WorldWideScience

Sample records for activated variable blazed

  1. Allegheny County Blazed Trails Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Shows the location of blazed trails in all Allegheny County parks. This is the same data used in the Allegheny County Parks Trails Mobile App, available for Apple...

  2. Professional BlazeDS Creating Rich Internet Applications with Flex and Java

    CERN Document Server

    Tiwari, Shashank

    2009-01-01

    A hands-on guide to creating Rich Internet Applications (RIA) using BlazeDS. BlazeDS enables you to easily connect to back-end distributed data and push data in real time to Adobe Flex and Adobe AIR applications in order to garner more responsive Rich Internet Application (RIA) experiences. It is a scalable option for Flex and Java integration and allows you to create excellent RIAs with both Flex and Java. This informative resource provides you with detailed examples and walkthroughs that explain the best practices for creating RIAs using BlazeDS. You'll begin with the essentials of BlazeDS a

  3. The BLAZE language - A parallel language for scientific programming

    Science.gov (United States)

    Mehrotra, Piyush; Van Rosendale, John

    1987-01-01

    A Pascal-like scientific programming language, BLAZE, is described. BLAZE contains array arithmetic, forall loops, and APL-style accumulation operators, which allow natural expression of fine grained parallelism. It also employs an applicative or functional procedure invocation mechanism, which makes it easy for compilers to extract coarse grained parallelism using machine specific program restructuring. Thus BLAZE should allow one to achieve highly parallel execution on multiprocessor architectures, while still providing the user with conceptually sequential control flow. A central goal in the design of BLAZE is portability across a broad range of parallel architectures. The multiple levels of parallelism present in BLAZE code, in principle, allow a compiler to extract the types of parallelism appropriate for the given architecture while neglecting the remainder. The features of BLAZE are described and it is shown how this language would be used in typical scientific programming.

  4. The BLAZE language: A parallel language for scientific programming

    Science.gov (United States)

    Mehrotra, P.; Vanrosendale, J.

    1985-01-01

    A Pascal-like scientific programming language, Blaze, is described. Blaze contains array arithmetic, forall loops, and APL-style accumulation operators, which allow natural expression of fine grained parallelism. It also employs an applicative or functional procedure invocation mechanism, which makes it easy for compilers to extract coarse grained parallelism using machine specific program restructuring. Thus Blaze should allow one to achieve highly parallel execution on multiprocessor architectures, while still providing the user with onceptually sequential control flow. A central goal in the design of Blaze is portability across a broad range of parallel architectures. The multiple levels of parallelism present in Blaze code, in principle, allow a compiler to extract the types of parallelism appropriate for the given architecture while neglecting the remainder. The features of Blaze are described and shows how this language would be used in typical scientific programming.

  5. Blazing the trail: Official Report : Singapore 2010 Youth Olympic Games

    OpenAIRE

    2012-01-01

    The official report of the 1st Youth Olympic Games, “Blazing the trail: Official Report: Singapore 2010 Youth Olympic Games” consisted of one volume, published in French and English. The French version was published only in electronic form

  6. Blazed Grating Resonance Conditions and Diffraction Efficiency Optical Transfer Function

    KAUST Repository

    Stegenburgs, Edgars

    2017-01-08

    We introduce a general approach to study diffraction harmonics or resonances and resonance conditions for blazed reflecting gratings providing knowledge of fundamental diffraction pattern and qualitative understanding of predicting parameters for the most efficient diffraction.

  7. Blazed Grating Resonance Conditions and Diffraction Efficiency Optical Transfer Function

    KAUST Repository

    Stegenburgs, Edgars; Alias, Mohd Sharizal B.; Ng, Tien Khee; Ooi, Boon S.

    2017-01-01

    We introduce a general approach to study diffraction harmonics or resonances and resonance conditions for blazed reflecting gratings providing knowledge of fundamental diffraction pattern and qualitative understanding of predicting parameters for the most efficient diffraction.

  8. A Python Script for Aligning the STIS Echelle Blaze Function

    Science.gov (United States)

    Baer, Malinda; Proffitt, Charles R.; Lockwood, Sean A.

    2018-01-01

    Accurate flux calibration for the STIS echelle modes is heavily dependent on the proper alignment of the blaze function for each spectral order. However, due to changes in the instrument alignment over time and between exposures, the blaze function can shift in wavelength. This may result in flux calibration inconsistencies of up to 10%. We present the stisblazefix Python module as a tool for STIS users to correct their echelle spectra. The stisblazefix module assumes that the error in the blaze alignment is a linear function of spectral order, and finds the set of shifts that minimizes the flux inconsistencies in the overlap between spectral orders. We discuss the uses and limitations of this tool, and show that its use can provide significant improvements to the default pipeline flux calibration for many observations.

  9. Education, Ethics and Values: A Response to Peter Blaze ...

    African Journals Online (AJOL)

    Education, Ethics and Values: A Response to Peter Blaze Corcoran's Keynote Address, EEASA 2003. ... while there is much value in the principles of the Earth Charter for guiding educational practice, educators should also consider some of the dilemmas of simply appropriating univeral ethical frameworks to guide practice.

  10. Variables associated with active spondylolysis.

    Science.gov (United States)

    Gregg, Chris D; Dean, Sarah; Schneiders, Anthony G

    2009-11-01

    Retrospective non-experimental study. To investigate variables associated with active spondylolysis. A retrospective study audited clinical data over a two year period from patients with suspected spondylolysis that were referred for a SPECT bone scan. Six exploratory variables were identified and analysed using uni- and multi-variate regression from 82 patient records to determine the association between symptomatic, physical and demographic characteristics, and the presence of an active spondylolysis. Tertiary level multidisciplinary private practice sports medicine clinic. All patients with low back pain that required a SPECT bone scan to confirm suspected spondylolysis. 82 subjects were included in the final sample group. The six exploratory variables included Age, Gender, Injury duration, Injury onset, Sports participation and the result of the Single Leg Hyperextension Test. The dependent outcome variable was the result of the SPECT bone scan (scan-positive or scan-negative). Adolescent males had a higher incidence of spondylolysis detected by SPECT bone scan compared to other patients and a statistically significant association was demonstrated for both age (p=0.01) and gender (p=0.01). Subjects with an active spondylolysis were nearly five times more likely to be male and aged less than 20 years. Furthermore, the likelihood ratio indicated that adolescent males with suspected spondylolysis were three and a half times more likely to have a positive bone scan result. The Single Leg Hyperextension Test did not demonstrate a statistically significant association with spondylolysis (p=0.47). Clinicians assessing for a predisposition to the development of spondylolysis should consider the gender and age of the patient and not rely on the predictive ability of the Single Leg Hyperextension Test.

  11. Towards freeform curved blazed gratings using diamond machining

    Science.gov (United States)

    Bourgenot, C.; Robertson, D. J.; Stelter, D.; Eikenberry, S.

    2016-07-01

    Concave blazed gratings greatly simplify the architecture of spectrographs by reducing the number of optical components. The production of these gratings using diamond-machining offers practically no limits in the design of the grating substrate shape, with the possibility of making large sag freeform surfaces unlike the alternative and traditional method of holography and ion etching. In this paper, we report on the technological challenges and progress in the making of these curved blazed gratings using an ultra-high precision 5 axes Moore-Nanotech machine. We describe their implementation in an integral field unit prototype called IGIS (Integrated Grating Imaging Spectrograph) where freeform curved gratings are used as pupil mirrors. The goal is to develop the technologies for the production of the next generation of low-cost, compact, high performance integral field unit spectrometers.

  12. Fast tunable blazed MEMS grating for external cavity lasers

    Science.gov (United States)

    Tormen, Maurizio; Niedermann, Philippe; Hoogerwerf, Arno; Shea, Herbert; Stanley, Ross

    2017-11-01

    Diffractive MEMS are interesting for a wide range of applications, including displays, scanners or switching elements. Their advantages are compactness, potentially high actuation speed and in the ability to deflect light at large angles. We have designed and fabricated deformable diffractive MEMS grating to be used as tuning elements for external cavity lasers. The resulting device is compact, has wide tunability and a high operating speed. The initial design is a planar grating where the beams are free-standing and attached to each other using leaf springs. Actuation is achieved through two electrostatic comb drives at either end of the grating. To prevent deformation of the free-standing grating, the device is 10 μm thick made from a Silicon on Insulator (SOI) wafer in a single mask process. At 100V a periodicity tuning of 3% has been measured. The first resonant mode of the grating is measured at 13.8 kHz, allowing high speed actuation. This combination of wide tunability and high operating speed represents state of the art in the domain of tunable MEMS filters. In order to improve diffraction efficiency and to expand the usable wavelength range, a blazed version of the deformable MEMS grating has been designed. A key issue is maintaining the mechanical properties of the original device while providing optically smooth blazed beams. Using a process based on anisotropic KOH etching, blazed gratings have been obtained and preliminary characterization is promising.

  13. Blazing the trail essays by leading women in science

    CERN Document Server

    Ideal, Emma

    2013-01-01

    Name a famous scientist. Got one? Now name a famous physicist. Ok, now name a famous female physicist. Ok, now name a famous living female physicist. Stumped? In Blazing the Trail: Essays by Leading Women in Science, 35 highly successful physicists, engineers, and chemists share their personal histories, their passion for discovery, and their secrets for success with the next generation. Essayists candidly recount their experiences – both positive and negative – with an uplifting tone, focusing on lessons learned along the way. The combination of personal stories and advice sends a powerful message to all young women considering scientific careers: I did it, so can you. Here’s how.

  14. Diffraction Efficiency Testing of Sinusoidal and Blazed Off-Plane Reflection Gratings

    Science.gov (United States)

    Tutt, James H.; McEntaffer, Randall L.; Marlowe, Hannah; Miles, Drew M.; Peterson, Thomas J.; Deroo, Casey T.; Scholze, Frank; Laubis, Christian

    2016-09-01

    Reflection gratings in the off-plane mount have the potential to enhance the performance of future high resolution soft X-ray spectrometers. Diffraction efficiency can be optimized through the use of blazed grating facets, achieving high-throughput on one side of zero-order. This paper presents the results from a comparison between a grating with a sinusoidally grooved profile and two gratings that have been blazed. The results show that the blaze does increase throughput to one side of zero-order; however, the total throughput of the sinusoidal gratings is greater than the blazed gratings, suggesting the method of manufacturing the blazed gratings does not produce precise facets. The blazed gratings were also tested in their Littrow and anti-Littrow configurations to quantify diffraction efficiency sensitivity to rotations about the grating normal. Only a small difference in the energy at which efficiency is maximized between the Littrow and anti-Littrow configurations is seen with a small shift in peak efficiency towards higher energies in the anti-Littrow case. This is due to a decrease in the effective blaze angle in the anti-Littrow mounting. This is supported by PCGrate-SX V6.1 modeling carried out for each blazed grating which predicts similar response trends in the Littrow and anti-Littrow orientations.

  15. Blazed vector gratings fabricated using photosensitive polymer liquid crystals and control of polarization diffraction

    Science.gov (United States)

    Ono, Hiroshi; Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Noda, Kohei; Kawatsuki, Nobuhiro

    2014-03-01

    The blazed vector grating possessing antisymmetric distributions of the birefringence were fabricated by exposing the line-focused linearly polarized ultraviolet light on the photosensitive polymer liquid crystals. The polarization states of the diffraction beams can be highly and widely controlled by designing the blazed structures, and the diffraction properties were well-explained by Jones calculus.

  16. Highly efficient blazed grating with multilayer coating for tender X-ray energies

    NARCIS (Netherlands)

    Senf, F.; Bijkerk, Frederik; Eggenstein, F.; Gwalt, G.; Huang, Qiushi; van de Kruijs, Robbert Wilhelmus Elisabeth; Kutz, O.; Lemke, S.; Louis, Eric; Mertin, M.; Packe, I.; Rudolph, I.; Schafers, F.; Siewert, F.; Sokolov, A.; Sturm, Jacobus Marinus; Waberski, C.; Wang, Z.; Wolf, J.; Zeschke, T.; Erko, A.

    2016-01-01

    For photon energies of 1 – 5 keV, blazed gratings with multilayer coating are ideally suited for the suppression of stray and higher orders light in grating monochromators. We developed and characterized a blazed 2000 lines/mm grating coated with a 20 period Cr/C- multilayer. The multilayer

  17. A MEMS torsion magnetic sensor with reflective blazed grating integration

    International Nuclear Information System (INIS)

    Long, Liang; Zhong, Shaolong

    2016-01-01

    A novel magnetic sensor based on a permanent magnet and blazed grating is presented in this paper. The magnetic field is detected by measuring the diffracted wavelength of the blazed grating which is changed by the torsion motion of a torsion sensitive micro-electromechanical system (MEMS) structure with a permanent magnet attached. A V-shape grating structure is obtained by wet etching on a (1 0 0) SOI substrate. When the magnet is magnetized in different directions, the in-plane or out-of-plane magnetic field is detected by a sensor. The MEMS magnetic sensor with a permanent magnet is fabricated after analytical design and bulk micromachining processes. The magnetic-sensing capability of the sensor is tested by fiber-optic detection system. The result shows the sensitivities of the in-plane and out-of-plane magnetic fields are 3.6 pm μ T −1 and 5.7 pm μ T −1 , respectively. Due to utilization of the permanent magnet and fiber-optic detection, the sensor shows excellent capability of covering the high-resolution detection of low-frequency signals. In addition, the sensitive direction of the magnetic sensor can be easily switched by varying the magnetized direction of the permanent magnet, which offers a simple way to achieve tri-axis magnetic sensor application. (paper)

  18. Exchange rate variability, market activity and heterogeneity

    OpenAIRE

    Rime, Dagfinn; Sucarrat, Genaro

    2007-01-01

    We study the role played by geographic and bank-size heterogeneity in the relation between exchange rate variability and market activity. We find some support for the hypothesis that increases in short-term global interbank market activity, which can be interpreted as due to variation in information arrival, increase variability. However, our results do not suggest that local short-term activity increases variability. With respect to long-term market activity, which can be interpreted as a me...

  19. Developing Dynamic Single Page Web Applications Using Meteor : Comparing JavaScript Frameworks: Blaze and React

    OpenAIRE

    Yetayeh, Asabeneh

    2017-01-01

    This paper studies Meteor which is a JavaScript full-stack framework to develop interactive single page web applications. Meteor allows building web applications entirely in JavaScript. Meteor uses Blaze, React or AngularJS as a view layer and Node.js and MongoDB as a back-end. The main purpose of this study is to compare the performance of Blaze and React. A multi-user Blaze and React web applications with similar HTML and CSS were developed. Both applications were deployed on Heroku’s w...

  20. Blaze-DEMGPU: Modular high performance DEM framework for the GPU architecture

    Directory of Open Access Journals (Sweden)

    Nicolin Govender

    2016-01-01

    Full Text Available Blaze-DEMGPU is a modular GPU based discrete element method (DEM framework that supports polyhedral shaped particles. The high level performance is attributed to the light weight and Single Instruction Multiple Data (SIMD that the GPU architecture offers. Blaze-DEMGPU offers suitable algorithms to conduct DEM simulations on the GPU and these algorithms can be extended and modified. Since a large number of scientific simulations are particle based, many of the algorithms and strategies for GPU implementation present in Blaze-DEMGPU can be applied to other fields. Blaze-DEMGPU will make it easier for new researchers to use high performance GPU computing as well as stimulate wider GPU research efforts by the DEM community.

  1. Meteor Beliefs Project: Shakespeare revisited and the Elizabethan stage's `blazing star'

    Science.gov (United States)

    Gheorghe, Andrei Dorian; McBeath, Alastair

    2007-06-01

    Some fresh Shakespearean citations of meteors, further to those given previously in the Project, are presented, along with a discussion of the Elizabethan stage's use of the `blazing star', with especial reference to the great comet of 1577.

  2. Blazed vector grating liquid crystal cells with photocrosslinkable polymeric alignment films fabricated by one-step polarizer rotation method

    Science.gov (United States)

    Kawai, Kotaro; Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Noda, Kohei; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2014-12-01

    Blazed vector grating liquid crystal (LC) cells, in which the directors of low-molar-mass LCs are antisymmetrically distributed, were fabricated by one-step exposure of an empty glass cell inner-coated with a photocrosslinkable polymer LC (PCLC) to UV light. By adopting a LC cell structure, twisted nematic (TN) and homogeneous (HOMO) alignments were obtained in the blazed vector grating LC cells. Moreover, the diffraction efficiency of the blazed vector grating LC cells was greatly improved by increasing the thickness of the device in comparison with that of a blazed vector grating with a thin film structure obtained in our previous study. In addition, the diffraction efficiency and polarization states of ±1st-order diffracted beams from the resultant blazed vector grating LC cells were controlled by designing a blazed pattern in the alignment films, and these diffraction properties were well explained on the basis of Jones calculus and the elastic continuum theory of nematic LCs.

  3. Trail Blazing or Jam Session? Towards a New Concept of Clinical Decision-making.

    Science.gov (United States)

    Risør, Torsten

    2017-04-01

    Clinical decision-making (CDM) is key in learning to be a doctor as the defining activity in their clinical work. CDM is often portrayed in the literature as similar to 'trail blazing'; the doctor as the core agent, clearing away obstacles on the path towards diagnosis and treatment. However, in a fieldwork of young doctors in Denmark, it was difficult connect their practice to this image. This paper presents the exploration of this discrepancy in the heart of medical practice and how an alternative image emerged; that of a 'jam session'. The exploration is represented as a case-based hypothesis-testing: first, a theoretically and empirically informed hypothesis (H0) of how doctors perform CDM is developed. In H0, CDM is a stepwise process of reasoning about clinical data, often influenced by outside contextual factors. Then, H0 is tested against a case from ethnographic fieldwork with doctors going through internship. Although the case is chosen for characteristics that make it 'most likely' to verify the hypothesis, verification proves difficult. The case challenges preconceptions in CDM literature about chronology, context, objectivity, cognition, agency, and practice. The young doctor is found not to make decisions, but rather to participate in CDM; an activity akin to the dynamics found in a jam session. Their participation circles in and through four concurrent interrelated constructions that suggest a new conceptualization of CDM; a starting point for a deeper understanding of actual practice in a changing clinical environment.

  4. Optical superimposed vortex beams generated by integrated holographic plates with blazed grating

    Science.gov (United States)

    Zhang, Xue-Dong; Su, Ya-Hui; Ni, Jin-Cheng; Wang, Zhong-Yu; Wang, Yu-Long; Wang, Chao-Wei; Ren, Fei-Fei; Zhang, Zhen; Fan, Hua; Zhang, Wei-Jie; Li, Guo-Qiang; Hu, Yan-Lei; Li, Jia-Wen; Wu, Dong; Chu, Jia-Ru

    2017-08-01

    In this paper, we demonstrate that the superposition of two vortex beams with controlled topological charges can be realized by integrating two holographic plates with blazed grating. First, the holographic plate with blazed grating was designed and fabricated by laser direct writing for generating well-separated vortex beam. Then, the relationship between the periods of blazed grating and the discrete angles of vortex beams was systemically investigated. Finally, through setting the discrete angle and different revolving direction of the holographic plates, the composite fork-shaped field was realized by the superposition of two vortex beams in a particular position. The topological charges of composite fork-shaped field (l = 1, 0, 3, and 4) depend on the topological charges of compositional vortex beams, which are well agreed with the theoretical simulation. The method opens up a wide range of opportunities and possibilities for applying in optical communication, optical manipulations, and photonic integrated circuits.

  5. Active commuting: prevalence, barriers, and associated variables.

    Science.gov (United States)

    Silva, Kelly Samara; Vasques, Daniel Giordani; Martins, Caroline de Oliveira; Williams, Laura Ashley; Lopes, Adair S

    2011-08-01

    Research has demonstrated that adolescents who actively commute have higher levels of physical activity (PA), which have declined precipitously over the past 30 years. The purpose of this study was to describe the prevalence of active commuting to school; and to identify barriers associated with active commuting. A cross-sectional study was conducted with 1672 students (46.8% boys and 53.2% girls) from 11 to 17 years of age in Caxias do Sul/RS, Brazil. The students were asked to answer questionnaires about active transport, PA, and sedentary behaviors. They also completed a cardiovascular fitness test and body composition measurements. The study used a multivariate Poisson regression analysis. A total of 62.5% of students were observed to actively commute and the prevalence ratio (PR) of not actively commuting was associated with the type of school (Private: 2.41; 1.47, 3.95) and the time spent on commuting (>20 min: 1.93; 1.23, 3.03). The associated barriers to passive commuting were distance (3.02; 1.95, 4.71), crime/danger (2.65; 1.82, 3.85), and traffic (1.75; 1.19, 2.58). This study showed that environmental variables were strongly associated with active commuting. However, no alterations in body composition or other behavioral variables were observed after adjustment.

  6. Optical Variability of Active Galactic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kozłowski, Szymon, E-mail: simkoz@astrouw.edu.pl [Astronomical Observatory, University of Warsaw, Warsaw (Poland)

    2017-09-21

    Variability studies of active galactic nuclei (AGNs) typically use either power spectral density (PSD) and structure function (SF) analyses or direct modeling of light curves with the damped random walk (DRW) and the continuous autoregressive moving average (CARMA) models. A fair fraction of research publications on the subject are flawed, and simply report incorrect results, because they lack a deep understanding of where these methods originate from and what their limitations are. For example, SF analyses typically lack or use a wrong noise subtraction procedure, leading to flat SFs. DRW, on the other hand, can only be used if the experiment length is sufficient, at least ten times the signal decorrelation time scale τ, and if the data show the power-law SF slope of γ ≡ 0.5.

  7. Directional enhancement of selected high-order-harmonics from intense laser irradiated blazed grating targets.

    Science.gov (United States)

    Zhang, Guobo; Chen, Min; Liu, Feng; Yuan, Xiaohui; Weng, Suming; Zheng, Jun; Ma, Yanyun; Shao, Fuqiu; Sheng, Zhengming; Zhang, Jie

    2017-10-02

    Relativistically intense laser solid target interaction has been proved to be a promising way to generate high-order harmonics, which can be used to diagnose ultrafast phenomena. However, their emission direction and spectra still lack tunability. Based upon two-dimensional particle-in-cell simulations, we show that directional enhancement of selected high-order-harmonics can be realized using blazed grating targets. Such targets can select harmonics with frequencies being integer times of the grating frequency. Meanwhile, the radiation intensity and emission area of the harmonics are increased. The emission direction is controlled by tailoring the local blazed structure. Theoretical and electron dynamics analysis for harmonics generation, selection and directional enhancement from the interaction between multi-cycle laser and grating target are carried out. These studies will benefit the generation and application of laser plasma-based high order harmonics.

  8. Large-Area Binary Blazed Grating Coupler between Nanophotonic Waveguide and LED

    Directory of Open Access Journals (Sweden)

    Hongqiang Li

    2014-01-01

    Full Text Available A large-area binary blazed grating coupler for the arrayed waveguide grating (AWG demodulation integrated microsystem on silicon-on-insulator (SOI was designed for the first time. Through the coupler, light can be coupled into the SOI waveguide from the InP-based C-band LED for the AWG demodulation integrated microsystem to function. Both the length and width of the grating coupler are 360 μm, as large as the InP-based C-band LED light emitting area in the system. The coupler was designed and optimized based on the finite difference time domain method. When the incident angle of the light source is 0°, the coupling efficiency of the binary blazed grating is 40.92%, and the 3 dB bandwidth is 72 nm at a wavelength of 1550 nm.

  9. High efficiency multilayer blazed gratings for EUV and soft X-rays: Recent developments

    International Nuclear Information System (INIS)

    Voronov, Dmitriy; Ahn, Minseung; Anderson, Erik; Cambie, Rossana; Chang, Chih-Hao; Goray, Leonid; Gullikson, Eric; Heilmann, Ralf; Salmassi, Farhad; Schattenburg, Mark; Warwick, Tony; Yashchuk, Valeriy; Padmore, Howard

    2011-01-01

    Multilayer coated blazed gratings with high groove density are the best candidates for use in high resolution EUV and soft x-ray spectroscopy. Theoretical analysis shows that such a grating can be potentially optimized for high dispersion and spectral resolution in a desired high diffraction order without significant loss of diffraction efficiency. In order to realize this potential, the grating fabrication process should provide a perfect triangular groove profile and an extremely smooth surface of the blazed facets. Here we report on recent progress achieved at the Advanced Light Source (ALS) in fabrication of high quality multilayer coated blazed gratings. The blazed gratings were fabricated using scanning beam interference lithography followed by wet anisotropic etching of silicon. A 200 nm period grating coated with a Mo/Si multilayer composed with 30 bi-layers demonstrated an absolute efficiency of 37.6percent in the 3rd diffraction order at 13.6 nm wavelength. The groove profile of the grating was thoroughly characterized with atomic force microscopy before and after the multilayer deposition. The obtained metrology data were used for simulation of the grating efficiency with the vector electromagnetic PCGrate-6.1 code. The simulations showed that smoothing of the grating profile during the multilayer deposition is the main reason for efficiency losses compared to the theoretical maximum. Investigation of the grating with cross-sectional transmission electron microscopy revealed a complex evolution of the groove profile in the course of the multilayer deposition. Impact of the shadowing and smoothing processes on growth of the multilayer on the surface of the sawtooth substrate is discussed.

  10. Line spread functions of blazed off-plane gratings operated in the Littrow mounting

    Science.gov (United States)

    DeRoo, Casey T.; McEntaffer, Randall L.; Miles, Drew M.; Peterson, Thomas J.; Marlowe, Hannah; Tutt, James H.; Donovan, Benjamin D.; Menz, Benedikt; Burwitz, Vadim; Hartner, Gisela; Allured, Ryan; Smith, Randall K.; Günther, Ramses; Yanson, Alex; Vacanti, Giuseppe; Ackermann, Marcelo

    2016-04-01

    Future soft x-ray (10 to 50 Å) spectroscopy missions require higher effective areas and resolutions to perform critical science that cannot be done by instruments on current missions. An x-ray grating spectrometer employing off-plane reflection gratings would be capable of meeting these performance criteria. Off-plane gratings with blazed groove facets operating in the Littrow mounting can be used to achieve excellent throughput into orders achieving high resolutions. We have fabricated two off-plane gratings with blazed groove profiles via a technique that uses commonly available microfabrication processes, is easily scaled for mass production, and yields gratings customized for a given mission architecture. Both fabricated gratings were tested in the Littrow mounting at the Max Planck Institute for Extraterrestrial Physics (MPE) PANTER x-ray test facility to assess their performance. The line spread functions of diffracted orders were measured, and a maximum resolution of 800±20 is reported. In addition, we also observe evidence of a blaze effect from measurements of relative efficiencies of the diffracted orders.

  11. Note: Optimization of magnifying a polarization angle with Littrow layout blazed gratings.

    Science.gov (United States)

    Sasao, H; Arakawa, H; Imazawa, R; Kawano, Y; Itami, K; Kubo, H

    2017-03-01

    Magnification of a polarization angle with Littrow layout gratings has been developed. High magnification with a factor of 7.7 using two gratings in Littrow layout was experimentally proved. The magnification range was investigated by calculation at a wavelength of 10.6 μm. The method can be applied for a high magnification factor >30. Larger groove numbers and smaller blaze angles are suitable for the large magnification. Statistical fluctuation of the diffracted polarization angle is compared with that of the incident polarization angle.

  12. Data presentation options to manage variability in physical activity research.

    Science.gov (United States)

    Valbuena, Diego; Miller, Bryon G; Samaha, Andrew L; Miltenberger, Raymond G

    2017-07-01

    This paper presents seven tactics for managing the variability evident in some physical activity data. High levels of variability in daily step-count data from pedometers or accelerometers can make typical visual inspection difficult. Therefore, the purpose of the current paper is to discuss several strategies that might facilitate the visual interpretation of highly variable data. The seven strategies discussed in this paper are phase mean and median lines, daily average per week, weekly cumulative, proportion of baseline, 7-day moving average, change point detection, and confidence intervals. We apply each strategy to a data set and discuss the advantages and disadvantages. © 2017 Society for the Experimental Analysis of Behavior.

  13. Variability in individual activity bursts improves ant foraging success.

    Science.gov (United States)

    Campos, Daniel; Bartumeus, Frederic; Méndez, Vicenç; Andrade, José S; Espadaler, Xavier

    2016-12-01

    Using experimental and computational methods, we study the role of behavioural variability in activity bursts (or temporal activity patterns) for individual and collective regulation of foraging in A. senilis ants. First, foraging experiments were carried out under special conditions (low densities of ants and food and absence of external cues or stimuli) where individual-based strategies are most prevalent. By using marked individuals and recording all foraging trajectories, we were then able to precisely quantify behavioural variability among individuals. Our main conclusions are that (i) variability of ant trajectories (turning angles, speed, etc.) is low compared with variability of temporal activity profiles, and (ii) this variability seems to be driven by plasticity of individual behaviour through time, rather than the presence of fixed behavioural stereotypes or specialists within the group. The statistical measures obtained from these experimental foraging patterns are then used to build a general agent-based model (ABM) which includes the most relevant properties of ant foraging under natural conditions, including recruitment through pheromone communication. Using the ABM, we are able to provide computational evidence that the characteristics of individual variability observed in our experiments can provide a functional advantage (in terms of foraging success) to the group; thus, we propose the biological basis underpinning our observations. Altogether, our study reveals the potential utility of experiments under simplified (laboratory) conditions for understanding information-gathering in biological systems. © 2016 The Author(s).

  14. CHARACTERIZING THE OPTICAL VARIABILITY OF BRIGHT BLAZARS: VARIABILITY-BASED SELECTION OF FERMI ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Ruan, John J.; Anderson, Scott F.; MacLeod, Chelsea L.; Becker, Andrew C.; Davenport, James R. A.; Ivezić, Željko; Burnett, T. H.; Kochanek, Christopher S.; Plotkin, Richard M.; Sesar, Branimir; Stuart, J. Scott

    2012-01-01

    We investigate the use of optical photometric variability to select and identify blazars in large-scale time-domain surveys, in part to aid in the identification of blazar counterparts to the ∼30% of γ-ray sources in the Fermi 2FGL catalog still lacking reliable associations. Using data from the optical LINEAR asteroid survey, we characterize the optical variability of blazars by fitting a damped random walk model to individual light curves with two main model parameters, the characteristic timescales of variability τ, and driving amplitudes on short timescales σ-circumflex. Imposing cuts on minimum τ and σ-circumflex allows for blazar selection with high efficiency E and completeness C. To test the efficacy of this approach, we apply this method to optically variable LINEAR objects that fall within the several-arcminute error ellipses of γ-ray sources in the Fermi 2FGL catalog. Despite the extreme stellar contamination at the shallow depth of the LINEAR survey, we are able to recover previously associated optical counterparts to Fermi active galactic nuclei with E ≥ 88% and C = 88% in Fermi 95% confidence error ellipses having semimajor axis r < 8'. We find that the suggested radio counterpart to Fermi source 2FGL J1649.6+5238 has optical variability consistent with other γ-ray blazars and is likely to be the γ-ray source. Our results suggest that the variability of the non-thermal jet emission in blazars is stochastic in nature, with unique variability properties due to the effects of relativistic beaming. After correcting for beaming, we estimate that the characteristic timescale of blazar variability is ∼3 years in the rest frame of the jet, in contrast with the ∼320 day disk flux timescale observed in quasars. The variability-based selection method presented will be useful for blazar identification in time-domain optical surveys and is also a probe of jet physics.

  15. ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Kouzuma, S.; Yamaoka, H.

    2012-01-01

    We present the properties of the ensemble variability V for nearly 5000 near-infrared active galactic nuclei (AGNs) selected from the catalog of Quasars and Active Galactic Nuclei (13th Edition) and the SDSS-DR7 quasar catalog. From three near-infrared point source catalogs, namely, Two Micron All Sky Survey (2MASS), Deep Near Infrared Survey (DENIS), and UKIDSS/LAS catalogs, we extract 2MASS-DENIS and 2MASS-UKIDSS counterparts for cataloged AGNs by cross-identification between catalogs. We further select variable AGNs based on an optimal criterion for selecting the variable sources. The sample objects are divided into subsets according to whether near-infrared light originates by optical emission or by near-infrared emission in the rest frame; and we examine the correlations of the ensemble variability with the rest-frame wavelength, redshift, luminosity, and rest-frame time lag. In addition, we also examine the correlations of variability amplitude with optical variability, radio intensity, and radio-to-optical flux ratio. The rest-frame optical variability of our samples shows negative correlations with luminosity and positive correlations with rest-frame time lag (i.e., the structure function, SF), and this result is consistent with previous analyses. However, no well-known negative correlation exists between the rest-frame wavelength and optical variability. This inconsistency might be due to a biased sampling of high-redshift AGNs. Near-infrared variability in the rest frame is anticorrelated with the rest-frame wavelength, which is consistent with previous suggestions. However, correlations of near-infrared variability with luminosity and rest-frame time lag are the opposite of these correlations of the optical variability; that is, the near-infrared variability is positively correlated with luminosity but negatively correlated with the rest-frame time lag. Because these trends are qualitatively consistent with the properties of radio-loud quasars reported

  16. Individual Variability in Brain Activity: A Nuisance or an Opportunity?

    Science.gov (United States)

    Van Horn, John Darrell; Grafton, Scott T; Miller, Michael B

    2008-12-01

    Functional imaging research has been heavily influenced by results based on population-level inference. However, group average results may belie the unique patterns of activity present in the individual that ordinarily are considered random noise. Recent advances in the evolution of MRI hardware have led to significant improvements in the stability and reproducibility of blood oxygen level dependent (BOLD) measurements. These enhancements provide a unique opportunity for closer examination of individual patterns of brain activity. Three objectives can be accomplished by considering brain scans at the individual level; (1) Mapping functional anatomy at a fine grained analysis; (2) Determining if an individual scan is normative with respect to a reference population; and (3) Understanding the sources of intersubject variability in brain activity. In this review, we detail these objectives, briefly discuss their histories and present recent trends in the analyses of individual variability. Finally, we emphasize the unique opportunities and challenges for understanding individual differences through international collaboration among Pacific Rim investigators.

  17. Characterizing the Optical Variability of Bright Blazars: Variability-based Selection of Fermi Active Galactic Nuclei

    Science.gov (United States)

    Ruan, John J.; Anderson, Scott F.; MacLeod, Chelsea L.; Becker, Andrew C.; Burnett, T. H.; Davenport, James R. A.; Ivezić, Željko; Kochanek, Christopher S.; Plotkin, Richard M.; Sesar, Branimir; Stuart, J. Scott

    2012-11-01

    We investigate the use of optical photometric variability to select and identify blazars in large-scale time-domain surveys, in part to aid in the identification of blazar counterparts to the ~30% of γ-ray sources in the Fermi 2FGL catalog still lacking reliable associations. Using data from the optical LINEAR asteroid survey, we characterize the optical variability of blazars by fitting a damped random walk model to individual light curves with two main model parameters, the characteristic timescales of variability τ, and driving amplitudes on short timescales \\hat{\\sigma }. Imposing cuts on minimum τ and \\hat{\\sigma } allows for blazar selection with high efficiency E and completeness C. To test the efficacy of this approach, we apply this method to optically variable LINEAR objects that fall within the several-arcminute error ellipses of γ-ray sources in the Fermi 2FGL catalog. Despite the extreme stellar contamination at the shallow depth of the LINEAR survey, we are able to recover previously associated optical counterparts to Fermi active galactic nuclei with E >= 88% and C = 88% in Fermi 95% confidence error ellipses having semimajor axis r beaming. After correcting for beaming, we estimate that the characteristic timescale of blazar variability is ~3 years in the rest frame of the jet, in contrast with the ~320 day disk flux timescale observed in quasars. The variability-based selection method presented will be useful for blazar identification in time-domain optical surveys and is also a probe of jet physics.

  18. Beta activity measurements in high, variable gamma backgrounds

    International Nuclear Information System (INIS)

    Stanga, D.; Sandu, E.; Craciun, L.

    1997-01-01

    In many cases beta activity measurements must be performed in high and variable gamma backgrounds. In such instances it is necessary to use well-shielded detectors but this technique is limited to laboratory equipment and frequently insufficient. In order to perform in a simple manner beta activity measurements in high and variable backgrounds a software-aided counting technique have been developed and a counting system have been constructed. This technique combines the different counting techniques with traditional method of successive measurement of the sample and background. The counting system is based on a programmable multi-scaler which is endowed with appropriate software and allow all operations to be performed via keyboard in an interactive fashion. Two large - area proportional detectors were selected in order to have the same background and the same gamma response within 5%. A program has been developed for the counting data analysis and beta activity computing. The software-aided counting technique has been implemented for beta activity measurement in high and variable backgrounds. (authors)

  19. Human activity and climate variability project: annual report 2001

    International Nuclear Information System (INIS)

    Harle, K.J.; Heijnis, H.; Henderson-Sellers, A.; Sharmeen, S.; Zahorowski, W.

    2002-01-01

    Knowledge of the state of the Australian environment, including natural climate variability, prior to colonial settlement is vital if we are to define and understand the impact of over two hundred years of post-industrial human activity on our landscape. ANSTO, in conjunction with university partners, is leading a major research effort to provide natural archives of human activity and climate variability over the last 500 years in Australia, utilising a variety of techniques, including lead-210 and radiocarbon dating and analyses of proxy indicators (such as microfossils) as well as direct evidence (such as trace elements) of human activity and climate variability. The other major project objectives were to contribute to the understanding of the impact of human induced and natural aerosols in the East Asian region on climate through analysis and sourcing of fine particles and characterisation of air samples using radon concentrations and to contribute to the improvement of land surface parameterisation schemes and investigate the potential to use stable isotopes to improve global climate models and thus improve our understanding of future climate

  20. Active surge control for variable speed axial compressors.

    Science.gov (United States)

    Lin, Shu; Yang, Chunjie; Wu, Ping; Song, Zhihuan

    2014-09-01

    This paper discusses active surge control in variable speed axial compressors. A compression system equipped with a variable area throttle is investigated. Based on a given compressor model, a fuzzy logic controller is designed for surge control and a proportional speed controller is used for speed control. The fuzzy controller uses measurements of the change of pressure rise as well as the change of mass flow to determine the throttle opening. The presented approach does not require the knowledge of system equilibrium or the surge line. Numerical simulations show promising results. The proposed fuzzy logic controller performs better than a backstepping controller and is capable to suppress surge at different operating points. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Daily Physical Activity and Cognitive Function Variability in Older Adults.

    Science.gov (United States)

    Phillips, Christine B; Edwards, Jerri D; Andel, Ross; Kilpatrick, Marcus

    2016-04-01

    Physical activity (PA) is believed to preserve cognitive function in older adulthood, though little is known about these relationships within the context of daily life. The present microlongitudinal pilot study explored within- and between-person relationships between daily PA and cognitive function and also examined within-person effect sizes in a sample of community-dwelling older adults. Fifty-one healthy participants (mean age = 70.1 years) wore an accelerometer and completed a cognitive assessment battery for five days. There were no significant associations between cognitive task performance and participants' daily or average PA over the study period. Effect size estimates indicated that PA explained 0-24% of within-person variability in cognitive function, depending on cognitive task and PA dose. Results indicate that PA may have near-term cognitive effects and should be explored as a possible strategy to enhance older adults' ability to perform cognitively complex activities within the context of daily living.

  2. High temperature mechanical properties on multi stage blazed fin body with ultra fine off-set fin for compact heat exchanger

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro; Muto, Yasushi

    2003-01-01

    Three stage blazed plate fin body with ultra fine off-set fin (thickness x height x pitch x off-set pitch = 0.22 mm x 1.2 mm x 1.6 mm x 5 mm) for 600 MWt High Temperature Gas Cooled Reactor Gas Turbin (HTGR-GT) system was fabricated and tested on its high temperature mechanical properties and the following results were derived. (1) tested body shows almost the same strength an fatigue behavior of SUS 304 as main structural material at elevated temperatures up to 873 K, (2) static and fatigue fracture mainly occurred at ultra fine off-set and (3) high temperature strength and fatigue life are improved by blazing technique to double side walls of the fin by Ni blaze material. (author)

  3. VARIABILITY IN ACTIVE GALACTIC NUCLEI FROM PROPAGATING TURBULENT RELATIVISTIC JETS

    Energy Technology Data Exchange (ETDEWEB)

    Pollack, Maxwell; Pauls, David; Wiita, Paul J., E-mail: wiitap@tcnj.edu [Department of Physics, The College of New Jersey P.O. Box 7718, Ewing, NJ 08628-0718 (United States)

    2016-03-20

    We use the Athena hydrodynamics code to model propagating two-dimensional relativistic jets as approximations to the growth of radio-loud active galactic nuclei for various input jet velocities and jet-to-ambient matter density ratios. Using results from these simulations we estimate the changing synchrotron emission by summing the fluxes from a vertical strip of zones behind the reconfinement shock, which is nearly stationary, and from which a substantial portion of the flux variability should arise. We explore a wide range of timescales by considering two light curves from each simulation; one uses a relativistic turbulence code with bulk velocities taken from our simulations as input, while the other uses the bulk velocity data to compute fluctuations caused by variations in the Doppler boosting due to changes in the direction and the speed of the flow through all zones in the strip. We then calculate power spectral densities (PSDs) from the light curves for both turbulent and bulk velocity origins for variability. The range of the power-law slopes of the PSDs for the turbulence induced variations is −1.8 to −2.3, while for the bulk velocity produced variations this range is −2.1 to −2.9; these are in agreement with most observations. When superimposed, these power spectra span a very large range in frequency (about five decades), with the turbulent fluctuations yielding most of the shorter timescale variations and the bulk flow changes dominating the longer periods.

  4. VARIABILITY IN ACTIVE GALACTIC NUCLEI FROM PROPAGATING TURBULENT RELATIVISTIC JETS

    International Nuclear Information System (INIS)

    Pollack, Maxwell; Pauls, David; Wiita, Paul J.

    2016-01-01

    We use the Athena hydrodynamics code to model propagating two-dimensional relativistic jets as approximations to the growth of radio-loud active galactic nuclei for various input jet velocities and jet-to-ambient matter density ratios. Using results from these simulations we estimate the changing synchrotron emission by summing the fluxes from a vertical strip of zones behind the reconfinement shock, which is nearly stationary, and from which a substantial portion of the flux variability should arise. We explore a wide range of timescales by considering two light curves from each simulation; one uses a relativistic turbulence code with bulk velocities taken from our simulations as input, while the other uses the bulk velocity data to compute fluctuations caused by variations in the Doppler boosting due to changes in the direction and the speed of the flow through all zones in the strip. We then calculate power spectral densities (PSDs) from the light curves for both turbulent and bulk velocity origins for variability. The range of the power-law slopes of the PSDs for the turbulence induced variations is −1.8 to −2.3, while for the bulk velocity produced variations this range is −2.1 to −2.9; these are in agreement with most observations. When superimposed, these power spectra span a very large range in frequency (about five decades), with the turbulent fluctuations yielding most of the shorter timescale variations and the bulk flow changes dominating the longer periods

  5. Spectropolarimetry, variability, and the taxonomy of active galactic nuclei

    International Nuclear Information System (INIS)

    Goodrich, R.W.

    1988-01-01

    Two subclasses of active galactic nuclei (AGN) are studied using spectropolarimetry, with the intent of defining the relationships of the subclasses to other classes of AGNs, and to study the physics of the objects themselves. In the Seyfert 1.8/1.9 class there is good evidence for dust just outside of the broad-line regions in two objects, IRAS 1958-183 and NGC 2622. Spectropolarimetry of the latter object reveals the presence of dust moving at ∼ -800 s -1 along the our line-of-sight, and causing much of the polarization in the object. In addition, three of these objects have undergone extreme variability. Combining IDS data from Osterbrock and collaborators with the more recent CCD data it is shown that in all three cases the changes in both broad emission line fluxes and featureless continuum are consistent with changes in the line-of-sight reddening to the broad-line region. Together with the polarimetric evidence for dust and IRAS photometry this strongly suggests that the Seyfert 1.8/1.9 character is caused by dust and the consequent reddening and extinction. Variability occurs when dust clouds evaporate or move out of line-of-sight, and the extinction then changes. In the so-called narrow line Seyfert 1s spectropolarimetry reveals seven highly-polarized objects. In Mrk 1239 there is evidence for at least two components of polarization, one probably due to dust reflection. In two other objects, Mrk 766 and IRAS 1509-211, the polarization also appears to indicate dust reflection as the polarigenic mechanism. There is a weak circumstantial evidence for an association of the low-density region and the polarizing source, provided by comparison of the radio axes and polarization position angles in Mrk 766 and Mrk 1126

  6. Variability in foF2 at an equatorial station and the influence of magnetic activity

    International Nuclear Information System (INIS)

    Adeniyi, J.O.; Radicella, S.M.

    2003-01-01

    Variability in foF2 is investigated for an equatorial station in the African region. Variability during the day time at high solar activity varies between 10 and 30 percent. It varies between 10 and 20 percent at high solar activity. Magnetic storms increase the variability at both solar activity periods. (author)

  7. Cataclysmic Variables and Active Binary Stars in Omega Centauri

    Science.gov (United States)

    Arias, T.; Brochmann, M.; Dorfman, J. L.; White, M. V.; Cool, A. M.

    2004-12-01

    We report findings from our ongoing research on the globular cluster Omega Centauri (NGC 5139) using a 3x3 mosaic of Wide Field Camera pointings with the HST Advanced Camera for Surveys (ACS). The data consist of F435W (B435), F625W (R625), and F658N (Hα ) images and cover roughly 10x10 arcminutes, out to beyond the cluster's half-mass radius. Our current work is a search for cataclysmic variables (CVs) and active binaries (ABs) (e.g., RS CVn and BY Dra stars) as counterparts to X-ray point sources previously detected with Chandra. The ACS field encompasses 109 of the Chandra sources, 20-50 of which are likely to be cluster members according to our statistical estimates (the rest being primarily active galaxies). Using DAOPHOT to obtain photometry in 20x20 arcsecond patches surrounding each X-ray source, we are constructing color-magnitude diagrams to search for stars with Hα -R625 and/or B435-R625 colors indicative of CVs or ABs in ˜ 1 arcsecond Chandra error circles. With roughly half of the patches analyzed, several AB candidates and only a small number of CV candidates have emerged. Our tentative conclusion is that CVs may be significantly rarer in Omega Cen than in 47 Tuc, in contrast to the comparable numbers ( ˜100) predicted for these two clusters from tidal capture theory (Di Stefano and Rappaport 1994). Alternatively, the CVs could be strongly concentrated toward the cluster center, and thus not yet appear in our sample. To date, most of the patches we have analyzed are 3-4 arcminutes from the cluster center and thus are outside the cluster core (radius 2.6 arcminutes). Our continuing work should soon enable us to resolve this question. This work is supported by NASA grant GO-9442 from the Space Telescope Science Institute.

  8. Active Luminous Blue Variables in the Large Magellanic Cloud

    Energy Technology Data Exchange (ETDEWEB)

    Walborn, Nolan R. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Gamen, Roberto C.; Lajús, Eduardo Fernández [Instituto de Astrofísica de La Plata, CONICET–UNLP and Facultad de Ciencias Astronómicas y Geofísicas, UNLP, Paseo del Bosque s/n, La Plata (Argentina); Morrell, Nidia I. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Barbá, Rodolfo H. [Departamento de Física y Astronomía, Universidad de La Serena, Cisternas 1200 Norte, La Serena (Chile); Angeloni, Rodolfo, E-mail: walborn@stsci.edu, E-mail: rgamen@fcaglp.unlp.edu.ar, E-mail: eflajus@fcaglp.unlp.edu.ar, E-mail: nmorrell@lco.cl, E-mail: rbarba@dfuls.cl, E-mail: rangelon@gemini.edu [Gemini Observatory, Colina El Pino, Casilla 603, La Serena (Chile)

    2017-07-01

    We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

  9. Active Luminous Blue Variables in the Large Magellanic Cloud

    Science.gov (United States)

    Walborn, Nolan R.; Gamen, Roberto C.; Morrell, Nidia I.; Barbá, Rodolfo H.; Fernández Lajús, Eduardo; Angeloni, Rodolfo

    2017-07-01

    We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca II] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

  10. Active Luminous Blue Variables in the Large Magellanic Cloud

    International Nuclear Information System (INIS)

    Walborn, Nolan R.; Gamen, Roberto C.; Lajús, Eduardo Fernández; Morrell, Nidia I.; Barbá, Rodolfo H.; Angeloni, Rodolfo

    2017-01-01

    We present extensive spectroscopic and photometric monitoring of two famous and currently highly active luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC), together with more limited coverage of three further, lesser known members of the class. R127 was discovered as an Ofpe/WN9 star in the 1970s but entered a classical LBV outburst in or about 1980 that is still in progress, thus enlightening us about the minimum state of such objects. R71 is currently the most luminous star in the LMC and continues to provide surprises, such as the appearance of [Ca ii] emission lines, as its spectral type becomes unprecedentedly late. Most recently, R71 has developed inverse P Cyg profiles in many metal lines. The other objects are as follows: HDE 269582, now a “second R127” that has been followed from Ofpe/WN9 to A type in its current outburst; HDE 269216, which changed from late B in 2014 to AF in 2016, its first observed outburst; and R143 in the 30 Doradus outskirts. The light curves and spectroscopic transformations are correlated in remarkable detail and their extreme reproducibility is emphasized, both for a given object and among all of them. It is now believed that some LBVs proceed directly to core collapse. One of these unstable LMC objects may thus oblige in the near future, teaching us even more about the final stages of massive stellar evolution.

  11. The active liquid Earth - importance of temporal and spatial variability

    Science.gov (United States)

    Arheimer, Berit

    2016-04-01

    The Planet Earth is indeed liquid and active - 71 percent of its surface is water-covered and this water never rests. Thanks to the water cycle, our planet's water supply is constantly moving from one place to another and from one form to another. Only 2.5% of the water is freshwater and it exists in the air as water vapor; it hits the ground as rain and snow; it flows on the surface from higher to lower altitudes in rivers, lakes, and glaciers; and it flows in the ground in soil, aquifers, and in all living organisms until it reaches the sea. On its way over the Earth's crust, some returns quickly to vapor again, while some is trapped and exposed to many "fill and spill" situations for a long journey. The variability in the water balance is crucial for hydrological understanding and modelling. The water cycle may appear simple, but magnitudes and rates in fluxes are very different from one place to another, resulting from variable drivers such as solar energy, precipitation and gravity in co-evolution with geology, soil, vegetation and fauna. The historical evolution, the temporal fluxes and diversity in space continue to fascinate hydrological scientists. Specific physical processes may be well known, but their boundary conditions, interactions and rate often remain unknown at a specific site and are difficult to monitor in nature. This results in mysterious features where trends in drivers do not match runoff, like the Sahelian Paradox or discharge to the Arctic Ocean. Humans have always interfered with the water cycle and engineering is fundamental for water regulation and re-allocation. Some 80% of the river flow from the northern part of the Earth is affected by fragmentation of the river channels by dams. In water management, there is always a tradeoff between upstream and downstream activities, not only regarding total water quantities but also for temporal patterns and water quality aspects. Sharing a water resource can generate conflicts but geopolitical

  12. Human activity and climate variability project - annual report 2002

    International Nuclear Information System (INIS)

    Chambers, S.; Harle, K.J.; Sharmeen, S.; Zahorowski, W.; Cohen, D.; Heijnis, H.; Henderson-Sellers, A

    2002-01-01

    Work is well underway on identifying the spatial and temporal extent, direction and range of trace element transport across Tasmania through analysis of lake sediments; A follow up investigation of sedimentation and pollution in the Nattai River catchment following the devastating 2001 bushfires in the region has been completed; The project has been extended to include investigations of evidence of human impacts in the highly sensitive and ecologically important Great Lakes of coastal NSW. This has involved the expansion of our collaboration to include Geoscience Australia; Contributions have been made to the IGBP HITE project. Further contributions will be made as the evidence gathered is drawn together and interpreted; Over the coming year, focus will be placed on completion of the investigation of the extent of aerial transport of trace elements across Tasmania over the last 200 years as well as evidence for human activity and impacts on the Great Lakes region of NSW. Further investigation of potential climate signals from sites in northern Australia will also be made. The first 12 months of data for all ACE-Asia radon and fine particle sites is now available with preliminary analyses performed; The seasonal variability of background radon concentration at each of the radon monitoring sites has been characterised for the available data; Major components related to industrial pollution and soil sources in China have been identified and quantified; Regional and seasonal variations and trends in aerosol constituents have been measured and compared across more than 2.8Mk 2 of sampling area; The Hok Tsui and Kosan detectors were visited for general maintenance and recalibration; A grant application to the APN has been submitted in support of regional inventory analyses based on radon time series; Progress on the processing and interpretation of radon data was presented at the Cape Grim Science Meeting (6-7 February 2002) and the 7th Biennial SPERA Conference on

  13. Human activity and climate variability project - annual report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, S; Harle, K J; Sharmeen, S; Zahorowski, W; Cohen, D; Heijnis, H; Henderson-Sellers, A [Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia)

    2002-07-01

    Work is well underway on identifying the spatial and temporal extent, direction and range of trace element transport across Tasmania through analysis of lake sediments; A follow up investigation of sedimentation and pollution in the Nattai River catchment following the devastating 2001 bushfires in the region has been completed; The project has been extended to include investigations of evidence of human impacts in the highly sensitive and ecologically important Great Lakes of coastal NSW. This has involved the expansion of our collaboration to include Geoscience Australia; Contributions have been made to the IGBP HITE project. Further contributions will be made as the evidence gathered is drawn together and interpreted; Over the coming year, focus will be placed on completion of the investigation of the extent of aerial transport of trace elements across Tasmania over the last 200 years as well as evidence for human activity and impacts on the Great Lakes region of NSW. Further investigation of potential climate signals from sites in northern Australia will also be made. The first 12 months of data for all ACE-Asia radon and fine particle sites is now available with preliminary analyses performed; The seasonal variability of background radon concentration at each of the radon monitoring sites has been characterised for the available data; Major components related to industrial pollution and soil sources in China have been identified and quantified; Regional and seasonal variations and trends in aerosol constituents have been measured and compared across more than 2.8Mk{sup 2} of sampling area; The Hok Tsui and Kosan detectors were visited for general maintenance and recalibration; A grant application to the APN has been submitted in support of regional inventory analyses based on radon time series; Progress on the processing and interpretation of radon data was presented at the Cape Grim Science Meeting (6-7 February 2002) and the 7th Biennial SPERA Conference on

  14. Can co-activation reduce kinematic variability? A simulation study.

    NARCIS (Netherlands)

    Selen, L.P.J.; Beek, P.J.; van Dieen, J.H.

    2005-01-01

    Impedance modulation has been suggested as a means to suppress the effects of internal 'noise' on movement kinematics. We investigated this hypothesis in a neuro-musculo-skeletal model. A prerequisite is that the muscle model produces realistic force variability. We found that standard Hill-type

  15. Recent and past musical activity predicts cognitive aging variability: direct comparison with general lifestyle activities.

    Science.gov (United States)

    Hanna-Pladdy, Brenda; Gajewski, Byron

    2012-01-01

    Studies evaluating the impact of modifiable lifestyle factors on cognition offer potential insights into sources of cognitive aging variability. Recently, we reported an association between extent of musical instrumental practice throughout the life span (greater than 10 years) on preserved cognitive functioning in advanced age. These findings raise the question of whether there are training-induced brain changes in musicians that can transfer to non-musical cognitive abilities to allow for compensation of age-related cognitive declines. However, because of the relationship between engagement in general lifestyle activities and preserved cognition, it remains unclear whether these findings are specifically driven by musical training or the types of individuals likely to engage in greater activities in general. The current study controlled for general activity level in evaluating cognition between musicians and nomusicians. Also, the timing of engagement (age of acquisition, past versus recent) was assessed in predictive models of successful cognitive aging. Seventy age and education matched older musicians (>10 years) and non-musicians (ages 59-80) were evaluated on neuropsychological tests and general lifestyle activities. Musicians scored higher on tests of phonemic fluency, verbal working memory, verbal immediate recall, visuospatial judgment, and motor dexterity, but did not differ in other general leisure activities. Partition analyses were conducted on significant cognitive measures to determine aspects of musical training predictive of enhanced cognition. The first partition analysis revealed education best predicted visuospatial functions in musicians, followed by recent musical engagement which offset low education. In the second partition analysis, early age of musical acquisition (memory in musicians, while analyses for other measures were not predictive. Recent and past musical activity, but not general lifestyle activities, predicted variability

  16. Diagnostic for two-mode variable valve activation device

    Science.gov (United States)

    Fedewa, Andrew M

    2014-01-07

    A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

  17. Variability of the Lyman alpha flux with solar activity

    International Nuclear Information System (INIS)

    Lean, J.L.; Skumanich, A.

    1983-01-01

    A three-component model of the solar chromosphere, developed from ground based observations of the Ca II K chromospheric emission, is used to calculate the variability of the Lyman alpha flux between 1969 and 1980. The Lyman alpha flux at solar minimum is required in the model and is taken as 2.32 x 10 11 photons/cm 2 /s. This value occurred during 1975 as well as in 1976 near the commencement of solar cycle 21. The model predicts that the Lyman alpha flux increases to as much as 5 x 10 11 photons/cm 2 /s at the maximum of the solar cycle. The ratio of the average fluxes for December 1979 (cycle maximum) and July 1976 (cycle minimum) is 1.9. During solar maximum the 27-day solar rotation is shown to cause the Lyman alpha flux to vary by as much as 40% or as little as 5%. The model also shows that the Lyman alpha flux varies over intermediate time periods of 2 to 3 years, as well as over the 11-year sunspot cycle. We conclude that, unlike the sunspot number and the 10.7-cm radio flux, the Lyman alpha flux had a variability that was approximately the same during each of the past three cycles. Lyman alpha fluxes calculated by the model are consistent with measurements of the Lyman alpha flux made by 11 of a total of 14 rocket experiments conducted during the period 1969--1980. The model explains satisfactorily the absolute magnitude, long-term trends, and the cycle variability seen in the Lyman alpha irradiances by the OSO 5 satellite experiment. The 27-day variability observed by the AE-E satellite experiment is well reproduced. However, the magntidue of the AE-E 1 Lyman alpha irradiances are higher than the model calculations by between 40% and 80%. We suggest that the assumed calibration of the AE-E irradiances is in error

  18. Recent and Past Musical Activity Predicts Cognitive Aging Variability: Direct Comparison with Leisure Activities

    Directory of Open Access Journals (Sweden)

    Brenda eHanna-Pladdy

    2012-07-01

    Full Text Available Studies evaluating the impact of modifiable lifestyle factors on cognition offer potential insights into sources of cognitive aging variability. Recently, we reported an association between extent of musical instrumental practice throughout the life span (greater than 10 years on preserved cognitive functioning in advanced age . These findings raise the question of whether there are training-induced brain changes in musicians that can transfer to nonmusical cognitive abilities to allow for compensation of age-related cognitive declines. However, because of the relationship between engagement in lifestyle activities and preserved cognition, it remains unclear whether these findings are specifically driven by musical training or the types of individuals likely to engage in greater activities in general. The current study examined the type of leisure activity (musical versus other as well as the timing of engagement (age of acquisition, past versus recent in predictive models of successful cognitive aging. Seventy age and education matched older musicians (> 10 years and nonmusicians (ages 59-80 were evaluated on neuropsychological tests and life-style activities (AAP. Partition analyses were conducted on significant cognitive measures to explain performance variance in musicians. Musicians scored higher on tests of phonemic fluency, verbal immediate recall, judgment of line orientation (JLO, and Letter Number Sequencing (LNS, but not the AAP. The first partition analysis revealed education best predicted JLO in musicians, followed by recent musical engagement which offset low education. In the second partition analysis, early age of musical acquisition (< 9 years predicted enhanced LNS in musicians, while analyses for AAP, verbal recall and fluency were not predictive. Recent and past musical activity, but not leisure activity, predicted variability across verbal and visuospatial domains in aging. Early musical acquisition predicted auditory

  19. Biological activity of antitumoural MGBG: the structural variable.

    Science.gov (United States)

    Marques, M P M; Gil, F P S C; Calheiros, R; Battaglia, V; Brunati, A M; Agostinelli, E; Toninello, A

    2008-05-01

    The present study aims at determining the structure-activity relationships (SAR's) ruling the biological function of MGBG (methylglyoxal bis(guanylhydrazone)), a competitive inhibitor of S-adenosyl-L-methionine decarboxylase displaying anticancer activity, involved in the biosynthesis of the naturally occurring polyamines spermidine and spermine. In order to properly understand its biochemical activity, MGBG's structural preferences at physiological conditions were ascertained, by quantum mechanical (DFT) calculations.

  20. Photometric Variability of Four Coronally Active Stars J. C. Pandey ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    ray surveys with the Einstein and the ROSAT observatories and found to be associated with bright late- type stars. Many of these stars have not been studied in detail for their chromospheric and coronal activity, and their nature is not fully ...

  1. Intra-Individual Variability of Physical Activity in Older Adults With and Without Mild Alzheimer's Disease.

    Science.gov (United States)

    Watts, Amber; Walters, Ryan W; Hoffman, Lesa; Templin, Jonathan

    2016-01-01

    Physical activity shows promise for protection against cognitive decline in older adults with and without Alzheimer's disease (AD). To better understand barriers to adoption of physical activity in this population, a clear understanding of daily and weekly activity patterns is needed. Most accelerometry studies report average physical activity over an entire wear period without considering the potential importance of the variability of physical activity. This study evaluated individual differences in the amount and intra-individual variability of physical activity and determined whether these differences could be predicted by AD status, day of wear, age, gender, education, and cardiorespiratory capacity. Physical activity was measured via accelerometry (Actigraph GT3X+) over one week in 86 older adults with and without AD (n = 33 and n = 53, respectively). Mixed-effects location-scale models were estimated to evaluate and predict individual differences in the amount and intra-individual variability of physical activity. Results indicated that compared to controls, participants with AD averaged 21% less activity, but averaged non-significantly greater intra-individual variability. Women and men averaged similar amounts of physical activity, but women were significantly less variable. The amount of physical activity differed significantly across days of wear. Increased cardiorespiratory capacity was associated with greater average amounts of physical activity. Investigation of individual differences in the amount and intra-individual variability of physical activity provided insight into differences by AD status, days of monitor wear, gender, and cardiovascular capacity. All individuals regardless of AD status were equally consistent in their physical activity, which may have been due to a highly sedentary sample and/or the early disease stage of those participants with AD. These results highlight the value of considering individual differences in both the amount and

  2. Effects of environmental variables on invasive amphibian activity: Using model selection on quantiles for counts

    Science.gov (United States)

    Muller, Benjamin J.; Cade, Brian S.; Schwarzkoph, Lin

    2018-01-01

    Many different factors influence animal activity. Often, the value of an environmental variable may influence significantly the upper or lower tails of the activity distribution. For describing relationships with heterogeneous boundaries, quantile regressions predict a quantile of the conditional distribution of the dependent variable. A quantile count model extends linear quantile regression methods to discrete response variables, and is useful if activity is quantified by trapping, where there may be many tied (equal) values in the activity distribution, over a small range of discrete values. Additionally, different environmental variables in combination may have synergistic or antagonistic effects on activity, so examining their effects together, in a modeling framework, is a useful approach. Thus, model selection on quantile counts can be used to determine the relative importance of different variables in determining activity, across the entire distribution of capture results. We conducted model selection on quantile count models to describe the factors affecting activity (numbers of captures) of cane toads (Rhinella marina) in response to several environmental variables (humidity, temperature, rainfall, wind speed, and moon luminosity) over eleven months of trapping. Environmental effects on activity are understudied in this pest animal. In the dry season, model selection on quantile count models suggested that rainfall positively affected activity, especially near the lower tails of the activity distribution. In the wet season, wind speed limited activity near the maximum of the distribution, while minimum activity increased with minimum temperature. This statistical methodology allowed us to explore, in depth, how environmental factors influenced activity across the entire distribution, and is applicable to any survey or trapping regime, in which environmental variables affect activity.

  3. Design Method of Active Disturbance Rejection Variable Structure Control System

    Directory of Open Access Journals (Sweden)

    Yun-jie Wu

    2015-01-01

    Full Text Available Based on lines cluster approaching theory and inspired by the traditional exponent reaching law method, a new control method, lines cluster approaching mode control (LCAMC method, is designed to improve the parameter simplicity and structure optimization of the control system. The design guidelines and mathematical proofs are also given. To further improve the tracking performance and the inhibition of the white noise, connect the active disturbance rejection control (ADRC method with the LCAMC method and create the extended state observer based lines cluster approaching mode control (ESO-LCAMC method. Taking traditional servo control system as example, two control schemes are constructed and two kinds of comparison are carried out. Computer simulation results show that LCAMC method, having better tracking performance than the traditional sliding mode control (SMC system, makes the servo system track command signal quickly and accurately in spite of the persistent equivalent disturbances and ESO-LCAMC method further reduces the tracking error and filters the white noise added on the system states. Simulation results verify the robust property and comprehensive performance of control schemes.

  4. Vigorous physical activity predicts higher heart rate variability among younger adults.

    Science.gov (United States)

    May, Richard; McBerty, Victoria; Zaky, Adam; Gianotti, Melino

    2017-06-14

    Baseline heart rate variability (HRV) is linked to prospective cardiovascular health. We tested intensity and duration of weekly physical activity as predictors of heart rate variability in young adults. Time and frequency domain indices of HRV were calculated based on 5-min resting electrocardiograms collected from 82 undergraduate students. Hours per week of both moderate and vigorous activity were estimated using the International Physical Activity Questionnaire. In regression analyses, hours of vigorous physical activity, but not moderate activity, significantly predicted greater time domain and frequency domain indices of heart rate variability. Adjusted for weekly frequency, greater daily duration of vigorous activity failed to predict HRV indices. Future studies should test direct measurements of vigorous activity patterns as predictors of autonomic function in young adulthood.

  5. Heart Rate Variability in Nonlinear Rats with Different Orientation and Exploratory Activity in the Open Field.

    Science.gov (United States)

    Kur'yanova, E V; Teplyi, D L; Zhukova, Yu D; Zhukovina, N V

    2015-12-01

    The basic behavioral activity of nonlinear rats was evaluated from the sum of crossed peripheral and central squares and peripheral and central rearing postures in the open fi eld test. This index was low (30 episodes). Male rats with high score of orientation and exploratory activity were characterized by higher indexes of total heart rate variability than rats with low or intermediate activity. Specimens with a greater contribution of VLF waves into the total power spectrum of heart rate variability were shown to dominate among the rats with high behavioral activity. Our results are consistent with the notions of a suprasegmental nature of VLF waves.

  6. Trail Blazing or Jam Session? Towards a new Concept of Clinical Decision-Making

    OpenAIRE

    Risør, Torsten

    2016-01-01

    Manuscript. Published version available at http://dx.doi.org/10.1080/13648470.2016.1239695 Clinical decision-making (CDM) is key in learning to be a doctor as the defining activity in their clinical work. CDM is often portrayed in the literature as similar to ‘trail blazing’; the doctor as the core agent, clearing away obstacles on the path towards diagnosis and treatment. However, in a fieldwork of young doctors in Denmark, it was difficult connect their practice to this image....

  7. Blazing a trail: an interview with Conergy's Hans-Martin Rueter

    International Nuclear Information System (INIS)

    Rueter, H.M.; Jones, J.

    2006-01-01

    The Conergy company, based in Hamburg, is active on five continents and is one of the world's most successful renewable energy businesses. Its turnover is about 800 million Euros and it has a staff of 1200. Hans-Martin Rueter founded the company in 1998 and is currently its Chief Executive Officer. In an interview, he revealed that he expects the renewables market will be worth US$300 billion by 2015. He sees three major market sectors to be exploited: they are (a) power-plant scale installations; (b) 'solitaire' installations such as homeowners might purchase and (c) network systems using a combination of systems such as PV with wind. Rueter is already expanding into new markets worldwide and becoming less dependent on the German market. He explains his strategy for finding new markets and providing what the customer wants. (author)

  8. Variability of activity profile during medium-sided games in professional soccer

    DEFF Research Database (Denmark)

    Rago, Vincenzo; Silva, João R; Mohr, Magni

    2018-01-01

    BACKGROUND: In Southern European countries it is very frequent to perform medium-sized games (MSG) as last training drill. We analyzed the individual variability and changes in activity patterns during MSG throughout the preseason. METHODS: Activity profile during MSGs (10v10+goalkeepers, duratio...

  9. Differing Relationship of Psycho-Social Variables with Active Ulcerative Colitis or Crohn's Disease.

    Science.gov (United States)

    Sarid, Orly; Slonim-Nevo, Vered; Schwartz, Doron; Friger, Michael; Sergienko, Ruslan; Pereg, Avihu; Vardi, Hillel; Chernin, Elena; Singer, Terri; Greenberg, Dan; Odes, Shmuel

    2018-03-09

    How psycho-social variables affect the degree of disease activity in patients with ulcerative colitis (UC) or Crohn's disease (CD) is incompletely understood. Therefore, we measured and compared the impact of psycho-social variables on the active disease state in UC and CD. One hundred and twenty-two UC and 305 CD patients with active disease completed questionnaires detailing their psychological symptoms, threatening experiences, disease-coping strategies, satisfaction with life, quality of life, and demographics. UC and CD patients were aged (mean, SD) 38.6 ± 14.0 and 45.2 ± 15.1 years, respectively. The psychological symptom index (median, IQR) was greater in UC 1.24 (0.8) than CD 0.9 (0.8), p psycho-social variables on the active disease state differs between UC and CD, thus indicating a need for specifically tailored psychotherapies.

  10. Variability-based active galactic nucleus selection using image subtraction in the SDSS and LSST era

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yumi; Gibson, Robert R.; Becker, Andrew C.; Ivezić, Željko; Connolly, Andrew J.; Ruan, John J.; Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); MacLeod, Chelsea L., E-mail: ymchoi@astro.washington.edu [Physics Department, U.S. Naval Academy, 572 Holloway Road, Annapolis, MD 21402 (United States)

    2014-02-10

    With upcoming all-sky surveys such as LSST poised to generate a deep digital movie of the optical sky, variability-based active galactic nucleus (AGN) selection will enable the construction of highly complete catalogs with minimum contamination. In this study, we generate g-band difference images and construct light curves (LCs) for QSO/AGN candidates listed in Sloan Digital Sky Survey Stripe 82 public catalogs compiled from different methods, including spectroscopy, optical colors, variability, and X-ray detection. Image differencing excels at identifying variable sources embedded in complex or blended emission regions such as Type II AGNs and other low-luminosity AGNs that may be omitted from traditional photometric or spectroscopic catalogs. To separate QSOs/AGNs from other sources using our difference image LCs, we explore several LC statistics and parameterize optical variability by the characteristic damping timescale (τ) and variability amplitude. By virtue of distinguishable variability parameters of AGNs, we are able to select them with high completeness of 93.4% and efficiency (i.e., purity) of 71.3%. Based on optical variability, we also select highly variable blazar candidates, whose infrared colors are consistent with known blazars. One-third of them are also radio detected. With the X-ray selected AGN candidates, we probe the optical variability of X-ray detected optically extended sources using their difference image LCs for the first time. A combination of optical variability and X-ray detection enables us to select various types of host-dominated AGNs. Contrary to the AGN unification model prediction, two Type II AGN candidates (out of six) show detectable variability on long-term timescales like typical Type I AGNs. This study will provide a baseline for future optical variability studies of extended sources.

  11. Ankle torque steadiness is related to muscle activation variability and co-activation in children with cerebral palsy

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Rose, Martin; Sløk, Rikke

    2009-01-01

    The aims of this study were to: (1) investigate the significance of muscle activation variability and coactivation for the ability to perform steady submaximal ankle torque (torque steadiness) in healthy children and those with cerebral palsy (CP), and (2) assess ankle function during isometric...... contractions in those children. Fourteen children with CP who walked with equinus foot deformity and 14 healthy (control) children performed maximal and steady submaximal ankle dorsi- and plantarflexions. Dorsiflexion torque steadiness was related to agonist and antagonist muscle activation variability as well...

  12. Variability of activity profile during medium-sided games in professional soccer.

    Science.gov (United States)

    Rago, Vincenzo; Silva, João R; Mohr, Magni; Barreira, Daniel; Krustrup, Peter; Rebelo, António N

    2018-04-24

    In Southern European countries it is very frequent to perform medium-sized games (MSG) as last training drill. We analyzed the individual variability and changes in activity patterns during MSG throughout the preseason. Activity profile during MSGs (10v10+goalkeepers, duration: 10-min, field length: 50 m, width: 90 m, area per player: 204.5 m2) was quantified using a GPS in 14 professional male players (6 defenders, 5 midfielders 5 and attackers). Inter-individual variability was higher for high-intensity (HIR), very-high speed (VHS), maximum acceleration (Accmax) and maximum deceleration (Decmax) distance (CV=25.2 to 43.3%), compared to total distance (TD), total acceleration (Acctot) and total deceleration (Dectot) distance (CV= 8.3 to 18.3 %). Defenders showed higher variability in TD, HIR, VHS, Acctot and Dectot (ES= 1.30 to 11.28) compared to the other field positions, whereas attackers showed higher variability in HIR, VHS Accmax and Decmax (ES=-4.92 to 2.07) than other the field positions. Variability in TD regularly increased (ES= -2.13 to -0.91) towards the end of the preseason, while HIR and VHS variability tended to increase over the 3rd and the 4th preseason week (ES=-0.94 to -3.05). However, the behavior of variability across the preseason period was more unpredictable for Acctot and Dectot, both decreasing in the 3rd week (ES= 0.70 to 1.20), while Decmax increased in the 4th week (ES=-0.91±0.59). During MSGs, individual variability of activity differs among field positions, and tends to increase with either speed or acceleration intensity, underlining the need of an individualized approach for training load monitoring.

  13. Programmed Cell-to-Cell Variability in Ras Activity Triggers Emergent Behaviors during Mammary Epithelial Morphogenesis

    Directory of Open Access Journals (Sweden)

    Jennifer S. Liu

    2012-11-01

    Full Text Available Variability in signaling pathway activation between neighboring epithelial cells can arise from local differences in the microenvironment, noisy gene expression, or acquired genetic changes. To investigate the consequences of this cell-to-cell variability in signaling pathway activation on coordinated multicellular processes such as morphogenesis, we use DNA-programmed assembly to construct three-dimensional MCF10A microtissues that are mosaic for low-level expression of activated H-Ras. We find two emergent behaviors in mosaic microtissues: cells with activated H-Ras are basally extruded or lead motile multicellular protrusions that direct the collective motility of their wild-type neighbors. Remarkably, these behaviors are not observed in homogeneous microtissues in which all cells express the activated Ras protein, indicating that heterogeneity in Ras activity, rather than the total amount of Ras activity, is critical for these processes. Our results directly demonstrate that cell-to-cell variability in pathway activation within local populations of epithelial cells can drive emergent behaviors during epithelial morphogenesis.

  14. Stardust Blazes MOA Trail

    Science.gov (United States)

    Faris, Grant B.; Bryant, Larry W.

    2010-01-01

    Mission Operations Assurance (MOA) started at the Jet Propulsion Laboratory (JPL) with the Magellan and Galileo missions of the late 80's. It continued to develop and received a significant impetus with the failures of two successive missions to Mars in the late 90's. MOA continued to evolve with each successive project at JPL achieving its current maturity with the Stardust sample return to Earth.

  15. Spatial and Temporal Variability and Trends in 2001-2016 Global Fire Activity

    Science.gov (United States)

    Earl, Nick; Simmonds, Ian

    2018-03-01

    Fire regimes across the globe have great spatial and temporal variability, and these are influence by many factors including anthropogenic management, climate, and vegetation types. Here we utilize the satellite-based "active fire" product, from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, to statistically analyze variability and trends in fire activity from the global to regional scales. We split up the regions by economic development, region/geographical land use, clusters of fire-abundant areas, or by religious/cultural influence. Weekly cycle tests are conducted to highlight and quantify part of the anthropogenic influence on fire regime across the world. We find that there is a strong statistically significant decline in 2001-2016 active fires globally linked to an increase in net primary productivity observed in northern Africa, along with global agricultural expansion and intensification, which generally reduces fire activity. There are high levels of variability, however. The large-scale regions exhibit either little change or decreasing in fire activity except for strong increasing trends in India and China, where rapid population increase is occurring, leading to agricultural intensification and increased crop residue burning. Variability in Canada has been linked to a warming global climate leading to a longer growing season and higher fuel loads. Areas with a strong weekly cycle give a good indication of where fire management is being applied most extensively, for example, the United States, where few areas retain a natural fire regime.

  16. Exploring associations between parental and peer variables, personal variables and physical activity among adolescents: a mediation analysis.

    Science.gov (United States)

    Verloigne, Maïté; Veitch, Jenny; Carver, Alison; Salmon, Jo; Cardon, Greet; De Bourdeaudhuij, Ilse; Timperio, Anna

    2014-09-18

    This study aimed to investigate how parental and peer variables are associated with moderate- to-vigorous intensity physical activity (MVPA) on week- and weekend days among Australian adolescents (13-15 y), and whether perceived internal barriers (e.g. lack of time), external barriers (e.g. lack of others to be physically active with) and self-efficacy mediated these associations. Cross-sectional data were drawn from the Health, Eating and Play Study, conducted in Melbourne, Australia. Adolescents (mean age = 14.11 ± 0.59 years, 51% girls) and one of their parents completed a questionnaire and adolescents wore an ActiGraph accelerometer for a week (n = 134). Mediating effects of perceived barriers and self-efficacy were tested using MacKinnon's product-of-coefficients test based on multilevel linear regression analyses. Parental logistic support was positively related to MVPA on weekdays (τ = 0.035) and weekend days (τ = 0.078), peer interest (τ =0.036) was positively related to MVPA on weekdays, and parental control (τ = -0.056) and parental concern (τ = -0.180) were inversely related to MVPA on weekdays. Internal barriers significantly mediated the association between parental logistic support and MVPA on weekdays (42.9% proportion mediated). Self-efficacy and external barriers did not mediate any association. Interventions aiming to increase adolescents' MVPA should involve parents, as parental support may influence MVPA on weekdays by reducing adolescents' perceived internal barriers. Longitudinal and experimental research is needed to confirm these findings and to investigate other personal mediators.

  17. X-ray spectra and time variability of active galactic nuclei

    International Nuclear Information System (INIS)

    Mushotzky, R.F.

    1984-02-01

    The X-ray spectra of broad line active galactic nuclei (AGN) of all types (Seyfert I's, NELG's, broadline radio galaxies) are well fit by a power law in the .5 to 100 keV band of man energy slope alpha .68 + or - .15. There is, as yet, no strong evidence for time variability of this slope in a given object. The constraints that this places on simple models of the central energy source are discussed. BL Lac objects have quite different X-ray spectral properties and show pronounced X-ray spectral variability. On time scales longer than 12 hours most radio quiet AGN do not show strong, delta I/I .5, variability. The probability of variability of these AGN seems to be inversely related to their luminosity. However characteristics timescales for variability have not been measured for many objects. This general lack of variability may imply that most AGN are well below the Eddington limit. Radio bright AGN tend to be more variable than radio quiet AGN on long, tau approx 6 month, timescales

  18. The discrete and localized nature of the variable emission from active regions

    Science.gov (United States)

    Arndt, Martina Belz; Habbal, Shadia Rifai; Karovska, Margarita

    1994-01-01

    Using data from the Extreme Ultraviolet (EUV) Spectroheliometer on Skylab, we study the empirical characteristics of the variable emission in active regions. These simultaneous multi-wavelength observations clearly confirm that active regions consist of a complex of loops at different temperatures. The variable emission from this complex has very well-defined properties that can be quantitatively summarized as follows: (1) It is localized predominantly around the footpoints where it occurs at discrete locations. (2) The strongest variability does not necessarily coincide with the most intense emission. (3) The fraction of the area of the footpoints, (delta n)/N, that exhibits variable emission, varies by +/- 15% as a function of time, at any of the wavelengths measured. It also varies very little from footpoint to footpoint. (4) This fractional variation is temperature dependent with a maximum around 10(exp 5) K. (5) The ratio of the intensity of the variable to the average background emission, (delta I)/(bar-I), also changes with temperature. In addition, we find that these distinctive characteristics persist even when flares occur within the active region.

  19. Ankle torque steadiness is related to muscle activation variability and coactivation in children with cerebral palsy

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Rose, Martin Høyer; Sløk, Rikke

    2009-01-01

    The aims of this study were to: (1) investigate the significance of muscle activation variability and coactivation for the ability to perform steady submaximal ankle torque (torque steadiness) in healthy children and those with cerebral palsy (CP), and (2) assess ankle function during isometric...

  20. Physical activity, mindfulness meditation, or heart rate variability biofeedback for stress reduction: a randomized controlled trial

    NARCIS (Netherlands)

    van der Zwan, J.E.; de Vente, W.; Huizink, A.C.; Bögels, S.M.; de Bruin, E.I.

    2015-01-01

    In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing

  1. On the achievable performance using variable geometry active secondary suspension systems in commercial vehicles

    NARCIS (Netherlands)

    Evers, W.J.; Besselink, I.G.M.; Teerhuis, A.P.; Nijmeijer, H.

    2011-01-01

    There is a need to further improve driver comfort in commercial vehicles. The variable geometry active suspension offers an interesting option to achieve this in an energy efficient way. However, the optimal control strategy and the overal performance potential remains unclear. The aim of this paper

  2. Comparative study of anthropometric variables in female classical ballet dancers, volleyball players and physically active subjects

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Vaz

    2009-01-01

    Full Text Available The objective of this study was to compare anthropometric variables (body weight, height, and percent body fat and plantarflexion and dorsiflexion range of motion (ROM between three different groups of women: classical ballet dancers (n=14, volleyball players (n=22 and physically active subjects (n=13. The assumption was that different functional requirements should produce differences in the anthropometric variables and ROM between the three groups. Body weight and height were higher in volleyball players (66.42 ± 5.8 kg; 174.77 ± 5.6 cm, followed by physically active women (59.93 ±10.3 kg; 164 ± 7.5 cm and ballet dancers (49.25 ± 4.5 kg; 157.03 ± 3.6 cm (p<0.05. Percent body fat was higher in physically active women (30.67 ± 4.6% compared to theother two groups, which showed similar percentages (volleyball players: 24.93 ± 4.1%; ballet dancers: 21.94 ± 4.3%. The three groups were similar in terms of total ankle ROM and active dorsiflexion ROM between the right and left sides. However, plantarflexion ROM was higher in ballet dancers (~83°, followed by physically active women (~68° and volleyball players who presented the smallest ROM (~60°. The different requirements imposed by the three distinct physical activities seem to be responsible for changes in some of the anthropometric variables and ankle joint ROM.

  3. Active pauses induce more variable electromyographic pattern of the trapezius muscle activity during computer work

    DEFF Research Database (Denmark)

    Samani, Afshin; Holtermann, Andreas; Søgaard, Karen

    2009-01-01

    , with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 2 min at two different work paces (low/high). Bipolar SEMG from four parts of the trapezius muscle was recorded. The relative rest time was higher for the lower parts compared with the upper......The aim of this laboratory study was to evaluate effects of active and passive pauses and investigate the distribution of the trapezius surface electromyographic (SEMG) activity during computer mouse work. Twelve healthy male subjects performed four sessions of computer work for 10 min in one day...... of the trapezius (pwork with active pause compared with passive one (p

  4. Anatomic and Pathologic Variability During Radiotherapy for a Hybrid Active Breath-Hold Gating Technique

    International Nuclear Information System (INIS)

    Glide-Hurst, Carri K.; Gopan, Ellen; Hugo, Geoffrey D.

    2010-01-01

    Purpose: To evaluate intra- and interfraction variability of tumor and lung volume and position using a hybrid active breath-hold gating technique. Methods and Materials: A total of 159 repeat normal inspiration active breath-hold CTs were acquired weekly during radiotherapy for 9 lung cancer patients (12-21 scans per patient). A physician delineated the gross tumor volume (GTV), lungs, and spinal cord on the first breath-hold CT, and contours were propagated semiautomatically. Intra- and interfraction variability of tumor and lung position and volume were evaluated. Tumor centroid and border variability were quantified. Results: On average, intrafraction variability of lung and GTV centroid position was 0.1). Increases in free-breathing tidal volume were associated with increases in breath-hold ipsilateral lung volume (p < 0.05). Conclusions: The breath-hold technique was reproducible within 2 mm during each fraction. Interfraction variability of GTV position and shape was substantial because of tumor volume and breath-hold lung volume change during therapy. These results support the feasibility of a hybrid breath-hold gating technique and suggest that online image guidance would be beneficial.

  5. Match-to-match variability in high-speed running activity in a professional soccer team.

    Science.gov (United States)

    Carling, Christopher; Bradley, Paul; McCall, Alan; Dupont, Gregory

    2016-12-01

    This study investigated variability in competitive high-speed running performance in an elite soccer team. A semi-automated tracking system quantified running performance in 12 players over a season (median 17 matches per player, 207 observations). Variability [coefficient of variation (CV)] was compared for total sprint distance (TSD, >25.2 km/h), high-speed running (HSR, 19.8-25.2 km/h), total high-speed running (THSR, ≥19.8 km/h); THSR when the team was in and out of ball possession, in individual ball possession, in the peak 5 min activity period; and distance run according to individual maximal aerobic speed (MAS). Variability for % declines in THSR and distance covered at ≥80% MAS across halves, at the end of play (final 15 min vs. mean for all 15 min periods) and transiently (5 min period following peak 5 min activity period), was analysed. Collectively, variability was higher for TSD versus HSR and THSR and lowest for distance run at ≥80% MAS (CVs: 37.1%, 18.1%, 19.8% and 11.8%). THSR CVs when the team was in/out of ball possession, in individual ball possession and during the peak 5 min period were 31.5%, 26.1%, 60.1% and 23.9%. Variability in THSR declines across halves, at the end of play and transiently, ranged from 37.1% to 142.6%, while lower CVs were observed in these metrics for running at ≥80% MAS (20.9-53.3%).These results cast doubt on the appropriateness of general measures of high-speed activity for determining variability in an elite soccer team, although individualisation of HSR thresholds according to fitness characteristics might provide more stable indicators of running performance and fatigue occurrence.

  6. Cardiovascular Reactivity: its Association with Physical Activity, and Some Hemodynamic and Anthropometric Variables

    Directory of Open Access Journals (Sweden)

    Milagros Lisset León Regal

    2016-09-01

    Full Text Available Background: several studies show the influence of physical activity as a protective factor of the cardiovascular system. New evidence forcorroborating this are needed to ensure the prevention of cardiovascular disease. Objective: to determine the relationship between cardiovascular hyperactivity, physical activity and some homodynamic and anthropometric variables in normotensive individuals. Methods: a descriptive correlational cross-sectional study was conducted. The universe of the study consisted of the population between 15 and 74 of the municipality of Cienfuegos in 2010, the sample was 644. The variables were considered: sex, skin colour, age, height, weight, index of body mass, abdominal waist, blood pressures: systolic, diastolic, average and differential (basal and sustained weight test and physical activity. Pearson Chi- square test was calculated and t was applied for comparison of average independent samples with a significance level of p = 0,05. Prevalence ratios were determined with a confidence interval of 95 %. Results: the prevalence of cardiovascular hyperactivity was higher in the group of 65-74 years and males. Cardiovascular hyperactives showed values of the average hemodynamic variables studied cardiovascular over normoreactive. There is an association between physical activity and better cardiovascular response in normal weight individuals. Conclusions: there is an association between increased blood pressure and obesity in cardiovascular hyperactivity. Physical activity is associated with cardiovascular normoreactivity in normal weight.

  7. Spatial variability of caesium-137 activities in soils in the Jura mountains

    International Nuclear Information System (INIS)

    Pimou-Heumou, G.; Lucot, E.; Crini, N.; Briot, M.; Badot, P.M.

    2011-01-01

    275 soil samples were taken in the catchment area of the upper part of the Doubs river located in the Jura mountains according to a sampling strategy designed to evaluate the extent of the spatial variability of 137 Cs activities and to identify its main sources. 137 Cs activities ranged between about 1000 and 12000 Bq.m -2 with an average of approximately 3600 Bq.m -2 . The spatial variability of the contamination is high: 137 Cs activity shows statistically significant links with altitude, soil organic matter and land cover, whereas the other studied parameters, i.e. soil type and topographic position, do not constitute significant sources of variation. These results are discussed in terms of evaluation of the radioactive contamination on a regional scale. They show that to be satisfactory, a sampling strategy must necessarily take into account the various types of land cover. (authors)

  8. Electrical Activity in a Time-Delay Four-Variable Neuron Model under Electromagnetic Induction

    Directory of Open Access Journals (Sweden)

    Keming Tang

    2017-11-01

    Full Text Available To investigate the effect of electromagnetic induction on the electrical activity of neuron, the variable for magnetic flow is used to improve Hindmarsh–Rose neuron model. Simultaneously, due to the existence of time-delay when signals are propagated between neurons or even in one neuron, it is important to study the role of time-delay in regulating the electrical activity of the neuron. For this end, a four-variable neuron model is proposed to investigate the effects of electromagnetic induction and time-delay. Simulation results suggest that the proposed neuron model can show multiple modes of electrical activity, which is dependent on the time-delay and external forcing current. It means that suitable discharge mode can be obtained by selecting the time-delay or external forcing current, which could be helpful for further investigation of electromagnetic radiation on biological neuronal system.

  9. Active Power Filter DC Bus Voltage Piecewise Reaching Law Variable Structure Control

    Directory of Open Access Journals (Sweden)

    Baolian Liu

    2014-01-01

    Full Text Available The DC bus voltage stability control is one key technology to ensure that Active Power Filter (APF operates stably. The external disturbances such as power grid and load fluctuation and the system parameters changing may affect the stability of APF DC bus voltage and the normal operation of APF. The mathematical model of DC bus voltage is established according to power balance principle and a DC bus voltage piecewise reaching law variable structure control algorithm is proposed to solve the above problem, and the design method is given. The simulation and experiment results proved that the proposed variable structure control algorithm can eliminate the chattering problem existing in traditional variable structure control effectively, is insensitive to system disturbance, and has good robustness and fast dynamic response speed and stable DC bus voltage with small fluctuation. The above advantages ensure the compensation effect of APF.

  10. Sediment microbial activity and its relation to environmental variables along the eastern Gulf of Finland coastline

    Science.gov (United States)

    Polyak, Yulia; Shigaeva, Tatyana; Gubelit, Yulia; Bakina, Ludmila; Kudryavtseva, Valentina; Polyak, Mark

    2017-07-01

    Sediment microbial activity and its relationship with the main environmental factors and pollutants were examined in the coastal area of the eastern Gulf of Finland, Baltic Sea. The activity of two common oxidoreductase enzymes: dehydrogenase (DA) and catalase (CA) varied significantly between 13 study sites. In the Neva Bay the highest microbial activities (DA: 2.64 mg TFF (10 g- 1) day- 1, CA: 6.29 mg H2O2 g- 1) were recorded, while in the outer estuary the minimum values of dehydrogenase and catalase were measured. DA, CA, and abundances of culturable heterotrophic bacteria (CHB) were positively correlated with each other, while biomass of green opportunistic algae was independent of both microbial activities and CHB. Enzymatic activity was found to be strongly positively correlated with sediment particle size and organic matter content, but unrelated to the other studied environmental parameters (temperature, pH, and salinity). Principal components analysis (PCA), controlling for environmental variables, supported direct effects of metal and oil contamination on sediment microbial activity. Also it had shown the similar patterns for algal biomass and metals. Our results suggest that copper and hydrocarbons are the main anthropogenic variables influencing enzyme distribution along the eastern Gulf of Finland coastline.

  11. LASR-Guided Variability Subtraction: The Linear Algorithm for Significance Reduction of Stellar Seismic Activity

    Science.gov (United States)

    Horvath, Sarah; Myers, Sam; Ahlers, Johnathon; Barnes, Jason W.

    2017-10-01

    Stellar seismic activity produces variations in brightness that introduce oscillations into transit light curves, which can create challenges for traditional fitting models. These oscillations disrupt baseline stellar flux values and potentially mask transits. We develop a model that removes these oscillations from transit light curves by minimizing the significance of each oscillation in frequency space. By removing stellar variability, we prepare each light curve for traditional fitting techniques. We apply our model to $\\delta$-Scuti KOI-976 and demonstrate that our variability subtraction routine successfully allows for measuring bulk system characteristics using traditional light curve fitting. These results open a new window for characterizing bulk system parameters of planets orbiting seismically active stars.

  12. Semi-active variable stiffness vibration control of vehicle seat suspension using an MR elastomer isolator

    International Nuclear Information System (INIS)

    Du, Haiping; Li, Weihua; Zhang, Nong

    2011-01-01

    This paper presents a study on continuously variable stiffness control of vehicle seat suspension using a magnetorheological elastomer (MRE) isolator. A concept design for an MRE isolator is proposed in the paper and its behavior is experimentally evaluated. An integrated seat suspension model, which includes a quarter-car suspension and a seat suspension with a driver body model, is used to design a sub-optimal H ∞ controller for an active isolator. The desired control force generated by this active isolator is then emulated by the MRE isolator through its continuously variable stiffness property when the actuating condition is met. The vibration control effect of the MRE isolator is evaluated in terms of driver body acceleration responses under both bump and random road conditions. The results show that the proposed control strategy achieves better vibration reduction performance than conventional on–off control

  13. Active Power Filter DC Bus Voltage Piecewise Reaching Law Variable Structure Control

    OpenAIRE

    Liu, Baolian; Ding, Zujun; Zhao, Huanyu; Jin, Defei

    2014-01-01

    The DC bus voltage stability control is one key technology to ensure that Active Power Filter (APF) operates stably. The external disturbances such as power grid and load fluctuation and the system parameters changing may affect the stability of APF DC bus voltage and the normal operation of APF. The mathematical model of DC bus voltage is established according to power balance principle and a DC bus voltage piecewise reaching law variable structure control algorithm is proposed to solve the ...

  14. Linear variable differential transformer sensor using glass-covered amorphous wires as active core

    International Nuclear Information System (INIS)

    Chiriac, H.; Hristoforou, E.; Neagu, Maria; Pieptanariu, M.

    2000-01-01

    Results concerning linear variable differential transformer (LVDT) displacement sensor using as movable core glass-covered amorphous wires are presented. The LVDT response is linear for a displacement of the movable core up to about 14 mm, with an accuracy of 1 μm. LVDT using glass-covered amorphous wire as an active core presents a high sensitivity and good mechanical and corrosion resistance

  15. EPSPS variability, gene expression, and enzymatic activity in glyphosate-resistant biotypes of Digitaria insularis.

    Science.gov (United States)

    Galeano, E; Barroso, A A M; Vasconcelos, T S; López-Rubio, A; Albrecht, A J P; Victoria Filho, R; Carrer, H

    2016-08-12

    Weed resistance to herbicides is a natural phenomenon that exerts selection on individuals in a population. In Brazil, glyphosate resistance was recently detected in Digitaria insularis. The objective of this study was to elucidate mechanisms of weed resistance in this plant, including genetic variability, allelism, amino acid substitutions, gene expression, and enzymatic activity levels. Most of these have not previously been studied in this species. D. insularis DNA sequences were used to analyze genetic variability. cDNA from resistant and susceptible plants was used to identify mutations, alleles, and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) expression, using real-time quantitative reverse transcription-polymerase chain reaction. In addition, EPSPS activity was measured. We found a decrease in genetic variability between populations related to glyphosate application. Substitutions from proline to threonine and tyrosine to cysteine led to a decrease in EPSPS affinity for the glyphosate. In addition, the EPSPS enzymatic activity was slightly higher in resistant plants, whereas EPSPS gene expression was almost identical in both biotypes, suggesting feedback regulation at different levels. To conclude, our results suggest new molecular mechanisms used by D. insularis to increase glyphosate resistance.

  16. Information content of neural networks with self-control and variable activity

    International Nuclear Information System (INIS)

    Bolle, D.; Amari, S.I.; Dominguez Carreta, D.R.C.; Massolo, G.

    2001-01-01

    A self-control mechanism for the dynamics of neural networks with variable activity is discussed using a recursive scheme for the time evolution of the local field. It is based upon the introduction of a self-adapting time-dependent threshold as a function of both the neural and pattern activity in the network. This mechanism leads to an improvement of the information content of the network as well as an increase of the storage capacity and the basins of attraction. Different architectures are considered and the results are compared with numerical simulations

  17. Active galactic nucleus X-ray variability in the XMM-COSMOS survey

    Energy Technology Data Exchange (ETDEWEB)

    Lanzuisi, G.; Ponti, G.; Salvato, M.; Brusa, M.; Nandra, P. K.; Merloni, A.; Rosario, D. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Hasinger, G.; Sanders, D. [Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822-1839 (United States); Cappelluti, N.; Comastri, A.; Gilli, R. [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Bongiorno, A. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Roma Via Frascati 33, I-00040, Monte Porzio Catone (Italy); Lusso, E.; Steinhardt, C. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Silverman, J.; Schramm, M. [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) 5-1-5 Kashiwanoha Kashiwa, Chiba 277-8583 (Japan); Trump, J. [University of California Observatories/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Vignali, C. [Dipartimento di Fisica e Astronomia, Universitá di Bologna, viale Berti Pichat 6/2, I-40127 Bologna (Italy); Kartaltepe, J., E-mail: lanzuisi@noa.gr [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); and others

    2014-02-01

    We used the observations carried out by XMM in the COSMOS field over 3.5 yr to study the long term variability of a large sample of active galactic nuclei (AGNs) (638 sources) in a wide range of redshifts (0.1 < z < 3.5) and X-ray luminosities (10{sup 41} < L {sub 0.5-10} <10{sup 45.5}). Both a simple statistical method to assess the significance of variability and the Normalized Excess Variance (σ{sub rms}{sup 2}) parameter were used to obtain a quantitative measurement of the variability. Variability is found to be prevalent in most AGNs, whenever we have good statistics to measure it, and no significant differences between type 1 and type 2 AGNs were found. A flat (slope –0.23 ± 0.03) anti-correlation between σ{sub rms}{sup 2} and X-ray luminosity is found when all significantly variable sources are considered together. When divided into three redshift bins, the anti-correlation becomes stronger and evolving with z, with higher redshift AGNs being more variable. We prove, however, that this effect is due to the pre-selection of variable sources: when considering all of the sources with an available σ{sub rms}{sup 2} measurement, the evolution in redshift disappears. For the first time, we were also able to study long term X-ray variability as a function of M {sub BH} and Eddington ratio for a large sample of AGNs spanning a wide range of redshifts. An anti-correlation between σ{sub rms}{sup 2} and M {sub BH} is found, with the same slope of anti-correlation between σ{sub rms}{sup 2} and X-ray luminosity, suggesting that the latter may be a by-product of the former. No clear correlation is found between σ{sub rms}{sup 2} and the Eddington ratio in our sample. Finally, no correlation is found between the X-ray σ{sub rms}{sup 2} and optical variability.

  18. Population activity statistics dissect subthreshold and spiking variability in V1.

    Science.gov (United States)

    Bányai, Mihály; Koman, Zsombor; Orbán, Gergő

    2017-07-01

    variability. Our work shows that stimulus-dependent changes in pairwise but not in single-cell statistics can differentiate between two widely used models of neuronal variability. Contrasting model predictions with neuronal data provides hints on the noise sources in spiking and provides constraints on statistical models of population activity. Copyright © 2017 the American Physiological Society.

  19. Stride dynamics, gait variability and prospective falls risk in active community dwelling older women.

    Science.gov (United States)

    Paterson, Kade; Hill, Keith; Lythgo, Noel

    2011-02-01

    Measures of walking instability such as stride dynamics and gait variability have been shown to identify future fallers in older adult populations with gait limitations or mobility disorders. This study investigated whether measures of walking instability can predict future fallers (over a prospective 12 month period) in a group of healthy and active older women. Ninety-seven healthy active women aged between 55 and 90 years walked for 7 min around a continuous walking circuit. Gait data recorded by a GAITRite(®) walkway and foot-mounted accelerometers were used to calculate measures of stride dynamics and gait variability. The participant's physical function and balance were assessed. Fall incidence was monitored over the following 12 months. Inter-limb differences (p≤0.04) in stride dynamics were found for fallers (one or more falls) aged over 70 years, and multiple fallers (two or more falls) aged over 55 years, but not in non-fallers or a combined group of single and non-fallers. No group differences were found in the measures of physical function, balance or gait, including variability. Additionally, no gait variable predicted falls. Reduced coordination of inter-limb dynamics was found in active healthy older fallers and multiple fallers despite no difference in other measures of intrinsic falls risk. Evaluating inter-limb dynamics may be a clinically sensitive technique to detect early gait instability and falls risk in high functioning older adults, prior to change in other measures of physical function, balance and gait. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Increasing Children's Voluntary Physical Activity Outside of School Hours Through Targeting Social Cognitive Theory Variables.

    Science.gov (United States)

    Annesi, James J; Walsh, Stephanie M; Greenwood, Brittney L

    2016-10-01

    Volume of moderate-to-vigorous physical activity completed during the elementary school day is insufficient, and associated with health risks. Improvements in theory-based psychosocial factors might facilitate increased out-of-school physical activity. A behaviorally based after-school care protocol, Youth Fit 4 Life, was tested for its association with increased voluntary, out-of-school physical activity and improvements in its theory-based psychosocial predictors in 9- to 12-year-olds. Increases over 12 weeks in out-of-school physical activity, and improvements in self-regulation for physical activity, exercise self-efficacy, and mood, were significantly greater in the Youth Fit 4 Life group (n = 88) when contrasted with a typical care control group (n = 57). Changes in the 3 psychosocial variables significantly mediated the group-physical activity change relationship (R(2) = .31, P theory-based psychosocial changes within a structured after-school care physical activity program was associated with increases in children's overall time being physically active. After replication, large scale application will be warranted. © The Author(s) 2016.

  1. Evaluation of sympathetic nerve system activity with MIBG. Comparison with heart rate variability

    International Nuclear Information System (INIS)

    Kurata, Chinori; Wakabayashi, Yasushi; Shouda, Sakae; Mikami, Tadashi; Tawarahara, Kei; Sugiyama, Tsuyoshi; Nakano, Tomoyasu; Suzuki, Toshihiko.

    1997-01-01

    Authors attempted to elucidate the relations of plasma concentration of norepinephrine (pNE) and findings of heart rate variability and MIBG myocardial scintigraphy and evaluated cardiac autonomic nervous activity in chronic renal failure. Subjects were 211 patients with various heart diseases (coronary artery lesion, cardiomyopathy, hypertension, diabetes mellitus, renal failure and so on), 60 patients with artificial kidney due to chronic renal failure, 13 of whom were found to have coronary arterial disease by Tl myocardial scintigraphy, and 14 normal volunteers. ECG was recorded with the portable recorder for heart rate variability. Together with collection of blood for pNE measurement, myocardial scintigraphy was done at 15 and 150 min after intravenous administration of 111 MBq of MIBG for acquisition of early and delayed, respectively, images of the frontal breast. Accumulation at and elimination during the time points of MIBG were computed in cps unit. Variability of heart rate was found to have the correlation positive with MIBG delayed accumulation and negative with the elimination, and pNE, negative with heart rate variability and the delayed accumulation and positive with the elimination. Thus cardiac autonomic nervous abnormality was suggested to occur before uremic cardiomyopathy. (K.H.)

  2. Sources of variability in the determination by evaporation method of gross alpha activity in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, A.; Corbacho, J.A. [LARUEX, Caceres (Spain). Environmental Radioactivity Lab.

    2013-07-01

    Determining the gross alpha activity concentration of water samples is one way to screen for waters whose radionuclide content is so high that its consumption could imply surpassing the Total Indicative Dose as defined in European Directive 98/83/EC. One of the most commonly used methods to prepare the sources to measure gross alpha activity in water samples is desiccation. Its main advantages are the simplicity of the procedure, the low cost of source preparation, and the possibility of simultaneously determining the gross beta activity. The preparation of the source, the construction of the calibration curves, and the measurement procedure itself involve, however, various factors that may introduce sufficient variability into the results to significantly affect the screening process. We here identify the main sources of this variability, and propose specific procedures to follow in the desiccation process that will reduce the uncertainties, and ensure that the result is indeed representative of the sum of the activities of the alpha emitters present in the sample. (orig.)

  3. Dose Response Association between Physical Activity and Biological, Demographic, and Perceptions of Health Variables

    Directory of Open Access Journals (Sweden)

    Paul D. Loprinzi

    2013-08-01

    Full Text Available Background: Few population-based studies have examined the association between physical activity (PA and cardiovascular disease risk factors, demographic variables, and perceptions of health status, and we do not have a clear understanding of the dose-response relationship among these variables. Methods: Data from the 2003-2006 National Health and Nutrition Examination Survey was used to examine the dose-response relationship between objectively measured PA and metabolic syndrome (and its individual cardiovascular disease risk factors, demographic variables, and perceptions of health. After exclusions, 5,538 participants 18 years or older were included in the present study, with 2,538 participants providing fasting glucose and 2,527 providing fasting triglyceride data. PA was categorized into deciles. Results: Overall, the health benefits showed a general pattern of increase with each increasing levels of PA. Of the ten PA classifications examined, participants in the highest moderate-to-vigorous physical activity (MVPA category (at least 71 min/day had the lowest odds of developing metabolic syndrome. Conclusion: At a minimum, sedentary adults should strive to meet current PA guidelines (i.e., 150 min/week of MVPA, with additional positive benefits associated with engaging in three times this level of PA.

  4. Variability and Stability in Daily Moderate-to-Vigorous Physical Activity among 10 Year Old Children

    Science.gov (United States)

    Pereira, Sara; Gomes, Thayse Natacha; Borges, Alessandra; Santos, Daniel; Souza, Michele; dos Santos, Fernanda K.; Chaves, Raquel N.; Katzmarzyk, Peter T.; Maia, José A. R.

    2015-01-01

    Day-to-day variability and stability of children’s physical activity levels across days of the week are not well understood. Our aims were to examine the day-to-day variability of moderate-to-vigorous physical activity (MVPA), to determine factors influencing the day-to-day variability of MVPA and to estimate stability of MVPA in children. The sample comprises 686 Portuguese children (10 years of age). MVPA was assessed with an accelerometer, and BMI was computed from measured height and weight. Daily changes in MVPA and their correlates (gender, BMI, and maturity) were modeled with a multilevel approach, and tracking was calculated using Foulkes & Davies γ. A total of 51.3% of boys and 26.2% of girls achieved 60 min/day of MVPA on average. Daily MVPA was lower during the weekend (23.6% of boys and 13.6% of girls comply with the recommended 60 min/day of MVPA) compared to weekdays (60.8% and 35.4%, boys and girls, respectively). Normal weight children were more active than obese children and no effect was found for biological maturation. Tracking is low in both boys (γ = 0.59 ± 0.01) and girls (γ = 0.56 ± 0.01). Children’s MVPA levels during a week are highly unstable. In summary, boys are more active than girls, maturation does not affect their MVPA, and obese children are less likely to meet 60 min/day of MVPA. These results highlight the importance of providing opportunities for increasing children’s daily MVPA on all days of week, especially on the weekend. PMID:26262632

  5. Respiratory symptoms and active tuberculosis in a prison in Southern Brazil: associated epidemiologic variables

    Directory of Open Access Journals (Sweden)

    Jeane Zanini Rocha

    2013-10-01

    Full Text Available Backgound and Objectives: This study is justified by the high TB prevalence in prisons, which constitutes a public health problem and aims to estimate the prevalence of active tuberculosis (TB and determine the variables associated with respiratory symptoms in a prison in Brazil. Methods: This is a descriptive study of 262 inmates divided into respiratory symptomatic and asymptomatic groups. Samples were evaluated by microscopy following the cultivation of the sputum from symptomatic individuals. Associated epidemiological variables were also evaluated. Results: Among the 262 inmates included, 178 (68% were considered symptomatic, and of these, 25 (14% were diagnosed with active TB. The contribution of culturing in the detection of TB cases was 48%. The prevalence of active TB was 9,542/100.000. Low educational level, use of drugs and alcohol, prison recidivism, and previous TB and HIV-positive status were associated with the presence of respiratory symptoms. Being male, single, black, a prison recidivist, an alcoholic and HIV-seropositive was associated with the development of TB. The rate of TB/HIV co infection was 60%. The outcome was death in 12% of patients. Drug therapy interruption was reported by 96% of patients. Conclusions: The studied population showed a high prevalence of TB and TB/HIV co-infection. In addition, the rates of drug therapy interruption and mortality were alarmingly elevated. KEYWORDS: Epidemiology. Tuberculosis. Coinfections. HIV infection. Prisons.

  6. Relationships between sea-bed radionuclide activities and some sedimentological variables

    International Nuclear Information System (INIS)

    Ligero, R.A.; Ramos-Lerate, I.; Barrera, M.; Casas-Ruiz, M.

    2001-01-01

    Natural radionuclides ( 232 Th, 226 Ra, 40 K) and 137 Cs, coming from atmospheric radioactive fallout, have been measured in sea-bed sediments of the Bay of Cadiz (South Western Spain). In this report, multivariate analysis methods have been employed to study the relationships between the activities of the radionuclides and some sedimentological variables like granulometric facies, organic content and apparent density. The correlation functions found show that it is possible to determine, with a satisfactory degree of approximation, the granulometric facies of the sediments using only radiometric information

  7. Construction of Blaze at the University of Illinois at Chicago: A Shared, High-Performance, Visual Computer for Next-Generation Cyberinfrastructure-Accelerated Scientific, Engineering, Medical and Public Policy Research

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Maxine D. [Acting Director, EVL; Leigh, Jason [PI

    2014-02-17

    The Blaze high-performance visual computing system serves the high-performance computing research and education needs of University of Illinois at Chicago (UIC). Blaze consists of a state-of-the-art, networked, computer cluster and ultra-high-resolution visualization system called CAVE2(TM) that is currently not available anywhere in Illinois. This system is connected via a high-speed 100-Gigabit network to the State of Illinois' I-WIRE optical network, as well as to national and international high speed networks, such as the Internet2, and the Global Lambda Integrated Facility. This enables Blaze to serve as an on-ramp to national cyberinfrastructure, such as the National Science Foundation’s Blue Waters petascale computer at the National Center for Supercomputing Applications at the University of Illinois at Chicago and the Department of Energy’s Argonne Leadership Computing Facility (ALCF) at Argonne National Laboratory. DOE award # DE-SC005067, leveraged with NSF award #CNS-0959053 for “Development of the Next-Generation CAVE Virtual Environment (NG-CAVE),” enabled us to create a first-of-its-kind high-performance visual computing system. The UIC Electronic Visualization Laboratory (EVL) worked with two U.S. companies to advance their commercial products and maintain U.S. leadership in the global information technology economy. New applications are being enabled with the CAVE2/Blaze visual computing system that is advancing scientific research and education in the U.S. and globally, and help train the next-generation workforce.

  8. Characterizing biological variability in livestock blood cholinesterase activity for biomonitoring organophosphate nerve agent exposure

    Energy Technology Data Exchange (ETDEWEB)

    Halbrook, R.S.; Shugart, L.R.; Watson, A.P.; Munro, N.B.; Linnabary, R.D. (Environmental Sciences Division, Oak Ridge National Laboratory, TN (United States))

    1992-09-01

    A biomonitoring protocol, using blood cholinesterase (ChE) activity in livestock as a monitor of potential organophosphate nerve agent exposure during the planned destruction of US unitary chemical warfare agent stockpiles, is described. The experimental design included analysis of blood ChE activity in individual healthy sheep, horses, and dairy and beef cattle during a 10- to 12-month period. Castrated and sexually intact males, pregnant and lactating females, and adult and immature animals were examined through at least one reproductive cycle. The same animals were used throughout the period of observation and were not exposed to ChE-inhibiting organophosphate or carbamate compounds. A framework for an effective biomonitoring protocol within a monitoring area includes establishing individual baseline blood ChE activity for a sentinel group of 6 animals on the bases of blood samples collected over a 6-month period, monthly collection of blood samples for ChE-activity determination during monitoring, and selection of adult animals as sentinels. Exposure to ChE-inhibiting compounds would be suspected when all blood ChE activity of all animals within the sentinel group are decreased greater than 20% from their own baseline value. Sentinel species selection is primarily a logistical and operational concern; however, sheep appear to be the species of choice because within-individual baseline ChE activity and among age and gender group ChE activity in sheep had the least variability, compared with data from other species. This protocol provides an effective and efficient means for detecting abnormal depressions in blood ChE activity in livestock and can serve as a valuable indicator of the extent of actual plume movement and/or deposition in the event of organophosphate nerve agent release.

  9. ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; Berian James, J. [Astronomy Department, University of California, Berkeley, CA 94720-7450 (United States); Brink, Henrik [Dark Cosmology Centre, Juliane Maries Vej 30, 2100 Copenhagen O (Denmark); Long, James P.; Rice, John, E-mail: jwrichar@stat.berkeley.edu [Statistics Department, University of California, Berkeley, CA 94720-7450 (United States)

    2012-01-10

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL-where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up-is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  10. ACTIVE LEARNING TO OVERCOME SAMPLE SELECTION BIAS: APPLICATION TO PHOTOMETRIC VARIABLE STAR CLASSIFICATION

    International Nuclear Information System (INIS)

    Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; Berian James, J.; Brink, Henrik; Long, James P.; Rice, John

    2012-01-01

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL—where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up—is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  11. Active Learning to Overcome Sample Selection Bias: Application to Photometric Variable Star Classification

    Science.gov (United States)

    Richards, Joseph W.; Starr, Dan L.; Brink, Henrik; Miller, Adam A.; Bloom, Joshua S.; Butler, Nathaniel R.; James, J. Berian; Long, James P.; Rice, John

    2012-01-01

    Despite the great promise of machine-learning algorithms to classify and predict astrophysical parameters for the vast numbers of astrophysical sources and transients observed in large-scale surveys, the peculiarities of the training data often manifest as strongly biased predictions on the data of interest. Typically, training sets are derived from historical surveys of brighter, more nearby objects than those from more extensive, deeper surveys (testing data). This sample selection bias can cause catastrophic errors in predictions on the testing data because (1) standard assumptions for machine-learned model selection procedures break down and (2) dense regions of testing space might be completely devoid of training data. We explore possible remedies to sample selection bias, including importance weighting, co-training, and active learning (AL). We argue that AL—where the data whose inclusion in the training set would most improve predictions on the testing set are queried for manual follow-up—is an effective approach and is appropriate for many astronomical applications. For a variable star classification problem on a well-studied set of stars from Hipparcos and Optical Gravitational Lensing Experiment, AL is the optimal method in terms of error rate on the testing data, beating the off-the-shelf classifier by 3.4% and the other proposed methods by at least 3.0%. To aid with manual labeling of variable stars, we developed a Web interface which allows for easy light curve visualization and querying of external databases. Finally, we apply AL to classify variable stars in the All Sky Automated Survey, finding dramatic improvement in our agreement with the ASAS Catalog of Variable Stars, from 65.5% to 79.5%, and a significant increase in the classifier's average confidence for the testing set, from 14.6% to 42.9%, after a few AL iterations.

  12. Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control

    Science.gov (United States)

    Nguyen, Nhan T. (Inventor)

    2016-01-01

    An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.

  13. Leisure time physical activity, screen time, social background, and environmental variables in adolescents.

    Science.gov (United States)

    Mota, Jorge; Gomes, Helena; Almeida, Mariana; Ribeiro, José Carlos; Santos, Maria Paula

    2007-08-01

    This study analyzes the relationships between leisure time physical activity (LTPA), sedentary behaviors, socioeconomic status, and perceived environmental variables. The sample comprised 815 girls and 746 boys. In girls, non-LTPA participants reported significantly more screen time. Girls with safety concerns were more likely to be in the non-LTPA group (OR = 0.60) and those who agreed with the importance of aesthetics were more likely to be in the active-LTPA group (OR = 1.59). In girls, an increase of 1 hr of TV watching was a significant predictor of non-LTPA (OR = 0.38). LTPA for girls, but not for boys, seems to be influenced by certain modifiable factors of the built environment, as well as by time watching TV.

  14. Comparative evaluation of activity-based costing and variable costing: a case study at IPEN

    International Nuclear Information System (INIS)

    Esteves, Josefina Maria da Silva SILVA

    2010-01-01

    This research aims to compare the results with the application of Activity Based Costing and Variable Costing methods in an administrative unit of the Brazilian Federal Government: the Radiopharmacy Facility of IPEN (Institute for Energy and Nuclear Research), which produces radiopharmaceuticals products and develops R and D activities. Faced with the need to adopt a more economical and managerial public administration, this research has provided information to assess which of the two costing methods proves more suitable for cost management in that unit. The research is exploratory and a single-case study. We traced about 80% of material costs by observation 'in loco' of the entire manufacturing process of technetium generator, which represents the main product in terms of production volume and revenues. The results show that the Contribution Margin Variable Costing of 29.12% is very close to the operating income of 28.86%, ahead of support activities, obtained by ABC. It is also noted that the operational result of the product does not change by using either one or another costing method. In the two costing methods the end result is 24.20%. This occurs because the production is on demand. There is no inventory of finished product because it is radioactive. The research has revealed that both methods provide useful information for the management and optimization of costs and results of processes/activities, and that the two methods, in this case, may be used in an integrated and complementary approach, enabling to use the best information content of both. (author)

  15. Physical activity levels of community-dwelling older adults are influenced by winter weather variables.

    Science.gov (United States)

    Jones, G R; Brandon, C; Gill, D P

    2017-07-01

    Winter weather conditions may negatively influence participation of older adults in daily physical activity (PA). Assess the influence of winter meteorological variables, day-time peak ambient temperature, windchill, humidity, and snow accumulation on the ground to accelerometer measured PA values in older adults. 50 community-dwelling older adults (77.4±4.7yrs; range 71-89; 12 females) living in Southwestern Ontario (Latitude 42.9°N Longitude 81.2° W) Canada, wore a waist-borne accelerometer during active waking hours (12h) for 7 consecutive days between February and April 2007. Hourly temperature, windchill, humidity, and snowfall accumulation were obtained from meteorological records and time locked to hourly accelerometer PA values. Regression analysis revealed significant relationships between time of day, ambient daytime high temperature and a humidity for participation in PA. Windchill temperature added no additional influence over PA acclamation already influenced by ambient day-time temperature and the observed variability in PA patterns relative to snow accumulation over the study period was too great to warrant its inclusion in the model. Most PA was completed in the morning hours and increased as the winter month's transitioned to spring (February through April). An equation was developed to adjust for winter weather conditions using temperature, humidity and time of day. Accurate PA assessment during the winter months must account for the ambient daytime high temperatures, humidity, and time of day. These older adults were more physically active during the morning hours and became more active as the winter season transitioned to spring. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Directory of Open Access Journals (Sweden)

    Lourdes Gallego-Calvo

    2015-12-01

    Full Text Available Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001. No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05. After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05. These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.

  17. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Energy Technology Data Exchange (ETDEWEB)

    Gallego-Calvo, L.; Gatica, M.C.; Santiago-Moreno, J.; Guzmán, J.L.; Zarazaga, L.

    2015-07-01

    Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer. (Author)

  18. Effect of process variables on the production of Polyhydroxyalkanoates by activated sludge

    Directory of Open Access Journals (Sweden)

    Mokhtarani Nader

    2012-09-01

    Full Text Available Abstract Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge and determining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogen ratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is much lower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  19. Effect of Process Variables on the Production of Polyhydroxyalkanoates by Activated Sludge

    Directory of Open Access Journals (Sweden)

    Nader Mokhtarani

    2012-09-01

    Full Text Available Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge anddetermining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogenratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is muchlower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  20. On heart rate variability and autonomic activity in homeostasis and in systemic inflammation.

    Science.gov (United States)

    Scheff, Jeremy D; Griffel, Benjamin; Corbett, Siobhan A; Calvano, Steve E; Androulakis, Ioannis P

    2014-06-01

    Analysis of heart rate variability (HRV) is a promising diagnostic technique due to the noninvasive nature of the measurements involved and established correlations with disease severity, particularly in inflammation-linked disorders. However, the complexities underlying the interpretation of HRV complicate understanding the mechanisms that cause variability. Despite this, such interpretations are often found in literature. In this paper we explored mathematical modeling of the relationship between the autonomic nervous system and the heart, incorporating basic mechanisms such as perturbing mean values of oscillating autonomic activities and saturating signal transduction pathways to explore their impacts on HRV. We focused our analysis on human endotoxemia, a well-established, controlled experimental model of systemic inflammation that provokes changes in HRV representative of acute stress. By contrasting modeling results with published experimental data and analyses, we found that even a simple model linking the autonomic nervous system and the heart confound the interpretation of HRV changes in human endotoxemia. Multiple plausible alternative hypotheses, encoded in a model-based framework, equally reconciled experimental results. In total, our work illustrates how conventional assumptions about the relationships between autonomic activity and frequency-domain HRV metrics break down, even in a simple model. This underscores the need for further experimental work towards unraveling the underlying mechanisms of autonomic dysfunction and HRV changes in systemic inflammation. Understanding the extent of information encoded in HRV signals is critical in appropriately analyzing prior and future studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Geographic Variability and Anti-Staphylococcal Activity of the Chrysophaentins and Their Synthetic Fragments

    Directory of Open Access Journals (Sweden)

    Jared T. Hammill

    2012-05-01

    Full Text Available Drug-resistant Staphylococcus aureus is a continuing public health concern, both in the hospital and community settings. Antibacterial compounds that possess novel structural scaffolds and are effective against multiple S. aureus strains, including current drug-resistant ones, are needed. Previously, we have described the chrysophaentins, a family of bisdiarylbutene macrocycles from the chrysophyte alga Chrysophaeum taylori that inhibit the growth of S. aureus and methicillin-resistant S. aureus (MRSA. In this study we have analyzed the geographic variability of chrysophaentin production in C. taylori located at different sites on the island of St. John, U.S. Virgin Islands, and identified two new linear chrysophaentin analogs, E2 and E3. In addition, we have expanded the structure activity relationship through synthesis of fragments comprising conserved portions of the chrysophaentins, and determined the antimicrobial activity of natural chrysophaentins and their synthetic analogs against five diverse S. aureus strains. We find that the chrysophaentins show similar activity against all S. aureus strains, regardless of their drug sensitivity profiles. The synthetic chrysophaentin fragments indeed mimic the natural compounds in their spectrum of antibacterial activity, and therefore represent logical starting points for future medicinal chemistry studies of the natural products and their analogs.

  2. Context matters! sources of variability in weekend physical activity among families: a repeated measures study

    Directory of Open Access Journals (Sweden)

    Robert J. Noonan

    2017-04-01

    Full Text Available Abstract Background Family involvement is an essential component of effective physical activity (PA interventions in children. However, little is known about the PA levels and characteristics of PA among families. This study used a repeated measures design and multiple data sources to explore the variability and characteristics of weekend PA among families. Methods Families (including a ‘target’ child aged 9–11 years, their primary caregiver(s and siblings aged 6–8 years were recruited through primary schools in Liverpool, UK. Participants completed a paper-based PA diary and wore an ActiGraph GT9X accelerometer on their left wrist for up to 16 weekend days. ActiGraph.csv files were analysed using the R-package GGIR version 1.1–4. Mean minutes of moderate-to-vigorous PA (MVPA for each weekend of measurement were calculated using linear mixed models, and variance components were estimated for participant (inter-individual, weekend of measurement, and residual error (intra-individual. Intraclass correlation coefficients (ICC were calculated from the proportion of total variance accounted for by inter-individual sources, and used as a measure of reliability. Diary responses were summed to produce frequency counts. To offer contextual insight into weekend PA among family units, demographic, accelerometer, and diary data were combined to form two case studies representative of low and high active families. Results Twenty-five participants from 7 families participated, including 7 ‘target’ children (mean age 9.3 ± 1.1 years, 4 boys, 6 siblings (mean age 7.2 ± 0.7 years; 4 boys and 12 adults (7 mothers and 5 fathers. There was a high degree of variability in target children’s (ICC = 0.55, siblings (ICC = 0.38, and mothers’ MVPA (ICC = 0.58, but not in fathers’ MVPA (ICC = 0.83. Children’s weekend PA was mostly unstructured in nature and undertaken with friends, whereas a greater proportion of parents’ weekend

  3. MEASURING X-RAY VARIABILITY IN FAINT/SPARSELY SAMPLED ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Allevato, V. [Department of Physics, University of Helsinki, Gustaf Haellstroemin katu 2a, FI-00014 Helsinki (Finland); Paolillo, M. [Department of Physical Sciences, University Federico II, via Cinthia 6, I-80126 Naples (Italy); Papadakis, I. [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, 71003 Heraklion (Greece); Pinto, C. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584-CA Utrecht (Netherlands)

    2013-07-01

    We study the statistical properties of the normalized excess variance of variability process characterized by a ''red-noise'' power spectral density (PSD), as in the case of active galactic nuclei (AGNs). We perform Monte Carlo simulations of light curves, assuming both a continuous and a sparse sampling pattern and various signal-to-noise ratios (S/Ns). We show that the normalized excess variance is a biased estimate of the variance even in the case of continuously sampled light curves. The bias depends on the PSD slope and on the sampling pattern, but not on the S/N. We provide a simple formula to account for the bias, which yields unbiased estimates with an accuracy better than 15%. We show that the normalized excess variance estimates based on single light curves (especially for sparse sampling and S/N < 3) are highly uncertain (even if corrected for bias) and we propose instead the use of an ''ensemble estimate'', based on multiple light curves of the same object, or on the use of light curves of many objects. These estimates have symmetric distributions, known errors, and can also be corrected for biases. We use our results to estimate the ability to measure the intrinsic source variability in current data, and show that they could also be useful in the planning of the observing strategy of future surveys such as those provided by X-ray missions studying distant and/or faint AGN populations and, more in general, in the estimation of the variability amplitude of sources that will result from future surveys such as Pan-STARRS and LSST.

  4. A standardized approach to study human variability in isometric thermogenesis during low-intensity physical activity

    Directory of Open Access Journals (Sweden)

    Delphine eSarafian

    2013-07-01

    Full Text Available Limitations of current methods: The assessment of human variability in various compartments of daily energy expenditure (EE under standardized conditions is well defined at rest (as basal metabolic rate and thermic effect of feeding, and currently under validation for assessing the energy cost of low-intensity dynamic work. However, because physical activities of daily life consist of a combination of both dynamic and isometric work, there is also a need to develop standardized tests for assessing human variability in the energy cost of low-intensity isometric work.Experimental objectives: Development of an approach to study human variability in isometric thermogenesis by incorporating a protocol of intermittent leg press exercise of varying low-intensity isometric loads with measurements of EE by indirect calorimetry. Results: EE was measured in the seated position with the subject at rest or while intermittently pressing both legs against a press-platform at 5 low-intensity isometric loads (+5, +10, + 15, +20 and +25 kg force, each consisting of a succession of 8 cycles of press (30 s and rest (30 s. EE, integrated over each 8-min period of the intermittent leg press exercise, was found to increase linearly across the 5 isometric loads with a correlation coefficient (r > 0.9 for each individual. The slope of this EE-Load relationship, which provides the energy cost of this standardized isometric exercise expressed per kg force applied intermittently (30 s in every min, was found to show good repeatability when assessed in subjects who repeated the same experimental protocol on 3 separate days: its low intra-individual coefficient of variation (CV of ~ 10% contrasted with its much higher inter-individual CV of 35%; the latter being mass-independent but partly explained by height. Conclusion: This standardized approach to study isometric thermogenesis opens up a new avenue for research in EE phenotyping and metabolic predisposition to obesity

  5. Photosynthetic activity, photoprotection and photoinhibition in intertidal microphytobenthos as studied in situ using variable chlorophyll fluorescence

    Science.gov (United States)

    Serôdio, João; Vieira, Sónia; Cruz, Sónia

    2008-06-01

    The photosynthetic activity of microphytobenthos biofilms was studied in situ on an intertidal mudflat of the Ria de Aveiro, Portugal. Time series of physical variables characterizing the microenvironment at the sediment photic zone (incident solar irradiance, temperature, salinity), photophysiological parameters and productive biomass of undisturbed microalgal assemblages were measured during daytime low-tide periods along one spring-neap tidal cycle, with the objective of (1) characterizing the short-term variability in photosynthetic activity in situ, (2) relating it with the changing environmental conditions and (3) with the operation of physiologically (xanthophyll cycle) and behaviorally (vertical migration) based photoprotective processes, and (4) assessing the occurrence of photoinhibition. Pulse Amplitude Modulated (PAM) fluorometry was applied to measure photosynthetic activity (the effective and maximum quantum yield of photosystem II, Δ F/ Fm' and Fv/ Fm; the photosynthesis index EFY; rapid light-response curves (RLC)), the photoprotective operation of the xanthophyll cycle and photoinhibition (non-photochemical quenching, NPQ; quantum efficiency of open RCs, Fv'/ Fm'), and vertical migration (productive biomass, Fo). The photosynthetic activity was found to be strongly affected by the cumulative light dose received during the morning low-tide periods. The fluorescence indices Δ F/ Fm', EFY, Fv'/ Fm' and RLC parameters were more depressed under high irradiances when clear sky was present during the morning low tide than when foggy conditions reduced the light dose received during a comparable period. Productive biomass exhibited maximum values in the first hours of the morning, followed by a steep decrease when irradiance reached moderate levels, due to the downward migration of the microalgae. This photophobic migratory response appeared to display a photoprotective role, allowing Δ F/ Fm' to remain near optimum values until irradiance reached

  6. Investigating the variability of active galactic nuclei using combined multi-quarter Kepler data

    Energy Technology Data Exchange (ETDEWEB)

    Revalski, Mitchell; Nowak, Dawid; Wiita, Paul J. [Department of Physics, The College of New Jersey, P.O. Box 7718, Ewing, NJ 08628 (United States); Wehrle, Ann E. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); Unwin, Stephen C., E-mail: revalsm1@tcnj.edu [Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 321-100, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2014-04-10

    We used photometry from the Kepler satellite to characterize the variability of four radio-loud active galactic nuclei (AGNs) on timescales from years to minutes. The Kepler satellite produced nearly continuous high precision data sets which provided better temporal coverage than possible with ground based observations. We have now accumulated 11 quarters of data, eight of which were reported in our previous paper. In addition to constructing power spectral densities (PSDs) and characterizing the variability of the last three quarters, we have linked together the individual quarters using a multiplicative scaling process, providing data sets spanning ∼2.8 yr with >98% coverage at a 30 minute sampling rate. We compute PSDs on these connected data sets that yield power law slopes at low frequencies in the approximate range of –1.5 to –2.0, with white noise seen at higher frequencies. These PSDs are similar to those of both the individual quarters and to those of ground-based optical observations of other AGNs. We also have explored a PSD binning method intended to reduce a bias toward shallow slope fits by evenly distributing the points within the PSDs. This tends to steepen the computed PSD slopes, especially when the low frequencies are relatively poorly fit. We detected flares lasting several days in which the brightness increased by ∼15%-20% in one object, as well a smaller flare in another. Two AGNs showed only small, ∼1%-2%, fluctuations in brightness.

  7. Activity Pattern Profiles: Relationship With Affect, Daily Functioning, Impairment, and Variables Related to Life Goals.

    Science.gov (United States)

    Esteve, Rosa; López-Martínez, Alicia E; Peters, Madelon L; Serrano-Ibáñez, Elena R; Ruíz-Párraga, Gema T; González-Gómez, Henar; Ramírez-Maestre, Carmen

    2017-05-01

    The aim of this cross-sectional study was to identify subgroups of patients on the basis of their activity patterns and to investigate their relationship with life goals, optimism, affect, and functioning. The sample was comprised of 276 patients with chronic musculoskeletal pain. Hierarchical cluster analysis was performed on the activity pattern variables and the resulting clusters were compared using 1-way analysis of variance. The 4-cluster was the optimal solution. The 4 clusters comprised: 1) avoiders: patients with high levels of avoidance and low levels of persistence, who use pacing to reduce pain, 2) doers: patients with high levels of persistence and low levels of pacing and avoidance, 3) extreme cyclers: patients with high levels of avoidance and persistence and low levels of pacing, and 4) medium cyclers: patients with moderately high levels of avoidance and persistence and high levels of pacing. Comparison of the clusters showed that doers had the most adaptive profile, whereas avoiders, followed by extreme cyclers, had unhealthy profiles. Doers showed a high level of optimism and a good balance between goal value, expectancy, and conflict. It is useful to distinguish profiles on the basis of various activity patterns. In contrast to profiles characterized by avoidance, profiles characterized by high persistence and low avoidance were associated with adaptive results. Patients with this profile also showed a high level of optimism and a good balance between goal value, expectancy, and conflict. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  8. The effects of metronome breathing on the variability of autonomic activity measurements.

    Science.gov (United States)

    Driscoll, D; Dicicco, G

    2000-01-01

    Many chiropractors hypothesize that spinal manipulation affects the autonomic nervous system (ANS). However, the ANS responses to chiropractic manipulative therapy are not well documented, and more research is needed to support this hypothesis. This study represents a step toward the development of a reliable method by which to document that chiropractic manipulative therapy does affect the ANS by exploring the use of paced breathing as a way to reduce the inherent variability in ANS measurements. To examine the hypothesis that the variability of ANS measurements would be reduced if breathing were paced to a metronome at 12 breaths/min. The study was performed at Parker College Research Institute. Eight normotensive subjects were recruited from the student body and staff. Respiration frequency was measured through a strain gauge. A 3-lead electrocardiogram (ECG) was used to register the electric activity of the heart, and arterial tonometry monitors were used to record the left and right radial artery blood pressures. Signals were recorded on an IBM-compatible computer with a sampling frequency of 100 Hz. Normal breathing was used for the first 3 recordings, and breathing was paced to a metronome for the final 3 recordings at 12 breaths/min. Fourier analysis was performed on the beat-by-beat fluctuations of the ECG-determined R-R interval and systolic arterial pressure (SBP). Low-frequency fluctuations (LF; 0.04-0.15 Hz) reflected sympathetic activity, whereas high-frequency fluctuations (HF; 0.15-0.4 Hz) represented parasympathetic activity. Sympathovagal indices were determined from the ratio of the two bandwidths (LF/HF). The coefficient of variation (CV%) for autonomic parameters was calculated ([average/SD] x 100%) to compare breathing normally and breathing to a metronome with respect to variability. One-way analysis of variance was used to detect differences. A value of P Metronome breathing did not produce any significant changes in blood pressure for the

  9. Active queue management controller design for TCP communication networks: Variable structure control approach

    International Nuclear Information System (INIS)

    Chen, C.-K.; Liao, T.-L.; Yan, J.-J.

    2009-01-01

    On the basis of variable structure control (VSC), an active queue management (AQM) controller is presented for a class of TCP communication networks. In the TCP/IP networks, the packet drop probability is limited between 0 and 1. Therefore, we modeled TCP/AQM as a rate-based non-linear system with a saturated input. The objective of the VSC-based AQM controller is to achieve the desired queue size and to guarantee the asymptotic stability of the closed-loop TCP non-linear system with saturated input. The performance and effectiveness of the proposed control law are then validated for different network scenarios through numerical simulations in both MATLAB and Network Simulator-2 (NS-2). Both sets of simulation results have confirmed that the proposed scheme outperforms other AQM schemes.

  10. Active queue management controller design for TCP communication networks: Variable structure control approach

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.-K. [Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan (China); Liao, T.-L. [Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan (China)], E-mail: tlliao@mail.ncku.edu; Yan, J.-J. [Department of Computer and Communication, Shu-Te University, Kaohsiung 824, Taiwan (China)

    2009-04-15

    On the basis of variable structure control (VSC), an active queue management (AQM) controller is presented for a class of TCP communication networks. In the TCP/IP networks, the packet drop probability is limited between 0 and 1. Therefore, we modeled TCP/AQM as a rate-based non-linear system with a saturated input. The objective of the VSC-based AQM controller is to achieve the desired queue size and to guarantee the asymptotic stability of the closed-loop TCP non-linear system with saturated input. The performance and effectiveness of the proposed control law are then validated for different network scenarios through numerical simulations in both MATLAB and Network Simulator-2 (NS-2). Both sets of simulation results have confirmed that the proposed scheme outperforms other AQM schemes.

  11. The role of physical activity and heart rate variability for the control of work related stress.

    Science.gov (United States)

    Tonello, Laís; Rodrigues, Fábio B; Souza, Jeniffer W S; Campbell, Carmen S G; Leicht, Anthony S; Boullosa, Daniel A

    2014-01-01

    Physical activity (PA) and exercise are often used as tools to reduce stress and therefore the risk for developing cardiovascular diseases (CVD). Meanwhile, heart rate variability (HRV) has been utilized to assess both stress and PA or exercise influences. The objective of the present review was to examine the current literature in regards to workplace stress, PA/exercise and HRV to encourage further studies. We considered original articles from known databases (PubMed, ISI Web of Knowledge) over the last 10 years that examined these important factors. A total of seven studies were identified with workplace stress strongly associated with reduced HRV in workers. Longitudinal workplace PA interventions may provide a means to improve worker stress levels and potentially cardiovascular risk with mechanisms still to be clarified. Future studies are recommended to identify the impact of PA, exercise, and fitness on stress levels and HRV in workers and their subsequent influence on cardiovascular health.

  12. The role of physical activity and heart rate variability for the control of work related stress

    Directory of Open Access Journals (Sweden)

    Laís eTonello

    2014-02-01

    Full Text Available Physical activity (PA and exercise are often used as tools to reduce stress and therefore the risk for developing cardiovascular diseases. Meanwhile, heart rate variability (HRV has been utilised to assess both stress and PA or exercise influences. The objective of the present mini review was to examine the current literature in regards to workplace stress, PA/exercise and HRV to encourage further studies. We considered original articles from known databases (PubMed, ISI Web of Knowledge over the last 10 years that examined these important factors. A total of 7 studies were identified with workplace stress strongly associated with reduced HRV in workers. Longitudinal workplace PA interventions may provide a means to improve worker stress levels and potentially cardiovascular risk with mechanisms still to be clarified. Future studies are recommended to identify the impact of PA, exercise and fitness on stress levels and HRV in workers and their subsequent influence on cardiovascular health.

  13. [Increased sympathetic activity assessed by spectral analysis of heart rate variability in patients with CRPS I].

    Science.gov (United States)

    Schulze, J; Troeger, C

    2010-02-01

    The complex regional pain syndrome type I (CRPS I) is a painful neuropathic disorder with an antecedent disproportionate trauma leading to spontaneous pain, hyperalgesia, impaired motor function, swelling, changes in sweating and vascular abnormalities without nerve injury. Whether this syndrome is the result of central or peripheral autonomic dysfunction is still a matter of debate. The purpose of this study was to determine the activity of the sympathetic nervous system in patients with CRPS I by power spectral analysis of heart rate variability. This is a pilot study on 6 patients (mean age 50 years; 4 female, 2 male) diagnosed as suffering from CRPS I and 6 age-matched healthy controls. In the pain-free interval and after taking rest for 5 min, 512 subsequent heart beats were obtained with an ECG standard lead II in the supine and then sitting position. Using an autoregressive model, power spectral densities were calculated for the following frequency bands: CRPS I compared to the healthy controls in the supine position (LF/HF=4.01 vs. LF/HF=1.27; p=0.041). The application of stress by changing to the sitting position even increased that difference (6.72 vs. 1.93). Our results support the hypothesis that the pathogenesis of the early stage CRPS I might be related to an increased sympathetic activity. By assessing the autonomic influence on the heart rate variability in CRPS I patients we could also conclude that this disturbance occurs rather at a central level. Georg Thieme Verlag KG Stuttgart, New York.

  14. Physical Activity and Heart Rate Variability in Older Adults: The Cardiovascular Health Study

    Science.gov (United States)

    Soares-Miranda, Luisa; Sattelmair, Jacob; Chaves, Paulo; Duncan, Glen; Siscovick, David S; Stein, Phyllis K; Mozaffarian, Dariush

    2014-01-01

    Background Cardiac mortality and electrophysiologic dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity (PA) among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults. Methods and Results We evaluated serial longitudinal measures of both PA and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard-deviation-of-all-normal-to-normal-intervals (SDNN, p-trend=0.009, 0.02, 0.06, respectively) and ultra-low-frequency-power (p-trend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with higher short-term-fractal-scaling-exponent (p-trend=0.003) and lower Poincare ratio (p-trend=0.02), markers of less erratic sinus patterns. Conclusions Greater total leisure-time activity, as well as walking alone, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual PA later in life. PMID:24799513

  15. Plume Activity and Tidal Deformation on Enceladus Influenced by Faults and Variable Ice Shell Thickness.

    Science.gov (United States)

    Běhounková, Marie; Souček, Ondřej; Hron, Jaroslav; Čadek, Ondřej

    2017-09-01

    We investigated the effect of variations in ice shell thickness and of the tiger stripe fractures crossing Enceladus' south polar terrain on the moon's tidal deformation by performing finite element calculations in three-dimensional geometry. The combination of thinning in the polar region and the presence of faults has a synergistic effect that leads to an increase of both the displacement and stress in the south polar terrain by an order of magnitude compared to that of the traditional model with a uniform shell thickness and without faults. Assuming a simplified conductive heat transfer and neglecting the heat sources below the ice shell, we computed the global heat budget of the ice shell. For the inelastic properties of the shell described by a Maxwell viscoelastic model, we show that unrealistically low average viscosity of the order of 10 13 Pa s is necessary for preserving the volume of the ocean, suggesting the important role of the heat sources in the deep interior. Similarly, low viscosity is required to predict the observed delay of the plume activity, which hints at other delaying mechanisms than just the viscoelasticity of the ice shell. The presence of faults results in large spatial and temporal heterogeneity of geysering activity compared to the traditional models without faults. Our model contributes to understanding the physical mechanisms that control the fault activity, and it provides potentially useful information for future missions that will sample the plume for evidence of life. Key Words: Enceladus-Tidal deformation-Faults-Variable ice shell thickness-Tidal heating-Plume activity and timing. Astrobiology 17, 941-954.

  16. Variability in Saponin Content, Cancer Antiproliferative Activity and Physicochemical Properties of Concentrated Agave Sap.

    Science.gov (United States)

    Santos-Zea, Liliana; Rosas-Pérez, Aratza Mireya; Leal-Díaz, Ana María; Gutiérrez-Uribe, Janet A

    2016-08-01

    Concentrated agave sap (CAS) has gained popularity as an unrefined sweetener. It is obtained by boiling "aguamiel" that contains phytochemicals with diverse bioactivities. Saponins have been the most widely studied agave phytochemicals due to their cancer antiproliferative effect but their concentration may vary due to maturity of the agave plant and collection site. In this study, 18 CAS samples produced in different states of Mexico were analyzed using multivariate methods to determine which physicochemical or phytochemical parameters were responsible for variation. Additionally, extracts with different saponin profiles were tested to determine possible correlations with antiproliferative activity. Total soluble solids, pH, and water activity were similar to those reported for other agave sweeteners. Antioxidant capacity of samples was correlated to browning index. Eleven steroidal saponins were found in CAS samples and they were the main source of variability. Magueyoside B, a kammogenin tetraglycoside, was the most abundant saponin in all samples. With respect to bioactivity, multivariate analysis indicated that magueyoside B and a gentrogenin tetraglycoside were compounds strongly related with bioactivity. CAS from Hidalgo, Puebla, and Veracruz had higher concentration of magueyoside B than from the other kamogenin tetraglycoside found in the samples from other Mexican states. These results could be used as a first approach to characterize and standardize CAS to validate the potential health benefits derived from its consumption. © 2016 Institute of Food Technologists®

  17. The geovisualisation window of the temporal and spatial variability for Volunteered Geographic Information activities

    Science.gov (United States)

    Medynska-Gulij, Beata; Myszczuk, Miłosz

    2012-11-01

    This study presents an attempt to design geographical visualisation tools that allow to tackle the immensity of spatial data provided by Volunteered Geographic Information (VGI), both in terms of temporal and spatial aspects. In accordance with the assumptions made at the conceptual stage, the final action was the implementation of the window entitled ‘Geovisualisation of the Panoramio.com Activities in District of Poznan 2011’ into the web browser. The concept has been based on a division of the geovisualisation window into three panels, of which the most important - in order to capture spatial variability - have statistical maps at the general level (dot map and choropleth map), while at the detailed level - a dot map on a topographic reference map or tourist map. For two ranges, temporal variability is presented by graphs, while a review of attributes of individual activities of the social website in question is set forward in the table panel. The element that visually interlinks all of the panels is the emphasised individual activity. Problemem podjetym w tych badaniach stało sie wykorzystanie metod z nurtu geograficznej wizualizacji do wskazania cech fenomenu VGI w zakresie zmiennosci czasowo-przestrzennej. Zgodnie z załozeniami poczynionymi w etapie koncepcyjnym finalnym działaniem stało sie zaimplementowanie do przegladarki internetowej okna pod tytułem: ”Geowizualizacja aktywnosci społecznosci Panoramio.com w powiecie poznanskim w 2011 roku”. Koncepcja została oparta na podziale okna geowizualizacji na trzy panele, z których najwazniejsze znaczenie dla uchwycenia zmiennosci przestrzennej na poziomie ogólnym ma kartogram, natomiast na poziomie szczegółowym mapa kropkowa wyswietlana na podkładzie mapy topograficznej lub turystycznej. Zmiennosc czasowa w dwóch zakresach prezentuja wykresy, a przeglad atrybutów poszczególnych aktywnosci prezentowanego portalu społecznosciowego zapewnia tabela. Elementem spajajacym wizualnie wszystkie

  18. The sequence of cortical activity inferred by response latency variability in the human ventral pathway of face processing.

    Science.gov (United States)

    Lin, Jo-Fu Lotus; Silva-Pereyra, Juan; Chou, Chih-Che; Lin, Fa-Hsuan

    2018-04-11

    Variability in neuronal response latency has been typically considered caused by random noise. Previous studies of single cells and large neuronal populations have shown that the temporal variability tends to increase along the visual pathway. Inspired by these previous studies, we hypothesized that functional areas at later stages in the visual pathway of face processing would have larger variability in the response latency. To test this hypothesis, we used magnetoencephalographic data collected when subjects were presented with images of human faces. Faces are known to elicit a sequence of activity from the primary visual cortex to the fusiform gyrus. Our results revealed that the fusiform gyrus showed larger variability in the response latency compared to the calcarine fissure. Dynamic and spectral analyses of the latency variability indicated that the response latency in the fusiform gyrus was more variable than in the calcarine fissure between 70 ms and 200 ms after the stimulus onset and between 4 Hz and 40 Hz, respectively. The sequential processing of face information from the calcarine sulcus to the fusiform sulcus was more reliably detected based on sizes of the response variability than instants of the maximal response peaks. With two areas in the ventral visual pathway, we show that the variability in response latency across brain areas can be used to infer the sequence of cortical activity.

  19. Drivers of time-activity budget variability during breeding in a pelagic seabird.

    Directory of Open Access Journals (Sweden)

    Gavin M Rishworth

    Full Text Available During breeding, animal behaviour is particularly sensitive to environmental and food resource availability. Additionally, factors such as sex, body condition, and offspring developmental stage can influence behaviour. Amongst seabirds, behaviour is generally predictably affected by local foraging conditions and has therefore been suggested as a potentially useful proxy to indicate prey state. However, besides prey availability and distribution, a range of other variables also influence seabird behavior, and these need to be accounted for to increase the signal-to-noise ratio when assessing specific characteristics of the environment based on behavioural attributes. The aim of this study was to use continuous, fine-scale time-activity budget data from a pelagic seabird (Cape gannet, Morus capensis to determine the influence of intrinsic (sex and body condition and extrinsic (offspring and time variables on parent behaviour during breeding. Foraging trip duration and chick provisioning rates were clearly sex-specific and associated with chick developmental stage. Females made fewer, longer foraging trips and spent less time at the nest during chick provisioning. These sex-specific differences became increasingly apparent with chick development. Additionally, parents in better body condition spent longer periods at their nests and those which returned later in the day had longer overall nest attendance bouts. Using recent technological advances, this study provides new insights into the foraging behaviour of breeding seabirds, particularly during the post-guarding phase. The biparental strategy of chick provisioning revealed in this study appears to be an example where the costs of egg development to the female are balanced by paternal-dominated chick provisioning particularly as the chick nears fledging.

  20. Long-term variability of supratidal coastal boulder activation in Brittany (France)

    Science.gov (United States)

    Autret, Ronan; Dodet, Guillaume; Suanez, Serge; Roudaut, Gildas; Fichaut, Bernard

    2018-03-01

    High-energy supratidal coastal boulder deposit (SCBD) dynamics were investigated on Vierge Island and Pors Carn Point, north and south of western Brittany, France, respectively. Morphological changes induced by boulder transport and quarrying were quantified using high-resolution topographic survey data taken between 2012 and 2017. Additional in-situ wave parameters and water levels were also recorded over this period (2014-2017) in order to compute the maximum water levels and assess the relationship between SCBD morphological changes and specific hydrodynamic conditions. During extreme water levels (for maximum water levels exceeding a one in ten year event), SCBDs were broadly reworked (up to 40% of the total volume). During lower intensity events, for which maximum water levels were still very high, morphological changes represented 1% to 5% of the total volume. These morphological and hydrodynamic observations were then used to calibrate a chronology of SCBD activation events based on 70 years of hindcast winter maximum water levels. These long-term time-series showed great interannual variability in SCBD activation but no significant long-term trend. Winter-frequency SCBD activation was better correlated to the WEPA index (r = 0.46) than the NAO index (r = 0.1). Therefore, the WEPA index can be considered to be a more significant climate proxy for assessing storm-related geomorphic changes in the temperate latitudes of the N-E Atlantic basin (36°-52° N), including the Brittany coast. The potential of SCBDs as a morphological storm proxy for macrotidal high-energy rocky coasts is addressed.

  1. Variable Accuracy of Wearable Heart Rate Monitors during Aerobic Exercise.

    Science.gov (United States)

    Gillinov, Stephen; Etiwy, Muhammad; Wang, Robert; Blackburn, Gordon; Phelan, Dermot; Gillinov, A Marc; Houghtaling, Penny; Javadikasgari, Hoda; Desai, Milind Y

    2017-08-01

    Athletes and members of the public increasingly rely on wearable HR monitors to guide physical activity and training. The accuracy of newer, optically based monitors is unconfirmed. We sought to assess the accuracy of five optically based HR monitors during various types of aerobic exercise. Fifty healthy adult volunteers (mean ± SD age = 38 ± 12 yr, 54% female) completed exercise protocols on a treadmill, a stationary bicycle, and an elliptical trainer (±arm movement). Each participant underwent HR monitoring with an electrocardiogaphic chest strap monitor (Polar H7), forearm monitor (Scosche Rhythm+), and two randomly assigned wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, and TomTom Spark Cardio), one on each wrist. For each exercise type, HR was recorded at rest, light, moderate, and vigorous intensity. Agreement between HR measurements was assessed using Lin's concordance correlation coefficient (rc). Across all exercise conditions, the chest strap monitor (Polar H7) had the best agreement with ECG (rc = 0.996) followed by the Apple Watch (rc = 0.92), the TomTom Spark (rc = 0.83), and the Garmin Forerunner (rc = 0.81). Scosche Rhythm+ and Fitbit Blaze were less accurate (rc = 0.75 and rc = 0.67, respectively). On treadmill, all devices performed well (rc = 0.88-0.93) except the Fitbit Blaze (rc = 0.76). While bicycling, only the Garmin, Apple Watch, and Scosche Rhythm+ had acceptable agreement (rc > 0.80). On the elliptical trainer without arm levers, only the Apple Watch was accurate (rc = 0.94). None of the devices was accurate during elliptical trainer use with arm levers (all rc < 0.80). The accuracy of wearable, optically based HR monitors varies with exercise type and is greatest on the treadmill and lowest on elliptical trainer. Electrode-containing chest monitors should be used when accurate HR measurement is imperative.

  2. Pronounced between-subject and circadian variability in thymidylate synthase and dihydropyrimidine dehydrogenase enzyme activity in human volunteers

    NARCIS (Netherlands)

    Jacobs, Bart A W; Deenen, Maarten J; Pluim, Dick; van Hasselt, J G Coen; Krähenbühl, Martin D; van Geel, Robin M J M; de Vries, Niels; Rosing, Hilde; Meulendijks, Didier; Burylo, Artur M; Cats, Annemieke; Beijnen, Jos H; Huitema, Alwin D R; Schellens, Jan H M

    AIMS: The enzymatic activity of dihydropyrimidine dehydrogenase (DPD) and thymidylate synthase (TS) are important for the tolerability and efficacy of the fluoropyrimidine drugs. In the present study, we explored between-subject variability (BSV) and circadian rhythmicity in DPD and TS activity in

  3. Cellular variability of RpoS expression underlies subpopulation activation of an integrative and conjugative element.

    Directory of Open Access Journals (Sweden)

    Ryo Miyazaki

    Full Text Available Conjugative transfer of the integrative and conjugative element ICEclc in the bacterium Pseudomonas knackmussii is the consequence of a bistable decision taken in some 3% of cells in a population during stationary phase. Here we study the possible control exerted by the stationary phase sigma factor RpoS on the bistability decision. The gene for RpoS in P. knackmussii B13 was characterized, and a loss-of-function mutant was produced and complemented. We found that, in absence of RpoS, ICEclc transfer rates and activation of two key ICEclc promoters (P(int and P(inR decrease significantly in cells during stationary phase. Microarray and gene reporter analysis indicated that the most direct effect of RpoS is on P(inR, whereas one of the gene products from the P(inR-controlled operon (InrR transmits activation to P(int and other ICEclc core genes. Addition of a second rpoS copy under control of its native promoter resulted in an increase of the proportion of cells expressing the P(int and P(inR promoters to 18%. Strains in which rpoS was replaced by an rpoS-mcherry fusion showed high mCherry fluorescence of individual cells that had activated P(int and P(inR, whereas a double-copy rpoS-mcherry-containing strain displayed twice as much mCherry fluorescence. This suggested that high RpoS levels are a prerequisite for an individual cell to activate P(inR and thus ICEclc transfer. Double promoter-reporter fusions confirmed that expression of P(inR is dominated by extrinsic noise, such as being the result of cellular variability in RpoS. In contrast, expression from P(int is dominated by intrinsic noise, indicating it is specific to the ICEclc transmission cascade. Our results demonstrate how stochastic noise levels of global transcription factors can be transduced to a precise signaling cascade in a subpopulation of cells leading to ICE activation.

  4. Chitotriosidase enzyme activity: is this a possible chronic inflammation marker in children with common variable immunodeficiency and early atherosclerosis?

    Science.gov (United States)

    Azarsız, Elif; Karaca, Neslihan; Levent, Erturk; Kutukculer, Necil; Sozmen, Eser

    2017-11-01

    Background Common variable immunodeficiency is a rare clinically symptomatic primary immunodeficiency disorder which manifests a wide variability of symptoms, complications. Atherosclerosis in common variable immunodeficiency patients has not been investigated yet contrary to other severe clinical complications. We aimed to investigate the chitotriosidase enzyme's role as an inflammation and atherosclerosis marker in paediatric common variable immunodeficiency patients. Methods Common variable immunodeficiency patients (n = 24) and healthy controls (n = 23) evaluated for chitotriosidase activity with other inflammation markers (hsCRP, myeloperoxidase, serum amyloid A, ferritin), lipid profile and echocardiographic findings (carotid artery intima media thickness - cIMT, brachial artery flow-mediated vazodilatation - FMD%). Results In patients, the mean chitotriosidase activity (8.98 ± 6.28) was significantly higher than the controls (5.17 ± 3.42) ( P = 0.014). Chitotriosidase showed positive relation with hs-CRP ( P = 0.011) and SAA ( P = 0.011) but had no relation with ferritin ( P = 0.155), HDL ( P = 0.152) or LDL-cholesterol ( P = 0.380). Mean cIMT increased in patients compared with the controls ( P variable immunodeficiency patients demonstrated in vivo the presence of activated macrophages indicating ongoing inflammation. Echocardiographic diastolic functional deficiency, increased cIMT and decreased FMD% may be accepted as early atherosclerotic findings, but none of them showed relationship with chitotriosidase activities.

  5. Hydrothermal activity at slow-spreading ridges: variability and importance of magmatic controls

    Science.gov (United States)

    Escartin, Javier

    2016-04-01

    Hydrothermal activity along mid-ocean ridge axes is ubiquitous, associated with mass, chemical, and heat exchanges between the deep lithosphere and the overlying envelopes, and sustaining chemiosynthetic ecosystems at the seafloor. Compared with hydrothermal fields at fast-spreading ridges, those at slow spreading ones show a large variability as their location and nature is controlled or influenced by several parameters that are inter-related: a) tectonic setting, ranging from 'volcanic systems' (along the rift valley floor, volcanic ridges, seamounts), to 'tectonic' ones (rift-bounding faults, oceanic detachment faults); b) the nature of the host rock, owing to compositional heterogeneity of slow-spreading lithosphere (basalt, gabbro, peridotite); c) the type of heat source (magmatic bodies at depth, hot lithosphere, serpentinization reactions); d) and the associated temperature of outflow fluids (high- vs.- low temperature venting and their relative proportion). A systematic review of the distribution and characteristics of hydrothermal fields along the slow-spreading Mid-Atlantic Ridge suggests that long-lived hydrothermal activity is concentrated either at oceanic detachment faults, or along volcanic segments with evidence of robust magma supply to the axis. A detailed study of the magmatically robust Lucky Strike segment suggests that all present and past hydrothermal activity is found at the center of the segment. The association of these fields to central volcanos, and the absence of indicators of hydrothermal activity along the remaining of the ridge segment, suggests that long-lived hydrothermal activity in these volcanic systems is maintained by the enhanced melt supply and the associated magma chamber(s) required to build these volcanic edifices. In this setting, hydrothermal outflow zones at the seafloor are systematically controlled by faults, indicating that hydrothermal fluids in the shallow crust exploit permeable fault zones to circulate. While

  6. Variable-Intensity Simulated Team-Sport Exercise Increases Daily Protein Requirements in Active Males.

    Science.gov (United States)

    Packer, Jeffrey E; Wooding, Denise J; Kato, Hiroyuki; Courtney-Martin, Glenda; Pencharz, Paul B; Moore, Daniel R

    2017-01-01

    Protein requirements are generally increased in strength and endurance trained athletes relative to their sedentary peers. However, less is known about the daily requirement for this important macronutrient in individuals performing variable intensity, stop-and-go type exercise that is typical for team sport athletes. The objective of the present study was to determine protein requirements in active, trained adult males performing a simulated soccer match using the minimally invasive indicator amino acid oxidation (IAAO) method. After 2 days of controlled diet (1.2 g⋅kg -1 ⋅day -1 protein), seven trained males (23 ± 1 years; 177.5 ± 6.7 cm; 82.3 ± 6.1 kg; 13.5% ± 4.7% body fat; 52.3 ± 5.9 ml O 2 ⋅kg -1 ⋅min -1 ; mean ± SD) performed an acute bout of variable intensity exercise in the form of a modified Loughborough Intermittent Shuttle Test (4 × 15 min of exercise over 75 min). Immediately after exercise, hourly meals were consumed providing a variable amount of protein (0.2-2.6 g⋅kg -1 ⋅day -1 ) and sufficient energy and carbohydrate (6 g⋅kg -1 ⋅day -1 ). Protein was provided as a crystalline amino acids modeled after egg protein with the exception of phenylalanine and tyrosine, which were provided in excess to ensure the metabolic partitioning of the indicator amino acid (i.e., [1- 13 C]phenylalanine included within the phenylalanine intake) was directed toward oxidation when protein intake was limiting. Whole body phenylalanine flux and 13 CO 2 excretion (F 13 CO 2 ) were determined at metabolic and isotopic steady state from urine and breath samples, respectively. Biphasic linear regression analysis was performed on F 13 CO 2 to determine the estimated average requirement (EAR) for protein with a safe intake defined as the upper 95% confidence interval. Phenylalanine flux was not impacted by protein intake ( P  = 0.45). Bi-phase linear regression ( R 2  = 0.64) of F 13 CO 2 resulted

  7. Variable-Intensity Simulated Team-Sport Exercise Increases Daily Protein Requirements in Active Males

    Directory of Open Access Journals (Sweden)

    Jeffrey E. Packer

    2017-12-01

    Full Text Available Protein requirements are generally increased in strength and endurance trained athletes relative to their sedentary peers. However, less is known about the daily requirement for this important macronutrient in individuals performing variable intensity, stop-and-go type exercise that is typical for team sport athletes. The objective of the present study was to determine protein requirements in active, trained adult males performing a simulated soccer match using the minimally invasive indicator amino acid oxidation (IAAO method. After 2 days of controlled diet (1.2 g⋅kg−1⋅day−1 protein, seven trained males (23 ± 1 years; 177.5 ± 6.7 cm; 82.3 ± 6.1 kg; 13.5% ± 4.7% body fat; 52.3 ± 5.9 ml O2⋅kg−1⋅min-1; mean ± SD performed an acute bout of variable intensity exercise in the form of a modified Loughborough Intermittent Shuttle Test (4 × 15 min of exercise over 75 min. Immediately after exercise, hourly meals were consumed providing a variable amount of protein (0.2–2.6 g⋅kg−1⋅day−1 and sufficient energy and carbohydrate (6 g⋅kg−1⋅day−1. Protein was provided as a crystalline amino acids modeled after egg protein with the exception of phenylalanine and tyrosine, which were provided in excess to ensure the metabolic partitioning of the indicator amino acid (i.e., [1-13C]phenylalanine included within the phenylalanine intake was directed toward oxidation when protein intake was limiting. Whole body phenylalanine flux and 13CO2 excretion (F13CO2 were determined at metabolic and isotopic steady state from urine and breath samples, respectively. Biphasic linear regression analysis was performed on F13CO2 to determine the estimated average requirement (EAR for protein with a safe intake defined as the upper 95% confidence interval. Phenylalanine flux was not impacted by protein intake (P = 0.45. Bi-phase linear regression (R2 = 0.64 of F13CO2 resulted in an EAR

  8. Familial influences on the full range of variability in attention and activity levels during adolescence: A longitudinal twin study.

    Science.gov (United States)

    Peng, Chun-Zi; Grant, Julia D; Heath, Andrew C; Reiersen, Angela M; Mulligan, Richard C; Anokhin, Andrey P

    2016-05-01

    To investigate familial influences on the full range of variability in attention and activity across adolescence, we collected maternal ratings of 339 twin pairs at ages 12, 14, and 16, and estimated the transmitted and new familial influences on attention and activity as measured by the Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behavior Scale. Familial influences were substantial for both traits across adolescence: genetic influences accounted for 54%-73% (attention) and 31%-73% (activity) of the total variance, and shared environmental influences accounted for 0%-22% of the attention variance and 13%-57% of the activity variance. The longitudinal stability of individual differences in attention and activity was largely accounted for by familial influences transmitted from previous ages. Innovations over adolescence were also partially attributable to familial influences. Studying the full range of variability in attention and activity may facilitate our understanding of attention-deficit/hyperactivity disorder's etiology and intervention.

  9. Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

    Science.gov (United States)

    Ashizawa, Kunitaka; Sato, Takehiro; Tokuhashi, Kazumasa; Ishii, Daisuke; Okamoto, Satoru; Yamanaka, Naoaki; Oki, Eiji

    This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30msec, which is acceptable for on-demand broadcast services.

  10. Kelvin wave coupling from TIMED and GOCE: Inter/intra-annual variability and solar activity effects

    Science.gov (United States)

    Gasperini, Federico; Forbes, Jeffrey M.; Doornbos, Eelco N.; Bruinsma, Sean L.

    2018-06-01

    The primary mechanism through which energy and momentum are transferred from the lower atmosphere to the thermosphere is through the generation and propagation of atmospheric waves. It is becoming increasingly evident that a few waves from the tropical wave spectrum preferentially propagate into the thermosphere and contribute to modify satellite drag. Two of the more prominent and well-established tropical waves are Kelvin waves: the eastward-propagating 3-day ultra-fast Kelvin wave (UFKW) and the eastward-propagating diurnal tide with zonal wave number 3 (DE3). In this work, Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperatures at 110 km and Gravity field and steady-state Ocean Circulation Explorer (GOCE) neutral densities and cross-track winds near 260 km are used to demonstrate vertical coupling in this height regime due to the UFKW and DE3. Significant inter- and intra-annual variability is found in DE3 and the UFKW, with evidence of latitudinal broadening and filtering of the latitude structures with height due to the effect of dissipation and mean winds. Additionally, anti-correlation between the vertical penetration of these waves to the middle thermosphere and solar activity level is established and explained through the effect of molecular dissipation.

  11. Regularity, variability and bi-stability in the activity of cerebellar purkinje cells.

    Science.gov (United States)

    Rokni, Dan; Tal, Zohar; Byk, Hananel; Yarom, Yosef

    2009-01-01

    Recent studies have demonstrated that the membrane potential of Purkinje cells is bi-stable and that this phenomenon underlies bi-modal simple spike firing. Membrane potential alternates between a depolarized state, that is associated with spontaneous simple spike firing (up state), and a quiescent hyperpolarized state (down state). A controversy has emerged regarding the relevance of bi-stability to the awake animal, yet recordings made from behaving cat Purkinje cells have demonstrated that at least 50% of the cells exhibit bi-modal firing. The robustness of the phenomenon in vitro or in anaesthetized systems on the one hand, and the controversy regarding its expression in behaving animals on the other hand suggest that state transitions are under neuronal control. Indeed, we have recently demonstrated that synaptic inputs can induce transitions between the states and suggested that the role of granule cell input is to control the states of Purkinje cells rather than increase or decrease firing rate gradually. We have also shown that the state of a Purkinje cell does not only affect its firing but also the waveform of climbing fiber-driven complex spikes and the associated calcium influx. These findings call for a reconsideration of the role of Purkinje cells in cerebellar function. In this manuscript we review the recent findings on Purkinje cell bi-stability and add some analyses of its effect on the regularity and variability of Purkinje cell activity.

  12. Where's the Noise? Key Features of Spontaneous Activity and Neural Variability Arise through Learning in a Deterministic Network.

    Directory of Open Access Journals (Sweden)

    Christoph Hartmann

    2015-12-01

    Full Text Available Even in the absence of sensory stimulation the brain is spontaneously active. This background "noise" seems to be the dominant cause of the notoriously high trial-to-trial variability of neural recordings. Recent experimental observations have extended our knowledge of trial-to-trial variability and spontaneous activity in several directions: 1. Trial-to-trial variability systematically decreases following the onset of a sensory stimulus or the start of a motor act. 2. Spontaneous activity states in sensory cortex outline the region of evoked sensory responses. 3. Across development, spontaneous activity aligns itself with typical evoked activity patterns. 4. The spontaneous brain activity prior to the presentation of an ambiguous stimulus predicts how the stimulus will be interpreted. At present it is unclear how these observations relate to each other and how they arise in cortical circuits. Here we demonstrate that all of these phenomena can be accounted for by a deterministic self-organizing recurrent neural network model (SORN, which learns a predictive model of its sensory environment. The SORN comprises recurrently coupled populations of excitatory and inhibitory threshold units and learns via a combination of spike-timing dependent plasticity (STDP and homeostatic plasticity mechanisms. Similar to balanced network architectures, units in the network show irregular activity and variable responses to inputs. Additionally, however, the SORN exhibits sequence learning abilities matching recent findings from visual cortex and the network's spontaneous activity reproduces the experimental findings mentioned above. Intriguingly, the network's behaviour is reminiscent of sampling-based probabilistic inference, suggesting that correlates of sampling-based inference can develop from the interaction of STDP and homeostasis in deterministic networks. We conclude that key observations on spontaneous brain activity and the variability of neural

  13. Changes in Physical Activity and Psychological Variables Following a Web-Based Motivational Interviewing Intervention: Pilot Study.

    Science.gov (United States)

    Karnes, Sasha L; Meyer, Barbara B; Berger, Lisa M; Brondino, Michael J

    2015-10-29

    Web-based interventions for enhancing physical activity participation are in demand for application in health care settings. Recent research suggests Web-based interventions that are based on motivational interviewing are effective to increase physical activity. It is unclear whether motivational interviewing can influence targeted psychological variables such as perceived readiness, willingness, and ability to participate in physical activity. The aims of this study were to determine whether there were changes in physical activity and psychological variables associated with readiness, willingness, and perceived ability to participate in physical activity following completion of a novel Web-based intervention. The goal of the motivational interviewing-based intervention was to increase physical activity. Twenty-three underactive or inactive urban dwelling adults were recruited at a medical office for participation in a 4-session Web-based intervention lasting approximately 15 minutes per week. Sessions were based on principles of motivational interviewing. Assessment of physical activity was conducted using pedometers immediately prior to intervention participation (pre) and immediately post intervention (post1). Self-report assessments of physical activity and psychological variables were conducted using online surveys at pre, post1, and again at one month following intervention participation (post2). Comparisons of pre and post1 pedometer recordings revealed significant increases in steps per day (t22=2.09, P=.049). There were also significant changes in total physical activity energy expenditure per week (χ(2) 2=8.4, P=.02) and in moderate intensity physical activity energy expenditure per week (χ(2) 2=13.9, Ptool to promote physical activity in health care settings. Additional research is needed to test the effectiveness of motivational interviewing compared to a control condition and to refine content by considering mediation by psychological variables in a

  14. Role of wind forcing and eddy activity in the intraseasonal variability of the barrier layer in the South China Sea

    Science.gov (United States)

    Liang, Zhanlin; Xie, Qiang; Zeng, Lili; Wang, Dongxiao

    2018-03-01

    In addition to widely discussed seasonal variability, the barrier layer (BL) of the South China Sea (SCS) also exhibits significant intraseasonal variability (ISV) and plays an important role in the upper heat and salt balances. The characteristics and mechanisms of spatiotemporal variations in the BL are investigated using an eddy-resolving ocean model OFES (OGCM For the Earth Simulator) ouput and related atmospheric and oceanic processes. The active intraseasonal BL variability in the SCS occurs mainly during the late summer/autumn and winter and exhibits remarkable differences between these two periods. The BL ISV in late summer/autumn occurs in the southern basin, while in winter, it is limited to the northwestern basin. To further discuss the evolution and driving thermodynamic mechanisms, we quantify the processes that control the variability of intraseasonal BL. Different mechanisms for the intraseasonal BL variability for these two active periods are investigated based on the case study and composite analysis. During late summer/autumn, the active BL in the southern basin is generated by advected and local freshwater, and then decays rapidly with the enhanced wind. In winter, anticyclonic eddy activity is associated with the evolution of the BL by affecting the thermocline and halocline variations, while wind stress and wind stress curl have no obvious influence on BL.

  15. Analyses of heart rate variability in young soccer players: the effects of sport activity.

    Science.gov (United States)

    Bricout, Véronique-Aurélie; Dechenaud, Simon; Favre-Juvin, Anne

    2010-04-19

    The use of heart rate variability (HRV) in the management of sport training is a practice which tends to spread, especially in order to prevent the occurrence of states of fatigue. To estimate the HRV parameters obtained using a heart rate recording, according to different loads of sporting activities, and to make the possible link with the appearance of fatigue. Eight young football players, aged 14.6 years+/-2 months, playing at league level in Rhône-Alpes, training for 10 to 20 h per week, were followed over a period of 5 months, allowing to obtain 54 recordings of HRV in three different conditions: (i) after rest (ii) after a day with training and (iii) after a day with a competitive match. Under the effect of a competitive match, the HRV temporal indicators (heart rate, RR interval, and pNN50) were significantly altered compared to the rest day. The analysis of the sympathovagal balance rose significantly as a result of the competitive constraint (0.72+/-0.17 vs. 0.90+/-0.20; pHRV is an objective and non-invasive monitoring of management of the training of young sportsmen. HRV analysis allowed to highlight any neurovegetative adjustments according to the physical loads. Thus, under the effect of an increase of physical and psychological constraints that a football match represents, the LF/HF ratio rises significantly; reflecting increased sympathetic stimulation, which beyond certain limits could be relevant to prevent the emergence of a state of fatigue. 2009 Elsevier B.V. All rights reserved.

  16. All guns blazing: management and survival of massive valproic acid overdose – case report and literature review

    Directory of Open Access Journals (Sweden)

    Al Jawder S

    2018-01-01

    Full Text Available Shaikha Al Jawder,1 Eiman AlJishi,2 Shaikhah Al-Otaibi,2 Mohammed S Al-Shahrani3 1King Hamad University Hospital, Busaiteen, Bahrain; 2Emergency Medicine Department, 3Emergency and Critical Care Department, King Fahad Hospital of the University, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia Abstract: A 51-year-old woman, who intentionally ingested a massive dose of ~60 g of valproic acid which she was using as a mood stabilizer for bipolar affective disorder, presented within 30 minutes of ingestion to the emergency department. The patient was asymptomatic and was immediately started on decontamination therapy with activated charcoal (AC. Drug serum levels, liver functions, and ammonia levels were tested and followed up during treatment. Due to the massive ingestion and continuous rise in serum drug levels, the patient received regular multiple doses of AC, as well as l-carnitine for liver protection. The patient was started on extracorporeal therapy in the form of renal replacement therapy in the intensive care unit (ICU, followed by intermittent hemodialysis. Drug serum levels dropped significantly. Ammonia levels showed improvement with treatment. The patient was discharged from the ICU after 14 days of treatment. She was stable and in good condition with no residual hepatic or central nervous system (CNS manifestations. Keywords: valproic acid, multiple dose activated charcoal, l-carnitine, hemodialysis

  17. Trends and Variability of Global Fire Emissions Due To Historical Anthropogenic Activities

    Science.gov (United States)

    Ward, Daniel S.; Shevliakova, Elena; Malyshev, Sergey; Rabin, Sam

    2018-01-01

    Globally, fires are a major source of carbon from the terrestrial biosphere to the atmosphere, occurring on a seasonal cycle and with substantial interannual variability. To understand past trends and variability in sources and sinks of terrestrial carbon, we need quantitative estimates of global fire distributions. Here we introduce an updated version of the Fire Including Natural and Agricultural Lands model, version 2 (FINAL.2), modified to include multiday burning and enhanced fire spread rate in forest crowns. We demonstrate that the improved model reproduces the interannual variability and spatial distribution of fire emissions reported in present-day remotely sensed inventories. We use FINAL.2 to simulate historical (post-1700) fires and attribute past fire trends and variability to individual drivers: land use and land cover change, population growth, and lightning variability. Global fire emissions of carbon increase by about 10% between 1700 and 1900, reaching a maximum of 3.4 Pg C yr-1 in the 1910s, followed by a decrease to about 5% below year 1700 levels by 2010. The decrease in emissions from the 1910s to the present day is driven mainly by land use change, with a smaller contribution from increased fire suppression due to increased human population and is largest in Sub-Saharan Africa and South Asia. Interannual variability of global fire emissions is similar in the present day as in the early historical period, but present-day wildfires would be more variable in the absence of land use change.

  18. Distinguishing the impacts of human activities and climate variability on runoff and sediment load change based on paired periods with similar weather conditions

    NARCIS (Netherlands)

    Wang, Fei; Hessel, Rudi; Mu, Xingmin; Maroulis, Jerry; Zhao, Guangju; Geissen, Violette; Ritsema, Coen

    2015-01-01

    Runoff and sediment loads from river basin are largely affected by the interplay of climate variability and human activities within the basin. However, distinguishing the impacts of climate variability and human activities would vastly improve our knowledge of water resources, climate variability

  19. Sensitivity of temporal heart rate variability in Poincaré plot to changes in parasympathetic nervous system activity.

    Science.gov (United States)

    Karmakar, Chandan K; Khandoker, Ahsan H; Voss, Andreas; Palaniswami, Marimuthu

    2011-03-03

    A novel descriptor (Complex Correlation Measure (CCM)) for measuring the variability in the temporal structure of Poincaré plot has been developed to characterize or distinguish between Poincaré plots with similar shapes. This study was designed to assess the changes in temporal structure of the Poincaré plot using CCM during atropine infusion, 70° head-up tilt and scopolamine administration in healthy human subjects. CCM quantifies the point-to-point variation of the signal rather than gross description of the Poincaré plot. The physiological relevance of CCM was demonstrated by comparing the changes in CCM values with autonomic perturbation during all phases of the experiment. The sensitivities of short term variability (SD1), long term variability (SD2) and variability in temporal structure (CCM) were analyzed by changing the temporal structure by shuffling the sequences of points of the Poincaré plot. Surrogate analysis was used to show CCM as a measure of changes in temporal structure rather than random noise and sensitivity of CCM with changes in parasympathetic activity. CCM was found to be most sensitive to changes in temporal structure of the Poincaré plot as compared to SD1 and SD2. The values of all descriptors decreased with decrease in parasympathetic activity during atropine infusion and 70° head-up tilt phase. In contrast, values of all descriptors increased with increase in parasympathetic activity during scopolamine administration. The concordant reduction and enhancement in CCM values with parasympathetic activity indicates that the temporal variability of Poincaré plot is modulated by the parasympathetic activity which correlates with changes in CCM values. CCM is more sensitive than SD1 and SD2 to changes of parasympathetic activity.

  20. The Impact of Perceptual, Economic, and Demographic Variables on Entrepreneurial Activity in Globally Diverse Ecosystems: Evidence from GEM Data

    Science.gov (United States)

    Adams, Kenneth Raymond

    2016-01-01

    Leveraging a sample of more than 198,000 adult entrepreneurs, both currently involved in the startup of a business or formerly involved in business creation, this study investigates the perceptual, societal impression, economic, and demographic variables that are predictive with an individual's decision to engage in entrepreneurial activity.…

  1. Measurement of inter- and intra-annual variability of landscape fire activity at a continental scale: The Australian case

    Science.gov (United States)

    Grant J. Williamson; Lynda D. Prior; Matt Jolly; Mark A. Cochrane; Brett P. Murphy; David M. J. S. Bowman

    2016-01-01

    Climate dynamics at diurnal, seasonal and inter-annual scales shape global fire activity, although difficulties of assembling reliable fire and meteorological data with sufficient spatio-temporal resolution have frustrated quantification of this variability. Using Australia as a case study, we combine data from 4760 meteorological stations with 12 years of satellite-...

  2. Intra-subject variability in muscle activity and co-contraction during jumps and landings in children and adults

    DEFF Research Database (Denmark)

    Raffalt, P C; Alkjaer, T; Simonsen, E B

    2017-01-01

    -subject variability in the muscle activity. Co-contraction was quantified for two thigh muscle pairs and one plantar flexor/dorsiflexor muscle pair and group differences were assessed (two-way ANOVA). No significant differences were observed in the less eccentric demanding CMJ while significantly higher muscle...

  3. Solar Irradiance Variability is Caused by the Magnetic Activity on the Solar Surface.

    Science.gov (United States)

    Yeo, Kok Leng; Solanki, Sami K; Norris, Charlotte M; Beeck, Benjamin; Unruh, Yvonne C; Krivova, Natalie A

    2017-09-01

    The variation in the radiative output of the Sun, described in terms of solar irradiance, is important to climatology. A common assumption is that solar irradiance variability is driven by its surface magnetism. Verifying this assumption has, however, been hampered by the fact that models of solar irradiance variability based on solar surface magnetism have to be calibrated to observed variability. Making use of realistic three-dimensional magnetohydrodynamic simulations of the solar atmosphere and state-of-the-art solar magnetograms from the Solar Dynamics Observatory, we present a model of total solar irradiance (TSI) that does not require any such calibration. In doing so, the modeled irradiance variability is entirely independent of the observational record. (The absolute level is calibrated to the TSI record from the Total Irradiance Monitor.) The model replicates 95% of the observed variability between April 2010 and July 2016, leaving little scope for alternative drivers of solar irradiance variability at least over the time scales examined (days to years).

  4. VARIATIONS IN NEUROMUSCULAR ACTIVITY OF THIGH MUSCLES DURING WHOLE-BODY VIBRATION IN CONSIDERATION OF DIFFERENT BIOMECHANICAL VARIABLES

    Directory of Open Access Journals (Sweden)

    Dennis Perchthaler

    2013-09-01

    Full Text Available The intention of this study was to systematically analyze the impact of biomechanical variables in terms of different vibration frequencies, amplitudes and knee angles on quadriceps femoris and hamstring activity during exposure to whole-body vibration (WBV. 51 healthy men and women (age 55 ± 8 years voluntary participated in the study and were randomly allocated to five different vibration-frequency groups. Each subject performed 9 static squat positions (3 amplitudes x 3 knee angles on a side alternating vibration platform. Surface electromyography (EMG was used to record the neuromuscular activity of the quadriceps femoris and hamstring muscles. Maximal voluntary contractions (MVCs were performed prior to the measurements to normalize the EMG signals. A three-way mixed ANOVA was performed to analyze the different effects of the biomechanical variables on muscle activity. Depending on the biomechanical variables, EMG muscle activity ranged between 18.2 and 74.1 % MVC in the quadriceps femoris and between 5.2 and 27. 3 % MVC in the hamstrings during WBV. The highest levels of muscle activation were found at high frequencies and large amplitudes. Especially in the quadriceps femoris muscle, a WBV frequency of 30 Hz led to a significant increase in muscle activity compared to the other tested frequencies. However, it seems that knee angle is only relevant for the quadriceps femoris muscle. The results of this study should give more information for developing individual training protocols for WBV treatment in different practical applications

  5. Effects of human activities and climate variability on water resources in the Saveh plain, Iran.

    Science.gov (United States)

    Mohammadi Ghaleni, M; Ebrahimi, K

    2015-02-01

    Quantity and quality distribution of surface water and groundwater are changing under the impacts of both climate variability and human activities. The main goal of this paper is to evaluate the abovementioned impacts on the water resources in the Saveh plain, central Iran. To achieve this aim, spatial and temporal changes of the surface and groundwater quality and quantity have been analyzed, using hydrometric and meteorological data. The nonparametric Mann-Kendall test was used to identify trends and change points in the annual rainfall and runoff for the period of 1946 to 2011. In order to analyze the impacts of the Saveh Dam on runoff, the dam operation year, 1994, was considered as a change point. Mann-Kendall test results show that rainfall time series was divided into two parts, namely, 1966-1989 and 1990-2007, and averages of annual rainfall in five stations increase from 10 to 21 %. Also, runoff time series was divided into two parts, namely, 1946-1995 and 1996-2007 and averages of annual runoff in four stations decrease from 8 to 83 %. Results show that rainfall changes in Shahabasi, Razin, Jalayer, Emamabad, and Ahmadabad stations increased from 9 to 33 % before and after 1994. Nevertheless, runoff decreased from 24 to 81 %. The results indicate that the greatest lack of runoff between stations is at Shahabasi station and one important reason for the severe lack is operation of the Saveh Dam in 1994. Highest groundwater level decline, about 168.67 cm, occurred in 1994 that is the operation year of the Saveh Dam. Trend analysis of surface water quality show that electrical conductivity increased 957.34 μmho/cm before and after 1994. Also, the Wilcox water quality classification method has been reduced from C3-S1 to C4-S2. Average groundwater electrical conductivity (EC) during 1999-2003 and 2004-2009 increased to 89.6 μmho/cm. Also, the groundwater quality indices for agricultural usages are classified in four classes including, C4-S2 16, C4-S1 46, C3-S

  6. TIME VARIABILITY OF EMISSION LINES FOR FOUR ACTIVE T TAURI STARS. I. OCTOBER–DECEMBER IN 2010

    International Nuclear Information System (INIS)

    Chou, Mei-Yin; Takami, Michihiro; Karr, Jennifer L.; Shang Hsien; Liu, Hauyu Baobab; Manset, Nadine; Beck, Tracy; Pyo, Tae-Soo; Chen, Wen-Ping; Panwar, Neelam

    2013-01-01

    We present optical spectrophotometric monitoring of four active T Tauri stars (DG Tau, RY Tau, XZ Tau, RW Aur A) at high spectral resolution (R ∼> 1 × 10 4 ), to investigate the correlation between time variable mass ejection seen in the jet/wind structure of the driving source and time variable mass accretion probed by optical emission lines. This may allow us to constrain the understanding of the jet/wind launching mechanism, the location of the launching region, and the physical link with magnetospheric mass accretion. In 2010, observations were made at six different epochs to investigate how daily and monthly variability might affect such a study. We perform comparisons between the line profiles we observed and those in the literature over a period of decades and confirm the presence of time variability separate from the daily and monthly variability during our observations. This is so far consistent with the idea that these line profiles have a long-term variability (3-20 yr) related to episodic mass ejection suggested by the structures in the extended flow components. We also investigate the correlations between equivalent widths and between luminosities for different lines. We find that these correlations are consistent with the present paradigm of steady magnetospheric mass accretion and emission line regions that are close to the star.

  7. TIME VARIABILITY OF EMISSION LINES FOR FOUR ACTIVE T TAURI STARS. I. OCTOBER-DECEMBER IN 2010

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Mei-Yin; Takami, Michihiro; Karr, Jennifer L.; Shang Hsien; Liu, Hauyu Baobab [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Manset, Nadine [Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743 (United States); Beck, Tracy [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Pyo, Tae-Soo [Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States); Chen, Wen-Ping; Panwar, Neelam [Institute of Astronomy, National Central University, Taoyuan County 32001, Taiwan (China)

    2013-04-15

    We present optical spectrophotometric monitoring of four active T Tauri stars (DG Tau, RY Tau, XZ Tau, RW Aur A) at high spectral resolution (R {approx}> 1 Multiplication-Sign 10{sup 4}), to investigate the correlation between time variable mass ejection seen in the jet/wind structure of the driving source and time variable mass accretion probed by optical emission lines. This may allow us to constrain the understanding of the jet/wind launching mechanism, the location of the launching region, and the physical link with magnetospheric mass accretion. In 2010, observations were made at six different epochs to investigate how daily and monthly variability might affect such a study. We perform comparisons between the line profiles we observed and those in the literature over a period of decades and confirm the presence of time variability separate from the daily and monthly variability during our observations. This is so far consistent with the idea that these line profiles have a long-term variability (3-20 yr) related to episodic mass ejection suggested by the structures in the extended flow components. We also investigate the correlations between equivalent widths and between luminosities for different lines. We find that these correlations are consistent with the present paradigm of steady magnetospheric mass accretion and emission line regions that are close to the star.

  8. Increased topographical variability of task-related activation in perceptive and motor associative regions in adult autistics

    Directory of Open Access Journals (Sweden)

    Marie-Pier Poulin-Lord

    2014-01-01

    Conclusion: Different and possibly unique strategies are used by each autistic individual. That enhanced variability in localization of activations in the autistic group is found in regions typically more variable in non-autistics raises the possibility that autism involves an enhancement and/or an alteration of typical plasticity mechanisms. The current study also highlights the necessity to verify, in fMRI studies involving autistic people, that hypoactivation at the group level does not result from each individual successfully completing a task using a unique brain allocation, even by comparison to his own group.

  9. Chromospheric activity of periodic variable stars (including eclipsing binaries) observed in DR2 LAMOST stellar spectral survey

    Science.gov (United States)

    Zhang, Liyun; Lu, Hongpeng; Han, Xianming L.; Jiang, Linyan; Li, Zhongmu; Zhang, Yong; Hou, Yonghui; Wang, Yuefei; Cao, Zihuang

    2018-05-01

    The LAMOST spectral survey provides a rich databases for studying stellar spectroscopic properties and chromospheric activity. We cross-matched a total of 105,287 periodic variable stars from several photometric surveys and databases (CSS, LINEAR, Kepler, a recently updated eclipsing star catalogue, ASAS, NSVS, some part of SuperWASP survey, variable stars from the Tsinghua University-NAOC Transient Survey, and other objects from some new references) with four million stellar spectra published in the LAMOST data release 2 (DR2). We found 15,955 spectra for 11,469 stars (including 5398 eclipsing binaries). We calculated their equivalent widths (EWs) of their Hα, Hβ, Hγ, Hδ and Caii H lines. Using the Hα line EW, we found 447 spectra with emission above continuum for a total of 316 stars (178 eclipsing binaries). We identified 86 active stars (including 44 eclipsing binaries) with repeated LAMOST spectra. A total of 68 stars (including 34 eclipsing binaries) show chromospheric activity variability. We also found LAMOST spectra of 12 cataclysmic variables, five of which show chromospheric activity variability. We also made photometric follow-up studies of three short period targets (DY CVn, HAT-192-0001481, and LAMOST J164933.24+141255.0) using the Xinglong 60-cm telescope and the SARA 90-cm and 1-m telescopes, and obtained new BVRI CCD light curves. We analyzed these light curves and obtained orbital and starspot parameters. We detected the first flare event with a huge brightness increase of more than about 1.5 magnitudes in R filter in LAMOST J164933.24+141255.0.

  10. Long-term variability and impact on human health of biologically active UV radiation in Moscow

    Science.gov (United States)

    Zhdanova, Ekaterina; Chubarova, Natalia

    2014-05-01

    Measurements of erythemally weighted UV irradiance (Qer) have been performed at the Meteorological Observatory of Moscow State University since 1999 with the UVB-1 YES pyranometers. These types of devices are broadband with a spectral sensitivity curve close to the action spectrum of erythema. Main uncertainties of UVB-1 YES measurements include the difference in spectral curves of the instrument and the action spectrum of erythema, as well as the deviation from the cosine law. These uncertainties were taken into account in the database of Qer measurements (Chubarova, 2008. Additional corrections of UVB-1 measurements at low ambient temperatures have been made. We analyze interannual, seasonal and diurnal Qer changes over the time period 1999-2012. In addition, the comparisons with the results of UV reconstruction model (Chubarova, 2008) are made. This model allows us to evaluate relative changes in Qer due to variations in total ozone, effective cloud amount transmission, aerosol and cloud optical thickness since 1968. It is important to note that the main reason for UV irradiance monitoring development is the strong influence of UV irradiance on the biosphere and especially on human health mainly on human skin (CIE, 1993, CIE, 2006) and eyes (Oriowo, M. et al., 2001). Based on the detailed studies we have shown the possibility of utilizing UVB-1 pyranometers for measuring the eye-damage UV radiation. Parallel measurements by the Bentham DTM-300 spectrometer and the UVB-1 YES pyranometer at the Innsbruck Medical University (Austria) have provided us the calibration factor in eye-damage units for this broadband instrument. Influence of main geophysical factors on different types of UV irradiance is estimated by means the RAF ideology (Booth, Madronich, 1994). We discuss the responses of different types of biologically active UV radiation to the impact of various atmospheric factors. The UV conditions (deficiency, optimum, excess for human) are analyzed according to

  11. Psychosocial Variables Related to Why Women are Less Active than Men and Related Health Implications

    OpenAIRE

    Edwards, Elizabeth Skidmore; Sackett, Sarah Carson

    2016-01-01

    This article reviews psychosocial influences on women's participation in physical activity as they differ from men and how associated activity differences impact women's risk for a number of chronic diseases. This topic directly aligns with the mission of this special edition related to disparities in women's health as the typically lower level of physical activity in females directly impacts their health. On average, females participate in physical activity at lower rates than their male cou...

  12. Randomized Trial of a Lifestyle Physical Activity Intervention for Breast Cancer Survivors: Effects on Transtheoretical Model Variables.

    Science.gov (United States)

    Scruggs, Stacie; Mama, Scherezade K; Carmack, Cindy L; Douglas, Tommy; Diamond, Pamela; Basen-Engquist, Karen

    2018-01-01

    This study examined whether a physical activity intervention affects transtheoretical model (TTM) variables that facilitate exercise adoption in breast cancer survivors. Sixty sedentary breast cancer survivors were randomized to a 6-month lifestyle physical activity intervention or standard care. TTM variables that have been shown to facilitate exercise adoption and progress through the stages of change, including self-efficacy, decisional balance, and processes of change, were measured at baseline, 3 months, and 6 months. Differences in TTM variables between groups were tested using repeated measures analysis of variance. The intervention group had significantly higher self-efficacy ( F = 9.55, p = .003) and perceived significantly fewer cons of exercise ( F = 5.416, p = .025) at 3 and 6 months compared with the standard care group. Self-liberation, counterconditioning, and reinforcement management processes of change increased significantly from baseline to 6 months in the intervention group, and self-efficacy and reinforcement management were significantly associated with improvement in stage of change. The stage-based physical activity intervention increased use of select processes of change, improved self-efficacy, decreased perceptions of the cons of exercise, and helped participants advance in stage of change. These results point to the importance of using a theory-based approach in interventions to increase physical activity in cancer survivors.

  13. Variability and seasonality of active transportation in USA: evidence from the 2001 NHTS

    Science.gov (United States)

    2011-01-01

    Background Active transportation including walking and bicycling is an important source of physical activity. Promoting active transportation is a challenge for the fields of public health and transportation. Descriptive data on the predictors of active transportation, including seasonal patterns in active transportation in the US as a whole, is needed to inform interventions and policies. Methods This study analyzed monthly variation in active transportation for the US using National Household Travel Survey 2001 data. For each age group of children, adolescents, adults and elderly, logistic regression models were used to identify predictors of the odds of active transportation including gender, race/ethnicity, household income level, geographical region, urbanization level, and month. Results The probability of engaging in active transportation was generally higher for children and adolescents than for adults and the elderly. Active transportation was greater in the lower income groups (except in the elderly), was lower in the South than in other regions of the US, and was greater in areas with higher urbanization. The percentage of people using active transportation exhibited clear seasonal patterns: high during summer months and low during winter months. Children and adolescents were more sensitive to seasonality than other age groups. Women, non-Caucasians, persons with lower household income, who resided in the Midwest or Northeast, and who lived in more urbanized areas had greater seasonal variation. Conclusions These descriptive results suggest that interventions and policies that target the promotion of active transportation need to consider socio-demographic factors and seasonality. PMID:21917136

  14. Raw material variability of an active pharmaceutical ingredient and its relevance for processability in secondary continuous pharmaceutical manufacturing.

    Science.gov (United States)

    Stauffer, F; Vanhoorne, V; Pilcer, G; Chavez, P-F; Rome, S; Schubert, M A; Aerts, L; De Beer, T

    2018-06-01

    Active Pharmaceutical Ingredients (API) raw material variability is not always thoroughly considered during pharmaceutical process development, mainly due to low quantities of drug substance available. However, synthesis, crystallization routes and production sites evolve during product development and product life cycle leading to changes in physical material attributes which can potentially affect their processability. Recent literature highlights the need for a global approach to understand the link between material synthesis, material variability, process and product quality. The study described in this article aims at explaining the raw material variability of an API using extensive material characterization on a restricted number of representative batches using multivariate data analysis. It is part of a larger investigation trying to link the API drug substance manufacturing process, the resulting physical API raw material attributes and the drug product continuous manufacturing process. Eight API batches produced using different synthetic routes, crystallization, drying, delumping processes and processing equipment were characterized, extensively. Seventeen properties from seven characterization techniques were retained for further analysis using Principal Component Analysis (PCA). Three principal components (PCs) were sufficient to explain 92.9% of the API raw material variability. The first PC was related to crystal length, agglomerate size and fraction, flowability and electrostatic charging. The second PC was driven by the span of the particle size distribution and the agglomerates strength. The third PC was related to surface energy. Additionally, the PCA allowed to summarize the API batch-to-batch variability in only three PCs which can be used in future drug product development studies to quantitatively evaluate the impact of the API raw material variability upon the drug product process. The approach described in this article could be applied to any

  15. Relationship of moderate and low isometric lumbar extension through architectural and muscular activity variables: a cross sectional study

    International Nuclear Information System (INIS)

    Cuesta-Vargas, Antonio I; Gonzalez-Sanchez, Manuel

    2013-01-01

    No study relating the changes obtained in the architecture of erector spinae (ES) muscle were registered with ultrasound and different intensities of muscle contraction recorded by surface EMG (electromyography) on the ES muscle was found. The aim of this study was analyse the relationship in the response of the ES muscle during isometric moderate and light lumbar isometric extension considering architecture and functional muscle variables. Cross-sectional study. 46 subjects (52% men) with a group mean age of 30.4 (±7.78). The participants developed isometric lumbar extension while performing moderate and low isometric trunk and hip extension in a sitting position with hips flexed 90 degrees and the lumbar spine in neutral position. During these measurements, electromyography recordings and ultrasound images were taken bilaterally. Bilaterally pennation angle, muscle thickness, torque and muscle activation were measured. This study was developed at the human movement analysis laboratory of the Health Science Faculty of the University of Malaga (Spain). Strong and moderate correlations were found at moderate and low intensities contraction between the variable of the same intensity, with correlation values ranging from 0.726 (Torque Moderate – EMG Left Moderate) to 0.923 (Angle Left Light – Angle Right Light) (p < 0.001). This correlation is observed between the variables that describe the same intensity of contraction, showing a poor correlation between variables of different intensities. There is a strong relationship between architecture and function variables of ES muscle when describe an isometric lumbar extension at light or moderate intensity

  16. Increased Force Variability Is Associated with Altered Modulation of the Motorneuron Pool Activity in Autism Spectrum Disorder (ASD).

    Science.gov (United States)

    Wang, Zheng; Kwon, Minhyuk; Mohanty, Suman; Schmitt, Lauren M; White, Stormi P; Christou, Evangelos A; Mosconi, Matthew W

    2017-03-25

    Force control deficits have been repeatedly documented in autism spectrum disorder (ASD). They are associated with worse social and daily living skill impairments in patients suggesting that developing a more mechanistic understanding of the central and peripheral processes that cause them may help guide the development of treatments that improve multiple outcomes in ASD. The neuromuscular mechanisms underlying force control deficits are not yet understood. Seventeen individuals with ASD and 14 matched healthy controls completed an isometric index finger abduction test at 60% of their maximum voluntary contraction (MVC) during recording of the first dorsal interosseous (FDI) muscle to determine the neuromuscular processes associated with sustained force variability. Central modulation of the motorneuron pool activation of the FDI muscle was evaluated at delta (0-4 Hz), alpha (4-10 Hz), beta (10-35 Hz) and gamma (35-60 Hz) frequency bands. ASD patients showed greater force variability than controls when attempting to maintain a constant force. Relative to controls, patients also showed increased central modulation of the motorneuron pool at beta and gamma bands. For controls, reduced force variability was associated with reduced delta frequency modulation of the motorneuron pool activity of the FDI muscle and increased modulation at beta and gamma bands. In contrast, delta, beta, and gamma frequency oscillations were not associated with force variability in ASD. These findings suggest that alterations of central mechanisms that control motorneuron pool firing may underlie the common and often impairing symptoms of ASD.

  17. Computer work and self-reported variables on anthropometrics, computer usage, work ability, productivity, pain, and physical activity.

    Science.gov (United States)

    Madeleine, Pascal; Vangsgaard, Steffen; Hviid Andersen, Johan; Ge, Hong-You; Arendt-Nielsen, Lars

    2013-08-01

    Computer users often report musculoskeletal complaints and pain in the upper extremities and the neck-shoulder region. However, recent epidemiological studies do not report a relationship between the extent of computer use and work-related musculoskeletal disorders (WMSD).The aim of this study was to conduct an explorative analysis on short and long-term pain complaints and work-related variables in a cohort of Danish computer users. A structured web-based questionnaire including questions related to musculoskeletal pain, anthropometrics, work-related variables, work ability, productivity, health-related parameters, lifestyle variables as well as physical activity during leisure time was designed. Six hundred and ninety office workers completed the questionnaire responding to an announcement posted in a union magazine. The questionnaire outcomes, i.e., pain intensity, duration and locations as well as anthropometrics, work-related variables, work ability, productivity, and level of physical activity, were stratified by gender and correlations were obtained. Women reported higher pain intensity, longer pain duration as well as more locations with pain than men (P women scored poorer work ability and ability to fulfil the requirements on productivity than men (P work ability/productivity (P work ability reported by women workers relate to their higher risk of contracting WMSD. Overall, this investigation confirmed the complex interplay between anthropometrics, work ability, productivity, and pain perception among computer users.

  18. Soft X-ray variability and the covering fraction of active galactic nuclei

    International Nuclear Information System (INIS)

    Wachter, K.W.; Strauss, M.A.; Filippenko, A.V.

    1988-01-01

    A model to explain the observed soft X-ray variability to some low-luminosity Seyfert 1 galaxies is developed. The variability is due to changes in the covering fraction of the central source as broad-line clouds move across our line of sight. A formalism is developed which is used to demonstrate how analysis of a soft X-ray light curve can provide three important quantities: the radius of the X-ray emitting region, the radius of a typical broad-line cloud, and the electron density in the cloud. It is shown that the results are rather insensitive to the assumed radial dependence of the surface brightness of the source, but are quite sensitive to a large dispersion in cloud sizes. 55 references

  19. The Influence of Tidal Activities on Hydrologic Variables of Paka River, Terengganu, Malaysia

    International Nuclear Information System (INIS)

    Mohd EkhwanToriman; Mohd Ekhwan Toriman; Muhammad Barzani Gasim; Haniff Muhamad

    2015-01-01

    A hydrological study was conducted to determine their characteristics at Paka River, Terengganu. Seven sampling stations were identified in this study. Sampling was started from the estuary of Paka River, and ended about 14 km away from the estuary as each station was 2 km apart from each other. Sampling was carried out at two different water tides (low and high water tides) and two durational variations which represented by the wet and dry periods. Hydrological variables such as river velocity, river width and river depth were measured by using specific equipment. River width was measured by using a range finder (model Bushnell 20-0001), river depth was measured by using a depth meter (model Speedtech SM-5) and river velocity was measured by using a flow meter/current flow meter (model FP101). Station 1 that located at the downstream identified by highest readings for hydrological variables both water tides during the first and second samplings compared to stations 7 which located at the upstream. Higher readings of hydrological variables were also shown during dry season since low freshwater flow due to less rainfall intensity in the upstream area. (author)

  20. The Influence of Tidal Activities on Hydrologic Variables of Marang River, Terengganu, Malaysia

    International Nuclear Information System (INIS)

    Mohd Ekhwan Toriman; Mohd Ekhwan Toriman; Muhammad Barzani Gasim; Nur Hidayah Ariffin; Haniff Muhamad; Norsyuhada Hairoma

    2015-01-01

    A study was conducted at Marang River, Terengganu on determination of hydrological variation of Marang River at seven sampling stations. Sampling stations were selected along Marang River started from downstream to upstream. Each station was located 2 km apart from each other. Sampling was done twice; the first sampling was in 13 November 2012 (rainy season) and was repeated for second sampling on 24 February 2013 (dry season). Hydrological measurements of river such as velocity, river width and river depth were measured by using specific equipment. River velocity was measured by using flow meter (model FP101), river width was measured by using a range finder (model Bushnell 20-0001) and river depth was measured by using depth meter. Primary data of hydrological measurements of Marang River were measured and analyzed for each sampling station. Overall, station 1 shows the highest readings for most hydrological variables at both water tides during the first and second samplings. Station 1 that was located at the Marang River estuary identified by higher hydrological variables due to seawater movement during high tide as compared to stations 7 which located at the upstream. During dry season hydrological variables were slightly decrease since low freshwater flow from the upstream due to less rainfall intensity. (author)

  1. (Tele)Connectivity in climate variability at different spatial/temporal scales in relation to solar and geomagnetic activity

    Czech Academy of Sciences Publication Activity Database

    Paluš, Milan; Hartman, David; Vejmelka, Martin; Novotná, Dagmar

    2011-01-01

    Roč. 13, - (2011), s. 9579 ISSN 1607-7962. [European Geosciences Union General Assembly 2011. 03.04.2011-08.04.2011, Vienna] R&D Projects: GA AV ČR IAA300420805 Institutional research plan: CEZ:AV0Z10300504; CEZ:AV0Z30420517 Keywords : climate variability * phase coherence * synchronization * North Atlantic Oscillation * solar activity Subject RIV: BB - Applied Statistics, Operational Research

  2. [The influence of variable and constant magnetic fields on biota and biological activity of ordinary chernozem soils].

    Science.gov (United States)

    Denisova, T V; Kazeev, K Sh

    2007-01-01

    In model experiments on influence variable magnetic fields of industrial frequency (50 Hz) an induction of 1500 and of 6000 mkTl and the constant magnetic field an induction of 6000 mkTl and of 15000 mkTl during 5 days of exposure on biological properties of chernozem ordinary is shown, that the soil microflora is more sensitive to magnetic fields, than enzymes activity. Bacteria are more sensitive, than microscopic mushrooms. Dehydrogenase it is steady against influence of all variants. Constant magnetic field by the induction of 15000 mkTl rendered practically identical authentic overwhelming influence on catalase and saccharase activity - on 51 and 47% accordingly.

  3. Variability of atmospheric krypton-85 activity concentrations observed close to the ITCZ in the southern hemisphere.

    Science.gov (United States)

    Bollhöfer, A; Schlosser, C; Ross, J O; Sartorius, H; Schmid, S

    2014-01-01

    Krypton-85 activity concentrations in surface air have been measured at Darwin, which is located in northern Australia and is influenced by seasonal monsoonal activity. Measurements between August 2007 and May 2010 covered three wet seasons. The mean activity concentration of krypton-85 measured during this period was 1.31±0.02Bqm(-3). A linear model fitted to the average monthly data, using month and monsoon as predictors, shows that krypton-85 activity concentration measured during the sampling period has declined by 0.01Bqm(-3) per year. Although there is no statistically significant difference in mean activity concentration of krypton-85 between wet and dry season, the model implies that activity concentration is higher by about 0.015Bqm(-3) during months influenced by the monsoon when a north westerly flow prevails. Backward dispersion runs using the Lagrangian particle dispersion model Hysplit4 highlight possible source regions during an active monsoon located deep in the northern hemisphere, and include reprocessing facilities in Japan and India. However, the contribution of these facilities to krypton-85 activity concentrations in Darwin would be less than 0.003Bqm(-3). Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  4. Psychosocial Variables Related to Why Women are Less Active than Men and Related Health Implications

    Directory of Open Access Journals (Sweden)

    Elizabeth Skidmore Edwards

    2016-01-01

    Full Text Available This article reviews psychosocial influences on women's participation in physical activity as they differ from men and how associated activity differences impact women's risk for a number of chronic diseases. This topic directly aligns with the mission of this special edition related to disparities in women's health as the typically lower level of physical activity in females directly impacts their health. On average, females participate in physical activity at lower rates than their male counterparts. These lower rates of physical activity are directly related to both incidence of and outcomes from cardiovascular disease, type 2 diabetes, and breast and gynecological cancers. The relationship between psychosocial factors that are understood to affect physical activity differs between men and women. Specifically, self-efficacy, social support, and motivation are empirically substantiated factors that found to impact physical activity participation among women differently than men. Understanding these relationships is integral to designing effective interventions to target physical activity participation in women so that the related health risks are adequately addressed.

  5. Pre-analytical and Analytical Variables Affecting the Measurement of Plasma-Derived Microparticle Tissue Factor Activity

    Science.gov (United States)

    Lee, RD; Barcel, DA; Williams, JC; Wang, JG; Boles, JC; Manly, DA; Key, NS; Mackman, N

    2011-01-01

    Introduction Elevated levels of tissue factor positive (TF+) microparticles (MPs) are observed in plasma from a variety of patients with an increased risk of thrombosis. We and others have described the measurement of TF activity in MPs isolated from plasma. The aim of this study was to investigate the effects of pre-analytical and analytical variables on TF activity of MPs isolated from blood of healthy volunteers treated ex vivo with or without bacterial lipopolysaccharide. Materials and Methods We evaluated the following parameters: use of different centrifugation speeds to isolate the MPs; comparison of TF activity of MPs isolated from platelet poor plasma versus platelet free plasma; effect of freeze/thaw on MP TF activity; and comparison of the MP TF activity assay with the measurement of TF protein by ELISA or flow cytometry. Results MPs prepared from platelet poor plasma by centrifugation at 20,000 × g or 100,000 × g for 15 minutes had similar levels of TF activity. However, significantly less TF activity was found in MPs isolated from platelet free plasma compared with platelet poor plasma. Interestingly, freeze/thawing of the plasma showed donor to donor variation in MP TF activity, with a moderate increase in some individuals. Conclusion TF+ MPs can be quantitatively isolated from platelet poor or platelet free plasma by centrifugation at 20,000 × g for 15 minutes. Measurement of MP TF activity in plasma can be used to detect a prothrombotic state in patients with various diseases. PMID:21737126

  6. The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population.

    Science.gov (United States)

    Campbell, Candice; Kress, Jeff; Schroeder, Jan; Donlin, Ayla; Rozenek, Ralph

    2016-01-01

    The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB) Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level activity participants (7,500 steps/day) in weight, age, and the number of medications reported. Males performed better than females on the two-footed jump test and reactive postural test FAB assessments. High-level activity participants performed significantly better than low-level activity participants on all FAB assessments except stand with feet together and eyes closed, reach forward to object, and walk with head turns.

  7. The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population

    Directory of Open Access Journals (Sweden)

    Candice Campbell MS

    2016-12-01

    Full Text Available The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level activity participants (7,500 steps/day in weight, age, and the number of medications reported. Males performed better than females on the two-footed jump test and reactive postural test FAB assessments. High-level activity participants performed significantly better than low-level activity participants on all FAB assessments except stand with feet together and eyes closed, reach forward to object, and walk with head turns.

  8. Animal-Assisted Activity: Effects of a Complementary Intervention Program on Psychological and Physiological Variables.

    Science.gov (United States)

    Nepps, Peggy; Stewart, Charles N; Bruckno, Stephen R

    2014-07-01

    Animal-assisted activity is the use of trained animals for the therapeutic, motivational, or educational benefit of patients. Subjects of this study were 218 patients hospitalized on the mental health unit of a community hospital with an existing, complementary animal-assisted activity program. Half of the patients participated in a 1-hour session of animal-assisted activity. The other half, who served as a comparison group, participated in a 1-hour stress management program. It was hypothesized that an animal-assisted activity program would improve ratings of depression, anxiety, and pain and the associated physiological measures of stress and discomfort. Self-report ratings of depression, anxiety, and pain were collected before and after treatment sessions, and blood pressure, pulse, and salivary cortisol were measured. There were significant decreases in depression (P animal-assisted activity program, comparable to those in the more traditional stress management group. © The Author(s) 2014.

  9. Essential Oil Variability and Biological Activities of Tetraclinis articulata (Vahl) Mast. Wood According to the Extraction Time.

    Science.gov (United States)

    Djouahri, Abderrahmane; Saka, Boualem; Boudarene, Lynda; Baaliouamer, Aoumeur

    2016-12-01

    In the present work, the hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) kinetics of essential oil (EO) extracted from Tetraclinis articulata (Vahl) Mast. wood was conducted, in order to assess the impact of extraction time and technique on chemical composition and biological activities. Gas chromatography (GC) and GC/mass spectrometry analyses showed significant differences between the extracted EOs, where each family class or component presents a specific kinetic according to extraction time, technique and especially for the major components: camphene, linalool, cedrol, carvacrol and α-acorenol. Furthermore, our findings showed a high variability for both antioxidant and anti-inflammatory activities, where each activity has a specific effect according to extraction time and technique. The highlighted variability reflects the high impact of extraction time and technique on chemical composition and biological activities, which led to conclude that we should select EOs to be investigated carefully depending on extraction time and technique, in order to isolate the bioactive components or to have the best quality of EO in terms of biological activities and preventive effects in food. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

  10. Characterisation of silent and active genes for a variable large protein of Borrelia recurrentis

    Directory of Open Access Journals (Sweden)

    Scragg Ian G

    2002-10-01

    Full Text Available Abstract Background We report the characterisation of the variable large protein (vlp gene expressed by clinical isolate A1 of Borrelia recurrentis; the agent of the life-threatening disease louse-borne relapsing fever. Methods The major vlp protein of this isolate was characterised and a DNA probe created. Use of this together with standard molecular methods was used to determine the location of the vlp1B. recurrentis A1 gene in both this and other isolates. Results This isolate was found to carry silent and expressed copies of the vlp1B. recurrentis A1 gene on plasmids of 54 kbp and 24 kbp respectively, whereas a different isolate, A17, had only the silent vlp1B. recurrentis A17 on a 54 kbp plasmid. Silent and expressed vlp1 have identical mature protein coding regions but have different 5' regions, both containing different potential lipoprotein leader sequences. Only one form of vlp1 is transcribed in the A1 isolate of B. recurrentis, yet both 5' upstream sequences of this vlp1 gene possess features of bacterial promoters. Conclusion Taken together these results suggest that antigenic variation in B. recurrentis may result from recombination of variable large and small protein genes at the junction between lipoprotein leader sequence and mature protein coding region. However, this hypothetical model needs to be validated by further identification of expressed and silent variant protein genes in other B. recurrentis isolates.

  11. Interleaved Buck Converter with Variable Number of Active Phases and a Predictive Current Sharing Scheme

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Garcia, O.; Oliver, J. A.

    2008-01-01

    The efficiency of an interleaved Buck converter is typically low at light load conditions because of the switching losses in each of the switching stages. Improvements in the converter efficiency can be achieved by dynamically changing the number of active phases depending on the load current....... This paper addresses the issues related to the transient response of the converter when the number of active phases is changed by a digital control scheme. The problem arises because the current in the individual phases of the interleaved Buck converter will not be equal immediately after the controller has...... changed the number of active phases. This paper proposes a current equalisation scheme that adjusts the duty cycle of each phase in a manner that ensures equal average inductor current in all active phases in one or two PWM periods. The current equalisation scheme relies on the measurement of the output...

  12. The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population

    OpenAIRE

    Campbell, Candice; Kress, Jeff; Schroeder, Jan; Donlin, Ayla; Rozenek, Ralph

    2016-01-01

    The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB) Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level...

  13. The Spatial Variability of Soil Dehydrogenase Activity: A Survey in Urban Soils

    OpenAIRE

    Kizilkaya, Ridvan; Aşkin, Tayfun

    2007-01-01

    Information on soil microorganisms and their activity used to determine microbiological characteristics are very important for soil quality and productivity. Studies of enzyme activities provide information on the biochemical processes occurring in soil. There is growing evidence that soil biological parameters may be potential and sensitive indicators of soil ecological conditions and soil management. Soil microbiological parameters may be evaluated statistically due to application of geosta...

  14. Chemical Variability and Biological Activities of Brassica rapa var. rapifera Parts Essential Oils Depending on Geographic Variation and Extraction Technique.

    Science.gov (United States)

    Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Terfi, Souhila; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

    2017-06-01

    In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. Gas-chromatography (GC) and GC/mass spectrometry (MS) analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation and microwave-assisted hydrodistillation techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  15. Rainfall erosivity and sediment load over the Poyang Lake Basin under variable climate and human activities since the 1960s

    Science.gov (United States)

    Gu, Chaojun; Mu, Xingmin; Gao, Peng; Zhao, Guangju; Sun, Wenyi; Yu, Qiang

    2018-03-01

    Accelerated soil erosion exerts adverse effects on water and soil resources. Rainfall erosivity reflects soil erosion potential driven by rainfall, which is essential for soil erosive risk assessment. This study investigated the spatiotemporal variation of rainfall erosivity and its impacts on sediment load over the largest freshwater lake basin of China (the Poyang Lake Basin, abbreviate to PYLB). The spatiotemporal variations of rainfall erosivity from 1961 to 2014 based on 57 meteorological stations were detected using the Mann-Kendall test, linear regression, and kriging interpolation method. The sequential t test analysis of regime shift (STARS) was employed to identify the abrupt changes of sediment load, and the modified double mass curve was used to assess the impacts of rainfall erosivity variability on sediment load. It was found that there was significant increase (P change-points were identified in both 1985 and 2003. It was found that take annual rainfall erosivity as the explanatory variables of the double mass curves is more reasonable than annual rainfall and erosive rainfall. The estimation via the modified double mass curve demonstrated that compared with the period before change-point (1961-1984), the changes of rainfall erosivity increased 8.0 and 2.1% of sediment load during 1985-2002 and 2003-2014, respectively. Human activities decreased 50.2 and 69.7% of sediment load during the last two periods, which indicated effects of human activities on sediment load change was much larger than that of rainfall erosivity variability in the PYLB.

  16. Variable frequency operation of active stall wind farms using a dc connection to grid

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Sorensen, Poul

    2005-01-01

    Currently, there is an increasing trend to connect large MW wind farms to the transmISSIon system. Requirements that focus on the influence of the farms on the grid stability and power quality, and on the control capabilities of wind farms have already been established. The main trends of modern...... wind turbines/farms are clearly the variable speed operation and a grid connection through a power electronic interface, especially using doubly-fed induction generators. Using power electronics the control capabilities of these wind turbines/farms are extended and thus the grid requirements...... are fulfilled. However, the traditional squirrel-cage generators based wind turbines/wind farms directly connected to the grid have less control capabilities. These wind turbines/farms cannot regulate their production and contribute to power system stability. A DC transmission system for connection...

  17. Variability of disease activity in patients treated with ranibizumab for neovascular age-related macular degeneration.

    Science.gov (United States)

    Enders, P; Scholz, P; Muether, P S; Fauser, S

    2016-08-01

    PurposeTo analyze choroidal neovasularization (CNV) activity and recurrence patterns in patients with neovascular age-related macular degeneration (nAMD) treated with ranibizumab, and the correlation with individual intraocular vascular endothelial growth factor (VEGF) suppression time (VST).MethodsPost-hoc analysis of data from a prospective, non-randomized clinical study. Patients with nAMD treated with ranibizumab on a pro re nata regimen. Disease activity was analyzed monthly by spectral-domain optical coherence tomography and correlated with VSTs.ResultsOverall, 73 eyes of 73 patients were included in the study with a mean follow-up of 717 days (range: 412-1239 days). Overall, the mean CNV-activity-free interval was 76.5 days (range: 0-829 days). The individual range of the length of dry intervals was high. A total of 42% of patients had a range of more than 90 days. Overall, 16% of patients showed persistent activity. And 12% stayed dry after the initial ranibizumab treatment. No significant correlation was found between the CNV-recurrence pattern and VST (P=0.12).ConclusionsCNV activity in nAMD is irregular, which is reflected in the range of the duration of dry intervals and late recurrences. The biomarker VST solely seems not to be sufficient to explain recurrence pattern of CNV in all AMD patients.

  18. Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia.

    Science.gov (United States)

    Bhardwaj, P; Naja, M; Kumar, R; Chandola, H C

    2016-03-01

    The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 2003-2013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 2003-2013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110-176 %) over the forest region compared to the cropland (34-62 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia.

  19. The Seasonal and Intraseasonal Variability of Diurnal Cloud Activity over the Tibetan Plateau

    OpenAIRE

    Hatsuki, Fujinami; Tetsuzo, Yasunari; Institute of Geoscience, University of Tsukuba; Institute of Geoscience, University of Tsukuba

    2001-01-01

    Seasonal variation of diurnal cloud activity(abbreviated DCA)over the Tibetan Plateau throughout the year is examined using 3-hourly geostationary meteorological satellite(GMS)data for 6-years(1989-1994). The DCA shows two distinct variance maxima in the seasonal cycle. One is in spring(pre-monsoon season), and the other is in the summer monsoon season. The DCA begins in late January, and reaches its maximum from March through April. The active DCA extends over almost the whole of the plateau...

  20. Hybrid Active Filter with Variable Conductance for Harmonic Resonance Suppression in Industrial Power Systems

    DEFF Research Database (Denmark)

    Lee, Tzung-Lin; Wang, Yen-Ching; Li, Jian-Cheng

    2015-01-01

    Unintentional series and/or parallel resonances, due to the tuned passive filter and the line inductance, may result in severe harmonic distortion in the industrial power system. This paper presents a hybrid active filter to suppress harmonic resonance and reduce harmonic distortion as well...... expensive. A reasonable trade-off between filtering performances and cost is to use the hybrid active filter. Design consideration are presented and experimental results are provided to validate effectiveness of the proposed method. Furthermore, this paper discusses filtering performances on line impedance...

  1. Active Power and Flux Control of a Self-Excited Induction Generator for a Variable-Speed Wind Turbine Generation

    Energy Technology Data Exchange (ETDEWEB)

    Na, Woonki; Muljadi, Eduard; Leighty, Bill; Kim, Jonghoon

    2017-05-11

    A Self-Excited Induction Generation (SEIG) for a variable speed wind turbine generation(VS-WG) is normally considered to be a good candidate for implementation in stand-alone applications such as battery charging, hydrogenation, water pumping, water purification, water desalination, and etc. In this study, we have examined a study on active power and flux control strategies for a SEIG for a variable speed wind turbine generation. The control analysis for the proposed system is carried out by using PSCAD software. In the process, we can optimize the control design of the system, thereby enhancing and expediting the control design procedure for this application. With this study, this control design for a SEIG for VS-WG can become the industry standard for analysis and development in terms of SEIG.

  2. Variability in HOMA-IR, lipoprotein profile and selected hormones in young active men.

    Science.gov (United States)

    Keska, Anna; Lutoslawska, Grazyna; Czajkowska, Anna; Tkaczyk, Joanna; Mazurek, Krzysztof

    2013-01-01

    Resistance to insulin actions is contributing to many metabolic disturbances. Such factors as age, sex, nutrition, body fat, and physical activity determine body insulin resistance. Present study attempted to asses insulin resistance and its metabolic effects with respect to energy intake in young, lean, and active men. A total of 87 men aged 18-23 participated in the study. Plasma levels of glucose, insulin, lipoproteins, cortisol, and TSH were determined. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) and calculated using homeostatic model. The median value of HOMA-IR (1.344) was used to divide subjects into two groups. Men did not differ in anthropometric parameters, daily physical activity, and plasma TSH and cortisol levels. However, in men with higher HOMA-IR significantly lower daily energy intake was observed concomitantly with higher TG, TC, and HDL-C concentrations in plasma versus their counterparts with lower HOMA-IR. Exclusively in subjects with higher HOMA-IR significant and positive correlation was noted between HOMA-IR and TC and LDL-C. We concluded that despite a normal body weight and physical activity, a subset of young men displayed unfavorable changes in insulin sensitivity and lipid profile, probably due to insufficient energy intake.

  3. Active visual search in non-stationary scenes: coping with temporal variability and uncertainty

    Science.gov (United States)

    Ušćumlić, Marija; Blankertz, Benjamin

    2016-02-01

    Objective. State-of-the-art experiments for studying neural processes underlying visual cognition often constrain sensory inputs (e.g., static images) and our behavior (e.g., fixed eye-gaze, long eye fixations), isolating or simplifying the interaction of neural processes. Motivated by the non-stationarity of our natural visual environment, we investigated the electroencephalography (EEG) correlates of visual recognition while participants overtly performed visual search in non-stationary scenes. We hypothesized that visual effects (such as those typically used in human-computer interfaces) may increase temporal uncertainty (with reference to fixation onset) of cognition-related EEG activity in an active search task and therefore require novel techniques for single-trial detection. Approach. We addressed fixation-related EEG activity in an active search task with respect to stimulus-appearance styles and dynamics. Alongside popping-up stimuli, our experimental study embraces two composite appearance styles based on fading-in, enlarging, and motion effects. Additionally, we explored whether the knowledge obtained in the pop-up experimental setting can be exploited to boost the EEG-based intention-decoding performance when facing transitional changes of visual content. Main results. The results confirmed our initial hypothesis that the dynamic of visual content can increase temporal uncertainty of the cognition-related EEG activity in active search with respect to fixation onset. This temporal uncertainty challenges the pivotal aim to keep the decoding performance constant irrespective of visual effects. Importantly, the proposed approach for EEG decoding based on knowledge transfer between the different experimental settings gave a promising performance. Significance. Our study demonstrates that the non-stationarity of visual scenes is an important factor in the evolution of cognitive processes, as well as in the dynamic of ocular behavior (i.e., dwell time and

  4. Successful emotion regulation is predicted by amygdala activity and aspects of personality: A latent variable approach.

    Science.gov (United States)

    Morawetz, Carmen; Alexandrowicz, Rainer W; Heekeren, Hauke R

    2017-04-01

    The experience of emotions and their cognitive control are based upon neural responses in prefrontal and subcortical regions and could be affected by personality and temperamental traits. Previous studies established an association between activity in reappraisal-related brain regions (e.g., inferior frontal gyrus and amygdala) and emotion regulation success. Given these relationships, we aimed to further elucidate how individual differences in emotion regulation skills relate to brain activity within the emotion regulation network on the one hand, and personality/temperamental traits on the other. We directly examined the relationship between personality and temperamental traits, emotion regulation success and its underlying neuronal network in a large sample (N = 82) using an explicit emotion regulation task and functional MRI (fMRI). We applied a multimethodological analysis approach, combing standard activation-based analyses with structural equation modeling. First, we found that successful downregulation is predicted by activity in key regions related to emotion processing. Second, the individual ability to successfully upregulate emotions is strongly associated with the ability to identify feelings, conscientiousness, and neuroticism. Third, the successful downregulation of emotion is modulated by openness to experience and habitual use of reappraisal. Fourth, the ability to regulate emotions is best predicted by a combination of brain activity and personality as well temperamental traits. Using a multimethodological analysis approach, we provide a first step toward a causal model of individual differences in emotion regulation ability by linking biological systems underlying emotion regulation with descriptive constructs. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Day/Night Variability in Blood Pressure: Influence of Posture and Physical Activity

    Science.gov (United States)

    2013-01-01

    BACKGROUND Blood pressure (BP) is highest during the day and lowest at night. Absence of this rhythm is a predictor of cardiovascular morbidity and mortality. Contributions of changes in posture and physical activity to the 24-hour day/night rhythm in BP are not well understood. We hypothesized that postural changes and physical activity contribute substantially to the day/night rhythm in BP. METHODS Fourteen healthy, sedentary, nonobese, normotensive men (aged 19–50 years) each completed an ambulatory and a bed rest condition during which BP was measured every 30–60 minutes for 24 hours. When ambulatory, subjects followed their usual routines without restrictions to capture the “normal” condition. During bed rest, subjects were constantly confined to bed in a 6-degree head-down position; therefore posture was constant, and physical activity was minimized. Two subjects were excluded from analysis because of irregular sleep timing. RESULTS The systolic and diastolic BP reduction during the sleep period was similar in ambulatory (−11±2mmHg/−8±1mmHg) and bed rest conditions (−8±3mmHg/−4±2mmHg; P = 0.38/P = 0.12). The morning surge in diastolic BP was attenuated during bed rest (P = 0.001), and there was a statistical trend for the same effect in systolic BP (P = 0.06). CONCLUSIONS A substantial proportion of the 24-hour BP rhythm remained during bed rest, indicating that typical daily changes in posture and/or physical activity do not entirely explain 24-hour BP variation under normal ambulatory conditions. However, the morning BP increase was attenuated during bed rest, suggesting that the adoption of an upright posture and/or physical activity in the morning contributes to the morning BP surge. PMID:23535155

  6. Chemical variability and antioxidant activity of the leaves of chosen highbush blueberry (Vaccinium corymbosum L.) cultivars

    OpenAIRE

    Janiuk M.; Najda A.; Gantner M.; Błażewicz-Woźniak M.

    2013-01-01

    The paper deals with the chemical composition and antioxidant activity of aqueous extracts from leaves of two highbush blueberry varieties: ‘Bluecrop’ and ‘Northland’. The study revealed differences in the content of the analyzed components. Leaves of cv. ‘Bluecrop’ were characterized by a higher content of chlorophyll, flavonoids and anthocyanins, while the leaves of cv. ‘Northland’ contained more reducing sugars and total phenolic acids, tannins, and essential oils. Capacity of neutrali...

  7. Parallel Processing and Learning: Variability and Chaos in Self- Organization of Activity in Groups of Neurons

    Science.gov (United States)

    1993-03-09

    neurotransmission and neuromodulation (Soinila and Mpitsos, 1992; Soinila ct al., 1992). It is necessary, as these and other publications (e.g., Mpitsos and...neurotransmitters and neuromodulators affect the activity of neural assemblies, and (b) how individual transmitters act within the framework of the many...examined mammalian tissues that may he useful ajs model s~sqerni to examine distributed function in neurotransmission and neuromodulation (Soinila and

  8. Black hole variability and the star formation-active galactic nucleus connection: Do all star-forming galaxies host an active galactic nucleus?

    International Nuclear Information System (INIS)

    Hickox, Ryan C.; Chen, Chien-Ting J.; Civano, Francesca M.; Hainline, Kevin N.; Mullaney, James R.; Alexander, David M.; Goulding, Andy D.

    2014-01-01

    We investigate the effect of active galactic nucleus (AGN) variability on the observed connection between star formation and black hole accretion in extragalactic surveys. Recent studies have reported relatively weak correlations between observed AGN luminosities and the properties of AGN hosts, which has been interpreted to imply that there is no direct connection between AGN activity and star formation. However, AGNs may be expected to vary significantly on a wide range of timescales (from hours to Myr) that are far shorter than the typical timescale for star formation (≳100 Myr). This variability can have important consequences for observed correlations. We present a simple model in which all star-forming galaxies host an AGN when averaged over ∼100 Myr timescales, with long-term average AGN accretion rates that are perfectly correlated with the star formation rate (SFR). We show that reasonable prescriptions for AGN variability reproduce the observed weak correlations between SFR and L AGN in typical AGN host galaxies, as well as the general trends in the observed AGN luminosity functions, merger fractions, and measurements of the average AGN luminosity as a function of SFR. These results imply that there may be a tight connection between AGN activity and SFR over galaxy evolution timescales, and that the apparent similarities in rest-frame colors, merger rates, and clustering of AGNs compared to 'inactive' galaxies may be due primarily to AGN variability. The results provide motivation for future deep, wide extragalactic surveys that can measure the distribution of AGN accretion rates as a function of SFR.

  9. Plume Activity and Tidal Deformation on Enceladus Influenced by Faults and Variable Ice Shell Thickness

    Science.gov (United States)

    Běhounková, Marie; Souček, Ondřej; Hron, Jaroslav; Čadek, Ondřej

    2017-09-01

    We investigated the effect of variations in ice shell thickness and of the tiger stripe fractures crossing Enceladus' south polar terrain on the moon's tidal deformation by performing finite element calculations in three-dimensional geometry. The combination of thinning in the polar region and the presence of faults has a synergistic effect that leads to an increase of both the displacement and stress in the south polar terrain by an order of magnitude compared to that of the traditional model with a uniform shell thickness and without faults. Assuming a simplified conductive heat transfer and neglecting the heat sources below the ice shell, we computed the global heat budget of the ice shell. For the inelastic properties of the shell described by a Maxwell viscoelastic model, we show that unrealistically low average viscosity of the order of 10^{13} Pa s is necessary for preserving the volume of the ocean, suggesting the important role of the heat sources in the deep interior. Similarly, low viscosity is required to predict the observed delay of the plume activity, which hints at other delaying mechanisms than just the viscoelasticity of the ice shell. The presence of faults results in large spatial and temporal heterogeneity of geysering activity compared to the traditional models without faults. Our model contributes to understanding the physical mechanisms that control the fault activity, and it provides potentially useful information for future missions that will sample the plume for evidence of life.

  10. The Role of Heart-Rate Variability Parameters in Activity Recognition and Energy-Expenditure Estimation Using Wearable Sensors.

    Science.gov (United States)

    Park, Heesu; Dong, Suh-Yeon; Lee, Miran; Youn, Inchan

    2017-07-24

    Human-activity recognition (HAR) and energy-expenditure (EE) estimation are major functions in the mobile healthcare system. Both functions have been investigated for a long time; however, several challenges remain unsolved, such as the confusion between activities and the recognition of energy-consuming activities involving little or no movement. To solve these problems, we propose a novel approach using an accelerometer and electrocardiogram (ECG). First, we collected a database of six activities (sitting, standing, walking, ascending, resting and running) of 13 voluntary participants. We compared the HAR performances of three models with respect to the input data type (with none, all, or some of the heart-rate variability (HRV) parameters). The best recognition performance was 96.35%, which was obtained with some selected HRV parameters. EE was also estimated for different choices of the input data type (with or without HRV parameters) and the model type (single and activity-specific). The best estimation performance was found in the case of the activity-specific model with HRV parameters. Our findings indicate that the use of human physiological data, obtained by wearable sensors, has a significant impact on both HAR and EE estimation, which are crucial functions in the mobile healthcare system.

  11. Knowledge of the benefits of physical-sport activity in older people according to socio demographic variables

    OpenAIRE

    Clemente Remón, Ángel Luis; Del Hierro Pinés, David; Jiménez Benito, Víctor; Sacedón Ramallo, Diego; Santacruz Lozano, José Antonio; Cerro Herrero, David

    2017-01-01

    This investigation pretends to know the degree of knowledge of the benefits of the practice of physical-sports activities for older people in an urban population of over 100,000 inhabitants (Alcalá de Henares) and the relationship according to socio-demographic variables. The quantitative used methodology has consisted of the realization of interviews face to face to a random sample of 133 people over 65 years of this population. The instrument used in the investigation has consisted of a que...

  12. On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

    Directory of Open Access Journals (Sweden)

    Aouss Gabash

    2016-02-01

    Full Text Available It has recently been shown that using battery storage systems (BSSs to provide reactive power provision in a medium-voltage (MV active distribution network (ADN with embedded wind stations (WSs can lead to a huge amount of reverse power to an upstream transmission network (TN. However, unity power factors (PFs of WSs were assumed in those studies to analyze the potential of BSSs. Therefore, in this paper (Part-I, we aim to further explore the pure reactive power potential of WSs (i.e., without BSSs by investigating the issue of variable reverse power flow under different limits on PFs in an electricity market model. The main contributions of this work are summarized as follows: (1 Introducing the reactive power capability of WSs in the optimization model of the active-reactive optimal power flow (A-R-OPF and highlighting the benefits/impacts under different limits on PFs. (2 Investigating the impacts of different agreements for variable reverse power flow on the operation of an ADN under different demand scenarios. (3 Derivation of the function of reactive energy losses in the grid with an equivalent-π circuit and comparing its value with active energy losses. (4 Balancing the energy curtailment of wind generation, active-reactive energy losses in the grid and active-reactive energy import-export by a meter-based method. In Part-II, the potential of the developed model is studied through analyzing an electricity market model and a 41-bus network with different locations of WSs.

  13. Pressurised electro-osmotic dewatering of activated and anaerobically digested sludges: electrical variables analysis.

    Science.gov (United States)

    Citeau, M; Olivier, J; Mahmoud, A; Vaxelaire, J; Larue, O; Vorobiev, E

    2012-09-15

    Pressurised electro-osmotic dewatering (PEOD) of two sewage sludges (activated and anaerobically digested) was studied under constant electric current (C.C.) and constant voltage (C.V.) with a laboratory chamber simulating closely an industrial filter. The influence of sludge characteristics, process parameters, and electrode/filter cloth position was investigated. The next parameters were tested: 40 and 80 A/m², 20, 30, and 50 V-for digested sludge dewatering; and 20, 40 and 80 A/m², 20, 30, and 50 V-for activated sludge dewatering. Effects of filter cloth electric resistance and initial cake thickness were also investigated. The application of PEOD provides a gain of 12 points of dry solids content for the digested sludge (47.0% w/w) and for the activated sludge (31.7% w/w). In PEOD processed at C.C. or at C.V., the dewatering flow rate was similar for the same electric field intensity. In C.C. mode, both the electric resistance of cake and voltage increase, causing a temperature rise by ohmic effect. In C.V. mode, a current intensity peak was observed in the earlier dewatering period. Applying at first a constant current and later on a constant voltage, permitted to have better control of ohmic heating effect. The dewatering rate was not significantly affected by the presence of filter cloth on electrodes, but the use of a thin filter cloth reduced remarkably the energy consumption compared to a thicker one: 69% of reduction energy input at 45% w/w of dry solids content. The reduction of the initial cake thickness is advantageous to increase the final dry solids content. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Chemical variability and antioxidant activity of the leaves of chosen highbush blueberry (Vaccinium corymbosum L. cultivars

    Directory of Open Access Journals (Sweden)

    Małgorzata Janiuk

    2013-04-01

    Full Text Available The paper deals with the chemical composition and antioxidant activity of aqueous extracts from leaves of two highbush blueberry varieties: ‘Bluecrop’ and ‘Northland’. The study revealed differences in the content of the analyzed components. Leaves of cv. ‘Bluecrop’ were characterized by a higher content of chlorophyll, flavonoids and anthocyanins, while the leaves of cv. ‘Northland’ contained more reducing sugars and total phenolic acids, tannins, and essential oils. Capacity of neutralizing the free radicals (DPPH in leaves of both tested cultivars was found at comparable levels.

  15. Preparation of Active Absorbent for Flue Gas Desulfurization From Coal Bottom Ash: Effect of Absorbent Preparation Variables

    Directory of Open Access Journals (Sweden)

    Chang Chin Li, Lee Keat Teong, Subhash Bhatia and Abdul Rahman Mohamed

    2012-08-01

    Full Text Available An active absorbent for flue gas desulfurization was prepared from coal bottom ash, calcium oxide (CaO and calcium sulfate by hydro-thermal process. The absorbent was examined for its micro-structural properties. The experiments conducted were based on Design Of Experiments (DOE according to 23 factorial design. The effect of various absorbent preparation variables such as ratio of CaO to bottom ash (A, hydration temperature (B and hydration period (C towards the BET (Brunauer-Emmett-Teller specific surface area of the absorbent were studied. At a CaO to bottom ash ratio = 2, hydration temperature = 200 ?C and hydration period = 10 hrs, absorbent with a surface area of 90.1 m2/g was obtained. Based on the analysis of the factorial design, it was concluded that factor A and C as well as the interaction of factors ABC and BC are the significant factors that effect the BET surface area of the absorbent. A linear mathematical model that describes the relation between the independent variables and interaction between variables towards the BET specific surface area of the absorbent was also developed. Analysis of variance (ANOVA showed that the model was significant at 1% level.Key Words: Absorbent, Bottom Ash, Design Of Experiments, Desulfurization, Surface Area.

  16. Physical activity as a health factor modifying heart rate variability (HRV

    Directory of Open Access Journals (Sweden)

    Nowosielska-Swadzba Danuta

    2015-03-01

    Full Text Available Purpose: The aim of the research was the evaluation of the selected HRV factors of the training volleyball players in two training periods and non-training people. Materials and methods : The study involved 8 leading volleyball players aged 20-23 and 13 non-training persons aged 19-26. The study of the training players was conducted twice: in the pre-competition and in the competition period. The study for the non-training persons was conducted once. The selected factors of the spectral analysis have been evaluated: TP [ms 2], share of LF and HF power [n.u], LF/HF indicator and time analysis factors: RR [ms], HR [1/min], RMSSD [ms]. Results : Statistically significant differences appeared only in the selected time analysis factors (RR, HR, between the group of the training and non-training persons. Other differences in the evaluated parameters were not statistically significant. Conclusions : Physical activity influences on the HRV growth. HRV measurement may serve for the control of the changes taking place in the AUN under the influence of the physical activity.

  17. Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism.

    Directory of Open Access Journals (Sweden)

    William B Stubblefield

    Full Text Available We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA-catalyzed clot lysis time (CLT in patients with intermediate-risk pulmonary embolism (PE.Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α2-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI, plasminogen activator Inhibitor 1 (PAI-1, thrombin time and D-dimer were quantified. Clotting was induced using CaCl2, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT was assessed by both thromboelastography (TEG and turbidimetry (A405.Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec. Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT.The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT.

  18. Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism.

    Science.gov (United States)

    Stubblefield, William B; Alves, Nathan J; Rondina, Matthew T; Kline, Jeffrey A

    2016-01-01

    We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA)-catalyzed clot lysis time (CLT) in patients with intermediate-risk pulmonary embolism (PE). Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α2-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI), plasminogen activator Inhibitor 1 (PAI-1), thrombin time and D-dimer were quantified. Clotting was induced using CaCl2, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT) was assessed by both thromboelastography (TEG) and turbidimetry (A405). Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec). Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT. The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT.

  19. Variability in north tropical atlantic over the last 20 000 years and holocene gulf stream activity

    International Nuclear Information System (INIS)

    Cleroux, C.

    2007-10-01

    Modern oceanographical studies shown that most of the ocean heat content in the North Atlantic Western Boundary Current region is stored in the upper 400 meters. To study past heat content and Gulf Stream activity, we performed coupled analyses of oxygen isotopic and trace elemental composition on several foraminifera species to reconstruct upper water column temperature and salinity. Calcification depths of Globorotalia inflata, Globorotalia truncatulinoides and Pulleniatina obliquiloculata have been constrain by correlating modern hydrographic data to oxygen isotopic measurement of North Atlantic core-top samples. We found that the three deep-dwelling foraminifera species have a preferred habitat at the base of the seasonal thermocline (Cleroux et al, 2007). The same set of North Atlantic core-tops has been used to define relationships between trace elemental compositions and temperature. We established calibrations between Mg/Ca ratio or Sr/Ca ratio and temperature for the three deep-dwelling foraminifera (Cleroux et al, submitted). We apply this strategy on the core MD99-2203 located off Cape Hatteras where the Gulf Stream separate from the United States coast. High-resolution surface reconstructions over the Holocene show low amplitude periodic temperature and salinity changes that could be related to NAO type mechanisms. Large hydrological changes in sub-surface reflect variations of Labrador current and Mode Water influences. Using recent studies on Mode Water formation and Gulf Stream heat advection, we interpret our results in term of ocean heat content and Gulf Stream activity. (author)

  20. Optimization of the Method of Active Ingredients Adding to the Base of Medicinal Films Depending on Certain Variables

    Directory of Open Access Journals (Sweden)

    L. L. Davtian

    2018-03-01

    Full Text Available The influence of variables of pharmaceutical factors on the technological processes of drugs manufacturing is incredibly important. Thus, in the development of a new drug in the form of medicinal films, the relevance and necessity of determining the effect of the methods of active substances adding on the effectiveness of the drug was determined. The aim is rationalization of the method of the active pharmaceutical ingredients adding into the composition of the developed drug. Materials and methods. As experimental samples we used medicinal films, which were made using various methods of active ingredients adding. The quality of the samples was evaluated by the antimicrobial activity against Clostridium sporogenes and Staphylococcus aureus, which was determined by the diffusion method in agar. Results. The study of the antimicrobial activity of medicinal films with various methods of active ingredients adding showed that the adding of metronidazole as an aqueous solution increases the antimicrobial activity of the films by 21.23%, 16.89%, 28.59%, respectively, compared with films of similar composition, in which metronidazole was added as a suspension, and the remaining ingredients were added by the same way. The introduction of chlorhexidine bigluconate and glucosamine hydrochloride in the film-forming solution lastly together with the solution of metronidazole increases the antimicrobial activity by 24.67%, which is probably due to the absence of contact between thermolabile ingredients and solutions of film-forming substances having a high dissolution temperature. Conclusions. The most rational is adding of metronidazole to the medicinal films in the form of a 0.01% aqueous solution in a mixture with the chlorhexidine bigluconate and glucosamine hydrochloride solution to the final film-forming solution.

  1. A hybrid active optical system for wave front preservation and variable focal distance

    Energy Technology Data Exchange (ETDEWEB)

    Cocco, Daniele, E-mail: daniele.cocco@elettra.trieste.i [Sincrotrone Trieste ScpA, 34012 Trieste (Italy); Bortoletto, Gianluca; Sergo, Rudi; Sostero, Giovanni; Cudin, Ivan [Sincrotrone Trieste ScpA, 34012 Trieste (Italy)

    2010-05-01

    A new Free Electron Laser (FEL) user facility, named FERMI-Elettra, is under construction at Sincrotrone Trieste (Italy). It is based on a seeded scheme to provide an almost perfect transform limited beam with fully spatial coherence. The wavelength range will be 100-3 nm with fundamental and will go down to 1 nm by using higher harmonics. It will be operative by autumn 2010. The exceptional characteristics of the source must be preserved until the experimental chamber, where a large set of different experiments will be performed. This condition poses very tight requirements to the design of the beamlines and, in particular, to the focusing optics. Here we will present the active optics system developed for Fermi but intended to be used also on the Elettra beamlines. It is based on the adoption of a hybrid active system composed by UHV compatible stepping motors and piezo ceramic actuators. These mirrors are supposed to provide focal distances from 0.8 m to infinity with an angle of incidence up to a few degrees and residual shape errors below 10 or 5 nm (depending on the wavelength). In this way it is possible to work with an almost perfect focused coherent beam as well as with a uniform defocused or unfocused image. The metrology results on the first 400 mm long mirror will be shown and the actuator system described. A strain gauge assembly, calibrated in Elettra by means of a long trace profiler, and controlled by a custom made electronic system developed by us, is used as a direct in situ encoder.

  2. Variable activation of immune response by quinoa (Chenopodium quinoa Willd.) prolamins in celiac disease.

    Science.gov (United States)

    Zevallos, Victor F; Ellis, H Julia; Suligoj, Tanja; Herencia, L Irene; Ciclitira, Paul J

    2012-08-01

    Celiac disease is an enteropathy triggered by dietary gluten found in wheat, barley, and rye. The current treatment is a strict gluten-free diet. Quinoa is a highly nutritive plant from the Andes, with low concentrations of prolamins, that has been recommended as part of a gluten-free diet; however, few experimental data support this recommendation. We aimed to determine the amount of celiac-toxic prolamin epitopes in quinoa cultivars from different regions of the Andes and the ability of these epitopes to activate immune responses in patients with celiac disease. The concentration of celiac-toxic epitopes was measured by using murine monoclonal antibodies against gliadin and high-molecular-weight glutenin subunits. Immune response was assessed by proliferation assays of celiac small intestinal T cells/interferon-γ (IFN-γ) and production of IFN-γ/IL-15 after organ culture of celiac duodenal biopsy samples. Fifteen quinoa cultivars were tested: 4 cultivars had quantifiable concentrations of celiac-toxic epitopes, but they were below the maximum permitted for a gluten-free food. Cultivars Ayacuchana and Pasankalla stimulated T cell lines at levels similar to those for gliadin and caused secretion of cytokines from cultured biopsy samples at levels comparable with those for gliadin. Most quinoa cultivars do not possess quantifiable amounts of celiac-toxic epitopes. However, 2 cultivars had celiac-toxic epitopes that could activate the adaptive and innate immune responses in some patients with celiac disease. These findings require further investigation in the form of in vivo studies, because quinoa is an important source of nutrients for patients with celiac disease.

  3. Multiple-source multiple-harmonic active vibration control of variable section cylindrical structures: A numerical study

    Science.gov (United States)

    Liu, Jinxin; Chen, Xuefeng; Gao, Jiawei; Zhang, Xingwu

    2016-12-01

    Air vehicles, space vehicles and underwater vehicles, the cabins of which can be viewed as variable section cylindrical structures, have multiple rotational vibration sources (e.g., engines, propellers, compressors and motors), making the spectrum of noise multiple-harmonic. The suppression of such noise has been a focus of interests in the field of active vibration control (AVC). In this paper, a multiple-source multiple-harmonic (MSMH) active vibration suppression algorithm with feed-forward structure is proposed based on reference amplitude rectification and conjugate gradient method (CGM). An AVC simulation scheme called finite element model in-loop simulation (FEMILS) is also proposed for rapid algorithm verification. Numerical studies of AVC are conducted on a variable section cylindrical structure based on the proposed MSMH algorithm and FEMILS scheme. It can be seen from the numerical studies that: (1) the proposed MSMH algorithm can individually suppress each component of the multiple-harmonic noise with an unified and improved convergence rate; (2) the FEMILS scheme is convenient and straightforward for multiple-source simulations with an acceptable loop time. Moreover, the simulations have similar procedure to real-life control and can be easily extended to physical model platform.

  4. The association between phenomena on the Sun, geomagnetic activity, meteorological variables, and cardiovascular characteristic of patients with myocardial infarction

    Science.gov (United States)

    Vencloviene, Jone; Babarskiene, Ruta; Slapikas, Rimvydas; Sakalyte, Gintare

    2013-09-01

    It has been found that solar and geomagnetic activity affects the cardiovascular system. Some evidence has been reported on the increase in the rate of myocardial infarction, stroke and myocardial infarction related deaths during geomagnetic storms. We investigated the association between cardiovascular characteristics of patients, admitted for myocardial infarction with ST elevation (STEMI), and geomagnetic activity (GMA), solar proton events (SPE), solar flares, and meteorological variables during admission. The data of 1,979 patients hospitalized at the Hospital of Lithuanian University of Health Sciences (Kaunas) were analyzed. We evaluated the association between environmental variables and patient's characteristics by multivariate logistic regression, controlling patient's gender and age. Two days after geomagnetic storms the risk of STEMI was over 1.5 times increased in patients who had a medical history of myocardial infarction, stable angina, renal or pulmonary diseases. The dose-response association between GMA level and STEMI risk for patients with renal diseases in history was observed. Two days after SPE the risk of STEMI in patients with stable angina in anamnesis was increased over 1.5 times, adjusting by GMA level. The SPE were associated with an increase of risk for patients with renal diseases in history. This study confirms the strongest effect of phenomena in the Sun in high risk patients.

  5. Response of piping system with semi-active variable stiffness damper under tri-directional seismic excitation

    International Nuclear Information System (INIS)

    Praveen Kumar; Jangid, R.S.; Reddy, G.R.

    2013-01-01

    Highlights: ► Piping system with semi-active variable stiffness damper is investigated under different seismic excitations. ► Switching control law and modified switching control law are adopted. ► There exist an optimum parameters of the SAVSD. ► Substantial reduction of the seismic response of piping system with SAVSD is observed. ► Good amount of energy dissipation is observed. -- Abstract: Seismic loads on piping system due to earthquakes can cause excessive vibrations, which can lead to serious instability resulting in damage or complete failure. In this paper, semi-active variable stiffness dampers (SAVSDs) have been studied to mitigate seismic response and vibration control of piping system used in the process industries, fossil and fissile fuel power plant. The SAVSD changes its stiffness depending upon the piping response and accordingly adds the control forces in the piping system. A study is conducted on the performance of SAVSD due to variation in device stiffness ratios in the switching control law and modified switching control law, which plays an important role in the present control algorithm of the damper. The effectiveness of the SAVSD in terms of reduction in the responses, namely, displacements, accelerations and base shear of the piping system is investigated by comparing uncontrolled responses under four different artificial earthquake motions with increasing amplitudes. The analytical results demonstrate that the SAVSDs under particular optimum parameters are very effective and practically implementable for the seismic response mitigation, vibration control and seismic requalification of piping systems

  6. Response of piping system with semi-active variable stiffness damper under tri-directional seismic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, E-mail: praveen@barc.gov.in [Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Jangid, R.S. [Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Reddy, G.R. [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2013-05-15

    Highlights: ► Piping system with semi-active variable stiffness damper is investigated under different seismic excitations. ► Switching control law and modified switching control law are adopted. ► There exist an optimum parameters of the SAVSD. ► Substantial reduction of the seismic response of piping system with SAVSD is observed. ► Good amount of energy dissipation is observed. -- Abstract: Seismic loads on piping system due to earthquakes can cause excessive vibrations, which can lead to serious instability resulting in damage or complete failure. In this paper, semi-active variable stiffness dampers (SAVSDs) have been studied to mitigate seismic response and vibration control of piping system used in the process industries, fossil and fissile fuel power plant. The SAVSD changes its stiffness depending upon the piping response and accordingly adds the control forces in the piping system. A study is conducted on the performance of SAVSD due to variation in device stiffness ratios in the switching control law and modified switching control law, which plays an important role in the present control algorithm of the damper. The effectiveness of the SAVSD in terms of reduction in the responses, namely, displacements, accelerations and base shear of the piping system is investigated by comparing uncontrolled responses under four different artificial earthquake motions with increasing amplitudes. The analytical results demonstrate that the SAVSDs under particular optimum parameters are very effective and practically implementable for the seismic response mitigation, vibration control and seismic requalification of piping systems.

  7. Intrinsic spontaneous brain activity predicts individual variability in associative memory in older adults.

    Science.gov (United States)

    Zheng, Zhiwei; Li, Rui; Xiao, Fengqiu; He, Rongqiao; Zhang, Shouzi; Li, Juan

    2018-04-19

    Older adults demonstrate notable individual differences in associative memory. Here, resting-state functional magnetic resonance imaging (rsfMRI) was used to investigate whether intrinsic brain activity at rest could predict individual differences in associative memory among cognitively healthy older adults. Regional amplitude of low-frequency fluctuations (ALFF) analysis and a correlation-based resting-state functional connectivity (RSFC) approach were used to analyze data acquired from 102 cognitively normal elderly who completed the paired-associative learning test (PALT) and underwent fMRI scans. Participants were divided into two groups based on the retrospective self-reports on whether or not they utilized encoding strategies during the PALT. The behavioral results revealed better associative memory performance in the participants who reported utilizing memory strategies compared with participants who reported not doing so. The fMRI results showed that higher associative memory performance was associated with greater functional connectivity between the right superior frontal gyrus and the right posterior cerebellum lobe in the strategy group. The regional ALFF values in the right superior frontal gyrus were linked to associative memory performance in the no-strategy group. These findings suggest that the regional spontaneous fluctuations and functional connectivity during rest may subserve the individual differences in the associative memory in older adults, and that this is modulated by self-initiated memory strategy use. © 2018 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  8. Structurally related hydrazone-based metal complexes with different antitumor activities variably induce apoptotic cell death.

    Science.gov (United States)

    Megger, Dominik A; Rosowski, Kristin; Radunsky, Christian; Kösters, Jutta; Sitek, Barbara; Müller, Jens

    2017-04-05

    Three new complexes bearing the tridentate hydrazone-based ligand 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)pyridine (L) were synthesized and structurally characterized. Biological tests indicate that the Zn(ii) complex [ZnCl 2 (L)] is of low cytotoxicity against the hepatocellular carcinoma cell line HepG2. In contrast, the Cu(ii) and Mn(ii) complexes [CuCl 2 (L)] and [MnCl 2 (L)] are highly cytotoxic with EC 50 values of 1.25 ± 0.01 μM and 20 ± 1 μM, respectively. A quantitative proteome analysis reveals that treatment of the cells with the Cu(ii) complex leads to a significantly altered abundance of 102 apoptosis-related proteins, whereas 38 proteins were up- or down-regulated by the Mn(ii) complex. A closer inspection of those proteins regulated only by the Cu(ii) complex suggests that the superior cytotoxic activity of this complex is likely to be related to an initiation of the caspase-independent cell death (CICD). In addition, an increased generation of reactive oxygen species (ROS) and a strong up-regulation of proteins responsive to oxidative stress suggest that alterations of the cellular redox metabolism likely contribute to the cytotoxicity of the Cu(ii) complex.

  9. Variability of phenolic content and antioxidant activity of two lettuce varieties under Fe deficiency.

    Science.gov (United States)

    Msilini, Najoua; Oueslati, Samia; Amdouni, Thouraya; Chebbi, Mohamed; Ksouri, Riadh; Lachaâl, Mokhtar; Ouerghi, Zeineb

    2013-06-01

    Fe deficiency affects food growth and quality in calcareous soils. In this study, the effect of Fe deficiency on growth parameters, phenolic content and antioxidant capacities of two lettuce shoots varieties (Romaine and Vista) were investigated. Fresh matter production, pigment (chlorophyll and carotenoid) and Fe2+ content were significantly reduced by Fe deficiency in both varieties. However, restriction of these parameters was particularly pronounced in Romaine variety as compared to Vista. Moreover, Fe deficiency caused decreases in the activity of antioxidant enzymes such as catalase and guaiacol peroxidase, whereas ascorbate peroxidase and malondialdehyde concentrations were not significantly affected. On the other hand, Fe deficiency in Vista variety induced an increase in polyphenol and flavonoid content as compared to Romaine variety. In addition, total antioxidant capacity and antiradical test against DPPH radical decreased in leaves of Romaine variety after 15 days of treatment. These results suggest that the higher polyphenol content in Vista variety supports the involvement of these components in the stability of antioxidant capacities and then in its protection against oxidative damage generated by Fe deficiency in lettuce plants. © 2012 Society of Chemical Industry.

  10. Mesospheric Na Variability and Dependence on Geomagnetic and Solar Activity over Arecibo

    Science.gov (United States)

    Jain, K.; Raizada, S.; Brum, C. G. M.

    2017-12-01

    The Sodium (Na) resonance lidars located at the Arecibo Observatory offer an excellent opportunity to study the mesosphere/lower thermosphere(MLT) region. Different metals like Fe, Mg, Na, K, Ca and their ions are deposited in the 80 - 120 km altitude range due to the ablation of meteors caused by frictional heating during their entry into the Earth's atmosphere. We present an investigation of the neutral mesospheric Na atom layers over Arecibo. Data on the Na concentrations was collected using a resonance lidar tuned to the of Na wavelength at 589 nm. This wavelength is achieved with a dye-laser pumped by the second harmonic (532 nm) generated from a state-of-the-art commercial Nd:YAG laser. The backscattered signal is received on a 0.8 m (diameter) Cassegrain telescope. The study is based on this data acquired from 1998-2017 and its relation to variations in geomagnetic and solar conditions. We also investigate seasonal and long term trends in the data. The nightly-averaged altitude profiles were modeled as Gaussian curves. From this modeled data we obtain parameters such as the peak, abundance, centroid and width of the main Na layer. Preliminary results show that the Na abundance is more sensitive to changes in geomagnetic and solar variations as compared to the width and centroid height. The seasonal variation exhibits higher peak densities during the local summer and has a secondary maximum during the winter [as shown in the attached figure]. Our analysis demonstrates a decrease in the peak and the abundance of Na atoms with the increase of solar and geomagnetic activity.

  11. Thin film-based optically variable security devices: From passive to active

    Science.gov (United States)

    Baloukas, Bill

    Counterfeiting costs the world economy billions of dollars every year. Aside from financial losses, counterfeiting also poses a great threat to the public's safety, for example through the existence of counterfeit passports (terrorism), pharmaceutical products (health hazards) and even airplane parts (safety issues). Optical security devices (OSDs) have therefore played a critical role in the fight against counterfeiting. It is the aim of the present thesis to show that through the use of metamerism and electrochromic materials, new types of active security devices with interesting features can be created; indeed, most present-day devices are passive in nature. I first demonstrate that the addition of metamerism in the design of interference filters can result in innovative features. Different structures which can be used in transmission and/or in reflection are designed, fabricated, and evaluated. The first structures which are presented here are based on a combination of two different metameric interference filters. Possessing widely different transmission spectra, these filters also offer different angular color shifts and, as a result, offer an opportunity of creating hidden image effects. Despite their interesting properties, such metameric devices are shown to be highly illuminant and observer sensitive; that is the color match is lost under most observation conditions. These issues are solved by a simpler structure based on the juxtaposition of an interference filter and a non-iridescent colored material. Throughout this study, I present the design approach, analyze the filters' sensitivity to deposition errors, and evaluate the performance of prototype devices prepared by dual ion beam sputtering. Following my work on passive metameric systems, I then propose to go one step further by implementing an active component using an electrochromic material. This novel concept, which is based on the joint use of a metameric filter and electrochromic device, offers

  12. Variability of Pinus halepensis Mill. Essential Oils and Their Antioxidant Activities Depending on the Stage of Growth During Vegetative Cycle.

    Science.gov (United States)

    Djerrad, Zineb; Djouahri, Abderrahmane; Kadik, Leila

    2017-04-01

    The impact of growth stages during vegetative cycle (B 0  - B 5 ) on chemical composition and antioxidant activities of Pinus halepensis Mill. needles essential oils was investigated for the first time. GC and GC/MS analyses pointed to a quantitative variability of components; terpene hydrocarbons derivatives, represented by α-pinene (8.5 - 12.9%), myrcene (17.5 - 21.6%), p-cymene (7.9 - 11.9%) and (Z)-β-caryophyllene (17.3 - 21.2%) as major components, decreased from 88.9% at B 0 growth stage to 66.9% at B 5 growth stage, whereas oxygenated derivatives, represented by caryophyllene oxide (5.4 - 12.6%) and terpinen-4-ol (0.4 - 3.3%) as major components, increased from 7% at B 0 growth stage to 28.4% at B 5 growth stage. Furthermore, our findings showed that essential oil of P. halepensis needles collected at B 5 growth stage possess higher antioxidant activities by four different testing systems than those collected at B 0  - B 4 growth stages. This highlighted variability led to conclude that we should select essential oils to be investigated carefully depending on growth stage, in order to have the highest effectiveness of essential oil in terms of biological activities for human health purposes. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  13. Human activities and climate variability drive fast-paced change across the world's estuarine-coastal ecosystems

    Science.gov (United States)

    Cloern, James E.; Abreu, Paulo C.; Carstensen, Jacob; Chauvaud, Laurent; Elmgren, Ragnar; Grall, Jacques; Greening, Holly; Johansson, John O.R.; Kahru, Mati; Sherwood, Edward T.; Xu, Jie; Yin, Kedong

    2016-01-01

    Time series of environmental measurements are essential for detecting, measuring and understanding changes in the Earth system and its biological communities. Observational series have accumulated over the past 2–5 decades from measurements across the world's estuaries, bays, lagoons, inland seas and shelf waters influenced by runoff. We synthesize information contained in these time series to develop a global view of changes occurring in marine systems influenced by connectivity to land. Our review is organized around four themes: (i) human activities as drivers of change; (ii) variability of the climate system as a driver of change; (iii) successes, disappointments and challenges of managing change at the sea-land interface; and (iv) discoveries made from observations over time. Multidecadal time series reveal that many of the world's estuarine–coastal ecosystems are in a continuing state of change, and the pace of change is faster than we could have imagined a decade ago. Some have been transformed into novel ecosystems with habitats, biogeochemistry and biological communities outside the natural range of variability. Change takes many forms including linear and nonlinear trends, abrupt state changes and oscillations. The challenge of managing change is daunting in the coastal zone where diverse human pressures are concentrated and intersect with different responses to climate variability over land and over ocean basins. The pace of change in estuarine–coastal ecosystems will likely accelerate as the human population and economies continue to grow and as global climate change accelerates. Wise stewardship of the resources upon which we depend is critically dependent upon a continuing flow of information from observations to measure, understand and anticipate future changes along the world's coastlines.

  14. Natural climate variability inferred from cosmogenic isotopes and other geophysical data and its impact on human activity

    International Nuclear Information System (INIS)

    Creer, K.M.

    2001-01-01

    The way how natural climate changes may have influenced anthropological development is discussed. The main characteristics of solar variability are reviewed: (1) as measured in detail over recent decades by instruments on-board artificial satellites; (2) as recorded in historical documents on the time-scale of centuries; and (3) as inferred on millennial time-scales from archived records of the cosmogenically generated isotopes 14 C and 10 Be. The older, proxy data comprise temperature changes reconstructed from tree ring studies and environmental changes deduced from multi-disciplinary studies of lake sediments. The effects of changes in ocean circulation and the sporadic influence of volcanic activity are also considered briefly. (author)

  15. Skewed distribution of circulating activated natural killer T (NKT) cells in patients with common variable immunodeficiency disorders (CVID).

    Science.gov (United States)

    Carvalho, Karina I; Melo, Karina M; Bruno, Fernanda R; Snyder-Cappione, Jennifer E; Nixon, Douglas F; Costa-Carvalho, Beatriz T; Kallas, Esper G

    2010-09-09

    Common variable immunodeficiency disorder (CVID) is the commonest cause of primary antibody failure in adults and children, and characterized clinically by recurrent bacterial infections and autoimmune manifestations. Several innate immune defects have been described in CVID, but no study has yet investigated the frequency, phenotype or function of the key regulatory cell population, natural killer T (NKT) cells. We measured the frequencies and subsets of NKT cells in patients with CVID and compared these to healthy controls. Our results show a skewing of NKT cell subsets, with CD4+ NKT cells at higher frequencies, and CD8+ NKT cells at lower frequencies. However, these cells were highly activated and expression CD161. The NKT cells had a higher expression of CCR5 and concomitantly expression of CCR5+CD69+CXCR6 suggesting a compensation of the remaining population of NKT cells for rapid effector action.

  16. Modulation of brain activity by multiple lexical and word form variables in visual word recognition: A parametric fMRI study.

    Science.gov (United States)

    Hauk, Olaf; Davis, Matthew H; Pulvermüller, Friedemann

    2008-09-01

    Psycholinguistic research has documented a range of variables that influence visual word recognition performance. Many of these variables are highly intercorrelated. Most previous studies have used factorial designs, which do not exploit the full range of values available for continuous variables, and are prone to skewed stimulus selection as well as to effects of the baseline (e.g. when contrasting words with pseudowords). In our study, we used a parametric approach to study the effects of several psycholinguistic variables on brain activation. We focussed on the variable word frequency, which has been used in numerous previous behavioural, electrophysiological and neuroimaging studies, in order to investigate the neuronal network underlying visual word processing. Furthermore, we investigated the variable orthographic typicality as well as a combined variable for word length and orthographic neighbourhood size (N), for which neuroimaging results are still either scarce or inconsistent. Data were analysed using multiple linear regression analysis of event-related fMRI data acquired from 21 subjects in a silent reading paradigm. The frequency variable correlated negatively with activation in left fusiform gyrus, bilateral inferior frontal gyri and bilateral insulae, indicating that word frequency can affect multiple aspects of word processing. N correlated positively with brain activity in left and right middle temporal gyri as well as right inferior frontal gyrus. Thus, our analysis revealed multiple distinct brain areas involved in visual word processing within one data set.

  17. Solar spectral irradiance variability of some chromospheric emission lines through the solar activity cycles 21-23

    Directory of Open Access Journals (Sweden)

    Göker Ü.D.

    2017-01-01

    Full Text Available A study of variations of solar spectral irradiance (SSI in the wave-length ranges 121.5 nm-300.5 nm for the period 1981-2009 is presented. We used various data for ultraviolet (UV spectral lines and international sunspot number (ISSN from interactive data centers such as SME (NSSDC, UARS (GDAAC, SORCE (LISIRD and SIDC, respectively. We reduced these data by using the MATLsoftware package. In this respect, we revealed negative correlations of intensities of UV (289.5 nm-300.5 nm spectral lines originating in the solar chromosphere with the ISSN index during the unusually prolonged minimum between the solar activity cycles (SACs 23 and 24. We also compared our results with the variations of solar activity indices obtained by the ground-based telescopes. Therefore, we found that plage regions decrease while facular areas are increasing in SAC 23. However, the decrease in plage regions is seen in small sunspot groups (SGs, contrary to this, these regions in large SGs are comparable to previous SACs or even larger as is also seen in facular areas. Nevertheless, negative correlations between ISSN and SSI data indicate that these variations are in close connection with the classes of sunspots/SGs, faculae and plage regions. Finally, we applied the time series analysis of spectral lines corresponding to the wavelengths 121.5 nm-300.5 nm and made comparisons with the ISSN data. We found an unexpected increase in the 298.5 nm line for the Fe II ion. The variability of Fe II ion 298.5 nm line is in close connection with the facular areas and plage regions, and the sizes of these solar surface indices play an important role for the SSI variability, as well. So, we compared the connection between the sizes of faculae and plage regions, sunspots/SGs, chemical elements and SSI variability. Our future work will be the theoretical study of this connection and developing of a corresponding model.

  18. Chemical Variability, Antioxidant and Antifungal Activities of Essential Oils and Hydrosol Extract of Calendula arvensis L. from Western Algeria.

    Science.gov (United States)

    Belabbes, Rania; Dib, Mohammed El Amine; Djabou, Nassim; Ilias, Faiza; Tabti, Boufeldja; Costa, Jean; Muselli, Alain

    2017-05-01

    The chemical composition of the essential oils and hydrosol extract from aerial parts of Calendula arvensis L. was investigated using GC-FID and GC/MS. Intra-species variations of the chemical compositions of essential oils from 18 Algerian sample locations were investigated using statistical analysis. Chemical analysis allowed the identification of 53 compounds amounting to 92.3 - 98.5% with yields varied of 0.09 - 0.36% and the main compounds were zingiberenol 1 (8.7 - 29.8%), eremoligenol (4.2 - 12.5%), β-curcumene (2.1 - 12.5%), zingiberenol 2 (4.6 - 19.8%) and (E,Z)-farnesol (3.5 - 23.4%). The study of the chemical variability of essential oils allowed the discrimination of two main clusters confirming that there is a relation between the essential oil compositions and the harvest locations. Different concentrations of essential oil and hydrosol extract were prepared and their antioxidant activity were assessed using three methods (2,2-diphenyl-1-picrylhydrazyl, Ferric-Reducing Antioxidant Power Assay and β-carotene). The results showed that hydrosol extract presented an interesting antioxidant activity. The in vitro antifungal activity of hydrosol extract produced the best antifungal inhibition against Penicillium expansum and Aspergillus niger, while, essential oil was inhibitory at relatively higher concentrations. Results showed that the treatments of pear fruits with essential oil and hydrosol extract presented a very interesting protective activity on disease severity of pears caused by P. expansum. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  19. A novel de novo activating mutation in STAT3 identified in a patient with common variable immunodeficiency (CVID).

    Science.gov (United States)

    Russell, Mark A; Pigors, Manuela; Houssen, Maha E; Manson, Ania; Kelsell, David; Longhurst, Hilary; Morgan, Noel G

    2018-02-01

    Common variable immunodeficiency (CVID) is characterised by repeated infection associated with primary acquired hypogammaglobulinemia. CVID frequently has a complex aetiology but, in certain cases, it has a monogenic cause. Recently, variants within the gene encoding the transcription factor STAT3 were implicated in monogenic CVID. Here, we describe a patient presenting with symptoms synonymous with CVID, who displayed reduced levels of IgG and IgA, repeated viral infections and multiple additional co-morbidities. Whole-exome sequencing revealed a de novo novel missense mutation in the coiled-coil domain of STAT3 (c.870A>T; p.K290N). Accordingly, the K290N variant of STAT3 was generated, and a STAT3 responsive dual-luciferase reporter assay revealed that the variant strongly enhances STAT3 transcriptional activity both under basal and stimulated (with IL-6) conditions. Overall, these data complement earlier studies in which CVID-associated STAT3 mutations are predicted to enhance transcriptional activity, suggesting that such patients may respond favourably to IL-6 receptor antagonists (e.g. tocilizumab). Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Temporal variability in Cu speciation, phytotoxicity, and soil microbial activity of Cu-polluted soils as affected by elevated temperature.

    Science.gov (United States)

    Fu, Qing-Long; Weng, Nanyan; Fujii, Manabu; Zhou, Dong-Mei

    2018-03-01

    Global warming has obtained increasing attentions due to its multiple impacts on agro-ecosystem. However, limited efforts had been devoted to reveal the temporal variability of metal speciation and phytotoxicity of heavy metal-polluted soils affected by elevated temperature under the global warming scenario. In this study, effects of elevated temperature (15 °C, 25 °C, and 35 °C) on the physicochemical properties, microbial metabolic activities, and phytotoxicity of three Cu-polluted soils were investigated by a laboratory incubation study. Soil physicochemical properties were observed to be significantly altered by elevated temperature with the degree of temperature effect varying in soil types and incubation time. The Biolog and enzymatic tests demonstrated that soil microbial activities were mainly controlled and decreased with increasing incubation temperature. Moreover, plant assays confirmed that the phytotoxicity and Cu uptake by wheat roots were highly dependent on soil types but less affected by incubation temperature. Overall, the findings in this study have highlighted the importance of soil types to better understand the temperature-dependent alternation of soil properties, Cu speciation and bioavailability, as well as phytotoxicity of Cu-polluted soils under global warming scenario. The present study also suggests the necessary of investigating effects of soil types on the transport and accumulation of toxic elements in soil-crop systems under global warming scenario. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. A single-chain variable fragment intrabody prevents intracellular polymerization of Z α1-antitrypsin while allowing its antiproteinase activity.

    Science.gov (United States)

    Ordóñez, Adriana; Pérez, Juan; Tan, Lu; Dickens, Jennifer A; Motamedi-Shad, Neda; Irving, James A; Haq, Imran; Ekeowa, Ugo; Marciniak, Stefan J; Miranda, Elena; Lomas, David A

    2015-06-01

    Mutant Z α1-antitrypsin (E342K) accumulates as polymers within the endoplasmic reticulum (ER) of hepatocytes predisposing to liver disease, whereas low levels of circulating Z α1-antitrypsin lead to emphysema by loss of inhibition of neutrophil elastase. The ideal therapy should prevent polymer formation while preserving inhibitory activity. Here we used mAb technology to identify interactors with Z α1-antitrypsin that comply with both requirements. We report the generation of an mAb (4B12) that blocked α1-antitrypsin polymerization in vitro at a 1:1 molar ratio, causing a small increase of the stoichiometry of inhibition for neutrophil elastase. A single-chain variable fragment (scFv) intrabody was generated based on the sequence of mAb4B12. The expression of scFv4B12 within the ER (scFv4B12KDEL) and along the secretory pathway (scFv4B12) reduced the intracellular polymerization of Z α1-antitrypsin by 60%. The scFv4B12 intrabody also increased the secretion of Z α1-antitrypsin that retained inhibitory activity against neutrophil elastase. MAb4B12 recognized a discontinuous epitope probably located in the region of helices A/C/G/H/I and seems to act by altering protein dynamics rather than binding preferentially to the native state. This novel approach could reveal new target sites for small-molecule intervention that may block the transition to aberrant polymers without compromising the inhibitory activity of Z α1-antitrypsin. © FASEB.

  2. Concurrent sympathetic activation and vagal withdrawal in hyperthyroidism: Evidence from detrended fluctuation analysis of heart rate variability

    Science.gov (United States)

    Chen, Jin-Long; Shiau, Yuo-Hsien; Tseng, Yin-Jiun; Chiu, Hung-Wen; Hsiao, Tzu-Chien; Wessel, Niels; Kurths, Jürgen; Chu, Woei-Chyn

    2010-05-01

    Despite many previous studies on the association between hyperthyroidism and the hyperadrenergic state, controversies still exist. Detrended fluctuation analysis (DFA) is a well recognized method in the nonlinear analysis of heart rate variability (HRV), and it has physiological significance related to the autonomic nervous system. In particular, an increased short-term scaling exponent α1 calculated from DFA is associated with both increased sympathetic activity and decreased vagal activity. No study has investigated the DFA of HRV in hyperthyroidism. This study was designed to assess the sympathovagal balance in hyperthyroidism. We performed the DFA along with the linear analysis of HRV in 36 hyperthyroid Graves’ disease patients (32 females and 4 males; age 30 ± 1 years, means ± SE) and 36 normal controls matched by sex, age and body mass index. Compared with the normal controls, the hyperthyroid patients revealed a significant increase ( Phyperthyroid 1.28±0.04 versus control 0.91±0.02), long-term scaling exponent α2 (1.05±0.02 versus 0.90±0.01), overall scaling exponent α (1.11±0.02 versus 0.89±0.01), low frequency power in normalized units (LF%) and the ratio of low frequency power to high frequency power (LF/HF); and a significant decrease ( Phyperthyroidism is characterized by concurrent sympathetic activation and vagal withdrawal. This sympathovagal imbalance state in hyperthyroidism helps to explain the higher prevalence of atrial fibrillation and exercise intolerance among hyperthyroid patients.

  3. Investigation of the effect of kaolin and tissue factor-activated citrated whole blood, on clot forming variables, as evaluated by thromboelastograph

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Andersen, S.

    2008-01-01

    ), and maximum clot strength (amplitude [MA]) were evaluated, together with day-to-day variation, the coefficient of variance (CV%), and the effect of citrate storage time. RESULTS: Clot formation variables were equally affected by TF 1:17,000 and kaolin activation, whereas R was significantly longer when TF 1......:42,500 was used. The CV for the different variables varied from 3 to 13 percent with no significant differences between assays. Storage of citrated WB significantly affected the TEG variables in a hypercoagulable direction. Only the R, however, was significantly affected (12%) when samples rested for 0 and 30...... minutes were evaluated with kaolin as the activator. CONCLUSION: The TEG assays evaluated were reproducible and present with an acceptable CV% for routine clinical practice. Kaolin and TF 1:17,000 equally affected the clot formation variables. Storage of WB for up to 30 minutes in citrate did not, except...

  4. Quantifying the effects of climate variability and human activities on runoff for Kaidu River Basin in arid region of northwest China

    Science.gov (United States)

    Chen, Zhongsheng; Chen, Yaning; Li, Baofu

    2013-02-01

    Much attention has recently been focused on the effects that climate variability and human activities have had on runoff. In this study, data from the Kaidu River Basin in the arid region of northwest China were analyzed to investigate changes in annual runoff during the period of 1960-2009. The nonparametric Mann-Kendall test and the Mann-Kendall-Sneyers test were used to identify trend and step change point in the annual runoff. It was found that the basin had a significant increasing trend in annual runoff. Step change point in annual runoff was identified in the basin, which occurred in the year around 1993 dividing the long-term runoff series into a natural period (1960-1993) and a human-induced period (1994-2009). Then, the hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. In 1994-2009, climate variability was the main factor that increased runoff with contribution of 90.5 %, while the increasing percentage due to human activities only accounted for 9.5 %, showing that runoff in the Kaidu River Basin is more sensitive to climate variability than human activities. This study quantitatively distinguishes the effects between climate variability and human activities on runoff, which can do duty for a reference for regional water resources assessment and management.

  5. Nutritional variables predict chances of returning home and activities of daily living in post-acute geriatric care

    Science.gov (United States)

    Maeda, Keisuke; Koga, Takayuki; Akagi, Junji

    2018-01-01

    Background Little is known about the association between malnutrition and the chances of returning home from post-acute facilities in older adult patients. This study aimed to understand whether malnutrition and malnutrition-related factors would be determinants for returning home and activities of daily living (ADL) at discharge after post-acute care. Methods Patients aged ≥65 years living at home before the onset of an acute disease and admitted to a post-acute ward were enrolled (n=207) in this prospective observational study. Malnutrition was defined based on the criteria of the European Society for Clinical Nutrition and Metabolism. Nutritional parameters included the nutritional intake at the time of admission and oral conditions evaluated by the Oral Health Assessment Tool (OHAT). The Barthel Index was used to assess daily activities. A Cox regression analysis of the length of stay was performed. Multivariable linear regression analyses to determine associations between malnutrition, returning home, and ADL at discharge were performed, after adjusting the variables of acute care setting. Results The mean patient age was 84.7±6.7 years; 38% were men. European Society for Clinical Nutrition and Metabolism-defined malnutrition was observed in 129 (62.3%) patients, and 118 (57.0%) of all patients returned home. Multivariable regression analyses showed that malnutrition was a negative predictor of returning home (hazard ratio: 0.517 [0.351–0.761], p=0.001), and an increase in the nutritional intake (kcal/kg/d) was a positive predictor of the Barthel Index at discharge (coefficient: 0.34±0.15, p=0.021). The OHAT was not associated with returning home and ADL. Conclusion Malnutrition and nutritional intake are associated with returning home and ADL at discharge, respectively, after post-acute care. Further studies investigating the effects of a nutritional intervention for post-acute patients would be necessary. PMID:29416323

  6. Model of Transient Process Where Three-Phase Transducer Feeds Induction Motor Equivalent as a Variable Active-Inductive Load

    Directory of Open Access Journals (Sweden)

    Nenad Marković

    2016-01-01

    Full Text Available The paper presents a new approach in the analysis of a transient state in a system where the feeding source is a transducer-IGBT inverter and load is introduced through the induction motor with its R-L parameters. Induction motors with different parameters of powers and power factors are tested. MATLAB simulation of the three-phase inverter that feeds the induction machine has replaced the missing lab equipment with which mathematical model of this system was verified. According to the selected parameters of the inverter and induction machine and through the simulation in the MATLAB program, the results are obtained in the form of diagrams that verify the model of a transient state of the induction machine operation when it operates as a motor which is presented as a variable R-L load. The transient process of the system three-phase bridge inverter whose active-inductive load is the induction machine in the conditions of the change of the load parameters is analyzed. The model of the transient process in the system formed by the inverter in PWM (Pulse Width Modulation converter and induction machine is developed in the time domain and phase coordinates.

  7. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

    Energy Technology Data Exchange (ETDEWEB)

    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

  8. Activity rhythms and the influence of some environmental variables on summer ungulate behaviour in Ordesa-Monte Perdido National Park

    Directory of Open Access Journals (Sweden)

    Aldezabal, A.

    1999-12-01

    Full Text Available We have studied daily activity rhythms and time-budgets of four large herbivores (cattle, sheep, goats and chamois which form a multi-species grazing system in a summer pastoral unit of the Central Pyrenees. Also, the influence of some environmental variables (altitude, slope and plant cover on the main activities has been appraised. Grazing is the activity to which most time is dedicated in all the species: cattle 48%, sheep 53%, goats 55% and chamois 68%. Cattle is the species with the highest resting rate (41% and sheep is the species spends most time walking (35%. Results suggest the existence of an inverse relationship between body size and grazing time. Cattle show two clear grazing peaks during the day at early morning and late evening. Contrary to this, sheep and chamois show a multimodal pattern, with some peaks for this activity throughout the day. Environmental factors clearly influence cattle and chamois activities. Sheep and goats show a less definite pattern in respect to environmental factors, probably because of their herded condition.

    [es] Se estudian los ritmos de actividad diarios y la distribución del tiempo entre diferentes actividades, de cuatro grandes herbívoros (vacas, ovejas, cabras y rebecos que utilizan durante el verano la misma unidad pastoral (Puerto de Góriz, Parque Nacional de Ordesa en el Pirineo Central. Asimismo, se determina la influencia de diversas variables ambientales (altitud, pendiente y cobertura vegetal sobre la conducta de dichos rumiantes. El pastoreo es la actividad a la que más tiempo dedican todas las especies: vacas 48%, ovejas 53%, cabras 55% y rebecos 68%. El ganado vacuno es la especie que más tiempo dedica al descanso (41% y el ovino el que más tiempo emplea en desplazarse (35%. Los resultados sugieren la existencia de una relación inversa entre tamaño corporal y tiempo dedicado al pastoreo, ya apuntada por otros autores. Vacas y cabras presentan dos períodos máximos de

  9. The influence of physical activity during pregnancy on maternal, fetal or infant heart rate variability: a systematic review.

    Science.gov (United States)

    Dietz, Pavel; Watson, Estelle D; Sattler, Matteo C; Ruf, Wolfgang; Titze, Sylvia; van Poppel, Mireille

    2016-10-26

    Physical activity (PA) during pregnancy has been shown to be associated with several positive effects for mother, fetus, and offspring. Heart rate variability (HRV) is a noninvasive and surrogate marker to determine fetal overall health and the development of fetal autonomic nervous system. In addition, it has been shown to be significantly influenced by maternal behavior. However, the influence of maternal PA on HRV has not yet been systematically reviewed. Therefore, the aim of this systematic review was to assess the influence of regular maternal PA on maternal, fetal or infant HRV. A systematic literature search following a priori formulated criteria of studies that examined the influence of regular maternal PA (assessed for a minimum period of 6 weeks) on maternal, fetal or infant HRV was performed in the databases Pubmed and SPORTDiscus. Quality of each study was assessed using the standardized Quality Assessment Tool for Quantitative Studies (QATQS). Nine articles were included into the present systematic review: two intervention studies, one prospective longitudinal study, and six post-hoc analysis of subsets of the longitudinal study. Of these articles four referred to maternal HRV, five to fetal HRV, and one to infant HRV. The overall global rating for the standardized quality assessment of the articles was moderate to weak. The articles regarding the influence of maternal PA on maternal HRV indicated contrary results. Five of five articles regarding the influence of maternal PA on fetal HRV showed increases of fetal HRV on most parameters depending on maternal PA. The article referring to infant HRV (measured one month postnatal) showed an increased HRV. Based on the current evidence available, our overall conclusion is that the hypothesis that maternal PA influences maternal HRV cannot be supported, but there is a trend that maternal PA might increase fetal and infant HRV (clinical conclusion). Therefore, we recommend that further, high quality studies

  10. THE LONGEST TIMESCALE X-RAY VARIABILITY REVEALS EVIDENCE FOR ACTIVE GALACTIC NUCLEI IN THE HIGH ACCRETION STATE

    International Nuclear Information System (INIS)

    Zhang Youhong

    2011-01-01

    The All Sky Monitor (ASM) on board the Rossi X-ray Timing Explorer has continuously monitored a number of active galactic nuclei (AGNs) with similar sampling rates for 14 years, from 1996 January to 2009 December. Utilizing the archival ASM data of 27 AGNs, we calculate the normalized excess variances of the 300-day binned X-ray light curves on the longest timescale (between 300 days and 14 years) explored so far. The observed variance appears to be independent of AGN black-hole mass and bolometric luminosity. According to the scaling relation of black-hole mass (and bolometric luminosity) from galactic black hole X-ray binaries (GBHs) to AGNs, the break timescales that correspond to the break frequencies detected in the power spectral density (PSD) of our AGNs are larger than the binsize (300 days) of the ASM light curves. As a result, the singly broken power-law (soft-state) PSD predicts the variance to be independent of mass and luminosity. Nevertheless, the doubly broken power-law (hard-state) PSD predicts, with the widely accepted ratio of the two break frequencies, that the variance increases with increasing mass and decreases with increasing luminosity. Therefore, the independence of the observed variance on mass and luminosity suggests that AGNs should have soft-state PSDs. Taking into account the scaling of the break timescale with mass and luminosity synchronously, the observed variances are also more consistent with the soft-state than the hard-state PSD predictions. With the averaged variance of AGNs and the soft-state PSD assumption, we obtain a universal PSD amplitude of 0.030 ± 0.022. By analogy with the GBH PSDs in the high/soft state, the longest timescale variability supports the standpoint that AGNs are scaled-up GBHs in the high accretion state, as already implied by the direct PSD analysis.

  11. Expression of activation-induced cytidine deaminase gene in B lymphocytes of patients with common variable immunodeficiency.

    Science.gov (United States)

    Abolhassani, Hassan; Farrokhi, Amir Salek; Pourhamdi, Shabnam; Mohammadinejad, Payam; Sadeghi, Bamdad; Moazzeni, Seyed-Mohammad; Aghamohammadi, Asghar

    2013-08-01

    Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by reduced serum level of IgG, IgA or IgM and recurrent bacterial infections. Class switch recombination (CSR) as a critical process in immunoglobulin production is defective in a group of CVID patients. Activation-induced cytidine deaminase (AID) protein is an important molecule involving CSR process. The aim of this study was to investigate the AID gene mRNA production in a group of CVID patients indicating possible role of this molecule in this disorder. Peripheral blood mononuclear cells (PBMC) of 29 CVID patients and 21 healthy controls were isolated and stimulated by CD40L and IL-4 to induce AID gene expression. After 5 days AID gene mRNA production was investigated by real time polymerase chain reaction. AID gene was expressed in all of the studied patients. However the mean density of extracted AID mRNA showed higher level in CVID patients (230.95±103.04 ng/ml) rather than controls (210.00±44.72 ng/ml; P=0.5). CVID cases with lower level of AID had decreased total level of IgE (P=0.04) and stimulated IgE production (P=0.02); while cases with increased level of AID presented higher level of IgA (P=0.04) and numbers of B cells (P=0.02) and autoimmune disease (P=0.02). Different levels of AID gene expression may have important roles in dysregulation of immune system and final clinical presentation in CVID patients. Therefore investigating the expression of AID gene can help in classifying CVID patients.

  12. Seasonal patterns of activity and community structure in an amphibian assemblage at a pond network with variable hydrology

    Science.gov (United States)

    Vignoli, Leonardo; Bologna, Marco A.; Luiselli, Luca

    2007-03-01

    We studied community structure and seasonal activity patterns in a system of four ponds with seasonally-variable hydrology at a Mediterranean area in central Italy. We used a set of field methods to assess species presence and relative frequency of observation. The network of ponds was inhabited by six species of amphibians, two salamanders and four frogs. The breeding phenology of the six species did not vary remarkably among ponds, but there were significant differences among species in use of ponds. Factorial analysis of pond similarity drawn from percentage composition of the amphibian fauna, revealed that each of the four ponds was treatable as independent units, with no influence of relative inter-pond distance. PCA analysis allowed us to spatially arrange the amphibian species into three main groups: two were monospecific groups (i.e., Triturus vulgaris and Bufo bufo) and the third consisted of those species that selected not only the largest-deepest ponds, but also the ephemeral ones (i.e., Triturus carnifex, Hyla intermedia, the green frogs and Rana dalmatina). Our results suggest that the inter-pond differences in riparian vegetation, water depth, aquatic vegetation structure/abundance, and soil composition may produce differences among pond ecological characteristics (i.e., water turbidity and temperature, shelter availability, abundance of oviposition micro-sites), which may in turn influence different patterns of use by amphibians. To our knowledge, this is the first study emphasizing the potential role of heterochrony in the maintenance of a high species richness in Mediterranean amphibian communities. Preservation of freshwater vertebrate biodiversity requires management and protection not only of the main ponds and water bodies but also the temporary and ephemeral shallow ponds.

  13. Variability in cold front activities modulating cool-season evaporation from a southern inland water in the USA

    International Nuclear Information System (INIS)

    Liu Heping; Blanken, Peter D; Weidinger, Tamas; Nordbo, Annika; Vesala, Timo

    2011-01-01

    Understanding seasonal variations in the evaporation of inland waters (e.g., lakes and reservoirs) is important for water resource management as well as the prediction of the hydrological cycles in response to climate change. We analyzed eddy covariance-based evaporation measurements from the Ross Barnett Reservoir (32 deg. 26'N, 90 0 02'W; which is always ice-free) in central Mississippi during the cool months (i.e., September-March) of 2007 and 2008, and found that the variability in cold front activities (i.e., passages of cold fronts and cold/dry air masses behind cold fronts) played an important role in modulating the exchange of sensible (H) and latent (λE) heat fluxes. Our analysis showed that 2007's warmer cool season had smaller mean H and λE than 2008's cooler cool season. This implies that the warmer cool season did not accelerate evaporation and heat exchange between the water surface and the atmosphere. Instead, more frequent cold fronts and longer periods of cold/dry air masses behind the cold fronts in 2008 resulted in overall larger H and λE as compared with 2007, this primarily taking the form of sporadic short-term rapid 'pulses' of H and λE losses from the water's surface. These results suggest that future climate-induced changes in frequency of cold fronts and the meteorological properties of the air masses behind cold fronts (e.g., wind speeds, temperature, and humidity), rather than other factors of climate change, would produce significant variations in the water surface's energy fluxes and subsequent evaporation rates.

  14. Inter-Labeler and Intra-Labeler Variability of Condition Severity Classification Models Using Active and Passive Learning Methods

    Science.gov (United States)

    Nissim, Nir; Shahar, Yuval; Boland, Mary Regina; Tatonetti, Nicholas P; Elovici, Yuval; Hripcsak, George; Moskovitch, Robert

    2018-01-01

    Background and Objectives Labeling instances by domain experts for classification is often time consuming and expensive. To reduce such labeling efforts, we had proposed the application of active learning (AL) methods, introduced our CAESAR-ALE framework for classifying the severity of clinical conditions, and shown its significant reduction of labeling efforts. The use of any of three AL methods (one well known [SVM-Margin], and two that we introduced [Exploitation and Combination_XA]) significantly reduced (by 48% to 64%) condition labeling efforts, compared to standard passive (random instance-selection) SVM learning. Furthermore, our new AL methods achieved maximal accuracy using 12% fewer labeled cases than the SVM-Margin AL method. However, because labelers have varying levels of expertise, a major issue associated with learning methods, and AL methods in particular, is how to best to use the labeling provided by a committee of labelers. First, we wanted to know, based on the labelers’ learning curves, whether using AL methods (versus standard passive learning methods) has an effect on the Intra-labeler variability (within the learning curve of each labeler) and inter-labeler variability (among the learning curves of different labelers). Then, we wanted to examine the effect of learning (either passively or actively) from the labels created by the majority consensus of a group of labelers. Methods We used our CAESAR-ALE framework for classifying the severity of clinical conditions, the three AL methods and the passive learning method, as mentioned above, to induce the classifications models. We used a dataset of 516 clinical conditions and their severity labeling, represented by features aggregated from the medical records of 1.9 million patients treated at Columbia University Medical Center. We analyzed the variance of the classification performance within (intra-labeler), and especially among (inter-labeler) the classification models that were induced by

  15. Inter-labeler and intra-labeler variability of condition severity classification models using active and passive learning methods.

    Science.gov (United States)

    Nissim, Nir; Shahar, Yuval; Elovici, Yuval; Hripcsak, George; Moskovitch, Robert

    2017-09-01

    Labeling instances by domain experts for classification is often time consuming and expensive. To reduce such labeling efforts, we had proposed the application of active learning (AL) methods, introduced our CAESAR-ALE framework for classifying the severity of clinical conditions, and shown its significant reduction of labeling efforts. The use of any of three AL methods (one well known [SVM-Margin], and two that we introduced [Exploitation and Combination_XA]) significantly reduced (by 48% to 64%) condition labeling efforts, compared to standard passive (random instance-selection) SVM learning. Furthermore, our new AL methods achieved maximal accuracy using 12% fewer labeled cases than the SVM-Margin AL method. However, because labelers have varying levels of expertise, a major issue associated with learning methods, and AL methods in particular, is how to best to use the labeling provided by a committee of labelers. First, we wanted to know, based on the labelers' learning curves, whether using AL methods (versus standard passive learning methods) has an effect on the Intra-labeler variability (within the learning curve of each labeler) and inter-labeler variability (among the learning curves of different labelers). Then, we wanted to examine the effect of learning (either passively or actively) from the labels created by the majority consensus of a group of labelers. We used our CAESAR-ALE framework for classifying the severity of clinical conditions, the three AL methods and the passive learning method, as mentioned above, to induce the classifications models. We used a dataset of 516 clinical conditions and their severity labeling, represented by features aggregated from the medical records of 1.9 million patients treated at Columbia University Medical Center. We analyzed the variance of the classification performance within (intra-labeler), and especially among (inter-labeler) the classification models that were induced by using the labels provided by seven

  16. The relationship between prostate volume and prostate-specific antigen variability: data from the Baltimore Longitudinal Study of Aging and the Johns Hopkins Active Surveillance Program.

    Science.gov (United States)

    Nichols, John H; Loeb, Stacy; Metter, E Jeffrey; Ferrucci, Luigi; Carter, H Ballentine

    2012-05-01

    Study Type--Prognostic (cohort). Level of Evidence 2b. What's known on the subject? And what does the study add? Previous studies have attempted to characterize the normal biological variability in PSA among men without prostate cancer. These reports suggest that PSA variability is unrelated to age, but there are conflicting data on its association with the baseline PSA level. There are limited published data regarding the effects of prostate volume on PSA variability. A prior study assessing whether prostate volume changes would confound the use of PSA velocity in clinical practice reported that prostate volume changes were not significantly related to PSA changes. This study did not directly address the effect of baseline prostate volume on serial PSA variability. The objective of the current study was to further examine the relationship between prostate volume and PSA variability. Our hypothesis was that larger baseline prostate volume would be associated with increased PSA variability in men without known prostate cancer and in those with suspected small-volume disease. The results of the study suggest that baseline PSA, not prostate volume, is the primary driver of PSA variability in these populations. • To clarify the relationship between serial prostate-specific antigen (PSA) variability and prostate volume in both cancer-free participants from the Baltimore Longitudinal Study of Aging (BLSA) and patients with low-risk prostate cancer from the Johns Hopkins Active Surveillance Program (AS). • In all, 287 men from the BLSA and 131 patients from the AS were included in the analysis, all with at least two PSA measurements and concurrent prostate volume measurements. • PSA variability was calculated in ng/mL per year, and a linear mixed-effects model was used to determine the relative effects of prostate volume, baseline PSA and age on PSA change over time. • In a model with prostate volume, age and baseline PSA, there was no significant relationship

  17. Sympathetic Activity, Assessed by Power Spectral Analysis of Heart Rate Variability, in White-Coat, Masked and Sustained Hypertension Versus True Normotension

    Czech Academy of Sciences Publication Activity Database

    Fagard, R.H.; Stolarz, K.; Kuznetsova, T.; Seidlerová, J.; Tikhonoff, V.; Grodzicki, T.; Nikitin, Y.; Filipovský, J.; Peleška, Jan; Casiglia, E.; Thijs, L.; Staessen, J.A.; Kawecka-Jaszcz, K.

    2007-01-01

    Roč. 25, č. 11 (2007), s. 2280-2285 ISSN 0263-6352 Institutional research plan: CEZ:AV0Z10300504 Keywords : heart rate variability * masked hypertension * power spectral analysis * sympathetic activity * white-coat hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.364, year: 2007

  18. Analysis of variability in multi-day GPS imputed activity-travel diaries using multi-dimensional sequence alignment and panel effects regression models

    NARCIS (Netherlands)

    Xianyu, J.; Rasouli, S.; Timmermans, H.J.P.

    The use of GPS devices and smartphones has made feasible the collection of multi-day activity-travel diaries. In turn, the availability of multi-day travel diary data opens up new avenues for analyzing dynamics of individual travel behavior. This paper addresses the issue of day-to-day variability

  19. Free energy of activation. Definition, properties, and dependent variables with special reference to linear free energy relations

    International Nuclear Information System (INIS)

    Levine, R.D.

    1979-01-01

    The reaction rate constant is expressed as Z exp(-G/sub a//RT). Z is the binary collision frequency. G/sub a/, the free energy of activation, is shown to be the difference between the free energy of the reactive reactants and the free energy of all reactants. The results are derived from both a statistical mechanical and a collision theoretic point of view. While the later is more suitable for an ab-initio computation of the reaction rate, it is the former that lends itself to the search of systematics and of correlations and to compaction of data. Different thermodynamic-like routes to the characterization of G/sub a/ are thus explored. The two most promising ones appear to be the use of thermodynamic type cycles and the changes of dependent variables using the Legendre transform technique. The dependence of G/sub a/ on ΔG 0 , the standard free energy change in the reaction, is examined from the later point of view. It is shown that one can rigorously express this dependence as G/sub a/ = αΔG 0 + G/sub a/ 0 M(α). Here α is the Bronsted slope, α = -par. delta ln k(T)/par. delta(ΔG 0 /RT), G/sub a/ 0 is independent of ΔG 0 and M(α), the Legendre transform of G/sub a/, is a function only of α. For small changes in ΔG 0 , the general result reduces to the familiar ''linear'' free energy relation delta G/sub a/ = α delta ΔG 0 . It is concluded from general considerations that M(α) is a symmetric, convex function of α and hence that α is a monotonically increasing function of ΔG 0 . Experimental data appear to conform well to the form α = 1/[1 + exp(-ΔG 0 /G/sub s/ 0 )]. A simple interpretation of the ΔG 0 dependence of G/sub a/, based on an interpolation of the free energy from that of the reagents to that of the products, is offered. 4 figures, 69 references

  20. First Year Observations of Antarctic Circumpolar Current Variability and Internal Wave Activity from the DIMES Mooring Array

    Science.gov (United States)

    Brearley, J. A.; Sheen, K. L.; Naveira-Garabato, A. C.

    2012-04-01

    A key component of DIMES (Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean) is the deployment of a two-year cross-shaped mooring array in the Antarctic Circumpolar Current to the east of Drake Passage close to 57°W. Motivation for the cluster arises from the need to understand how eddies dissipate in the Southern Ocean, and specifically how much energy is extracted from the mesoscale by breaking internal waves, which in turn leads to turbulent mixing. The location of the mooring cluster was chosen to fulfil these objectives, being situated in a region of pronounced finestructure with high eddy kinetic energy and rough topography. The array, comprising 34 current meters and Microcats and a downward-looking ADCP, was first deployed in December 2009 and serviced in December 2010. Time series of current meter results from the most heavily-instrumented 'C' mooring indicate that a strong (up to 80 cms-1) surface-intensified north-eastward directed ACC occupies the region for most of the year, with over 85% of the variability in current speed being accounted for by equivalent barotropic fluctuations. A strong mean poleward heat flux is observed at the site, which compares favourably in magnitude with literature results from other ACC locations. Interestingly, four episodes of mid-depth (~2000 m) current speed maxima, each of a few days duration, were found during the 360-day time series, a situation also observed by the lowered ADCP during mooring servicing in December 2010. Early results indicate that these episodes, which coincide with time minima in stratification close to 2000 m, could profoundly influence the nature of eddy-internal wave interactions at these times. Quantification of the energy budget at the mooring cluster has been a key priority. When compared with previous moorings located in Drake Passage (Bryden, 1977), a near threefold-increase in mean eddy kinetic energy (EKE) is observed despite a small reduction in the mean kinetic energy

  1. Impact of Late Holocene climate variability and anthropogenic activities on Biscayne Bay (Florida, U.S.A.): evidence from diatoms

    Science.gov (United States)

    Wachnicka, Anna; Gaiser, Evelyn; Wingard, Lynn; Briceño, Henry; Harlem, Peter

    2013-01-01

    Shallow marine ecosystems are experiencing significant environmental alterations as a result of changing climate and increasing human activities along coasts. Intensive urbanization of the southeast Florida coast and intensification of climate change over the last few centuries changed the character of coastal ecosystems in the semi-enclosed Biscayne Bay, Florida. In order to develop management policies for the Bay, it is vital to obtain reliable scientific evidence of past ecological conditions. The long-term records of subfossil diatoms obtained from No Name Bank and Featherbed Bank in the Central Biscayne Bay, and from the Card Sound Bank in the neighboring Card Sound, were used to study the magnitude of the environmental change caused by climate variability and water management over the last ~ 600 yr. Analyses of these records revealed that the major shifts in the diatom assemblage structures at No Name Bank occurred in 1956, at Featherbed Bank in 1966, and at Card Sound Bank in 1957. Smaller magnitude shifts were also recorded at Featherbed Bank in 1893, 1942, 1974 and 1983. Most of these changes coincided with severe drought periods that developed during the cold phases of El Niño Southern Oscillation (ENSO), Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO), or when AMO was in warm phase and PDO was in the cold phase. Only the 1983 change coincided with an unusually wet period that developed during the warm phases of ENSO and PDO. Quantitative reconstructions of salinity using the weighted averaging partial least squares (WA-PLS) diatom-based salinity model revealed a gradual increase in salinity at the three coring locations over the last ~ 600 yr, which was primarily caused by continuously rising sea level and in the last several decades also by the reduction of the amount of freshwater inflow from the mainland. Concentration of sediment total nitrogen (TN), total phosphorus (TP) and total organic carbon (TOC) increased in the

  2. FATHI YAKAN THE PIONEER OF ISLAMIC ACTIVISM IN LEBANON

    Directory of Open Access Journals (Sweden)

    Robert G. Rabil

    2013-05-01

    Full Text Available This article explores the ideology of Fathi Yakan, the pioneer of Sunni Islamism in Lebanon and a principal founder of the Islamist party al-­‐Jama'a al-­‐Islamiya.  It also traces the establishment of  al_Jama'a as the first organized Islamist party in Lebanon.  As Secretary General of al-­‐Jama'a, Fathi Yakan blazed the ideological trail for Islamism's participation in Lebanon's political realm.  Significantly, Yakan's political activism, in much the same vein as that of Druze "Socialist" Kamal Jumblat, was also more about removing Maronite hegemony over the state.

  3. Impact of the configuration of stretching and ocean-atmosphere coupling on tropical cyclone activity in the variable-resolution GCM ARPEGE

    Energy Technology Data Exchange (ETDEWEB)

    Daloz, Anne Sophie; Chauvin, Fabrice [CNRM-GAME, Groupe de Modelisation Grande Echelle et Climat, Toulouse Cedex 1 (France); Roux, Frank [Universite de Toulouse, Laboratoire d' Aerologie, Centre National de la Recherche Scientifique, Toulouse (France)

    2012-11-15

    This study starts by investigating the impact of the configuration of the variable-resolution atmospheric grid on tropical cyclone (TC) activity. The French atmospheric general circulation model ARPEGE, the grid of which is rotated and stretched over the North Atlantic basin, was used with prescribed sea surface temperatures. The study clearly shows that changing the position of the stretching pole strongly modifies the representation of TC activity over the North Atlantic basin. A pole in the centre of the North Atlantic basin provides the best representation of the TC activity for this region. In a second part, the variable-resolution climate model ARPEGE is coupled with the European oceanic global climate model NEMO in order to study the impact of ocean-atmosphere coupling on TC activity over the North Atlantic basin. Two pre-industrial runs, a coupled simulation and a simulation forced by the sea surface temperatures from the coupled one, are compared. The results show that the coupled simulation is more active in the Caribbean Sea and the Gulf of Mexico while the forced simulation is more active over eastern Florida and the eastern Atlantic. The difference in the distribution of TC activity is certainly linked with the location of TC genesis. In the forced simulation, tropical cyclogenesis is closer to the west African coast than in the coupled simulation. Moreover, the difference in TC activity over the eastern Atlantic seems to be related to two different mechanisms: the difference in African easterly wave activity over the west of Africa and the cooling produced, in the coupled simulation, by African easterly waves over the eastern Atlantic. Finally, the last part studies the impact of changing the frequency of ocean-atmosphere coupling on Atlantic TC activity. Increasing the frequency of coupling decreases the density of TC activity over the North Atlantic basin. However, it does not modify the spatial distribution of the TC activity. TC rainfalls are

  4. Impact of Pubertal Development and Physical Activity on Heart Rate Variability in Overweight and Obese Children in Taiwan

    Science.gov (United States)

    Chen, Su-Ru; Chiu, Hung-Wen; Lee, Yann-Jinn; Sheen, Tzong-Chi; Jeng, Chii

    2012-01-01

    Child obesity is frequently associated with dysfunction of autonomic nervous system. Children in pubertal development were suggested to be vulnerable to autonomic nervous system problems such as decrease of heart rate variability from dysregulation of metabolic control. This study explored the influence of pubertal development on autonomic nervous…

  5. The History of Variable Stars: A Fresh Look

    Science.gov (United States)

    Hatch, R. A.

    2012-06-01

    (Abstract only) For historians of astronomy, variable stars are important for a simple reason - stars change. But good evidence suggests this is a very modern idea. Over the millennia, our species has viewed stars as eternal and unchanging, forever fixed in time and space - indeed, the Celestial Dance was a celebration of order, reason, and stability. But everything changed in the period between Copernicus and Newton. According to tradition, two New Stars announced the birth of the New Science. Blazing across the celestial stage, Tycho's Star (1572) and Kepler's Star (1604) appeared dramatically - and just as unexpectedly - disappeared forever. But variable stars were different. Mira Ceti, the oldest, brightest, and most controversial variable star, was important because it appeared and disappeared again and again. Mira was important because it did not go away. The purpose of this essay is to take a fresh look at the history of variable stars. In re-thinking the traditional narrative, I begin with the first sightings of David Fabricius (1596) and his contemporaries - particularly Hevelius (1662) and Boulliau (1667) - to new traditions that unfolded from Newton and Maupertuis to Herschel (1780) and Pigott (1805). The essay concludes with important 19th-century developments, particularly by Argelander (1838), Pickering (1888), and Lockyer (1890). Across three centuries, variable stars prompted astronomers to re-think all the ways that stars were no longer "fixed." New strategies were needed. Astronomers needed to organize, to make continuous observations, to track changing magnitudes, and to explain stellar phases. Importantly - as Mira suggested from the outset - these challenges called for an army of observers with the discipline of Spartans. But recruiting that army required a strategy, a set of theories with shared expectations. Observation and theory worked hand-in-hand. In presenting new historical evidence from neglected printed sources and unpublished

  6. Effect of task-oriented training and high-variability practice on gross motor performance and activities of daily living in children with spastic diplegia.

    Science.gov (United States)

    Kwon, Hae-Yeon; Ahn, So-Yoon

    2016-10-01

    [Purpose] This study investigates how a task-oriented training and high-variability practice program can affect the gross motor performance and activities of daily living for children with spastic diplegia and provides an effective and reliable clinical database for future improvement of motor performances skills. [Subjects and Methods] This study randomly assigned seven children with spastic diplegia to each intervention group including that of a control group, task-oriented training group, and a high-variability practice group. The control group only received neurodevelopmental treatment for 40 minutes, while the other two intervention groups additionally implemented a task-oriented training and high-variability practice program for 8 weeks (twice a week, 60 min per session). To compare intra and inter-relationships of the three intervention groups, this study measured gross motor performance measure (GMPM) and functional independence measure for children (WeeFIM) before and after 8 weeks of training. [Results] There were statistically significant differences in the amount of change before and after the training among the three intervention groups for the gross motor performance measure and functional independence measure. [Conclusion] Applying high-variability practice in a task-oriented training course may be considered an efficient intervention method to improve motor performance skills that can tune to movement necessary for daily livelihood through motor experience and learning of new skills as well as change of tasks learned in a complex environment or similar situations to high-variability practice.

  7. Spatial variability of isoproturon mineralizing activity within an agricultural field: geostatistical analysis of simple physicochemical and microbiological soil parameters.

    Science.gov (United States)

    El Sebai, T; Lagacherie, B; Soulas, G; Martin-Laurent, F

    2007-02-01

    We assessed the spatial variability of isoproturon mineralization in relation to that of physicochemical and biological parameters in fifty soil samples regularly collected along a sampling grid delimited across a 0.36 ha field plot (40 x 90 m). Only faint relationships were observed between isoproturon mineralization and the soil pH, microbial C biomass, and organic nitrogen. Considerable spatial variability was observed for six of the nine parameters tested (isoproturon mineralization rates, organic nitrogen, genetic structure of the microbial communities, soil pH, microbial biomass and equivalent humidity). The map of isoproturon mineralization rates distribution was similar to that of soil pH, microbial biomass, and organic nitrogen but different from those of structure of the microbial communities and equivalent humidity. Geostatistics revealed that the spatial heterogeneity in the rate of degradation of isoproturon corresponded to that of soil pH and microbial biomass.

  8. Change in goal ratings as a mediating variable between self-efficacy and physical activity in older men.

    Science.gov (United States)

    Hall, Katherine S; Crowley, Gail M; McConnell, Eleanor S; Bosworth, Hayden B; Sloane, Richard; Ekelund, Carola C; Morey, Miriam C

    2010-06-01

    Few studies have examined the associations between exercise self-efficacy, goals, and physical activity over time. This study examines whether self-selected goals mediate the changes in exercise self-efficacy on physical activity over 12 months. Data are derived from 313 older men participating in the Veterans LIFE Study. Changes in exercise self-efficacy were significantly associated with changes in physical activity both directly (betas = 0.25 and 0.24, p goal ratings (betas = 0.19 and 0.20, p goal setting continued to partially mediate the relationship between exercise self-efficacy and physical activity when covariates were added to the models. This study extends the application of social cognitive and goal-setting theories to physical activity by showing that goals partially mediate the relationship between exercise self-efficacy and physical activity over time.

  9. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    . Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular......)? How much harder is it to debug a program as variability increases? How do developers debug programs with variability? In what ways does variability affect bugs? In this Ph.D. thesis, I set off to address such issues through different perspectives using empirical research (based on controlled...... experiments) in order to understand quantitatively and qualitatively the impact of variability on programmers at bug finding and on buggy programs. From the program (and bug) perspective, the results show that variability is ubiquitous. There appears to be no specific nature of variability bugs that could...

  10. Personal power-frequency magnetic field exposure in women recruited at an infertility clinic: association with physical activity and temporal variability

    OpenAIRE

    Lewis, Ryan C.; Hauser, Russ; Wang, Lu; Kavet, Robert; Meeker, John D.

    2015-01-01

    Current epidemiologic approaches for studying exposure to power-frequency magnetic fields and the risk of miscarriage are potentially biased due to lack of attention to the relationship of exposure with physical activity and within-individual variability in exposures over time. This analysis examines these two issues using data from a longitudinal pilot study of 40 women recruited from an infertility clinic that contributed data for up to three 24-h periods separated by a median of 3.6 weeks....

  11. Biobehavioral Triggers of Cardiac Arrhythmia during Daily Life: The Role of Emotion, Physical Activity, and Heart Rate Variability

    National Research Council Canada - National Science Library

    McCeney, Melissa K

    2004-01-01

    Biobehavioral factors, such as physical activity and emotions, have been associated with adverse cardiac outcomes, including myocardial ischemia and infarction, in individuals with coronary artery disease...

  12. Meeting report: batch-to-batch variability in estrogenic activity in commercial animal diets--importance and approaches for laboratory animal research.

    Science.gov (United States)

    Heindel, Jerrold J; vom Saal, Frederick S

    2008-03-01

    We report information from two workshops sponsored by the National Institutes of Health that were held to a) assess whether dietary estrogens could significantly impact end points in experimental animals, and b) involve program participants and feed manufacturers to address the problems associated with measuring and eliminating batch-to-batch variability in rodent diets that may lead to conflicting findings in animal experiments within and between laboratories. Data were presented at the workshops showing that there is significant batch-to-batch variability in estrogenic content of commercial animal diets, and that this variability results in differences in experimental outcomes. A combination of methods were proposed to determine levels of total estrogenic activity and levels of specific estrogenic constituents in soy-containing, casein-containing, and other soy-free rodent diets. Workshop participants recommended that researchers pay greater attention to the type of diet being used in animal studies and choose a diet whose estrogenic activity (or lack thereof) is appropriate for the experimental model and end points of interest. Information about levels of specific phytoestrogens, as well as estrogenic activity caused by other contaminants and measured by bioassay, should be disclosed in scientific publications. This will require laboratory animal diet manufacturers to provide investigators with information regarding the phytoestrogen content and other estrogenic compounds in commercial diets used in animal research.

  13. Comparative field study: impact of laboratory assay variability on the assessment of recombinant factor IX Fc fusion protein (rFIXFc) activity.

    Science.gov (United States)

    Sommer, Jurg M; Buyue, Yang; Bardan, Sara; Peters, Robert T; Jiang, Haiyan; Kamphaus, George D; Gray, Elaine; Pierce, Glenn F

    2014-11-01

    Due to variability in the one-stage clotting assay, the performance of new factor IX (FIX) products should be assessed in this assay. The objective of this field study was to evaluate the accuracy of measuring recombinant FIX Fc fusion protein (rFIXFc) activity in clinical haemostasis laboratories using the one-stage clotting assay. Human haemophilic donor plasma was spiked with rFIXFc or BeneFIX® at 0.80, 0.20, or 0.05 IU/ml based on label potency. Laboratories tested blinded samples using their routine one-stage assay and in-house FIX plasma standard. The mean spike recoveries for BeneFIX (n=30 laboratories) were 121 %, 144 %, and 168 % of expected at nominal 0.80, 0.20, and 0.05 IU/ml concentrations, respectively. Corresponding rFIXFc spike recoveries were 88 %, 107 %, and 132 % of expected, respectively. All BeneFIX concentrations were consistently overestimated by most laboratories. rFIXFc activity was reagent-dependent; ellagic acid and silica gave higher values than kaolin, which underestimated rFIXFc. BeneFIX demonstrated significantly reduced chromogenic assay activity relative to one-stage assay results and nominal activity, while rFIXFc activity was close to nominal activity at three concentrations with better dilution linearity than the typical one-stage assay. In conclusion, laboratory- and reagent-specific assay variabilities were revealed, with progressively higher variability at lower FIX concentrations. Non-parallelism against the FIX plasma standard was observed in all one-stage assays with rFIXFc and BeneFIX, leading to significant overestimation of FIX activity at lower levels and generally high inter-laboratory variability. Compared to the accuracy currently achieved in clinical laboratories when measuring other rFIX products, most laboratories measured rFIXFc activity with acceptable accuracy and reliability using routine one-stage assay methods and commercially available plasma standards.

  14. Selective activation around the left occipito-temporal sulcus for words relative to pictures: Individual variability or false positives?

    NARCIS (Netherlands)

    Wright, Nicholas D.; Mechelli, Andrea; Noppeney, Uta; Veltman, Dick J.; Rombouts, Serge A. R. B.; Glensman, Janice; Haynes, John-Dylan; Price, Cathy J.

    2008-01-01

    We used high-resolution fMRI to investigate claims that learning to read r !sults in greater left occipito-temporal (OT) activation for written words relative to pictures of objects. In tl e first experiment, 9/16 subjects performing a one-back task showed activation in >= 1 left OT voxel for word:

  15. Mutants of Micromonospora viridifaciens sialidase have highly variable activities on natural and non-natural substrates

    DEFF Research Database (Denmark)

    Jers, Carsten; Guo, Yao; Kepp, Kasper Planeta

    2015-01-01

    This study aimed to improve the hydrolase activity of the well-characterised bacterial sialidase from Micromonospora viridifaciens. The enzyme and its mutated versions were produced in Bacillus subtilis and secreted to the growth medium. Twenty amino acid positions in or near the active site were...

  16. Variable training does not lead to better motor learning compared to repetitive training in children with and without DCD when exposed to active video games.

    Science.gov (United States)

    Bonney, Emmanuel; Jelsma, Dorothee; Ferguson, Gillian; Smits-Engelsman, Bouwien

    2017-03-01

    Little is known about the influence of practice schedules on motor learning and skills transfer in children with and without developmental coordination disorder (DCD). Understanding how practice schedules affect motor learning is necessary for motor skills development and rehabilitation. The study investigated whether active video games (exergames) training delivered under variable practice led to better learning and transfer than repetitive practice. 111 children aged 6-10 years (M=8.0, SD=1.0) with no active exergaming experience were randomized to receive exergames training delivered under variable (Variable Game Group (VGG), n=56) or repetitive practice schedule (Repetitive Game Group (RGG), n=55). Half the participants were identified as DCD using the DSM-5 criteria, while the rest were typically developing (TD), age-matched children. Both groups participated in two 20min sessions per week for 5 weeks. Both participant groups (TD and DCD) improved equally well on game performance. There was no significant difference in positive transfer to balance tasks between practice schedules (Repetitive and Variable) and participant groups (TD and DCD). Children with and without DCD learn balance skills quite well when exposed to exergames. Gains in learning and transfer are similar regardless of the form of practice schedule employed. This is the first paper to compare the effect of practice schedules on learning in children with DCD and those with typical development. No differences in motor learning were found between repetitive and variable practice schedules. When children with and without DCD spend the same amount of time on exergames, they do not show any differences in acquisition of motor skills. Transfer of motor skills is similar in children with and without DCD regardless of differences in practice schedules. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Spatial and Temporal Variability of Carbon Dioxide Using Structure Functions in Urban Areas: Insights for Future Active Remote CO2 Sensors

    Science.gov (United States)

    Choi, Yonghoon; Yang, Melissa; Kooi, Susan A.; Browell, Edward V.; DiGangi, Joshua P.

    2015-01-01

    High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaigns during July 2011 over Washington DC/Baltimore, MD; January-February 2013 over the San Joaquin Valley, CA; September 2013 over Houston, TX; and July-August 2014 over Denver, CO. Each of these campaigns have approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 kilometers) at 6-8 different sites in each of the urban areas. In this study, we used structure function analysis, which is a useful way to quantify spatial and temporal variability, by displaying differences with average observations, to evaluate the variability of CO2 in the 0-2 kilometers range (representative of the planetary boundary layer). These results can then be used to provide guidance in the development of science requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission to measure near-surface CO2 variability in different urban areas. We also compare the observed in-situ CO2 variability with the variability of the CO2 column-averaged optical depths in the 0-1 kilometer and 0-3.5 kilometers altitude ranges in the four geographically different urban areas, using vertical weighting functions for potential future ASCENDS lidar CO2 sensors operating in the 1.57 and 2.05 millimeter measurement regions. In addition to determining the natural variability of CO2 near the surface and in the column, radiocarbon method using continuous CO2 and CO measurements are used to examine the variation of emission quantification between anthropogenic and biogenic sources in the DC/Maryland urban site.

  18. Selective Activation Around the Left Occipito-Temporal Sulcus for Words Relative to Pictures: Individual Variability or False Positives?

    OpenAIRE

    Wright, Nicholas D; Mechelli, Andrea; Noppeney, Uta; Veltman, Dick J; Rombouts, Serge ARB; Glensman, Janice; Haynes, John-Dylan; Price, Cathy J

    2007-01-01

    We used high-resolution fMRI to investigate claims that learning to read results in greater left occipito-temporal (OT) activation for written words relative to pictures of objects. In the first experiment, 9/16 subjects performing a one-back task showed activation in ?1 left OT voxel for words relative to pictures (P < 0.05 uncorrected). In a second experiment, another 9/15 subjects performing a semantic decision task activated ?1 left OT voxel for words relative to pictures. However, at thi...

  19. CCN Activity, Variability and Influence on Droplet Formation during the HygrA-Cd Campaign in Athens

    Directory of Open Access Journals (Sweden)

    Aikaterini Bougiatioti

    2017-06-01

    Full Text Available Measurements of cloud condensation nuclei (CCN concentrations (cm−3 at five levels of supersaturation between 0.2–1%, together with remote sensing profiling and aerosol size distributions, were performed at an urban background site of Athens during the Hygroscopic Aerosols to Cloud Droplets (HygrA-CD campaign. The site is affected by local emissions and long-range transport, as portrayed by the aerosol size, hygroscopicity and mixing state. Application of a state-of-the-art droplet parameterization is used to link the observed size distribution measurements, bulk composition, and modeled boundary layer dynamics with potential supersaturation, droplet number, and sensitivity of these parameters for clouds forming above the site. The sensitivity is then used to understand the source of potential droplet number variability. We find that the importance of aerosol particle concentration levels associated with the background increases as vertical velocities increase. The updraft velocity variability was found to contribute 58–90% (68.6% on average to the variance of the cloud droplet number, followed by the variance in aerosol number (6–32%, average 23.2%. Therefore, although local sources may strongly modulate CCN concentrations, their impact on droplet number is limited by the atmospheric dynamics expressed by the updraft velocity regime.

  20. Spatial variability of isoproturon mineralizing activity within an agricultural field: Geostatistical analysis of simple physicochemical and microbiological soil parameters

    Energy Technology Data Exchange (ETDEWEB)

    El Sebai, T. [UMR Microbiologie et Geochimie des Sols, INRA/CMSE, 17 Rue Sully, BP 86510, 21065 Dijon Cedex (France); Lagacherie, B. [UMR Microbiologie et Geochimie des Sols, INRA/CMSE, 17 Rue Sully, BP 86510, 21065 Dijon Cedex (France); Soulas, G. [UMR Microbiologie et Geochimie des Sols, INRA/CMSE, 17 Rue Sully, BP 86510, 21065 Dijon Cedex (France); Martin-Laurent, F. [UMR Microbiologie et Geochimie des Sols, INRA/CMSE, 17 Rue Sully, BP 86510, 21065 Dijon Cedex (France)]. E-mail: fmartin@dijon.inra.fr

    2007-02-15

    We assessed the spatial variability of isoproturon mineralization in relation to that of physicochemical and biological parameters in fifty soil samples regularly collected along a sampling grid delimited across a 0.36 ha field plot (40 x 90 m). Only faint relationships were observed between isoproturon mineralization and the soil pH, microbial C biomass, and organic nitrogen. Considerable spatial variability was observed for six of the nine parameters tested (isoproturon mineralization rates, organic nitrogen, genetic structure of the microbial communities, soil pH, microbial biomass and equivalent humidity). The map of isoproturon mineralization rates distribution was similar to that of soil pH, microbial biomass, and organic nitrogen but different from those of structure of the microbial communities and equivalent humidity. Geostatistics revealed that the spatial heterogeneity in the rate of degradation of isoproturon corresponded to that of soil pH and microbial biomass. - In field spatial variation of isoproturon mineralization mainly results from the spatial heterogeneity of soil pH and microbial C biomass.

  1. Spatial variability of isoproturon mineralizing activity within an agricultural field: Geostatistical analysis of simple physicochemical and microbiological soil parameters

    International Nuclear Information System (INIS)

    El Sebai, T.; Lagacherie, B.; Soulas, G.; Martin-Laurent, F.

    2007-01-01

    We assessed the spatial variability of isoproturon mineralization in relation to that of physicochemical and biological parameters in fifty soil samples regularly collected along a sampling grid delimited across a 0.36 ha field plot (40 x 90 m). Only faint relationships were observed between isoproturon mineralization and the soil pH, microbial C biomass, and organic nitrogen. Considerable spatial variability was observed for six of the nine parameters tested (isoproturon mineralization rates, organic nitrogen, genetic structure of the microbial communities, soil pH, microbial biomass and equivalent humidity). The map of isoproturon mineralization rates distribution was similar to that of soil pH, microbial biomass, and organic nitrogen but different from those of structure of the microbial communities and equivalent humidity. Geostatistics revealed that the spatial heterogeneity in the rate of degradation of isoproturon corresponded to that of soil pH and microbial biomass. - In field spatial variation of isoproturon mineralization mainly results from the spatial heterogeneity of soil pH and microbial C biomass

  2. Pharmacokinetic variability of clarithromycin and differences in CYP3A4 activity in patients with cystic fibrosis

    DEFF Research Database (Denmark)

    Dalbøge, C S; Nielsen, X C; Dalhoff, K

    2014-01-01

    3A4-activity and clarithromycin metabolism was demonstrated (P cystic fibrosis patients may cause treatment failure. The Erythromycin Breath Test could be valuable in identifying cystic fibrosis patients in risk...

  3. Longitudinal variability of time-location/activity patterns of population at different ages: a longitudinal study in California

    Directory of Open Access Journals (Sweden)

    Cassady Diana L

    2011-09-01

    Full Text Available Abstract Background Longitudinal time-activity data are important for exposure modeling, since the extent to which short-term time-activity data represent long-term activity patterns is not well understood. This study was designed to evaluate longitudinal variations in human time-activity patterns. Method We report on 24-hour recall diaries and questionnaires collected via the internet from 151 parents of young children (mostly under age 55, and from 55 older adults of ages 55 and older, for both a weekday and a weekend day every three months over an 18-month period. Parents also provided data for their children. The self-administrated diary and questionnaire distinguished ~30 frequently visited microenvironments and ~20 activities which we selected to represent opportunities for exposure to toxic environmental compounds. Due to the non-normal distribution of time-location/activity data, we employed generalized linear mixed-distribution mixed-effect models to examine intra- and inter-individual variations. Here we describe variation in the likelihood of and time spent engaging in an activity or being in a microenvironment by age group, day-type (weekday/weekend, season (warm/cool, sex, employment status, and over the follow-up period. Results As expected, day-type and season influence time spent in many location and activity categories. Longitudinal changes were also observed, e.g., young children slept less with increasing follow-up, transit time increased, and time spent on working and shopping decreased during the study, possibly related to human physiological changes with age and changes in macro-economic factors such as gas prices and the economic recession. Conclusions This study provides valuable new information about time-activity assessed longitudinally in three major age groups and greatly expands our knowledge about intra- and inter-individual variations in time-location/activity patterns. Longitudinal variations beyond weekly and

  4. Seasonal and diel variability in dissolved DNA and in microbial biomass and activity in a subtropical estuary

    International Nuclear Information System (INIS)

    Paul, J.H.; Deflaun, M.F.; Jeffrey, W.H.; David, A.W.

    1988-01-01

    Dissolved DNA and microbial biomass and activity parameters were measured over a 15-month period at three stations along a salinity gradient in Tampa Bay, Fla. Dissolved DNA showed seasonal variation, with minimal values in December and January and maximal values in summer months (July and August). This pattern of seasonal variation followed that of particulate DNA and water temperature and did not correlate with bacterioplankton (direct counts and [ 3 H] thymidine incorporation) or phytoplankton (chlorophyll α and 14 CO 2 fixation) biomass and activity. Microautotrophic populations showed maxima in the spring and fall, whereas microheterotrophic activity was greatest in late summer (September). Both autotrophic and heterotrophic microbial activity was greatest at the high estuarine (low salinity) station and lowest at the mouth of the bay (high salinity station), irrespective of season. Dissolved DNA carbon and phosphorus constituted 0.11 +/- 0.05% of the dissolved organic carbon and 6.6 +/- 6.5% of the dissolved organic phosphorus, respectively. Strong diel periodicity was noted in dissolved DNA and in microbial activity in Bayboro Harbor during the dry season. A noon maximum in primary productivity was followed by an 8 p.m. maximum in heterotrophic activity and a midnight maximum in dissolved DNA. This diel periodicity was less pronounced in the wet season, when microbial parameters were strongly influenced by episodic inputs of freshwater

  5. Studying The Spectral Shape And The X-ray/uv Variability Of Active Galactic Nuclei With Data From Swift And Xmm Archives

    Science.gov (United States)

    Turriziani, Sara

    2011-01-01

    Many efforts have been made in understanding the underlying origin of variability in Active Galactic Nuclei (AGN), but at present they could give still no conclusive answers. Since a deeper knowledge of variability will enable to understand better the accretion process onto supermassive black holes, I built the first ensemble struction function analysis of the X-ray variability of samples of quasars with data from Swift and XMM-Newton archives in order to study the average properties of their variability. Moreover, it is known that UV and X-ray luminosities of quasars are correlated and recent studies quantified this relation across 5 orders of magnitude. In this context, I presents results on the X-ray/UV ratio from simultaneous observations in UV and X-ray bands of a sample of quasars with data from XMM-Newton archive. Lastly, I will present a complete sample of Swift/SDSS faint blazars and other non-thermal dominated AGNs. I used this sample to calculate the general statistical properties of faint blazars and radio galaxies and in particular their Radio LogN-LogS with fluxes down to 10 mJy, in order to gain knowledge on the contribution to Cosmic Microwave Background (CMB) and gamma-ray background radiation from the faint tail of the radio population. I acknowledge financial support through Grant ASI I/088/06/0.

  6. Influence of a virtual reality-based exercise protocol on the sit-to-stand activity kinematic variables in pregnant women: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Silvia Oliveira Ribeiro

    2017-07-01

    Full Text Available Abstract AIMS Changes resulting from the gestational period may lead to changes in the biomechanics of women, which can alter the performance of functional activities such as sit-to-stand. Thus, the objective of this study was to investigate the influence of a virtual reality-based exercise protocol on the kinematic variables of the sit-to-stand movement in women in their second and third gestational trimesters. METHODS The sample consisted of 44 women selected according to the eligibility criteria, allocated into 4 groups: control group, 2nd trimester (CG2T; experimental group, 2nd trimester (EG2T; control group, 3rd trimester (CG3T; and experimental group, 3rd trimester (EG3T. All the volunteers answered the identification and evaluation form and were sent to the kinematic evaluation through the Qualisys Motion Capture System®. An intervention with game therapy was performed in 12 sessions of 30 minutes each, three times a week. RESULTS No statistically significant differences were found intra- (P> 0.54 and inter-groups (P> 0.059 for kinematic variables. However, there was a tendency for improvement in the analyzed variables after the proposed protocol. CONCLUSIONS The data obtained suggest that the use of the Nintendo Wii Fit Plus® was not able to influence sit-to-stand kinematic variables in the analyzed women.

  7. Variable activation in striatal subregions across components of a social influence task in young adult cannabis users.

    Science.gov (United States)

    Gilman, Jodi M; Lee, Sang; Kuster, John K; Lee, Myung Joo; Kim, Byoung Woo; van der Kouwe, Andre; Blood, Anne J; Breiter, Hans C

    2016-05-01

    Decades of research have demonstrated the importance of social influence in initiation and maintenance of drug use, but little is known about neural mechanisms underlying social influence in young adults who use recreational drugs. To better understand whether the neural and/or behavioral response to social influence differs in young adults using illicit drugs, 20 marijuana-using young adults (MJ) aged 18-25, and 20 controls (CON) performed a decision-making task in the context of social influence, while they underwent functional magnetic resonance imaging scans. A priori analyses focused on the nucleus accumbens (NAc), with post hoc analyses in the rest of the striatum. In this task, participants could choose to either follow or go against group influence. When subjects applied social information to response choice selection (independent of following or going against group influence), we observed activation in the middle striatum (caudate), in the MJ group only, that extended ventrally into the NAc. MJ users but not CON showed greater activation in the NAc but not the caudate while making choices congruent with group influence as opposed to choices going against group influence. Activation in the NAc when following social influence was associated with amount of drug use reported. In contrast, during the feedback phase of the task we observed significant NAc activation in both MJ and CON, along with dorsal caudate activation only in MJ participants. This NAc activation did not correlate with drug use. This study shows that MJ users, but not CON, show differential brain activation across striatal subregions when applying social information to make a decision, following versus going against a group of peers, or receiving positive feedback. The current work suggests that differential neural sensitivity to social influence in regions such as the striatum may contribute to the development and/or maintenance of marijuana use.

  8. Personal power-frequency magnetic field exposure in women recruited at an infertility clinic: association with physical activity and temporal variability.

    Science.gov (United States)

    Lewis, Ryan C; Hauser, Russ; Wang, Lu; Kavet, Robert; Meeker, John D

    2016-03-01

    Current epidemiologic approaches for studying exposure to power-frequency magnetic fields and the risk of miscarriage are potentially biased due to lack of attention to the relationship of exposure with physical activity and within-individual variability in exposures over time. This analysis examines these two issues using data from a longitudinal pilot study of 40 women recruited from an infertility clinic that contributed data for up to three 24-h periods separated by a median of 3.6 weeks. Physical activity was positively associated with peak exposure metrics. Higher physical activity within environments did not necessarily lead to higher peak exposures, suggesting that movement between and not within environments increases one's probability of encountering a high field source. Peak compared with central tendency metrics were more variable over time. Future epidemiology studies associated with peak exposure metrics should adjust for physical activity and collect more than 1 d of exposure measurement to reduce bias. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Understanding Variability, Habit and the Effect of Long Period Activity Plan in Modal Choices: A Day to Day, Week to Week Analysis on Panel Data

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Cirillo, Cinzia

    2014-01-01

    Understanding variability in individual behaviour is crucial for the comprehension of travel patterns and for the development and evaluation of planning policies. In the last 30 years a vast body of research has approached the issue in a variety of ways, but there are no studies on the intrinsic ...... choice made is influenced by the duration of the activity and the weekly structure of the activities. Finally, models improve significantly when panel correlation is accounted for. But it seems that inertia can explain to some extent for panel effect.......Understanding variability in individual behaviour is crucial for the comprehension of travel patterns and for the development and evaluation of planning policies. In the last 30 years a vast body of research has approached the issue in a variety of ways, but there are no studies on the intrinsic...... variability in the individual preferences for mode choices in absence of external changes (or shocks) in the transportation infrastructures (i.e. introduction of new modes or major reorganization of the transportation system). This requires using continuous panel data. Few papers have studied mode choice...

  10. Soft X-ray variability over the present minimum of solar activity as observed by SphinX

    Science.gov (United States)

    Gburek, S.; Siarkowski, M.; Kepa, A.; Sylwester, J.; Kowalinski, M.; Bakala, J.; Podgorski, P.; Kordylewski, Z.; Plocieniak, S.; Sylwester, B.; Trzebinski, W.; Kuzin, S.

    2011-04-01

    Solar Photometer in X-rays (SphinX) is an instrument designed to observe the Sun in X-rays in the energy range 0.85-15.00 keV. SphinX is incorporated within the Russian TESIS X and EUV telescope complex aboard the CORONAS-Photon satellite which was launched on January 30, 2009 at 13:30 UT from the Plesetsk Cosmodrome, northern Russia. Since February, 2009 SphinX has been measuring solar X-ray radiation nearly continuously. The principle of SphinX operation and the content of the instrument data archives is studied. Issues related to dissemination of SphinX calibration, data, repository mirrors locations, types of data and metadata are discussed. Variability of soft X-ray solar flux is studied using data collected by SphinX over entire mission duration.

  11. Activity pattern of Cuniculus paca (Rodentia: Cuniculidae in relation to lunar illumination and other abiotic variables in the southern Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Fernanda Michalski

    2011-12-01

    Full Text Available Understanding what influences the activity of organisms is important for both ecological understanding and species conservation. Using data from 2,707 camera trap days distributed across 24 forest sites, we present quantitative analyses of the activity pattern of Cuniculus paca (Linnaeus, 1766 in southern Amazonia. We compared the activity pattern of this species across four designated subsets of the 24-hours diel cycle (dawn, dusk, day and night. Using linear regression models we tested the influence of season, temperature and rainfall on the activity patterns of C. paca (paca. We also evaluated the nocturnal photos of paca (N = 111 as a function of the degree of lunar illumination in order to test the prediction that pacas minimize their activity during moon phase when illumination is brighter. Pacas were not recorded during the day but were active at dawn, dusk and night time. We found differences in the influence of the abiotic variables on the nocturnal activity of pacas in the study area. There was no significant difference between the observed (expressed as the frequency of total counts of independent photos over the five classes of lunar illumination and the expected activity of pacas, based on the frequency of days in the lunar cycle with different classes of lunar illumination, whereas lunar illumination had a weak negative influence on the timing of paca activity (i.e. pacas were active closer to sunset with increasing lunar illumination. However, the timing of nocturnal activity in pacas was not influenced by season, temperature or rainfall. Our findings highlight the ecological plasticity of this Neotropical rodent which has a key function in the maintenance of Neotropical forests.

  12. Selective activation around the left occipito-temporal sulcus for words relative to pictures: individual variability or false positives?

    Science.gov (United States)

    Wright, Nicholas D; Mechelli, Andrea; Noppeney, Uta; Veltman, Dick J; Rombouts, Serge A R B; Glensman, Janice; Haynes, John-Dylan; Price, Cathy J

    2008-08-01

    We used high-resolution fMRI to investigate claims that learning to read results in greater left occipito-temporal (OT) activation for written words relative to pictures of objects. In the first experiment, 9/16 subjects performing a one-back task showed activation in > or =1 left OT voxel for words relative to pictures (P or =1 left OT voxel for words relative to pictures. However, at this low statistical threshold false positives need to be excluded. The semantic decision paradigm was therefore repeated, within subject, in two different scanners (1.5 and 3 T). Both scanners consistently localised left OT activation for words relative to fixation and pictures relative to words, but there were no consistent effects for words relative to pictures. Finally, in a third experiment, we minimised the voxel size (1.5 x 1.5 x 1.5 mm(3)) and demonstrated a striking concordance between the voxels activated for words and pictures, irrespective of task (naming vs. one-back) or script (English vs. Hebrew). In summary, although we detected differential activation for words relative to pictures, these effects: (i) do not withstand statistical rigour; (ii) do not replicate within or between subjects; and (iii) are observed in voxels that also respond to pictures of objects. Our findings have implications for the role of left OT activation during reading. More generally, they show that studies using low statistical thresholds in single subject analyses should correct the statistical threshold for the number of comparisons made or replicate effects within subject. (c) 2007 Wiley-Liss, Inc.

  13. Gis-approach for variability assessment of soil electric conductivity under pedoturbation activity of mole rat (Spalax microphthalmus

    Directory of Open Access Journals (Sweden)

    T. М. Konovalova

    2010-06-01

    Full Text Available The results of the investigation of the impact of the mole rat’s activity on soil electric conductivity have been presented. GIS-technology have been shown to be effective for assessment of the pedoturbation activity effect on the soil surface heterogeneity formation. Method of the one-dimension spatial coordinated array transformation into matrix form has been proposed for following multidimension statistic analysis application. The quantity estimation of the mole rats role in formation of the habitat nanorelief-level diversity has been obtained by means of indexes of the landscape complexity and diversity.

  14. Functional variability in butyrylcholinesterase activity regulates intrathecal cytokine and astroglial biomarker profiles in patients with Alzheimer's disease

    DEFF Research Database (Denmark)

    Darreh-Shori, Taher; Vijayaraghavan, Swetha; Aeinehband, Shahin

    2013-01-01

    Butyrylcholinesterase (BuChE) activity is associated with activated astrocytes in Alzheimer's disease brain. The BuChE-K variant exhibits 30%-60% reduced acetylcholine (ACh) hydrolyzing capacity. Considering the increasing evidence of an immune-regulatory role of ACh, we investigated if genetic...... findings, such as high cerebral glucose utilization, low β-amyloid load, and less severe progression of clinical symptoms. In vitro analysis on human astrocytes confirmed the involvement of a regulated BuChE status in the astroglial responses to TNF-α and ACh. Histochemical analysis in a rat model of nerve...

  15. Spatial variability of soil electrical conductivity under the mole rats (Spalax microphthalmus digging activity at the different scales

    Directory of Open Access Journals (Sweden)

    A. V. Zhukov

    2012-07-01

    Full Text Available The soil mounds emerged owing to the mole rats’ digging activity have been shown to be characterised by less electrical conductivity than surrounded soil. This effect is due to the changes of the mounds bulk’s density and moisture. The effect of the mole rats’ digging activity on the soil electrical conductivity has been found not to be restricted by the geometrical border of the mounds. The mounds are surrounded by 1–1.5 m halo of increased soil electrical conductivity. The halo size is increased with the aging of the mound and with the compacting of their aggregation.

  16. Flicker Mitigation by Active Power Control of Variable-Speed Wind Turbines With Full-Scale Back-to-Back Power Converters

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Wang, Zhaoan

    2009-01-01

    /EMTDC. Flicker emission of this system is investigated. Reactive power compensation is mostly adopted for flicker mitigation. However, the flicker mitigation technique shows its limits, when the grid impedance angle is low in some distribution networks. A new method of flicker mitigation by controlling active...... power is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the dc-link voltage of the full-scale converter. Simulation results show that damping the 3p active power oscillation by using the flicker mitigation controller...... is an effective means for flicker mitigation of variable-speed wind turbines with full-scale back-to-back power converters during continuous operation....

  17. Spatial variability of enzyme activities and microbial biomass in the upper layers of Quercus petraea forest soil

    Czech Academy of Sciences Publication Activity Database

    Šnajdr, Jaroslav; Valášková, Vendula; Merhautová, Věra; Herinková, Jana; Cajthaml, Tomáš; Baldrian, Petr

    2008-01-01

    Roč. 40, č. 9 (2008), s. 2068-2075 ISSN 0038-0717 R&D Projects: GA MŠk LC06066; GA MZe QH72216; GA AV ČR KJB600200516 Institutional research plan: CEZ:AV0Z50200510 Keywords : enzyme activity * forest soil * lignocellulose Subject RIV: EE - Microbiology, Virology Impact factor: 2.926, year: 2008

  18. Between- and within-day variability in physical activity and inactivity in 9- and 15-year-old European children

    DEFF Research Database (Denmark)

    Nilsson, A; Anderssen, S A; Andersen, Lars Bo

    2008-01-01

    To examine differences in levels of physical activity (PA), time spent at moderate-to-vigorous intensity PA (MVPA) and time spent sedentary between and within days in children from four European countries, 1954 9 - and 15-year-olds were included. PA was measured during 2 weekdays and 2 weekend days...

  19. Variability of biological effects of silicas: Different degrees of activation of the fifth component of complement by amorphous silicas

    International Nuclear Information System (INIS)

    Governa, Mario; Amati, Monica; Fenoglio, Ivana; Valentino, Matteo; Coloccini, Sabrina; Bolognini, Lucia; Carlo Botta, Gian; Emanuelli, Monica; Pierella, Francesca; Volpe, Anna Rita; Astolfi, Paola; Carmignani, Marco; Fubini, Bice

    2005-01-01

    A biogenic and a pyrogenic amorphous silica were incubated in normal human plasma and compared on a per unit surface basis for their ability to split C5 molecules and yield small C5a peptides. Since C5a peptides induce selective chemotactic attraction of polymorphonuclear leukocytes (PMN), measurement of PMN-induced chemotaxis was used as an index of C5 activation. Though to a lesser extent than the crystalline forms, amorphous silicas can promote the cleavage of C5 protein and generation of C5a-like fragment. The biogenic silica, which differs from the pyrogenic variety in particle shape, level of contaminants, and degree of surface hydrophilicity, besides specific surface, induced a greater response. Both silicas activated C5 through a process which seems to involve multiple events similar to those induced by crystalline silica. C5 molecules are adsorbed and hydroxyl radicals are generated through Haber Weiss cycles catalyzed by the redox-active iron present at the particle surface either as trace impurities or chelated from plasma by silanol groups. In turn, these radicals convert native C5 to an oxidized C5-like form C5(H 2 O 2 ). Finally, C5(H 2 O 2 ) is cleaved by protease enzymatic action of plasma kallikrein activated by the same silica dusts, yielding a product, C5a(H 2 O 2 ), having the same functional characteristic as C5a

  20. Blazing the Trail for Astronomy Education Research

    Science.gov (United States)

    Bailey, Janelle M.; Lombardi, Doug

    2015-01-01

    Education research has long considered student learning of topics in astronomy and the space sciences, but astronomy education research as a sub-field of discipline-based education research is relatively new. Driven by a growing interest among higher education astronomy educators in improving the general education, introductory science survey…

  1. Peter Bauer: Blazing the Trail of Development

    OpenAIRE

    Ian Vasquez

    2007-01-01

    Peter Bauer was a pioneer in development economics and his contributions to the field have been vindicated by the collapse of central planning. Through most of his career, however, Bauer was marginalized by the economics profession. Even after the fall of the Berlin Wall, economists frequently neglect Bauer’s work. Two survey articles on trade and development by Anne Krueger are presented as examples of that neglect. Bauer’s emphasis on choice, his interdisciplinary methodology, and his c...

  2. Nuclear: rebirth or blaze of glory?

    International Nuclear Information System (INIS)

    Monod, O.

    2009-01-01

    Actually, 439 nuclear power plants are operating and 41 new projects represent an increase of 9.2% of the installed power. Because of the objectives of carbon dioxide reduction to fight against the climatic change countries that thought stopping the construction of new nuclear power plants are changing their mind. United kingdom, Belgium and even Germany plan to change their energy policy. So a new market appears the nuclear market, but it is expansive and needs a long time to be implemented. It is to noticed that the enrichment and the radioactive waste management are profitable for an important nuclear park. So a country that has less than ten power plants has no economical reason to take these points itself. The energy demand growths faster than the nuclear supply. An other point to take into account is the ageing of nuclear power plants. Actually, in usa the nuclear power plants are built for forty years but they try to extend their lifetime for twenty years. In france, the system is different, any ten years the Authority of Safety (A.S.N.) visits the sites and notices the works to do to continue for ten years; the operator chooses between making the works or stop the plant. The most important problem stays the question of radioactive waste, if the countries leaders in this technology are ready to treat these waste they do not want to storage them, any country candidate to nuclear power will have to find a geological layer, secure for 10000 years and money to necessary to its construction. (N.C.)

  3. CARDIORESPIRATORY FITNESS, ACTIVITY LEVEL, HEALTH-RELATED ANTHROPOMETRIC VARIABLES, SEDENTARY BEHAVIOUR AND SOCIOECONOMIC STATUS IN A SAMPLE OF IRANIAN 7-11 YEAR OLD BOYS

    Directory of Open Access Journals (Sweden)

    Samad Esmaeilzadeh

    2013-01-01

    Full Text Available The purpose of this study was to evaluate cardiorespiratory fitness (CRF, activity level, some health-related anthropometric variables, sedentary behaviour and socioeconomic status (SES of 7-11 year old boys in the city of Ardabil, Iran. Of 21 253 school boys aged 7-11 years, 766 participated in this study using the cluster sampling method. Subjects underwent standard anthropometry. One-mile test was used to evaluate ·VO2max. BMI cut-off points were used to identify weight status. Child’s TV watching and video playing daily time (TVVPT was taken for sedentary behaviour evaluation. SES and activity level were measured by standard questionnaires. Of all participants, 8.9�0(N=68 of students had CRF lower than normal and 58.6�0(N=449 of them had inadequate physical activity. There was a significant adverse relationship between ·VO2max and body mass index (BMI, waist to height ratio (WHtR, waist circumference (WC, and fat mass (FM (p<0.05. A significant direct association between SES and both FM and TVVPT was observed (p<0.05. Significantly lower physical activity and ·VO2max, and higher TVVPT were observed in the obese boys than their counterparts (p<0.05. The results of this study indicated a significant relationship between CRF and physical activity, and health-related anthropometric variables in a selected sample of 7-11 year boys. Moreover, the obese subjects had not only lower physical activity but also longer sedentary behaviour time than their counterparts.

  4. Heart rate variability reveals that a decrease in parasympathetic ('rest-and-digest') activity dominates autonomic stress responses in a free-living seabird.

    Science.gov (United States)

    Müller, Martina S; Vyssotski, Alexei L; Yamamoto, Maki; Yoda, Ken

    2017-10-01

    The autonomic stress response, often referred to as the 'fight-or-flight' response, is a highly conserved physiological reaction to stress in vertebrates that occurs via a decrease in parasympathetic (PNS) activity, which promotes self-maintenance 'rest and digest' processes, and an increase in sympathetic (SNS) activity, which prepares an animal for danger ('fight-or-flight'). Though the PNS and SNS both innervate most organs, they often control different tissues and functions within those organs (though the pacemaker of the heart is controlled by both). Moreover the PNS and SNS are regulated independently. Yet until now, most studies of autonomic stress responses in non-model species focused only on the SNS response. We used external electrocardiogram loggers to measure heart rate and heart rate variability indexes that reflect PNS and SNS activity in a seabird, the Streaked Shearwater (Calonectris leucomelas), during the stress of handling, and during recovery in the nest burrow or during restraint in a cloth bag. We show for the first time in a free-living animal that the autonomic stress response is mediated primarily by a rapid decrease in PNS activity: handling stress induced a large and long-lasting depression of PNS 'rest-and-digest' activity that required two hours to recover. We also found evidence for a substantially smaller and shorter-lasting SNS 'fight-or-flight' response. Confinement in a cloth bag was less stressful for birds than handling, but more stressful than recovering in nest burrows. We show that quantifying autonomic activity from heart rate variability is effective for non-invasively studying stress physiology in free-living animals. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths - III. Characterization of total flux density and polarization variability of relativistic jets

    Science.gov (United States)

    Agudo, Iván; Thum, Clemens; Ramakrishnan, Venkatessh; Molina, Sol N.; Casadio, Carolina; Gómez, José L.

    2018-01-01

    We report on the first results of the POLAMI (Polarimetric Monitoring of AGNs with Millimetre Wavelengths) programme, a simultaneous 3.5 and 1.3 mm full-Stokes-polarization monitoring of a sample of 36 of the brightest active galactic nuclei in the northern sky with the IRAM 30 m telescope. Through a systematic statistical study of data taken from 2006 October (from 2009 December for the case of the 1.3 mm observations) to 2014 August, we characterize the variability of the total flux density and linear polarization. We find that all sources in the sample are highly variable in total flux density at both 3.5 and 1.3 mm, as well as in spectral index, which (except in particularly prominent flares) is found to be optically thin between these two wavelengths. The total flux-density variability at 1.3 mm is found, in general, to be faster, and to have larger fractional amplitude and flatter power-spectral-density slopes than at 3.5 mm. The polarization degree is on average larger at 1.3 mm than at 3.5 mm, by a factor of 2.6. The variability of linear polarization degree is faster and has higher fractional amplitude than for total flux density, with the typical time-scales during prominent polarization peaks being significantly faster at 1.3 mm than at 3.5 mm. The polarization angle at both 3.5 and 1.3 mm is highly variable. Most of the sources show one or two excursions of >180° on time-scales from a few weeks to about a year during the course of our observations. The 3.5 and 1.3 mm polarization angle evolution follows each other rather well, although the 1.3 mm data show a clear preference to more prominent variability on the short time-scales, i.e. weeks. The data are compatible with multizone models of conical jets involving smaller emission regions for the shortest-wavelength emitting sites. Such smaller emitting regions should also be more efficient in energising particle populations, as implied by the coherent evolution of the spectral index and the total flux

  6. Platelet activation, adhesion, inflammation, and aggregation potential are altered in the presence of electronic cigarette extracts of variable nicotine concentrations.

    Science.gov (United States)

    Hom, Sarah; Chen, Li; Wang, Tony; Ghebrehiwet, Berhane; Yin, Wei; Rubenstein, David A

    2016-11-01

    Tobacco smoke extracts prepared from both mainstream and sidestream smoking have been associated with heightened platelet activation, aggregation, adhesion, and inflammation. Conversely, it has been shown that pure nicotine inhibits similar platelet functions. In this work, we 1) evaluated the effects of e-cigarette extracts on platelet activities and 2) elucidated the differences between the nicotine-dependent and non-nicotine dependent (e.g. fine particulate matter or toxic compounds) effects of tobacco and e-cigarette products on platelet activities. To accomplish these goals, platelets from healthy volunteers (n = 50) were exposed to tobacco smoke extracts, e-cigarette vapor extracts, and pure nicotine and changes in platelet activation, adhesion, aggregation, and inflammation were evaluated, using optical aggregation, flow cytometry, and ELISA methods. Interestingly, the exposure of platelets to e-vapor extracts induced a significant up-regulation in the expression of the pro-inflammatory gC1qR and cC1qR and induced a marked increase in the deposition of C3b as compared with traditional tobacco smoke extracts. Similarly, platelet activation, as measured by a prothrombinase based assay, and platelet aggregation were also significantly enhanced after exposure to e-vapor extracts. Finally, platelet adhesion potential toward fibrinogen, von Willebrand factor, and other platelets was also enhanced after exposure to e-cigarette vapor extracts. In the presence of pure nicotine, platelet functions were observed to be inhibited, which further suggests that other constituents of tobacco smoke and electronic vapor can antagonize platelet functions, however, the presence of nicotine in extracts somewhat perpetuated the platelet functional changes in a dose-dependent manner.

  7. On Day-to-Day Variability of Global Lightning Activity as Quantified from Background Schumann Resonance Observations

    Science.gov (United States)

    Mushtak, V. C.; Williams, E. R.

    2011-12-01

    Among the palette of methods (satellite, VLF, ELF) for monitoring global lightning activity, observations of the background Schumann resonances (SR) provide a unique prospect for estimating the integrated activity of global lightning activity in absolute units (coul2 km2/sec). This prospect is ensured by the SR waves' low attenuation, with wavelengths commensurate with the dimensions of dominant regional lightning "chimneys", and by the accumulating methodology for background SR techniques. Another benefit is the reduction of SR measurements into a compact set of resonance characteristics (modal frequencies, intensities, and quality factors). Suggested and tested in numerical simulations by T.R. Madden in the 1960s, the idea to invert the SR characteristics for the global lightning source has been farther developed, statistically substantiated, and practically realized here on the basis of the computing power and the quantity of experimental material way beyond what the SR pioneers had at their disposal. The critical issue of the quality of the input SR parameters is addressed by implementing a statistically substantiated sanitizing procedure to dispose of the fragments of the observed time series containing unrepresentative elements - local interference of various origin and strong ELF transients originating outside the major "chimneys" represented in the source model. As a result of preliminary research, a universal empirical sanitizing criterion has been established. Due to the fact that the actual observations have been collected from a set of individually organized ELF stations with various equipment sets and calibration techniques, the relative parameters in both input (the intensities) and output (the "chimney" activities) are being used as far as possible in the inversion process to avoid instabilities caused by calibration inconsistencies. The absolute regional activities - and so the sought for global activity in absolute units - is determined in the

  8. Human activity and climate variability impacts on sediment discharge and runoff in the Yellow River of China

    Science.gov (United States)

    He, Yi; Wang, Fei; Mu, Xingmin; Guo, Lanqin; Gao, Peng; Zhao, Guangju

    2017-07-01

    We analyze the variability of sediment discharge and runoff in the Hekou-Longmen segment in the middle reaches of the Yellow River, China. Our analysis is based on Normalized Difference Vegetation Index (NDVI), sediment discharge, runoff, and monthly meteorological data (1961-2010). The climate conditions are controlled via monthly regional average precipitation and potential evapotranspiration (ET0) that are calculated with the Penman-Monteith method. Data regarding water and soil conservation infrastructure and their effects were investigated as causal factors of runoff and sediment discharge changes. The results indicated the following conclusions: (1) The sediment concentration, sediment discharge, and annual runoff, varied considerably during the study period and all of these factors exhibited larger coefficients of variation than ET0 and precipitation. (2) Sediment discharge, annual runoff, and sediment concentration significantly declined over the study period in a linear fashion. This was accompanied by an increase in ET0 and decline in precipitation that were not significant. (3) Within paired years with similar precipitation and potential evapotranspiration conditions (SPEC), all pairs showed a decline in runoff, sediment discharge, and sediment concentration. (4) Human impacts in this region were markedly high as indicated by NDVI, and soil and water measurements, and especially the soil and water conservation infrastructure resulting in an approximately 312 Mt year-1 of sediment deposition during 1960-1999.

  9. Physiological variability and in vitro antifungal activity against Botrytis cinerea causing botrytis gray mold of chickpea (Cicer arietinum L.)

    Energy Technology Data Exchange (ETDEWEB)

    Hosen, M. I.; Ahmed, A. U.; Islam, M. R.

    2010-07-01

    Physiological variability was studied in 10 isolates of Botrytis cinerea causing botrytis gray mold of chickpea, collected from diverse agro climatic areas in Bangladesh. The optimum temperature and pH for the best mycelial radial growth of B. cinerea were 20 degree centigrade and 4.5, respectively. The mycelial radial growth increased with the temperature up to 20 degree centigrade thereafter it decreased gradually up to 30 degree centigrade and no growth was observed at 35 degree centigrade. Chickpea dextrose agar (CDA) medium supported the highest mycelial radial growth (79.17 mm). The quickest (in 5 days) sclerotia initiation was recorded on chickpea destrose agar and lentil dextrose agar (LDA) culture media while the highest number of spores (2.5104 mL{sup -}1) were recorded on LDA medium. The antagonist Trichoderma harzianum was found to be a good bio-control agent against B. cinerea. Among the seven fungicides Bavistin 50 WP (Carbendazim), CP-Zim 50 WP (Carbendazim), Sunphanate 70 WP (Thiophanate methyl) and Rovral 50 WP (Iprodione) were the most effective to inhibit the mycelial radial growth of B. cinerea at 500 mg L{sup -}1 concentration. (Author) 13 refs.

  10. EVALUATION OF WORK PLACE GROUP AND INTERNET BASED PHYSICAL ACTIVITY INTERVENTIONS ON PSYCHOLOGICAL VARIABLES ASSOCIATED WITH EXERCISE BEHAVIOR CHANGE

    Directory of Open Access Journals (Sweden)

    Kimberley A. Dawson

    2008-12-01

    Full Text Available The purpose of this research was to compare group-based and internet-based physical activity interventions in terms of desirability, participant characteristics, exercise self-efficacy, and barrier self-efficacy. Pretest questionnaires were completed prior to voluntary enrollment into either of the ten-week physical activity interventions. Both interventions were based on Social Cognitive Theory and the Transtheoretical Model. Interventions were followed with posttest questionnaires. Results demonstrated that the internet intervention attracted more participants, but only the group-based participants showed significant increases in exercise and barrier self-efficacy. At pretest, participants who selected the internet intervention were significantly lower in life and job satisfaction than those who selected the group intervention. Results suggest that traditional group-based exercise interventions are helpful for improving cognitions associated with exercise behavior change (e.g., exercise self-efficacy and that the internet intervention may help employees who fall into an "unhappy employee" typology

  11. Diel activity and variability in habitat use of white sea bream in a temperate marine protected area.

    Science.gov (United States)

    Di Lorenzo, Manfredi; Fernández, Tomás Vega; Badalamenti, Fabio; Guidetti, Paolo; Starr, Richard M; Giacalone, Vincenzo Maximiliano; Di Franco, Antonio; D'Anna, Giovanni

    2016-05-01

    Fish populations are often comprised of individuals that use habitats and associated resources in different ways. We placed sonic transmitters in, and tracked movements of, white sea bream (Diplodus sargus sargus) in the no-take zone of a Mediterranean marine protected area: the Torre Guaceto marine protected area, (Adriatic Sea, Italy). Tagged fish displayed three types of diel activity patterns in three different habitats: sand, rocky reefs and "matte" of the seagrass Posidonia oceanica. Individuals were more active during the day than at night. Overall, white sea bream displayed a remarkable behavioural plasticity in habitat use. Our results indicate that the observed behavioural plasticity in the marine protected area could be the result of multiple ecological and environmental drivers such as size, sex and increased intra-specific competition. Our findings support the view that habitat diversity helps support high densities of fishes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  13. Subsurface flow pathway dynamics in the active layer of coupled permafrost-hydrogeological systems under seasonal and annual temperature variability.

    Science.gov (United States)

    Frampton, Andrew

    2017-04-01

    There is a need for improved understanding of the mechanisms controlling subsurface solute transport in the active layer in order to better understand permafrost-hydrological-carbon feedbacks, in particular with regards to how dissolved carbon is transported in coupled surface and subsurface terrestrial arctic water systems under climate change. Studying solute transport in arctic systems is also relevant in the context of anthropogenic pollution which may increase due to increased activity in cold region environments. In this contribution subsurface solute transport subject to ground surface warming causing permafrost thaw and active layer change is studied using a physically based model of coupled cryotic and hydrogeological flow processes combined with a particle tracking method. Changes in subsurface water flows and solute transport travel times are analysed for different modelled geological configurations during a 100-year warming period. Results show that for all simulated cases, the minimum and mean travel times increase non-linearly with warming irrespective of geological configuration and heterogeneity structure. The timing of the start of increase in travel time depends on heterogeneity structure, combined with the rate of permafrost degradation that also depends on material thermal and hydrogeological properties. These travel time changes are shown to depend on combined warming effects of increase in pathway length due to deepening of the active layer, reduced transport velocities due to a shift from horizontal saturated groundwater flow near the surface to vertical water percolation deeper into the subsurface, and pathway length increase and temporary immobilization caused by cryosuction-induced seasonal freeze cycles. The impact these change mechanisms have on solute and dissolved substance transport is further analysed by integrating pathway analysis with a Lagrangian approach, incorporating considerations for both dissolved organic and inorganic

  14. Supercritical fluid extraction from spent coffee grounds and coffee husks: antioxidant activity and effect of operational variables on extract composition.

    Science.gov (United States)

    Andrade, Kátia S; Gonçalvez, Ricardo T; Maraschin, Marcelo; Ribeiro-do-Valle, Rosa Maria; Martínez, Julian; Ferreira, Sandra R S

    2012-01-15

    The present study describes the chemical composition and the antioxidant activity of spent coffee grounds and coffee husks extracts, obtained by supercritical fluid extraction (SFE) with CO(2) and with CO(2) and co-solvent. In order to evaluate the high pressure method in terms of process yield, extract composition and antioxidant activity, low pressure methods, such as ultrasound (UE) and soxhlet (SOX) with different organic solvents, were also applied to obtain the extracts. The conditions for the SFE were: temperatures of 313.15K, 323.15K and 333.15K and pressures from 100 bar to 300 bar. The SFE kinetics and the mathematical modeling of the overall extraction curves (OEC) were also investigated. The extracts obtained by LPE (low pressure extraction) with ethanol showed the best results for the global extraction yield (X(0)) when compared to SFE results. The best extraction yield was 15±2% for spent coffee grounds with ethanol and 3.1±04% for coffee husks. The antioxidant potential was evaluated by DPPH method, ABTS method and Folin-Ciocalteau method. The best antioxidant activity was showed by coffee husk extracts obtained by LPE. The quantification and the identification of the extracts were accomplished using HPLC analysis. The main compounds identified were caffeine and chlorogenic acid for the supercritical extracts from coffee husks. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Poisson-Fermi modeling of ion activities in aqueous single and mixed electrolyte solutions at variable temperature

    Science.gov (United States)

    Liu, Jinn-Liang; Eisenberg, Bob

    2018-02-01

    The combinatorial explosion of empirical parameters in tens of thousands presents a tremendous challenge for extended Debye-Hückel models to calculate activity coefficients of aqueous mixtures of the most important salts in chemistry. The explosion of parameters originates from the phenomenological extension of the Debye-Hückel theory that does not take steric and correlation effects of ions and water into account. By contrast, the Poisson-Fermi theory developed in recent years treats ions and water molecules as nonuniform hard spheres of any size with interstitial voids and includes ion-water and ion-ion correlations. We present a Poisson-Fermi model and numerical methods for calculating the individual or mean activity coefficient of electrolyte solutions with any arbitrary number of ionic species in a large range of salt concentrations and temperatures. For each activity-concentration curve, we show that the Poisson-Fermi model requires only three unchanging parameters at most to well fit the corresponding experimental data. The three parameters are associated with the Born radius of the solvation energy of an ion in electrolyte solution that changes with salt concentrations in a highly nonlinear manner.

  16. The Use of Cluster Analysis for Non-Continuous Variables in the Assessment of Dietary Behaviours and Physical Activities in Primary School Children

    Directory of Open Access Journals (Sweden)

    Zalewska Magdalena

    2015-12-01

    Full Text Available Physical activity, along with proper nutrition, is a very important element in child development. Lack of everyday, regular physical activity among young people is a public health problem. The aim of the study was to use cluster analysis to assess the relationship between nutrition and physical activity levels of primary school children. The study included 682 students from randomly selected elementary schools and was performed using a proprietary questionnaire during the 2013/2014 school year. The questionnaire contained questions about eating habits and physical activity, as well as the socio-economic conditions of families. Clusters of students of similar dietary habits were identified using cluster analysis and subsequently compared in terms of physical activity level. We identified four clusters, characterized by relative internal homogeneity and at the same time variability between one another in terms of number of meals throughout the day and time of their consumption. The most important characteristic of Cluster 1 was eating four meals a day including breakfast, which is the most important meal of the day. The diets of children in Cluster 2 abounded with raw vegetables and fruits. Students in Cluster 3 were characterized by a regular and varied diet. The least appropriate behaviour in the field of nutrition was observed among students belonging to Cluster 4. Cluster analysis in the studied population allowed relationships between dietary habits and physical activity to be described. By using the UIAF indicator (Moderate to Intense Physical Activity, a statistically significant association between the eating habits of the children and their physical activity levels was observed. A sufficient level of physical activity was observed in most students belonging to Cluster 3, and high levels of physical activity were observed in a small percentage of children belonging Cluster 4. An average level of physical activity was observed in a high

  17. Morphological variability, lectin binding and Na+,K+-activated adenosine triphosphatase activity of isolated Müller (glial) cells from the rabbit retina.

    Science.gov (United States)

    Reichenbach, A; Dettmer, D; Brückner, G; Neumann, M; Birkenmeyer, G

    1985-03-22

    Rabbit retinal Müller cells were isolated by means of papaine and mechanical dissociation. These cells were shown to have a well preserved morphology and to preserve viability for many hours. Intense wheat germ agglutinin binding occurs on the photoreceptor side of Müller cells, especially in the microvillous region. Rabbit retinal Müller cells have a Na+,K+-activated adenosine triphosphatase activity in the same order of magnitude as brain astroglial cells.

  18. Immobilization/Stabilization of Ficin Extract on Glutaraldehyde-Activated Agarose Beads. Variables That Control the Final Stability and Activity in Protein Hydrolyses

    Directory of Open Access Journals (Sweden)

    El-Hocine Siar

    2018-04-01

    Full Text Available Ficin extract has been immobilized on different 4% aminated-agarose beads. Using just ion exchange, immobilization yield was poor and expressed activity did not surpass 10% of the offered enzyme, with no significant effects on enzyme stability. The treatment with glutaraldehyde of this ionically exchanged enzyme produced an almost full enzyme inactivation. Using aminated supports activated with glutaraldehyde, immobilization was optimal at pH 7 (at pH 5 immobilization yield was 80%, while at pH 9, the immobilized enzyme became inactivated. At pH 7, full immobilization was accomplished maintaining 40% activity versus a small synthetic substrate and 30% versus casein. Ficin stabilization upon immobilization could be observed but it depended on the inactivation pH and the substrate employed, suggesting the complexity of the mechanism of inactivation of the immobilized enzyme. The maximum enzyme loading on the support was determined to be around 70 mg/g. The loading has no significant effect on the enzyme stability or enzyme activity using the synthetic substrate but it had a significant effect on the activity using casein; the biocatalysts activity greatly decreased using more than 30 mg/g, suggesting that the near presence of other immobilized enzyme molecules may generate some steric hindrances for the casein hydrolysis.

  19. Spatial variability in photosynthetic and heterotrophic activity drives localized δ13C org fluctuations and carbonate precipitation in hypersaline microbial mats.

    Science.gov (United States)

    Houghton, J; Fike, D; Druschel, G; Orphan, V; Hoehler, T M; Des Marais, D J

    2014-11-01

    Modern laminated photosynthetic microbial mats are ideal environments to study how microbial activity creates and modifies carbon and sulfur isotopic signatures prior to lithification. Laminated microbial mats from a hypersaline lagoon (Guerrero Negro, Baja California, Mexico) maintained in a flume in a greenhouse at NASA Ames Research Center were sampled for δ(13) C of organic material and carbonate to assess the impact of carbon fixation (e.g., photosynthesis) and decomposition (e.g., bacterial respiration) on δ(13) C signatures. In the photic zone, the δ(13) C org signature records a complex relationship between the activities of cyanobacteria under variable conditions of CO2 limitation with a significant contribution from green sulfur bacteria using the reductive TCA cycle for carbon fixation. Carbonate is present in some layers of the mat, associated with high concentrations of bacteriochlorophyll e (characteristic of green sulfur bacteria) and exhibits δ(13) C signatures similar to DIC in the overlying water column (-2.0‰), with small but variable decreases consistent with localized heterotrophic activity from sulfate-reducing bacteria (SRB). Model results indicate respiration rates in the upper 12 mm of the mat alter in situ pH and HCO3- concentrations to create both phototrophic CO2 limitation and carbonate supersaturation, leading to local precipitation of carbonate minerals. The measured activity of SRB with depth suggests they variably contribute to decomposition in the mat dependent on organic substrate concentrations. Millimeter-scale variability in the δ(13) C org signature beneath the photic zone in the mat is a result of shifting dominance between cyanobacteria and green sulfur bacteria with the aggregate signature overprinted by heterotrophic reworking by SRB and methanogens. These observations highlight the impact of sedimentary microbial processes on δ(13) C org signatures; these processes need to be considered when attempting to relate

  20. Soluble urokinase plasminogen activator receptor, C-reactive protein and triglyceride are associated with heart rate variability in non-diabetic Danes

    DEFF Research Database (Denmark)

    Intzilakis, Theodoros; Hartmann, Gro; Mouridsen, Mette R

    2013-01-01

    and is a predictor of poor outcome. As HRV and its determinants in non-diabetic individuals have not been studied properly, the aim of this observational study was to evaluate possible associations between HRV vs. impaired fasting glucose, insulin resistance, lipidaemia and markers of inflammation and immune......Heart rate variability (HRV) is associated with an increased risk of cardiovascular morbidity and mortality. HRV is in part a function of the activity of the autonomic nervous system and has been associated with low-grade inflammation. In patients with type 2 diabetes, HRV is decreased...

  1. Climate change and climate variability impacts on rainfed agricultural activities and possible adaptation measures. A Mexican case study

    Energy Technology Data Exchange (ETDEWEB)

    Conde, C.; Ferrer, R. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico Circuito Exterior, Mexico, D.F. (Mexico)]. E-mail: e-mail: conde@servidor.unam.mx; Orozco, S. [Escuela de Agrobiologia, Universidad Autonoma de Tlaxcala, Tlaxcala (Mexico)

    2006-07-15

    Climate extreme events (such as those associated to strong El Nino events) highly affect Mexican agriculture, since more than sixty percent of it is rainfed. The basic crop cultivated is maize, which is still the main source of nutrients for a large portion of the rural population in the country. Within the project Capacity Building for Stage II Adaptation to Climate Change in Central America, Mexico and Cuba, we analyze the strategies developed by maize producers in the central region of the country to cope with climatic adverse events. Impact on rainfed maize due to climate variability and climate change conditions are studied using a crop simulation model. Several adaptation measures can be evaluated using that model. However, the effect of other stressors must be considered in an assessment of the adaptive capacity of small farmers to climate variability and change. Key stakeholders' involvement in the region helped us to decide which of the adaptive measures could be viable under the current conditions and under future climatic conditions. The construction of greenhouses, the use of compost, and dripping irrigation, were some of the techniques selected with the participation of the stakeholders. The enthusiastic responses to these measures allow us to consider that they can prevail in the future, under climate change conditions. However, the adaptation to climate change includes -besides the stated techniques- the generation of the capacities to cope with climatic adverse events, that is, to enhance the adaptive capacities to climate change among the key stakeholders. [Spanish] Los eventos climaticos extremos (como los asociados con eventos fuertes de El Nino) afectan de manera importante a la agricultura mexicana, ya que mas del sesenta por ciento de ella es de temporal, esto es, depende fundamentalmente de una buena temporada de lluvias para producir. El cultivo que se siembra es basicamente maiz, que todavia es la principal fuente de nutrientes para

  2. Essential Oil Variability of Tetraclinis articulata (Vahl) Mast. Parts During Its Phenological Cycle and Incidence on the Antioxidant and Antimicrobial Activities.

    Science.gov (United States)

    Djouahri, Abderrahmane; Saka, Boualem; Boudarene, Lynda; Lamari, Lynda; Sabaou, Nasserdine; Baaliouamer, Aoumeur

    2017-02-01

    The impact of phenological stages (vegetative, flowering and fruiting stages) on chemical composition, antioxidant, and antimicrobial activities of Tetraclinis articulata (Vahl) Mast. parts essential oils were investigated for the first time. GC and GC/MS analyses pointed to a quantitative variability of components; terpene hydrocarbons derivatives, represented by α-pinene (16.38 ± 0.19 - 31.78 ± 0.35%) and limonene (3.41 ± 0.07 - 9.49 ± 0.14%) as major components, predominate at the vegetative stage, whereas oxygenated derivatives, represented by camphor (16.11 ± 0.23 - 26.17 ± 0.29%) and bornyl acetate (15.21 ± 0.21 - 27.33 ± 0.33%) as major components, predominate at the fruiting stage. Furthermore, our findings showed that the plant parts collected at the fruiting stage possess the highest antioxidant activity and the best antimicrobial activity against the tested microorganisms, than plant parts collected at the vegetative and flowering stages. This highlighted variability reflects the high impact of phenological cycle on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on phenological stage, in order to have the highest effectiveness of essential oil in terms of biological activities for human health purposes. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  3. Comparison of structured and unstructured physical activity training on predicted VO2max and heart rate variability in adolescents - a randomized control trial.

    Science.gov (United States)

    Sharma, Vivek Kumar; Subramanian, Senthil Kumar; Radhakrishnan, Krishnakumar; Rajendran, Rajathi; Ravindran, Balasubramanian Sulur; Arunachalam, Vinayathan

    2017-05-01

    Physical inactivity contributes to many health issues. The WHO-recommended physical activity for adolescents encompasses aerobic, resistance, and bone strengthening exercises aimed at achieving health-related physical fitness. Heart rate variability (HRV) and maximal aerobic capacity (VO2max) are considered as noninvasive measures of cardiovascular health. The objective of this study is to compare the effect of structured and unstructured physical training on maximal aerobic capacity and HRV among adolescents. We designed a single blinded, parallel, randomized active-controlled trial (Registration No. CTRI/2013/08/003897) to compare the physiological effects of 6 months of globally recommended structured physical activity (SPA), with that of unstructured physical activity (USPA) in healthy school-going adolescents. We recruited 439 healthy student volunteers (boys: 250, girls: 189) in the age group of 12-17 years. Randomization across the groups was done using age and gender stratified randomization method, and the participants were divided into two groups: SPA (n=219, boys: 117, girls: 102) and USPA (n=220, boys: 119, girls: 101). Depending on their training status and gender the participants in both SPA and USPA groups were further subdivided into the following four sub-groups: SPA athlete boys (n=22) and girls (n=17), SPA nonathlete boys (n=95) and girls (n=85), USPA athlete boys (n=23) and girls (n=17), and USPA nonathlete boys (n=96) and girls (n=84). We recorded HRV, body fat%, and VO2 max using Rockport Walk Fitness test before and after the intervention. Maximum aerobic capacity and heart rate variability increased significantly while heart rate, systolic blood pressure, diastolic blood pressure, and body fat percentage decreased significantly after both SPA and USPA intervention. However, the improvement was more in SPA as compared to USPA. SPA is more beneficial for improving cardiorespiratory fitness, HRV, and reducing body fat percentage in terms of

  4. Cognitive Variability

    Science.gov (United States)

    Siegler, Robert S.

    2007-01-01

    Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…

  5. Subjective Positive and Negative Sleep Variables Differentially Affect Cellular Immune Activity in a Breast Cancer Survivor: A Time-series Analysis Approach

    Directory of Open Access Journals (Sweden)

    Magdalena Singer

    2018-01-01

    Full Text Available This study on a breast cancer survivor suffering from cancer-related fatigue (CaRF and depression investigated the bidirectional relationship between cellular immune activity and subjective sleep. The 49-year-old patient (breast cancer diagnosis 5 years before the study, currently in remission collected her full urine output for 28 days in 12-h intervals (8:00 p.m. to 8:00 a.m. and 8:00 a.m. to 8:00 p.m.. These urine samples were used to determine urinary neopterin (cellular immune activation marker and creatinine concentrations via high-pressure liquid chromatography (HPLC. Each morning, the patient answered questions on five sleep variables: sleep quality (SQ, sleep recreational value (SRV, total sleep time (TST, total wake time (TWT, and awakenings during sleep period (ADS. For the purpose of this study, the time series of the nighttime urinary neopterin levels and the five sleep variables were determined. Using centered moving average (CMA smoothing and cross-correlational analysis, this study showed that increases in the positive sleep variables SQ and SRV were followed by urinary neopterin concentration decreases after 96–120 h (SQ, lag 4: r = −0.411; p = 0.044; SRV: lag 4: r = −0.472; p = 0.021 and 120–144 h (SRV, lag 5: r = −0.464; p = 0.026. Increases in the negative sleep variable TWT, by contrast, were followed by increases in urinary neopterin concentrations 72–96 h later (lag 3: r = 0.522; p = 0.009. No systematic effects in the other direction, i.e., from urinary neopterin levels to sleep, were observed in this study. Although preliminary, the findings of this study highlight the benefit of carefully investigating temporal delays and directions of effects when studying the dynamic relationship between sleep and immune variables in the natural context of everyday life.

  6. Short-Term Variability and Power Spectral Density Analysis of the Radio-Loud Active Galactic Nucleus 3C 390.3

    Science.gov (United States)

    Gliozzi, Mario; Papadakis, Iossif E.; Eracleous, Michael; Sambruna, Rita M.; Ballantyne, David R.; Braito, Valentina; Reeves, James N.

    2009-09-01

    We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T br = 43+34 -25 days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T br, M BH, and L bol, followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.

  7. SHORT-TERM VARIABILITY AND POWER SPECTRAL DENSITY ANALYSIS OF THE RADIO-LOUD ACTIVE GALACTIC NUCLEUS 3C 390.3

    International Nuclear Information System (INIS)

    Gliozzi, Mario; Papadakis, Iossif E.; Eracleous, Michael; Sambruna, Rita M.; Ballantyne, David R.; Braito, Valentina; Reeves, James N.

    2009-01-01

    We investigate the short-term variability properties and the power spectral density (PSD) of the broad-line radio galaxy (BLRG) 3C 390.3 using observations made by XMM-Newton, RXTE, and Suzaku on several occasions between 2004 October and 2006 December. The main aim of this work is to derive model-independent constraints on the origin of the X-ray emission and on the nature of the central engine in 3C 390.3. On timescales of the order of few hours, probed by uninterrupted XMM-Newton light curves, the flux of 3C 390.3 is consistent with being constant in all energy bands. On longer timescales, probed by the 2-day RXTE and Suzaku observations, the flux variability becomes significant. The latter observation confirms that the spectral variability behavior of 3C 390.3 is consistent with the spectral evolution observed in (radio-quiet) Seyfert galaxies: the spectrum softens as the source brightens. The correlated variability between soft and hard X-rays, observed during the Suzaku exposure and between the two XMM-Newton pointings, taken 1 week apart, argues against scenarios characterized by the presence of two distinct variable components in the 0.5-10 keV X-ray band. A detailed PSD analysis carried out over five decades in frequency suggests the presence of a break at T br = 43 +34 -25 days at a 92% confidence level. This is the second tentative detection of a PSD break in a radio-loud, non-jet dominated active galactic nucleus (AGN), after the BLRG 3C 120, and appears to be in general agreement with the relation between T br , M BH , and L bol , followed by Seyfert galaxies. Our results indicate that the X-ray variability properties of 3C 390.3 are broadly consistent with those of radio-quiet AGN, suggesting that the X-ray emission mechanism in 3C 390.3 is similar to that of nearby Seyfert galaxies without any significant contribution from a jet component.

  8. The genus Artemisia L. in the northern region of Saudi Arabia: essential oil variability and antibacterial activities.

    Science.gov (United States)

    Guetat, Arbi; Al-Ghamdi, Faraj A; Osman, Ahmed K

    2017-03-01

    Four species of the genus Artemisia L. (Artemisia monosperma, Artemisia scoparia, Artemisia judaica and Artemisia sieberi) growing in the northern region of Saudi Arabia were investigated with respect to their volatile oil contents. The yield of oil varied between 0.30 and 0.41%, % (w/w). A. monosperma showed the highest number of compounds with 30 components representing 93.78% of oil composition. However, A. judaica showed the lowest number of compounds with only 16 components representing 87.47% of essential oil. A. scoparia and A. sieberi are both composed of 17 components, representing 97.14 and 94.2% of total oil composition. A. sieberi and A. judaica were dominated by spathulenol (30.42 and 28.41%, respectively). For A. monosperma, butanoic acid (17.87%) was a major component. However, A. scoparia was a chemotype of acenaphthene. (83.23%). Essential oil of studied species showed high antibacterial activities against common human pathogens.

  9. Assessing the diurnal variability of pharmaceutical and personal care products in a full-scale activated sludge plant

    International Nuclear Information System (INIS)

    Salgado, R.; Marques, R.; Noronha, J.P.; Mexia, J.T.; Carvalho, G.; Oehmen, A.; Reis, M.A.M.

    2011-01-01

    An intensive sampling campaign has been carried out in a municipal wastewater treatment plant (WWTP) to assess the dynamics of the influent pharmaceutical active compounds (PhAC) and musks. The mass loadings of these compounds in wastewater influents displayed contrasting diurnal variations depending on the compound. The musks and some groups of PhACs tended to follow a similar diurnal trend as compared to macropollutants, while the majority of PhACs followed either the opposite trend or no repeatable trend. The total musk loading to the WWTP was 0.74 ± 0.25 g d -1 , whereas the total PhAC mass loading was 84.7 ± 63.8 g d -1 . Unlike the PhACs, the musks displayed a high repeatability from one sampling day to the next. The range of PhAC loadings in the influent to WWTPs can vary several orders of magnitude from one day or week to the next, representing a challenge in obtaining data for steady-state modelling purposes. - Highlights: → Investigated the variations in influent wastewater pharmaceutical and musk loadings. → A high number of different pharmaceutical and musk compounds was analysed. → Many pharmaceutical groups displayed different characteristic patterns. → A representative steady-state pattern was observable for musks, not pharmaceuticals. → The results are relevant to the design of sampling campaigns for modelling purposes. - The diurnal variations of pharmaceuticals and musks were studied in an activated sludge plant, where the loadings of the musks were more repeatable than the pharmaceuticals.

  10. Mechanism of thioredoxin-catalyzed disulfide reduction. Activation of the buried thiol and role of the variable active-site residues

    NARCIS (Netherlands)

    Carvalho, A.P.; Swart, M.; van Stralen, J.N.P.; Fernandes, P.A.; Ramos, M.E.; Bickelhaupt, F.M.

    2008-01-01

    Thioredoxins (Trx) are enzymes with a characteristic CXYC active-site motif that catalyze the reduction of disulfide bonds in other proteins. We have theoretically explored this reaction mechanism, both in the gas phase and in water, using density functional theory. The mechanism of disulfide

  11. Radiocaesium variability within sheep flocks. Relationships between the 137Cs activity concentrations of individual ewes within a flock and between ewes and their progeny

    International Nuclear Information System (INIS)

    Beresford, N.A.; Barnett, C.L.; Crout, N.M.J.; Morris, C.C.

    1995-01-01

    As a consequence of radiocaesium deposition following the Chernobyl accident the movement and slaughter of sheep were restricted within some upland areas of the United Kingdom. Considerable variability in the radiocaesium activity concentrations between individual sheep within flocks has been recorded. This paper reports studies conducted to investigate the reasons for this within flock variability on three farms in the restricted area of west Cumbria. On each farm, study sheep were selected and live-monitored over the period 1991-93. Results from all three study farms showed a correlation in the 137 Cs activity concentration of individual sheep on different monitoring occasions. This observation suggested that a few sheep on each farm are likely to be responsible for the continuation of restrictions on many of the affected holdings. Comparisons between monitoring data obtained in summer and autumn months were better correlated than those involving data collected in the winter and spring. Prior to weaning there was a linear relationship between the 137 Cs levels in the muscle of a lamb and that in the muscle of its dam. Given these observations it is suggested that, in successive years, ewes identified as consistently having high radiocaesium levels in their muscle will produce lambs which will also have comparatively high levels of radiocaesium; the limited data available support this hypothesis. However, no relationship between the 137 Cs activity concentration of a ewe and its lamb was evident post-weaning, thereby discounting any possibility of an inherited effect. On one of the farms a significant difference was found between the 137 Cs activity concentration of different breeds of sheep

  12. Variability of the groundwater sulfate concentration in fractured rock slopes: a tool to identify active unstable areas

    Directory of Open Access Journals (Sweden)

    S. Binet

    2009-12-01

    Full Text Available Water chemical analysis of 100 springs from the Orco and the Tinée valleys (Western Italy and Southern France and a 7 year groundwater chemistry monitoring of the 5 main springs were performed. All these springs drain from crystalline rock slopes. Some of these drain from currently active gravitational slope deformations.

    All groundwaters flowing through presently unstable slopes show anomalies in the sulfate concentrations compared to stable aquifers. Particularly, an increase of sulfate concentrations was observed repeatedly after each of five consecutive landslides on the La Clapière slope, thus attesting to the mechanical deformations are at the origin of this concentration change. Significant changes in the water chemistry are produced even from slow (mm/year and low magnitude deformations of the geological settings.

    Pyrite nuclei in open fractures were found to be coated by iron oxides. This suggests that the increase of dissolved sulfate relates to oxidative dissolution of Pyrite. Speciation calculations of Pyrite versus Gypsum confirmed that observed changes in the sulfate concentrations is predominantly provided from Pyrite. Calculated amounts of dissolved minerals in the springs water was obtained through inverse modelling of the major ion water analysis data. It is shown that the concentration ratio of calculated dissolved Pyrite versus calculated dissolved gneiss rock allows us to unambiguously distinguish water from stable and unstable areas. This result opens an interesting perspective for the follow-up of sliding or friction dynamic in landslides or in (a seismic faults.

  13. Climatic controls of the interannual to decadal variability in Saudi Arabian dust activity: Towards the development of a seasonal prediction tool

    Science.gov (United States)

    Yu, Y.; Notaro, M.; Liu, Z.; Alkolibi, F.; Fadda, E.; Bakhrjy, F.

    2013-12-01

    Atmospheric dust significantly influences the climate system, as well as human life in Saudi Arabia. Skillful seasonal prediction of dust activity with climatic variables will help prevent some negative social impacts of dust storms. Yet, the climatic regulators on Saudi Arabian dust activity remain largely unaddressed. Remote sensing and station observations show consistent seasonal cycles in Saudi Arabian dust activity, which peaks in spring and summer. The climatic controls on springtime and summertime Saudi Arabian dust activity during 1975-2010 are studied using observational and reanalysis data. Empirical Orthogonal Function (EOF) of the observed Saudi Arabian dust storm frequency shows a dominant homogeneous pattern across the country, which has distinct interannual and decadal variations, as revealed by the power spectrum. Regression and correlation analyses reveal that Saudi Arabian dust activity is largely tied to precipitation on the Arabian Peninsula in spring and northwesterly (Shamal) wind in summer. On the seasonal-interannual time scale, warm El Niño-Southern Oscillation (ENSO) phase (El Niño) in winter-to-spring inhibits spring dust activity by increasing the precipitation over the Rub'al Khali Desert, a major dust source region on the southern Arabian Peninsula; warm ENSO and warm Indian Ocean Basin Mode (IOBM) in winter-to-spring favor less summer dust activity by producing anomalously low sea-level pressure over eastern north Africa and Arabian Peninsula, which leads to the reduced Shamal wind speed. The decadal variation in dust activity is likely associated with the Atlantic Multidecadal Oscillation (AMO), which impacts Sahel rainfall and North African dust, and likely dust transport to Saudi Arabia. The Pacific Decadal Oscillation (PDO) and tropical Indian Ocean SST also have influence on the decadal variation in Saudi Arabian dust activity, by altering precipitation over the Arabian Peninsula and summer Shamal wind speed. Using eastern

  14. Activity Monitoring and Heart Rate Variability as Indicators of Fall Risk: Proof-of-Concept for Application of Wearable Sensors in the Acute Care Setting.

    Science.gov (United States)

    Razjouyan, Javad; Grewal, Gurtej Singh; Rishel, Cindy; Parthasarathy, Sairam; Mohler, Jane; Najafi, Bijan

    2017-07-01

    Growing concern for falls in acute care settings could be addressed with objective evaluation of fall risk. The current proof-of-concept study evaluated the feasibility of using a chest-worn sensor during hospitalization to determine fall risk. Physical activity and heart rate variability (HRV) of 31 volunteers admitted to a 29-bed adult inpatient unit were recorded using a single chest-worn sensor. Sensor data during the first 24-hour recording were analyzed. Participants were stratified using the Hendrich II fall risk assessment into high and low fall risk groups. Univariate analysis revealed age, daytime activity, nighttime side lying posture, and HRV were significantly different between groups. Results suggest feasibility of wearable technology to consciously monitor physical activity, sleep postures, and HRV as potential markers of fall risk in the acute care setting. Further study is warranted to confirm the results and examine the efficacy of the proposed wearable technology to manage falls in hospitals. [Journal of Gerontological Nursing, 43(7), 53-62.]. Copyright 2017, SLACK Incorporated.

  15. Aspirin Hydrolysis in Plasma Is a Variable Function of Butyrylcholinesterase and Platelet-activating Factor Acetylhydrolase 1b2 (PAFAH1b2)*

    Science.gov (United States)

    Zhou, Gang; Marathe, Gopal K.; Hartiala, Jaana; Hazen, Stanley L.; Allayee, Hooman; Tang, W. H. Wilson; McIntyre, Thomas M.

    2013-01-01

    Aspirin is rapidly hydrolyzed within erythrocytes by a heterodimer of PAFAH1b2/PAFAH1b3 but also in plasma by an unidentified activity. Hydrolysis in both compartments was variable, with a 12-fold variation in plasma among 2226 Cleveland Clinic GeneBank patients. Platelet inhibition by aspirin was suppressed in plasma that rapidly hydrolyzed aspirin. Plasma aspirin hydrolysis was significantly higher in patients with coronary artery disease compared with control subjects (16.5 ± 4.4 versus 15.1 ± 3.7 nmol/ml/min; p = 3.4 × 10−8). A genome-wide association study of 2054 GeneBank subjects identified a single locus immediately adjacent to the BCHE (butyrylcholinesterase) gene associated with plasma aspirin hydrolytic activity (lead SNP, rs6445035; p = 9.1 × 10−17). However, its penetrance was low, and plasma from an individual with an inactivating mutation in BCHE still effectively hydrolyzed aspirin. A second aspirin hydrolase was identified in plasma, the purification of which showed it to be homomeric PAFAH1b2. This is distinct from the erythrocyte PAFAH1b2/PAFAH1b3 heterodimer. Inhibitors showed that both butyrylcholinesterase (BChE) and PAFAH1b2 contribute to aspirin hydrolysis in plasma, with variation primarily reflecting non-genetic variation of BChE activity. Therefore, aspirin is hydrolyzed in plasma by two enzymes, BChE and a new extracellular form of platelet-activating factor acetylhydrolase, PAFAH1b2. Hydrolytic effectiveness varies widely primarily from non-genetic variation of BChE activity that affects aspirin bioavailability in blood and the ability of aspirin to inhibit platelet aggregation. PMID:23508960

  16. Interaction between Neural and Cardiac Systems during the Execution of the Stroop Task by Young Adults: Electroencephalographic Activity and Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Soraya L. Sá Canabarro

    2017-02-01

    Full Text Available Executive processes and heart rate variability (HRV are supposedly regulated by an integrated inhibitory neurovisceral network mainly coordinated by the prefrontal cortex. Inhibitory control, a core executive function, is demanded by the Stroop task. This study aimed to assess the interaction between electroencephalographic activity and HRV of 50 healthy undergraduate students while performing a computerized version of the Stroop task with three stages (paradigmatic congruent – CS – and incongruent – IS – stages in addition to a stage in which words were phonetically similar to color names – PSS. Behavioral results suggested a Stroop interference effect among the stages, with greater difficulty in IS followed by PSS. A pattern of cortical activation in a frontoparietal gradient with left lateralization and involvement of the prefrontal, temporal and occipital cortices was found especially in IS and PSS, which might be correlated to executive control of behavior, inhibitory control, mental representation of words, preparation of the verbal response, and processing of visual stimuli. Mean power of brain activity (μV was higher for IS and PSS for all tested frequency oscillations. HRV parameters of SDNN and pNN50 were smaller in PSS compared to the other stages, while rMSSD was higher for CS, suggesting higher mental stress for IS and PSS. During PSS, LF/HF ratio was negatively correlated with EEG power in frontal, central and temporal regions whilst rMSSD was positively correlated with activity in frontal and parietal regions. Therefore, marked prefrontal cortex activity was associated with parasympathetic dominance, which is in line with the integrated inhibitory neural network model. In summation, the execution of the Stroop task required increased recruitment of prefrontal cortical areas and led to high mental stress, but, as it was associated with parasympathetic dominance of HRV control, conflict was solved and subjects behaved

  17. Aspirin hydrolysis in plasma is a variable function of butyrylcholinesterase and platelet-activating factor acetylhydrolase 1b2 (PAFAH1b2).

    Science.gov (United States)

    Zhou, Gang; Marathe, Gopal K; Hartiala, Jaana; Hazen, Stanley L; Allayee, Hooman; Tang, W H Wilson; McIntyre, Thomas M

    2013-04-26

    Aspirin is rapidly hydrolyzed within erythrocytes by a heterodimer of PAFAH1b2/PAFAH1b3 but also in plasma by an unidentified activity. Hydrolysis in both compartments was variable, with a 12-fold variation in plasma among 2226 Cleveland Clinic GeneBank patients. Platelet inhibition by aspirin was suppressed in plasma that rapidly hydrolyzed aspirin. Plasma aspirin hydrolysis was significantly higher in patients with coronary artery disease compared with control subjects (16.5 ± 4.4 versus 15.1 ± 3.7 nmol/ml/min; p = 3.4 × 10(-8)). A genome-wide association study of 2054 GeneBank subjects identified a single locus immediately adjacent to the BCHE (butyrylcholinesterase) gene associated with plasma aspirin hydrolytic activity (lead SNP, rs6445035; p = 9.1 × 10(-17)). However, its penetrance was low, and plasma from an individual with an inactivating mutation in BCHE still effectively hydrolyzed aspirin. A second aspirin hydrolase was identified in plasma, the purification of which showed it to be homomeric PAFAH1b2. This is distinct from the erythrocyte PAFAH1b2/PAFAH1b3 heterodimer. Inhibitors showed that both butyrylcholinesterase (BChE) and PAFAH1b2 contribute to aspirin hydrolysis in plasma, with variation primarily reflecting non-genetic variation of BChE activity. Therefore, aspirin is hydrolyzed in plasma by two enzymes, BChE and a new extracellular form of platelet-activating factor acetylhydrolase, PAFAH1b2. Hydrolytic effectiveness varies widely primarily from non-genetic variation of BChE activity that affects aspirin bioavailability in blood and the ability of aspirin to inhibit platelet aggregation.

  18. Multi-Objective Sliding Mode Control on Vehicle Cornering Stability with Variable Gear Ratio Actuator-Based Active Front Steering Systems

    Science.gov (United States)

    Ma, Xinbo; Wong, Pak Kin; Zhao, Jing; Xie, Zhengchao

    2016-01-01

    Active front steering (AFS) is an emerging technology to improve the vehicle cornering stability by introducing an additional small steering angle to the driver’s input. This paper proposes an AFS system with a variable gear ratio steering (VGRS) actuator which is controlled by using the sliding mode control (SMC) strategy to improve the cornering stability of vehicles. In the design of an AFS system, different sensors are considered to measure the vehicle state, and the mechanism of the AFS system is also modelled in detail. Moreover, in order to improve the cornering stability of vehicles, two dependent objectives, namely sideslip angle and yaw rate, are considered together in the design of SMC strategy. By evaluating the cornering performance, Sine with Dwell and accident avoidance tests are conducted, and the simulation results indicate that the proposed SMC strategy is capable of improving the cornering stability of vehicles in practice. PMID:28036037

  19. Global genetic analyses reveal strong inter-ethnic variability in the loss of activity of the organic cation transporter OCT1.

    Science.gov (United States)

    Seitz, Tina; Stalmann, Robert; Dalila, Nawar; Chen, Jiayin; Pojar, Sherin; Dos Santos Pereira, Joao N; Krätzner, Ralph; Brockmöller, Jürgen; Tzvetkov, Mladen V

    2015-01-01

    The organic cation transporter OCT1 (SLC22A1) mediates the uptake of vitamin B1, cationic drugs, and xenobiotics into hepatocytes. Nine percent of Caucasians lack or have very low OCT1 activity due to loss-of-function polymorphisms in OCT1 gene. Here we analyzed the global genetic variability in OCT1 to estimate the therapeutic relevance of OCT1 polymorphisms in populations beyond Caucasians and to identify evolutionary patterns of the common loss of OCT1 activity in humans. We applied massively parallel sequencing to screen for coding polymorphisms in 1,079 unrelated individuals from 53 populations worldwide. The obtained data was combined with the existing 1000 Genomes data comprising an additional 1,092 individuals from 14 populations. The identified OCT1 variants were characterized in vitro regarding their cellular localization and their ability to transport 10 known OCT1 substrates. Both the population genetics data and transport data were used in tandem to generate a world map of loss of OCT1 activity. We identified 16 amino acid substitutions potentially causing loss of OCT1 function and analyzed them together with five amino acid substitutions that were not expected to affect OCT1 function. The variants constituted 16 major alleles and 14 sub-alleles. Six major alleles showed improper subcellular localization leading to substrate-wide loss in activity. Five major alleles showed correct subcellular localization, but substrate-specific loss of activity. Striking differences were observed in the frequency of loss of OCT1 activity worldwide. While most East Asian and Oceanian individuals had completely functional OCT1, 80 % of native South American Indians lacked functional OCT1 alleles. In East Asia and Oceania the average nucleotide diversity of the loss-of-function variants was much lower than that of the variants that do not affect OCT1 function (ratio of 0.03) and was significantly lower than the theoretically expected heterozygosity (Tajima's D = -1

  20. Origins of intersubject variability of blood oxygenation level dependent and arterial spin labeling fMRI: implications for quantification of brain activity.

    Science.gov (United States)

    Gaxiola-Valdez, Ismael; Goodyear, Bradley G

    2012-12-01

    Accurate localization of brain activity using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) has been challenged because of the large BOLD signal within distal veins. Arterial spin labeling (ASL) techniques offer greater sensitivity to the microvasculature but possess low temporal resolution and limited brain coverage. In this study, we show that the physiological origins of BOLD and ASL depend on whether percent change or statistical significance is being considered. For BOLD and ASL fMRI data collected during a simple unilateral hand movement task, we found that in the area of the contralateral motor cortex the centre of gravity (CoG) of the intersubject coefficient of variation (CV) of BOLD fMRI was near the brain surface for percent change in signal, whereas the CoG of the intersubject CV for Z-score was in close proximity of sites of brain activity for both BOLD and ASL. These findings suggest that intersubject variability of BOLD percent change is vascular in origin, whereas the origin of inter-subject variability of Z-score is neuronal for both BOLD and ASL. For longer duration tasks (12 s or greater), however, there was a significant correlation between BOLD and ASL percent change, which was not evident for short duration tasks (6 s). These findings suggest that analyses directly comparing percent change in BOLD signal between pre-defined regions of interest using short duration stimuli, as for example in event-related designs, may be heavily weighted by large-vessel responses rather than neuronal responses. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  2. Physical activity, body mass index and heart rate variability-based stress and recovery in 16 275 Finnish employees: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Tiina Föhr

    2016-08-01

    Full Text Available Abstract Background Physical inactivity, overweight, and work-related stress are major concerns today. Psychological stress causes physiological responses such as reduced heart rate variability (HRV, owing to attenuated parasympathetic and/or increased sympathetic activity in cardiac autonomic control. This study’s purpose was to investigate the relationships between physical activity (PA, body mass index (BMI, and HRV-based stress and recovery on workdays, among Finnish employees. Methods The participants in this cross-sectional study were 16 275 individuals (6863 men and 9412 women; age 18–65 years; BMI 18.5–40.0 kg/m2. Assessments of stress, recovery and PA were based on HRV data from beat-to-beat R-R interval recording (mainly over 3 days. The validated HRV-derived variables took into account the dynamics and individuality of HRV. Stress percentage (the proportion of stress reactions, workday and working hours, and stress balance (ratio between recovery and stress reactions, sleep describe the amount of physiological stress and recovery, respectively. Variables describing the intensity (i.e. magnitude of recognized reactions of physiological stress and recovery were stress index (workday and recovery index (sleep, respectively. Moderate to vigorous PA was measured and participants divided into the following groups, based on calculated weekly PA: inactive (0 min, low (0 300 min. BMI was calculated from self-reported weight and height. Linear models were employed in the main analyses. Results High PA was associated with lower stress percentages (during workdays and working hours and stress balance. Higher BMI was associated with higher stress index, and lower stress balance and recovery index. These results were similar for men and women (P < 0.001 for all. Conclusion Independent of age and sex, high PA was associated with a lower amount of stress on workdays. Additionally, lower BMI was associated with better recovery during

  3. Variable stars

    International Nuclear Information System (INIS)

    Feast, M.W.; Wenzel, W.; Fernie, J.D.; Percy, J.R.; Smak, J.; Gascoigne, S.C.B.; Grindley, J.E.; Lovell, B.; Sawyer Hogg, H.B.; Baker, N.; Fitch, W.S.; Rosino, L.; Gursky, H.

    1976-01-01

    A critical review of variable stars is presented. A fairly complete summary of major developments and discoveries during the period 1973-1975 is given. The broad developments and new trends are outlined. Essential problems for future research are identified. (B.R.H. )

  4. Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests.

    Directory of Open Access Journals (Sweden)

    Ralf Lauterbach

    Full Text Available Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008-2010 in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming.

  5. Understanding the risks associated with the use of new psychoactive substances (NPS): high variability of active ingredients concentration, mislabelled preparations, multiple psychoactive substances in single products.

    Science.gov (United States)

    Zamengo, Luca; Frison, Giampietro; Bettin, Chiara; Sciarrone, Rocco

    2014-08-17

    New psychoactive substances (NPS), are now a large group of substances of abuse not yet completely controlled by international drug conventions, which may pose a public health threat. Anxiety, paranoia, hallucinations, seizures, hyperthermia and cardiotoxicity are some of the common adverse effects associated with these compounds. In this paper, three case reports taken from the archive of processed cases of the authors' laboratory are presented and discussed to stress the risks of possible adverse consequences for NPS users: in particular, (i) the risk deriving from the difficulty of predicting the actual consumed dose, due to variability of active ingredients concentration in consumed products, (ii) the risk deriving from the difficulty of predicting the actual active ingredients present in consumed products, as opposed to those claimed by the manufacturer, and (iii) the risk deriving from the difficulty of predicting the actual pharmacological and toxicological effects related to the simultaneous consumption of different psychoactive ingredients contained in single products, whose interactions are mostly unknown. Each of them individually provide a source of concern for possible serious health related consequences. However, they should be considered in conjunction with each others, with the worldwide availability of NPS through the web and also with the incessantly growing business derived from the manipulation and synthesis of new substances. The resulting scenario is that of a cultural challenge which demands a global approach from different fields of knowledge. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Comparison of Physiological and Psychological Relaxation Using Measurements of Heart Rate Variability, Prefrontal Cortex Activity, and Subjective Indexes after Completing Tasks with and without Foliage Plants.

    Science.gov (United States)

    Park, Sin-Ae; Song, Chorong; Oh, Yun-Ah; Miyazaki, Yoshifumi; Son, Ki-Cheol

    2017-09-20

    The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV), prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD) method and a profile of mood state questionnaire (POMS). Results showed that the natural logarithmic (ln) ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2-3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants.

  7. Comparison of Physiological and Psychological Relaxation Using Measurements of Heart Rate Variability, Prefrontal Cortex Activity, and Subjective Indexes after Completing Tasks with and without Foliage Plants

    Directory of Open Access Journals (Sweden)

    Sin-Ae Park

    2017-09-01

    Full Text Available The objective of this study was to compare physiological and psychological relaxation by assessing heart rate variability (HRV, prefrontal cortex activity, and subjective indexes while subjects performed a task with and without foliage plants. In a crossover experimental design, 24 university students performed a task transferring pots with and without a foliage plant for 3 min. HRV and oxyhemoglobin (oxy-Hb concentration in the prefrontal cortex were continuously measured. Immediately thereafter, subjective evaluation of emotions was performed using a modified semantic differential (SD method and a profile of mood state questionnaire (POMS. Results showed that the natural logarithmic (ln ratio of low frequency/high frequency, as an estimate of sympathetic nerve activity, was significantly lower while performing the task with foliage plants for the average 3 min measurement interval. Oxy-Hb concentration in the left prefrontal cortex showed a tendency to decrease in the 2–3 min interval in the task with foliage plants compared to the task without plants. Moreover, significant psychological relaxation according to POMS score and SD was demonstrated when the task involved foliage plants. In conclusion, the task involving foliage plants led to more physiological and psychological relaxation compared with the task without foliage plants.

  8. Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunde [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Zhou, Aiguo, E-mail: aiguozhou@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China); Gan, Yiqun; Li, Xiaoqian [State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074 (China); School of Environmental Studies, China University of Geosciences, Wuhan 430074 (China)

    2016-04-01

    Stable carbon isotope analysis has the potential to be used for assessing the performance of in situ remediation of organic contaminants. Successful application of this isotope technique requires understanding the magnitude and variability in carbon isotope fractionation associated with the reactions under consideration. This study investigated the influence of inorganic anions (sulfate, bicarbonate, and chloride) on carbon isotope fractionation of trichloroethene (TCE) during its degradation by persulfate activated with zero-valent iron. The results demonstrated that the significant carbon isotope fractionation (enrichment factors ε ranging from − 3.4 ± 0.3 to − 4.3 ± 0.3 ‰) was independent on the zero-iron dosage, sulfate concentration, and bicarbonate concentration. However, the ε values (ranging from − 7.0 ± 0.4 to − 13.6 ± 1.2 ‰) were dependent on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during TCE degradation by persulfate activated with zero-valent iron. The dependence of ε values on chloride concentration, indicated that TCE degradation mechanisms may be different from the degradation mechanism caused by sulfate radical (SO{sub 4}·{sup −}). Ignoring the effect of chloride on ε value may cause numerous uncertainties in quantitative assessment of the performance of the in situ chemical oxidation (ISCO). - Highlights: • Significant C isotope fractionation for TCE degradation by Fe{sup 0} activated persulfate. • The enrichment factors was independent of Fe{sup 0}, SO{sub 4}{sup 2−}, or HCO{sub 3}{sup −} concentration. • Cl{sup −} significantly influenced the carbon isotope fractionation.

  9. DISCOVERY OF γ -RAY EMISSION FROM THE RADIO-INTERMEDIATE QUASAR III ZW 2: VIOLENT JET ACTIVITY WITH INTRADAY γ -RAY VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Neng-Hui; Xin, Yu-Liang; Fan, Yi-Zhong [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Fan, Xu-Liang [Graduate University of Chinese Academy of Sciences, Yuquan Road 19, Beijing 100049 (China); Weng, Shan-Shan [Department of Physics, Nanjing Normal University, Nanjing 210046 (China); Li, Shao-Kun [Key Laboratory for the Structure and Evolution of Celestial Objects, Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Chen, Liang, E-mail: liaonh@pmo.ac.cn, E-mail: yzfan@pmo.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

    2016-10-01

    III Zw 2 is the prototype of radio-intermediate quasars. Although there is the evidence of possessing strong jet, significant γ -ray emission has not been reported before. In this work, we carry out a detailed analysis of the latest Fermi -LAT Pass  8 data. No significant γ -ray signal has been detected in the time-averaged 7-year Fermi -LAT data of III Zw 2; however, we have identified two distinct γ -ray flares with isotropic luminosities of ∼10{sup 45} erg s{sup −1}. Multiwavelength data analysis (also including the optical photometric observations from Yunnan Observatories) are presented and the main finding is simultaneous optical and γ -ray flares of III Zw 2 appearing in 2009 November. Violent γ -ray variability with a doubling timescale of 2.5 hr was detected in another γ -ray flare in May 2010, for which the 3-hr γ -ray peak flux is ∼250 times of the average flux in 7 years. Rather similar behaviors are observed in blazars and the blazar model can reasonably reproduce the spectral energy distribution of III Zw 2 in a wide energy range, strongly suggesting that its central engine resembles that of blazars. In view of its core, which shares radio similarities with young radio sources, together with weak extended radio lobe emission, we suggest that III Zw 2 harbors a recurrent activity core and thus serves as a valuable target for investigating the fueling and triggering of the activity in radio-loud active galactic nuclei.

  10. Variability in carbon isotope fractionation of trichloroethene during degradation by persulfate activated with zero-valent iron: Effects of inorganic anions

    International Nuclear Information System (INIS)

    Liu, Yunde; Zhou, Aiguo; Gan, Yiqun; Li, Xiaoqian

    2016-01-01

    Stable carbon isotope analysis has the potential to be used for assessing the performance of in situ remediation of organic contaminants. Successful application of this isotope technique requires understanding the magnitude and variability in carbon isotope fractionation associated with the reactions under consideration. This study investigated the influence of inorganic anions (sulfate, bicarbonate, and chloride) on carbon isotope fractionation of trichloroethene (TCE) during its degradation by persulfate activated with zero-valent iron. The results demonstrated that the significant carbon isotope fractionation (enrichment factors ε ranging from − 3.4 ± 0.3 to − 4.3 ± 0.3 ‰) was independent on the zero-iron dosage, sulfate concentration, and bicarbonate concentration. However, the ε values (ranging from − 7.0 ± 0.4 to − 13.6 ± 1.2 ‰) were dependent on the chloride concentration, indicating that chloride could significantly affect carbon isotope fractionation during TCE degradation by persulfate activated with zero-valent iron. The dependence of ε values on chloride concentration, indicated that TCE degradation mechanisms may be different from the degradation mechanism caused by sulfate radical (SO_4·"−). Ignoring the effect of chloride on ε value may cause numerous uncertainties in quantitative assessment of the performance of the in situ chemical oxidation (ISCO). - Highlights: • Significant C isotope fractionation for TCE degradation by Fe"0 activated persulfate. • The enrichment factors was independent of Fe"0, SO_4"2"−, or HCO_3"− concentration. • Cl"− significantly influenced the carbon isotope fractionation.

  11. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  12. Individual Movement Variability Magnitudes Are Explained by Cortical Neural Variability.

    Science.gov (United States)

    Haar, Shlomi; Donchin, Opher; Dinstein, Ilan

    2017-09-13

    Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction that are thought to be governed by distinct neural processes. Here, we report that individual subjects (males and females) exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects explained their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We therefore propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities. SIGNIFICANCE STATEMENT Neural activity and movement kinematics are remarkably variable. Although intertrial variability is rarely studied, here, we demonstrate that individual human subjects exhibit distinct magnitudes of neural and kinematic variability that are reproducible across movements to different targets and when performing these movements with either arm. Furthermore, when examining the relationship between cortical variability and movement variability, we find that cortical fMRI variability in parietal cortex of individual subjects explained their movement extent variability. This enabled us to explain why some subjects

  13. Associations of physical activity, fitness, and body composition with heart rate variability-based indicators of stress and recovery on workdays: a cross-sectional study.

    Science.gov (United States)

    Teisala, Tiina; Mutikainen, Sara; Tolvanen, Asko; Rottensteiner, Mirva; Leskinen, Tuija; Kaprio, Jaakko; Kolehmainen, Marjukka; Rusko, Heikki; Kujala, Urho M

    2014-01-01

    The purpose of this study was to investigate how physical activity (PA), cardiorespiratory fitness (CRF), and body composition are associated with heart rate variability (HRV)-based indicators of stress and recovery on workdays. Additionally, we evaluated the association of objectively measured stress with self-reported burnout symptoms. Participants of this cross-sectional study were 81 healthy males (age range 26-40 y). Stress and recovery on workdays were measured objectively based on HRV recordings. CRF and anthropometry were assessed in laboratory conditions. The level of PA was based on a detailed PA interview (MET index [MET-h/d]) and self-reported activity class. PA, CRF, and body composition were significantly associated with levels of stress and recovery on workdays. MET index (P stress during working hours whereas body fat percentage (P = 0.005) was positively associated. Overall, 27.5% of the variance of total stress on workdays (P = 0.001) was accounted for by PA, CRF, and body composition. Body fat percentage and body mass index were negatively associated with night-time recovery whereas CRF was positively associated. Objective work stress was associated (P = 0.003) with subjective burnout symptoms. PA, CRF, and body composition are associated with HRV-based stress and recovery levels, which needs to be taken into account in the measurement, prevention, and treatment of work-related stress. The HRV-based method used to determine work-related stress and recovery was associated with self-reported burnout symptoms, but more research on the clinical importance of the methodology is needed.

  14. The Man behind the Curtain: X-Rays Drive the UV through NIR Variability in the 2013 Active Galactic Nucleus Outburst in NGC 2617

    Science.gov (United States)

    Shappee, B. J.; Prieto, J. L.; Grupe, D.; Kochanek, C. S.; Stanek, K. Z.; De Rosa, G.; Mathur, S.; Zu, Y.; Peterson, B. M.; Pogge, R. W.; Komossa, S.; Im, M.; Jencson, J.; Holoien, T. W.-S.; Basu, U.; Beacom, J. F.; Szczygieł, D. M.; Brimacombe, J.; Adams, S.; Campillay, A.; Choi, C.; Contreras, C.; Dietrich, M.; Dubberley, M.; Elphick, M.; Foale, S.; Giustini, M.; Gonzalez, C.; Hawkins, E.; Howell, D. A.; Hsiao, E. Y.; Koss, M.; Leighly, K. M.; Morrell, N.; Mudd, D.; Mullins, D.; Nugent, J. M.; Parrent, J.; Phillips, M. M.; Pojmanski, G.; Rosing, W.; Ross, R.; Sand, D.; Terndrup, D. M.; Valenti, S.; Walker, Z.; Yoon, Y.

    2014-06-01

    After the All-Sky Automated Survey for SuperNovae discovered a significant brightening of the inner region of NGC 2617, we began a ~70 day photometric and spectroscopic monitoring campaign from the X-ray through near-infrared (NIR) wavelengths. We report that NGC 2617 went through a dramatic outburst, during which its X-ray flux increased by over an order of magnitude followed by an increase of its optical/ultraviolet (UV) continuum flux by almost an order of magnitude. NGC 2617, classified as a Seyfert 1.8 galaxy in 2003, is now a Seyfert 1 due to the appearance of broad optical emission lines and a continuum blue bump. Such "changing look active galactic nuclei (AGNs)" are rare and provide us with important insights about AGN physics. Based on the Hβ line width and the radius-luminosity relation, we estimate the mass of central black hole (BH) to be (4 ± 1) × 107 M ⊙. When we cross-correlate the light curves, we find that the disk emission lags the X-rays, with the lag becoming longer as we move from the UV (2-3 days) to the NIR (6-9 days). Also, the NIR is more heavily temporally smoothed than the UV. This can largely be explained by a simple model of a thermally emitting thin disk around a BH of the estimated mass that is illuminated by the observed, variable X-ray fluxes.

  15. Poincaré plot analysis of ultra-short-term heart rate variability during recovery from exercise in physically active men.

    Science.gov (United States)

    Gomes, Rayana L; Marques Vanderlei, Luiz C; Garner, David M; Ramos Santana, Milana D; de Abreu, Luiz C; Valenti, Vitor E

    2017-04-26

    Recently there has been increasing interest in the study of ultra-short- term heart rate variability (HRV) in sports performance and exercise physiology. In order to improve standardization of this specific analysis, we evaluated the ultra-short-term HRV analysis through SD1Poincaré index to identify exercise induced responses. We investigated 35 physically active men aged between 18 and 35 years old. Volunteers performed physical exercise on treadmill with intensity of 6.0 km / hour + 1% slope in the first five minutes for physical "warming up." This was followed by 25 minutes with intensity equivalent to 60% of Vmax, with the same slope according to the Conconi threshold. HRV was analyzed in the following periods: the five-minute period before the exercise and the five-minute period immediately after the exercise, the five minutes were divided into five segments of 60 RR intervals. Ultra-short-term RMSSD and SD1 analysis were performed. Ultra-short-term RMSSD and SD1 were significantly (panalysis with the Poincaré plot detected changes in HRV after exercise. Ultra-short-term HRV analysis through Poincaré plot identified heart rate autonomic responses induced by aerobic exercise.

  16. Partial dust obscuration in active galactic nuclei as a cause of broad-line profile and lag variability, and apparent accretion disc inhomogeneities

    Science.gov (United States)

    Gaskell, C. Martin; Harrington, Peter Z.

    2018-04-01

    The profiles of the broad emission lines of active galactic nuclei (AGNs) and the time delays in their response to changes in the ionizing continuum ("lags") give information about the structure and kinematics of the inner regions of AGNs. Line profiles are also our main way of estimating the masses of the supermassive black holes (SMBHs). However, the profiles often show ill-understood, asymmetric structure and velocity-dependent lags vary with time. Here we show that partial obscuration of the broad-line region (BLR) by outflowing, compact, dusty clumps produces asymmetries and velocity-dependent lags similar to those observed. Our model explains previously inexplicable changes in the ratios of the hydrogen lines with time and velocity, the lack of correlation of changes in line profiles with variability of the central engine, the velocity dependence of lags, and the change of lags with time. We propose that changes on timescales longer than the light-crossing time do not come from dynamical changes in the BLR, but are a natural result of the effect of outflowing dusty clumps driven by radiation pressure acting on the dust. The motion of these clumps offers an explanation of long-term changes in polarization. The effects of the dust complicate the study of the structure and kinematics of the BLR and the search for sub-parsec SMBH binaries. Partial obscuration of the accretion disc can also provide the local fluctuations in luminosity that can explain sizes deduced from microlensing.

  17. Role of Climate Variability and Human Activity on Poopó Lake Droughts between 1990 and 2015 Assessed Using Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Frédéric Satgé

    2017-02-01

    Full Text Available In 2015, an emergency state was declared in Bolivia when Poopó Lake dried up. Climate variability and the increasing need for water are potential factors responsible for this situation. Because field data are missing over the region, no statements are possible about the influence of mentioned factors. This study is a preliminary step toward the understanding of Poopó Lake drought using remote sensing data. First, atmospheric corrections for Landsat (FLAASH and L8SR, seven satellite derived indexes for extracting water bodies, MOD16 evapotranspiration, PERSIANN-CDR and MSWEP rainfall products potentiality were assessed. Then, the fluctuations of Poopó Lake extent over the last 26 years are presented for the first time jointly, with the mean regional annual rainfall. Three main droughts are highlighted between 1990 and 2015: two are associated with negative annual rainfall anomalies in 1994 and 1995 and one associated with positive annual rainfall anomaly in 2015. This suggests that other factors than rainfall influenced the recent disappearance of the lake. The regional evapotranspiration increased by 12.8% between 2000 and 2014. Evapotranspiration increase is not homogeneous over the watershed but limited over the main agriculture regions. Agriculture activity is one of the major factors contributing to the regional desertification and recent disappearance of Poopó Lake.

  18. TEC variability over Havana

    International Nuclear Information System (INIS)

    Lazo, B.; Alazo, K.; Rodriguez, M.; Calzadilla, A.

    2003-01-01

    The variability of total electron content (TEC) measured over Havana using ATS-6, SMS-1 and GOES-3 geosynchronous satellite signals has been investigated for low, middle and high solar activity periods from 1974 to 1982. The obtained results show that standard deviation is smooth during nighttime hours and maximum at noon or postnoon hours. Strong solar activity dependence of standard deviation with a maximum values during HSA has been found. (author)

  19. The man behind the curtain: X-rays drive the UV through NIR variability in the 2013 active galactic nucleus outburst in NGC 2617

    Energy Technology Data Exchange (ETDEWEB)

    Shappee, B. J.; Kochanek, C. S.; Stanek, K. Z.; De Rosa, G.; Mathur, S.; Zu, Y.; Peterson, B. M.; Pogge, R. W.; Jencson, J.; Holoien, T.W-S.; Basu, U.; Beacom, J. F.; Adams, S. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Prieto, J. L. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Grupe, D. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Komossa, S. [Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Im, M. [CEOU/Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Szczygieł, D. M. [Warsaw University Astronomical Observatory, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Brimacombe, J. [Coral Towers Observatory, Cairns, Queensland A-4870 (Australia); Campillay, A., E-mail: shappee@astronomy.ohio-state.edu [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); and others

    2014-06-10

    After the All-Sky Automated Survey for SuperNovae discovered a significant brightening of the inner region of NGC 2617, we began a ∼70 day photometric and spectroscopic monitoring campaign from the X-ray through near-infrared (NIR) wavelengths. We report that NGC 2617 went through a dramatic outburst, during which its X-ray flux increased by over an order of magnitude followed by an increase of its optical/ultraviolet (UV) continuum flux by almost an order of magnitude. NGC 2617, classified as a Seyfert 1.8 galaxy in 2003, is now a Seyfert 1 due to the appearance of broad optical emission lines and a continuum blue bump. Such 'changing look active galactic nuclei (AGNs)' are rare and provide us with important insights about AGN physics. Based on the Hβ line width and the radius-luminosity relation, we estimate the mass of central black hole (BH) to be (4 ± 1) × 10{sup 7} M {sub ☉}. When we cross-correlate the light curves, we find that the disk emission lags the X-rays, with the lag becoming longer as we move from the UV (2-3 days) to the NIR (6-9 days). Also, the NIR is more heavily temporally smoothed than the UV. This can largely be explained by a simple model of a thermally emitting thin disk around a BH of the estimated mass that is illuminated by the observed, variable X-ray fluxes.

  20. Acute effects of Finnish sauna and cold-water immersion on haemodynamic variables and autonomic nervous system activity in patients with heart failure.

    Science.gov (United States)

    Radtke, Thomas; Poerschke, Daniel; Wilhelm, Matthias; Trachsel, Lukas D; Tschanz, Hansueli; Matter, Friederike; Jauslin, Daniel; Saner, Hugo; Schmid, Jean-Paul

    2016-04-01

    The haemodynamic response to Finnish sauna and subsequent cold-water immersion in heart failure patients is unknown. Haemodynamic response to two consecutive Finnish sauna (80℃) exposures, followed by a final head-out cold-water immersion (12℃) was measured in 37 male participants: chronic heart failure (n = 12, 61.8 ± 9.2 years), coronary artery disease (n = 13, 61.2 ± 10.6 years) and control subjects (n = 12, 60.9 ± 8.9 years). Cardiac output was measured non-invasively with an inert gas rebreathing method prior to and immediately after the first sauna exposure and after cold-water immersion, respectively. Blood pressure was measured before, twice during and after sauna. The autonomic nervous system was assessed by power spectral analysis of heart rate variability. Total power, low-frequency and high-frequency components were evaluated. The low frequency/high frequency ratio was used as a marker of sympathovagal balance. Sauna and cold-water immersion were well tolerated by all subjects. Cardiac output and heart rate significantly increased in all groups after sauna and cold-water immersion (p heart failure patients. In coronary artery disease patients and controls a prolonged increase in low frequency/high frequency ratio was observed after the first sauna exposure. Acute exposure to Finnish sauna and cold-water immersion causes haemodynamic alterations in chronic heart failure patients similarly to control subjects and in particular did not provoke an excessive increase in adrenergic activity or complex arrhythmias. © The European Society of Cardiology 2015.

  1. Metrology of variable-line-spacing x-ray gratings using the APS Long Trace Profiler

    Science.gov (United States)

    Sheung, Janet; Qian, Jun; Sullivan, Joseph; Thomasset, Muriel; Manton, Jonathan; Bean, Sunil; Takacs, Peter; Dvorak, Joseph; Assoufid, Lahsen

    2017-09-01

    As resolving power targets have increased with each generation of beamlines commissioned in synchrotron radiation facilities worldwide, diffraction gratings are quickly becoming crucial optical components for meeting performance targets. However, the metrology of variable-line-spacing (VLS) gratings for high resolution beamlines is not widespread; in particular, no metrology facility at any US DOE facility is currently equipped to fully characterize such gratings. To begin to address this issue, the Optics Group at the Advanced Photon Source at Argonne, in collaboration with SOLEIL and with support from Brookhaven National Laboratory (BNL), has developed an alternative beam path addition to the Long Trace Profiler (LTP) at Argonne's Advanced Photon Source. This significantly expands the functionality of the LTP not only to measure mirrors surface slope profile at normal incidence, but also to characterize the groove density of VLS diffraction gratings in the Littrow incidence up to 79°, which covers virtually all diffraction gratings used at synchrotrons in the first order. The LTP light source is a 20mW HeNe laser, which yields enough signal for diffraction measurements to be performed on low angle blazed gratings optimized for soft X-ray wavelengths. We will present the design of the beam path, technical requirements for the optomechanics, and our data analysis procedure. Finally, we discuss challenges still to be overcome and potential limitations with use of the LTP to perform metrology on diffraction gratings.

  2. Variable collimator

    International Nuclear Information System (INIS)

    Richey, J.B.; McBride, T.R.; Covic, J.

    1979-01-01

    This invention describes an automatic variable collimator which controls the width and thickness of X-ray beams in X-ray diagnostic medical equipment, and which is particularly adapted for use with computerized axial tomographic scanners. A two-part collimator is provided which shapes an X-ray beam both prior to its entering an object subject to radiographic analysis and after the attenuated beam has passed through the object. Interposed between a source of radiation and the object subject to radiographic analysis is a first or source collimator. The source collimator causes the X-ray beam emitted by the source of radiation to be split into a plurality of generally rectangular shaped beams. Disposed within the source collimator is a movable aperture plate which may be used to selectively vary the thickness of the plurality of generally rectangular shaped beams transmitted through the source collimator. A second or receiver collimator is interposed between the object subject to radiographic analysis and a series of radiation detectors. The receiver collimator is disposed to receive the attenuated X-ray beams passing through the object subject to radiographic analysis. Located within the receiver collimator are a plurality of movable aperture plates adapted to be displaced relative to a plurality of fixed aperture plates for the purpose of varying the width and thickness of the attenuated X-ray beams transmitted through the object subject to radiographic analysis. The movable aperture plates of the source and receiver collimators are automatically controlled by circuitry which is provided to allow remote operation of the movable aperture plates

  3. Efficient Estimation of Spectral Moments and the Polarimetric Variables on Weather Radars, Sonars, Sodars, Acoustic Flow Meters, Lidars, and Similar Active Remote Sensing Instruments

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A method for estimation of Doppler spectrum, its moments, and polarimetric variables on pulsed weather radars which uses over sampled echo components at a rate...

  4. A long-term time series of global and diffuse photosynthetically active radiation in the Mediterranean: interannual variability and cloud effects

    Directory of Open Access Journals (Sweden)

    P. Trisolino

    2018-06-01

    Full Text Available Measurements of global and diffuse photosynthetically active radiation (PAR have been carried out on the island of Lampedusa, in the central Mediterranean Sea, since 2002. PAR is derived from observations made with multi-filter rotating shadowband radiometers (MFRSRs by comparison with a freshly calibrated PAR sensor and by relying on the on-site Langley plots. In this way, a long-term calibrated record covering the period 2002–2016 is obtained and is presented in this work. The monthly mean global PAR peaks in June, with about 160 W m−2, while the diffuse PAR reaches 60 W m−2 in spring or summer. The global PAR displays a clear annual cycle with a semi amplitude of about 52 W m−2. The diffuse PAR annual cycle has a semi amplitude of about 12 W m−2. A simple method to retrieve the cloud-free PAR global and diffuse irradiances in days characterized by partly cloudy conditions has been implemented and applied to the dataset. This method allows retrieval of the cloud-free evolution of PAR and calculation of the cloud radiative effect, CRE, for downwelling PAR. The cloud-free monthly mean global PAR reaches 175 W m−2 in summer, while the diffuse PAR peaks at about 40 W m−2. The cloud radiative effect, CRE, on global and diffuse PAR is calculated as the difference between all-sky and cloud-free measurements. The annual average CRE is about −14.7 W m−2 for the global PAR and +8.1 W m−2 for the diffuse PAR. The smallest CRE is observed in July, due to the high cloud-free condition frequency. Maxima (negative for the global, and positive for the diffuse component occur in March–April and in October, due to the combination of elevated PAR irradiances and high occurrence of cloudy conditions. Summer clouds appear to be characterized by a low frequency of occurrence, low altitude, and low optical thickness, possibly linked to the peculiar marine boundary layer structure. These properties also contribute

  5. The shunt from the cyclooxygenase to lipoxygenase pathway in human osteoarthritic subchondral osteoblasts is linked with a variable expression of the 5-lipoxygenase-activating protein.

    Science.gov (United States)

    Maxis, Kelitha; Delalandre, Aline; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Duval, Nicolas; Lajeunesse, Daniel

    2006-01-01

    Osteoarthritis (OA) is characterized by articular cartilage degradation and hypertrophic bone changes with osteophyte formation and abnormal bone remodeling. Two groups of OA patients were identified via the production of variable and opposite levels of prostaglandin E2 (PGE2) or leukotriene B4 (LTB4) by subchondral osteoblasts, PGE2 levels discriminating between low and high subgroups. We studied whether the expression of 5-lipoxygenase (5-LO) or 5-LO-activating protein (FLAP) is responsible for the shunt from prostaglandins to leukotrienes. FLAP mRNA levels varied in low and high OA groups compared with normal, whereas mRNA levels of 5-LO were similar in all osteoblasts. Selective inhibition of cyclooxygenase-2 (COX-2) with NS-398-stimulated FLAP expression in the high OA osteoblasts subgroup, whereas it was without effect in the low OA osteoblasts subgroup. The addition of PGE2 to the low OA osteoblasts subgroup decreased FLAP expression but failed to affect it in the high OA osteoblasts subgroup. LTB4 levels in OA osteoblasts were stimulated about twofold by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plus transforming growth factor-beta (TGF-beta), a situation corresponding to their effect on FLAP mRNA levels. Treatments with 1,25(OH)2D3 and TGF-beta also modulated PGE2 production. TGF-beta stimulated PGE2 production in both OA osteoblast groups, whereas 1,25(OH)2D3 alone had a limited effect but decreased the effect of TGF-beta in the low OA osteoblasts subgroup. This modulation of PGE2 production was mirrored by the synthesis of COX-2. IL-18 levels were only slightly increased in a subgroup of OA osteoblasts compared with normal; however, no relationship was observed overall between IL-18 and PGE2 levels in normal and OA osteoblasts. These results suggest that the shunt from the production of PGE2 to LTB4 is through regulation of the expression of FLAP, not 5-LO, in OA osteoblasts. The expression of FLAP in OA osteoblasts is also modulated differently by 1,25(OH

  6. Diabetes and Technology for Increased Activity (DaTA Study: The effects of exercise and technology on heart rate variability and metabolic syndrome risk factors.

    Directory of Open Access Journals (Sweden)

    Melanie I Stuckey

    2013-09-01

    Full Text Available This study tested the hypothesis that an eight-week exercise intervention supported by mobile health (mHealth technology would improve metabolic syndrome (MetS risk factors and heart rate variability (HRV in a population with MetS risk factors. Participants (n=12; 3 male; aged 56.9±7.0y reported to the laboratory for assessment of MetS risk factors and fitness (VO2max at baseline (V0 and after eight-weeks (V2 of intervention. Participants received an individualized exercise prescription and a mHealth technology kit for remote monitoring of blood pressure (BP, blood glucose, physical activity and body weight via smartphone. Participants underwent 24-h ambulatory monitoring of R-R intervals following V0 and V2. Low and high frequency powers of HRV were assessed from the recording and the ratio of low-to-high frequency powers and low and high frequency power in normalized units were calculated. One-way repeated measures analysis of variance showed that waist circumference (V0: 113.1±11.0cm, V2: 108.1±14.7cm; p=0.004 and diastolic BP (V0: 81±6mmHg, V2: 76±11mmHg; p=0.04 were reduced and VO2max increased (V0: 31.3ml/kg/min, V2: 34.8ml/kg/min; p=0.02 with no changes in other MetS risk factors. Low and high frequency powers in normalized units were reduced (V0: 75.5±12.0, V2: 72.0±12.1; p=0.03 and increased (V0: 24.5±12.0, V2: 28.0±12.1; p=0.03, respectively, with no other changes in HRV. Over the intervention period, changes in systolic BP were correlated negatively with the changes in R-R interval (r=-0.600; p=0.04 and positively with the changes in heart rate (r=0.611; p=0.03, with no other associations between MetS risk factors and HRV parameters. Thus, this eight-week mHealth supported exercise intervention improved MetS risk factors and HRV parameters, but only changes in systolic BP were associated with improved autonomic function.

  7. Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults.

    Science.gov (United States)

    Pedersen, E S L; Danquah, I H; Petersen, C B; Tolstrup, J S

    2016-12-03

    Accelerometers can obtain precise measurements of movements during the day. However, the individual activity pattern varies from day-to-day and there is limited evidence on measurement days needed to obtain sufficient reliability. The aim of this study was to examine variability in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees. We included control participants (n = 135) from the Take a Stand! Intervention; a cluster randomized controlled trial conducted in 19 offices. Sitting time and physical activity were measured using an ActiGraph GT3X+ fixed on the thigh and data were processed using Acti4 software. Variability was examined for sitting time, standing time, steps and time spent in moderate-to-vigorous physical activity (MVPA) per day by multilevel mixed linear regression modelling. Results of this study showed that the number of days needed to obtain a reliability of 80% when measuring sitting time was 4.7 days for work and 5.5 days for leisure time. For physical activity at work, 4.0 days and 4.2 days were required to measure steps and MVPA, respectively. During leisure time, more monitoring time was needed to reliably estimate physical activity (6.8 days for steps and 5.8 days for MVPA). The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time. The domain specific variability is of great importance to researchers and health promotion workers planning to use objective measures of sedentary behaviour and physical activity. Clinical trials NCT01996176 .

  8. Understanding Variability, Habit and the Effect of Long Period Activity Plan in Modal Choices: A Day to Day, Week to Week Analysis on Panel Data

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Cirillo, Cinzia

    2014-01-01

    Understanding variability in individual behaviour is crucial for the comprehension of travel patterns and for the development and evaluation of planning policies. In the last 30 years a vast body of research has approached the issue in a variety of ways, but there are no studies on the intrinsic ...

  9. Understanding Solar Cycle Variability

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2017-07-10

    The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to a generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.

  10. [The effects of 16-weeks pilates mat program on anthropometric variables and body composition in active adult women after a short detraining period].

    Science.gov (United States)

    Vaquero-Cristóbal, Raquel; Alacid, Fernando; Esparza-Ros, Francisco; Muyor, José M; López-Miñarro, Pedro Ángel

    2015-04-01

    previous studies have analysed the effect of mat Pilates practice on anthropometric variables and body composition in sedentaries. To date no researchs have investigated the benefits of Pilates on these variables after a short detraining period. to determine the effect of a 16-week mat Pilates program on anthropometric variables, body composition and somatotype of women with previous practice experience after three weeks of detraining period. twenty-one women underwent a complete anthropometric assessment according with ISAK guidelines before and after a 16 week mat Pilates program (two days, one hour). All women had one to three years of mat Pilates experience and came to three weeks of detraining period (Christmas holiday). women showed significant decreases for body mass, BMI, upper limb (biceps and triceps) and trunk (subscapular, iliac crest, supraspinale and abdominal) individual skinfolds, 6 and 8 skinfold sums, endomorphy and fat mass; and a significant increases for muscle mass. The mean somatotype was classified as mesomorphic endomorph in the pre- (4.91, 4.01, 1.47) and post-test (4.68, 4.16, 1.69). Eight women changed their somatotype clasification after the intervention program. the practice of mat Pilates for 16 weeks caused changes associated with health state improvements on anthropometric variables, especially on skinfolds which significantly decreased, body composition (fat and muscle masses decreased and increased, respectively) and somatotype (there was a significantly decreased on the endomorph component in experienced women after three week of detraning. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  11. A Meta-Analytic Review of the Theories of Reasoned Action and Planned Behavior in Physical Activity: Predictive Validity and the Contribution of Additional Variables.

    Science.gov (United States)

    Hagger, Martin S.; Chatzisarantis, Nikos L. D.; Biddle, Stuart J. H.

    2002-01-01

    Examined relations between behavior, intentions, attitudes, subjective norms, perceived behavioral control, self-efficacy, and past behaviors using the Theories of Reasoned Action (TRA) and Planned Behavior (TPB) in physical activity. This quantitative integration of the physical activity literature supported the major relationships of the…

  12. Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults

    DEFF Research Database (Denmark)

    Lunde Pedersen, Eva Sophie; Danquah, I H; Petersen, C B

    2016-01-01

    in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees. METHODS: We included control participants (n = 135) from the Take a Stand! Intervention; a cluster randomized controlled trial conducted in 19 offices. Sitting time....... RESULTS: Results of this study showed that the number of days needed to obtain a reliability of 80% when measuring sitting time was 4.7 days for work and 5.5 days for leisure time. For physical activity at work, 4.0 days and 4.2 days were required to measure steps and MVPA, respectively. During leisure...... time, more monitoring time was needed to reliably estimate physical activity (6.8 days for steps and 5.8 days for MVPA). CONCLUSIONS: The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time. The domain specific variability is of great...

  13. Semi-Automatic Evaluation of Intrasubject Variability and Inter-session of Cerebral Activation Areas by Neuro functional Magnetic Resonance (FMRI)

    International Nuclear Information System (INIS)

    Rascovsky, Simon; Delgado, Jorge Andres; Sanz, Alexander

    2008-01-01

    To verify the reproducibility of word generation, text comprehension, antonyms generation and motor/somatosensory RMF protocols in a test-retest evaluation through a semiautomatic stereotaxical localization method for activation comparison. Methods: Word generation, text comprehension, antonyms generation and motor/somatosensory FMRI paradigms were applied on 8 healthy subjects on two separate sessions, performing the evaluation of inter-session activations through conjunction and cluster analysis. Results: Activations according to Brodmann areas were reproducible in 50%, 62.5% and 75% for word generation, text comprehension and antonyms generation respectively. For the motor paradigms, right motor conjoined activations were found in 86% of subjects and in 100% of subjects for left conjoined activations. Conclusions: The semi-automatic method of determining inter-session areas of common activation allows its use for functional cytoarchitectonic localization of fMRI activations with minimal intervention, and can be used as a quality control measure of the different paradigms used in RMF, minimizing observer bias.

  14. Exposure to chronic variable social stress during adolescence alters affect-related behaviors and adrenocortical activity in adult male and female inbred mice.

    Science.gov (United States)

    Caruso, Michael J; Kamens, Helen M; Cavigelli, Sonia A

    2017-09-01

    Rodent models provide valuable insight into mechanisms that underlie vulnerability to adverse effects of early-life challenges. Few studies have evaluated sex differences in anxiogenic or depressogenic effects of adolescent social stress in a rodent model. Furthermore, adolescent stress studies often use genetically heterogeneous outbred rodents which can lead to variable results. The current study evaluated the effects of adolescent social stress in male and female inbred (BALB/cJ) mice. Adolescent mice were exposed to repeat cycles of alternating social isolation and social novelty for 4 weeks. Adolescent social stress increased anxiety-related behaviors in both sexes and depression-related behavior in females. Locomotion/exploratory behavior was also decreased in both sexes by stress. Previously stressed adult mice produced less basal fecal corticosteroids than controls. Overall, the novel protocol induced sex-specific changes in anxiety- and depression-related behaviors and corticoid production in inbred mice. The chronic variable social stress protocol used here may be beneficial to systematically investigate sex-specific neurobiological mechanisms underlying adolescent stress vulnerability where genetic background can be controlled. © 2017 Wiley Periodicals, Inc.

  15. Functional connectivity and neuronal variability of resting state activity in bipolar disorder--reduction and decoupling in anterior cortical midline structures.

    Science.gov (United States)

    Magioncalda, Paola; Martino, Matteo; Conio, Benedetta; Escelsior, Andrea; Piaggio, Niccolò; Presta, Andrea; Marozzi, Valentina; Rocchi, Giulio; Anastasio, Loris; Vassallo, Linda; Ferri, Francesca; Huang, Zirui; Roccatagliata, Luca; Pardini, Matteo; Northoff, Georg; Amore, Mario

    2015-02-01

    The cortical midline structures seem to be involved in the modulation of different resting state networks, such as the default mode network (DMN) and salience network (SN). Alterations in these systems, in particular in the perigenual anterior cingulate cortex (PACC), seem to play a central role in bipolar disorder (BD). However, the exact role of the PACC, and its functional connections to other midline regions (within and outside DMN) still remains unclear in BD. We investigated functional connectivity (FC), standard deviation (SD, as a measure of neuronal variability) and their correlation in bipolar patients (n = 40) versus healthy controls (n = 40), in the PACC and in its connections in different frequency bands (standard: 0.01-0.10 Hz; Slow-5: 0.01-0.027 Hz; Slow-4: 0.027-0.073 Hz). Finally, we studied the correlations between FC alterations and clinical-neuropsychological parameters and we explored whether subgroups of patients in different phases of the illness present different patterns of FC abnormalities. We found in BD decreased FC (especially in Slow-5) from the PACC to other regions located predominantly in the posterior DMN (such as the posterior cingulate cortex (PCC) and inferior temporal gyrus) and in the SN (such as the supragenual anterior cingulate cortex and ventrolateral prefrontal cortex). Second, we found in BD a decoupling between PACC-based FC and variability in the various target regions (without alteration in variability itself). Finally, in our subgroups explorative analysis, we found a decrease in FC between the PACC and supragenual ACC (in depressive phase) and between the PACC and PCC (in manic phase). These findings suggest that in BD the communication, that is, information transfer, between the different cortical midline regions within the cingulate gyrus does not seem to work properly. This may result in dysbalance between different resting state networks like the DMN and SN. A deficit in the anterior DMN-SN connectivity

  16. Gender variability in electromyographic activity, in vivo behaviour of the human gastrocnemius and mechanical capacity during the take-off phase of a countermovement jump.

    Science.gov (United States)

    Rubio-Arias, Jacobo Ángel; Ramos-Campo, Domingo Jesús; Peña Amaro, José; Esteban, Paula; Mendizábal, Susana; Jiménez, José Fernando

    2017-11-01

    The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound). Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs. Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women. Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  17. The phase differences of the interdecadal variabilities of tropical cyclone activity in the peak and late seasons over the western North Pacific

    Science.gov (United States)

    Fan, Tingting; Xu, Shibin; Huang, Fei; Zhao, Jinping

    2018-04-01

    This study compares the interdecadal variations in tropical cyclone (TC) activities over the western North Pacific (WNP) basin during the peak season (July-September) and late season (October-December) of 1955-2014 and explores the possible physical mechanisms behind the variations. Both the peak- and late-season tropical storm (TS) days show distinct interdecadal variations, while the late-season TS days lead the peak-season TS days by approximately 4 years on an interdecadal time scale. The late-season TC activity is related to the east-west sea surface temperature (SST) gradient across the equatorial Pacific. The westerly winds induced by the SST gradient can reduce the vertical wind shear and increase the low-level vorticity, which favors TC genesis over the TC genesis region. The peak-season TC activity appears to relate to the SST gradient between the Indian Ocean and the Central Pacific. The westerly wind induced by the SST gradient can reduce the vertical wind shear and increase the mid-level relative humidity, thereby enhancing the TC activity. The full picture of the interdecadal variation in the WNP TC activity during the peak and late seasons revealed in this study provides a new perspective on the seasonal TC forecasts and future projections.

  18. Possible changes in the dose of biologically active ultraviolet radiation received by the biosphere in the summertime Arctic due to total ozone interannual variability

    Energy Technology Data Exchange (ETDEWEB)

    Gruzdev, Aleksandr N. (Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow (Russian Federation))

    1994-12-01

    Data for total ozone measurements since 1972 from the world ozone measuring network have been analyzed to study ozone interannual variability and estimate its possible effect on the UV-B dose received by the arctic biosphere. Possible interannual changes in the UV-B dose received by DNA associated with overall interannual ozone variability, as well as with the quasi-biennial oscillation (QBO) in total ozone were computed for different summer months. In general, the largest interannual variations in UV-B dose may occur in the Russian Arctic, whereas the possible variations in the Canadian Arctic are the smallest. Overall variations in the UV-B dose received by DNA can exceed 25% (2[sigma] criterion) in the Taimyr and Severnaya Zemlya for June and July, and 30% in the Laptev Sea for August. In the European sector of the Arctic, the possible variations are greater than 10%, and can exceed 15% in the north Norwegian Sea for July and 20% in Spitsbergen for August. Possible overall variations in the Canadian Arctic and Alaska are [<=]10%, reaching 15% in Alaska for August, however. The total ozone QBO can also cause essential and (statistically) predicted changes in UV-B radiation. In general, the UV-B dose received by DNA is found to be greater in the Arctic during the westerly phase of the QBO of the equatorial stratospheric wind at 50 mb level than during the easterly phase. The difference can reach or exceed 15% (relative to the mean value) in Taimyr for June and in Severnaya Zemlya for July and August. In northern Europe and Iceland, the difference can reach 10% for August. In the Canadian Arctic, the QBO-related effect is small. In Alaska, the appropriate difference in UV-B dose has an opposite sign for August, exceeding 5% in magnitude

  19. Analysis According to Certain Variables of Scientific Literacy among Gifted Students That Participate in Scientific Activities at Science and Art Centers

    Science.gov (United States)

    Kömek, Emre; Yagiz, Dursun; Kurt, Murat

    2015-01-01

    The purpose of this study is to analyze scientific literacy levels relevant to science and technology classes among gifted students that participate in scientific activities at science and art centers. This study investigated whether there was a significant difference in scientific literacy levels among gifted students according to the areas of…

  20. The Relationship between Pedometer-Determined and Self-Reported Physical Activity and Body Composition Variables in College-Aged Men and Women

    Science.gov (United States)

    Mestek, Michael L.; Plaisance, Eric; Grandjean, Peter

    2008-01-01

    Pedometer-determined physical activity (PA) is inversely related to body composition in middle-aged adults; however, researchers have not established such a relationship in college students. Objective and Participants: In this study, the authors attempted to characterize PA and examine its relationship with body composition in undergraduate…

  1. Social Cognitive and Planned Behavior Variables Associated with Stages of Change for Physical Activity in Spinal Cord Injury: A Multivariate Analysis

    Science.gov (United States)

    Keegan, John; Ditchman, Nicole; Dutta, Alo; Chiu, Chung-Yi; Muller, Veronica; Chan, Fong; Kundu, Madan

    2016-01-01

    Purpose: To apply the constructs of social cognitive theory (SCT) and the theory of planned behavior (TPB) to understand the stages of change (SOC) for physical activities among individuals with a spinal cord injury (SCI). Method: Ex post facto design using multivariate analysis of variance (MANOVA). The participants were 144 individuals with SCI…

  2. Variability in In Vitro Macrophage Activation by Commercially Diverse Bulk Echinacea Plant Material is Predominantly Due to Bacterial Lipoproteins and Lipopolysaccharides

    Science.gov (United States)

    We previously reported that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea and other botanicals depends upon bacterial lipopolysaccharides and Braun-type bacterial lipoproteins. We determined the contribution made by these bacterial components to the overa...

  3. Time-variant coherence between heart rate variability and EEG activity in epileptic patients: an advanced coupling analysis between physiological networks

    International Nuclear Information System (INIS)

    Piper, D; Schiecke, K; Pester, B; Witte, H; Benninger, F; Feucht, M

    2014-01-01

    Time-variant coherence analysis between the heart rate variability (HRV) and the channel-related envelopes of adaptively selected EEG components was used as an indicator for the occurrence of (correlative) couplings between the central autonomic network (CAN) and the epileptic network before, during and after epileptic seizures. Two groups of patients were investigated, a group with left and a group with right hemispheric temporal lobe epilepsy. The individual EEG components were extracted by a signal-adaptive approach, the multivariate empirical mode decomposition, and the envelopes of each resulting intrinsic mode function (IMF) were computed by using Hilbert transform. Two IMFs, whose envelopes were strongly correlated with the HRV’s low-frequency oscillation (HRV-LF; ≈0.1 Hz) before and after the seizure were identified. The frequency ranges of these IMFs correspond to the EEG delta-band. The time-variant coherence was statistically quantified and tensor decomposition of the time-frequency coherence maps was applied to explore the topography-time-frequency characteristics of the coherence analysis. Results allow the hypothesis that couplings between the CAN, which controls the cardiovascular-cardiorespiratory system, and the ‘epileptic neural network’ exist. Additionally, our results confirm the hypothesis of a right hemispheric lateralization of sympathetic cardiac control of the HRV-LF. (paper)

  4. A model of involvement in work-related learning and development activity: the effects of individual, situational, motivational, and age variables.

    Science.gov (United States)

    Maurer, Todd J; Weiss, Elizabeth M; Barbeite, Francisco G

    2003-08-01

    Eight hundred employees from across the U.S. work force participated in a detailed 13-month longitudinal study of involvement in learning and development activities. A new model was posited and tested in which the hypothesized sequence was as follows: worker age --> individual and situational antecedents --> perceived benefits of participation and self-efficacy for development --> attitudes toward development --> intentions to participate --> participation. The results depict a person who is oriented toward employee development as having participated in development activities before, perceiving themselves as possessing qualities needed for learning, having social support for development at work and outside of work, being job involved, having insight into his or her career, and believing in the need for development, in his or her ability to develop skills and to receive intrinsic benefits from participating. Given the aging work force, a detailed treatment of age differences in development is presented. Implications for new ideas in practice and future research are discussed.

  5. Variable importance in latent variable regression models

    NARCIS (Netherlands)

    Kvalheim, O.M.; Arneberg, R.; Bleie, O.; Rajalahti, T.; Smilde, A.K.; Westerhuis, J.A.

    2014-01-01

    The quality and practical usefulness of a regression model are a function of both interpretability and prediction performance. This work presents some new graphical tools for improved interpretation of latent variable regression models that can also assist in improved algorithms for variable

  6. Basin scale variability of active diazotrophs and nitrogen fixation in the North Pacific, from the tropics to the subarctic Bering Sea

    Science.gov (United States)

    Shiozaki, Takuhei; Bombar, Deniz; Riemann, Lasse; Hashihama, Fuminori; Takeda, Shigenobu; Yamaguchi, Tamaha; Ehama, Makoto; Hamasaki, Koji; Furuya, Ken

    2017-06-01

    Nitrogen-fixing microorganisms (diazotrophs) provide biologically available nitrogen to plankton communities and thereby greatly influence the productivity in many marine regions. Various cyanobacterial groups have traditionally been considered the major oceanic diazotrophs, but later noncyanobacterial and presumably heterotrophic diazotrophs were also found to be widespread and potentially important in nitrogen fixation. However, the distribution and activity of different diazotroph groups is still poorly constrained for most oceanic ecosystems. Here we examined diazotroph community structure and activity along a 7500 km south-north transect between the central equatorial Pacific and the Bering Sea. Nitrogen fixation contributed up to 84% of new production in the upper waters of the subtropical gyre, where the diazotroph community included the gammaproteobacterium γ-24774A11 and highly active cyanobacterial phylotypes (>50% of total nifH transcript abundance). Nitrogen fixation was sometimes detectable down to 150 m depth and extended horizontally to the edge of the gyre at around 35°N. Nitrogen fixation was even detected far north on the Bering Sea shelf. In the Alaskan Coastal Waters on the Bering Sea shelf, low nitrate together with high dissolved iron concentrations seemed to foster diazotroph growth, including a prominent role of UCYN-A2, which was abundant near the surface (1.2×105 nifH gene copies L-1). Our study provides evidence for nitrogen fixation in the Bering Sea and suggests a clear contrast in the composition of diazotrophs between the tropical/subtropical gyre and the separate waters in the cold northern regions of the North Pacific.

  7. Effect of Process Variables, Adsorption Kinetics and Equilibrium Studies of Hexavalent Chromium Removal from Aqueous Solution by Date Seeds and its Activated Carbon by ZnCl2

    Directory of Open Access Journals (Sweden)

    Samar K. Theydan

    2018-03-01

    Full Text Available The adsorption of hexavalent chromium by preparing activated carbon from date seeds with zinc chloride as chemical activator and granular date seeds was studied in a batch system. The characteristics of date seeds and prepared activated carbon (ZAC were determined and found to have a surface area 500.01 m2/g and 1050.01 m2/g , respectively and iodine number of 485.78 mg/g and 1012.91 mg/g, respectively. The effects of PH value (2-12, initial sorbate concentration(50-450mg/L, adsorbent weight (0.004-0.036g and contact time (30-150 min on the adsorption process were studied . For Cr(VI adsorption on ZAC, at 120 min time contact, pH solution 2 and 0.02 adsorbent weight will achieve an amount of 35.6 mg/g adsorbed . While when use date seeds as adsorbent , conditions of 3 solution pH, 0.02 absorbent weight , and 120 contact time gave 26.49 mg/g adsorbed amount. Using both Langmuir, Freundlich and Sips models were explain the dsorption isotherms. It declare that the Sips model fits well with the experimental data with a maximum Cr( VI adsorption capacity for (ZAC and granular date stone 233.493 and 208.055 mg/g, respectively . The kinetics data which obtained at different initial Cr(VI concentrations were examined by using pseudo-first-order, pseudo-second-order, and intra-particle diffusion models . The result gained showed that the second-order model was only describing well the empirical kinetics data of both (ZAC and granular date seeds. It was noticed that the granular date seeds has adsorption performance lower than the (ZAC.

  8. Solar Variability and Planetary Climates

    CERN Document Server

    Calisesi, Y; Gray, L; Langen, J; Lockwood, M

    2007-01-01

    Variations in solar activity, as revealed by variations in the number of sunspots, have been observed since ancient times. To what extent changes in the solar output may affect planetary climates, though, remains today more than ever a subject of controversy. In 2000, the SSSI volume on Solar Variability and Climate reviewed the to-date understanding of the physics of solar variability and of the associated climate response. The present volume on Solar Variability and Planetary Climates provides an overview of recent advances in this field, with particular focus at the Earth's middle and lower atmosphere. The book structure mirrors that of the ISSI workshop held in Bern in June 2005, the collection of invited workshop contributions and of complementary introductory papers synthesizing the current understanding in key research areas such as middle atmospheric processes, stratosphere-troposphere dynamical coupling, tropospheric aerosols chemistry, solar storm influences, solar variability physics, and terrestri...

  9. Geological constraints on continental arc activity since 720 Ma: implications for the link between long-term climate variability and episodicity of continental arcs

    Science.gov (United States)

    Cao, W.; Lee, C. T.

    2016-12-01

    Continental arc volcanoes have been suggested to release more CO2 than island arc volcanoes due to decarbonation of wallrock carbonates in the continental upper plate through which the magmas traverse (Lee et al., 2013). Continental arcs may thus play an important role in long-term climate. To test this hypothesis, we compiled geological maps to reconstruct the surface distribution of granitoid plutons and the lengths of ancient continental arcs. These results were then compiled into a GIS framework and incorporated into GPlates plate reconstructions. Our results show an episodic nature of global continental arc activity since 720 Ma. The lengths of continental arcs were at minimums during most of the Cryogenian ( 720-670 Ma), the middle Paleozoic ( 460-300 Ma) and the Cenozoic ( 50-0 Ma). Arc lengths were highest during the Ediacaran ( 640-570 Ma), the early Paleozoic ( 550-430 Ma) and the entire Mesozoic with peaks in the Early Triassic ( 250-240 Ma), Late Jurassic-Early Cretaceous ( 160-130 Ma), and Late Cretaceous ( 90-65 Ma). The extensive continental arcs in the Ediacaran and early Paleozoic reflect the Pan-African events and circum-Gondwana subduction during the assembly of the Gondwana supercontinent. The Early Triassic peak is coincident with the final closure of the paleo-Asian oceans and the onset of circum-Pacific subduction associated with the assembly of the Pangea supercontinent. The Jurassic-Cretaceous peaks reflect the extensive continental arcs established in the western Pacific, North and South American Cordillera, coincident with the initial dispersal of the Pangea. Continental arcs are favored during the final assembly and the early-stage dispersal of a supercontinent. Our compilation shows a temporal match between continental arc activity and long-term climate at least since 720 Ma. For example, continental arc activity was reduced during the Cryogenian icehouse event, and enhanced during the Early Paleozoic and Jurassic-Cretaceous greenhouse

  10. Vitamin D receptor variability and physical activity are jointly associated with low handgrip strength and osteoporosis in community-dwelling elderly people in Taiwan: the Taichung Community Health Study for Elders (TCHS-E).

    Science.gov (United States)

    Wu, F-Y; Liu, C-S; Liao, L-N; Li, C-I; Lin, C-H; Yang, C-W; Meng, N-H; Lin, W-Y; Chang, C-K; Hsiao, J-H; Li, T-C; Lin, C-C

    2014-07-01

    We studied 472 elders to assess joint association of vitamin D receptor (VDR) variability and physical activity on low handgrip strength (LHS) and osteoporosis (OST). Our findings showed that higher risks of OST were associated with physically inactive elders with some specific VDR variations, highlighting the importance of promotion program for physical activity. The aim of this study was to determine the joint association between VDR variability and physical activity on LHS and OST in community-dwelling elders. Bone mineral density of the lumbar spine (LS), the femoral neck (FN), and the total hip were measured by dual-energy X-ray absorptiometry. Four single-nucleotide polymorphisms (SNPs) (rs7975232, rs1544410, rs2239185, and rs3782905) of the VDR gene were examined in 472 participants. Physical inactivity and each of the four SNPs were jointly associated with a significantly greater risk of LHS in people than that associated with each of the VDR SNPs or low physical activity alone. Physically inactive men with the AG or AA genotype of rs2239185 had a significantly greater risk of overall, LS, and FN OST than those of physically active men with the GG genotype [odds ratio (OR) 3.57, 95 % confidence interval (CI) 1.10-11.65; OR 4.74, 95 % CI 1.43-15.70; and OR 5.06, 95 % CI 1.08-23.71, respectively]. Similarly, physically inactive women with the CG or CC genotype of rs3782905 and the AG or AA genotype of rs1544410 had a significantly greater risk of FN OST than physically active women with the GG genotype (OR 5.33, 95 % CI 1.23-23.06 and OR 5.36, 95 % CI 1.11-25.94, respectively). VDR polymorphisms and physical activity are jointly associated with LHS and OST in elders. Health care programs should promote physical activity among elders as a cost-effective way to prevent LHS and OST, especially in those who may be genetically predisposed.

  11. Pilotní studie ročního režimu pohybové aktivity gymnaziálních studentek [Variability of year-round physical activity in high school girls – pilot study

    Directory of Open Access Journals (Sweden)

    Marek Pelcl

    2008-03-01

    Full Text Available Tato studie analyzuje výsledky výzkumu u devíti gymnaziálních dívek, které dobrovolně celý školní rok 2005-06 nosily krokoměry k monitorování pohybové aktivity a její variability v průběhu jejich školní docházky a volného času. Korigovaná data byla zpracována opakovanou analýzou rozptylu a zjištěny byly významné rozdíly mezi dny v týdnu, měsíci, dny s vyučovacími jednotkami tělesné výchovy a bez tělesné výchovy a ročními obdobími. [The adolescent period seems to be critical in age-related decline of physical activity. To infl uence physical activity behavior in children and youth, it is necessary to determine factors aff ecting physical activity which are related to seasonal, monthly or weekly period. Therefore, the purpose of this study is to collect one year pedometer self-monitoring data to fi nd out the year-round variability of physical activity in high school girls. Nine volunteering girls from a high school participated in this study. Girls were asked to wear pedometer at their waist during each day of one year and record steps per day and daily behavior. We obtained 2118 person-day, each girl recorded 303 days. The days with lowest number of steps were Saturday and Sunday. The highest number of steps was obtained on days with regular physical education lesson – Wednesday. The month with the lowest average number steps/day was February and the average number steps/day was the highest in June. Although this study has several limitations (e.g. low sample size, the variability in year-round physical activity has been found across days and autumn, winter, and spring months.

  12. Essential oil of Azorella cryptantha collected in two different locations from San Juan Province, Argentina: chemical variability and anti-insect and antimicrobial activities.

    Science.gov (United States)

    López, Sandra; Lima, Beatriz; Aragón, Liliana; Espinar, Luis Ariza; Tapia, Alejandro; Zacchino, Susana; Zygadlo, Julio; Feresin, Gabriela Egly; López, María Liza

    2012-08-01

    The essential oils (EOs) of two populations of Azorella cryptantha (Clos) Reiche, a native species from San Juan Province, were obtained by hydrodistillation in a Clevenger-type apparatus and characterized by GC-FID and GC/MS analyses. The compounds identified amounted to 92.3 and 88.7% of the total oil composition for A. cryptantha from Bauchaceta (Ac-BAU) and Agua Negra (Ac-AN), respectively. The EO composition for the two populations was similar, although with differences in the identity and content of the main compounds and also in the identity of minor components. The main compounds of the Ac-BAU EO were α-pinene, α-thujene, sabinene, δ-cadinene, δ-cadinol, trans-β-guaiene, and τ-muurolol, while α-pinene, α-thujene, β-pinene, γ-cadinene, τ-cadinol, δ-cadinene, τ-muurolol, and a not identified compound were the main constituents of the Ac-AN EO, which also contained 3.0% of oxygenated monoterpenes. The repellent activity on Triatoma infestans nymphs was 100 and 92% for the Ac-AN and Ac-BAU EOs, respectively. Regarding the toxic effects on Ceratitis capitata, the EOs were very active with LD(50) values lower than 11 μg/fly. The dermatophytes Microsporum gypseum, Trichophyton rubrum, and T. mentagrophytes and the bacterial strains Escherichia coli LM(1), E. coli LM(2), and Yersinia enterocolitica PI were more sensitive toward the Ac-AN EO (MIC 125 μg/ml) than toward the Ac-BAU EO. This is the first report on the composition of A. cryptantha EO and its anti-insect and antimicrobial properties. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

  13. Investigation of load reduction for a variable speed, variable pitch, and variable coning wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, K. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    A two bladed, variable speed and variable pitch wind turbine was modeled using ADAMS{reg_sign} to evaluate load reduction abilities of a variable coning configuration as compared to a teetered rotor, and also to evaluate control methods. The basic dynamic behavior of the variable coning turbine was investigated and compared to the teetered rotor under constant wind conditions as well as turbulent wind conditions. Results indicate the variable coning rotor has larger flap oscillation amplitudes and much lower root flap bending moments than the teetered rotor. Three methods of control were evaluated for turbulent wind simulations. These were a standard IPD control method, a generalized predictive control method, and a bias estimate control method. Each control method was evaluated for both the variable coning configuration and the teetered configuration. The ability of the different control methods to maintain the rotor speed near the desired set point is evaluated from the RMS error of rotor speed. The activity of the control system is evaluated from cycles per second of the blade pitch angle. All three of the methods were found to produce similar results for the variable coning rotor and the teetered rotor, as well as similar results to each other.

  14. Solar-cosmic-ray variability

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1976-01-01

    The maximum flux of particles from solar events that should be considered in designing the shielding for a space habitation is discussed. The activities of various radionuclides measured in the top few centimeters of lunar rocks are used to examine the variability of solar cosmic ray fluxes over the last five million years. 10 references

  15. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Elio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); School of Advanced International Studies on Nuclear, Theoretical and Nonlinear Methodologies-Bari (Italy)], E-mail: fisio2@fisiol.uniba.it; Federici, Antonio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); Zbilut, Joseph P. [Department of Molecular Biophysics and Physiology, Rush University Medical Center, 1653W Congress, Chicago, IL 60612 (United States)

    2009-08-15

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  16. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    International Nuclear Information System (INIS)

    Conte, Elio; Federici, Antonio; Zbilut, Joseph P.

    2009-01-01

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  17. Patterns and variability in geochemical signatures and microbial activity within and between diverse cold seep habitats along the lower continental slope, Northern Gulf of Mexico

    Science.gov (United States)

    Bowles, Marshall; Hunter, Kimberley S.; Samarkin, Vladimir; Joye, Samantha

    2016-07-01

    We collected 69 sediment cores from distinct ecological and geological settings along the deep slope in the Northern Gulf of Mexico to evaluate whether specific geochemical- or habitat-related factors correlated with rates of microbial processes and geochemical signatures. By collecting replicate cores from distinct habitats across multiple sites, we illustrate and quantify the heterogeneity of cold seep geochemistry and microbial activity. These data also document the factors driving unique aspects of the geochemistry of deep slope gas, oil and brine seeps. Surprisingly little variation was observed between replicate (n=2-5) cores within sites for most analytes (except methane), implying that the common practice of collecting one core for geochemical analysis can capture the signature of a habitat in most cases. Depth-integrated concentrations of methane, dissolved inorganic carbon (DIC), and calcium were the predominant geochemical factors that correlated with a site's ecological or geological settings. Pore fluid methane concentration was related to the phosphate and DIC concentration, as well as to rates of sulfate reduction. While distinctions between seep habitats were identified from geochemical signatures, habitat specific geochemistry varied little across sites. The relative concentration of dissolved inorganic nitrogen versus phosphorus suggests that phosphorus availability limits biomass production at cold seeps. Correlations between calcium, chloride, and phosphate concentrations were indicative of brine-associated phosphate transport, suggesting that in addition to the co-migration of methane, dissolved organic carbon, and ammonium with brine, phosphate delivery is also associated with brine advection.

  18. Investigation of variable compositions on the removal of technetium from Hanford Waste Treatment Plant low activity waste melter off-gas condensate simulant

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, Kathryn M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, John M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-03-29

    The Low Activity Waste (LAW) vitrification facility at the Hanford Waste Treatment and Immobilization Plant (WTP) will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the offgas system. The plan for disposition of this stream during baseline operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. The primary reason to recycle this stream is so that the semi-volatile 99Tc isotope eventually becomes incorporated into the glass. This stream also contains non-radioactive salt components that are problematic in the melter, so diversion of this stream to another process would eliminate recycling of these salts and would enable simplified operation of the LAW melter and the Pretreatment Facilities. This diversion from recycling this stream within WTP would have the effect of decreasing the LAW vitrification mission duration and quantity of glass waste. The concept being tested here involves removing the 99Tc so that the decontaminated aqueous stream, with the problematic salts, can be disposed elsewhere.

  19. Variability of filtration and food assimilation rates, respiratory activity and multixenobiotic resistance (MXR mechanism in the mussel Perna perna under lead influence

    Directory of Open Access Journals (Sweden)

    M. L. PESSATTI

    Full Text Available The economic importance that myticulture is conquering in Santa Catarina State (South of Brazil explains the crescent search for new coastal sites for farming. Physiological and biochemical studies of the mussel Perna perna are important to the establishment of methodologies for program assessment and environmental monitoring, allowing to infer about site quality and possible influences of xenobiotic agents on coastal areas. In order to evaluate effects caused by lead poisoning (1.21 mumol.L-1, the mussels were maintained at constant temperature (25ºC and fed with Chaetoceros gracilis for 15 days. The control group was acclimatized in sea water 30‰. At the end of this period time, physiological measurements were carried out along with statistic analysis for filtration rates, lead assimilation and overall respiratory activity. The mechanism of multixenobiotic resistance (MXR was particularly evaluated in standardized gill fragments using rhodamine B accumulation and its quantification under fluorescence optical microscopy. Regarding the control group, results had shown that the mussels maintenance in a lead-poisoned environment caused higher filtration rates (1.04 and 2.3 and L.h-1.g-1; p < 0.05 and lower assimilation rates (71.96% and 54.1%, respectively. Also it was confirmed a lesser rhodamine B accumulation in the assays under influence of lead, suggesting that this metal induces the MXR mechanism expression in mussel P. perna. These results indicate that such physiological and biochemical alterations in the mussels can modify the energy fluxes of its metabolism, resulting in possible problems on the coastal systems used as cultivating sites.

  20. Variability of filtration and food assimilation rates, respiratory activity and multixenobiotic resistance (MXR mechanism in the mussel Perna perna under lead influence

    Directory of Open Access Journals (Sweden)

    PESSATTI M. L.

    2002-01-01

    Full Text Available The economic importance that myticulture is conquering in Santa Catarina State (South of Brazil explains the crescent search for new coastal sites for farming. Physiological and biochemical studies of the mussel Perna perna are important to the establishment of methodologies for program assessment and environmental monitoring, allowing to infer about site quality and possible influences of xenobiotic agents on coastal areas. In order to evaluate effects caused by lead poisoning (1.21 mumol.L-1, the mussels were maintained at constant temperature (25ºC and fed with Chaetoceros gracilis for 15 days. The control group was acclimatized in sea water 30?. At the end of this period time, physiological measurements were carried out along with statistic analysis for filtration rates, lead assimilation and overall respiratory activity. The mechanism of multixenobiotic resistance (MXR was particularly evaluated in standardized gill fragments using rhodamine B accumulation and its quantification under fluorescence optical microscopy. Regarding the control group, results had shown that the mussels maintenance in a lead-poisoned environment caused higher filtration rates (1.04 and 2.3 and L.h-1.g-1; p < 0.05 and lower assimilation rates (71.96% and 54.1%, respectively. Also it was confirmed a lesser rhodamine B accumulation in the assays under influence of lead, suggesting that this metal induces the MXR mechanism expression in mussel P. perna. These results indicate that such physiological and biochemical alterations in the mussels can modify the energy fluxes of its metabolism, resulting in possible problems on the coastal systems used as cultivating sites.

  1. Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yongju, E-mail: ychoi81@snu.ac.kr [Department of Civil and Environmental Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Cho, Yeo-Myoung; Luthy, Richard G. [Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020 (United States); Werner, David [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2016-01-15

    Highlights: • The model accounts for the heterogeneity of AC distribution in field applications. • AC amendment effectiveness is predicted for ten sediment sites. • An HOC mass transfer model and calibrated parameters provide reliable predictions. • AC amendment is predicted to be effective for most sites. • K{sub ow}, K{sub d}, and equilibrium-based calculations are useful indicators. - Abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2–3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol–water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.

  2. Essential Oils of Myrtaceae Species Growing Wild in Tunisia: Chemical Variability and Antifungal Activity Against Biscogniauxia mediterranea, the Causative Agent of Charcoal Canker.

    Science.gov (United States)

    Yangui, Islem; Zouaoui Boutiti, Meriem; Boussaid, Mohamed; Messaoud, Chokri

    2017-07-01

    The chemical composition of five Eucalyptus species and five Myrtus communis L. populations was investigated using GC/MS and GC-FID. For Eucalyptus essential oils, 32 compounds, representing 88.56 - 96.83% of the total oil according to species, were identified. The main compounds were 1,8-cineole, α-pinene, p-cymene, γ-gurjunene, α-aromadendrene, and β-phellandrene. For Myrtle essential oils, 26 compounds, representing 93.13 - 98.91% of the total oil were identified. α-Pinene, 1,8-cineole, linalool, and myrtenyl acetate were found to be the major compounds. Principal component analysis (PCA) showed chemical differentiation between Eucalyptus species and between Myrtle populations. Biscogniauxia mediterranea, the causative agent of charcoal canker, was identified according to its morphological and molecular characteristics. Essential oils of the investigated Eucalyptus species and Myrtle populations were tested for their antifungal capacity against this fungus. The antifungal activity varied according to the essential oil composition. Biscogniauxia mediterranea exhibited powerful resistance to some essential oils including them of Eucalyptus lehmannii and Eucalyptus sideroxylon but it was very sensitive to Eucalyptus camaldulensis oil (IC 50  = 3.83 mg/ml) and M. communis oil from Zaghouan (IC 50  = 1 mg/ml). This sensitivity was found to be correlated to some essential oil compounds such as p-cymene, carvacrol, cuminaldehyde, and linalool. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  3. Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics

    International Nuclear Information System (INIS)

    Choi, Yongju; Cho, Yeo-Myoung; Luthy, Richard G.; Werner, David

    2016-01-01

    Highlights: • The model accounts for the heterogeneity of AC distribution in field applications. • AC amendment effectiveness is predicted for ten sediment sites. • An HOC mass transfer model and calibrated parameters provide reliable predictions. • AC amendment is predicted to be effective for most sites. • K ow , K d , and equilibrium-based calculations are useful indicators. - Abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2–3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol–water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.

  4. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  5. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  6. A variable stiffness joint with electrospun P(VDF-TrFE-CTFE) variable stiffness springs

    NARCIS (Netherlands)

    Carloni, Raffaella; Lapp, Valerie I.; Cremonese, Andrea; Belcari, Juri; Zucchelli, Andrea

    This letter presents a novel rotational variable stiffness joint that relies on one motor and a set of variable stiffness springs. The variable stiffness springs are leaf springs with a layered design, i.e., an electro-active layer of electrospun aligned nanofibers of poly(vinylidene

  7. Blazing New Trails: Strengthening Policy Research in Gifted Education

    Science.gov (United States)

    Plucker, Jonathan A.; Makel, Matthew C.; Matthews, Michael S.; Peters, Scott J.; Rambo-Hernandez, Karen E.

    2017-01-01

    Policy research in gifted education has occurred at much lower rates than other areas of research within the field, such as identification and talent development. However, without changes and implementation of these policies, systematic change is unlikely to occur. Therefore, the purpose of this article is to argue that policy research should be a…

  8. Blazing the energy trail: The Municipal Energy Management Program

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    The Urban Consortium Energy Task Force pioneers energy and environmental solutions for US cities and counties. When local officials participate in the task force, they open the door to many resources for their communities. The US is entering a period of renewed interest in energy management. Improvements in municipal energy management allow communities to free up energy operating funds to meet other needs. These improvements can even keep energy dollars in the community through the purchase of services and products used to save energy. With this idea in mind, the US Department of Energy Municipal Energy Management Program has funded more than 250 projects that demonstrate innovative energy technologies and management tools in cities and counties through the Urban Consortium Energy Task Force (UCETF). UCETF helps the US Department of Energy foster municipal energy management through networks with cities and urbanized counties and through links with three national associations of local governments. UCETF provides funding for projects that demonstrate innovative and realistic technologies, strategies, and methods that help urban America become more energy efficient and environmentally responsible. The task force provides technical support to local jurisdictions selected for projects. UCETF also shares information about successful energy management projects with cities and counties throughout the country via technical reports and project papers. The descriptions included here capsulize a sample of UCETF`s demonstration projects around the country.

  9. Using cognitive status to predict crash risk: blazing new trails?

    Science.gov (United States)

    Staplin, Loren; Gish, Kenneth W; Sifrit, Kathy J

    2014-02-01

    A computer-based version of an established neuropsychological paper-and-pencil assessment tool, the Trail-Making Test, was applied with approximately 700 drivers aged 70 years and older in offices of the Maryland Motor Vehicle Administration. This was a volunteer sample that received a small compensation for study participation, with an assurance that their license status would not be affected by the results. Analyses revealed that the study sample was representative of Maryland older drivers with respect to age and indices of prior driving safety. The relationship between drivers' scores on the Trail-Making Test and prospective crash experience was analyzed using a new outcome measure that explicitly takes into account error responses as well as correct responses, the error-compensated completion time. For the only reliable predictor of crash risk, Trail-Making Test Part B, this measure demonstrated a modest gain in specificity and was a more significant predictor of future safety risk than the simple time-to-completion measure. Improved specificity and the potential for autonomous test administration are particular advantages of this measure for use with large populations, in settings such as health care or driver licensing. © 2013.

  10. Programming parallel architectures - The BLAZE family of languages

    Science.gov (United States)

    Mehrotra, Piyush

    1989-01-01

    This paper gives an overview of the various approaches to programming multiprocessor architectures that are currently being explored. It is argued that two of these approaches, interactive programming environments and functional parallel languages, are particularly attractive, since they remove much of the burden of exploiting parallel architectures from the user. This paper also describes recent work in the design of parallel languages. Research on languages for both shared and nonshared memory multiprocessors is described.

  11. Programming parallel architectures: The BLAZE family of languages

    Science.gov (United States)

    Mehrotra, Piyush

    1988-01-01

    Programming multiprocessor architectures is a critical research issue. An overview is given of the various approaches to programming these architectures that are currently being explored. It is argued that two of these approaches, interactive programming environments and functional parallel languages, are particularly attractive since they remove much of the burden of exploiting parallel architectures from the user. Also described is recent work by the author in the design of parallel languages. Research on languages for both shared and nonshared memory multiprocessors is described, as well as the relations of this work to other current language research projects.

  12. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  13. Clinical efficacy of efonidipine hydrochloride, a T-type calcium channel inhibitor, on sympathetic activities. Examination using spectral analysis of heart rate/blood pressure variabilities and 123I-Metaiodobenzylguanidine myocardial scintigraphy

    International Nuclear Information System (INIS)

    Harada, Kenji; Nomura, Masahiro; Nishikado, Akiyoshi; Uehara, Kouzoh; Nakaya, Yutaka; Ito, Susumu

    2003-01-01

    Dihydropyridine Ca antagonists cause reflex tachycardia related to their hypotensive effects. Efonidipine hydrochloride has inhibitory effects on T-type Ca channels, even as it inhibits reflex tachycardia. In the present study, the influence of efonidipine hydrochloride on heart rate and autonomic nervous function was investigated. Using an electrocardiogram and a tonometric blood pressure measurement, autonomic nervous activity was evaluated using spectral analysis of heart rate/systolic blood pressure variability. Three protocols were used: a single dose of efonidipine hydrochloride was administered orally to healthy subjects with resting heart rate values of 75 beats/min or more (high-heart rate (HR) group) and to healthy subjects with resting heart rate values less than 75 beats/min (low-HR group); efonidipine hydrochloride was newly administered to untreated patients with essential hypertension, and autonomic nervous activity was investigated after a 4-week treatment period; and patients with high heart rate values (≥75 beats/min) who had been treated with a dihydropyridine L-type Ca channel inhibitor for 1 month or more were switched to efonidipine hydrochloride and any changes in autonomic nervous activity were investigated. In all protocols, administration of efonidipine hydrochloride decreased the heart rate in patients with a high heart rate, reduced sympathetic nervous activity, and enhanced parasympathetic nervous activity. In addition, myocardial scintigraphy with 123 I-metaiodobenzylguanidine showed significant improvement in the washout rate and heart to mediastinum (H/M) ratio of patients who were switched from other dihydropyridine Ca antagonists to efonidipine hydrochloride. Efonidipine hydrochloride inhibits increases in heart rate and has effects on the autonomic nervous system. It may be useful for treating hypertension and angina pectoris, and may also have a cardiac protective function. (author)

  14. Observations of fast variable objects

    International Nuclear Information System (INIS)

    Alekseev, G.N.

    1978-01-01

    A problem on studying fast variable astronomic objects is considered. The basis of the method used in the experiment is a detailed photoelectric study of a fast variableness along with spectroscopy of a high time resolution. Power spectrum of the SS Cyg brightness oscillations and autocorrelation function of the AX Mon brightness are analyzed as an example. To provide a reliable identification of parameters of star active regions responsible for the fast variableness, an experiment is proposed, the ''synchronous spectroscopy'' method being used. The method is based on the supposition about temporary stationarity of occasional processes within the limits of the time scale of several hours. The block diagram of the experiment is described

  15. There Is No Further Gain from Calculating Disease Activity Score in 28 Joints with High Sensitivity Assays of C-Reactive Protein Because of High Intraindividual Variability of CRP: A Cross Sectional Study and Theoretical Consideration

    DEFF Research Database (Denmark)

    Jensen Hansen, Inger Marie; Asmussen Andreasen, Rikke; Antonsen, Steen

    Background/Purpose: The threshold for reporting of C-reactive protein (CRP) differs from laboratory to laboratory. Moreover, CRP values are affected by the intra individual biological variability.[1] With respect to disease activity score in 28 joints (DAS28) and Rheumatoid Arthritis (RA), precise...... threshold for reporting CRP is important due to the direct effects of CRP on calculating DAS28, patient classification and subsequent treatment decisions[2] Methods: This study consists of two sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 with regard...... to the biological variation and reporting limit for CRP and a cross sectional study of all RA patients from our department (n=876) applying our theoretical results. In the second section, we calculate DAS28 twice with actual CRP and CRP=9, the latter to elucidate the positive consequences of changing the lower...

  16. There Is No Further Gain from Calculating Disease Activity Score in 28 Joints with High Sensitivity Assays of C-Reactive Protein Because of High Intraindividual Variability of CRP

    DEFF Research Database (Denmark)

    Jensen Hansen, Inger Marie; Asmussen Andreasen, Rikke; Antonsen, Steen

    2016-01-01

    Background/Purpose: The threshold for reporting of C-reactive protein (CRP) differs from laboratory to laboratory. Moreover, CRP values are affected by the intra individual biological variability.[1] With respect to disease activity score in 28 joints (DAS28) and Rheumatoid Arthritis (RA), precise...... threshold for reporting CRP is important due to the direct effects of CRP on calculating DAS28, patient classification and subsequent treatment decisions[2] Methods: This study consists of two sections: a theoretical consideration discussing the performance of CRP in calculating DAS28 with regard...... to the biological variation and reporting limit for CRP and a cross sectional study of all RA patients from our department (n=876) applying our theoretical results. In the second section, we calculate DAS28 twice with actual CRP and CRP=9, the latter to elucidate the positive consequences of changing the lower...

  17. α-Glucosidase inhibitor miglitol attenuates glucose fluctuation, heart rate variability and sympathetic activity in patients with type 2 diabetes and acute coronary syndrome: a multicenter randomized controlled (MACS) study.

    Science.gov (United States)

    Shimabukuro, Michio; Tanaka, Atsushi; Sata, Masataka; Dai, Kazuoki; Shibata, Yoshisato; Inoue, Yohei; Ikenaga, Hiroki; Kishimoto, Shinji; Ogasawara, Kozue; Takashima, Akira; Niki, Toshiyuki; Arasaki, Osamu; Oshiro, Koichi; Mori, Yutaka; Ishihara, Masaharu; Node, Koichi

    2017-07-06

    Little is known about clinical associations between glucose fluctuations including hypoglycemia, heart rate variability (HRV), and the activity of the sympathetic nervous system (SNS) in patients with acute phase of acute coronary syndrome (ACS). This pilot study aimed to evaluate the short-term effects of glucose fluctuations on HRV and SNS activity in type 2 diabetes mellitus (T2DM) patients with recent ACS. We also examined the effect of suppressing glucose fluctuations with miglitol on these variables. This prospective, randomized, open-label, blinded-endpoint, multicenter, parallel-group comparative study included 39 T2DM patients with recent ACS, who were randomly assigned to either a miglitol group (n = 19) or a control group (n = 20). After initial 24-h Holter electrocardiogram (ECG) (Day 1), miglitol was commenced and another 24-h Holter ECG (Day 2) was recorded. In addition, continuous glucose monitoring (CGM) was performed throughout the Holter ECG. Although frequent episodes of subclinical hypoglycemia (≤4.44 mmo/L) during CGM were observed on Day 1 in the both groups (35% of patients in the control group and 31% in the miglitol group), glucose fluctuations were decreased and the minimum glucose level was increased with substantial reduction in the episodes of subclinical hypoglycemia to 7.7% in the miglitol group on Day 2. Holter ECG showed that the mean and maximum heart rate and mean LF/HF were increased on Day 2 in the control group, and these increases were attenuated by miglitol. When divided 24-h time periods into day-time (0700-1800 h), night-time (1800-0000 h), and bed-time (0000-0700 h), we found increased SNS activity during day-time, increased maximum heart rate during night-time, and glucose fluctuations during bed-time, which were attenuated by miglitol treatment. In T2DM patients with recent ACS, glucose fluctuations with subclinical hypoglycemia were associated with alterations of HRV and SNS activity, which were mitigated by

  18. Heart rate variability in newborns.

    Science.gov (United States)

    Javorka, K; Lehotska, Z; Kozar, M; Uhrikova, Z; Kolarovszki, B; Javorka, M; Zibolen, M

    2017-09-22

    Heart rate (HR) and heart rate variability (HRV) in newborns is influenced by genetic determinants, gestational and postnatal age, and other variables. Premature infants have a reduced HRV. In neonatal HRV evaluated by spectral analysis, a dominant activity can be found in low frequency (LF) band (combined parasympathetic and sympathetic component). During the first postnatal days the activity in the high frequency (HF) band (parasympathetic component) rises, together with an increase in LF band and total HRV. Hypotrophy in newborn can cause less mature autonomic cardiac control with a higher contribution of sympathetic activity to HRV as demonstrated by sequence plot analysis. During quiet sleep (QS) in newborns HF oscillations increase - a phenomenon less expressed or missing in premature infants. In active sleep (AS), HRV is enhanced in contrast to reduced activity in HF band due to the rise of spectral activity in LF band. Comparison of the HR and HRV in newborns born by physiological vaginal delivery, without (VD) and with epidural anesthesia (EDA) and via sectio cesarea (SC) showed no significant differences in HR and in HRV time domain parameters. Analysis in the frequency domain revealed, that the lowest sympathetic activity in chronotropic cardiac chronotropic regulation is in the VD group. Different neonatal pathological states can be associated with a reduction of HRV and an improvement in the health conditions is followed by changes in HRV what can be use as a possible prognostic marker. Examination of heart rate variability in neonatology can provide information on the maturity of the cardiac chronotropic regulation in early postnatal life, on postnatal adaptation and in pathological conditions about the potential dysregulation of cardiac function in newborns, especially in preterm infants.

  19. Development of a dual luciferase activity and fluorescamine protein assay adapted to a 384 micro-well plate format: Reducing variability in human luciferase transactivation cell lines aimed at endocrine active substances

    Science.gov (United States)

    Brennan, Jennifer; Tillitt, Donald E.

    2018-01-01

    There is a need to adapt cell bioassays to 384-well and 1536-well formats instead of the traditional 96-well format as high-throughput screening (HTS) demands increase. However, the sensitivity and performance of the bioassay must be re-verified in these higher micro-well plates, and verification of cell health must also be HT (high-throughput). We have adapted two commonly used human breast luciferase transactivation cell bioassays, the recently re-named estrogen agonist/antagonist screening VM7Luc4E2 cell bioassay (previously designated BG1Luc4E2) and the androgen/glucocorticoid screening MDA-kb2 cell bioassay, to 384-well formats for HTS of endocrine-active substances (EASs). This cost-saving adaptation includes a fast, accurate, and easy measurement of protein amount in each well via the fluorescamine assay with which to normalize luciferase activity of cell lysates without requiring any transfer of the cell lysates. Here we demonstrate that by accounting for protein amount in the cell lysates, antagonistic agents can easily be distinguished from cytotoxic agents in the MDA-kb2 and VM7Luc4E2 cell bioassays. Additionally, we demonstrate via the fluorescamine assay improved interpretation of luciferase activity in wells along the edge of the plate (the so-called “edge effect”), thereby increasing usable wells to the entire plate, not just interior wells.

  20. Cataclysmic Variable Stars

    Science.gov (United States)

    Hellier, Coel

    2001-01-01

    Cataclysmic variable stars are the most variable stars in the night sky, fluctuating in brightness continually on timescales from seconds to hours to weeks to years. The changes can be recorded using amateur telescopes, yet are also the subject of intensive study by professional astronomers. That study has led to an understanding of cataclysmic variables as binary stars, orbiting so closely that material transfers from one star to the other. The resulting process of accretion is one of the most important in astrophysics. This book presents the first account of cataclysmic variables at an introductory level. Assuming no previous knowledge of the field, it explains the basic principles underlying the variability, while providing an extensive compilation of cataclysmic variable light curves. Aimed at amateur astronomers, undergraduates, and researchers, the main text is accessible to those with no mathematical background, while supplementary boxes present technical details and equations.

  1. Understanding Brown Dwarf Variability

    Science.gov (United States)

    Marley, Mark S.

    2013-01-01

    Surveys of brown dwarf variability continue to find that roughly half of all brown dwarfs are variable. While variability is observed amongst all types of brown dwarfs, amplitudes are typically greatest for L-T transition objects. In my talk I will discuss the possible physical mechanisms that are responsible for the observed variability. I will particularly focus on comparing and contrasting the effects of changes in atmospheric thermal profile and cloud opacity. The two different mechanisms will produce different variability signatures and I will discuss the extent to which the current datasets constrain both mechanisms. By combining constraints from studies of variability with existing spectral and photometric datasets we can begin to construct and test self-consistent models of brown dwarf atmospheres. These models not only aid in the interpretation of existing objects but also inform studies of directly imaged giant planets.

  2. Variability of BL Lacertae type object

    Energy Technology Data Exchange (ETDEWEB)

    Cayatte, V

    1987-10-01

    This object is among the brightest and the most violently variable of this galaxy class with active nuclei. It has been studied in many wavelength domains and in polarimetry. Some important results are reported here and more particularly on its variability. These observations bring some elements for a better knowledge of the inner source.

  3. Short-timescale variability in cataclysmic binaries

    International Nuclear Information System (INIS)

    Cordova, F.A.; Mason, K.O.

    1982-01-01

    Rapid variability, including flickering and pulsations, has been detected in cataclysmic binaries at optical and x-ray frequencies. In the case of the novalike variable TT Arietis, simultaneous observations reveal that the x-ray and optical flickering activity is strongly correlated, while short period pulsations are observed that occur at the same frequencies in both wavelength bands

  4. The nebular variables

    CERN Document Server

    Glasby, John S

    1974-01-01

    The Nebular Variables focuses on the nebular variables and their characteristics. Discussions are organized by type of nebular variable, namely, RW Aurigae stars, T Orionis stars, T Tauri stars, and peculiar nebular objects. Topics range from light variations of the stars to their spectroscopic and physical characteristics, spatial distribution, interaction with nebulosity, and evolutionary features. This volume is divided into four sections and consists of 25 chapters, the first of which provides general information on nebular variables, including their stellar associations and their classifi

  5. Ultrasonic variables affecting inspection

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.; Whiting, A.R.; McElroy, J.T.

    1977-01-01

    There are many variables which affect the detection of the effects and reproducibility of results when utilizing ultrasonic techniques. The most important variable is the procedure, as this document specifies, to a great extent, the controls that are exercised over the other variables. The most important variable is personnel with regards to training, qualification, integrity, data recording, and data analysis. Although the data is very limited, these data indicate that, if the procedure is carefully controlled, reliability of defect detection and reproducibility of results are both approximately 90 percent for reliability of detection, this applies to relatively small defects as reliability increases substantially as defect size increases above the recording limit. (author)

  6. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  7. Collective variables and dissipation

    International Nuclear Information System (INIS)

    Balian, R.

    1984-09-01

    This is an introduction to some basic concepts of non-equilibrium statistical mechanics. We emphasize in particular the relevant entropy relative to a given set of collective variables, the meaning of the projection method in the Liouville space, its use to establish the generalized transport equations for these variables, and the interpretation of dissipation in the framework of information theory

  8. Variability: A Pernicious Hypothesis.

    Science.gov (United States)

    Noddings, Nel

    1992-01-01

    The hypothesis of greater male variability in test results is discussed in its historical context, and reasons feminists have objected to the hypothesis are considered. The hypothesis acquires political importance if it is considered that variability results from biological, rather than cultural, differences. (SLD)

  9. Reinforcing Saccadic Amplitude Variability

    Science.gov (United States)

    Paeye, Celine; Madelain, Laurent

    2011-01-01

    Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we…

  10. POVMs and hidden variables

    International Nuclear Information System (INIS)

    Stairs, Allen

    2007-01-01

    Recent results by Paul Busch and Adan Cabello claim to show that by appealing to POVMs, non-contextual hidden variables can be ruled out in two dimensions. While the results of Busch and Cabello are mathematically correct, interpretive problems render them problematic as no hidden variable proofs

  11. Interdependence Among Organizational Variables

    Science.gov (United States)

    Knowles, M. C.

    1975-01-01

    The interrelationship between a set of organizational variables was investigated at 14 work organizations within a company. The variables were production, quality, costs, job satisfaction of operatives, job satisfaction of supervisors, work anxiety, accidents, absence, labor turnover, and industrial unrest. (Author)

  12. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  13. Eternity Variables to Simulate Specifications

    NARCIS (Netherlands)

    Hesselink, WH; Boiten, EA; Moller, B

    2002-01-01

    Simulation of specifications is introduced as a unification and generalization of refinement mappings, history variables, forward simulations, prophecy variables, and backward simulations. Eternity variables are introduced as a more powerful alternative for prophecy variables and backward

  14. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  15. Several complex variables

    International Nuclear Information System (INIS)

    Field, M.J.

    1976-01-01

    Topics discussed include the elementary of holomorphic functions of several complex variables; the Weierstrass preparation theorem; meromorphic functions, holomorphic line bundles and divisors; elliptic operators on compact manifolds; hermitian connections; the Hodge decomposition theorem. ( author)

  16. Variable-Rate Premiums

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — These interest rates are used to value vested benefits for variable rate premium purposes as described in PBGC's regulation on Premium Rates (29 CFR Part 4006) and...

  17. Variable Pricing Feasibility Assessment

    National Research Council Canada - National Science Library

    2004-01-01

    ...) and Willard Bishop Consulting (Barrington, IL) to evaluate the practicality of using a variable pricing system within DeCA to maintain an average of 30 percent customer savings and lower appropriated fund costs...

  18. Evolution of variable stars

    International Nuclear Information System (INIS)

    Becker, S.A.

    1986-08-01

    Throughout the domain of the H R diagram lie groupings of stars whose luminosity varies with time. These variable stars can be classified based on their observed properties into distinct types such as β Cephei stars, δ Cephei stars, and Miras, as well as many other categories. The underlying mechanism for the variability is generally felt to be due to four different causes: geometric effects, rotation, eruptive processes, and pulsation. In this review the focus will be on pulsation variables and how the theory of stellar evolution can be used to explain how the various regions of variability on the H R diagram are populated. To this end a generalized discussion of the evolutionary behavior of a massive star, an intermediate mass star, and a low mass star will be presented. 19 refs., 1 fig., 1 tab

  19. Calculus of one variable

    CERN Document Server

    Grossman, Stanley I

    1986-01-01

    Calculus of One Variable, Second Edition presents the essential topics in the study of the techniques and theorems of calculus.The book provides a comprehensive introduction to calculus. It contains examples, exercises, the history and development of calculus, and various applications. Some of the topics discussed in the text include the concept of limits, one-variable theory, the derivatives of all six trigonometric functions, exponential and logarithmic functions, and infinite series.This textbook is intended for use by college students.

  20. Software Testing Requires Variability

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2003-01-01

    Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic...... impact in software production. As is also apparent from the call for papers these perspectives focus on qualities such as reuse, adaptability, and maintainability....

  1. Suspended graphene variable capacitor

    OpenAIRE

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

    2016-01-01

    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  2. Millijansky radio variability in SDSS stripe 82

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, J. A.; Becker, R. H. [University of California, 1 Shields Avenue, Davis, CA 95616 (United States); White, R. L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Richards, G. T., E-mail: hodge@mpia.de [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

    2013-06-01

    We report on a blind survey for extragalactic radio variability that was carried out by comparing two epochs of data from the Faint Images of the Radio Sky at Twenty centimeters survey with a third epoch from a new 1.4 GHz survey of SDSS Stripe 82. The three epochs are spaced seven years apart and have an overlapping area of 60 deg{sup 2}. We uncover 89 variable sources down to the millijansky level, 75 of which are newly identified, and we find no evidence for transient phenomena. This new sample of variable sources allows us to infer an upper limit to the mean characteristic timescale of active galactic nucleus radio variability of 14 yr. We find that only 1% of extragalactic sources have fractional variability f {sub var} > 3, while 44% of Galactic sources vary by this much. The variable sample contains a larger fraction of quasars than a comparable non-variable control sample, though the majority of the variable sources appear to be extended galaxies in the optical. This implies that either quasars are not the dominant contributor to the variability of the sample, or that the deep optical data allow us to detect the host galaxies of some low-z quasars. We use the new, higher resolution data to report on the morphology of the variable sources. Finally, we show that the fraction of sources that are variable remains constant or increases at low flux densities. This may imply that next generation radio surveys with telescopes like Australian Square Kilometer Array Pathfinder and MeerKAT will see a constant or even increasing fraction of variable sources down into the sub-millijansky regime.

  3. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  4. Variable stator radial turbine

    Science.gov (United States)

    Rogo, C.; Hajek, T.; Chen, A. G.

    1984-01-01

    A radial turbine stage with a variable area nozzle was investigated. A high work capacity turbine design with a known high performance base was modified to accept a fixed vane stagger angle moveable sidewall nozzle. The nozzle area was varied by moving the forward and rearward sidewalls. Diffusing and accelerating rotor inlet ramps were evaluated in combinations with hub and shroud rotor exit rings. Performance of contoured sidewalls and the location of the sidewall split line with respect to the rotor inlet was compared to the baseline. Performance and rotor exit survey data are presented for 31 different geometries. Detail survey data at the nozzle exit are given in contour plot format for five configurations. A data base is provided for a variable geometry concept that is a viable alternative to the more common pivoted vane variable geometry radial turbine.

  5. Clinical variables in radiotracer biodistributions

    International Nuclear Information System (INIS)

    Lentle, B.C.; Scott, J.R.; Schmidt, R.P.; Noujaim, A.A.

    1981-01-01

    Radionuclide dosimetry must, by its nature, define tissue irradiation in terms of mean exposure in a population of a statistically acceptable size. In the daily practice of clinical nuclear medicine there are, however, quite large variations in the biodistribution of tracers and thus in resulting radiation doses. Age is a variable, particularly in respect of bone-seeking tracers. Sex imposes variations in radiation dose on account of the differing anatomical configurations of the gonads. Breast uptake and excretion of certain tracers in women are additional variables. Activity and occupation are occasional variables. Numerous iatrogenic causes of altered radiotracer biodistributions have been described. Cancer chemotherapy is a particularly potent cause of changed biodistributions while even a trivial matter such as preparing the skin with an iodine containing antiseptic may cause displacement of technetium from its compounds. In the blocking of thyroid uptake of radioiodines, there is good precedent for the manipulation of regional tissue dosimetry. It is possible to go beyond the mere cataloguing of these effects to look creatively at the subject of comparative tissue biodistributions and hence comparative dosimetry. Effects such as the clinical observation of the interference by cis-platinum with the usual biodistribution of radio-gallium suggest that such compounds can be used as probes each to lead to a better understanding of the mechanism of action of the other

  6. Internal variables in thermoelasticity

    CERN Document Server

    Berezovski, Arkadi

    2017-01-01

    This book describes an effective method for modeling advanced materials like polymers, composite materials and biomaterials, which are, as a rule, inhomogeneous. The thermoelastic theory with internal variables presented here provides a general framework for predicting a material’s reaction to external loading. The basic physical principles provide the primary theoretical information, including the evolution equations of the internal variables. The cornerstones of this framework are the material representation of continuum mechanics, a weak nonlocality, a non-zero extra entropy flux, and a consecutive employment of the dissipation inequality. Examples of thermoelastic phenomena are provided, accompanied by detailed procedures demonstrating how to simulate them.

  7. Resiliencia y variables sociodemograficas

    OpenAIRE

    Calero Martinez, Edgar David

    2015-01-01

    En el presente trabajo se aborda la definición de una de las variables dentro de lo que se denomina Capital psicológico positivo, la Resiliencia, sus principales características y algunas de las variables socio demográficas que en el estudio pretenden ver el nivel de relación existente entre cada una de ellas (indirecta o directamente) en el proceso resiliente de una persona para posteriores discusiones y su implicación dentro de la gestión empresarial y sus direcciones futuras.

  8. Effects of the Youth Fit 4 Life physical activity/nutrition protocol on body mass index, fitness and targeted social cognitive theory variables in 9- to 12-year-olds during after-school care.

    Science.gov (United States)

    Annesi, James J; Walsh, Stephanie M; Greenwood, Brittney L; Mareno, Nicole; Unruh-Rewkowski, Jennifer L

    2017-04-01

    Childhood overweight and obesity is unacceptably high in industrialised nations. School-based interventions have largely been atheoretical and ineffective. This study aimed to test a new theory-based protocol for its effects on measures of fitness and body mass index (BMI), and its proposed psychosocial mediators, during elementary after-school (out-of-school hours) care. Nine- to 12-year-old participants of YMCA-based after-school care in the southeastern Unites States were randomised into either the experimental Youth Fit 4 Life (YF4L) treatment group (n = 86) or a typical care group (n = 55) for 45 min/day. YF4L is based on social cognitive theory, emphasising mastery over physical activities and the development of self-management/self-regulatory skills to support healthy behaviours. Physiological and psychosocial variables were assessed over a 9-month elementary school year. Of the overall sample, 28% were overweight or obese at baseline. YF4L was associated with significantly greater improvements in BMI, and measures of self-regulation, mood, self-efficacy, cardiovascular endurance and strength over both 3 and 9 months. Changes in self-regulation, mood and self-efficacy significantly mediated the treatment type-BMI relationship over both 3 months (R 2 = 0.12, P = 0.002) and 9 months (R 2 = 0.13, P = 0.001), with change in self-regulation being a significant independent mediator. Changes in BMI and self-regulation reciprocally reinforced one another. Gender was not a significant moderator of those relationships. The YF4L treatment mitigated rise in BMI in 9- to 12-year-old enrollees of after-school care. The treatment's basis in social cognitive theory was supported. Because of its positive effects and ability to utilise existing staff, large-scale application is warranted after sufficient replication. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  9. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  10. Spatio-temporal variability of lightning and convective activity over South/South-East Asia with an emphasis during El Niño and La Niña

    Science.gov (United States)

    Saha, Upal; Siingh, Devendraa; Midya, S. K.; Singh, R. P.; Singh, A. K.; Kumar, S.

    2017-11-01

    The present analysis investigates the spatio-temporal variability of the convective parameters and associated lightning flash rates during the period 1997-2013 including the El Niño and La Niña episode. It reveals that north-western and north-eastern part along the foothills of Himalayas as well as Indo-China peninsular region and South China Sea are much convective prone zones over the South/South-East Asia. The terrain/orography of the Himalayan range, the influence of cross-equatorial low-level jet and large-scale circulation during pre-monsoon and active phase of monsoon, the western Pacific Warm Pool with increased sea surface temperature as well as the solar-heating-originated local instability instigate the convective anomaly to propagate over the north-western and north eastern Indian sub-continent along with the Indo-China peninsula and South China Sea respectively. The land surfaces of the Indian sub-continent and the sea surface of South China Sea possesses significant correlation with lightning flash rates and convective parameters whereas the sea surface surrounding Indian sub-continent do not show such good correlations among them. Although, the occurrence of convective activities during the El Niño (La Niña) gets reduced (increased), the occurrence of lightning flashes gets enhanced (diminished) during this period which may be the direct consequence of warming atmosphere in relation to changing patterns of regional climate. Fig. S2 Spatial trend distribution per year of (a) LFR, (b) CAPE, (c) SCP, (d) LI, (e) CINE and (f) AT anomaly over South/South-East Asia during January-December for the years 1997-2013 (Trend is significant at 95% confidence level). Fig. S3 Correlation maps of LFR with (a) CAPE, (b) SCP, (c) CINE and (d) LI over South/South-East Asia during January-December for the years 1997-2013. Fig. S4 Synoptic wind direction patterns during (a)-(b) El Niño (May 2002 - February 2003) conditions and (c)-(d) La Niña (July 1998 - March

  11. INTER-EXAMINER VARIABILITY

    African Journals Online (AJOL)

    Objective: To establish whether inter-examiner variability is still a significant factor for the undergraduate orthopaedic clinical ... D. The scores for each student were tabulated and the range, mean, and pass rate determined for each of the examiners. ... has not the heart to reject the man”, consistently gave higher scores (1).

  12. Several real variables

    CERN Document Server

    Kantorovitz, Shmuel

    2016-01-01

    This undergraduate textbook is based on lectures given by the author on the differential and integral calculus of functions of several real variables. The book has a modern approach and includes topics such as: •The p-norms on vector space and their equivalence •The Weierstrass and Stone-Weierstrass approximation theorems •The differential as a linear functional; Jacobians, Hessians, and Taylor's theorem in several variables •The Implicit Function Theorem for a system of equations, proved via Banach’s Fixed Point Theorem •Applications to Ordinary Differential Equations •Line integrals and an introduction to surface integrals This book features numerous examples, detailed proofs, as well as exercises at the end of sections. Many of the exercises have detailed solutions, making the book suitable for self-study. Several Real Variables will be useful for undergraduate students in mathematics who have completed first courses in linear algebra and analysis of one real variable.

  13. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  14. All Those Independent Variables.

    Science.gov (United States)

    Meacham, Merle L.

    This paper presents a case study of a sixth grade remedial math class which illustrates the thesis that only the "experimental attitude," not the "experimental method," is appropriate in the classroom. The thesis is based on the fact that too many independent variables exist in a classroom situation to allow precise measurement. The case study…

  15. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  16. Surfing wave climate variability

    Science.gov (United States)

    Espejo, Antonio; Losada, Iñigo J.; Méndez, Fernando J.

    2014-10-01

    International surfing destinations are highly dependent on specific combinations of wind-wave formation, thermal conditions and local bathymetry. Surf quality depends on a vast number of geophysical variables, and analyses of surf quality require the consideration of the seasonal, interannual and long-term variability of surf conditions on a global scale. A multivariable standardized index based on expert judgment is proposed for this purpose. This index makes it possible to analyze surf conditions objectively over a global domain. A summary of global surf resources based on a new index integrating existing wave, wind, tides and sea surface temperature databases is presented. According to general atmospheric circulation and swell propagation patterns, results show that west-facing low to middle-latitude coasts are more suitable for surfing, especially those in the Southern Hemisphere. Month-to-month analysis reveals strong seasonal variations in the occurrence of surfable events, enhancing the frequency of such events in the North Atlantic and the North Pacific. Interannual variability was investigated by comparing occurrence values with global and regional modes of low-frequency climate variability such as El Niño and the North Atlantic Oscillation, revealing their strong influence at both the global and the regional scale. Results of the long-term trends demonstrate an increase in the probability of surfable events on west-facing coasts around the world in recent years. The resulting maps provide useful information for surfers, the surf tourism industry and surf-related coastal planners and stakeholders.

  17. Tides and Decadal Variability

    Science.gov (United States)

    Ray, Richard D.

    2003-01-01

    This paper reviews the mechanisms by which oceanic tides and decadal variability in the oceans are connected. We distinguish between variability caused by tides and variability observed in the tides themselves. Both effects have been detected at some level. The most obvious connection with decadal timescales is through the 18.6-year precession of the moon's orbit plane. This precession gives rise to a small tide of the same period and to 18.6-year modulations in the phase and amplitudes of short-period tides. The 18.6-year "node tide" is very small, no more than 2 cm anywhere, and in sea level data it is dominated by the ocean's natural Variability. Some authors have naively attributed climate variations with periods near 19 years directly to the node tide, but the amplitude of the tide is too small for this mechanism to be operative. The more likely explanation (Loder and Garrett, JGR, 83, 1967-70, 1978) is that the 18.6-y modulations in short-period tides, especially h e principal tide M2, cause variations in ocean mixing, which is then observed in temperature and other climatic indicators. Tidally forced variability has also been proposed by some authors, either in response to occasional (and highly predictable) tidal extremes or as a nonlinear low-frequency oscillation caused by interactions between short-period tides. The former mechanism can produce only short-duration events hardly more significant than normal tidal ranges, but the latter mechanism can in principle induce low-frequency oscillations. The most recent proposal of this type is by Keeling and Whorf, who highlight the 1800-year spectral peak discovered by Bond et al. (1997). But the proposal appears contrived and should be considered, in the words of Munk et al. (2002), "as the most likely among unlikely candidates."

  18. The Chandra Source Catalog: Source Variability

    Science.gov (United States)

    Nowak, Michael; Rots, A. H.; McCollough, M. L.; Primini, F. A.; Glotfelty, K. J.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Evans, I.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Plummer, D. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; van Stone, D. W.; Winkelman, S. L.; Zografou, P.

    2009-09-01

    The Chandra Source Catalog (CSC) contains fields of view that have been studied with individual, uninterrupted observations that span integration times ranging from 1 ksec to 160 ksec, and a large number of which have received (multiple) repeat observations days to years later. The CSC thus offers an unprecedented look at the variability of the X-ray sky over a broad range of time scales, and across a wide diversity of variable X-ray sources: stars in the local galactic neighborhood, galactic and extragalactic X-ray binaries, Active Galactic Nuclei, etc. Here we describe the methods used to identify and quantify source variability within a single observation, and the methods used to assess the variability of a source when detected in multiple, individual observations. Three tests are used to detect source variability within a single observation: the Kolmogorov-Smirnov test and its variant, the Kuiper test, and a Bayesian approach originally suggested by Gregory and Loredo. The latter test not only provides an indicator of variability, but is also used to create a best estimate of the variable lightcurve shape. We assess the performance of these tests via simulation of statistically stationary, variable processes with arbitrary input power spectral densities (here we concentrate on results of red noise simulations) at variety of mean count rates and fractional root mean square variabilities relevant to CSC sources. We also assess the false positive rate via simulations of constant sources whose sole source of fluctuation is Poisson noise. We compare these simulations to an assessment of the variability found in real CSC sources, and estimate the variability sensitivities of the CSC.

  19. RADIO VARIABILITY IN SEYFERT NUCLEI

    International Nuclear Information System (INIS)

    Mundell, C. G.; Ferruit, P.; Nagar, N.; Wilson, A. S.

    2009-01-01

    within the central ∼<50 pc. If flares in radio light curves correspond to ejection of new relativistic components or emergence of shocks in the underlying flow, improved monitoring and high-resolution imaging using VLBI techniques are required to confirm that radio jets are intrinsically non-relativistic during quiescence but that Seyferts, as black-hole-driven active galactic nuclei (AGN), have the capacity to accelerate relativistic jets during radio flares. Finally, we conclude that our results taken together with the increased detection rate of flat spectrum radio nuclei in Seyferts imaged at VLBI resolutions and the detection of variable water megamaser emission support the paradigm of intermittent periods of quiescence and nuclear outburst across the Seyfert population.

  20. Variable Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

    2007-01-01

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

  1. On Complex Random Variables

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

  2. Technological Capability's Predictor Variables

    Directory of Open Access Journals (Sweden)

    Fernanda Maciel Reichert

    2011-03-01

    Full Text Available The aim of this study was to identify the factors that influence in configuration of the technological capability of companies in sectors with medium-low technological intensity. To achieve the goal proposed in this article a survey was carried out. Based on the framework developed by Lall (1992 which classifies firms in basic, intermediate and advanced level of technological capability; it was found that the predominant technological capability is intermediate, with 83.7% of respondent companies (plastics companies in Brazil. It is believed that the main contribution of this study is the finding that the dependent variable named “Technological Capability” can be explained at a rate of 65% by six variables: development of new processes; selection of the best equipment supplier; sales of internally developed new technology to third parties; design and manufacture of equipment; study of the work methods and perform inventory control; and improvement of product quality.

  3. Variable Kernel Density Estimation

    OpenAIRE

    Terrell, George R.; Scott, David W.

    1992-01-01

    We investigate some of the possibilities for improvement of univariate and multivariate kernel density estimates by varying the window over the domain of estimation, pointwise and globally. Two general approaches are to vary the window width by the point of estimation and by point of the sample observation. The first possibility is shown to be of little efficacy in one variable. In particular, nearest-neighbor estimators in all versions perform poorly in one and two dimensions, but begin to b...

  4. Short timescale variability in the faint sky variability survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2006-01-01

    We present the V-band variability analysis of the Faint Sky Variability Survey (FSVS). The FSVS combines colour and time variability information, from timescales of 24 minutes to tens of days, down to V = 24. We find that �1% of all point sources are variable along the main sequence reaching �3.5%

  5. Articulatory variability in cluttering.

    Science.gov (United States)

    Hartinger, Mariam; Mooshammer, Christine

    2008-01-01

    In order to investigate the articulatory processes of the hasty and mumbled speech in cluttering, the kinematic variability was analysed by means of electromagnetic midsagittal articulography. In contrast to persons with stuttering, those with cluttering improve their intelligibility by concentrating on their speech task. Variability has always been an important criterion in comparable studies of stuttering and is discussed in terms of the stability of the speech motor system. The aim of the current study was to analyse the spatial and temporal variability in the speech of three persons with cluttering (PWC) and three control speakers. All participants were native speakers of German. The speech material consisted of repetitive CV syllables and loan words such as 'emotionalisieren', because PWC have the severest problems with long words with a complex syllable structure. The results showed a significantly higher coefficient of variation for PWC in loan word production, both in the temporal and in the spatial domain, whereas the means of displacements and durations did not differ between groups. These findings were discussed in terms of the effects of the linguistic complexity, since for the syllable repetition task, no significant differences between PWC and controls were found. Copyright 2008 S. Karger AG, Basel.

  6. About hidden influence of predictor variables: Suppressor and mediator variables

    Directory of Open Access Journals (Sweden)

    Milovanović Boško

    2013-01-01

    Full Text Available In this paper procedure for researching hidden influence of predictor variables in regression models and depicting suppressor variables and mediator variables is shown. It is also shown that detection of suppressor variables and mediator variables could provide refined information about the research problem. As an example for applying this procedure, relation between Atlantic atmospheric centers and air temperature and precipitation amount in Serbia is chosen. [Projekat Ministarstva nauke Republike Srbije, br. 47007

  7. A canonical neural mechanism for behavioral variability

    Science.gov (United States)

    Darshan, Ran; Wood, William E.; Peters, Susan; Leblois, Arthur; Hansel, David

    2017-05-01

    The ability to generate variable movements is essential for learning and adjusting complex behaviours. This variability has been linked to the temporal irregularity of neuronal activity in the central nervous system. However, how neuronal irregularity actually translates into behavioural variability is unclear. Here we combine modelling, electrophysiological and behavioural studies to address this issue. We demonstrate that a model circuit comprising topographically organized and strongly recurrent neural networks can autonomously generate irregular motor behaviours. Simultaneous recordings of neurons in singing finches reveal that neural correlations increase across the circuit driving song variability, in agreement with the model predictions. Analysing behavioural data, we find remarkable similarities in the babbling statistics of 5-6-month-old human infants and juveniles from three songbird species and show that our model naturally accounts for these `universal' statistics.

  8. Effects of short-term variability of meteorological variables on soil temperature in permafrost regions

    Science.gov (United States)

    Beer, Christian; Porada, Philipp; Ekici, Altug; Brakebusch, Matthias

    2018-03-01

    Effects of the short-term temporal variability of meteorological variables on soil temperature in northern high-latitude regions have been investigated. For this, a process-oriented land surface model has been driven using an artificially manipulated climate dataset. Short-term climate variability mainly impacts snow depth, and the thermal diffusivity of lichens and bryophytes. These impacts of climate variability on insulating surface layers together substantially alter the heat exchange between atmosphere and soil. As a result, soil temperature is 0.1 to 0.8 °C higher when climate variability is reduced. Earth system models project warming of the Arctic region but also increasing variability of meteorological variables and more often extreme meteorological events. Therefore, our results show that projected future increases in permafrost temperature and active-layer thickness in response to climate change will be lower (i) when taking into account future changes in short-term variability of meteorological variables and (ii) when representing dynamic snow and lichen and bryophyte functions in land surface models.

  9. Changes in heart rate variability and QT variability during the first trimester of pregnancy.

    Science.gov (United States)

    Carpenter, R E; D'Silva, L A; Emery, S J; Uzun, O; Rassi, D; Lewis, M J

    2015-03-01

    The risk of new-onset arrhythmia during pregnancy is high, presumably relating to changes in both haemodynamic and cardiac autonomic function. The ability to non-invasively assess an individual's risk of developing arrhythmia during pregnancy would therefore be clinically significant. We aimed to quantify electrocardiographic temporal characteristics during the first trimester of pregnancy and to compare these with non-pregnant controls. Ninety-nine pregnant women and sixty-three non-pregnant women underwent non-invasive cardiovascular and haemodynamic assessment during a protocol consisting of various physiological states (postural manoeurvres, light exercise and metronomic breathing). Variables measured included stroke volume, cardiac output, heart rate, heart rate variability, QT and QT variability and QTVI (a measure of the variability of QT relative to that of RR). Heart rate (p pregnancy only during the supine position (p pregnancy in all physiological states (p pregnancy in all states (p pregnancy is associated with substantial changes in heart rate variability, reflecting a reduction in parasympathetic tone and an increase in sympathetic activity. QTVI shifted to a less favourable value, reflecting a greater than normal amount of QT variability. QTVI appears to be a useful method for quantifying changes in QT variability relative to RR (or heart rate) variability, being sensitive not only to physiological state but also to gestational age. We support the use of non-invasive markers of cardiac electrical variability to evaluate the risk of arrhythmic events in pregnancy, and we recommend the use of multiple physiological states during the assessment protocol.

  10. Evidence on climatic variability and prehistoric human activities between 165 B.C. and A.D. 1400 derived from subfossil Scots pines (Pinus sylvestris L. found in a lake in Utsjoki, northernmost Finland

    Directory of Open Access Journals (Sweden)

    Zetterberg, P.

    1994-12-01

    Full Text Available Samples from 1265 subfossil pines have been collected from small lakes and peat deposits in the forest-limit zone of northern Fennoscandia in order to study past variations of climate. Many of the subfossils have been dated by dendrochronology and the chronology constructed from the measured ring-width data extends as a continuous master curve from the present back until 165 B.C. and after a short gap until about 7000 years before the present time. This material has greatly increased the number of dated pine megafossils in northern Finland which had previously been restricted only to radiocarbon-dated samples. In addition to the year-by-year information provided by tree-ring width data, the temporal distribution of pine megafossils found in the vicinity of the forest-limit zone also provides information on past climatic changes. The 102 pine subfossils collected from Lake Ailigas, in Utsjoki, form part of the above material. They provide information about past variations in pine growth caused, to a large degree, by changing climate at this one site, but they also give glimpses of the local activities of Prehistoric Man. The data from 90 of these trees have been successfully dated using dendrochronological techniques and the results show that all of them grew during the time period beginning 3000 years before present, and that 79 pines lived during the time span 165 B.C. to A.D. 1952. In several lakes in the forest-limit zone, some subfossil trees are much older than those in Lake Ailigas. The relatively young ages of the subfossils at this site indicates that the lake has been in existence probably only during the past 3000 years, forming when climate turned more humid than in earlier times. The present continuous master curve is about 600 years longer than the earlier published pine chronology for northern Sweden, though this has recently been extended to A.D. 1. In the present study, the life spans of individual dated pines are considered in

  11. Progress report: Variable Energy Cyclotron Centre, Calcutta

    International Nuclear Information System (INIS)

    1999-01-01

    This volume of the progress report brings out the scientific and technical activities of Variable Energy Cyclotron Centre, Calcutta during the year 1999. This includes brief review of the various R and D activities of the Centre and outside users of the cyclotron from the universities and other research institutes. The operational activities of the cyclotron with ECR ion sources, accelerator oriented research activities, activities on detector, target and electronics are reported. The activities of the Computer and Informatics group are described. The status report of the ongoing projects is also provided. The main activities of the superconducting cyclotron project, radioactive ion beam project, heavy ion experimental facility, advanced computational facility, recovery and analysis of helium from hot springs and material science research are described

  12. Climate variability and change

    International Nuclear Information System (INIS)

    Manton, M.

    2006-01-01

    When Australia's climate should not be definite barrier to the population reaching 30 million by 2050, it is recognised that our climate has limited the development of the nation over the past 200 years. Indeed in 1911, based on a comparison of the climate and development between the US and Australia. Griffith Taylor predicted that Australia's population would be 19 million at the end of the 20th century, which is a pretty good 90-year forecast. The climate constraint is not only due to much of the country being semi-arid with an annual rainfall below 400 millimetres, but also due to the large year-to-year variability of rainfall across the country

  13. Variable cycle engine

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A.P.; Sprunger, E.V.

    1980-09-16

    A variable cycle turboshaft engine includes a remote fan system and respective high and low pressure systems for selectively driving the fan system in such a manner as to provide VTOL takeoff capability and minimum specific fuel consumption (SFC) at cruise and loiter conditions. For takeoff the fan system is primarily driven by the relatively large low pressure system whose combustor receives the motive fluid from a core bypass duct and, for cruise and loiter conditions, the fan system is driven by both a relatively small high pressure core and the low pressure system with its combustor inoperative. A mixer is disposed downstream of the high pressure system for mixing the relatively cold air from the bypass duct and the relatively hot air from the core prior to its flow to the low pressure turbine.

  14. Statistical variability of hydro-meteorological variables as indicators ...

    African Journals Online (AJOL)

    Statistical variability of hydro-meteorological variables as indicators of climate change in north-east Sokoto-Rima basin, Nigeria. ... water resources development including water supply project, agriculture and tourism in the study area. Key word: Climate change, Climatic variability, Actual evapotranspiration, Global warming ...

  15. Climate variability and change

    CERN Document Server

    Grassl, H

    1998-01-01

    Many factors influence climate. The present knowledge concerning the climate relevance of earth orbital parameters, solar luminosity, volcanoes, internal interactions, and human activities will be reported as well as the vulnerability of emission scenarios for given stabilization goals for greenhouse gas concentrations and the main points of the Kyoto Protocol

  16. The Performance of Variable Annuities

    OpenAIRE

    Michael J. McNamara; Henry R. Oppenheimer

    1991-01-01

    Variable annuities have become increasingly important in retirement plans. This paper provides an examination of the investment performance of variable annuities for the period year-end 1973 to year-end 1988. Returns, risk, and selectivity measures are analyzed for the sample of annuities, for individual variable annuities, and for subsamples of annuities with similar portfolio size and turnover. While the investment returns of variable annuities were greater than inflation over the period, t...

  17. Strong Decomposition of Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jørgensen, Jørgen; Kagan, Abram M.; Pitt, Loren D.

    2007-01-01

    A random variable X is stongly decomposable if X=Y+Z where Y=Φ(X) and Z=X-Φ(X) are independent non-degenerated random variables (called the components). It is shown that at least one of the components is singular, and we derive a necessary and sufficient condition for strong decomposability...... of a discrete random variable....

  18. Preservice Teachers' Understanding of Variable

    Science.gov (United States)

    Brown, Sue; Bergman, Judy

    2013-01-01

    This study examines the research on middle school students' understanding of variables and explores preservice elementary and middle school teachers' knowledge of variables. According to research studies, middle school students have limited understanding of variables. Many studies have examined the performance of middle school students and offered…

  19. Solar Variability Magnitudes and Timescales

    Science.gov (United States)

    Kopp, Greg

    2015-08-01

    The Sun’s net radiative output varies on timescales of minutes to many millennia. The former are directly observed as part of the on-going 37-year long total solar irradiance climate data record, while the latter are inferred from solar proxy and stellar evolution models. Since the Sun provides nearly all the energy driving the Earth’s climate system, changes in the sunlight reaching our planet can have - and have had - significant impacts on life and civilizations.Total solar irradiance has been measured from space since 1978 by a series of overlapping instruments. These have shown changes in the spatially- and spectrally-integrated radiant energy at the top of the Earth’s atmosphere from timescales as short as minutes to as long as a solar cycle. The Sun’s ~0.01% variations over a few minutes are caused by the superposition of convection and oscillations, and even occasionally by a large flare. Over days to weeks, changing surface activity affects solar brightness at the ~0.1% level. The 11-year solar cycle has comparable irradiance variations with peaks near solar maxima.Secular variations are harder to discern, being limited by instrument stability and the relatively short duration of the space-borne record. Proxy models of the Sun based on cosmogenic isotope records and inferred from Earth climate signatures indicate solar brightness changes over decades to millennia, although the magnitude of these variations depends on many assumptions. Stellar evolution affects yet longer timescales and is responsible for the greatest solar variabilities.In this talk I will summarize the Sun’s variability magnitudes over different temporal ranges, showing examples relevant for climate studies as well as detections of exo-solar planets transiting Sun-like stars.

  20. Variable angle correlation spectroscopy

    International Nuclear Information System (INIS)

    Lee, Y.K.; Lawrence Berkeley Lab., CA

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13 C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system

  1. Integration i flere variable

    DEFF Research Database (Denmark)

    Markvorsen, Steen

    2010-01-01

    Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum-integraler. Udgangspu......Denne note handler om parameterfremstillinger for kurver, flader og rumlige områder og om integration af funktioner på sådanne geometriske objekter. Formålet er primært at opstille og motivere de generelle definitioner og beregninger af henholdsvis kurve- \\, flade- \\, og rum......-integralerne. Undervejs introduceres \\texttt{Integrator8}. Det er en pakke med Maple procedurer, som er udviklet specielt med henblik på eksempelbaseret visuel læring af de indledende integrationsbegreber og deres mangfoldige anvendelser. Vi giver eksempler på, hvordan integration i flere variable anvendes til beregning...... og forståelse af rumfang, vægt, massemidtpunkter, inertimomenter, kraftmomenter, etc. Flowkurverne for et givet vektorfelt i rummet kan findes og visualiseres med \\texttt{Integrator8}. De vigtige begreber divergens og rotation for et vektorfelt fremtræder derved som naturlige størrelser til...

  2. Climate variability and climate change

    International Nuclear Information System (INIS)

    Rind, D.

    1990-01-01

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century

  3. Climate variability and climate change

    International Nuclear Information System (INIS)

    Rind, D.

    1991-01-01

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century. 19 refs.; 3 figs.; 2 tabs

  4. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  5. Structure and Evolution of Magnetic Cataclysmic Variables

    Science.gov (United States)

    Andronov, I. L.

    2007-06-01

    Theoretical models and observational results are reviewed. The general picture of the structure and evolution of cataclysmic variables (CV) is presented, together with a brief discussion of additional mechanisms of intrinsic variability of the components and magnetic activity of secondaries. Special attention is paid to the accretion structures - flow, disk, column - which are affected by the magnetic field of the white dwarf. The mass and angular momentum transfer in asynchronous MCVs leads to a "propeller" stage of rapid synchronization, after which the "idlings" of the white dwarf are altered to "swingings" with a characteristic time of century(ies). The disk- magnetic field interaction leads to precession of the white dwarf, which causes quasi-periodic changes of the equilibrium rotational period. "Shot noise" in cataclysmic variables is discussed based on one-bandpass and multi-color observations.

  6. Gaia DR1 documentation Chapter 6: Variability

    Science.gov (United States)

    Eyer, L.; Rimoldini, L.; Guy, L.; Holl, B.; Clementini, G.; Cuypers, J.; Mowlavi, N.; Lecoeur-Taïbi, I.; De Ridder, J.; Charnas, J.; Nienartowicz, K.

    2017-12-01

    This chapter describes the photometric variability processing of the Gaia DR1 data. Coordination Unit 7 is responsible for the variability analysis of over a billion celestial sources. In particular the definition, design, development, validation and provision of a software package for the data processing of photometrically variable objects. Data Processing Centre Geneva (DPCG) responsibilities cover all issues related to the computational part of the CU7 analysis. These span: hardware provisioning, including selection, deployment and optimisation of suitable hardware, choosing and developing software architecture, defining data and scientific workflows as well as operational activities such as configuration management, data import, time series reconstruction, storage and processing handling, visualisation and data export. CU7/DPCG is also responsible for interaction with other DPCs and CUs, software and programming training for the CU7 members, scientific software quality control and management of software and data lifecycle. Details about the specific data treatment steps of the Gaia DR1 data products are found in Eyer et al. (2017) and are not repeated here. The variability