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Sample records for stable periodic behavior

  1. PERIODIC BEHAVIORS

    NARCIS (Netherlands)

    Napp, Diego; Put, Marius van der; Shankar, Shiva

    2010-01-01

    This paper studies behaviors that are defined on a torus, or equivalently, behaviors defined in spaces of periodic functions, and establishes their basic properties analogous to classical results of Malgrange, Palamodov, Oberst et al. for behaviors on R(n). These properties-in particular the

  2. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  3. Discontinuous Spirals of Stable Periodic Oscillations

    DEFF Research Database (Denmark)

    Sack, Achim; Freire, Joana G.; Lindberg, Erik

    2013-01-01

    We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...

  4. Occurrence of stable periodic modes in a pendulum with cubic ...

    Indian Academy of Sciences (India)

    The effect of parametric modulation and secondary har- monic forcing in this transition have been analyzed in detail and reported earlier by the authors [5,7]. ... In the present work, the crossover from periodicity to chaos is discussed with a detailed .... value of q2 above which only resonance can take place is given by q.

  5. Copper stable isotopes to trace copper behavior in wetland systems.

    Science.gov (United States)

    Babcsányi, Izabella; Imfeld, Gwenaël; Granet, Mathieu; Chabaux, François

    2014-05-20

    Wetlands are reactive zones of the landscape that can sequester metals released by industrial and agricultural activities. Copper (Cu) stable isotope ratios (δ(65)Cu) have recently been used as tracers of transport and transformation processes in polluted environments. Here, we used Cu stable isotopes to trace the behavior of Cu in a stormwater wetland receiving runoff from a vineyard catchment (Alsace, France). The Cu loads and stable isotope ratios were determined in the dissolved phase, suspended particulate matter (SPM), wetland sediments, and vegetation. The wetland retained >68% of the dissolved Cu and >92% of the SPM-bound Cu, which represented 84.4% of the total Cu in the runoff. The dissolved Cu became depleted in (65)Cu when passing through the wetland (Δ(65)Cuinlet-outlet from 0.03‰ to 0.77‰), which reflects Cu adsorption to aluminum minerals and organic matter. The δ(65)Cu values varied little in the wetland sediments (0.04 ± 0.10‰), which stored >96% of the total Cu mass within the wetland. During high-flow conditions, the Cu flowing out of the wetland became isotopically lighter, indicating the mobilization of reduced Cu(I) species from the sediments and Cu reduction within the sediments. Our results demonstrate that the Cu stable isotope ratios may help trace Cu behavior in redox-dynamic environments such as wetlands.

  6. Stable one-dimensional periodic waves in Kerr-type saturable and quadratic nonlinear media

    Energy Technology Data Exchange (ETDEWEB)

    Kartashov, Yaroslav V [ICFO-Institut de Ciencies Fotoniques, and Department of Signal Theory and Communications, Universitat Politecnica de Catalunya, E-08034 Barcelona (Spain); Egorov, Alexey A [Physics Department, M V Lomonosov Moscow State University, 119899, Moscow (Russian Federation); Vysloukh, Victor A [Departamento de Fisica y Matematicas, Universidad de las Americas-Puebla, Santa Catarina Martir, 72820, Puebla, Cholula (Mexico); Torner, Lluis [ICFO-Institut de Ciencies Fotoniques, and Department of Signal Theory and Communications, Universitat Politecnica de Catalunya, E-08034 Barcelona (Spain)

    2004-05-01

    We review the latest progress and properties of the families of bright and dark one-dimensional periodic waves propagating in saturable Kerr-type and quadratic nonlinear media. We show how saturation of the nonlinear response results in the appearance of stability (instability) bands in a focusing (defocusing) medium, which is in sharp contrast with the properties of periodic waves in Kerr media. One of the key results discovered is the stabilization of multicolour periodic waves in quadratic media. In particular, dark-type waves are shown to be metastable, while bright-type waves are completely stable in a broad range of energy flows and material parameters. This yields the first known example of completely stable periodic wave patterns propagating in conservative uniform media supporting bright solitons. Such results open the way to the experimental observation of the corresponding self-sustained periodic wave patterns.

  7. The effect of temperature on generic stable periodic structures in the parameter space of dissipative relativistic standard map

    Science.gov (United States)

    Horstmann, Ana C. C.; Albuquerque, Holokx A.; Manchein, Cesar

    2017-05-01

    In this work, we have characterized changes in the dynamics of a two-dimensional relativistic standard map in the presence of dissipation and specially when it is submitted to thermal effects modeled by a Gaussian noise reservoir. By the addition of thermal noise in the dissipative relativistic standard map (DRSM) it is possible to suppress typical stable periodic structures (SPSs) embedded in the chaotic domains of parameter space for large enough temperature strengths. Smaller SPSs are first affected by thermal effects, starting from their borders, as a function of temperature. To estimate the necessary temperature strength capable to destroy those SPSs we use the largest Lyapunov exponent to obtain the critical temperature (TC) diagrams. For critical temperatures the chaotic behavior takes place with the suppression of periodic motion, although the temperature strengths considered in this work are not so large to convert the deterministic features of the underlying system into a stochastic ones.

  8. Effect of Different Cultivation Periods on Soil Stable Organic Carbon Pool in Citrus Orchard

    Directory of Open Access Journals (Sweden)

    WANG Yi-xiang

    2015-08-01

    Full Text Available Effect of different cultivation periods on soil stable organic carbon pools and fractions in citrus orchard was investigated to provide scientific basis on the study of orchard soil carbon sequestration by the temporal-spatial substitution method and physical and chemical fractionation method. The results showed that the citrus orchard planted in 1954 compared with the citrus orchard planted in 1980, the content of total organic carbon increased by 27.16%, organic carbon content in macro-aggregates increased by 13.59%, organic carbon content in micro-aggregates increased by 80.19%, organic carbon content of heavy fraction increased by 29.25%, resistant organic carbon content increased by 32.00%, black carbon content increased by 4.01%. Organic carbon which combined with micro-aggregates was protected, and resistant organic carbon and black carbon were recalcitrant organic carbon in soil, this indicated that the stable organic carbon fractions gradually enriched in soil with the increase of growing periods, which was conducive to improve carbon sink in citrus orchard soil.

  9. Distribution and behavior of radionuclides and stable elements in Lake Obuchi

    International Nuclear Information System (INIS)

    Ueda, Shinji; Hasegawa, Hidenao; Hisamatsu, Shun'ichi; Inaba, Jiro

    2000-01-01

    Distribution and behavior of radionuclides and related stable elements in the lake water of brackish Lake Obuchi were investigated by field observations. Concentrations of 238 U and stable elements were measured at various points in the lake, and compiled to obtain the elemental distributions and variation characteristics. The concentrations of 238 U in the lake water were higher in areas nearer to the Pacific Ocean, and correlated well with those of Na, K, Ca, Mg and Sr (r = 0.86 to 0.92). These observations implied that 238 U in the lake originated from seawater. The bottom layer water was reductive during July and September (stratified period) in deep areas (> 3 m). In this condition, concentrations of PO 4 3- -P, NH 4 + -N, Fe and Mn in the water increased. Concentration ratios of 238 U to those of Na strongly suggested the following conclusions. The concentrations of 238 U in the turn-over period were represented by a simple mixture of seawater and fresh water. However, in the stratified period, part of the 238 U was lost from the seawater near the bottom of the lake due to the reductive condition. (author)

  10. Early visual ERPs show stable body-sensitive patterns over a 4-week test period

    Science.gov (United States)

    Groves, Katie; Kennett, Steffan; Gillmeister, Helge

    2018-01-01

    Event-related potential (ERP) studies feature among the most cited papers in the field of body representation, with recent research highlighting the potential of ERPs as neuropsychiatric biomarkers. Despite this, investigation into how reliable early visual ERPs and body-sensitive effects are over time has been overlooked. This study therefore aimed to assess the stability of early body-sensitive effects and visual P1, N1 and VPP responses. Participants were asked to identify pictures of their own bodies, other bodies and houses during an EEG test session that was completed at the same time, once a week, for four consecutive weeks. Results showed that amplitude and latency of early visual components and their associated body-sensitive effects were stable over the 4-week period. Furthermore, correlational analyses revealed that VPP component amplitude might be more reliable than VPP latency and specific electrode sites might be more robust indicators of body-sensitive cortical activity than others. These findings suggest that visual P1, N1 and VPP responses, alongside body-sensitive N1/VPP effects, are robust indications of neuronal activity. We conclude that these components are eligible to be considered as electrophysiological biomarkers relevant to body representation. PMID:29438399

  11. Stable reconstruction of Arctic sea level for the 1950-2010 period

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde; Andersen, Ole Baltazar; Nielsen, Allan Aasbjerg

    2016-01-01

    Reconstruction of historical Arctic sea level is generally difficult due to the limited coverage and quality of both tide gauge and altimetry data in the area. Here a strategy to achieve a stable and plausible reconstruction of Arctic sea level from 1950 to today is presented. This work is based......, a datum-fit of each tide gauges is used and the method takes into account the entirety of each tide gauge record. This makes the Arctic sea level reconstruction much less prone to drifting.From our reconstruction, we found that the Arctic mean sea level trend is around 1.5 mm +/- 0.3 mm/y for the period...... on the combination of tide gauge records and a new 20-year reprocessed satellite altimetry derived sea level pattern. Hence the study is limited to the area covered by satellite altimetry (68ºN and 82ºN). It is found that timestep cumulative reconstruction as suggested by Church and White (2000) may yield widely...

  12. Switching behavior and novel stable states of magnetic hexagonal nanorings

    Energy Technology Data Exchange (ETDEWEB)

    Yasir Rafique, M., E-mail: myasir.rafique@ciitlahore.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Pan, Liqing; Guo, Zhengang [College of Science and Research Institute for New Energy, China Three Gorges University, Yichang 443002 (China)

    2017-06-15

    Micromagnetic simulations for Cobalt hexagonal shape nanorings show onion (O) and vortex state (V) along with new state named “tri-domain state”. The tri-domain state is observed in sufficiently large width of ring. The magnetic reversible mechanism and transition of states are explained with help of vector field display. The transitions from one state to other occur by propagation of domain wall. The vertical parts of hexagonal rings play important role in developing the new “tri-domain” state. The behaviors of switching fields from onion to tri-domain (HO-Tr), tri-domain to vortex state (HTr-V) and vortex to onion state and “states size” are discussed in term of geometrical parameter of ring.

  13. Investigating economic specialization on the central Peruvian coast: A reconstruction of Late Intermediate Period Ychsma diet using stable isotopes.

    Science.gov (United States)

    Marsteller, Sara J; Zolotova, Natalya; Knudson, Kelly J

    2017-02-01

    Hypothetical models of socioeconomic organization in pre-Columbian societies generated from the rich ethnohistoric record in the New World require testing against the archaeological and bioarchaeological record. Here, we test ethnohistorian Maria Rostworowski's horizontality model of socioeconomic specialization for the Central Andean coast by reconstructing dietary practices in the Late Intermediate Period (c. AD 900-1470) Ychsma polity to evaluate complexities in social behaviors prior to Inka imperial influence. Stable carbon and nitrogen isotope analysis of archaeological human bone collagen and apatite (δ 13 C col[VPDB], δ 15 N col[AIR] , δ 13 C ap[VPDB] ) and locally available foods is used to reconstruct the diets of individuals from Armatambo (n = 67), associated ethnohistorically with fishing, and Rinconada Alta (n = 46), associated ethnohistorically with agriculture. Overall, mean δ 15 N col[AIR] is significantly greater at Armatambo, while mean δ 13 C col[VPDB] and mean δ 13 C ap[VPDB] are not significantly different between the two sites. Within large-scale trends, adult mean δ 13 C ap[VPDB] is significantly greater at Armatambo. In addition, nearly one-third of Armatambo adults and adolescents show divergent δ 15 N col[AIR] values. These results indicate greater reliance on marine resources at Armatambo versus Rinconada Alta, supporting the ethnohistoric model of socioeconomic specialization for the Central Andean coast. Deviations from large-scale dietary trends suggest complexities not accounted for by the ethnohistoric model, including intra-community subsistence specialization and/or variation in resource access. © 2016 Wiley Periodicals, Inc.

  14. Rheology behaviors of stable electrohydrodynamic direct-write jet

    Science.gov (United States)

    Wang, Xiang; Zheng, Gaofeng; Xu, Lei; Wang, Han; Li, Wenwang

    2016-10-01

    Electrohydrodynamic direct-write (EDW) is a novel direct-write technology to fabricate micro/nano-structures from viscoelastic solution, which had displayed great application potential in organic electronic device. Due to the shorter spinneret to substrate distance, the rheology behaviors of EDW charged jet played an important role in defining the line width or diameter of the direct-written micro/nano-structures. High speed camera is utilized to observe the rheology process of EDW charged jet, and solidified jets are measured by SEM that offers a quantitative method to investigate the diameter evolution of jet. The diameter of charged jet and nanofiber injected from solid probe increase with the increasing of polymer solution concentration. Attribute to the larger diameter and higher solvent content, charged jet injected from hollow nozzle displayed greater fluid viscoelasticity, and then stretched into micro structure of flat film under the gravitation on the substrate. The diameter of charged jet and line width of thin film injected from nozzle decrease with the increasing of polymer concentration.

  15. Behavior and Convergence of Wasserstein Metric in the Framework of Stable Distributions

    Czech Academy of Sciences Publication Activity Database

    Omelchenko, Vadym

    2012-01-01

    Roč. 2012, č. 30 (2012), s. 124-138 ISSN 1212-074X R&D Projects: GA ČR GAP402/10/0956 Institutional research plan: CEZ:AV0Z10750506 Institutional support: RVO:67985556 Keywords : Wasserstein Metric * Stable Distributions * Empirical Distribution Function Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2013/E/omelchenko-behavior and convergence of wasserstein metric in the framework of stable distributions.pdf

  16. Stable algorithm for the computation of the electromagnetic field distribution of eigenmodes of periodic diffraction structures.

    Science.gov (United States)

    Bezus, Evgeni A; Doskolovich, Leonid L

    2012-11-01

    In the present work, a stable algorithm for the calculation of the electromagnetic field distributions of the eigenmodes of one-dimensional diffraction gratings is presented. The proposed approach is based on the method for the computation of the propagation constants of Bloch waves of such structures previously presented by Cao et al.[J. Opt. Soc. Am. A 19, 335 (2002)] and uses a modified S-matrix algorithm to ensure numerical stability.

  17. Prospective Analysis of Behavioral Economic Predictors of Stable Moderation Drinking Among Problem Drinkers Attempting Natural Recovery.

    Science.gov (United States)

    Tucker, Jalie A; Cheong, JeeWon; Chandler, Susan D; Lambert, Brice H; Pietrzak, Brittney; Kwok, Heather; Davies, Susan L

    2016-12-01

    As interventions have expanded beyond clinical treatment to include brief interventions for persons with less severe alcohol problems, predicting who can achieve stable moderation drinking has gained importance. Recent behavioral economic (BE) research on natural recovery has shown that active problem drinkers who allocate their monetary expenditures on alcohol and saving for the future over longer time horizons tend to have better subsequent recovery outcomes, including maintenance of stable moderation drinking. This study compared the predictive utility of this money-based "Alcohol-Savings Discretionary Expenditure" (ASDE) index with multiple BE analogue measures of behavioral impulsivity and self-control, which have seldom been investigated together, to predict outcomes of natural recovery attempts. Community-dwelling problem drinkers, enrolled shortly after stopping abusive drinking without treatment, were followed prospectively for up to a year (N = 175 [75.4% male], M age = 50.65 years). They completed baseline assessments of preresolution drinking practices and problems, analogue behavioral choice tasks (Delay Discounting, Melioration-Maximization, and Alcohol Purchase Tasks), and a Timeline Followback interview including expenditures on alcohol compared to voluntary savings (ASDE index) during the preresolution year. Multinomial logistic regression models showed that, among the BE measures, only the ASDE index predicted stable moderation drinking compared to stable abstinence or unstable resolutions involving relapse. As hypothesized, stable moderation was associated with more balanced preresolution allocations to drinking and savings (odds ratio = 1.77, 95% confidence interval = 1.02 to 3.08, p behavior regulation processes than abstinence. The ASDE's unique predictive utility may rest on its comprehensive representation of contextual elements to support this patterning of behavioral allocation. Stable low-risk drinking, but not abstinence

  18. Stable Early Maternal Report of Behavioral Inhibition Predicts Lifetime Social Anxiety Disorder in Adolescence

    Science.gov (United States)

    Chronis-Tuscano, Andrea; Degnan, Kathryn Amey; Pine, Daniel S.; Perez-Edgar, Koraly; Henderson, Heather A.; Diaz, Yamalis; Raggi, Veronica L.; Fox, Nathan A.

    2009-01-01

    The odds of a lifetime diagnosis of social anxiety disorder increased by 3.79 times for children who had a stable report of behavioral inhibition from their mothers. This finding has important implications for the early identification and prevention of social anxiety disorder.

  19. A behavioral and cognitive profile of clinically stable HIV-infected children

    NARCIS (Netherlands)

    Nozyce, ML; Lee, SS; Wiznia, A; Nachman, S; Mofenson, LM; Smith, ME; Yogev, R; McIntosh, K; Stanley, K; Pelton, S

    OBJECTIVE. The purpose of this research was to characterize behavioral and cognitive profiles of clinically and immunologically stable antiretroviral-experienced HIV-infected children. METHODS. Two hundred seventy-four previously treated HIV-infected children aged 2 to 17 years were assessed for

  20. Comparative biogeochemical behaviors of iron-55 and stable iron in the marine environment

    International Nuclear Information System (INIS)

    Weimer, W.C.; Langford, J.C.; Jenkins, C.E.

    1978-01-01

    Studies of atmospheric aerosols have demonstrated that much of the 55 Fe associated with the aerosol input to the oceans is present as either an amorphous or hydrous iron oxide or as very small particulate species attached to the surfaces of the large aerosol particles. By comparison, nearly all of the stable iron is bound in the mineral phase of aerosol particles. This difference in the chemical and physical forms of the radioactive and stable iron isotopes results in the 55 Fe being more biologically available than is the stable iron. This difference in availability is responsible for the transfer of a much higher specific activity 55 Fe to certain ocean organisms and man relative to the specific activity of the total aerosol or of sea water. This differential biological uptake of the radioactive element and its stable element counterpart points out that natural levels of stable elements in the marine environment may not effectively dilute radioelements or other stable elements of anthropogenic sources. The effectiveness of dilution by natural sources depends on the chemical and physical forms of the materials in both the source terms and the receiving environments. The large difference in specific activities of 55 Fe in aerosols and sea water relative to ocean organisms reflects the independent behaviors of 55 Fe and stable iron

  1. The auxetic behavior of an expanded periodic cellular structure

    Science.gov (United States)

    Ciolan, Mihaela A.; Lache, Simona; Velea, Marian N.

    2018-02-01

    Within nowadays research, when it comes to lightweight sandwich panels, periodic cellular structures are considered real trendsetters. One of the most used type of core in producing sandwich panels is the honeycomb. However, due to its relatively high manufacturing cost, this structure has limited applications; therefore, research has been carried out in order to develop alternative solutions. An example in this sense is the ExpaAsym cellular structure, developed at the Transilvania University of Braşov; it represents a periodic cellular structure manufactured through a mechanically expansion process of a previously cut and perforated sheet material. The relative density of the structure was proven to be significantly lower than the one of the honeycomb. This gives a great advantage to the structure, due to the fact that when the internal angle A of the unit cell is 60°, after the mechanical expansion it results a hexagonal structure. The main objective of this paper is to estimate the in-plane Poisson ratios of the structure, in terms of its geometrical parameters. It is therefore analytically shown that for certain values of the geometric parameters, the in-plane Poisson ratios have negative values when the internal angle exceeds 90°, which determines its auxetic behavior.

  2. Stretchable Spin Valve with Stable Magnetic Field Sensitivity by Ribbon-Patterned Periodic Wrinkles.

    Science.gov (United States)

    Li, Huihui; Zhan, Qingfeng; Liu, Yiwei; Liu, Luping; Yang, Huali; Zuo, Zhenghu; Shang, Tian; Wang, Baomin; Li, Run-Wei

    2016-04-26

    A strain-relief structure by combining the strain-engineered periodic wrinkles and the parallel ribbons was employed to fabricate flexible dual spin valves onto PDMS substrates in a direct sputtering method. The strain-relief structure can accommodate the biaxial strain accompanying with stretching operation (the uniaxial applied tensile strain and the induced transverse compressive strain due to the Poisson effect), thus significantly reducing the influence of the residual strain on the giant magnetoresistance (GMR) performance. The fabricated GMR dual spin-valve sensor exhibits the nearly unchanged MR ratio of 9.9%, magnetic field sensitivity up to 0.69%/Oe, and zero-field resistance in a wide range of stretching strain, making it promising for applications on a conformal shape or a movement part.

  3. A stable and robust calibration scheme of the log-periodic power law model

    Science.gov (United States)

    Filimonov, V.; Sornette, D.

    2013-09-01

    We present a simple transformation of the formulation of the log-periodic power law formula of the Johansen-Ledoit-Sornette (JLS) model of financial bubbles that reduces it to a function of only three nonlinear parameters. The transformation significantly decreases the complexity of the fitting procedure and improves its stability tremendously because the modified cost function is now characterized by good smooth properties with in general a single minimum in the case where the model is appropriate to the empirical data. We complement the approach with an additional subordination procedure that slaves two of the nonlinear parameters to the most crucial nonlinear parameter, the critical time tc, defined in the JLS model as the end of the bubble and the most probable time for a crash to occur. This further decreases the complexity of the search and provides an intuitive representation of the results of the calibration. With our proposed methodology, metaheuristic searches are not longer necessary and one can resort solely to rigorous controlled local search algorithms, leading to a dramatic increase in efficiency. Empirical tests on the Shanghai Composite index (SSE) from January 2007 to March 2008 illustrate our findings.

  4. Stable dipole solitons and soliton complexes in the nonlinear Schrödinger equation with periodically modulated nonlinearity

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, M. E., E-mail: gloriouslair@gmail.com, E-mail: galfimov@yahoo.com; Alfimov, G. L., E-mail: gloriouslair@gmail.com, E-mail: galfimov@yahoo.com [National Research University of Electronic Technology MIET, Zelenograd, Moscow 124498 (Russian Federation); Malomed, Boris A., E-mail: malomed@post.tau.ac.il [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Laboratory of Nonlinear-Optical Informatics, ITMO University, St. Petersburg 197101 (Russian Federation)

    2016-07-15

    We develop a general classification of the infinite number of families of solitons and soliton complexes in the one-dimensional Gross-Pitaevskii/nonlinear Schrödinger equation with a nonlinear lattice pseudopotential, i.e., periodically modulated coefficient in front of the cubic term, which takes both positive and negative local values. This model finds direct implementations in atomic Bose-Einstein condensates and nonlinear optics. The most essential finding is the existence of two branches of dipole solitons (DSs), which feature an antisymmetric shape, being essentially squeezed into a single cell of the nonlinear lattice. This soliton species was not previously considered in nonlinear lattices. We demonstrate that one branch of the DS family (namely, which obeys the Vakhitov-Kolokolov criterion) is stable, while unstable DSs spontaneously transform into stable fundamental solitons (FSs). The results are obtained in numerical and approximate analytical forms, the latter based on the variational approximation. Some stable bound states of FSs are found too.

  5. Panic disorder : A baseline period : predictability of agoraphobic avoidance behavior

    NARCIS (Netherlands)

    De Jong, G.Majella; Bouman, Theo K.

    1995-01-01

    This study addresses the relationship between panic symptomatology and situational avoidance behaviour. Eighty panic disordered patients were involved with various degrees of agoraphobia, ranging from nonavoidant to extremely avoidant. Subjects recorded panic attacks by means of a diary for a period

  6. Collective periodicity in mean-field models of cooperative behavior

    Czech Academy of Sciences Publication Activity Database

    Collet, F.; Dai Pra, P.; Formentin, Marco

    2015-01-01

    Roč. 22, č. 5 (2015), s. 1461-1482 ISSN 1021-9722 R&D Projects: GA ČR GAP201/12/2613 Institutional support: RVO:67985556 Keywords : Interacting diffusions * Noise-induced periodicity * Homoclinic bifurcation Subject RIV: JC - Computer Hardware ; Software Impact factor: 0.797, year: 2015 http://library.utia.cas.cz/separaty/2015/SI/formentin-0444594.pdf

  7. Periodic Limb Movements During Sleep Mimicking REM Sleep Behavior Disorder: A New Form of Periodic Limb Movement Disorder.

    Science.gov (United States)

    Gaig, Carles; Iranzo, Alex; Pujol, Montserrat; Perez, Hernando; Santamaria, Joan

    2017-03-01

    To describe a group of patients referred because of abnormal sleep behaviors that were suggestive of rapid eye movement (REM) sleep behavior disorder (RBD) in whom video-polysomnography ruled out RBD and showed the reported behaviors associated with vigorous periodic limb movements during sleep (PLMS). Clinical history and video-polysomnography review of patients identified during routine visits in a sleep center. Patients were 15 men and 2 women with a median age of 66 (range: 48-77) years. Reported sleep behaviors were kicking (n = 17), punching (n = 16), gesticulating (n = 8), falling out of bed (n = 5), assaulting the bed partner (n = 2), talking (n = 15), and shouting (n = 10). Behaviors resulted in injuries in 3 bed partners and 1 patient. Twelve (70.6%) patients were not aware of displaying abnormal sleep behaviors that were only noticed by their bed partners. Ten (58.8%) patients recalled unpleasant dreams such as being attacked or chased. Video-polysomnography showed (1) frequent and vigorous stereotyped PLMS involving the lower limbs, upper limbs, and trunk (median PLMS index 61.2; median PLMS index in NREM sleep 61.9; during REM sleep only 8 patients had PLMS and their median PLMS index in REM sleep was 39.5); (2) abnormal behaviors (e.g., punching, groaning) during some of the arousals that immediately followed PLMS in NREM sleep; and (3) ruled out RBD and other sleep disorders such as obstructive sleep apnea. Dopaminergic agents were prescribed in 14 out of the 17 patients and resulted in improvement of abnormal sleep behaviors and unpleasant dreams in all of them. After dopaminergic treatment, follow-up video-polysomnography in 7 patients showed a decrease in the median PLMS index from baseline (108.9 vs. 19.2, p = .002) and absence of abnormal behaviors during the arousals. Abnormal sleep behaviors and unpleasant dreams simulating RBD symptomatology may occur in patients with severe PLMS. In these cases, video-polysomnography ruled out RBD and

  8. The effect of housing on dairy cattle behavior during the transition period

    DEFF Research Database (Denmark)

    Campler, Magnus Robert Bertil

    2014-01-01

    Lying- and feeding behavior in dairy cows are important factors for assessing welfare, and there is considerable knowledge about how the housing of dairy cows can affect these behaviors. To date, most studies on dairy cow behavior has focused on the lactation period, but there is less knowledge...... about the behavior of dairy cows‘ during the transition period around calving (defined as 3 weeks before calving to 3 weeks after calving). During the transition period, dairy cows undergo both physical- and behavioral changes during a short time span. Since most cows are housed in facilities...... with freestalls until the day before calving or signs of imminent calving in Denmark (and northern Europe), the aim of this PhD was to investigate the effect of a straw yard housing system during the last 4 weeks of the dry period compared to freestalls on; 1) lying-, feeding- and agonistic behavior before...

  9. Behavior of radionuclides and stable elements in the ecosystem in brackish Lake Obuchi

    International Nuclear Information System (INIS)

    Kondo, Kunio; Ueda, Shinji; Kawabata, Hitoshi; Hasegawa, Hidenao

    1998-01-01

    The behaviors and movements of radionuclides in a brackish environment, Lake Obuchi and its ecosystem were investigated with an aim to evaluate the safety of radioactive materials discharged into the lake. the organic materials in the sediment samples taken from Lake Obuchi were mainly composed of plant planktons and contained various radionuclides; 0.12-1.08 μg/g of 232 Th, 1.69-2.44 μg/g of 238 U, 0.0112-0.0176 Bq/g dry weight. The concentration of stable element was 145.6-357.3 μg/g for Mn, 82.5-128.2 μg/g for Sr, 0.81-1.65 μg/g for Cs and 11.2-16.5 μg/g dry weight for Pb. Plant planktons were found to mediate the accumulation of elements into lake sediments. Therefore, the species composition, distribution and ecological positioning of those planktons were important factors for the behaviors and movements of such elements. Then, the relationship between the concentrations of 137 Cs and Cs was studied with phytoplankton and a positive correlation (r=0.95) was found at both concentrations, suggesting that the adsorptions of the two elements onto the lake sediments were similar. (M.N.)

  10. Type-D personality is a stable taxonomy in post-MI patients over an 18-month period

    DEFF Research Database (Denmark)

    Martens, Elisabeth J; Kupper, Nina; Pedersen, Susanne S.

    2007-01-01

    type-D personality comprises a risk factor for adverse prognosis in patients with cardiovascular disease (CVD). However, concerns that type-D personality may not be a stable personality taxonomy and that progression of CVD may contribute to the manifestation of type-D personality have been voiced...

  11. Spatial analysis of annual mean stable isotopes in precipitation across Japan based on an intensive observation period throughout 2013.

    Science.gov (United States)

    Ichiyanagi, Kimpei; Tanoue, Masahiro

    2016-01-01

    Spatial distribution of annual mean stable isotopes in precipitation (δ(18)O, δ(2)H) was observed at 56 sites across Japan throughout 2013. Annual mean δ(18)O values showed a strong latitude effect, from -12.4 ‰ in the north to -5.1 ‰ in the south. Annual mean d-excess values ranged from 8 to 21 ‰, and values on the Sea of Japan side in Northern and Eastern Japan were relatively higher than those on the Pacific Ocean side. The local meteoric water line (LMWL) and isotope effects were based on the annual mean values from all sites across Japan as divided into distinct regions: the Sea of Japan side to the Pacific Ocean side and Northeastern to Southwestern Japan. Slopes and intercepts of LMWL ranged from 7.4 to 7.8 and 9.8 to 13.0, respectively. Slopes for latitude, altitude, and temperature effects ranged from -0.27 to -0.48 ‰/°N, -0.0034 to -0.0053 ‰/m, and 0.36 to 0.46 ‰/°C, respectively, with statistically significance at the 99 % level. However, there was no precipitation amount effect. From the result of a multiple regression analysis, the empirical formula of annual mean δ(18)O in precipitation from latitude and altitude for all sites across Japan was determined to be δ(18) O = -0.348 (LAT) - 0.00307 (ALT) + 4.29 (R(2) = 0.59). Slopes for latitude and altitude ranged from - 0.28 to - 0.51, and - 0.0019 to - 0.0045, respectively. Even though site distribution was uneven, these equations are the first trial estimation for annual mean stable isotopes in precipitation across Japan. Further research performed on the monthly basis is required to elucidate factors controlling the spatiotemporal variability of stable isotopes in precipitation across Japan.

  12. The development of patterns of stable, transient, and school-age onset aggressive behavior in young children.

    Science.gov (United States)

    Kingston, L; Prior, M

    1995-03-01

    To examine the development of patterns of aggressive behavior in children from the age of 2 to 8 years. Children with early histories of aggressive behavior were selected from a community sample of 2,400 infants participating in a longitudinal study. The sample was divided into four groups: children with stable aggressive behavior, those with transient aggression, those with aggression only after age 5 years (late onset), and a comparison group of nonaggressive children. Children with stable aggressive behavior were characterized by a difficult temperament, hostile sibling interactions, maternal perception of the child as difficult, and harsher child-rearing practices. Children whose early aggression decreased over time and those who became aggressive only after entering school could not be reliably classified with the selected family variables. Teacher ratings of temperament factors of task orientation and reactivity and ability ratings correctly classified 74% of children whose aggression began at school-age. Children with persistent aggressive behavior differed from those who improved, predominantly in terms of symptom severity. Problems with aggression can be identified early in development, and a significant proportion of aggressive children are at risk for continuing social and scholastic difficulties. Knowledge of associated factors may play an important role in prevention.

  13. Critical role of androgen receptor in the postnatal period in male sexual behavior in rats.

    Science.gov (United States)

    Yamada, Shunji; Ohoya, Miku; Takanami, Keiko; Matsuda, Ken Ichi; Kawata, Mitsuhiro

    2015-11-16

    Gonadal hormones have a developmental role in organization of the nervous system that regulates sexually dimorphic behavior. It is well known that androgen secreted from testes in the perinatal period is converted to estrogen by aromatase in rodent brain, and that estrogen and its receptor play a pivotal role in masculinization of brain structure and function. Treatment with flutamide, an androgen receptor (AR) antagonist, during the perinatal period inhibits development of malespecific brain structure and function, suggesting that androgen signaling via AR also influences brain masculinization. In this study, we investigated which stage during the postnatal period is critical for androgen signaling in brain masculinization. The postnatal period was designated as postnatal days (PD) 0-22, and divided into stages I (PD 0-7), II (PD 8-14), and III (PD 15-22). Newborn male rats were given flutamide subcutaneously in each stage. After adulthood, the effects of postnatal flutamide treatment on brain masculinization were evaluated byanalysis of male sexual behavior. Continuous inhibition of AR throughout stages I and II caused a robust reduction of the intromission ratio and ejaculation frequency compared with other groups. AR inhibition in stage I, II, or III did not cause any change. AR inhibition had no effect onmount behavior. These results show that stage-specific AR activation in the first two postnatal weeks may contribute to brain masculinization mediating male sexual behavior in adulthood. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Neonatal oxytocin and vasopressin manipulation alter social behavior during the juvenile period in Mongolian gerbils.

    Science.gov (United States)

    Taylor, Jack H; Cavanaugh, Jon; French, Jeffrey A

    2017-07-01

    Oxytocin and vasopressin are important modulators of a wide variety of social behaviors, and increasing evidence is showing that these neuropeptides are important organizational effectors of later-life behavior as well. We treated day-old gerbil pups with oxytocin, vasopressin, an oxytocin receptor antagonist, a vasopressin V1a receptor antagonist, or saline control, and then measured received parental responsiveness during the early postnatal period and juvenile social behavior during weaning. Neonatal vasopressin treatment enhanced sociality in males, but not females, at both developmental time points. When pups were individually placed outside the nest, parents were more responsive to male pups treated with vasopressin compared with littermates, and vasopressin treated male pups exhibited increased play with littermates as juveniles. These results show that vasopressin during very early life can enhance social interactions throughout early development. © 2017 Wiley Periodicals, Inc.

  15. Importance of bringing dogs in contact with children during their socialization period for better behavior.

    Science.gov (United States)

    Arai, Sato; Ohtani, Nobuyo; Ohta, Mitsuaki

    2011-06-01

    Much attention has been given to the role that dogs play in the social, physical, and psychological development of children. Furthermore, dogs are now playing a new important role in animal-assisted education (AAE). However, some dogs have difficulty getting along with children. The aim of this study was to demonstrate how dogs' contact with children during and after their socialization period influenced their responses toward children. In total, 31 pet dogs were divided into three groups. Group 1 dogs had been in contact with children during the canine socialization period (between 3 and 12 weeks of age); Group 2 dogs had been in contact with children after this socialization period; Group 3 dogs seldom had contact with children. As soon as a child entered the room, the dog was presented three stimuli by the child over the course of several intervals. The dogs' responses were evaluated by analyzing behavior and heart rates. The dogs that had been in contact with children during their socialization period did not show aggressive behavior or excited behavior toward the child in our test. Moreover, their heart rates were significantly decreased even during the last stimulus, which involved the child running around the dog while calling its name. This study suggested that the dogs having contact with children during socialization period might not show inappropriate responses toward children and could be suitable for taking part in AAE.

  16. The Influence of Daily Periods on the Drinking Behavior in Romanian Black and White Primiparous Cows

    Directory of Open Access Journals (Sweden)

    Silvia Erina

    2011-10-01

    Full Text Available The study was carried out on 9 Romanian Black and White cows in their first one hundred days of lactation. The aim of this study was to determine some aspect of drinking behavior of the cows in 24 hours that were divided into 3 day periods (intervals: 07:00-14:00 (I1, 14:00-21:00 (I2, 21:00-07:00 (I3. During the experiments, the following drinking behavior aspects were determined: the number of drinkings and the length of drinking periods per 24 hours, in the fibrous-succulents administration order of forages (O1 and succulents-fibrous order (O2. Data was computed by ANOVA/MANOVA. Results showed that the daily periods had an influence on the number of drinkings and drinking length, the lowest number of drinkings occurred during the night interval I3 (4.20 and the highest number together with the longest drinking period occurred in the second interval I2 (12.47 and 1062.50 seconds. In both administration order of forages ( O1 and O2 there were a very significant differences (p<0.001 between I1 and I2 in favour of I2, between I1 and I3 in favour of I1 and between I2 and I3 in favour of I2, for number of drinkings periods and for length of drinking periods.

  17. Stable time patterns of railway suicides in Germany: comparative analysis of 7,187 cases across two observation periods (1995–1998; 2005–2008)

    Science.gov (United States)

    2014-01-01

    Background The majority of fatalities on the European Union (EU) railways are suicides, representing about 60% of all railway fatalities. The aim of this study was to compare time patterns of suicidal behaviour on railway tracks in Germany between two observation periods (1995–1998 and 2005–2008) in order to investigate their stability and value in railway suicide prevention. Methods Cases were derived from the National Central Registry of person accidents on the German railway network (STABAG). The association of daytime, weekday and month with the mean number of suicides was analysed applying linear regression. Potential differences by observation period were assessed by adding observation period and the respective interaction terms into the linear regression. A 95% confidence interval for the mean number of suicides was computed using the t distribution. Results A total of 7,187 railway suicides were recorded within both periods: 4,102 (57%) in the first period (1995–1998) and 3,085 (43%) in the second (2005–2008). The number of railway suicides was highest on Mondays and Tuesdays in the first period with an average of 3.2 and 3.5 events and of 2.6 events on both days in the second period. In both periods, railway suicides were more common between 6:00 am and noon, and between 6:00 pm and midnight. Seasonality was only prominent in the period 1995–1998. Conclusions Over the course of two observation periods, the weekday and circadian patterns of railway suicides remained stable. Therefore, these patterns should be an integral part of railway suicide preventive measures, e.g. gatekeeper training courses. PMID:24498876

  18. Stable time patterns of railway suicides in Germany: comparative analysis of 7,187 cases across two observation periods (1995-1998; 2005-2008).

    Science.gov (United States)

    Lukaschek, Karoline; Baumert, Jens; Erazo, Natalia; Ladwig, Karl-Heinz

    2014-02-06

    The majority of fatalities on the European Union (EU) railways are suicides, representing about 60% of all railway fatalities. The aim of this study was to compare time patterns of suicidal behaviour on railway tracks in Germany between two observation periods (1995-1998 and 2005-2008) in order to investigate their stability and value in railway suicide prevention. Cases were derived from the National Central Registry of person accidents on the German railway network (STABAG). The association of daytime, weekday and month with the mean number of suicides was analysed applying linear regression. Potential differences by observation period were assessed by adding observation period and the respective interaction terms into the linear regression. A 95% confidence interval for the mean number of suicides was computed using the t distribution. A total of 7,187 railway suicides were recorded within both periods: 4,102 (57%) in the first period (1995-1998) and 3,085 (43%) in the second (2005-2008). The number of railway suicides was highest on Mondays and Tuesdays in the first period with an average of 3.2 and 3.5 events and of 2.6 events on both days in the second period. In both periods, railway suicides were more common between 6:00 am and noon, and between 6:00 pm and midnight. Seasonality was only prominent in the period 1995-1998. Over the course of two observation periods, the weekday and circadian patterns of railway suicides remained stable. Therefore, these patterns should be an integral part of railway suicide preventive measures, e.g. gatekeeper training courses.

  19. Modeling study of droplet behavior during blowdown period of large break LOCA based on experimental data

    International Nuclear Information System (INIS)

    Sakaba, Hiroshi; Umezawa, Shigemitsu; Teramae, Tetsuya; Furukawa, Yuji

    2004-01-01

    During LOCA (Loss Of Coolant Accident) in PWR, droplets behavior during blowdown period is one of the important phenomena. For example, the spattering from falling liquid film that flows from upper plenum generates those droplets in core region. The behavior of droplets in such flow has strong effect for cladding temperature behavior because these droplets are able to remove heat from a reactor core by its direct contact on fuel rods and its evaporation at the surface. For safety analysis of LOCA in PWR, it is necessary to evaluate droplet diameter precisely in order to predict fuel cladding temperature changing by the calculation code. Based on the test results, a new droplet behavior model was developed for the MCOBRA/TRC code that predicts the droplet behavior during such LOCA events. Furthermore, the verification calculations that simulated some blowdown tests were performed using by the MCOBRA/TRAC code. These results indicated the validity of this droplet model during blow down cooling period. The experiment was focused on investigating the Weber number of steady droplet in the blow down phenomenon of large break LOCA. (author)

  20. The role of oxytocin in mothers' theory of mind and interactive behavior during the perinatal period.

    Science.gov (United States)

    MacKinnon, Anna L; Gold, Ian; Feeley, Nancy; Hayton, Barbara; Carter, C Sue; Zelkowitz, Phyllis

    2014-10-01

    The present longitudinal study examined the relations between plasma oxytocin, theory of mind, and maternal interactive behavior during the perinatal period. A community sample of women was assessed at 12-14 weeks gestation, 32-34 weeks gestation, and 7-9 weeks postpartum. Oxytocin during late pregnancy was significantly positively correlated with a measure of theory of mind, and predicted theory of mind ability after controlling for parity, maternal education, prenatal psychosocial risk, and general anxiety, measured during the first trimester. Theory of mind was associated with less remote and less depressive maternal interactive behavior. Oxytocin, across all time points, was not directly related to maternal interactive behavior. However, there was a significant indirect effect of oxytocin during late pregnancy on depressive maternal behavior via theory of mind ability. These preliminary findings suggest that changes in the oxytocinergic system during the perinatal period may contribute to the awareness of social cues, which in turn plays a role in maternal interactive behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Binge Eating Behavior and Weight Loss Maintenance over a 2-Year Period

    Directory of Open Access Journals (Sweden)

    Carly R. Pacanowski

    2014-01-01

    Full Text Available Objective. To investigate the relationship between binge eating behavior and weight loss maintenance over a two-year period in adults. Design. Secondary data analysis using the Keep It Off study, a randomized trial evaluating an intervention to promote weight loss maintenance. Participants. 419 men and women (ages: 20 to 70 y; BMI: 20–44 kg/m2 who had intentionally lost ≥10% of their weight during the previous year. Measurements. Body weight was measured and binge eating behavior over the past 6 months was reported at baseline, 12 months and 24 months. Height was measured at baseline. Results. Prevalence of binge eating at baseline was 19.4% (n=76. Prevalence of binge eating at any time point was 30.1% (n=126. Although rate of weight regain did not differ significantly between those who did or did not report binge eating at baseline, binge eating behavior across the study period (additive value of presence or absence at each time point was significantly associated with different rates of weight regain. Conclusion. Tailoring weight loss maintenance interventions to address binge eating behavior is warranted given the prevalence and the different rates of weight regain experienced by those reporting this behavior.

  2. Binge Eating Behavior and Weight Loss Maintenance over a 2-Year Period

    Science.gov (United States)

    Pacanowski, Carly R.; Senso, Meghan M.; Crain, A. Lauren; Sherwood, Nancy E.

    2014-01-01

    Objective. To investigate the relationship between binge eating behavior and weight loss maintenance over a two-year period in adults. Design. Secondary data analysis using the Keep It Off study, a randomized trial evaluating an intervention to promote weight loss maintenance. Participants. 419 men and women (ages: 20 to 70 y; BMI: 20–44 kg/m2) who had intentionally lost ≥10% of their weight during the previous year. Measurements. Body weight was measured and binge eating behavior over the past 6 months was reported at baseline, 12 months and 24 months. Height was measured at baseline. Results. Prevalence of binge eating at baseline was 19.4% (n = 76). Prevalence of binge eating at any time point was 30.1% (n = 126). Although rate of weight regain did not differ significantly between those who did or did not report binge eating at baseline, binge eating behavior across the study period (additive value of presence or absence at each time point) was significantly associated with different rates of weight regain. Conclusion. Tailoring weight loss maintenance interventions to address binge eating behavior is warranted given the prevalence and the different rates of weight regain experienced by those reporting this behavior. PMID:24891946

  3. Binge Eating Behavior and Weight Loss Maintenance over a 2-Year Period

    OpenAIRE

    Carly R. Pacanowski; Meghan M. Senso; Kristin Oriogun; A. Lauren Crain; Nancy E. Sherwood

    2014-01-01

    Objective. To investigate the relationship between binge eating behavior and weight loss maintenance over a two-year period in adults. Design. Secondary data analysis using the Keep It Off study, a randomized trial evaluating an intervention to promote weight loss maintenance. Participants. 419 men and women (ages: 20 to 70 y; BMI: 20–44 kg/m2) who had intentionally lost ≥10% of their weight during the previous year. Measurements. Body weight was measured and binge eating behavior over the pa...

  4. The Global Behavior of a Periodic Epidemic Model with Travel between Patches

    Directory of Open Access Journals (Sweden)

    Luosheng Wen

    2012-01-01

    Full Text Available We establish an SIS (susceptible-infected-susceptible epidemic model, in which the travel between patches and the periodic transmission rate are considered. As an example, the global behavior of the model with two patches is investigated. We present the expression of basic reproduction ratio R0 and two theorems on the global behavior: if R0 1, then it is unstable; if R0 > 1, the disease is uniform persistence. Finally, two numerical examples are given to clarify the theoretical results.

  5. Second-order two-scale method for bending behaviors of composite plate with periodic configuration

    International Nuclear Information System (INIS)

    Zhu Guoqing; Cui Junzhi

    2010-01-01

    In this paper, the second-order two-scale analysis method for bending behaviors of the plate made from composites with 3-D periodic configuration is presented by means of construction way. It can capture the microscopic 3-D mechanics behaviors caused from 3-D micro-structures. First, directly starting from the 3-D elastic plate model of composite materials with 3-D periodic configuration, three cell models are defined, and correspondingly the three classes of cell functions only defined on 3 normalized cells are constructed. And then, the effective homogenization parameters of composites are calculated from those local functions, it leads to a 2-D homogenized laminar plate problem. Next, to solve it the homogenization solution is obtained. Finally, the second-order two-scale solution is constructed from the micro-cell functions and the homogenization solution.

  6. Increase in HIV diagnoses among men who have sex with men in New Zealand from a stable low period.

    Science.gov (United States)

    Saxton, Peter J W; Dickson, Nigel P; McAllister, Susan M; Sharples, Katrina; Hughes, Anthony J

    2011-09-01

    To describe trends in HIV diagnoses among men who have sex with men (MSM) in New Zealand 1996-2008, and to identify characteristics associated with HIV diagnoses in the resurgent phase. Data collected through routine surveillance of HIV infection, where the mode of transmission included homosexual contact, were analysed over the period 1996-2008. Annual HIV diagnoses were low during 1996-2000, rose sharply between 2001 and 2005, and remained at an elevated plateau between 2006 and 2008. Over a quarter were attributed to HIV infection acquired overseas (28.6%). Trends in diagnoses of locally acquired HIV infection closely mirrored the trend of three diagnosis phases. Increases in locally acquired HIV occurred among virtually all characteristics of MSM. However, compared with MSM diagnosed in the low phase 1996-2000, individuals diagnosed in the resurgent phase 2001-05 were more likely to be aged 30-39, to have tested HIV-negative within the previous 2 years, to live in the Northern region encompassing Auckland, and to be of non-European ethnicity. The per capita HIV diagnosis rate among MSM was lowest in 1997, at 22.0 per million males aged 15-64, and highest in 2005 at 66.7 per million. The increase in HIV diagnoses among MSM in New Zealand was primarily due to an increase in locally acquired HIV infection, which disproportionately affected some groups of MSM. Factors driving this change in local epidemic conditions need to be identified. The rate of new HIV diagnoses among MSM remains low by international standards.

  7. Asymptotic behavior for a dissipative plate equation in $R^N$ with periodic coefficients

    Directory of Open Access Journals (Sweden)

    Eleni Bisognin

    2008-03-01

    Full Text Available In this work we study the asymptotic behavior of solutions of a dissipative plate equation in $mathbb{R}^N$ with periodic coefficients. We use the Bloch waves decomposition and a convenient Lyapunov function to derive a complete asymptotic expansion of solutions as $to infty$. In a first approximation, we prove that the solutions for the linear model behave as the homogenized heat kernel.

  8. Influence of modulation periods on the tribological behavior of Si/a-C: H multilayer film

    Science.gov (United States)

    Zhu, Linan; Wu, Yanxia; Zhang, Shujiao; Yu, Shengwang; Tang, Bin; Liu, Ying; Zhou, Bing; Shen, Yanyan

    2018-01-01

    A series of Si/a-C: H multilayer films with different modulation periods were fabricated on stainless steel and silicon substrates by radio-frequency magnetron sputtering. The influence of the modulation period on the structure, morphology, mechanical properties and tribological behaviors in different environments (air, simulated acid rain, and NaCl solution) was investigated. The results show that the content of the sp2 hybrid carbon, surface roughness and hardness of the multilayer film increased firstly and then decreased with the decreased modulation period. Furthermore, the combination of the sublayer agrees well with the formation of the SiC crystal at the interface. Interestingly, the films show quite substantially different tribological properties in various test environments. The lowest friction coefficient is 0.2 for the S1 film in air. However, the lowest friction coefficient can reach 0.13 in solution. Importantly, the tribological behavior of the multilayer film is mainly determined by its hardness, as well as surface roughness in air while it is closely related with modulation period and interface structure in solution.

  9. Stable isotopes reveal rail-associated behavior in a threatened carnivore.

    Science.gov (United States)

    Hopkins, John B; Whittington, Jesse; Clevenger, Anthony P; Sawaya, Michael A; St Clair, Colleen Cassady

    2014-01-01

    Human-wildlife conflict is a leading cause of adult mortality for large carnivores worldwide. Train collision is the primary cause of mortality for threatened grizzly bears (Ursus arctos) in Banff National Park. We investigated the use of stable isotope analysis as a tool for identifying bears that use the railway in Banff. Rail-associated bears had higher δ(15)N and δ(34)S values than bears sampled away from the rail, but similar δ(13)C values. Because elevated δ(15)N values are indicative of higher animal protein consumption, rail-associated bears likely preyed on ungulates that foraged along the rail or scavenged on train-killed animals. The higher δ(34)S values in bear hair could have resulted from bears consuming sulfur pellets spilled on the rail or through the uptake of sulfur in the plants bears or animals consumed. Similar δ(13)C values suggest that the two types of bears had generally similar plant-based diets. Results from this study suggest that stable isotopes analysis could be used as a non-invasive, affordable, and efficient technique to identify and monitor bears that forage on the railway in Banff and potentially other transportation corridors worldwide.

  10. Sensitive Periods, Vasotocin-Family Peptides, and the Evolution and Development of Social Behavior

    Directory of Open Access Journals (Sweden)

    Nicole M. Baran

    2017-08-01

    Full Text Available Nonapeptides, by modulating the activity of neural circuits in specific social contexts, provide an important mechanism underlying the evolution of diverse behavioral phenotypes across vertebrate taxa. Vasotocin-family nonapeptides, in particular, have been found to be involved in behavioral plasticity and diversity in social behavior, including seasonal variation, sexual dimorphism, and species differences. Although nonapeptides have been the focus of a great deal of research over the last several decades, the vast majority of this work has focused on adults. However, behavioral diversity may also be explained by the ways in which these peptides shape neural circuits and influence social processes during development. In this review, I synthesize comparative work on vasotocin-family peptides during development and classic work on early forms of social learning in developmental psychobiology. I also summarize recent work demonstrating that early life manipulations of the nonapeptide system alter attachment, affiliation, and vocal learning in zebra finches. I thus hypothesize that vasotocin-family peptides are involved in the evolution of social behaviors through their influence on learning during sensitive periods in social development.

  11. Sensitive Periods, Vasotocin-Family Peptides, and the Evolution and Development of Social Behavior.

    Science.gov (United States)

    Baran, Nicole M

    2017-01-01

    Nonapeptides, by modulating the activity of neural circuits in specific social contexts, provide an important mechanism underlying the evolution of diverse behavioral phenotypes across vertebrate taxa. Vasotocin-family nonapeptides, in particular, have been found to be involved in behavioral plasticity and diversity in social behavior, including seasonal variation, sexual dimorphism, and species differences. Although nonapeptides have been the focus of a great deal of research over the last several decades, the vast majority of this work has focused on adults. However, behavioral diversity may also be explained by the ways in which these peptides shape neural circuits and influence social processes during development. In this review, I synthesize comparative work on vasotocin-family peptides during development and classic work on early forms of social learning in developmental psychobiology. I also summarize recent work demonstrating that early life manipulations of the nonapeptide system alter attachment, affiliation, and vocal learning in zebra finches. I thus hypothesize that vasotocin-family peptides are involved in the evolution of social behaviors through their influence on learning during sensitive periods in social development.

  12. Early life adversity during the infant sensitive period for attachment: Programming of behavioral neurobiology of threat processing and social behavior.

    Science.gov (United States)

    Opendak, Maya; Gould, Elizabeth; Sullivan, Regina

    2017-06-01

    Animals, including humans, require a highly coordinated and flexible system of social behavior and threat evaluation. However, trauma can disrupt this system, with the amygdala implicated as a mediator of these impairments in behavior. Recent evidence has further highlighted the context of infant trauma as a critical variable in determining its immediate and enduring consequences, with trauma experienced from an attachment figure, such as occurs in cases of caregiver-child maltreatment, as particularly detrimental. This review focuses on the unique role of caregiver presence during early-life trauma in programming deficits in social behavior and threat processing. Using data primarily from rodent models, we describe the interaction between trauma and attachment during a sensitive period in early life, which highlights the role of the caregiver's presence in engagement of attachment brain circuitry and suppressing threat processing by the amygdala. These data suggest that trauma experienced directly from an abusive caregiver and trauma experienced in the presence of caregiver cues produce similar neurobehavioral deficits, which are unique from those resulting from trauma alone. We go on to integrate this information into social experience throughout the lifespan, including consequences for complex scenarios, such as dominance hierarchy formation and maintenance. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Early life adversity during the infant sensitive period for attachment: Programming of behavioral neurobiology of threat processing and social behavior

    Directory of Open Access Journals (Sweden)

    Maya Opendak

    2017-06-01

    Full Text Available Animals, including humans, require a highly coordinated and flexible system of social behavior and threat evaluation. However, trauma can disrupt this system, with the amygdala implicated as a mediator of these impairments in behavior. Recent evidence has further highlighted the context of infant trauma as a critical variable in determining its immediate and enduring consequences, with trauma experienced from an attachment figure, such as occurs in cases of caregiver-child maltreatment, as particularly detrimental. This review focuses on the unique role of caregiver presence during early-life trauma in programming deficits in social behavior and threat processing. Using data primarily from rodent models, we describe the interaction between trauma and attachment during a sensitive period in early life, which highlights the role of the caregiver’s presence in engagement of attachment brain circuitry and suppressing threat processing by the amygdala. These data suggest that trauma experienced directly from an abusive caregiver and trauma experienced in the presence of caregiver cues produce similar neurobehavioral deficits, which are unique from those resulting from trauma alone. We go on to integrate this information into social experience throughout the lifespan, including consequences for complex scenarios, such as dominance hierarchy formation and maintenance.

  14. Mating behavior, population growth, and the operational sex ratio: a periodic two-sex model approach.

    Science.gov (United States)

    Jenouvrier, Stéphanie; Caswell, Hal; Barbraud, Christophe; Weimerskirch, Henri

    2010-06-01

    We present a new approach to modeling two-sex populations, using periodic, nonlinear two-sex matrix models. The models project the population growth rate, the population structure, and any ratio of interest (e.g., operational sex ratio). The periodic formulation permits inclusion of highly seasonal behavioral events. A periodic product of the seasonal matrices describes annual population dynamics. The model is nonlinear because mating probability depends on the structure of the population. To study how the vital rates influence population growth rate, population structure, and operational sex ratio, we used sensitivity analysis of frequency-dependent nonlinear models. In nonlinear two-sex models the vital rates affect growth rate directly and also indirectly through effects on the population structure. The indirect effects can sometimes overwhelm the direct effects and are revealed only by nonlinear analysis. We find that the sensitivity of the population growth rate to female survival is negative for the emperor penguin, a species with highly seasonal breeding behavior. This result could not occur in linear models because changes in population structure have no effect on per capita reproduction. Our approach is applicable to ecological and evolutionary studies of any species in which males and females interact in a seasonal environment.

  15. Field measurements of stable fly (Diptera: Muscidae) demography, fecundity, and survival based on daily trap catches at a beef farm in southern Ontario over a 5-yr period.

    Science.gov (United States)

    Beresford, D V; Sutcliffe, J F

    2012-11-01

    We sampled stable fly, Stomoxys calcitrans (L.), populations using a CO2 baited cloth trap (Nzi trap) each day throughout the summer and autumn at a beef farm near Peterborough, Ontario, Canada, from 1997 to 2001. Females (2,512) were dissected for ovarian age-grading, to produce a demographic profile of farm populations. The number of follicles were counted to produce fecundity estimates. The developmental periods of adult female stages, measured as accumulated degree-days above 10 degrees C, were determined for a lab colony of stable flies. These measurements were used to calculate survival in terms of degree-days of the farm populations each year. Of the 2,512 females caught, 42.4% were nulliparous on average each year. The median follicle size at insemination was 305 microm in the field populations, and 495 microm in the colony. Farm caught females had an average of 49.15 follicles per ovary overall, with the body size (leg length) and fecundity increasing slightly with age. On average, 44.5% (SE 3.2%) of nulliparous females survived to become parous, and of these, 45.7% (SE 2.1%) survived the uniparous state to become multiparous. Years of higher rainfall had increased fecundity; rainfall did not appear to affect survival.

  16. A mathematical model for period-memorizing behavior in Physarum plasmodium.

    Science.gov (United States)

    Tachikawa, Masashi

    2010-04-21

    Mathematical models to describe period-memorizing behavior in Physarum plasmodium are reported. In constructing the model, we first examine the basic characteristics required for the class of models, then create a minimal linear model to fulfill these requirements. We also propose two modifications of the minimal model, nonlinearization and noise addition, which improve the reproducibility of experimental evidences. Differences in the mechanisms and in the reproducibility of experiments between our models and the previous models are discussed. (c) 2010 Elsevier Ltd. All rights reserved.

  17. Sensitive periods in epigenetics: bringing us closer to complex behavioral phenotypes.

    Science.gov (United States)

    Nagy, Corina; Turecki, Gustavo

    2012-08-01

    Genetic studies have attempted to elucidate causal mechanisms for the development of complex disease, but genome-wide associations have been largely unsuccessful in establishing these links. As an alternative link between genes and disease, recent efforts have focused on mechanisms that alter the function of genes without altering the underlying DNA sequence. Known as epigenetic mechanisms, these include DNA methylation, chromatin conformational changes through histone modifications, ncRNAs and, most recently, 5-hydroxymethylcytosine. Although DNA methylation is involved in normal development, aging and gene regulation, altered methylation patterns have been associated with disease. It is generally believed that early life constitutes a period during which there is increased sensitivity to the regulatory effects of epigenetic mechanisms. The purpose of this review is to outline the contribution of epigenetic mechanisms to genomic function, particularly in the development of complex behavioral phenotypes, focusing on the sensitive periods.

  18. Busy period analysis, rare events and transient behavior in fluid flow models

    Directory of Open Access Journals (Sweden)

    Søren Asmussen

    1994-01-01

    Full Text Available We consider a process {(Jt,Vt}t≥0 on E×[0,∞, such that {Jt} is a Markov process with finite state space E, and {Vt} has a linear drift ri on intervals where Jt=i and reflection at 0. Such a process arises as a fluid flow model of current interest in telecommunications engineering for the purpose of modeling ATM technology. We compute the mean of the busy period and related first passage times, show that the probability of buffer overflow within a busy cycle is approximately exponential, and give conditioned limit theorems for the busy cycle with implications for quick simulation. Further, various inequalities and approximations for transient behavior are given. Also explicit expressions for the Laplace transform of the busy period are found. Mathematically, the key tool is first passage probabilities and exponential change of measure for Markov additive processes.

  19. Similarities and Differences in Behavioral State Organization during Sleep Periods in the Perinatal Infant before and after Birth.

    Science.gov (United States)

    Groome, Lynne J.; And Others

    1997-01-01

    Examined consistency in behavioral state organization for 30 fetuses and neonates. Assessed heart rate pattern and presence or absence of eye and gross body movements during sleep, finding quiet sleep (QS), active sleep (AS), and indeterminate states in nearly identical proportions. Duration of enclosed QS epochs provided only stable measure of…

  20. Behavior of radon, chemical compounds and stable elements in underground water

    International Nuclear Information System (INIS)

    Lopez R, N.; Segovia, N.; Lopez, M.B.E.; Pena, P.; Armienta, M.A.; Godinez, L.; Seidel, J.L.

    2001-01-01

    The radon behavior, chemical compounds, major and trace elements in water samples of four springs and three wells of urban and agricultural zones around the Jocotitlan volcano and El Oro region was determined, both of them located in the medium part of the Mexican neo-volcanic axis. The 222 Rn was measured by the liquid scintillation method, the analysis of major components was realized with conventional chemical techniques, while the trace elements were quantified using an Icp-Ms. The average values of the radon concentrations obtained during one year were constant relatively, in an interval from 0.97 to 4.99 Bq/lt indicating a fast transport from the reload area toward the sampling points. the compounds, major and trace elements showed differences which indicate distinct origins of water from the site studies. (Author)

  1. Teenage pregnancy, epidemiological behavior in Las Tunas during the period 2012 - 2014

    Directory of Open Access Journals (Sweden)

    Enelis Reyes Reyes

    2015-06-01

    Full Text Available Background: teenage pregnancy is a medical risk to be considered, not only for determining an increase of maternal morbidity and an estimated of 2 to 3 times infant mortality, but also as one of the most important factors in the occurrence of congenital malformations.Objective: to determine the epidemiological behavior of teenage pregnancy in Las Tunas province during the period 2012 - 2014.Methods: a descriptive, observational and retrospective study of the behavior of teenage pregnancy was carried out in the province and time period previously stated. The study was performed in municipalities and People's Councils. The universe consisted of 148 169 women of childbearing age and the sample comprised 3 309 pregnant female teenagers from 12 to 19 years old.Results: the phenomenon of teenage pregnancy continues, but the province and its municipalities show favorable data; 2013 was the one of the most negative results, being Manatí and Amancio municipalities the most significant ones; in all the municipalities there are People's Councils with results that are higher than municipal and provincial averages. The adolescent fertility rate in the province was between 39.0 and 45.2 per 1000, being 2013 and Amancio municipality the ones with the highest incidence.Conclusions: although the teenage pregnancy continues, the province and its municipalities show favorable data, resulting from an integrated and successful health programs, involving Provincial Genetics Network work.

  2. Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

    International Nuclear Information System (INIS)

    Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone; Kelecom, Alphonse; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova; Dores, Luis Augusto de Carvalho Bresser

    2011-01-01

    The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

  3. Importance of All Movement Behaviors in a 24 Hour Period for Overall Health

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Chaput

    2014-12-01

    Full Text Available Physical inactivity and childhood obesity are well-recognized public health concerns that are associated with a range of adverse health outcomes. Historically, the benefits of physical activity (e.g., moderate-to-vigorous physical activity—MVPA to overall health have dominated discussions and emerging evidence indicates that a broader, more integrated approach is needed to better understand and address current public health crises. Existing guidelines for children and youth around the world only focus on MVPA, and recently sedentary behavior, despite an accumulating body of evidence showing that light-intensity physical activity (LPA such as walking can provide important health benefits. Furthermore, there is accumulating support for the importance of adequate sleep and that these behaviors moderate the health impact of each other. Ignoring the other components of the movement continuum (i.e., sleep, sedentary time, LPA while focusing efforts exclusively on MVPA (accounting for <5% of the time in a 24 h period limits the potential to optimize the health benefits of movement behaviors. In order to address this limitation, experts in Canada are currently developing the world’s first Integrated 24 Hour Movement Behaviour Guidelines for Children and Youth to help advance an integrated healthy active living agenda that has the potential to significantly improve the overall health and well-being of children and youth.

  4. Theory of hydrogen shell flashes on accreting white dwarfs. II. The stable shell burning and the recurrence period of shell flashes

    International Nuclear Information System (INIS)

    Fujimoto, M.Y.

    1982-01-01

    By means of analytical solutions of the envelope, thermal properties of hydrogen shell burning on accreting white dwarfs are studied and a general picture for their progress is presented which is described by two parameters, the accretion rate and the mass of the white dwarf. On a white dwarf, the thermal behavior of gas in the burning shell depends on the configuration of the envelope, which gives birth to two distinct types of stable configurations in thermal equilibrium, a high and a low state. In the high state, the nuclear shell burning makes up for the energy loss from the surface. There exists the lower limit to the envelope mass for this state. The nuclear burning rate lies in a narrow range of about a factor of 2.5, irrespective of the mass of the white dwarf, while the range itself varies greatly with the latter. In the low state, the nuclear burning is extinct, and yet the compressional heating by accreted gas balances with the cooling through the diffusion of heat. Therefore, the structure depends on the accretion rate. Thermal instability of nuclear burning sets the upper limit to the envelope mass of this state

  5. [Epidemiologic behavior of malignant digestive tract tumors over a five year period in Veracruz, Mexico].

    Science.gov (United States)

    Roesch-Dietlen, F; Jiménez-García, V A; Remes-Troche, J M; Rubio-Arce, J F; López-Salinas, A; Ruiz-Juárez, I; Grube-Pagola, P; Silva-Cañetas, C F

    2012-01-01

    Tumors of the digestive system are considered to be a public health problem because of their elevated mortality rate. In Mexico, gastric cancer and colon cancer rank fourth and fifth, respectively, following tracheal, bronchial, and lung cancer, and there has been an increase in their frequency in the last few years. However, there are no specific studies that have evaluated their epidemiologic behavior in Veracruz. To determine the frequency of digestive system cancer in five health institutions in the city of Veracruz and to describe its epidemiologic behavior over a five-year period. Annual statistics from the following hospitals were reviewed: the Instituto Mexicano del Seguro Social, the Secretaría de Salud, the Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Petróleos Mexicanos, and the Secretaría de la Defensa Nacional within the time frame of January 2005 to December 2009. Diagnoses based on histopathology were recorded, along with patient age and sex. A total of 1803 cases of digestive tract cancers were detected: 52% were men and 48% were women. A yearly increase in the number of cases was observed with colon cancer being in first place, followed by stomach cancer and rectal cancer. The increase in digestive system cancer cases over the last five years in Veracruz underlines the need to evaluate the implementation of screening programs for the at-risk population and to study the different etiologic factors involved in its manifestation.

  6. period-Regulated Feeding Behavior and TOR Signaling Modulate Survival of Infection.

    Science.gov (United States)

    Allen, Victoria W; O'Connor, Reed M; Ulgherait, Matthew; Zhou, Clarice G; Stone, Elizabeth F; Hill, Vanessa M; Murphy, Keith R; Canman, Julie C; Ja, William W; Shirasu-Hiza, Mimi M

    2016-01-25

    Most metazoans undergo dynamic, circadian-regulated changes in behavior and physiology. Currently, it is unknown how circadian-regulated behavior impacts immunity against infection. Two broad categories of defense against bacterial infection are resistance, control of microbial growth, and tolerance, control of the pathogenic effects of infection. Our study of behaviorally arrhythmic Drosophila circadian period mutants identified a novel link between nutrient intake and tolerance of infection with B. cepacia, a bacterial pathogen of rising importance in hospital-acquired infections. We found that infection tolerance in wild-type animals is stimulated by acute exposure to dietary glucose and amino acids. Glucose-stimulated tolerance was induced by feeding or direct injection; injections revealed a narrow window for glucose-stimulated tolerance. In contrast, amino acids stimulated tolerance only when ingested. We investigated the role of a known amino-acid-sensing pathway, the TOR (Target of Rapamycin) pathway, in immunity. TORC1 is circadian regulated and inhibition of TORC1 decreased resistance, as in vertebrates. Surprisingly, inhibition of the less well-characterized TOR complex 2 (TORC2) dramatically increased survival, through both resistance and tolerance mechanisms. This work suggests that dietary intake on the day of infection by B. cepacia can make a significant difference in long-term survival. We further demonstrate that TOR signaling mediates both resistance and tolerance of infection and identify TORC2 as a novel potential therapeutic target for increasing survival of infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Strategies/Behaviors That Successful Superintendents Use to Build Strong Relationships and Trust during Their Entry Period

    Science.gov (United States)

    Green, C. K.

    2012-01-01

    The purpose of the study was to identify strategies/behaviors that successful superintendents used to build strong relationships and trust with their school boards within their entry period. The following research questions guided the study: (1) What strategies/behaviors are successful superintendents using to build strong relationships and trust…

  8. Analyzing the Relationship of Organizational Trust and Organizational Culture with Knowledge Sharing Behavior in Teachers of Second Intermediate Period

    Science.gov (United States)

    Shahhosseini, Sakineh; Nadi, Mohammad Ali

    2015-01-01

    The present paper aims to study the relationship of organizational trust, organizational culture with knowledge sharing behavior among teachers of Second Intermediate Period in the City of Isfahan. Research method was correlation and statistical population included all teachers of Second Intermediate Period of Isfahan in academic year 2013-2014 (N…

  9. The labor supply and fertility behavior of married women: a three-period model.

    Science.gov (United States)

    Lehrer, E; Nerlove, M

    1981-01-01

    By emphasizing the importance of dividing the family life cycle into various stages for the analysis of fertility and female labor supply, this discussion adds to the literature on female time allocation. This is a period analysis in which the life cycle is divided into 3 stages: the pre-1st birth interval, the childrearing stage, and a final period that begins when all the children have reached school age. As far as is known, this study is the first about life cycle phenomenon in which life cycle stage is distinguished by the presence and age of children. Previous studies represent life cycle stage by age, usually of the mother. The presence and age of children, at least with regard to female labor supply decisions, is considered as a more signifiant indicator of where a family is in its life cycle. A 3-period theoretical model is presented for the analysis of fertility behavior, female investment in human capital, labor supply, and wages. This gives a general framework within which to analyze the interactions among these various aspects of family decision making. Several simplifying assumptions are made in order to reduce the problem to manageable proportions. The focal point of the model is the wife; the possible endogeneity of many of the husband's actions is neglected. Data from the 1973 National Survey of Family Growth were used to examine empirically the determinants of fertility and female work. The sample was restricted in several ways. Only women who were formally married, with at least 1 child, and in the 3rd stage of the life cycle at the time of the survey were considered. All of those cases in which the wife had been married more than once, as well as those in which twins or adopted children were reported, were eliminated. The sample size was 1485. The results show that the influence of exogenous variables on the female labor supply varied substantially among the life cycle stages. The husband's income has no impact on the wife's market work in the

  10. Effects of exposure to radiation during the fetal period on behavior and growth in baby mice

    International Nuclear Information System (INIS)

    Naruse, Ichiro; Kameyama, Yoshiro

    1979-01-01

    In order to study the effects of exposure to a small dose of radiation during the fetal period upon behavior and growth, 2 groups of 13-day-old fetal mice were irradiated. One group consisted of 18 fetal mice given 25 R and the other of 15 given 100 R. The control group consisted of 18 fetal mice 13 days old. After birth they were all placed in the center of an open area (50 x 50 x 25 cm) for 3 minutes so as to determine the number of squares traversed ad lib. (the number which their extremities traversed for 3 minutes) and the time day when they began walking and grooming. After they were observed for 3 minutes, the time at which reflex actions such as speedy righting and auditory startle were observed was confirmed. There were no differnces between the 25 R-irradiated group and the control group. In the 100 R-irradiated group, walking was observed earlier than in the control group, and the number of squares traversed increased. (Ichikawa, K.)

  11. The Stochastic Resonance Behaviors of a Generalized Harmonic Oscillator Subject to Multiplicative and Periodically Modulated Noises

    Directory of Open Access Journals (Sweden)

    Suchuan Zhong

    2016-01-01

    Full Text Available The stochastic resonance (SR characteristics of a generalized Langevin linear system driven by a multiplicative noise and a periodically modulated noise are studied (the two noises are correlated. In this paper, we consider a generalized Langevin equation (GLE driven by an internal noise with long-memory and long-range dependence, such as fractional Gaussian noise (fGn and Mittag-Leffler noise (M-Ln. Such a model is appropriate to characterize the chemical and biological solutions as well as to some nanotechnological devices. An exact analytic expression of the output amplitude is obtained. Based on it, some characteristic features of stochastic resonance phenomenon are revealed. On the other hand, by the use of the exact expression, we obtain the phase diagram for the resonant behaviors of the output amplitude versus noise intensity under different values of system parameters. These useful results presented in this paper can give the theoretical basis for practical use and control of the SR phenomenon of this mathematical model in future works.

  12. The Retrofit Puzzle Extended: Optimal Fleet Owner Behavior over Multiple Time Periods

    Science.gov (United States)

    2009-08-04

    In "The Retrofit Puzzle: Optimal Fleet Owner Behavior in the Context of Diesel Retrofit Incentive Programs" (1) an integer program was developed to model profit-maximizing diesel fleet owner behavior when selecting pollution reduction retrofits. Flee...

  13. Temperature variability at Dürres Maar, Germany during the Migration Period and at High Medieval Times, inferred from stable carbon isotopes of Sphagnum cellulose

    Directory of Open Access Journals (Sweden)

    A. Lücke

    2011-09-01

    Full Text Available This paper presents a high resolution reconstruction of local growing season temperature (GST anomalies at Dürres Maar, Germany, spanning the last two millennia. The GST anomalies were derived from a stable carbon isotope time series of cellulose chemically extracted from Sphagnum leaves (δ13Ccellulose separated from a kettle-hole peat deposit of several metres thickness. The temperature reconstruction is based on the Sphagnum δ13Ccellulose/temperature dependency observed in calibration studies. Reconstructed GST anomalies show considerable centennial and decadal scale variability. A cold and presumably wet phase with below-average temperature is reconstructed between the 4th and 7th century AD which is in accordance with the so called European Migration Period, marking the transition from the Late Roman Period to the Early Middle Ages. At High Medieval Times, the amplitude in the reconstructed temperature variability is most likely overestimated; nevertheless, above-average temperatures are obvious during this time span, which are followed by a temperature decrease. On the contrary, a pronounced Late Roman Climate Optimum, often described as similarly warm or even warmer as medieval times, could not be detected. The temperature signal of the Little Ice Age (LIA is not preserved in Dürres Maar due to considerable peat cutting that takes place in the first half of the 19th century. The local GST anomalies show a remarkable agreement to northern hemispheric temperature reconstructions based on tree-ring datasets and are also in accordance with climate reconstructions on the basis of lake sediments, glacier advances and retreats, and historical datasets. Most notably, e.g., during the Early Middle Ages and at High Medieval Times, temperatures were neither low nor high in general. Rather high frequency temperature variability with multiple narrow intervals of below- and above-average temperatures at maximum lasting a few decades are

  14. Effects of Cognitive Behavioral Therapy for Insomnia on Sleep-Related Cognitions Among Patients With Stable Heart Failure.

    Science.gov (United States)

    Redeker, Nancy S; Jeon, Sangchoon; Andrews, Laura; Cline, John; Mohsenin, Vahid; Jacoby, Daniel

    2017-07-26

    Cognitive behavioral therapy for insomnia (CBT-I) improves insomnia and fatigue among chronic heart failure (HF) patients, but the extent to which sleep-related cognitions explain CBT-I outcomes in these patients is unknown. We examined the effects of CBT-I on sleep-related cognitions, associations between changes in sleep-related cognitions and changes in sleep and symptoms after CBT-I, and the extent to which cognitions mediated the effects of CBT-I. Stable New York Heart Association Class II-III HF patients (total n = 51; n = 26 or 51.0% women; M age = 59.1 ± 15.1 years). HF patients were randomized in groups to group CBT-I (n = 30) or attention control (HF self-management education, n = 21) and completed actigraphy, the Insomnia Severity Index, Pittsburgh Sleep Quality Index, Dysfunctional Beliefs and Attitudes about Sleep (DBAS) and Sleep Disturbance Questionnaires (SDQ), and self-reported fatigue, depression, anxiety, and sleepiness (baseline, immediately after treatment, six months). We used mixed-effects modeling, mediation analysis with a bootstrapping approach, and Pearson correlations. There was a statistically significant group × mult time effect on DBAS. DBAS mediated the effects of CBT-I on insomnia severity and partially mediated CBT-I effects on fatigue. Improvements in dysfunctional cognitions were associated with improved sleep quality, insomnia severity, sleep latency and decreased fatigue, depression, and anxiety, with sustained effects at six months. Improvement in dysfunctional sleep-related cognitions is an important mechanism for CBT-I effects among HF patients who are especially vulnerable to poor sleep and high symptom burden.

  15. Break-even concentration and periodic behavior of a stochastic chemostat model with seasonal fluctuation

    Science.gov (United States)

    Zhao, Dianli; Yuan, Sanling

    2017-05-01

    This paper formulates a single-species stochastic chemostat model with periodic coefficients due to seasonal fluctuation. When the noise is small, a modified break-even concentration is identified, whose value below or above the averaged concentration of the input nutrient can completely determine whether the microorganism will persist or not, where an accuracy decay rate is given for extinction. In case of persistence, existence of the random positive periodic solution is proved for the considered model. Further, the random periodic solution is shown to be globally attractive under some mild extra condition. The periodic dynamics obtained in this paper are supported by computer simulations.

  16. Light Curve Stability and Period Behavior of the Contact Binary TZ Boo

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... New CCD observations of the eclipsing binary TZ Boo in BVR bands were carried out in 2006 (presented three new minima) and used together with all published minima to study and update the orbital period of the system TZ Boo by means of an (O–C) diagram. The period variation from 1926 to 2011 is ...

  17. Light Curve Stability and Period Behavior of the Contact Binary TZ ...

    Indian Academy of Sciences (India)

    Abstract. New CCD observations of the eclipsing binary TZ Boo in. BVR bands were carried out in 2006 (presented three new minima) and used together with all published minima to study and update the orbital period of the system TZ Boo by means of an (O–C) diagram. The period variation from 1926 to 2011 is ...

  18. Long-time Behavior of Isolated Periodically Driven Interacting Lattice Systems

    Directory of Open Access Journals (Sweden)

    Luca D’Alessio

    2014-12-01

    Full Text Available We study the dynamics of isolated interacting spin chains that are periodically driven by sudden quenches. Using full exact diagonalization of finite chains, we show that these systems exhibit three distinct regimes. For short driving periods, the Floquet Hamiltonian is well approximated by the time-averaged Hamiltonian, while for long periods, the evolution operator exhibits properties of random matrices of a circular ensemble (CE. In between, there is a crossover regime. Based on a finite-size scaling analysis and analytic arguments, we argue that, for thermodynamically large systems and nonvanishing driving periods, the evolution operator always exhibits properties of the CE of random matrices. Consequently, the Floquet Hamiltonian is a nonlocal Hamiltonian with multispin interaction terms, and the driving leads to the equivalent of an infinite temperature state at long times. These results are connected to the breakdown of the Magnus expansion and are expected to hold beyond the specific lattice model considered.

  19. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  20. Solitons and quasi-periodic behaviors in an inhomogeneous optical fiber

    Science.gov (United States)

    Yang, Jin-Wei; Gao, Yi-Tian; Su, Chuan-Qi; Zuo, Da-Wei; Feng, Yu-Jie

    2017-01-01

    In this paper, a fifth-order variable-coefficient nonlinear Schrödinger equation for the attosecond pulses in an inhomogeneous optical fiber is studied. With the aid of auxiliary functions, we obtain the variable-coefficient Hirota bilinear equations and corresponding integrable constraints. Under those constraints, we obtain the Lax pair, conservation laws, one-, two- and three-soliton solutions via the Hirota method and symbolic computation. Soliton structures and interactions are discussed: (1) For the one soliton, we discuss the influence of the group velocity dispersion term α(x) and fifth-order dispersion term δ(x) on the velocities and structures of the solitons, where x is the normalized propagation along the fiber, and derive a constraint contributing to the stationary soliton; (2) For the two solitons, we analyze the interactions between them with different values of α(x) and δ(x), and derive the quasi-periodic formulae for three cases of the bound states: When α(x) and δ(x) are the linear functions of x, quasi-periodic attraction and repulsion lead to the redistribution of the energy of the two solitons, and ratios among the quasi-periods are derived; When α(x) and δ(x) are the quadratic functions of x, the ratios among them are also obtained; When α(x) and δ(x) are the periodic functions of x, bi-periodic phenomena are obtained; (3) For the three solitons, including the parabolic, cubic, periodic and stationary structures, interactions among them with different values of the α(x) and δ(x) are presented.

  1. A critical period of sleep for development of courtship circuitry and behavior in Drosophila.

    Science.gov (United States)

    Kayser, Matthew S; Yue, Zhifeng; Sehgal, Amita

    2014-04-18

    Most animals sleep more early in life than in adulthood, but the function of early sleep is not known. Using Drosophila, we found that increased sleep in young flies was associated with an elevated arousal threshold and resistance to sleep deprivation. Excess sleep results from decreased inhibition of a sleep-promoting region by a specific dopaminergic circuit. Experimental hyperactivation of this circuit in young flies results in sleep loss and lasting deficits in adult courtship behaviors. These deficits are accompanied by impaired development of a single olfactory glomerulus, VA1v, which normally displays extensive sleep-dependent growth after eclosion. Our results demonstrate that sleep promotes normal brain development that gives rise to an adult behavior critical for species propagation and suggest that rapidly growing regions of the brain are most susceptible to sleep perturbations early in life.

  2. PSYCHOLOGICAL DETERMINANTS OF PRONENESS TO CONFLICT BEHAVIOR IN THE PERIOD OF STUDENTSHIP

    Directory of Open Access Journals (Sweden)

    N. A. Bunjak

    2013-03-01

    Full Text Available The University student is claimed to be one of the most important ?gure today whо deter mines the future of the society and its progressive development and democratic transformations. In the dif?cult conditions of life, characterizing the situation in the country nowadays contemporary students are often uncertain about their future and in connection with this, experience negative emotional states which might cause intrapersonal con?icts. The contemporary youth is characterized nowadays by numerous con?icts in which the development of the age speci?c achievements  takes  place,  namely:  self-actualization,  self-expression,  competition,  defending one’s own values, attitudes and passions. The paper presents the results of an anonymous survey in testing of Ternopil National university students aimed at de?ning the relationships between the frequency of the intrapersonal con?icts experienced by the young people and psychological factors causing them. The proneness to the con?ict behavior of the personality has been shown to be caused by such psychological characteristics of the individual as the level of self-esteem, the level of aggression, anxiety, frustration, rigidity and locus of control. It is postulated in the paper that high proneness of the personality to the con?ict behavior can be adequately described with reference to a set of personality properties which jointly de?ne and enhance the levels of con?ict. This set of characteristics act as psychological determinants of con?icts. The analysis of the survey designed to de?ne the sources of the students’ proneness to the con?ict behavior shows that the problem requires further theoretical research and empirical studies to obtain a more comprehensive picture of the possible causes of proneness to this type of behavior.

  3. [Regulation of behavior in the period between the world wars: Robert Musil and Kurt Lewin].

    Science.gov (United States)

    Innerhofer, Roland; Rothe, Katja

    2010-12-01

    The paper attempts to reconstruct the proto-cybernetic concept of regulation which emerged in early 20th century both in biology and psychology, and was critically reflected in literature. The basic premise is that Kurt Lewin's field-theoretical psychology played a crucial role in the development of behavioral self-regulation concepts. The goal is to show (1) that Lewin's early experiments and theories were based on the idea of a dynamic process of self-regulation determined by the actors and their personal motivation and interaction, (2) that this concept of self-regulation functioned as a camouflage for power-strategies that aimed to regulate and optimize the economic production and social reproduction processes, (3) that in Robert Musil's fragmentary, 'fringing' novel The Man without Qualities the attempt to optimize the social and economic behavior and to establish a homeostatic state proved to be a complete failure. As a notable result, this 'literary test' of behavioral self-regulation revealed the violence and imbalance of power inherent in this concept of self-regulation and its practical implementation.

  4. Is Young Adulthood a Critical Period for Suicidal Behavior among Sexual Minorities? Results from a US National Sample.

    Science.gov (United States)

    Fish, Jessica N; Rice, Cara E; Lanza, Stephanie T; Russell, Stephen T

    2018-03-29

    The developmental timing of suicide-related disparities between heterosexuals and sexual minorities (i.e., lesbian/gay and bisexual (LGB) people) is an understudied area that has critical prevention implications. In addition to developmentally situated experiences that shape risk for suicidality in the general population, sexual minorities also experience unique social stressors (e.g., anti-LGB stigma) that may alter their risk for suicidal behavior at different ages. Using a nationally representative US sample of adults, we assessed age-varying rates of suicidal behavior among heterosexuals and sexual minorities ages 18 to 60 and the age-varying association between anti-LGB discrimination and suicidal behavior. We also tested whether these age-varying prevalences and associations differed for men and women and for sexual minorities who did and did not endorse a sexual minority identity. Results indicate a critical period for suicide behavior risk for sexual minorities during young adulthood, with the highest rates of risk at age 18 followed by a steady decline until the early 40s. Disparities were particularly robust for sexual minorities who identified as lesbian, gay, or bisexual. This pattern was present for both men and women, though sexual minority women in their 30s were more likely to report suicidal behavior than heterosexuals and sexual minority men. Sexual minorities who experienced anti-LGB discrimination were more likely to report suicidal behavior, but the significance of this association was limited to those under 30. The effect of discrimination on suicidal behavior was stronger among young adult sexual minority men, relative to sexual minority women, but was present for a wider age range for sexual minority women (until age 30) relative to sexual minority men (until age 25).

  5. Effects of exposure to glyphosate in male and female mice behavior in pubertal period

    Directory of Open Access Journals (Sweden)

    Andréia de Oliveira Joaquim

    2014-12-01

    Full Text Available The present study aims to investigate the effects of pre-pubertal exposure of male and female mice to a commercial formulation of glyphosate on sexual dimorphism observed in animal models of emotionality, anxiety and depression. For this, mice were exposed from 23 days of age (PND until PND 45 to glyphosate (50 mg/kg, per os or saline solution, and, ten days after the end of treatments, male and female mice were observed in the open field (OF, elevated plus maze (EPM or forced swimming test (FWT. Results showed that exposure to glyphosate: 1 reduced the locomotion frequency of male mice similarly to female mice in the OF and female mice had an increase in rearing behavior and in the immobility time; 2 reduced in male mice the motor activity both in the OF and EPM, while no effects were observed in female mice; 3 in the SWT male mice had a decreased time of float similarly female mice. We concluded that pre-pubertal exposure to glyphosate reduced in male mice the capacity of exploration in the OF and EPM tests suggesting that the herbicide interfered with the central mechanism related to brain masculinization of exploratory and anxiety behavioral models. In the FWT it was observed a decreased depressive response in male mice while in female an increased response was detected.

  6. Dopamine and serotonin signaling during two sensitive developmental periods differentially impact adult aggressive and affective behaviors in mice

    Science.gov (United States)

    Yu, Qinghui; Teixeira, Cátia M.; Mahadevia, Darshini; Huang, Yung-Yu; Balsam, Daniel; Mann, J John; Gingrich, Jay A; Ansorge, Mark S.

    2014-01-01

    Pharmacologic blockade of monoamine oxidase A (MAOA) or serotonin transporter (5-HTT) has antidepressant and anxiolytic efficacy in adulthood. Yet, genetically conferred MAOA or 5-HTT hypo-activity is associated with altered aggression and increased anxiety/depression. Here we test the hypothesis that increased monoamine signaling during development causes these paradoxical aggressive and affective phenotypes. We find that pharmacologic MAOA blockade during early postnatal development (P2-P21) but not during peri-adolescence (P22-41) increases anxiety- and depression-like behavior in adult (> P90) mice, mimicking the effect of P2-21 5-HTT inhibition. Moreover, MAOA blockade during peri-adolescence, but not P2-21 or P182-201, increases adult aggressive behavior, and 5-HTT blockade from P22-P41 reduced adult aggression. Blockade of the dopamine transporter, but not the norepinephrine transporter, during P22-41 also increases adult aggressive behavior. Thus, P2-21 is a sensitive period during which 5-HT modulates adult anxiety/depression-like behavior, and P22-41 is a sensitive period during which DA and 5-HT bi-directionally modulate adult aggression. Permanently altered DAergic function as a consequence of increased P22-P41 monoamine signaling might underlie altered aggression. In support of this hypothesis, we find altered aggression correlating positively with locomotor response to amphetamine challenge in adulthood. Proving that altered DA function and aggression are causally linked, we demonstrate that optogenetic activation of VTA DAergic neurons increases aggression. It therefore appears that genetic and pharmacologic factors impacting dopamine and serotonin signaling during sensitive developmental periods can modulate adult monoaminergic function and thereby alter risk for aggressive and emotional dysfunction. PMID:24589889

  7. POPs, Fatty acids, lipid and Stable Isotopes data - The behavioral ecology of deep-diving odontocetes in the Bahamas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project will use a unique set of individual-based data to quantify and model the behavioral ecology of six Department of Defense priority cetacean species in...

  8. Are tutor behaviors in problem-based learning stable?: a generalizability study of social congruence, expertise and cognitive congruence.

    Science.gov (United States)

    Williams, Judith C; Alwis, W A M; Rotgans, Jerome I

    2011-10-01

    The purpose of this study was to investigate the stability of three distinct tutor behaviors (1) use of subject-matter expertise, (2) social congruence and (3) cognitive congruence, in a problem-based learning (PBL) environment. The data comprised the input from 16,047 different students to a survey of 762 tutors administered in three consecutive semesters. Over the three semesters each tutor taught two of the same course and one different course. A generalizability study was conducted to determine whether the tutor behaviors were generalizable across the three measurement occasions. The results indicate that three semesters are sufficient to make generalizations about all three tutor behaviors. In addition the results show that individual differences between tutors account for the greatest differences in levels of expertise, social congruence and cognitive congruence. The study concludes that tutor behaviors are fairly consistent in PBL and somewhat impervious to change. Implications of these findings for tutor training are discussed.

  9. Critical and sensitive periods for reversing the effects of mechanosensory deprivation on behavior, nervous system, and development in Caenorhabditis elegans.

    Science.gov (United States)

    Rai, Susan; Rankin, Catharine H

    2007-09-15

    In these studies the nematode Caenorhabditis elegans was used as a model to investigate ways to reverse the effects of mechanosensory deprivation on behavior and development. Rose et al. (J Neurosci 2005; 25:7159-7168) showed that worms reared in isolation responded significantly less to a mechanical tap stimulus, were significantly smaller, and expressed significantly lower levels of a postsynaptic glutamate receptor subunit on the command interneurons of the tap response circuit and a presynaptic vesicle marker in the tap sensory neurons compared with worms raised in groups. Here, brief mechanical stimulation at any time throughout development reversed the effects of isolation on the response to tap and on postsynaptic glutamate receptor expression on the command interneurons, suggesting there is no critical period for these measures. In contrast to the high level of plasticity in glutamate receptor subunit expression on the interneurons, low levels of stimulation only rescued vesicle expression in the tap sensory neurons early in development and progressively higher levels of stimulation were required as the worm developed, suggesting a sensitive period immediately after hatching, followed by a period of decreasing plasticity. Stimulation during the first three stages of larval development, but not later, rescued the effects of isolation on worm length, suggesting there is a critical period for this measure that ends in the third larval stage. These results indicate that different effects of early isolation required different amounts and/or timing of stimulation to be reversed. (c) 2007 Wiley Periodicals, Inc.

  10. Trends in contraceptive patterns and behaviors during a period of fertility transition in China: 1988-2006.

    Science.gov (United States)

    Zheng, Xiaoying; Tan, Lingfang; Ren, Qiang; Cui, Zhijun; Wu, Junqing; Lin, Ting; He, Jie; Chen, Hua

    2012-09-01

    This paper explores how contraceptive patterns and behaviors changed during the course of China's population transition and a period of low fertility from 1988 to 2006. Based on data from Chinese nationwide surveys of family planning and reproductive health undertaken in 1988, 1997, 2001 and 2006, this study uses a multinomial logit model to analyze changes in, regional differences in and determinants of contraceptive behaviors during this period. The overall prevalence of contraceptive use among married women aged 15-49 years changed little during these 20 years, holding steady at about 90%. However, there were notable changes in the method mix: the predominant methods used were the long-term methods of the intrauterine device (IUD) and female sterilization, and contraceptive use gradually shifted from sterilization to IUDs and condoms. There existed a close relationship between contraceptive methods used and sociodemographic characteristics. Hans, rural, old and less educated women are more likely to use sterilization, while minorities, urban, young and educated women are more likely to use IUDs. There are marked changes in the method mix among different demographic groups during the course of China's population transition and a period of low fertility. The findings indicate that future works aimed at promoting reproductive health should be diverse among different populations. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Differences in delta13C and delta15N stable isotopes in the pearly razorfish Xyrichtys novacula related to the sex, location and spawning period.

    Science.gov (United States)

    Box, A; Deudero, S; Blanco, A; Grau, A M; Riera, F

    2010-06-01

    In the present study, Xyrichtys novacula (Labridae) were sampled at five locations around the islands of Ibiza and Formentera (western Mediterranean Sea). Isotopic signatures of delta13C, delta15N and the C:N ratio were analysed in relation to locality, sex and size differences. delta13C and delta15N partitioning was also studied in the reproductive spawning period. There were significant differences in the delta13C signature between localities for both sexes, but not for delta15N. Sex differences were also found with a mean +/-s.e. value of -17.38 +/- 0.06 per thousand delta13C and 8.36 +/- 0.05 per thousand delta(15)N for females and -17.17 +/- 0.07 per thousand delta13C and 8.80 +/- 0.06 per thousand delta15N for males. Increasing total length in both sexes was positively correlated with delta15N enrichment and a significant positive linear regression was established for both variables. During the reproductive spawning period, there were changes in delta13C fractioning with enrichment in postspawning females and males (with respect to prespawning and spawning periods) and delta(15)N impoverishment in postspawning females (with respect to prespawning and spawning periods). Xyrichtys novacula uses local food sources, as confirmed by delta(13)C and delta(15)N, and females and males use different food sources, thus avoiding intraspecific competition. This was confirmed by delta15N enrichment as size increased. Spawning leads to special requirements for gonad maturation, which is reflected in the isotopic signatures for both sexes.

  12. Investigating the wetting behavior of a surface with periodic reentrant structures using integrated microresonators

    Science.gov (United States)

    Klingel, S.; Oesterschulze, E.

    2017-08-01

    The apparent contact angle is frequently used as an indicator of the wetting state of a surface in contact with a liquid. However, the apparent contact angle is subject to hysteresis that depends furthermore strongly on both the material properties and the roughness and structure of the sample surface. In this work, we show that integrated microresonators can be exploited to determine the wetting state by measuring both the frequency shift caused by the hydrodynamic mass of the liquid and the change in the quality factor as a result of damping. For this, we integrated electrically driven hybrid bridge resonators (HBRs) into a periodically structured surface intended for wetting experiments. We could clearly differentiate between the Wenzel state and the Cassie-Baxter state because the resonant frequency and quality factor of the HBR changed by over 35% and 40%, respectively. This offers the capability to unambiguously distinguish between the different wetting states.

  13. Hysteretic behavior in seawater intrusion in response to discontinuous drought periods

    Science.gov (United States)

    Salandin, P.; Darvini, G.

    2017-12-01

    The seawater intrusion (SWI) represents a relevant problem for communities living in many coastal regions and in small islands, where the amount of fresh water available for human consumption or irrigation purposes depends on the equilibrium between the natural groundwater recharge from precipitations and the surrounding sea. This issue is exacerbated by climate changes, and, as a consequence, the reduction of natural groundwater recharge and the decrease the seaward flows of fresh water rather than sea level rise, as recently demonstrated by Ketabchi et al. (2016), leads to magnify the seawater intrusion into coastal aquifers. The temporal fluctuation of the fresh water table level are a natural consequence of the interaction of the aquifer with a water body or due to the seasonal replenishment of the water table. The severe and prolonged drought phenomena as that observed in last years in some areas of the Mediterranean, as over the central western Mediterranean basin, Italy and Spain, where a decreasing trend in total precipitation was detected (Alpert et al., 2002) in addition to the rise in temperature, enlarges the variation of the freshwater flux and can magnify the progression of the saline wedge. In the present study we demonstrate that the presence of varying boundary constraints or forcing factors may lead to hysteretic behavior in saltwater intrusion, showing dependence of the saline wedge on historic conditions. Therefore, the dynamic behavior of SWI may depend on both the present and past forcing conditions. To this aim different transient simulations supported by evidences deduced from a physical model are carried out to assess the presence of the hysteretic effects in the SWI phenomenon and to evaluate its influence in the management of the coastal aquifers for both the rational exploitation and the corrected management of water resources. About 70% of the world's population dwells in coastal zones. Therefore the optimal exploitation of fresh

  14. Periodic nanostructures imprinted on high-temperature stable sol–gel films by ultraviolet-based nanoimprint lithography for photovoltaic and photonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Back, Franziska [Schott AG, Research and Technology Development, Hattenbergstraße 10, 55122 Mainz (Germany); Fraunhofer-Institut für Silicatforschung ISC, Neunerplatz 2, 97082 Würzburg (Germany); Bockmeyer, Matthias; Rudigier-Voigt, Eveline [Schott AG, Research and Technology Development, Hattenbergstraße 10, 55122 Mainz (Germany); Löbmann, Peer [Fraunhofer-Institut für Silicatforschung ISC, Neunerplatz 2, 97082 Würzburg (Germany)

    2014-07-01

    Nanostructured sol–gel films with high-temperature stability are used in the area of electronics, photonics or biomimetic materials as light-trapping architectures in solar cells, displays, waveguides or as superhydrophobic surfaces with a lotus effect. In this work, high-temperature stable 2-μm nanostructured surfaces were prepared by ultraviolet-based nanoimprint lithography using an alkoxysilane binder incorporating modified silica nanoparticles. Material densification during thermal curing and microstructural evolution which are destined for a high structural fidelity of nanostructured films were investigated in relation to precursor chemistry, particle morphology and particle content of the imprint resist. The mechanism for densification and shrinkage of the films was clarified and correlated with the structural fidelity to explain the influence of the geometrical design on the optical properties. A high internal coherence of the microstructure of the nanostructured films results in a critical film thickness of > 5 μm. The structured glassy layers with high inorganic content show thermal stability up to 800 °C and have a high structural fidelity > 90% with an axial shrinkage of 16% and a horizontal shrinkage of 1%. This material allows the realization of highly effective light-trapping architectures for polycrystalline silicon thin-film solar cells on glass but also for the preparation of 2D photonic crystals for telecommunication wavelengths. - Highlights: • Fundamental research • Hybrid sol–gel material with high-temperature stability and contour accuracy • Ensuring of cost-efficient and industrially feasible processing • Application in photonic and photovoltaic.

  15. Growth increment periodicity in the shell of the razor clam Ensis directus using stable isotopes as a method to validate age

    Directory of Open Access Journals (Sweden)

    J. F. M. F. Cardoso

    2013-07-01

    Full Text Available To evaluate the role of the razor clam Ensis directus in Dutch coastal waters, understanding its population dynamics is important. As such, the age structure of the population forms a key parameter. Accurate age determination in bivalve shells is not always straightforward due to the difficulty of interpreting externally visible growth lines. In the present paper, we aimed at validating the seasonality in growth line formation using visual techniques in combination with stable oxygen and carbon isotope analyses (δ18O and δ13C. High δ18O values in the shell coincided with growth marks on the external surface of the valve and in acetate peels of the shell's cross section. Most shell δ18O samples were assigned to the months from June to September. From November to March no samples were retrieved, indicating that the shell did not grow. The lowest reconstructed temperature (6.3 °C suggests that ~ 6 °C may be the threshold temperature for growth. Nevertheless, most of the reconstructed values fell above 14.5 °C, indicating that growth occurred mainly in the summer at relatively high temperatures. Shell δ13C profiles followed a more or less seasonal cycle, but no direct relationship could be made between δ13C values and annual growth lines. Although counting external annual growth lines led to a correct estimation of age and consequently of growth rates, we recommend analysing acetate peels of cross sections to support the distinction between annual lines and disturbance lines.

  16. Analyses of stable isotopes in camelids collagen bones from Tulan Ravine, Atacama Puna, early formative period (CA 3,1000-2,400BP)

    International Nuclear Information System (INIS)

    Lopez, Patricio; Cartajena, Isabel; Nunez, Lautaro

    2013-01-01

    This paper presents the results of isotope analysis (δ 13 C y δ 15 N) conducted on bone collagen found in Lama guanicoe and Lama glama remains from Tulan-85 and Tulan-54 archaeological sites. Both sites have been dated to the Early Formative Period (ca. 3,100-2,400 ap) and are located southeast of the Atacama Puna basin. Faunal samples were selected using anatomical and morphometric criteria. The results indicate divergences in the diets of both species, reflecting vegetation variation in the Tulan Quebrada caused by altitude differences and linked to hunting and herding areas [es

  17. Kinetic and hysteretic behavior of ATP hydrolysis of the highly stable dimeric ATP synthase of Polytomella sp.

    Science.gov (United States)

    Villavicencio-Queijeiro, Alexa; Pardo, Juan Pablo; González-Halphen, Diego

    2015-06-01

    The F1FO-ATP synthase of the colorless alga Polytomella sp. exhibits a robust peripheral arm constituted by nine atypical subunits only present in chlorophycean algae. The isolated dimeric enzyme exhibits a latent ATP hydrolytic activity which can be activated by some detergents. To date, the kinetic behavior of the algal ATPase has not been studied. Here we show that while the soluble F1 sector exhibits Michaelis-Menten kinetics, the dimer exhibits a more complex behavior. The kinetic parameters (Vmax and Km) were obtained for both the F1 sector and the dimeric enzyme as isolated or activated by detergent, and this activation was also seen on the enzyme reconstituted in liposomes. Unlike other ATP synthases, the algal dimer hydrolyzes ATP on a wide range of pH and temperature. The enzyme was inhibited by oligomycin, DCCD and Mg-ADP, although oligomycin induced a peculiar inhibition pattern that can be attributed to structural differences in the algal subunit-c. The hydrolytic activity was temperature-dependent and exhibited activation energy of 4 kcal/mol. The enzyme also exhibited a hysteretic behavior with a lag phase strongly dependent on temperature but not on pH, that may be related to a possible regulatory role in vivo. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  19. Categorisation of northern California rainfall for periods with and without a radar brightband using stable isotopes and a novel automated precipitation collector†

    Directory of Open Access Journals (Sweden)

    Tyler B. Coplen

    2015-12-01

    Full Text Available During landfall of extratropical cyclones between 2005 and 2011, nearly 1400 precipitation samples were collected at intervals of 30-min time resolution with novel automated collectors at four NOAA sites in northern California [Alta (ATA, Bodega Bay (BBY, Cazadero (CZD and Shasta Dam (STD] during 43 events. Substantial decreases were commonly followed hours later by substantial increases in hydrogen isotopic composition (δ 2HVSMOW where VSMOW is Vienna Standard Mean Ocean Water and oxygen isotopic composition (δ 18OVSMOW of precipitation. These variations likely occur as pre-cold frontal precipitation generation transitions from marine vapour masses having low rainout to cold cloud layers having much higher rainout (with concomitant brightband signatures measured by an S-band profiling radar and lower δ 2HVSMOW values of precipitation, and finally to shallower, warmer precipitating clouds having lower rainout (with non-brightband signatures and higher δ 2HVSMOW values of precipitation, in accord with ‘seeder–feeder’ precipitation. Of 82 intervals identified, a remarkable 100.5 ‰ decrease in δ 2HVSMOW value was observed for a 21 January 2010 event at BBY. Of the 61 intervals identified with increases in δ 2HVSMOW values as precipitation transitioned to shallower, warmer clouds having substantially less rainout (the feeder part of the seeder–feeder mechanism, a remarkable increase in δ 2HVSMOW value of precipitation of 82.3 ‰ was observed for a 10 February 2007 event at CZD. All CZD and ATA events having δ 2HVSMOW values of precipitation below −105 ‰ were atmospheric rivers (ARs, and of the 13 events having δ 2HVSMOW values of precipitation below −80 ‰, 77 % were ARs. Cloud echo-top heights (a proxy for atmospheric temperature were available for 23 events. The mean echo-top height is greater for higher rainout periods than that for lower rainout periods in 22 of the 23 events. The lowest δ 2HVSMOW of precipitation of

  20. Pastoralism in Northern Peru during Pre-Hispanic Times: Insights from the Mochica Period (100–800 AD) Based on Stable Isotopic Analysis of Domestic Camelids

    Science.gov (United States)

    Dufour, Elise; Goepfert, Nicolas; Gutiérrez Léon, Belkys; Chauchat, Claude; Franco Jordán, Régulo; Sánchez, Segundo Vásquez

    2014-01-01

    Llama (Lama glama) and alpaca (Vicugna pacos) are the only large domesticated animals indigenous to the Americas. Pastoralism occupies a fundamental economic, social and religious role in Andean life. Today, camelid livestock are confined to the ecozone of the puna (above 3,500 masl), while their presence on the Pacific coast during pre-Hispanic times is attested by archaeological skeletal remains. This study aims to document herding practices on the northern Peruvian coast during the Early Intermediate Period (200 BC-600 AD) by gaining insights into diet, location of breeding and mobility of archaeological camelids from the funerary and ritual contexts of two Mochica sites, Uhle Platform in Huacas de Moche and El Brujo. The three first early years and the long-term life histories of the animals were documented by the combined bulk analysis of bone collagen (δ13Ccol and δ15Ncol) and bone structural carbonate (δ13Cbone and δ18Obone) and the serial analysis of structural carbonate of molar tooth enamel (δ13Cenamel and δ18Oenamel). Mochica camelids were bred in the low and/or middle valleys, unlike their modern counterparts, who are restricted to highland puna C3 pastures. Archaeological camelids had diverse and complex life histories, usually with substantial maize foddering. An ontogenetic switch in diet and possible residential mobility during the course of life were identified for some specimens. Although the inference of geographic origin from δ18Obone and δ18Oenamel values was limited because of the lack of understanding of the influence of environmental and biological factors, tooth enamel analysis has great potential for exploring camelid herding practices and Andean pastoralism. Our study suggested that Mochica herders adapted their practices to the difficult lowland environment and that herding practices were varied and not restricted to breeding at higher altitudes. The role of maize in different aspects of the economic life of the Mochicas is also

  1. Pastoralism in northern Peru during pre-Hispanic times: insights from the Mochica Period (100-800 AD) based on stable isotopic analysis of domestic camelids.

    Science.gov (United States)

    Dufour, Elise; Goepfert, Nicolas; Gutiérrez Léon, Belkys; Chauchat, Claude; Jordán, Régulo Franco; Vásquez Sánchez, Segundo

    2014-01-01

    Llama (Lama glama) and alpaca (Vicugna pacos) are the only large domesticated animals indigenous to the Americas. Pastoralism occupies a fundamental economic, social and religious role in Andean life. Today, camelid livestock are confined to the ecozone of the puna (above 3,500 masl), while their presence on the Pacific coast during pre-Hispanic times is attested by archaeological skeletal remains. This study aims to document herding practices on the northern Peruvian coast during the Early Intermediate Period (200 BC-600 AD) by gaining insights into diet, location of breeding and mobility of archaeological camelids from the funerary and ritual contexts of two Mochica sites, Uhle Platform in Huacas de Moche and El Brujo. The three first early years and the long-term life histories of the animals were documented by the combined bulk analysis of bone collagen (δ(13)C col and δ(15)N col) and bone structural carbonate (δ(13)C bone and δ(18)O bone) and the serial analysis of structural carbonate of molar tooth enamel (δ(13)C enamel and δ(18)O enamel). Mochica camelids were bred in the low and/or middle valleys, unlike their modern counterparts, who are restricted to highland puna C3 pastures. Archaeological camelids had diverse and complex life histories, usually with substantial maize foddering. An ontogenetic switch in diet and possible residential mobility during the course of life were identified for some specimens. Although the inference of geographic origin from δ(18)O bone and δ(18)O enamel values was limited because of the lack of understanding of the influence of environmental and biological factors, tooth enamel analysis has great potential for exploring camelid herding practices and Andean pastoralism. Our study suggested that Mochica herders adapted their practices to the difficult lowland environment and that herding practices were varied and not restricted to breeding at higher altitudes. The role of maize in different aspects of the economic life

  2. In-soil radon anomalies as precursors of earthquakes: a case study in the SE slope of Mt. Etna in a period of quite stable weather conditions

    International Nuclear Information System (INIS)

    Vizzini, Fabio; Brai, Maria

    2012-01-01

    In-soil radon concentrations as well as climatic parameters (temperature, atmospheric pressure and relative humidity) were collected in St. Venerina (Eastern Sicily – Italy) from March 19th to May 22nd 2009, close to an active fault system called Timpe Fault System (TFS), which is strictly linked to the geodynamics of Mt. Etna. During the monitoring period no drastic climatic variations were observed and, on the other hand, important seismic events were recorded close to the monitoring site. A seismic swarm composed of 5 earthquakes was observed in the Milo area on March 25th (M max = 2.7) at just 5.1 km from the site, and on May 13th an earthquake of 3.6 magnitude was recorded in the territory of St. Venerina, at just 3.2 km from the site; the earthquake was felt by the population and reported by all local and regional media. The in-soil radon concentrations have shown anomalous increases possibly linked to the earthquakes recorded, but certainly not attributable to local meteorology. To verify this assumption the average radon concentration and the standard deviation (σ) have been calculated and the regions of ±1.5σ and ±2σ deviation from the average concentration have been investigated. Moreover, to further minimise the contribution of the meteorological parameters on the in-soil radon fluctuations, a multiple regressions method has been used. To distinguish those earthquakes which could generate in-soil radon anomalies as precursors, the Dobrovolsky radius has been applied. The results obtained suggests that a clear correlation between earthquakes and in-soil radon increases exist, and that the detection of the in-soil radon anomalies becomes surely simpler in particular favourable conditions: weather stability, earthquakes within the Dobrovolsky radius and close to the monitoring area. Moreover, the absence of large variations of the climatic parameters, which could generate incoherent noise components to the radon signal, has made the radon

  3. In-soil radon anomalies as precursors of earthquakes: a case study in the SE slope of Mt. Etna in a period of quite stable weather conditions.

    Science.gov (United States)

    Vizzini, Fabio; Brai, Maria

    2012-11-01

    In-soil radon concentrations as well as climatic parameters (temperature, atmospheric pressure and relative humidity) were collected in St. Venerina (Eastern Sicily - Italy) from March 19th to May 22nd 2009, close to an active fault system called Timpe Fault System (TFS), which is strictly linked to the geodynamics of Mt. Etna. During the monitoring period no drastic climatic variations were observed and, on the other hand, important seismic events were recorded close to the monitoring site. A seismic swarm composed of 5 earthquakes was observed in the Milo area on March 25th (M(max) = 2.7) at just 5.1 km from the site, and on May 13th an earthquake of 3.6 magnitude was recorded in the territory of St. Venerina, at just 3.2 km from the site; the earthquake was felt by the population and reported by all local and regional media. The in-soil radon concentrations have shown anomalous increases possibly linked to the earthquakes recorded, but certainly not attributable to local meteorology. To verify this assumption the average radon concentration and the standard deviation (σ) have been calculated and the regions of ±1.5σ and ±2σ deviation from the average concentration have been investigated. Moreover, to further minimise the contribution of the meteorological parameters on the in-soil radon fluctuations, a multiple regressions method has been used. To distinguish those earthquakes which could generate in-soil radon anomalies as precursors, the Dobrovolsky radius has been applied. The results obtained suggests that a clear correlation between earthquakes and in-soil radon increases exist, and that the detection of the in-soil radon anomalies becomes surely simpler in particular favourable conditions: weather stability, earthquakes within the Dobrovolsky radius and close to the monitoring area. Moreover, the absence of large variations of the climatic parameters, which could generate incoherent noise components to the radon signal, has made the radon fluctuations

  4. Pastoralism in northern Peru during pre-Hispanic times: insights from the Mochica Period (100-800 AD based on stable isotopic analysis of domestic camelids.

    Directory of Open Access Journals (Sweden)

    Elise Dufour

    Full Text Available Llama (Lama glama and alpaca (Vicugna pacos are the only large domesticated animals indigenous to the Americas. Pastoralism occupies a fundamental economic, social and religious role in Andean life. Today, camelid livestock are confined to the ecozone of the puna (above 3,500 masl, while their presence on the Pacific coast during pre-Hispanic times is attested by archaeological skeletal remains. This study aims to document herding practices on the northern Peruvian coast during the Early Intermediate Period (200 BC-600 AD by gaining insights into diet, location of breeding and mobility of archaeological camelids from the funerary and ritual contexts of two Mochica sites, Uhle Platform in Huacas de Moche and El Brujo. The three first early years and the long-term life histories of the animals were documented by the combined bulk analysis of bone collagen (δ(13C col and δ(15N col and bone structural carbonate (δ(13C bone and δ(18O bone and the serial analysis of structural carbonate of molar tooth enamel (δ(13C enamel and δ(18O enamel. Mochica camelids were bred in the low and/or middle valleys, unlike their modern counterparts, who are restricted to highland puna C3 pastures. Archaeological camelids had diverse and complex life histories, usually with substantial maize foddering. An ontogenetic switch in diet and possible residential mobility during the course of life were identified for some specimens. Although the inference of geographic origin from δ(18O bone and δ(18O enamel values was limited because of the lack of understanding of the influence of environmental and biological factors, tooth enamel analysis has great potential for exploring camelid herding practices and Andean pastoralism. Our study suggested that Mochica herders adapted their practices to the difficult lowland environment and that herding practices were varied and not restricted to breeding at higher altitudes. The role of maize in different aspects of the economic

  5. Intermittent behavior of the logistic system

    Science.gov (United States)

    Mayer-Kress, G.; Haken, H.

    1981-03-01

    In the discrete logistic model a transition to chaotic behavior via intermittency occurs in a neighborhood of periodic bands. Intermittent behavior is also induced if a stable periodic orbit is perturbed by low-level external noise, whereas alterations due to computer digitalisation produce remarkable periodicities. We compare our numerical results with the predictions of Pomeau and Manneville for the Lorenz system.

  6. Statistic analysis of grouping in evaluation of the behavior of stable chemical elements and physical-chemical parameters in effluent from uranium mining

    International Nuclear Information System (INIS)

    Pereira, Wagner de S.

    2013-01-01

    The Ore Treatment Unit (UTM) is a uranium mine off. The statistical analysis of clustering was used to evaluate the behavior of stable chemical elements and physico-chemical variables in their effluents. The use of cluster analysis proved effective in the evaluation, allowing to identify groups of chemical elements in physico-chemical variables and group analyzes (element and variables ). As a result, we can say, based on the analysis of the data, a strong link between Ca and Mg and between Al and TR 2 O 3 (rare earth oxides) in the UTM effluents. The SO 4 was also identified as strongly linked to total solids and dissolved and these linked to electrical conductivity. Other associations existed, but were not as strongly linked. Additional collections for seasonal evaluation are required so that assessments can be confirmed. Additional statistics analysis (ordination techniques) should be used to help identify the origins of the groups identified in this analysis. (author)

  7. A study of the behavior of labor industrial productivity in the regions of Brazil during the period 1996 to 2010

    Directory of Open Access Journals (Sweden)

    Edileuza Vital Galeano

    2013-12-01

    Full Text Available The objective of this paper is to present an empirical study of the behavior of labor industrial productivity in the regions of Brazil during the period 1996 to 2010 by groups of technology intensity. It was used the shift-share method. The results indicated that in the groups of sectors that showed positive growth rates were the competitive advantages inherent to each region that explained, in most cases, the growth of labor productivity. There was predominance of technology absorbing sectors in prejudice of sectors that generate technological spillovers. The growth of labor productivity in the extractive industry showed a upward trend, while the manufacturing industry showed downward trend, evidencing a stagnation of labor productivity at the national level. There are evidences of a reprimarization process of industrial activities through the specialization in commodities.

  8. Variations of Geomagnetic Cosmic Ray Thresholds and Their Latitudinal Behavior in the Period of Solar Disturbance in September 2005

    Science.gov (United States)

    Tyasto, M. I.; Danilova, O. A.; Sdobnov, V. E.

    2018-01-01

    The period of interplanetary, geomagnetic and solar disturbances of September 7-15, 2005, is characterized by two sharp increases of solar wind velocity to 1000 km/s and great Dst variation of the geomagnetic field ( 140 nT). The time variations of theoretical and experimental geomagnetic thresholds observed during this strong geomagnetic storm, their connection with solar wind parameters and the Dst index, and the features of latitudinal behavior of geomagnetic thresholds at particular times of the storm were studied. The theoretical geomagnetic thresholds were calculated with cosmic ray particle tracing in the magnetic field of the disturbed magnetosphere described by Ts01 model. The experimental geomagnetic thresholds were specified by spectrographic global survey according to the data of cosmic ray registration by the global station network.

  9. Adsorption Behavior of High Stable Zr-Based MOFs for the Removal of Acid Organic Dye from Water

    Directory of Open Access Journals (Sweden)

    Ke-Deng Zhang

    2017-02-01

    Full Text Available Zirconium based metal organic frameworks (Zr-MOFs have become popular in engineering studies due to their high mechanical stability, thermostability and chemical stability. In our work, by using a theoretical kinetic adsorption isotherm, we can exert MOFs to an acid dye adsorption process, experimentally exploring the adsorption of MOFs, their external behavior and internal mechanism. The results indicate their spontaneous and endothermic nature, and the maximum adsorption capacity of this material for acid orange 7 (AO7 could be up to 358 mg·g−1 at 318 K, estimated by the Langmuir isotherm model. This is ascribed to the presence of an open active metal site that significantly intensified the adsorption, by majorly increasing the interaction strength with the adsorbates. Additionally, the enhanced π delocalization and suitable pore size of UiO-66 gave rise to the highest host–guest interaction, which further improves both the adsorption capacity and separation selectivity at low concentrations. Furthermore, the stability of UiO-66 was actually verified for the first time, through comparing the structure of the samples before and after adsorption mainly by Powder X-ray diffraction and thermal gravimetric analysis.

  10. PERIOD2 Variants Are Associated with Abdominal Obesity, Psycho-Behavioral Factors, and Attrition in the Dietary Treatment of Obesity

    Science.gov (United States)

    GARAULET, MARTA; CORBALÁN-TUTAU, M. DOLORES; MADRID, JUAN A.; BARAZA, JUAN C.; PARNELL, LAURENCE D.; LEE, YU-CHI; ORDOVAS, JOSE M.

    2015-01-01

    The purpose of this research was to test for association between polymorphisms in the circadian clock–related gene PERIOD2 (PER2) and attrition in patients prone to withdrawal from a behavioral weight-reduction program based on the Mediterranean diet. A total of 454 overweight/obese participants (women=380, men=74), aged 20 to 65 years, who attended outpatient clinics specializing in obesity between January and December 2008, were studied. Anthropometric, biochemical, and dietary-intake variables were analyzed. Effectiveness of the program was assessed, and a questionnaire of barriers to weight loss was considered. Multivariate analysis and logistic regression models were performed. Results indicate that PER2 polymorphisms rs2304672C>G and rs4663302C>T were associated with abdominal obesity (Pdieting than those who completed treatment. Frequency of rs4663307 minor allele was significantly greater in withdrawers than in those who successfully completed treatment (PG minor allele carriers had a greater probability of dropping out, displaying extreme snacking, experiencing stress with dieting, eating when bored, and skipping breakfast than noncarriers. PER2 is implicated in attrition in weight-loss treatment and may modulate eating-behavior–related phenotypes. These findings could represent a step toward personalized health care and nutrition based on a combination of genotyping and psycho-behavioral characterization. PMID:20497782

  11. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  12. Comparison of SAFER behavior assessment results in shelter dogs at intake and after a 3-day acclimation period.

    Science.gov (United States)

    Bennett, Sara L; Weng, Hsin-Yi; Walker, Sheryl L; Placer, Margaret; Litster, Annette

    2015-01-01

    In this study, it was hypothesized that different results would be obtained by canine behavior assessments performed within 24 hr of shelter intake (Day 0) and after a 3-day acclimation period (Day 3). Safety Assessment for Evaluating Rehoming assessments were performed on 33 dogs at 2 municipal shelters. Agreements between Day 0 and Day 3 varied among subtests, and no consistent temporal patterns were observed. Weighted kappa statistics for each subtest ranged from .28 to .78, and percentage discordance was 0% to 18%. In a 2nd analysis, subtests skipped due to serious aggression were replaced with scores corresponding to serious aggression, and missing values for the Food subtest were replaced with scores for no aggression if the dog did not eat. For subtests skipped due to severe aggression, more than 50% of the dogs had scores indicating low aggression on the other assessment. Eight of 16 dogs who did not eat on Day 0 ate on Day 3; 2 showed aggression. Until the ideal time to test can be identified, it should be based on the individual dog's welfare status, and testing of dogs showing severe stress should be avoided.

  13. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  14. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  15. Emotional-Behavioral Resilience among Children of First-Time Mothers with and without Depression across the Early Childhood Period

    Science.gov (United States)

    Giallo, Rebecca; Gartland, Deirdre; Woolhouse, Hannah; Mensah, Fiona; Westrupp, Elizabeth; Nicholson, Jan; Brown, Stephanie

    2018-01-01

    The deleterious effects of maternal depression on child emotional and behavioral development are well documented, yet many children exposed to maternal depression experience positive outcomes. The aim of this study was to identify psychosocial factors associated with the emotional-behavioral resilience of four-year-old children of first-time…

  16. A Study of Information-Seeking Behaviors and Processes of New Zealand Men during Periods of Life-Stress

    Science.gov (United States)

    Wellstead, Peta

    2014-01-01

    New Zealand men have poor health outcomes in a range of domains compared to women. They also report barriers (both personal and structural) in their information-seeking behaviors and processes to improve health and wellbeing. This paper reports a research project in progress that is investigating the information-seeking behaviors and processes of…

  17. Demographic predictors of consistency and change in heterosexuals' attitudes toward homosexual behavior over a two-year period.

    Science.gov (United States)

    Patrick, Kent; Heywood, Wendy; Simpson, Judy M; Pitts, Marian K; Richters, Juliet; Shelley, Julia M; Smith, Anthony M

    2013-01-01

    This study investigated demographic predictors of consistency and change in heterosexual people's attitudes toward homosexual behavior. A nationally representative sample of Australian men and women were recruited via random digit dialling in 2004 through 2005. Participants completed annual computer-assisted telephone interviews over the next five years. Questions about attitudes toward male and female homosexual behavior were assessed at Wave 1 (2004-2005) and Wave 3 (2006-2007) of the study. The majority of the sample reported tolerance of both male and female homosexual behavior (with women slightly more tolerant than men). Multivariate analyses showed that those who regularly attended religious services were more likely to consistently disapprove of homosexual behavior and more likely to change from tolerant to disapproving. Among those who were initially tolerant, younger respondents and those with higher educations were less likely to become homophobic. The results of this study show that individual attitudes toward homosexual behavior are open to change, particularly toward a more tolerant position. Religiosity appears to be consistently associated with the development and reinforcement of homophobic tendencies.

  18. Collision of invariant bundles of quasi-periodic attractors in the dissipative standard map.

    Science.gov (United States)

    Calleja, Renato; Figueras, Jordi-Lluís

    2012-09-01

    We perform a numerical study of the breakdown of hyperbolicity of quasi-periodic attractors in the dissipative standard map. In this study, we compute the quasi-periodic attractors together with their stable and tangent bundles. We observe that the loss of normal hyperbolicity comes from the collision of the stable and tangent bundles of the quasi-periodic attractor. We provide numerical evidence that, close to the breakdown, the angle between the invariant bundles has a linear behavior with respect to the perturbing parameter. This linear behavior agrees with the universal asymptotics of the general framework of breakdown of hyperbolic quasi-periodic tori in skew product systems.

  19. Practical Physical and Behavioral Measures to Assess the Socialization Spectrum of Cats in a Shelter-Like Setting during a Three Day Period

    Directory of Open Access Journals (Sweden)

    Margaret Slater

    2013-12-01

    Full Text Available Animal welfare organizations routinely accept large numbers of cats with unknown histories, and whose backgrounds vary from well-socialized pets to cats that have had little or no contact with humans. Agencies are challenged with making the determination of socialization level in a highly stressful environment where cats are often too frightened to show typical behaviors. A variety of structured behavioral assessments were conducted in a shelter-like environment, from intake through a three day holding period, on cats from the full range of socialization as reported by their caregivers. Our results show that certain behaviors such as rubbing, playing, chirping, having the tail up or being at the front of the cage were found to be unique to More Socialized cats. While not all more socialized cats showed these behaviors, cats that did were socialized. Assessing the cats throughout the three day period was beneficial in eliciting key behaviors from shyer and more frightened cats. These results will be used in future work to develop an assessment tool to identify the socialization status of cats as a standardized guide for transparent and reliable disposition decisions and higher live release rates for cats in animal shelters.

  20. Respiratory Sinus Arrhythmia and Heart Period in Infancy as Correlates of Later Oppositional Defiant and Callous-Unemotional Behaviors

    Science.gov (United States)

    Wagner, Nicholas; Mills-Koonce, Roger; Willoughby, Michael; Propper, Cathi; Rehder, Peter; Gueron-Sela, Noa

    2017-01-01

    Extant literature suggests that oppositional defiant disorder (ODD) and callous-unemotional (CU) behaviors in childhood and adolescence are associated with distinct patterns of psychophysiological functioning, and that individual differences in these patterns have implications for developmental pathways to disorder. Very little is known about the…

  1. Changes of loggerhead turtle (Caretta caretta) dive behavior associated with tropical storm passage during the inter-nesting period

    DEFF Research Database (Denmark)

    Wilson, Maria; Tucker, Anton D.; Beedholm, Kristian

    2017-01-01

    turtles in the Gulf of Mexico, which regularly has hurricanes and tropical storms during nesting season. We contrast the behavioral patterns and swimming energetics of these two turtles, the first tracked in calm weather and the second tracked before, during and after a tropical storm. Turtle 1 was highly...

  2. Physical and Behavioral Measures that Predict Cats’ Socialization in an Animal Shelter Environment during a Three Day Period

    Directory of Open Access Journals (Sweden)

    Margaret Slater

    2013-12-01

    Full Text Available Animal welfare organizations typically take in cats with unknown levels of socialization towards humans, ranging from unsocialized cats well-socialized but lost pets. Agencies typically determine the socialization status and disposition options of cats within three days, when even a well-socialized pet may be too frightened of the unfamiliar surroundings to display its typical behavior. This is the third part of a three-phase project to develop and evaluate a reliable and valid tool to predict cats’ socialization levels. We recruited cats from the full spectrum of socialization and, using information from the cats’ caregivers regarding typical behavior toward familiar and unfamiliar people, assigned each cat to a Socialization Category. This information was compared to the cats’ behavior during three days of structured assessments conducted in a shelter-like setting. The results of logistic regression modeling generated two models using assessments from the mornings of the second and third day, focusing on predicting shyer or more aloof but socialized cats. Using the coefficients from each of these models, two sets of points were calculated which were useful in differentiating More and Less Socialized cats. In combination with key socialized behaviors, these points were able to fairly accurately identify More and Less Socialized cats.

  3. Sexual and contraceptive behavior among female university students in Sweden - repeated surveys over a 25-year period.

    Science.gov (United States)

    Stenhammar, Christina; Ehrsson, Ylva Tiblom; Åkerud, Helena; Larsson, Margareta; Tydén, Tanja

    2015-03-01

    To study female students' sexual and contraceptive behavior and compare these results with earlier surveys. Comparative, repeated cross-sectional surveys, started in 1989 and repeated every fifth year. Contraceptive counseling delivered at a Student Health Center in Sweden. Female university students (n = 359). Multiple-choice waiting-room questionnaire. Sexual and contraceptive behavior. In 1989, age at first intercourse was 17.6 years vs. 16.7 years in 2014, number of lifetime sexual partners was 4.0 vs. 12.1 in 2014, and number of sexual partners during the previous 12 months was 1.0 vs. 2.8 in 2014. Condom use during first intercourse with the latest partner decreased from 49% to 41% (n = 172 in 2009 vs. n = 148 in 2014: p used a condom during anal sex. A total of 70% (n = 251) made use of pornography, and 48% (n = 121) considered their sexual behavior affected by pornography. Eighty-nine percent (n = 291) wanted two to three children and 9% (n = 33) had thought about freezing eggs for the future. The female students' knowledge about increasing age being correlated with decreased fertility varied. Sexual behavior among female university students has gradually changed during the last 25 years and behavior appears more risky today. As this may have consequences on future reproductive health, it is vital to inform women about consistent and correct condom use and about the limitations of the fertile window. © 2015 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).

  4. The behavior of matter under nonequilibrium conditions: Fundamental aspects and applications. Progress Report for period April 15, 1990 - April 14, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Prigogine, I.

    1990-12-01

    Our report contains a brief summary of what has been achieved over the period of the contract. We have studied the behavior of matter under equilibrium conditions on three levels: (1) on the microscopic level in the frame of classical mechanics or of quantum theory; (2) on the stochastic level, which includes fluctuations; and (3) on the phenomenological, macroscopic level described by nonlinear equations. We first report on the level (1), then report on the levels (2) and (3).

  5. Hypothyroidism during neonatal and perinatal period induced by thyroidectomy of the mother causes depressive-like behavior in prepubertal rats

    OpenAIRE

    Ortiz-Butron, Rocio

    2010-01-01

    Marisol Pineda-Reynoso, Edgar Cano-Europa, Vanessa Blas-Valdivia, Adelaida Hernandez-Garcia, Margarita Franco-Colin, Rocio Ortiz-ButronDepartamento de Fisiología ‘Mauricio Russek Berman,’ Escuela Nacional de Ciencias Biológicas, IPN, Carpio y Plan de Ayala, MéxicoAbstract: The objective of this study was to see if neonatal and perinatal hypothyroidism caused anxiety and depressive-like behaviors. Twenty female Wistar rats were randomly divi...

  6. Hypothyroidism during neonatal and perinatal period induced by thyroidectomy of the mother causes depressive-like behavior in prepubertal rats

    Directory of Open Access Journals (Sweden)

    Marisol Pineda-Reynoso

    2010-04-01

    Full Text Available Marisol Pineda-Reynoso, Edgar Cano-Europa, Vanessa Blas-Valdivia, Adelaida Hernandez-Garcia, Margarita Franco-Colin, Rocio Ortiz-ButronDepartamento de Fisiología ‘Mauricio Russek Berman,’ Escuela Nacional de Ciencias Biológicas, IPN, Carpio y Plan de Ayala, MéxicoAbstract: The objective of this study was to see if neonatal and perinatal hypothyroidism caused anxiety and depressive-like behaviors. Twenty female Wistar rats were randomly divided into two groups: 1 thyroidectomy caused hypothyroidism, in which the thyroid gland had been removed and the parathyroid reimplanted; and 2 false thyroidectomy. The thyroidectomy was made on rats anesthetized with ketamine-xylazine. The rats were mated and one day after giving birth, eight pups were assigned to each group randomly and they were distributed into two groups: a hypothyroid group containing male pups of a hypothyroid mother with a hypothyroid wet nurse; and a euthyroid group of male pups of a euthyroid mother with a euthyroid wet nurse. We analyzed the behavioral test at a prepubertal age. The neonatal and perinatal hypothyroidism caused by the mother’s thyroidectomy caused a decrease in body weight and length. We found that the neonatal and perinatal hypothyroidism enhanced the total exploratory activity without affecting social contact and the time spent in the open and closed arms in an elevated plus-maze. The hypothyroidism caused immobility without altering the lower climbing duration in the swimming test. This study shows a novel model to cause neonatal and perinatal hypothyroidism without using pharmacological drugs. We demonstrated that hypothyroid animals had a reduction in body weight and length, a retardation of neurodevelopment, and they had depressive-like behavior.Keywords: perinatal hypothyroidism, thyroidectomy, thyroid hormone, behavior, metabolism

  7. Effect of Static Load Hold Periods on the Corrosion Fatigue Behavior of Austenitic Stainless Steels in Simulated BWR Environments

    Science.gov (United States)

    Seifert, H. P.; Ritter, S.; Leber, H.

    The effect of static load hold times of 6 to 744 h on corrosion fatigue life of low- and highcarbon and stabilized austenitic stainless steels was investigated with both sharply notched and pre-cracked fracture mechanics specimens in simulated boiling water reactor (BWR) hydrogen (HWC) and normal water chemistry (NWC) at 288 °C. With regard to continuous cyclic saw tooth loading with a load ratio R close to zero in HWC environment, an increase of the genuine corrosion fatigue initiation life was observed with increasing static load hold periods at maximum or mean load of the applied load range, which seemed to saturate for long hold periods above 12 to 24 h. On the other hand, static hold periods at minimum load, where potential microcracks are closed, had no effect on genuine fatigue initiation life. Furthermore, the static load hold times had very little effect on the subsequent stationary short corrosion fatigue crack growth rates. Static hold times of up to 744 h had no effect on the corrosion fatigue crack growth rates in pre-cracked solution annealed stainless steel specimens in NWC and HWC environment. No significant effect of static load hold times on the technical corrosion fatigue initiation life are thus expected based on these preliminary results and the current US NRC regulatory guide 1.207 seems to be adequate from this point of view. A credit for a mitigating effect of long static load hold periods in the field cannot be derived from this work.

  8. Application of Behavioral Analysis Phase of PRECEDE Model on Women’s Psychological Well-being in the Menopausal Period

    Directory of Open Access Journals (Sweden)

    Mahdi Moshki

    2015-08-01

    Full Text Available Background and Aims Positive psychology introduce mental health as a positive psychological functioning and represent it as wellbeing psychology and having positive characteristics such as self-esteem, positive social relationships, and life satisfaction. The purpose of this study was to investigate the psychological wellbeing of postmenopausal women based on the behavioral analysis phase of PRECEDE model. Materials and Methods This study is a cross-sectional survey and carried out through random sampling in the case of 110 postmenopausal women at Ferdows city, Iran in 2014. The psychological wellbeing variable was studied by Ryff test, including 84 questions and six components containing autonomy, purposeful in life, dominance on environment, personal development, positive relationships with others, and self-acceptance. The collected data were analyzed by SPSS v.20 using descriptive statistics and analytic statistics through correlation and ANOVA. Results The mean age of participants and the average number of their children were 51.62 ± 4.26 and 3.42 ± 1.38, respectively. 61.80 percent of participants had primary education. Pearson correlation test indicated a positive and significant relationship between psychological wellbeing and predisposing factors (knowledge, attitude toward menopause, environmentalbehavioral factors, enabling factors and reinforcing factors (P < 0.01. Conclusion The results indicated that increasing awareness, creating positive attitude and promoting healthy behaviors are the effective steps to improve the psychological wellbeing in postmenopausal women. * Corresponding Author: Gonabad University of Medical Sciences, Faculty of Public Health. Email: Fpf357@gmail.com

  9. [Suicide and suicidal behavior among asylum seekers in Denmark during the period 2001-2003. A retrospective study].

    Science.gov (United States)

    Staehr, Mia Antoni; Munk-Andersen, Ebbe

    2006-04-24

    Our aim was to examine suicidal behaviours among asylum seekers in Denmark. A retrospective quantitative analysis of data from reports to the Danish Red Cross Asylum Department on suicidal behaviours among persons over 15 years of age in the period 2001-2003 and from 54 medical records of suicidal asylum seekers in Denmark in 2001 was carried out. The number of suicide attempts by asylum seekers in 2001 was 3.4 times higher than by Danish residents. Furthermore, the rate of suicide attempts by asylum seekers grew in the following two years. Suicidal behaviours are most frequent among asylum seekers between 30 and 39 years of age. There are national differences. The preferred method of suicide attempt is intake of medicine. Stress-related diagnoses constitute three fourths of all diagnoses. One analysis suggests that the long waiting time (average 20.8 months) faced by asylum seekers combined with rejection of asylum cases may trigger a rapid suicidal reaction. Other factors may also be active, as 44% of suicide attempts occur within six months after arrival in the country. The results are discussed in relation to other research on the vulnerability of refugees, immigrants and asylum seekers and also in relation to length of waiting time, growing mental morbidity and the increasing number of rejections of asylum applications during recent years, a period characterized by a reduction of staff at the asylum centers. It is recommended that prevention of suicidal behaviour shall be given higher legal and administrative priority.

  10. Emerging Adulthood: Developmental Period Facilitative of the Addictions.

    Science.gov (United States)

    Sussman, Steve; Arnett, Jeffrey Jensen

    2014-06-01

    Following adolescence and prior to young adulthood is a life developmental period that has been referred to as "emerging adulthood." This period of life involves an extended duration of learning and experimentation before settling into a career and stable relationship. Risky behaviors may be most tolerated or even promoted during emerging adulthood. Various substance and behavioral addictions are most likely to be realized during this period. Understanding what differentiates emerging adults that develop or do not develop full-blown addictions will assist in the creation of more efficacious prevention and cessation programs. © The Author(s) 2014.

  11. Sensitive Period for the Recovery of the Response Rate of the Wind-Evoked Escape Behavior of Unilaterally Cercus-Ablated Crickets (Gryllus bimaculatus).

    Science.gov (United States)

    Takuwa, Hiroyuki; Kanou, Masamichi

    2015-04-01

    We examined the compensational recovery of the response rate (relative occurrence) of the wind-evoked escape behavior in unilaterally cercus-ablated crickets (Gryllus bimaculatus) and elucidated the existence of a sensitive period for such recovery by rearing the crickets under different conditions. In one experiment, each cricket was reared in an apparatus called a walking inducer (WI) to increase the sensory input to the remaining cercus, i.e., the self-generated wind caused by walking. In another experiment, each cricket was reared in a small plastic case separate from the outside atmosphere (wind-free: WF). In this rearing condition, the cricket did not experience self-generated wind as walking was prohibited. During the recovery period after the unilateral cercus ablation, the crickets were reared under either the WI or WF condition to investigate the role of the sensory inputs on the compensational recovery of the response rate. The compensational recovery of the response rate occurred only in the crickets reared under the WI condition during the early period after the ablation. In particular, WI rearing during the first three days after the ablation resulted in the largest compensational recovery in the response rate. In contrast, no compensational recovery was observed in the crickets reared under the WF condition during the first three days. These results suggest that a sensitive period exists in which sensory inputs from the remaining cercus affect the compensational recovery of the response rate more effectively than during other periods.

  12. Study of REE behaviors, fluid inclusions, and O, S stable Isotopes in Zafar-abad iron skarn deposit, NW Divandarreh, Kordestan province

    Directory of Open Access Journals (Sweden)

    Mehrdad Barati

    2014-10-01

    Full Text Available Introduction The Zafar-abad iron ore deposit, situated in the NW part of Divandarreh (lat. 36°01'14" and long. 46°58'22". The ore body is located on the northern margin of the Sanandaj-Sirjan igneous metamorphic zone. The Zafar-abad Fe-skarn deposit is one of the important, medium- size mineral deposits in western Iran. REE patterns of skarn magnetite were among others studied in Skarn deposit by (Taylor, 1979 Hydrothermal alteration and fluid-rock interaction significantly affect total contents of REE and their patterns in fluids. Moreover, fractionation of REE by chemical complication, adsorption effects and redox reactions are characteristic processes determining REE behavior during crystallization. Stable isotope data for oxygen and sulfur have been widely used with great success to trace the origin and evolution history of paleo-hydrothermal fluids of meteoric, magmatic, and metamorphic. Materials and methods The present study investigates REE and stable Isotope geochemistry of magnetite and pyrite in Zafar-abad deposit and temperature of trapped fluid inclusions based on geothermometry analysis. In order to study the major, trace and REE compositions of Zafar-abad magnetite, twelve samples were collected from surface of ore exposures. The emphasis during sampling was on ores with primary textures. Discussion The Zafar-abad district is situated in Mesozoic and Cenozoic sedimentary, meta-sedimentary and meta-igneous rocks in Sanandaj-Sirjan igneous metamorphic zone. Sedimentary sequences dominantly composed of calcareous and conglomerate rocks. Various meta-sedimentary rocks are intercalated with the sedimentary rocks, and comprise biotite and muscovite-rich schist, calc-schist, calc-silicate rock. Several distinct ductile tectonic fabrics have been identified around the Zafar-abad deposit. The main ore body at Zafar-abad is in the form of a roughly horizontal, discordant, lens to tabular-shaped body plunging 10° NW, where it appears to

  13. Contribution of nucleus accumbens core (AcbC to behavior control during a learned resting period: introduction of a novel task and lesion experiments.

    Directory of Open Access Journals (Sweden)

    Chika Sato

    Full Text Available In recent years, the study of resting state neural activity has received much attention. To better understand the roles of different brain regions in the regulation of behavioral activity in an arousing or a resting period, we developed a novel behavioral paradigm (8-arm food-foraging task; 8-arm FFT using the radial 8-arm maze and examined how AcbC lesions affect behavioral execution and learning. Repetitive training on the 8-arm FFT facilitated motivation of normal rats to run quickly to the arm tips and to the center platform before the last-reward collection. Importantly, just after this point and before confirmation of no reward at the next arm traverse, locomotor activity decreased. This indicates that well-trained rats can predict the absence of the reward at the end of food seeking and then start another behavior, namely planned resting. Lesions of the AcbC after training selectively impaired this reduction of locomotor activity after the last-reward collection without changing activity levels before the last-reward collection. Analysis of arm-selection patterns in the lesioned animals suggests little influence of the lesion in the ability to predict the reward absence. AcbC lesions did not change exploratory locomotor activity in an open-field test in which there were no rewards. This suggests that the AcbC controls the activity level of planned resting behavior shaped by the 8-arm FFT. Rats receiving training after AcbC lesioning showed a reduction in motivation for reward seeking. Thus, the AcbC also plays important roles not only in controlling the activity level after the last-reward collection but also in motivational learning for setting the activity level of reward-seeking behavior.

  14. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  15. Bird Risk Behaviors and Fatalities at the Altamont Pass Wind Resource Area: Period of Performance, March 1998--December 2000

    Energy Technology Data Exchange (ETDEWEB)

    Thelander, C. G.; Smallwood, K. S.; Rugge, L.

    2003-12-01

    It has been documented that wind turbine operations at the Altamont Pass Wind Resource Area kill large numbers of birds of multiple species, including raptors. We initiated a study that integrates research on bird behaviors, raptor prey availability, turbine design, inter-turbine distribution, landscape attributes, and range management practices to explain the variation in avian mortality at two levels of analysis: the turbine and the string of turbines. We found that inter-specific differences in intensities of use of airspace within close proximity did not explain the variation in mortality among species. Unique suites of attributes relate to mortality of each species, so species-specific analyses are required to understand the factors that underlie turbine-caused fatalities. We found that golden eagles are killed by turbines located in the canyons and that rock piles produced during preparation of the wind tower laydown areas related positively to eagle mortality, perhaps due to the use of these rock piles as cover by desert cottontails. Other similar relationships between fatalities and environmental factors are identified and discussed. The tasks remaining to complete the project are summarized.

  16. Introducing fecal stable isotope analysis in primate weaning studies.

    Science.gov (United States)

    Reitsema, Laurie J

    2012-10-01

    This research investigates the potential of a new, noninvasive method for determining age of weaning among primates using stable carbon and nitrogen isotope ratios in feces. Analysis of stable isotope ratios in body tissues is a well-established method in archeology and ecology for reconstructing diet. This is the first study to investigate weaning in primates using fecal stable isotope ratios. Diets of a single François' langur (Trachypithecus francoisi) mother-infant pair at the Toledo Zoo are reconstructed using this technique to track changes in infant suckling behavior over the weaning period. Stable isotope ratios in feces are sampled instead of more traditional samples such as bone or hair to enable daily, noninvasive snapshots of weaning status. Isotopic assessments of weaning status are compared to visual assessments to identify any discordance between the two. Three measurements documented the transition from breast milk to solid foods: stable carbon isotope ratios (δ(13)C), stable nitrogen isotope ratios (δ(15)N), and nitrogen content of feces (%N). It appears that solid foods were introduced at approximately 2 months of infant age, but that nursing continued into the 12th month, when sample collection ceased. Stable isotope data exposed a much longer weaning period than what was expected based on previously published data for captive langurs, and clarified visual estimates of weaning status. This reflects the method's sensitivity to suckling at night and ability to distinguish actual nursing from comfort nursing. After testing this method with zoo animals, it can readily be applied among wild populations. An isotopic approach to weaning provides a new, accurate, and biologically meaningful assessment of interbirth intervals, and facilitates a better understanding of mother-infant interactions. Both of these outcomes are critical for developing successful conservation strategies for captive and wild primates. © 2012 Wiley Periodicals, Inc.

  17. Perceptions and behaviors related to hand hygiene for the prevention of H1N1 influenza transmission among Korean university students during the peak pandemic period

    Directory of Open Access Journals (Sweden)

    Kim Seon-Ung

    2010-07-01

    Full Text Available Abstract Background This study was performed to better assess the perceptions, motivating factors, and behaviors associated with the use of hand washing to prevent H1N1 influenza transmission during the peak pandemic period in Korea. Methods A cross-sectional survey questionnaire was completed by 942 students at a university campus in Suwon, Korea, between December 1 and 8, 2009. The survey included questions regarding individual perceptions, motivating factors, and behaviors associated with hand washing for the prevention of H1N1 influenza transmission. Results Compared to one year prior, 30.3% of participants reported increasing their hand washing frequency. Female students were more likely to practice more frequent hand washing. Women also perceived the effectiveness of hand washing to be lower, and illness severity and personal susceptibility to H1N1 infection to be higher. Study participants who were female (OR: 1.79-3.90 who perceived of hand washing to be effective (OR: 1.34-12.15 and illness severity to be greater (OR: 1.00-3.12 washed their hands more frequently. Conclusions Korean students increased their frequency of hand hygiene practices during the pandemic, with significant gender differences existing in the attitudes and behaviors related to the use of hand hygiene as a means of disease prevention. Here, the factors that affected hand washing behavior were similar to those identified at the beginning of the H1N1 or SARS pandemics, suggesting that public education campaigns regarding hand hygiene are effective in altering individual hand hygiene habits during the peak periods of influenza transmission.

  18. The Effect of Centering Pregnancy versus Traditional Prenatal Care Models on Improved Adolescent Health Behaviors in the Perinatal Period.

    Science.gov (United States)

    Trotman, Gylynthia; Chhatre, Gayatri; Darolia, Renuka; Tefera, Eshetu; Damle, Lauren; Gomez-Lobo, Veronica

    2015-10-01

    To determine if the CenteringPregnancy model of prenatal care improves maternal health behaviors in adolescent pregnancy. We conducted a retrospective chart review comparing 150 pregnant adolescents who received prenatal care between 2008 to 2012 with CenteringPregnancy to those receiving care in traditional prenatal care models with either multiprovider or single-provider visits. Outcome measures included weight gain during pregnancy, compliance to prenatal care appointments, infant feeding method, postpartum follow up and contraceptive use postpartum. A χ(2) analysis was used to compare outcomes between the 3 groups at a 2-tailed α of .05. Fifty individuals were evaluated in each group. Adolescents in the CenteringPregnancy group were more likely to comply with prenatal and postpartum visits and to meet the 2009 Institute of Medicine gestational weight guidelines for weight gain in pregnancy than were adolescents in either multiprovider (62.0% vs 38.0%, P = .02) or single-provider (62.0% vs 38.0%, P = .02) groups. The CenteringPregnancy group was also more likely to solely breastfeed compared with adolescents in the multiprovider group (40.0% vs 20.0%, P = .03) and include breastfeeding in addition to bottle-feeding compared with both multiprovider (32.0% vs 14.0%, P = .03) and single-provider (32.0% vs 12.0%, P = .03) patient groups. Additionally, the CenteringPregnancy group had increased uptake of long-acting reversible contraception and were less likely to suffer from postpartum depression. CenteringPregnancy Prenatal Care program aids in compliance to prenatal visits, appropriate weight gain, increased uptake of highly effective contraception, and breastfeeding among adolescent mothers. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  19. Asymmetry of agricultural water consumption in arid regions during alternating decadal scale wet and dry periods: explanation using behavioral economics

    Science.gov (United States)

    Tian, Fuqiang

    2017-04-01

    Increase of human water consumption for agriculture and consequent degradation of the ecological environment is a common feature in many arid regions. Understanding the driving mechanisms behind this phenomenon is of critical importance for regional sustainable development. In this study, analyses of temporal patterns of human water consumption are carried out in three hyper-arid inland basins, i.e., Aral Sea Basin in Central Asia, and the Tarim and Heihe River Basins in Northwestern China. Multi-decadal time series of hydrological and human consumption data are divided into decadal sequences of wet and dry years. During the wet phases, the greater water availability inspires economic expansion and human water consumption experiences growth at a rate faster than that of incoming water. During the dry phases, however, the expanded economy (e.g., irrigation land expansion in an agriculture-based economy) has been managed to sustain or even to increase production by over-exploitation of water with sophisticated technologies. Inability to reduce human water consumption at a rate commensurate with the decrease of incoming water supply leads to serious ecosystem degradation. This asymmetric human water consumption response of society to decadal scale hydrologic variability can be explained in terms of prospect theory drawn from behavioral economics, which states that people tend to be risk averse when facing gains and show risk preference when facing losses. In the three socio-hydrological case studies, direct economic gain/loss has relatively low value but high certainty when compared to indirect economic loss/gain (such as environmental or sustainability loss/gain), which has high value but with high uncertainty. According to prospect theory, people tend to gain direct economic benefits at the expense of environmental degradation and at the risk of system collapse. The outcomes of this study have major implications for water resources management at long time scales

  20. Unexpected Covariant Behavior of the Aegean and Ionian Seas in the Period 1987-2008 by Means of a Nondimensional Sea Surface Height Index

    Science.gov (United States)

    Reale, M.; Salon, S.; Crise, A.; Farneti, R.; Mosetti, R.; Sannino, G.

    2017-10-01

    In this work, we use a set of recent multiyear simulations to develop a simplified sea surface height index (SSH). The index characterizes the dynamics of Ionian upper layer circulation and its links with sea surface height and salinity in the Southern Adriatic and Aegean Seas during the period 1987-2008. The analysis highlights a covariant behavior between Ionian Sea and Aegean Sea associated with a mutual zonal exchange of water masses with different salinity characteristics. Our analysis confirms that the variability observed in the period 1987-2008 in the upper layer circulation of the Ionian was driven by the salinity variability in the Southern Adriatic and Aegean Sea. This study supports and reinforces the hypothesis that two observed BiOS-like reversals reflect the existence of multiple equilibrium states in the Mediterranean Thermohaline circulation in the Eastern Mediterranean and that a complete characterization of observed variability needs to take into account a fully coupled Adriatic-Ionian-Aegean System.

  1. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  2. Variation in the large-scale organization of gene expression levels in the hippocampus relates to stable epigenetic variability in behavior.

    Directory of Open Access Journals (Sweden)

    Mark D Alter

    2008-10-01

    Full Text Available Despite sharing the same genes, identical twins demonstrate substantial variability in behavioral traits and in their risk for disease. Epigenetic factors-DNA and chromatin modifications that affect levels of gene expression without affecting the DNA sequence-are thought to be important in establishing this variability. Epigenetically-mediated differences in the levels of gene expression that are associated with individual variability traditionally are thought to occur only in a gene-specific manner. We challenge this idea by exploring the large-scale organizational patterns of gene expression in an epigenetic model of behavioral variability.To study the effects of epigenetic influences on behavioral variability, we examine gene expression in genetically identical mice. Using a novel approach to microarray analysis, we show that variability in the large-scale organization of gene expression levels, rather than differences in the expression levels of specific genes, is associated with individual differences in behavior. Specifically, increased activity in the open field is associated with increased variance of log-transformed measures of gene expression in the hippocampus, a brain region involved in open field activity. Early life experience that increases adult activity in the open field also similarly modifies the variance of gene expression levels. The same association of the variance of gene expression levels with behavioral variability is found with levels of gene expression in the hippocampus of genetically heterogeneous outbred populations of mice, suggesting that variation in the large-scale organization of gene expression levels may also be relevant to phenotypic differences in outbred populations such as humans. We find that the increased variance in gene expression levels is attributable to an increasing separation of several large, log-normally distributed families of gene expression levels. We also show that the presence of these

  3. Stable states in a strong IR field

    Science.gov (United States)

    Zhong, Changchun; Robicheaux, Francis

    2015-05-01

    It is found that 10% of atoms stay in the quasi-stable states after being exposed to intense laser or microwave (MW) pulses, even though the pulses' intensity is much stronger than that needed for static fields ionization. The reason why atoms survive those strong pulses has attracted growing attentions. A. Arakelyan et al. have observed the optical spectra of the surviving Lithium atoms after interaction with intense 38-GHz MW fields for more than 1000 cycles, and the spectra exhibit a periodic train of peaks 38 GHz apart. It suggests that those weakly bound Rydberg electrons seldom go back to the ionic core, where the cycle average energy exchange happens. In this study, we are interested in the electron behavior in the presence of intense infrared fields with a much shorter wavelength (1000 nm). By solving the full 3D time dependent Schrodinger equation, we calculate the spectra of the surviving atoms under intense IR fields. Our numerical calculations show atoms survive the intense field in quasi-stable states for a long time, and the optical spectra are obviously modulated by the IR frequency. Through tuning the ponderomotive energy, we see how field parameters affect the behavior of electrons. Different atoms, such as Hydrogen, Helium, Lithium, and Sodium, are tested to see how atom's energy structures influence the results.

  4. Numerical investigation of frictional behavior and energy loss in mixed-hydrodynamic contact of piston ring pack with deformed cylinder liner during warm-up period of SI-engine

    International Nuclear Information System (INIS)

    Usman, Ali; Park, Cheol Woo

    2016-01-01

    Highlights: • Lubrication remains purely hydrodynamic in first half of the liner warm-up period. • Viscous friction dominates boundary friction in the entire warm-up process. • Ring-pack causes several times more energy loss in cold start of the engine. • Low-viscosity grade oils show more stable temperature-dependent performance. • Oil transport to combustion chamber increases substantially during warm-up. - Abstract: A substantial amount of fuel energy is used to overcome internal friction of an engine. Power loss in piston ring-pack accounts for a major portion of this energy loss. Circumferential clearances caused by distorted bores alter the tribological behavior of the piston ring–liner (PRL) interface. This change in performance of the interface intensifies during warm-up of an engine. Mixed-hydrodynamic lubrication model is considered to evaluate the development of tribo-characteristics in piston ring-pack contact with a non-circular liner during the warm-up phase of a spark ignition (SI) engine. Variations in modes of energy loss caused by bore-distortion during the warm-up period are analyzed. Oil transport to the combustion chamber throughout the warm-up process is studied. Five different viscosity-grades are considered to compare performance of the interface. Results show that viscous shearing of lubricant oil is largely responsible for frictional loss in the warm-up phase. Circumferential variation in film thickness decrease parasitic losses in cold temperatures, but increases oil transport both in cold and in warm conditions.

  5. Short communication: Relationship between serum cortisol concentration and defensive behavioral responses of dairy cows exposed to natural infestation by stable fly, Stomoxys calcitrans.

    Science.gov (United States)

    Vitela-Mendoza, I; Cruz-Vázquez, C; Solano-Vergara, J; Orihuela-Trujillo, A

    2016-12-01

    The aim of this study was conducted to evaluate the effect of natural infestation by Stomoxys calcitrans on the behavioral and adrenocortical responses of dairy cattle. Twenty Holstein cows randomly selected were individually sprayed with insecticide once every 7d, whereas no insecticide was applied to the other 20 animals. The average number of flies per cow was estimated daily, and the frequency of fly-avoidance behaviors was measured daily; plasma cortisol concentration was measured each morning. No flies were ever counted on the treated cows at any time during the experiment, whereas an average of 17.13±1.14 (±standard error) flies/d were recorded on untreated cows. Tail movement was the most frequent behavior displayed, with stamps or kicks showing the highest increment rate (41.2×) when fly population increased from zero to greater than 51 flies/cow. Cortisol concentration increased to a maximum of 56.81±39.53ng/mL with 26 to 30 flies/cow per day. Coefficients of determination between the number of flies, cortisol concentration, tail movements, and stamps or kicks were 0.73, 0.78, and 0.81, respectively. The multiple correlation coefficient was 0.90, with 81% of the variation in cortisol concentration explainable by variation in the number of flies per cow and the frequency of fly-avoidance behaviors. It was concluded that plasma cortisol concentration is linearly related to a combination of the number of flies and the frequency of fly-dislodging behaviors, producing a maximum response before reaching maximum fly loads. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Hippocampal cell fate regulation by chronic cocaine during periods of adolescent vulnerability: Consequences of cocaine exposure during adolescence on behavioral despair in adulthood.

    Science.gov (United States)

    García-Cabrerizo, R; Keller, B; García-Fuster, M J

    2015-09-24

    Given that adolescence represents a critical moment for shaping adult behavior and may predispose to disease vulnerability later in life, the aim of this study was to find a vulnerable period during adolescence in which hippocampal cell fate regulation was altered by cocaine exposure, and to evaluate the long-term consequences of a cocaine experience during adolescence in affecting hippocampal plasticity and behavioral despair in adulthood. Study I: Male rats were treated with cocaine (15mg/kg, i.p.) or saline for 7 consecutive days during adolescence (early post-natal day (PND) 33-39, mid PND 40-46, late PND 47-53). Hippocampal plasticity (i.e., cell fate regulation, cell genesis) was evaluated 24h after the last treatment dose during the course of adolescence (PND 40, PND 47, PND 54). Study II: The consequences of cocaine exposure during adolescence (PND 33-39 or PND 33-46; 7 or 14days) were measured in adulthood at the behavioral (i.e., forced swim test, PND 62-63) and molecular (hippocampal cell markers, PND 64) levels. Chronic cocaine during early adolescence dysregulated FADD forms only in the hippocampus (HC), as compared to other brain regions, and during mid adolescence, impaired cell proliferation (Ki-67) and increased PARP-1 cleavage (a cell death maker) in the HC. Interestingly, chronic cocaine exposure during adolescence did not alter the time adult rats spent immobile in the forced swim test. These results suggest that this paradigm of chronic cocaine administration during adolescence did not contribute to the later manifestation of behavioral despair (i.e., one pro-depressive symptom) as measured by the forced swim test in adulthood. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. A cholinergic-regulated circuit coordinates the maintenance and bi-stable states of a sensory-motor behavior during Caenorhabditis elegans male copulation.

    Directory of Open Access Journals (Sweden)

    Yishi Liu

    2011-03-01

    Full Text Available Penetration of a male copulatory organ into a suitable mate is a conserved and necessary behavioral step for most terrestrial matings; however, the detailed molecular and cellular mechanisms for this distinct social interaction have not been elucidated in any animal. During mating, the Caenorhabditis elegans male cloaca is maintained over the hermaphrodite's vulva as he attempts to insert his copulatory spicules. Rhythmic spicule thrusts cease when insertion is sensed. Circuit components consisting of sensory/motor neurons and sex muscles for these steps have been previously identified, but it was unclear how their outputs are integrated to generate a coordinated behavior pattern. Here, we show that cholinergic signaling between the cloacal sensory/motor neurons and the posterior sex muscles sustains genital contact between the sexes. Simultaneously, via gap junctions, signaling from these muscles is transmitted to the spicule muscles, thus coupling repeated spicule thrusts with vulval contact. To transit from rhythmic to sustained muscle contraction during penetration, the SPC sensory-motor neurons integrate the signal of spicule's position in the vulva with inputs from the hook and cloacal sensilla. The UNC-103 K(+ channel maintains a high excitability threshold in the circuit, so that sustained spicule muscle contraction is not stimulated by fewer inputs. We demonstrate that coordination of sensory inputs and motor outputs used to initiate, maintain, self-monitor, and complete an innate behavior is accomplished via the coupling of a few circuit components.

  8. Overweight and Obese Adolescent Girls: The Importance of Promoting Sensible Eating and Activity Behaviors from the Start of the Adolescent Period

    Directory of Open Access Journals (Sweden)

    Alwyn S. Todd

    2015-02-01

    Full Text Available The adolescent period is associated with changes in eating and activity behaviors in girls. Less reliance on parental provision and choice of food, coupled with a decrease in participation in physical activity and sport, can create an energy imbalance, predisposing to weight gain. Physiological alterations to body composition, reduction in insulin sensitivity, and psychological adjustments may further amplify the risk of becoming overweight and maintaining an unhealthy level of body fat into childbearing years. During pregnancy excess body fat is a risk factor for poor pregnancy outcomes and may predispose an infant to a lifelong heightened risk of being overweight and developing chronic disease. Interventions aimed at preventing the accumulation of body fat in adolescent girls and young women may have far reaching impact and be critically important in reducing intergenerational weight gain. Lifestyle interventions in adolescence have the potential to modify adult obesity risk by switching at-risk individuals from a high to lower obesity risk trajectory. This paper discusses multiple approaches to assist at-risk individuals reduce obesity risk. A key focus is placed on engagement in food preparation and choice, and opportunities for physical activity and sport. Support, education, and opportunity at home and at school, are often associated with the success of lifestyle interventions, and may enable adolescents to make positive choices, and engage in health promoting behaviors during adolescence and childbearing years.

  9. Overweight and Obese Adolescent Girls: The Importance of Promoting Sensible Eating and Activity Behaviors from the Start of the Adolescent Period

    Science.gov (United States)

    Todd, Alwyn S.; Street, Steven J.; Ziviani, Jenny; Byrne, Nuala M.; Hills, Andrew P.

    2015-01-01

    The adolescent period is associated with changes in eating and activity behaviors in girls. Less reliance on parental provision and choice of food, coupled with a decrease in participation in physical activity and sport, can create an energy imbalance, predisposing to weight gain. Physiological alterations to body composition, reduction in insulin sensitivity, and psychological adjustments may further amplify the risk of becoming overweight and maintaining an unhealthy level of body fat into childbearing years. During pregnancy excess body fat is a risk factor for poor pregnancy outcomes and may predispose an infant to a lifelong heightened risk of being overweight and developing chronic disease. Interventions aimed at preventing the accumulation of body fat in adolescent girls and young women may have far reaching impact and be critically important in reducing intergenerational weight gain. Lifestyle interventions in adolescence have the potential to modify adult obesity risk by switching at-risk individuals from a high to lower obesity risk trajectory. This paper discusses multiple approaches to assist at-risk individuals reduce obesity risk. A key focus is placed on engagement in food preparation and choice, and opportunities for physical activity and sport. Support, education, and opportunity at home and at school, are often associated with the success of lifestyle interventions, and may enable adolescents to make positive choices, and engage in health promoting behaviors during adolescence and childbearing years. PMID:25690003

  10. Seismic Behavior of RNC-Isolated Bridges: A Comparative Study under Near-Fault, Long-Period, and Pulse-Like Ground Motions

    Directory of Open Access Journals (Sweden)

    Mohammed Ismail

    2016-01-01

    Full Text Available This paper introduces a recent seismic isolation system, named Roll-in-Cage (RNC isolator, for efficient protection of bridges against destructive earthquakes. The RNC isolator is a rolling-based isolation system with several integrated features in a single unit providing all the necessary functions of vertical rigid support, horizontal flexibility, full stability, hysteretic energy dissipation, and resistance to minor vibration loads. Besides, it is distinguished by a self-stopping (buffer mechanism to limit the peak bearing displacement under abrupt severe excitations, a linear gravity-based self-recentering mechanism to prevent permanent dislocations after excitations, and a notable resistance to axial tension. A three-span box-girder prestressed concrete bridge is investigated under a set of different destructive real and synthetic earthquakes including near-fault, long-period, and pulse-like ground motions. As a performance measure, the responses of isolated and nonisolated cases are compared. In addition, the RNC isolator’s behavior is then compared with those of other isolation systems including HDB, FPS, and LRB. The results confirmed that the RNC isolator has a superior behavior in achieving a balance between the peak displacements and accelerations of the isolated deck, relative other isolation systems, besides being the most (relatively efficient isolator in the great majority of studies performed.

  11. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  12. Repeated, Intermittent Social Defeat across the Entire Juvenile Period Resulted in Behavioral, Physiological, Hormonal, Immunological, and Neurochemical Alterations in Young Adult Male Golden Hamsters.

    Science.gov (United States)

    Yu, Wei-Chun; Liu, Ching-Yi; Lai, Wen-Sung

    2016-01-01

    The developing brain is vulnerable to social defeat during the juvenile period. As complements of human studies, animal models of social defeat provide a straightforward approach to investigating the functional and neurobiological consequences of social defeats. Taking advantage of agonist behavior and social defeat in male golden hamster, a set of 6 experiments was conducted to investigate the consequences at multiple levels in young adulthood resulting from repeated, intermittent social defeats or "social threats" across the entire juvenile period. Male hamsters at postnatal day 28 (P28) were randomly assigned to either the social defeat, "social threat", or arena control group, and they correspondingly received a series of nine social interaction trials (i.e., either social defeat, "social threat", or arena control conditions) from P33 to P66. At the behavioral level (Experiment 1), we found that repeated social defeats (but not "social threats") significantly impacted locomotor activity in the familiar context and social interaction in the familiar/unfamiliar social contexts. At the physiological and hormonal levels (Experiments 2 and 3), repeated social defeat significantly enhanced the cortisol and norepinephrine concentrations in blood. Enlargement of the spleen was also found in the social defeat and "social threat" groups. At the immunological level (Experiment 4), the social defeat group showed lower levels of pro-inflammatory cytokines in the hypothalamus and hippocampus but higher concentration of IL-6 in the striatum compared to the other two groups. At the neurochemical level (Experiment 5), the socially defeated hamsters mainly displayed reductions of dopamine, dopamine metabolites, and 5-HT levels in the striatum and decreased level of 5-HT in the hippocampus. In Experiment 6, an increase in the spine density of hippocampal CA1 pyramidal neurons was specifically observed in the "social threat" group. Collectively, our findings indicate that repeated

  13. Behaviorism

    Science.gov (United States)

    Moore, J.

    2011-01-01

    Early forms of psychology assumed that mental life was the appropriate subject matter for psychology, and introspection was an appropriate method to engage that subject matter. In 1913, John B. Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the…

  14. Behavior

    NARCIS (Netherlands)

    Bouwman, L.I.

    2014-01-01

    Health behaviors are people’s actions, some purposefully deployed to promote or protect health; some thoughtlessly undertaken without concern for their potential risk to health; some consciously, even defiantly, deployed regardless of consequences to health. Risk behaviors are specific forms of

  15. Behavior of radon, chemical compounds and stable elements in underground water; Comportamiento de radon, compuestos quimicos y elementos estables en agua subterranea

    Energy Technology Data Exchange (ETDEWEB)

    Lopez R, N.; Segovia, N.; Lopez, M.B.E.; Pena, P. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Godinez, L. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L. [ISTEEM, M.S.E. Montpellier (France)

    2001-07-01

    The radon behavior, chemical compounds, major and trace elements in water samples of four springs and three wells of urban and agricultural zones around the Jocotitlan volcano and El Oro region was determined, both of them located in the medium part of the Mexican neo-volcanic axis. The {sup 222} Rn was measured by the liquid scintillation method, the analysis of major components was realized with conventional chemical techniques, while the trace elements were quantified using an Icp-Ms. The average values of the radon concentrations obtained during one year were constant relatively, in an interval from 0.97 to 4.99 Bq/lt indicating a fast transport from the reload area toward the sampling points. the compounds, major and trace elements showed differences which indicate distinct origins of water from the site studies. (Author)

  16. Is the HIV epidemic stable among MSM in Mexico? HIV prevalence and risk behavior results from a nationally representative survey among men who have sex with men.

    Directory of Open Access Journals (Sweden)

    Sergio Bautista-Arredondo

    Full Text Available BACKGROUND: Recent evidence points to the apparent increase of HIV prevalence among men who have sex with men (MSM in different settings with concentrated epidemics, including the Latin American region. In 2011, Mexico implemented an ambitious HIV prevention program in all major cities, funded by the Global Fund to Fight Aids, Tuberculosis and Malaria. The program was intended to strengthen the prevention response for the most at risk populations: MSM and injecting drug users. This paper presents the HIV prevalence results of a nationally representative baseline survey in 24 Mexican cities throughout the 5 regions in the country and reports the socio-demographic and sexual risk behaviors that predict the probability of infection. METHODS: The survey was implemented in two phases. We first identified and characterized places where MSM gather in each city and then conducted in a second phase, a seroprevalence survey that included rapid HIV testing and a self-administered questionnaire. The prevalence of HIV was estimated by adjusting for positive predicted value. We applied a probit model to estimate the probability of having a positive result from the HIV test as a function of socio-demographic characteristics and self-reported sexual risk behaviors. RESULTS: We found an overall HIV prevalence among MSM gathering in meeting points of 16.9% [95% CI: 15.6-18.3], significantly higher than previously reported estimates. Our regression results suggest that the risk of infection increases with age, with the number of sexual partners, and among those who play a receptive sexual role, and the risk decreases with higher education. DISCUSSION: Our findings suggest a higher HIV prevalence among MSM than previously acknowledged and that a significant regional variability exist throughout the country. These two findings combined, signal an important dynamic in the epidemic that should be better understood and promptly addressed with strong prevention efforts

  17. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  18. Laboratory and field methods for stable isotope analysis in human biology.

    Science.gov (United States)

    Reitsema, Laurie J

    2015-01-01

    Stable isotope analysis (SIA; carbon, hydrogen, nitrogen, sulfur, and oxygen) of human tissues offers a means for assessing diet among living humans. Stable isotope ratios of broad categories of food and drink food vary systematically, and stable isotope ratios in consumer tissues represent a composite of the isotopic ratios of food and drink consumed during an individual's life. Isotopic evidence for diet is independent of errors in informant recall, and accrues during time periods when researchers are absent. Beyond diet reconstruction, tissue stable isotope ratios are sensitive to excursions from homeostasis, such as starvation and rapid growth. Because of their relationship to diet, geographic location, hydration, and nutritional status, stable isotope signatures in human tissues offer a window into human biocultural adaptations, past and present. This article describes methods for SIA that may be usefully applied in studies of living humans, with emphasis placed on carbon and nitrogen. Some of the ecological, physiological, and evolutionary applications of stable isotope data among living humans are discussed. By incorporating SIA in research, human biologists facilitate a productive dialog with bioarchaeologists, who routinely use stable isotope evidence, mingling different perspectives on human biology and behavior. © 2015 Wiley Periodicals, Inc.

  19. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  20. Infrared Spectroscopy and Stable Isotope Geochemistry of Hydrous Silicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Stolper, Edward

    2007-03-05

    The focus of this DOE-funded project has been the study of volatile components in magmas and the atmosphere. Over the twenty-one year period of this project, we have used experimental petrology and stable isotope geochemistry to study the behavior and properties of volatile components dissolved in silicate minerals and melts and glasses. More recently, we have also studied the concentration and isotopic composition of CO2 in the atmosphere, especially in relation to air quality issues in the Los Angeles basin.

  1. Effect of Mobile Phone Microwaves on Fetal Period of Balb-C Mice in Histological Characteristics of Hippocampus and Learning Behaviors

    Directory of Open Access Journals (Sweden)

    Ali Moghimi

    2009-09-01

    Full Text Available Objective(sThe possible risks of radio-frequency electromagnetic fields (EMF for the living organisms and human body are a growing concern for our society. In this study, we examined the possibility of changes in working memory and hippocampal histological characteristics effects in mice brain following whole body exposure to microwave radiation.Materials and MethodsDuring gestation period, we exposed mice for 4 hr to Global system for mobile communications (GSM, Specific Absorption Rate (SAR of 200 mW/kg. Pregnant control mice were sham-exposed or free in a cage without further restraining. Three month after exposure animals were prepared for behavioral (Radial Arm Maze (RAM and Morris Water Maze (MWM and histological studies.ResultsThe results showed that microwave exposed mice were slower than sham, and control in finding the platform. Analyses of error rates in RAM and MWM performance revealed significant differences which emphasize the effect of acute exposure to pulsed microwaves in deficit of spatial reference memory in the mice. However in this study exposed group didn’t show any statistically significant loss of hippocampal CA1, CA3 neurons versus controls or sham. ConclusionWe conclude that there is evidence from the current study that exposure to MW radiation under parameters examined caused decrements in the ability of mice to learn the spatial memory task.

  2. Population Games, Stable Games, and Passivity

    Directory of Open Access Journals (Sweden)

    Michael J. Fox

    2013-10-01

    Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

  3. Analysis of the behavior and characteristics of thyroid lesions identified by biopsy fine needle aspiration and gammagraphic diagnosis: Hospital Calderon Guardia: period 2004-2006

    International Nuclear Information System (INIS)

    Serrano Frago, Erasmo

    2007-01-01

    Thyroid lesions have meant one of the most important pathological entities in the Costa Rican population for many years, which have been increased by new diagnostic examinations and early detection and timely thanks to the preventive medicine that is exerted on the security of the country. After the nuclear accident Chernobyl in the former Soviet Union for several decades ago has shown an increase in neoplastic lesions as well as was appreciated after the implementation of the first atomic bomb in World War II, this behavior is the interest to see how thyroid pathology develops in the environment and what have been the Costa Rican experiences in correlation with the expected time to the global statistics. The behavior pattern observed of the lessons of the thyroid gland and based on clinical findings and in some cases together with scintigraphy have allowed to study the development seen through the ultrasound and cytopathological result. The behavior of the patients was similar to global statistics, being most frequent the benign lesions than malignant, and the scintigraphy correlation with lesions were found to be cold was significant for determination of malignant or suspicious for malignancy. Some of these lesions that were suspicious for malignancy scintigraphy and ultrasound were benign have been found to fall within the expected rate for this type of injury. The study consisted of sampling in 2023 noted that the prevalence was 9:1 in women compared with men, which agrees as thyroid diseases are more common in women than in men as well as the expected results in malignant lesions that remained the same behavior. As expected in the age ranges of suffering from thyroid lesions remained between the fifth and sixth decade of life, which has allowed to observe the frequency of different benign and malignant lesions that occurred during this study in the decades and periods covered. While before the study of thyroid lesions was occupied by scintigraphy and

  4. Effects of acetic acid or sodium acetate infused into the rumen or abomasum on feeding behavior and metabolic response of cows in the postpartum period.

    Science.gov (United States)

    Gualdrón-Duarte, Laura B; Allen, Michael S

    2018-03-01

    Effects of continuous isomolar infusions of acetic acid (AcA) or sodium acetate (NAc) infused into the rumen (RU) or into the abomasum (AB) on feeding behavior, dry matter intake (DMI), and metabolic response of cows in the early postpartum period were evaluated. Six rumen-cannulated multiparous Holstein cows (11.8 ± 3.9 d in milk; mean ± SD) were utilized in a 6 × 6 Latin square design experiment balanced for carryover effects with a 2 × 3 factorial arrangement of treatments. Treatments were AcA and NAc, with sodium chloride (CON) as a control, infused at a rate of ˜0.75 mol/h (0.5 L/h) into the RU or AB for the first 8 h following feeding, with a rest day between infusion days. Treatment sequences were assigned randomly to cows. Feeding behavior was recorded by a computerized data acquisition system and blood was sampled at 0, 4, and 8 h relative to the start of infusion. We hypothesized that AcA is more hypophagic than NAc, and that infusion into the AB is more hypophagic than infusion into the RU. Dry matter intakes (DMI) for the CON treatments were similar at 6.2 kg/8 h for RU and 6.1 kg/8 h for AB, and the AcA and NAc treatments interacted with site of infusion to affect DMI. The NAc-RU treatment did not reduce DMI (7.0 kg/8 h), whereas AcA-RU (2.6 kg/8 h), AcA-AB (3.7 kg/8 h), and NAc-AB (4.0 kg/8 h) decreased DMI compared with CON. Following infusions of AcA compared with NAc, there was a residual effect on DMI for the remainder of the day, but treatments did not affect DMI during the rest day. Treatments increased plasma acetate and β-hydroxybutyrate concentrations over time (interaction) and decreased plasma insulin concentration compared with CON. Plasma glucose concentration decreased over time after AcA-AB infusion compared with other treatments and CON. Plasma nonesterified fatty acid concentration increased over time for AcA compared with NAc and CON, suggesting an increase in lipolysis to compensate the decrease in DMI. In contrast to the

  5. Period Cramps

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Period Cramps KidsHealth / For Kids / Period Cramps Print en español ... a girl who gets them. What Are Period Cramps? Lots of girls experience cramps before or during ...

  6. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  7. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  8. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    IAS Admin

    After Maynard-Smith and Price [1] mathematically derived why a given behaviour or strategy was adopted by a certain proportion of the population at a given time, it was shown that a strategy which is currently stable in a population need not be stable in evolutionary time (across generations). Additionally it was sug-.

  9. Occurrence of stable periodic modes in a pendulum with cubic ...

    Indian Academy of Sciences (India)

    In this work the driven Froude pendulum is studied by the harmonic balancing method; the resulting nonlinear response curves are studied further for resonance and stability of symmetric oscillations with relatively low damping. The stability analysis is carried out by transforming the system of equations to the linear Mathieu ...

  10. Problem Periods

    Science.gov (United States)

    ... during your menstrual cycle Premenstrual syndrome (PMS) Problem periods Getting enough sleep Looking and feeling your best Fighting germs Your sexuality What are STDs and STIs? Seeing the doctor Quizzes Links to more information on girls' bodies girlshealth glossary girlshealth.gov home http://www.girlshealth.gov/ Home ... Problem periods It’s common to have ...

  11. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  12. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  13. Historiske perioder

    DEFF Research Database (Denmark)

    2017-01-01

    For at forstå fortiden og fortællingerne om den, må vi skabe en form for orden og systematik. Her spiller inddelingen af fortiden i historiske perioder en afgørende rolle – og historiske perioder er da også et kompetencemål efter 6. klasse. Videoen diskuterer forskellige principper...... for periodisering. Kronologi og sammenhænge hænger naturligt sammen med historiske perioder. Videoen handler også om forståelser og brug af synkrone og diakrone sammenhænge i faget....

  14. A flexion period for attachment formation in isolated chicks to unfamiliar peers visualized in a developmental trajectory space through behavioral multivariate correlation analysis.

    Science.gov (United States)

    Mimura, Koki; Nakamura, Shun; Koshiba, Mamiko

    2013-06-28

    Attachment formation is crucial for social animals to survive in natural environments. Predisposition and imprinting mechanisms have been well documented as a process of con-specific affiliation development. However, it is unclear how neonatal stage attachment formation leads to juvenile peer sociality. Here we have developed an animal model (Gallus gallus domesticus) and a method of quantitative behavioral analysis, to study the developmental trajectory from postnatal day (P) 3 through to P21. Domestic chicks were raised in either group or isolated conditions and we focused on social behavior during a two-minute meeting context with unfamiliar group peers at P3, 7, 13, 16, and 21. Results showed that relative to isolated chicks, group reared chicks were more active behaviorally, when facing peers at P3 and that this activity declined slightly over development, up to P13. Isolated chicks that had not met any animals except humans, exhibited a major change in social behavior around P7, in particular, with increasing activity (head moving velocity and rotation velocity) and distress calls. This modulation disappeared after P13, suggesting the existence of a sensitive window for behavior toward peers around P7. These findings in isolated chicks suggest the maturation of new neuronal substrates for peer-social emotion and cognition, resulting in a new combination of behavioral modules. Copyright © 2013. Published by Elsevier Ireland Ltd.

  15. Substance abuse in early adolescents and HIV preventive behaviors: findings from a school-based cross-sectional survey for the period from 2009 to 2013, Bangkok Thailand.

    Science.gov (United States)

    Thepthien, B; Altaf, L; Chuchareon, P; Srivanichakron, S

    2016-10-01

    This study is first of its kind in Bangkok, and is a five-year (2009-2013) cross-sectional web-based survey to examine HIV preventive behaviors related to substance abuse among adolescents (N = 16,913). The questionnaire was self-administered. Logistic regression was used to analyze the data. The relationship between different types of substance abuse with risky and preventive behaviors was assessed. Male participants reported more substance abuse as compared to females. The risk behaviors observed among the substance abusers include increased sexual experience, multiple sex partners, no use of condoms, and injection drug use. The preventive behaviors include having a high self-risk assessment, going for HIV testing (highest in methamphetamine users), and screening for sexually transmitted infection. Logistic regression suggests that risky behaviors (e.g., sexual experience, injection drug use) are more common in substance abusers. Adolescents are clearly at a high risk. Behavioral preventive measures are needed to reduce or delay premature substance exposure to prevent a wide range of health problems and risks such as HIV and AIDS, injection drug use and unprotected sex.

  16. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  17. Induction period

    International Nuclear Information System (INIS)

    Land, C.E.; Tokunaga, M.

    1984-01-01

    Induction period is the temporal aspect of the excess cancer risk that follows an exposure to ionizing radiation. Operationally, it can be thought of as the time from an exposure of brief duration to the diagnosis of any resultant cancer. Whereas the magnitude of excess risk can be described by a single number, such as the average yearly excess risk over some fixed time interval after exposure, the temporal distribution requires a histogram or a curve, that is, an array or continuum of numbers. The study of induction period involves a search for a simple way of describing the temporal distribution of risk, that is, a way of describing a continuum by using only one or two numbers. In other words, the goal is to describe induction period probabilistically, using a parametric model with a few parameters

  18. Behavioral Interference and C/EBP[Beta] Expression in the Insular-Cortex Reveal a Prolonged Time Period for Taste Memory Consolidation

    Science.gov (United States)

    Elkobi, Alina; Jacobson-Pick, Shlomit; Karni, Avi; Rosenblum, Kobi; Merhav, Maayan; Kuulmann-Vander, Shelly

    2006-01-01

    Memory consolidation is defined as the time window during which the memory trace is susceptible to behavioral, electrical, or pharmacological interventions. Here, the authors presented rats with two novel tastes at consecutive time intervals. Clear interference was evident when a novel taste formed the second taste input whereby, surprisingly, the…

  19. Periodical Economics

    OpenAIRE

    King, Andrew

    2016-01-01

    This is the first overview of the economics of nineteenth-century periodicals and newspapers. While media economics is an established field in business studies, the chapter redefines economics by looking at value systems including capitalist ones but no confined to them. Original case studies are offered as models for research into the economics of nineteenth-century print culture.

  20. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  1. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General ... Using some examples of classical games, we show how evolutionary game theory can help understand behavioural decisions of animals.

  2. Manifolds admitting stable forms

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van; Panák, Martin; Vanžura, Jiří

    2008-01-01

    Roč. 49, č. 1 (2008), s. 101-11 ISSN 0010-2628 R&D Projects: GA ČR(CZ) GP201/05/P088 Institutional research plan: CEZ:AV0Z10190503 Keywords : stable forms * automorphism groups Subject RIV: BA - General Mathematics

  3. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  4. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  5. The stable subgroup graph

    Directory of Open Access Journals (Sweden)

    Behnaz Tolue

    2018-07-01

    Full Text Available In this paper we introduce stable subgroup graph associated to the group $G$. It is a graph with vertex set all subgroups of $G$ and two distinct subgroups $H_1$ and $H_2$ are adjacent if $St_{G}(H_1\\cap H_2\

  6. ADVANCED POWER SYSTEMS - ASH BEHAVIOR IN POWER SYSTEMS. INCLUDES THE SEMIANNUAL REPORT FOR THE PERIOD JANUARY 01, 1998 - JUNE 30, 1998.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature; Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined; Identify the relationship between the temperature of critical viscosity (T{sub cv}) as measured in a viscometer and the crystallization occurring in the melt; Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles; Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems; and Evaluate corrosion for alloys being used in supercritical combustion systems.

  7. Exposure to a Highly Caloric Palatable Diet During Pregestational and Gestational Periods Affects Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Adiposity and Anxiety-Like Behaviors in Male Rat Offspring.

    Science.gov (United States)

    Ramírez-López, María Teresa; Vázquez, Mariam; Bindila, Laura; Lomazzo, Ermelinda; Hofmann, Clementine; Blanco, Rosario Noemí; Alén, Francisco; Antón, María; Decara, Juan; Ouro, Daniel; Orio, Laura; Suarez, Juan; Lutz, Beat; Rodríguez de Fonseca, Fernando; Gómez de Heras, Raquel

    2015-01-01

    Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol) at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory, and emotions.

  8. Exposure to a highly caloric palatable diet during pregestational and gestational periods affects hypothalamic and hippocampal endocannabinoid levels at birth and induces adiposity and anxiety-like behaviors in male rat offspring

    Directory of Open Access Journals (Sweden)

    Maria Teresa eRamírez-López

    2016-01-01

    Full Text Available Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and, although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory and emotions.

  9. Dynamics of spiral waves in excitable media subjected to external periodic forcing

    Science.gov (United States)

    Schrader, A.; Braune, M.; Engel, H.

    1995-07-01

    We provide a survey of the behavior of meandering spiral waves in excitable media under periodic modulation of excitability. Model calculations were performed in a modified Oregonator model for the photosensitive Belousov-Zhabotinsky reaction. The spiral's dynamic is followed by its tip motion. We find mode locking if the path curvature period is a rational multiple of the modulation period and resonance response of the spiral's rotation period. A general ordering structure in terms of the Farey tree is observed. The complex motion of the spiral's tip is found to be composed of harmonics of the modulation period. For large forcing amplitudes we observe an overlap of entrainment bands resulting in bi- stable behavior and in the breakup of the spiral at the end of the major entrainment band.

  10. Periodic paralysis.

    Science.gov (United States)

    Fialho, Doreen; Griggs, Robert C; Matthews, Emma

    2018-01-01

    The periodic paralyses are a group of skeletal muscle channelopathies characterizeed by intermittent attacks of muscle weakness often associated with altered serum potassium levels. The underlying genetic defects include mutations in genes encoding the skeletal muscle calcium channel Ca v 1.1, sodium channel Na v 1.4, and potassium channels K ir 2.1, K ir 3.4, and possibly K ir 2.6. Our increasing knowledge of how mutant channels affect muscle excitability has resulted in better understanding of many clinical phenomena which have been known for decades and sheds light on some of the factors that trigger attacks. Insights into the pathophysiology are also leading to new therapeutic approaches. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  12. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  13. Stable SU(5) monopoles with higher magnetic charge

    International Nuclear Information System (INIS)

    Miyamoto, S.; Sato, H.; Tomohiro, S.

    1985-01-01

    Taking into account the electroweak breaking effects, some multiply charged monopoles were shown to be stable by Gardner and Harvey. We give the explicit Ansa$uml: tze for finite-energy, nonsingular solutions of these stable higher-strength monopoles with eg = 1,(3/2),3. We also give the general stability conditions and the detailed behavior of the interaction potentials between two monopoles which produce the stable higher-strength monopoles

  14. Local Search Approaches in Stable Matching Problems

    Directory of Open Access Journals (Sweden)

    Toby Walsh

    2013-10-01

    Full Text Available The stable marriage (SM problem has a wide variety of practical applications, ranging from matching resident doctors to hospitals, to matching students to schools or, more generally, to any two-sided market. In the classical formulation, n men and n women express their preferences (via a strict total order over the members of the other sex. Solving an SM problem means finding a stable marriage where stability is an envy-free notion: no man and woman who are not married to each other would both prefer each other to their partners or to being single. We consider both the classical stable marriage problem and one of its useful variations (denoted SMTI (Stable Marriage with Ties and Incomplete lists where the men and women express their preferences in the form of an incomplete preference list with ties over a subset of the members of the other sex. Matchings are permitted only with people who appear in these preference lists, and we try to find a stable matching that marries as many people as possible. Whilst the SM problem is polynomial to solve, the SMTI problem is NP-hard. We propose to tackle both problems via a local search approach, which exploits properties of the problems to reduce the size of the neighborhood and to make local moves efficiently. We empirically evaluate our algorithm for SM problems by measuring its runtime behavior and its ability to sample the lattice of all possible stable marriages. We evaluate our algorithm for SMTI problems in terms of both its runtime behavior and its ability to find a maximum cardinality stable marriage. Experimental results suggest that for SM problems, the number of steps of our algorithm grows only as O(n log(n, and that it samples very well the set of all stable marriages. It is thus a fair and efficient approach to generate stable marriages. Furthermore, our approach for SMTI problems is able to solve large problems, quickly returning stable matchings of large and often optimal size, despite the

  15. Bifurcations of a periodically forced microbial continuous culture model with restrained growth rate

    Science.gov (United States)

    Ren, Jingli; Yuan, Qigang

    2017-08-01

    A three dimensional microbial continuous culture model with a restrained microbial growth rate is studied in this paper. Two types of dilution rates are considered to investigate the dynamic behaviors of the model. For the unforced system, fold bifurcation and Hopf bifurcation are detected, and numerical simulations reveal that the system undergoes degenerate Hopf bifurcation. When the system is periodically forced, bifurcation diagrams for periodic solutions of period-one and period-two are given by researching the Poincaré map, corresponding to different bifurcation cases in the unforced system. Stable and unstable quasiperiodic solutions are obtained by Neimark-Sacker bifurcation with different parameter values. Periodic solutions of various periods can occur or disappear and even change their stability, when the Poincaré map of the forced system undergoes Neimark-Sacker bifurcation, flip bifurcation, and fold bifurcation. Chaotic attractors generated by a cascade of period doublings and some phase portraits are given at last.

  16. Study of the impact of educational behavioral interventions on fatigue in mothers in the postpartum period in the groups of face-to-face and electronic training

    Directory of Open Access Journals (Sweden)

    Zahra Gholami

    2017-01-01

    Full Text Available Background: Maternal fatigue in the postpartum period include factors that affect the quality of life and health of both the mother and newborn. This study aimed to investigate two educational approaches regarding mother's fatigue in the postpartum period. Materials and Methods: This experimental study was performed among 110 pregnant mothers during their postpartum care using random sampling. The participants were divided in three groups, namely, face-to-face, e-learning, and control groups. Interventions included individual meetings between the researcher and mothers in the face-to-face group and giving educational compact disc to the e-learning department to improve maternal fatigue. Personal information and fertility data was obtained (before training; the maternal fatigue questionnaire Fatigue Severity Scale (FSS was completed before and after any type of (face-to-face, e-learning, and control education. Obtained data were analyzed using one-way analysis of variance (ANOVA and repeated-measures ANOVA. Results: Results showed that both face-to-face and e-learning methods had similar maternal fatigue scores. The average change on the maternal fatigue score in the second treatment was (p = 0.02 and the third treatment was (p < 0.001among three groups that was indicative of significant statistical differences. Similarly, there was no statistically significant difference in the average maternal fatigue score between the two groups before the intervention and in the second and third groups after the intervention. Therefore, over time, the training was unaffected. Conclusions: The findings of this study indicate that both face-to-face and e-learning methods are effective to reduce maternal postpartum fatigue.

  17. Effect of Reynolds Number and Periodic Unsteady Wake Flow Condition on Boundary Layer Development, Separation, and Intermittency Behavior Along the Suction Surface of a Low Pressure Turbine Blade

    Science.gov (United States)

    Schobeiri, M. T.; Ozturk, B.; Ashpis, David E.

    2007-01-01

    The paper experimentally studies the effects of periodic unsteady wake flow and different Reynolds numbers on boundary layer development, separation and re-attachment along the suction surface of a low pressure turbine blade. The experimental investigations were performed on a large scale, subsonic unsteady turbine cascade research facility at Turbomachinery Performance and Flow Research Laboratory (TPFL) of Texas A&M University. The experiments were carried out at Reynolds numbers of 110,000 and 150,000 (based on suction surface length and exit velocity). One steady and two different unsteady inlet flow conditions with the corresponding passing frequencies, wake velocities, and turbulence intensities were investigated. The reduced frequencies chosen cover the operating range of LP turbines. In addition to the unsteady boundary layer measurements, surface pressure measurements were performed. The inception, onset, and the extent of the separation bubble information collected from the pressure measurements were compared with the hot wire measurements. The results presented in ensemble-averaged, and the contour plot forms help to understand the physics of the separation phenomenon under periodic unsteady wake flow and different Reynolds number. It was found that the suction surface displayed a strong separation bubble for these three different reduced frequencies. For each condition, the locations defining the separation bubble were determined carefully analyzing and examining the pressure and mean velocity profile data. The location of the boundary layer separation was dependent of the Reynolds number. It is observed that starting point of the separation bubble and the re-attachment point move further downstream by increasing Reynolds number from 110,000 to 150,000. Also, the size of the separation bubble is smaller when compared to that for Re=110,000.

  18. Bordism, stable homotopy and adams spectral sequences

    CERN Document Server

    Kochman, Stanley O

    1996-01-01

    This book is a compilation of lecture notes that were prepared for the graduate course "Adams Spectral Sequences and Stable Homotopy Theory" given at The Fields Institute during the fall of 1995. The aim of this volume is to prepare students with a knowledge of elementary algebraic topology to study recent developments in stable homotopy theory, such as the nilpotence and periodicity theorems. Suitable as a text for an intermediate course in algebraic topology, this book provides a direct exposition of the basic concepts of bordism, characteristic classes, Adams spectral sequences, Brown-Peter

  19. Measuring Stellar Rotation Periods with Kepler

    DEFF Research Database (Denmark)

    Nielsen, M. B.; Gizon, L.; Schunker, H.

    2013-01-01

    We measure rotation periods for 12151 stars in the Kepler field, based on photometric variability caused by stellar activity. Our analysis returns stable rotation periods over at least six out of eight quarters of Kepler data. This large sample of stars enables us to study rotation periods...

  20. Stable isotope analysis in primatology: a critical review.

    Science.gov (United States)

    Sandberg, Paul A; Loudon, James E; Sponheimer, Matt

    2012-11-01

    Stable isotope analysis has become an important tool in ecology over the last 25 years. A wealth of ecological information is stored in animal tissues in the relative abundances of the stable isotopes of several elements, particularly carbon and nitrogen, because these isotopes navigate through ecological processes in predictable ways. Stable carbon and nitrogen isotopes have been measured in most primate taxonomic groups and have yielded information about dietary content, dietary variability, and habitat use. Stable isotopes have recently proven useful for addressing more fine-grained questions about niche dynamics and anthropogenic effects on feeding ecology. Here, we discuss stable carbon and nitrogen isotope systematics and critically review the published stable carbon and nitrogen isotope data for modern primates with a focus on the problems and prospects for future stable isotope applications in primatology. © 2012 Wiley Periodicals, Inc.

  1. Thermally Stable, Latent Olefin Metathesis Catalysts

    OpenAIRE

    Thomas, Renee M.; Fedorov, Alexey; Keitz, Benjamin K.; Grubbs, Robert H.

    2011-01-01

    Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A sterically hindered N-tert-butyl substituent on the NHC ligand of the ruthenium complex was found to i...

  2. Experimental study of void behavior in a suppression pool of a boiling water reactor during the blowdown period of a loss of coolant accident

    Science.gov (United States)

    Rassame, Somboon

    The possible failure of an Emergency Core Cooling System (ECCS) train due to a large amount of entrained gas in the ECCS pump suction piping in a Loss of Coolant Accident (LOCA) is one of the potential engineering problems faced in a Boiling Water Reactor (BWR) power plant. To analyze potential gas intrusion into the ECCS pump suction piping, the study of void behavior in the Suppression Pool (SP) during the LOCA is necessary. The void fraction distribution and void penetration are considered as the key parameters in the problem analysis. Two sets of experiments, namely, steady-state tests and transient tests were conducted using the Purdue University Multi-Dimensional Integral Test Assembly for ESBWR application (PUMA-E) to study void behavior in the SP during the blowdown. The design of the test apparatus used is based on the scaling analysis from a prototypical BWR containment (MARK-I) with consideration of the downcomer size, the SP water level, and the downcomer water submergence depth. Several instruments were installed to obtain the required experimental data, such as inlet gas volumetric flow, void fraction, pressure, and temperature. For the steady-state tests, the air was injected through a downcomer pipe in the SP in order to simulate the physical phenomena in the SP during the initial blowdown of LOCA. Thirty tests were performed with two different downcomer sizes (0.076 and 0.102 m), various air volumetric flow rates or flux (0.003 to 0.153 m3/s or 0.5 to 24.7 m/s), initial downcomer void conditions (fully filled with water, partially void, and completely void) and air velocity ramp rates (one to two seconds). Two phases of the experiment were observed, namely, the initial phase and the quasi-steady phase. The initial phase produced the maximum void penetration depth; and the quasi-steady phase showed less void penetration with oscillation in the void penetration. The air volumetric flow rate was found to have a minor effect on the void fraction

  3. Periodic or chaotic bursting dynamics via delayed pitchfork bifurcation in a slow-varying controlled system

    Science.gov (United States)

    Yu, Yue; Zhang, Zhengdi; Han, Xiujing

    2018-03-01

    In this work, we aim to demonstrate the novel routes to periodic and chaotic bursting, i.e., the different bursting dynamics via delayed pitchfork bifurcations around stable attractors, in the classical controlled Lü system. First, by computing the corresponding characteristic polynomial, we determine where some critical values about bifurcation behaviors appear in the Lü system. Moreover, the transition mechanism among different stable attractors has been introduced including homoclinic-type connections or chaotic attractors. Secondly, taking advantage of the above analytical results, we carry out a study of the mechanism for bursting dynamics in the Lü system with slowly periodic variation of certain control parameter. A distinct delayed supercritical pitchfork bifurcation behavior can be discussed when the control item passes through bifurcation points periodically. This delayed dynamical behavior may terminate at different parameter areas, which leads to different spiking modes around different stable attractors (equilibriums, limit cycles, or chaotic attractors). In particular, the chaotic attractor may appear by Shilnikov connections or chaos boundary crisis, which leads to the occurrence of impressive chaotic bursting oscillations. Our findings enrich the study of bursting dynamics and deepen the understanding of some similar sorts of delayed bursting phenomena. Finally, some numerical simulations are included to illustrate the validity of our study.

  4. Comportamiento de infecciones nosocomiales en un período de doce años Behavior of nosocomial infections in a 12-year period

    Directory of Open Access Journals (Sweden)

    Mercedes Ravelo González

    2008-06-01

    Full Text Available INTRODUCCIÓN. Son objetivos de esta presentación determinar el comportamiento de las infecciones nosocomiales en el Servicio de Neonatología del Hospital General Provincial Docente de Morón y describir los tipos de infecciones, los factores predisponentes, los microorganismos aislados y la resistencia de dichos gérmenes a los antibióticos de uso habitual en nuestro medio. MÉTODOS. Se realizó un estudio observacional descriptivo en el período de marzo de 1995 a diciembre de 2006. La obtención de los datos fue por revisión documental (historias clínicas y estos se presentan en tablas de distribución de frecuencia. Se realizaron medidas de tendencia central (media aritmética y mediana. RESULTADOS. La tasa de infección observada fue de 12,3. La sepsis generalizada fue el tipo de infección que más se presentó, y sus factores de riesgo más importantes fueron el bajo peso al nacer y la prematuridad. El estafilococo coagulasa-negativo fue el microorganismo más aislado en estudios microbiológicos. En todos los tubos endotraqueales estudiados se obtuvo crecimiento de gérmenes, así como también en catéteres venosos. Los gérmenes grampositivos presentaron elevada resistencia a las penicilinas y cefalosporinas de primera generación. CONCLUSIONES. Las infecciones nosocomiales constituyen un importante problema en nuestro servicio, y se debe trabajar para optimizar la intervención intensiva a nuestros pacientes y actuar sobre sus factores de riesgo.INTRODUCTION. This paper is aimed at determining the behavior of nosocomial infections in the Neonatology Service of the Provincial General Hospital of Morón and at describing the types of infections, the predisposing factors, the isolated microorganisms and the resistance of these germs to the usual antibiotics in our environment. METHODS. An observational descriptive study was carried out from March 1995 to December 2006. Data were obtained by documentary review (medical histories and

  5. Stable isotope methodology and its application to nutrition and gastroenterology

    International Nuclear Information System (INIS)

    Klein, P.D.; Hachey, D.L.; Wong, W.W.; Abrams, S.A.

    1993-01-01

    This report describes the activities of the Stable Isotope Laboratory in its function as a core resource facility for stable isotope applications in human nutrition research. Three aspects are covered: Training of visitors, assessment of new instrumentation, and development of new methodology. The research achievements of the laboratory are indicated in the publications that appeared during this period. (author). 23 refs

  6. Climatologia do comportamento do período chuvoso da região sudeste do Brasil Climatology of the rainy period behavior in the southeast region of Brazil

    Directory of Open Access Journals (Sweden)

    Rosandro Boligon Minuzzi

    2007-12-01

    Full Text Available Foram analisados dados diários de 203 estações pluviométricas localizadas na região Sudeste do Brasil, com o objetivo de caracterizar climaticamente e analisar a tendência do comportamento do período chuvoso. Os resultados indicam que o período chuvoso inicia mais cedo (entre 13 e 22 de setembro e tem maior duração (210 a 229 dias na região litorânea de São Paulo. Comportamento oposto ao observado nas regiões Norte e Vale do Jequitinhonha, em Minas Gerais, onde o período chuvoso inicia em média, entre os dias 23 de outubro a 2 de novembro, durando apenas 136 a 155 dias. As datas de início e a duração do período chuvoso estão fortemente correlacionadas entre si, bem como, entre o total de precipitação e a duração do período chuvoso em praticamente todo o Sudeste do Brasil. De modo geral, desde meados da década de 1970, o período chuvoso tem iniciado precocemente e durado mais no Sudeste do Brasil. Quanto à quantidade de chuva, esta tem ocorrido em maiores quantidades somente na área MG3 (sudeste de Minas Gerais e no estado de São Paulo.Daily data from 203 pluviometric stations, located in the Southeast region of Brazil, were studied with the objective to characterize climatically and analyze the tendency of the behavior of the rainy period. The results indicate that the rainy period begins early (between 13 and September 22th and has larger duration (210 to 229 days at the coastal area of São Paulo. Behavior opposed to the observed in the areas North and Vale do Jequitinhonha, in Minas Gerais, where the rainy period begins on average, among October 23th on November 2nd, only lasting 136 to 155 days. The duration and the dates at the beginning of the rainy period are strongly correlated, as well as, among the precipitation total and the duration of the rainy period in practically the whole Southeast region of Brazil. In general, from middles of the 1970's, the rainy period has started earlier and lasted more in the

  7. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  8. Effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses for a five-day period on behavioral and biochemical indicators of pain, stress, and inflammation.

    Science.gov (United States)

    Everett, James B; Schumacher, Jim; Doherty, Thomas J; Black, Randi A; Amelse, Lisa L; Krawczel, Peter; Coetzee, Johann F; Whitlock, Brian K

    2018-01-01

    OBJECTIVE To determine the effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses on behavioral and biochemical indicators of pain, stress, and inflamation. ANIMALS 20 Tennessee Walking Horses. PROCEDURES Horses were randomly assigned to 2 treatment groups: keg shoes (control; n = 10) or stacked wedge pads and exercise with chains (10). Ten days before treatment application, an accelerometer was attached at the left metatarsus of each horse to record daily activity. Horses were exercised for 20 minutes daily, beginning on day -7. On day 0, exercise ceased, the forefeet were trimmed, and the assigned treatment was applied. From days 1 through 5, horses were exercised as before. Blood samples for measurement of plasma cortisol, substance P, and fibrinogen concentrations were collected on days -5, 1, and 5 before and after exercise and every 30 minutes thereafter for 6 hours. RESULTS No significant differences in plasma concentrations of cortisol, substance P, and fibrinogen were detected between groups. Although lying behaviors changed after shoes were applied, these behaviors did not differ significantly between groups. Shoeing appeared to have altered behavior to a greater extent than did the type of treatment applied. CONCLUSIONS AND CLINICAL RELEVANCE Application of stacked wedge pads and chains to the forefeet of horses for a 5-day period as performed in this study evoked no acute or subacute stress or nociceptive response as measured. Although these findings should not be extrapolated to the long-term use of such devices in Tennessee Walking Horses performing the running walk, the data should be considered when making evidence-based decisions relating to animal welfare and the use of stacked wedge pads and chains.

  9. A qualitative study of the instructional behaviors and practices of a dyad of educators in self-contained and inclusive co-taught secondary biology classrooms during a nine-week science instruction grading period

    Science.gov (United States)

    Hardy, Shanon D.

    The Individuals with Disabilities Education Act (IDEA) (1997) mandates that students with disabilities have access to the general education curriculum. School districts have developed a variety of service delivery models to provide challenging educational experiences for all students. Co-teaching or collaborative teaching is the most widely used of the different service delivery models. While the philosophy of inclusion is widely accepted, the efficacy of the various inclusion models has recently been the focus of educational research. Researchers have questioned whether the presence of a special educator in the general education classroom has resulted in students with high incidence disabilities receiving specialized instruction. A qualitative study was designed to examine the instructional behaviors and practices exhibited and used by a dyad of educators in self-contained learning disabilities and inclusive co-taught secondary Biology classrooms during a nine-week science instruction grading period. In addition to utilizing interviews, observations, and classroom observation scales to answer the research questions, supporting student data (time-sampling measurement/opportunity to learn and student grades) were collected. The study concluded that the presence of a special educator in a co-taught classroom: (1) did contribute to the creation of a new learning environment, and notable changes in the instructional behaviors and practices of a general educator; (2) did contribute to limited specialized instruction for students with disabilities in the co-taught classrooms and embedded (not overt) special education practices related to the planning and decision-making of the educators; (3) did contribute to the creation of a successful co-teaching partnership including the use of effective teaching behaviors; and (4) did impact success for some of the students with disabilities in the co-taught classrooms; but (5) did not ensure the continuation of some of the new

  10. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.

    2015-04-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  11. Influence of horse stable environment on human airways

    Directory of Open Access Journals (Sweden)

    Pringle John

    2009-05-01

    Full Text Available Abstract Background Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. Methods The horse stable environment and stable-workers (n = 13 in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Results Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-β-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Conclusion Biomarkers involved in the development of airway diseases have been studied in relation to

  12. Technical Note: Calcium and carbon stable isotope ratios as paleodietary indicators.

    Science.gov (United States)

    Melin, Amanda D; Crowley, Brooke E; Brown, Shaun T; Wheatley, Patrick V; Moritz, Gillian L; Yit Yu, Fred Tuh; Bernard, Henry; DePaolo, Donald J; Jacobson, Andrew D; Dominy, Nathaniel J

    2014-08-01

    Calcium stable isotope ratios are hypothesized to vary as a function of trophic level. This premise raises the possibility of using calcium stable isotope ratios to study the dietary behaviors of fossil taxa and to test competing hypotheses on the adaptive origins of euprimates. To explore this concept, we measured the stable isotope composition of contemporary mammals in northern Borneo and northwestern Costa Rica, two communities with functional or phylogenetic relevance to primate origins. We found that bone collagen δ(13) C and δ(15) N values could differentiate trophic levels in each assemblage, a result that justifies the use of these systems to test the predicted inverse relationship between bioapatite δ(13) C and δ(44) Ca values. As expected, taxonomic carnivores (felids) showed a combination of high δ(13) C and low δ(44) Ca values; however, the δ(44) Ca values of other faunivores were indistinguishable from those of primary consumers. We suggest that the trophic insensitivity of most bioapatite δ(44) Ca values is attributable to the negligible calcium content of arthropod prey. Although the present results are inconclusive, the tandem analysis of δ(44) Ca and δ(13) C values in fossils continues to hold promise for informing paleodietary studies and we highlight this potential by drawing attention to the stable isotope composition of the Early Eocene primate Cantius. © 2014 Wiley Periodicals, Inc.

  13. Dynamical attraction to stable processes

    OpenAIRE

    Fisher, Albert M.; Talet, Marina

    2012-01-01

    We apply dynamical ideas within probability theory, proving an almost-sure invariance principle in log density for stable processes. The familiar scaling property (self-similarity) of the stable process has a stronger expression, that the scaling flow on Skorokhod path space is a Bernoulli flow. We prove that typical paths of a random walk with i.i.d. increments in the domain of attraction of a stable law can be paired with paths of a stable process so that, after applying a non-random regula...

  14. Advances in primate stable isotope ecology-Achievements and future prospects.

    Science.gov (United States)

    Crowley, Brooke E; Reitsema, Laurie J; Oelze, Vicky M; Sponheimer, Matt

    2016-10-01

    Stable isotope biogeochemistry has been used to investigate foraging ecology in non-human primates for nearly 30 years. Whereas early studies focused on diet, more recently, isotopic analysis has been used to address a diversity of ecological questions ranging from niche partitioning to nutritional status to variability in life history traits. With this increasing array of applications, stable isotope analysis stands to make major contributions to our understanding of primate behavior and biology. Most notably, isotopic data provide novel insights into primate feeding behaviors that may not otherwise be detectable. This special issue brings together some of the recent advances in this relatively new field. In this introduction to the special issue, we review the state of isotopic applications in primatology and its origins and describe some developing methodological issues, including techniques for analyzing different tissue types, statistical approaches, and isotopic baselines. We then discuss the future directions we envision for the field of primate isotope ecology. Am. J. Primatol. 78:995-1003, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  15. Changing people's perceptions and behavior through partnerships and education: followup on a case study from Minnesota

    Science.gov (United States)

    Tim Kelly; Ron Sushak; Pamela Jakes

    2001-01-01

    A follow-up survey of residents in southeastern Minnesota shows that environmental values were stable over a 5-year period. The authors were unable to measure any impacts of a Minnesota Department of Natural Resources comprehensive watershed planning initiative in the Wells Creek watershed on residents' behaviors and attitudes and perceptions about the...

  16. Change in Autism Symptoms and Maladaptive Behaviors in Adolescents and Adults with an Autism Spectrum Disorder

    Science.gov (United States)

    Shattuck, Paul T.; Seltzer, Marsha Mailick; Greenberg, Jan S.; Orsmond, Gael I.; Bolt, Daniel; Kring, Sheilah; Lounds, Julie; Lord, Catherine

    2007-01-01

    This study examined change prospectively in autism symptoms and maladaptive behaviors during a 4.5 year period in 241 adolescents and adults with an autism spectrum disorder who were 10-52 years old (mean=22.0) when the study began. Although many individuals' symptoms remained stable, a greater proportion of the sample experienced declines than…

  17. Synthetic chemistry with periodic mesostructures at high pressure.

    Science.gov (United States)

    Mandal, Manik; Landskron, Kai

    2013-11-19

    Over the last two decades, researchers have studied extensively the synthesis of mesostructured materials, which could be useful for drug delivery, catalytic cracking of petroleum, or reinforced plastics, among other applications. However, until very recently researchers used only temperature as a thermodynamic variable for synthesis, completely neglecting pressure. In this Account, we show how pressure can affect the synthetic chemistry of periodic mesoporous structures with desirable effects. In its simplest application, pressure can crystallize the pore walls of periodic mesoporous silicas, which are difficult to crystallize otherwise. The motivation for the synthesis of periodic mesoporous silica materials (with pore sizes from 2 to 50 nm) 20 years ago was to replace the microporous zeolites (which have pore sizes of amorphous nature of the mesoporous materials' channel walls. To address this problem, we developed the concept of "nanocasting at high pressure". Through this approach, we produced hitherto-unavailable, periodic mesostructured silicas with crystalline pore walls. In nanocasting, we compress a periodic mesostructured composite (e.g. a periodic mesoporous silica with carbon-filled pores) and subsequently heat it to induce the selective crystallization of one of the two phases. We attain the necessary high pressure for synthesis using piston-cylinder and multianvil apparatuses. Using periodic mesostructured silica/carbon nanocomposites as starting material, we have produced periodic mesoporous coesite and periodic mesoporous quartz. The quartz material is highly stable under harsh hydrothermal conditions (800°C in pure steam), verifying that crystallinity in the channel walls of periodic mesoporous silicas increases their hydrothermal stability. Even without including the carbon phase in the silica pores, we could obtain mesoporous coesite materials. We found similar behavior for periodic mesoporous carbons, which convert into transparent, mesoporous

  18. WORKSHOP: Stable particle motion

    International Nuclear Information System (INIS)

    Ruggiero, Alessandro G.

    1993-01-01

    Full text: Particle beam stability is crucial to any accelerator or collider, particularly big ones, such as Brookhaven's RHIC heavy ion collider and the larger SSC and LHC proton collider schemes. A workshop on the Stability of Particle Motion in Storage Rings held at Brookhaven in October dealt with the important issue of determining the short- and long-term stability of single particle motion in hadron storage rings and colliders, and explored new methods for ensuring it. In the quest for realistic environments, the imperfections of superconducting magnets and the effects of field modulation and noise were taken into account. The workshop was divided into three study groups: Short-Term Stability in storage rings, including chromatic and geometric effects and correction strategies; Long-Term Stability, including modulation and random noise effects and slow varying effects; and Methods for determining the stability of particle motion. The first two were run in parallel, but the third was attended by everyone. Each group considered analytical, computational and experimental methods, reviewing work done so far, comparing results and approaches and underlining outstanding issues. By resolving conflicts, it was possible to identify problems of common interest. The workshop reaffirmed the validity of methods proposed several years ago. Major breakthroughs have been in the rapid improvement of computer capacity and speed, in the development of more sophisticated mathematical packages, and in the introduction of more powerful analytic approaches. In a typical storage ring, a particle may be required to circulate for about a billion revolutions. While ten years ago it was only possible to predict accurately stability over about a thousand revolutions, it is now possible to predict over as many as one million turns. If this trend continues, in ten years it could become feasible to predict particle stability over the entire storage period. About ninety participants

  19. On the behavior of ion implanted silicon strip detectors in high intensity low energy heavy ion beam experiments

    CERN Document Server

    Bradfield, W; Parker, P D; Visser, D W

    2002-01-01

    In a recent investigation of the development of leakage currents in Silicon Strip Detectors used in experiments with high intensity stable beams, anomalous behavior was observed. Over a very short period of time the leakage current rose to levels that could be damaging to the detectors. A discussion of this evidence and how the problem was solved, with a viable model, will be given, leading to guidelines for use of such detectors in a stable beam environment.

  20. 77 FR 60113 - Acceptance of Public Submissions Regarding the Study of Stable Value Contracts

    Science.gov (United States)

    2012-10-02

    ...; File No. S7-32-11] Acceptance of Public Submissions Regarding the Study of Stable Value Contracts...'') are reopening the comment period for a study to determine whether stable value contracts (``SVCs... method. ``Stable Value Contract Study'' must be in the subject field of responses submitted via email...

  1. Change in Autism Symptoms and Maladaptive Behaviors in Adolescents and Adults with an Autism Spectrum Disorder

    OpenAIRE

    Shattuck, Paul T.; Seltzer, Marsha Mailick; Greenberg, Jan S.; Orsmond, Gael I.; Bolt, Daniel; Kring, Sheilah; Lounds, Julie; Lord, Catherine

    2006-01-01

    This study examined change prospectively in autism symptoms and maladaptive behaviors during a 4.5 year period in 241 adolescents and adults with an autism spectrum disorder who were 10–52 years old (mean = 22.0) when the study began. Although many individuals’ symptoms remained stable, a greater proportion of the sample experienced declines than increases in their level of autism symptoms and maladaptive behaviors, and there were significant improvements in mean levels of symptoms. Individua...

  2. Elastic Stable Intramedullary Nailing for Treatment of Pediatric Tibial Fractures

    OpenAIRE

    Sandeep Gurung; Dipendra KC; Roshni Khatri

    2016-01-01

    Introduction: Tibia fractures in the skeletally immature patient can usually be treated with above knee cast or patellar tendon bearing cast. The purpose of our study was to evaluate epidemiology and outcome of Elastic stable intramedullary nailing fixation of pediatric tibial shaft fractures treated at our institution. Methods: Over a period of one year, fifty pediatric patients of tibial shaft fractures, with average age of 9.68 yr (SD=2.37), were treated with elastic stable intramedul...

  3. Shelf-Stable Food Safety

    Science.gov (United States)

    ... is an MRE? Is an MRE shelf stable? What foods are packaged in retort packages? What is aseptic ... type of package is used for aseptic processing? What foods are packaged in aseptic packages? Can I microwave ...

  4. Aggressive Fibromatosis: Evidence for a Stable Phase

    Directory of Open Access Journals (Sweden)

    Gillian Mitchell

    1998-01-01

    Full Text Available Purpose. Aggressive fibromatosis (AF is an uncommon locally infiltrating benign disease of soft tissue for which treatment comprises complete surgical resection. Radiotherapy can be given postoperatively if the margin is incompletely resected. If the tumour is inoperable radiotherapy provides an alternative treatment. Hormone therapy and cytotoxic chemotherapy have also been used for unresectable or recurrent disease. All treatment modalities carry an associated morbidity. We believe that the natural history of aggressive fibromatosis may include a period of stable disease without progression, during which time, treatment is not always necessary.

  5. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  6. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  7. Dysmenorrhea: Painful Periods

    Science.gov (United States)

    ... Search FAQs Dysmenorrhea: Painful Periods Page Navigation ▼ ACOG Pregnancy Book Dysmenorrhea: Painful Periods Patient Education FAQs Dysmenorrhea: Painful Periods Patient Education Pamphlets - Spanish ...

  8. The nature of stable insomnia phenotypes.

    Science.gov (United States)

    Pillai, Vivek; Roth, Thomas; Drake, Christopher L

    2015-01-01

    We examined the 1-y stability of four insomnia symptom profiles: sleep onset insomnia; sleep maintenance insomnia; combined onset and maintenance insomnia; and neither criterion (i.e., insomnia cases that do not meet quantitative thresholds for onset or maintenance problems). Insomnia cases that exhibited the same symptom profile over a 1-y period were considered to be phenotypes, and were compared in terms of clinical and demographic characteristics. Longitudinal. Urban, community-based. Nine hundred fifty-four adults with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition based current insomnia (46.6 ± 12.6 y; 69.4% female). None. At baseline, participants were divided into four symptom profile groups based on quantitative criteria. Follow-up assessment 1 y later revealed that approximately 60% of participants retained the same symptom profile, and were hence judged to be phenotypes. Stability varied significantly by phenotype, such that sleep onset insomnia (SOI) was the least stable (42%), whereas combined insomnia (CI) was the most stable (69%). Baseline symptom groups (cross-sectionally defined) differed significantly across various clinical indices, including daytime impairment, depression, and anxiety. Importantly, however, a comparison of stable phenotypes (longitudinally defined) did not reveal any differences in impairment or comorbid psychopathology. Another interesting finding was that whereas all other insomnia phenotypes showed evidence of an elevated wake drive both at night and during the day, the 'neither criterion' phenotype did not; this latter phenotype exhibited significantly higher daytime sleepiness despite subthreshold onset and maintenance difficulties. By adopting a stringent, stability-based definition, this study offers timely and important data on the longitudinal trajectory of specific insomnia phenotypes. With the exception of daytime sleepiness, few clinical differences are apparent across stable phenotypes.

  9. Stable Boundary Layer Education (STABLE) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Turner, David D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The properties of, and the processes that occur in, the nocturnal stable boundary layer are not well understood, making it difficult to represent adequately in numerical models. The nocturnal boundary layer often is characterized by a temperature inversion and, in the Southern Great Plains region, a low-level jet. To advance our understanding of the nocturnal stable boundary layer, high temporal and vertical resolution data on the temperature and wind properties are needed, along with both large-eddy simulation and cloud-resolving modeling.

  10. Stable Ferroelectric Behavior of Nb-Modified Bi0.5K0.5TiO3-Bi(Mg0.5Ti0.5)O3 Lead-Free Relaxor Ferroelectric Ceramics

    Science.gov (United States)

    Zaman, Arif; Malik, Rizwan Ahmed; Maqbool, Adnan; Hussain, Ali; Ahmed, Tanveer; Song, Tae Kwon; Kim, Won-Jeong; Kim, Myong-Ho

    2018-03-01

    Crystal structure, dielectric, ferroelectric, piezoelectric, and electric field-induced strain properties of lead-free Nb-modified 0.96Bi0.5K0.5TiO3-0.04Bi(Mg0.5Ti0.5)O3 (BKT-BMT) piezoelectric ceramics were investigated. Crystal structure analysis showed a gradual phase transition from tetragonal to pseudocubic phase with increasing Nb content. The optimal piezoelectric property of small-signal d 33 was enhanced up to ˜ 68 pC/N with a lower coercive field ( E c) of ˜ 22 kV/cm and an improved remnant polarization ( P r) of ˜ 13 μC/cm2 for x = 0.020. A relaxor-like behavior with a frequency-dependent Curie temperature T m was observed, and a high T m around 320°C was obtained in the investigated system. This study suggests that the ferroelectric properties of BKT-BMT was significantly improved by means of Nb substitution. The possible shift of depolarization temperature T d toward high temperature T m may have triggered the spontaneous relaxor to ferroelectric phase transition with long-range ferroelectric order without any traces of a nonergodic relaxor state in contradiction with Bi0.5Na0.5TiO3-based systems. The possible enhancement in ferroelectric and piezoelectric properties near the critical composition x = 0.020 may be attributed to the increased anharmonicity of lattice vibrations which may facilitate the observed phase transition from a low-symmetry tetragonal to a high-symmetry cubic phase with a decrease in the lattice anisotropy of an undoped sample. This highly flexible (at a unit cell level) narrow compositional range triggers the enhancement of d 33 and P r values.

  11. Periodic Control of Power Electronic Converters

    DEFF Research Database (Denmark)

    Zhou, Keliang; Danwei, Wang; Yang, Yongheng

    Advanced power electronic converters convert, control and condition electricity. Power converters require control strategies for periodic signal compensation to assure good power quality and stable power system operation. This comprehensive text presents the most recent internal model principle...... based periodic control technology, which offers the perfect periodic control solution for power electronic conversion. It also provides complete analysis and synthesis methods for periodic control systems, and plenty of practical examples to demonstrate the validity of proposed periodic control...... technology for power converters. It proposes a unified framework for housing periodic control schemes for power converters, and provides a general proportional-integral-derivative control solution to periodic signal compensation in extensive engineering applications. Periodic Control of Power Electronic...

  12. Periodic and quasiperiodic revivals in periodically driven interacting quantum systems

    Science.gov (United States)

    Luitz, David J.; Lazarides, Achilleas; Bar Lev, Yevgeny

    2018-01-01

    Recently it has been shown that interparticle interactions generically destroy dynamical localization in periodically driven systems, resulting in diffusive transport and heating. In this Rapid Communication we rigorously construct a family of interacting driven systems which are dynamically localized and effectively decoupled from the external driving potential. We show that these systems exhibit tunable periodic or quasiperiodic revivals of the many-body wave function and thus of all physical observables. By numerically examining spinless fermions on a one-dimensional lattice we show that the analytically obtained revivals of such systems remain stable for finite systems with open boundary conditions while having a finite lifetime in the presence of static spatial disorder. We find this lifetime to be inversely proportional to the disorder strength.

  13. Monitoring Period and Amplitude Changes in Classical Cepheids

    Science.gov (United States)

    Erickson, Mary; Engle, Scott; Guinan, Edward; Wells, Mark

    2018-01-01

    Classical Cepheids are a specific class of radially pulsating variable stars and are fundamentally important to Astronomy and Cosmology. Their pulsations can be used to determine accurate distances, both inside the Milky Way and to other galaxies throughout the Universe, via the well-studied Period-Luminosity Relationship (the Leavitt Law). This makes Cepheids “standard candles,” and they are helping Astronomers refine the expansion rate and age of the Universe.Though Cepheid pulsations were long-theorized to be completely stable, we now know that they undergo small but observable changes in their pulsation periods. The rates of the period change give us invaluable information on the Cepheids themselves, and the advent of reliable all-sky photometry surveys has allowed Cepheid pulsations to be monitored more easily than ever before.Five Cepheids were analyzed for this study – AA Gem, BB Gem, RZ Gem, AD Gem, and DX Gem. Photometric data were obtained from two sources: ASAS (the All-Sky Automated Survey) and the RCT (Robotically Controlled Telescope) at Kitt Peak National Observatory in Arizona, whose consortium Villanova is a member of. This photometry is combined with available data from the literature. The two instruments combined give a longer time span, and increased precision, from which period variations can be monitored. This gives us an excellent look at how the pulsations of these 5 Cepheids are evolving over time. The pulsation behavior of the 5 Cepheids studies will be presented, along with their calculated stellar parameters.

  14. Numerical Simulation of Cylindrical Solitary Waves in Periodic Media

    KAUST Repository

    Quezada de Luna, Manuel

    2013-07-14

    We study the behavior of nonlinear waves in a two-dimensional medium with density and stress relation that vary periodically in space. Efficient approximate Riemann solvers are developed for the corresponding variable-coefficient first-order hyperbolic system. We present direct numerical simulations of this multiscale problem, focused on the propagation of a single localized perturbation in media with strongly varying impedance. For the conditions studied, we find little evidence of shock formation. Instead, solutions consist primarily of solitary waves. These solitary waves are observed to be stable over long times and to interact in a manner approximately like solitons. The system considered has no dispersive terms; these solitary waves arise due to the material heterogeneity, which leads to strong reflections and effective dispersion.

  15. Diffractons: Solitary Waves Created by Diffraction in Periodic Media

    KAUST Repository

    Ketcheson, David I.

    2015-03-31

    A new class of solitary waves arises in the solution of nonlinear wave equations with constant impedance and no dispersive terms. These solitary waves depend on a balance between nonlinearity and a dispersion-like effect due to spatial variation in the sound speed of the medium. A high-order homogenized model confirms this effective dispersive behavior, and its solutions agree well with those obtained by direct simulation of the variable-coefficient system. These waves are observed to be long-time stable, globally attracting solutions that arise in general as solutions to nonlinear wave problems with periodically varying sound speed. They share some properties with known classes of solitary waves but possess important differences as well.

  16. Contribution of stable isotopes to the study of pharmacokinetics of magnesium salts; Apport des isotopes stables a l'etude de la pharmacocinetique de sels de magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Benech, H

    1999-05-28

    The use of stable isotopes as labels is becoming an attractive tool for the study of magnesium behavior in humans. It has been used two stable isotopes of magnesium, {sup 25}Mg and {sup 26}Mg, to measure the absolute bioavailability of a pharmaceutical form of magnesium. (N.C.)

  17. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    Rekers, J.W.

    1986-01-01

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  18. Monitoring of stable glaucoma patients

    NARCIS (Netherlands)

    K.M. Holtzer-Goor (Kim); N.S. Klazinga (Niek); M.A. Koopmanschap (Marc); H.G. Lemij (Hans); T. Plochg; E. van Sprundel (Esther)

    2010-01-01

    textabstractA high workload for ophthalmologists and long waiting lists for patients challenge the organization of ophthalmic care. Tasks that require less specialized skills, like the monitoring of stable (well controlled) glaucoma patients could be substituted from ophthalmologists to other

  19. Absent menstrual periods - secondary

    Science.gov (United States)

    Amenorrhea - secondary; No periods - secondary; Absent periods - secondary; Absent menses - secondary; Absence of periods - secondary ... Secondary amenorrhea can occur due to natural changes in the body. For example, the most common cause of secondary ...

  20. Is Sensation Seeking a Stable Trait or Does It Change over Time?

    Science.gov (United States)

    Lynne-Landsman, Sarah D.; Graber, Julia A.; Nichols, Tracy R.; Botvin, Gilbert J.

    2011-01-01

    The theory of sensation seeking has conceptualized this construct as a stable personality trait associated with a variety of problem behaviors. Reckless behavior theory posits that increases in reckless behavior during adolescence can be attributed, in part, to increases in sensation seeking. This study evaluated patterns of stability and change…

  1. Complex Behavior in Simple Models of Biological Coevolution

    Science.gov (United States)

    Rikvold, Per Arne

    We explore the complex dynamical behavior of simple predator-prey models of biological coevolution that account for interspecific and intraspecific competition for resources, as well as adaptive foraging behavior. In long kinetic Monte Carlo simulations of these models we find quite robust 1/f-like noise in species diversity and population sizes, as well as power-law distributions for the lifetimes of individual species and the durations of quiet periods of relative evolutionary stasis. In one model, based on the Holling Type II functional response, adaptive foraging produces a metastable low-diversity phase and a stable high-diversity phase.

  2. Molecular nanomagnet in periodic magnetic field

    International Nuclear Information System (INIS)

    Sinitsyn, N.A.

    2002-01-01

    The behavior of molecular nanomagnets in periodic magnetic field transverse to the easy axis direction is investigated. It is shown that at sufficiently strong field the tunneling time can be considerably reduced

  3. Stable and Dynamic Coding for Working Memory in Primate Prefrontal Cortex

    Science.gov (United States)

    Watanabe, Kei; Funahashi, Shintaro; Stokes, Mark G.

    2017-01-01

    Working memory (WM) provides the stability necessary for high-level cognition. Influential theories typically assume that WM depends on the persistence of stable neural representations, yet increasing evidence suggests that neural states are highly dynamic. Here we apply multivariate pattern analysis to explore the population dynamics in primate lateral prefrontal cortex (PFC) during three variants of the classic memory-guided saccade task (recorded in four animals). We observed the hallmark of dynamic population coding across key phases of a working memory task: sensory processing, memory encoding, and response execution. Throughout both these dynamic epochs and the memory delay period, however, the neural representational geometry remained stable. We identified two characteristics that jointly explain these dynamics: (1) time-varying changes in the subpopulation of neurons coding for task variables (i.e., dynamic subpopulations); and (2) time-varying selectivity within neurons (i.e., dynamic selectivity). These results indicate that even in a very simple memory-guided saccade task, PFC neurons display complex dynamics to support stable representations for WM. SIGNIFICANCE STATEMENT Flexible, intelligent behavior requires the maintenance and manipulation of incoming information over various time spans. For short time spans, this faculty is labeled “working memory” (WM). Dominant models propose that WM is maintained by stable, persistent patterns of neural activity in prefrontal cortex (PFC). However, recent evidence suggests that neural activity in PFC is dynamic, even while the contents of WM remain stably represented. Here, we explored the neural dynamics in PFC during a memory-guided saccade task. We found evidence for dynamic population coding in various task epochs, despite striking stability in the neural representational geometry of WM. Furthermore, we identified two distinct cellular mechanisms that contribute to dynamic population coding. PMID

  4. Toward Practical Secure Stable Matching

    Directory of Open Access Journals (Sweden)

    Riazi M. Sadegh

    2017-01-01

    Full Text Available The Stable Matching (SM algorithm has been deployed in many real-world scenarios including the National Residency Matching Program (NRMP and financial applications such as matching of suppliers and consumers in capital markets. Since these applications typically involve highly sensitive information such as the underlying preference lists, their current implementations rely on trusted third parties. This paper introduces the first provably secure and scalable implementation of SM based on Yao’s garbled circuit protocol and Oblivious RAM (ORAM. Our scheme can securely compute a stable match for 8k pairs four orders of magnitude faster than the previously best known method. We achieve this by introducing a compact and efficient sub-linear size circuit. We even further decrease the computation cost by three orders of magnitude by proposing a novel technique to avoid unnecessary iterations in the SM algorithm. We evaluate our implementation for several problem sizes and plan to publish it as open-source.

  5. Application of stable isotope to breath test

    International Nuclear Information System (INIS)

    Sasaki, Yasuto

    1988-01-01

    Needles to say, radioisotopes have good characteristics as a tracer for examining biological functions. In fact, scyntigraphy is widely used over Japan. It is true, however, that there are some difficulties in applying radioisotopes to humans. Thus, greater attention began to be attracted to stable isotopes in the late 1960s, because these substances can be used for infants and pregnant women. They can be stored for a long period of time since they do not suffer damping as in the case of radioisotopes. In addition to serving as a tracer, stable isotopes can provide structural-chemical information including the position of isotope labels, and the mass and atomic composition of fragment ions. Such techniques as NMR spectroscopy is employed for this purpose. The method is currently used to perform examinations of congenital metabolic disorders. The carbon isotopes of 13 C and 14 C are used for breath test. Compounds labeled with these isotopes are administered and their ratio to the total CO 2 in breath is measured to diagnose diseases. In the early 1970s, 13 C has come into use for breath test. Similar breath test is applied to diagnosis of the bacterial overgrowth syndrome and ileal dysfunction syndrome. (Nogami, K.)

  6. Towards stable acceleration in LINACS

    CERN Document Server

    Dubrovskiy, A D

    2014-01-01

    Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

  7. Stable Oxygen-18 and Deuterium Isotopes

    DEFF Research Database (Denmark)

    Müller, Sascha

    The application of stable Oxygen-18 (18O) and Deuterium (2H) isotopes, as a tracer for fluxes between different compartments of the water cycle was subject of the present PhD-thesis. During a three year period, temporal data from a wide range of water cycle constituents was collected from...... the Skjern River catchment, Denmark. The presented applications focused on studying the isotopic 'input signal' to the hydrosphere in the form of precipitation, the isotopic 'output signal' with its related dynamic processes at a coastal saltwater-freshwater interface (groundwater isotopes) and the temporal...... development within a given lowland headwater catchment (stream water isotopes). Based on our investigations on the precipitation isotopic composition a local meteoric water line (LMWL) was constructed and expressed as: δ2H=7.4 δ18O + 5.36‰. Moreover, we showed that under maritime temperature climate influence...

  8. Stability of Periodically Focused Intense Particle Beams

    International Nuclear Information System (INIS)

    Pakter, R.; Rizzato, F. B.

    2001-01-01

    A stability analysis of periodically focused intense particle beams based on the beam envelope equation is performed. We show that (i) the scenario, as the focusing field increases, is not the existence of a single threshold above which stable matched (equilibrium) solutions are absent, as generally believed, but the existence of successive regions of stability interrupted by gaps of instability; (ii) the beam can be focused to tighter radii using new stable matched solutions found for focusing field strengths greater than the previous threshold. Self-consistent simulations validate the findings

  9. Spectral Behavior of the "Stable Shell" Star HD 179343

    Czech Academy of Sciences Publication Activity Database

    Iliev, L.; Kubát, Jiří

    2010-01-01

    Roč. 20, Suppl. (2010), s. 33-37 ISSN 1220-5168 Institutional research plan: CEZ:AV0Z10030501 Keywords : variable star s * Be/shell star s * spectral observations Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  10. Contribution of stable isotopes to the study of pharmacokinetics of magnesium salts

    International Nuclear Information System (INIS)

    Benech, H.

    1999-01-01

    The use of stable isotopes as labels is becoming an attractive tool for the study of magnesium behavior in humans. It has been used two stable isotopes of magnesium, 25 Mg and 26 Mg, to measure the absolute bioavailability of a pharmaceutical form of magnesium. (N.C.)

  11. Metal stable isotope signatures as tracers in environmental geochemistry.

    Science.gov (United States)

    Wiederhold, Jan G

    2015-03-03

    The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers. This review presents the application of metal stable isotopes as source and process tracers in environmental studies, in particular by using mixing and Rayleigh model approaches. The most important concepts of mass-dependent and mass-independent metal stable isotope fractionation are introduced, and the extent of natural isotopic variations for different elements is compared. A particular focus lies on a discussion of processes (redox transformations, complexation, sorption, precipitation, dissolution, evaporation, diffusion, biological cycling) which are able to induce metal stable isotope fractionation in environmental systems. Additionally, the usefulness and limitations of metal stable isotope signatures as tracers in environmental geochemistry are discussed and future perspectives presented.

  12. High precision and stable structures for particle detectors

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude

    1999-01-01

    The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

  13. Thyrotoxic periodic paralysis

    Science.gov (United States)

    ... have a family history of periodic paralysis or thyroid disorders. Emergency symptoms include: Difficulty breathing, speaking, or swallowing ... Prevention Genetic counseling may be advised. Treating the thyroid disorder prevents attacks of weakness. Alternative Names Periodic paralysis - ...

  14. Your First Period

    Science.gov (United States)

    ... on your abdomen or lower back. What is amenorrhea? Amenorrhea means not having a period. It is normal ... or less often than every 45 days. Glossary Amenorrhea: The absence of menstrual periods. Egg: The female ...

  15. Stable Hemiaminals: 2-Aminopyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Anna Kwiecień

    2015-08-01

    Full Text Available Stable hemiaminals can be obtained in the one-pot reaction between 2-aminopyrimidine and nitrobenzaldehyde derivatives. Ten new hemiaminals have been obtained, six of them in crystal state. The molecular stability of these intermediates results from the presence of both electron-withdrawing nitro groups as substituents on the phenyl ring and pyrimidine ring, so no further stabilisation by intramolecular interaction is required. Hemiaminal molecules possess a tetrahedral carbon atom constituting a stereogenic centre. As the result of crystallisation in centrosymmetric space groups both enantiomers are present in the crystal structure.

  16. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  17. Stable agents for imaging investigations

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    This invention concerns highly stable compounds useful in preparing technetium 99m based scintiscanning exploration agents. The compounds of this invention include a pertechnetate reducing agent or a solution of oxidized pertechnetate and an efficient proportion, sufficient to stabilize the compounds in the presence of oxygen and of radiolysis products, of ascorbic acid or a pharmaceutically acceptable salt or ester of this acid. The invention also concerns a perfected process for preparing a technetium based exploration agent, consisting in codissolving the ascorbic acid or a pharmaceutically acceptable salt or ester of such an acid and a pertechnetate reducing agent in a solution of oxidized pertechnetate [fr

  18. Book Reviews in Periodicals.

    Science.gov (United States)

    Ettelt, Harold J.

    All recent issues of periodicals found which contain indexed book reviews are listed in this compilation from Drake Memorial Library at the New York State University at Brockport. The periodicals are listed by 29 subject headings in this informal guide designed to be used at Drake Library. The number of reviews in the periodical in a recent year…

  19. The Periodic Pyramid

    Science.gov (United States)

    Hennigan, Jennifer N.; Grubbs, W. Tandy

    2013-01-01

    The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

  20. Controlling hyperchaos and periodic synchronization in DOPO with parameter modulated by an external periodic signal

    Energy Technology Data Exchange (ETDEWEB)

    Feng Xiuqin [Department of Physics, ChangChun University of Science and Technology, ChangChun 130022 (China)], E-mail: Fengxq@cust.edu.cn; Shen Ke [Department of Physics, ChangChun University of Science and Technology, ChangChun 130022 (China)

    2008-02-15

    Hyperchaotic behaviors can be controlled and converted into periodic behaviors by modulating the detuned parameters using an external periodic signal in degenerated optical parameter oscillator (DOPO). Numerical simulations show that the period number differs on the account of the modulating coefficient. Increasing the modulating coefficient, the DOPO results in conversion to periodic orbits. Subsequently it is converted into period 2, and then into period 1. It was also shown that the periodic orbits of the DOPOs modulated through external periodic signal can result in identical synchronization or anti-synchronization only in the case that the largest Lyapunov exponent of the system is negative. Thus synchronization types and evolution process of synchronization is determined by modulating coefficient and initial conditions.

  1. Asymptotically Almost Periodic Solutions for a Class of Stochastic Functional Differential Equations

    Directory of Open Access Journals (Sweden)

    Aimin Liu

    2014-01-01

    Full Text Available This work is concerned with the quadratic-mean asymptotically almost periodic mild solutions for a class of stochastic functional differential equations dxt=Atxt+Ft,xt,xtdt+H(t,xt,xt∘dW(t. A new criterion ensuring the existence and uniqueness of the quadratic-mean asymptotically almost periodic mild solutions for the system is presented. The condition of being uniformly exponentially stable of the strongly continuous semigroup {Tt}t≥0 is essentially removed, which is generated by the linear densely defined operator A∶D(A⊂L2(ℙ,ℍ→L2(ℙ,ℍ, only using the exponential trichotomy of the system, which reflects a deeper analysis of the behavior of solutions of the system. In this case the asymptotic behavior is described through the splitting of the main space into stable, unstable, and central subspaces at each point from the flow’s domain. An example is also given to illustrate our results.

  2. Modeling synchronized calling behavior of Japanese tree frogs.

    Science.gov (United States)

    Aihara, Ikkyu

    2009-07-01

    We experimentally observed synchronized calling behavior of male Japanese tree frogs Hyla japonica; namely, while isolated single frogs called nearly periodically, a pair of interacting frogs called synchronously almost in antiphase or inphase. In this study, we propose two types of phase-oscillator models on different degrees of approximations, which can quantitatively explain the phase and frequency properties in the experiment. Moreover, it should be noted that, although the second model is obtained by fitting to the experimental data of the two synchronized states, the model can also explain the transitory dynamics in the interactive calling behavior, namely, the shift from a transient inphase state to a stable antiphase state. We also discuss the biological relevance of the estimated parameter values to calling behavior of Japanese tree frogs and the possible biological meanings of the synchronized calling behavior.

  3. Stable cosmology in chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

    2018-02-01

    The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

  4. Long-term stable surface modification of DLC coatings

    Directory of Open Access Journals (Sweden)

    Gotzmann Gaby

    2017-09-01

    Full Text Available The use of coatings based on diamond like carbon (DLC for medical applications was established during the last years. Main advantages of these coatings are its high hardness, good wear and friction behavior and its biocompatibility. Using low-energy electron-beam treatment, we addressed the surface modification of DLC coatings. The aim was to generate new biofunctional surface characteristics that are long-term stable.

  5. Do planetary seasons play a role in attaining stable climates?

    Science.gov (United States)

    Olsen, Kasper Wibeck; Bohr, Jakob

    2018-02-01

    A simple phenomenological account for planetary climate instabilities is presented. The description is based on the standard model where the balance of incoming stellar radiation and outward thermal radiation is described by the effective planet temperature. Often, it is found to have three different points, or temperatures, where the influx of radiation is balanced with the out-flux, even with conserved boundary conditions. Two of these points are relatively long-term stable, namely the point corresponding to a cold climate and the point corresponding to a hot climate. In a classical sense these points are equilibrium balance points. The hypothesis promoted in this paper is the possibility that the intermediate third point can become long-term stable by being driven dynamically. The initially unstable point is made relatively stable over a long period by the presence of seasonal climate variations.

  6. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  7. Effects of growth pattern and dietary protein level during rearing on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing and laying period

    NARCIS (Netherlands)

    Emous, van R.A.; Kwakkel, R.P.; Krimpen, van M.M.; Hendriks, W.H.

    2014-01-01

    An experiment was conducted to evaluate the effect of growth patterns (GP) and dietary crude protein levels (CP) during rearing (2–22 weeks of age) on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing

  8. Stable rotating dipole solitons in nonlocal media

    DEFF Research Database (Denmark)

    Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.

    2006-01-01

    We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....

  9. Uses of stable isotopes in fish ecology

    Science.gov (United States)

    Analyses of fish tissues (other than otoliths) for stable isotope ratios can provide substantial information on fish ecology, including physiological ecology. Stable isotopes of nitrogen and carbon frequently are used to determine the mix of diet sources for consumers. Stable i...

  10. Stable States of Biological Organisms

    Science.gov (United States)

    Yukalov, V. I.; Sornette, D.; Yukalova, E. P.; Henry, J.-Y.; Cobb, J. P.

    2009-04-01

    A novel model of biological organisms is advanced, treating an organism as a self-consistent system subject to a pathogen flux. The principal novelty of the model is that it describes not some parts, but a biological organism as a whole. The organism is modeled by a five-dimensional dynamical system. The organism homeostasis is described by the evolution equations for five interacting components: healthy cells, ill cells, innate immune cells, specific immune cells, and pathogens. The stability analysis demonstrates that, in a wide domain of the parameter space, the system exhibits robust structural stability. There always exist four stable stationary solutions characterizing four qualitatively differing states of the organism: alive state, boundary state, critical state, and dead state.

  11. Theory of stable allocations II

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2015-01-01

    Full Text Available The Swedish Royal Academy awarded the 2012 Nobel Prize in Economics to Lloyd Shapley and Alvin Roth, for the theory of stable allocations and the practice of market design. These two American researchers worked independently from each other, combining basic theory and empirical investigations. Through their experiments and practical design they generated a flourishing field of research and improved the performance of many markets. Shapley provided the fundamental theoretical contribution to this field of research, whereas Roth, a professor at the Harvard University in Boston, developed and upgraded these theoretical investigations by applying them to the American market of medical doctors. Namely, their research helps explain the market processes at work, for instance, when doctors are assigned to hospitals, students to schools and human organs for transplant to recipients.

  12. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  13. Middle Helladic Period

    DEFF Research Database (Denmark)

    Sarri, Kalliopi

    1999-01-01

    administration, e.g. the administrative buildings and the sealing of products, were abandoned. The economic decline of the Middle Bronze Age affected the social stratification as well. The changes in social stratification appear in a series of completely new burial customs which show the prevalence of social......The Middle Bronze Age on Mainland Greece is also known as the Middle Helladic period. The chronological framework of this period extends from the beginnings of the second millenium - roughly 1900 - until 1550 BC, that is until the beginnings of the Mycenaean period. The Middle Helladic period...... is considered as the dark period of the cultural decline. The remains of the material culture reveal a clear retrogression while the information available on the social stratification and economy are so few and problematic in interpretation that this period is considered as the "Middle Age of Greek Prehistory...

  14. [Scientific periodicals: quality criteria].

    Science.gov (United States)

    Ferreira, Maria Cecilia Gonzaga; Krzyzanowski, Rosaly Favero

    2003-05-01

    This paper presents a historical literature review on the evaluation of periodicals and the methodology employed for their evaluation. It emphasizes the attention that should be given to the contents of the periodicals and their format based on technical standards in order to reach a global quality of the publications. This paper includes a summary of the most important aspects of the technical standards for periodicals and scientific articles.

  15. Painful menstrual periods

    Science.gov (United States)

    Menstruation - painful; Dysmenorrhea; Periods - painful; Cramps - menstrual; Menstrual cramps ... related activities for a few days during each menstrual cycle. Painful menstruation is the leading cause of ...

  16. Uptake and distribution of 137Cs, stable Cs and K in rice plants

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Hasegawa, Hidenao

    2003-01-01

    The uptake and distributions of 137 Cs, stable Cs and K were determined for rice plant components, including polished rice, rice bran, hulls, leaves, stems, and roots. The distribution of 137 Cs in polished rice and rice bran was similar to that of stable Cs, while that of K was different. The concentration ratios of Cs/K in leaves increased in older leaf blade positions, which meant that the translocation rate of stable Cs, was slower than that of K. At harvest the dry weight of polished rice accounted for 34% of the entire rice plant, while the distributions of stable Cs in the polished rice and the non-edible parts were 7 and 93%, respectively. These findings suggest that the transfer and distribution of stable Cs in rice plants are different from those of K, and the behavior of stable Cs provides a useful analogue in predicting the fate of 137 Cs in an agricultural environment. (author)

  17. Second Period Access Report

    DEFF Research Database (Denmark)

    Maisondieu, Christophe; Giebhardt, Jochen; Tetu, Amelie

    The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive....

  18. The Living Periodic Table

    Science.gov (United States)

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  19. [Partner relationships in menopausal period].

    Science.gov (United States)

    Szpak, Rafał; Folwarczny, Wiesław; Drozdzol, Agnieszka; Szuścik, Adam; Skrzypulec, Agnieszka; Skrzypulec, Violetta

    2010-02-01

    Evaluation of partner relationships in menopausal period. A questionnaire study was performed in a group of 67 women (age: 45-55 years) and their partners. The inclusion criteria were: presence of climacteric symptoms, stable partnership, consent to research. 40 women and their spouses were included into the final study group. The investigative tool was based on 3 scales: Marriage Bond Scale (SWM); Scale of Attractiveness (SKAT); GREEN Scale evaluating intensification of menopausal symptoms and a set of additional questions concerning socio-demographical data, marital sexuality and substitute hormonal therapy. Mean age of respondents was 52 years. Most of the women demonstrated an amenorrhea (90%). Climacteric symptoms such as: hot flush, stress, depressive moods (87.5% each), musculoarticular pain (80%) occurred in various degree. 97.5% of women did not use a substitute hormonal treatment. The mean result of SWM for women and their partners scored 237 which is 79% of the total value. A correlation between exacerbation of menopausal signs and SWM score was not found. The co-attractiveness ratio counted on the basis of SKAT scale scored 30 points on average, which constitutes 74% of the maximum. Approximately 58% of the men accepted symptoms related to menopause in their partners; they tolerated changes appearing in the climacteric period, however; 100% of men did not talk about menopausal problems with their partners and did not support them in this difficult time. Men find their partners attractive in the perimenopausal period, accepting their partners and problems related to menopause. Most of the male respondents understand changes occurring in their partners, however, they do not help them to deal with them.

  20. On some periodicity effects

    DEFF Research Database (Denmark)

    Sorokin, Sergey V.

    2015-01-01

    The talk is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of wave-guide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim...... of the talk is to illustrate these issues in simple examples and to discuss possible applications and generalisations. First, the eigenfrequency spectra of finite periodic structures are compared with the location of stop-bands for their infinite counterparts for a hierarchy of four mathematical models....... In each case, special attention is paid to eigenfrequencies and eigenmodes of a single periodicity cell with appropriate boundary conditions. The influence of the amount of periodicity cells in a finite compound structure on its eigenfrequency spectrum is analyzed. Several features common...

  1. Periods and Nori motives

    CERN Document Server

    Huber, Annette

    2017-01-01

    This book casts the theory of periods of algebraic varieties in the natural setting of Madhav Nori’s abelian category of mixed motives. It develops Nori’s approach to mixed motives from scratch, thereby filling an important gap in the literature, and then explains the connection of mixed motives to periods, including a detailed account of the theory of period numbers in the sense of Kontsevich-Zagier and their structural properties. Period numbers are central to number theory and algebraic geometry, and also play an important role in other fields such as mathematical physics. There are long-standing conjectures about their transcendence properties, best understood in the language of cohomology of algebraic varieties or, more generally, motives. Readers of this book will discover that Nori’s unconditional construction of an abelian category of motives (over fields embeddable into the complex numbers) is particularly well suited for this purpose. Notably, Kontsevich's formal period algebra represents a to...

  2. Effects of Reserpine on Reproduction and Serotonin Immunoreactivity in the Stable Fly Stomoxys Calcitrans (L.)

    Science.gov (United States)

    Biogenic amines are known to play critical roles in key insect behaviors such as feeding and reproduction. This study documents the effects of reserpine on mating and egg-laying behaviors of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), which is one of the most economically significa...

  3. Use of Spacecraft Data to Drive Regions on Mars where Liquid Water would be Stable

    Science.gov (United States)

    Lobitz, Brad; Wood, Byron L.; Averner, Maurice M.; McKay, Christopher P.; MacElroy, Robert D.

    2001-01-01

    Combining Viking pressure and temperature data with Mars Orbital Laser Altimeter (MOLA) topography data we have computed the fraction of the martian year during which pressure and temperature allow for liquid water to be stable on the martian surface. We find that liquid water would be stable within the Hellas and Argyre basin and over the northern lowlands equatorward of about 40 degrees. The location with the maximum period of stable conditions for liquid water is in the southeastern portion of Utopia Planitia where 34% of the year liquid water would be stable if it was present. Locations of stability appear to correlate with the distribution of valley networks.

  4. Upper Limit of the Periodic Table and Synthesis of Superheavy Elements

    Directory of Open Access Journals (Sweden)

    Khazan A.

    2007-04-01

    Full Text Available For the first time, using the heaviest possible element, the diagram for known nuclides and stable isotopes is constructed. The direction of search of superheavy elements is indicated. The Periodic Table with an eighth period is tabulated.

  5. Can coconut oil and treadmill exercise during the critical period of brain development ameliorate stress-related effects on anxiety-like behavior and episodic-like memory in young rats?

    Science.gov (United States)

    da Silva, Débora de Cássia; Tavares, Maryane Gabriela; do Nascimento, Camila Karina Brito; Lira, Eduardo Carvalho; Dos Santos, Ângela Amâncio; Maia, Luciana Maria Silva de Seixas; Batista-de-Oliveira Hornsby, Manuella

    2018-03-08

    Virgin coconut oil (CO) and treadmill exercise have been reported to improve memory performance in young rats. CO has also been associated with antistress properties in young, stressed mice. Therefore, in this study we aimed to investigate whether CO and treadmill exercise could synergistically ameliorate the effects of chronic stress on anxiety-like behavior and episodic-like memory in young rats. The rats received CO and were exercised (Ex) from the 15 th to the 45 th day of life. The animals were supplemented with CO (10 mL kg -1 day -1 ) or a vehicle (V, distilled water and 0.009% Cremophor) via oral gavage. The Ex animals were placed for 30 min day -1 on a treadmill, with the speed gradually increasing from the first week to the last. From the 46 th to the 54 th postnatal day, with the exception of the 51 st and the 52 nd day, all rats were subjected to restraint stress. Afterwards, all rats underwent the open-field test to evaluate locomotor activity and anxiety-like behavior. To evaluate episodic-like memory, all animals underwent tests to recognize object identity and special location. Lastly, lipid profile and murinometric parameters were evaluated. A two-way ANOVA test followed by a Tukey test demonstrated that the CO&Ex group explored more of the unprotected central area of the OFT (27.04 ± 4.03 s, p < 0.01), when compared to the control group (15.36 ± 2.54 s). CO&Ex spent more time exploring the novel location of the object (71.62 ± 3.04%, p < 0.01), when compared to the control group (58.62 ± 2.48%). CO and exercise during lactation can ameliorate the effects of stress on anxiety-like behavior and episodic-like memory in young rats.

  6. Classically Stable Nonsingular Cosmological Bounces

    Science.gov (United States)

    Ijjas, Anna; Steinhardt, Paul J.

    2016-09-01

    One of the fundamental questions of theoretical cosmology is whether the Universe can undergo a nonsingular bounce, i.e., smoothly transit from a period of contraction to a period of expansion through violation of the null energy condition (NEC) at energies well below the Planck scale and at finite values of the scale factor such that the entire evolution remains classical. A common claim has been that a nonsingular bounce either leads to ghost or gradient instabilities or a cosmological singularity. In this Letter, we consider a well-motivated class of theories based on the cubic Galileon action and present a procedure for explicitly constructing examples of a nonsingular cosmological bounce without encountering any pathologies and maintaining a subluminal sound speed for comoving curvature modes throughout the NEC violating phase. We also discuss the relation between our procedure and earlier work.

  7. Thermally stable nanoparticles on supports

    Science.gov (United States)

    Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

    2012-11-13

    An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

  8. Stable Treemaps via Local Moves.

    Science.gov (United States)

    Sondag, Max; Speckmann, Bettina; Verbeek, Kevin

    2018-01-01

    Treemaps are a popular tool to visualize hierarchical data: items are represented by nested rectangles and the area of each rectangle corresponds to the data being visualized for this item. The visual quality of a treemap is commonly measured via the aspect ratio of the rectangles. If the data changes, then a second important quality criterion is the stability of the treemap: how much does the treemap change as the data changes. We present a novel stable treemapping algorithm that has very high visual quality. Whereas existing treemapping algorithms generally recompute the treemap every time the input changes, our algorithm changes the layout of the treemap using only local modifications. This approach not only gives us direct control over stability, but it also allows us to use a larger set of possible layouts, thus provably resulting in treemaps of higher visual quality compared to existing algorithms. We further prove that we can reach all possible treemap layouts using only our local modifications. Furthermore, we introduce a new measure for stability that better captures the relative positions of rectangles. We finally show via experiments on real-world data that our algorithm outperforms existing treemapping algorithms also in practice on either visual quality and/or stability. Our algorithm scores high on stability regardless of whether we use an existing stability measure or our new measure.

  9. Historically defined autobiographical periods

    DEFF Research Database (Denmark)

    Brown, Norman R.; Hansen, Tia G. B.; Lee, Peter J.

    2012-01-01

    over time and theoretical implications are discussed, notably by introducing a new approach to autobiographical memory, Transition Theory, which assumes that autobiographical memory is organized by transitional events that can be selfinitiated or externally imposed - historically defined......The chapter reviews a research programme that has demonstrated the existence of historically defined autobiographical periods and identified the conditions that bring them about. Data from four samples of World War II-generation adults show that historically defined autobiographical periods endure...... autobiographical periods are the latter....

  10. Periodic Properties and Inquiry: Student Mental Models Observed during a Periodic Table Puzzle Activity

    Science.gov (United States)

    Larson, Kathleen G.; Long, George R.; Briggs, Michael W.

    2012-01-01

    The mental models of both novice and advanced chemistry students were observed while the students performed a periodic table activity. The mental model framework seems to be an effective way of analyzing student behavior during learning activities. The analysis suggests that students do not recognize periodic trends through the examination of…

  11. Hypokalemic periodic paralysis

    Science.gov (United States)

    ... Rott K, Rudel R, Lehmann-Horn F. Muscle channelopathies: myotor and periodic paralyses. In: Darras BT, Jones ... Elsevier; 2015:chap 38. Kerchner GA, Ptacek LJ. Channelopathies. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy ...

  12. Hyperkalemic periodic paralysis

    Science.gov (United States)

    ... Rott K, Rudel R, Lehmann-Horn F. Muscle channelopathies: myotonias and periodic paralyses. In: Darras BT, Jones ... Elsevier; 2015:chap 38. Kerchner GA, Ptacek LJ. Channelopathies: episodic and electrical disorders of nervous system. In: ...

  13. The Periodic Table CD.

    Science.gov (United States)

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  14. Setting the Periodic Table.

    Science.gov (United States)

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  15. Establishing contract periods

    International Nuclear Information System (INIS)

    Huffman, F.C.

    1978-01-01

    The lead time for executing the Adjustable Fixed-Commitment (AFC) contract and exceptions which may be considered are discussed. The initial delivery period is also discussed. Delays, deferrals, and schedule adjustment charges are finally considered

  16. Familial Periodic Paralyses

    Science.gov (United States)

    ... hypokalemic form. Muscle spasms are common. View Full Definition Treatment Treatment of the periodic paralyses focuses on preventing further attacks and relieving acute symptoms. Avoiding carbohydrate-rich meals and strenuous exercise, and taking acetazolamide daily may ...

  17. Super periodic potential

    Science.gov (United States)

    Hasan, Mohammd; Mandal, Bhabani Prasad

    2018-04-01

    In this paper we introduce the concept of super periodic potential (SPP) of arbitrary order n, n ∈I+, in one dimension. General theory of wave propagation through SPP of order n is presented and the reflection and transmission coefficients are derived in their closed analytical form by transfer matrix formulation. We present scattering features of super periodic rectangular potential and super periodic delta potential as special cases of SPP. It is found that the symmetric self-similarity is the special case of super periodicity. Thus by identifying a symmetric fractal potential as special cases of SPP, one can obtain the tunnelling amplitude for a particle from such fractal potential. By using the formalism of SPP we obtain the close form expression of tunnelling amplitude of a particle for general Cantor and Smith-Volterra-Cantor potentials.

  18. Problem behaviors of children adopted from the former soviet union.

    Science.gov (United States)

    Robinson, Cheryl B; McGuinness, Teena M; Azuero, Andres; Pallansch, Leona

    2015-02-01

    The purpose of this article is to report the results of behavioral assessments collected at three time points of a cohort of children adopted from the former Soviet Union with particular emphasis on the impact of the adoptive family on problem behaviors. Families adopting from the former USSR are concerned about the influence of pre-adoptive circumstances on their child's future health. The study utilized data gathered in 1998 when the children's mean age was close to 8 years, in 2001 when the children were entering early adolescence, and in 2006 when the average age of the children was just over 15 years. The authors hypothesized that the negative impact of risk factors decreases over time, and that a family environment that is stable and supportive is inversely related to problem behaviors. The Child Behavior Checklist, the Family Environment Scale, and a parental report form were used for data collection. Significant relationships between family environment and problem behaviors over time were found, with lower levels of conflict and higher levels of cohesion associated to lower problem behaviors. Being female does contribute to problem behavior with the passage of time. Although the magnitude of these effects was small to moderate, a protective family environment may assist in decreasing problem behaviors. © 2015 Wiley Periodicals, Inc.

  19. Feeding behavior and nutrient intake in spiny forest-dwelling ring-tailed lemurs (Lemur catta) during early gestation and early to mid-lactation periods: compensating in a harsh environment.

    Science.gov (United States)

    Gould, Lisa; Power, Michael L; Ellwanger, Nicholas; Rambeloarivony, Hajamanitra

    2011-07-01

    Strong resource seasonality in Madagascar has led to the evolution of female feeding priority and weaning synchrony in most lemur species. For these taxa, pregnancy/early lactation periods coincide with low food availability, and weaning of infants is timed with increased resources at the onset of the rainy season. Reproductive females experience high metabolic requirements, which they must accommodate, particularly when food resources are scarce. Female ring-tailed lemurs (Lemur catta) residing in spiny forest habitat must deal with resource scarcity, high temperatures (∼36-40°C) and little shade in early to mid-lactation periods. Considered "income breeders," these females must use resources obtained from the environment instead of relying on fat stores; thus, we expected they would differ from same-sized males in time spent on feeding and in the intake of food and nutrients. We investigated these variables in two groups (N = 11 and 12) of Lemur catta residing in spiny forest habitat during early gestation and early to mid-lactation periods. Focal animal data and food plant samples were collected, and plants were analyzed for protein, kcal, and fiber. We found no sex differences for any feeding or nutrient intake variable for the top five food species consumed. Females in early gestation spent more time feeding compared with early/mid-lactation. Physiological compensation for spiny forest-dwelling females may be tied to greater time spent resting compared with gallery forest conspecifics, consuming foods high in protein, calories, and water, reduced home range defense in a sparsely populated habitat, and for Lemur catta females in general, production of relatively dilute milk compared with many strepsirrhines. Copyright © 2011 Wiley-Liss, Inc.

  20. MULTIPLE STABLE PERIODIC SOLUTIONS IN A MODEL FOR THE HORMONAL REGULATION OF THE MENSTRUAL CYCLE

    Science.gov (United States)

    ABSTRACTThe pituitary hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the ovarian hormones, estradiol (E2), progesterone (P4), and inhibin (Ih), are five hormones important for the regulation and maintenance of the human menstrual cycle. The...

  1. The benthos of South Lake, St Lucia following a period of stable ...

    African Journals Online (AJOL)

    and reptile predators is dependent on the biomass and variety of benthic invertebrates. The present survey was conducted in conjunction with, and ...... FORBES, A.T. & HILL, B.J. 1969. The physiological ability of a marine crab Hymenosoma orbiculare Desm. to live in a sub- tropical freshwater lake. Trans. roy. Soc. s.

  2. Stable all-fiber photonic temporal differentiator using a long-period fibergrating interferometer

    Czech Academy of Sciences Publication Activity Database

    Slavík, Radan; Park, Y.; Krčmařík, David; Azana, J.

    2009-01-01

    Roč. 282, č. 12 (2009), s. 2339-2342 ISSN 0030-4018 R&D Projects: GA ČR(CZ) GA102/07/0999; GA AV ČR KJB200670601 Institutional research plan: CEZ:AV0Z20670512 Keywords : optical fibre filters Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2009

  3. Stable nocturnal spectral characteristics over a vineyard (Conference Presentation)

    Science.gov (United States)

    Prueger, John H.; Alfieri, joesph G.; Hipps, Lawrence E.; Kustas, William P.; Neale, Christopher M.

    2016-10-01

    Vineyards are agricultural surfaces that present a unique structural perturbation to the mean wind flow. As part of the Grape Remote Sensing Atmospheric Profiling and Evapotranspiration Experiment (GRAPEX) a 10-m profile tower of three sonic anemometers at 2, 3.75 and 8 m above ground level in in a mature vineyard having was deployed to measure high frequency diurnal variations of 3-dimensional velocity components (u, v, w) and temperature (T) throughout the growing season. Previous work has been published involving eddy covariance measurements in vineyards but these mostly represented convective daytime unstable conditions. Significantly less has been published about turbulence in vineyards during stable nocturnal periods. Hence, in this study we focused on the nocturnal stable periods under clear skies and relatively light winds typical of the northern portion of California's Central Valley. Our objective was to characterize and evaluate turbulent exchange processes in the layer near the top of a vine canopy during nocturnal periods which are often characterized by weak and intermittent turbulence. Spectra, cospectra and coherence plots were evaluated for nocturnal periods. The spectra suggest there are periods of intermittent turbulence with features indicative of local and regional scale processes. Additionally the impact of the vine structure and spacing on slow meandering flows enhance the decomposition of organized turbulent eddies resulting in intricate mechanical turbulence generated by intermittent eddies that are rapidly decomposed as eddies interact with the vine structure and spacing. Preliminary results will be discussed that provide insight into turbulence characteristics at several heights above a canopy vineyard as affected by vine structure and spacing, wind speed, direction and stable conditions.

  4. Periodic perturbations of quadratic planar polynomial vector fields

    Directory of Open Access Journals (Sweden)

    MARCELO MESSIAS

    2002-06-01

    Full Text Available In this work are studied periodic perturbations, depending on two parameters, of quadratic planar polynomial vector fields having an infinite heteroclinic cycle, which is an unbounded solution joining two saddle points at infinity. The global study envolving infinity is performed via the Poincaré compactification. The main result obtained states that for certain types of periodic perturbations, the perturbed system has quadratic heteroclinic tangencies and transverse intersections between the local stable and unstable manifolds of the hyperbolic periodic orbits at infinity. It implies, via the Birkhoff-Smale Theorem, in a complex dynamical behavior of the solutions of the perturbed system, in a finite part of the phase plane.Neste trabalho são estudadas perturbações periódicas, dependendo de dois parâmetros, de campos vetoriais polinomiais planares que possuem um ciclo heteroclínico infinito, que consiste de uma solução ilimitada, que conecta dois pontos de sela no infinito. O estudo global do campo vetorial, envolvendo o infinito, foi elaborado utilizando-se a compactificação de Poincaré. O resultado principal estabelece que, para certo tipo de perturbação periódica, o sistema apresenta tangências heteroclínicas e intersecção transversal das variedades invariantes de órbitas periódicas no infinito, o que implica, via o Teorema de Birkhoff-Smale, em um comportamento dinâmico bastante complexo das soluções do sistema perturbado, em uma região finita do plano de fase.

  5. Analysis of network clustering behavior of the Chinese stock market

    Science.gov (United States)

    Chen, Huan; Mai, Yong; Li, Sai-Ping

    2014-11-01

    Random Matrix Theory (RMT) and the decomposition of correlation matrix method are employed to analyze spatial structure of stocks interactions and collective behavior in the Shanghai and Shenzhen stock markets in China. The result shows that there exists prominent sector structures, with subsectors including the Real Estate (RE), Commercial Banks (CB), Pharmaceuticals (PH), Distillers&Vintners (DV) and Steel (ST) industries. Furthermore, the RE and CB subsectors are mostly anti-correlated. We further study the temporal behavior of the dataset and find that while the sector structures are relatively stable from 2007 through 2013, the correlation between the real estate and commercial bank stocks shows large variations. By employing the ensemble empirical mode decomposition (EEMD) method, we show that this anti-correlation behavior is closely related to the monetary and austerity policies of the Chinese government during the period of study.

  6. Periodic safety analyses

    International Nuclear Information System (INIS)

    Gouffon, A.; Zermizoglou, R.

    1990-12-01

    The IAEA Safety Guide 50-SG-S8 devoted to 'Safety Aspects of Foundations of Nuclear Power Plants' indicates that operator of a NPP should establish a program for inspection of safe operation during construction, start-up and service life of the plant for obtaining data needed for estimating the life time of structures and components. At the same time the program should ensure that the safety margins are appropriate. Periodic safety analysis are an important part of the safety inspection program. Periodic safety reports is a method for testing the whole system or a part of the safety system following the precise criteria. Periodic safety analyses are not meant for qualification of the plant components. Separate analyses are devoted to: start-up, qualification of components and materials, and aging. All these analyses are described in this presentation. The last chapter describes the experience obtained for PWR-900 and PWR-1300 units from 1986-1989

  7. Periodic table of elements

    International Nuclear Information System (INIS)

    Fluck, E.; Heumann, K.G.

    1985-01-01

    Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de

  8. A periodic table for cancer.

    Science.gov (United States)

    Epstein, Richard J

    2015-01-01

    Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific 'periodic table' that guides rational formulation of survival-enhancing anticancer treatment strategies.

  9. Characterization of stable fly (Diptera: Muscidae) larval developmental habitat at round hay bale feeding sites.

    Science.gov (United States)

    Talley, Justin; Broce, Alberto; Zurek, Ludek

    2009-11-01

    In this study, we examined the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), larval developmental habitat within the round hay bale feeding sites on cattle pastures, and we identified three zones with distinct characteristics around two types of hay feeders (ring and cone). The parameters monitored in each zone included stable fly emergence, substrate temperature, moisture, pH, thickness of hay-manure layer, and concentration of fecal coliform bacteria (Escherichia coli and Klebsiella oxytoca) as indicators of fecal material. All measurements were conducted during the period of high stable fly prevalence (HSF) in May-June and low stable fly prevalence (LSF) in July-August to better understand the environmental factors influencing stable fly seasonality. Substrate temperature and fecal coliform concentration were the only two significantly different factors between HSF and LSF. Temperatures ranged from 21 to 25 degrees C during HSF versus 25-30 degrees C in LSF but all were within the range for successful stable fly development. Fecal coliform concentrations ranged from 4.2 x 10(3) to 4.1 x 10(4) colony-forming units (CFU)/g of the substrate during HSF and from undetectable (stable fly development (egg to adult). Temperature was significantly higher and stable fly developmental time significantly shorter in all substrates containing hay when compared with that of manure alone, but no significant differences were detected in stable fly emergence among the substrates. These results strongly indicate that the fecal microbial community plays an important role in stable fly larval development in hay feeding sites and that it is the main factor behind stable fly developmental seasonality on pastures. Our results also demonstrate that animal manure mixed with hay provides conditions for faster stable fly development than manure alone; however, hay does not significantly affect overall stable fly emergence.

  10. From stable to unstable anomaly-induced inflation

    Energy Technology Data Exchange (ETDEWEB)

    Paula Netto, Tiberio de [Universidade Federal de Juiz de Fora, Departamento de Fisica, ICE, Juiz de Fora, MG (Brazil); Pelinson, Ana M. [Universidade Federal de Santa Catarina, Departamento de Fisica, CFM, Bairro da Trindade, Florianopolis, SC (Brazil); Shapiro, Ilya L. [Universidade Federal de Juiz de Fora, Departamento de Fisica, ICE, Juiz de Fora, MG (Brazil); Tomsk State Pedagogical University and Tomsk State University, Tomsk (Russian Federation); Starobinsky, Alexei A. [L.D. Landau Institute for Theoretical Physics RAS, Moscow (Russian Federation); Utrecht University, Department of Physics and Astronomy, Institute for Theoretical Physics, Utrecht (Netherlands)

    2016-10-15

    Quantum effects derived through conformal anomaly lead to an inflationary model that can be either stable or unstable. The unstable version requires a large dimensionless coefficient of about 5 x 10{sup 8} in front of the R{sup 2} term that results in the inflationary regime in the R+R{sup 2} (''Starobinsky'') model being a generic intermediate attractor. In this case the non-local terms in the effective action are practically irrelevant, and there is a 'graceful exit' to a low curvature matter-like dominated stage driven by high-frequency oscillations of R - scalarons, which later decay to pairs of all particles and antiparticles, with the amount of primordial scalar (density) perturbations required by observations. The stable version is a genuine generic attractor, so there is no exit from it. We discuss a possible transition from stable to unstable phases of inflation. It is shown that this transition is automatic if the sharp cut-off approximation is assumed for quantum corrections in the period of transition. Furthermore, we describe two different quantum mechanisms that may provide a required large R{sup 2}-term in the transition period. (orig.)

  11. Periodic Table of Students.

    Science.gov (United States)

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  12. A Modern Periodic Table.

    Science.gov (United States)

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  13. Hereditary periodic fever syndromes

    NARCIS (Netherlands)

    McDermott, MF; Frenkel, J

    Hereditary periodic fever syndromes are defined by recurrent attacks of generalised inflammation for which no infectious or auto-immune cause can be identified. For most of these disorders, the molecular basis has recently been elucidated. This has opened the prospect of novel therapeutic

  14. Almost periodic Schroedinger operators

    International Nuclear Information System (INIS)

    Bellissard, J.; Lima, R.

    1984-01-01

    These lectures are devoted to recent developments in the theory of almost-periodic Schroedinger Operators. We specially describe the algebraic point of view, with applications to gap-labelling theorems. Particular models are also presented which exhibit various spectral properties. (orig.)

  15. Transition to instability in a periodically kicked Bose-Einstein condensate on a ring

    International Nuclear Information System (INIS)

    Liu Jie; Zhang Chuanwei; Raizen, Mark G.; Niu Qian

    2006-01-01

    A periodically kicked ring of a Bose-Einstein condensate is considered as a nonlinear generalization of the quantum kicked rotor, where the nonlinearity stems from the mean-field interactions between the condensed atoms. For weak interactions, periodic motion (antiresonance) becomes quasiperiodic (quantum beating) but remains stable. There exists a critical strength of interactions beyond which quasiperiodic motion becomes chaotic, resulting in an instability of the condensate manifested by exponential growth in the number of noncondensed atoms. In the stable regime, the system remains predominantly in the two lowest energy states and may be mapped onto a spin model, from which we obtain an analytic expression for the beat frequency and discuss the route to instability. We numerically explore a parameter regime for the occurrence of instability and reveal the characteristic density profile for both condensed and noncondensed atoms. The Arnold diffusion to higher energy levels is found to be responsible for the transition to instability. Similar behavior is observed for dynamically localized states (essentially quasiperiodic motions), where stability remains for weak interactions but is destroyed by strong interactions

  16. A timeline of stable isotopes and mass spectrometry in the life sciences.

    Science.gov (United States)

    Lehmann, Wolf D

    2017-01-01

    This review retraces the role of stable isotopes and mass spectrometry in the life sciences. The timeline is divided into four segments covering the years 1920-1950, 1950-1980, 1980-2000, and 2000 until today. For each period methodic progress and typical applications are discussed. Application of stable isotopes is driven by improvements of mass spectrometry, chromatography, and related fields in sensitivity, mass accuracy, structural specificity, complex sample handling ability, data output, and data evaluation. We currently experience the vision of omics-type analyses, that is, the comprehensive identification and quantification of a complete compound class within one or a few analytical runs. This development is driven by stable isotopes without competition by radioisotopes. In metabolic studies as classic field of isotopic tracer experiments, stable isotopes and radioisotopes were competing solutions, with stable isotopes as the long-term junior partner. Since the 1990s the number of metabolic studies with radioisotopes decreases, whereas stable isotope studies retain their slow but stable upward tendency. Unique fields of stable isotopes are metabolic tests in newborns, metabolic experiments in healthy controls, newborn screening for inborn errors, quantification of drugs and drug metabolites in doping control, natural isotope fractionation in geology, ecology, food authentication, or doping control, and more recently the field of quantitative omics-type analyses. There, cells or whole organisms are systematically labeled with stable isotopes to study proteomic differences or specific responses to stimuli or genetic manipulation. The duo of stable isotopes and mass spectrometry will probably continue to grow in the life sciences, since it delivers reference-quality quantitative data with molecular specificity, often combined with informative isotope effects. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:58-85, 2017. © 2016 Wiley Periodicals, Inc.

  17. Torpedo: topic periodicity discovery from text data

    Science.gov (United States)

    Wang, Jingjing; Deng, Hongbo; Han, Jiawei

    2015-05-01

    Although history may not repeat itself, many human activities are inherently periodic, recurring daily, weekly, monthly, yearly or following some other periods. Such recurring activities may not repeat the same set of keywords, but they do share similar topics. Thus it is interesting to mine topic periodicity from text data instead of just looking at the temporal behavior of a single keyword/phrase. Some previous preliminary studies in this direction prespecify a periodic temporal template for each topic. In this paper, we remove this restriction and propose a simple yet effective framework Torpedo to mine periodic/recurrent patterns from text, such as news articles, search query logs, research papers, and web blogs. We first transform text data into topic-specific time series by a time dependent topic modeling module, where each of the time series characterizes the temporal behavior of a topic. Then we use time series techniques to detect periodicity. Hence we both obtain a clear view of how topics distribute over time and enable the automatic discovery of periods that are inherent in each topic. Theoretical and experimental analyses demonstrate the advantage of Torpedo over existing work.

  18. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    Eck, C.F.

    1979-01-01

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  19. physico-chemical and stable isotopes

    African Journals Online (AJOL)

    This paper details the mineralogical, chemical and stable isotope abundances of calcrete in the Letlhakeng fossil valley. The stable isotope abundances (O and C) of calcretes yielded some values which were tested against the nature of the calcretes – pedogenic or groundwater type. The Kgalagadi (Kalahari) is a vast ...

  20. Modelling stable atmospheric boundary layers over snow

    NARCIS (Netherlands)

    Sterk, H.A.M.

    2015-01-01

    Thesis entitled:

    Modelling Stable Atmospheric Boundary Layers over Snow

    H.A.M. Sterk

    Wageningen, 29th of April, 2015

    Summary

    The emphasis of this thesis is on the understanding and forecasting of the Stable Boundary Layer (SBL) over snow-covered surfaces. SBLs

  1. Modelling stable atmospheric boundary layers over snow

    NARCIS (Netherlands)

    Sterk, H.A.M.

    2015-01-01

    Thesis entitled: Modelling Stable Atmospheric Boundary Layers over Snow H.A.M. Sterk Wageningen, 29th of April, 2015 Summary The emphasis of this thesis is on the understanding and forecasting of the Stable Boundary Layer (SBL) over snow-covered surfaces. SBLs typically form at night and in polar

  2. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  3. Stable Agrobacterium -mediated transformation of the halophytic ...

    African Journals Online (AJOL)

    Stable Agrobacterium-mediated transformation of the halophytic Leymus chinensis (Trin.) Yan-Lin Sun, Soon-Kwan Hong. Abstract. In this study, an efficient procedure for stable Agrobacterium-mediated transformation of Leymus chinensis (Trin.) was established. Agrobacterium tumefaciens strain EHA105, harboring a ...

  4. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  5. Stable Fly, (L., Dispersal and Governing Factors

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2015-01-01

    Full Text Available Although the movement of stable fly, Stomoxys calcitrans (L., has been studied, its extent and significance has been uncertain. On a local scale (13 km is mainly wind-driven by weather fronts that carry stable flies from inland farm areas for up to 225 km to beaches of northwestern Florida and Lake Superior. Stable flies can reproduce for a short time each year in washed-up sea grass, but the beaches are not conducive to establishment. Such movement is passive and does not appear to be advantageous to stable fly's survival. On a regional scale, stable flies exhibit little genetic differentiation, and on the global scale, while there might be more than one “lineage”, the species is nevertheless considered to be panmictic. Population expansion across much of the globe likely occurred from the late Pleistocene to the early Holocene in association with the spread of domesticated nomad livestock and particularly with more sedentary, penned livestock.

  6. Sustained long-period seismicity at Shishaldin Volcano, Alaska

    Science.gov (United States)

    Petersen, Tanja; Caplan-Auerbach, Jacqueline; McNutt, Stephen R.

    2006-01-01

    From September 1999 through April 2004, Shishaldin Volcano, Aleutian Islands, Alaska, exhibited a continuous and extremely high level of background seismicity. This activity consisted of many hundreds to thousands of long-period (LP; 1–2 Hz) earthquakes per day, recorded by a 6-station monitoring network around Shishaldin. The LP events originate beneath the summit at shallow depths (0–3 km). Volcano tectonic events and tremor have rarely been observed in the summit region. Such a high rate of LP events with no eruption suggests that a steady state process has been occurring ever since Shishaldin last erupted in April–May 1999. Following the eruption, the only other signs of volcanic unrest have been occasional weak thermal anomalies and an omnipresent puffing volcanic plume. The LP waveforms are nearly identical for time spans of days to months, but vary over longer time scales. The observations imply that the spatially close source processes are repeating, stable and non-destructive. Event sizes vary, but the rate of occurrence remains roughly constant. The events range from magnitude ∼0.1 to 1.8, with most events having magnitudes eruptive activity. Every indication is that the high rate of seismicity will continue without reflecting a hazardous state. Sealing of the conduit and/or change in gas flux, however, would be expected to change Shishaldin's behavior.

  7. Microwave generation of stable atmospheric-pressure fireballs in air

    Science.gov (United States)

    Stephan, Karl D.

    2006-11-01

    The generation of stable buoyant fireballs in a microwave cavity in air at atmospheric pressure without the use of vaporized solids is described. These fireballs have some of the characteristics of ball lightning and resemble those reported by Dikhtyar and Jerby [Phys. Rev. Lett. 96, 045002 (2006)], although of a different color, and do not require the presence of molten or vaporized material. Mechanisms of microwave plasma formation and fluid dynamics can account for the observed behavior of the fireballs, which do not appear to meet the accepted definition of dusty plasmas in this case. Relevance to models of ball lightning and industrial applications are discussed.

  8. Nonlinear density waves in a marginally stable gravitating disk

    International Nuclear Information System (INIS)

    Korchagin, V.I.

    1986-01-01

    The evolution of short nonlinear density waves in a disk at the stability limit is studied for arbitrary values of the radial wave number k/sub r/. For waves with wave numbers that do not lie at the minimum of the dispersion curve, the behavior of the amplitude is described by a nonlinear parabolic equation; however, stationary soliton solutions cannot exist in such a system since there is no dispersion spreading of a packet. For wave numbers lying at the minimum of the dispersion curve, soliton structures with determined amplitude are possible. In stable gravitating disks and in a disk at the stability limit, two physically different types of soliton can exist

  9. Stable corrugated state of the two-dimensional electron gas

    International Nuclear Information System (INIS)

    Mendez-Moreno, R.M.; Moreno, M.; Ortiz, M.A.

    1991-01-01

    A corrugated and stable ground state is found for the two-dimensional electron gas in both the normal paramagnetic and the fully polarized phases. The self-consistent Hartree-Fock method is used with a modulated set of trial wave functions within the deformable jellium model. The results for high metallic densities reproduce the usual noncorrugated ferromagnetic electron-gas behavior. A transition to a paramagnetic corrugated state for values of r s ∼6.5 is predicted. At lower densities r s ∼30, a second transition to a corrugated ferromagnetic phase is suggested

  10. Testing seasonality of the Late Cretaceous Western Interior Seaway with stable isotope analysis of ammonites (Baculites)

    Science.gov (United States)

    Ellis, N.; Tobin, T. S.

    2017-12-01

    Common to the Western Interior Seaway, Baculites is a genus of ammonite with a straight-shelled morphology that serve as index fossils for the Late Cretaceous. Powdered shell samples were generated along growth sequences from several large Baculites fragments (20 - 40 cm) that preserve original aragonite. Stable isotope ratios (δ13C, δ18O) were determined for samples using standard techniques. Sine curves were fit to δ18O and δ13C signals, where the seasonal temperature differential is expressed as the amplitude of the δ18O signal. The periods of the signals represent one annual cycle, from which preliminary Baculites growth rate estimates have been established. Additionally, carbon and oxygen isotope data obtained by Fatheree et al. [1998] were re-analyzed and fit to a sine curve. All of the Baculites that produced usable data and the Fatheree et al. [1998] Baculites produced similar periods (30 - 35 cm), suggesting that Baculites likely utilized an r-type life strategy where they reach maturity rapidly, produce large amounts of offspring, and die within a few years. Understanding their life behaviors is critical to the use of Baculites as a paleoclimate proxy since potential migration, both geographic and in the water column, may influence carbon and oxygen isotope signals. The sinusoidal nature of the isotope signals observed in several Baculites suggests that seasonal inputs are most prevalent. Changes in ammonite activity and/or behavior driven by seasonal progression, seasonally mediated environmental changes, or combinations of these are hypothesized inputs that may result in the observed sinusoidal signals. Amplitudes of δ18O signals suggest seawater temperature variance that is consistent with the paleolatitudes associated with the Baculites specimens sampled. Ammonites from higher paleolatitudes yielded larger amplitude signals indicating greater seasonality at these locations. Further experimentation with Baculites aptychi is ongoing and may yield

  11. England and Wales: Stable fertility and pronounced social status differences

    Directory of Open Access Journals (Sweden)

    Wendy Sigle-Rushton

    2008-07-01

    Full Text Available For nearly three decades, the total fertility rate in England and Wales has remained high relative to other European countries, and stable at about 1.7 births per woman. In this chapter, we examine trends in both period and cohort fertility throughout the twentieth century, and demonstrate some important differences across demographic and social groups in the timing and quantum of fertility. Breaking with a market-oriented and laissez-faire approach to work and family issues, the last 10 years have seen the introduction of new social and economic policies aimed at providing greater support to families with children. However, the effect of the changes is likely to be limited to families on the lower end of the income scale. Rather than facilitating work and parenthood, some policies create incentives for a traditional gendered division of labour. Fertility appears to have remained stable despite, rather than because of, government actions.

  12. Selection of medical treatment in stable angina pectoris

    DEFF Research Database (Denmark)

    Ardissino, D; Savonitto, S; Egstrup, K

    1995-01-01

    pectoris. BACKGROUND: The characteristics of anginal symptoms and the results of exercise testing are considered of great importance for selecting medical treatment in patients with chronic stable angina pectoris. However, little information is available on how this first evaluation may be used to select......, the patients were randomly allocated to double-blind treatment for 6 weeks with either metoprolol (Controlled Release, 200 mg once daily) or nifedipine (Retard, 20 mg twice daily) according to a parallel group design. At the end of this period, exercise tests were repeated 1 to 4 h after drug intake. RESULTS....... CONCLUSIONS: The results of a baseline exercise test, but not the characteristics of anginal symptoms, may offer useful information for selecting medical treatment in stable angina pectoris....

  13. Periodic mesoporous silica gels

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.T.; Martin, J.E.; Odinek, J.G. [and others

    1996-06-01

    We have synthesized monolithic particulate gels of periodic mesoporous silica by adding tetramethoxysilane to a homogeneous alkaline micellar precursor solution. The gels exhibit 5 characteristic length scales over 4 orders of magnitude: fractal domains larger than the particle size (>500 nm), particles that are {approximately}150 to 500 nm in diameter, interparticle pores that are on the order of the particle size, a feature in the gas adsorption measurements that indicates pores {approximately}10-50 nm, and periodic hexagonal arrays of {approximately}3 nm channels within each particle. The wet gel monoliths exhibit calculated densities as low as {approximately}0.02 g/cc; the dried and calcined gels have bulk densities that range from {approximately}0.3-0.5 g/cc. The materials possess large interparticle ({approximately}1.0-2.3 cc/g) and intraparticle ({approximately}0.6 cc/g) porosities.

  14. Measuring thermal behavior in smaller insects: A case study in Drosophila melanogaster demonstrates effects of sex, geographic origin, and rearing temperature on adult behavior.

    Science.gov (United States)

    Rajpurohit, Subhash; Schmidt, Paul S

    2016-10-01

    Measuring thermal behavior in smaller insects is particularly challenging. In this study, we describe a new horizontal thermal gradient apparatus designed to study adult thermal behavior in small insects and apply it using D. melanogaster as a model and case study. Specifically, we used this apparatus and associated methodology to examine the effects of sex, geographic origin, and developmental rearing temperature on temperature preferences exhibited by adults in a controlled laboratory environment. The thermal gradient established by the apparatus was stable over diurnal and calendar time. Furthermore, the distribution of adult flies across thermal habitats within the apparatus remained stable following the period of acclimation, as evidenced by the high degree of repeatability across both biological and technical replicates. Our data demonstrate significant and predictable variation in temperature preference for all 3 assayed variables. Behaviorally, females were more sensitive than males to higher temperatures. Flies originating from high latitude, temperate populations exhibited a greater preference for cooler temperatures; conversely, flies originating from low latitude, tropical habitats demonstrated a relative preference for higher temperatures. Similarly, larval rearing temperature was positively associated with adult thermal behavior: low culture temperatures increased the relative adult preference for cooler temperatures, and this response was distinct between the sexes and for flies from the temperate and subtropical geographic regions. Together, these results demonstrate that the temperature chamber apparatus elicits robust, predictable, and quantifiable thermal preference behavior that could readily be applied to other taxa to examine the role of temperature-mediated behavior in a variety of contexts.

  15. Centroid motion in periodically focused beams

    International Nuclear Information System (INIS)

    Moraes, J.S.; Pakter, R.; Rizzato, F.B.

    2005-01-01

    The role of the centroid dynamics in the transport of periodically focused particle beams is investigated. A Kapchinskij-Vladimirskij equilibrium distribution for an off-axis beam is derived. It is shown that centroid and envelope dynamics are uncoupled and that unstable regions for the centroid dynamics overlap with previously stable regions for the envelope dynamics alone. Multiparticle simulations validate the findings. The effects of a conducting pipe encapsulating the beam are also investigated. It is shown that the charge induced at the pipe may generate chaotic orbits which can be detrimental to the adequate functioning of the transport mechanism

  16. The intrinsic periodic fluctuation of forest: a theoretical model based on diffusion equation

    Science.gov (United States)

    Zhou, J.; Lin, G., Sr.

    2015-12-01

    Most forest dynamic models predict the stable state of size structure as well as the total basal area and biomass in mature forest, the variation of forest stands are mainly driven by environmental factors after the equilibrium has been reached. However, although the predicted power-law size-frequency distribution does exist in analysis of many forest inventory data sets, the estimated distribution exponents are always shifting between -2 and -4, and has a positive correlation with the mean value of DBH. This regular pattern can not be explained by the effects of stochastic disturbances on forest stands. Here, we adopted the partial differential equation (PDE) approach to deduce the systematic behavior of an ideal forest, by solving the diffusion equation under the restricted condition of invariable resource occupation, a periodic solution was gotten to meet the variable performance of forest size structure while the former models with stable performance were just a special case of the periodic solution when the fluctuation frequency equals zero. In our results, the number of individuals in each size class was the function of individual growth rate(G), mortality(M), size(D) and time(T), by borrowing the conclusion of allometric theory on these parameters, the results perfectly reflected the observed "exponent-mean DBH" relationship and also gave a logically complete description to the time varying form of forest size-frequency distribution. Our model implies that the total biomass of a forest can never reach a stable equilibrium state even in the absence of disturbances and climate regime shift, we propose the idea of intrinsic fluctuation property of forest and hope to provide a new perspective on forest dynamics and carbon cycle research.

  17. Stable Organic Neutral Diradical via Reversible Coordination.

    Science.gov (United States)

    Lu, Zhenpin; Quanz, Henrik; Burghaus, Olaf; Hofmann, Jonas; Logemann, Christian; Beeck, Sebastian; Schreiner, Peter R; Wegner, Hermann A

    2017-12-27

    We report the formation of a stable neutral diboron diradical simply by coordination of an aromatic dinitrogen compound to an ortho-phenyldiborane. This process is reversible upon addition of pyridine. The diradical species is stable above 200 °C. Computations are consistent with an open-shell triplet diradical with a very small open-shell singlet-triplet energy gap that is indicative of the electronic disjointness of the two radical sites. This opens a new way of generating stable radicals with fascinating electronic properties useful for a large variety of applications.

  18. Polysheroidal periodic functions

    International Nuclear Information System (INIS)

    Truskova, N.F.

    1985-01-01

    Separation of variables in the Helmholtz N-dimensional (N≥4) equation in polyspheroidal coordinate systems leads to the necessity of solving equations going over into equations for polyspheroidal periodic functions used for solving the two-centre problem in quantum mechanics, the three-body problem with Coulomb interaction, etc. For these functions the expansions are derived in terms of the Jacobi polynomials and Bessel functions. Their basic properties, asymptotics are considered. The algorithm of their computer calculations is developed. The results of numerical calculations are given

  19. Periodic and chaotic oscillations in a tumor and immune system interaction model with three delays

    International Nuclear Information System (INIS)

    Bi, Ping; Ruan, Shigui; Zhang, Xinan

    2014-01-01

    In this paper, a tumor and immune system interaction model consisted of two differential equations with three time delays is considered in which the delays describe the proliferation of tumor cells, the process of effector cells growth stimulated by tumor cells, and the differentiation of immune effector cells, respectively. Conditions for the asymptotic stability of equilibria and existence of Hopf bifurcations are obtained by analyzing the roots of a second degree exponential polynomial characteristic equation with delay dependent coefficients. It is shown that the positive equilibrium is asymptotically stable if all three delays are less than their corresponding critical values and Hopf bifurcations occur if any one of these delays passes through its critical value. Numerical simulations are carried out to illustrate the rich dynamical behavior of the model with different delay values including the existence of regular and irregular long periodic oscillations

  20. Periodic and aperiodic synchronization in skilled action

    Directory of Open Access Journals (Sweden)

    Fred eCummins

    2011-12-01

    Full Text Available Synchronized action is considered as a manifestation of shared skill. Most synchronized behaviors in humans and other animals are based on periodic repetition. Aperiodic synchronization of complex action is found in the experimental task of synchronous speaking, in which naive subjects read a common text in lock step. The demonstration of synchronized behavior without a periodic basis is presented as a challenge for theoretical understanding. A unified treatment of periodic and aperiodic synchronization is suggested by replacing the sequential processing model of cognitivist approaches with the more local notion of a task-specific sensorimotor coordination. On this view, skilled action is the imposition of constraints on the co-variation of movement and sensory flux such that the boundary conditions that define the skill are met. This non-cognitivist approach originates in the work of John Dewey. It allows a unification of the treatment of sensorimotor synchronization in simple rhythmic behavior and in complex skilled behavior and it suggests that skill sharing is a uniquely human trait of considerable import.

  1. The behavioral repertoire of the black-and-white ruffed lemur, Varecia variegata variegata (Primates: Lemuridae).

    Science.gov (United States)

    Pereira, M E; Seeligson, M L; Macedonia, J M

    1988-01-01

    A stable social group of 7 semifree-ranging black-and-white ruffed lemurs (Varecia variegata variegata) was studied for 4 months to catalog the behavioral repertoire of this species. Observations focussed on particular aspects of behavior were conducted before and after this 4-month period to supplement information gathered. Behavior in 11 major categories is detailed: postures, terrestrial locomotion, arboreal locomotion, feeding behavior, vocalizations, scent-marking, affinitive social behavior, agonistic social behavior, play behavior, sexual behavior, and parental behavior. Ruffed lemurs frequently used body positions and locomotor patterns unusual among lemurids, including bipedal hanging and long-descent leaps. These behaviors reinforce dental evidence that Varecia are among the most frugivorous of the Malagasy lemurs. Low intragroup cohesion, infrequent social interaction, and antiphonal use of several long-distance vocalizations suggest that ruffed lemurs naturally exhibit fission-fusion sociality. Social structure based on interindividual familiarity probably extends across foraging parties for several of the diurnally active lemurs; however, thus far only Varecia seems likely to exhibit fission-fusion sociality analogous to that seen in spider monkeys and chimpanzees.

  2. Long-Term Evaluation of Abnormal Behavior in Adult Ex-laboratory Chimpanzees (Pan troglodytes Following Re-socialization

    Directory of Open Access Journals (Sweden)

    Karl Crailsheim

    2013-01-01

    Full Text Available Adverse rearing conditions are considered a major factor in the development of abnormal behavior. We investigated the overall levels, the prevalence and the diversity of abnormal behavior of 18 adult former laboratory chimpanzees, who spent about 20 years single caged, over a two-year period following re-socialization. According to the onset of deprivation, the individuals were classified as early deprived (EDs, mean: 1.2 years or late deprived (LDs, mean: 3.6 years. The results are based on 187.5 hours of scan sampling distributed over three sample periods: subsequent to re-socialization and during the first and second year of group-living. While the overall levels and the diversity of abnormal behavior remained stable over time in this study population, the amplifying effects of age at onset of deprivation became apparent as the overall levels of abnormal behavior of EDs were far above those of LDs in the first and second year of group-living, but not immediately after re-socialization. The most prevalent abnormal behaviors, including eating disorders and self-directed behaviors, however, varied in their occurrence within subjects across the periods. Most important, the significance of social companionship became obvious as the most severe forms of abnormal behavior, such as dissociative and self-injurious behaviors declined.

  3. A generalized, periodic nonlinearity-reduced interferometer for straightness measurements

    International Nuclear Information System (INIS)

    Wu Chienming

    2008-01-01

    Periodic nonlinearity is a systematic error limiting the accuracy of displacement measurements at the nanometer level. However, an interferometer with a displacement measurement accuracy of less than 1 nm is required in nanometrology and in fundamental scientific research. To meet this requirement, a generalized, periodic nonlinearity-reduced interferometer, based on three construction principles has been developed for straightness measurements. These three construction principles have resulted in an interferometer with a highly stable design with reduced periodic nonlinearity. Verifications by a straightness interferometer have demonstrated that the periodic nonlinearity was less than 40 pm. The results also demonstrate that the interferometer design is capable of subnanometer accuracy and is useful in nanometrology

  4. Understanding the molecular mechanism of pulse current charging for stable lithium-metal batteries.

    Science.gov (United States)

    Li, Qi; Tan, Shen; Li, Linlin; Lu, Yingying; He, Yi

    2017-07-01

    High energy and safe electrochemical storage are critical components in multiple emerging fields of technologies. Rechargeable lithium-metal batteries are considered to be promising alternatives for current lithium-ion batteries, leading to as much as a 10-fold improvement in anode storage capacity (from 372 to 3860 mAh g -1 ). One of the major challenges for commercializing lithium-metal batteries is the reliability and safety issue, which is often associated with uneven lithium electrodeposition (lithium dendrites) during the charging stage of the battery cycling process. We report that stable lithium-metal batteries can be achieved by simply charging cells with square-wave pulse current. We investigated the effects of charging period and frequency as well as the mechanisms that govern this process at the molecular level. Molecular simulations were performed to study the diffusion and the solvation structure of lithium cations (Li + ) in bulk electrolyte. The model predicts that loose association between cations and anions can enhance the transport of Li + and eventually stabilize the lithium electrodeposition. We also performed galvanostatic measurements to evaluate the cycling behavior and cell lifetime under pulsed electric field and found that the cell lifetime can be more than doubled using certain pulse current waveforms. Both experimental and simulation results demonstrate that the effectiveness of pulse current charging on dendrite suppression can be optimized by choosing proper time- and frequency-dependent pulses. This work provides a molecular basis for understanding the mechanisms of pulse current charging to mitigating lithium dendrites and designing pulse current waveforms for stable lithium-metal batteries.

  5. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  6. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  7. Bartolome Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17'S, 90 deg 33' W. Champion Island: 1 deg, 15'S, 90 deg, 05' W. Urvina Bay (Isabela...

  8. Allan Hills Stable Water Isotopes, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes stable water isotope values at 10 m resolution along an approximately 5 km transect through the main icefield of the Allan Hills Blue Ice...

  9. Applications of stable isotopes in clinical pharmacology

    Science.gov (United States)

    Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

    2011-01-01

    This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the pharmacokinetic profile or mode of action of a drug substance. Secondly, stable isotopes may be used for the assessment of drug products or drug delivery systems by determination of parameters such as the bioavailability or the release profile. Thirdly, patients may be assessed in relation to patient-specific drug treatment; this concept is often called personalized medicine. In this article, the application of stable isotope technology in the aforementioned three areas is reviewed, with emphasis on developments over the past 25 years. The applications are illustrated with examples from clinical studies in humans. PMID:21801197

  10. Tannaka duality and stable infinity-categories

    OpenAIRE

    Iwanari, Isamu

    2014-01-01

    We introduce the notion of fine tannakian infinity-categories and prove Tannaka duality results for symmetric monoidal stable infinity-categories over a field of characteristic zero. We also discuss several examples.

  11. On Stable Marriages and Greedy Matchings

    Energy Technology Data Exchange (ETDEWEB)

    Manne, Fredrik; Naim, Md; Lerring, Hakon; Halappanavar, Mahantesh

    2016-12-11

    Research on stable marriage problems has a long and mathematically rigorous history, while that of exploiting greedy matchings in combinatorial scientific computing is a younger and less developed research field. In this paper we consider the relationships between these two areas. In particular we show that several problems related to computing greedy matchings can be formulated as stable marriage problems and as a consequence several recently proposed algorithms for computing greedy matchings are in fact special cases of well known algorithms for the stable marriage problem. However, in terms of implementations and practical scalable solutions on modern hardware, the greedy matching community has made considerable progress. We show that due to the strong relationship between these two fields many of these results are also applicable for solving stable marriage problems.

  12. Period Variations for the Cepheid VZ Cyg

    Science.gov (United States)

    Sirorattanakul, Krittanon; Engle, Scott; Pepper, Joshua; Wells, Mark; Laney, Clifton D.; Rodriguez, Joseph E.; Stassun, Keivan G.

    2017-12-01

    The Cepheid Period-Luminosity law is a key rung on the extragalactic distance ladder. However, numerous Cepheids are known to undergo period variations. Monitoring, refining, and understanding these period variations allows us to better determine the parameters of the Cepheids themselves and of the instability strip in which they reside, and to test models of stellar evolution. VZ Cyg, a classical Cepheid pulsating at ˜4.864 days, has been observed for over 100 years. Combining data from literature observations, the Kilodegree Extremely Little Telescope (KELT) transit survey, and new targeted observations with the Robotically Controlled Telescope (RCT) at Kitt Peak, we find a period change rate of dP/dt = -0.0642 ± 0.0018 s yr-1. However, when only the recent observations are examined, we find a much higher period change rate of dP/dt = -0.0923 ± 0.0110 s yr-1. This higher rate could be due to an apparent long-term (P ≈ 26.5 years) cyclic period variation. The possible interpretations of this single Cepheid’s complex period variations underscore both the need to regularly monitor pulsating variables and the important benefits that photometric surveys such as KELT can have on the field. Further monitoring of this interesting example of Cepheid variability is recommended to confirm and better understand the possible cyclic period variations. Further, Cepheid timing analyses are necessary to fully understand their current behaviors and parameters, as well as their evolutionary histories.

  13. Issues and opportunities in accelerator mass spectrometry for stable isotopes.

    Science.gov (United States)

    Matteson, Sam

    2008-01-01

    Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development. Copyright 2008 Wiley Periodicals, Inc.

  14. The Reactivity of Stable Metallacyclobutenes and Vinylcarbenes

    OpenAIRE

    Holland, Ryan Lynn

    2016-01-01

    Chapter 1. Historical Development of Stable Metallacyclobutenes Fred Tebbe and co-workers synthesized the first stable metallacyclobutene complexes in the late 1970’s by treatment of an intermediate titanium methylene species – later popularized as the “Tebbe reagent” – with acetylenes. Robert Grubbs at Caltech further studied this system, using it to detail a degenerate metathesis reaction and to isolate a metallacyclobutane complex – which was implicated in the emerging field of alkene meta...

  15. Stable atomic hydrogen: Polarized atomic beam source

    International Nuclear Information System (INIS)

    Niinikoski, T.O.; Penttilae, S.; Rieubland, J.M.; Rijllart, A.

    1984-01-01

    We have carried out experiments with stable atomic hydrogen with a view to possible applications in polarized targets or polarized atomic beam sources. Recent results from the stabilization apparatus are described. The first stable atomic hydrogen beam source based on the microwave extraction method (which is being tested ) is presented. The effect of the stabilized hydrogen gas density on the properties of the source is discussed. (orig.)

  16. Quantification of long-term wastewater fluxes at the surface water/groundwater-interface: an integrative model perspective using stable isotopes and acesulfame.

    Science.gov (United States)

    Engelhardt, I; Barth, J A C; Bol, R; Schulz, M; Ternes, T A; Schüth, C; van Geldern, R

    2014-01-01

    The suitability of acesulfame to trace wastewater-related surface water fluxes from streams into the hyporheic and riparian zones over long-term periods was investigated. The transport behavior of acesulfame was compared with the transport of water stable isotopes (δ(18)O or δ(2)H). A calibrated model based on a joint inversion of temperature, acesulfame, and piezometric pressure heads was employed in a model validation using data sets of acesulfame and water stable isotopes collected over 5months in a stream and groundwater. The spatial distribution of fresh water within the groundwater resulting from surface water infiltration was estimated by computing groundwater ages and compared with the predicted acesulfame plume obtained after 153day simulation time. Both, surface water ratios calculated with a mixing equation from water stable isotopes and simulated acesulfame mass fluxes, were investigated for their ability to estimate the contribution of wastewater-related surface water inflow within groundwater. The results of this study point to limitations for the application of acesulfame to trace surface water-groundwater interactions properly. Acesulfame completely missed the wastewater-related surface water volumes that still remained in the hyporheic zone under stream-gaining conditions. In contrast, under stream-losing conditions, which developed after periods of stagnating hydraulic exchange, acesulfame based predictions lead to an overestimation of the surface water volume of up to 25% in the riparian zone. If slow seepage velocities prevail a proportion of acesulfame might be stored in smaller pores, while when released under fast flowing water conditions it will travel further downstream with the groundwater flow direction. Therefore, under such conditions acesulfame can be a less-ideal tracer in the hyporheic and riparian zones and additional monitoring with other environmental tracers such as water stable isotopes is highly recommended. © 2013 Elsevier

  17. A crawling robot driven by multi-stable origami

    Science.gov (United States)

    Pagano, Alexander; Yan, Tongxi; Chien, Brian; Wissa, A.; Tawfick, S.

    2017-09-01

    Using origami folding to construct and actuate mechanisms and machines offers attractive opportunities from small, scalable, and cheap robots to deployable adaptive structures. This paper presents the design of a bio-inspired origami crawling robot constructed by folding sheets of paper. The origami building block structure is based on the Kresling crease pattern (CP), a chiral tower with a polygonal base, which expands and contracts through coupled longitudinal and rotational motion similar to a screw. We design the origami to have multi-stable structural equilibria which can be tuned by changing the folding CP. Kinematic analysis of these structures based on rigid-plates and hinges at fold lines precludes the shape transformation associated with the bistability of the physical models. To capture the kinematics of the bi-stable origami, the panels’ deformation behavior is modeled utilizing principles of virtual folds. Virtual folds approximate material bending by hinged, rigid panels, which facilitates the development of a kinematic solution via rigid-plate rotation analysis. As such, the kinetics and stability of folded structures are investigated by assigning suitable torsional spring constants to the fold lines. The results presented demonstrate the effect of fold-pattern geometries on the snapping behavior of the bi-stable origami structure based on the Kresling pattern. The crawling robot is presented as a case study for the use of this origami structure to mimic crawling locomotion. The robot is comprised of two origami towers nested inside a paper bellow, and connected by 3D printed end plates. DC motors are used to actuate the expansion and contraction of the internal origami structures to achieve forward locomotion and steering. Beyond locomotion, this simple design can find applications in manipulators, booms, and active structures.

  18. Periodically modulated dark states

    Science.gov (United States)

    Han, Yingying; Zhang, Jun; Zhang, Wenxian

    2018-04-01

    Phenomena of electromagnetically induced transparency (PEIT) may be interpreted by the Autler-Townes Splitting (ATS), where the coupled states are split by the coupling laser field, or by the quantum destructive interference (QDI), where the atomic phases caused by the coupling laser and the probe laser field cancel. We propose modulated experiments to explore the PEIT in an alternative way by periodically modulating the coupling and the probe fields in a Λ-type three-level system initially in a dark state. Our analytical and numerical results rule out the ATS interpretation and show that the QDI interpretation is more appropriate for the modulated experiments. Interestingly, dark state persists in the double-modulation situation where control and probe fields never occur simultaneously, which is significant difference from the traditional dark state condition. The proposed experiments are readily implemented in atomic gases, artificial atoms in superconducting quantum devices, or three-level meta-atoms in meta-materials.

  19. Stable Encoding of Task Structure Coexists With Flexible Coding of Task Events in Sensorimotor Striatum

    Science.gov (United States)

    Kubota, Yasuo; Liu, Jun; Hu, Dan; DeCoteau, William E.; Eden, Uri T.; Smith, Anne C.

    2009-01-01

    The sensorimotor striatum, as part of the brain's habit circuitry, has been suggested to store fixed action values as a result of stimulus-response learning and has been contrasted with a more flexible system that conditionally assigns values to behaviors. The stability of neural activity in the sensorimotor striatum is thought to underlie not only normal habits but also addiction and clinical syndromes characterized by behavioral fixity. By recording in the sensorimotor striatum of mice, we asked whether neuronal activity acquired during procedural learning would be stable even if the sensory stimuli triggering the habitual behavior were altered. Contrary to expectation, both fixed and flexible activity patterns appeared. One, representing the global structure of the acquired behavior, was stable across changes in task cuing. The second, a fine-grain representation of task events, adjusted rapidly. Such dual forms of representation may be critical to allow motor and cognitive flexibility despite habitual performance. PMID:19625536

  20. OPEC behavior

    Science.gov (United States)

    Yang, Bo

    This thesis aims to contribute to a further understanding of the real dynamics of OPEC production behavior and its impacts on the world oil market. A literature review in this area shows that the existing studies on OPEC still have some major deficiencies in theoretical interpretation and empirical estimation technique. After a brief background review in chapter 1, chapter 2 tests Griffin's market-sharing cartel model on the post-Griffin time horizon with a simultaneous system of equations, and an innovative hypothesis of OPEC's behavior (Saudi Arabia in particular) is then proposed based on the estimation results. Chapter 3 first provides a conceptual analysis of OPEC behavior under the framework of non-cooperative collusion with imperfect information. An empirical model is then constructed and estimated. The results of the empirical studies in this thesis strongly support the hypothesis that OPEC has operated as a market-sharing cartel since the early 1980s. In addition, the results also provide some support of the theory of non-cooperative collusion under imperfect information. OPEC members collude under normal circumstances and behave competitively at times in response to imperfect market signals of cartel compliance and some internal attributes. Periodic joint competition conduct plays an important role in sustaining the collusion in the long run. Saudi Arabia acts as the leader of the cartel, accommodating intermediate unfavorable market development and punishing others with a tit-for-tat strategy in extreme circumstances.

  1. Behavioral epigenetics.

    Science.gov (United States)

    Moore, David S

    2017-01-01

    Why do we grow up to have the traits we do? Most 20th century scientists answered this question by referring only to our genes and our environments. But recent discoveries in the emerging field of behavioral epigenetics have revealed factors at the interface between genes and environments that also play crucial roles in development. These factors affect how genes work; scientists now know that what matters as much as which genes you have (and what environments you encounter) is how your genes are affected by their contexts. The discovery that what our genes do depends in part on our experiences has shed light on how Nature and Nurture interact at the molecular level inside of our bodies. Data emerging from the world's behavioral epigenetics laboratories support the idea that a person's genes alone cannot determine if, for example, he or she will end up shy, suffering from cardiovascular disease, or extremely smart. Among the environmental factors that can influence genetic activity are parenting styles, diets, and social statuses. In addition to influencing how doctors treat diseases, discoveries about behavioral epigenetics are likely to alter how biologists think about evolution, because some epigenetic effects of experience appear to be transmissible from generation to generation. This domain of research will likely change how we think about the origins of human nature. WIREs Syst Biol Med 2017, 9:e1333. doi: 10.1002/wsbm.1333 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

  2. NEBIVOLOL IN TREATMENT OF STABLE EXERTIONAL ANGINA PECTORIS

    Directory of Open Access Journals (Sweden)

    Y. V. Gavrilov

    2015-12-01

    Full Text Available Aim. To evaluate antianginal and antiischemic efficiency of nebivolol in patients with stable angina pectoris.Material and methods. 100 patients with ischemic heart disease showing stable exertional angina pectoris and having no contraindications to beta-blockers were studied. After 5-7 days of control period 50 randomly selected patients began to take nebivolol in initial dose of 5mg once daily and 50 patients started to take metoprolol in initial dose of 50 mg twice daily. Duration of treatment was 8 weeks. Efficiency of treatment was assessed according to the results of control treadmill assessment and control daily ECG monitoring.Results. 56-day therapy with nebivolol at a dose of 7,5 mg per day results in increase in duration of treadmill test before angina or ST depression (p<0.05. Antianginal and antiischemic effect of nebivolol 7.5 mg once daily is rather similar with that of metoprolol in average daily dose of 175 mg. Nebivolol compared to metoprolol significantly (p<0.05 more effectively reduces the number of silent myocardial ischemia.Conclusion. Nebivolol is an efficient antianginal and antiischemic drug for patients with stable exertional angina pectoris.

  3. NEBIVOLOL IN TREATMENT OF STABLE EXERTIONAL ANGINA PECTORIS

    Directory of Open Access Journals (Sweden)

    Y. V. Gavrilov

    2007-01-01

    Full Text Available Aim. To evaluate antianginal and antiischemic efficiency of nebivolol in patients with stable angina pectoris.Material and methods. 100 patients with ischemic heart disease showing stable exertional angina pectoris and having no contraindications to beta-blockers were studied. After 5-7 days of control period 50 randomly selected patients began to take nebivolol in initial dose of 5mg once daily and 50 patients started to take metoprolol in initial dose of 50 mg twice daily. Duration of treatment was 8 weeks. Efficiency of treatment was assessed according to the results of control treadmill assessment and control daily ECG monitoring.Results. 56-day therapy with nebivolol at a dose of 7,5 mg per day results in increase in duration of treadmill test before angina or ST depression (p<0.05. Antianginal and antiischemic effect of nebivolol 7.5 mg once daily is rather similar with that of metoprolol in average daily dose of 175 mg. Nebivolol compared to metoprolol significantly (p<0.05 more effectively reduces the number of silent myocardial ischemia.Conclusion. Nebivolol is an efficient antianginal and antiischemic drug for patients with stable exertional angina pectoris.

  4. Period doubling in a model of magnetoconvection with Ohmic heating

    International Nuclear Information System (INIS)

    Osman, M. B. H.

    2000-01-01

    In this work it has been studied an idealized model of rotating nonlinear magneto convection to investigate the effects of Ohmic heating. In the over stable region it was found that Ohmic heating can lead to a period-doubling sequence

  5. Periodic Boundary Motion in Thermal Turbulence

    International Nuclear Information System (INIS)

    Zhang, Jun; Libchaber, Albert

    2000-01-01

    A free-floating plate is introduced in a Benard convection cell with an open surface. It partially covers the cell and distorts the local heat flux, inducing a coherent flow that in turn moves the plate. Remarkably, the plate can be driven to a periodic motion even under the action of a turbulent fluid. The period of the oscillation depends on the coverage ratio, and on the Rayleigh number of the convective system. The plate oscillatory behavior observed in this experiment may be related to a geological model, in which continents drift in a quasiperiodic fashion. (c) 2000 The American Physical Society

  6. Stability of Bisexual Behavior and Extent of Viral Bridging Behavior Among Men Who Have Sex with Men and Women.

    Science.gov (United States)

    Friedman, M Reuel; Stall, Ron; Plankey, Michael; Shoptaw, Steve; Herrick, A L; Surkan, Pamela J; Teplin, Linda; Silvestre, Anthony J

    2017-05-01

    Bisexual men experience significant health disparities likely related to biphobia. Biphobia presents via several preconceptions, including that bisexuality is transitory, and that bisexual men act as viral bridges between men who have sex with men and heterosexual populations. We analyzed data from a prospective cohort of gay and bisexual men, the Multicenter AIDS Cohort Study, to test these preconceptions. Men reporting both male and female sexual partners (MSMW) between 2002 and 2009 (n = 111) were classified as behaviorally bisexual. We assessed five hypotheses over two domains (transience of bisexual behavior and viral bridging). No evidence was found supporting the transitory nature of bisexuality. Trajectories of bisexual behavior were not transient over time. We found little evidence to support substantial viral bridging behavior. Notably, HIV-positive MSMW reported lower proportions of female partners than HIV-negative MSMW. Our results provide no empirical support for bisexual transience and scant support for viral bridging hypotheses. Our results provide key data showing that male bisexual behavior may be stable over long time periods and that behaviorally bisexual men's risk to female sexual partners may be lower than expected.

  7. [Childhood periodic syndromes].

    Science.gov (United States)

    Cuvellier, J-C; Lépine, A

    2010-01-01

    This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis

  8. Time—periodic weak solutions

    Directory of Open Access Journals (Sweden)

    Eliana Henriques de Brito

    1990-01-01

    Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.

  9. Theoretical chemistry periodicities in chemistry and biology

    CERN Document Server

    Eyring, Henry

    1978-01-01

    Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

  10. Resonances in a periodically driven bosonic system

    Science.gov (United States)

    Quelle, Anton; Smith, Cristiane Morais

    2017-11-01

    Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localization. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a noninteracting model, characterized by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.

  11. Period Changes of 23 Field RR Lyrae Stars

    Directory of Open Access Journals (Sweden)

    Soo-Chang Rey

    1994-12-01

    Full Text Available The secular period behavior of 23 field RR Lyrae stars is studied in order to determine if the observed period changes could be attributed, at least in the mean, to stellar evolution. The sample of stars is subdivided into two Oosterhoff groups based on the metallicity and period-shift. Despite the small sample size, we found a distinct bias toward positive period changes in the group variables. The period changes of the group variables in globular clusters. This provides yet another support for the Lee, Demarque, and Zinn(1990 evolutionary models of RR Lyrae stars and their explanation of the Sandage period-shift effect.

  12. Stable chaos in fluctuation driven neural circuits

    International Nuclear Information System (INIS)

    Angulo-Garcia, David; Torcini, Alessandro

    2014-01-01

    Highlights: • Nonlinear instabilities in fluctuation driven (balanced) neural circuits are studied. • Balanced networks display chaos and stable phases at different post-synaptic widths. • Linear instabilities coexists with nonlinear ones in the chaotic regime. • Erratic motion appears also in linearly stable phase due to stable chaos. - Abstract: We study the dynamical stability of pulse coupled networks of leaky integrate-and-fire neurons against infinitesimal and finite perturbations. In particular, we compare mean versus fluctuations driven networks, the former (latter) is realized by considering purely excitatory (inhibitory) sparse neural circuits. In the excitatory case the instabilities of the system can be completely captured by an usual linear stability (Lyapunov) analysis, whereas the inhibitory networks can display the coexistence of linear and nonlinear instabilities. The nonlinear effects are associated to finite amplitude instabilities, which have been characterized in terms of suitable indicators. For inhibitory coupling one observes a transition from chaotic to non chaotic dynamics by decreasing the pulse-width. For sufficiently fast synapses the system, despite showing an erratic evolution, is linearly stable, thus representing a prototypical example of stable chaos

  13. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    Faust, H.; Jung, K.; Krumbiegel, P.

    1993-01-01

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  14. Climatic signals in multiple highly resolved stable isotope records from Greenland

    DEFF Research Database (Denmark)

    Vinther, Bo Møllesøe; Dahl-Jensen, Dorthe; Johnsen, Sigfus Johann

    2010-01-01

    summer temperatures and the first principal component of the summer season stable isotope data is 0.56, increasing to 0.66 for decadally filtered data. Winter season stable isotope data from ice core records that reach more than 1400 years back in time suggest that the warm period that began in the 1920s...... raised southern Greenland temperatures to the same level as those that prevailed during the warmest intervals of the Medieval Warm Period some 900-1300 years ago. This observation is supported by a southern Greenland ice core borehole temperature inversion. As Greenland borehole temperature inversions...

  15. Effective search for stable segregation configurations at grain boundaries with data-mining techniques

    Science.gov (United States)

    Kiyohara, Shin; Mizoguchi, Teruyasu

    2018-03-01

    Grain boundary segregation of dopants plays a crucial role in materials properties. To investigate the dopant segregation behavior at the grain boundary, an enormous number of combinations have to be considered in the segregation of multiple dopants at the complex grain boundary structures. Here, two data mining techniques, the random-forests regression and the genetic algorithm, were applied to determine stable segregation sites at grain boundaries efficiently. Using the random-forests method, a predictive model was constructed from 2% of the segregation configurations and it has been shown that this model could determine the stable segregation configurations. Furthermore, the genetic algorithm also successfully determined the most stable segregation configuration with great efficiency. We demonstrate that these approaches are quite effective to investigate the dopant segregation behaviors at grain boundaries.

  16. Topical tazarotene vs. coal tar in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, U.; Kaur, I.; Dogra, S.; De, D.; Kumar, B. [Postgraduate Institute of Medical Education & Research, Chandigarh (India)

    2010-07-15

    The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% {+-} 9.43 and 77.37% {+-} 10.93 with tazarotene and CCT, respectively (P {gt} 0.05). A reduction in ESI score of {gt} 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis.

  17. A Compact Unconditionally Stable Method for Time-Domain Maxwell's Equations

    Directory of Open Access Journals (Sweden)

    Zhuo Su

    2013-01-01

    Full Text Available Higher order unconditionally stable methods are effective ways for simulating field behaviors of electromagnetic problems since they are free of Courant-Friedrich-Levy conditions. The development of accurate schemes with less computational expenditure is desirable. A compact fourth-order split-step unconditionally-stable finite-difference time-domain method (C4OSS-FDTD is proposed in this paper. This method is based on a four-step splitting form in time which is constructed by symmetric operator and uniform splitting. The introduction of spatial compact operator can further improve its performance. Analyses of stability and numerical dispersion are carried out. Compared with noncompact counterpart, the proposed method has reduced computational expenditure while keeping the same level of accuracy. Comparisons with other compact unconditionally-stable methods are provided. Numerical dispersion and anisotropy errors are shown to be lower than those of previous compact unconditionally-stable methods.

  18. Visualization and manipulation of meta-stable polarization variants in multiferroic materials

    Directory of Open Access Journals (Sweden)

    Moonkyu Park

    2013-04-01

    Full Text Available Here we demonstrate the role of meta-stable polarization variants in out-of-plane polarization switching behavior in epitaxially grown BiFeO3 thin films using angle-resolved piezoresponse force microscopy (AR-PFM. The out-of-plane polarization switching mainly occurred at the boundary between meta-stable and stable polarization domains, and was accompanied by a significant change in in-plane domain configuration from complicated structure with 12 polarization variants to simple stripe structure with 4 polarization variants. These results imply that the biased tip rearranges the delicately balanced domain configuration, which is determined by the competition between electrostatic and strain energies, into simple interweaving one that is more thermodynamically stable.

  19. Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome (RLS)

    Science.gov (United States)

    ... the syndrome. Risk factors include the following: A sedentary lifestyle Smoking Obesity Many people with narcolepsy or rapid eye movement (REM) behavior disorder move their legs periodically during sleep. Both ...

  20. Critical period for acoustic preference in mice.

    Science.gov (United States)

    Yang, Eun-Jin; Lin, Eric W; Hensch, Takao K

    2012-10-16

    Preference behaviors are often established during early life, but the underlying neural circuit mechanisms remain unknown. Adapting a unique nesting behavior assay, we confirmed a "critical period" for developing music preference in C57BL/6 mice. Early music exposure between postnatal days 15 and 24 reversed their innate bias for silent shelter, which typically could not be altered in adulthood. Instead, exposing adult mice treated acutely with valproic acid or carrying a targeted deletion of the Nogo receptor (NgR(-/-)) unmasked a strong plasticity of preference consistent with a reopening of the critical period as seen in other systems. Imaging of cFos expression revealed a prominent neuronal activation in response to the exposed music in the prelimbic and infralimbic medial prefrontal cortex only under conditions of open plasticity. Neither behavioral changes nor selective medial prefrontal cortex activation was observed in response to pure tone exposure, indicating a music-specific effect. Open-field center crossings were increased concomitant with shifts in music preference, suggesting a potential anxiolytic effect. Thus, music may offer both a unique window into the emotional state of mice and a potentially efficient assay for molecular "brakes" on critical period plasticity common to sensory and higher order brain areas.

  1. Consumer Behavior Research

    Directory of Open Access Journals (Sweden)

    Kaveh Peighambari

    2016-04-01

    Full Text Available This article analyzes 12 years of recent scholarly research on consumer behavior published in the five leading international journals in this field. Analyzing academic contributions to a specific area of research provides valuable insights into how it has evolved over a defined period. The approach was to briefly discuss content analysis and its application in scholarly literature review studies. The methodology used here involves the classification of topics to evaluate key trends in consumer behavior literature. It includes a ranking of topics published, typology of the published articles, the research classification in terms of methodologies, and analysis techniques. The most cited articles in the field and within each journal are also examined. The comprehensive literature review of consumer behavior research undertaken in this article could advance the discipline of consumer behavior research by elucidating the evolution of consumer behavior literature in the studied period.

  2. Ruin probability with claims modeled by a stationary ergodic stable process

    NARCIS (Netherlands)

    Mikosch, T; Samorodnitsky, G

    2000-01-01

    For a random walk with negative drift we study the exceedance probability (ruin probability) of a high threshold. The steps of this walk (claim sizes) constitute a stationary ergodic stable process. We study how ruin occurs in this situation and evaluate the asymptotic behavior of the ruin

  3. Temperature and Humidity Control in Livestock Stables

    DEFF Research Database (Denmark)

    Hansen, Michael; Andersen, Palle; Nielsen, Kirsten M.

    2010-01-01

    The paper describes temperature and humidity control of a livestock stable. It is important to have a correct air flow pattern in the livestock stable in order to achieve proper temperature and humidity control as well as to avoid draught. In the investigated livestock stable the air flow...... is controlled using wall mounted ventilation flaps. In the paper an algorithm for air flow control is presented meeting the needs for temperature and humidity while taking the air flow pattern in consideration. To obtain simple and realisable controllers a model based control design method is applied....... In the design dynamic models for temperature and humidity are very important elements and effort is put into deriving and testing the models. It turns out that non-linearities are dominating in both models making feedback linearization the natural design method. The air controller as well as the temperature...

  4. On some topological properties of stable measures

    DEFF Research Database (Denmark)

    Nielsen, Carsten Krabbe

    1996-01-01

    Summary The paper shows that the set of stable probability measures and the set of Rational Beliefs relative to a given stationary measure are closed in the strong topology, but not closed in the topology of weak convergence. However, subsets of the set of stable probability measures which...... are characterized by uniformity of convergence of the empirical distribution are closed in the topology of weak convergence. It is demonstrated that such subsets exist. In particular, there is an increasing sequence of sets of SIDS measures who's union is the set of all SIDS measures generated by a particular...... system and such that each subset consists of stable measures. The uniformity requirement has a natural interpretation in terms of plausibility of Rational Beliefs...

  5. Concentration of stable elements in food products

    Energy Technology Data Exchange (ETDEWEB)

    Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

    1980-01-01

    Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed.

  6. Travelling waves in models of neural tissue: from localised structures to periodic waves

    NARCIS (Netherlands)

    Meijer, Hil Gaétan Ellart; Coombes, Stephen

    2014-01-01

    We consider travelling waves (fronts, pulses and periodics) in spatially extended one dimensional neural field models. We demonstrate for an excitatory field with linear adaptation that, in addition to an expected stable pulse solution, a stable anti-pulse can exist. Varying the adaptation strength

  7. Lotka-Volterra systems in environments with randomly disordered temporal periodicity

    Science.gov (United States)

    Naess, Arvid; Dimentberg, Michael F.; Gaidai, Oleg

    2008-08-01

    A generalized Lotka-Volterra model for a pair of interacting populations of predators and prey is studied. The model accounts for the prey’s interspecies competition and therefore is asymptotically stable, whereas its oscillatory behavior is induced by temporal variations in environmental conditions simulated by those in the prey’s reproduction rate. Two models of the variations are considered, each of them combining randomness with “hidden” periodicity. The stationary joint probability density function (PDF) of the number of predators and prey is calculated numerically by the path integration (PI) method based on the use of characteristic functions and the fast Fourier transform. The numerical results match those for the asymptotic case of white-noise variations for which an analytical solution is available. Several examples are studied, with calculations of important characteristics of oscillations, for example the expected rate of up-crossings given the level of the predator number. The calculated PDFs may be of predominantly random (unimodal) or predominantly periodic nature (bimodal). Thus, the PI method has been demonstrated to be a powerful tool for studies of the dynamics of predator-prey pairs. The method captures the random oscillations as observed in nature, taking into account potential periodicity in the environmental conditions.

  8. Faster and Simpler Approximation of Stable Matchings

    Directory of Open Access Journals (Sweden)

    Katarzyna Paluch

    2014-04-01

    Full Text Available We give a 3 2 -approximation algorithm for finding stable matchings that runs in O(m time. The previous most well-known algorithm, by McDermid, has the same approximation ratio but runs in O(n3/2m time, where n denotes the number of people andm is the total length of the preference lists in a given instance. In addition, the algorithm and the analysis are much simpler. We also give the extension of the algorithm for computing stable many-to-many matchings.

  9. Modelling stable water isotopes: Status and perspectives

    Directory of Open Access Journals (Sweden)

    Werner M.

    2010-12-01

    Full Text Available Modelling of stable water isotopes H2 18O and HDO within various parts of the Earth’s hydrological cycle has clearly improved our understanding of the interplay between climatic variations and related isotope fractionation processes. In this article key principles and major research results of stable water isotope modelling studies are described. Emphasis is put on research work using explicit isotope diagnostics within general circulation models as this highly complex model setup bears many resemblances with studies using simpler isotope modelling approaches.

  10. Dynamics of a Levitron under a periodic magnetic forcing

    Science.gov (United States)

    Pérez, Alberto T.; García-Sánchez, Pablo

    2015-02-01

    The Levitron is a toy that consists of a spinning top that levitates over a magnetic base for a few minutes, until air drag decreases the spin rate below a certain limit. Stable levitation, lasting hours or even days, has been achieved for Levitrons that were externally driven by either an air jet or an alternating magnetic field. We report measurements of stable levitation for the latter case. We show that the top precession couples with the frequency of the alternating field, so that the precession period equals the period of the field. In addition, the top rotates around itself with the same period. We present numerical simulations that reproduce the essential features of this dynamics. It is also shown that the magnetic torque that drives the top is due to a misalignment between the magnetic dipole moment and the mechanical axis of the top.

  11. Examination of constitutive model for evaluating long-term mechanical behavior of buffer. 3

    International Nuclear Information System (INIS)

    Takaji, Kazuhiko; Shigeno, Yoshimasa; Shimogouchi, Takafumi; Shiratake, Toshikazu; Tamura, Hirokuni

    2004-02-01

    On the R and D of the high-level radioactive waste repository, it is essential that Engineered Barrier System (EBS) is stable mechanically over a long period of time for maintaining each ability required to EBS. After closing the repository, the various external forces will be affected to buffer intricately for a long period of time. So, to make clear the mechanical deformation behavior of buffer against the external force is important, because of carrying out safety assessment of EBS accurately. In this report, several sets of parameters are chosen for the previously selected two constitutive models, Sekiguchi-Ohta model and Adachi-Oka model, and the element tests and mock-up tests are simulated using these parameters. Through the simulation, applicability of the constitutive models and parameters is examined. Moreover, simulation analyses of EBS using these parameters is examined. Moreover, simulation analyses of EBS using these parameters were carried out, and mechanical behavior is evaluated over a long period of time. Analysis estimated the amount of settlement of the over pack, the stress state of buffer material, the reaction force to a base rock, etc., and the result that EBS is mechanically stable over a long period of time was obtained. Next, in order to prove analyses results a side, literature survey was conducted about geological age, the dynamics history of a Smectite layer. The outline plan was drawn up about the natural analogue verification method and preliminary examination was performed about the applicability of Freezing Sampling'. (author)

  12. Postaccident changes in heath status of the Chornobyl cleanup workers 1986-1987 (period of observation 1988-2012)

    International Nuclear Information System (INIS)

    Buzunov, V.O.; Vojchulene, Yu.S.; Domashevs'ka, T.Je.; Khabarova, T.P.; Kortushyin, G.Yi.

    2015-01-01

    Long-term cohort epidemiological study (period of observation 1988-2012) has been conducted using data of the State Registry of Ukraine of Persons Affected by the Chornobyl Accident. Study cohort - 196,423 males-participants of the Chornobyl recovery operations in 1986-1987. Epidemiological and mathematical- and-statistical methods were used. We have found a dramatic deterioration of the Chornobyl cleanup workers' health due to the growth of wide range of nontumor diseases, especially circulatory, digestive, respiratory, endocrine, genitourinary and nervous system diseases. In postaccident period, disability and mortality have increased significantly due to nontumor diseases. Circulatory diseases make major contribution to the structure of causes of disability and death. When studying the dynamics of nontumor incidence, we have found that in 1988-1992 the highest, throughout postaccident period, rate of mental and behavioral disorders, diseases of the nervous system was mainly due to disorders of the autonomic nervous system. Since 1993-1997, rate of this pathology has significantly reduced and remained stable in subsequent years of observation. Thus, we can assume that in the early postaccident period, stress factor in combination with radiation one had the greatest impact on health of cleanup workers, resulting in the development of other nontumor diseases in the remote postaccident period. The study revealed an evident increase in nontumor incidence, disability and mortality from nontumor diseases among Chornobyl cleanup workers 1986-1987; the highest rate of nontumor incidence was observed 12-21 years after the Chornobyl accident

  13. Periodic oscillation and exponential stability of delayed CNNs

    Science.gov (United States)

    Cao, Jinde

    2000-05-01

    Both the global exponential stability and the periodic oscillation of a class of delayed cellular neural networks (DCNNs) is further studied in this Letter. By applying some new analysis techniques and constructing suitable Lyapunov functionals, some simple and new sufficient conditions are given ensuring global exponential stability and the existence of periodic oscillatory solution of DCNNs. These conditions can be applied to design globally exponentially stable DCNNs and periodic oscillatory DCNNs and easily checked in practice by simple algebraic methods. These play an important role in the design and applications of DCNNs.

  14. On exponential stability and periodic solutions of CNNs with delays

    Science.gov (United States)

    Cao, Jinde

    2000-03-01

    In this Letter, the author analyses further problems of global exponential stability and the existence of periodic solutions of cellular neural networks with delays (DCNNs). Some simple and new sufficient conditions are given ensuring global exponential stability and the existence of periodic solutions of DCNNs by applying some new analysis techniques and constructing suitable Lyapunov functionals. These conditions have important leading significance in the design and applications of globally stable DCNNs and periodic oscillatory DCNNs and are weaker than those in the earlier works [Phys. Rev. E 60 (1999) 3244], [J. Comput. Syst. Sci. 59 (1999)].

  15. Stable isotope analysis of dynamic lipidomics.

    Science.gov (United States)

    Brandsma, Joost; Bailey, Andrew P; Koster, Grielof; Gould, Alex P; Postle, Anthony D

    2017-08-01

    Metabolic pathway flux is a fundamental element of biological activity, which can be quantified using a variety of mass spectrometric techniques to monitor incorporation of stable isotope-labelled substrates into metabolic products. This article contrasts developments in electrospray ionisation mass spectrometry (ESI-MS) for the measurement of lipid metabolism with more established gas chromatography mass spectrometry and isotope ratio mass spectrometry methodologies. ESI-MS combined with diagnostic tandem MS/MS scans permits the sensitive and specific analysis of stable isotope-labelled substrates into intact lipid molecular species without the requirement for lipid hydrolysis and derivatisation. Such dynamic lipidomic methodologies using non-toxic stable isotopes can be readily applied to quantify lipid metabolic fluxes in clinical and metabolic studies in vivo. However, a significant current limitation is the absence of appropriate software to generate kinetic models of substrate incorporation into multiple products in the time domain. Finally, we discuss the future potential of stable isotope-mass spectrometry imaging to quantify the location as well as the extent of lipid synthesis. This article is part of a Special Issue entitled: BBALIP_Lipidomics Opinion Articles edited by Sepp Kohlwein. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    Petrography, compositional characteristics and stable isotope geochemistry of the Ewekoro formation from Ibese Corehole, eastern Dahomey basin, southwestern Nigeria. ME Nton, MO ... Preserved pore types such as; intercrystaline, moldic and vuggy pores were observed as predominant conduits for fluids. The major ...

  17. petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    PROF EKWUEME

    Subsurface samples of the predominantly carbonate Ewekoro Formation, obtained from Ibese core hole within the Dahomey basin were used in this study. Investigations entail petrographic, elemental composition as well as stable isotopes (carbon and oxygen) geochemistry in order to deduce the different microfacies and ...

  18. Substitution of stable isotopes in Chlorella

    Science.gov (United States)

    Flaumenhaft, E.; Katz, J. J.; Uphaus, R. A.

    1969-01-01

    Replacement of biologically important isotopes in the alga Chlorella by corresponding heavier stable isotopes produces increasingly greater deviations from the normal cell size and changes the quality and distribution of certain cellular components. The usefulness of isotopically altered organisms increases interest in the study of such permuted organisms.

  19. Champion Island, Galapagos Stable Oxygen Calibration Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Galapagos Coral Stable Oxygen Calibration Data. Sites: Bartolome Island: 0 deg, 17 min S, 90 deg 33 min W. Champion Island: 1 deg, 15 min S, 90 deg, 05 min W. Urvina...

  20. Stable propagation of 'selfish'genetic elements

    Indian Academy of Sciences (India)

    Unknown

    viruses such as the Epstein-Barr virus (Harris et al 1985;. Kanda et al 2001) and bovine papilloma virus (Lehman and Botchan 1998; Ilves et al 1999), which exist pre- dominantly as extrachromosomal episomes, have been shown to utilize chromosome tethering as a means for stable segregation. The tethering mechanism ...

  1. Unconditionally stable perfectly matched layer boundary conditions

    NARCIS (Netherlands)

    De Raedt, H.; Michielsen, K.

    2007-01-01

    A brief review is given of a systematic, product-formula based approach to construct unconditionally stable algorithms for solving the time-dependent Maxwell equations. The fundamental difficulties that arise when we want to incorporate uniaxial perfectly matched layer boundary conditions into this

  2. Facies, dissolution seams and stable isotope compositions

    Indian Academy of Sciences (India)

    Stable isotope analysis of the limestone shows that 13C and 18O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution ...

  3. Connected domination stable graphs upon edge addition ...

    African Journals Online (AJOL)

    A set S of vertices in a graph G is a connected dominating set of G if S dominates G and the subgraph induced by S is connected. We study the graphs for which adding any edge does not change the connected domination number. Keywords: Connected domination, connected domination stable, edge addition ...

  4. Stable magnetic remanence in antiferromagnetic goethite.

    Science.gov (United States)

    Strangway, D W; McMahon, B E; Honea, R M

    1967-11-10

    Goethite, known to be antiferromagnetic, acquires thermoremanent magnetization at its Neel temperature of 120 degrees C. This remanence, extremely stable, is due to the presence of unbalanced spins in the antiferromagnetic structure; the spins may result from grain size, imperfections, or impurities.

  5. Period doubling in period-one steady states

    Science.gov (United States)

    Wang, Reuben R. W.; Xing, Bo; Carlo, Gabriel G.; Poletti, Dario

    2018-02-01

    Nonlinear classical dissipative systems present a rich phenomenology in their "route to chaos," including period doubling, i.e., the system evolves with a period which is twice that of the driving. However, typically the attractor of a periodically driven quantum open system evolves with a period which exactly matches that of the driving. Here, we analyze a periodically driven many-body open quantum system whose classical correspondent presents period doubling. We show that by studying the dynamical correlations, it is possible to show the occurrence of period doubling in the quantum (period-one) steady state. We also discuss that such systems are natural candidates for clean and intrinsically robust Floquet time crystals.

  6. Preparation and characterization of stable aqueous higher-order fullerenes

    International Nuclear Information System (INIS)

    Aich, Nirupam; Flora, Joseph R V; Saleh, Navid B

    2012-01-01

    Stable aqueous suspensions of nC 60 and individual higher fullerenes, i.e. C 70 , C 76 and C 84 , are prepared by a calorimetric modification of a commonly used liquid–liquid extraction technique. The energy requirement for synthesis of higher fullerenes has been guided by molecular-scale interaction energy calculations. Solubilized fullerenes show crystalline behavior by exhibiting lattice fringes in high resolution transmission electron microscopy images. The fullerene colloidal suspensions thus prepared are stable with a narrow distribution of cluster radii (42.7 ± 0.8 nm, 46.0 ± 14.0 nm, 60 ± 3.2 nm and 56.3 ± 1.1 nm for nC 60 , nC 70 , nC 76 and nC 84 , respectively) as measured by time-resolved dynamic light scattering. The ζ-potential values for all fullerene samples showed negative surface potentials with similar magnitude ( − 38.6 ± 5.8 mV, − 39.1 ± 4.2 mV, − 38.9 ± 5.8 mV and − 41.7 ± 5.1 mV for nC 60 , nC 70 , nC 76 and nC 84 , respectively), which provide electrostatic stability to the colloidal clusters. This energy-based modified solubilization technique to produce stable aqueous fullerenes will likely aid in future studies focusing on better applicability, determination of colloidal properties, and understanding of environmental fate, transport and toxicity of higher-order fullerenes. (paper)

  7. Photolysis of Periodate and Periodic Acid in Aqueous Solution

    DEFF Research Database (Denmark)

    Sehested, Knud; Kläning, U. K.

    1978-01-01

    The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH

  8. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

    Burton, K. W.; Parkinson, I. J.; Gíslason, S. G. R.

    2016-12-01

    The strontium (Sr) stable isotope composition of rivers is strongly controlled by the balance of carbonate to silicate weathering (Krabbenhöft et al. 2010; Pearce et al. 2015). However, rivers draining silicate catchments possess distinctly heavier Sr stable isotope values than their bedrock compositions, pointing to significant fractionation during weathering. Some have argued for preferential release of heavy Sr from primary phases during chemical weathering, others for the formation of secondary weathering minerals that incorporate light isotopes. This study presents high-precision double-spike Sr stable isotope data for soils, rivers, ground waters and estuarine waters from Iceland, reflecting both natural weathering and societal impacts on those environments. The bedrock in Iceland is dominantly basaltic, d88/86Sr ≈ +0.27, extending to lighter values for rhyolites. Geothermal waters range from basaltic Sr stable compositions to those akin to seawater. Soil pore waters reflect a balance of input from primary mineral weathering, precipitation and litter recycling and removal into secondary phases and vegetation. Rivers and ground waters possess a wide range of d88/86Sr compositions from +0.101 to +0.858. Elemental and isotope data indicate that this fractionation primarily results from the formation or dissolution of secondary zeolite (d88/86Sr ≈ +0.10), but also carbonate (d88/86Sr ≈ +0.22) and sometimes anhydrite (d88/86Sr ≈ -0.73), driving the residual waters to heavier or lighter values, respectively. Estuarine waters largely reflect mixing with seawater, but are also be affected by adsorption onto particulates, again driving water to heavy values. Overall, these data indicate that the stability and nature of secondary weathering phases, exerts a strong control on the Sr stable isotope composition of silicate rivers. [1] Krabbenhöft et al. (2010) Geochim. Cosmochim. Acta 74, 4097-4109. [2] Pearce et al. (2015) Geochim. Cosmochim. Acta 157, 125-146.

  9. Development of a Safety Management Web Tool for Horse Stables.

    Science.gov (United States)

    Leppälä, Jarkko; Kolstrup, Christina Lunner; Pinzke, Stefan; Rautiainen, Risto; Saastamoinen, Markku; Särkijärvi, Susanna

    2015-11-12

    Managing a horse stable involves risks, which can have serious consequences for the stable, employees, clients, visitors and horses. Existing industrial or farm production risk management tools are not directly applicable to horse stables and they need to be adapted for use by managers of different types of stables. As a part of the InnoEquine project, an innovative web tool, InnoHorse, was developed to support horse stable managers in business, safety, pasture and manure management. A literature review, empirical horse stable case studies, expert panel workshops and stakeholder interviews were carried out to support the design. The InnoHorse web tool includes a safety section containing a horse stable safety map, stable safety checklists, and examples of good practices in stable safety, horse handling and rescue planning. This new horse stable safety management tool can also help in organizing work processes in horse stables in general.

  10. Gap solitons in periodic Schrodinger lattice system with nonlinear hopping

    Directory of Open Access Journals (Sweden)

    Ming Cheng

    2016-10-01

    Full Text Available This article concerns the periodic discrete Schrodinger equation with nonlinear hopping on the infinite integer lattice. We obtain the existence of gap solitons by the linking theorem and concentration compactness method together with a periodic approximation technique. In addition, the behavior of such solutions is studied as $\\alpha\\to 0$. Notice that the nonlinear hopping can be sign changing.

  11. Stable Lévy motion with inverse Gaussian subordinator

    Science.gov (United States)

    Kumar, A.; Wyłomańska, A.; Gajda, J.

    2017-09-01

    In this paper we study the stable Lévy motion subordinated by the so-called inverse Gaussian process. This process extends the well known normal inverse Gaussian (NIG) process introduced by Barndorff-Nielsen, which arises by subordinating ordinary Brownian motion (with drift) with inverse Gaussian process. The NIG process found many interesting applications, especially in financial data description. We discuss here the main features of the introduced subordinated process, such as distributional properties, existence of fractional order moments and asymptotic tail behavior. We show the connection of the process with continuous time random walk. Further, the governing fractional partial differential equations for the probability density function is also obtained. Moreover, we discuss the asymptotic distribution of sample mean square displacement, the main tool in detection of anomalous diffusion phenomena (Metzler et al., 2014). In order to apply the stable Lévy motion time-changed by inverse Gaussian subordinator we propose a step-by-step procedure of parameters estimation. At the end, we show how the examined process can be useful to model financial time series.

  12. Stable long-term chronic brain mapping at the single-neuron level.

    Science.gov (United States)

    Fu, Tian-Ming; Hong, Guosong; Zhou, Tao; Schuhmann, Thomas G; Viveros, Robert D; Lieber, Charles M

    2016-10-01

    Stable in vivo mapping and modulation of the same neurons and brain circuits over extended periods is critical to both neuroscience and medicine. Current electrical implants offer single-neuron spatiotemporal resolution but are limited by such factors as relative shear motion and chronic immune responses during long-term recording. To overcome these limitations, we developed a chronic in vivo recording and stimulation platform based on flexible mesh electronics, and we demonstrated stable multiplexed local field potentials and single-unit recordings in mouse brains for at least 8 months without probe repositioning. Properties of acquired signals suggest robust tracking of the same neurons over this period. This recording and stimulation platform allowed us to evoke stable single-neuron responses to chronic electrical stimulation and to carry out longitudinal studies of brain aging in freely behaving mice. Such advantages could open up future studies in mapping and modulating changes associated with learning, aging and neurodegenerative diseases.

  13. The rise and fall of periodic 'drumbeat' seismicity at Tungurahua volcano, Ecuador

    Science.gov (United States)

    Bell, Andrew F.; Hernandez, Stephen; Gaunt, H. Elizabeth; Mothes, Patricia; Ruiz, Mario; Sierra, Daniel; Aguaiza, Santiago

    2017-10-01

    Highly periodic 'drumbeat' long period (LP) earthquakes have been described from several andesitic and dacitic volcanoes, commonly accompanying incremental ascent and effusion of viscous magma. However, the processes controlling the occurrence and characteristics of drumbeat, and LP earthquakes more generally, remain contested. Here we use new quantitative tools to describe the emergence, evolution, and degradation of drumbeat LP seismicity at the andesitic Tungurahua volcano, Ecuador, in April 2015. The signals were recorded during an episode of minor explosive activity and ash emission, without lava effusion, and are the first to be reported at Tungurahua during the ongoing 17 yrs of eruption. Following four days of high levels of continuous and 'pulsed' tremor, highly-periodic LP earthquakes first appear on 10 April. Over the next four days, inter-event times and event amplitudes evolve through a series of step-wise transitions between stable behaviors, each involving a decrease in the degree of periodicity. Families of similar waveforms persist before, during, and after drumbeat activity, but the activity levels of different families change coincidentally with transitions in event rate, amplitude, and periodicity. A complex micro-seismicity 'initiation' sequence shows pulse-like and stepwise changes in inter-event times and amplitudes in the hours preceding the onset of drumbeat activity that indicate a partial de-coupling between event size and rate. The observations increase the phenomenology of drumbeat LP earthquakes, and suggest that at Tungurahua they result from gas flux and rapid depressurization controlled by shear failure of the margins of the ascending magma column.

  14. Neuroendocrine mechanisms underlying behavioral stability: implications for the evolutionary origin of personality.

    Science.gov (United States)

    Duckworth, Renée A

    2015-12-01

    Personality traits are behaviors that show limited flexibility over time and across contexts, and thus understanding their origin requires an understanding of what limits behavioral flexibility. Here, I suggest that insight into the evolutionary origin of personality traits requires determining the relative importance of selection and constraint in producing limits to behavioral flexibility. Natural selection as the primary cause of limits to behavioral flexibility assumes that the default state of behavior is one of high flexibility and predicts that personality variation arises through evolution of buffering mechanisms to stabilize behavioral expression, whereas the constraint hypothesis assumes that the default state is one of limited flexibility and predicts that the neuroendocrine components that underlie personality variation are those most constrained in flexibility. Using recent work on the neurobiology of sensitive periods and maternal programming of offspring behavior, I show that some of the most stable aspects of the neuroendocrine system are structural components and maternally induced epigenetic effects. Evidence of numerous constraints to changes in structural features of the neuroendocrine system and far fewer constraints to flexibility of epigenetic systems suggests that structural constraints play a primary role in the origin of behavioral stability and that epigenetic programming may be more important in generating adaptive variation among individuals. © 2015 New York Academy of Sciences.

  15. Nanoprocessing of metastable nm-period multilayers

    Science.gov (United States)

    Gorbunov, A. A.; Richter, J.; Pompe, W.

    Nanometer-period nickel-carbon multilayers were used as a medium for the fabrication of nanostructures by gap voltage manipulations in a scanning tunneling microscope. The written metallic structures were stable over at least several weeks. No traces of tip material were found in the processed areas. Two well-distinguished hillock-like nanostructure types were observed depending on the tip-sample separation, polarity and interaction time. Relatively slow local annealing under positive sample potential without a direct tip-sample contact resulted in the formation of nanostructures about 20 nm wide and a few nm high. Rapid melting followed by metal melt extrusion was observed if the tip contacted the sample during the nanostructure formation. These metal-like structures were tens of nm high and had a good electronic contrast to the initial carbon-coated surface. The formation of nanostructures was strongly dependent on the tip condition. Possible mechanisms of nanostructure formation are discussed.

  16. The influence of contrast media on kidney function in patients with stable coronary artery disease

    DEFF Research Database (Denmark)

    Reuter, Simon Bertram; Harutyunyan, Marina; Mygind, Naja Dam

    2014-01-01

    AIMS: To investigate the incidence of contrast media-induced nephropathy (CIN) in patients with stable coronary artery disease (CAD) referred for elective coronary intervention following hydration routines. The reversibility of CIN was followed in a 6 month-period. METHODS AND RESULTS: A total...... coronary interventions. Kidney function and the amount of contrast media used was not a predictor of CIN development. The induced CIN was not completely normalized in a 6-month follow-up period....

  17. Periodic feedback stabilization for linear periodic evolution equations

    CERN Document Server

    Wang, Gengsheng

    2016-01-01

    This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

  18. Obsessive Compulsive Disorder in Pregnancy and Postpartum Period

    Directory of Open Access Journals (Sweden)

    Mehmet Emin Demirkol

    2018-03-01

    Full Text Available Pregnancy and postpartum period are risky periods about occurrence and recurrence of many psychiatric disorders. General opinion is that obsessive compulsive disorder is more common in pregnancy and postpartum period than the normal population. Obsessions and compulsions should be questionned in these periods. Obsessions are generally about contagion and agression, compulsions are generally about washing and cleaning. Selective serotonin reuptake inhibitors and cognitive behavioral therapy are the first rank treatment options. In this article we briefly reviewed prevalence, etiology, comorbidities, clinical features and treatment options of obsessive compulsive disorder in pregnancy and postpartum period.

  19. 76 FR 8325 - Periodic Reporting

    Science.gov (United States)

    2011-02-14

    ... End-to-End Periodicals. Request at 1. The Request includes proposals for interim service performance... Periodicals, non-retail Media Mail, Library Mail, Bound Printed Matter Parcels, and Stamp Fulfillment Services...

  20. 76 FR 80312 - Periodic Reporting

    Science.gov (United States)

    2011-12-23

    ...) automation and Area Distribution Center (ADC) automation flats in First-Class Mail, Periodicals, and Standard... pallet bundle sortation in the cost model for Periodicals flats. Currently, cells for the coverage of...

  1. The redoubtable ecological periodic table

    Science.gov (United States)

    Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

  2. Is there a stable isotope evidence for the CO 2 fertiliser effect

    Indian Academy of Sciences (India)

    Stable carbon and hydrogen isotope ratios of cellulose extracted from annual growth rings (covering the time period 1980-1993) in an oak tree from Kalamazoo, SW Michigan provide a basis to investigate at a physiological level how the fertilization effect may operate. The carbon isotope ratios show that the intercellular ...

  3. Stillbirth rates in singleton pregnancies in a stable population at Karl ...

    African Journals Online (AJOL)

    To determine the changes in stillbirth rates in singleton pregnancies in a stable population over a period of 50 years. Methods. Stillbirth rates for ... stillbirths, neonatal deaths and deliveries, from which the stillbirth rates for fetuses ≥500 g ... from black residential areas have recently increased rapidly, the study was limited to ...

  4. Can δ15N and δ13C stable isotopes and fatty acid signatures ...

    African Journals Online (AJOL)

    Temporal changes in fatty acid composition and δ15N, δ13C stable isotope values of the phytobenthos growing on artificial clay substrates under natural conditions over a 28-day period at an upstream and a downstream site in the Kowie River near Grahamstown were investigated in 2012. High concentrations of diatom ...

  5. Understanding repetitive travel mode choices in a stable context: A panel study approach

    DEFF Research Database (Denmark)

    Thøgersen, John

    2006-01-01

    It is argued that most travel mode choices are repetitive and made in a stable context. As an example, the everyday use of public transport is analyzed based on a panel survey with a random sample of about 1300 Danish residents interviewed up to three times in the period 1998-2000. The use...

  6. Betelgeuse Period Analysis Using VSTAR

    Science.gov (United States)

    Dempsey, F.

    2015-06-01

    (Abstract only) Betelgeuse was studied using the VSTAR software package and analysis of the observations in the AAVSO database. Period analysis derived a period of 376 days, in comparison with literature periods of 420 days using satellite UV data but significantly different from the VSX period of 2,335 days. The unique set of PEP observations of this star is also shown and advantage of PEP Johnson V observations is shown in comparison with the visual observations.

  7. Temperature-amplitude coupling for stable biological rhythms at different temperatures.

    Science.gov (United States)

    Kurosawa, Gen; Fujioka, Atsuko; Koinuma, Satoshi; Mochizuki, Atsushi; Shigeyoshi, Yasufumi

    2017-06-01

    Most biological processes accelerate with temperature, for example cell division. In contrast, the circadian rhythm period is robust to temperature fluctuation, termed temperature compensation. Temperature compensation is peculiar because a system-level property (i.e., the circadian period) is stable under varying temperature while individual components of the system (i.e., biochemical reactions) are usually temperature-sensitive. To understand the mechanism for period stability, we measured the time series of circadian clock transcripts in cultured C6 glioma cells. The amplitudes of Cry1 and Dbp circadian expression increased significantly with temperature. In contrast, other clock transcripts demonstrated no significant change in amplitude. To understand these experimental results, we analyzed mathematical models with different network topologies. It was found that the geometric mean amplitude of gene expression must increase to maintain a stable period with increasing temperatures and reaction speeds for all models studied. To investigate the generality of this temperature-amplitude coupling mechanism for period stability, we revisited data on the yeast metabolic cycle (YMC) period, which is also stable under temperature variation. We confirmed that the YMC amplitude increased at higher temperatures, suggesting temperature-amplitude coupling as a common mechanism shared by circadian and 4 h-metabolic rhythms.

  8. Patterns in Stable Isotope Values of Nitrogen and Carbon in ...

    Science.gov (United States)

    Stable isotope measurements of nitrogen and carbon (15N, 13ddC) are often used to characterize estuarine, nearshore, and open ocean ecosystems. Reliable information about the spatial distribution of base-level stable isotope values, often represented by primary producers, is critical to interpreting values in these ecosystems. While base-level isotope data are generally readily available for estuaries, nearshore coastal waters, and the open ocean, the continental shelf is less studied. To address this, and as a first step toward developing a surrogate for base-level isotopic signature in this region, we collected surface and deep water samples from the United States’ eastern continental shelf in the Western Atlantic Ocean, from the Gulf of Maine to Cape Hatteras, periodically between 2000 and 2013. During the study, particulate matter 15dN values ranged from 0.8 to 17.4‰, and 13dC values from −26.4 to −15.6‰over the region. We used spatial autocorrelation analysis and random forest modeling to examine the spatial trends and potential environmental drivers of the stable isotope values. We observed general trends toward lower values for both nitrogen and carbon isotopes at the seaward edge of the shelf. Conversely, higher 15dN and 13dC values were observed on the landward edge of the shelf, in particular in the southern portion of the sampling area. Across all sites, the magnitude of the difference between the 15dN of subsurface and surface particulate m

  9. 76 FR 296 - Periodic Reporting

    Science.gov (United States)

    2011-01-04

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of proposed... consider a proposed change in certain analytical methods used in periodic reporting. The proposed change... rulemaking proceeding to consider changes in the analytical methods approved for use in periodic reporting.\\1...

  10. 76 FR 20906 - Periodic Reporting

    Science.gov (United States)

    2011-04-14

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of proposed... a proposed change in certain analytical methods used in periodic reporting. This action responds to... periodic reporting.\\1\\ \\1\\ Petition of the United States Postal Service Requesting Initiation of a...

  11. 75 FR 1301 - Periodic Reporting

    Science.gov (United States)

    2010-01-11

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Proposed rule... rulemaking proceeding to consider changes in the analytical methods approved for use in periodic reporting.\\1... Docket No. RM2009-10, Order on Analytical Principles Used in Periodic Reporting (Proposals Three through...

  12. 76 FR 71498 - Periodic Reporting

    Science.gov (United States)

    2011-11-18

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of proposed... informal rulemaking on proposed changes in certain analytical methods used in periodic reporting. The... consider changes in the analytical methods approved for use in periodic reporting.\\1\\ These changes are...

  13. 75 FR 65593 - Periodic Reporting

    Science.gov (United States)

    2010-10-26

    ... 39 CFR Part 3020 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of temporary... that a transition period likely would be needed before full compliance with new reporting rules could... Service filed a request for temporary waivers from periodic reporting of service performance measurement...

  14. Unconditionally energy stable numerical schemes for phase-field vesicle membrane model

    Science.gov (United States)

    Guillén-González, F.; Tierra, G.

    2018-02-01

    Numerical schemes to simulate the deformation of vesicles membranes via minimizing the bending energy have been widely studied in recent times due to its connection with many biological motivated problems. In this work we propose a new unconditionally energy stable numerical scheme for a vesicle membrane model that satisfies exactly the conservation of volume constraint and penalizes the surface area constraint. Moreover, we extend these ideas to present an unconditionally energy stable splitting scheme decoupling the interaction of the vesicle with a surrounding fluid. Finally, the well behavior of the proposed schemes are illustrated through several computational experiments.

  15. Local neuropeptide signaling modulates serotonergic transmission to shape the temporal organization of C. elegans egg-laying behavior.

    Directory of Open Access Journals (Sweden)

    Navonil Banerjee

    2017-04-01

    Full Text Available Animal behaviors are often composed of distinct alternating behavioral states. Neuromodulatory signals are thought to be critical for establishing stable behavioral states and for orchestrating transitions between them. However, we have only a limited understanding of how neuromodulatory systems act in vivo to alter circuit performance and shape behavior. To address these questions, we have investigated neuromodulatory signaling in the context of Caenorhabditis elegans egg-laying. Egg-laying activity cycles between discrete states-short bursts of egg deposition (active phases that alternate with prolonged quiescent periods (inactive phases. Here using genetic, pharmacological and optogenetic approaches for cell-specific activation and inhibition, we show that a group of neurosecretory cells (uv1 located in close spatial proximity to the egg-laying neuromusculature direct the temporal organization of egg-laying by prolonging the duration of inactive phases. We demonstrate that the modulatory effects of the uv1 cells are mediated by peptides encoded by the nlp-7 and flp-11 genes that act locally to inhibit circuit activity, primarily by inhibiting vesicular release of serotonin from HSN motor neurons. This peptidergic inhibition is achieved, at least in part, by reducing synaptic vesicle abundance in the HSN motor neurons. By linking the in vivo actions of specific neuropeptide signaling systems with the generation of stable behavioral outcomes, our study reveals how cycles of neuromodulation emanating from non-neuronal cells can fundamentally shape the organization of a behavioral program.

  16. Periodic and homoclinic orbits in a toy climate model

    Directory of Open Access Journals (Sweden)

    M. Toner

    1994-01-01

    Full Text Available A two dimensional system of autonomous nonlinear ordinary differential equations models glacier growth and temperature changes on an idealized planet. We apply standard perturbative techniques from dynamical systems theory to study small amplitude periodic orbits about a constant equilibrium. The equations are put in cononical form and the local phase space topology is examined. Maximum and minimum periods of oscillation are obtained and related to the radius of the orbit. An adjacent equilibrium is shown to have saddle character and the inflowing and outflowing manifolds of this saddle are studied using numerical integration. The inflowing manifolds show the region of attraction for the periodic orbit. As the frequency gets small, the adjacent (saddle equilibrium approaches the radius of the periodic orbit. The bifurcation of the periodic orbit to a stable homoclinic orbit is observed when an inflowing manifold and an outflowing manifold of the adjacent equilibrium cross.

  17. The primatologist as a behavioral engineer.

    Science.gov (United States)

    Martin, Allison L

    2017-01-01

    The field of primate behavior management has had only limited success in preventing and treating abnormal behaviors, such as stereotypy and self-injury, in captive non-human primates (NHP). In contrast, applied behavior analysts have had great success in treating similar topographies of behavior in human clinical settings. By adapting and adopting the behavioral principles and methodologies commonly used by applied behavior analysts, primatologists may be able to develop more effective ways to analyze, reduce, and prevent these aberrant behaviors in NHP. This article reviews studies that have used behavior analytic techniques to successfully address problem behaviors in NHP. Additionally, relevant literature from the field of applied behavior analysis is reviewed to illustrate how adopting a theoretical framework that emphasizes the determination of the underlying operant functions of behavior could lead to new behavioral technologies and advance the field of captive primate management. Am. J. Primatol. 79:e22500, 2017. © 2015 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. On The Roman Domination Stable Graphs

    Directory of Open Access Journals (Sweden)

    Hajian Majid

    2017-11-01

    Full Text Available A Roman dominating function (or just RDF on a graph G = (V,E is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u = 0 is adjacent to at least one vertex v for which f(v = 2. The weight of an RDF f is the value f(V (G = Pu2V (G f(u. The Roman domination number of a graph G, denoted by R(G, is the minimum weight of a Roman dominating function on G. A graph G is Roman domination stable if the Roman domination number of G remains unchanged under removal of any vertex. In this paper we present upper bounds for the Roman domination number in the class of Roman domination stable graphs, improving bounds posed in [V. Samodivkin, Roman domination in graphs: the class RUV R, Discrete Math. Algorithms Appl. 8 (2016 1650049].

  19. Design of optically stable image reflector system.

    Science.gov (United States)

    Tsai, Chung-Yu

    2013-08-01

    The design of a partially optically stable (POS) reflector system, in which the exit ray direction and image pose are unchanged as the reflector system rotates about a specific directional vector, was presented in an earlier study by the current group [Appl. Phys. B100, 883-890 (2010)]. The present study further proposes an optically stable image (OSI) reflector system, in which not only is the optical stability property of the POS system retained, but the image position and total ray path length are also fixed. An analytical method is proposed for the design of OSI reflector systems comprising multiple reflectors. The validity of the proposed approach is demonstrated by means of two illustrative examples.

  20. Stable microfluidic flow focusing using hydrostatics.

    Science.gov (United States)

    Gnyawali, Vaskar; Saremi, Mohammadali; Kolios, Michael C; Tsai, Scott S H

    2017-05-01

    We present a simple technique to generate stable hydrodynamically focused flows by driving the flow with hydrostatic pressure from liquid columns connected to the inlets of a microfluidic device. Importantly, we compare the focused flows generated by hydrostatic pressure and classical syringe pump driven flows and find that the stability of the hydrostatic pressure driven technique is significantly better than the stability achieved via syringe pumps, providing fluctuation-free focused flows that are suitable for sensitive microfluidic flow cytometry applications. We show that the degree of flow focusing with the hydrostatic method can be accurately controlled by the simple tuning of the liquid column heights. We anticipate that this approach to stable flow focusing will find many applications in microfluidic cytometry technologies.

  1. Utilization of stable isotopes in medicine

    International Nuclear Information System (INIS)

    1980-11-01

    The ten lectures given at this round table are presented together with a discussion. Five lectures, relating to studies in which deuterium oxide was employed as a tracer of body water, dealt with pulmonary water measurements in man and animals, the total water pool in adipose subjects, and liquid compartments in children undergoing hemodyalisis. The heavy water is analysed by infrared spectrometry and a new double spectrodoser is described. Two studies using 13 C as tracer, described the diagnosis of liver troubles and diabetes respectively. A general review of the perspectives of the application of stable isotopes in clinical medicine is followed by a comparison of the use of stable and radioactive isotopes in France [fr

  2. Elastic Stable Intramedullary Nailing for Treatment of Pediatric Tibial Fractures

    Directory of Open Access Journals (Sweden)

    Sandeep Gurung

    2016-06-01

    Full Text Available Introduction: Tibia fractures in the skeletally immature patient can usually be treated with above knee cast or patellar tendon bearing cast. The purpose of our study was to evaluate epidemiology and outcome of Elastic stable intramedullary nailing fixation of pediatric tibial shaft fractures treated at our institution. Methods: Over a period of one year, fifty pediatric patients of tibial shaft fractures, with average age of 9.68 yr (SD=2.37, were treated with elastic stable intramedullary nail. Demographic data, union and complication rate were evaluated. Results: There were 36 closed and 14 open fractures. The average time to union was 11.6 weeks  (SD=2.65 for close and  14.3 weeks (SD=2.62 for open fracture. There were no instances of growth arrest, remanipulations, or refracture. Conclusion: We conclude that flexible intramedullary fixation is an easy and effective method of management of both open and closed unstable fractures of the tibia in children.

  3. Optical bi-stable shutter development/improvement

    Science.gov (United States)

    Lizon, J. L.; Haddad, N.; Castillo, R.

    2012-09-01

    Two of the VLT instruments (Giraffe and VIMOS) are using the large magnetic E/150 from Prontor (with an aperture diameter of 150 mm). As we were facing an unacceptable number of failures with this component some improvement plan was discussed already in 2004. The final decision for starting this program was conditioned by the decision from the constructor to stop the production. The opportunity was taken to improve the design building a fully bi-stable mechanism in order to reduce the thermal dissipation. The project was developed in collaboration between the two main ESO sites doing the best use of the manpower and of the technical capability available at the two centers. The project took advantage of the laser Mask Manufacturing Unit and the invar sheets used to prepare the VIMOS MOS mask to fabricate the shutter petals. Our paper describes the development including the intensive and long optimization period. To conclude this optimization we proceed with a long life test on two units. These units have demonstrate a very high level of reliability (up to 100 000 cycles without failure which can be estimated to an equivalent 6 years of operation of the instrument) A new bi-stable shutter driver and controller have also been developed. Some of the highlights of this unit are the fully configurable coil driving parameters, usage of braking strategy to dump mechanical vibration and reduce mechanical wearing, configurable usage of OPEN and CLOSE sensors, non volatile storage of parameters, user friendly front panel interface.

  4. A belief-based evolutionarily stable strategy

    OpenAIRE

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-01-01

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed st...

  5. Periodic waves in nonlinear metamaterials

    International Nuclear Information System (INIS)

    Liu, Wen-Jun; Xiao, Jing-Hua; Yan, Jie-Yun; Tian, Bo

    2012-01-01

    Periodic waves are presented in this Letter. With symbolic computation, equations for monochromatic waves are studied, and analytic periodic waves are obtained. Factors affecting properties of periodic waves are analyzed. Nonlinear metamaterials, with the continuous distribution of the dielectric permittivity obtained, are different from the ones with the discrete distribution. -- Highlights: ► Equations for the monochromatic waves in transverse magnetic polarization have been studied. ► Analytic periodic waves for the equations have been obtained. ► Periodic waves are theoretically presented and studied in the nonlinear metamaterials.

  6. Stable iodine prophylaxis. Recommendations of the 2nd UK Working Group on Stable Iodine Prophylaxis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The Working Group reviewed the revised Who guidance and the information published since 1991 on the risks of thyroid cancer in children from radioiodine and the risks of side effects from stable iodine. In particular, it reviewed data compiled on the incidence of thyroid cancers in children following the accident at the Chernobyl nuclear power plant in 1986. It considered whether the NRPB Earls were still appropriate, in the light of the new data. It also reviewed a range of other recommendations given by the 1st Working Group, concerning the chemical form of stable iodine tablets and practical issues concerning implementation of stable iodine prophylaxis. Finally, it reviewed the Patient Information Leaflet that is required, by law, to be included in each box of tablets and provided suggestions for information to be included in a separate information leaflet to be handed out to the public when stable iodine tablets are distributed.

  7. Detonation of Meta-stable Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, Allen; Kuhl, Allen L.; Fried, Laurence E.; Howard, W. Michael; Seizew, Michael R.; Bell, John B.; Beckner, Vincent; Grcar, Joseph F.

    2008-05-31

    We consider the energy accumulation in meta-stable clusters. This energy can be much larger than the typical chemical bond energy (~;;1 ev/atom). For example, polymeric nitrogen can accumulate 4 ev/atom in the N8 (fcc) structure, while helium can accumulate 9 ev/atom in the excited triplet state He2* . They release their energy by cluster fission: N8 -> 4N2 and He2* -> 2He. We study the locus of states in thermodynamic state space for the detonation of such meta-stable clusters. In particular, the equilibrium isentrope, starting at the Chapman-Jouguet state, and expanding down to 1 atmosphere was calculated with the Cheetah code. Large detonation pressures (3 and 16 Mbar), temperatures (12 and 34 kilo-K) and velocities (20 and 43 km/s) are a consequence of the large heats of detonation (6.6 and 50 kilo-cal/g) for nitrogen and helium clusters respectively. If such meta-stable clusters could be synthesized, they offer the potential for large increases in the energy density of materials.

  8. Nonparametric Inference for Periodic Sequences

    KAUST Repository

    Sun, Ying

    2012-02-01

    This article proposes a nonparametric method for estimating the period and values of a periodic sequence when the data are evenly spaced in time. The period is estimated by a "leave-out-one-cycle" version of cross-validation (CV) and complements the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both theoretically and by simulation.We also propose a nonparametric test of the null hypothesis that the data have constantmean against the alternative that the sequence of means is periodic. Finally, our methodology is demonstrated on three well-known time series: the sunspots and lynx trapping data, and the El Niño series of sea surface temperatures. © 2012 American Statistical Association and the American Society for Quality.

  9. Periodic optical variability of radio-detected ultracool dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Harding, L. K.; Golden, A.; Singh, Navtej; Sheehan, B.; Butler, R. F. [Centre for Astronomy, National University of Ireland, Galway, University Road, Galway (Ireland); Hallinan, G. [Cahill Center for Astrophysics, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Boyle, R. P. [Vatican Observatory Research Group, Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Zavala, R. T., E-mail: lkh@astro.caltech.edu [United States Naval Observatory, Flagstaff Station, Flagstaff, AZ 86001 (United States)

    2013-12-20

    A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic variability, and the nature of this variability remains unclear. Here, we report on multi-epoch optical photometric monitoring of six radio-detected dwarfs, spanning the ∼M8-L3.5 spectral range, conducted to investigate the ubiquity of periodic optical variability in radio-detected ultracool dwarfs. This survey is the most sensitive ground-based study carried out to date in search of periodic optical variability from late-type dwarfs, where we obtained 250 hr of monitoring, delivering photometric precision as low as ∼0.15%. Five of the six targets exhibit clear periodicity, in all cases likely associated with the rotation period of the dwarf, with a marginal detection found for the sixth. Our data points to a likely association between radio and optical periodic variability in late-M/early-L dwarfs, although the underlying physical cause of this correlation remains unclear. In one case, we have multiple epochs of monitoring of the archetype of pulsing radio dwarfs, the M9 TVLM 513–46546, spanning a period of 5 yr, which is sufficiently stable in phase to allow us to establish a period of 1.95958 ± 0.00005 hr. This phase stability may be associated with a large-scale stable magnetic field, further strengthening the correlation between radio activity and periodic optical variability. Finally, we find a tentative spin-orbit alignment of one component of the very low mass binary, LP 349–25.

  10. Are the neural correlates of conscious contents stable or plastic?

    DEFF Research Database (Denmark)

    Sandberg, Kristian; Overgaard, Morten; Rees, Geraint

    2012-01-01

    of the same recording session. Very similar accuracies were obtained when the data used to train and test the classifier were gathered on different days within a week. However, when training/testing data were separated by 2.5 years, prediction accuracy was reduced drastically, to a level comparable to when...... the classifier was trained on a different participant. We discuss whether this drop in accuracy can best be explained by changes in the predictive signal in terms of timing, topography or underlying sources. Our results thus show that the neural correlates of conscious perception of a particular stimulus...... are stable within a time frame of days, but not across years. This may be taken as an indication that our experience of the same visual stimulus changes slowly across long periods of time, or alternatively the results may be understood in terms of multiple realizability....

  11. Two stable steady states in the Hodgkin-Huxley axons

    OpenAIRE

    Aihara, K.; Matsumoto, G.

    1983-01-01

    Two stable steady states were found in the numerical solution of the Hodgkin-Huxley equations for the intact squid axon bathed in potassium-rich sea water with an externally applied inward current. Under the conditions the two stable steady-states exist, the Hodgkin-Huxley equations have a complex bifurcation structure including, in addition to the two stable steady-states, a stable limit cycle, two unstable equilibrium points, and one asymptotically stable equilibrium point. It was also conc...

  12. Aquatic Habits of Cetacean Ancestors: Integrating Bone Microanatomy and Stable Isotopes.

    Science.gov (United States)

    Cooper, Lisa Noelle; Clementz, Mark T; Usip, Sharon; Bajpai, Sunil; Hussain, S Taseer; Hieronymus, Tobin L

    2016-12-01

    The earliest cetaceans were interpreted as semi-aquatic based on the presence of thickened bones and stable oxygen isotopes in tooth enamel. However, the origin of aquatic behaviors in cetacean relatives (e.g., raoellids, anthracotheres) remains unclear. This study reconstructs the origins of aquatic behaviors based on long bone microanatomy and stable oxygen isotopes of tooth enamel in modern and extinct cetartiodactylans. Our findings are congruent with published accounts that microanatomy can be a reliable indicator of aquatic behaviors in taxa that are obligatorily aquatic, and also highlight that some "semi-aquatic" behaviors (fleeing into the water to escape predation) may have a stronger relationship to bone microanatomy than others (herbivory in near-shore aquatic settings). Bone microanatomy is best considered with other lines of information in the land-to-sea transition of cetaceans, such as stable isotopes. This study extends our understanding of the progression of skeletal phenotypes associated with habitat shifts in the relatives of cetaceans. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  13. Combined use of fallout radionuclides and stable isotopes for investigating soil erosion processes in a Moroccan watershed

    Science.gov (United States)

    Benmansour, Moncef; Mabit, Lionel; Zouagui, Anis; Amenzou, Nouredinne; Sabir, Mohamed; Nouira, Asmae; Brandt, Christian; Rasche, Frank; Naimi, Mustapha; Chikhaoui, Mohamed; Marah, Hamid; Benkdad, Azzouz; Taous, Fouad

    2015-04-01

    On-site and off-site impacts associated with land degradation by soil erosion are a major concern in Morocco. This study aimed to use fallout radionuclides (FRNs): Caesium-137 (137Cs), excess Lead-210 (210Pbex) and Beryllium-7 (7Be) in combination with carbon and nitrogen stable isotopes (i.e. Carbon-13 (13C) and Nitrogen-15 (15N)) in estimating soil loss in the "My Bouchta" watershed and the origin of sediment deposits in a downstream water reservoir (i.e. "Talembout"). Using 137Cs, the net soil erosion rate, for the "My Bouchta" watershed over a period of 50 years, was estimated at 23 t/ha/yr with a main sediment contribution (> 90{%}) from the agricultural fields, the forest and shrub fields contributing to less than 10{%} of the overall sediment production. This result indicates clearly the role and the effectiveness of the forest plantations and vegetation cover to protect soil resource against erosion processes. The use of the 210Pb^ex technique in three different fields further highlighted that soil erosion rates over a period of 100 years were lower than those obtained by 137Cs reflecting the increase of soil loss during the last decades. Tests of fallout 7Be associated with short rainfall events in four fields confirmed the results obtained with 137Cs, that areas under natural vegetation were protected against erosion. Sedimentation rates were assessed for the "Talembout" water reservoir and the mean values obtained for two sediment cores using 210Pbex and the Constant Rate of Supply (CRS) model were about 0.51-0.58 g/cm^2/yr. The obtained results showed also a significant yearly increase of the sedimentation rate. The results derived from the stable isotopes depth profiles indicated similar behavior for forest and shrub fields. Furthermore, strong correlation between δ13C and total C was observed for this type of land use while for the agricultural fields, the correlation was not significant. In addition, the sediment profile of N-15 indicated an

  14. Periodicity of DNA in exons

    Directory of Open Access Journals (Sweden)

    Kinghorn Brian

    2004-08-01

    Full Text Available Abstract Background The periodic pattern of DNA in exons is a known phenomenon. It was suggested that one of the initial causes of periodicity could be the universal (RNYnpattern (R = A or G, Y = C or U, N = any base of ancient RNA. Two major questions were addressed in this paper. Firstly, the cause of DNA periodicity, which was investigated by comparisons between real and simulated coding sequences. Secondly, quantification of DNA periodicity was made using an evolutionary algorithm, which was not previously used for such purposes. Results We have shown that simulated coding sequences, which were composed using codon usage frequencies only, demonstrate DNA periodicity very similar to the observed in real exons. It was also found that DNA periodicity disappears in the simulated sequences, when the frequencies of codons become equal. Frequencies of the nucleotides (and the dinucleotide AG at each location along phase 0 exons were calculated for C. elegans, D. melanogaster and H. sapiens. Two models were used to fit these data, with the key objective of describing periodicity. Both of the models showed that the best-fit curves closely matched the actual data points. The first dynamic period determination model consistently generated a value, which was very close to the period equal to 3 nucleotides. The second fixed period model, as expected, kept the period exactly equal to 3 and did not detract from its goodness of fit. Conclusions Conclusion can be drawn that DNA periodicity in exons is determined by codon usage frequencies. It is essential to differentiate between DNA periodicity itself, and the length of the period equal to 3. Periodicity itself is a result of certain combinations of codons with different frequencies typical for a species. The length of period equal to 3, instead, is caused by the triplet nature of genetic code. The models and evolutionary algorithm used for characterising DNA periodicity are proven to be an effective tool

  15. Stable Breathing in Patients With Obstructive Sleep Apnea Is Associated With Increased Effort but Not Lowered Metabolic Rate.

    Science.gov (United States)

    de Melo, Camila M; Taranto-Montemurro, Luigi; Butler, James P; White, David P; Loring, Stephen H; Azarbarzin, Ali; Marques, Melania; Berger, Philip J; Wellman, Andrew; Sands, Scott A

    2017-10-01

    In principle, if metabolic rate were to fall during sleep in a patient with obstructive sleep apnea (OSA), ventilatory requirements could be met without increased respiratory effort thereby favoring stable breathing. Indeed, most patients achieve periods of stable flow-limited breathing without respiratory events for periods during the night for reasons that are unclear. Thus, we tested the hypothesis that in patients with OSA, periods of stable breathing occur when metabolic rate (VO2) declines. Twelve OSA patients (apnea-hypopnea index >15 events/h) completed overnight polysomnography including measurements of VO2 (using ventilation and intranasal PO2) and respiratory effort (esophageal pressure). Contrary to our hypothesis, VO2 did not differ between stable and unstable breathing periods in non-REM stage 2 (208 ± 20 vs. 213 ± 18 mL/min), despite elevated respiratory effort during stable breathing (26 ± 2 versus 23 ± 2 cmH2O, p = .03). However, VO2 was lowered during deeper sleep (244 to 179 mL/min from non-REM stages 1 to 3, p = .04) in conjunction with more stable breathing. Further analysis revealed that airflow obstruction curtailed metabolism in both stable and unstable periods, since CPAP increased VO2 by 14% in both cases (p = .02, .03, respectively). Patients whose VO2 fell most during sleep avoided an increase in PCO2 and respiratory effort. OSA patients typically convert from unstable to stable breathing without lowering metabolic rate. During sleep, OSA patients labor with increased respiratory effort but fail to satisfy metabolic demand even in the absence of overt respiratory events. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  16. Polaritons in periodic and quasiperiodic structures

    CERN Document Server

    Albuquerque, Eudenilson L

    2004-01-01

    In recent years there have been exciting developments in techniques for producing multilayered structures of different materials, often with thicknesses as small as only a few atomic layers. These artificial structures, known as superlattices, can either be grown with the layers stacked in an alternating fashion (the periodic case) or according to some other well-defined mathematical rule (the quasiperiodic case). This book describes research on the excitations (or wave-like behavior) of these materials, with emphasis on how the material properties are coupled to photons (the quanta of the l

  17. SAS3A analysis of natural convection boiling behavior in the Sodium Boiling Test Facility

    International Nuclear Information System (INIS)

    Klein, G.A.

    1979-01-01

    An analysis of natural convection boiling behavior in the Sodium Boiling Test (SBT) Facility has been performed using the SAS3A computer code. The predictions from this analysis indicate that stable boiling can be achieved for extensive periods of time for channel powers less than 1.4 kW and indicate intermittent dryout at higher powers up to at least 1.7 kW. The results of this anaysis are in reasonable agreement with the SBT Facility test results

  18. Effect of Systematic Hydrogenation on the Phase Behavior and Nanostructural Dimensions of Block Copolymers.

    Science.gov (United States)

    Ashraf, Arman R; Ryan, Justin J; Satkowski, Michael M; Smith, Steven D; Spontak, Richard J

    2018-01-31

    Unsaturated polydienes are frequently hydrogenated to yield polyolefins that are more chemically stable. Here, the effects of partial hydrogenation on the phase behavior and nanostructure of polyisoprene-containing block copolymers are investigated. To ensure access to the order-disorder transition temperature (T ODT ) over a wide temperature range, we examine copolymers with at least one random block. Dynamic rheological and scattering measurements indicate that T ODT increases linearly with increasing hydrogenation. Small-angle scattering reveals that the temperature-dependence of the Flory-Huggins parameter changes and the microdomain period increases, while the interfacial thickness decreases. The influence of hydrogenation becomes less pronounced in more constrained multiblock copolymers.

  19. Trajectories and the influencing factors of behavior problems in preschool children: a longitudinal study in Guangzhou, China.

    Science.gov (United States)

    Bao, Peng; Jing, Jin; Jin, Yu; Hu, Xumin; Liu, Buyun; Hu, Min

    2016-06-01

    Since child mental health problem was a global health issue, many researchers in western countries has focused on the trajectory of it to provide evidence for prevention programs. We designed this study to determine the trajectories of children's behavior problems, and to explore the effect of parent predictors on children's behavior problems in Guangzhou, China. Children (N = 1480) for this longitudinal, population-based survey, were recruited from eight regular kindergartens (October, 2010) across four districts in Guangzhou. Repeated measurement design analysis was used to compare the variation in behavioral problems by gender, only child status, and temperament. Logistic regression was applied to analyze the effect of parents' risks (maternal depression, parenting style) on the change in child problem behaviors. The scores of behavior problems (externalizing, emotional, social communication problems) were stable during the entire preschool period by gender and child number. Children with difficult temperament exhibited more problem behaviors than children with easy temperament in the early years, and the misbehaviors declined significantly over time. Moreover, maternal depression and the increase in excessive interference/over protective or punishing parenting strategies resulted in an increase in child behavior problems. There was no difference between the only-child status and child with siblings in the trajectory of problem behaviors. Parent factors were significant predictions of trajectory of child behavior problem during preschool age.

  20. Periodically Driven Array of Single Rydberg Atoms

    Science.gov (United States)

    Basak, Sagarika; Chougale, Yashwant; Nath, Rejish

    2018-03-01

    An array of single Rydberg atoms driven by a temporally modulated atom-field detuning is studied. The periodic modulation effectively modifies the Rabi coupling, leading to unprecedented dynamics in the presence of Rydberg-Rydberg interactions, in particular, blockade enhancement, antiblockades, and state-dependent population trapping. Interestingly, the Schrieffer-Wolf transformation reveals a fundamental process in Rydberg gases, correlated Rabi coupling, which stems from the extended nature of the Rydberg-Rydberg interactions. Also, the correlated coupling provides an alternative depiction for the Rydberg blockade, exhibiting a nontrivial behavior in the presence of periodic modulation. The dynamical localization of a many-body configuration in a driven Rydberg lattice is discussed.

  1. The Bloch Approximation in Periodically Perforated Media

    International Nuclear Information System (INIS)

    Conca, C.; Gomez, D.; Lobo, M.; Perez, E.

    2005-01-01

    We consider a periodically heterogeneous and perforated medium filling an open domain Ω of R N . Assuming that the size of the periodicity of the structure and of the holes is O(ε),we study the asymptotic behavior, as ε → 0, of the solution of an elliptic boundary value problem with strongly oscillating coefficients posed in Ω ε (Ω ε being Ω minus the holes) with a Neumann condition on the boundary of the holes. We use Bloch wave decomposition to introduce an approximation of the solution in the energy norm which can be computed from the homogenized solution and the first Bloch eigenfunction. We first consider the case where Ωis R N and then localize the problem for abounded domain Ω, considering a homogeneous Dirichlet condition on the boundary of Ω

  2. Stable isotopes (carbon, nitrogen, sulfur), diet, and anthropometry in urban Colombian women: investigating socioeconomic differences.

    Science.gov (United States)

    Bender, Richard L; Dufour, Darna L; Valenzuela, Luciano O; Cerling, Thure E; Sponheimer, Matt; Reina, Julio C; Ehleringer, James R

    2015-01-01

    We conducted stable isotope and dietary analyses of women from higher and lower socioeconomic status (SES) groups in Cali, Colombia. The objectives were to test between-group differences in stable isotope, dietary, and anthropometric characteristics, and to evaluate relationships between diet and stable isotope values. Hair samples from 38 women (mean age 33.4) from higher and lower SES groups were analyzed for δ(13) C, δ(15) N, and δ(34) S values. Dietary intake was assessed via 24-h recalls. Anthropometric variables measured were body mass index, five body circumferences, and six skinfold thicknesses. Mean δ(13) C and δ(15) N values of the higher SES group (-16.4 and 10.3‰) were significantly greater than those of the lower SES group (-17.2 and 9.6‰; P stable isotope values (P Stable isotope values revealed a difference between SES groups that was not explained by the dietary data. The relationship between diet and stable isotope composition is complex. © 2014 Wiley Periodicals, Inc.

  3. Using safe materials to control Varroa mites with studying grooming behavior of honey bees and morphology of Varroa over winter

    Directory of Open Access Journals (Sweden)

    Hossam F. Abou-Shaara

    2017-12-01

    Full Text Available Extracts of drone larvae and propolis as safe materials are anticipated to boost the grooming behavior of honey bees against Varroa mites. It is also expected that grooming behavior of bees and morphology of Varroa are stable during the least active period of the year to bee colonies (i.e winter. Sugar syrup alone or mixed with drone larvae extract or propolis extract were examined as potential Varroa control materials to test these hypothesizes. Moreover, percentages of groomed mites along with body lengths and widths of Varroa were studied on weekly basis during winter. The results showed that propolis extract was able to increase the number of fallen mites under field conditions but with lethal impacts on bee workers in the laboratory than extract of drone larvae or sugar syrup. All the treatments were not able to boost the grooming behavior of bees. The results proved that grooming behavior was stable during winter. Therefore, it is better to select colonies with grooming potential against Varroa during winter in selection programs. December was significantly the minimal month in percentage of groomed mites based on the overall means. Means of measured characteristics of Varroa declined significantly over the study period. For beekeepers, using sugar syrup as spray on bees during regularly colony inspection can help managing Varroa populations without harming the bees.

  4. Hydraulic Balance of a Eucalyptus urophylla Plantation in Response to Periodic Drought in Low Subtropical China

    Science.gov (United States)

    Zhang, Zhenzhen; Zhao, Ping; McCarthy, Heather R.; Ouyang, Lei; Niu, Junfeng; Zhu, Liwei; Ni, Guangyan; Huang, Yuqing

    2016-01-01

    A clear understanding of hydraulic regulation in cultivated plants is crucial for addressing challenges to forest water cycling due to climate changes in low subtropical China. Experiments were conducted to determine the hydrologic balance of a Eucalyptus urophylla plantation in response to periodic drought. Trees displayed lower stomatal conductance (GS) and leaf water potentials (ΨL) during the dry periods. A decrease of 22.4% was found for the maximum reference GS (GS at D = 1 kPa; GSref-max). Accordingly, specific hydraulic conductivity (ks) decreased by 45.3 – 65.6% from the wet to the dry season, depending on the tree size. Fairly stable leaf stomatal conductance (gs) with decreasing ΨL (ΨL Eucalyptus species. Additionally, the lower stomatal sensitivity (-m = 0.53) in the dry season might also be responsible for the high WUE, since we found an anisohydric behavior that was associated with photosynthetically active radiation (Q0). Larger trees were found to use water more efficiently than small trees, due to the higher sensitivity of ks to decreasing ΨL. This was also verified by the decreasing leaf carbon isotope discrimination (Δ13C) with increasing tree diameter. However, further studies are needed to determine the universality of these results for other Eucalyptus species in this region. PMID:27725821

  5. From Periodic Properties to a Periodic Table Arrangement

    Science.gov (United States)

    Besalú, Emili

    2013-01-01

    A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…

  6. Periodic instantons and scattering amplitudes

    International Nuclear Information System (INIS)

    Khlebnikov, S.Yu.; Rubakov, V.A.; Tinyakov, P.G.

    1991-04-01

    We discuss the role of periodic euclidean solutions with two turning points and zero winding number (periodic instantons) in instanton induced processes below the sphaleron energy E sph . We find that the periodic instantons describe certain multiparticle scattering events leading to the transitions between topologically distinct vacua. Both the semiclassical amplitudes and inital and final states of these transitions are determined by the periodic instantons. Furthermore, the corresponding probabilities are maximal among all states of given energy. We show that at E ≤ E sph , the periodic instantons can be approximated by infinite chains of ordinary instantons and anti-instantons, and they naturally emerge as deformations of the zero energy instanton. In the framework of 2d abelian Higgs model and 4d electroweak theory we show, however, that there is not obvious relation between periodic instantons and two-particle scattering amplitudes. (orig.)

  7. Scaling limits of periodic monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Rafael [Department of Applied Mathematics and Theoretical Physics,Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Department of Mathematical Sciences,South Road, Durham DH1 3LE (United Kingdom)

    2015-01-13

    The purpose of this note is to explore the structure of singly periodic monopoles for different values of the size to period ratio. The transition between a chain of small monopoles and the approximately two dimensional chain of large monopoles takes us through a region with an unintuitive dependence on the periodic direction. The focus is mainly on the smooth SU(2) monopole of charge 2.

  8. The cognitive-behavioral system of leadership: cognitive antecedents of active and passive leadership behaviors

    Science.gov (United States)

    Dóci, Edina; Stouten, Jeroen; Hofmans, Joeri

    2015-01-01

    In the present paper, we propose a cognitive-behavioral understanding of active and passive leadership. Building on core evaluations theory, we offer a model that explains the emergence of leaders’ active and passive behaviors, thereby predicting stable, inter-individual, as well as variable, intra-individual differences in both types of leadership behavior. We explain leaders’ stable behavioral tendencies by their fundamental beliefs about themselves, others, and the world (core evaluations), while their variable, momentary behaviors are explained by the leaders’ momentary appraisals of themselves, others, and the world (specific evaluations). By introducing interactions between the situation the leader enters, the leader’s beliefs, appraisals, and behavior, we propose a comprehensive system of cognitive mechanisms that underlie active and passive leadership behavior. PMID:26441721

  9. The cognitive-behavioral system of leadership: cognitive antecedents of active and passive leadership behaviors.

    Science.gov (United States)

    Dóci, Edina; Stouten, Jeroen; Hofmans, Joeri

    2015-01-01

    In the present paper, we propose a cognitive-behavioral understanding of active and passive leadership. Building on core evaluations theory, we offer a model that explains the emergence of leaders' active and passive behaviors, thereby predicting stable, inter-individual, as well as variable, intra-individual differences in both types of leadership behavior. We explain leaders' stable behavioral tendencies by their fundamental beliefs about themselves, others, and the world (core evaluations), while their variable, momentary behaviors are explained by the leaders' momentary appraisals of themselves, others, and the world (specific evaluations). By introducing interactions between the situation the leader enters, the leader's beliefs, appraisals, and behavior, we propose a comprehensive system of cognitive mechanisms that underlie active and passive leadership behavior.

  10. Addiction treatment and stable housing among a cohort of injection drug users.

    Directory of Open Access Journals (Sweden)

    Anita Palepu

    Full Text Available Unstable housing and homelessness is prevalent among injection drug users (IDU. We sought to examine whether accessing addiction treatment was associated with attaining stable housing in a prospective cohort of IDU in Vancouver, Canada.We used data collected via the Vancouver Injection Drug User Study (VIDUS between December 2005 and April 2010. Attaining stable housing was defined as two consecutive "stable housing" designations (i.e., living in an apartment or house during the follow-up period. We assessed exposure to addiction treatment in the interview prior to the attainment of stable housing among participants who were homeless or living in single room occupancy (SRO hotels at baseline. Bivariate and multivariate associations between the baseline and time-updated characteristics and attaining stable housing were examined using Cox proportional hazard regression models.Of the 992 IDU eligible for this analysis, 495 (49.9% reported being homeless, 497 (50.1% resided in SRO hotels, and 380 (38.3% were enrolled in addiction treatment at the baseline interview. Only 211 (21.3% attained stable housing during the follow-up period and of this group, 69 (32.7% had addiction treatment exposure prior to achieving stable housing. Addiction treatment was inversely associated with attaining stable housing in a multivariate model (adjusted hazard ratio [AHR]=0.71; 95% CI: 0.52-0.96. Being in a partnered relationship was positively associated with the primary outcome (AHR=1.39; 95% CI: 1.02-1.88. Receipt of income assistance (AHR=0.65; 95% CI: 0.44-0.96, daily crack use (AHR=0.69; 95% CI: 0.51-0.93 and daily heroin use (AHR=0.63; 95% CI: 0.43-0.92 were negatively associated with attaining stable housing.Exposure to addiction treatment in our study was negatively associated with attaining stable housing and may have represented a marker of instability among this sample of IDU. Efforts to stably house this vulnerable group may be occurring in contexts

  11. Microbiological characterization of stable resuspended dust

    Directory of Open Access Journals (Sweden)

    Nora Kováts

    2016-06-01

    Full Text Available Objectives: Air quality in the stables is characterized by elevated level of dust and aeroallergens which are supposed to directly cause or exacerbate several respiratory disorders. The most often recognized problem is recurrent airway obstruction (RAO, previously known as chronic obstructive pulmonary disease (COPD. There is some indication that aeroallergens (among them endotoxins may also cause inflammation in human airways and may exceed safe levels in stables. Monitoring studies have covered mainly the determination of the concentration of respirable particles and of culturable fungi and their toxins. However, these particles do not only directly affect the respiratory system, but might act as a carrier conveying toxic contaminants and biological agents such as bacteria. In a typical, 20-horse Hungarian stable, microbial community of respirable fraction of resuspended dust has been characterized to reveal if these particles convey hazardous pathogenic bacteria, posing risk to either horses or staff. Material and Methods: Resuspended dust was sampled using a mobile instrument. The instrument contains a PARTISOL-FRM model 2000 sampler that was operated at a flow rate of 16.7 l/min and a cyclone separator which collected the particulate matter with an aerodynamic size between 1 μm and 10 μm (PM1–10 fraction. Microbial taxa were identified by culture-independent next generation sequencing (NGS of variable 16S ribosomal ribonucleic acid (rRNA gene regions. Results: In total, 1491 different taxa were identified, of them 384 were identified to species level, 961 to genus level. The sample was dominated by common ubiquitous soil and organic material-dwelling taxa. Conclusions: Pathogens occurred at low abundance, and were represented by mostly facultative human pathogens, with the prevalence of Staphylococcus species.

  12. Stable channel of reclaimed tidal lowland

    Science.gov (United States)

    Syarifudin, Achmad; Imanuddin, Momon S.; Moerwanto, Arie S.; Suryadi, F. X.

    2017-11-01

    This study aimed to develop models of the Operation and Maintenance in the reclaimed tidal marsh area to get a stable channel. The research location is reclaimed tidal delta area Telang I Primary 8 representing land typology A/B and a survey conducted in 13 South Secondary Schemes following existing tertiary Telang I. MIKE - 11 computer models used used to analyze the movement of sediment in the channel in both the Primary channel 8, SPD, SDU and tertiary channels in block 13 South. Calibration model with multiple channels in the field of physical parameters has been performed to obtain results close to the results of measurement modeling sediment movement in the channel. The integration models of MIKE - 11 models with various scenarios are used to model the operation and maintenance of the channel in the tidal marsh area to get a stable channel. According to the scheme P8 - 13S, OM models obtained 75 percent, in which the secondary channel (SPD/SDU) and built flap gate in tertiary channel, get a well prototype model of the stable channel (equilibriums), where the average erosion on P8 at a distance of 3,200 m in the amount of 4,472,049 m3 and the mean sedimentation in the SPD of 963,836 m3 and mean of sedimentation in the tertiary channel of 3,508,213 m3. Similarly, on average erosion P8 by 4,135,649 m3 and the mean sedimentation in the SDU of 681,304 m3 and the mean sedimentation in the tertiary channel of 3,454,345 m3.

  13. Stable isogeometric analysis of trimmed geometries

    Science.gov (United States)

    Marussig, Benjamin; Zechner, Jürgen; Beer, Gernot; Fries, Thomas-Peter

    2017-04-01

    We explore extended B-splines as a stable basis for isogeometric analysis with trimmed parameter spaces. The stabilization is accomplished by an appropriate substitution of B-splines that may lead to ill-conditioned system matrices. The construction for non-uniform knot vectors is presented. The properties of extended B-splines are examined in the context of interpolation, potential, and linear elasticity problems and excellent results are attained. The analysis is performed by an isogeometric boundary element formulation using collocation. It is argued that extended B-splines provide a flexible and simple stabilization scheme which ideally suits the isogeometric paradigm.

  14. Warm Parenting Associated with Decreasing or Stable Child BMI during Treatment.

    Science.gov (United States)

    Rhee, Kyung E; Jelalian, Elissa; Boutelle, Kerri; Dickstein, Susan; Seifer, Ronald; Wing, Rena

    2016-04-01

    While authoritative parenting, which includes high levels of warmth and behavioral control, has been associated with lower risk of obesity, little is known about how general parenting impacts child weight loss during treatment. Our goal was to examine the relationship between several general parenting dimensions and 'decreasing /stable' child BMI during a 16-week family-based behavioral weight control program. Forty-four overweight parent-child dyads (child age 8 to 12 years) enrolled in the program. Families were videotaped at baseline eating dinner in their home. Using the General Parenting Observational Scale (GPOS), meals were coded for several general parenting dimensions. Primary outcome was percent of children whose BMI 'decreased or stayed the same.' Multivariable logistic regression was used to determine the relationship between general parenting and decreasing/stable child BMI. Forty families (91%) completed the program. Children had a mean BMI change of -0.40 (SD 1.57), which corresponds to a -0.15 (SD 0.20) change in BMI z-score (BMI-Z); 75% of children had decreasing/stable BMI. In the unadjusted models, lower parent BMI, higher parent education, and higher levels of parental warmth were significantly associated with decreasing/stable child BMI. In the multivariable model, only higher level of warmth was associated with increased odds of decreasing/stable child BMI (OR = 1.28; 95% CI, 1.01, 1.62). Baseline parental warmth may influence a child's ability to lower/maintain BMI during a standard family-based behavioral weight control program. Efforts to increase parent displays of warmth and emotional support towards their overweight child may help to increase the likelihood of treatment success.

  15. Remarks on stable and quasi-stable k-strings at large N

    International Nuclear Information System (INIS)

    Armoni, A.; Shifman, M.

    2003-01-01

    We discuss k-strings in the large-N Yang-Mills theory and its supersymmetric extension. Whereas the tension of the bona fide (stable) QCD string is expected to depend only on the N-ality of the representation, tensions that depend on specific representation R are often reported in the lattice literature. In particular, adjoint strings are discussed and found in certain simulations. We clarify this issue by systematically exploiting the notion of the quasi-stable strings which becomes well-defined at large N. The quasi-stable strings with representation-dependent tensions decay, but the decay rate (per unit length per unit time) is suppressed as Λ 2 F(N) where F(N) falls off as a function of N. It can be determined on the case-by-case basis. The quasi-stable strings eventually decay into stable strings whose tension indeed depends only on the N-ality. We also briefly review large-N arguments showing why the Casimir formula for the string tension cannot be correct, and present additional arguments in favor of the sine formula. Finally, we comment on the relevance of our estimates to Euclidean lattice measurements

  16. Periodization of Duffing oscillators suspended on elastic structure: Mechanical explanation

    Energy Technology Data Exchange (ETDEWEB)

    Czolczynski, K. [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland)]. E-mail: dzanta@ck-sg.p.lodz.pl; Kapitaniak, T. [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland); Perlikowski, P. [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland); Stefanski, A. [Division of Dynamics, Technical University of Lodz, Stefanowskiego 1/15, 90-924 Lodz (Poland)

    2007-05-15

    We consider the dynamics of chaotic oscillators suspended on the elastic structure. We show that for the given conditions of the structure, initially uncorrelated chaotic oscillators can synchronize both in chaotic and periodic regimes. The phenomena of the periodization, i.e., the behavior of nonlinear oscillators become periodic as a result of interaction with elastic structure, have been observed. We formulate the criterion for periodization of double well-potential Duffing oscillator evolution in terms of the forces and displacements in the spring elements. We argue that the observed phenomena are generic in the parameter space and independent of the number of oscillators and their location on the elastic structure.

  17. High northern geomagnetic field behavior and new constraints on the Gilsá event: Paleomagnetic and 40Ar/39Ar results of ∼0.5–3.1 Ma basalts from Jökuldalur, Iceland

    DEFF Research Database (Denmark)

    Døssing Andreasen, Arne; Muxworthy, Adrian R.; Supakulopas, Radchagrit

    2016-01-01

    .2–1.83 Ma, thus filling a large data gap of the high-northern stable field behavior. We obtain a median VADM of 57±3ZAm2 (VDM of 60±5Am2), which is higher than the median VADM of 16 intensity estimates from Antarctica (39±7 ZAm2) from the same period. A higher northern field is also found when using less...

  18. Special Features In Turbulent Mixing. Comparison between Periodic and Non Periodic Case

    Directory of Open Access Journals (Sweden)

    Mihai Costescu

    2006-12-01

    Full Text Available After hundreds of years of stability study, the problems of flow kinematics are far from complete solving. A modern theory appears in this field: the mixing theory. Its mathematical methods and techniques developed the significant relation between turbulence and chaos. The turbulence is an important feature of dynamic systems with few freedom degrees, the so-called far from equilibrium systems. These are widespread between the models of excitable media.Studying a mixing for a flow implies the analysis of successive stretching and folding phenomena for its particles, the influence of parameters and initial conditions. In the previous works, the study of the 3D non-periodic models exhibited a quite complicated behavior, involving some significant events - the so-called rare events. The variation of parameters had a great influence on the length and surface deformations. The 2D (periodic case is simpler, but significant events can also issue for irrational values of the length and surface versors, as was the situation in 3D case.The comparison between 2D and 3D case revealed interesting properties; therefore a modified 2D (periodic model is tested. The numerical simulations were realized in MapleVI, for searching special mathematical events. Continuing this work both from analytical and numeric standpoint would relieve useful properties for the turbulent mixing. A proximal target is to test some special functions for the periodic model, and to study the behavior of the structures realized by the model.

  19. Forward Period Analysis Method of the Periodic Hamiltonian System.

    Directory of Open Access Journals (Sweden)

    Pengfei Wang

    Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

  20. Forward Period Analysis Method of the Periodic Hamiltonian System.

    Science.gov (United States)

    Wang, Pengfei

    2016-01-01

    Using the forward period analysis (FPA), we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit) solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT) scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

  1. Detecting periodicities with Gaussian processes

    Directory of Open Access Journals (Sweden)

    Nicolas Durrande

    2016-04-01

    Full Text Available We consider the problem of detecting and quantifying the periodic component of a function given noise-corrupted observations of a limited number of input/output tuples. Our approach is based on Gaussian process regression, which provides a flexible non-parametric framework for modelling periodic data. We introduce a novel decomposition of the covariance function as the sum of periodic and aperiodic kernels. This decomposition allows for the creation of sub-models which capture the periodic nature of the signal and its complement. To quantify the periodicity of the signal, we derive a periodicity ratio which reflects the uncertainty in the fitted sub-models. Although the method can be applied to many kernels, we give a special emphasis to the Matérn family, from the expression of the reproducing kernel Hilbert space inner product to the implementation of the associated periodic kernels in a Gaussian process toolkit. The proposed method is illustrated by considering the detection of periodically expressed genes in the arabidopsis genome.

  2. Atomic spectroscopy in periodic fields

    International Nuclear Information System (INIS)

    Yudin, V I; Yu Basalaev, M; Taichenachev, A V

    2017-01-01

    Using the density matrix formalism, we prove the existence of the periodic steady-state for an arbitrary periodically driven system described by linear dynamic equations. The presented derivation simultaneously contains a simple and effective computational algorithm, which automatically guarantees a full account of all frequency components. (paper)

  3. 76 FR 30893 - Periodic Reporting

    Science.gov (United States)

    2011-05-27

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of proposed... proceeding to consider changes in the analytical methods approved for use in periodic reporting.\\1\\ Proposal...

  4. 76 FR 28696 - Periodic Reporting

    Science.gov (United States)

    2011-05-18

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Notice of proposed... approved for use in periodic reporting.\\1\\ Proposal Two is a set of four changes that the Postal Service...

  5. 75 FR 7426 - Periodic Reporting

    Science.gov (United States)

    2010-02-19

    ... 39 CFR Part 3050 Periodic Reporting AGENCY: Postal Regulatory Commission. ACTION: Advance notice of... approved for use in periodic reporting.\\1\\ The Postal Service labels its proposal ``Proposal One'' because it intends that it relate to the FY 2010 rather than the FY 2009 compliance reporting cycle. Proposal...

  6. Quasi Periodic Oscillations in Blazars

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy; Volume 35; Issue 3. Quasi Periodic Oscillations in Blazars ... Here we report our recent discoveries of Quasi-Periodic Oscillations (QPOs) in blazars time series data in X-ray and optical electromagnetic bands. Any such detection can give important ...

  7. Rationalization of Comet Halley's periods

    Science.gov (United States)

    Belton, Michael J. S.

    1990-01-01

    The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days.

  8. Incorporating Spectra Into Periodic Timing

    Science.gov (United States)

    Connors, Alanna; Hong, J.; Protopapas, P.; Kashyap, V.

    2011-09-01

    The Chandra surveys have resulted in a wealth of data on low-luminosity X-ray sources (Lx 1030-34 erg/s) of Galactic scales beyond the local solar neighborhood. Many of these are compact binaries, in particular, cataclysmic variables, often identified by their periodic X-ray variability and spectra. Hong et al. (2009, 2011) have used energy quantiles (Hong, Schlegel & Grindlay, 2004) as a fast, robust indicator of spectral hardness and absorption of the X-ray sources. Energy quantiles also enable a simple but effective illustration of spectral changes with phase in these periodic systems: e.g. absorption by the accreting material is understood to drive the periodic light-curves. An interesting question is how to best make use of the information encapsulated in the periodic change in energy spectrum, along with the periodic change in intensity, especially for cases of ambiguous period determination? And, how to do it computationally efficiently? A first approach is to do the period search in intensity, as is standard; and then use a criterion of spectral variation to verify possible periods. Huijse, Zegers & Protopapas (2011) recently demonstrated a powerful period estimation technique using information potential and correntropy embedded in the light curve. Similar quantities based on energies (or energy quantiles) of X-ray photons can serve as criteria of spectral variation. A different approach treats the spectrum variations and intensity variations completely independently, searching through period-space in each, and then combining the results. A more general method would include both at the same time, looking for statistically significant variations above what is expected for a constant (in intensity and spectrum).

  9. Multivariate Max-Stable Spatial Processes

    KAUST Repository

    Genton, Marc G.

    2014-01-06

    Analysis of spatial extremes is currently based on univariate processes. Max-stable processes allow the spatial dependence of extremes to be modelled and explicitly quantified, they are therefore widely adopted in applications. For a better understanding of extreme events of real processes, such as environmental phenomena, it may be useful to study several spatial variables simultaneously. To this end, we extend some theoretical results and applications of max-stable processes to the multivariate setting to analyze extreme events of several variables observed across space. In particular, we study the maxima of independent replicates of multivariate processes, both in the Gaussian and Student-t cases. Then, we define a Poisson process construction in the multivariate setting and introduce multivariate versions of the Smith Gaussian extremevalue, the Schlather extremal-Gaussian and extremal-t, and the BrownResnick models. Inferential aspects of those models based on composite likelihoods are developed. We present results of various Monte Carlo simulations and of an application to a dataset of summer daily temperature maxima and minima in Oklahoma, U.S.A., highlighting the utility of working with multivariate models in contrast to the univariate case. Based on joint work with Simone Padoan and Huiyan Sang.

  10. Color stable manganese-doped phosphors

    Science.gov (United States)

    Lyons, Robert Joseph [Burnt Hills, NY; Setlur, Anant Achyut [Niskayuna, NY; Deshpande, Anirudha Rajendra [Twinsburg, OH; Grigorov, Ljudmil Slavchev [Sofia, BG

    2012-08-28

    A process for preparing color stable Mn.sup.+4 doped phosphors includes providing a phosphor of formula I; A.sub.x[MF.sub.y]:Mn.sup.+4 I and contacting the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid; A.sub.x[MF.sub.y]; II wherein A is Li, Na, K, Rb, Cs, NR.sub.4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MF.sub.y] ion; and y is 5, 6 or 7. In particular embodiments, M is Si, Ge, Sn, Ti, Zr, or a combination thereof. A lighting apparatus capable of emitting white light includes a semiconductor light source; and a phosphor composition radiationally coupled to the light source, and which includes a color stable Mn.sup.+4 doped phosphor.

  11. Magnesium stable isotope ecology using mammal tooth enamel.

    Science.gov (United States)

    Martin, Jeremy E; Vance, Derek; Balter, Vincent

    2015-01-13

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (δ(13)C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (δ(44)Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (δ(26)Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for δ(26)Mg, δ(13)C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that δ(26)Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this (26)Mg enrichment up the trophic chain is due to a (26)Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using δ(26)Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel δ(26)Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages.

  12. Stable tridimensional bubble clusters in multi-bubble sonoluminescence (MBSL).

    Science.gov (United States)

    Rosselló, J M; Dellavale, D; Bonetto, F J

    2015-01-01

    In the present work, stable clusters made of multiple sonoluminescent bubbles are experimentally and theoretically studied. Argon bubbles were acoustically generated and trapped using bi-frequency driving within a cylindrical chamber filled with a sulfuric acid aqueous solution (SA85w/w). The intensity of the acoustic pressure field was strong enough to sustain, during several minutes, a large number of positionally and spatially fixed (without pseudo-orbits) sonoluminescent bubbles over an ellipsoidally-shaped tridimensional array. The dimensions of the ellipsoids were studied as a function of the amplitude of the applied low-frequency acoustic pressure (PAc(LF)) and the static pressure in the fluid (P0). In order to explain the size and shape of the bubble clusters, we performed a series of numerical simulations of the hydrodynamic forces acting over the bubbles. In both cases the observed experimental behavior was in excellent agreement with the numerical results. The simulations revealed that the positionally stable region, mainly determined by the null primary Bjerknes force (F→Bj), is defined as the outer perimeter of an axisymmetric ellipsoidal cluster centered in the acoustic field antinode. The role of the high-frequency component of the pressure field and the influence of the secondary Bjerknes force are discussed. We also investigate the effect of a change in the concentration of dissolved gas on the positional and spatial instabilities through the cluster dimensions. The experimental and numerical results presented in this paper are potentially useful for further understanding and modeling numerous current research topics regarding multi-bubble phenomena, e.g. forces acting on the bubbles in multi-frequency acoustic fields, transient acoustic cavitation, bubble interactions, structure formation processes, atomic and molecular emissions of equal bubbles and nonlinear or unsteady acoustic pressure fields in bubbly media. Copyright © 2014 Elsevier B

  13. Magnesium stable isotope ecology using mammal tooth enamel

    Science.gov (United States)

    Martin, Jeremy E.; Vance, Derek; Balter, Vincent

    2015-01-01

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (δ13C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (δ44Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (δ26Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for δ26Mg, δ13C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that δ26Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this 26Mg enrichment up the trophic chain is due to a 26Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using δ26Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel δ26Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages. PMID:25535375

  14. On the Evolutionary Stability of 'Tough' Bargaining Behavior

    DEFF Research Database (Denmark)

    Poulsen, Anders

    2003-01-01

    This paper investigates whether 'tough' bargaining behavior, which gives rise to inefficiency, can be evolutionary stable. We show that in a two-stage Nash Demand Game such behavior survives. We also study the Ultimatum Game. Here evolutionary selection wipes out all tough behavior, as long as th...

  15. Stable dissipative optical vortex clusters by inhomogeneous effective diffusion.

    Science.gov (United States)

    Li, Huishan; Lai, Shiquan; Qui, Yunli; Zhu, Xing; Xie, Jianing; Mihalache, Dumitru; He, Yingji

    2017-10-30

    We numerically show the generation of robust vortex clusters embedded in a two-dimensional beam propagating in a dissipative medium described by the generic cubic-quintic complex Ginzburg-Landau equation with an inhomogeneous effective diffusion term, which is asymmetrical in the two transverse directions and periodically modulated in the longitudinal direction. We show the generation of stable optical vortex clusters for different values of the winding number (topological charge) of the input optical beam. We have found that the number of individual vortex solitons that form the robust vortex cluster is equal to the winding number of the input beam. We have obtained the relationships between the amplitudes and oscillation periods of the inhomogeneous effective diffusion and the cubic gain and diffusion (viscosity) parameters, which depict the regions of existence and stability of vortex clusters. The obtained results offer a method to form robust vortex clusters embedded in two-dimensional optical beams, and we envisage potential applications in the area of structured light.

  16. Optical Periodicity Analysis of 3C 446 using Period04

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... All the data of the blazar 3C446 at 8, 4.8, 14 and 22 GHz, presented in publications from 1977 to 2006, have been compiled to generate light curves. The light curves show violent activity of 3C446. Using Period04 analysis method, we have found that there is a period of 7.2 yr, which is consistent with the ...

  17. American option valuation under time changed tempered stable Lévy processes

    Science.gov (United States)

    Gong, Xiaoli; Zhuang, Xintian

    2017-01-01

    Given that the underlying assets in financial markets exhibit stylized facts such as leptokurtosis, asymmetry, clustering properties and heteroskedasticity effect, this paper presents a novel model for pricing American option under the assumptions that the stock price processes are governed by time changed tempered stable Lévy process. As this model is constructed by introducing random time changes into tempered stable (TS) processes which specially refer to normal tempered stable (NTS) distribution as well as classical tempered stable (CTS) distribution, it permits infinite jumps as well as capturing random varying time in stochastic volatility, consequently taking into account the empirical facts such as leptokurtosis, skewness and volatility clustering behaviors. We employ the Fourier-cosine technique to calculate American option and propose the improved Particle Swarm optimization (IPSO) intelligent algorithm for model calibration. To demonstrate the advantage of the constructed model, we carry out empirical research on American index option in financial markets across wide ranges of models, with the time changing normal tempered stable distribution model yielding a superior performance than others.

  18. Floquet-Bloch theory for polymers in a periodic

    Science.gov (United States)

    Pablo Pedro, Ricardo; Tempel, David; Alexander-Katz, Alfredo

    2014-03-01

    Anderson localization in disordered systems predicts the localization of electronic wave functions and the resulting absence of diffusion. The phenomenon is much more general and has been observed in a variety of systems. In the case of the polymer, the behavior of it in a periodic potential is equivalent to the behavior of a quantum-machanicial particle in a periodic potential. According to this mapping our results for polymers in a periodic potential ara valid for localization of a quantum-mechanical particle in a periodic potential. Besides, one of our motivations for studying polymers in a periodic potential is because it reveals interesting aspects of a self-organization of the adsorbed polymers onto a surface with periodic potential. In order to describe the properties of time-periodic polymer system, we consider the potential time dependent which is periodic in time and space and we evaluate the solutions using the powerful nonperturbative Floquet-Bloch theory which is formulated for linear systems. Finally, we also consider a more interesting problem of when disorder is included in the time-periodic system, where localization of the wave function can occur.

  19. Generating the Nighttime Light of the Human Settlements by Identifying Periodic Components from DMSP/OLS Satellite Imagery.

    Science.gov (United States)

    Letu, Husi; Hara, Masanao; Tana, Gegen; Bao, Yuhai; Nishio, Fumihiko

    2015-09-01

    Nighttime lights of the human settlements (hereafter, "stable lights") are seen as a valuable proxy of social economic activity and greenhouse gas emissions at the subnational level. In this study, we propose an improved method to generate the stable lights from Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) daily nighttime light data for 1999. The study area includes Japan, China, India, and other 10 countries in East Asia. A noise reduction filter (NRF) was employed to generate a stable light from DMSP/OLS time-series daily nighttime light data. It was found that noise from amplitude of the 1-year periodic component is included in the stable light. To remove the amplitude of the 1-year periodic component noise included in the stable light, the NRF method was improved to extract the periodic component. Then, new stable light was generated by removing the amplitude of the 1-year periodic component using the improved NRF method. The resulting stable light was evaluated by comparing it with the conventional nighttime stable light provided by the National Oceanic and Atmosphere Administration/National Geophysical Data Center (NOAA/NGDC). It is indicated that DNs of the NOAA stable light image are lower than those of the new stable light image. This might be attributable to the influence of attenuation effects from thin warm water clouds. However, due to overglow effect of the thin cloud, light area in new stable light is larger than NOAA stable light. Furthermore, the cumulative digital numbers (CDNs) and number of light area pixels (NLAP) of the generated stable light and NOAA/NGDC stable light were applied to estimate socioeconomic variables of population, electric power consumption, gross domestic product, and CO2 emissions from fossil fuel consumption. It is shown that the correlations of the population and CO2FF with new stable light data are higher than those in NOAA stable light data; correlations of the EPC and GDP with NOAA

  20. Effects of constant immigration on the dynamics and persistence of stable and unstable Drosophila populations

    Science.gov (United States)

    Dey, Snigdhadip; Joshi, Amitabh

    2013-01-01

    Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively stable or unstable dynamics. In unstable populations with oscillations of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immigration enhanced persistence without affecting constancy whereas high immigration increased constancy without enhancing persistence. In relatively stable populations with erratic fluctuations of amplitude close to the mean population size, both low and high immigration enhanced persistence. In these populations, the amplitude of fluctuations relative to mean population size went down due to immigration, and their dynamics were altered to low-period cycles. The effects of immigration on the population size distribution and intrinsic dynamics of stable versus unstable populations differed considerably, suggesting that the mechanisms by which immigration reduced extinction risk depended on underlying dynamics in complex ways. PMID:23470546