and design algorithms for solving them. These algorithms outperform other bi-clustering methods as they are designed specifically for solving the set of problems mentioned above. We use our approach to trace the co-evolution of fungal, eukaryotic, and mammalian genes at high resolution across the different parts of the corresponding phylogenetic trees. Specifically, we discover regions in the fungi tree that are enriched with positive evolution. We show that metabolic genes exhibit a remarkable level of co-evolution and different patterns of co-evolution in various biological datasets. In addition, we find that protein complexes that are related to gene expression exhibit non-homogenous levels of co-evolution across different parts of the fungi evolutionary line. In the case of mammalian evolution

Quanta - evolution - mind. An essay about nature, science, and reality

International Nuclear Information System (INIS)

Eidemueller, Dirk

2017-01-01

The first part gives a survey about the surprising properties of quantum physics and their most important interpretations. We contrast the new quantum-physical principles of the description of nature with those of classical physics. In the second part we perform in the framework of the reductionism debate an extensive analysis of the understanding of reality represented by the evolutionary theory of knowledge and subject this a critique by means of several central points. A special point of view lies hereby beside the results of quantum philosophy on the relation of physics, chemistry, and biology as well as on the body-soul problem. in the third part we deal with the mutual theories, which follow from the evolution theory and the quantum philosophy for our picture of world.

A BRIEF NOTE ON MINERAL EVOLUTION AND BIOCHEMISTRY

Directory of Open Access Journals (Sweden)

José María Amigó

2014-12-01

Full Text Available The natural inorganic materials (minerals and rocks exceed the limits of the Earth.Therefore, the geology, which is the study of the Earth, represents only a small part of thenatural inorganic world. Certain questions about the genesis of the universe are related tothe evolution of our solar system and the evolution of life on our planet. In this paper, recentcontributions from experimental physical natural-sciences to the formation of the universe(about 15 billion BP coupled with the occurrence of minerals (4 million years BP and thebiochemical appearance of life (not more than 3 million years on the Earth are discussed.When Earth was formed, none of the more than 4,400 minerals we know today were existed.Cosmologists estimate that nearly ten billion years after the Big Bang the first elementsproduced by the melting process. The geological history of mineral evolution on the Earthis an interesting tool to study terrestrial and/or extraterrestrial mineralogy in regard toastronomy, biology, chemistry and other experimental natural sciences

Tidal instability in exoplanetary systems evolution

Directory of Open Access Journals (Sweden)

Le Gal P.

2011-02-01

Full Text Available A new element is proposed to play a role in the evolution of extrasolar planetary systems: the tidal (or elliptical instability. It comes from a parametric resonance and takes place in any rotating fluid whose streamlines are (even slightly elliptically deformed. Based on theoretical, experimental and numerical works, we estimate the growth rate of the instability for hot-jupiter systems, when the rotation period of the star is known. We present the physical process, its application to stars, and preliminary results obtained on a few dozen systems, summarized in the form of a stability diagram. Most of the systems are trapped in the so-called "forbidden zone", where the instability cannot grow. In some systems, the tidal instability is able to grow, at short timescales compared to the system evolution. Implications are discussed in the framework of misaligned transiting systems, as the rotational axis of the star would be unstable in systems where this elliptical instability grows.

Cosmic Collisions: Galaxy Mergers and Evolution

Science.gov (United States)

Trouille, Laura; Willett, Kyle; Masters, Karen; Lintott, Christopher; Whyte, Laura; Lynn, Stuart; Tremonti, Christina A.

2014-08-01

Over the years evidence has mounted for a significant mode of galaxy evolution via mergers. This process links gas-rich, spiral galaxies; starbursting galaxies; active galactic nuclei (AGN); post-starburst galaxies; and gas-poor, elliptical galaxies, as objects representing different phases of major galaxy mergers. The post-starburst phase is particularly interesting because nearly every galaxy that evolves from star-forming to quiescent must pass through it. In essence, this phase is a sort of galaxy evolution “bottleneck” that indicates that a galaxy is actively evolving through important physical transitions. In this talk I will present the results from the ‘Galaxy Zoo Quench’ project - using post-starburst galaxies to place observational constraints on the role of mergers and AGN activity in quenching star formation. `Quench’ is the first fully collaborative research project with Zooniverse citizen scientists online; engaging the public in all phases of research, from classification to data analysis and discussion to writing the article and submission to a refereed journal.

Evolution of entropy in different types of non-Markovian three-level ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 5. Evolution of entropy in different types of non-Markovian three-level systems: Single reservoir vs. two independent reservoirs. JAGHOURI HAKIMEH SARBISHAEI MOHSEN JAVIDAN KUROSH. Regular Volume 86 Issue 5 May 2016 pp 997-1008 ...

Evolution of solar magnetic fields - A new approach to MHD initial-boundary value problems by the method of nearcharacteristics

Science.gov (United States)

Nakagawa, Y.

1980-01-01

A method of analysis for the MHD initial-boundary problem is presented in which the model's formulation is based on the method of nearcharacteristics developed by Werner (1968) and modified by Shin and Kot (1978). With this method, the physical causality relationship can be traced from the perturbation to the response as in the method of characteristics, while achieving the advantage of a considerable reduction in mathematical procedures. The method offers the advantage of examining not only the evolution of nonforce free fields, but also the changes of physical conditions in the atmosphere accompanying the evolution of magnetic fields. The physical validity of the method is demonstrated with examples, and their significance in interpreting observations is discussed.

Autosolitons in applied physics and traffic flow

International Nuclear Information System (INIS)

Kerner, B.S.

1996-01-01

A review of investigations of autosolitons in nonlinear systems which are of interest for the applied physics and for the transportation research is presented. Autosolitons are solitary intrinsic states which can be formed in a broad class of physical, chemical, biological dissipative distributed media and in traffic flow. Properties of autosolitons which are general for physical systems and for traffic flow will be discussed. Based on results of recent investigations of traffic jams in traffic flow, a comparison of nonlinear characteristics of traffic jams and with nonlinear properties of autosolitons which can be formed in active systems with diffusion will be given. Forms, properties, processes of evolution of autosolitons in traffic flow, in semiconductors and in gas discharge plasma are considered. copyright 1996 American Institute of Physics

A physically based 3-D model of ice cliff evolution over debris-covered glaciers

NARCIS (Netherlands)

Buri, Pascal; Miles, Evan S.; Steiner, J.F.; Immerzeel, W.W.; Wagnon, Patrick; Pellicciotti, Francesca

2016-01-01

We use high-resolution digital elevation models (DEMs) from unmanned aerial vehicle (UAV) surveys to document the evolution of four ice cliffs on the debris-covered tongue of Lirung Glacier, Nepal, over one ablation season. Observations show that out of four cliffs, three different patterns of

What HERA May Provide?

Energy Technology Data Exchange (ETDEWEB)

Jung, Hannes; /DESY; De Roeck, Albert; /CERN; Bartels, Jochen; /Hamburg U., Inst. Theor. Phys. II; Behnke, Olaf; Blumlein, Johannes; /DESY; Brodsky, Stanley; /SLAC /Durham U., IPPP; Cooper-Sarkar, Amanda; /Oxford U.; Deak, Michal; /DESY; Devenish, Robin; /Oxford U.; Diehl, Markus; /DESY; Gehrmann, Thomas; /Zurich U.; Grindhammer, Guenter; /Munich, Max Planck Inst.; Gustafson, Gosta; /CERN /Lund U., Dept. Theor. Phys.; Khoze, Valery; /Durham U., IPPP; Knutsson, Albert; /DESY; Klein, Max; /Liverpool U.; Krauss, Frank; /Durham U., IPPP; Kutak, Krzysztof; /DESY; Laenen, Eric; /NIKHEF, Amsterdam; Lonnblad, Leif; /Lund U., Dept. Theor. Phys.; Motyka, Leszek; /Hamburg U., Inst. Theor. Phys. II /Birmingham U. /Southern Methodist U. /DESY /Piemonte Orientale U., Novara /CERN /Paris, LPTHE /Hamburg U. /Penn State U.

2011-11-10

More than 100 people participated in a discussion session at the DIS08 workshop on the topic What HERA may provide. A summary of the discussion with a structured outlook and list of desirable measurements and theory calculations is given. The HERA accelerator and the HERA experiments H1, HERMES and ZEUS stopped running in the end of June 2007. This was after 15 years of very successful operation since the first collisions in 1992. A total luminosity of {approx} 500 pb{sup -1} has been accumulated by each of the collider experiments H1 and ZEUS. During the years the increasingly better understood and upgraded detectors and HERA accelerator have contributed significantly to this success. The physics program remains in full swing and plenty of new results were presented at DIS08 which are approaching the anticipated final precision, fulfilling and exceeding the physics plans and the previsions of the upgrade program. Most of the analyses presented at DIS08 were still based on the so called HERA I data sample, i.e. data taken until 2000, before the shutdown for the luminosity upgrade. This sample has an integrated luminosity of {approx} 100 pb{sup -1}, and the four times larger statistics sample from HERA II is still in the process of being analyzed.

Physical, chemical and mineralogical evolution of the Tolhuaca geothermal system, southern Andes, Chile: Insights into the interplay between hydrothermal alteration and brittle deformation

Science.gov (United States)

Sanchez-Alfaro, Pablo; Reich, Martin; Arancibia, Gloria; Pérez-Flores, Pamela; Cembrano, José; Driesner, Thomas; Lizama, Martin; Rowland, Julie; Morata, Diego; Heinrich, Christoph A.; Tardani, Daniele; Campos, Eduardo

2016-09-01

In this study, we unravel the physical, chemical and mineralogical evolution of the active Tolhuaca geothermal system in the Andes of southern Chile. We used temperature measurements in the deep wells and geochemical analyses of borehole fluid samples to constrain present-day fluid conditions. In addition, we reconstructed the paleo-fluid temperatures and chemistry from microthermometry and LA-ICP-MS analysis of fluid inclusions taken from well-constrained parageneses in vein samples retrieved from a 1000 m borehole core. Based on core logging, mineralogical observations and fluid inclusions data we identify four stages (S1-S4) of progressive hydrothermal alteration. An early heating event (S1) was followed by the formation of a clay-rich cap in the upper zone (propylitic alteration assemblage at greater depth (S2). Boiling, flashing and brecciation occurred later (S3), followed by a final phase of fluid mixing and boiling (S4). The evolution of hydrothermal alteration at Tolhuaca has produced a mineralogical, hydrological and structural vertical segmentation of the system through the development of a low-permeability, low-cohesion clay-rich cap at shallow depth. The quantitative chemical analyses of fluid inclusions and borehole fluids reveal a significant change in chemical conditions during the evolution of Tolhuaca. Whereas borehole (present-day) fluids are rich in Au, B and As, but Cu-poor (B/Na 100.5, As/Na 10- 1.1, Cu/Na 10- 4.2), the paleofluids trapped in fluid inclusions are Cu-rich but poor in B and As (B/Na 10- 1, As/Na 10- 2.5, Cu/Na 10- 2.5 in average). We interpret the fluctuations in fluid chemistry at Tolhuaca as the result of transient supply of metal-rich, magmatically derived fluids where As, Au and Cu are geochemically decoupled. Since these fluctuating physical and chemical conditions at the reservoir produced a mineralogical vertical segmentation of the system that affects the mechanical and hydrological properties of host rock, we explored

Standard cosmological evolution in the f(R) model to Kaluza-Klein cosmology

International Nuclear Information System (INIS)

Aghmohammadi, A; Abolhassani, M R; Saaidi, Kh; Vajdi, A

2009-01-01

In this paper, using f(R) theory of gravity we explicitly calculate cosmological evolution in the presence of a perfect fluid source in four- and five-dimensional space-time in which this cosmological evolution in self-creation is presented by Reddy et al (2009 Int. J. Theor. Phys. 48 10). An exact cosmological model is presented using a relation between Einstein's gravity field equation components due to a metric with the same component from f(R) theory of gravity. Some physics and kinematical properties of the model are also discussed.

Cosmology and Particle Physics/Human evolution and infectious disease/Cognitive evolution (1 page - 3 subjects)

CERN Multimedia

Carroll, Sean; Hauser, Marc D

2007-01-01

"On the theoretical side, particle phenomenologists will continue to develop physics beyond the Standard Model; string theorists are connecting ore strongly to cosmology and astrophysics/With the recent advent of whole-genome sequencing and increasingly complete surveys of genetic variation, we are now routinely studying 500 thousand variations at a time, enabling complete genome wide surveys in many human populations and in specific disease populations./The most exciting developments today sit at the intersection between science and philosophy.

Mechanical basis of morphogenesis and convergent evolution of spiny seashells

KAUST Repository

Chirat, R.; Moulton, D. E.; Goriely, A.

2013-01-01

Convergent evolution is a phenomenon whereby similar traits evolved independently in not closely related species, and is often interpreted in functional terms. Spines in mollusk seashells are classically interpreted as having repeatedly evolved as a defense in response to shell-crushing predators. Here we consider the morphogenetic process that shapes these structures and underlies their repeated emergence. We develop a mathematical model for spine morphogenesis based on the mechanical interaction between the secreting mantle edge and the calcified shell edge to which the mantle adheres during shell growth. It is demonstrated that a large diversity of spine structures can be accounted for through small variations in control parameters of this natural mechanical process. This physical mechanism suggests that convergent evolution of spines can be understood through a generic morphogenetic process, and provides unique perspectives in understanding the phenotypic evolution of this second largest phylum in the animal kingdom.

Mechanical basis of morphogenesis and convergent evolution of spiny seashells

KAUST Repository

Chirat, R.

2013-03-25

Convergent evolution is a phenomenon whereby similar traits evolved independently in not closely related species, and is often interpreted in functional terms. Spines in mollusk seashells are classically interpreted as having repeatedly evolved as a defense in response to shell-crushing predators. Here we consider the morphogenetic process that shapes these structures and underlies their repeated emergence. We develop a mathematical model for spine morphogenesis based on the mechanical interaction between the secreting mantle edge and the calcified shell edge to which the mantle adheres during shell growth. It is demonstrated that a large diversity of spine structures can be accounted for through small variations in control parameters of this natural mechanical process. This physical mechanism suggests that convergent evolution of spines can be understood through a generic morphogenetic process, and provides unique perspectives in understanding the phenotypic evolution of this second largest phylum in the animal kingdom.

Statistical approach to thermal evolution of neutron stars

International Nuclear Information System (INIS)

Beznogov, M V; Yakovlev, D G

2015-01-01

Studying thermal evolution of neutron stars (NSs) is one of a few ways to investigate the properties of superdense matter in their cores. We study the cooling of isolated NSs (INSs) and deep crustal heating of transiently accreting NSs in X-ray transients (XRTs, binary systems with low-mass companions). Currently, nearly 50 of such NSs are observed, and one can apply statistical methods to analyze the whole dataset. We propose a method for such analysis based on thermal evolution theory for individual stars and on averaging the results over NS mass distributions. We calculate the distributions of INSs and accreting NSs (ANSs) in XRTs over cooling and heating diagrams respectively. Comparing theoretical and observational distributions one can infer information on physical properties of superdense matter and on mass distributions of INSs and ANSs. (paper)

B physics at the tevatron

International Nuclear Information System (INIS)

1998-07-01

Precision B-physics results from the CDF and D0 Collaborations based on data collected during the Tevatron 1992-96 run are presented. In particular we discuss the measurement of the B s meson lifetime, B c meson observation, and B 0 - anti B 0 mixing results obtained using time-evolution analyses. Prospects for the next Tevatron run, starting in 1999, are also reported

Diffractive Production of Jets and Weak Bosons, and Tests of Hard-Scattering Factorization

CERN Document Server

Alvero, L; Terrón, J; Whitmore, J; Alvero, Lyndon; Collins, John C.; Terron, Juan; Whitmore, Jim

1999-01-01

We extract diffractive parton densities from diffractive, deep inelastic (DIS) ep data from the ZEUS experiment. Then we use these fits to predict the diffractive production of jets and of W's and Z's in p\\bar p collisions at the Tevatron. Although the DIS data require a hard quark density in the pomeron, we find fairly low rates for the Tevatron processes (a few percent of the inclusive cross section). This results from the combined effects of Q^{2} evolution and of a normalization of the parton densities to the data. The calculated rates for W production are generally consistent with the preliminary data from the Tevatron. However, the jet data from CDF with a ``Roman pot'' trigger are substantially lower than the results of our calculations; if confirmed, this would signal a breakdown of hard-scattering factorization.

The Universe Untangled; Modern physics for everyone

Science.gov (United States)

Pillitteri, Abigail

2017-04-01

Physics has always been a tricky subject for the general public. Millions are fascinated by the laws of the physical world, but there has been a lack of books written specifically for general readers. The Universe Untangled is for those who are curious; yet do not have an extensive mathematical background. It uses images, analogies and comprehensible language to cover popular topics of interest including the evolution of the Universe, fundamental forces, the nature of space and time, and the quest for knowing the unknown.

dimensional generalized KP equation

Indian Academy of Sciences (India)

Wei Tan

2017-10-31

Oct 31, 2017 ... ysed the rational localization of the lump solutions of eq. ... vide more information and more physical insight into ... a limit behaviour. More importantly, we have also dis- cussed that the space–time structure changes of lump.

PREFACE: X Mexican School on Gravitation and Mathematical Physics: ''Reaching a Century: Classical and Modified General Relativity's Attempts to explain de evolution of the Universe''

Science.gov (United States)

Bárcenas, R. B.; Hernández, H. H. H.; Sabido, M.

2015-11-01

The collection of papers in this volume was presented during the X Mexican School on Gravitation and Mathematical Physics, which was held in Playa del Carmen, Quintana Roo, México, December 1-5, 2014. The Mexican School on Gravitation and Mathematical Physics is a series of conferences sponsored by the Mexican Physical Society that started in 1994 with the purposes of discussing and exchanging current ideas in gravitational physics. Each Mexican School has been devoted to a particular subject, and these have included supergravity, branes, black holes, the early Universe, observational cosmology, quantum gravity and numerical relativity. In this ocasion the theme of the school was Reaching a Century: Classical and Modified General Relativity's Attempts to explain the evolution of the Universe, which focused on the discussion of classical and modified aspects of general relativity. Following our previous Schools, world leaders in the field were invited to give courses and plenary lectures. More specialized talks were also presented in parallel sessions, and some of them have been included in these proceedings. The contributions in this volume have been reviewed and represent some of the courses, plenary talks and contributed talks presented during our X School. We are indebted to the contributors of these proceedings as well as to the rest of the participants in our Mexican School all for making of it a complete success. As for financial support we should mention the Mexican National Science and Technology Council (CONACyT), the Royal Society of London (UK), the Mexican Physical Society (SMF), as well as several Institutions including: Centro de Investigación y Estudios Avanzados (CINVESTAV), Universidad Autónoma Metropolitana Iztapalapa (UAM-I), Universidad de Guanajuato (UG), and Universidad Nacional Autónoma de México (UNAM).

Cyclicity, episodicity, and continuity in accretionary wedge evolution: insights from geophysical imaging and physical analogue experiments

Science.gov (United States)

Kukowski, N.

2009-04-01

of the incoming layer and thrust initiation, growth of the thrust slice, underthrusting and accretion of the thrust slice to the initiation of the next thrust slice. Each of these sub-processes generates a characteristic uplift pattern. As accretionary cycles take place in characteristic time periods of some ten thousands to some hundred thousands of years, the related uplift pattern may provide a key to investigate the timing of wedge evolution in the field. The spatio-temporal activity pattern of thrusts as observed in laboratory wedges suggests a mechanic segmentation of these wedges. Critical taper analysis shows that wedge segments may be sub-critical, critical, stable, or super-critical, depending on their geometry and physical properties. Similar segmentation also seems to be important in nature, as an inner, older wedge segment e.g. may act as a dynamic backstop for more recent accretion. Besides testing the influence of specific parameters on wedge evolution, scaled sandbox experiments also offer to consider transient boundary conditions, e.g. of material input to the wedge. Structurally and kinematically, laboratory wedges generated through episodical material input differ from wedges which have formed as a result of continuous input. Therefore, wedge structures as observed in such experimental wedges may offer a possibility to detect episodical accretion and periods of subduction erosion in natural wedges, such as at the South-Central Chilean convergent margin.

Astrophysics and the evolution of the universe

CERN Document Server

Kisslinger, Leonard S

2014-01-01

The aim of this book is to teach undergraduate college or university students the basic physics concepts needed to understand the mathematics which describes the evolution of the universe, and based on this to teach the astrophysical theories behind evolution from very early times to the present. The book does not require students to have extensive knowledge of mathematics, like calculus, and includes material that explains concepts such as velocity, acceleration, and force. Based on this, fascinating topics such as Dark Matter, measuring Dark Energy via supernovae velocities, and the creation of mass via the Higgs mechanism are explained. All college students with an interest in science, especially astronomy, without extensive mathematical backgrounds should be able to use and learn from this book. Adults interested in topics like dark energy and the Higgs boson, which are in the news, can make use of this book as well.

Moving interfaces and quasilinear parabolic evolution equations

CERN Document Server

Prüss, Jan

2016-01-01

In this monograph, the authors develop a comprehensive approach for the mathematical analysis of a wide array of problems involving moving interfaces. It includes an in-depth study of abstract quasilinear parabolic evolution equations, elliptic and parabolic boundary value problems, transmission problems, one- and two-phase Stokes problems, and the equations of incompressible viscous one- and two-phase fluid flows. The theory of maximal regularity, an essential element, is also fully developed. The authors present a modern approach based on powerful tools in classical analysis, functional analysis, and vector-valued harmonic analysis. The theory is applied to problems in two-phase fluid dynamics and phase transitions, one-phase generalized Newtonian fluids, nematic liquid crystal flows, Maxwell-Stefan diffusion, and a variety of geometric evolution equations. The book also includes a discussion of the underlying physical and thermodynamic principles governing the equations of fluid flows and phase transitions...

Stardust in Laboratory & Evolution of Early Solar System f y S Sy

Indian Academy of Sciences (India)

kkmarhas

2008-09-13

Sep 13, 2008 ... Picture book of presolar grains! Graphite grains. Silicon carbide. Corundum. 500nm. Spinel grains. Silicate grain. Silicon Nitride. Spinel grains. Silicate grain. Silicon Nitride. Presolar Grains &. Evolution of Early Solar System. Kuljeet K. Marhas. 13th September 2008. Physical Research Laboratory ...

Gravothermal aspects in evolution of the stars and the universe

International Nuclear Information System (INIS)

Sugimoto, Daiichiro; Eriguchi, Yoshiharu; Hachisu, Izumi.

1982-01-01

In celestial bodies and the universe self-gravity plays an essential role in determining their nature and evolution. Global thermodynamics of such self-gravitating systems is discussed. They exhibit thermodynamically peculiar nature such as negative specific heat, and, depending on parameters involved, they have no state of stable thermal equilibrium within the framework of Newtonian gravity. The expansion of the universe produces a change in the thermodynamic boundary conditions for subsystems embedded in the universe. Such situations are related with the origin of their evolution (or, in other words, emergence of diversities, orders or spatial structures) and generation of information. Such phenomena are known in relation to stellar evolution, gravothermal catastrophe of self-gravitating systems (star itself or gravitational many body system), formation of black holes and evolution of the universe. Their inter-relations are clarified from the standpoint of thermodynamics of self-gravitating systems, black holes, dissipative open systems and irreversible processes, and of cosmology. It is shown that the expansion of the universe and the effect of self-gravity are essential in generation of information and as a ponderamotive force of evolution. The laws of physics including the second law of thermodynamics hold even in such processes. Thus, the generation of information is formulated rigorously, while the concept of evolution can be defined not in a simple and unique fashion but in relation with ''apparent'' concept of common sense in which some interaction is overlooked. (author)

Global aspects of stream evolution in the solar wind

International Nuclear Information System (INIS)

Gosling, J.T.

1984-01-01

A spatially variable coronal expansion, when coupled with solar rotation, leads to the formation of high speed solar wind streams which evolve considerably with increasing heliocentric distance. Initially the streams steepen for simple kinematic reasons, but this steepening is resisted by pressure forces, leading eventually to the formation of forward-reverse shock pairs in the distant heliosphere. The basic physical processes responsible for stream steepening an evolution are explored and model calculations are compared with actual spacecraft observations of the process. The solar wind stream evolution problem is relatively well understood both observationally and theoretically. Tools developed in achieving this understanding should be applicable to other astrophysical systems where a spatially or temporally variable outflow is associated with a rotating object. 27 references, 13 figures

Temporal evolution of plasma density in femtosecond light filaments

International Nuclear Information System (INIS)

Wang Haitao; Fan Chengyu; Shen Hong; Qiao Chunhong; Zhang Jinghui; Zhang Pengfei; Ma Huimin; Xu Huiling

2012-01-01

By using a legible and comprehensive physical model describing the generation and evolvement of ion densities in the plasma channel induced by intense femtosecond laser pulse, the work studied the temporal evolution of the plasma densities in femtosecond light filaments. It shows that the contribution of the ionization of oxygen and nitrogen molecules to the total electron densities varies much for different laser pulse shapes, and the pulse shapes have more effects on the lifetime of the higher density plasma. It is necessary to control the pulse shape for efficient using of the plasma channel. Pulses of long duration and short wavelength can obtain a plasma channel with higher electron density, but the channel lifetime thoroughly depends on the later evolution of the self-guided channel. (authors)

Quality-of-service provisioning for dynamic heterogeneous wireless sensor networks

NARCIS (Netherlands)

Steine, M.

2013-01-01

A Wireless Sensor Network (WSN) consists of a large collection of spatially dis- tributed autonomous devices with sensors to monitor physical or environmental conditions, such as air-pollution, temperature and traffic flow. By cooperatively processing and communicating information to central

The next generation of galaxy evolution models: A symbiosis of stellar populations and chemical abundances

Science.gov (United States)

Kotulla, Ralf

2012-10-01

Over its lifespan Hubble has invested significant effort into detailed observations of galaxies both in the local and distant universe. To extract the physical information from the observed {spectro-}photometry requires detailed and accurate models. Stellar population synthesis models are frequently used to obtain stellar masses, star formation rate, galaxy ages and star formation histories. Chemical evolution models offer another valuable and complementary approach to gain insight into many of the same aspects, yet these two methods have rarely been used in combination.Our proposed next generation of galaxy evolution models will help us improve our understanding of how galaxies form and evolve. Building on GALEV evolutionary synthesis models we incorporate state-of-the-art input physics for stellar evolution of binaries and rotating stars as well as new spectral libraries well matched to the modern observational capabilities. Our improved chemical evolution model allows us to self-consistently trace abundances of individual elements, fully accounting for the increasing initial abundances of successive stellar generations. GALEV will support variable Initial Mass Functions {IMF}, enabling us to test recent observational findings of a non-universal IMF by predicting chemical properties and integrated spectra in an integrated and consistent manner.HST is the perfect instrument for testing this approach. Its wide wavelength coverage from UV to NIR enables precise SED fitting, and with its spatial resolution we can compare the inferred chemical evolution to studies of star clusters and resolved stellar populations in nearby galaxies.

Evolution of sexual asymmetry

Directory of Open Access Journals (Sweden)

Hoekstra Rolf F

2004-09-01

Full Text Available Abstract Background The clear dominance of two-gender sex in recent species is a notorious puzzle of evolutionary theory. It has at least two layers: besides the most fundamental and challenging question why sex exists at all, the other part of the problem is equally perplexing but much less studied. Why do most sexual organisms use a binary mating system? Even if sex confers an evolutionary advantage (through whatever genetic mechanism, why does it manifest that advantage in two, and exactly two, genders (or mating types? Why not just one, and why not more than two? Results Assuming that sex carries an inherent fitness advantage over pure clonal multiplication, we attempt to give a feasible solution to the problem of the evolution of dimorphic sexual asymmetry as opposed to monomorphic symmetry by using a spatial (cellular automaton model and its non-spatial (mean-field approximation. Based on a comparison of the spatial model to the mean-field approximation we suggest that spatial population structure must have played a significant role in the evolution of mating types, due to the largely clonal (self-aggregated spatial distribution of gamete types, which is plausible in aquatic habitats for physical reasons, and appears to facilitate the evolution of a binary mating system. Conclusions Under broad ecological and genetic conditions the cellular automaton predicts selective removal from the population of supposedly primitive gametes that are able to mate with their own type, whereas the non-spatial model admits coexistence of the primitive type and the mating types. Thus we offer a basically ecological solution to a theoretical problem that earlier models based on random gamete encounters had failed to resolve.

Simulating galactic dust grain evolution on a moving mesh

Science.gov (United States)

McKinnon, Ryan; Vogelsberger, Mark; Torrey, Paul; Marinacci, Federico; Kannan, Rahul

2018-05-01

Interstellar dust is an important component of the galactic ecosystem, playing a key role in multiple galaxy formation processes. We present a novel numerical framework for the dynamics and size evolution of dust grains implemented in the moving-mesh hydrodynamics code AREPO suited for cosmological galaxy formation simulations. We employ a particle-based method for dust subject to dynamical forces including drag and gravity. The drag force is implemented using a second-order semi-implicit integrator and validated using several dust-hydrodynamical test problems. Each dust particle has a grain size distribution, describing the local abundance of grains of different sizes. The grain size distribution is discretised with a second-order piecewise linear method and evolves in time according to various dust physical processes, including accretion, sputtering, shattering, and coagulation. We present a novel scheme for stochastically forming dust during stellar evolution and new methods for sub-cycling of dust physics time-steps. Using this model, we simulate an isolated disc galaxy to study the impact of dust physical processes that shape the interstellar grain size distribution. We demonstrate, for example, how dust shattering shifts the grain size distribution to smaller sizes resulting in a significant rise of radiation extinction from optical to near-ultraviolet wavelengths. Our framework for simulating dust and gas mixtures can readily be extended to account for other dynamical processes relevant in galaxy formation, like magnetohydrodynamics, radiation pressure, and thermo-chemical processes.

Embodied artificial evolution: Artificial evolutionary systems in the 21st Century.

Science.gov (United States)

Eiben, A E; Kernbach, S; Haasdijk, Evert

2012-12-01

Evolution is one of the major omnipresent powers in the universe that has been studied for about two centuries. Recent scientific and technical developments make it possible to make the transition from passively understanding to actively using evolutionary processes. Today this is possible in Evolutionary Computing, where human experimenters can design and manipulate all components of evolutionary processes in digital spaces. We argue that in the near future it will be possible to implement artificial evolutionary processes outside such imaginary spaces and make them physically embodied. In other words, we envision the "Evolution of Things", rather than just the evolution of digital objects, leading to a new field of Embodied Artificial Evolution (EAE). The main objective of this paper is to present a unifying vision in order to aid the development of this high potential research area. To this end, we introduce the notion of EAE, discuss a few examples and applications, and elaborate on the expected benefits as well as the grand challenges this developing field will have to address.

The evolution of ambulatory ECG monitoring.

Science.gov (United States)

Kennedy, Harold L

2013-01-01

Ambulatory Holter electrocardiographic (ECG) monitoring has undergone continuous technological evolution since its invention and development in the 1950s era. With commercial introduction in 1963, there has been an evolution of Holter recorders from 1 channel to 12 channel recorders with increasingly smaller storage media, and there has evolved Holter analysis systems employing increasingly technologically advanced electronics providing a myriad of data displays. This evolution of smaller physical instruments with increasing technological capacity has characterized the development of electronics over the past 50 years. Currently the technology has been focused upon the conventional continuous 24 to 48 hour ambulatory ECG examination, and conventional extended ambulatory monitoring strategies for infrequent to rare arrhythmic events. However, the emergence of the Internet, Wi-Fi, cellular networks, and broad-band transmission has positioned these modalities at the doorway of the digital world. This has led to an adoption of more cost-effective strategies to these conventional methods of performing the examination. As a result, the emergence of the mobile smartphone coupled with this digital capacity is leading to the recent development of Holter smartphone applications. The potential of point-of-care applications utilizing the Holter smartphone and a vast array of new non-invasive sensors is evident in the not too distant future. The Holter smartphone is anticipated to contribute significantly in the future to the field of global health. © 2013.

Health physics information management

International Nuclear Information System (INIS)

Schauss, R.D.

1982-01-01

The records that men have kept over the centuries have made the civilizations of man possible. Recorded history shows that our progress is closely correlated to man's ability to communicate recorded facts to others, and to effectively use knowledge gained by others. During the past few decades our ability to store and use information, and to reach larger audiences has grown dramatically. The advent of computers is discussed and their evolution to the state-of-the-art is described. Data bases, batch and on-line processing, centralized and distributed processing as well as other computer jargon are generally explained and examples are given as they apply specifically to health physics programs. It is proposed that systems designed to manage information cannot be adapted to health physics problems without extensive involvement of the HP who must use the computerized program. Specific problems which arise during the development of a computerized health physics program are explained

Overcoming misconceptions in quantum mechanics with the time evolution operator

International Nuclear Information System (INIS)

Garcia Quijas, P C; Arevalo Aguilar, L M

2007-01-01

Recently, there have been many efforts to use the research techniques developed in the field of physics education research to improve the teaching and learning of quantum mechanics. In particular, part of this research is focusing on misconceptions held by students. For instance, a set of misconceptions is associated with the concept of stationary states. In this paper, we argue that a possible way to remove these is to solve the Schroedinger equation using the evolution operator method (EOM), and stress the fact that to find stationary states is only the first step in solving that equation. The EOM consists in solving the Schroedinger equation by direct integration, i.e. Ψ(x, t) = U(t)Ψ(x, 0), where U(t)=e -itH-hat/h is the time evolution operator, and Ψ(x, 0) is the initial state. We apply the evolution operator method in the case of the harmonic oscillator

Atomic, molecular, and optical physics charged particles

CERN Document Server

Dunning, F B

1995-01-01

With this volume, Methods of Experimental Physics becomes Experimental Methods in the Physical Sciences, a name change which reflects the evolution of todays science. This volume is the first of three which will provide a comprehensive treatment of the key experimental methods of atomic, molecular, and optical physics; the three volumes as a set will form an excellent experimental handbook for the field. The wide availability of tunable lasers in the pastseveral years has revolutionized the field and lead to the introduction of many new experimental methods that are covered in these volumes. Traditional methods are also included to ensure that the volumes will be a complete reference source for the field.

The micro-quasars, witness of the extremes physics

International Nuclear Information System (INIS)

2002-01-01

Hopeful the micro-quasars, the astronomers reveal indirectly the black holes presence, invisible in the galaxies. They are extraordinary laboratories to understand the high energies physics and test the general relativity. For the first time, an international scientific team observes their energy emissions evolution. (A.L.B.)

Dynamic evolution of double Λ five-level atom interacting with one ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 89; Issue 6. Dynamic evolution ... Five-level atom; squeezing; collapse revivals. Abstract. In this paper, the model describing a double Λ five-level atom interacting with a single mode electromagnetic cavity field in the (off) non-resonate case is studied. We obtained the ...

1932: ''annus mirabilis'' for nuclear physics

International Nuclear Information System (INIS)

Hughes, J.

1998-01-01

1932 was an extraordinary year for nuclear physics: J. Chadwick discovered the neutron, C.D.Anderson identified the positron and the first artificial disintegration was realised with a particle accelerator by J.Cockcroft and E.Walton. These 3 discoveries transformed nuclear physics by providing basis on which any new research could be led. The neutron allowed the discovery of artificial radioactivity by Joliot-Curie in 1934 and later the discovery of nuclear fission by O. Hahn, F. Strassman and L. Meitner. The positron brought new concepts about cosmic radiation and drew the way to the discovery of new particles. Artificial disintegration paved the way to the ever-bigger machines. It was the beginning of the era of breaking nuclei. 1932 deserves its title of ''annus mirabilis'' of physics. This article presents the quick evolution of ideas, concepts in nuclear physics in the thirties. (A.C.)

Diet-microbe co-metabolic interactions in wild primates reveal clues on human evolution

Czech Academy of Sciences Publication Activity Database

Gomez, A. M.; Rothman, J. M.; Petrželková, Klára Judita; Yeoman, C. J.; Vlčková, K.; Umana, J. D.; Carr, M.; Modrý, D.; Tod, A.; Nelson, K.; Stumpf, R. M.; Wilson, B. A.; White, B. A.; Leigh, S. R.

2015-01-01

Roč. 156, č. 60 (2015), s. 149 ISSN 0002-9483. [Annual Meeting of the American Association of Physical Anthropologists /84./. 25.03.2015-28.03.2015, St Louis] Institutional support: RVO:68081766 Keywords : wild primates * human evolution Subject RIV: EE - Microbiology, Virology

The polarised valence quark distribution from semi-inclusive DIS

Czech Academy of Sciences Publication Activity Database

Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Arbuzov, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernet, C.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.; Chapiro, A.; Chiosso, M.; Cicuttin, A.; Colantoni, M.; Costa, S.; Crespo, M.; Dalla Torre, S.; Dafni, T.; Das, S.; Dasgupta, S. S.; De Masi, R.; Dedek, N.; Denisov, O.; Dhara, L.; Diaz, V.; Dinkelbach, A.; Donskov, S.; Dorofeev, V.; Doshita, N.; Duic, V.; Dünnweber, W.; Eversheim, P.; Eyrich, W.; Faessler, M.; Falaleev, V.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Franz, J.; Friedrich, J.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A.; Grabmüller, S.; Grajek, O.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Hedicke, S.; Heinsius, F.; Hermann, R.; Hess, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; d'Hose, N.; Ilgner, C.; Ioukaev, A.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Janata, A.; Jasinski, P.; Joosten, R.; Jouravlev, N. I.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.; Khokhlov, Y.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.; Kolosov, V.; Komissarov, E.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V.; Korentchenko, A.; Korzenev, A.; Kotzinian, A.; Koutchinski, N.; Kouznetsov, O.; Kral, A.; Kravchuk, N.; Kroumchtein, Z.; Kuhn, R.; Kunne, F.; Kurek, K.; Ladygin, M.; Lamanna, M.; Le Goff, J.; Lednev, A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A.; Meyer, W.; Mielech, A.; Mikhailov, Y.; Moinester, M.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nähle, O.; Nassalski, J.; Neliba, S.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.; Nikolaev, K.; Olshevsky, A.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panknin, R.; Panzieri, D.; Paul, S.; Pawlukiewicz-Kaminska, B.; Peshekhonov, D.; Peshekhonov, V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.; Pretz, J.; Procureur, S.; Quintans, C.; Rajotte, J.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Reggiani, D.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Rozhdestvensky, A.; Ryabchikov, D.; Samoylenko, V.; Sandacz, A.; Santos, H.; Sapozhnikov, M.; Sarkar, S.; Savin, I.; Schiavon, P.; Schill, C.; Schmitt, L.; Schönmeier, P.; Schröder, W.; Shevchenko, O.; Siebert, H.; Silva, L.; Sinha, L.; Sissakian, A.; Slunecka, M.; Smirnov, G.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Stinzing, F.; Stolarski, M.; Sugonyaev, V.; Sulc, M.; Sulej, R.; Tchalishev, V.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.; Venugopal, G.; Virius, M.; Vlassov, N.; Vossen, A.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wirth, S.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhao, J.; Ziegler, R.; Zvyagin, A.

2008-01-01

Roč. 660, č. 5 (2008), s. 458-465 ISSN 0370-2693 R&D Projects: GA MŠk ME 492 Institutional research plan: CEZ:AV0Z20650511 Keywords : deep inelastic scattering * structure functions Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.034, year: 2008

High energy physics and cosmology

International Nuclear Information System (INIS)

Silk, J.I.; Davis, M.

1989-01-01

This research will focus on the implications of recent theories and experiments in high energy physics for the evolution of the early Universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including the development of constraints on the inflationary predictions of scale--free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon. We will examine the observable imprint of primordial density fluctuations on the cosmic microwave background radiation curved cosmological models. Most astronomical evidence points to an open universe: one of our goals is to reconcile this conclusion with the particle physics input. We will investigate the response of the matter distribution to a network of cosmic strings produced during an early symmetry-breaking transition, and compute the resulting cosmic microwave background anisotropies. We will simulate the formation of large-scale structures whose dynamics are dominated by weakly interacting particles such as axions, massive neutrinos or photinos in order to model the formation of galaxies, galaxy clusters and superclusters. We will study of the distortions in the microwave background radiation, both spectral and angular, that are produced by ionized gas associated with forming clusters and groups of galaxies. We will also study constraints on exotic cooling mechanisms involving axions and majorons set by stellar evolution and the energy input into low mass stars by cold dark matter annihilation galactic nuclei. We will compute the detailed gamma ray spectrum predicted by various cold dark matter candidates undergoing annihilation in the galactic halo and bulge

[High energy physics and cosmology

International Nuclear Information System (INIS)

Silk, J.I.; Davis, M.

1988-01-01

This research will focus on the implications of recent theories and experiments in high energy physics for the evolution of the early Universe, and on the constraints that cosmological considerations can place on such theories. Several problems are under investigation, including the development of constraints on the inflationary predictions of scale-free primordial fluctuations in a universe at critical closure density by studying their linear and non-linear evolution after they re-enter the particle horizon. We will examine the observable imprint of primordial density fluctuations on the cosmic microwave background radiation in curved cosmological models. Most astronomical evidence points to an open universe: one of our goals is to reconcile this conclusion with the particle physics input. We will investigate the response of the matter distribution to a network of cosmic strings produced during an early symmetry--breaking transition, and compute the resulting cosmic microwave background anisotropies. We will simulate the formation of large--scale structures whose dynamics are dominated by weakly interacting particles such as axions massive neutrinos or photinos in order to model the formation of galaxies, galaxy clusters and superclusters. We will study the distortions in the microwave background radiation, both spectral and angular, that are produced by ionized gas associated with forming clusters and groups of galaxies. We will also study constraints on exotic cooling mechanisms involving axions and majorons set by stellar evolution and the energy input into low mass stars by cold dark matter annihilation in galactic nuclei. We will compute the detailed gamma ray spectrum predicted by various cold dark matter candidates undergoing annihilation in the galactic halo and bulge

Recent results from the H1 collaboration at HERA

International Nuclear Information System (INIS)

Feltesse, J.

1994-01-01

New results from the H1 experiment at the electron-proton collider HERA are reported. Evidence for hard scattering in gamma diffraction in photoproduction events is presented. The hadronic final state in low x deep inelastic scattering (DIS) events has been analyzed. Transverse energy flow and cross section for production of jets at high x j are compared to the expectations of present Monte Carlo programs and to analytical calculations based on the BFKL evolution equation. DIS interactions with no hadronic energy flow in a large interval of rapidity around the incident proton direction are presented. The data are compared to models based on deep inelastic pomeron scattering or on MVD contributions. Measured cross sections for the production of multijet in DIS events at HERA are used to provide a preliminary measurement of the strong coupling constant alpha s , together with the first direct measurement of the gluon density in the proton. The cross section of the charged current process e - p → ν e + hadrons is measured. The effects of the W propagator term is visible for the first time. New limits on leptoquarks, leptogluons, Squarks from R-parity violating supersymmetry and on excited leptons are given. (author). 20 figs., 34 refs

EXPLORING PHYSICIANS' DISSATISFACTION AND WORK-RELATED STRESS: DEVELOPMENT OF THE PhyDis SCALE

Directory of Open Access Journals (Sweden)

Monica Pedrazza

2016-08-01

physicians' dissatisfaction with reference to attachment styles, which is recognized as being a central variable of individual difference supporting caregiving practices. This study represents an original and innovative attempt to address physicians’ dissatisfaction and job satisfaction. The PhyDis scale has been developed and, in line with international findings, our results indicate that role uncertainty and loss of social esteem are the most dissatisfying factors.

Exploring Physicians' Dissatisfaction and Work-Related Stress: Development of the PhyDis Scale.

Science.gov (United States)

Pedrazza, Monica; Berlanda, Sabrina; Trifiletti, Elena; Bressan, Franco

2016-01-01

reference to attachment styles, which is recognized as being a central variable of individual difference supporting caregiving practices. This study represents an original and innovative attempt to address physicians' dissatisfaction and job satisfaction. The PhyDis scale has been developed and, in line with international findings, our results indicate that role uncertainty and loss of social esteem are the most dissatisfying factors.

Controlling Tensegrity Robots Through Evolution

Science.gov (United States)

Iscen, Atil; Agogino, Adrian; SunSpiral, Vytas; Tumer, Kagan

2013-01-01

Tensegrity structures (built from interconnected rods and cables) have the potential to offer a revolutionary new robotic design that is light-weight, energy-efficient, robust to failures, capable of unique modes of locomotion, impact tolerant, and compliant (reducing damage between the robot and its environment). Unfortunately robots built from tensegrity structures are difficult to control with traditional methods due to their oscillatory nature, nonlinear coupling between components and overall complexity. Fortunately this formidable control challenge can be overcome through the use of evolutionary algorithms. In this paper we show that evolutionary algorithms can be used to efficiently control a ball-shaped tensegrity robot. Experimental results performed with a variety of evolutionary algorithms in a detailed soft-body physics simulator show that a centralized evolutionary algorithm performs 400 percent better than a hand-coded solution, while the multi-agent evolution performs 800 percent better. In addition, evolution is able to discover diverse control solutions (both crawling and rolling) that are robust against structural failures and can be adapted to a wide range of energy and actuation constraints. These successful controls will form the basis for building high-performance tensegrity robots in the near future.

Relativistic heavy ion physics

International Nuclear Information System (INIS)

Hill, J.C.; Wohn, F.K.

1992-01-01

In 1992 a proposal by the Iowa State University experimental nuclear physics group entitled ''Relativistic Heavy Ion Physics'' was funded by the US Department of Energy, Office of Energy Research, for a three-year period beginning November 15, 1991. This is a progress report for the first six months of that period but, in order to give a wider perspective, we report here on progress made since the beginning of calendar year 1991. In the first section, entitled ''Purpose and Trends,'' we give some background on the recent trends in our research program and its evolution from an emphasis on nuclear structure physics to its present emphasis on relativistic heavy ion and RHIC physics. The next section, entitled, ''Physics Research Programs,'' is divided into three parts. First, we discuss our participation in the program to develop a large detector named PHENIX for the RHIC accelerator. Second, we outline progress made in the study of electromagnetic dissociation (ED). A highlight of this endeavor is experiments carried out with the 197 Au beam from the AGS accelerator in April 1991. Third, we discuss progress in completion of our nuclear structure studies. In the final section a list of publications, invited talks and contributed talks starting in 1991 is given

Preinjury Psychological Status, Injury Severity and Postdeployment Posttraumatic Stress Disorder

Science.gov (United States)

2011-05-01

separation anxiety disorder), gaining weight (anorexia nervosa), having multiple physical symptoms ( somatization dis- order), or having a serious illness... hypochondriasis ), and the anxiety and worry do not occur exclusively in relation to PTSD. On the basis of responses to questions related to depression

Evolution of Hot Gas in Elliptical Galaxies

Science.gov (United States)

Mathews, William G.

2004-01-01

This theory grant was awarded to study the curious nature, origin and evolution of hot gas in elliptical galaxies and their surrounding groups. Understanding the properties of this X-ray emitting gas has profound implications over the broad landscape of modern astrophysics: cosmology, galaxy formation, star formation, cosmic metal enrichment, galactic structure and dynamics, and the physics of hot gases containing dust and magnetic fields. One of our principal specific objectives was to interpret the marvelous new observations from the XMM and Chandru satellite X-ray telescopes.

On the time evolution operator for time-dependent quadratic Hamiltonians

International Nuclear Information System (INIS)

Fernandez, F.M.

1989-01-01

The Schroedinger equation with a time-dependent quadratic Hamiltonian is investigated. The time-evolution operator is written as a product of exponential operators determined by the Heisenberg equations of motion. This product operator is shown to be global in the occupation number representation when the Hamiltonian is Hermitian. The success of some physical applications of the product-form representation is explained

Some applications of multivariate statistics to physical anthropology

NARCIS (Netherlands)

van Vark, GN

This paper presents some of the results of the cooperation between the author, a physical anthropologist, and Willem Schaafsma. The subjects of study to be discussed in this paper all refer to human evolution, in particular to the process of hominisation. It is described how the interest of the

Spectral transform and solvability of nonlinear evolution equations

International Nuclear Information System (INIS)

Degasperis, A.

1979-01-01

These lectures deal with an exciting development of the last decade, namely the resolving method based on the spectral transform which can be considered as an extension of the Fourier analysis to nonlinear evolution equations. Since many important physical phenomena are modeled by nonlinear partial wave equations this method is certainly a major breakthrough in mathematical physics. We follow the approach, introduced by Calogero, which generalizes the usual Wronskian relations for solutions of a Sturm-Liouville problem. Its application to the multichannel Schroedinger problem will be the subject of these lectures. We will focus upon dynamical systems described at time t by a multicomponent field depending on one space coordinate only. After recalling the Fourier technique for linear evolution equations we introduce the spectral transform method taking the integral equations of potential scattering as an example. The second part contains all the basic functional relationships between the fields and their spectral transforms as derived from the Wronskian approach. In the third part we discuss a particular class of solutions of nonlinear evolution equations, solitons, which are considered by many physicists as a first step towards an elementary particle theory, because of their particle-like behaviour. The effect of the polarization time-dependence on the motion of the soliton is studied by means of the corresponding spectral transform, leading to new concepts such as the 'boomeron' and the 'trappon'. The rich dynamic structure is illustrated by a brief report on the main results of boomeron-boomeron and boomeron-trappon collisions. In the final section we discuss further results concerning important properties of the solutions of basic nonlinear equations. We introduce the Baecklund transform for the special case of scalar fields and demonstrate how it can be used to generate multisoliton solutions and how the conservation laws are obtained. (HJ)

"¡Pobre pierna que sólo sirve para andar!" Female (Dis)empowerments, (Dis)ability, and Space in Literary and Filmic "Tristana"

Science.gov (United States)

Muñoz-Muriana, Sara

2015-01-01

This current study explores the function of physical space as a metaphor for freedom and sexual expression in Benito Pérez Galdós's novel Tristana (1892) and Luis Buñuel's loose filmic adaptation (1970). The female walk, a foundational activity in the formative process of the subject, will serve Tristana as a path towards emancipation and freedom,…

Physics of biological membranes

Science.gov (United States)

Mouritsen, Ole G.

The biological membrane is a complex system consisting of an aqueous biomolecular planar aggregate of predominantly lipid and protein molecules. At physiological temperatures, the membrane may be considered a thin (˜50Å) slab of anisotropic fluid characterized by a high lateral mobility of the various molecular components. A substantial fraction of biological activity takes place in association with membranes. As a very lively piece of condensed matter, the biological membrane is a challenging research topic for both the experimental and theoretical physicists who are facing a number of fundamental physical problems including molecular self-organization, macromolecular structure and dynamics, inter-macromolecular interactions, structure-function relationships, transport of energy and matter, and interfacial forces. This paper will present a brief review of recent theoretical and experimental progress on such problems, with special emphasis on lipid bilayer structure and dynamics, lipid phase transitions, lipid-protein and lipid-cholesterol interactions, intermembrane forces, and the physical constraints imposed on biomembrane function and evolution. The paper advocates the dual point of view that there are a number of interesting physics problems in membranology and, at the same time, that the physical properties of biomembranes are important regulators of membrane function.

Anthropic principle and the structure of the physical world

Energy Technology Data Exchange (ETDEWEB)

Carr, B J; Rees, M J [Cambridge Univ. Inst. of Astronomy (UK)

1979-04-12

It is stated that the basic features of galaxies, stars, planets and the everyday world are essentially determined by a few microphysical constants and by the effects of gravitation. Many interrelations between different scales that at first sight seem surprising are straightforward consequences of simple physical arguments. Several aspects of our Universe - some of which seem to be prerequisites for the evolution of any form of life -depend rather delicately on apparent 'coincidences' among the physical constants.

Topological constraints and their breakdown in dynamical evolution

International Nuclear Information System (INIS)

Goldstein, Raymond E; Moffatt, H Keith; Pesci, Adriana I

2012-01-01

A variety of physical and biological systems exhibit dynamical behaviour that has some explicit or implicit topological features. Here, the term ‘topological’ is meant to convey the idea of structures, e.g. physical knots, links or braids, that have some measure of invariance under continuous deformation. Dynamical evolution is then subject to the topological constraints that express this invariance. The simplest problem arising in these systems is the determination of minimum-energy structures (and routes towards these structures) permitted by such constraints, and elucidation of mechanisms by which the constraints may be broken. In more complex nonequilibrium cases there can be recurring singularities associated with topological rearrangements driven by continuous injection of energy. In this brief overview, motivated by an upcoming program on ‘Topological Dynamics in the Physical and Biological Sciences’ at the Isaac Newton Institute for Mathematical Sciences, we present a summary of this class of dynamical systems and discuss examples of important open problems. (invited articles)

RADIO SOURCE FEEDBACK IN GALAXY EVOLUTION

International Nuclear Information System (INIS)

Shabala, Stanislav; Alexander, Paul

2009-01-01

We present a galaxy evolution model which incorporates a physically motivated implementation of active galactic nucleus feedback. Intermittent jets inflate cocoons of radio plasma which then expand supersonically, shock heating the ambient gas. The model reproduces observed star formation histories to the highest redshifts for which reliable data exist, as well as the observed galaxy color bimodality. Intermittent radio source feedback also naturally provides a way of keeping the black hole and spheroid growth in step. We find possible evidence for a top-heavy initial mass function for z > 2, consistent with observations of element abundances, and submillimeter and Lyman break galaxy counts.

Evolution of disability in traffic accident victims in rehabilitation, characterized by the International Classification of Functioning, Disability and Health (ICF

Directory of Open Access Journals (Sweden)

Ligia Regina de Oliveira

Full Text Available Abstract Introduction: The International Classification of Functioning, Disability and Health (ICF enables monitoring of the clinical evolution of a patient. Objective: This study aimed to characterize the evolution of disabilities in patients undergoing physical therapy following traffic accidents, using the ICF. Methods: A longitudinal study of 53 accident victims was conducted between April and October 2010, in a rehabilitation unit in the capital of Mato Grosso State, Brazil. Data from physical therapy evaluation were collected in 2 stages and coded by the ICF. Results: The average time between evaluation and reevaluation was 73.4 days. The evolution of functional impairment demonstrated a reduction in the number of patients with deficits, except for muscle tone functions. On initial evaluation, 90.6% had difficulty with sensory functions and pain, varying from mild to complete, decreasing to 67.9% on reevaluation, with pain still mostly present. Almost all patients (96.2% had a disability of neuromusculoskeletal and movement related functions on initial assessment, with a decrease to 15.7% of patients on reevaluation. The greatest improvements were observed in the categories of muscle strength (36.7% and gait pattern (30.6%. On reevaluation, improvement was also observed regarding perceived impairment of body structures, especially for those with severe and complete disability. Conclusion: The study confirmed a reduction in the percentage of patients with some form of disability, and positive development in functional capacity. The use of ICF enabled evaluation of physical disabilities and monitoring of the evolution of patients undergoing physical therapy.

THE EFFECT OF MASS LOSS ON THE TIDAL EVOLUTION OF EXTRASOLAR PLANET

International Nuclear Information System (INIS)

Guo, J. H.

2010-01-01

By combining mass loss and tidal evolution of close-in planets, we present a qualitative study on their tidal migrations. We incorporate mass loss in tidal evolution for planets with different masses and find that mass loss could interfere with tidal evolution. In an upper limit case (β = 3), a significant portion of mass may be evaporated in a long evolution timescale. Evidence of greater modification of the planets with an initial separation of about 0.1 AU than those with a = 0.15 AU can be found in this model. With the assumption of a large initial eccentricity, the planets with initial mass ≤1 M J and initial distance of about 0.1 AU could not survive. With the supposition of β = 1.1, we find that the loss process has an effect on the planets with low mass at a ∼ 0.05 AU. In both cases, the effect of evaporation on massive planets can be neglected. Also, heating efficiency and initial eccentricity have significant influence on tidal evolution. We find that even low heating efficiency and initial eccentricity have a significant effect on tidal evolution. Our analysis shows that evaporation on planets with different initial masses can accelerate (decelerate) the tidal evolution due to the increase (decrease) in tide of the planet (star). Consequently, the effect of evaporation cannot be neglected in evolutionary calculations of close-in planets. The physical parameters of HD 209458b can be fitted by our model.

Future Directions in Medical Physics

Science.gov (United States)

Jeraj, Robert

Medical Physics is a highly interdisciplinary field at the intersection between physics and medicine and biology. Medical Physics is aiming at development of novel applications of physical processes and techniques in various areas of medicine and biology. Medical Physics had and continues to have profound impact by developing improved imaging and treatment technologies, and helping to advance our understanding of the complexity of the disease. The general trend in medicine towards personalized therapy, and emphasis on accelerated translational research is having a profound impact on medical physics as well. In the traditional stronghold for medical physicists - radiation therapy - the new reality is shaping in the form of biologically conformal and combination therapies, as well as advanced particle therapy approaches, such as proton and ion therapies. Rapid increase in faster and more informative multi-modality medical imaging is bringing a wealth of information that is being complemented with data obtained from genomic profiling and other biomarkers. Novel data analysis and data mining approaches are proving grounds for employment of various artificial intelligence methods that will help further improving clinical decision making for optimization of various therapies as well as better understanding of the disease properties and disease evolution, ultimately leading to improved clinical outcomes.

The Creative Power of Formal Analogies in Physics: The Case of Albert Einstein

Science.gov (United States)

Gingras, Yves

2015-01-01

In order to show how formal analogies between different physical systems play an important conceptual work in physics, this paper analyzes the evolution of Einstein's thoughts on the structure of radiation from the point of view of the formal analogies he used as "lenses" to "see" through the "black box" of Planck's…

The Evolution of a Symbol: Mokorotlo and National Identity in Lesotho

African Journals Online (AJOL)

The conical grass hat known as Mokorotlo is considered to be part of the national dress of Lesotho. This paper will trace the physical and cultural evolution of the hat, as part of the emergence of a national identity in Lesotho during the twentieth century. The level of cultural prominence which these hats have obtained ...

MONTE CARLO SIMULATIONS OF GLOBULAR CLUSTER EVOLUTION. V. BINARY STELLAR EVOLUTION

International Nuclear Information System (INIS)

Chatterjee, Sourav; Umbreit, Stefan; Rasio, Frederic A.; Fregeau, John M.

2010-01-01

We study the dynamical evolution of globular clusters containing primordial binaries, including full single and binary stellar evolution using our Monte Carlo cluster evolution code updated with an adaptation of the single and binary stellar evolution codes SSE and BSE from Hurley et al. We describe the modifications that we have made to the code. We present several test calculations and comparisons with existing studies to illustrate the validity of the code. We show that our code finds very good agreement with direct N-body simulations including primordial binaries and stellar evolution. We find significant differences in the evolution of the global properties of the simulated clusters using stellar evolution compared with simulations without any stellar evolution. In particular, we find that the mass loss from the stellar evolution acts as a significant energy production channel simply by reducing the total gravitational binding energy and can significantly prolong the initial core contraction phase before reaching the binary-burning quasi-steady state of the cluster evolution. We simulate a large grid of models varying the initial cluster mass, binary fraction, and concentration parameter, and we compare properties of the simulated clusters with those of the observed Galactic globular clusters (GGCs). We find that simply including stellar evolution in our simulations and assuming the typical initial cluster half-mass radius is approximately a few pc independent of mass, our simulated cluster properties agree well with the observed GGC properties such as the core radius and the ratio of the core radius to the half-mass radius. We explore in some detail qualitatively different clusters in different phases of their evolution and construct synthetic Hertzsprung-Russell diagrams for these clusters.

Effective Strategies for Teaching Evolution: The Primary Evolution Project

Science.gov (United States)

Hatcher, Chris

2015-01-01

When Chris Hatcher joined the Primary Evolution Project team at the University of Reading, his goal was to find effective strategies to teach evolution in a way that keeps children engaged and enthused. Hatcher has collaborated with colleagues at the University's Institute of Education to break the evolution unit down into distinct topics and…