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Sample records for activity rating pa-r

  1. PaR-PaR Laboratory Automation Platform

    SciTech Connect

    Linshiz, G; Stawski, N; Poust, S; Bi, CH; Keasling, JD; Hilson, NJ

    2013-05-01

    Labor-intensive multistep biological tasks, such as the construction and cloning of DNA molecules, are prime candidates for laboratory automation. Flexible and biology-friendly operation of robotic equipment is key to its successful integration in biological laboratories, and the efforts required to operate a robot must be much smaller than the alternative manual lab work. To achieve these goals, a simple high-level biology-friendly robot programming language is needed. We have developed and experimentally validated such a language: Programming a Robot (PaR-PaR). The syntax and compiler for the language are based on computer science principles and a deep understanding of biological workflows. PaR-PaR allows researchers to use liquid-handling robots effectively, enabling experiments that would not have been considered previously. After minimal training, a biologist can independently write complicated protocols for a robot within an hour. Adoption of PaR-PaR as a standard cross-platform language would enable hand-written or software-generated robotic protocols to be shared across laboratories.

  2. PaR-PaR laboratory automation platform.

    PubMed

    Linshiz, Gregory; Stawski, Nina; Poust, Sean; Bi, Changhao; Keasling, Jay D; Hillson, Nathan J

    2013-05-17

    Labor-intensive multistep biological tasks, such as the construction and cloning of DNA molecules, are prime candidates for laboratory automation. Flexible and biology-friendly operation of robotic equipment is key to its successful integration in biological laboratories, and the efforts required to operate a robot must be much smaller than the alternative manual lab work. To achieve these goals, a simple high-level biology-friendly robot programming language is needed. We have developed and experimentally validated such a language: Programming a Robot (PaR-PaR). The syntax and compiler for the language are based on computer science principles and a deep understanding of biological workflows. PaR-PaR allows researchers to use liquid-handling robots effectively, enabling experiments that would not have been considered previously. After minimal training, a biologist can independently write complicated protocols for a robot within an hour. Adoption of PaR-PaR as a standard cross-platform language would enable hand-written or software-generated robotic protocols to be shared across laboratories.

  3. Urinary-Type Plasminogen Activator Receptor (uPA/R)/α3β1 Integrin Signaling, Altered Gene Expression, and Oral Tumor Progression

    PubMed Central

    Ghosh, Supurna; Koblinski, Jennifer; Johnson, Jeffrey; Liu, Yueying; Ericsson, Aaron; Davis, J. Wade; Shi, Zonggao; Ravosa, Matthew J.; Crawford, Susan; Frazier, Shellaine; Stack, M. Sharon

    2009-01-01

    Oral squamous cell carcinoma (OSCC) has 50% 5-year survival rate, highlighting our limited understanding of the molecular events that contribute to disease progression. Microarray analyses of primary oral tumors have identified urinary type plasminogen activator (uPA) and its receptor (uPAR) as key genes associated with human OSCC progression. The uPAR functions both as a proteinase receptor and an integrin ligand, modifying proteolysis, migration, integrin signaling and cellular transcription. In the current study, uPAR expression levels were modified in OSCC cells, followed by analysis of tumor growth in an in vivo orthotopic xenograft model and by transcriptional profiling. Overexpression of uPAR resulted in more infiltrative and less differentiated tumors, with ill-defined borders, cytologic atypia, and enhanced vascularity. Analysis of serial sections of both murine experimental tumors and microarrayed human OSCC demonstrated a statistically significant association between uPAR and α3 integrin co-localization in areas exhibiting ERK phosphorylation, suggesting that uPAR/α3 integrin interaction potentiates ERK signaling in vivo. This is supported by cDNA microarray analysis which showed differential expression of 148 genes (113 up, 35 down). Validation of gene expression changes in human OSCC using immunohistochemistry and quantitative real-time PCR showed increased growth factors, proteinases/inhibitor and matrix components in uPAR-overexpressing tumors. Together these results support a model wherein increased uPAR expression promotes α3β1 integrin association, resulting in increased MAPK signaling and transcriptional activation, leading to the formation of more aggressive tongue tumors. This combined approach has efficacy to identify additional biomarkers and/or prognostic indicators associated with aggressive human OSCC. PMID:20145038

  4. Project Plan 7930 Cell G PaR Remote Handling System Replacement

    SciTech Connect

    Kinney, Kathryn A

    2009-10-01

    For over 40 years the US Department of Energy (DOE) and its predecessors have made Californium-252 ({sup 252}Cf) available for a wide range of industries including medical, nuclear fuels, mining, military and national security. The Radiochemical Engineering Development Center (REDC) located within the Oak Ridge National Laboratory (ORNL) processes irradiated production targets from the High Flux Isotope Reactor (HFIR). Operations in Building 7930, Cell G provide over 70% of the world's demand for {sup 252}Cf. Building 7930 was constructed and equipped in the mid-1960s. Current operations for {sup 252}Cf processing in Building 7930, Cell G require use of through-the-wall manipulators and the PaR Remote Handling System. Maintenance and repairs for the manipulators is readily accomplished by removal of the manipulator and relocation to a repair shop where hands-on work can be performed in glove boxes. Contamination inside cell G does not currently allow manned entry and no provisions were created for a maintenance area inside the cell. There has been no maintenance of the PaR system or upgrades, leaving operations vulnerable should the system have a catastrophic failure. The Cell G PaR system is currently being operated in a run to failure mode. As the manipulator is now 40+ years old there is significant risk in this method of operation. In 2006 an assessment was completed that resulted in recommendations for replacing the manipulator operator control and power centers which are used to control and power the PaR manipulator in Cell G. In mid-2008 the chain for the bridge drive failed and subsequent examinations indicated several damaged links (see Figure 1). To continue operations the PaR manipulator arm is being used to push and pull the bridge as a workaround. A retrieval tool was fabricated, tested and staged inside Cell G that will allow positioning of the bridge and manipulator arm for removal from the cell should the PaR system completely fail. A fully

  5. PaR Tensile Truss for Nuclear Decontamination and Decommissioning - 12467

    SciTech Connect

    Doebler, Gary R.

    2012-07-01

    Remote robotics and manipulators are commonly used in nuclear decontamination and decommissioning (D and D) processes. D and D robots are often deployed using rigid telescoping masts in order to apply and counteract side loads. However, for very long vertical reaches (15 meters or longer) and high lift capacities, a telescopic is usually not practical due to the large cross section and weight required to make the mast stiff and resist seismic forces. For those long vertical travel applications, PaR Systems has recently developed the Tensile Truss, a rigid, hoist-driven 'structure' that employs six independent wire rope hoists to achieve long vertical reaches. Like a mast, the Tensile Truss is typically attached to a bridge-mounted trolley and is used as a platform for robotic manipulators and other remotely operated tools. For suspended, rigid deployment of D and D tools with very long vertical reaches, the Tensile Truss can be a better alternative than a telescoping mast. Masts have length limitations that can make them impractical or unworkable as lengths increase. The Tensile Truss also has the added benefits of increased safety, ease of decontamination, superior stiffness and ability to withstand excessive side loading. A Tensile Truss system is currently being considered for D and D operations and spent fuel recovery at the Fukushima Daiichi Nuclear Power Plant in Japan. This system will deploy interchangeable tools such as underwater hydraulic manipulators, hydraulic shears and crushers, grippers and fuel grapples. (authors)

  6. Range 7 Scanner Integration with PaR Robot Scanning System

    NASA Technical Reports Server (NTRS)

    Schuler, Jason; Burns, Bradley; Carlson, Jeffrey; Minich, Mark

    2011-01-01

    An interface bracket and coordinate transformation matrices were designed to allow the Range 7 scanner to be mounted on the PaR Robot detector arm for scanning the heat shield or other object placed in the test cell. A process was designed for using Rapid Form XOR to stitch data from multiple scans together to provide an accurate 3D model of the object scanned. An accurate model was required for the design and verification of an existing heat shield. The large physical size and complex shape of the heat shield does not allow for direct measurement of certain features in relation to other features. Any imaging devices capable of imaging the entire heat shield in its entirety suffers a reduced resolution and cannot image sections that are blocked from view. Prior methods involved tools such as commercial measurement arms, taking images with cameras, then performing manual measurements. These prior methods were tedious and could not provide a 3D model of the object being scanned, and were typically limited to a few tens of measurement points at prominent locations. Integration of the scanner with the robot allows for large complex objects to be scanned at high resolution, and for 3D Computer Aided Design (CAD) models to be generated for verification of items to the original design, and to generate models of previously undocumented items. The main components are the mounting bracket for the scanner to the robot and the coordinate transformation matrices used for stitching the scanner data into a 3D model. The steps involve mounting the interface bracket to the robot's detector arm, mounting the scanner to the bracket, and then scanning sections of the object and recording the location of the tool tip (in this case the center of the scanner's focal point). A novel feature is the ability to stitch images together by coordinates instead of requiring each scan data set to have overlapping identifiable features. This setup allows models of complex objects to be developed

  7. Energy utilization rates during shuttle extravehicular activities.

    PubMed

    Waligora, J M; Kumar, K V

    1995-01-01

    The work rates or energy utilization rates during EVA are major factors in sizing of life support systems. These rates also provide a measure of ease of EVA and its cost in crew fatigue. From the first Shuttle EVA on the STS-6 mission in 1983, we have conducted 59 man-EVA and 341 man-hours of EVA. Energy utilization rates have been measured on each of these EVA. Metabolic rate was measured during each EVA using oxygen utilization corrected for suit leakage. From 1981-1987, these data were available for average data over the EVA or over large segments of the EVA. Since 1987, EVA oxygen utilization data were available at 2-minute intervals. The average metabolic rate on Shuttle EVA (194 kcal/hr.) has been significantly lower than metabolic rates during Apollo and Skylab missions. Peak rates have been below design levels, infrequent, and of short duration. The data suggest that the energy cost of tasks may be inversely related to the degree of training for the task. The data provide insight on the safety margins provided by life support designs and on the energy cost of Station construction EVA.

  8. Energy utilization rates during shuttle extravehicular activities.

    PubMed

    Waligora, J M; Kumar, K V

    1995-01-01

    The work rates or energy utilization rates during EVA are major factors in sizing of life support systems. These rates also provide a measure of ease of EVA and its cost in crew fatigue. From the first Shuttle EVA on the STS-6 mission in 1983, we have conducted 59 man-EVA and 341 man-hours of EVA. Energy utilization rates have been measured on each of these EVA. Metabolic rate was measured during each EVA using oxygen utilization corrected for suit leakage. From 1981-1987, these data were available for average data over the EVA or over large segments of the EVA. Since 1987, EVA oxygen utilization data were available at 2-minute intervals. The average metabolic rate on Shuttle EVA (194 kcal/hr.) has been significantly lower than metabolic rates during Apollo and Skylab missions. Peak rates have been below design levels, infrequent, and of short duration. The data suggest that the energy cost of tasks may be inversely related to the degree of training for the task. The data provide insight on the safety margins provided by life support designs and on the energy cost of Station construction EVA. PMID:11540993

  9. Rates of evaporation from swimming pools in active use

    SciTech Connect

    Smith, C.C.; Loef, G.O.G.; Jones, R.W.

    1998-10-01

    The rates of water evaporation from indoor and outdoor swimming pools in active use have been measured and compared with evaporation rates from unoccupied pools and with values calculated by the equation W = (95 + 0.425 v) (pw-pa)Y, where W is evaporation rate, lb/h ft{sup 2}; v is air velocity at water surface, ft/min.; pw is saturation vapor pressure at water temperature, in. Hg; pa is saturation vapor pressure at air dewpoint, in. Hg; and Y is latent heat at pool temperature, Btu/lb. In undisturbed pools, evaporation rates were measured and found to be 74% of the rates obtained by use of the equation. Rates of evaporation from pools in active use increase with the number of swimmers, rising 40--70% above the rates from a quiet water surface. Measurements of evaporation from a pool in use by 15--20 swimmers per 1,000 ft{sup 2} were found to average 26% higher than the rate calculated by the equation.

  10. Dilutional Control of Prothrombin Activation at Physiologically Relevant Shear Rates

    PubMed Central

    Haynes, Laura M.; Dubief, Yves C.; Orfeo, Thomas; Mann, Kenneth G.

    2011-01-01

    The generation of proteolyzed prothrombin species by preassembled prothrombinase in phospholipid-coated glass capillaries was studied at physiologic shear rates (100–1000 s−1). The concentration of active thrombin species (α-thrombin and meizothrombin) reaches a steady state, which varies inversely with shear rate. When corrected for shear rate, steady-state levels of active thrombin species exhibit no variation and a Michaelis-Menten analysis reveals that chemistry of this reaction is invariant between open and closed systems; collectively, these data imply that variations with shear rate arise from dilutional effects. Significantly, the major products observed include nonreactive species arising from the loss of prothrombin's phospholipid binding domain (des F1 species). A numerical model developed to investigate the spatial and temporal distribution of active thrombin species within the capillary reasonably approximates the observed output of total thrombin species at different shears; it also predicts concentrations of active thrombin species in the wall region sufficient to account for observed levels of des FI species. The predominant feedback formation of nonreactive species and high levels of the primarily anticoagulant intermediate meizothrombin (∼40% of total active thrombin species) may provide a mechanism to prevent thrombus propagation downstream of a site of thrombosis or hemorrhage. PMID:21281592

  11. Activity concentrations and dose rates from decorative granite countertops.

    PubMed

    Llope, W J

    2011-06-01

    The gamma radiation emitted from a variety of commercial decorative granites available for use in U.S. homes has been measured with portable survey meters as well as an NaI(Th) gamma spectrometer. The (40)K, U-nat, and (232)Th activity concentrations were determined using a full-spectrum analysis. The dose rates that would result from two different arrangements of decorative granite slabs as countertops were explored in simulations involving an adult anthropomorphic phantom.

  12. Global Earthquake Activity Rate models based on version 2 of the Global Strain Rate Map

    NASA Astrophysics Data System (ADS)

    Bird, P.; Kreemer, C.; Kagan, Y. Y.; Jackson, D. D.

    2013-12-01

    Global Earthquake Activity Rate (GEAR) models have usually been based on either relative tectonic motion (fault slip rates and/or distributed strain rates), or on smoothing of seismic catalogs. However, a hybrid approach appears to perform better than either parent, at least in some retrospective tests. First, we construct a Tectonic ('T') forecast of shallow (≤ 70 km) seismicity based on global plate-boundary strain rates from version 2 of the Global Strain Rate Map. Our approach is the SHIFT (Seismic Hazard Inferred From Tectonics) method described by Bird et al. [2010, SRL], in which the character of the strain rate tensor (thrusting and/or strike-slip and/or normal) is used to select the most comparable type of plate boundary for calibration of the coupled seismogenic lithosphere thickness and corner magnitude. One difference is that activity of offshore plate boundaries is spatially smoothed using empirical half-widths [Bird & Kagan, 2004, BSSA] before conversion to seismicity. Another is that the velocity-dependence of coupling in subduction and continental-convergent boundaries [Bird et al., 2009, BSSA] is incorporated. Another forecast component is the smoothed-seismicity ('S') forecast model of [Kagan & Jackson, 1994, JGR; Kagan & Jackson, 2010, GJI], which was based on optimized smoothing of the shallow part of the GCMT catalog, years 1977-2004. Both forecasts were prepared for threshold magnitude 5.767. Then, we create hybrid forecasts by one of 3 methods: (a) taking the greater of S or T; (b) simple weighted-average of S and T; or (c) log of the forecast rate is a weighted average of the logs of S and T. In methods (b) and (c) there is one free parameter, which is the fractional contribution from S. All hybrid forecasts are normalized to the same global rate. Pseudo-prospective tests for 2005-2012 (using versions of S and T calibrated on years 1977-2004) show that many hybrid models outperform both parents (S and T), and that the optimal weight on S

  13. Rate-invariant recognition of humans and their activities.

    PubMed

    Veeraraghavan, Ashok; Srivastava, Anuj; Roy-Chowdhury, Amit K; Chellappa, Rama

    2009-06-01

    Pattern recognition in video is a challenging task because of the multitude of spatio-temporal variations that occur in different videos capturing the exact same event. While traditional pattern-theoretic approaches account for the spatial changes that occur due to lighting and pose, very little has been done to address the effect of temporal rate changes in the executions of an event. In this paper, we provide a systematic model-based approach to learn the nature of such temporal variations (time warps) while simultaneously allowing for the spatial variations in the descriptors. We illustrate our approach for the problem of action recognition and provide experimental justification for the importance of accounting for rate variations in action recognition. The model is composed of a nominal activity trajectory and a function space capturing the probability distribution of activity-specific time warping transformations. We use the square-root parameterization of time warps to derive geodesics, distance measures, and probability distributions on the space of time warping functions. We then design a Bayesian algorithm which treats the execution rate function as a nuisance variable and integrates it out using Monte Carlo sampling, to generate estimates of class posteriors. This approach allows us to learn the space of time warps for each activity while simultaneously capturing other intra- and interclass variations. Next, we discuss a special case of this approach which assumes a uniform distribution on the space of time warping functions and show how computationally efficient inference algorithms may be derived for this special case. We discuss the relative advantages and disadvantages of both approaches and show their efficacy using experiments on gait-based person identification and activity recognition. PMID:19398409

  14. Stock price change rate prediction by utilizing social network activities.

    PubMed

    Deng, Shangkun; Mitsubuchi, Takashi; Sakurai, Akito

    2014-01-01

    Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as performance of simulated trading because success or failure of prediction is better measured by profits or losses the investors gain or suffer. In this paper, we propose a hybrid model that combines multiple kernel learning (MKL) and genetic algorithm (GA). MKL is adopted to optimize the stock price change rate prediction models that are expressed in a multiple kernel linear function of different types of features extracted from different sources. GA is used to optimize the trading rules used in the simulated trading by fusing the return predictions and values of three well-known overbought and oversold technical indicators. Accumulated return and Sharpe ratio were used to test the goodness of performance of the simulated trading. Experimental results show that our proposed model performed better than other models including ones using state of the art techniques.

  15. Stock Price Change Rate Prediction by Utilizing Social Network Activities

    PubMed Central

    Mitsubuchi, Takashi; Sakurai, Akito

    2014-01-01

    Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as performance of simulated trading because success or failure of prediction is better measured by profits or losses the investors gain or suffer. In this paper, we propose a hybrid model that combines multiple kernel learning (MKL) and genetic algorithm (GA). MKL is adopted to optimize the stock price change rate prediction models that are expressed in a multiple kernel linear function of different types of features extracted from different sources. GA is used to optimize the trading rules used in the simulated trading by fusing the return predictions and values of three well-known overbought and oversold technical indicators. Accumulated return and Sharpe ratio were used to test the goodness of performance of the simulated trading. Experimental results show that our proposed model performed better than other models including ones using state of the art techniques. PMID:24790586

  16. Stock price change rate prediction by utilizing social network activities.

    PubMed

    Deng, Shangkun; Mitsubuchi, Takashi; Sakurai, Akito

    2014-01-01

    Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as performance of simulated trading because success or failure of prediction is better measured by profits or losses the investors gain or suffer. In this paper, we propose a hybrid model that combines multiple kernel learning (MKL) and genetic algorithm (GA). MKL is adopted to optimize the stock price change rate prediction models that are expressed in a multiple kernel linear function of different types of features extracted from different sources. GA is used to optimize the trading rules used in the simulated trading by fusing the return predictions and values of three well-known overbought and oversold technical indicators. Accumulated return and Sharpe ratio were used to test the goodness of performance of the simulated trading. Experimental results show that our proposed model performed better than other models including ones using state of the art techniques. PMID:24790586

  17. Brownian aggregation rate of colloid particles with several active sites

    SciTech Connect

    Nekrasov, Vyacheslav M.; Yurkin, Maxim A.; Chernyshev, Andrei V.; Polshchitsin, Alexey A.; Yakovleva, Galina E.; Maltsev, Valeri P.

    2014-08-14

    We theoretically analyze the aggregation kinetics of colloid particles with several active sites. Such particles (so-called “patchy particles”) are well known as chemically anisotropic reactants, but the corresponding rate constant of their aggregation has not yet been established in a convenient analytical form. Using kinematic approximation for the diffusion problem, we derived an analytical formula for the diffusion-controlled reaction rate constant between two colloid particles (or clusters) with several small active sites under the following assumptions: the relative translational motion is Brownian diffusion, and the isotropic stochastic reorientation of each particle is Markovian and arbitrarily correlated. This formula was shown to produce accurate results in comparison with more sophisticated approaches. Also, to account for the case of a low number of active sites per particle we used Monte Carlo stochastic algorithm based on Gillespie method. Simulations showed that such discrete model is required when this number is less than 10. Finally, we applied the developed approach to the simulation of immunoagglutination, assuming that the formed clusters have fractal structure.

  18. In-core detector activation rate for a PWR assembly

    SciTech Connect

    Todosow, M.; Eisenhart, L.D.

    1982-01-01

    The in-core detector system is the principal source of information for determining relative assembly powers, and maximum fuel rod powers in a reactor core. The detector signals are used in conjunction with pre-calculated factors, and appropriate normalizations, to obtain measured power values. Considerable reliance is placed on the accuracy of in-core detector inferred power distributions in reactor operations, and in the verification of calculational methods. The objective of this study was to compare results from standard design codes for the in-core detector activation rate (and the fission rate distribution in an assembly), to results obtained from a detailed calculation performed with a continuous energy Monte Carlo program with ENDF/B-V nuclear data.

  19. ACCRETION RATE AND THE PHYSICAL NATURE OF UNOBSCURED ACTIVE GALAXIES

    SciTech Connect

    Trump, Jonathan R.; Impey, Christopher D.; Gabor, Jared M.; Diamond-Stanic, Aleksandar M.; Kelly, Brandon C.; Civano, Francesca; Hao, Heng; Lanzuisi, Giorgio; Merloni, Andrea; Salvato, Mara; Urry, C. Megan; Jahnke, Knud; Nagao, Tohru; Taniguchi, Yoshi; Koekemoer, Anton M.; Liu, Charles; Mainieri, Vincenzo; Scoville, Nick Z.

    2011-05-20

    We show how accretion rate governs the physical properties of a sample of unobscured broad-line, narrow-line, and lineless active galactic nuclei (AGNs). We avoid the systematic errors plaguing previous studies of AGN accretion rates by using accurate intrinsic accretion luminosities (L{sub int}) from well-sampled multiwavelength spectral energy distributions from the Cosmic Evolution Survey, and accurate black hole masses derived from virial scaling relations (for broad-line AGNs) or host-AGN relations (for narrow-line and lineless AGNs). In general, broad emission lines are present only at the highest accretion rates (L{sub int}/L{sub Edd} > 10{sup -2}), and these rapidly accreting AGNs are observed as broad-line AGNs or possibly as obscured narrow-line AGNs. Narrow-line and lineless AGNs at lower specific accretion rates (L{sub int}/L{sub Edd} < 10{sup -2}) are unobscured and yet lack a broad-line region. The disappearance of the broad emission lines is caused by an expanding radiatively inefficient accretion flow (RIAF) at the inner radius of the accretion disk. The presence of the RIAF also drives L{sub int}/L{sub Edd} < 10{sup -2} narrow-line and lineless AGNs to have ratios of radio-to-optical/UV emission that are 10 times higher than L{sub int}/L{sub Edd} > 10{sup -2} broad-line AGNs, since the unbound nature of the RIAF means it is easier to form a radio outflow. The IR torus signature also tends to become weaker or disappear from L{sub int}/L{sub Edd} < 10{sup -2} AGNs, although there may be additional mid-IR synchrotron emission associated with the RIAF. Together, these results suggest that specific accretion rate is an important physical 'axis' of AGN unification, as described by a simple model.

  20. Active microbreak effects on musculoskeletal comfort ratings in meatpacking plants.

    PubMed

    Genaidy, A M; Delgado, E; Bustos, T

    1995-02-01

    This study was conducted to examine whether a system of active microbreaks can reduce the discomfort perceived by employees in a meatpacking plant. Moreover, the relationship between the discomfort perceived on the job and musculoskeletal capability was investigated. Twenty-eight men employed in a local meatpacking plant participated in a study conducted over a period of four weeks. Results indicated that active microbreaks significantly reduced the level of discomfort perceived by employees during the course of the working day. The subjective ratings of perceived discomfort correlated significantly with anthropometric, strength and background information (R2 = 0.66). The physical characteristics of Caucasian employees were higher than those of their Hispanic counterparts. Moreover, the physical characteristics of meatpacking employees were significantly lower than those reported in the literature for employees engaged in manual handling tasks. PMID:7895738

  1. Effect of sedentary activities on resting metabolic rate.

    PubMed

    Dietz, W H; Bandini, L G; Morelli, J A; Peers, K F; Ching, P L

    1994-03-01

    We examined the effect of television viewing on resting metabolic rate (RMR) in a cohort of 9 obese and 18 nonobese girls aged 10.4 +/- 1.1 y. RMR was measured while girls watched television, read, or sat quietly for 15 min. Movement was assessed by using activity monitors and a manual count of movements observed on a videotape. Absolute RMR was greater for the obese girls, but no significant treatment effect existed for absolute RMR within either group. Although measured activity did not differ, observed movements were greater when the girls were sitting quietly. Total observed and measured movements were significantly correlated with the CV of the minute-by-minute RMR. These results suggest that television viewing does not alter RMR. Although children appear to fidget more when sitting quietly than when they read or watch television, fidgeting appears to affect the minute-to-minute variation of RMR rather than the level of resting energy expenditure.

  2. Production of carboxylates from high rate activated sludge through fermentation.

    PubMed

    Cagnetta, C; Coma, M; Vlaeminck, S E; Rabaey, K

    2016-10-01

    The aim of this work was to study the key parameters affecting fermentation of high rate activated A-sludge to carboxylates, including pH, temperature, inoculum, sludge composition and iron content. The maximum volatile fatty acids production was 141mgCg(-1) VSSfed, at pH 7. Subsequently the potential for carboxylate and methane production for A-sludge from four different plants at pH 7 and 35°C were compared. Initial BOD of the sludge appeared to be key determining carboxylate yield from A-sludge. Whereas methanogenesis could be correlated linearly to the quantity of ferric used for coagulation, fermentation did not show a dependency on iron presence. This difference may enable a strategy whereby A-stage sludge is separated to achieve fermentation, and iron dosing for phosphate removal is only implemented at the B-stage. PMID:27020399

  3. The star formation rates of active galactic nuclei host galaxies

    NASA Astrophysics Data System (ADS)

    Ellison, Sara L.; Teimoorinia, Hossen; Rosario, David J.; Mendel, J. Trevor

    2016-05-01

    Using artificial neural network predictions of total infrared luminosities (LIR), we compare the host galaxy star formation rates (SFRs) of ˜21 000 optically selected active galactic nuclei (AGN), 466 low-excitation radio galaxies (LERGs) and 721 mid-IR-selected AGN. SFR offsets (ΔSFR) relative to a sample of star-forming `main-sequence' galaxies (matched in M⋆, z and local environment) are computed for the AGN hosts. Optically selected AGN exhibit a wide range of ΔSFR, with a distribution skewed to low SFRs and a median ΔSFR = -0.06 dex. The LERGs have SFRs that are shifted to even lower values with a median ΔSFR = -0.5 dex. In contrast, mid-IR-selected AGN have, on average, SFRs enhanced by a factor of ˜1.5. We interpret the different distributions of ΔSFR amongst the different AGN classes in the context of the relative contribution of triggering by galaxy mergers. Whereas the LERGs are predominantly fuelled through low accretion rate secular processes which are not accompanied by enhancements in SFR, mergers, which can simultaneously boost SFRs, most frequently lead to powerful, obscured AGN.

  4. SOLAR ROTATION RATE DURING THE CYCLE 24 MINIMUM IN ACTIVITY

    SciTech Connect

    Antia, H. M.; Basu, Sarbani E-mail: sarbani.basu@yale.ed

    2010-09-01

    The minimum of solar cycle 24 is significantly different from most other minima in terms of its duration as well as its abnormally low levels of activity. Using available helioseismic data that cover epochs from the minimum of cycle 23 to now, we study the differences in the nature of the solar rotation between the minima of cycles 23 and 24. We find that there are significant differences between the rotation rates during the two minima. There are differences in the zonal-flow pattern too. We find that the band of fast rotating region close to the equator bifurcated around 2005 and recombined by 2008. This behavior is different from that during the cycle 23 minimum. By autocorrelating the zonal-flow pattern with a time shift, we find that in terms of solar dynamics, solar cycle 23 lasted for a period of 11.7 years, consistent with the result of Howe et al. (2009). The autocorrelation coefficient also confirms that the zonal-flow pattern penetrates through the convection zone.

  5. Study of coolant activation and dose rates with flow rate and power perturbations in pool-type research reactors

    SciTech Connect

    Mirza, N.M.; Mirza, S.M.; Ahmad, N. )

    1991-12-01

    This paper reports on a computer code using the multigroup diffusion theory based LEOPARD and ODMUG programs that has been developed to calculate the activity in the coolant leaving the core of a pool-type research reactor. Using this code, the dose rates at various locations along the coolant path with varying coolant flow rate and reactor power perturbations are determined. A flow rate decrease from 1000 to 145 m{sup 3}/h is considered. The results indicate that a flow rate decrease leads to an increase in the coolant outlet temperature, which affects the neutron group constants and hence the group fluxes. The activity in the coolant leaving the core increases with flow rate decrease. However, at the inlet of the holdup tank, the total dose rate first increases, then passes through a maximum at {approximately} 500 m{sup 3}/h, and finally decreases with flow rate decrease. The activity at the outlet of the holdup tank is mainly due to {sup 24}Na and {sup 56}Mn, and it increases by {approximately} 2% when the flow rate decreases from 1000 to 145 m{sup 3}/h. In an accidental power rise at constant flow rate, the activity in the coolant increases, and the dose rates at all the points along the coolant path show a slight nonlinear rise as the reactor power density increases.

  6. Distinguishing fall activities from normal activities by angular rate characteristics and high-speed camera characterization.

    PubMed

    Nyan, M N; Tay, F E H; Tan, A W Y; Seah, K H W

    2006-10-01

    Distinguishing sideways and backward falls from normal activities of daily living using angular rate sensors (gyroscopes) was explored in this paper. Gyroscopes were secured on a shirt at the positions of sternum (S), front of the waist (FW) and right underarm (RU) to measure angular rate in lateral and sagittal planes of the body during falls and normal activities. Moreover, the motions of the fall incidents were captured by a high-speed camera at a frame rate of 250 frames per second (fps) to study the body configuration during fall. The high-speed camera and the sensor data capture system were activated simultaneously to synchronize the picture frame of high-speed camera and the sensor data. The threshold level for each sensor was set to distinguish fall activities from normal activities. Lead time of fall activities (time after threshold value is surpassed to the time when the hip hits the ground) and relative angle of body configuration (angle beta between the vertical line and the line from the center point of the foot or the center point between the two legs to that of the waist) at the threshold level were studied. For sideways falls, lead times of sensors at positions FW and S were about 200-220ms and 135-182ms, respectively. The lead time of the slippery backward fall (about 98ms) from the sensor at position RU was shorter than that of the sideways falls from the sensors at positions FW and S. The relative angle of body configuration at threshold level for sideways and backward falls were about 40-43 degrees for the sensor at position FW, about 43-52 degrees for the sensor at position S and about 54 degrees for the sensor at position RU, respectively. This is the first study that investigates fall dynamics in detection of fall before the person hits the ground using angular rate sensors (gyroscopes). PMID:16406739

  7. Rates of Physical Activity among Appalachian Adolescents in Ohio

    ERIC Educational Resources Information Center

    Hortz, Brian; Stevens, Emily; Holden, Becky; Petosa, R. Lingyak

    2009-01-01

    Purpose: The purpose of this study was to describe the physical activity behavior of high school students living in the Appalachian region of Ohio. Methods: A cross-sectional sample of 1,024 subjects from 11 schools in Appalachian Ohio was drawn. Previously validated instruments were used to measure physical activity behavior over 7 days.…

  8. A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

    PubMed

    Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

    2016-04-01

    How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation.

  9. A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

    PubMed

    Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

    2016-04-01

    How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation. PMID:27052834

  10. Active Supervision and Its Impact upon Parolee Recidivism Rates

    ERIC Educational Resources Information Center

    Ostermann, Michael

    2013-01-01

    Studies that compare recidivism rates between parolees and unconditionally released inmates typically attach these statuses upon release, and then follow these groups until they either fail or meet the censor date. However, this method of identifying former inmates as parolees does not comport with how parolees are conceptualized by the agencies…

  11. Resonance of about-weekly human heart rate rhythm with solar activity change.

    PubMed

    Cornelissen, G; Halberg, F; Wendt, H W; Bingham, C; Sothern, R B; Haus, E; Kleitman, E; Kleitman, N; Revilla, M A; Revilla, M; Breus, T K; Pimenov, K; Grigoriev, A E; Mitish, M D; Yatsyk, G V; Syutkina, E V

    1996-12-01

    In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

  12. Development of a therapist activity rating scale: preliminary findings.

    PubMed

    Conte, H R; Plutchik, R; Picard, S; Karasu, T B

    1993-06-01

    A 61-item scale was constructed of relatively explicit descriptions of behavior in which a psychotherapist might engage. The scale is largely noninferential, is basically atheoretical but applicable to psychodynamically oriented therapy, may be completed by either the therapist or an independent rater with minimal training, and may be used to rate entire therapy sessions or specific segments of sessions. The scale shows high interrater reliability and discriminant validity. PMID:8337316

  13. ACTIVE: a program to calculate and plot reaction rates from ANISN calculated fluxes

    SciTech Connect

    Judd, J.L.

    1981-12-01

    The ACTIVE code calculates spatial heating rates, tritium production rates, neutron reaction rates, and energy spectra from particle fluxes calculated by ANISN. ACTIVE has a variety of input options including the capability to plot all calculated spatial distributions. The code was primarily designed for use with fusion first wall/blanket systems, but could be applied to any one-dimensional problem.

  14. Physical Activity in Individuals with Severe Mental Illness: Client versus Case Manager Ratings

    ERIC Educational Resources Information Center

    Bezyak, Jill L.; Chan, Fong; Lee, Eun-Jeong; Catalano, Denise; Chiu, Chung-Yi

    2012-01-01

    The "Physical Activity Scale for Individuals With Physical Disabilities" was examined as a physical activity measure for people with severe mental illness. Case manager ratings were more closely related to body mass index than clients' ratings, challenging the accuracy of self-report physical activity measures for individuals with severe mental…

  15. 77 FR 38397 - Agency Information Collection (Interest Rate Reduction Refinancing Loan Worksheet) Activities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Interest Rate Reduction Refinancing Loan Worksheet) Activities....'' SUPPLEMENTARY INFORMATION: Title: Interest Rate Reduction Refinancing Loan Worksheet, VA Form 26-8923....

  16. Multivariate speech activity dector based on the syllable rate

    NASA Astrophysics Data System (ADS)

    Smith, David C.; Townsend, Jeffrey N.; Nelson, Douglas J.

    1998-10-01

    Computationally efficient algorithms which perform speech activity detection have significant potential economic and labor saving benefit, by automating an extremely tedious manual process. In many applications, it is desirable to extract intervals of speech which are obtained by segments of other signal types. In the past, algorithms which successfully discriminate between speech and one specific other signal type have been developed. Frequently, these algorithms fail when the specific non-speech signal is replaced by a different non-speech discrimination problem. Typically, several signal specific discriminators are blindly combined with predictable negative results. Moreover, when a large number of discriminators are involved, dimensions reduction is achieved using Principal Components, which optimally compresses signal variance into the fewest number of dimensions. Unfortunately, these new coordinates are not necessarily optimal for discrimination. In this paper we apply graphical tools to determine a set of discriminators which produce excellent speech vs. non-clustering, thereby eliminating the guesswork in selecting good feature vectors. This cluster structure provides a basis for a general multivariate speech vs. non-speech discriminator, which compares very favorably with the TALKATIVE speech extraction algorithm.

  17. Validation of Algorithms for Basal Insulin Rate Reductions in Type 1 Diabetic Patients Practising Physical Activity

    ClinicalTrials.gov

    2013-04-19

    Type 1 Diabetes With a Subcutaneous Insulin Pump; Adjustment of the Recommended Basal Insulin Flow Rate in the Event of Physical Activity; Adjustment of the Recommended Prandial Insulin in the Event of Physical Activity

  18. The relationship between body temperature, heart rate, breathing rate, and rate of oxygen consumption, in the tegu lizard (Tupinambis merianae) at various levels of activity.

    PubMed

    Piercy, Joanna; Rogers, Kip; Reichert, Michelle; Andrade, Denis V; Abe, Augusto S; Tattersall, Glenn J; Milsom, William K

    2015-12-01

    The present study determined whether EEG and/or EMG recordings could be used to reliably define activity states in the Brazilian black and white tegu lizard (Tupinambis merianae) and then examined the interactive effects of temperature and activity states on strategies for matching O2 supply and demand. In a first series of experiments, the rate of oxygen consumption (VO2), breathing frequency (fR), heart rate (fH), and EEG and EMG (neck muscle) activity were measured in different sleep/wake states (sleeping, awake but quiet, alert, or moving). In general, metabolic and cardio-respiratory changes were better indictors of the transition from sleep to wake than were changes in the EEG and EMG. In a second series of experiments, the interactive effects of temperature (17, 27 and 37 °C) and activity states on fR, tidal volume (VT), the fraction of oxygen extracted from the lung per breath (FIO2-FEO2), fH, and the cardiac O2 pulse were quantified to determine the relative roles of each of these variables in accommodating changes in VO2. The increases in oxygen supply to meet temperature- and activity-induced increases in oxygen demand were produced almost exclusively by increases in fH and fR. Regression analysis showed that the effects of temperature and activity state on the relationships between fH, fR and VO2 was to extend a common relationship along a single curve, rather than separate relationships for each metabolic state. For these lizards, the predictive powers of fR and fH were maximized when the effects of changes in temperature, digestive state and activity were pooled. However, the best r(2) values obtained were 0.63 and 0.74 using fR and fH as predictors of metabolic rate, respectively.

  19. The relationship between body temperature, heart rate, breathing rate, and rate of oxygen consumption, in the tegu lizard (Tupinambis merianae) at various levels of activity.

    PubMed

    Piercy, Joanna; Rogers, Kip; Reichert, Michelle; Andrade, Denis V; Abe, Augusto S; Tattersall, Glenn J; Milsom, William K

    2015-12-01

    The present study determined whether EEG and/or EMG recordings could be used to reliably define activity states in the Brazilian black and white tegu lizard (Tupinambis merianae) and then examined the interactive effects of temperature and activity states on strategies for matching O2 supply and demand. In a first series of experiments, the rate of oxygen consumption (VO2), breathing frequency (fR), heart rate (fH), and EEG and EMG (neck muscle) activity were measured in different sleep/wake states (sleeping, awake but quiet, alert, or moving). In general, metabolic and cardio-respiratory changes were better indictors of the transition from sleep to wake than were changes in the EEG and EMG. In a second series of experiments, the interactive effects of temperature (17, 27 and 37 °C) and activity states on fR, tidal volume (VT), the fraction of oxygen extracted from the lung per breath (FIO2-FEO2), fH, and the cardiac O2 pulse were quantified to determine the relative roles of each of these variables in accommodating changes in VO2. The increases in oxygen supply to meet temperature- and activity-induced increases in oxygen demand were produced almost exclusively by increases in fH and fR. Regression analysis showed that the effects of temperature and activity state on the relationships between fH, fR and VO2 was to extend a common relationship along a single curve, rather than separate relationships for each metabolic state. For these lizards, the predictive powers of fR and fH were maximized when the effects of changes in temperature, digestive state and activity were pooled. However, the best r(2) values obtained were 0.63 and 0.74 using fR and fH as predictors of metabolic rate, respectively. PMID:26285591

  20. The influence of sensor orientation on activity-based rate responsive pacing. Sensor Orientation Study Group.

    PubMed

    Theres, H; Philippon, F; Melzer, C; Combs, W; Prest-Berg, K

    1998-11-01

    Piezoelectric activity-based rate responsive pacemakers are commonly implanted with the sensor facing inward. This study was conducted to assess the safe and effective rate response of an activity-based rate responsive pacemaker implanted with the sensor facing outward. A comparison were made to a previously studied patient group with sensor facing inward. Patient and pacemaker data was collected at predischarge and 2-month follow-up. Two-minute hall walks in conjunction with programmer-assisted rate response assessment were utilized to standardize initial rate response parameter settings for both patient groups. At 2-month follow-up, sensor rate response to a stage 3 limited CAEP protocol was recorded. Adequate sensor rate response was achieved for both patient groups. No difference was noted in reported patient complications for both groups. A statistically significant difference in programmed rate response curve setting and activity threshold for the two groups was noted at 2-month follow-up. Adequate sensor rate response was achieved for a patient population implanted with an activity-based rate responsive pacemaker with sensor facing outward. In this orientation, one higher rate response curve setting and an activity threshold one value more sensitive were required on average when compared to the normal sensor orientation group. PMID:9826862

  1. Middle School Student's Heart Rates during Different Curricular Activities in Physical Education

    ERIC Educational Resources Information Center

    Gao, Zan; Hannon, James C.; Carson, Russell L.

    2009-01-01

    The purpose of this study was to determine if students' heart rate outcomes in physical education varied as a function of activity and grade. A total of 146 sixth to eighth graders participated in different activities (i.e., walking/jogging, line dancing, soccer, and catch ball). Their average heart rate (AHR) and percentage of time in and above…

  2. Heart Rates of High School Physical Education Students during Team Sports, Individual Sports, and Fitness Activities

    ERIC Educational Resources Information Center

    Laurson, Kelly R.; Brown, Dale D.; Cullen, Robert W.; Dennis, Karen K.

    2008-01-01

    This study examined how activity type influenced heart rates and time spent in target heart rate zones of high school students participating in physical education classes. Significantly higher average heart rates existed for fitness (142 plus or minus 24 beats per minute [bpm]) compared to team (118 plus or minus 24 bpm) or individual (114 plus or…

  3. How the heterogeneous infection rate effect on the epidemic spreading in activity-driven network

    NASA Astrophysics Data System (ADS)

    Han, Dun; Li, Dandan; Chen, Chao; Sun, Mei

    2016-01-01

    In this paper, we research the impact of the heterogeneous infection rate on the epidemic spread in the activity-driven networks. By using the mean field approximation, the epidemic threshold is theoretically obtained. Several immunization strategies that could curb the epidemic spread are presented. Based on the theoretical analysis and simulation results, we obtain that the epidemic would be prevented effectively if the infection rate strongly correlates with the individual activity. However, if infection rate has a little correlation with the individual activity, most of the individuals may be infected. In addition, the epidemic can be suppressed soon if the individuals with high activity are immunized preferentially.

  4. Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

    PubMed

    Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

    2015-01-01

    Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms.

  5. Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

    PubMed

    Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

    2015-01-01

    Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. PMID:26177621

  6. The solar cycle variation of the rates of CMEs and related activity

    NASA Technical Reports Server (NTRS)

    Webb, David F.

    1991-01-01

    Coronal mass ejections (CMEs) are an important aspect of the physics of the corona and heliosphere. This paper presents results of a study of occurrence frequencies of CMEs and related activity tracers over more than a complete solar activity cycle. To properly estimate occurrence rates, observed CME rates must be corrected for instrument duty cycles, detection efficiencies away from the skyplane, mass detection thresholds, and geometrical considerations. These corrections are evaluated using CME data from 1976-1989 obtained with the Skylab, SMM and SOLWIND coronagraphs and the Helios-2 photometers. The major results are: (1) the occurrence rate of CMEs tends to track the activity cycle in both amplitude and phase; (2) the corrected rates from different instruments are reasonably consistent; and (3) over the long term, no one class of solar activity tracer is better correlated with CME rate than any other (with the possible exception of type II bursts).

  7. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... activated carbon? 60.1330 Section 60.1330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Requirements § 60.1330 How do I monitor the injection rate of activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet...

  8. 38 CFR 4.22 - Rating of disabilities aggravated by active service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... aggravated by active service. 4.22 Section 4.22 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... aggravated by active service. In cases involving aggravation by active service, the rating will reflect only the degree of disability over and above the degree existing at the time of entrance into the...

  9. 38 CFR 4.22 - Rating of disabilities aggravated by active service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... aggravated by active service. 4.22 Section 4.22 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... aggravated by active service. In cases involving aggravation by active service, the rating will reflect only the degree of disability over and above the degree existing at the time of entrance into the...

  10. 38 CFR 4.22 - Rating of disabilities aggravated by active service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... aggravated by active service. 4.22 Section 4.22 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... aggravated by active service. In cases involving aggravation by active service, the rating will reflect only the degree of disability over and above the degree existing at the time of entrance into the...

  11. 38 CFR 4.22 - Rating of disabilities aggravated by active service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... aggravated by active service. 4.22 Section 4.22 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... aggravated by active service. In cases involving aggravation by active service, the rating will reflect only the degree of disability over and above the degree existing at the time of entrance into the...

  12. 38 CFR 4.22 - Rating of disabilities aggravated by active service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... aggravated by active service. 4.22 Section 4.22 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... aggravated by active service. In cases involving aggravation by active service, the rating will reflect only the degree of disability over and above the degree existing at the time of entrance into the...

  13. Comparing Participants' Rating and Compendium Coding to Estimate Physical Activity Intensities

    ERIC Educational Resources Information Center

    Masse, Louise C.; Eason, Karen E.; Tortolero, Susan R.; Kelder, Steven H.

    2005-01-01

    This study assessed agreement between participants' rating (PMET) and compendium coding (CMET) of estimating physical activity intensity in a population of older minority women. As part of the Women on the Move study, 224 women completed a 7-day activity diary and wore an accelerometer for 7 days. All activities recorded were coded using PMET and…

  14. 40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or... dioxins/furans and mercury stack test, determine the average carbon feed rate in kilograms (or pounds)...

  15. Cardiovascular and Cerebrovascular Control on Return from International Space Station (CCISS)- Heart Rate and Activity

    NASA Astrophysics Data System (ADS)

    Hughson, R. L.; Shoemaker, J. K.; Blaber, A. P.; Arbeille, Ph.; Zuj, K. A.; Greaves, D. K.

    2008-06-01

    CCISS is a project to study the cardiovascular and cerebrovascular responses of astronauts before, during and after long-duration (>60-day) stays on the International Space Station. The CCISS experiments consist of three phases that are designed to achieve an integrated examination of components responsible for return of blood to the heart, the pumping of blood from the heart and the distribution to the vascular territories including the brain. In this report the data are obtained from the 24-h monitoring of physical activity (Actiwatch on wrist and ankle) and of heart rate (Holter monitor). The data show clear patterns of change in physical activity from predominantly leg-based on Earth to relatively little activity of the ankles with maintained or increased activity of the wrists on ISS. Both on Earth and on ISS the largest changes in heart rate occur during the periods of leg activity. Average heart rate was changed little during the periods of minimal activity or of sleep in comparisons of Earth with in-flight recording both within the first two weeks of flight and the last two weeks. These data clearly show the importance of monitoring heart rate and physical activity simultaneously and show that attempts to derive indicators of autonomic activity from spectral analysis of heart rate variability should not be performed in the absence of knowledge of both variables.

  16. Relationship between the electrochemical activity of Raney nickel and the rate of hydrogenation of maleic acid

    SciTech Connect

    Pervii, E.N.; Sofronkov, A.N.; Fedyshina, N.M.

    1986-02-10

    The purpose of this investigation was to determine the conditions in which a direct correlation exists between the rate of hydrogenation of maleic acid and the electrochemical activity of catalysts of hydrogen ionization. The rate of maleic acid hydrogenation in presence of Raney nickel catalyst was studied by a combination of volumetric and potentiometric methods.

  17. The active metabolic rate predicts a male spider's proximity to females and expected fitness.

    PubMed

    Kasumovic, Michael M; Seebacher, Frank

    2013-04-23

    Conspicuous traits, such as weaponry and body size, are often correlated with fitness. By contrast, we understand less about how inconspicuous physiological traits affect fitness. Not only is linking physiology directly to fitness a challenge, but in addition, behavioural studies most often focus on resting or basal metabolic rates, resulting in a poor understanding of how active metabolic rates affect fitness. Here we use the golden orb-web spider (Nephila plumipes), a species for which proximity to a female on the web predicts a male's paternity share, to examine the role of resting and active metabolic rates in fitness. Using a semi-natural experimental set-up, we show that males closer to a female have higher active metabolic rates than males further from females. This higher metabolic activity is paralleled by increased citrate synthase activity, suggesting greater mitochondrial densities. Our results link both higher active metabolic rates and increased citrate synthase activity with fitness. Coupled with the behaviour and life history of N. plumipes, these results provide insight into the evolution of physiological systems.

  18. Association of Orofacial Muscle Activity and Movement during Changes in Speech Rate and Intensity

    ERIC Educational Resources Information Center

    McClean, Michael D.; Tasko, Stephen M.

    2003-01-01

    Understanding how orofacial muscle activity and movement covary across changes in speech rate and intensity has implications for the neural control of speech production and the use of clinical procedures that manipulate speech prosody. The present study involved a correlation analysis relating average lower-lip and jaw-muscle activity to lip and…

  19. CK2 activity is modulated by growth rate in Saccharomyces cerevisiae

    SciTech Connect

    Tripodi, Farida; Cirulli, Claudia; Reghellin, Veronica; Marin, Oriano; Brambilla, Luca; Schiappelli, Maria Patrizia; Porro, Danilo; Vanoni, Marco; Alberghina, Lilia; Coccetti, Paola

    2010-07-16

    Research highlights: {yields} CK2 subunits are nuclear both in glucose and in ethanol growing yeast cells. {yields} CK2 activity is modulated in S. cerevisiae. {yields} CK2 activity is higher in conditions supporting higher growth rates. {yields} V{sub max} is higher in faster growing cells, while K{sub m} is not affected. -- Abstract: CK2 is a highly conserved protein kinase controlling different cellular processes. It shows a higher activity in proliferating mammalian cells, in various types of cancer cell lines and tumors. The findings presented herein provide the first evidence of an in vivo modulation of CK2 activity, dependent on growth rate, in Saccharomyces cerevisiae. In fact, CK2 activity, assayed on nuclear extracts, is shown to increase in exponential growing batch cultures at faster growth rate, while localization of catalytic and regulatory subunits is not nutritionally modulated. Differences in intracellular CK2 activity of glucose- and ethanol-grown cells appear to depend on both increase in molecule number and k{sub cat}. Also in chemostat cultures nuclear CK2 activity is higher in faster growing cells providing the first unequivocal demonstration that growth rate itself can affect CK2 activity in a eukaryotic organism.

  20. Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

    USGS Publications Warehouse

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2014-01-01

    An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

  1. Vibration, acceleration, gravitation, and movement: activity controlled rate adaptive pacing during treadmill exercise testing and daily life activities.

    PubMed

    Candinas, R; Jakob, M; Buckingham, T A; Mattmann, H; Amann, F W

    1997-07-01

    Activity-based sensors for rate adaptive pacing have been available for several years and now include several different types: vibration; acceleration; gravitation; and movement. However, a systematic comparison evaluating the relative advantages and disadvantages of these various sensors has received little study. The purpose of the present study was to compare these sensor subtypes using treadmill testing and an outdoor test circuit, which simulated daily life activities and included both uphill and downhill walking. Pacemakers were strapped on the chest of healthy volunteers and connected to one channel of an ambulatory recording device, which also recorded the subject's intrinsic heart rate. The pacemakers were programmed using an initial treadmill test to standardize the rate responsive parameters for each device. Nine different pacemaker models were studied including 3 vibration-based (Elite, Synchrony, Metros), 4 acceleration-based (Relay, Excel, Ergos, Trilogy), 1 gravitational-based (Swing), and 1 movement-based (Sensorithm) device. All devices demonstrated a prompt rate response with casual walking on flat ground. The vibration-, gravitational-, and movement-based pacemakers showed a pronounced rate decline during more strenuous work, e.g., walking uphill. This phenomenon was absent in the accelerometer-based units. In particular, the vibration- and movement-based units showed a higher rate with walking downhill compared to uphill. An optimally tuned rate behavior on the treadmill usually did not provide an optimal rate behavior during daily activities and there was a tendency to overstimulation during low workload. The development of the two newest sensors (gravitational and movement) did not result in an improved performance of rate response behavior. Overall, the accelerometer-based pacemakers simulated or paralleled sinus rate behavior the most closely.

  2. Relationship between self-reported activity levels and actual heart rates in teenagers

    SciTech Connect

    Terblanche, A.P.S.; Ozkaynak, H.; Spengler, J.D.; Butler, D.A. )

    1991-08-01

    A study was designed to explore the relationship between self-reported activity levels and actual heart rate (HR) as measured by a portable heart rate monitor. Twenty-two teenagers (8 boys, 14 girls, median age of 16) from Watertown High School, Massachusetts participated in this pilot study which involved continuous monitoring of HR during normal daily activities and simultaneous completion of a time-activity diary. There were 31 successful monitoring sessions ranging from 1.9 to 17 hours with a median monitoring time of 12.6 hours. Four unsuccessful monitoring sessions were experienced due to equipment failure. Apart from participant cooperation, the single most important factor affecting the feasibility of continuous heart rate monitoring was found to be equipment design. Th overall average heart rate observed was 88.4 bpm (SD = 24.3). An individual's correlation coefficient for perceived activity level (documented in half-hour intervals) and heart rate (averaged over the half-hour intervals) varied from 0.24 to 0.89. More than half of the correlation coefficients were below 0.40. There was a significant difference between average heart rate for time spent indoors (90 bpm) versus outdoors (103 bpm) even after correcting for sleeping time. It is concluded that continuous HR monitoring with simultaneous completion of a time/activity dairy is feasible and is a promising source of information for studies on exposure to air pollutants.

  3. Improving consumption rate estimates by incorporating wild activity into a bioenergetics model.

    PubMed

    Brodie, Stephanie; Taylor, Matthew D; Smith, James A; Suthers, Iain M; Gray, Charles A; Payne, Nicholas L

    2016-04-01

    Consumption is the basis of metabolic and trophic ecology and is used to assess an animal's trophic impact. The contribution of activity to an animal's energy budget is an important parameter when estimating consumption, yet activity is usually measured in captive animals. Developments in telemetry have allowed the energetic costs of activity to be measured for wild animals; however, wild activity is seldom incorporated into estimates of consumption rates. We calculated the consumption rate of a free-ranging marine predator (yellowtail kingfish, Seriola lalandi) by integrating the energetic cost of free-ranging activity into a bioenergetics model. Accelerometry transmitters were used in conjunction with laboratory respirometry trials to estimate kingfish active metabolic rate in the wild. These field-derived consumption rate estimates were compared with those estimated by two traditional bioenergetics methods. The first method derived routine swimming speed from fish morphology as an index of activity (a "morphometric" method), and the second considered activity as a fixed proportion of standard metabolic rate (a "physiological" method). The mean consumption rate for free-ranging kingfish measured by accelerometry was 152 J·g(-1)·day(-1), which lay between the estimates from the morphometric method (μ = 134 J·g(-1)·day(-1)) and the physiological method (μ = 181 J·g(-1)·day(-1)). Incorporating field-derived activity values resulted in the smallest variance in log-normally distributed consumption rates (σ = 0.31), compared with the morphometric (σ = 0.57) and physiological (σ = 0.78) methods. Incorporating field-derived activity into bioenergetics models probably provided more realistic estimates of consumption rate compared with the traditional methods, which may further our understanding of trophic interactions that underpin ecosystem-based fisheries management. The general methods used to estimate active metabolic rates of free-ranging fish

  4. Seafloor hydrothermal activity and spreading rates: the Eocene carbon dioxide greenhouse revisted.

    PubMed

    Kasting, J F; Richardson, S M

    1985-01-01

    A suggestion has been made that enhanced rates of hydrothermal activity during the Eocene could have caused a global warming by adding calcium to the ocean and pumping CO2 into the atmosphere (Owen and Rea, 1984). This phenomenon was purported to be consistent with the predictions of the CO2 geochemical cycle model of Berner, Lasaga and Garrels (1983) (henceforth BLAG). In fact, however, the BLAG model predicts only a weak connection between hydrothermal activity and atmospheric CO2 levels. By contrast, it predicts a strong correlation between seafloor spreading rates and pCO2, since the release rate of CO2 from carbonate metamorphism is assumed to be proportional to the mean spreading rate. The Ecocene warming can be conveniently explained if the BLAG model is extended by assuming that the rate of carbonate metamorphism is also proportional to the total length of the midocean ridges from which the spreading originates.

  5. Seafloor hydrothermal activity and spreading rates: the Eocene carbon dioxide greenhouse revisted

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.; Richardson, S. M.

    1985-01-01

    A suggestion has been made that enhanced rates of hydrothermal activity during the Eocene could have caused a global warming by adding calcium to the ocean and pumping CO2 into the atmosphere (Owen and Rea, 1984). This phenomenon was purported to be consistent with the predictions of the CO2 geochemical cycle model of Berner, Lasaga and Garrels (1983) (henceforth BLAG). In fact, however, the BLAG model predicts only a weak connection between hydrothermal activity and atmospheric CO2 levels. By contrast, it predicts a strong correlation between seafloor spreading rates and pCO2, since the release rate of CO2 from carbonate metamorphism is assumed to be proportional to the mean spreading rate. The Ecocene warming can be conveniently explained if the BLAG model is extended by assuming that the rate of carbonate metamorphism is also proportional to the total length of the midocean ridges from which the spreading originates.

  6. Seafloor hydrothermal activity and spreading rates - The Eocene carbon dioxide greenhouse revisited

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.; Richardson, S. M.

    1985-01-01

    A suggestion has been made that enhanced rates of hydrothermal activity during the Eocene could have caused a global warming by adding calcium to the ocean and pumping CO2 into the atmosphere (Owen and Rea, 1984). This phenomenon was purported to be consistent with the predictions of the CO2 geochemical cycle model of Berner, Lasaga and Garrels (1983) (henceforth BLAG). In fact, however, the BLAG model predicts only a weak connection between hydrothermal activity and atmospheric CO2 levels. By contrast, it predicts a strong correlation between seafloor spreading rates and pCO2, since the release rate of CO2 from carbonate metamorphism is assumed to be proportional to the mean spreading rate. The Eocene warming can be conveniently explained if the BLAG model is extended by assuming that the rate of carbonate metamorphism is also proportional to the total length of the midocean ridges from which the spreading originates.

  7. Seafloor hydrothermal activity and spreading rates: the Eocene carbon dioxide greenhouse revisted.

    PubMed

    Kasting, J F; Richardson, S M

    1985-01-01

    A suggestion has been made that enhanced rates of hydrothermal activity during the Eocene could have caused a global warming by adding calcium to the ocean and pumping CO2 into the atmosphere (Owen and Rea, 1984). This phenomenon was purported to be consistent with the predictions of the CO2 geochemical cycle model of Berner, Lasaga and Garrels (1983) (henceforth BLAG). In fact, however, the BLAG model predicts only a weak connection between hydrothermal activity and atmospheric CO2 levels. By contrast, it predicts a strong correlation between seafloor spreading rates and pCO2, since the release rate of CO2 from carbonate metamorphism is assumed to be proportional to the mean spreading rate. The Ecocene warming can be conveniently explained if the BLAG model is extended by assuming that the rate of carbonate metamorphism is also proportional to the total length of the midocean ridges from which the spreading originates. PMID:11539654

  8. Direct measurement of activation time and nucleation rate in capillary-condensed water nanomeniscus

    SciTech Connect

    Sung, Baekman; Kim, Jongwoo; Stambaugh, Corey; Chang, Sung-Jin; Jhe, Wonho

    2013-11-18

    We demonstrate real-time observation of nucleation of the single water nanomeniscus formed via capillary condensation. We directly measure (i) activation time by time-resolved atomic force microscopy and (ii) nucleation rate by statistical analysis of its exponential distribution, which is the experimental evidence that the activation process is stochastic and follows the Poisson statistics. It implies that formation of the water nanomeniscus is triggered by nucleation, which requires activation for producing a nucleus. We also find the dependence of the nucleation rate on the tip-sample distance and temperature.

  9. Engineered epidermal growth factor mutants with faster binding on-rates correlate with enhanced receptor activation

    PubMed Central

    Lahti, Jennifer L.; Lui, Bertrand H.; Beck, Stayce E.; Lee, Stephen S.; Ly, Daphne P.; Longaker, Michael T.; Yang, George P.; Cochran, Jennifer R.

    2011-01-01

    Receptor tyrosine kinases (RTKs) regulate critical cell signaling pathways, yet the properties of their cognate ligands that influence receptor activation are not fully understood. There is great interest in parsing these complex ligand-receptor relationships using engineered proteins with altered binding properties. Here we focus on the interaction between two engineered epidermal growth factor (EGF) mutants and the EGF receptor (EGFR), a model member of the RTK superfamily. We found that EGF mutants with faster kinetic on-rates stimulate increased EGFR activation compared to wild-type EGF. These findings support previous predictions that faster association rates correlate with enhanced receptor activity. PMID:21439278

  10. Detection rates of the MODIS active fire product in the United States

    USGS Publications Warehouse

    Hawbaker, T.J.; Radeloff, V.C.; Syphard, A.D.; Zhu, Z.; Stewart, S.I.

    2008-01-01

    MODIS active fire data offer new information about global fire patterns. However, uncertainties in detection rates can render satellite-derived fire statistics difficult to interpret. We evaluated the MODIS 1??km daily active fire product to quantify detection rates for both Terra and Aqua MODIS sensors, examined how cloud cover and fire size affected detection rates, and estimated how detection rates varied across the United States. MODIS active fire detections were compared to 361 reference fires (??? 18??ha) that had been delineated using pre- and post-fire Landsat imagery. Reference fires were considered detected if at least one MODIS active fire pixel occurred within 1??km of the edge of the fire. When active fire data from both Aqua and Terra were combined, 82% of all reference fires were found, but detection rates were less for Aqua and Terra individually (73% and 66% respectively). Fires not detected generally had more cloudy days, but not when the Aqua data were considered exclusively. MODIS detection rates decreased with fire size, and the size at which 50% of all fires were detected was 105??ha when combining Aqua and Terra (195??ha for Aqua and 334??ha for Terra alone). Across the United States, detection rates were greatest in the West, lower in the Great Plains, and lowest in the East. The MODIS active fire product captures large fires in the U.S. well, but may under-represent fires in areas with frequent cloud cover or rapidly burning, small, and low-intensity fires. We recommend that users of the MODIS active fire data perform individual validations to ensure that all relevant fires are included. ?? 2008 Elsevier Inc. All rights reserved.

  11. Estimated neutron-activation data for TFTR. Part II. Biological dose rate from sample-materials activation

    SciTech Connect

    Ku, L.; Kolibal, J.G.

    1982-06-01

    The neutron induced material activation dose rate data are summarized for the TFTR operation. This report marks the completion of the second phase of the systematic study of the activation problem on the TFTR. The estimations of the neutron induced activation dose rates were made for spherical and slab objects, based on a point kernel method, for a wide range of materials. The dose rates as a function of cooling time for standard samples are presented for a number of typical neutron spectrum expected during TFTR DD and DT operations. The factors which account for the variations of the pulsing history, the characteristic size of the object and the distance of observation relative to the standard samples are also presented.

  12. Changes in muscle activation patterns when running step rate is increased.

    PubMed

    Chumanov, Elizabeth S; Wille, Christa M; Michalski, Max P; Heiderscheit, Bryan C

    2012-06-01

    Running with a step rate 5-10% greater than one's preferred can substantially reduce lower extremity joint moments and powers, and has been suggested as a possible strategy to aid in running injury management. The purpose of this study was to examine how neuromuscular activity changes with an increase in step rate during running. Forty-five injury-free, recreational runners participated in this study. Three-dimensional motion, ground reaction forces, and electromyography (EMG) of 8 muscles (rectus femoris, vastus lateralis, medial gastrocnemius, tibialis anterior, medial and lateral hamstrings, and gluteus medius and maximus) were recorded as each subject ran at their preferred speed for three different step rate conditions: preferred, +5% and +10% of preferred. Outcome measures included mean normalized EMG activity for each muscle at specific periods during the gait cycle. Muscle activities were found to predominantly increase during late swing, with no significant change in activities during the loading response. This increased muscle activity in anticipation of foot-ground contact likely alters the landing posture of the limb and the subsequent negative work performed by the joints during stance phase. Further, the increased activity observed in the gluteus maximus and medius suggests running with a greater step rate may have therapeutic benefits to those with anterior knee pain.

  13. Flexibility in metabolic rate and activity level determines individual variation in overwinter performance.

    PubMed

    Auer, Sonya K; Salin, Karine; Anderson, Graeme J; Metcalfe, Neil B

    2016-11-01

    Energy stores are essential for the overwinter survival of many temperate and polar animals, but individuals within a species often differ in how quickly they deplete their reserves. These disparities in overwinter performance may be explained by differences in their physiological and behavioral flexibility in response to food scarcity. However, little is known about whether individuals exhibit correlated or independent changes in these traits, and how these phenotypic changes collectively affect their winter energy use. We examined individual flexibility in both standard metabolic rate and activity level in response to food scarcity and their combined consequences for depletion of lipid stores among overwintering brown trout (Salmo trutta). Metabolism and activity tended to decrease, yet individuals exhibited striking differences in their physiological and behavioral flexibility. The rate of lipid depletion was negatively related to decreases in both metabolic and activity rates, with the smallest lipid loss over the simulated winter period occurring in individuals that had the greatest reductions in metabolism and/or activity. However, changes in metabolism and activity were negatively correlated; those individuals that decreased their SMR to a greater extent tended to increase their activity rates, and vice versa, suggesting among-individual variation in strategies for coping with food scarcity.

  14. Computation of Rate Constants for Diffusion of Small Ligands to and from Buried Protein Active Sites.

    PubMed

    Wang, P-H; De Sancho, D; Best, R B; Blumberger, J

    2016-01-01

    The diffusion of ligands to actives sites of proteins is essential to enzyme catalysis and many cellular signaling processes. In this contribution we review our recently developed methodology for calculation of rate constants for diffusion and binding of small molecules to buried protein active sites. The diffusive dynamics of the ligand obtained from molecular dynamics simulation is coarse grained and described by a Markov state model. Diffusion and binding rate constants are then obtained either from the reactive flux formalism or by fitting the time-dependent population of the Markov state model to a phenomenological rate law. The method is illustrated by applications to diffusion of substrate and inhibitors in [NiFe] hydrogenase, CO-dehydrogenase, and myoglobin. We also discuss a recently developed sensitivity analysis that allows one to identify hot spots in proteins, where mutations are expected to have the strongest effects on ligand diffusion rates.

  15. Computation of Rate Constants for Diffusion of Small Ligands to and from Buried Protein Active Sites.

    PubMed

    Wang, P-H; De Sancho, D; Best, R B; Blumberger, J

    2016-01-01

    The diffusion of ligands to actives sites of proteins is essential to enzyme catalysis and many cellular signaling processes. In this contribution we review our recently developed methodology for calculation of rate constants for diffusion and binding of small molecules to buried protein active sites. The diffusive dynamics of the ligand obtained from molecular dynamics simulation is coarse grained and described by a Markov state model. Diffusion and binding rate constants are then obtained either from the reactive flux formalism or by fitting the time-dependent population of the Markov state model to a phenomenological rate law. The method is illustrated by applications to diffusion of substrate and inhibitors in [NiFe] hydrogenase, CO-dehydrogenase, and myoglobin. We also discuss a recently developed sensitivity analysis that allows one to identify hot spots in proteins, where mutations are expected to have the strongest effects on ligand diffusion rates. PMID:27497172

  16. Variation in energy expenditure among black-legged kittiwakes: Effects of activity-specific metabolic rates and activity budgets

    USGS Publications Warehouse

    Jodice, P.G.R.; Roby, D.D.; Suryan, R.M.; Irons, D.B.; Kaufman, A.M.; Turco, K.R.; Visser, G.H.

    2003-01-01

    We sought to determine the effect of variation in time-activity budgets (TABs) and foraging behavior on energy expenditure rates of parent black-legged kittiwakes (Rissa tridactyla). We quantified TABs using direct observations of radio-tagged adults and simultaneously measured field metabolic rates (FMR) of these same individuals (n = 20) using the doubly labeled water technique. Estimated metabolic rates of kittiwakes attending their brood at the nest or loafing near the colony were similar (ca. 1.3 x basal metabolic rate [BMR]), although loafing during foraging trips was more costly (2.9 x BMR). Metabolic rates during commuting flight (7.3 x BMR) and prey-searching flight (6.2 x BMR) were similar, while metabolic rates during plunge diving were much higher (ca. 47 x BMR). The proportion of the measurement interval spent foraging had a positive effect on FMR (R2 = 0.68), while the combined proportion of time engaged in nest attendance and loafing near the colony had a negative effect on FMR (R2 = 0.72). Thus, more than two-thirds of the variation in kittiwake FMR could be explained by the allocation of time among various activities. The high energetic cost of plunge diving relative to straight flight and searching flight suggests that kittiwakes can optimize their foraging strategy under conditions of low food availability by commuting long distances to feed in areas where gross foraging efficiency is high.

  17. The Apparent Rates of Crossbridge Attachment and Detachment Estimated from Atpase Activity in Insect Flight Muscle

    PubMed Central

    Güth, K.; Poole, K. J. V.; Maughan, D.; Kuhn, H. J.

    1987-01-01

    The ATPase activity of single fibers of small fiber bundles (one to three fibers) of insect flight muscle was measured when fibers were repetitively released and restretched by 1.5% of their initial length. The ATPase activity increased with increasing duration of release-restretch pulses applied at a constant repetition frequency, reaching a maximum at a duration of ∼20 ms. For a given duration, the average ATPase activity also increased with increasing frequency of applied length changes and reached a maximum (200% of the isometric ATPase) at a frequency of ∼50 Hz. The data could be fitted to a two-state model in which the apparent rate of crossbridge detachment is enhanced when the crossbridges are mechanically released. Estimates of the apparent rates of attachment and detachment in the isometrically contracting state and of the enhanced detachment rate of unloaded crossbridges were derived from fits to the two-state model. After short pulses of releasing and restretching the fiber the force was low and increased after the restretch in a roughly exponential manner to the initial level. The rate at which force increased after a release-restretch pulse was similar to the sum of the apparent attachment and detachment rates for the isometrically contracting muscle derived from the ATPase activity measurements. PMID:19431712

  18. K153R polymorphism in myostatin gene increases the rate of promyostatin activation by furin.

    PubMed

    Szláma, György; Trexler, Mária; Buday, László; Patthy, László

    2015-01-30

    Recent studies demonstrated an association between the K153R polymorphism in the myostatin gene with extreme longevity, lower muscle strength and obesity but the molecular basis of these associations has not been clarified. Here, we show that the K153R mutation significantly increases the rate of proteolysis of promyostatin by furin, but has no effect on the activity of the latent complex or the cleavage of the latent complex by bone morphogenetic protein 1 (BMP-1). The increased rate of activation of K153R mutant promyostatin may explain why this polymorphism is associated with obesity, lower muscle strength and extension of lifespan.

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

    PubMed

    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 (<20 episodes), intermediate (20-29 episodes), or high (>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.

  20. Physicochemical properties influencing denitrification rate and microbial activity in denitrification bioreactors

    NASA Astrophysics Data System (ADS)

    Schmidt, C. A.

    2012-12-01

    The use of N-based fertilizer will need to increase to meet future demands, yet existing applications have been implicated as the main source of coastal eutrophication and hypoxic zones. Producing sufficient crops to feed a growing planet will require efficient production in combination with sustainable treatment solutions. The long-term success of denitrification bioreactors to effectively remove nitrate (NO¬3), indicates this technology is a feasible treatment option. Assessing and quantifying the media properties that affect NO¬3 removal rate and microbial activity can improve predictions on bioreactor performance. It was hypothesized that denitrification rates and microbial biomass would be correlated with total C, NO¬3 concentration, metrics of organic matter quality, media surface area and laboratory measures of potential denitrification rate. NO¬3 removal rates and microbial biomass were evaluated in mesocosms filled with different wood treatments and the unique influence of these predictor variables was determined using a multiple linear regression analysis. NO3 reduction rates were independent of NO¬3 concentration indicating zero order reaction kinetics. Temperature was strongly correlated with denitrification rate (r2=0.87; Q10=4.7), indicating the variability of bioreactor performance in differing climates. Fiber quality, and media surface area were strong (R>0.50), unique predictors of rates and microbial biomass, although C:N ratio and potential denitrification rate did not predict actual denitrification rate or microbial biomass. Utilizing a stepwise multiple linear regression, indicates that the denitrification rate can be effectively (r2=0.56;p<0.0001) predicted if the groundwater temperature, neutral detergent fiber and surface area alone are quantified. These results will assist with the widespread implementation of denitrification bioreactors to achieve significant N load reductions in large watersheds. The nitrate reduction rate as a

  1. Generalization of the Activated Complex Theory of Reaction Rates. I. Quantum Mechanical Treatment

    DOE R&D Accomplishments Database

    Marcus, R. A.

    1964-01-01

    In its usual form activated complex theory assumes a quasi-equilibrium between reactants and activated complex, a separable reaction coordinate, a Cartesian reaction coordinate, and an absence of interaction of rotation with internal motion in the complex. In the present paper a rate expression is derived without introducing the Cartesian assumption. The expression bears a formal resemblance to the usual one and reduces to it when the added assumptions of the latter are introduced.

  2. Autonomic control of heart rate during forced activity and digestion in the snake Boa constrictor.

    PubMed

    Wang, T; Taylor, E W; Andrade, D; Abe, A S

    2001-10-01

    Reptiles, particularly snakes, exhibit large and quantitatively similar increments in metabolic rate during muscular exercise and following a meal, when they are apparently inactive. The cardiovascular responses are similar during these two states, but the underlying autonomic control of the heart remains unknown. We describe both adrenergic and cholinergic tonus on the heart during rest, during enforced activity and during digestion (24-36 h after ingestion of 30 % of their body mass) in the snake Boa constrictor. The snakes were equipped with an arterial catheter for measurements of blood pressure and heart rate, and autonomic tonus was determined following infusion of the beta-adrenergic antagonist propranolol (3 mg kg(-1)) and the muscarinic cholinoceptor antagonist atropine (3 mg kg(-1)). The mean heart rate of fasting animals at rest was 26.4+/-1.4 min(-1), and this increased to 36.1+/-1.4 min(-1) (means +/- S.E.M.; N=8) following double autonomic block (atropine and propranolol). The calculated cholinergic and adrenergic tones were 60.1+/-9.3 % and 19.8+/-2.2 %, respectively. Heart rate increased to 61.4+/-1.5 min(-1) during enforced activity, and this response was significantly reduced by propranolol (maximum values of 35.8+/-1.6 min(-1)), but unaffected by atropine. The cholinergic and adrenergic tones were 2.6+/-2.2 and 41.3+/-1.9 % during activity, respectively. Double autonomic block virtually abolished tachycardia associated with enforced activity (heart rate increased significantly from 36.1+/-1.4 to 37.6+/-1.3 min(-1)), indicating that non-adrenergic, non-cholinergic effectors are not involved in regulating heart rate during activity. Blood pressure also increased during activity. Digestion was accompanied by an increase in heart rate from 25.6+/-1.3 to 47.7+/-2.2 min(-1) (N=8). In these animals, heart rate decreased to 44.2+/-2.7 min(-1) following propranolol infusion and increased to 53.9+/-1.8 min(-1) after infusion of atropine, resulting in small

  3. Changes in the electrical activity of dog cardiac Purkinje fibres at high heart rates.

    PubMed Central

    Boyett, M R; Fedida, D

    1984-01-01

    Rate-dependent changes in the electrical activity of dog Purkinje fibres have been studied. At high rates of stimulation the rate of repolarization is greater, the action potential is shorter, the maximum diastolic potential is increased, the pace-maker potential is reduced in amplitude, and on cessation of rapid stimulation there can be a suppression of spontaneous activity. After an increase of the stimulus frequency there is an abrupt shortening of the action potential, which can be attributed to incomplete recovery of the plateau currents; this is followed by a progressive decline in action potential duration over the next several hundred seconds. The factor responsible for the slow changes in duration could also be responsible for the accompanying increase in maximum diastolic potential because this develops along a similar time course. These slow changes in electrical activity have been investigated with the phase-plane technique. They are the result of an increase in the net outward current over a wide range of potentials (approximately -10 to approximately -90 mV) during the repolarization phase of the action potential. In voltage-clamp experiments background current has been observed to be strongly rate dependent: the background current during a test voltage-clamp pulse after a train of action potentials is more outward at higher stimulus frequencies. When the frequency is increased, background current slowly becomes more outward over several hundred seconds, and this change therefore occurs along the appropriate time course to explain the slow alteration in electrical activity under these conditions. The extra outward background current at high rates is relatively independent of membrane potential in the range from -110 to -40 mV (more circumstantial evidence indicates that this range may extend to at least +10 mV); this potential dependence is similar to that of the Na-K-pump current (Eisner & Lederer, 1980). Strophanthidin and ouabain, agents known to

  4. Patterns of physical activity determined by heart rate monitoring among diabetic children

    PubMed Central

    Massin, M; Lebrethon, M; Rocour, D; Gerard, P; Bourguignon, J

    2005-01-01

    Background: Children with type 1 diabetes should be encouraged to participate in physical activity because exercise can benefit insulin sensitivity and improve known risk factors for atherosclerosis. Methods: Physical activity patterns of 127 children and adolescents with stable type 1 diabetes were investigated by 24 hour continuous heart rate monitoring. The percentage of heart rate reserve was used to measure the amounts of physical activity at different intensities. The results were compared with normative data. Results: Diabetic preschoolchildren accumulated 192.7 (78.1), 39.1 (24.3), and 21.3 (9.4) minutes/day (mean (SD)) of light, moderate, and vigorous physical activity, respectively. At the same activity levels, diabetic schoolchildren accumulated 168.9 (76.7), 37.9 (15.9), and 19.0 (14.8) minutes/day, and diabetic teenagers accumulated 166.3 (67.5), 45.6 (26.9), and 25.2 (15.3) minutes/day. Diabetic schoolchildren were significantly more active than healthy peers when considering moderate activity; diabetic teenagers were significantly more active when considering moderate and vigorous activity. There was a negative correlation between the most recent glycated haemoglobin and the time spent in light activities in schoolchildren, and a negative correlation between mean glycated haemoglobin for one year and time spent in light and moderate activities in schoolchildren. Conclusion: The majority of our diabetic patients meet the classical paediatric guidelines for physical activity and compare favourably with their healthy peers. PMID:15941770

  5. Influence of temperature and activity on the metabolic rate of adult Drosophila melanogaster.

    PubMed

    Berrigan, D; Partridge, L

    1997-12-01

    We measured metabolic rates of adult male Drosophila melanogaster allowed to evolve in the laboratory at 18 and 25 degrees C and compared these with measurements of metabolic rates of flies collected along a latitudinal gradient in Australia. Metabolic rates of flies that had evolved in the laboratory at low temperature were 5-7% higher than those of flies allowed to evolve at high temperature. Metabolic rates of field collected increased with latitude when measured at 18 degrees C but not at higher temperature (25 degrees C) and were about 9% greater in high latitude (approximately 41'00) flies than low latitude (16'53) flies. Metabolic rate was strongly influenced by measurement temperature; estimated Q10s ranged from 1.79 to 2.5 for measurements made at 18 and 25 degrees C. Metabolic rate scaled isometrically with body mass; the estimated slope of a ln-ln regression of metabolic rate and body mass was 1.03 +/- 0.1. We used our measures of metabolic rate and activity to estimate the minimum cost of transport (MCOT) while walking. The estimates of MCOT have high standard errors (lab, 34.30 +/- 14.2 ml O2/g/km; and field, 38.0 +/- 17.0 ml O2/g/km); however, they differ by only 3-9% from predicted values based on allometric relationships reported in the literature.

  6. Relationship of lipogenic enzyme activities to the rate of rat liver fatty acid synthesis

    SciTech Connect

    Nelson, G.; Kelley, D.; Schmidt, P.; Virk, S.; Serrato, C.

    1986-05-01

    The mechanism by which diet regulates liver lipogenesis is unclear. Here the authors report how dietary alterations effect the activities of key enzymes of fatty acid (FA) synthesis. Male Sprague-Dawley rats, 400-500 g, were fasted for 48h and then refed a fat-free, high carbohydrate (HC) diet (75% cal. from sucrose) for 0,3,9,24 and 48h, or refed a HC diet for 48h, then fed a high-fat (HF) diet (44% cal. from corn oil) for 3,9,24 and 48h. The FA synthesis rate and the activities of acetyl CoA carboxylase (AC), fatty acid synthase (FAS), ATP citrate lyase (CL), and glucose 6-phosphate dehydrogenase (G6PDH) were determined in the livers. FA synthesis was assayed with /sup 3/H/sub 2/O, enzyme activities were measured spectrophotometrically except for AC which was assayed with /sup 14/C-bicarbonate. There was no change in the activity of AC during fasting or on the HC diet. Fasting decreased the rate of FA synthesis by 25% and the activities of FAS and CL by 50%; refeeding the HC diet induced parallel changes in FA synthesis and the activities of FAS, CL, and G6PDH. After 9h on the HF diet, FA synthesis had decreased sharply, AC activity increased significantly while no changes were detected in the other activities. Subsequently FA synthesis did not change while the activities of the enzymes decreased slowly. These enzymes did not appear to regulate FA synthesis during inhibition of lipogenesis, but FAS, CL or G6PDH may be rate limiting in the induction phase. Other key factors may regulate FA synthesis during dietary alterations.

  7. Size distribution and emission rate measurement of fine and ultrafine particle from indoor human activities

    NASA Astrophysics Data System (ADS)

    Géhin, Evelyne; Ramalho, Olivier; Kirchner, Séverine

    Human indoor activities generate airborne particles which contribute to the increase of aerosol concentration levels in the home. The particle size distribution emission rate was measured for 18 different activities (burning candle or incense, cooking, spray use, computer printing and household cleaning). The particle emission rate was calculated from concentration measurements with a DMS500 (CAMBUSTION) in an experimental chamber (2.36 ± 0.05 m 3). The results showed that ultrafine particles are emitted during these activities and the lowest number distribution mode was 6 nm for one of the burning candles. All the cooking activities had similar emissions with a mode between 20 and 40 nm. The measured size distributions were represented in a database by the sum of 1, 2 or 3 lognormal distributions. The measured total emission rate ranged between 0.06 × 10 10 and 13.10 × 10 10 s -1 and the highest emission rate was measured for the self cleaning oven program (pyrolysis).

  8. Generalization of the Activated Complex Theory of Reaction Rates. II. Classical Mechanical Treatment

    DOE R&D Accomplishments Database

    Marcus, R. A.

    1964-01-01

    In its usual classical form activated complex theory assumes a particular expression for the kinetic energy of the reacting system -- one associated with a rectilinear motion along the reaction coordinate. The derivation of the rate expression given in the present paper is based on the general kinetic energy expression.

  9. 40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false How do I monitor the injection rate of activated carbon? 62.15275 Section 62.15275 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements...

  10. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false How do I monitor the injection rate of activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small...

  11. 40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false How do I monitor the injection rate of activated carbon? 62.15275 Section 62.15275 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements...

  12. 40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false How do I monitor the injection rate of activated carbon? 62.15275 Section 62.15275 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements...

  13. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false How do I monitor the injection rate of activated carbon? 60.1330 Section 60.1330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste...

  14. 40 CFR 62.15275 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false How do I monitor the injection rate of activated carbon? 62.15275 Section 62.15275 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS FOR DESIGNATED FACILITIES AND POLLUTANTS Federal Plan Requirements...

  15. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false How do I monitor the injection rate of activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small...

  16. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How do I monitor the injection rate of activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small...

  17. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false How do I monitor the injection rate of activated carbon? 60.1330 Section 60.1330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste...

  18. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false How do I monitor the injection rate of activated carbon? 60.1330 Section 60.1330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste...

  19. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false How do I monitor the injection rate of activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for Small...

  20. 40 CFR 60.1330 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How do I monitor the injection rate of activated carbon? 60.1330 Section 60.1330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste...

  1. Validity of heart rate, pedometry, and accelerometry for predicting the energy cost of children's activities.

    PubMed

    Eston, R G; Rowlands, A V; Ingledew, D K

    1998-01-01

    Heart rate telemetry is frequently used to estimate daily activity in children and to validate other methods. This study compared the accuracy of heart rate monitoring, pedometry, triaxial accelerometry, and uniaxial accelerometry for estimating oxygen consumption during typical children's activities. Thirty Welsh children (mean age 9.2 +/- 0.8 yr) walked (4 and 6 km/h) and ran (8 and 10 km/h) on a treadmill, played catch, played hopscotch, and sat and crayoned. Heart rate, body accelerations in three axes, pedometry counts, and oxygen uptake were measured continuously during each 4-min activity. Oxygen uptake was expressed as a ratio of body mass raised to the power of 0.75 [scaled oxygen uptake (sVO2)]. All measures correlated significantly (P < 0.001) with sVO2. A multiple-regression equation that included triaxial accelerometry counts and heart rate predicted sVO2 better than any measure alone (R2 = 0.85, standard error of the estimate = 9.7 ml.kg-0.75.min-1). The best of the single measures was triaxial accelerometry (R2 = 0.83, standard error of the estimate = 10.3 ml.kg-0.75.min-1). It is concluded that a triaxial accelerometer provides the best assessment of activity. Pedometry offers potential for large population studies.

  2. Dopamine activation in Neuroticism as measured by spontaneous eye blink rate.

    PubMed

    Barbato, Giuseppe; Della Monica, Ciro; Costanzo, Antonio; De Padova, Vittoria

    2012-01-18

    Personality dimensions have been associated with different psychobiological systems. However, no agreement exists in literature on a specific role of a single neurotransmitter for each of the dimensions investigated. We studied the relationship of Neuroticism, Extraversion and Psychoticism as assessed by Eysenck Personality Inventory (EPI) with spontaneous eye blink rate (BR), a non-invasive measure of central dopamine activity. A total of sixty-three healthy subjects (40 females, 23 males, mean age 24.2±3.9) were studied. Spontaneous blink rate and time of blink suppression were assessed by EOG measurement. Levels of Extraversion and Neuroticism were inversely correlated. In contrast with previous findings, a significant correlation between blink rate measures and Neuroticism was found. No significant correlation between blink measures and either Extraversion, or Psychoticism were found. The results appear consistent with a lower threshold for activation in neuroticism as suggested by Eysenck's original model.

  3. [Influence of different combination of mental activity and respiratory cycle on heart rate variability].

    PubMed

    Sun, F L; Li, D M; Li, G Y

    1996-03-01

    By means of spectral analysis of P-R interval, different characteristics of heart rate variability in different form of respiratory exercise was observed. The results of observation on 32 volunteers showed that mental activity that affected respiration can influence the function of autonomic nerve system in a different way. When the mind was concentrated at the inspiration, the function of autonomic nerve system was kept in balance, and both the sympathetic and the vagal activities enhanced significantly and while mind concentrated at the expiration could induce a reduction of vagal activity so as to produce marked change in the sympathovagal balance.

  4. Timing and Variability of Galactose Metabolic Gene Activation Depend on the Rate of Environmental Change

    PubMed Central

    Ma, Bo; Ott, William; Josić, Krešimir; Bennett, Matthew R.

    2015-01-01

    Modulation of gene network activity allows cells to respond to changes in environmental conditions. For example, the galactose utilization network in Saccharomyces cerevisiae is activated by the presence of galactose but repressed by glucose. If both sugars are present, the yeast will first metabolize glucose, depleting it from the extracellular environment. Upon depletion of glucose, the genes encoding galactose metabolic proteins will activate. Here, we show that the rate at which glucose levels are depleted determines the timing and variability of galactose gene activation. Paradoxically, we find that Gal1p, an enzyme needed for galactose metabolism, accumulates more quickly if glucose is depleted slowly rather than taken away quickly. Furthermore, the variability of induction times in individual cells depends non-monotonically on the rate of glucose depletion and exhibits a minimum at intermediate depletion rates. Our mathematical modeling suggests that the dynamics of the metabolic transition from glucose to galactose are responsible for the variability in galactose gene activation. These findings demonstrate that environmental dynamics can determine the phenotypic outcome at both the single-cell and population levels. PMID:26200924

  5. Measuring the activities of higher organisms in activated sludge by means of mechanical shearing pretreatment and oxygen uptake rate.

    PubMed

    Hao, Xiaodi; Wang, Qilin; Cao, Yali; van Loosdrecht, Mark C M

    2010-07-01

    A pretreatment method was developed to assess the activities of higher organisms. The method is based on mechanical shearing to damage the large cells of the protozoan and metazoan community in activated sludge. The procedure was confirmed through experimentation to be effective in determining the activities of higher organisms by comparing oxygen uptake rates (OURs) before and after the higher organisms were eradicated. Shearing led to disintegration of flocs, which could be effectively reconstituted by centrifugation. The reconstitution of the sludge flocs was essential since otherwise the activity of the floc mass would be too high due to lack of diffusion limitation. Mechanical shearing had no influence on the morphology, quantity and specific activity of yeasts, and it was inferred that bacteria smaller than yeasts in size would also not be influenced by the applied shearing procedure. Moreover, the effect of filamentous organisms on the measured activities of higher organisms was experimentally demonstrated and analyzed, and determined to be so weak that it could be ignored. Based on these tests, five typical activated sludge processes were selected to measure the contribution of higher organisms to the original OUR. The measured activities of higher organisms ranged from 9.4 to 25.0% of the original OURs.

  6. Fast molecular evolution associated with high active metabolic rates in poison frogs.

    PubMed

    Santos, Juan C

    2012-08-01

    Molecular evolution is simultaneously paced by mutation rate, genetic drift, and natural selection. Life history traits also affect the speed of accumulation of nucleotide changes. For instance, small body size, rapid generation time, production of reactive oxygen species (ROS), and high resting metabolic rate (RMR) are suggested to be associated with faster rates of molecular evolution. However, phylogenetic correlation analyses failed to support a relationship between RMR and molecular evolution in ectotherms. In addition, RMR might underestimate the metabolic budget (e.g., digestion, reproduction, or escaping predation). An alternative is to test other metabolic rates, such as active metabolic rate (AMR), and their association with molecular evolution. Here, I present comparative analyses of the associations between life history traits (i.e., AMR, RMR, body mass, and fecundity) with rates of molecular evolution of and mitochondrial loci from a large ectotherm clade, the poison frogs (Dendrobatidae). My results support a strong positive association between mass-specific AMR and rates of molecular evolution for both mitochondrial and nuclear loci. In addition, I found weaker and genome-specific covariates such as body mass and fecundity for mitochondrial and nuclear loci, respectively. No direct association was found between mass-specific RMR and rates of molecular evolution. Thus, I provide a mechanistic hypothesis of the link between AMRs and the rate of molecular evolution based on an increase in ROS within germ line cells during periodic bouts of hypoxia/hyperoxia related to aerobic exercise. Finally, I propose a multifactorial model that includes AMR as a predictor of the rate of molecular evolution in ectothermic lineages.

  7. Measurement of Microbial Activity and Growth in the Ocean by Rates of Stable Ribonucleic Acid Synthesis

    PubMed Central

    Karl, David M.

    1979-01-01

    A relatively simple and extremely sensitive technique for measuring rates of stable ribonucleic acid (RNA) synthesis was devised and applied to bacterial cultures and seawater samples. The procedure is based upon the uptake and incorporation of exogenous radiolabeled adenine into cellular RNA. To calculate absolute rates of synthesis, measurements of the specific radioactivity of the intracellular adenosine 5′-triphosphate pools (precursor to RNA) and of the total amount of radioactivity incorporated into stable cellular RNA per unit time are required. Since the rate of RNA synthesis is positively correlated with growth rate, measurements of RNA synthesis should be extremely useful for estimating and comparing the productivities of microbial assemblages in nature. Adenosine 5′-triphosphate, adenylate energy charge, and rates of stable RNA synthesis have been measured at a station located in the Columbian Basin of the Caribbean Sea. A subsurface peak in RNA synthesis (and therefore growth) was located within the dissolved oxygen minimum zone (450 m), suggesting in situ microbiological utilization of dissolved molecular oxygen. Calculations of the specific rates of RNA synthesis (i.e., RNA synthesis per unit of biomass) revealed that the middepth maximum corresponded to the highest specific rate of growth (420 pmol of adenine incorporated into RNA·day−1) of all depths sampled, including the euphotic zone. The existence of an intermediate depth zone of active microbial growth may be an important site for nutrient regeneration and may serve as a source of reduced carbon for mesopelagic and deep sea environments. PMID:16345461

  8. A Model for Variable Levee Formation Rates in an Active Lava Flow

    NASA Technical Reports Server (NTRS)

    Glaze, L. S.; Baloga, S. M.; Mouginis-Mark, P.; Crisp, J.

    2004-01-01

    Channelized lava flows on Mars and the Earth often feature levees and collateral margins that change in volume along the path of the flow. Consistent with field observations of terrestrial flows, this suggests that the rate of levee formation varies with distance and other factors. Previous models have assumed a constant rate of levee growth, specified by a single parameter, lambda. The rate of levee formation for lava flows is a good indicator of the mass eruption rate and rheology of the flow. Insight into levee formation will help us better understand whether or not the effusion rate was constant during an eruption, and once local topography is considered, allows us to look at cooling and/or rheology changes downslope. Here we present a more realistic extension of the levee formation model that treats the rate of levee growth as a function of distance along the flow path. We show how this model can be used with a terrestrial flow and a long lava flow on Mars. The key statement of the new formulation is the rate of transfer from the active component to the levees (or other passive components) through an element dx along the path of the flow. This volumetric transfer equation is presented.

  9. OBSERVATIONAL LIMITS ON TYPE 1 ACTIVE GALACTIC NUCLEUS ACCRETION RATE IN COSMOS

    SciTech Connect

    Trump, Jonathan R.; Impey, Chris D.; Gabor, Jared; Kelly, Brandon C.; Elvis, Martin; Hao Heng; Huchra, John P.; Merloni, Andrea; Bongiorno, Angela; Brusa, Marcella; Cappelluti, Nico; McCarthy, Patrick J.; Koekemoer, Anton; Nagao, Tohru; Salvato, Mara; Scoville, Nick Z.

    2009-07-20

    We present black hole masses and accretion rates for 182 Type 1 active galactic nuclei (AGNs) in COSMOS. We estimate masses using the scaling relations for the broad H {beta}, Mg II, and C IV emission lines in the redshift ranges 0.16 < z < 0.88, 1 < z < 2.4, and 2.7 < z < 4.9. We estimate the accretion rate using an Eddington ratio L{sub I}/L{sub Edd} estimated from optical and X-ray data. We find that very few Type 1 AGNs accrete below L{sub I} /L{sub Edd} {approx} 0.01, despite simulations of synthetic spectra which show that the survey is sensitive to such Type 1 AGNs. At lower accretion rates the broad-line region may become obscured, diluted, or nonexistent. We find evidence that Type 1 AGNs at higher accretion rates have higher optical luminosities, as more of their emission comes from the cool (optical) accretion disk with respect to shorter wavelengths. We measure a larger range in accretion rate than previous works, suggesting that COSMOS is more efficient at finding low accretion rate Type 1 AGNs. However, the measured range in accretion rate is still comparable to the intrinsic scatter from the scaling relations, suggesting that Type 1 AGNs accrete at a narrow range of Eddington ratio, with L{sub I} /L{sub Edd} {approx} 0.1.

  10. ALGORITHMS FOR ESTIMATING RESTING METABOLIC RATE AND ACTIVITY SPECIFIC VENTILATION RATES FOR USE IN COMPLEX EXPOSURE AND INTAKE DOSE MODELS

    EPA Science Inventory

    This work summarizes advancements made that allow for better estimation of resting metabolic rate (RMR) and subsequent estimation of ventilation rates (i.e., total ventilation (VE) and alveolar ventilation (VA)) for individuals of both genders and all ages. ...

  11. Changes in the spectrum and rates of extracellular enzyme activities in seawater following aggregate formation

    NASA Astrophysics Data System (ADS)

    Ziervogel, K.; Steen, A. D.; Arnosti, C.

    2010-03-01

    Marine snow aggregates are heavily colonized by heterotrophic microorganisms that express high levels of hydrolytic activities, making aggregates hotspots for carbon remineralization in the ocean. To assess how aggregate formation influences the ability of seawater microbial communities to access organic carbon, we compared hydrolysis rates of six polysaccharides in coastal seawater after aggregates had been formed (via incubation on a roller table) with hydrolysis rates in seawater from the same site that had not incubated on a roller table (referred to as whole seawater). Hydrolysis rates in the aggregates themselves were up to three orders of magnitude higher on a volume basis than in whole seawater. The enhancement of enzyme activity in aggregates relative to whole seawater differed by substrate, suggesting that the enhancement was under cellular control, rather than due to factors such as lysis or grazing. A comparison of hydrolysis rates in whole seawater with those in aggregate-free seawater, i.e. the fraction of water from the roller bottles that did not contain aggregates, demonstrated a nuanced microbial response to aggregate formation. Activities of laminarinase and xylanase enzymes in aggregate-free seawater were higher than in whole seawater, while activities of chondroitin, fucoidan, and arabinogalactan hydrolyzing enzymes were lower than in whole seawater. These data suggest that aggregate formation enhanced production of laminarinase and xylanase enzymes, and the enhancement also affected the surrounding seawater. Decreased activities of chondroitin, fucoidan, and arabinoglactan-hydrolyzing enzymes in aggregate-free seawaters relative to whole seawater are likely due to shifts in enzyme production by the aggregate-associated community, coupled with the effects of enzyme degradation. Enhanced activities of laminarin- and xylan-hydrolyzing enzymes in aggregate-free seawater were due at least in part to cell-free enzymes. Measurements of enzyme

  12. Declining rates of physical activity in the United States: what are the contributors?

    PubMed

    Brownson, Ross C; Boehmer, Tegan K; Luke, Douglas A

    2005-01-01

    This review describes current patterns and long-term trends (up to 50 years when possible) related to (a) physical activity, (b) employment and occupation, (c) travel behavior, (d) land use, and (e) related behaviors (e.g., television watching). On the basis of available data, the following trends were observed according to type of physical activity: relatively stable or slightly increasing levels of leisure-time physical activity, declining work-related activity, declining transportation activity, declining activity in the home, and increasing sedentary activity. These result in an overall trend of declining total physical activity. Large differences were noted in the rates of walking for transportation across metropolitan statistical areas. A strong linear increase existed in vehicle miles traveled per person over the past half century, coupled with a strong and consistent trend toward Americans living in suburbs. Although it is difficult to precisely quantify owing to the lack of long-term data, it is apparent that a combination of changes to the built environment and increases in the proportion of the population engaging in sedentary activities put the majority of the American population at high risk of physical inactivity. PMID:15760296

  13. Wireless patch sensor for remote monitoring of heart rate, respiration, activity, and falls.

    PubMed

    Chan, Alexander M; Selvaraj, Nandakumar; Ferdosi, Nima; Narasimhan, Ravi

    2013-01-01

    Unobtrusive continuous monitoring of important vital signs and activity metrics has the potential to provide remote health monitoring, at-home screening, and rapid notification of critical events such as heart attacks, falls, or respiratory distress. This paper contains validation results of a wireless Bluetooth Low Energy (BLE) patch sensor consisting of two electrocardiography (ECG) electrodes, a microcontroller, a tri-axial accelerometer, and a BLE transceiver. The sensor measures heart rate, heart rate variability (HRV), respiratory rate, posture, steps, and falls and was evaluated on a total of 25 adult participants who performed breathing exercises, activities of daily living (ADLs), various stretches, stationary cycling, walking/running, and simulated falls. Compared to reference devices, the heart rate measurement had a mean absolute error (MAE) of less than 2 bpm, time-domain HRV measurements had an RMS error of less than 15 ms, respiratory rate had an MAE of 1.1 breaths per minute during metronome breathing, posture detection had an accuracy of over 95% in two of the three patch locations, steps were counted with an absolute error of less than 5%, and falls were detected with a sensitivity of 95.2% and specificity of 100%.

  14. Effect of signs of oestrus, disease stressors and cow activity on pregnancy rate following artificial insemination.

    PubMed

    Bijker, I; Christley, R M; Smith, R F; Dobson, H

    2015-04-18

    The objective was to examine (a) how pregnancy rate on one farm (500 cows) was affected by signs of oestrus and disease stressors and (b) whether pregnancy rate could be maximised by considering cow activity. The signs of oestrus and timings were recorded at artificial insemination (AI), and cow activity was monitored by neck collars. Pregnancy rate tended to be higher in animals that displayed standing oestrus (35 v 26 per cent; P=0.06) but was 10 per cent lower in those cows with an elevated somatic cell count (SCC; >200,000 cells/ml milk) within 0-4 or 4-8 weeks prior to AI (P=0.01 and 0.05, respectively), irrespective of the incidence of clinical mastitis prior to AI. Cow activity data were available for 525 inseminations (from a total of 1299). The mean interval from increased activity to AI in all cows (11 hours 32 minutes; 95 per cent CI 10 hours 40 minutes to 12 hours 24 minutes) was not different for cows that did or did not establish a pregnancy (P=0.90). The pregnancy rate improved to the average of unaffected cows if AI was delayed by about eight hours in animals with an elevated SCC 0-4 weeks prior to AI (P=0.025), indicating that, in cows with prior elevated SCC, AI could be repeated approximately eight hours later to achieve maximum pregnancy rates.

  15. Modeling adsorption rate of organic micropollutants present in landfill leachates onto granular activated carbon.

    PubMed

    Ocampo-Pérez, Raúl; Abdel daiem, Mahmoud M; Rivera-Utrilla, José; Méndez-Díaz, José D; Sánchez-Polo, Manuel

    2012-11-01

    The overall adsorption rate of single micropollutants present in landfill leachates such as phthalic acid (PA), bisphenol A (BPA), diphenolic acid (DPA), 2,4-dichlorophenoxy-acetic acid (2,4-D), and 4-chloro-2-methylphenoxyacetic acid (MCPA) on two commercial activated carbons was studied. The experimental data obtained were interpreted by using a diffusional model (PVSDM) that considers external mass transport, intraparticle diffusion, and adsorption on an active site. Furthermore, the concentration decay data were interpreted by using kinetics models. Results revealed that PVSDM model satisfactorily fitted the experimental data of adsorption rate on activated carbon. The tortuosity factor of the activated carbons used ranged from 2 to 4. The contribution of pore volume diffusion represented more than 92% of intraparticle diffusion confirming that pore volume diffusion is the controlling mechanism of the overall rate of adsorption and surface diffusion can be neglected. The experimental data were satisfactorily fitted the kinetic models. The second-order kinetic model was better fitted the experimental adsorption data than the first-order model. PMID:22858399

  16. Type Ib BMP receptors mediate the rate of commissural axon extension through inhibition of cofilin activity

    PubMed Central

    Yamauchi, Ken; Varadarajan, Supraja G.; Li, Joseph E.; Butler, Samantha J.

    2013-01-01

    Bone morphogenetic proteins (BMPs) have unexpectedly diverse activities establishing different aspects of dorsal neural circuitry in the developing spinal cord. Our recent studies have shown that, in addition to spatially orienting dorsal commissural (dI1) axons, BMPs supply ‘temporal’ information to commissural axons to specify their rate of growth. This information ensures that commissural axons reach subsequent signals at particular times during development. However, it remains unresolved how commissural neurons specifically decode this activity of BMPs to result in their extending axons at a specific speed through the dorsal spinal cord. We have addressed this question by examining whether either of the type I BMP receptors (Bmpr), BmprIa and BmprIb, have a role controlling the rate of commissural axon growth. BmprIa and BmprIb exhibit a common function specifying the identity of dorsal cell fate in the spinal cord, whereas BmprIb alone mediates the ability of BMPs to orient axons. Here, we show that BmprIb, and not BmprIa, is additionally required to control the rate of commissural axon extension. We have also determined the intracellular effector by which BmprIb regulates commissural axon growth. We show that BmprIb has a novel role modulating the activity of the actin-severing protein cofilin. These studies reveal the mechanistic differences used by distinct components of the canonical Bmpr complex to mediate the diverse activities of the BMPs. PMID:23250207

  17. Individual and synergistic effects of sniffing frequency and flow rate on olfactory bulb activity.

    PubMed

    Courtiol, Emmanuelle; Hegoburu, Chloé; Litaudon, Philippe; Garcia, Samuel; Fourcaud-Trocmé, Nicolas; Buonviso, Nathalie

    2011-12-01

    Is faster or stronger sniffing important for the olfactory system? Odorant molecules are captured by sniffing. The features of sniffing constrain both the temporality and intensity of the input to the olfactory structures. In this context, it is clear that variations in both the sniff frequency and flow rate have a major impact on the activation of olfactory structures. However, the question of how frequency and flow rate individually or synergistically impact bulbar output has not been answered. We have addressed this question using multiple experimental approaches. In double-tracheotomized, anesthetized rats, we recorded both the bulbar local field potential (LFP) and mitral/tufted cells' activities when the sampling flow rate and frequency were controlled independently. We found that a tradeoff between the sampling frequency and the flow rate could maintain olfactory bulb sampling-related rhythmicity and that only an increase in flow rate could induce a faster, odor-evoked response. LFP and sniffing were recorded in awake rats. We found that sampling-related rhythmicity was maintained during high-frequency sniffing. Furthermore, we observed that the covariation between the frequency and flow rate, which was necessary for the tradeoff seen in the anesthetized preparations, also occurred in awake animals. Our study shows that the sampling frequency and flow rate can act either independently or synergistically on bulbar output to shape the neuronal message. The system likely takes advantage of this flexibility to adapt sniffing strategies to animal behavior. Our study provides additional support for the idea that sniffing and olfaction function in an integrated manner.

  18. [Analysis of scalp potential activity and heart rate variability during volitional control of heart beat].

    PubMed

    Yu, Xiao-Lin; Zhang, Jian-Bao; Wang, Jue

    2009-07-01

    In the study the changes of scalp potential and cardiac autonomic nervous system during volitional control of heart beat are explored with the wavelet packet parameters and approximate entropy (ApEn) of Electroencephalogram (EEG) and heart rate variability. The results show that volition can control heart beat and the changes of brain activity are earlier than that of autonomic activity. But its control of heart beat is very different from the motor nervous system because different cortical positions are respectively concerned during the quick and slow control of heart beat. The pre-central areas of brain are correlated with parasympathetic activity by which HR is controlled to slow down. The post-central areas of brain are correlated with sympathetic activity by which HR is controlled to accelerate.

  19. Changes in the Hurst Exponent of Heart Rate Variability during Physical Activity

    NASA Astrophysics Data System (ADS)

    Aoyagi, Naoko; Kiyono, Ken; Struzik, Zbigniew R.; Yamamoto, Yoshiharu

    2005-08-01

    We examine fractal scaling properties of heart rate variability using detrended fluctuation analysis (DFA), during physical activity in healthy subjects. We analyze 11 records of healthy subjects, which include both usual daily activity and experimental exercise. The subjects were asked to ride on a bicycle ergometer for 2.5 hours, and maintained a heartbeat interval of 500-600 ms. In order to estimate the long-range correlation in the series of heartbeat intervals during controlled physical activity, we apply DFA to the data set with the third-order polynomial trend removed. For all records during exercise, we observe a characteristic crossover phenomenon at ≈ 300 beats. The scaling exponent in the range > 300 beats (> 3 minutes) during exercise decreases and tends to be closer to white noise (≈ 0.5), which corresponds to uncorrelated behavior. The long-range scaling exponent during exercise is significantly lower than that during daily activity in this range. Contrary to the currently held view, our results indicate a breakdown in long-range correlations and 1/f-like scaling, rather than the increase in the Hurst exponent characteristic of a (congestive) increase in afterload and observed, e.g., in congestive heart failure (CHF) patients. Further, our results suggest an increased load imbalance induced departure from critical-like behavior, which has recently been reported in healthy human heart rate during daily activity.

  20. Escape rate of an active Brownian particle over a potential barrier.

    PubMed

    Burada, P S; Lindner, B

    2012-03-01

    We study the dynamics of an active Brownian particle with a nonlinear friction function located in a spatial cubic potential. For strong but finite damping, the escape rate of the particle over the spatial potential barrier shows a nonmonotonic dependence on the noise intensity. We relate this behavior to the fact that the active particle escapes from a limit cycle rather than from a fixed point and that a certain amount of noise can stabilize the sojourn of the particle on this limit cycle. PMID:22587135

  1. Changes in the spectrum and rates of extracellular enzyme activities in seawater following aggregate formation

    NASA Astrophysics Data System (ADS)

    Ziervogel, K.; Steen, A. D.; Arnosti, C.

    2009-12-01

    Marine snow aggregates are heavily colonized by heterotrophic microorganisms that express high levels of hydrolytic activities, making aggregates hotspots for carbon remineralization in the ocean. To assess how aggregate formation influences the ability of seawater microbial communities to access organic carbon, we compared hydrolysis rates of six polysaccharides in coastal seawater after aggregates had been formed (via incubation on a roller table) with hydrolysis rates in seawater from the same site that had not incubated on a roller table (referred to as whole seawater). Hydrolysis rates in the aggregates themselves were up to three orders of magnitude higher on a volume basis than in whole seawater. The enhancement of enzyme activity in aggregates relative to whole seawater differed by substrate, suggesting that the enhancement was under cellular control, rather than due to factors such as lysis or grazing. A comparison of hydrolysis rates in whole seawater with those in aggregate-free seawater, i.e. the fraction of water from the roller bottles that did not contain aggregates, demonstrated a nuanced microbial response to aggregate formation. Activities of laminarinase and xylanase enzymes in aggregate-free seawater were higher than in whole seawater, while activities of chondroitin, fucoidan, and arabinogalactan hydrolyzing enzymes were lower than in whole seawater. These data suggest that aggregate formation enhanced production of laminarinase and xylanase enzymes, and the enhancement also affected the surrounding seawater. Decreased activities of chondroitin, fucoidan, and arabinoglactan-hydrolyzing enzymes in aggregate-free seawater relative to whole seawater are likely due to shifts in enzyme production by the aggregate-associated community, coupled with the effects of enzyme degradation. Enhanced activities of laminarin- and xylan-hydrolyzing enzymes in aggregate-free seawater were due at least in part to cell-free enzymes. Measurements of enzyme lifetime

  2. Meta-Analytic Connectivity Modelling Revisited: Controlling for Activation Base Rates

    PubMed Central

    Langner, Robert; Rottschy, Claudia; Laird, Angela R.; Fox, Peter T.; Eickhoff, Simon B.

    2014-01-01

    Co-activation of distinct brain regions is a measure of functional interaction, or connectivity, between those regions. The co-activation pattern of a given region can be investigated using seed-based activation likelihood estimation meta-analysis of functional neuroimaging data stored in databases such as BrainMap. This method reveals inter-regional functional connectivity by determining brain regions that are consistently co-activated with a given region of interest (the “seed”) across a broad range of experiments. In current implementations of this meta-analytic connectivity modelling (MACM), significant spatial convergence (i.e. consistent co-activation) is distinguished from noise by comparing it against an unbiased null-distribution of random spatial associations between experiments according to which all grey-matter voxels have the same chance of convergence. As the a priori probability of finding activation in different voxels markedly differs across the brain, computing such a quasi-rectangular null-distribution renders the detection of significant convergence more likely in those voxels that are frequently activated. Here, we propose and test a modified MACM approach that takes this activation frequency bias into account. In this new specific co-activation likelihood estimation (SCALE) algorithm, a null-distribution is generated that reflects the base rate of reporting activation in any given voxel and thus equalizes the a priori chance of finding across-study convergence in each voxel of the brain. Using four exemplary seed regions (right visual area V4, left anterior insula, right intraparietal sulcus, and subgenual cingulum), our tests corroborated the enhanced specificity of the modified algorithm, indicating that SCALE may be especially useful for delineating distinct core networks of co-activation. PMID:24945668

  3. Analysis of Fetal Heart Rate and Uterine Activity Signals by Using Apple II Plus Microcomputer *

    PubMed Central

    Yeh, Sze-ya; Jilek, Jiri; Yeh, Michael M.

    1981-01-01

    Intrapartum electronic fetal monitoring has been used widely for over a decade in obstetric practice. Its main purpose is to provide information about the labor and fetal conditions so that better obstetrical care can be provided. However, there is certain information obtained from monitoring which needs electronic or computer aids to make them useful clinically. This study describes the experience of using the Apple II plus microcomputer in obtaining and analyzing fetal heart rate and uterine activity signals from the intrapartum clinical monitor. This was done by building an analog-to-digital converting board and by using 6502 microprocessor machine language routines. Approximately 60 to 80 minutes of tracings can be processed before 30 kilobytes of memory are filled. The data is then transferred to a 5¼″ diskette for permanent storage and for future data reduction. With this approach, uterine activity units and fetal heart rate variability indices are calculated.

  4. Slip Rates of Main Active Fault Zones Through Turkey Inferred From GPS Observations

    NASA Astrophysics Data System (ADS)

    Ozener, H.; Aktug, B.; Dogru, A.; Tasci, L.; Acar, M.; Emre, O.; Yilmaz, O.; Turgut, B.; Halicioglu, K.; Sabuncu, A.; Bal, O.; Eraslan, A.

    2015-12-01

    Active Fault Map of Turkey was revised and published by General Directorate of Mineral Research and Exploration in 2012. This map reveals that there are about 500 faults can generate earthquakes.In order to understand the earthquake potential of these faults, it is needed to determine the slip rates. Although many regional and local studies were performed in the past, the slip rates of the active faults in Turkey have not been determined. In this study, the block modelling, which is the most common method to produce slip rates, will be done. GPS velocities required for block modeling is being compiled from the published studies and the raw data provided then velocity field is combined. To form a homogeneous velocity field, different stochastic models will be used and the optimal velocity field will be achieved. In literature, GPS site velocities, which are computed for different purposes and published, are combined globally and this combined velocity field are used in the analysis of strain accumulation. It is also aimed to develop optimal stochastic models to combine the velocity data. Real time, survey mode and published GPS observations is being combined in this study. We also perform new GPS observations. Furthermore, micro blocks and main fault zones from Active Fault Map Turkey will be determined and homogeneous velocity field will be used to infer slip rates of these active faults. Here, we present the result of first year of the study. This study is being supported by THE SCIENTIFIC AND TECHNOLOGICAL RESEARCH COUNCIL OF TURKEY (TUBITAK)-CAYDAG with grant no. 113Y430.

  5. Key Factors Influencing Rates of Heterotrophic Sulfate Reduction in Active Seafloor Hydrothermal Massive Sulfide Deposits.

    PubMed

    Frank, Kiana L; Rogers, Karyn L; Rogers, Daniel R; Johnston, David T; Girguis, Peter R

    2015-01-01

    Hydrothermal vents are thermally and geochemically dynamic habitats, and the organisms therein are subject to steep gradients in temperature and chemistry. To date, the influence of these environmental dynamics on microbial sulfate reduction has not been well constrained. Here, via multivariate experiments, we evaluate the effects of key environmental variables (temperature, pH, H2S, [Formula: see text], DOC) on sulfate reduction rates and metabolic energy yields in material recovered from a hydrothermal flange from the Grotto edifice in the Main Endeavor Field, Juan de Fuca Ridge. Sulfate reduction was measured in batch reactions across a range of physico-chemical conditions. Temperature and pH were the strongest stimuli, and maximum sulfate reduction rates were observed at 50°C and pH 6, suggesting that the in situ community of sulfate-reducing organisms in Grotto flanges may be most active in a slightly acidic and moderate thermal/chemical regime. At pH 4, sulfate reduction rates increased with sulfide concentrations most likely due to the mitigation of metal toxicity. While substrate concentrations also influenced sulfate reduction rates, energy-rich conditions muted the effect of metabolic energetics on sulfate reduction rates. We posit that variability in sulfate reduction rates reflect the response of the active microbial consortia to environmental constraints on in situ microbial physiology, toxicity, and the type and extent of energy limitation. These experiments help to constrain models of the spatial contribution of heterotrophic sulfate reduction within the complex gradients inherent to seafloor hydrothermal deposits.

  6. Properties of human motor units after prolonged activity at a constant firing rate.

    PubMed

    Johnson, K V B; Edwards, S C; Van Tongeren, C; Bawa, P

    2004-02-01

    The primary purpose of this study was to examine if there are changes in the intrinsic properties of spinal motoneurons after prolonged submaximal contractions. To do this, we assessed whether or not the synaptic drive to motoneurons needs to increase in order to maintain a constant firing rate of a motor unit. Recruitment of new units and an increase in total electromyographic (EMG) activity of the muscle of interest were taken as estimates of an increase in synaptic drive. Subjects were asked to maintain a constant firing rate of a clearly identifiable (targeted) motor unit from the first dorsal interosseous muscle for approximately 10 min, while surface EMG and force were recorded simultaneously. For the 60 units studied, the duration of the constant-firing-rate period ranged from 73 to 1,140 s (448 +/- 227 s; mean +/- SD). There was a significant increase ( t-test, p<0.001) in the magnitude of mean surface EMG, and DC force while the targeted motoneuron maintained a constant rate suggesting an increase in the net excitatory input to the motoneuron pool. Changes occurring simultaneously in other parameters, namely, variability in interspike interval, magnitude of force fluctuations, the duration of motor unit action potentials, and the median power frequency of surface EMG were also computed. The firing rates of 16 concurrently firing motoneurons, not controlled by the subject, remained constant. The key finding of this study is that after prolonged activity, a motoneuron requires a stronger excitatory input to maintain its firing rate. Additional results are indicative of significant changes in the characteristics of the synaptic inputs, changes at the neuromuscular junction (both pre- and postsynaptic regions) and the sarcolemma.

  7. Key Factors Influencing Rates of Heterotrophic Sulfate Reduction in Active Seafloor Hydrothermal Massive Sulfide Deposits

    PubMed Central

    Frank, Kiana L.; Rogers, Karyn L.; Rogers, Daniel R.; Johnston, David T.; Girguis, Peter R.

    2015-01-01

    Hydrothermal vents are thermally and geochemically dynamic habitats, and the organisms therein are subject to steep gradients in temperature and chemistry. To date, the influence of these environmental dynamics on microbial sulfate reduction has not been well constrained. Here, via multivariate experiments, we evaluate the effects of key environmental variables (temperature, pH, H2S, SO42−, DOC) on sulfate reduction rates and metabolic energy yields in material recovered from a hydrothermal flange from the Grotto edifice in the Main Endeavor Field, Juan de Fuca Ridge. Sulfate reduction was measured in batch reactions across a range of physico-chemical conditions. Temperature and pH were the strongest stimuli, and maximum sulfate reduction rates were observed at 50°C and pH 6, suggesting that the in situ community of sulfate-reducing organisms in Grotto flanges may be most active in a slightly acidic and moderate thermal/chemical regime. At pH 4, sulfate reduction rates increased with sulfide concentrations most likely due to the mitigation of metal toxicity. While substrate concentrations also influenced sulfate reduction rates, energy-rich conditions muted the effect of metabolic energetics on sulfate reduction rates. We posit that variability in sulfate reduction rates reflect the response of the active microbial consortia to environmental constraints on in situ microbial physiology, toxicity, and the type and extent of energy limitation. These experiments help to constrain models of the spatial contribution of heterotrophic sulfate reduction within the complex gradients inherent to seafloor hydrothermal deposits. PMID:26733984

  8. Key Factors Influencing Rates of Heterotrophic Sulfate Reduction in Active Seafloor Hydrothermal Massive Sulfide Deposits.

    PubMed

    Frank, Kiana L; Rogers, Karyn L; Rogers, Daniel R; Johnston, David T; Girguis, Peter R

    2015-01-01

    Hydrothermal vents are thermally and geochemically dynamic habitats, and the organisms therein are subject to steep gradients in temperature and chemistry. To date, the influence of these environmental dynamics on microbial sulfate reduction has not been well constrained. Here, via multivariate experiments, we evaluate the effects of key environmental variables (temperature, pH, H2S, [Formula: see text], DOC) on sulfate reduction rates and metabolic energy yields in material recovered from a hydrothermal flange from the Grotto edifice in the Main Endeavor Field, Juan de Fuca Ridge. Sulfate reduction was measured in batch reactions across a range of physico-chemical conditions. Temperature and pH were the strongest stimuli, and maximum sulfate reduction rates were observed at 50°C and pH 6, suggesting that the in situ community of sulfate-reducing organisms in Grotto flanges may be most active in a slightly acidic and moderate thermal/chemical regime. At pH 4, sulfate reduction rates increased with sulfide concentrations most likely due to the mitigation of metal toxicity. While substrate concentrations also influenced sulfate reduction rates, energy-rich conditions muted the effect of metabolic energetics on sulfate reduction rates. We posit that variability in sulfate reduction rates reflect the response of the active microbial consortia to environmental constraints on in situ microbial physiology, toxicity, and the type and extent of energy limitation. These experiments help to constrain models of the spatial contribution of heterotrophic sulfate reduction within the complex gradients inherent to seafloor hydrothermal deposits. PMID:26733984

  9. A mathematical method for extracting cell secretion rate from affinity biosensors continuously monitoring cell activity.

    PubMed

    Gao, Yandong; Zhou, Qing; Matharu, Zimple; Liu, Ying; Kwa, Timothy; Revzin, Alexander

    2014-03-01

    Our laboratory has previously developed miniature aptasensors that may be integrated at the site of a small group of cells for continuous detection of cell secreted molecules such as inflammatory cytokine interferon gamma (IFN-γ). In a system such as this, the signal measured at the sensor surfaces is a complex function of transport, reaction, as well as of cellular activity. Herein, we report on the development of a mathematical framework for extracting cell production rates from binding curves generated with affinity biosensors. This framework consisted of a diffusion-reaction model coupled to a root finding algorithm for determining cell production rates values causing convergence of a predetermined criterion. To experimentally validate model predictions, we deployed a microfluidic device with an integrated biosensor for measuring the IFN-γ release from CD4 T cells. We found close agreement between secretion rate observed theoretically and those observed experimentally. After taking into account the differences in sensor geometry and reaction kinetics, the method for cell secretion rate determination described in this paper may be broadly applied to any biosensor continuously measuring cellular activity.

  10. Isothermal titration calorimetry determination of individual rate constants of trypsin catalytic activity.

    PubMed

    Aguirre, César; Condado-Morales, Itzel; Olguin, Luis F; Costas, Miguel

    2015-06-15

    Determination of individual rate constants for enzyme-catalyzed reactions is central to the understanding of their mechanism of action and is commonly obtained by stopped-flow kinetic experiments. However, most natural substrates either do not fluoresce/absorb or lack a significant change in their spectra while reacting and, therefore, are frequently chemically modified to render adequate molecules for their spectroscopic detection. Here, isothermal titration calorimetry (ITC) was used to obtain Michaelis-Menten plots for the trypsin-catalyzed hydrolysis of several substrates at different temperatures (278-318K): four spectrophotometrically blind lysine and arginine N-free esters, one N-substituted arginine ester, and one amide. A global fitting of these data provided the individual rate constants and activation energies for the acylation and deacylation reactions, and the ratio of the formation and dissociation rates of the enzyme-substrate complex, leading also to the corresponding free energies of activation. The results indicate that for lysine and arginine N-free esters deacylation is the rate-limiting step, but for the N-substituted ester and the amide acylation is the slowest step. It is shown that ITC is able to produce quality kinetic data and is particularly well suited for those enzymatic reactions that cannot be measured by absorption or fluorescence spectroscopy.

  11. The Light-Curve and Rotation Rate of 'Active Asteroid' 313P/Gibbs

    NASA Astrophysics Data System (ADS)

    Milewski, Dave Gerald

    2016-10-01

    The 'Active Asteroids' are a strange, yet newly discovered class of small bodies in the Solar System that have the orbital and dynamical properties of asteroids, but also the physical properties of comets (ejection of dust and volatile materials). Of the known ~25 Active Asteroids discovered thus far (Jewitt, Hseih, Argwal, 2015), only 4 have been known to be active on subsequent multiple occasions 238P/Read, 133P/Elst-Pizarro, 324P/La Sagra, (Jewitt et al. 2016) and 313P/Gibbs. In this work, we have determined the rotation rate and light-curve for Active Asteroid 313P/Gibbs using the Keck 10-m telescope to better understand the mechanisms and drivers of subsequent activity in this Solar System Small Body so that we may form a more complete picture of this population, better characterize them, and add to our inventory of Solar System small bodies to form a more complete model of the formation of the Solar System as well as what this may imply for future detection of activity in the Active Asteroid population.

  12. Solar Magnetic Activity Cycles, Coronal Potential Field Models and Eruption Rates

    NASA Astrophysics Data System (ADS)

    Petrie, G. J. D.

    2013-05-01

    We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the National Solar Observatory's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun vector spectro-magnetograph, the spectro-magnetograph and the 512-channel magnetograph instruments, and from Stanford University's Wilcox Solar Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Polar field changes are found to be well correlated with active fields over most of the period studied, except between 2003 and 2006 when the active fields did not produce significant polar field changes. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the activity cycle. All non-axisymmetric multipole strengths are well correlated with the activity cycle. The tilt of the solar dipole is therefore almost entirely due to active-region fields. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This influence of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking, Solar Eruptive Event Detection System, and Nobeyama radioheliograph prominence eruption catalogs, the rate of solar eruptions is found to be systematically higher for active years between 2003 and 2012 than for those between 1997 and 2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.

  13. SOLAR MAGNETIC ACTIVITY CYCLES, CORONAL POTENTIAL FIELD MODELS AND ERUPTION RATES

    SciTech Connect

    Petrie, G. J. D.

    2013-05-10

    We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the National Solar Observatory's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun vector spectro-magnetograph, the spectro-magnetograph and the 512-channel magnetograph instruments, and from Stanford University's Wilcox Solar Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Polar field changes are found to be well correlated with active fields over most of the period studied, except between 2003 and 2006 when the active fields did not produce significant polar field changes. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the activity cycle. All non-axisymmetric multipole strengths are well correlated with the activity cycle. The tilt of the solar dipole is therefore almost entirely due to active-region fields. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This influence of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking, Solar Eruptive Event Detection System, and Nobeyama radioheliograph prominence eruption catalogs, the rate of solar eruptions is found to be systematically higher for active years between 2003 and 2012 than for those between 1997 and 2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.

  14. Energy expenditure in children predicted from heart rate and activity calibrated against respiration calorimetry.

    PubMed

    Treuth, M S; Adolph, A L; Butte, N F

    1998-07-01

    The purpose of this study was to predict energy expenditure (EE) from heart rate (HR) and activity calibrated against 24-h respiration calorimetry in 20 children. HR, oxygen consumption (VO2), carbon dioxide production (VCO2), and EE were measured during rest, sleep, exercise, and over 24 h by room respiration calorimetry on two separate occasions. Activity was monitored by a leg vibration sensor. The calibration day (day 1) consisted of specified behaviors categorized as inactive (lying, sitting, standing) or active (two bicycle sessions). On the validation day (day 2), the child selected activities. Separate regression equations for VO2, VCO2, and EE for method 1 (combining awake and asleep using HR, HR2, and HR3), method 2 (separating awake and asleep), and method 3 (separating awake into active and inactive, and combining activity and HR) were developed using the calibration data. For day 1, the errors were similar for 24-h VO2, VCO2, and EE among methods and also among HR, HR2, and HR3. The methods were validated using measured data from day 2. There were no significant differences in HR, VO2, VCO2, respiratory quotient, and EE values during rest, sleep, or over the 24 h between days 1 and 2. Applying the linear HR equations to day 2 data, the errors were the lowest with the combined HR/activity method (-2.6 +/- 5.2%, -4.1 +/- 5.9%, -2.9 +/- 5.1% for VO2, VCO2, and EE, respectively). To demonstrate the utility of the HR/activity method, HR and activity were monitored for 24 h at home (day 3). Free-living EE was predicted as 7,410 +/- 1,326 kJ/day. In conclusion, the combination of HR and activity is an acceptable method for determining EE not only for groups of children, but for individuals.

  15. ESTIMATION OF MICROBIAL REDUCTIVE TRANSFORMATION RATES FOR CHLORINATED BENZENES AND PHENOLS USING A QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP APPROACH

    EPA Science Inventory

    A set of literature data was used to derive several quantitative structure-activity relationships (QSARs) to predict the rate constants for the microbial reductive dehalogenation of chlorinated aromatics. Dechlorination rate constants for 25 chloroaromatics were corrected for th...

  16. Outdoor physical activity and self rated health in older adults living in two regions of the U.S.

    PubMed Central

    2012-01-01

    Background Older adults spend little time outdoors and many are physically inactive. The relationship between outdoor physical activity and self rated health has not been studied in older adults. This paper aimed to assess the relation of location of physical activity to self rated health and physical activity minutes. This was an observational study of ambulatory adults 66 years and older conducted in 2005–2008. Participants (N = 754) completed survey measures of physical activity location and self rated health, and wore an accelerometer to objectively assess physical activity. A mixed model linear regression procedure adjusted for neighborhood clustering effects. Differences in self rated health and physical activity minutes were compared across three physical activity settings (indoor only, outdoor only, both indoor and outdoor). Results Minutes of moderate to vigorous physical activity were significantly greater in those who were physically active at least once a week outdoors compared with those who were physically active indoors only. Self rated health was significantly related to being physically active but did not vary by location of activity. Conclusions Older adults who were physically active outdoors accumulated significantly more physical activity, but self-rated health was not significantly greater than those being physically active indoors. PMID:22846594

  17. Correlations of regional postmortem enzyme activities with premortem local glucose metabolic rates in Alzheimer's disease.

    PubMed

    McGeer, E G; McGeer, P L; Harrop, R; Akiyama, H; Kamo, H

    1990-12-01

    Correlations were sought between local cerebral metabolic rates (LCMRs) for glucose in various regions of the cortex, determined in premortem PET scans, with the regional activities of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), beta-glucuronidase (Gluc, a probable index of reactive gliosis), and phosphate-activated glutaminase (PAG, a possible indice of the large pyramidal neurons) measured on postmortem tissue. Significant negative correlations between LCMRs and Gluc activities were found in 6 PET-scanned cases of Alzheimer disease (AD), and positive correlations of LCMRs with PAG were found in 5. By contrast, a positive correlation with ChAT and AChE was found in only 1. The results are consistent with the metabolic deficits in AD being primarily a reflection of local neuronal loss and gliosis. Similar data on two cases of Huntington's disease showed no significant correlations, while 1 patient with Parkinson dementia showed a significant (negative) correlation only with Gluc.

  18. Health literacy rates in a sample of active duty military personnel.

    PubMed

    Weld, Konstantine Keian; Padden, Diane; Ricciardi, Richard; Bibb, Sandra C Garmon

    2009-11-01

    The results reported in this article are from a larger descriptive study examining the health literacy rates in active duty military personnel receiving health care within a culture of universal access. The purpose of this article is to describe the health literacy skills among a sample of active duty military personnel with comparison to the national population. Data were collected using the shortened version of the Test of Functional Health Literacy in Adults (S-TOFHLA) and the Rapid Estimate of Adult Literacy in Medicine (REALM) in a convenience sample of 155 active duty subjects at a major military hospital from January 2007 through May 2007. Results indicate that military personnel have adequate health literacy skills although variations were noted on the basis of health training and race/ethnicity. Although the S-TOFHLA was found to be a practical tool for assessing health literacy in a high-tempo health care setting, additional reliability and validity testing is needed.

  19. Seasonal variation in metabolic rate, flight activity and body size of Anopheles gambiae in the Sahel

    PubMed Central

    Huestis, Diana L.; Yaro, Alpha S.; Traoré, Adama I.; Dieter, Kathryne L.; Nwagbara, Juliette I.; Bowie, Aleah C.; Adamou, Abdoulaye; Kassogué, Yaya; Diallo, Moussa; Timbiné, Seydou; Dao, Adama; Lehmann, Tovi

    2012-01-01

    SUMMARY Malaria in Africa is vectored primarily by the Anopheles gambiae complex. Although the mechanisms of population persistence during the dry season are not yet known, targeting dry season mosquitoes could provide opportunities for vector control. In the Sahel, it appears likely that M-form A. gambiae survive by aestivation (entering a dormant state). To assess the role of eco-physiological changes associated with dry season survival, we measured body size, flight activity and metabolic rate of wild-caught mosquitoes throughout 1 year in a Sahelian locality, far from permanent water sources, and at a riparian location adjacent to the Niger River. We found significant seasonal variation in body size at both the Sahelian and riparian sites, although the magnitude of the variation was greater in the Sahel. For flight activity, significant seasonality was only observed in the Sahel, with increased flight activity in the wet season when compared with that just prior to and throughout the dry season. Whole-organism metabolic rate was affected by numerous biotic and abiotic factors, and a significant seasonal component was found at both locations. However, assay temperature accounted completely for seasonality at the riparian location, while significant seasonal variation remained after accounting for all measured variables in the Sahel. Interestingly, we did not find that mean metabolic rate was lowest during the dry season at either location, contrary to our expectation that mosquitoes would conserve energy and increase longevity by reducing metabolism during this time. These results indicate that mosquitoes may use mechanisms besides reduced metabolic rate to enable survival during the Sahelian dry season. PMID:22623189

  20. Spatial distribution of microorganisms and measurements of oxygen uptake rate and ammonia uptake rate activity in a drinking water biofilter.

    PubMed

    Madoni, P; Davoli, D; Fontani, N; Cucchi, A; Rossi, F

    2001-04-01

    The biofilm characteristics (population dynamics and biofilm composition) in a biological filter for the removal of iron, manganese and ammonium were studied in a drinking water treatment plant. The objective was to examine the spatial distribution and biological composition of active biomass that grows in a biological filter and to verify the effect of the backwashing on the quantity of fixed biomass and on the density and activity of the biological population. Heterotrophic microorganisms activity was higher in the upper layer of the filter. Nitrifying microorganisms colonized the biofilter in a stratified manner and their activity was higher in the second layer of the filter. A total of 14 species of ciliated protozoa and 7 species of filamentous microorganisms were found in the biofilters. Ciliates were concentrated in the filterbed layer in which the heterotrophic activity was higher. The grazing activity of ciliates on heterotrophic bacteria reduced the competition pressure on nitrifying microorganisms, supporting their growth and thus raising the ammonium removal efficiency. In general, filamentous microorganisms appeared to be indifferent to operating changes in the plant such as backwashing and filtering cycles. Crenothrix was the prevalent filamentous microorganism in terms of both frequency and abundance; it was found prevalently in the first layer where the oxidisation of iron and manganese occurred.

  1. Levels and Rates of Physical Activity in Older Adults with Multiple Sclerosis.

    PubMed

    Klaren, Rachel E; Sebastiao, Emerson; Chiu, Chung-Yi; Kinnett-Hopkins, Dominique; McAuley, Edward; Motl, Robert W

    2016-05-01

    There is much evidence supporting the safety and benefits of physical activity in adults with multiple sclerosis (MS) and recent evidence of beneficial effects on physical function in older adults with MS. However, there is very little known about physical activity participation in older adults with conditions such as MS. This study compared levels of physical activity (i.e., sedentary behavior, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)) and rates of meeting public health guidelines for MVPA (i.e., ≥30 min/day) among young (i.e., ages 20-39 years), middle-aged (i.e., ages 40-59 years) and older adults (i.e., ages ≥60 years) with MS. The sample included 963 persons with MS who provided demographic and clinical information and wore an accelerometer for a 7-day period. The primary analysis involved a between-subjects ANOVA on accelerometer variables (i.e., accelerometer wear time; number of valid days; sedentary behavior in min/day; LPA in min/day; and MVPA in min/day). Collectively, our data indicated that older adults with MS engaged in less MVPA and more sedentary behavior than middle-aged and young adults with MS. Such results highlight the importance of developing physical activity interventions as an effective means for managing the progression and consequences of MS in older adults. PMID:27330842

  2. Levels and Rates of Physical Activity in Older Adults with Multiple Sclerosis

    PubMed Central

    Klaren, Rachel E.; Sebastiao, Emerson; Chiu, Chung-Yi; Kinnett-Hopkins, Dominique; McAuley, Edward; Motl, Robert W.

    2016-01-01

    There is much evidence supporting the safety and benefits of physical activity in adults with multiple sclerosis (MS) and recent evidence of beneficial effects on physical function in older adults with MS. However, there is very little known about physical activity participation in older adults with conditions such as MS. This study compared levels of physical activity (i.e., sedentary behavior, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)) and rates of meeting public health guidelines for MVPA (i.e., ≥30 min/day) among young (i.e., ages 20-39 years), middle-aged (i.e., ages 40-59 years) and older adults (i.e., ages ≥60 years) with MS. The sample included 963 persons with MS who provided demographic and clinical information and wore an accelerometer for a 7-day period. The primary analysis involved a between-subjects ANOVA on accelerometer variables (i.e., accelerometer wear time; number of valid days; sedentary behavior in min/day; LPA in min/day; and MVPA in min/day). Collectively, our data indicated that older adults with MS engaged in less MVPA and more sedentary behavior than middle-aged and young adults with MS. Such results highlight the importance of developing physical activity interventions as an effective means for managing the progression and consequences of MS in older adults. PMID:27330842

  3. Measurements of Heart Rate and Accelerometry to Determine the Physical Activity Level in Boys Playing Paintball

    PubMed Central

    JARVI, MICHELLE; BROWN, GREGORY A; SHAW, BRANDON S.; SHAW, INA

    2013-01-01

    Paintball is a popular recreational sport played by 3.655 million Americans and may be sufficient physical activity to promote health. Paintball has been played as an organized sport since the 1980’s and is essentially a game of tag, except instead of touching an opponent by hand opponents are tagged by shooting them with a paintball that leaves a mark indicating who has been eliminated. A previous evaluation of paintball as physical activity had 13 subjects undergo a VO2max test to develop a heart rate (HR) /oxygen consumption relationship, and it was observed that heart rates during paintball were 68–73% of the measured maximal HR. The present study used accelerometry and HR monitors to evaluate the quantity and intensity of physical activity in boys playing paintball. Eleven boys (12.7 ± 1.0 y, 51.5 ± 11.3 kg, 161.8 ± 10.1 cm) engaged in a VO2max test to develop a HR/oxygen consumption correlation. On a separate day the boys played 7 games of outdoor paintball while wearing a HR monitor and accelerometer. The boys played paintball for 11.5 ± 6.2 minutes/game for a total of 80.6 ± 10.0 minutes of game play. Average HR during paintball play was 129.6 ± 6.6 beats/min, representing 39.9 ± 12.9% VO2max. Based on accelerometry, the boys accumulated 63.2 ± 15.6 minutes of moderate intensity activity and 2.6 ± 2.8 minutes of vigorous activity during paintball. These data suggest that playing paintball may be considered as physical activity that is > 3 METs, and thus health promoting. PMID:27182396

  4. Bacterivory Rate Estimates and Fraction of Active Bacterivores in Natural Protist Assemblages from Aquatic Systems†

    PubMed Central

    González, Juan M.

    1999-01-01

    Unlike the fraction of active bacterioplankton, the fraction of active bacterivores (i.e., those involved in grazing) during a specified time period has not been studied yet. Fractions of protists actively involved in bacterivory were estimated assuming that the distributions of bacteria and fluorescently labeled bacteria (FLB) ingested by protists follow Poisson distributions. Estimates were compared with experimental data obtained from FLB uptake experiments. The percentages of protists with ingested FLB (experimental) and the estimates obtained from Poisson distributions were similar for both flagellates and ciliates. Thus, the fraction of protists actively grazing on natural bacteria during a given time period could be estimated. The fraction of protists with ingested bacteria depends on the incubation time and reaches a saturating value. Aquatic systems with very different characteristics were analyzed; estimates of the fraction of protists actively grazing on bacteria ranged from 7 to 100% in the studied samples. Some nanoflagellates appeared to be grazing on specific bacterial sizes. Evidence indicated that there was no discrimination for or against bacterial surrogates (i.e., FLB); also, bacteria were randomly encountered by bacterivorous protists during these short-term uptake experiments. These analyses made it possible to estimate the ingestion rates from FLB uptake experiments by counting the number of flagellates containing ingested FLB. These results represent the first reported estimates of active bacterivores in natural aquatic systems; also, a proposed protocol for estimating in situ ingestion rates by protists represents a significant improvement and simplification to the current protocol and avoids the tedious work of counting the number of ingested FLB per protist. PMID:10103238

  5. Bacterivory rate estimates and fraction of active bacterivores in natural protist assemblages from aquatic systems

    PubMed

    Gonzalez

    1999-04-01

    Unlike the fraction of active bacterioplankton, the fraction of active bacterivores (i.e., those involved in grazing) during a specified time period has not been studied yet. Fractions of protists actively involved in bacterivory were estimated assuming that the distributions of bacteria and fluorescently labeled bacteria (FLB) ingested by protists follow Poisson distributions. Estimates were compared with experimental data obtained from FLB uptake experiments. The percentages of protists with ingested FLB (experimental) and the estimates obtained from Poisson distributions were similar for both flagellates and ciliates. Thus, the fraction of protists actively grazing on natural bacteria during a given time period could be estimated. The fraction of protists with ingested bacteria depends on the incubation time and reaches a saturating value. Aquatic systems with very different characteristics were analyzed; estimates of the fraction of protists actively grazing on bacteria ranged from 7 to 100% in the studied samples. Some nanoflagellates appeared to be grazing on specific bacterial sizes. Evidence indicated that there was no discrimination for or against bacterial surrogates (i.e., FLB); also, bacteria were randomly encountered by bacterivorous protists during these short-term uptake experiments. These analyses made it possible to estimate the ingestion rates from FLB uptake experiments by counting the number of flagellates containing ingested FLB. These results represent the first reported estimates of active bacterivores in natural aquatic systems; also, a proposed protocol for estimating in situ ingestion rates by protists represents a significant improvement and simplification to the current protocol and avoids the tedious work of counting the number of ingested FLB per protist.

  6. Association between Heart Rate Variability, Blood Pressure and Autonomic Activity in Cyclic Alternating Pattern during Sleep

    PubMed Central

    Kondo, Hideaki; Ozone, Motohiro; Ohki, Noboru; Sagawa, Yohei; Yamamichi, Keiichirou; Fukuju, Mitsuki; Yoshida, Takeshi; Nishi, Chikako; Kawasaki, Akiko; Mori, Kaori; Kanbayashi, Takashi; Izumi, Motomori; Hishikawa, Yasuo; Nishino, Seiji; Shimizu, Tetsuo

    2014-01-01

    Study Objectives: Cyclic alternating pattern (CAP) is frequently followed by changes in heart rate (HR) and blood pressure (BP), but the sequential associations between CAP and autonomic nerve activity have not been studied. The study aimed to reveal the precise changes in heart rate variability (HRV) during phase A of the CAP cycle. Design: Polysomnography was recorded according to the CAP Atlas (Terzano, 2002), and BP and electrocardiogram were simultaneously recorded. The complex demodulation method was used for analysis of HRV and evaluation of autonomic nerve activity. Setting: Academic sleep laboratory. Participants: Ten healthy males. Measurements and Results: The increase in HR (median [first quartile – third quartile]) for each subtype was as follows: A1, 0.64 (-0.30 to 1.69), A2, 1.44 (0.02 to 3.79), and A3, 6.24 (2.53 to 10.76) bpm (A1 vs. A2 P < 0.001, A1 vs. A3 P < 0.001, A2 vs. A3 P < 0.001). The increase in BP for each subtype was as follows: A1, 1.23 (-2.04 to 5.75), A2, 1.76 (-1.46 to 9.32), and A3, 12.51 (4.75 to 19.94) mm Hg (A1 vs. A2 P = 0.249, A1 vs. A3 P < 0.001, A2 vs. A3 P < 0.001). In all of phase A, the peak values for HR and BP appeared at 4.2 (3.5 to 5.4) and 8.4 (7.0 to 10.3) seconds, respectively, after the onset of phase A. The area under the curve for low-frequency and high-frequency amplitude significantly increased after the onset of CAP phase A (P < 0.001) and was higher in the order of subtype A3, A2, and A1 (P < 0.001). Conclusions: All phase A subtypes were accompanied with increased heart rate variability, and the largest heart rate variability was seen in subtype A3, while a tendency for less heart rate variability was seen in subtype A1. Citation: Kondo H; Ozone M; Ohki N; Sagawa Y; Yamamichi K; Fukuju M; Yoshida T; Nishi C; Kawasaki; Mori; Kanbayashi T; Izumi M; Hishikawa Y; Nishino S; Shimizu T. Association between heart rate variability, blood pressure and autonomic activity in cyclic alternating pattern during sleep

  7. PEE-PEO block copolymer exchange rate between micelles is detergent and temperature activated

    NASA Astrophysics Data System (ADS)

    Schantz, Allen; Saboe, Patrick; Lee, Hee-Young; Sines, Ian; Butler, Paul; Bishop, Kyle; Maranas, Janna; Kumar, Manish

    We examine the kinetics of polymer chain exchange between polymer/detergent micelles, a system relevant to the synthesis of protein-containing biomimetic membranes. Although chain exchange between polymer aggregates in water is too slow to observe, adding detergent allows us to determine chain exchange rates using time-resolved small-angle neutron scattering (TR-SANS). We examine a membrane-protein-relevant, vesicle-forming ultra-short polymer, Poly(ethyl ethylene)20-Poly(ethylene oxide)18 (PEE20-PEO18). PEE20-PEO18 is solubilized in mixed micelles with the membrane-protein-compatible non-ionic detergent octyl- β -D-glucoside (OG). We show that OG activates block copolymer exchange, and obtain rate constants at two detergent concentrations above the CMC (critical micellar concentration) of OG. We find that chain exchange increases two orders of magnitude when temperature increases from 308 to 338 K, and that even a 1 mg/mL increase in OG concentration leads to a noticeable increase in exchange rate. We also calculate the activation energy for chain exchange and find that it is much higher than for lipid exchange. These findings explain the need for high detergent concentration and/or temperature to synthesize densely packed polymer/protein membranes.

  8. Rapid cooling rates at an active mid-ocean ridge from zircon thermochronology

    USGS Publications Warehouse

    Schmitt, Axel K.; Perfit, Michael R.; Rubin, Kenneth H.; Stockli, Daniel F.; Smith, Matthew C.; Cotsonika, Laurie A.; Zellmer, Georg F.; Ridley, W. Ian

    2011-01-01

    Oceanic spreading ridges are Earth's most productive crust generating environment, but mechanisms and rates of crustal accretion and heat loss are debated. Existing observations on cooling rates are ambiguous regarding the prevalence of conductive vs. convective cooling of lower oceanic crust. Here, we report the discovery and dating of zircon in mid-ocean ridge dacite lavas that constrain magmatic differentiation and cooling rates at an active spreading center. Dacitic lavas erupted on the southern Cleft segment of the Juan de Fuca ridge, an intermediate-rate spreading center, near the intersection with the Blanco transform fault. Their U–Th zircon crystallization ages (29.3-4.6+4.8 ka; 1δ standard error s.e.) overlap with the (U–Th)/He zircon eruption age (32.7 ± 1.6 ka) within uncertainty. Based on similar 238U-230Th disequilibria between southern Cleft dacite glass separates and young mid-ocean ridge basalt (MORB) erupted nearby, differentiation must have occurred rapidly, within ~ 10–20 ka at most. Ti-in-zircon thermometry indicates crystallization at 850–900 °C and pressures > 70–150 MPa are calculated from H2O solubility models. These time-temperature constraints translate into a magma cooling rate of ~ 2 × 10-2 °C/a. This rate is at least one order-of-magnitude faster than those calculated for zircon-bearing plutonic rocks from slow spreading ridges. Such short intervals for differentiation and cooling can only be resolved through uranium-series (238U–230Th) decay in young lavas, and are best explained by dissipating heat convectively at high crustal permeability.

  9. Rapid cooling rates at an active mid-ocean ridge from zircon thermochronology

    NASA Astrophysics Data System (ADS)

    Schmitt, Axel K.; Perfit, Michael R.; Rubin, Kenneth H.; Stockli, Daniel F.; Smith, Matthew C.; Cotsonika, Laurie A.; Zellmer, Georg F.; Ridley, W. Ian; Lovera, Oscar M.

    2011-02-01

    Oceanic spreading ridges are Earth's most productive crust generating environment, but mechanisms and rates of crustal accretion and heat loss are debated. Existing observations on cooling rates are ambiguous regarding the prevalence of conductive vs. convective cooling of lower oceanic crust. Here, we report the discovery and dating of zircon in mid-ocean ridge dacite lavas that constrain magmatic differentiation and cooling rates at an active spreading center. Dacitic lavas erupted on the southern Cleft segment of the Juan de Fuca ridge, an intermediate-rate spreading center, near the intersection with the Blanco transform fault. Their U-Th zircon crystallization ages (29.3 - 4.6 + 4.8 ka; 1σ standard error s.e.) overlap with the (U-Th)/He zircon eruption age (32.7 ± 1.6 ka) within uncertainty. Based on similar 238U- 230Th disequilibria between southern Cleft dacite glass separates and young mid-ocean ridge basalt (MORB) erupted nearby, differentiation must have occurred rapidly, within ~ 10-20 ka at most. Ti-in-zircon thermometry indicates crystallization at 850-900 °C and pressures > 70-150 MPa are calculated from H 2O solubility models. These time-temperature constraints translate into a magma cooling rate of ~ 2 × 10 - 2 °C/a. This rate is at least one order-of-magnitude faster than those calculated for zircon-bearing plutonic rocks from slow spreading ridges. Such short intervals for differentiation and cooling can only be resolved through uranium-series ( 238U- 230Th) decay in young lavas, and are best explained by dissipating heat convectively at high crustal permeability.

  10. Effect of recirculation rate on methane production and SEBAR system performance using active stage digester.

    PubMed

    Tubtong, Cheevanuch; Towprayoon, Sirintornthep; Connor, Michael Anthony; Chaiprasert, Pawinee; Nopharatana, Annop

    2010-09-01

    A project was undertaken to examine the feasibility of treating organic wastes from Thai fruit and vegetable markets using the sequential batch anaerobic digester (SEBAR) approach. A key feature of the SEBAR system is the regular interchanging, or recirculation, of portions of leachate between each freshly filled digester and a support digester to which it is coupled until it is ready to operate independently. Leachate transfer from this support digester to the fresh waste digester provides additional alkalinity to help counteract the effects of early high acid release rates; it also helps build a balanced microbial population in the fresh waste digester. To optimize the leachate recirculation process, the effect of varying the quantities of leachate interchanged between freshly filled waste digesters and the still highly active support digesters to which they were coupled was studied. It was found that increasing the recirculation rate accelerated the onset of both waste degradation and methane production. The increasing of recirculation rate from 10% to 20% and 10% to 30% could reduce the SEBAR cycle period by approximately 7% and 22% without significant reduction in the amount of methane obtained from the systems. The methane yields were 0.0063, 0.0068 and 0.0077 l g(-1) VS added in the NEW digester per day using leachate recirculation rates of 10%, 20% and 30%, respectively. This finding has potentially important practical and economic implications for those using the SEBAR system to add value to market waste. PMID:20124320

  11. CHMP5 controls bone turnover rates by dampening NF-κB activity in osteoclasts

    PubMed Central

    Greenblatt, Matthew B.; Park, Kwang Hwan; Oh, Hwanhee; Kim, Jung-Min; Shin, Dong Yeon; Lee, Jae Myun; Lee, Jin Woo; Singh, Anju; Lee, Ki-young; Hu, Dorothy; Xiao, Changchun; Charles, Julia F.; Penninger, Josef M.; Lotinun, Sutada; Baron, Roland; Ghosh, Sankar

    2015-01-01

    Physiological bone remodeling requires that bone formation by osteoblasts be tightly coupled to bone resorption by osteoclasts. However, relatively little is understood about how this coupling is regulated. Here, we demonstrate that modulation of NF-κB signaling in osteoclasts via a novel activity of charged multivesicular body protein 5 (CHMP5) is a key determinant of systemic rates of bone turnover. A conditional deletion of CHMP5 in osteoclasts leads to increased bone resorption by osteoclasts coupled with exuberant bone formation by osteoblasts, resembling an early onset, polyostotic form of human Paget’s disease of bone (PDB). These phenotypes are reversed by haploinsufficiency for Rank, as well as by antiresorptive treatments, including alendronate, zolendronate, and OPG-Fc. Accordingly, CHMP5-deficient osteoclasts display increased RANKL-induced NF-κB activation and osteoclast differentiation. Biochemical analysis demonstrated that CHMP5 cooperates with the PDB genetic risk factor valosin-containing protein (VCP/p97) to stabilize the inhibitor of NF-κBα (IκBα), down-regulating ubiquitination of IκBα via the deubiquitinating enzyme USP15. Thus, CHMP5 tunes NF-κB signaling downstream of RANK in osteoclasts to dampen osteoclast differentiation, osteoblast coupling and bone turnover rates, and disruption of CHMP5 activity results in a PDB-like skeletal disorder. PMID:26195726

  12. Cortical Network Models of Firing Rates in the Resting and Active States Predict BOLD Responses.

    PubMed

    Bennett, Maxwell R; Farnell, Les; Gibson, William G; Lagopoulos, Jim

    2015-01-01

    Measurements of blood oxygenation level dependent (BOLD) signals have produced some surprising observations. One is that their amplitude is proportional to the entire activity in a region of interest and not just the fluctuations in this activity. Another is that during sleep and anesthesia the average BOLD correlations between regions of interest decline as the activity declines. Mechanistic explanations of these phenomena are described here using a cortical network model consisting of modules with excitatory and inhibitory neurons, taken as regions of cortical interest, each receiving excitatory inputs from outside the network, taken as subcortical driving inputs in addition to extrinsic (intermodular) connections, such as provided by associational fibers. The model shows that the standard deviation of the firing rate is proportional to the mean frequency of the firing when the extrinsic connections are decreased, so that the mean BOLD signal is proportional to both as is observed experimentally. The model also shows that if these extrinsic connections are decreased or the frequency of firing reaching the network from the subcortical driving inputs is decreased, or both decline, there is a decrease in the mean firing rate in the modules accompanied by decreases in the mean BOLD correlations between the modules, consistent with the observed changes during NREM sleep and under anesthesia. Finally, the model explains why a transient increase in the BOLD signal in a cortical area, due to a transient subcortical input, gives rises to responses throughout the cortex as observed, with these responses mediated by the extrinsic (intermodular) connections.

  13. Wear rate quantifying in real-time using the charged particle surface activation

    NASA Astrophysics Data System (ADS)

    Alexandreanu, B.; Popa-Simil, L.; Voiculescu, D.; Racolta, P. M.

    1997-02-01

    Surface activation, commonly known as Thin Layer Activation (TLA), is currently employed in over 30 accelerator laboratories around the world for wear and/or corrosion monitoring in industrial plants [1-6]. TLA was primarily designed and developed to meet requirements of potential industrial partners, in order to transfer this technique from research to industry. The method consists of accelerated ion bombardment of a surface of interest, e.g., a machine part subjected to wear. Loss of material owing to wear, erosive corrosion or abrasion is characterized by monitoring the resultant changes in radioactivity. In principle, depending upon the case at hand, one may choose to measure either the remnant activity of the component of interest or to monitor the activity of the debris. For applications of the second type, especially when a lubricating agent is involved, dedicated installations have been constructed and adapted to an engine or a tribological testing stand in order to assure oil circulation around an externally placed detection gauge. This way, the wear particles suspended in the lubricant can be detected and the material loss rates quantified in real time. Moreover, in specific cases, such as the one presented in this paper, remnant activity measurements prove to be useful tools for complementary results. This paper provides a detailed presentation of such a case: in situ resistance-to-wear testing of two types of piston rings.

  14. Intrinsic activity and poisoning rate for HCOOH oxidation on platinum stepped surfaces.

    PubMed

    Grozovski, Vitali; Climent, Víctor; Herrero, Enrique; Feliu, Juan M

    2010-08-21

    Pulsed voltammetry has been used to study formic acid oxidation on platinum stepped surfaces to determine the kinetics of the reaction and the role of the surface structure in the reactivity. From the current transients at different potentials, the intrinsic activity of the electrode through the active intermediate reaction path (j(theta = 0)), as well as the rate constant for the CO formation (k(ads)) have been calculated. The kinetics for formic acid oxidation through the active intermediate reaction path is strongly dependent on the surface structure of the electrode, with the highest activity found for the Pt(100) surface. The presence of steps, both on (100) and (111) terraces, does not increase the activity of these surfaces. CO formation only takes place in a narrow potential window very close to the local potential of zero total charge. The extrapolation of the results obtained with stepped surfaces with (111) terraces to zero step density indicates that CO formation should not occur on an ideal Pt(111) electrode. Additionally, the analysis of the Tafel slopes obtained for the different electrodes suggests that the oxidation of formic acid is strongly affected by the presence of adsorbed anions, hydrogen and water. PMID:20539876

  15. First-Rate Crops from Second-Rate Water: Classroom Activities Model a Real-World Problem.

    ERIC Educational Resources Information Center

    Zinn, Barbara; Gnut, Sara; Kafkafi, Uzi

    1999-01-01

    Describes an activity in which students try to assess the problematics of modifying brackish saline water to grow high-quality crops. Students grow seedlings in solution culture over a two-week period to learn about the effects of salts, ions, and essential plant nutrients. (WRM)

  16. Implicit trustworthiness ratings of self-resembling faces activate brain centers involved in reward.

    PubMed

    Platek, Steven M; Krill, Austen L; Wilson, Benjamin

    2009-01-01

    On the basis of Hamilton's (Hamilton, W. D. (1964). The genetical evolution of social behavior I, II. Journal of Theoretical Biology, 7, 17-52) theory of inclusive fitness, self-facial resemblance is hypothesized as a mechanism for self-referent phenotypic matching by which humans can detect kin. To understand the mechanisms underlying pro-sociality toward self-resembling faces, we investigated the neural correlates of implicit trustworthiness ratings for self-resembling faces. Here we show that idiosyncratic trustworthiness ratings of self-resembling faces predict brain activation in the ventral inferior, middle and medial frontal gyri, substrates involved in reward processing. These findings demonstrate that neural reward centers are implicated in evaluating implicit pro-social behaviors toward self-resembling faces. These findings suggest that humans have evolved to use neurocomputational architecture dedicated to face processing and reward evaluation for the differentiation of kin, which drives implicit idiosyncratic affectively regulated social interactions.

  17. Activation of peripheral opioid receptors has no effect on heart rate variability.

    PubMed

    Ellidokuz, Ender; Kaya, Dayimi; Uslan, Ihsan; Celik, Ataç; Esen, Ali Metin; Barutça, Irfan

    2008-06-01

    Opioid receptors involved in regulating the motility of the gastrointestinal tract have been localized in both contractile and neuronal tissues. Trimebutine, a peripheral opioid receptor agonist, modulates gastrointestinal motor activity in both directions and also may act on cardiac tissue. This study investigated the effects of trimebutine in clinical doses on cardiac autonomic functions with heart rate variability. The effect of trimebutine on cardiac autonomic outflows was evaluated in 11 healthy subjects. Trimebutine (200 mg) or placebo was administered orally at random in a double-blind, cross-over manner. Continuous electrocardiography recordings were obtained before and after drug administration during three states: rest, controlled breathing, and a hand grip exercise. Heart rate variability analysis showed that there was no significant difference between subjects administered with placebo or trimebutine throughout rest, controlled breathing, or the hand grip exercise. We concluded that trimebutine, in clinical doses, has no significant effect on cardiac autonomic functions. PMID:18449593

  18. Rest/Activity Rhythms and Mortality Rates in Older Men: MrOS Sleep Study

    PubMed Central

    Paudel, Misti L.; Taylor, Brent C.; Ancoli-Israel, Sonia; Blackwell, Terri; Stone, Katie L.; Tranah, Greg; Redline, Susan; Cummings, Steven R; Ensrud, Kristine E.

    2010-01-01

    Background An association between increased risk of mortality and disruptions in rest/activity circadian rhythms (RAR) has been shown among adults with dementia and with metastatic colorectal cancer. However the association among a more general population of older adults has not been studied. Methods Study population consisted of 2964 men aged 67 and older enrolled in the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) Study. Rest/activity patterns were measured with wrist actigraphy. RAR parameters were computed and expressed as quintiles, and included acrophase (time of peak activity level), amplitude (peak-to-nadir difference), mesor (middle of the peak), pseudo F-value (overall circadian rhythmicity), beta (steepness) and alpha (peak-to-trough width). Results After adjustment for multiple potential confounders, men in the lowest quintile of pseudo F-value had a 57% higher mortality rate (Hazard ratio [HR]=1.57, 95%CI, 1.03–2.39) compared with men in the highest quintile. This association was even stronger with increased risk of cardiovascular disease-related mortality (CVD) (HR=2.32, 95%CI, 1.04–5.22). Additionally, men in the lowest quintile of acrophase had a 2.8-fold higher rate of CVD-related mortality (HR=2.84, 95%CI, 1.29–6.24). There was no evidence of independent associations with amplitude, mesor, alpha, beta and risk of mortality. Conclusions Older men with less robust RAR and earlier acrophase timing, have modestly higher all-cause and CVD-related mortality rates. Further research should examine potential biological mechanisms underlying this association. PMID:20370475

  19. Rest/activity rhythms and mortality rates in older men: MrOS Sleep Study.

    PubMed

    Paudel, Misti L; Taylor, Brent C; Ancoli-Israel, Sonia; Blackwell, Terri; Stone, Katie L; Tranah, Greg; Redline, Susan; Cummings, Steven R; Ensrud, Kristine E

    2010-01-01

    An association between increased risk of mortality and disruptions in rest/activity circadian rhythms (RAR) has been shown among adults with dementia and with metastatic colorectal cancer. However, the association among a more general population of older adults has not been studied. Our study population consisted of 2964 men aged > or = 67 yrs of age enrolled in the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) Study. Rest/activity patterns were measured with wrist actigraphy. RAR parameters were computed and expressed as quintiles, and included acrophase (time of peak activity level), amplitude (peak-to-nadir difference), mesor (middle of the peak), pseudo F-value (overall circadian rhythmicity), beta (steepness), and alpha (peak-to-trough width). After adjustment for multiple potential confounders, men in the lowest quintile of pseudo F-value had a 57% higher mortality rate (hazard ratio [HR] = 1.57, 95% CI, 1.03-2.39) than men in the highest quintile. This association was even stronger with increased risk of cardiovascular disease-related mortality (CVD) (HR = 2.32, 95% CI, 1.04-5.22). Additionally, men in the lowest quintile of acrophase had a 2.8-fold higher rate of CVD-related mortality (HR = 2.84, 95% CI, 1.29-6.24). There was no evidence of independent associations with amplitude, mesor, alpha, beta, and mortality risk. Older men with less robust RAR and earlier acrophase timing have modestly higher all-cause and CVD-related mortality rates. Further research should examine potential biological mechanisms underlying this association. PMID:20370475

  20. Active Aging: Exploration into Self-Ratings of "Being Active," Out-of-Home Physical Activity, and Participation among Older Australian Adults Living in Four Different Settings.

    PubMed

    Aird, Rosemary L; Buys, Laurie

    2015-01-01

    We examined whether self-ratings of "being active" among older people living in four different settings (major city high and lower density suburbs, a regional city, and a rural area) were associated with out-of-home participation and outdoor physical activity. A mixed-methods approach (survey, travel diary, and GPS tracking over a one-week period) was used to gather data from 48 individuals aged over 55 years. Self-ratings of "being active" were found to be positively correlated with the number of days older people spent time away from home but unrelated to time traveled by active means (walking and biking). No significant differences in active travel were found between the four study locations, despite differences in their respective built environments. The findings suggest that additional strategies to the creation of "age-friendly" environments are needed if older people are to increase their levels of outdoor physical activity. "Active aging" promotion campaigns may need to explicitly identify the benefits of walking outdoors to ambulatory older people as a means of maintaining their overall health, functional ability, and participation within society in the long-term and also encourage the development of community-based programs in order to facilitate regular walking for this group. PMID:26346381

  1. Magneto-impedance sensor for quasi-noncontact monitoring of breathing, pulse rate and activity status

    NASA Astrophysics Data System (ADS)

    Corodeanu, S.; Chiriac, H.; Radulescu, L.; Lupu, N.

    2014-05-01

    Results on the development and testing of a novel magnetic sensor based on the detection of the magneto-impedance variation due to changes in the permeability of an amorphous wire are reported. The proposed application is the quasi-noncontact monitoring of the breathing frequency and heart rate for diagnosing sleep disorders. Patient discomfort is significantly decreased by transversally placing the sensitive element onto the surface of a flexible mattress in order to detect its deformation associated with cardiorespiratory activity and body movements. The developed sensor has a great application potential in monitoring the vital signs during sleep, with special advantages for children sleep monitoring.

  2. OSL dating of fluvial terraces for incision rate estimation and indication of neotectonic activity in Pamir

    NASA Astrophysics Data System (ADS)

    Fuchs, M. C.; Gloaguen, R.; Krbetschek, M.; Szulc, A.

    2012-04-01

    ThePamir owes its special attraction for geo-scientists to being among Earth's largest intra-continental orogens and to display some of the highest uplift rates as well as to host among the most powerful river systems on the planet. The evolution of the drainage network as a proxy for the landscape's response to tectonic signals provides a powerful tool to study neotectonics. The relation between tectonic forcing and surface response is indicated by structural anomalies (e.g. river-capture, river-reversal or -deflection) and spatial differences of process rates (e.g. incision rates). We combine OSL dating with remote sensing tectonic geomorphology in order to determine the zones of active deformation in the Quaternary. The local drainage system of the study region aligns mainly to the east-west-trending belts of shortening, which results from the ongoing northward propagation of the Indian plate. In contrast the major trunk river, the Panj, is unusual in that it deflects northwards and then doubles back to the southwest, cutting the southern and central Pamir doming and several other major Cenozoic deformation zones. We use fluvial terraces along the deflected north-south orientated part including the doubled back prolongation of the more or less normal orientated Panj. These sediment bodies are used as a geomorphic record to reveal changes in the balance between sediment flux and discharge. Dating these fluvial terraces by OSL provides the burial ages of the sediments indicating periods of sedimentation. The remains of those periods are far from equally distributed and mark the time of local conditions for sedimentation as especially the close neighbourhood of most of the terraces from the two youngest periods demonstrate. Precise measurements of the heights of the dated terraces with respect to the present river level based on relative kinematic GPS quantify the total vertical incision of the river subsequent to the sedimentation and abandonment. Incision rates

  3. Solar magnetic activity cycles, coronal potential field models and eruption rates

    NASA Astrophysics Data System (ADS)

    Petrie, Gordon

    2013-07-01

    We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the NSO's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun (SOLIS) vector spectro-magnetograph (VSM), the spectro-magnetograph and the 512-channel magnetograph instruments, and from the U. Stanford's Wilcox Solar Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the activity cycle. All non-axisymmetric multipole strengths are well correlated with the activity cycle. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This influence of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking (CACTus), Solar Eruptive Event Detection System (SEEDS), and Nobeyama radioheliograph prominence eruption catalogs, the rate of solar eruptions is found to be systematically higher for active years between 2003-2012 than for those between 1997-2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.

  4. Heart rate variability is related to self-reported physical activity in a healthy adolescent population.

    PubMed

    Henje Blom, Eva; Olsson, Erik M G; Serlachius, Eva; Ericson, Mats; Ingvar, Martin

    2009-08-01

    This study investigated whether there is a relationship between heart rate variability (HRV) versus lifestyle and risk factors for cardiovascular disease in a population of healthy adolescents. HRV is as an index of tonic autonomic activity and in adults HRV is related to lifestyle and risk factors for cardiovascular disease, but it is not known if this is the case in adolescents. HRV was registered for 4 min in sitting position in 99 healthy adolescents (age range 15 years 11 months-17 years 7 months) and repeated after 6 months. On both occasions there were significant correlations (P < 0.05) between physical activity and HRV, with respective r values: high frequency (HF) 0.26, 0.30; low frequency power (LF) 0.35, 0.29 and the standard deviation of inter-beat intervals (SDNN) 0.28, 0.37. There was no significant interaction between first and second measurements. In contrast, there were no correlations to sleeping patterns, eating habits and smoking. Risk factors for cardiovascular disease [body mass index (BMI = weight (kg)/length in m(2)), systolic blood pressure and p-glucose] did not show any repeatable significant correlations to HRV. Multiple regression models showed that physical activity was a predictor for HF, LF and SDNN in both measurements. In conclusion HF, LF and SDNN were reproducible after 6 months and were related to physical activity on both occasions.

  5. Use of mouthguard rates among university athletes during sport activities in Erzurum, Turkey.

    PubMed

    Yeşil Duymuş, Zeynep; Gungor, Hasan

    2009-06-01

    The purpose of this study was to determine the attitudes of mouthguard users in Erzurum, Turkey. The participants' appreciation in the use of protective devices, such as mouthguards, during sport activities was also evaluated. In this study, a 10-item questionnaire was distributed to 50 coaches and a 10-item questionnaire was distributed to 768 university athletes of three different sport modalities (basketball, soccer and volleyball) in the Atatürk University Sport Competitions. The Sport Competitions are composed of 20 faculty, except the faculty of dentistry. The result of the coaches' questionnaires indicated that none of the athletes used mouthguards while participating in sports. Of the coaches, 64% had seen orofacial trauma in their athletes during sport activities and 76% believed that mouthguards prevented oral injuries. Of the coaches, 76% reported that university athletes should use mouthguards in sport activities. The result of the university athletes' questionnaires revealed that the mouthguard utilization rate was 0%. Of all players, 78.1% were males (age 17-29) and 21.9% were females (age 18-23). Of all players, 7.31% had suffered from one or more type of oral injury while not wearing mouthguards. The results indicate that in Turkey, the use of mouthguards is rare in sports. It should be a combined duty of dentists, sports physicians, and coaches to encourage the use of mouthguards during training and sport activities. Doctors and dentists need to recommend a more intensive education of students in sports medicine and sports dentistry.

  6. High strength semi-active energy absorbers using shear- and mixedmode operation at high shear rates

    NASA Astrophysics Data System (ADS)

    Becnel, Andrew C.

    This body of research expands the design space of semi-active energy absorbers for shock isolation and crash safety by investigating and characterizing magnetorheological fluids (MRFs) at high shear rates ( > 25,000 1/s) under shear and mixed-mode operation. Magnetorheological energy absorbers (MREAs) work well as adaptive isolators due to their ability to quickly and controllably adjust to changes in system mass or impact speed while providing fail-safe operation. However, typical linear stroking MREAs using pressure-driven flows have been shown to exhibit reduced controllability as impact speed (shear rate) increases. The objective of this work is to develop MREAs that improve controllability at high shear rates by using pure shear and mixed shear-squeeze modes of operation, and to present the fundamental theory and models of MR fluids under these conditions. A proof of concept instrument verified that the MR effect persists in shear mode devices at shear rates corresponding to low speed impacts. This instrument, a concentric cylinder Searle cell magnetorheometer, was then used to characterize three commercially available MRFs across a wide range of shear rates, applied magnetic fields, and temperatures. Characterization results are presented both as flow curves according to established practice, and as an alternate nondimensionalized analysis based on Mason number. The Mason number plots show that, with appropriate correction coefficients for operating temperature, the varied flow curve data can be collapsed to a single master curve. This work represents the first shear mode characterization of MRFs at shear rates over 10 times greater than available with commercial rheometers, as well as the first validation of Mason number analysis to high shear rate flows in MRFs. Using the results from the magnetorheometer, a full scale rotary vane MREA was developed as part of the Lightweight Magnetorheological Energy Absorber System (LMEAS) for an SH-60 Seahawk helicopter

  7. Reference Values for the Marx Activity Rating Scale in a Young Athletic Population

    PubMed Central

    Cameron, Kenneth L.; Peck, Karen Y.; Thompson, Brandon S.; Svoboda, Steven J.; Owens, Brett D.; Marshall, Stephen W.

    2015-01-01

    Background: Activity-related patient-reported outcome measures are an important component of assessment after knee ligament injury in young and physically active patients; however, normative data for most activity scales are limited. Objective: To present reference values by sex for the Marx Activity Rating Scale (MARS) within a young and physically active population while accounting for knee ligament injury history and sex. Study Design: Cross-sectional study. Level of Evidence: Level 2. Methods: All incoming freshman entering a US Service Academy in June of 2011 were recruited to participate in this study. MARS was administered to 1169 incoming freshmen (203 women) who consented to participate within the first week of matriculation. All subjects were deemed healthy and medically fit for military service on admission. Subjects also completed a baseline questionnaire that asked for basic demographic information and injury history. We calculated means with standard deviations, medians with interquartile ranges, and percentiles for ordinal and continuous variables, and frequencies and proportions for dichotomous variables. We also compared median scores by sex and history of knee ligament injury using the Kruskal-Wallis test. MARS was the primary outcome of interest. Results: The median MARS score was significantly higher for men when compared with women (χ2 = 13.22, df = 1, P < 0.001) with no prior history of knee ligament injury. In contrast, there was no significant difference in median MARS scores between men and women (χ2 = 0.47, df = 1, P = 0.493) who reported a history of injury. Overall, median MARS scores were significantly higher among those who reported a history of knee ligament injury when compared with those who did not (χ2 = 9.06, df = 1, P = 0.003). Conclusion: Assessing activity as a patient-reported outcome after knee ligament injury is important, and reference values for these instruments need to account for the influence of prior injury and sex

  8. Cooling rate of an active Hawaiian lava flow from nighttime spectroradiometer measurements

    NASA Astrophysics Data System (ADS)

    Flynn, Luke P.; Mouginis-Mark, Peter J.

    1992-09-01

    A narrow-band spectroradiometer has been used to make nighttime measurements of the Phase 50 eruption of Pu'u O'o, on the East Rift Zone of Kilauea Volcano, Hawaii. On February 19, 1992, a GER spectroradiometer was used to determine the cooling rate of an active lava flow. This instrument collects 12-bit data between 0.35 to 3.0 microns at a spectral resolution of 1-5 nm. Thirteen spectra of a single area on a pahoehoe flow field were collected over a 59 minute period (21:27-22:26 HST) from which the cooling of the lava surface has been investigated. A two-component thermal mixing model (Flynn, 1992) applied to data for the flow immediately on emplacement gave a best-fit crustal temperature of 768 C, a hot component at 1150 C, and a hot radiating area of 3.6 percent of the total area. Over a 52-minute period (within the time interval between flow resurfacings) the lava flow crust cooled by 358 to 410 C at a rate that was as high as 15 C/min. The observations have significance both for satellite observations of active volcanoes and for numerical models of the cooling of lava flows during their emplacement.

  9. Fibre architecture and song activation rates of syringeal muscles are not lateralized in the European starling

    PubMed Central

    Uchida, A. M.; Meyers, R. A.; Cooper, B. G.; Goller, F.

    2010-01-01

    The songbird vocal organ, the syrinx, is composed of two sound generators, which are independently controlled by sets of two extrinsic and four intrinsic muscles. These muscles rank among the fastest vertebrate muscles, but the molecular and morphological foundations of this rapid physiological performance are unknown. Here we show that the four intrinsic muscles in the syrinx of male European starlings (Sturnus vulgaris) are composed of fast oxidative and superfast fibres. Dorsal and ventral tracheobronchialis muscles contain slightly more superfast fibres relative to the number of fast oxidative fibres than dorsal and ventral syringealis muscles. This morphological difference is not reflected in the highest, burst-like activation rate of the two muscle groups during song as assessed with electromyographic recordings. No difference in fibre type ratio was found between the corresponding muscles of the left and right sound generators. Airflow and electromyographic measurements during song indicate that maximal activation rate and speed of airflow regulation do not differ between the two sound sources. Whereas the potential for high-speed muscular control exists on both sides, the two sound generators are used differentially for modulation of acoustic parameters. These results show that large numbers of superfast fibre types are present in intrinsic syringeal muscles of a songbird, providing further confirmation of rapid contraction kinetics. However, syringeal muscles are composed of two fibre types which raises questions about the neuromuscular control of this heterogeneous muscle architecture. PMID:20228343

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

    PubMed

    van der Zwan, Judith Esi; de Vente, Wieke; Huizink, Anja C; Bögels, Susan M; de Bruin, Esther I

    2015-12-01

    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 stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints. PMID:26111942

  11. Cooling rate of an active Hawaiian lava flow from nighttime spectroradiometer measurements

    NASA Technical Reports Server (NTRS)

    Flynn, Luke P.; Mouginis-Mark, Peter J.

    1992-01-01

    A narrow-band spectroradiometer has been used to make nighttime measurements of the Phase 50 eruption of Pu'u O'o, on the East Rift Zone of Kilauea Volcano, Hawaii. On February 19, 1992, a GER spectroradiometer was used to determine the cooling rate of an active lava flow. This instrument collects 12-bit data between 0.35 to 3.0 microns at a spectral resolution of 1-5 nm. Thirteen spectra of a single area on a pahoehoe flow field were collected over a 59 minute period (21:27-22:26 HST) from which the cooling of the lava surface has been investigated. A two-component thermal mixing model (Flynn, 1992) applied to data for the flow immediately on emplacement gave a best-fit crustal temperature of 768 C, a hot component at 1150 C, and a hot radiating area of 3.6 percent of the total area. Over a 52-minute period (within the time interval between flow resurfacings) the lava flow crust cooled by 358 to 410 C at a rate that was as high as 15 C/min. The observations have significance both for satellite observations of active volcanoes and for numerical models of the cooling of lava flows during their emplacement.

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

    PubMed

    van der Zwan, Judith Esi; de Vente, Wieke; Huizink, Anja C; Bögels, Susan M; de Bruin, Esther I

    2015-12-01

    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 stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints.

  13. Masking of the circadian rhythms of heart rate and core temperature by the rest-activity cycle in man

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Connell, Linda J.; Graeber, R. Curtis

    1986-01-01

    Experiments were conducted to estimate the magnitude of the masking effect produced in humans by alternate periods of physical activity and rest or sleep on the circadian rhythms of heart rate and core temperature. The heart rate, rectal temperature, and nondominant wrist activity were monitored in 12 male subjects during 6 days of normal routine at home and during 6 days of controlled bed-rest regimen. The comparisons of averaged waveforms for the activity, heart rate, and temperature indicated that about 45 percent of the range of the circadian heart rate rhythm during normal routine and about 14 percent of the range of the circadian temperature rhythm were attributable to the effects of activity. The smaller effect of activity on the temperature rhythm may be partially attributable to the fact that core temperature is being more rigorously conserved than heart rate, at least during moderate exercise.

  14. Increased Efferent Cardiac Sympathetic Nerve Activity and Defective Intrinsic Heart Rate Regulation in Type 2 Diabetes.

    PubMed

    Thaung, H P Aye; Baldi, J Chris; Wang, Heng-Yu; Hughes, Gillian; Cook, Rosalind F; Bussey, Carol T; Sheard, Phil W; Bahn, Andrew; Jones, Peter P; Schwenke, Daryl O; Lamberts, Regis R

    2015-08-01

    Elevated sympathetic nerve activity (SNA) coupled with dysregulated β-adrenoceptor (β-AR) signaling is postulated as a major driving force for cardiac dysfunction in patients with type 2 diabetes; however, cardiac SNA has never been assessed directly in diabetes. Our aim was to measure the sympathetic input to and the β-AR responsiveness of the heart in the type 2 diabetic heart. In vivo recording of SNA of the left efferent cardiac sympathetic branch of the stellate ganglion in Zucker diabetic fatty rats revealed an elevated resting cardiac SNA and doubled firing rate compared with nondiabetic rats. Ex vivo, in isolated denervated hearts, the intrinsic heart rate was markedly reduced. Contractile and relaxation responses to β-AR stimulation with dobutamine were compromised in externally paced diabetic hearts, but not in diabetic hearts allowed to regulate their own heart rate. Protein levels of left ventricular β1-AR and Gs (guanine nucleotide binding protein stimulatory) were reduced, whereas left ventricular and right atrial β2-AR and Gi (guanine nucleotide binding protein inhibitory regulatory) levels were increased. The elevated resting cardiac SNA in type 2 diabetes, combined with the reduced cardiac β-AR responsiveness, suggests that the maintenance of normal cardiovascular function requires elevated cardiac sympathetic input to compensate for changes in the intrinsic properties of the diabetic heart.

  15. Inward-attention meditation increases parasympathetic activity: a study based on heart rate variability.

    PubMed

    Wu, Shr-Da; Lo, Pei-Chen

    2008-10-01

    Phenomenon of the heart rate variability (HRV) during various meditation techniques has been reported. However, most of these techniques emphasized the skill of slow breathing (<0.15 Hz). This paper reports our study on HRV during meditation which emphasizes inward attention. Inward attention has been an important approach for the Zen-meditation practitioners to enter into transcendental consciousness. Two groups of subjects were investigated, 10 experimental subjects with Zen-meditation experience and 10 control subjects without any meditation experience. We analyzed HRV both in time and frequency domains. The results revealed both common and different effects on HRV between inward-attention meditation and normal rest. The major difference of effects between two groups were the decrease of LF/HF ratio and LF norm as well as the increase of HF norm, which suggested the benefit of a sympathovagal balance toward parasympathetic activity. Moreover, we observed regular oscillating rhythms of the heart rate when the LF/HF ratio was small under meditation. According to previous studies, regular oscillations of heart rate signal usually appeared in the low-frequency band of HRV under slow breathing. Our findings showed that such regular oscillations could also appear in the high-frequency band of HRV but with smaller amplitude.

  16. Modeling the growth rate of distortion product otoacoustic emissions by active nonlinear oscillators.

    PubMed

    Sisto, Renata; Moleti, Arturo

    2004-09-01

    In this work, growth-rate curves of the 2 f1-f2 distortion product otoacoustic emission (DPOAE) are analyzed in a population of 30 noise exposed subjects, including both normal-hearing and hearing impaired subjects. A particular embedded limit-cycle oscillator equation is used to model the cochlear resonant response at the cochlear places of the primary and secondary tone frequencies (f2 and 2 f1-f2). The parameters of the oscillator equation can be directly interpreted in terms of effectiveness of the cochlear feedback mechanisms associated with the active filter amplification. A two-sources paradigm is included in the model, in agreement with experimental evidence and with the assumptions of more detailed full cochlear models based on the transmission line formalism. According to this paradigm, DPOAEs are nonlinearly generated at the cochlear place that is resonant at frequency f2, and coherently reflected at the 2 f1-f2 place. The analysis shows that the model, which had been previously used to describe the relaxation dynamics of transient evoked otoacoustic emissions (TEOAEs), also correctly predicts the observed growth rate of the DPOAE response as a function of the primary tones amplitude. A significant difference is observed between normal and impaired ears. The comparison between the growth rate curves at different frequencies provides information about the dependence of cochlear tuning on frequency.

  17. Effective Presentation of Metabolic Rate Information for Lunar Extravehicular Activity (EVA)

    NASA Technical Reports Server (NTRS)

    Mackin, Michael A.; Gonia, Philip; Lombay-Gonzalez, Jose

    2010-01-01

    During human exploration of the lunar surface, a suited crewmember needs effective and accurate information about consumable levels remaining in their life support system. The information must be presented in a manner that supports real-time consumable monitoring and route planning. Since consumable usage is closely tied to metabolic rate, the lunar suit must estimate metabolic rate from life support sensors, such as oxygen tank pressures, carbon dioxide partial pressure, and cooling water inlet and outlet temperatures. To provide adequate warnings that account for traverse time for a crewmember to return to a safe haven, accurate forecasts of consumable depletion rates are required. The forecasts must be presented to the crewmember in a straightforward, effective manner. In order to evaluate methods for displaying consumable forecasts, a desktop-based simulation of a lunar Extravehicular Activity (EVA) has been developed for the Constellation lunar suite s life-support system. The program was used to compare the effectiveness of several different data presentation methods.

  18. Viscous roots of active seismogenic faults revealed by geologic slip rate variations

    NASA Astrophysics Data System (ADS)

    Cowie, P. A.; Scholz, C. H.; Roberts, G.; Faure Walker, J.; Steer, P.

    2013-12-01

    Viscous flow at depth contributes to elastic strain accumulation along seismogenic faults during both post-seismic and inter-seismic phases of the earthquake cycle. Evaluating the importance of this contribution is hampered by uncertainties regarding (i) the extent to which viscous deformation occurs in shear zones or by distributed flow within the crust and/or upper mantle, and (ii) the value of the exponent, n, in the flow law that relates strain rate to applied stress. Geodetic data, rock deformation experiments, and field observations of exhumed (inactive) faults provide strong evidence for non-linear viscous flow but may not fully capture the long term, in situ behaviour of active fault zones. Here we demonstrate that strain rates derived from Holocene offsets on seismogenic normal faults in the actively uplifting and extending central and southern Italian Apennines may be used to address this issue. The measured strain rates, averaged over a time scale of 104 years, exhibit a well-defined power-law dependence on topographic elevation with a power-law exponent ≈ 3.0 (2.7 - 3.4 at 95% CI; 2.3 - 4.0 at 99% CI). Contemporary seismicity indicates that the upper crust in this area is at the threshold for frictional failure within an extensional stress field and therefore differential stress is directly proportional to elevation. Our data thus imply a relationship between strain rate and stress that is consistent with non-linear viscous flow, with n ≈ 3, but because the measurements are derived from slip along major crustal faults they do not represent deformation of a continuum. We know that, down-dip of the seismogenic part of active faults, cataclasis, hydrous alteration, and shear heating all contribute to grain size reduction and material weakening. These processes initiate localisation at the frictional-viscous transition and the development of mylonitic shear zones within the viscous regime. Furthermore, in quartzo-feldspathic crust, mylonites form a

  19. Elevated atmospheric CO2 increases microbial growth rates and enzymes activity in soil

    NASA Astrophysics Data System (ADS)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Dorodnikov, Maxim; Kuzyakov, Yakov

    2010-05-01

    Increasing the belowground translocation of assimilated carbon by plants grown under elevated CO2 can cause a shift in the structure and activity of the microbial community responsible for the turnover of organic matter in soil. We investigated the long-term effect of elevated CO2 in the atmosphere on microbial biomass and specific growth rates in root-free and rhizosphere soil. The experiments were conducted under two free air carbon dioxide enrichment (FACE) systems: in Hohenheim and Braunschweig, as well as in the intensively managed forest mesocosm of the Biosphere 2 Laboratory (B2L) in Oracle, AZ. Specific microbial growth rates (μ) were determined using the substrate-induced respiration response after glucose and/or yeast extract addition to the soil. We evaluated the effect of elevated CO2 on b-glucosidase, chitinase, phosphatase, and sulfatase to estimate the potential enzyme activity after soil amendment with glucose and nutrients. For B2L and both FACE systems, up to 58% higher μ were observed under elevated vs. ambient CO2, depending on site, plant species and N fertilization. The μ-values increased linearly with atmospheric CO2 concentration at all three sites. The effect of elevated CO2 on rhizosphere microorganisms was plant dependent and increased for: Brassica napus=Triticum aestivumrates directly (N limitation) and indirectly (changing the quantity of fine roots). So, 50% decrease in N fertilization caused the overall increase or decrease of microbial growth rates depending on plant species. The μ-value increase was lower for microorganisms growing on yeast extract then for those growing on glucose, i.e. the effect of elevated CO2 was smoothed on rich vs. simple substrate. So, the r/K strategies ratio can be better revealed by studying growth on simple (glucose) than on rich substrate mixtures (yeast extract). After adding glucose, enzyme activities under elevated CO2 were

  20. Arsenic Adsorption Equilibrium Concentration and Adsorption Rate of Activated Carbon Coated with Ferric-Aluminum Hydroxides

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Sugita, H.; Oguma, T.; Hara, J.; Takahashi, S.

    2015-12-01

    In some areas of developing countries, ground or well water contaminated with arsenic has been reluctantly used as drinking water. It is highly desirable that effective and inexpensive arsenic removal agents should be developed and provided to reduce the potential health risk. Previous studies demonstrated that activated carbon coated with ferric-aluminum hydroxides (Fe-Al-C) has high adsorptive potential for removal of arsenic. In this study, a series of experiments using Fe-Al-C were carried to discuss adsorption equilibrium time, adsorption equilibrium concentration and adsorption rate of arsenic for Fe-Al-C. Fe-Al-C used in this study was provided by Astec Co., Ltd. Powder reagent of disodium hydrogen arsenate heptahydrate was dissolved into ion-exchanged water. The solution was then further diluted with ion-exchanged water to be 1 and 10 mg/L as arsenic concentration. The pH of the solution was adjusted to be around 7 by adding HCl and/or NaOH. The solution was used as artificial arsenic contaminated water in two types of experiments (arsenic adsorption equilibrium and arsenic adsorption rate tests). The results of the arsenic equilibrium tests were showed that a time period of about 3 days to reach apparent adsorption equilibrium for arsenic. The apparent adsorption equilibrium concentration and adsorbed amount of arsenic on Fe-Al-C adsorbent could be estimated by application of various adsorption isotherms, but the distribution coefficient of arsenic between solid and liquid varies with experimental conditions such as initial concentration of arsenic and addition concentration of adsorbent. An adsorption rate equation that takes into account the reduction in the number of effective adsorption sites on the adsorbent caused by the arsenic adsorption reaction was derived based on the data obtained from the arsenic adsorption rate tests.

  1. The Very High Premature Mortality Rate among Active Professional Wrestlers Is Primarily Due to Cardiovascular Disease

    PubMed Central

    Herman, Christopher W.; Conlon, Anna S. C.; Rubenfire, Melvyn; Burghardt, Andrew R.; McGregor, Stephen J.

    2014-01-01

    Purpose Recently, much media attention has been given to the premature deaths in professional wrestlers. Since no formal studies exist that have statistically examined the probability of premature mortality in professional wrestlers, we determined survival estimates for active wresters over the past quarter century to establish the factors contributing to the premature mortality of these individuals. Methods Data including cause of death was obtained from public records and wrestling publications in wrestlers who were active between January 1, 1985 and December 31, 2011. 557 males were considered consistently active wrestlers during this time period. 2007 published mortality rates from the Center for Disease Control were used to compare the general population to the wrestlers by age, BMI, time period, and cause of death. Survival estimates and Cox hazard regression models were fit to determine incident premature deaths and factors associated with lower survival. Cumulative incidence function (CIF) estimates given years wrestled was obtained using a competing risks model for cause of death. Results The mortality for all wrestlers over the 26-year study period was.007 deaths/total person-years or 708 per 100,000 per year, and 16% of deaths occurred below age 50 years. Among wrestlers, the leading cause of deaths based on CIF was cardiovascular-related (38%). For cardiovascular-related deaths, drug overdose-related deaths and cancer deaths, wrestler mortality rates were respectively 15.1, 122.7 and 6.4 times greater than those of males in the general population. Survival estimates from hazard models indicated that BMI is significantly associated with the hazard of death from total time wrestling (p<0.0001). Conclusion Professional wrestlers are more likely to die prematurely from cardiovascular disease compared to the general population and morbidly obese wrestlers are especially at risk. Results from this study may be useful for professional wrestlers, as well as

  2. The benefit of artificial oocyte activation is dependent on the fertilization rate in a previous treatment cycle.

    PubMed

    Montag, Markus; Köster, Maria; van der Ven, Katrin; Bohlen, Ulrike; van der Ven, Hans

    2012-05-01

    Following intracytoplasmic sperm injection (ICSI), some patients present low or zero fertilization rates. Artificial oocyte activation has been proposed as a suitable means to overcome this problem. This study applied artificial oocyte activation in patient cohorts with a history of no fertilization (0%, group 1), fertilization between 1 and 29% (group 2) or fertilization between 30 and 50% (group 3) in initial ICSI cycles. In the following treatment cycles, oocytes were activated after ICSI using calcium ionophore. Fertilization, pregnancy and take-home baby rates were compared with the previous cycle without activation. In group 1, fertilization rate was 41.6%, embryos for transfer were available in 82.1% of cycles, giving a clinical pregnancy rate of 18.8% and take-home baby rate of 12.8%. In group 2, despite a lower transfer rate (87.9% versus 100%, P<0.05), there were higher fertilization and clinical pregnancy rates (44.4% versus 19.3% and 31.4% versus 12.8%, respectively, P<0.05) and take-home baby rate was 24.1% versus 12.8%. In group 3, fertilization rates differed (56.1% versus 36.8%; P<0.001) but all other parameters were similar. Artificial oocyte activation has great potential especially in patients showing compromised fertilization rates below 30% after standard ICSI. Following intracytoplasmic sperm injection (ICSI), some patients present very low or even zero fertilization rates after ICSI. Artificial oocyte activation has been proposed as a suitable means to overcome this problem. We applied artificial oocyte activation in patients which presented a history either no fertilization, fertilization between 0 and 30% or fertilization between 30 and 50% in initial ICSI cycles. In the following treatment cycles, oocytes were activated after ICSI using a calcium ionophore. Fertilization, pregnancy and take-home baby rates were compared to the previous cycle without activation. For the groups with previously 0% or 1-29% fertilization, we noted higher

  3. The Influence of Vibration on Muscle Activation and Rate of Force Development during Maximal Isometric Contractions.

    PubMed

    Humphries, Brendan; Warman, Geoff; Purton, Jason; Doyle, Tim L A; Dugan, Eric

    2004-03-01

    At present there appears to be a need for research conducted on the effects of vibration on the contractile ability of skeletal muscle tissue. The aim of this study was to address this issue by examining the effects of a superimposed muscle/tendon vibration at 50.42±1.16 Hz (acceleration 13.24 ± 0.18ms(-2): displacement ≈5mm) on muscular activation and maximal isometric contraction. Sixteen participants with a mean age, body mass, and height of 22 ± 4.4 years, 73.2 ± 11.7 kg and 173.1 ± 9.7 cms, respectively, were recruited for this study. Electromyography and accelerometry from the rectus femoris, and maximal isometric force data characteristics were collected from the dominant limb under conditions of vibration, and no-vibration. A superimposed 50 Hz vibration was used during the contraction phase for the maximal isometric leg extension for the condition of vibration. A one-way ANOVA revealed no significant (p > 0.05) differences between the vibration and no-vibration conditions for peak normalized EMGRMS (84.74% Vs 88.1%) values. An ANOVA revealed significant (p > 0.05) differences between the peak fundamental frequencies of the FFT between the conditions vibration (27.1 ± 12.2 Hz) and no-vibration (9.8 ± 3.5 Hz). Peak isometric force, peak rate of force development, rate of force development at times 0.05, 0.01, 0.1, 0.5 seconds, and rate of force development at 50, 75, and 90% of peak force were not significantly different. The results of this study suggest that the application of vibration stimulation at 50 Hz during the contraction does not contribute to muscle activation, or enhance force production for maximal isometric contractions. Key PointsThe application of a vibratory stimulation to the human body increases the normal acceleration resulting in an increase in force and a change in performanceThis study was to address this issue by examining the effects of a direct superimposed muscle/tendon vibration at 50 Hz on isometric strength

  4. The effect of variations of geomagnetic activity changing rate on trunk objects

    NASA Astrophysics Data System (ADS)

    Kozlov, V. I.; Mullayarov, V. A.; Grigor'ev, Yu. M.

    2015-11-01

    The frequency of occurrence of a certain level of the rate of change of geomagnetic activity can be expressed as a power law with an exponent of the order -1.7, and the probability of exceedance of a given level can be expressed by the law lg(P) = -0.0517 (dB / dt) - 0.1946. The largest high-frequency variations are noted during the recovery phase of magnetic bay and correspond to geomagnetic pulsations of the Pc5 range (a period of variations of 200-300 s). On a pipeline on these pulsations other high-frequency variations are imposed and they start earlier - from a maximum of bay of disturbance. It is noted the need of monitoring and forecasting of magnetic storms and recommendations on the allocation of periods, during which one cannot disable protection for preventive works.

  5. DNA transposon activity is associated with increased mutation rates in genes of rice and other grasses

    PubMed Central

    Wicker, Thomas; Yu, Yeisoo; Haberer, Georg; Mayer, Klaus F. X.; Marri, Pradeep Reddy; Rounsley, Steve; Chen, Mingsheng; Zuccolo, Andrea; Panaud, Olivier; Wing, Rod A.; Roffler, Stefan

    2016-01-01

    DNA (class 2) transposons are mobile genetic elements which move within their ‘host' genome through excising and re-inserting elsewhere. Although the rice genome contains tens of thousands of such elements, their actual role in evolution is still unclear. Analysing over 650 transposon polymorphisms in the rice species Oryza sativa and Oryza glaberrima, we find that DNA repair following transposon excisions is associated with an increased number of mutations in the sequences neighbouring the transposon. Indeed, the 3,000 bp flanking the excised transposons can contain over 10 times more mutations than the genome-wide average. Since DNA transposons preferably insert near genes, this is correlated with increases in mutation rates in coding sequences and regulatory regions. Most importantly, we find this phenomenon also in maize, wheat and barley. Thus, these findings suggest that DNA transposon activity is a major evolutionary force in grasses which provide the basis of most food consumed by humankind. PMID:27599761

  6. Finite element simulation of rate-dependent magneto-active polymer response

    NASA Astrophysics Data System (ADS)

    Haldar, K.; Kiefer, B.; Menzel, A.

    2016-10-01

    This contribution is concerned with the embedding of constitutive relations for magneto-active polymers (MAP) into finite element simulations. To this end, a recently suggested, calibrated, and validated material model for magneto-mechanically coupled and rate-dependent MAP response is briefly summarized in its continuous and algorithmic settings. Moreover, the strongly coupled field equations of finite deformation magneto-mechanics are reviewed. For the purpose of numerical simulation, a finite element model is then established based on the usual steps of weak form representation, discretization and consistent linearization. Two verifying inhomogeneous numerical examples are presented in which a classical ‘plate with a hole’ geometry is equipped with MAP properties and subjected to different types of time-varying mechanical and magnetic loading.

  7. The destructive negative binomial cure rate model with a latent activation scheme.

    PubMed

    Cancho, Vicente G; Bandyopadhyay, Dipankar; Louzada, Francisco; Yiqi, Bao

    2013-07-01

    A new flexible cure rate survival model is developed where the initial number of competing causes of the event of interest (say lesions or altered cells) follow a compound negative binomial (NB) distribution. This model provides a realistic interpretation of the biological mechanism of the event of interest as it models a destructive process of the initial competing risk factors and records only the damaged portion of the original number of risk factors. Besides, it also accounts for the underlying mechanisms that leads to cure through various latent activation schemes. Our method of estimation exploits maximum likelihood (ML) tools. The methodology is illustrated on a real data set on malignant melanoma, and the finite sample behavior of parameter estimates are explored through simulation studies.

  8. DNA transposon activity is associated with increased mutation rates in genes of rice and other grasses.

    PubMed

    Wicker, Thomas; Yu, Yeisoo; Haberer, Georg; Mayer, Klaus F X; Marri, Pradeep Reddy; Rounsley, Steve; Chen, Mingsheng; Zuccolo, Andrea; Panaud, Olivier; Wing, Rod A; Roffler, Stefan

    2016-01-01

    DNA (class 2) transposons are mobile genetic elements which move within their 'host' genome through excising and re-inserting elsewhere. Although the rice genome contains tens of thousands of such elements, their actual role in evolution is still unclear. Analysing over 650 transposon polymorphisms in the rice species Oryza sativa and Oryza glaberrima, we find that DNA repair following transposon excisions is associated with an increased number of mutations in the sequences neighbouring the transposon. Indeed, the 3,000 bp flanking the excised transposons can contain over 10 times more mutations than the genome-wide average. Since DNA transposons preferably insert near genes, this is correlated with increases in mutation rates in coding sequences and regulatory regions. Most importantly, we find this phenomenon also in maize, wheat and barley. Thus, these findings suggest that DNA transposon activity is a major evolutionary force in grasses which provide the basis of most food consumed by humankind. PMID:27599761

  9. [Heart rate and energy expenditure during extravehicular activity in different time of day].

    PubMed

    Stepanova, S I; Katuntsev, V P; Osipov, Iu Iu; Galichiĭ, V A

    2013-01-01

    The article discusses the comparative heart rate (HR) characteristics associated with day and night extravehicular activities (EVA). HR was commonly higher in the night but not in the daytime. Presumably, the reason is psychological and physiological challenges of the night work on the background of natural performance decrement. These circumstances could lead to elevation of psychic tension and, consequently, increase of heartbeats to a greater extent as compared with daytime EVA. According to the correlation analysis data, the pattern of HR relation to physical loads evaluated by energy expenditure in the daytime was other than at night, i.e. it was positive unlike the nighttime correlation. We cannot exclude it that in the daytime increase in cardiac output (CO) in response to physical work was largely due to increase in HR, whereas it was stroke volume that dominated during night work; at least, it could support CO fully in the periods of low loading.

  10. Factors influencing the rate of non-enzymatic activation of carboxylic and amino acids by ATP

    NASA Technical Reports Server (NTRS)

    Mullins, D. W., Jr.; Lacey, J. C., Jr.

    1981-01-01

    The nonenzymatic formation of adenylate anhydrides of carboxylic and amino acids is discussed as a necessary step in the origin of the genetic code and protein biosynthesis. Results of studies are presented which have shown the rate of activation to depend on the pKa of the carboxyl group, the pH of the medium, temperature, the divalent metal ion catalyst, salt concentration, and the nature of the amino acid. In particular, it was found that of the various amino acids investigated, phenylalanine had the greatest affinity for the adenine derivatives adenosine and ATP. Results thus indicate that selective affinities between amino acids and nucleotides were important during prebiotic chemical evolution, and may have played a major role in the origin of protein synthesis and genetic coding.

  11. A Growth-rate Indicator for Compton-thick Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Brightman, M.; Masini, A.; Ballantyne, D. R.; Baloković, M.; Brandt, W. N.; Chen, C.-T.; Comastri, A.; Farrah, D.; Gandhi, P.; Harrison, F. A.; Ricci, C.; Stern, D.; Walton, D. J.

    2016-07-01

    Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGNs) is difficult to measure. A statistically significant correlation between the Eddington ratio, λ Edd, and the X-ray power-law index, Γ, observed in unobscured AGNs offers an estimate of their growth rate from X-ray spectroscopy (albeit with large scatter). However, since X-rays undergo reprocessing by Compton scattering and photoelectric absorption when the line of sight to the central engine is heavily obscured, the recovery of the intrinsic Γ is challenging. Here we study a sample of local, predominantly CT megamaser AGNs, where the black hole mass, and thus Eddington luminosity, are well known. We compile results of the X-ray spectral fitting of these sources with sensitive high-energy (E > 10 keV) NuSTAR data, where X-ray torus models, which take into account the reprocessing effects have been used to recover the intrinsic Γ values and X-ray luminosities, L X. With a simple bolometric correction to L X to calculate λ Edd, we find a statistically significant correlation between Γ and λ Edd (p = 0.007). A linear fit to the data yields Γ = (0.41 ± 0.18)log10 λ Edd + (2.38 ± 0.20), which is statistically consistent with results for unobscured AGNs. This result implies that torus modeling successfully recovers the intrinsic AGN parameters. Since the megamasers have low-mass black holes (M BH ≈ 106–107 M ⊙) and are highly inclined, our results extend the Γ–λ Edd relationship to lower masses and argue against strong orientation effects in the corona, in support of AGN unification. Finally this result supports the use of Γ as a growth-rate indicator for accreting black holes, even for CT AGNs.

  12. A Growth-rate Indicator for Compton-thick Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Brightman, M.; Masini, A.; Ballantyne, D. R.; Baloković, M.; Brandt, W. N.; Chen, C.-T.; Comastri, A.; Farrah, D.; Gandhi, P.; Harrison, F. A.; Ricci, C.; Stern, D.; Walton, D. J.

    2016-07-01

    Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGNs) is difficult to measure. A statistically significant correlation between the Eddington ratio, λ Edd, and the X-ray power-law index, Γ, observed in unobscured AGNs offers an estimate of their growth rate from X-ray spectroscopy (albeit with large scatter). However, since X-rays undergo reprocessing by Compton scattering and photoelectric absorption when the line of sight to the central engine is heavily obscured, the recovery of the intrinsic Γ is challenging. Here we study a sample of local, predominantly CT megamaser AGNs, where the black hole mass, and thus Eddington luminosity, are well known. We compile results of the X-ray spectral fitting of these sources with sensitive high-energy (E > 10 keV) NuSTAR data, where X-ray torus models, which take into account the reprocessing effects have been used to recover the intrinsic Γ values and X-ray luminosities, L X. With a simple bolometric correction to L X to calculate λ Edd, we find a statistically significant correlation between Γ and λ Edd (p = 0.007). A linear fit to the data yields Γ = (0.41 ± 0.18)log10 λ Edd + (2.38 ± 0.20), which is statistically consistent with results for unobscured AGNs. This result implies that torus modeling successfully recovers the intrinsic AGN parameters. Since the megamasers have low-mass black holes (M BH ≈ 106-107 M ⊙) and are highly inclined, our results extend the Γ-λ Edd relationship to lower masses and argue against strong orientation effects in the corona, in support of AGN unification. Finally this result supports the use of Γ as a growth-rate indicator for accreting black holes, even for CT AGNs.

  13. Test Plan for Measuring Ventilation Rates and Combustible Gas Levels in TWRS Active Catch Tanks

    SciTech Connect

    NGUYEN, D.M.

    1999-10-25

    The purpose of this sampling activity is to obtain data to support an initial evaluation of potential hazards due to the presence of combustible gas in catch tanks that are currently operated by the River Protection Project (RPP). Results of the hazard analysis will be used to support closure of the flammable gas unreviewed safety question for these facilities. The data collection will be conducted in accordance with the Tank Safety Screening Data Quality Objective (Dukelow et al. 1995). Combustible gas, ammonia, and organic vapor levels in the headspace of the catch tanks will be field-measured using hand-held instruments. If a combustible gas level measurement in a tank exceeds an established threshold, gas samples will he collected in SUMMA' canisters for more extensive laboratory analysis. In addition, ventilation rates of some catch tanks will be measured to evaluate removal of flammable gas by air flowing through the tanks. This test plan identifies the sample collection, laboratory analysis, quality assurance, and reporting objectives for this data collection effort. The plan also provides the procedures for field measurement of combustible gas concentrations and ventilation rates.

  14. Rate limiting activity of charge transfer during lithiation from ionic liquids

    NASA Astrophysics Data System (ADS)

    Rodrigues, Marco-Tulio F.; Lin, Xinrong; Gullapalli, Hemtej; Grinstaff, Mark W.; Ajayan, Pulickel M.

    2016-10-01

    Given the increased use of room temperature ionic liquid electrolytes in Li-ion batteries, due to their non-flammability and negligible volatility, this study evaluates the lithiation kinetics to understand and improve the rate performance of Li-ion batteries. Lithium titanate spinel is used as a model electrode and the electrolyte is composed of LiTFSI and TFSI-coordinated alkoxy-modified phosphonium ionic liquid. Based on the analysis of activation energies for each process, we report that the charge-transfer reaction at the electrode/electrolyte interface is the rate-limiting step for cell operation. This finding is further supported by the observation that a 50-fold decrease in charge-transfer resistance at higher temperatures leads to a significant performance improvement over that of a traditional organic electrolyte at room temperature. Charge-transfer resistance and electrolyte wetting on the electrode surface are critical processes for optimal battery performance, and such processes need to be included when designing new ionic liquids in order to exceed the power density obtained with the use of current carbonate-based electrolytes.

  15. Potentiostatic activation of as-made graphene electrodes for high-rate performance in supercapacitors

    NASA Astrophysics Data System (ADS)

    Senthilkumar, Krishnan; Jeong, Seok; Lah, Myoung Soo; Sohn, Kee-Sun; Pyo, Myoungho

    2016-10-01

    A thermally expanded graphene oxide (EGO) electrode is electrochemically activated to simultaneously introduce electrolyte-accessible mesopores and oxygen functional groups. The former is produced via O2 evolution and the latter is incorporated by the intermediate hydroxyl radicals generated during the potentiostatic oxidation of H2O in 1 M H2SO4 at 1.2 V (vs. Ag/AgCl). When applied as a supercapacitor, the potentiostatically treated EGO (EGO-PS) shows significant enhancement in an electric-double layer (EDL) process with a noticeable Faradaic reaction and delivers high capacitance at fast charge/discharge (C/D) rates (334 F g-1 at 0.1 A g-1 and 230 F g-1 at 50 A g-1). In contrast to EGO-PS, EGO that is oxidized potentiodynamically (EGO-PD) shows negligible enhancement in EDL currents. EGO that is subjected to successive potential pulses also shows behaviors similar to EGO-PD, which indicates the importance of hydroxyl radical accumulation via a potentiostatic method for simultaneous functionalization and microstructural control of graphenes. The potentiostatic post-treatment presented here is a convenient post-treatment strategy that could be used to readily increase capacitance and simultaneously improve the high-rate performance of carbon-based electrodes.

  16. Escherichia coli-Derived Uracil Increases the Antibacterial Activity and Growth Rate of Lactobacillus plantarum.

    PubMed

    Ha, Eun-Mi

    2016-05-28

    Lactobacillus plantarum (L. plantarum) is a representative probiotic. In particular, L. plantarum is the first commensal bacterium to colonize the intestine of infants. For this reason, the initial settlement of L. plantarum can play an important role in determining an infant's health as well as their eventual health status as an adult. In addition, L. plantarum combats pathogenic infections (such as Escherichia coli (E. coli), one of the early pathogenic colonizers in an unhealthy infant gut) by secreting antimicrobial substances. The aim of this research was to determine how L. plantarum combats E. coli infection and why it is a representative probiotic in the intestine. Consequently, this research observed that E. coli releases uracil. L. plantarum specifically recognizes E. coli-derived uracil, which increases the growth rate and production of antimicrobial substance of L. plantarum. In addition, through the inhibitory activity test, this study postulates that the antimicrobial substance is a protein and can be considered a bacteriocin-like substance. Therefore, this research assumes that L. plantarum exerts its antibacterial ability by recognizing E. coli and increasing its growth rate as a result, and this phenomenon could be one of the reasons for L. plantarum settling in the intestine of infants as a beneficial bacterium. PMID:27012237

  17. Geometry, kinematics and slip rate along the Mosha active fault, Central Alborz, Iran

    NASA Astrophysics Data System (ADS)

    Ritz, J.-F.; Pics Geological Team

    2003-04-01

    The Mosha fault is one of the major active fault in Central Alborz as shown by its strong historical seismicity and its clear morphological signature. Situated at the vicinity of Tehran city, this ~150 km long ~N100°E trending fault represents an important potential seismic source that threatens the Iranian metropolis. In the framework of an Iranian-French joint research program (PICS) devoted to seismic hazard assessment in the Tehran region, we undertook a morphotectonic (determination of the cumulative displacements and the ages of offset morphologic markers) and paleoseismic (determination of the ages and magnitudes of ancient events) study along the Mosha fault. Our objectives are the estimation of the long-term slip rate (Upper Pleistocene-Holocene) and the mean recurrence interval of earthquakes along the different segments of the fault. Our investigations within the Tar Lake valley, along the eastern part of the fault potentially the site of the 1665 (VII, 6.5) historical earthquake - allows us to calculate a preliminary 2 ± 0.1 mm/yr minimum left lateral slip rate. If we assume a characteristic coseismic average displacement comprised between 0.35 m (Mw 6.5) and 1.2 m (Mw 7.1) calculated from Wells &Coppersmith’s functions (1994) and taking the moment magnitudes attributed to the 1665 and 1830 earthquakes (e.g. Berberian &Yeats, 2001) the mean maximum recurrence intervals along this segment of the Mosha fault are comprised between 160 and 620 yrs.

  18. Structure-Activity Relationships for Rates of Aromatic Amine Oxidation by Manganese Dioxide.

    PubMed

    Salter-Blanc, Alexandra J; Bylaska, Eric J; Lyon, Molly A; Ness, Stuart C; Tratnyek, Paul G

    2016-05-17

    New energetic compounds are designed to minimize their potential environmental impacts, which includes their transformation and the fate and effects of their transformation products. The nitro groups of energetic compounds are readily reduced to amines, and the resulting aromatic amines are subject to oxidation and coupling reactions. Manganese dioxide (MnO2) is a common environmental oxidant and model system for kinetic studies of aromatic amine oxidation. In this study, a training set of new and previously reported kinetic data for the oxidation of model and energetic-derived aromatic amines was assembled and subjected to correlation analysis against descriptor variables that ranged from general purpose [Hammett σ constants (σ(-)), pKas of the amines, and energies of the highest occupied molecular orbital (EHOMO)] to specific for the likely rate-limiting step [one-electron oxidation potentials (Eox)]. The selection of calculated descriptors (pKa, EHOMO, and Eox) was based on validation with experimental data. All of the correlations gave satisfactory quantitative structure-activity relationships (QSARs), but they improved with the specificity of the descriptor. The scope of correlation analysis was extended beyond MnO2 to include literature data on aromatic amine oxidation by other environmentally relevant oxidants (ozone, chlorine dioxide, and phosphate and carbonate radicals) by correlating relative rate constants (normalized to 4-chloroaniline) to EHOMO (calculated with a modest level of theory). PMID:27074054

  19. Neutron activation analysis of ceramic tiles and its component and radon exhalation rate.

    PubMed

    El-Shershaby, A; Sroor, A; Ahmed, F; Abdel-Haleem, A S; Abdel, Z

    2004-01-01

    The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiated with reactor for 4 h (in the Second Research Egyptian Reactor(Et-RR-2)) with thermal neutron flux 5.9 x 10(13) n/(cm2 x s). The gamma-ray spectra obtained were measured for several times by means of the hyper pure germanium detection system(HPGe). Also a solid state nuclear track detector(SSNTD) CR-39, was used to measure the emanation rate of radon for these samples. The radium concentrations were found to vary from 0.39-3.59 ppm and the emanation rates were found to vary from (0.728-5.688) x 10(-4) kg/(m2 x s). The elemental analysis of the ceramic tiles and ceramic composites have a great importance in assigning the physical properties and in turn the quality of the material.

  20. Heart rate and accelerometer data fusion for activity assessment of rescuers during emergency interventions.

    PubMed

    Curone, D; Tognetti, A; Secco, E L; Anania, G; Carbonaro, N; De Rossi, D; Magenes, G

    2010-05-01

    The current state of the art in wearable electronics is the integration of very small devices into textile fabrics, the so-called ¿smart garment.¿ The ProeTEX project is one of many initiatives dedicated to the development of smart garments specifically designed for people who risk their lives in the line of duty such as fire fighters and Civil Protection rescuers. These garments have integrated multipurpose sensors that monitor their activities while in action. To this aim, we have developed an algorithm that combines both features extracted from the signal of a triaxial accelerometer and one ECG lead. Microprocessors integrated in the garments detect the signal magnitude area of inertial acceleration, step frequency, trunk inclination, heart rate (HR), and HR trend in real time. Given these inputs, a classifier assigns these signals to nine classes differentiating between certain physical activities (walking, running, moving on site), intensities (intense, mild, or at rest) and postures (lying down, standing up). Specific classes will be identified as dangerous to the rescuer during operation, such as, ¿subject motionless lying down¿ or ¿subject resting with abnormal HR.¿ Laboratory tests were carried out on seven healthy adult subjects with the collection of over 4.5 h of data. The results were very positive, achieving an overall classification accuracy of 88.8%. PMID:20378475

  1. Physiologic rate of carrier-mediated Ca2+ entry matches active extrusion in human erythrocytes.

    PubMed

    Desai, S A; Schlesinger, P H; Krogstad, D J

    1991-08-01

    The intracellular Ca2+ concentration of nearly all cells is kept at submicromolar levels. The magnitudes of transmembrane Ca2+ movement that maintain this steady state in the human red blood cell have long been debated. Although there is agreement that the physiologic extrusion of Ca2+ by the well-characterized Ca2+. ATPase amounts to 45 mumol/liter cells per h (1982. Nature (Lond.). 298:478-481), the reported passive entry rates in physiological saline (2-20 mumol/liter cells per h) are all substantially lower. This discrepancy could be due to incomplete inhibition of the pump in the previous measurements of Ca2+ entry. We therefore examined both rate and mechanism of entry after completely inactivating the pump. This required pretreatment with iodoacetamide (to lower the intracellular ATP concentration) and vanadate (to inhibit any residual Ca2+ pump activity). The rate of Ca2+ entry (53 mumol/liter cells per h) was now found to be comparable to the accepted extrusion rate. Entry closely obeyed Michaelis-Menten kinetics (Vmax = 321 +/- 17 nmol Ca/g dry wt per h, Km = 1.26 +/- 0.13 mM), was competitively inhibited by external Sr2+ (Ki = 10.8 +/- 1.2 mM), and was accelerated by intracellular Ca2+. 45Ca2+ efflux from these pump-inactivated cells was also accelerated by either external Ca2+ or Sr2+. These accelerating effects of divalent cations on the opposite (trans) face of the membrane rule out a simple channel. Substrate-gated channels are also ruled out: cells equilibrated with 45Ca2+ lost the isotope when unlabeled Ca2+ or Sr2+ was added externally. Thus, passive Ca2+ movements occur predominantly by a reversible carrier-mediated mechanism for which Sr2+ is an alternate substrate. The carrier's intrinsic affinity constants for Ca2+ and Sr2+, 1.46 and 0.37 mM-1, respectively, indicate that Ca2+ is the preferred substrate.

  2. Evolution of earthquake rupture potential along active faults, inferred from seismicity rates and size distributions

    NASA Astrophysics Data System (ADS)

    Tormann, Thessa; Wiemer, Stefan; Enescu, Bogdan; Woessner, Jochen

    2016-04-01

    One of the major unresolved questions in seismology is the evolution in time and space of the earthquake rupture potential and thus time-dependent hazard along active faults. What happens after a major event: is the potential for further large events reduced as predicted from elastic rebound, or increased as proposed by current-state short-term clustering models? How does the rupture potential distribute in space, i.e. does it reveal imprints of stress transfer? Based on the rich earthquake record from the Pacific Plate along the Japanese coastline we investigate what information on spatial distributions and temporal changes of a normalized rupture potential (NRP) for different magnitudes can be derived from time-varying, local statistical characteristics of well and frequently observed small-to-moderate seismicity. Seismicity records show strong spatio-temporal variability in both activity rates and size distribution. We analyze 18 years of seismicity, including the massive 2011 M9 Tohoku earthquake and its aftermath. We show that the size distribution of earthquakes has significantly changed before (increased fraction of larger magnitudes) and after that mainshock (increased fraction of smaller magnitudes), strongest in areas of highest coseismic slip. Remarkably, a rapid recovery of this effect is observed within only few years. We combine this significant temporal variability in earthquake size distributions with local activity rates and infer the evolution of NRP distributions. We study complex spatial patterns and how they evolve, and more detailed temporal characteristics in a simplified spatial selection, i.e. inside and outside the high slip zone of the M9 earthquake. We resolve an immediate and strong NRP increase for large events prior to the Tohoku event in the subsequent high slip patch and a very rapid decrease inside this high-stress-release area, coupled with a lasting increase of NRP in the immediate surroundings. Even in the center of the Tohoku

  3. Pyruvate dehydrogenase kinase isoform 2 activity stimulated by speeding up the rate of dissociation of ADP.

    PubMed

    Bao, Haiying; Kasten, Shane A; Yan, Xiaohua; Hiromasa, Yasuaki; Roche, Thomas E

    2004-10-26

    Pyruvate dehydrogenase kinase 2 (PDK2) activity is stimulated by NADH and NADH plus acetyl-CoA via the reduction and reductive acetylation of the lipoyl groups of the dihydrolipoyl acetyltransferase (E2) component. Elevated K(+) and Cl(-) were needed for significant stimulation. Stimulation substantially increased both k(cat) and the K(m) for ATP; the fractional stimulation increased with the level of ATP. With an E2 structure lacking the pyruvate dehydrogenase (E1) binding domain, stimulation of PDK2 was retained, the K(m) for E1 decreased, and the equilibrium dissociation constant for ATP increased but remained much lower than the K(m) for ATP. Stimulation of PDK2 activity greatly reduced the fraction of bound ADP. These results fit an ordered reaction mechanism with ATP binding before E1 and stimulation increasing the rate of dissociation of ADP. Conversion of all of the lipoyl groups in the E2 60mer to the oxidized form (E2(ox)) greatly reduced k(cat) and the K(m) of PDK2 for ATP. Retention over an extended period of time of a low portion of reduced lipoyl groups maintains E2 in a state that supported much higher PDK2 activity than short-term (5 min) reduction of a large portion of lipoyl groups of E2(ox), but reduction of E2(ox) produced a larger fold stimulation. Reduction and to a greater extent reductive acetylation increased PDK2 binding to E2; conversion to E2(ox) did not significantly hinder binding. We suggest that passing even limited reducing equivalents among lipoyl groups maintains E2 lipoyl domains in a conformation that aids kinase function. PMID:15491151

  4. Effect of Tungsten on Primary Creep Deformation and Minimum Creep Rate of Reduced Activation Ferritic-Martensitic Steel

    NASA Astrophysics Data System (ADS)

    Vanaja, J.; Laha, Kinkar; Mathew, M. D.

    2014-10-01

    Effect of tungsten on transient creep deformation and minimum creep rate of reduced activation ferritic-martensitic (RAFM) steel has been assessed. Tungsten content in the 9Cr-RAFM steel has been varied between 1 and 2 wt pct, and creep tests were carried out over the stress range of 180 and 260 MPa at 823 K (550 °C). The tempered martensitic steel exhibited primary creep followed by tertiary stage of creep deformation with a minimum in creep deformation rate. The primary creep behavior has been assessed based on the Garofalo relationship, , considering minimum creep rate instead of steady-state creep rate . The relationships between (i) rate of exhaustion of transient creep r' with minimum creep rate, (ii) rate of exhaustion of transient creep r' with time to reach minimum creep rate, and (iii) initial creep rate with minimum creep rate revealed that the first-order reaction-rate theory has prevailed throughout the transient region of the RAFM steel having different tungsten contents. The rate of exhaustion of transient creep r' and minimum creep rate decreased, whereas the transient strain ɛ T increased with increase in tungsten content. A master transient creep curve of the steels has been developed considering the variation of with . The effect of tungsten on the variation of minimum creep rate with applied stress has been rationalized by invoking the back-stress concept.

  5. Increased cerebral activity suppresses baroreflex control of heart rate in freely moving mice.

    PubMed

    Masuki, Shizue; Nose, Hiroshi

    2009-12-01

    We assessed whether increased cerebral activity suppressed baroreflex control of heart rate (HR) and, if so, whether this occurred prior to the onset of locomotion in daily activity of mice. We measured mean arterial pressure (MAP, arterial catheter), cerebral blood flow in the motor cortex (CBF, laser-Doppler flowmetry), and electroencephalogram in free-moving mice (n = 8) during 12 daytime hours. The contribution of baroreflex control of HR to MAP regulation was determined during a total resting period for approximately 8 h from the cross-correlation function (R(t)) between spontaneous changes in HR (HR) and MAP (MAP) every 4 s and the sensitivity was determined from HR/MAP where R(t) was significant (P < 0.05). The power density ratio of theta to delta wave band in electroencephalogram (theta/delta), determined every 4 s as an index of cerebral activity, was positively correlated with CBF during 73 +/- 3% of the total resting period (P < 0.05) and with R(t) during 59 +/- 2% (P < 0.05). When each measurement during the resting period was divided into seven bins according to the level of theta/delta, CBF was 91 +/- 2% in the lowest bin and 118 +/- 3% in the highest bin (P < 0.001), R(t) was 0.69 +/- 0.06 and 0.27 +/- 0.04 (P < 0.001) and HR/MAP (beats min(1) mmHg(1)) was 12.4 +/- 0.9 and 7.5 +/- 0.9 (P < 0.001), respectively, with significant correlations with theta/delta (all P < 0.002). Moreover, mice started to move in approximately 30 sec after the sequential increases of theta/delta and R(t), mice started to move at 5 times higher probability than after a given time, followed by a rapid increase in MAP by approximately 10 mmHg. These results suggest that increased cerebral activity suppresses baroreflex control of HR and this might be related to the start of voluntary locomotion with a rapid increase in MAP. PMID:19805749

  6. Increased cerebral activity suppresses baroreflex control of heart rate in freely moving mice.

    PubMed

    Masuki, Shizue; Nose, Hiroshi

    2009-12-01

    We assessed whether increased cerebral activity suppressed baroreflex control of heart rate (HR) and, if so, whether this occurred prior to the onset of locomotion in daily activity of mice. We measured mean arterial pressure (MAP, arterial catheter), cerebral blood flow in the motor cortex (CBF, laser-Doppler flowmetry), and electroencephalogram in free-moving mice (n = 8) during 12 daytime hours. The contribution of baroreflex control of HR to MAP regulation was determined during a total resting period for approximately 8 h from the cross-correlation function (R(t)) between spontaneous changes in HR (HR) and MAP (MAP) every 4 s and the sensitivity was determined from HR/MAP where R(t) was significant (P < 0.05). The power density ratio of theta to delta wave band in electroencephalogram (theta/delta), determined every 4 s as an index of cerebral activity, was positively correlated with CBF during 73 +/- 3% of the total resting period (P < 0.05) and with R(t) during 59 +/- 2% (P < 0.05). When each measurement during the resting period was divided into seven bins according to the level of theta/delta, CBF was 91 +/- 2% in the lowest bin and 118 +/- 3% in the highest bin (P < 0.001), R(t) was 0.69 +/- 0.06 and 0.27 +/- 0.04 (P < 0.001) and HR/MAP (beats min(1) mmHg(1)) was 12.4 +/- 0.9 and 7.5 +/- 0.9 (P < 0.001), respectively, with significant correlations with theta/delta (all P < 0.002). Moreover, mice started to move in approximately 30 sec after the sequential increases of theta/delta and R(t), mice started to move at 5 times higher probability than after a given time, followed by a rapid increase in MAP by approximately 10 mmHg. These results suggest that increased cerebral activity suppresses baroreflex control of HR and this might be related to the start of voluntary locomotion with a rapid increase in MAP.

  7. Relation Between Prefrontal Cortex Activity and Respiratory Rate During Mental Stress Tasks: A Near-Infrared Spectroscopic Study.

    PubMed

    Murayama, Yuta; Hu, Lizhen; Sakatani, Kaoru

    2016-01-01

    In order to clarify the central mechanism controlling respiratory rate during mental stress, we examined the relation between prefrontal cortex (PFC) activity and respiratory rate during mental arithmetic (MA) tasks. Employing two-channel near-infrared spectroscopy (NIRS), we measured hemoglobin (Hb) concentration changes in the bilateral PFC during MA tasks in normal adults. To evaluate asymmetry of the PFC activity, we calculated the laterality index (LI); (R-L)/(R + L) of oxy-Hb concentration changes (R = right, L = left); positive LI scores indicate right-dominant activity, while negative scores indicate left-dominant activity. For measurements of respiratory rate, we employed a Kinect motion sensor (Microsoft). The MA tasks increased both oxy-Hb in the bilateral PFC and respiratory rate (p < 0.001). In addition, there was a significant correlation between LI and respiratory rate (r = 0.582, p < 0.02). These results indicate that the MA-induced activity in the right PFC was greater than that in the left PFC in subjects with large increases of respiratory rate, suggesting that the right PFC has a greater role in cerebral regulation of respiratory rate during mental stress. PMID:27526145

  8. Seasonal activity and tick-borne pathogen infection rates of Ixodes ricinus ticks in Hungary.

    PubMed

    Egyed, László; Elő, Péter; Sréter-Lancz, Zsuzsanna; Széll, Zoltán; Balogh, Zsuzsanna; Sréter, Tamás

    2012-04-01

    Ixodes ricinus is the most important tick species in Europe as it is most widely distributed and transmits the majority of tick-borne zoonotic pathogens. As limited data are available for Hungary, the aim of the present study was to investigate the seasonal timing of questing by I. ricinus and the infection rate of this tick species with all major tick-borne zoonotic pathogens. Monthly collections of I. ricinus were carried out over 3 consecutive years by dragging a blanket in 6 biotopes representing different areas of Hungary. Altogether, 1800 nymphs (300 per collection point) were screened as pooled samples (each of 5 specimens) by PCR-based methods for tick-borne pathogens. I. ricinus larvae, nymphs, and adults had bimodal activity patterns with a major peak in the spring. As newly moulted ticks of all stages are thought to emerge in the autumn of each year, it appears that most newly emerged ticks delayed their questing until the following spring. The minimum prevalence of Borrelia burgdorferi sensu lato was 2.5%. Borr. afzelii, Borr. burgdorferi sensu stricto, Borr. garinii, Borr. lusitaniae, and Borr. valaisiana were identified by hybridization. The minimum infection rate with spotted fever group rickettsiae was 1.9%. Rickettsia helvetica was identified in all biotopes. The minimum prevalence of Anaplasma phagocytophilum, Babesia divergens and Bab. microti was low (0.3-0.5%). Bartonella spp.-, Francisella tularensis-, and TBE virus-specific amplification products were not detected. Relative to the results of comparable studies carried out in the Carpathian Basin, the prevalence of tick-borne pathogens was low in Hungary. This might be attributed to the climatic difference between the lowland areas of Hungary and submountain areas of the surrounding countries involved in the studies.

  9. Chemoautotrophic carbon fixation rates and active bacterial communities in intertidal marine sediments.

    PubMed

    Boschker, Henricus T S; Vasquez-Cardenas, Diana; Bolhuis, Henk; Moerdijk-Poortvliet, Tanja W C; Moodley, Leon

    2014-01-01

    Chemoautotrophy has been little studied in typical coastal marine sediments, but may be an important component of carbon recycling as intense anaerobic mineralization processes in these sediments lead to accumulation of high amounts of reduced compounds, such as sulfides and ammonium. We studied chemoautotrophy by measuring dark-fixation of 13C-bicarbonate into phospholipid derived fatty acid (PLFA) biomarkers at two coastal sediment sites with contrasting sulfur chemistry in the Eastern Scheldt estuary, The Netherlands. At one site where free sulfide accumulated in the pore water right to the top of the sediment, PLFA labeling was restricted to compounds typically found in sulfur and ammonium oxidizing bacteria. At the other site, with no detectable free sulfide in the pore water, a very different PLFA labeling pattern was found with high amounts of label in branched i- and a-PLFA besides the typical compounds for sulfur and ammonium oxidizing bacteria. This suggests that other types of chemoautotrophic bacteria were also active, most likely Deltaproteobacteria related to sulfate reducers. Maximum rates of chemoautotrophy were detected in first 1 to 2 centimeters of both sediments and chemosynthetic biomass production was high ranging from 3 to 36 mmol C m(-2) d(-1). Average dark carbon fixation to sediment oxygen uptake ratios were 0.22±0.07 mol C (mol O2)(-1), which is in the range of the maximum growth yields reported for sulfur oxidizing bacteria indicating highly efficient growth. Chemoautotrophic biomass production was similar to carbon mineralization rates in the top of the free sulfide site, suggesting that chemoautotrophic bacteria could play a crucial role in the microbial food web and labeling in eukaryotic poly-unsaturated PLFA was indeed detectable. Our study shows that dark carbon fixation by chemoautotrophic bacteria is a major process in the carbon cycle of coastal sediments, and should therefore receive more attention in future studies on

  10. Chemoautotrophic carbon fixation rates and active bacterial communities in intertidal marine sediments.

    PubMed

    Boschker, Henricus T S; Vasquez-Cardenas, Diana; Bolhuis, Henk; Moerdijk-Poortvliet, Tanja W C; Moodley, Leon

    2014-01-01

    Chemoautotrophy has been little studied in typical coastal marine sediments, but may be an important component of carbon recycling as intense anaerobic mineralization processes in these sediments lead to accumulation of high amounts of reduced compounds, such as sulfides and ammonium. We studied chemoautotrophy by measuring dark-fixation of 13C-bicarbonate into phospholipid derived fatty acid (PLFA) biomarkers at two coastal sediment sites with contrasting sulfur chemistry in the Eastern Scheldt estuary, The Netherlands. At one site where free sulfide accumulated in the pore water right to the top of the sediment, PLFA labeling was restricted to compounds typically found in sulfur and ammonium oxidizing bacteria. At the other site, with no detectable free sulfide in the pore water, a very different PLFA labeling pattern was found with high amounts of label in branched i- and a-PLFA besides the typical compounds for sulfur and ammonium oxidizing bacteria. This suggests that other types of chemoautotrophic bacteria were also active, most likely Deltaproteobacteria related to sulfate reducers. Maximum rates of chemoautotrophy were detected in first 1 to 2 centimeters of both sediments and chemosynthetic biomass production was high ranging from 3 to 36 mmol C m(-2) d(-1). Average dark carbon fixation to sediment oxygen uptake ratios were 0.22±0.07 mol C (mol O2)(-1), which is in the range of the maximum growth yields reported for sulfur oxidizing bacteria indicating highly efficient growth. Chemoautotrophic biomass production was similar to carbon mineralization rates in the top of the free sulfide site, suggesting that chemoautotrophic bacteria could play a crucial role in the microbial food web and labeling in eukaryotic poly-unsaturated PLFA was indeed detectable. Our study shows that dark carbon fixation by chemoautotrophic bacteria is a major process in the carbon cycle of coastal sediments, and should therefore receive more attention in future studies on

  11. Active Faults of the Northwest Himalaya: Pattern, Rate, and Timing of Surface Rupturing Earthquakes

    NASA Astrophysics Data System (ADS)

    Yule, J.; Madden, C.; Gavillot, Y.; Hebeler, A.; Meigs, A.; Hussein, A.; Malik, M.; Bhat, M.; Kausar, A.; Ramzan, S.; Sayab, M.; Yeats, R. S.

    2012-12-01

    The 2005 Kashmir earthquake (Mw 7.6) is the only Himalayan earthquake to rupture the surface since the 15th to 16th century A.D. when >Mw 8.5 earthquakes ruptured the Himalayan Frontal thrust (HFT) in the central Himalaya. Megathrust-type earthquakes like these seem to relieve a majority of the accumulated interseismic strain and concentrate permanent strain across a narrow width at the deformation front (faults within the orogen appear to accommodate little strain). The 2005 within-plate rupture in Kashmir may be a clue that a different seismotectonic model applies to the northwest Himalaya where active deformation occurs on faults distributed more than 120 km across the orogen. An asymmetric anticline marks the deformation front in Kashmir where the HFT is inferred to be blind, though ~20 m-high escarpments suggest that unrecognized thrust fault(s) may reach the surface locally. Folded river terraces and dip data also suggest that this frontal fold contains a SW-dipping back thrust. In Pakistan the Salt Range thrust system (SRT) defines the thrust front. New mapping and preliminary OSL dates from deformed Holocene sediments exposed along the westernmost SRT reveal that the fault slips at 1-7 mm/yr and last ruptured within the last several thousand years. Within the orogenic wedge to the north of the deformation front, active shortening occurs along a system of surface-rupturing reverse faults, extending from the Balakot-Bagh fault (source of the 2005 Kashmir earthquake) to the Reasi fault (RF) in Indian Kashmir to the southeast. One strand of the RF displaces a 350 m-high, 80 ± 6 ka (preliminary OSL age) fluvial terrace, yielding a minimum shortening rate of 3-5 mm/yr. Trenches excavated across the RF nearby reveal a distinct angular unconformity that likely formed during a surface rupture ~4500 yrs BP. Farther north, three northeast-dipping reverse faults cut Quaternary terraces on the southwest side of the Kashmir Valley. Trenches expose evidence for at least

  12. Personal Exposure to Household Particulate Matter, Household Activities and Heart Rate Variability among Housewives

    PubMed Central

    Huang, Ya-Li; Chen, Hua-Wei; Han, Bor-Cheng; Liu, Chien-Wei; Chuang, Hsiao-Chi; Lin, Lian-Yu; Chuang, Kai-Jen

    2014-01-01

    Background The association between indoor air pollution and heart rate variability (HRV) has been well-documented. Little is known about effects of household activities on indoor air quality and HRV alteration. To investigate changes in HRV associated with changes in personal exposure to household particulate matter (PM) and household activities. Methods We performed 24-h continuous monitoring of electrocardiography and measured household PM exposure among 50 housewives. The outcome variables were log10-transformed standard deviation of normal-to-normal (NN) intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD). Household PM was measured as the mass concentration of PM with an aerodynamic diameter <2.5 µm (PM2.5). We used mixed-effects models to examine the association between household PM2.5 exposure and log10-transformed HRV indices. Results After controlling for potential confounders, an interquartile range change in household PM2.5 with 1- to 4-h mean was associated with 1.25–4.31% decreases in SDNN and 0.12–3.71% decreases in r-MSSD. Stir-frying, cleaning with detergent and burning incense may increase household PM2.5 concentrations and modify the effects of household PM2.5 on HRV indices among housewives. Conclusions Indoor PM2.5 exposures were associated with decreased SDNN and r-MSSD among housewives, especially during stir-frying, cleaning with detergent and burning incense. PMID:24594880

  13. Contribution of active-site glutamine to rate enhancement in ubiquitin carboxy terminal hydrolases

    PubMed Central

    Boudreaux, David; Chaney, Joseph; Maiti, Tushar K.; Das, Chittaranjan

    2012-01-01

    Ubiquitin carboxy terminal hydrolases (UCHs) are cysteine proteases featuring a classical cysteine-histidine-aspartate catalytic triad, also a highly conserved glutamine thought to be a part of the oxyanion hole. However, the contribution of this side chain to the catalysis by UCH enzymes is not known. Herein, we demonstrate that the glutamine side chain contributes to rate enhancement in UCHL1, UCHL3 and UCHL5. Mutation of the glutamine to alanine in these enzymes impairs the catalytic efficiency mainly due to a 16 to 30-fold reduction in kcat, which is consistent with a loss of approximately 2 kcal/mol in transition-state stabilization. However, the contribution to transition-state stabilization observed here is rather modest for the side chain’s role in oxyanion stabilization. Interestingly, we discovered that the carbonyl oxygen of this side chain is engaged in a C—H•••O hydrogen-bonding contact with the CεH group of the catalytic histidine. Upon further analysis, we found that this interaction is a common active-site structural feature in most cysteine proteases, including papain, belonging to families with the QCH(N/D) type of active-site configuration. It is possible that removal of the glutamine side chain might have abolished the C—H•••O interaction, which typically accounts for 2 kcal/mol of stabilization, leading to the effect on catalysis observed here. Additional studies performed on UCHL3 by mutating the glutamine to glutamate (strong C—H•••O acceptor but oxyanion destabilizer) and to lysine (strong oxyanion stabilizer but lacking C—H•••O hydrogen-bonding property) suggest that the C—H•••O hydrogen bond could contribute to catalysis. PMID:22284438

  14. Modeling of organic substrate transformation in the high-rate activated sludge process.

    PubMed

    Nogaj, Thomas; Randall, Andrew; Jimenez, Jose; Takacs, Imre; Bott, Charles; Miller, Mark; Murthy, Sudhir; Wett, Bernhard

    2015-01-01

    This study describes the development of a modified activated sludge model No.1 framework to describe the organic substrate transformation in the high-rate activated sludge (HRAS) process. New process mechanisms for dual soluble substrate utilization, production of extracellular polymeric substances (EPS), absorption of soluble substrate (storage), and adsorption of colloidal substrate were included in the modified model. Data from two HRAS pilot plants were investigated to calibrate and to validate the proposed model for HRAS systems. A subdivision of readily biodegradable soluble substrate into a slow and fast fraction were included to allow accurate description of effluent soluble chemical oxygen demand (COD) in HRAS versus longer solids retention time (SRT) systems. The modified model incorporates production of EPS and storage polymers as part of the aerobic growth transformation process on the soluble substrate and transformation processes for flocculation of colloidal COD to particulate COD. The adsorbed organics are then converted through hydrolysis to the slowly biodegradable soluble fraction. Two soluble substrate models were evaluated during this study, i.e., the dual substrate and the diauxic models. Both models used two state variables for biodegradable soluble substrate (SBf and SBs) and a single biomass population. The A-stage pilot typically removed 63% of the soluble substrate (SB) at an SRT <0.13 d and 79% at SRT of 0.23 d. In comparison, the dual substrate model predicted 58% removal at the lower SRT and 78% at the higher SRT, with the diauxic model predicting 32% and 70% removals, respectively. Overall, the dual substrate model provided better results than the diauxic model and therefore it was adopted during this study. The dual substrate model successfully described the higher effluent soluble COD observed in the HRAS systems due to the partial removal of SBs, which is almost completely removed in higher SRT systems.

  15. Augmented vagal heart rate modulation in active hypoestrogenic pre-menopausal women with functional hypothalamic amenorrhoea.

    PubMed

    O'Donnell, Emma; Goodman, Jack M; Morris, Beverly L; Floras, John S; Harvey, Paula J

    2015-11-01

    Compared with eumenorrhoeic women, exercise-trained women with functional hypothalamic amenorrhoea (ExFHA) exhibit low heart rates (HRs) and absent reflex renin-angiotensin-system activation and augmentation of their muscle sympathetic nerve response to orthostatic stress. To test the hypothesis that their autonomic HR modulation is altered concurrently, three age-matched (pooled mean, 24 ± 1 years; mean ± S.E.M.) groups of women were studied: active with either FHA (ExFHA; n=11) or eumenorrhoeic cycles (ExOv; n=17) and sedentary with eumenorrhoeic cycles (SedOv; n=17). Blood pressure (BP), HR and HR variability (HRV) in the frequency domain were determined during both supine rest and graded lower body negative pressure (LBNP; -10, -20 and -40 mmHg). Very low (VLF), low (LF) and high (HF) frequency power spectra (ms(2)) were determined and, owing to skewness, log10-transformed. LF/HF ratio and total power (VLF + LF + HF) were calculated. At baseline, HR and systolic BP (SBP) were lower (P<0.05) and HF and total power were higher (P<0.05) in ExFHA than in eumenorrhoeic women. In all groups, LBNP decreased (P<0.05) SBP, HF and total power and increased (P<0.05) HR and LF/HF ratio. However, HF and total power remained higher (P<0.05) and HR, SBP and LF/HF ratio remained lower (P<0.05) in ExFHA than in eumenorrhoeic women, in whom measures did not differ (P>0.05). At each stage, HR correlated inversely (P<0.05) with HF. In conclusion, ExFHA women demonstrate augmented vagal yet unchanged sympathetic HR modulation, both at rest and during orthostatic stress. Although the role of oestrogen deficiency is unclear, these findings are in contrast with studies reporting decreased HRV in hypoestrogenic post-menopausal women.

  16. Low effective activation energies for oxygen release from metal oxides: evidence for mass-transfer limits at high heating rates.

    PubMed

    Jian, Guoqiang; Zhou, Lei; Piekiel, Nicholas W; Zachariah, Michael R

    2014-06-01

    Oxygen release from metal oxides at high temperatures is relevant to many thermally activated chemical processes, including chemical-looping combustion, solar thermochemical cycles and energetic thermite reactions. In this study, we evaluated the thermal decomposition of nanosized metal oxides under rapid heating (~10(5) K s(-1)) with time-resolved mass spectrometry. We found that the effective activation-energy values that were obtained using the Flynn-Wall-Ozawa isoconversional method are much lower than the values found at low heating rates, indicating that oxygen transport might be rate-determining at a high heating rate.

  17. Multiple contexts of exposure: Activity spaces, residential neighborhoods, and self-rated health.

    PubMed

    Sharp, Gregory; Denney, Justin T; Kimbro, Rachel T

    2015-12-01

    Although health researchers have made progress in detecting place effects on health, existing work has largely focused on the local residential neighborhood and has lacked a temporal dimension. Little research has integrated both time and space to understand how exposure to multiple contexts - where adults live, work, shop, worship, and seek healthcare - influence and shape health and well-being. This study uses novel longitudinal data from the Los Angeles Family and Neighborhood Survey to delve deeper into the relationship between context and health by considering residential and activity space neighborhoods weighted by the amount of time spent in these contexts. Results from multilevel cross-classified logistic models indicate that contextual exposure to disadvantage, residential or non-residential, is independently associated with a higher likelihood of reporting poor or fair health. We also find support for a contextual incongruence hypothesis. For example, adults living in the most disadvantaged neighborhoods are more likely to report poor or fair health when they spend time in more advantaged neighborhoods than in more disadvantaged ones, while residents of more advantaged neighborhoods report worse health when they spend time in more disadvantaged areas. Our results suggest that certain types of place-based cumulative exposures are associated with a sense of relative neighborhood deprivation that potentially manifests in worse health ratings.

  18. A Discussion of Zero Spring Rate Mechanisms Used for the Active Isolation Mount Experiment

    NASA Technical Reports Server (NTRS)

    Teter, John E., Jr.

    1999-01-01

    In the summer of 1995 the Structural Dynamics Branch at NASA Langley Research Center set out to conceive a small, lightweight, low frequency isolation mount that could be used for spaceflight experiments. The Engineering Design Branch undertook the task of developing the isolation mount. This report describes the engineering process that led to three phases of a study entitled "Active Isolation Mounts" (AIM). A zero spring rate mechanism was used to achieve low fundamental frequencies for a payloads in the 1 to 10 pound range. It worked by balancing both a positive and a negative stiffness so that the net result was a small positive stiffness. The study demonstrated devices that could reduce the initial corner frequency by a factor of six for brief periods and a factor of two for extended periods. The designs were relatively simple and minimized weight, volume, and power. They could be scaled down and they were made of spaceflight compatible materials. All designs offered the ability to continuously vary the fundamental frequency. Yet, the goal of reducing the frequency by an order of magnitude was not achieved because the systems were too unstable at low frequencies. There was a trade between performance and stability.

  19. Differences in resting metabolic rate and physical activity patterns in lean and overweight/obese pregnant women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy requirements vary during pregnancy due to changes in physical activity (PA) and maternal fat stores. This study measured resting metabolic rate (RMR) and PA patterns in healthy lean and overweight/obese (OW) pregnant women. RMR was measured using indirect calorimetry (MOXUS), activity pattern...

  20. Lower temperature limits for activity of several Ixodid ticks (Acari: Ixodidae): effects of body size and rate of temperature change.

    PubMed

    Clark, D D

    1995-07-01

    Uncoordinated activity threshold temperature, the temperature below which ticks can no longer seek a host in a coordinated manner, and the activity threshold temperature, when all activity ceases, were examined for three species of ticks found in coastal sections of New York. The mean uncoordinated activity threshold and activity threshold temperatures were determined for nymphal, female and male Ixodes scapularis Say, nymphal, female, and male Amblyomma americanum (L.), and for female and male Dermacentor variabilis (Say). Only the uncoordinated activity threshold and activity threshold temperatures for adult I. scapularis were significantly correlated to the rate of temperature decrease. The mean uncoordinated activity threshold and activity threshold temperatures were significantly correlated to the mean size of each tick species.

  1. Impact of pubertal development and physical activity on heart rate variability in overweight and obese children in Taiwan.

    PubMed

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

    2012-08-01

    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 system function in overweight and obese children and the concurrent effects of their physical activity. Eighty-four overweight or obese children and 87 normal weighted controls were recruited. Autonomic nervous system function was studied by measuring heart rate variability. Results showed that the overweight/obese children had significantly lower heart rate variability. Overweight/obese children in puberty had significantly lower heart rate variability which was positively correlated with their physical activity levels. In conclusion, overweight/obesity adversely affects the autonomic nervous system function of children especially during their pubertal development. Overweight/obese children should be encouraged to engage in physical activities during puberty to improve their autonomic nervous system function.

  2. Strain rate sensitivity of mechanical properties and related thermal activation process in a two-phase {gamma} titanium aluminide

    SciTech Connect

    Lin, D.; Wang, Y.; Lin, Y.; Kim, Y.W.

    1997-12-31

    Tensile properties of a two-phase {gamma} titanium aluminide with duplex microstructure are tested under different strain rates from 5 {times} 10{sup {minus}5} to 5 {times} 10{sup {minus}3}s{sup {minus}1} at temperature from 1,123 K to 1,273 K. It is found that there exists approximate linear relationship between the flow stresses and the logarithm of the strain rate at different temperatures. The strain rate sensitivity can be explained by thermal activation theory, and dislocation climbing is identified as the rate controlling mechanism.

  3. The Study of External Dose Rate and Retained Body Activity of Patients Receiving 131I Therapy for Differentiated Thyroid Carcinoma

    PubMed Central

    Zhang, Haiying; Jiao, Ling; Cui, Songye; Wang, Liang; Tan, Jian; Zhang, Guizhi; He, Yajing; Ruan, Shuzhou; Fan, Saijun; Zhang, Wenyi

    2014-01-01

    Radiation safety is an integral part of targeted radionuclide therapy. The aim of this work was to study the external dose rate and retained body activity as functions of time in differentiated thyroid carcinoma patients receiving 131I therapy. Seventy patients were stratified into two groups: the ablation group (A) and the follow-up group (FU). The patients’ external dose rate was measured, and simultaneously, their retained body radiation activity was monitored at various time points. The equations of the external dose rate and the retained body activity, described as a function of hours post administration, were fitted. Additionally, the release time for patients was calculated. The reduction in activity in the group receiving a second or subsequent treatment was more rapid than the group receiving only the initial treatment. Most important, an expeditious method was established to indirectly evaluate the retained body activity of patients by measuring the external dose rate with a portable radiation survey meter. By this method, the calculated external dose rate limits are 19.2, 8.85, 5.08 and 2.32 μSv·h−1 at 1, 1.5, 2 and 3 m, respectively, according to a patient’s released threshold level of retained body activity <400 MBq. This study is beneficial for radiation safety decision-making. PMID:25337944

  4. [The estimation of daily physical activity with the coefficient of variation (CV) of heart rates continuously recorded].

    PubMed

    Tono-oka, T; Kaneko, I

    1993-05-01

    The daily level of physical activity was estimated using the heart rate monitor, PE3000 (Polar Electro, Finland). The level was expressed with the coefficient of variation (CV) of heart rates recorded from waking time to dinner time. In the course of a day of intense physical activity, CV was confirmed to rise significantly. Then the CV was estimated and compared among 3 age classes, young (10-18 years), middle-aged (30-47 years), and elderly (62-76 years). The CVs of young people were significantly higher than those of middle-aged (P < 0.001) and elderly (P < 0.01), regardless of sex. However there was no significant sex difference in all age classes. These results suggest that the CV is an accurate index of daily physical activity. Thus clinicians can use the CV of heart rates to estimate the level of physical activity of individuals which closely relates to QOL.

  5. An optimized pre-moderator improves uniformity of activation rate distribution in an ORNL phantom-IVNAA facility

    NASA Astrophysics Data System (ADS)

    Ebrahimi-Khankook, Atiyeh; Rafat-Motavalli, Laleh; Miri-Hakimabad, Seyyed Hashem

    2013-04-01

    Uniformity of activation rate distribution through the human body is extremely important for in vivo analysis of the body elements by neutron activation method. Achieving uniformity can be difficult because of the non-homogenous body shape and compositions. Pre-moderator is one of the most essential parts of the irradiation facility to provide uniform distribution over the sample. The aim of the present study was designation of an optimum pre-moderator, in terms of shape and material, which compensates the destructive effects of body shape and allows a satisfactory uniformity of activation rate in the sample. Our final calculations indicated that using two slabs of paraffin with a thickness of 1.8 cm as a pre-moderator in the presence of a reflector/moderator, achieve the most uniform distribution of activation rate in the body.

  6. Monitoring volcano precursory activity with the materials failure approach, using rates of cumulative seismic coda length

    SciTech Connect

    Cornelius, R.R.; Voight, B. . Dept. of Geosciences)

    1992-01-01

    The proportionality between the energy, E, of an elastic wave and the square of its amplitude led to the usage of Benioff diagrams'' for purposes of volcano monitoring. These diagrams show the time-integrated amplitude as [radical]E versus time. The authors propose to use accelerating cumulative coda length directly in volcano monitoring. This surrogate measure of energy'' is used for practical reasons, as it eliminates the intermediate step required for energy calculations with regional and instrument-specific constants. Rates of cumulative coda (s/day) may be used for the materials failure approach'' to eruption prediction, which fits data according to an empirical rate-acceleration relationship. The method allows numerical or graphical rate extrapolation towards the expected failure rate; eruption windows may be established. Rate series derived from either cumulative amplitude, cumulative coda, or calculated [radical]E can be analyzed by the materials failure approach equally well; neither series is favored by this method because of similar characteristics. They suggest rate interpolation from the time-integrated data over constant coda-increments instead of over constant time-increments. This results in an increasingly higher frequency of rate data towards the end of an accelerating time series. The end-weighted rate calculation emphasizes the latest precursory developments while it smooths noise at lower rates. Adjusting the applied constant coda-increment for rate calculations as a function of total encountered coda, is a technique for an automated and sequential update of the extrapolated failure time.

  7. Activity patterns, blood lactate concentrations and ratings of perceived exertion during a professional singles tennis tournament

    PubMed Central

    Mendez‐Villanueva, Alberto; Fernandez‐Fernandez, Jaime; Bishop, David; Fernandez‐Garcia, Benjamin; Terrados, Nicolas

    2007-01-01

    Objective To examine the game characteristics and physiological (ie, blood lactate concentration) and perceptual (ie, rating of perceived exertion, RPE) responses during actual tennis competition in professional performers. Methods Eight trained and internationally ranked (Association of Tennis Professionals rankings) male tennis players were studied during singles matches (best of three sets) played on an outdoor clay court surface during a professional, invitational tournament. Blood lactate concentrations (n = 53) and RPE (n = 113) were determined at selected changeovers during the game. The variables describing the characteristics of the matches, (a) duration of rallies (DRs); (b) rest time (RT); (c) effective playing time (EPT); and (d) shots per rally (SR), were determined from video recordings. Results The mean (SD) values for the match‐play activity variables were DR 7.5 (7.3) s, RT 16.2 (5.2) s, EPT 21.5 (4.9%), SR 2.7 (2.2) shots. Average blood lactate concentration and RPE values were 3.8 (2.0) mmol/l and 13 (2). Blood lactate concentrations and RPE values were significantly higher (p<0.01) in service games than in receiving games. Both blood lactate concentration and RPE values were significantly correlated with SR and DR (r = 0.80 to 0.28; p<0.001). Conclusions Blood lactate concentrations and RPE were found to be influenced by the characteristics of the match and the playing situation (ie, serving or returning). These specific situations might be used to alter the overload training stimulus during tennis on‐court practice. PMID:17237121

  8. Correlates of Heart Rate Measures with Incidental Physical Activity and Cardiorespiratory Fitness in Overweight Female Workers

    PubMed Central

    Tonello, Laís; Reichert, Felipe F.; Oliveira-Silva, Iransé; Del Rosso, Sebastián; Leicht, Anthony S.; Boullosa, Daniel A.

    2016-01-01

    Previous studies have suggested that physical activity (PA) levels and cardiorespiratory fitness (CRF) impact on the autonomic control of heart rate (HR). However, previous studies evaluating PA levels did not discriminate between incidental PA and regular exercise. We hypothesized that incidental PA “per se” would influence cardiac autonomic indices as assessed via HR variability (HRV) and HR recovery (HRR) in non-exercisers. Thus, the objective of this study was to investigate the relationships between objective PA levels, CRF, and cardiac autonomic indices in adult, regular non-exercising female workers. After familiarization with procedures and evaluation of body composition, 21 women completed a submaximal cycling test and evaluation of HRR on four different days. Resting (2-min seated and standing) and ambulatory (4-h) HRV were also recorded. Levels of PA were assessed by accelerometry over five consecutive days (i.e., Wednesday to Sunday). Maximum oxygen consumption (VO2max) was measured as an index of CRF. As reliability was low to moderate for most HR measures, relationships between these and PA and CRF were examined using the 4-day average measures. Significant correlations were identified between post-exercise HRR in the first min with various PA indices (daily moderate PA, daily vigorous PA, and the sum of vigorous and very vigorous daily PA). Additionally, VO2max was significantly correlated to HRV but not to HRR. The current results indicated that CRF was influential in enhancing HRV while incidental or non-exercise based PA was associated with greater autonomic reactivation in adult overweight women. Therefore, both CRF and non-exercise based PA contribute significant but diverse effects on cardiac health. The use of 4-day averages instead of single measures for evaluation of autonomic control of HR may provide a better indication of regular cardiac autonomic function that remains to be refined. PMID:26779034

  9. [Relation between oxygen uptake rate and biosorption of activated sludge against chemical substance].

    PubMed

    Mihara, Yuichi; Inoue, Tatsuaki; Yokota, Katsushi

    2005-02-01

    In this study, the elucidation of the toxicity mechanism was undertaken regarding the IC(50) of the oxygen uptake rate (OUR) with relevance to the biosorption as a toxicity evaluation of chemical substances for activated sludge (AS). At the IC(50) of<100 mg/l, malachite green (MG) and crystal violet (CV) were confirmed in the group showing relatively strong OUR inhibition. These dyes were markedly biosorbed by AS in a short time. The biosorption for AS showed a weak tendency in linear alkyl benzene sulfonate (LAS), alkyl ethoxy sulfonate (AES), alpha-olefine sulfonate (AOS), sodium dodecyl sulfate (SDS), formaldehyde (FA), benzalkonium chloride (BZaC), benzethonium chloride (BZeC), rhodamine 6G (R-6G) and fuchsine (Fuc) in which the IC(50) belonged to the 100-1000 mg/l group, when it was compared with CV and MG. In ethanol (EtOH), isopropanol (PrOH), nile blue (NB), evans blue (EB), methylene blue (MB), methyl orange (MO), paraquat (PQ), chlorophyllin (Chl) and auramine (Aur), the IC(50) was large, and the biosorption of AS was weak at 0-15%. The biosorption of MG for AS followed the adsorption isotherm equation Y=0.002X(0.511) of Freundrich. The correlation coefficient was gamma=0.998 (n=8), and a very high correlation was obtained. In the qualitative OUR curve by AS pretreated with MG or CV which belonged to the IC(50) small group, the inhibition of remarkable OUR was observed. Therefore, the findings of the present investigation suggest that the inhibition of the OUR for AS by the tested chemical substances was markedly affected by the biosorption.

  10. A correlation of the rate of N-hydroxylation of aminoazo dyes with their carcinogenic activity in the rat.

    PubMed

    Kimura, T; Kodama, M; Nagata, C

    1982-01-01

    The rate of formation of N-hydroxy-N-methyl-4-aminoazobenzene (N-OH-MAB) derivatives from N,N-dimethyl-4-aminoazobenzene (DAB) derivatives and from N-methyl-4-aminoazobenzene (MAB) derivatives was measured by the e.s.r. spectroscopy, and the rate of N-demethylation of DAB derivatives was measured by h.p.l.c. The rate of formation of N-OH-MAB derivatives from DAB derivatives showed a strong correlation with their carcinogenic activity. This reaction occurs in two-steps, i.e. N-demethylation followed by N-hydroxylation. The rate of N-demethylation of DAB derivatives was not correlated with their carcinogenic activity. On the other hand, the rate of N-hydroxylation of MAB derivatives was well correlated with the carcinogenic activity of corresponding DAB derivatives. These results suggest that the carcinogenic activity of DAB derivatives in the rat was dependent upon the enzyme concerned with N-hydroxylation. The positive carcinogenicity is limited to those derivatives with a rate of N-hydroxylation above the threshold value.

  11. Nectar intake rate is modulated by changes in sucking pump activity according to colony starvation in carpenter ants.

    PubMed

    Falibene, Agustina; Josens, Roxana

    2008-05-01

    Dynamics of fluid feeding has been deeply studied in insects. However, the ability to vary the nectar-intake rate depending only on the carbohydrate deprivation has been clearly demonstrated only in Camponotus mus ants. When insect morphometry and fluid properties remain constant, changes in intake rate could only be attributed to variations in sucking pump activity. Previous records of the electrical activity generated during feeding in C. mus have revealed two different signal patterns: the regular (RP, frequencies: 2-5 Hz) and the irregular (IP, frequencies: 7-12 Hz). This work studies the mechanism underlying food intake-rate modulation in ants by analysing whether these patterns are involved. Behaviour and electrical activity generated by ants at different starvation levels were analysed during feeding on sucrose solutions. Ants were able to modulate the intake rate for a variety of sucrose concentrations (10, 40 and 60%w/w). The IP only occurred for 60% of solutions and its presence did not affect the intake rate. However, during the RP generated under the starved state, we found frequencies up to 7.5 Hz. RP frequencies positively correlated with the intake-rate for all sucrose concentrations. Hence, intake-rate modulation according to sugar deprivation is mainly achieved by the ant's ability to vary the pumping frequency. PMID:18320196

  12. Nectar intake rate is modulated by changes in sucking pump activity according to colony starvation in carpenter ants.

    PubMed

    Falibene, Agustina; Josens, Roxana

    2008-05-01

    Dynamics of fluid feeding has been deeply studied in insects. However, the ability to vary the nectar-intake rate depending only on the carbohydrate deprivation has been clearly demonstrated only in Camponotus mus ants. When insect morphometry and fluid properties remain constant, changes in intake rate could only be attributed to variations in sucking pump activity. Previous records of the electrical activity generated during feeding in C. mus have revealed two different signal patterns: the regular (RP, frequencies: 2-5 Hz) and the irregular (IP, frequencies: 7-12 Hz). This work studies the mechanism underlying food intake-rate modulation in ants by analysing whether these patterns are involved. Behaviour and electrical activity generated by ants at different starvation levels were analysed during feeding on sucrose solutions. Ants were able to modulate the intake rate for a variety of sucrose concentrations (10, 40 and 60%w/w). The IP only occurred for 60% of solutions and its presence did not affect the intake rate. However, during the RP generated under the starved state, we found frequencies up to 7.5 Hz. RP frequencies positively correlated with the intake-rate for all sucrose concentrations. Hence, intake-rate modulation according to sugar deprivation is mainly achieved by the ant's ability to vary the pumping frequency.

  13. The role of vanadium additive in the activated sintering and shrinkage rate of tungsten-vanadium alloys

    NASA Astrophysics Data System (ADS)

    Arshad, Kameel; Zhang, Ying; Yuan, Yue; Zhao, Ming-Yue; Muhammad, Wazir; Zhou, Zhang-Jian; Lu, Guang-Hong

    2015-05-01

    Spark plasma sintering (SPS) is a common and effective way to fabricate tungsten-based materials for preliminary investigations of their application in fusion reactor. The selection of doping materials and their appropriate concentration in tungsten is important for activated consolidation and to improve the shrinkage rate during the sintering process. The impact of vanadium concentration on the shrinkage rate of tungsten-vanadium (W-V) alloys has been studied in this work. Improvement in the shrinkage rate and mechanical strength of W-V alloys has been achieved by increasing the V concentration. The residual porosity was gradually decreased and the activated sintering conditions got better with the increase of V concentration. The saturation of shrinkage rate has been found at 1550°C for W-10 wt.%V.

  14. Overall adsorption rate of metronidazole, dimetridazole and diatrizoate on activated carbons prepared from coffee residues and almond shells.

    PubMed

    Flores-Cano, J V; Sánchez-Polo, M; Messoud, J; Velo-Gala, I; Ocampo-Pérez, R; Rivera-Utrilla, J

    2016-03-15

    This study analyzed the overall adsorption rate of metronidazole, dimetridazole, and diatrizoate on activated carbons prepared from coffee residues and almond shells. It was also elucidated whether the overall adsorption rate was controlled by reaction on the adsorbent surface or by intraparticle diffusion. Experimental data of the pollutant concentration decay curves as a function of contact time were interpreted by kinetics (first- and second-order) and diffusion models, considering external mass transfer, surface and/or pore volume diffusion, and adsorption on an active site. The experimental data were better interpreted by a first-order than second-order kinetic model, and the first-order adsorption rate constant varied linearly with respect to the surface area and total pore volume of the adsorbents. According to the diffusion model, the overall adsorption rate is governed by intraparticle diffusion, and surface diffusion is the main mechanism controlling the intraparticle diffusion, representing >90% of total intraparticle diffusion.

  15. Overall adsorption rate of metronidazole, dimetridazole and diatrizoate on activated carbons prepared from coffee residues and almond shells.

    PubMed

    Flores-Cano, J V; Sánchez-Polo, M; Messoud, J; Velo-Gala, I; Ocampo-Pérez, R; Rivera-Utrilla, J

    2016-03-15

    This study analyzed the overall adsorption rate of metronidazole, dimetridazole, and diatrizoate on activated carbons prepared from coffee residues and almond shells. It was also elucidated whether the overall adsorption rate was controlled by reaction on the adsorbent surface or by intraparticle diffusion. Experimental data of the pollutant concentration decay curves as a function of contact time were interpreted by kinetics (first- and second-order) and diffusion models, considering external mass transfer, surface and/or pore volume diffusion, and adsorption on an active site. The experimental data were better interpreted by a first-order than second-order kinetic model, and the first-order adsorption rate constant varied linearly with respect to the surface area and total pore volume of the adsorbents. According to the diffusion model, the overall adsorption rate is governed by intraparticle diffusion, and surface diffusion is the main mechanism controlling the intraparticle diffusion, representing >90% of total intraparticle diffusion. PMID:26731310

  16. The Effects of Implementing Recitation Activities on Success Rates in a College Calculus Course

    ERIC Educational Resources Information Center

    Watt, Jeffrey X.; Feldhaus, Charles R.; Sorge, Brandon H.; Fore, Grant A.; Gavrin, Andrew D.; Marrs, Kathleen A.

    2014-01-01

    Over a period of six years, three different types of recitation sessions were implemented into the large enrollment section of a college calculus course. During the fall semesters, the results on the departmental final examination, the DFW rates, and the one-year retention rates of students as STEM majors were examined by the type of recitation…

  17. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three requirements: (a) Select a carbon injection system...

  18. Effect of different between-match recovery times on the activity profiles and injury rates of national rugby league players.

    PubMed

    Murray, Nick B; Gabbett, Tim J; Chamari, Karim

    2014-12-01

    Professional rugby league competition does not coincide with a standardized amount of recovery between matches; matches can be separated by as many as 10 days and as few as 5 days. These variations in recovery time could influence the match activity profiles and injury rates of players. This study investigated the effect of different between-match recovery times on the activity profiles and injury rates of National Rugby League (NRL) players. Forty-three elite male rugby league players participated in this study. Between-match recovery cycles were defined as short (separated by 5 or 6 days), medium (separated by 7 or 8 days), and long (separated by 9 or 10 days) recovery. Movement was recorded using a commercially available microtechnology unit, which provided information on speed, distance, and repeated high-intensity effort activity. Injuries sustained in either training or match play, which resulted in a missed match, were recorded. Significantly greater (p ≤ 0.05) relative total distance was covered after matches involving short recovery than those involving medium (effect size [ES] = 1.13) or long (ES = 1.08) recovery periods. This difference was because of greater low-speed activity. Injury rates for the adjustables positional group were the highest after short between-match recovery cycles, whereas the injury rates of hit-up forwards and outside backs positional groups were the highest after long between-match recovery cycles. These findings suggest that the activity profiles of NRL match play and the injury rates of specific playing positions are influenced by the amount of recovery between matches. The differences in the activity profiles and injury rates between short, medium, and long between-match recovery cycles should be considered when developing recovery strategies for professional rugby league players.

  19. Digestion of high rate activated sludge coupled to biochar formation for soil improvement in the tropics.

    PubMed

    Nansubuga, Irene; Banadda, Noble; Ronsse, Frederik; Verstraete, Willy; Rabaey, Korneel

    2015-09-15

    High rate activated sludge (HRAS) is well-biodegradable sludge enabling energy neutrality of wastewater treatment plants via anaerobic digestion. However, even through successful digestion a notable residue still remains. Here we investigated whether this residue can be converted to biochar, for its use as a fertilizer or as a solid fuel, and assessed its characteristics and overall process efficiency. In a first phase, HRAS was anaerobicaly digested under mesophilic conditions at a sludge retention time of 20 days. HRAS digested well (57.9 ± 6.2% VS degradation) producing on average 0.23 ± 0.04 L CH4 per gram VS fed. The digestate particulates were partially air-dried to mimic conditions used in developing countries, and subsequently converted to biochar by fixed-bed slow pyrolysis at a residence time of 15 min and at highest heating temperatures (HHT) of 300 °C, 400 °C and 600 °C. Subsequently, the produced chars were characterized by proximate analysis, CHN-elemental analysis, pH in solution and bomb calorimetry for higher heating value. The yield and volatile matter decreased with increasing HHT while ash content and fixed carbon increased with increasing HHT. The produced biochar showed properties optimal towards soil amendment when produced at a temperature of 600 °C with values of 5.91 wt%, 23.75 wt%, 70.35% on dry basis (db) and 0.44 for volatile matter, fixed carbon, ash content and H/C ratio, respectively. With regard to its use for energy purposes, the biochar represented a lower calorific value than the dried HRAS digestate likely due to high ash content. Based on these findings, it can be concluded that anaerobic digestion of HRAS and its subsequent biochar formation at HHT of 600 °C represents an attractive route for sludge management in tropic settings like in Uganda, coupling carbon capture to energy generation, carbon sequestration and nutrient recovery. PMID:26072019

  20. Digestion of high rate activated sludge coupled to biochar formation for soil improvement in the tropics.

    PubMed

    Nansubuga, Irene; Banadda, Noble; Ronsse, Frederik; Verstraete, Willy; Rabaey, Korneel

    2015-09-15

    High rate activated sludge (HRAS) is well-biodegradable sludge enabling energy neutrality of wastewater treatment plants via anaerobic digestion. However, even through successful digestion a notable residue still remains. Here we investigated whether this residue can be converted to biochar, for its use as a fertilizer or as a solid fuel, and assessed its characteristics and overall process efficiency. In a first phase, HRAS was anaerobicaly digested under mesophilic conditions at a sludge retention time of 20 days. HRAS digested well (57.9 ± 6.2% VS degradation) producing on average 0.23 ± 0.04 L CH4 per gram VS fed. The digestate particulates were partially air-dried to mimic conditions used in developing countries, and subsequently converted to biochar by fixed-bed slow pyrolysis at a residence time of 15 min and at highest heating temperatures (HHT) of 300 °C, 400 °C and 600 °C. Subsequently, the produced chars were characterized by proximate analysis, CHN-elemental analysis, pH in solution and bomb calorimetry for higher heating value. The yield and volatile matter decreased with increasing HHT while ash content and fixed carbon increased with increasing HHT. The produced biochar showed properties optimal towards soil amendment when produced at a temperature of 600 °C with values of 5.91 wt%, 23.75 wt%, 70.35% on dry basis (db) and 0.44 for volatile matter, fixed carbon, ash content and H/C ratio, respectively. With regard to its use for energy purposes, the biochar represented a lower calorific value than the dried HRAS digestate likely due to high ash content. Based on these findings, it can be concluded that anaerobic digestion of HRAS and its subsequent biochar formation at HHT of 600 °C represents an attractive route for sludge management in tropic settings like in Uganda, coupling carbon capture to energy generation, carbon sequestration and nutrient recovery.

  1. Structure-activity correlations for organophosphorus ester anticholinesterases. Part 2: CNDO/2 calculations applied to ester hydrolysis rates

    NASA Technical Reports Server (NTRS)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1984-01-01

    Quantitative structure-activity relationships are presented for the hydrolysis of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. CNDO/2 calculations provide values for molecular parameters that correlate with alkaline hydrolysis rates. For each subset of esters with the same leaving group, X, the CNDO-derived net atomic charge at the central phosphorus atom correlates well with the alkaline hydrolysis rate constants. For the whole set of esters with different leaving groups, equations are derived that relate charge, orbital energy and bond order to the hydrolysis rate constants.

  2. Correlation analysis between the rate of respiration in the root and the active components in licorice (Glycyrrhiza uralensis).

    PubMed

    Guo, Peijun; Sun, Zhirong; Liu, Wenlan; Chen, Long; DU, Yuan; Wei, Xinxin

    2014-01-01

    The aim of this study was to investigate the correlation between root respiration and the percentage of active components in licorice (Glycyrrhiza uralensis Fisch.), in order to provide a foundation for the regulation and modulation of the quality of G. uralensis. Respiration efflux of annual and biennial G. uralensis was determined using a Li-7000 CO2/H2O analyzer. The root systems were scanned at a resolution of 3,000 dpi using an Epson Expression 10000XL scanner. Root growth was determined by analyzing the scanned images using WinRHIZO version Pro2007d software and the rate of respiration in the root was subsequently calculated. In addition, the percentages of the five major active components in licorice, glycyrrhizic acid, glycyrrhizin, isoliquiritin, liquiritigenin and isoliquiritigenin, were detected using high-performance liquid chromatography (HPLC). The correlation between the root respiration and the percentage of the active components was investigated. Significant seasonal changes were observed in the rates of respiration of first and zero-class roots. In annual and biennial G. uralensis, the maximum and minimum values for rate of respiration were present in July (P<0.05) and November (P<0.05), respectively. The correlation coefficients between the five major active components and the rate of respiration were -0.304 (glycyrrhizin), -0.129 (liquiritigenin), -0.441 (glycyrrhizic acid; P<0.05), -0.471 (isoliquiritin; P<0.05) and 0.148 (isoliquiritigenin). The percentages of glycyrrhizic acid and isoliquiritin were significantly negatively correlated with the rate of respiration in annual and biennial G. uralensis. Understanding the correlation between the root rate of respiration and the active components in G. uralensis may be beneficial to ensuring the quality of cultivated G. uralensis.

  3. Frequency and rates of outdoor activities, and perceptions of places to perform these activities by Native Americans and Caucasians interviewed in Tennessee.

    PubMed

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Pittfield, Taryn; Marchioni, Meredith

    2012-12-01

    Activity patterns and perceptions play a key role in human health risk, management, and planning. A sample of 233 people attending a Native American festival in Cookeville, Tennessee was interviewed to determine the types, percent participation, and outdoor activities rates, and their perceptions of the importance of characteristics of nuclear sites. Results indicate that: (1) a high percentage of respondents used outdoor environments, (2) they used them for consumptive (hunting, fishing), non-consumptive (hiking, walking, bird-watching), and religious/sacred activities, (3) a higher percentage of respondents engaged in non-consumptive than consumptive activities, (4) praying or meditating, communing with nature, and bird-watching had the highest uses rates (5) the environmental characteristics rated the highest were lack of radionuclides that presented a health risk, no visible smog, clean air, and unpolluted water, (6) the presence of people, buildings and roads were rated the lowest, and (7) Native Americans had higher outdoor participation rates, participated more frequently, and evaluated environmental characteristics higher than did Caucasians. This information can be used by managers to create and maintain outdoor habitats that fit the needs of local people. Planning and management require information on public policy, human needs and requirements, and human perceptions and evaluations of environmental characteristics. PMID:23229153

  4. Frequency and rates of outdoor activities, and perceptions of places to perform these activities by Native Americans and Caucasians interviewed in Tennessee

    PubMed Central

    Gochfeld, Michael; Jeitner, Christian; Pittfield, Taryn

    2015-01-01

    Activity patterns and perceptions play a key role in human health risk, management, and planning. A survey of 233 people attending a Native American festival in Cookeville Tennessee were interviewed to determine the types, percent participation, and outdoor activities rates, and their perceptions of the importance of characteristics of sites. The indicate that: 1) a high percentage of respondents used outdoor environments, 2) they used them for consumptive (hunting, fishing), non-consumptive (hiking, walking, bird-watching), and religious/sacred activities, 3) a higher percentage of respondents engaged in non-consumptive than consumptive activities, 4) praying or meditating, communing with nature, and bird-watching had the highest uses rates 5) the environmental characteristics rated the highest were lack of radionuclides that presented a health risk, no visible smog, clean air, and unpolluted water, 6) presence of people, buildings and roads were rated the lowest and 7) Native Americans had higher participation rates, participated more frequently, and evaluated environmental characteristics higher than did Caucasians. This information can be used by managers to create and maintain outdoor habitats that fit the needs of local people. Planning and management require information on public policy, human needs and requirements, and human perceptions and evaluations of environmental characteristics. PMID:23229153

  5. Frequency and rates of outdoor activities, and perceptions of places to perform these activities by Native Americans and Caucasians interviewed in Tennessee

    PubMed Central

    Gochfeld, Michael; Jeitner, Christian; Pittfield, Taryn

    2015-01-01

    Activity patterns and perceptions play a key role in human health risk, management, and planning. A survey of 233 people attending a Native American festival in Cookeville Tennessee were interviewed to determine the types, percent participation, and outdoor activities rates, and their perceptions of the importance of characteristics of sites. The indicate that: 1) a high percentage of respondents used outdoor environments, 2) they used them for consumptive (hunting, fishing), non-consumptive (hiking, walking, bird-watching), and religious/sacred activities, 3) a higher percentage of respondents engaged in non-consumptive than consumptive activities, 4) praying or meditating, communing with nature, and bird-watching had the highest uses rates 5) the environmental characteristics rated the highest were lack of radionuclides that presented a health risk, no visible smog, clean air, and unpolluted water, 6) presence of people, buildings and roads were rated the lowest and 7) Native Americans had higher participation rates, participated more frequently, and evaluated environmental characteristics higher than did Caucasians. This information can be used by managers to create and maintain outdoor habitats that fit the needs of local people. Planning and management require information on public policy, human needs and requirements, and human perceptions and evaluations of environmental characteristics. PMID:23229153

  6. Frequency and rates of outdoor activities, and perceptions of places to perform these activities by Native Americans and Caucasians interviewed in Tennessee.

    PubMed

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Pittfield, Taryn; Marchioni, Meredith

    2012-12-01

    Activity patterns and perceptions play a key role in human health risk, management, and planning. A sample of 233 people attending a Native American festival in Cookeville, Tennessee was interviewed to determine the types, percent participation, and outdoor activities rates, and their perceptions of the importance of characteristics of nuclear sites. Results indicate that: (1) a high percentage of respondents used outdoor environments, (2) they used them for consumptive (hunting, fishing), non-consumptive (hiking, walking, bird-watching), and religious/sacred activities, (3) a higher percentage of respondents engaged in non-consumptive than consumptive activities, (4) praying or meditating, communing with nature, and bird-watching had the highest uses rates (5) the environmental characteristics rated the highest were lack of radionuclides that presented a health risk, no visible smog, clean air, and unpolluted water, (6) the presence of people, buildings and roads were rated the lowest, and (7) Native Americans had higher outdoor participation rates, participated more frequently, and evaluated environmental characteristics higher than did Caucasians. This information can be used by managers to create and maintain outdoor habitats that fit the needs of local people. Planning and management require information on public policy, human needs and requirements, and human perceptions and evaluations of environmental characteristics.

  7. The influence of broiler activity, growth rate, and litter on carbon dioxide balances for the determination of ventilation flow rates in broiler production.

    PubMed

    Calvet, S; Estellés, F; Cambra-López, M; Torres, A G; Van den Weghe, H F A

    2011-11-01

    Carbon dioxide balances are useful in determining ventilation rates in livestock buildings. These balances need an accurate estimation of the CO(2) produced by animals and their litter to determine the ventilation flows. To estimate the daily variation in ventilation flow, it is necessary to precisely know the daily variation pattern of CO(2) production, which mainly depends on animal activity. The objective of this study was to explore the applicability of CO(2) balances for determining ventilation flows in broiler buildings. More specifically, this work aimed to quantify the amount of CO(2) produced by the litter, as well as the amount of CO(2) produced by the broilers, as a function of productive parameters, and to analyze the influence of broiler activity on CO(2) emissions. Gas concentrations and ventilation flows were simultaneously measured in 3 trials, with 1 under experimental conditions and the other 2 in a commercial broiler farm. In the experimental assay, broiler activity was also determined. At the end of the experimental trial, on the day after the removal of the broilers, the litter accounted for 20% of the total CO(2) produced, and the broilers produced 3.71 L/h of CO(2) per kg of metabolic weight. On the commercial farm, CO(2) production was the same for the 2 cycles (2.60 L/h per kg of metabolic weight, P > 0.05). However, substantial differences were found between CO(2) and broiler activity patterns after changes in light status. A regression model was used to explain these differences (R(2) = 0.52). Carbon dioxide increased with bird activity, being on average 3.02 L/h per kg of metabolic weight for inactive birds and 4.73 L/h per kg of metabolic weight when bird activity was highest. Overall, CO(2) balances are robust tools for determining the daily average ventilation flows in broiler farms. These balances could also be applied at more frequent intervals, but in this case, particular care is necessary after light status changes because of

  8. Metabolic rate control during extravehicular activity simulations and measurement techniques during actual EVAS

    NASA Technical Reports Server (NTRS)

    Horrigan, D. J.

    1975-01-01

    A description of the methods used to control and measure metabolic rate during ground simulations is given. Work levels attained at the Space Environment Simulation Laboratory are presented. The techniques and data acquired during ground simulations are described and compared with inflight procedures. Data from both the Skylab and Apollo Program were utilized and emphasis is given to the methodology, both in simulation and during flight. The basic techniques of work rate assessment are described. They include oxygen consumption, which was useful for averages over long time periods, heart rate correlations based on laboratory calibrations, and liquid cooling garment temperature changes. The relative accuracy of these methods as well as the methods of real-time monitoring at the Mission Control Center are discussed. The advantages and disadvantages of each of the metabolic measurement techniques are discussed. Particular emphasis is given to the problem of utilizing oxygen decrement for short time periods and heart rate at low work levels. A summary is given of the effectiveness of work rate control and measurements; and current plans for future EVA monitoring are discussed.

  9. An Interactive Classroom Activity Demonstrating Reaction Mechanisms and Rate-Determining Steps

    ERIC Educational Resources Information Center

    Jennings, Laura D.; Keller, Steven W.

    2005-01-01

    An interactive classroom activity that includes two-step reaction of unwrapping and eating chocolate candies is described which brings not only the reaction intermediate, but also the reactants and products into macroscopic view. The qualitative activation barriers of both steps can be adjusted independently.

  10. Self-Rated Activity Levels and Longevity: Evidence from a 20 Year Longitudinal Study

    ERIC Educational Resources Information Center

    Mullee, Mark A.; Coleman, Peter G.; Briggs, Roger S. J.; Stevenson, James E.; Turnbull, Joanne C.

    2008-01-01

    The study reports on factors predicting the longevity of 328 people over the age of 65 drawn from an English city and followed over 20 years. Both the reported activities score and the individual's comparative evaluation of their own level of activity independently reduced the risk of death, even when health and cognitive status were taken into…

  11. Heart Rate and the Role of the Active Receiver during Contingent Electric Shock for Severe Self-Injurious Behavior

    ERIC Educational Resources Information Center

    Duker, Pieter C.; Van den Munckhof, Marcia

    2007-01-01

    Five individuals, who were treated for severe self-injurious behaviors (SIB) with contingent electric shock, participated. Hereby, each occurrence of the target response was followed by a remotely administered aversive consequence. Participants' heart rates were compared at times when the active device of the equipment for the above procedure was…

  12. A Unified Kinetics and Equilibrium Experiment: Rate Law, Activation Energy, and Equilibrium Constant for the Dissociation of Ferroin

    ERIC Educational Resources Information Center

    Sattar, Simeen

    2011-01-01

    Tris(1,10-phenanthroline)iron(II) is the basis of a suite of four experiments spanning 5 weeks. Students determine the rate law, activation energy, and equilibrium constant for the dissociation of the complex ion in acid solution and base dissociation constant for phenanthroline. The focus on one chemical system simplifies a daunting set of…

  13. Acute Effects of a Therapeutic Mobility Device on Physical Activity and Heart Rate in Children with Down Syndrome

    ERIC Educational Resources Information Center

    Hauck, Janet L.; Ulrich, Dale A.

    2015-01-01

    Purpose: The purpose of this feasibility study was to provide an opportunity to increase physical activity (PA) and heart rate (HR) for children with Down syndrome (DS) during unstructured group exercise utilizing a riding device called the Power Pumper®. Method: Twenty-four children aged 5 to 7 years old participated in this case-control study,…

  14. COMPARISON OF EXERCISE PARTICIPATION RATES FOR CHILDREN IN THE LITERATURE WITH THOSE IN EPA'S CONSOLIDATED HUMAN ACTIVITY DATABASE (CHAD)

    EPA Science Inventory

    CHAD contains over 22,000 person-days of human activity pattern survey data. Part of the database includes exercise participation rates for children 0-17 years old, as well as for adults. Analyses of this database indicates that approximately 34% of the 0-17 age group (herea...

  15. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice.

    PubMed

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-03-01

    Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4-6 h prior to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral parameters, especially when animals have altered circadian phenotype.

  16. Present-day impact cratering rate and contemporary gully activity on Mars.

    PubMed

    Malin, Michael C; Edgett, Kenneth S; Posiolova, Liliya V; McColley, Shawn M; Dobrea, Eldar Z Noe

    2006-12-01

    The Mars Global Surveyor Mars Orbiter Camera has acquired data that establish the present-day impact cratering rate and document new deposits formed by downslope movement of material in mid-latitude gullies on Mars. Twenty impacts created craters 2 to 150 meters in diameter within an area of 21.5 x 10(6) square kilometers between May 1999 and March 2006. The values predicted by models that scale the lunar cratering rate to Mars are close to the observed rate, implying that surfaces devoid of craters are truly young and that as yet unrecognized processes of denudation must be operating. The new gully deposits, formed since August 1999, are light toned and exhibit attributes expected from emplacement aided by a fluid with the properties of liquid water: relatively long, extended, digitate distal and marginal branches, diversion around obstacles, and low relief. The observations suggest that liquid water flowed on the surface of Mars during the past decade.

  17. Present-day impact cratering rate and contemporary gully activity on Mars.

    PubMed

    Malin, Michael C; Edgett, Kenneth S; Posiolova, Liliya V; McColley, Shawn M; Dobrea, Eldar Z Noe

    2006-12-01

    The Mars Global Surveyor Mars Orbiter Camera has acquired data that establish the present-day impact cratering rate and document new deposits formed by downslope movement of material in mid-latitude gullies on Mars. Twenty impacts created craters 2 to 150 meters in diameter within an area of 21.5 x 10(6) square kilometers between May 1999 and March 2006. The values predicted by models that scale the lunar cratering rate to Mars are close to the observed rate, implying that surfaces devoid of craters are truly young and that as yet unrecognized processes of denudation must be operating. The new gully deposits, formed since August 1999, are light toned and exhibit attributes expected from emplacement aided by a fluid with the properties of liquid water: relatively long, extended, digitate distal and marginal branches, diversion around obstacles, and low relief. The observations suggest that liquid water flowed on the surface of Mars during the past decade. PMID:17158321

  18. ENVIRONMENTAL DEPENDENCE OF THE STAR FORMATION RATE, SPECIFIC STAR FORMATION RATE, AND THE PRESENCE OF ACTIVE GALACTIC NUCLEI FOR HIGH STELLAR MASS AND LOW STELLAR MASS GALAXIES

    SciTech Connect

    Deng Xinfa; Song Jun; Chen Yiqing; Jiang Peng; Ding Yingping

    2012-07-10

    Using two volume-limited main galaxy samples of the Sloan Digital Sky Survey Data Release 8 (SDSS DR8), we explore the environmental dependence of the star formation rate (SFR), specific star formation rate (SSFR), and the presence of active galactic nuclei (AGNs) for high stellar mass (HSM) and low stellar mass (LSM) galaxies. It is found that the environmental dependence of the SFR and SSFR for luminous HSM galaxies and faint LSM ones remains very strong: galaxies in the lowest density regime preferentially have higher SFR and SSFR than galaxies in the densest regime, while the environmental dependence of the SFR and SSFR for luminous LSM galaxies is substantially reduced. Our result also shows that the fraction of AGNs in HSM galaxies decreases as a function of density, while the one in LSM galaxies depends very little on local density. In the faint LSM galaxy sample, the SFR and SSFR of galaxies strongly decrease with increasing density, but the fraction of AGNs depends very little on local density. Such a result can rule out that AGNs are fueled by the cold gas in the disk component of galaxies that is also driving the star formation of those galaxies.

  19. Assessment of heart rate variability based on mobile device for planning physical activity

    NASA Astrophysics Data System (ADS)

    Svirin, I. S.; Epishina, E. V.; Voronin, V. V.; Semenishchev, E. A.; Solodova, E. N.; Nabilskaya, N. V.

    2015-05-01

    In this paper we present a method for the functional analysis of human heart based on electrocardiography (ECG) signals. The approach using the apparatus of analytical and differential geometry and correlation and regression analysis. ECG contains information on the current condition of the cardiovascular system as well as on the pathological changes in the heart. Mathematical processing of the heart rate variability allows to obtain a great set of mathematical and statistical characteristics. These characteristics of the heart rate are used when solving research problems to study physiological changes that determine functional changes of an individual. The proposed method implemented for up-to-date mobile Android and iOS based devices.

  20. Active Traveling and Its Associations with Self-Rated Health, BMI and Physical Activity: A Comparative Study in the Adult Swedish Population.

    PubMed

    Berglund, Erik; Lytsy, Per; Westerling, Ragnar

    2016-01-01

    Active traveling to a daily occupation means that an individual uses an active way of traveling between two destinations. Active travel to work or other daily occupations offers a convenient way to increase physical activity levels which is known to have positive effects on several health outcomes. Frequently used concepts in city planning and regional planning today are to create environments for active commuting and active living. Even then, little research has focused on traveling modes and subjective health outcomes such as self-rated health (SRH). This study aimed to explore and investigate associations between travel mode and health-related outcomes, such as self-rated health (SRH), body mass index (BMI) and overall physical activity, in an adult population in Sweden. A cross-sectional study was conducted in a randomly selected population-based sample (n = 1786, age 45-75 years); the respondents completed a questionnaire about their regular travel mode, demographics, lifestyle, BMI and SRH. Chi-square tests and logistic regressions found that inactive traveling was associated with poor SRH, a greater risk of obesity or being overweight and overall physical inactivity. In addition, lifestyle factors, such as choice of food and smoking habits, were associated with SRH, BMI and overall physical activity. PMID:27136570

  1. Active Traveling and Its Associations with Self-Rated Health, BMI and Physical Activity: A Comparative Study in the Adult Swedish Population

    PubMed Central

    Berglund, Erik; Lytsy, Per; Westerling, Ragnar

    2016-01-01

    Active traveling to a daily occupation means that an individual uses an active way of traveling between two destinations. Active travel to work or other daily occupations offers a convenient way to increase physical activity levels which is known to have positive effects on several health outcomes. Frequently used concepts in city planning and regional planning today are to create environments for active commuting and active living. Even then, little research has focused on traveling modes and subjective health outcomes such as self-rated health (SRH). This study aimed to explore and investigate associations between travel mode and health-related outcomes, such as self-rated health (SRH), body mass index (BMI) and overall physical activity, in an adult population in Sweden. A cross-sectional study was conducted in a randomly selected population-based sample (n = 1786, age 45–75 years); the respondents completed a questionnaire about their regular travel mode, demographics, lifestyle, BMI and SRH. Chi-square tests and logistic regressions found that inactive traveling was associated with poor SRH, a greater risk of obesity or being overweight and overall physical inactivity. In addition, lifestyle factors, such as choice of food and smoking habits, were associated with SRH, BMI and overall physical activity. PMID:27136570

  2. Application of decision-making theory to the regulation of muscular work rate during self-paced competitive endurance activity.

    PubMed

    Renfree, Andrew; Martin, Louise; Micklewright, Dominic; St Clair Gibson, Alan

    2014-02-01

    Successful participation in competitive endurance activities requires continual regulation of muscular work rate in order to maximise physiological performance capacities, meaning that individuals must make numerous decisions with regards to the muscular work rate selected at any point in time. Decisions relating to the setting of appropriate goals and the overall strategic approach to be utilised are made prior to the commencement of an event, whereas tactical decisions are made during the event itself. This review examines current theories of decision-making in an attempt to explain the manner in which regulation of muscular work is achieved during athletic activity. We describe rational and heuristic theories, and relate these to current models of regulatory processes during self-paced exercise in an attempt to explain observations made in both laboratory and competitive environments. Additionally, we use rational and heuristic theories in an attempt to explain the influence of the presence of direct competitors on the quality of the decisions made during these activities. We hypothesise that although both rational and heuristic models can plausibly explain many observed behaviours in competitive endurance activities, the complexity of the environment in which such activities occur would imply that effective rational decision-making is unlikely. However, at present, many proposed models of the regulatory process share similarities with rational models. We suggest enhanced understanding of the decision-making process during self-paced activities is crucial in order to improve the ability to understand regulation of performance and performance outcomes during athletic activity.

  3. Application of decision-making theory to the regulation of muscular work rate during self-paced competitive endurance activity.

    PubMed

    Renfree, Andrew; Martin, Louise; Micklewright, Dominic; St Clair Gibson, Alan

    2014-02-01

    Successful participation in competitive endurance activities requires continual regulation of muscular work rate in order to maximise physiological performance capacities, meaning that individuals must make numerous decisions with regards to the muscular work rate selected at any point in time. Decisions relating to the setting of appropriate goals and the overall strategic approach to be utilised are made prior to the commencement of an event, whereas tactical decisions are made during the event itself. This review examines current theories of decision-making in an attempt to explain the manner in which regulation of muscular work is achieved during athletic activity. We describe rational and heuristic theories, and relate these to current models of regulatory processes during self-paced exercise in an attempt to explain observations made in both laboratory and competitive environments. Additionally, we use rational and heuristic theories in an attempt to explain the influence of the presence of direct competitors on the quality of the decisions made during these activities. We hypothesise that although both rational and heuristic models can plausibly explain many observed behaviours in competitive endurance activities, the complexity of the environment in which such activities occur would imply that effective rational decision-making is unlikely. However, at present, many proposed models of the regulatory process share similarities with rational models. We suggest enhanced understanding of the decision-making process during self-paced activities is crucial in order to improve the ability to understand regulation of performance and performance outcomes during athletic activity. PMID:24113898

  4. Characteristics and Activities of Teachers on Distance Learning Programs That Affect Their Ratings

    ERIC Educational Resources Information Center

    Stanišic Stojic, Svetlana M.; Dobrijevic, Gordana; Stanišic, Nemanja; Stanic, Nenad

    2014-01-01

    This paper presents an analysis of teachers' ratings on distance learning undergraduate study programs: 7,156 students enrolled in traditional and 528 students enrolled in distance learning studies took part in the evaluation questionnaire, assessing 71 teachers. The data were collected from the Moodle platform and from the Singidunum…

  5. Improving Reading Rate Activities for EFL Students: Timed Reading and Repeated Oral Reading

    ERIC Educational Resources Information Center

    Chang, Anna C. -S.

    2012-01-01

    This study investigates the effect of timed reading (TR) and repeated oral reading (RR) on 35 adult students of English as a foreign language. Students in the TR (n =18) and RR (n =17) groups read 52 and 26 passages respectively over a 13-week period. Reading rates and comprehension levels were measured at three occasions: pre-intervention,…

  6. Effects of Instructions, Biofeedback, and Cognitive Activities on Heart Rate Control

    ERIC Educational Resources Information Center

    White, Thomas W.; And Others

    1977-01-01

    In a factorial experiment, 90 male and 90 female subjects were given (a) either instructions to increase heart rate (HR), decrease HR, or no instructions to change their HR; (b) either true biofeedback, false biofeedback, or no biofeedback; and (c) either instructions concerning cognitions to help them change HR or no instructions concerning…

  7. Hostility Ratings by Parents at Risk for Child Abuse: Impact of Chronic and Temporary Schema Activation

    ERIC Educational Resources Information Center

    Farc, Maria-Magdalena; Crouch, Julie L.; Skowronski, John J.; Milner, Joel S.

    2008-01-01

    Objective: Two studies examined whether accessibility of hostility-related schema influenced ratings of ambiguous child pictures. Based on the social information processing model of child physical abuse (CPA), it was expected that CPA risk status would serve as a proxy for chronic accessibility of hostile schema, while priming procedures were used…

  8. 77 FR 5416 - Financial Derivatives Transactions To Offset Interest Rate Risk; Investment and Deposit Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... concerned about the impact of future rising interest rates on credit unions' balance sheets, especially... depending on the nature and complexity of an FCU's balance sheet. As noted in ANPR I, the Board is... a less complex balance sheet, is it sufficient for that FCU's staff to demonstrate a minimum...

  9. History dependence of rate covariation between neurons during persistent activity in an oculomotor integrator.

    PubMed

    Aksay, Emre; Major, Guy; Goldman, Mark S; Baker, Robert; Seung, H Sebastian; Tank, David W

    2003-11-01

    Persistent firing in response to a brief stimulus is a neural correlate of short-term memory in a variety of systems. In the oculomotor neural integrator, persistent firing that encodes eye position is maintained in response to transient saccadic eye-velocity commands. To a first approximation, firing rates in the integrator vary linearly with eye position. Thus, viewed across many cells, the pattern of persistent firing in the integrator may be constrained to a unique line of stable states. Here this idea was tested by examining the relationship between firing rates of simultaneously recorded neurons. Paired recordings were obtained in awake goldfish from neurons in hindbrain area I, an essential part of the horizontal eye-position integrator. During spontaneous eye movements consisting of sequential fixations at different horizontal positions, the pair relationship between the majority of cells on the same side of the integrator was not unique: for a given rate of one cell, the rate of the paired cell assumed different values that depended systematically on the preceding saccade history. This finding suggests that the set of persistent firing states that encode eye position is not constrained to a unique line, and that models with stable states restricted to a such a line need to be modified accordingly.

  10. Are variations in rates of attending cultural activities associated with population health in the United States?

    PubMed Central

    Wilkinson, Anna V; Waters, Andrew J; Bygren, Lars Olov; Tarlov, Alvin R

    2007-01-01

    Background Population studies conducted in Sweden have revealed an association between attendance at cultural activities and health. Using data from US residents, we examined whether the association could be observed in the US. Methods Participants in the current study included 1,244 individuals who participated in the 1998 General Social Survey. Results A significant association between cultural activities and self-reported health (SRH) was observed, even after controlling for age, gender, marital status, race, number of children, subjective social class, employment status, household income, and educational attainment. Specifically, the more cultural activities people reported attending, the better was their SRH. Conclusion The data confirm that an association between cultural activity and health is present in a US sample. The data do not mean that the association is causal, but they suggest that further longitudinal research is warranted. PMID:17764546

  11. Analysis of Heart Rate Levels during Middle School Physical Education Activities.

    ERIC Educational Resources Information Center

    Strand, Brad; Reeder, Steve

    1993-01-01

    Describes study results that help to explain why U.S. children are not as fit as many health and physical education professionals think they should be, and discusses whether aerobic activity is sufficient for physical fitness. (GLR)

  12. 45 CFR 235.64 - FFP rates, and activities and costs matchable as training expenditures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... activities and costs matchable as training expenditures. Under title I, IV-A, X, XIV, or XVI(AABD) of the Act... engaged to develop or conduct special programs; and (4) Costs of space, postage, teaching...

  13. Activity concentration of natural radionuclides and radon and thoron exhalation rates in rocks used as decorative wall coverings in Japan.

    PubMed

    Iwaoka, Kazuki; Hosoda, Masahiro; Tabe, Hiroyuki; Ishikawa, Tetsuo; Tokonami, Shinji; Yonehara, Hidenori

    2013-01-01

    In Japan, many dwellings have decorative wall coverings made from granite, andesite, tuff, gabbro, and marble. However, information regarding activity concentrations and radon (Rn) and thoron (Rn) exhalation rates for such rocks is very scarce. Therefore, samples of the granite, andesite, tuff, and marble that are used as wall coverings in Japan were collected from mining companies, and their activity concentrations and Rn and Rn exhalation rates were measured. Dose estimations for inhabitants living in houses built with these materials were also carried out. The activity concentration of natural radionuclides in all the materials was lower than the critical values described by the International Atomic Energy Agency (IAEA) (10,000 Bq kg for K and 1,000 Bq kg for all other radionuclides of natural origin). The maximum values of Rn and Rn mass exhalation rates for the granite samples were 0.12 and 430 mBq kg s, and those for the area exhalation rates were 1.8 and 6300 mBq m s, respectively; these values are higher than those for other samples. The maximum value of effective doses to inhabitants was 0.68 mSv y, which is lower than the intervention exemption level (1 mSv y) given in the International Commission on Radiological Protection (ICRP) Publication 82.

  14. Activity concentration of natural radionuclides and radon and thoron exhalation rates in rocks used as decorative wall coverings in Japan.

    PubMed

    Iwaoka, Kazuki; Hosoda, Masahiro; Tabe, Hiroyuki; Ishikawa, Tetsuo; Tokonami, Shinji; Yonehara, Hidenori

    2013-01-01

    In Japan, many dwellings have decorative wall coverings made from granite, andesite, tuff, gabbro, and marble. However, information regarding activity concentrations and radon (Rn) and thoron (Rn) exhalation rates for such rocks is very scarce. Therefore, samples of the granite, andesite, tuff, and marble that are used as wall coverings in Japan were collected from mining companies, and their activity concentrations and Rn and Rn exhalation rates were measured. Dose estimations for inhabitants living in houses built with these materials were also carried out. The activity concentration of natural radionuclides in all the materials was lower than the critical values described by the International Atomic Energy Agency (IAEA) (10,000 Bq kg for K and 1,000 Bq kg for all other radionuclides of natural origin). The maximum values of Rn and Rn mass exhalation rates for the granite samples were 0.12 and 430 mBq kg s, and those for the area exhalation rates were 1.8 and 6300 mBq m s, respectively; these values are higher than those for other samples. The maximum value of effective doses to inhabitants was 0.68 mSv y, which is lower than the intervention exemption level (1 mSv y) given in the International Commission on Radiological Protection (ICRP) Publication 82. PMID:23192085

  15. Fate of tetracycline resistant bacteria as a function of activated sludge process organic loading and growth rate.

    PubMed

    Kim, S; Jensen, J N; Aga, D S; Weber, A S

    2007-01-01

    The objective of this research was to elucidate the fate of tetracycline resistant bacteria as a function of activated sludge organic loading rate and growth rate. Techniques employed to evaluate the effect of these factors on the fate of tetracycline resistant bacteria were: (1) resistant bacteria concentrations in the SBR biomass; (2) production of tetracycline resistant bacteria as measured by a combination of effluent efflux and intentional solids wasting; (3) net specific growth rates as determined by an SBR population balance; and (4) percentage of resistance as determined by normalising resistant concentrations to total concentrations. Based on these evaluation parameters, increases in organic loading and growth rate both resulted in amplification of tetracycline resistance. These trends were observed for activated sludge reactors loaded with typical municipal background tetracycline concentrations (approximately 1 microg/L) and those receiving influent augmented with 250 microg/L tetracycline. Accordingly, biological wastewater treatment plants, such as the activated sludge process, may be significant sources of antibiotic resistance to the environment.

  16. Linear free energy relationships between aqueous phase hydroxyl radical reaction rate constants and free energy of activation.

    PubMed

    Minakata, Daisuke; Crittenden, John

    2011-04-15

    The hydroxyl radical (HO(•)) is a strong oxidant that reacts with electron-rich sites on organic compounds and initiates complex radical chain reactions in aqueous phase advanced oxidation processes (AOPs). Computer based kinetic modeling requires a reaction pathway generator and predictions of associated reaction rate constants. Previously, we reported a reaction pathway generator that can enumerate the most important elementary reactions for aliphatic compounds. For the reaction rate constant predictor, we develop linear free energy relationships (LFERs) between aqueous phase literature-reported HO(•) reaction rate constants and theoretically calculated free energies of activation for H-atom abstraction from a C-H bond and HO(•) addition to alkenes. The theoretical method uses ab initio quantum mechanical calculations, Gaussian 1-3, for gas phase reactions and a solvation method, COSMO-RS theory, to estimate the impact of water. Theoretically calculated free energies of activation are found to be within approximately ±3 kcal/mol of experimental values. Considering errors that arise from quantum mechanical calculations and experiments, this should be within the acceptable errors. The established LFERs are used to predict the HO(•) reaction rate constants within a factor of 5 from the experimental values. This approach may be applied to other reaction mechanisms to establish a library of rate constant predictions for kinetic modeling of AOPs. PMID:21410278

  17. Rates of dissolved organic carbon (DOC) production and bacterial activity in the eastern North Atlantic Subtropical Gyre during summer

    NASA Astrophysics Data System (ADS)

    Teira, E.; Pazó, M. J.; Quevedo, M.; Fuentes, M. V.; Niell, F. X.; Fernández, E.

    2003-04-01

    Rates of particulate organic carbon production, dissolved organic carbon production (DOC) and bacterial production were measured at 8 stations located in the eastern North Atlantic Subtropical Gyre during August 1998. Euphotic-depth-integrated particulate organic carbon (POC) production rate was on average 27 mg C m-2 h-1. The corresponding averaged integrated DOC production rate was 5 mg C m-2 h-1, i.e., about 20 % of total primary production. No statistically significant relationship was found between the rates of DOC and POC production, suggesting that other processes besides phytoplankton exudation, such as cell lysis or protist grazing, could substantially contribute to the release of DOC. Euphotic-depth-integrated bacterial biomass and production were, on average, 214 mg C m-2 and 1.4 mg C m-2 h-1, respectively. The lack of correlation between the rates of DOC release and bacterial activity, and a bacterial carbon demand (BCD, calculated by using an estimated bacterial growth efficiency ranging from 11 to 18%) in excess of DOC production suggest the existence of additional organic carbon sources (both allochthonous and/or autochthonous reservoirs), apart from in situ phytoplankton-derived DOC production, for the maintenance of bacterial activity in this region during summer.

  18. Robust heart rate estimation using wrist-based PPG signals in the presence of intense physical activities.

    PubMed

    Chengzhi Zong; Jafari, Roozbeh

    2015-08-01

    Heart rate tracking from a wrist-type photoplethysmogram (PPG) signal during intensive physical activities is a challenge that is attracting more attention thanks to the introduction of wrist-worn wearable computers. Commonly-used motion artifact rejection methods coupled with simple periodicity-based heart rate estimation techniques are incapable of achieving satisfactory heart rate tracking performance during intense activities. In this paper, we propose a two-stage solution. Firstly, we introduce an improved spectral subtraction method to reject the spectral components of motion artifacts. Secondly, instead of using heuristic mechanisms, we formalize the spectral peaks selection process as the shortest path search problem and validate its effectiveness. Analysis on the experimental results based on a published database shows that: (1) Our proposed method outperforms three other comparable methods with regards to heart rate estimation error. (2) The proposed method is a promising candidate for both offline cardiac health analysis and online heart rate tracking in daily life, even during intensive physical motions. PMID:26738168

  19. The effects of temperature and activity on intraspecific scaling of metabolic rates in a lungless salamander.

    PubMed

    Gifford, Matthew E; Clay, Timothy A; Peterman, William E

    2013-04-01

    The scaling of metabolic rate with body mass holds substantial predictive power as many biological processes depend on energy. A significant body of theory has been developed based on the assumption that metabolic rate scales with body mass as a power function with an exponent of 0.75, and that this scaling relationship is independent of temperature. Here we test this hypothesis at the intraspecific level in a lungless salamander using data on both standard and maximal metabolic rates (SMR and MMR, respectively). We also address a recently proposed alternative explanation that predicts systematic variation in this mass-scaling exponent, the metabolic level boundaries hypothesis (MLB). Consistent with predictions of the metabolic theory of ecology the mass scaling of SMR and MMR were independent of temperature, however, we find evidence that the mass-scaling exponent for SMR and MMR differ significantly from 0.75. Further, our data do not provide strong support for MLB. Mass-scaling exponents for MMR generally exceed those for SMR, although these differences are rarely statistically significant.

  20. Rate of hydrolysis in ATP synthase is fine-tuned by α-subunit motif controlling active site conformation

    PubMed Central

    Beke-Somfai, Tamás; Lincoln, Per; Nordén, Bengt

    2013-01-01

    Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. FoF1 ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F1 performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate. PMID:23345443

  1. Rate of hydrolysis in ATP synthase is fine-tuned by α-subunit motif controlling active site conformation.

    PubMed

    Beke-Somfai, Tamás; Lincoln, Per; Nordén, Bengt

    2013-02-01

    Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. F(o)F(1) ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F(1) performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate. PMID:23345443

  2. The interactions between temperature and activity levels in driving metabolic rate: theory, with empirical validation from contrasting ectotherms.

    PubMed

    Halsey, L G; Matthews, P G D; Rezende, E L; Chauvaud, L; Robson, A A

    2015-04-01

    The rate of change in resting metabolic rate (RMR) as a result of a temperature increase of 10 °C is termed the temperature coefficient (Q10), which is often used to predict how an organism's total MR will change with temperature. However, this method neglects a potentially key component of MR; changes in activity level (and thus activity MR; AMR) with temperature may significantly alter the relationship between MR and temperature. The present study seeks to describe how thermal effects on total MR estimated from RMR-temperature measurements can be misleading when the contribution of activity to total MR is neglected. A simple conceptual framework illustrates that since the relationship between activity levels and temperature can be different to the relationship between RMR and temperature, a consistent relationship between RMR and total MR cannot be assumed. Thus the thermal effect on total MR can be considerably different to the thermal effect on RMR. Simultaneously measured MR and activity from three ectotherm species with differing behavioural and physiological ecologies were used to empirically examine how changes in temperature drive changes in RMR, activity level, AMR and the Q10 of MR. These species exhibited varied activity- and MR-temperature relationships, underlining the difficulty in predicting thermal influences on activity levels and total MR. These data support a model showing that thermal effects on total MR will deviate from predictions based solely on RMR; this deviation will depend upon the difference in Q10 between AMR and RMR, and the relative contribution of AMR to total MR. To develop mechanistic, predictive models for species' metabolic responses to temperature changes, empirical information about the relationships between activity levels, MR and temperature, such as reported here, is required. This will supersede predictions based on RMR alone.

  3. The interactions between temperature and activity levels in driving metabolic rate: theory, with empirical validation from contrasting ectotherms.

    PubMed

    Halsey, L G; Matthews, P G D; Rezende, E L; Chauvaud, L; Robson, A A

    2015-04-01

    The rate of change in resting metabolic rate (RMR) as a result of a temperature increase of 10 °C is termed the temperature coefficient (Q10), which is often used to predict how an organism's total MR will change with temperature. However, this method neglects a potentially key component of MR; changes in activity level (and thus activity MR; AMR) with temperature may significantly alter the relationship between MR and temperature. The present study seeks to describe how thermal effects on total MR estimated from RMR-temperature measurements can be misleading when the contribution of activity to total MR is neglected. A simple conceptual framework illustrates that since the relationship between activity levels and temperature can be different to the relationship between RMR and temperature, a consistent relationship between RMR and total MR cannot be assumed. Thus the thermal effect on total MR can be considerably different to the thermal effect on RMR. Simultaneously measured MR and activity from three ectotherm species with differing behavioural and physiological ecologies were used to empirically examine how changes in temperature drive changes in RMR, activity level, AMR and the Q10 of MR. These species exhibited varied activity- and MR-temperature relationships, underlining the difficulty in predicting thermal influences on activity levels and total MR. These data support a model showing that thermal effects on total MR will deviate from predictions based solely on RMR; this deviation will depend upon the difference in Q10 between AMR and RMR, and the relative contribution of AMR to total MR. To develop mechanistic, predictive models for species' metabolic responses to temperature changes, empirical information about the relationships between activity levels, MR and temperature, such as reported here, is required. This will supersede predictions based on RMR alone. PMID:25575673

  4. Preceding muscle activity influences motor unit discharge and rate of torque development during ballistic contractions in humans.

    PubMed

    Van Cutsem, Michaël; Duchateau, Jacques

    2005-01-15

    To investigate the effect of initial conditions on the modulation of motor unit discharge during fast voluntary contractions, we compared ballistic isometric contractions of the ankle dorsiflexor muscles that were produced from either a resting state or superimposed on a sustained contraction. The torque of the dorsiflexors and the surface and intramuscular EMGs from the tibialis anterior were recorded. The results showed that the performance of a ballistic contraction from a sustained contraction ( approximately 25% maximal voluntary contraction (MVC)) had a negative effect on the maximal rate of torque development. Although the electromechanical delay was shortened, the EMG activity during the ballistic contraction was less synchronized. These observations were associated with a significant decline in the average discharge rate of single motor units (89.8 +/- 3.8 versus 115 +/- 5.8 Hz) and in the percentage of units (6.2 versus 15.5% of the whole sample) that exhibited double discharges at brief intervals (= 5 ms). High-threshold units that were not recruited during the sustained contraction displayed the same activation pattern, which indicates that the mechanisms responsible for the decline in discharge rate were not restricted to previously activated units, but appear to influence the entire motor unit pool. When a premotor silent period (SP) was observed at the transition from the sustained muscular activity to the ballistic contraction (19% of the trials), these adjustments in motor unit activity were not present, and the ballistic contractions were similar to those performed from a resting state. Together, these results indicate that initial conditions can influence the capacity for motor unit discharge rate and hence the performance of a fast voluntary contraction.

  5. Soil Enzyme Activities as Affected by Manure Types, Application Rates and Management Practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of manure can restore soil ecosystem services related to nutrient cycling and soil organic matter (SOM) dynamics through biochemical transformations mediated by soil enzymes. Enzyme activities are very crucial in soil metabolic functioning as they drive the decomposition of organic r...

  6. Brain activity in valuation regions while thinking about the future predicts individual discount rates.

    PubMed

    Cooper, Nicole; Kable, Joseph W; Kim, B Kyu; Zauberman, Gal

    2013-08-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future--specifically, to judge the subjective length of future time intervals--predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future.

  7. Brain Activity in Valuation Regions while Thinking about the Future Predicts Individual Discount Rates

    PubMed Central

    Cooper, Nicole; Kim, B. Kyu; Zauberman, Gal

    2013-01-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future—specifically, to judge the subjective length of future time intervals—predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future. PMID:23926268

  8. Measuring potential denitrification enzyme activity rates using the membrane inlet mass spectrometer

    EPA Science Inventory

    The denitrification enzyme activity (DEA) assay, provides a quantitative assessment of the multi enzyme, biological process of reactive nitrogen removal via the reduction of N03 to N2. Measured in soil, usually under non limiting carbon and nitrate concentrations, this short ter...

  9. Brain activity in valuation regions while thinking about the future predicts individual discount rates.

    PubMed

    Cooper, Nicole; Kable, Joseph W; Kim, B Kyu; Zauberman, Gal

    2013-08-01

    People vary widely in how much they discount delayed rewards, yet little is known about the sources of these differences. Here we demonstrate that neural activity in ventromedial prefrontal cortex (VMPFC) and ventral striatum (VS) when human subjects are asked to merely think about the future--specifically, to judge the subjective length of future time intervals--predicts delay discounting. High discounters showed lower activity for longer time delays, while low discounters showed the opposite pattern. Our results demonstrate that the correlation between VMPFC and VS activity and discounting occurs even in the absence of choices about future rewards, and does not depend on a person explicitly evaluating future outcomes or judging their self-relevance. This suggests a link between discounting and basic processes involved in thinking about the future, such as temporal perception. Our results also suggest that reducing impatience requires not suppression of VMPFC and VS activity altogether, but rather modulation of how these regions respond to the present versus the future. PMID:23926268

  10. Characterization of the Lightning Activity in Argentina, an Approach for Estimating the Annual Death Rate

    NASA Astrophysics Data System (ADS)

    Nicora, M. G.; Bürgesser, R. E.; Quel, E. J.; Avila, E.

    2013-05-01

    The information about lightning activity is fundamental to atmospheric surveillance due its relevant applications on different aspects as security, defense, early warning system and for generation of statistical data for planning infrastructure projects. Few countries in the world have its own lightning detection networks which allow monitoring the lightning activity inside its national border. The development of the World Wide Lightning Location Network (WWLLN) provides a confidence global lightning data with low cost, which was already used to characterize the lightning activity in several regions of the world. The aim of the present work is the use of the lightning data obtained by the WWLLN to make an analysis on the lightning activity over Argentina between the years 2005-2012. In order to achieve this objective the isoceraunic maps of Argentina were made. These maps will be incorporated to the standard IRAM 2184-11 "lightning protection". Furthermore, by using data of flash per km2 per year, we provide a model for estimating deaths from lightning. The model is based on the parameterizations of the flash density, population density and urbanization of a given region. The model was adapted for Argentina and Brazil in order to obtain an estimation of deaths in different regions. The results obtained allows to promote protective behaviors in the population.

  11. Comparison of heart-rate intensity and duration between sport games and traditional cardiovascular activities.

    PubMed

    Hannon, J C; Pellett, T L

    1998-12-01

    The present purpose was to ascertain whether participants who engaged in sport games (indoor soccer and basketball) could experience the same cardiovascular benefits as when they participated in traditional cardiovascular fitness activities (step aerobics and running). The results showed they did.

  12. Chitinase activities, scab resistance, mycorrhization rates and biomass of own-rooted and grafted transgenic apple

    PubMed Central

    Schäfer, Tina; Hanke, Magda-Viola; Flachowsky, Henryk; König, Stephan; Peil, Andreas; Kaldorf, Michael; Polle, Andrea; Buscot, François

    2012-01-01

    This study investigated the impact of constitutively expressed Trichoderma atroviride genes encoding exochitinase nag70 or endochitinase ech42 in transgenic lines of the apple cultivar Pinova on the symbiosis with arbuscular mycorrhizal fungi (AMF). We compared the exo- and endochitinase activities of leaves and roots from non-transgenic Pinova and the transgenic lines T386 and T389. Local and systemic effects were examined using own-rooted trees and trees grafted onto rootstock M9. Scab susceptibility was also assessed in own-rooted and grafted trees. AMF root colonization was assessed microscopically in the roots of apple trees cultivated in pots with artificial substrate and inoculated with the AMF Glomus intraradices and Glomus mosseae. Own-rooted transgenic lines had significantly higher chitinase activities in their leaves and roots compared to non-transgenic Pinova. Both of the own-rooted transgenic lines showed significantly fewer symptoms of scab infection as well as significantly lower root colonization by AMF. Biomass production was significantly reduced in both own-rooted transgenic lines. Rootstock M9 influenced chitinase activities in the leaves of grafted scions. When grafted onto M9, the leaf chitinase activities of non-transgenic Pinova (M9/Pinova) and transgenic lines (M9/T386 and M9/T389) were not as different as when grown on their own roots. M9/T386 and M9/T389 were only temporarily less infected by scab than M9/Pinova. M9/T386 and M9/T389 did not differ significantly from M9/Pinova in their root chitinase activities, AMF root colonization and biomass. PMID:22888297

  13. A cis-active regulatory gene in the mouse: direct demonstration of cis-active control of the rate of enzyme subunit synthesis

    SciTech Connect

    Bernstine, E.G.; Koh, C.

    1980-07-01

    Mouse mitochondrial malic enzyme (L-malate:NADP/sup +/ oxidoreductase (oxaloacetate-decarboxylating), EC1.1.1.40) is a tetrameric protein. Two alleles of the structural gene (Mod-2) are known which code for electrophoretically distinct enzyme subunits: Mod-2/sup a/ and Mod-2/sup b/. A regulatory gene (Mdr-1), closely linked to Mod-2 on chromosome 7, determines the rate of mitochondrial malic enzyme synthesis in brain. Two alleles of Mdr-1 are known: Mdr-1/sup a/ (high activity) and Mdr-1/sup b/ (low activity). By pulse-labeling with (/sup 35/S)methionine, immune precipitation, and isoelectric focusing under dissociating conditions, we have measured the relative rates of synthesis of the two types of enzyme subunit in animals of genotypes Mdr-1/sup a/ Mod-2/sup a//Mdr-1/sup a/ Mod-2/sup b/ and Mdr-1/sup a/ Mod-2/sup a//Mdr-1/sup b/ Mod-2/sup b/. The results show that in the former animals both types of subunit are made at an identical rate, whereas in the latter animals the Mod-2/sup a/ gene product is synthesized at a rate 2.2 times that of the Mod-2/sup b/-coded subunit. Thus we have unambiguously demonstrated that Mdr-1 is cis-active in its control of the expression of the Mod-2 structural gene.

  14. Gene switching rate determines response to extrinsic perturbations in the self-activation transcriptional network motif.

    PubMed

    de Franciscis, Sebastiano; Caravagna, Giulio; Mauri, Giancarlo; d'Onofrio, Alberto

    2016-01-01

    Gene switching dynamics is a major source of randomness in genetic networks, also in the case of large concentrations of the transcription factors. In this work, we consider a common network motif - the positive feedback of a transcription factor on its own synthesis - and assess its response to extrinsic noises perturbing gene deactivation in a variety of settings where the network might operate. These settings are representative of distinct cellular types, abundance of transcription factors and ratio between gene switching and protein synthesis rates. By investigating noise-induced transitions among the different network operative states, our results suggest that gene switching rates are key parameters to shape network response to external perturbations, and that such response depends on the particular biological setting, i.e. the characteristic time scales and protein abundance. These results might have implications on our understanding of irreversible transitions for noise-related phenomena such as cellular differentiation. In addition these evidences suggest to adopt the appropriate mathematical model of the network in order to analyze the system consistently to the reference biological setting. PMID:27256916

  15. Bacterial clearance rate and a new differential hemocyte staining method to assess immunostimulant activity in shrimp.

    PubMed

    Sritunyalucksana, Kallaya; Gangnonngiw, Warachin; Archakunakorn, Somwit; Fegan, Daniel; Flegel, Timothy W

    2005-01-25

    New methods were developed to assess immunostimulant efficacy in the black tiger shrimp Penaeus monodon. Test shrimp were fed with 2 or 4 % yeast extract (YE)-coated feed while controls were fed non-coated feed. After 4 wk of feeding, individual shrimp were assessed for total hemocyte counts (THC), the number of granular hemocytes (GH) and rate of bacterial clearance. For hemocyte counts, formalin-fixed hemolymph was stained with 1.2 % Rose Bengal in 50 % ethanol for 20 min at room temperature. Some of this mixture was used for THC with a hemocytometer while some was smeared on a microscope slide and left to dry before counterstaining with hematoxylin for GH counts. By this technique, high quality smears were obtained for accurate differential counts. Bacterial clearance assays were used to assess the sum effect of humoral and cellular defense mechanisms. Vibrio harveyi was injected intramuscularly at 1 x 10(8) cells per shrimp and hemolymph was collected in anticoagulant at 0, 15, 30 and 60 min post-injection for quadruplicate drop counts (20 microl) on TCBS agar. Total hemocyte counts for shrimp fed with 4 % YE were significantly higher (p < 0.05) than those for shrimp fed with non-coated feed. The percentage of granular cells and the rates of bacterial clearance for the YE-fed shrimp were higher than those for shrimp fed the control diet. These 2 methods provide a simple and rapid comparison of shrimp groups for differences in anti-bacterial defense capacity.

  16. Gene switching rate determines response to extrinsic perturbations in the self-activation transcriptional network motif

    PubMed Central

    de Franciscis, Sebastiano; Caravagna, Giulio; Mauri, Giancarlo; d’Onofrio, Alberto

    2016-01-01

    Gene switching dynamics is a major source of randomness in genetic networks, also in the case of large concentrations of the transcription factors. In this work, we consider a common network motif - the positive feedback of a transcription factor on its own synthesis - and assess its response to extrinsic noises perturbing gene deactivation in a variety of settings where the network might operate. These settings are representative of distinct cellular types, abundance of transcription factors and ratio between gene switching and protein synthesis rates. By investigating noise-induced transitions among the different network operative states, our results suggest that gene switching rates are key parameters to shape network response to external perturbations, and that such response depends on the particular biological setting, i.e. the characteristic time scales and protein abundance. These results might have implications on our understanding of irreversible transitions for noise-related phenomena such as cellular differentiation. In addition these evidences suggest to adopt the appropriate mathematical model of the network in order to analyze the system consistently to the reference biological setting. PMID:27256916

  17. Metabolic rates during rest and activity in differently tracheated spiders (Arachnida, Araneae): Pardosa lugubris (Lycosidae) and Marpissa muscosa (Salticidae).

    PubMed

    Schmitz, Anke

    2004-10-01

    With flow-through respirometry under video tracking, the CO(2) release of adult male and female Pardosa lugubris (wolf spider) and Marpissa muscosa (jumping spider) was measured during rest and activity. Activity metabolism was measured in phases in which the animals were spontaneously active and during forced exercise. Standard metabolic rates (V(CO2)/ t) were 1.43 nmol s(-1) g(-1) in M. muscosa and 1.7-1.8 nmol s(-1) g(-1) in P. lugubris. Egg production caused higher resting rates in females compared with the males in P. lugubris. Maximum mass-specific CO(2) release, the additional amount of CO(2 )released after activity and the factorial aerobic scope were higher in M. muscosa. Additionally, half-time recovery and the lag between end of activity and maximum CO(2) release were lower in the jumping spider. The results are consistent with the hypothesis that the well-developed tracheal system in jumping spiders increases the efficiency of the respiratory system in comparison with wolf spiders, which possess similarly developed lungs but only a simple tracheal system that is restricted to the opisthosoma.

  18. The rate of synthesis and decomposition of tissue proteins in hypokinesia and increased muscular activity

    NASA Technical Reports Server (NTRS)

    Fedorov, I. V.; Chernyy, A. V.; Fedorov, A. I.

    1978-01-01

    During hypokinesia and physical loading (swimming) of rats, the radioactivity of skeletal muscle, liver, kidney, heart, and blood proteins was determined after administration of radioactive amino acids. Tissue protein synthesis decreased during hypokinesia, and decomposition increased. Both synthesis and decomposition increased during physical loading, but anabolic processes predominated in the total tissue balance. The weights of the animals decreased in hypokinesia and increased during increased muscle activity.

  19. Absence of arterial baroreflex modulation of skin sympathetic activity and sweat rate during whole-body heating in humans

    NASA Technical Reports Server (NTRS)

    Wilson, T. E.; Cui, J.; Crandall, C. G.

    2001-01-01

    1. Prior findings suggest that baroreflexes are capable of modulating skin blood flow, but the effects of baroreceptor loading/unloading on sweating are less clear. Therefore, this project tested the hypothesis that pharmacologically induced alterations in arterial blood pressure in heated humans would lead to baroreflex-mediated changes in both skin sympathetic nerve activity (SSNA) and sweat rate. 2. In seven subjects mean arterial blood pressure was lowered (approximately 8 mmHg) and then raised (approximately 13 mmHg) by bolus injections of sodium nitroprusside and phenylephrine, respectively. Moreover, in a separate protocol, arterial blood pressure was reduced via steady-state administration of sodium nitroprusside. In both normothermia and heat-stress conditions the following responses were monitored: sublingual and mean skin temperatures, heart rate, beat-by-beat blood pressure, skin blood flow (laser-Doppler flowmetry), local sweat rate and SSNA (microneurography from peroneal nerve). 3. Whole-body heating increased skin and sublingual temperatures, heart rate, cutaneous blood flow, sweat rate and SSNA, but did not change arterial blood pressure. Heart rate was significantly elevated (from 74 +/- 3 to 92 +/- 4 beats x min(-1); P < 0.001) during bolus sodium nitroprusside-induced reductions in blood pressure, and significantly reduced (from 92 +/- 4 to 68 +/- 4 beats x min(-1); P < 0.001) during bolus phenylephrine-induced elevations in blood pressure, thereby demonstrating normal baroreflex function in these subjects. 4. Neither SSNA nor sweat rate was altered by rapid (bolus infusion) or sustained (steady-state infusion) changes in blood pressure regardless of the thermal condition. 5. These data suggest that SSNA and sweat rate are not modulated by arterial baroreflexes in normothermic or moderately heated individuals.

  20. Nitrate, ascorbic acid, mineral and antioxidant activities of Cosmos caudatus in response to organic and mineral-based fertilizer rates.

    PubMed

    Hassan, Siti Aishah; Mijin, Salumiah; Yusoff, Umi Kalsom; Ding, Phebe; Wahab, Puteri Edaroyati Megat

    2012-06-28

    The source and quantity of nutrients available to plants can affect the quality of leafy herbs. A study was conducted to compare quality of Cosmos caudatus in response to rates of organic and mineral-based fertilizers. Organic based fertilizer GOBI (8% N:8% P₂O₅:8% K₂O) and inorganic fertilizer (15% N, 15% P₂O₅, 15% K₂O) were evaluated based on N element rates at 0, 30, 60, 90, 120 kg h⁻¹. Application of organic based fertilizer reduced nitrate, improved vitamin C, antioxidant activity as well as nitrogen and calcium nutrients content. Antioxidant activity and chlorophyll content were significantly higher with increased fertilizer application. Fertilization appeared to enhance vitamin C content, however for the maximum ascorbic acid content, regardless of fertilizer sources, plants did not require high amounts of fertilizer.

  1. Topographic measures of cerebral activity during reading of text at fast- and slow-paced rates.

    PubMed

    Breznitz, Z; DeMarco, A; Hakerem, G

    1993-01-01

    Eight college level readers were given short paragraphs for reading, presented on a computer terminal in units of 2 or 3 words at a time. Two conditions were presented, a fast reading session with an inter-stimulus interval (ISI) of 1.1 seconds, and a slower session with an ISI of 1.2 seconds. EEG and ERP measures were obtained. ERP findings revealed a late central-posterior negativity which was sensitive to the effect of varying ISI by showing shorter latencies, of about 110 msec, to the smaller interval. An earlier component complex consisting of a bi-temporal-occipital negativity and frontal positivity was observed between 155 and 175 msec. This component was not observed to be sensitive to variation of ISI. Analysis of the unaveraged EEG activity by FFT and absolute power measures revealed that the activity was primarily slow wave (0-7.5 HZ), and right-sided. Findings suggested that the brain functions as an integrated whole during reading, activating a diffuse set of neural generators.

  2. Modeling fault diagnosis as the activation and use of a frame system. [for pilot problem-solving rating

    NASA Technical Reports Server (NTRS)

    Smith, Philip J.; Giffin, Walter C.; Rockwell, Thomas H.; Thomas, Mark

    1986-01-01

    Twenty pilots with instrument flight ratings were asked to perform a fault-diagnosis task for which they had relevant domain knowledge. The pilots were asked to think out loud as they requested and interpreted information. Performances were then modeled as the activation and use of a frame system. Cognitive biases, memory distortions and losses, and failures to correctly diagnose the problem were studied in the context of this frame system model.

  3. Effective charge on acetylcholinesterase active sites determined from the ionic strength dependence of association rate constants with cationic ligands.

    PubMed

    Nolte, H J; Rosenberry, T L; Neumann, E

    1980-08-01

    The reaction of the specific fluorescent cationic ligand N-methylacridinium with the active site of 11S acetylcholinesterase from electric eel was monitored by temperature-jump relaxation kinetics at a variety of ionic strengths. The ionic strength dependence of the bimolecular association rate constant is analyzed with a Brønsted-Debye-Hückel expression and leads to estimates of the association rate constant at zero ionic strength of K120 = 1.1 X 10(10) M-1 S-1 at 25 degrees C and the net charge number of the enzyme active site of ZE = -6.3. The ionic strength dependence of the second-order hydrolysis rate constant kcat/Kapp for acetylthiocholine under steady-state conditions is also very pronounced and indicates a value of ZE = -9. Thus, a large effective negative charge on the enzyme active site appears to be a general characteristic of its interaction with cationic ligands. The ionic strength dependence of Kcat/Kapp is identical with that of sodium chloride, sodium phosphate, and sodium citrate, thus ruling out any possibility that the phenomena arise from a specific, partially competitive binding of Na+ to the enzyme active site. Substitution of the calculated electrostatic parameters into theoretical equations indicates that the most significant effect of these ZE values is a 2-3 order of magnitude reduction in the rate constant for dissociation of the initial ligand-enzyme encounter complex; this decrease renders the bimolecular reaction diffusion controlled. The high value of k120 and the space requirements of six to nine charged groups suggest that regions of the enzyme surface area larger than the catalytic sites themselves are effective in trapping cationic ligands.

  4. Chronic baroreflex activation restores spontaneous baroreflex control and variability of heart rate in obesity-induced hypertension.

    PubMed

    Iliescu, Radu; Tudorancea, Ionut; Irwin, Eric D; Lohmeier, Thomas E

    2013-10-01

    The sensitivity of baroreflex control of heart rate is depressed in subjects with obesity hypertension, which increases the risk for cardiac arrhythmias. The mechanisms are not fully known, and there are no therapies to improve this dysfunction. To determine the cardiovascular dynamic effects of progressive increases in body weight leading to obesity and hypertension in dogs fed a high-fat diet, 24-h continuous recordings of spontaneous fluctuations in blood pressure and heart rate were analyzed in the time and frequency domains. Furthermore, we investigated whether autonomic mechanisms stimulated by chronic baroreflex activation and renal denervation-current therapies in patients with resistant hypertension, who are commonly obese-restore cardiovascular dynamic control. Increases in body weight to ∼150% of control led to a gradual increase in mean arterial pressure to 17 ± 3 mmHg above control (100 ± 2 mmHg) after 4 wk on the high-fat diet. In contrast to the gradual increase in arterial pressure, tachycardia, attenuated chronotropic baroreflex responses, and reduced heart rate variability were manifest within 1-4 days on high-fat intake, reaching 130 ± 4 beats per minute (bpm) (control = 86 ± 3 bpm) and ∼45% and <20%, respectively, of control levels. Subsequently, both baroreflex activation and renal denervation abolished the hypertension. However, only baroreflex activation effectively attenuated the tachycardia and restored cardiac baroreflex sensitivity and heart rate variability. These findings suggest that baroreflex activation therapy may reduce the risk factors for cardiac arrhythmias as well as lower arterial pressure.

  5. Relationship between hamstring activation rate and heel contact velocity: Factors influencing age-related slip-induced falls

    PubMed Central

    Lockhart, Thurmon E.; Kim, Sukwon

    2010-01-01

    The purpose of this research was to determine whether a decreased hamstring activation rate among the elderly is responsible for a higher horizontal heel contact velocity and increased likelihood of slip-induced falls compared to their younger counterparts. Twenty-eight subjects from two age groups (14 young and 14 old) walked across a linear walking track with embedded force platforms while wearing a fall arresting harness attached to an overhead arresting rig for safety. In order to obtain realistic unexpected slip-induced fall data, a soapy vinyl floor surface was hidden from the subjects and unexpectedly introduced. Synchronized kinematics, kinetic and electromyography (EMG) analyses during the heel contact phase of the gait cycle while walking over slippery and non-slippery floor surfaces were examined in the study. Normalized EMG data were examined in terms of hamstring activation rate and evaluated with heel contact velocity and friction demand characteristic (as measured by peak required coefficient of friction (RCOF)) on the dry vinyl floor surface. Furthermore, slip parameters (i.e. slip distances and slipping velocity) were assessed on the soapy vinyl floor surface. The results indicated that younger adults’ hamstring activation rate was higher than older adults, whereas younger adults’ heel contact velocity was not different from older adults. These results suggested that heel contact velocity in younger adults was sufficiently reduced before the heel contact phase of the gait cycle. This could be due to the outcome of higher hamstring activation rate in younger adults in comparison to older adults. However, lower friction demand (peak RCOF), shorter slip distances, slower peak sliding heel velocity and more falls among older adults suggested that the slip initiation characteristics were not the only factors contributing to slip-induced falls among the elderly. PMID:16112575

  6. Test plan for measuring ventilation rates and combustible gas levels in RPP active catch tanks

    SciTech Connect

    NGUYEN, D.M.

    1999-06-03

    The purpose of this test is to provide an initial screening of combustible gas concentrations in catch tanks that currently are operated by River Protection Project (RPP). The data will be used to determine whether or not additional data will be needed for closure of the flammable gas unreviewed safety question for these facilities. This test will involve field measurements of ammonia, organic vapor, and total combustible gas levels in the headspace of the catch tanks. If combustible gas level in a tank exceeds an established threshold, gas samples will be collected in SUMMA canisters for more extensive laboratory analysis. In addition, ventilation rates of some catch tanks will be measured to evaluate removal of flammable gas by air flow through the tanks.

  7. Test plan for measuring ventilation rates and combustible gas levels in TWRS active catch tanks

    SciTech Connect

    NGUYEN, D.M.

    1999-05-20

    The purpose of this test is to provide an initial screening of combustible gas concentrations in catch tanks that currently are operated by Tank Waste Remediation System (TWRS). The data will be used to determine whether or not additional data will be needed for closure of the flammable gas unreviewed safety question for these facilities. This test will involve field measurements of ammonia, organic vapor, and total combustible gas levels in the headspace of the catch tanks. If combustible gas level in a tank exceeds an established threshold, gas samples will be collected in SUMMA canisters for more extensive laboratory analysis. In addition, ventilation rates of some catch tanks will be measured to evaluate removal of flammable gas by air flow through the tanks.

  8. Efficient high repetition rate electro-optic Q-switched laser with an optically active langasite crystal.

    PubMed

    Ma, Shihui; Yu, Haohai; Zhang, Huaijin; Han, Xuekun; Lu, Qingming; Ma, Changqin; Boughton, Robert I; Wang, Jiyang

    2016-01-01

    With an optically active langasite (LGS) crystal as the electro-optic Q-switch, we demonstrate an efficient Q-switched laser with a repetition rate of 200 kHz. Based on the theoretical analysis of the interaction between optical activity and electro-optic property, the optical activity of the crystal has no influence on the birefringence during Q-switching if the quarter wave plate used was rotated to align with the polarization direction. With a Nd:LuVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime as the gain medium, a stable LGS Q-switched laser was designed with average output power of 4.39 W, corresponding to a slope efficiency of 29.4% and with a minimum pulse width of 5.1 ns. This work represents the highest repetition rate achieved so far in a LGS Q-switched laser and it can provide a practical Q-switched laser with a tunable high repetition rates for many applications, such as materials processing, laser ranging, medicine, military applications, biomacromolecule materials, remote sensing, etc.

  9. Efficient high repetition rate electro-optic Q-switched laser with an optically active langasite crystal

    PubMed Central

    Ma, Shihui; Yu, Haohai; Zhang, Huaijin; Han, Xuekun; Lu, Qingming; Ma, Changqin; Boughton, Robert I.; Wang, Jiyang

    2016-01-01

    With an optically active langasite (LGS) crystal as the electro-optic Q-switch, we demonstrate an efficient Q-switched laser with a repetition rate of 200 kHz. Based on the theoretical analysis of the interaction between optical activity and electro-optic property, the optical activity of the crystal has no influence on the birefringence during Q-switching if the quarter wave plate used was rotated to align with the polarization direction. With a Nd:LuVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime as the gain medium, a stable LGS Q-switched laser was designed with average output power of 4.39 W, corresponding to a slope efficiency of 29.4% and with a minimum pulse width of 5.1 ns. This work represents the highest repetition rate achieved so far in a LGS Q-switched laser and it can provide a practical Q-switched laser with a tunable high repetition rates for many applications, such as materials processing, laser ranging, medicine, military applications, biomacromolecule materials, remote sensing, etc. PMID:27461819

  10. Development and characterisation of ursolic acid nanocrystals without stabiliser having improved dissolution rate and in vitro anticancer activity.

    PubMed

    Song, Ju; Wang, Yancai; Song, Yuelin; Chan, Hokman; Bi, Chao; Yang, Xiao; Yan, Ru; Wang, Yitao; Zheng, Ying

    2014-02-01

    Ursolic acid (UA), which is a natural pentacyclic triterpenoid, has the potential to be developed as an anticancer drug, whereas its poor aqueous solubility and dissolution rate limit its clinical application. The aim of the present study was to develop UA nanocrystals to enhance its aqueous dispersibility, dissolution rate and anticancer activity. Following the investigation on the effects of stabiliser, the ratio of organic phase to aqueous solution and drug concentration, the UA nanocrystals without stabiliser were successfully prepared by anti-solvent precipitation approach. The nanocrystals maintained similar crystallinity with particle size, polydispersion index and zeta potential values of 188.0 ± 4.4 nm, 0.154 ± 0.022, and -25.0 ± 5.9 mV, respectively. Compared with the raw material, the UA nanocrystals showed good aqueous dispensability and a higher dissolution rate, and they could be completely dissolved in 0.5% SDS solution within 120 min. Moreover, the suspension of UA nanocrystals was physically stable after storage at 4°C for 7 weeks. By inducing G2/M phase cell cycle arrest, the UA nanocrystals significantly induced stronger cell growth inhibition activity against MCF-7 cells compared with free drug in vitro, although the uptake of free UA was approximately twice higher than that of the UA nanocrystals. The UA nanocrystals may be used as a potential delivery formulation for intravenous injection with enhanced dissolution velocity and anticancer activity. PMID:24022345

  11. Efficient high repetition rate electro-optic Q-switched laser with an optically active langasite crystal

    NASA Astrophysics Data System (ADS)

    Ma, Shihui; Yu, Haohai; Zhang, Huaijin; Han, Xuekun; Lu, Qingming; Ma, Changqin; Boughton, Robert I.; Wang, Jiyang

    2016-07-01

    With an optically active langasite (LGS) crystal as the electro-optic Q-switch, we demonstrate an efficient Q-switched laser with a repetition rate of 200 kHz. Based on the theoretical analysis of the interaction between optical activity and electro-optic property, the optical activity of the crystal has no influence on the birefringence during Q-switching if the quarter wave plate used was rotated to align with the polarization direction. With a Nd:LuVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime as the gain medium, a stable LGS Q-switched laser was designed with average output power of 4.39 W, corresponding to a slope efficiency of 29.4% and with a minimum pulse width of 5.1 ns. This work represents the highest repetition rate achieved so far in a LGS Q-switched laser and it can provide a practical Q-switched laser with a tunable high repetition rates for many applications, such as materials processing, laser ranging, medicine, military applications, biomacromolecule materials, remote sensing, etc.

  12. Efficient high repetition rate electro-optic Q-switched laser with an optically active langasite crystal.

    PubMed

    Ma, Shihui; Yu, Haohai; Zhang, Huaijin; Han, Xuekun; Lu, Qingming; Ma, Changqin; Boughton, Robert I; Wang, Jiyang

    2016-01-01

    With an optically active langasite (LGS) crystal as the electro-optic Q-switch, we demonstrate an efficient Q-switched laser with a repetition rate of 200 kHz. Based on the theoretical analysis of the interaction between optical activity and electro-optic property, the optical activity of the crystal has no influence on the birefringence during Q-switching if the quarter wave plate used was rotated to align with the polarization direction. With a Nd:LuVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime as the gain medium, a stable LGS Q-switched laser was designed with average output power of 4.39 W, corresponding to a slope efficiency of 29.4% and with a minimum pulse width of 5.1 ns. This work represents the highest repetition rate achieved so far in a LGS Q-switched laser and it can provide a practical Q-switched laser with a tunable high repetition rates for many applications, such as materials processing, laser ranging, medicine, military applications, biomacromolecule materials, remote sensing, etc. PMID:27461819

  13. Metabolic control of Clostridium thermocellum via inhibition of hydrogenase activity and the glucose transport rate.

    PubMed

    Li, Hsin-Fen; Knutson, Barbara L; Nokes, Sue E; Lynn, Bert C; Flythe, Michael D

    2012-02-01

    Clostridium thermocellum has the ability to catabolize cellulosic biomass into ethanol, but acetic acid, lactic acid, carbon dioxide, and hydrogen gas (H(2)) are also produced. The effect of hydrogenase inhibitors (H(2), carbon monoxide (CO), and methyl viologen) on product selectivity was investigated. The anticipated effect of these hydrogenase inhibitors was to decrease acetate production. However, shifts to ethanol and lactate production are also observed as a function of cultivation conditions. When the sparge gas of cellobiose-limited chemostat cultures was switched from N(2) to H(2), acetate declined, and ethanol production increased 350%. In resting cell suspensions, lactate increased when H(2) or CO was the inhibitor or when the cells were held at elevated hyperbaric pressure (6.8 atm). In contrast, methyl-viologen-treated resting cells produced twice as much ethanol as the other treatments. The relationship of chemostat physiology to methyl viologen inhibition was revealed by glucose transport experiments, in which methyl viologen decreased the rate of glucose transport by 90%. C. thermocellum produces NAD(+) from NADH by H(2), lactate, and ethanol production. When the hydrogenases were inhibited, the latter two products increased. However, excess substrate availability causes fructose 1,6-diphosphate, the glycolytic intermediate that triggers lactate production, to increase. Compensatory ethanol production was observed when the chemostat fluid dilution rate or methyl viologen decreased substrate transport. This research highlights the complex effects of high concentrations of dissolved gases in fermentation, which are increasingly envisioned in microbial applications of H(2) production for the conversion of synthetic gases to chemicals. PMID:22218768

  14. Bacterial clearance rate and a new differential hemocyte staining method to assess immunostimulant activity in shrimp.

    PubMed

    Sritunyalucksana, Kallaya; Gangnonngiw, Warachin; Archakunakorn, Somwit; Fegan, Daniel; Flegel, Timothy W

    2005-01-25

    New methods were developed to assess immunostimulant efficacy in the black tiger shrimp Penaeus monodon. Test shrimp were fed with 2 or 4 % yeast extract (YE)-coated feed while controls were fed non-coated feed. After 4 wk of feeding, individual shrimp were assessed for total hemocyte counts (THC), the number of granular hemocytes (GH) and rate of bacterial clearance. For hemocyte counts, formalin-fixed hemolymph was stained with 1.2 % Rose Bengal in 50 % ethanol for 20 min at room temperature. Some of this mixture was used for THC with a hemocytometer while some was smeared on a microscope slide and left to dry before counterstaining with hematoxylin for GH counts. By this technique, high quality smears were obtained for accurate differential counts. Bacterial clearance assays were used to assess the sum effect of humoral and cellular defense mechanisms. Vibrio harveyi was injected intramuscularly at 1 x 10(8) cells per shrimp and hemolymph was collected in anticoagulant at 0, 15, 30 and 60 min post-injection for quadruplicate drop counts (20 microl) on TCBS agar. Total hemocyte counts for shrimp fed with 4 % YE were significantly higher (p < 0.05) than those for shrimp fed with non-coated feed. The percentage of granular cells and the rates of bacterial clearance for the YE-fed shrimp were higher than those for shrimp fed the control diet. These 2 methods provide a simple and rapid comparison of shrimp groups for differences in anti-bacterial defense capacity. PMID:15759805

  15. Ventilation rates and activity levels of juvenile jumbo squid under metabolic suppression in the oxygen minimum zone.

    PubMed

    Trübenbach, Katja; Pegado, Maria R; Seibel, Brad A; Rosa, Rui

    2013-02-01

    The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O(2), 1 kPa, 10 °C) and measured metabolic rate, activity cycling patterns, swimming mode, escape jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, metabolic rate varied between 14 and 29 μmol O(2) g(-1) wet mass h(-1), depending on the level of activity. The mantle contraction frequency and strength were linearly correlated and increased significantly with activity level. Additionally, an increase in stroke volume and ventilatory volume per minute was observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rate dropped more than 75% during exposure to hypoxia. Maximum metabolic rate was not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity, indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squid also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameter (shortened diffusion pathway), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe 'deeply', with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per

  16. Foraging Activity Pattern Is Shaped by Water Loss Rates in a Diurnal Desert Rodent.

    PubMed

    Levy, Ofir; Dayan, Tamar; Porter, Warren P; Kronfeld-Schor, Noga

    2016-08-01

    Although animals fine-tune their activity to avoid excess heat, we still lack a mechanistic understanding of such behaviors. As the global climate changes, such understanding is particularly important for projecting shifts in the activity patterns of populations and communities. We studied how foraging decisions vary with biotic and abiotic pressures. By tracking the foraging behavior of diurnal desert spiny mice in their natural habitat and estimating the energy and water costs and benefits of foraging, we asked how risk management and thermoregulatory requirements affect foraging decisions. We found that water requirements had the strongest effect on the observed foraging decisions. In their arid environment, mice often lose water while foraging for seeds and cease foraging even at high energetic returns when water loss is high. Mice also foraged more often when energy expenditure was high and for longer times under high seed densities and low predation risks. Gaining insight into both energy and water balance will be crucial to understanding the forces exerted by changing climatic conditions on animal energetics, behavior, and ecology. PMID:27420785

  17. Appropriate Fe (II) Addition Significantly Enhances Anaerobic Ammonium Oxidation (Anammox) Activity through Improving the Bacterial Growth Rate

    PubMed Central

    Liu, Yiwen; Ni, Bing-Jie

    2015-01-01

    The application of anaerobic ammonium oxidation (Anammox) process is often limited by the slow growth rate of Anammox bacteria. As the essential substrate element that required for culturing Anammox sludge, Fe (II) is expected to affect Anammox bacterial growth. This work systematically studied the effects of Fe (II) addition on Anammox activity based on the kinetic analysis of specific growth rate using data from batch tests with an enriched Anammox sludge at different dosing levels. Results clearly demonstrated that appropriate Fe (II) dosing (i.e., 0.09 mM) significantly enhanced the specific Anammox growth rate up to 0.172 d−1 compared to 0.118 d−1 at regular Fe (II) level (0.03 mM). The relationship between Fe (II) concentration and specific Anammox growth rate was found to be well described by typical substrate inhibition kinetics, which was integrated into currently well-established Anammox model to describe the enhanced Anammox growth with Fe (II) addition. The validity of the integrated Anammox model was verified using long-term experimental data from three independent Anammox reactors with different Fe (II) dosing levels. This Fe (II)-based approach could be potentially implemented to enhance the process rate for possible mainstream application of Anammox technology, in order for an energy autarchic wastewater treatment. PMID:25644239

  18. Appropriate Fe (II) Addition Significantly Enhances Anaerobic Ammonium Oxidation (Anammox) Activity through Improving the Bacterial Growth Rate

    NASA Astrophysics Data System (ADS)

    Liu, Yiwen; Ni, Bing-Jie

    2015-02-01

    The application of anaerobic ammonium oxidation (Anammox) process is often limited by the slow growth rate of Anammox bacteria. As the essential substrate element that required for culturing Anammox sludge, Fe (II) is expected to affect Anammox bacterial growth. This work systematically studied the effects of Fe (II) addition on Anammox activity based on the kinetic analysis of specific growth rate using data from batch tests with an enriched Anammox sludge at different dosing levels. Results clearly demonstrated that appropriate Fe (II) dosing (i.e., 0.09 mM) significantly enhanced the specific Anammox growth rate up to 0.172 d-1 compared to 0.118 d-1 at regular Fe (II) level (0.03 mM). The relationship between Fe (II) concentration and specific Anammox growth rate was found to be well described by typical substrate inhibition kinetics, which was integrated into currently well-established Anammox model to describe the enhanced Anammox growth with Fe (II) addition. The validity of the integrated Anammox model was verified using long-term experimental data from three independent Anammox reactors with different Fe (II) dosing levels. This Fe (II)-based approach could be potentially implemented to enhance the process rate for possible mainstream application of Anammox technology, in order for an energy autarchic wastewater treatment.

  19. Appropriate Fe (II) addition significantly enhances anaerobic ammonium oxidation (Anammox) activity through improving the bacterial growth rate.

    PubMed

    Liu, Yiwen; Ni, Bing-Jie

    2015-01-01

    The application of anaerobic ammonium oxidation (Anammox) process is often limited by the slow growth rate of Anammox bacteria. As the essential substrate element that required for culturing Anammox sludge, Fe (II) is expected to affect Anammox bacterial growth. This work systematically studied the effects of Fe (II) addition on Anammox activity based on the kinetic analysis of specific growth rate using data from batch tests with an enriched Anammox sludge at different dosing levels. Results clearly demonstrated that appropriate Fe (II) dosing (i.e., 0.09 mM) significantly enhanced the specific Anammox growth rate up to 0.172 d(-1) compared to 0.118 d(-1) at regular Fe (II) level (0.03 mM). The relationship between Fe (II) concentration and specific Anammox growth rate was found to be well described by typical substrate inhibition kinetics, which was integrated into currently well-established Anammox model to describe the enhanced Anammox growth with Fe (II) addition. The validity of the integrated Anammox model was verified using long-term experimental data from three independent Anammox reactors with different Fe (II) dosing levels. This Fe (II)-based approach could be potentially implemented to enhance the process rate for possible mainstream application of Anammox technology, in order for an energy autarchic wastewater treatment. PMID:25644239

  20. Homogeneous ice nucleation from aqueous inorganic/organic particles representative of biomass burning: water activity, freezing temperatures, nucleation rates.

    PubMed

    Knopf, Daniel A; Rigg, Yannick J

    2011-02-10

    Homogeneous ice nucleation plays an important role in the formation of cirrus clouds with subsequent effects on the global radiative budget. Here we report on homogeneous ice nucleation temperatures and corresponding nucleation rate coefficients of aqueous droplets serving as surrogates of biomass burning aerosol. Micrometer-sized (NH(4))(2)SO(4)/levoglucosan droplets with mass ratios of 10:1, 1:1, 1:5, and 1:10 and aqueous multicomponent organic droplets with and without (NH(4))(2)SO(4) under typical tropospheric temperatures and relative humidities are investigated experimentally using a droplet conditioning and ice nucleation apparatus coupled to an optical microscope with image analysis. Homogeneous freezing was determined as a function of temperature and water activity, a(w), which was set at droplet preparation conditions. The ice nucleation data indicate that minor addition of (NH(4))(2)SO(4) to the aqueous organic droplets renders the temperature dependency of water activity negligible in contrast to the case of aqueous organic solution droplets. The mean homogeneous ice nucleation rate coefficient derived from 8 different aqueous droplet compositions with average diameters of ∼60 μm for temperatures as low as 195 K and a(w) of 0.82-1 is 2.18 × 10(6) cm(-3) s(-1). The experimentally derived freezing temperatures and homogeneous ice nucleation rate coefficients are in agreement with predictions of the water activity-based homogeneous ice nucleation theory when taking predictive uncertainties into account. However, the presented ice nucleation data indicate that the water activity-based homogeneous ice nucleation theory overpredicts the freezing temperatures by up to 3 K and corresponding ice nucleation rate coefficients by up to ∼2 orders of magnitude. A shift of 0.01 in a(w), which is well within the uncertainty of typical field and laboratory relative humidity measurements, brings experimental and predicted freezing temperatures and homogeneous ice

  1. Spontaneous efferent activity in branches of the vagus nerve controlling heart rate and ventilation in the dogfish.

    PubMed

    Barrett, D J; Taylor, E W

    1985-07-01

    Efferent activity was recorded from cranial nerves in the decerebrate dogfish (Scyliorhinus canicula) before and after injection of paralysing drugs. The recordings were made from the mandibular (Vth) and glossopharyngeal (IXth) nerves and the branchial (respiratory) and cardiac branches of the vagus (Xth) nerve. All the respiratory branches (Vth, IXth and Xth) and both cardiac branches fired rhythmic bursts of activity, synchronous with ventilation, which continued (at a higher rate) following paralysis, indicating that they originated in the CNS rather than arising reflexly from stimulation of pharyngeal mechanoreceptors. A burst of activity in the Vth nerve was followed by a burst in the IXth then, after a 30-ms delay, simultaneous bursts in the three respiratory branches of the Xth. The bursts in the branchial cardiac branches had a fixed phase relationship with activity in the respiratory branches, the onset of each burst preceding that in the immediately adjacent branch (branchial III), whereas the bursts in the visceral cardiac branches had a variable phase relationship with all other branches. The branchial cardiac branches alone contained units which fired sporadically between the bursts and increased their rate of firing during hypoxia. Both the bursting and non-bursting units responded to mechanical stimulation of the gill area. Separate oscillatory inputs driving the Vth, IXth and Xth respiratory motoneurones and an excitatory input to the bursting cardiac vagal motoneurones from expiratory motoneurones or the respiratory rhythm generator are implied by these relationships. The sporadically firing units in the branchial cardiac nerves clearly receive non-oscillatory inputs.

  2. Intrinsic activity and poisoning rate for HCOOH oxidation at Pt(100) and vicinal surfaces containing monoatomic (111) steps.

    PubMed

    Grozovski, Vitali; Climent, Víctor; Herrero, Enrique; Feliu, Juan M

    2009-08-01

    Pulsed voltammetry is used to study formic acid oxidation on Pt(2n-1,1,1) surfaces and determine the effects of the size of the (100) terrace and the (111) step density on the reaction mechanism. The intrinsic activity of the electrode through the active intermediate reaction path (j(theta=) (0)), as well as the rate constant for the CO formation (k(ads)), are calculated from the current transients obtained at different potentials. For surfaces with wide terraces, j(theta=) (0) and k(ads) are almost insensitive to the step density, which suggests that step and terrace sites have a similar activity for this reaction. For narrow terraces (n<6), the intrinsic activity diminishes. The dependence of the reaction rates on the electrode potential is also elucidated. The CO formation only takes place in a narrow potential window, very close to the potential of zero total charge, while the direct oxidation takes place even when the surface is covered by anions. The different behavior for both reactions suggests that the adsorption mode of formic acid is different for each path. PMID:19569091

  3. Acute effects of three different circuit weight training protocols on blood lactate, heart rate, and rating of perceived exertion in recreationally active women.

    PubMed

    Skidmore, Brook L; Jones, Margaret T; Blegen, Mark; Matthews, Tracey D

    2012-01-01

    Interval and circuit weight training are popular training methods for maximizing time-efficiency, and are purported to deliver greater physiological benefits faster than traditional training methods. Adding interval training into a circuit weight-training workout may further enhance the benefits of circuit weight training by placing increased demands upon the cardiovascular system. Our purpose was to compare acute effects of three circuit weight training protocols 1) traditional circuit weight training, 2) aerobic circuit weight training, and 3) combined circuit weight-interval training on blood lactate (BLA), heart rate (HR), and ratings of perceived exertion (RPE). Eleven recreationally active women completed 7 exercise sessions. Session 1 included measurements of height, weight, estimated VO2max, and 13 repetition maximum (RM) testing of the weight exercises. Sessions 2-4 were held on non-consecutive days for familiarization with traditional circuit weight training (TRAD), aerobic circuit weight training (ACWT), and combined circuit weight-interval training (CWIT) protocols. In sessions 5-7, TRAD, ACWT, and CWIT were performed in a randomized order ≥ 72 hr apart for measures of BLA, HR, and RPE at pre-exercise and following each of three mini-circuit weight training stations. Repeated-measures ANOVAs yielded significant interactions (p < 0.05) in BLA, HR, and RPE. Combined circuit weight-interval training (CWIT) produced higher BLA (7.31 ± 0.37 vs. TRAD: 3.99 ± 0.26, ACWT: 4.54 ± 0.31 mmol.L(-1)), HR (83.51 ± 1.18 vs. TRAD: 70.42 ± 1.67, ACWT: 74.13 ± 1.43 beats.min(-1)) and RPE (8.14 ± 0.41 vs. TRAD: 5.06 ± 0.43, ACWT: 6.15 ± 0.42) at all measures. Aerobic circuit weight training (ACWT) elicited greater RPE than traditional circuit weight training (TRAD) at all measures. Including combined circuit weight-interval training (CWIT) workouts into exercise programming may enhance fitness benefits and maximize time-efficiency more so than traditional

  4. Synchronizing Substrate Activation Rates in Multicomponent Reactions with Metal-Organic Framework Catalysts.

    PubMed

    Aguirre-Díaz, Lina María; Iglesias, Marta; Snejko, Natalia; Gutiérrez-Puebla, Enrique; Monge, M Ángeles

    2016-05-01

    A study on the influence of the cation coordination number, number of Lewis acid centers, concurrent existence of Lewis base sites, and structure topology on the catalytic activity of six new indium MOFs, has been carried out for multicomponent reactions (MCRs). The new indium polymeric frameworks, namely [In8 (OH)6 (popha)6 (H2 O)4 ]⋅3 H2 O (InPF-16), [In(popha)(2,2'-bipy)]⋅3 H2 O (InPF-17), [In3 (OH)3 (popha)2 (4,4'-bipy)]⋅4 H2 O (InPF-18), [In2 (popha)2 (4,4'-bipy)2 ]⋅3 H2 O (InPF-19), [In(OH)(Hpopha)]⋅0.5 (1,7-phen) (InPF-20), and [In(popha)(1,10-phen)]⋅4 H2 O (InPF-21) (InPF=indium polymeric framework, H3 popha=5-(4-carboxy-2-nitrophenoxy)isophthalic acid, phen=phenanthroline, bipy=bipyridine), have been hydrothermally obtained by using both conventional heating (CH) and microwave (MW) procedures. These indium frameworks show efficient Lewis acid behavior for the solvent-free cyanosilylation of carbonyl compounds, the one pot Passerini 3-component (P-3CR) and the Ugi 4-component (U-4CR) reactions. In addition, InPF-17 was found to be a highly reactive, recyclable, and environmentally benign catalyst, which allows the efficient synthesis of α-aminoacyl amides. The relationship between the Lewis base/acid active site and the catalytic performance is explained by the 2D seven-coordinated indium framework of the catalyst InPF-17. This study is an attempt to highlight the main structural and synthetic factors that have to be taken into account when planning a new, effective MOF-based heterogeneous catalyst for multicomponent reactions.

  5. Activation of the lipid droplet controls the rate of lipolysis of triglycerides in the insect fat body.

    PubMed

    Patel, Rajesh T; Soulages, Jose L; Hariharasundaram, Balaji; Arrese, Estela L

    2005-06-17

    The hydrolysis of triglyceride (TG) stored in the lipid droplets of the insect fat body is under hormonal regulation by the adipokinetic hormone (AKH), which triggers a rapid activation cAMP-dependent kinase cascade (protein kinase A (PKA)). The role of phosphorylation on two components of the lipolytic process, the TG-lipase and the lipid droplet, was investigated in fat body adipocytes. The activity of purified TG-lipase determined using in vivo TG-radiolabeled lipid droplets was unaffected by the phosphorylation of the lipase. However, the activity of purified lipase was 2.4-fold higher against lipid droplets isolated from hormone-stimulated fat bodies than against lipid droplets isolated from unstimulated tissue. In vivo stimulation of lipolysis promotes a rapid phosphorylation of a lipid droplet protein with an apparent mass of 42-44 kDa. This protein was identified as "Lipid Storage Droplet Protein 1" (Lsdp1). In vivo phosphorylation of this protein reached a peak approximately 10 min after the injection of AKH. Supporting a role of Lsdp1 in lipolysis, maximum TG-lipase activity was also observed with lipid droplets isolated 10 min after hormonal stimulation. The activation of lipolysis was reconstituted in vitro using purified insect PKA and TG-lipase and lipid droplets. In vitro phosphorylation of lipid droplets catalyzed by PKA enhanced the phosphorylation of Lsdp1 and the lipolytic rate of the lipase, demonstrating a prominent role PKA and protein phosphorylation on the activation of the lipid droplets. AKH-induced changes in the properties of the substrate do not promote a tight association of the lipase with the lipid droplets. It is concluded that the lipolysis in fat body adipocytes is controlled by the activation of the lipid droplet. This activation is achieved by PKA-mediated phosphorylation of the lipid droplet. Lsdp1 is the main target of PKA, suggesting that this protein is a major player in the activation of lipolysis in insects.

  6. Altered promoter recycling rates contribute to dominant-negative activity of human peroxisome proliferator-activated receptor-gamma mutations associated with diabetes.

    PubMed

    Li, Gang; Leff, Todd

    2007-04-01

    The transcription factor peroxisome proliferator-activated receptor-gamma (PPARgamma) plays an important role in regulating lipid and glucose metabolism and improves insulin sensitivity in diabetic patients when activated by thiazolidinedione drugs. Several loss-of-function mutations in PPARgamma have been identified that cause lipodystrophy and diabetes in humans. Because affected individuals are heterozygotes and have one normal PPARgamma allele, it is of interest to know whether these mutations act in a dominant-negative fashion to inhibit the activity of the wild-type (WT) receptor. Here we compare the molecular phenotypes of two previously identified PPARgamma mutations: P467L, reported to be dominant negative; and F388L, reported to be devoid of dominant-negative activity. We developed a competitive chromatin immunoprecipitation assay to measure the relative ability of mutant PPARgamma to compete with WT receptor for binding to a PPAR regulatory element (PPRE)-containing promoter. By determining the ratio of mutant and WT receptors bound to a PPRE over time, we estimated the relative promoter turnover rate of each receptor. This assay demonstrated that PPARgamma bearing the P467L had a reduced promoter turnover rate compared with the F388L receptor, and over time out-competed the WT receptor for promoter binding sites. We propose that the P467L receptor is dominant negative because in a cell containing both WT and mutant receptors, the majority of the PPAR-regulated promoters will be occupied by the transcriptionally defective mutant receptor. In contrast, the F388L mutation lacks dominant-negative activity because its more rapid promoter turnover rate prevented it from out-competing the WT receptor for promoter binding sites.

  7. [Change in cross-bridge activation rate constant (Kac) after six-minute walk in patients with heart failure].

    PubMed

    Takahashi, M; Takeda, K; Saotome, T; Kobayashi, N; Yagi, S

    1994-01-01

    Cardiac adrenergic activity is increased in patients with congestive heart failure (CHF) and is excessively increased during mild exercise. Changes in cardiac adrenergic activity were examined in normal individuals and patients with CHF before and after mild exercise using the cross-bridge activation rate constant (Ka), which may represent the adrenergic activity related to the working left ventricular myocardium. Ten normal volunteers and 31 patients with stable CHF underwent echocardiography. The left ventricular ejection fraction (LVEF) was measured in all the CHF patients using left ventriculography or radionuclide cineangiography. The patients were classified into two groups: group 1 with an LVEF > or = 50% (n = 16) and group 2 with an LVEF < 50% (n = 15). The cause of CHF was old myocardial infarction in 25 patients and dilated cardiomyopathy in 6. All subjects exercised by walking for 6 min after resting in the supine position for 30 min. The blood pressure, electrocardiogram, phonocardiogram, and M-mode echocardiogram were recorded simultaneously before and after exercise. The values of Ka and Kac (Ka corrected for the individual heart rate) were calculated from the QS2 interval and the heart rate (HR) as follows: Ka = 3/QS2 interval, and Kac = Ka +0.0249 (66-HR). Before exercise, the HR was significantly higher in group 2, but the Kac value showed no significant difference between all three groups. The increase of HR with exercise (delta HR) and the Kac value after exercise were not significantly different between all three groups.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7823284

  8. Inhibition and activation of enzymes. The effect of a modifier on the reaction rate and on kinetic parameters.

    PubMed

    Fontes, R; Ribeiro, J M; Sillero, A

    2000-01-01

    A combined analysis of enzyme inhibition and activation is presented, based on a rapid equilibrium model assumption in which one molecule of enzyme binds one molecule of substrate (S) and/or one molecule of a modifier X. The modifier acts as activator (essential or non-essential), as inhibitor (total or partial), or has no effect on the reaction rate (v), depending on the values of the equilibrium constants, the rate constants of the limiting velocity steps, and the concentration of substrate ([S]). Different possibilities have been analyzed from an equation written to emphasize that v = f([X]) is, in general and at a fixed [S], a hyperbolic function. Formulas for Su (the value of [S], different from zero, at which v is unaffected by the modifier) and v(su) (v at that particular [S]) were deduced. In Lineweaver-Burk plots, the straight lines related to different [X] generally cross in a point (P) with coordinates (Su, v(su)). In certain cases, point P is located in the first quadrant which implies that X acts as activator, as inhibitor, or has no effect, depending on [S]. Furthermore, we discuss: (1) the apparent Vmax and Km displayed by the enzyme in different situations; (2) the degree of effect (inhibition or activation) observed at different concentrations of substrate and modifier; (3) the concept of Ke, a parameter that depends on the concentration of substrate and helps to evaluate the effect of the modifier: it equals the value of [X] at which the increase or decrease in the reaction rate is half of that achieved at saturating [X]. Equations were deduced for the general case and for particular situations, and used to obtain computer-drawn graphs that are presented and discussed. Formulas for apparent Vmax, Km and Ke have been written in a way making it evident that these parameters can be expressed as pondered means.

  9. Platelets aggregation in pathological conditions: role of local shear rates and platelet activation delay time.

    NASA Astrophysics Data System (ADS)

    Li, He; Zarif Khalili Yazdani, Alireza; Karniadakis, George

    2015-11-01

    Platelets play an essential role in the initiation and formation of a thrombus, however their detailed motion in blood vessels with complex geometries, such as in the aneurysmal vessel or stenotic vessel in atherosclerosis, has not been studied systematically. Here, we perform spectral element simulations (NEKTAR code) to obtain the 3D flow field in blood vessel with cavities, and we apply the force coupling method (FCM) to simulate the motion of platelets in blood flow. Specifically, simulations of platelets are performed in a 0.25 mm diameter circular blood vessel with 1 mm length. Corresponding coarse-grained molecular dynamics simulations are employed to provide input to the NEKTAR-FCM code. Simulations are conducted at several different Reynolds numbers (Re). An ellipsoid-shaped cavity is selected to intersect with the middle part of the circular vessel to represent the aneurysmal part of the blood vessel. Based on the simulation results, we quantify how the platelets motion and aggregation in the blood vessel cavities depend on Re, platelet activation delay time, and the geometry of the cavities.

  10. Attention Cueing and Activity Equally Reduce False Alarm Rate in Visual-Auditory Associative Learning through Improving Memory.

    PubMed

    Nikouei Mahani, Mohammad-Ali; Haghgoo, Hojjat Allah; Azizi, Solmaz; Nili Ahmadabadi, Majid

    2016-01-01

    In our daily life, we continually exploit already learned multisensory associations and form new ones when facing novel situations. Improving our associative learning results in higher cognitive capabilities. We experimentally and computationally studied the learning performance of healthy subjects in a visual-auditory sensory associative learning task across active learning, attention cueing learning, and passive learning modes. According to our results, the learning mode had no significant effect on learning association of congruent pairs. In addition, subjects' performance in learning congruent samples was not correlated with their vigilance score. Nevertheless, vigilance score was significantly correlated with the learning performance of the non-congruent pairs. Moreover, in the last block of the passive learning mode, subjects significantly made more mistakes in taking non-congruent pairs as associated and consciously reported lower confidence. These results indicate that attention and activity equally enhanced visual-auditory associative learning for non-congruent pairs, while false alarm rate in the passive learning mode did not decrease after the second block. We investigated the cause of higher false alarm rate in the passive learning mode by using a computational model, composed of a reinforcement learning module and a memory-decay module. The results suggest that the higher rate of memory decay is the source of making more mistakes and reporting lower confidence in non-congruent pairs in the passive learning mode. PMID:27314235

  11. Attention Cueing and Activity Equally Reduce False Alarm Rate in Visual-Auditory Associative Learning through Improving Memory

    PubMed Central

    Haghgoo, Hojjat Allah; Azizi, Solmaz; Nili Ahmadabadi, Majid

    2016-01-01

    In our daily life, we continually exploit already learned multisensory associations and form new ones when facing novel situations. Improving our associative learning results in higher cognitive capabilities. We experimentally and computationally studied the learning performance of healthy subjects in a visual-auditory sensory associative learning task across active learning, attention cueing learning, and passive learning modes. According to our results, the learning mode had no significant effect on learning association of congruent pairs. In addition, subjects’ performance in learning congruent samples was not correlated with their vigilance score. Nevertheless, vigilance score was significantly correlated with the learning performance of the non-congruent pairs. Moreover, in the last block of the passive learning mode, subjects significantly made more mistakes in taking non-congruent pairs as associated and consciously reported lower confidence. These results indicate that attention and activity equally enhanced visual-auditory associative learning for non-congruent pairs, while false alarm rate in the passive learning mode did not decrease after the second block. We investigated the cause of higher false alarm rate in the passive learning mode by using a computational model, composed of a reinforcement learning module and a memory-decay module. The results suggest that the higher rate of memory decay is the source of making more mistakes and reporting lower confidence in non-congruent pairs in the passive learning mode. PMID:27314235

  12. Valued Life Activity Disability Played a Significant Role in Self-Rated Health among Adults with Chronic Health Conditions

    PubMed Central

    Katz, Patricia; Morris, Anne; Gregorich, Steve; Yazdany, Jinoos; Eisner, Mark; Yelin, Edward; Blanc, Paul

    2009-01-01

    Objective Because self-rated health (SRH) is strongly associated with health outcomes, it is important to identify factors that individuals take into account when they assess their health. We examined the role of valued life activities (VLAs), the wide range of activities deemed to be important to individuals, in SRH assessments. Study Design and Setting Data were from 3 cohort studies of individuals with different chronic conditions – rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and chronic obstructive pulmonary disease (COPD). Each cohort’s data were collected through structured telephone interviews. Logistic regression analyses identified factors associated with ratings of fair/poor SRH. All analyses included sociodemographic characteristics, general and disease-specific health-related factors, and general measures of physical functioning. Results Substantial portions of each group rated their health as fair/poor (RA 37%, SLE 47%, COPD 40%). In each group, VLA disability was strongly associated with fair/poor health (RA: OR=4.44 [1.86,10.62]; SLE: OR=3.60 [2.10,6.16]; COPD: OR=2.76 [1.30,5.85], even after accounting for covariates. Conclusion VLA disability appears to play a substantial role in individual perceptions of health, over and above other measures of health status, disease symptoms, and general physical functioning. PMID:18722089

  13. Rate Constants and Activation Energies for Gas‐Phase Reactions of Three Cyclic Volatile Methyl Siloxanes with the Hydroxyl Radical

    PubMed Central

    Safron, Andreas; Strandell, Michael; Kierkegaard, Amelie

    2015-01-01

    ABSTRACT Reaction with hydroxyl radicals (OH) is the major pathway for removal of cyclic volatile methyl siloxanes (cVMS) from air. We present new measurements of second‐order rate constants for reactions of the cVMS octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) with OH determined at temperatures between 313 and 353 K. Our measurements were made using the method of relative rates with cyclohexane as a reference substance and were conducted in a 140‐mL gas‐phase reaction chamber with online mass spectrometry analysis. When extrapolated to 298 K, our measured reaction rate constants of D4 and D5 with the OH radical are 1.9 × 10−12 (95% confidence interval (CI): (1.7–2.2) × 10−12) and 2.6 × 10−12 (CI: (2.3–2.9) × 10−12) cm3 molecule−1 s−1, respectively, which are 1.9× and 1.7× faster than previous measurements. Our measured rate constant for D6 is 2.8 × 10−12 (CI: (2.5–3.2) × 10−12) cm3 molecule−1 s−1 and to our knowledge there are no comparable laboratory measurements in the literature. Reaction rates for D5 were 33% higher than for D4 (CI: 30–37%), whereas the rates for D6 were only 8% higher than for D5 (CI: 5–10%). The activation energies of the reactions of D4, D5, and D6 with OH were not statistically different and had a value of 4300 ± 2800 J/mol.

  14. A cure rate survival model under a hybrid latent activation scheme.

    PubMed

    Borges, Patrick; Rodrigues, Josemar; Louzada, Francisco; Balakrishnan, Narayanaswamy

    2016-04-01

    In lifetimes studies, the occurrence of an event (such as tumor detection or death) might be caused by one of many competing causes. Moreover, both the number of causes and the time-to-event associated with each cause are not usually observable. The number of causes can be zero, corresponding to a cure fraction. In this article, we propose a method of estimating the numerical characteristics of unobservable stages (such as initiation, promotion and progression) of carcinogenesis from data on tumor size at detection in the presence of latent competing causes. To this end, a general survival model for spontaneous carcinogenesis under a hybrid latent activation scheme has been developed to allow for a simple pattern of the dynamics of tumor growth. It is assumed that a tumor becomes detectable when its size attains some threshold level (proliferation of tumorais cells (or descendants) generated by the malignant cell), which is treated as a random variable. We assume the number of initiated cells and the number of malignant cells (competing causes) both to follow weighted Poisson distributions. The advantage of this model is that it incorporates into the analysis characteristics of the stage of tumor progression as well as the proportion of initiated cells that had been 'promoted' to the malignant ones and the proportion of malignant cells that die before tumor induction. The lifetimes corresponding to each competing cause are assumed to follow a Weibull distribution. Parameter estimation of the proposed model is discussed through the maximum likelihood estimation method. A simulation study has been carried out in order to examine the coverage probabilities of the confidence intervals. Finally, we illustrate the usefulness of the proposed model by applying it to a real data involving malignant melanoma.

  15. Success rate, costs and long-term stability of treatment with activator/headgear combinations.

    PubMed

    Hedlund, Camilla; Feldmann, Ingalill

    2016-01-01

    The aims of this study were to evaluate treatment outcome with activator-headgear combinations carried out by general dental practitioners, overall costs, long-term stability and patients' satisfaction with treatment outcome. Patients who were recommended to start treatment in 2006 were included in this study (n = 97). Inclusion criteria were: Class II Division 1 with at least half a cusp width distal molar relationship, overjet ≥ 6 mm and presence of dental records. Data were collected, pre-treatment, post-treatment and 3 years after treatment for those with favorable outcome. Patients at follow-up completed a questionnaire about satisfaction with treatment outcome, perceived pain and discomfort during treatment, and subjective need for additional treatment. Eighty-five patients were analyzed, 52 boys and 33 girls (mean age 11.2 years SD 1.39). Thirty-five patients had successful treatment outcome, 15 partially successful and 35 had an unsuccessful outcome. Total costs for all 85 patients amounted to SEK 1 405 000 including both direct and indirect costs. Thirty-eight patients participated in the 3-year follow-up. Treatment outcomes were then categorized as successful in 28 patients, partially successful in 9 patients and 1 patient was judged as unsuccessful. Median values on VAS (0-100) for overall satisfaction with treatment and treatment outcome were high, 78 and 84 respectively. Median value for perceived pain and discomfort during treatment was 42. Just over half of the patients had a favorable treatment outcome. Patients with favorable outcome were stable over time and satisfied with treatment. PMID:27464383

  16. Rates of ankle and foot injuries in active-duty U.S. Army soldiers, 2000-2006.

    PubMed

    Wallace, Robert F; Wahi, Monika M; Hill, Owen T; Kay, Ashley B

    2011-03-01

    Ankle and foot injuries (AFI) are a major cause of Active-Duty Army (ADA) soldiers' time lost from training and combat operations. We used the Total Army Injury and Health Outcomes Database to compute the rates of AFI to identify high-risk ADA groups for the years 2000-2006. During this time, 16% of soldiers were clinically seen at least once for an AFI. Yearly, 60% to 70% of ADA soldiers with AFI had an ankle sprain/strain, and ankle sprain/strain had the highest 7-year rate of all AFIs (103 per 1,000). From 2000 to 2006, all AFI rates declined; however, enlisted male soldiers < or = 30 years of age without an advanced degree were at highest risk. A history of an AFI in the previous 2 years increased AFI rates by 93% to 160%. Our findings provide preliminary evidence for identifying specific ADA groups at high risk of AFI; these groups should be targeted for preventive interventions. PMID:21456354

  17. Quantitative Structure-Activity Relationships Study on the Rate Constants of Polychlorinated Dibenzo-p-Dioxins with OH Radical

    PubMed Central

    Qi, Chuansong; Zhang, Chenxi; Sun, Xiaomin

    2015-01-01

    The OH-initiated reaction rate constants (kOH) are of great importance to measure atmospheric behaviors of polychlorinated dibenzo-p-dioxins (PCDDs) in the environment. The rate constants of 75 PCDDs with the OH radical at 298.15 K have been calculated using high level molecular orbital theory, and the rate constants (kα, kβ, kγ and kOH) were further analyzed by the quantitative structure-activity relationships (QSAR) study. According to the QSAR models, the relations between rate constants and the numbers and positions of Cl atoms, the energy of the highest occupied molecular orbital (EHOMO), the energy of the lowest unoccupied molecular orbital (ELUMO), the difference ΔEHOMO-LUMO between EHOMO and ELUMO, and the dipole of oxidizing agents (D) were discussed. It was found that EHOMO is the main factor in the kOH. The number of Cl atoms is more effective than the number of relative position of these Cl atoms in the kOH. The kOH decreases with the increase of the substitute number of Cl atoms. PMID:26274950

  18. Sucrose phosphate synthase activity rises in correlation with high-rate cellulose synthesis in three heterotrophic systems.

    PubMed

    Babb, V M; Haigler, C H

    2001-11-01

    Based on work with cotton fibers, a particulate form of sucrose (Suc) synthase was proposed to support secondary wall cellulose synthesis by degrading Suc to fructose and UDP-glucose. The model proposed that UDP-glucose was then channeled to cellulose synthase in the plasma membrane, and it implies that Suc availability in cellulose sink cells would affect the rate of cellulose synthesis. Therefore, if cellulose sink cells could synthesize Suc and/or had the capacity to recycle the fructose released by Suc synthase back to Suc, cellulose synthesis might be supported. The capacity of cellulose sink cells to synthesize Suc was tested by analyzing the Suc phosphate synthase (SPS) activity of three heterotrophic systems with cellulose-rich secondary walls. SPS is a primary regulator of the Suc synthesis rate in leaves and some Suc-storing, heterotrophic organs, but its activity has not been previously correlated with cellulose synthesis. Two systems analyzed, cultured mesophyll cells of Zinnia elegans L. var. Envy and etiolated hypocotyls of kidney beans (Phaseolus vulgaris), contained differentiating tracheary elements. Cotton (Gossypium hirsutum L. cv Acala SJ-1) fibers were also analyzed during primary and secondary wall synthesis. SPS activity rose in all three systems during periods of maximum cellulose deposition within secondary walls. The Z. elegans culture system was manipulated to establish a tight linkage between the timing of tracheary element differentiation and rising SPS activity and to show that SPS activity did not depend on the availability of starch for degradation. The significance of these findings in regard to directing metabolic flux toward cellulose will be discussed. PMID:11706202

  19. The ligand activity of AGE-proteins to scavenger receptors is dependent on their rate of modification by AGEs.

    PubMed

    Nagai, Ryoji; Mera, Katsumi; Nakajou, Keisuke; Fujiwara, Yukio; Iwao, Yasunori; Imai, Hiroki; Murata, Toshinori; Otagiri, Masaki

    2007-12-01

    The cellular interaction of proteins modified with advanced glycation end-products (AGEs) is believed to induce several different biological responses, which are involved in the development of diabetic vascular complications. We report here that the ratio of protein glycation is implicated in its ligand activity to scavenger receptors. Although highly-modified AGE-bovine serum albumin (high-AGE-BSA) was significantly recognized by human monocyte-derived macrophages and Chinese hamster ovary cells which overexpress such scavenger receptors as CD36, SR-BI (scavenger receptor class B type-I), and LOX-1 (Lectin-like Ox-LDL receptor-1), the mildly-modified-AGE-BSA (mild-AGE-BSA) did not show any ligand activity to these cells. Furthermore, when (111)In-labeled high- or mild-AGE-BSA were injected into the tail vein of mice, the high-AGE-BSA was rapidly cleared from the circulation whereas the clearance rate of the mild-AGE-BSA was very slow, similar to the native BSA. These results demonstrate the first evidence that the ligand activity of the AGE-proteins to the scavenger receptors and its pharmacokinetic properties depend on their rate of modification by AGEs, and we should carefully prepare the AGE-proteins in vitro to clarify the physiological significance of the interaction between the AGE-receptors and AGE-proteins.

  20. Glucagon-like peptide-1 receptor stimulation increases blood pressure and heart rate and activates autonomic regulatory neurons

    PubMed Central

    Yamamoto, Hiroshi; Lee, Charlotte E.; Marcus, Jacob N.; Williams, Todd D.; Overton, J. Michael; Lopez, Marisol E.; Hollenberg, Anthony N.; Baggio, Laurie; Saper, Clifford B.; Drucker, Daniel J.; Elmquist, Joel K.

    2002-01-01

    Glucagon-like peptide-1 (GLP-1) released from the gut functions as an incretin that stimulates insulin secretion. GLP-1 is also a brain neuropeptide that controls feeding and drinking behavior and gastric emptying and elicits neuroendocrine responses including development of conditioned taste aversion. Although GLP-1 receptor (GLP-1R) agonists are under development for the treatment of diabetes, GLP-1 administration may increase blood pressure and heart rate in vivo. We report here that centrally and peripherally administered GLP-1R agonists dose-dependently increased blood pressure and heart rate. GLP-1R activation induced c-fos expression in the adrenal medulla and neurons in autonomic control sites in the rat brain, including medullary catecholamine neurons providing input to sympathetic preganglionic neurons. Furthermore, GLP-1R agonists rapidly activated tyrosine hydroxylase transcription in brainstem catecholamine neurons. These findings suggest that the central GLP-1 system represents a regulator of sympathetic outflow leading to downstream activation of cardiovascular responses in vivo. PMID:12093887

  1. Hormone-sensitive lipase, the rate-limiting enzyme in triglyceride hydrolysis, is expressed and active in beta-cells.

    PubMed

    Mulder, H; Holst, L S; Svensson, H; Degerman, E; Sundler, F; Ahrén, B; Rorsman, P; Holm, C

    1999-01-01

    Triglycerides in the beta-cell may be important for stimulus-secretion coupling, through provision of a lipid-derived signal, and for pathogenetic events in NIDDM, where lipids may adversely affect beta-cell function. In adipose tissues, hormone-sensitive lipase (HSL) is rate-limiting in triglyceride hydrolysis. Here, we investigated whether this enzyme is also expressed and active in beta-cells. Northern blot analysis and reverse transcription-polymerase chain reaction demonstrated that HSL is expressed in rat islets and in the clonal beta-cell lines INS-1, RINm5F, and HIT-T15. Western blot analysis identified HSL in mouse and rat islets and the clonal beta-cells. In mouse and rat, immunocytochemistry showed a predominant occurrence of HSL in beta-cells, with a presumed cytoplasmic localization. Lipase activity in homogenates of the rodent islets and clonal beta-cells constituted 2.1 +/- 0.6% of that in adipocytes; this activity was immunoinhibited by use of antibodies to HSL. The established HSL expression and activity in beta-cells offer a mechanism whereby lipids are mobilized from intracellular stores. Because HSL in adipocytes is activated by cAMP-dependent protein kinase (PKA), PKA-regulated triglyceride hydrolysis in beta-cells may participate in the regulation of insulin secretion, possibly by providing a lipid-derived signal, e.g., long-chain acyl-CoA and diacylglycerol.

  2. Rate of biodegradiation of toxic organic compounds while in contact with organics which are actively composting. Final report

    SciTech Connect

    Not Available

    1982-03-01

    Results are presented of a study to biodegrade toxic organic wastes and to determine the degree of breakdown of compounds while in contact with high-rate composting. An artificial compost mixture consisting of shredded newspaper, manure, wastewater treatment plant sludge, sawdust, peat moss, soil, powdered milk, and fertilizer was prepared. Toxic organic chemicals were mixed with this actively composting mixture to obtain a concentration of about 500 mg/kg. Samples were analyzed after seven days of composting and again after 30 days. Thirty-two of the 59 chemicals tested were found to be moderately to highly susceptible to biodegradation. The potential for success is shown to be very high for using high-rate composting to degrade organic wastes. The possibility of accelerating the decomposition of toxic wastes in soils is suggested.

  3. [Application of linear and nonlinear characteristics of heart rate variability in assessment of autonomic nervous system activity].

    PubMed

    Shi, Ping; Yu, Hongliu

    2014-04-01

    Calculation of linear parameters, such as time-domain and frequency-domain analysis of heart rate variability (HRV), is a conventional method for assessment of autonomic nervous system activity. Nonlinear phenomena are certainly involved in the genesis of HRV. In a seemingly random signal the Poincaré plot can easily demonstrate whether there is an underlying determinism in the signal. Linear and nonlinear analysis methods were applied in the computer words inputting experiments in this study for physiological measurement. This study therefore demonstrated that Poincaré plot was a simple but powerful graphical tool to describe the dynamics of a system.

  4. Theory of activated-rate processes under shear with application to shear-induced aggregation of colloids.

    PubMed

    Zaccone, Alessio; Wu, Hua; Gentili, Daniele; Morbidelli, Massimo

    2009-11-01

    Using an approximation scheme within the convective diffusion (two-body Smoluchowski) equation framework, we unveil the shear-driven aggregation mechanism at the origin of structure formation in sheared colloidal systems. The theory, verified against numerics and experiments, explains the induction time followed by explosive (irreversible) rise of viscosity observed in charge-stabilized colloidal and protein systems under steady shear. The Arrhenius-type equation with shear derived here, extending Kramers' theory in the presence of shear, clearly demonstrates the important role of shear drive in activated-rate processes as they are encountered in soft condensed matter.

  5. Major temporal variations in shortening rate absorbed along a large active fold of the southeastern Tianshan piedmont (China)

    NASA Astrophysics Data System (ADS)

    Saint-Carlier, Dimitri; Charreau, Julien; Lavé, Jérôme; Blard, Pierre-Henri; Dominguez, Stéphane; Avouac, Jean-Philippe; Wang, Shengli

    2016-01-01

    The investigation of deformation rates on a mountain piedmont can provide key information for improving our understanding of the overall dynamics of a mountain range. Here, we estimate the shortening rate absorbed by a Quaternary emergent detachment fold on the southeastern piedmont of the Tianshan (China). Our work is primarily based on new 10Be cosmogenic exposure dating of deformed alluvial surfaces. The method we have developed combines depth profiling with sampling of surface cobbles, thereby allowing exposure time, erosion rate and inheritance to be simultaneously constrained. The exposure ages of the uppermost uplifted alluvial surfaces are around 140 ± 17 ka, 130 ± 9 ka and 47 ± 9 ka, from west to east. A terrace lying below the 140 ka surface is dated at 65 ± 5 ka. The ages of the uplifted and folded alluvial surfaces were then combined with estimates of shortening obtained using two distinct methods: (1) the excess area method, where sedimentation rates, extracted from magnetostratigraphic studies, are used to determine the amount of sedimentation after the abandonment of the river; and (2) a folding model derived from sandbox experiments. The late Pleistocene shortening rates are shown to be between 0.4 ± 0.1 mm /yr and 0.8 ± 0.5 mm /yr on the western part of the fold and 2.1 ± 0.4 mm /yr along its central part. The central part of the frontal Yakeng anticline therefore accommodates up to 25% of the total shortening currently absorbed across the whole Eastern Tianshan range (8 mm/yr). However, this situation seems to have prevailed for only the last 150 ka, as the shortening rate absorbed by this nascent fold was previously ten times slower. While the initiation of folding of the Yakeng anticline can be traced back to 5.5 Ma ago, the basinward migration of the active deformation front onto the Yakeng fold is a relatively recent phenomenon and appears to be diachronous from west to east, probably in relation to the tectonic activity of the folds in

  6. Relating the Diversity, Abundance, and Activity of Ammonia-Oxidizing Archaeal Communities to Nitrification Rates in the Coastal Ocean

    NASA Astrophysics Data System (ADS)

    Tolar, B. B.; Smith, J. M.; Chavez, F.; Francis, C.

    2015-12-01

    Ammonia oxidation, the rate-limiting first step of nitrification, is an important link between reduced (ammonia) and oxidized (nitrate) nitrogen, and controls the relative distribution of these forms of inorganic nitrogen. This process is catalyzed via the ammonia monooxygenase enzyme of both ammonia-oxidizing Bacteria (AOB) and Archaea (AOA); the α subunit of this enzyme is encoded by the amoA gene and has been used as the molecular marker to detect this process. In the ocean, AOA are typically 10-1000 times more and are likely more active than AOB, and thus are key players in the marine nitrogen cycle. Monterey Bay is a dynamic site to study nitrification, as seasonal upwelling brings deep water and nutrients into surface waters, which can promote phytoplankton blooms and impact biogeochemical processes such as the nitrogen cycle. We have sampled two sites within Monterey Bay bimonthly for two years as part of the ongoing Monterey Bay Time Series (MBTS) to quantify AOA genes, transcripts, and nitrification rates. Two ecotypes of AOA are routinely found in Monterey Bay - the 'shallow' water column A (WCA) and 'deep' water column B (WCB) clades, which are thought to have distinct physiological properties and can be distinguished based on the amoA gene sequence. Previous work has shown a strong relationship between nitrification rates in Monterey Bay with the abundance of WCA amoA genes and transcripts. Additionally, we found a correlation between the relative abundance of Marine Group I (MGI) Thaumarchaeota 16S rRNA reads (as % of total) and the absolute abundance of AOA amoA genes (determined via qPCR) in Monterey Bay and the California Current System. AOA 16S rRNA gene abundances in turn correlated significantly with changes in nitrification rate with depth, while the relative abundance of genes and transcripts binned to a single AOA (Nitrosopumilus maritimus) was not significantly correlated to nitrification rate. Further analysis of the sequenced AOA

  7. Measured Mass-Loss Rates of Solar-like Stars as a Function of Age and Activity

    NASA Astrophysics Data System (ADS)

    Wood, Brian E.; Müller, Hans-Reinhard; Zank, Gary P.; Linsky, Jeffrey L.

    2002-07-01

    Collisions between the winds of solar-like stars and the local interstellar medium result in a population of hot hydrogen gas surrounding these stars. Absorption from this hot H I can be detected in high-resolution Lyα spectra of these stars from the Hubble Space Telescope. The amount of absorption can be used as a diagnostic for the stellar mass-loss rate. We present new mass-loss rate measurements derived in this fashion for four stars (ɛ Eri, 61 Cyg A, 36 Oph AB, and 40 Eri A). Combining these measurements with others, we study how mass loss varies with stellar activity. We find that for the solar-like GK dwarfs, the mass loss per unit surface area is correlated with X-ray surface flux. Fitting a power law to this relation yields M~F1.15+/-0.20X. The active M dwarf Proxima Cen and the very active RS CVn system λ And appear to be inconsistent with this relation. Since activity is known to decrease with age, the above power-law relation for solar-like stars suggests that mass loss decreases with time. We infer a power-law relation of M~t-2.00+/-0.52. This suggests that the solar wind may have been as much as 1000 times more massive in the distant past, which may have had important ramifications for the history of planetary atmospheres in our solar system, that of Mars in particular. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  8. Urokinase-like plasminogen activator receptor expression on disseminated breast cancer cells.

    PubMed

    Tögel, F; Datta, C; Badbaran, A; Kröger, N; Renges, H; Gieseking, F; Jänicke, F; Zander, A R; Krüger, W

    2001-02-01

    Disseminated tumor cells are detected frequently in bone marrow, peripheral blood, and cytokine-mobilized peripheral blood cell products of women undergoing high-dose therapy for breast cancer. Several attempts were made to purge autografts from contaminating cancer cells; however, the biological and clinical impact of these contaminations has not been clarified so far. Expression of distinct phenotypes is a surrogate marker for metastatic behavior of cancer cells. The expression of the urokinase-like plasminogen activator receptor seems to be a factor of high importance. It is not expressed by normal mammary tissue. Disseminated cancer cells from marrow, blood, and stem cell products have been investigated by double-stain technique for urokinase-like plasminogen activator receptor (uPA-R) expressing cytokeratin-positive cells. uPA-R(+)/CK(+) cells could be found in all qualities of samples; however, significantly less in G-CSF-mobilized peripheral blood stem cells compared to samples of other provenance (p = 0.02). It can be concluded that epithelial cells of malignant phenotype occur in blood, marrow, and autografts of breast cancer patients. Populations of disseminated tumor cells are phenotypically heterogeneous. Reduced uPA-R expression on cancer cells from leukapheresis samples might suggest a less aggressive nature of these cells compared to disseminated cells found in bone marrow. Furthermore, the data suggest that the phenotype of tumor cell contamination in leukapheresis products differs significantly from those of disseminated cancer cells in bone marrow or blood.

  9. Dependence of Guaiacol Peroxidase Activity and Lipid Peroxidation Rate in Drooping Birch (Betula pendula Roth) and Tillet (Tilia cordata Mill) Leaf on Motor Traffic Pollution Intensity.

    PubMed

    Erofeeva, Elena A

    2015-01-01

    Hormesis and paradoxical effects are frequently found for different plant parameters. These phenomena were also observed for lipid peroxidation (LP) rate at environmental pollution. However, the role of antioxidant enzymes, particularly guaiacol peroxidases (GPX), in a nonmonotonic variation in the LP rate remains insufficiently explored. Therefore, dependence of GPX activity and LP rate in Betula pendula and Tilia cordata leaf on motor traffic pollution intensity was studied. Regression analysis revealed dependences of LP rate and GPX activity on traffic intensity. In B pendula, GPX activity enhanced significantly (up to 2.8 times relatively control) under increased traffic that induced biphasic paradoxical effect for LP rate. In the first phase, LP level increased in comparison with the control, and in the second phase, it was normalized by enhanced GPX activity. In T cordata, dependences of GPX activity and LP rate on traffic pollution were paradoxical effects. However, there was no connection between change of GPX activity and LP rate under middle- and high-level pollution: LP level reduced relatively the control or normalized even if GPX activity was lower than the control. This indicates that in T cordata, other regulatory mechanisms instead of GPX were activated which could control LP rate under middle- and high-level pollution.

  10. High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation.

    PubMed

    Ekstrand, Eva-Maria; Karlsson, Marielle; Truong, Xu-Bin; Björn, Annika; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2016-10-01

    Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for the biogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibre sludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation. Two lab-scale reactors (4L) were run for 800days, one on fibre sludge (R1), and the other on fibre sludge and activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, the Ca:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abated by short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robust conditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4g volatile solids (VS)L(-1)day(-1), a hydraulic retention time of 4days and a methane production of 230±10NmL per g VS.

  11. Temperature dependence of the rate and activation parameters for tert-butyl chloride solvolysis: Monte Carlo simulation of confidence intervals

    NASA Astrophysics Data System (ADS)

    Sung, Dae Dong; Kim, Jong-Youl; Lee, Ikchoon; Chung, Sung Sik; Park, Kwon Ha

    2004-07-01

    The solvolysis rate constants ( kobs) of tert-butyl chloride are measured in 20%(v/v) 2-PrOH-H 2O mixture at 15 temperatures ranging from 0 to 39 °C. Examination of the temperature dependence of the rate constants by the weighted least squares fitting to two to four terms equations has led to the three-term form, ln kobs= a1+ a2T-1+ a3ln T, as the best expression. The activation parameters, ΔH ‡ and ΔS ‡, calculated by using three constants a1, a2 and a3 revealed the steady decrease of ≈1 kJ mol -1 per degree and 3.5 J K -1 mol -1 per degree, respectively, as the temperature rises. The sign change of ΔS ‡ at ≈20.0 °C and the large negative heat capacity of activation, ΔC p‡=-1020 J K -1 mol -1, derived are interpreted to indicate an S N1 mechanism and a net change from water structure breaking to electrostrictive solvation due to the partially ionic transition state. Confidence intervals estimated by the Monte Carlo method are far more precise than those by the conventional method.

  12. High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation.

    PubMed

    Ekstrand, Eva-Maria; Karlsson, Marielle; Truong, Xu-Bin; Björn, Annika; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2016-10-01

    Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for the biogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibre sludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation. Two lab-scale reactors (4L) were run for 800days, one on fibre sludge (R1), and the other on fibre sludge and activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, the Ca:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abated by short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robust conditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4g volatile solids (VS)L(-1)day(-1), a hydraulic retention time of 4days and a methane production of 230±10NmL per g VS. PMID:27453288

  13. Effect of heating rate and kinetic model selection on activation energy of nonisothermal crystallization of amorphous felodipine.

    PubMed

    Chattoraj, Sayantan; Bhugra, Chandan; Li, Zheng Jane; Sun, Changquan Calvin

    2014-12-01

    The nonisothermal crystallization kinetics of amorphous materials is routinely analyzed by statistically fitting the crystallization data to kinetic models. In this work, we systematically evaluate how the model-dependent crystallization kinetics is impacted by variations in the heating rate and the selection of the kinetic model, two key factors that can lead to significant differences in the crystallization activation energy (Ea ) of an amorphous material. Using amorphous felodipine, we show that the Ea decreases with increase in the heating rate, irrespective of the kinetic model evaluated in this work. The model that best describes the crystallization phenomenon cannot be identified readily through the statistical fitting approach because several kinetic models yield comparable R(2) . Here, we propose an alternate paired model-fitting model-free (PMFMF) approach for identifying the most suitable kinetic model, where Ea obtained from model-dependent kinetics is compared with those obtained from model-free kinetics. The most suitable kinetic model is identified as the one that yields Ea values comparable with the model-free kinetics. Through this PMFMF approach, nucleation and growth is identified as the main mechanism that controls the crystallization kinetics of felodipine. Using this PMFMF approach, we further demonstrate that crystallization mechanism from amorphous phase varies with heating rate.

  14. Increases in muscle sympathetic nerve activity, heart rate, respiration, and skin blood flow during passive viewing of exercise.

    PubMed

    Brown, Rachael; Kemp, Ursula; Macefield, Vaughan

    2013-01-01

    The cardiovascular and respiratory effects of exercise have been widely studied, as have the autonomic effects of imagined and observed exercise. However, the effects of observed exercise in the first person have not been documented, nor have direct recordings of muscle sympathetic nerve activity (MSNA) been obtained during observed or imagined exercise. The aim of the current study was to measure blood pressure, heart rate, respiration, skin blood flow, sweat release, and MSNA (via microelectrodes inserted into the common peroneal nerve), during observation of exercise from the first person point of view. It was hypothesized that the moving stimuli would produce robust compensatory increases in the above-mentioned parameters as effectively as those generated by mental imagery and-to a lesser extent-actual exercise. Nine subjects watched a first-person running video, allowing them to view the action from the perspective of the runner rather than viewing someone else perform the exercise. On average, statistically significant increases from baseline during the running phase were seen in heart rate, respiratory rate, skin blood flow, and burst amplitude of MSNA. These results suggest that observation of exercise in the first person is a strong enough stimulus to evoke "physiologically appropriate" autonomic responses that have a purely psychogenic origin.

  15. Simulated sudden increase in geomagnetic activity and its effect on heart rate variability: Experimental verification of correlation studies.

    PubMed

    Caswell, Joseph M; Singh, Manraj; Persinger, Michael A

    2016-08-01

    Previous research investigating the potential influence of geomagnetic factors on human cardiovascular state has tended to converge upon similar inferences although the results remain relatively controversial. Furthermore, previous findings have remained essentially correlational without accompanying experimental verification. An exception to this was noted for human brain activity in a previous study employing experimental simulation of sudden geomagnetic impulses in order to assess correlational results that had demonstrated a relationship between geomagnetic perturbations and neuroelectrical parameters. The present study employed the same equipment in a similar procedure in order to validate previous findings of a geomagnetic-cardiovascular dynamic with electrocardiography and heart rate variability measures. Results indicated that potential magnetic field effects on frequency components of heart rate variability tended to overlap with previous correlational studies where low frequency power and the ratio between low and high frequency components of heart rate variability appeared affected. In the present study, a significant increase in these particular parameters was noted during geomagnetic simulation compared to baseline recordings. PMID:27662787

  16. Simulated sudden increase in geomagnetic activity and its effect on heart rate variability: Experimental verification of correlation studies

    NASA Astrophysics Data System (ADS)

    Caswell, Joseph M.; Singh, Manraj; Persinger, Michael A.

    2016-08-01

    Previous research investigating the potential influence of geomagnetic factors on human cardiovascular state has tended to converge upon similar inferences although the results remain relatively controversial. Furthermore, previous findings have remained essentially correlational without accompanying experimental verification. An exception to this was noted for human brain activity in a previous study employing experimental simulation of sudden geomagnetic impulses in order to assess correlational results that had demonstrated a relationship between geomagnetic perturbations and neuroelectrical parameters. The present study employed the same equipment in a similar procedure in order to validate previous findings of a geomagnetic-cardiovascular dynamic with electrocardiography and heart rate variability measures. Results indicated that potential magnetic field effects on frequency components of heart rate variability tended to overlap with previous correlational studies where low frequency power and the ratio between low and high frequency components of heart rate variability appeared affected. In the present study, a significant increase in these particular parameters was noted during geomagnetic simulation compared to baseline recordings.

  17. Voluntary and involuntary running in the rat show different patterns of theta rhythm, physical activity, and heart rate.

    PubMed

    Li, Jia-Yi; Kuo, Terry B J; Yen, Jiin-Cherng; Tsai, Shih-Chih; Yang, Cheryl C H

    2014-05-01

    Involuntarily exercising rats undergo more physical and mental stress than voluntarily exercising rats; however, these findings still lack electrophysiological evidence. Many studies have reported that theta rhythm appears when there is mental stress and that it is affected by emotional status. Thus we hypothesized that the differences between voluntary and involuntary movement should also exist in the hippocampal theta rhythm. Using the wheel and treadmill exercise models as voluntary and involuntary exercise models, respectively, this study wirelessly recorded the hippocampal electroencephalogram, electrocardiogram, and three-dimensional accelerations of young male rats. Treadmill and wheel exercise produced different theta patterns in the rats before and during running. Even though the waking baselines for the two exercise types were recorded in different environments, there did not exist any significant difference after distinguishing the rats' sleep/wake status. When the same movement-related parameters are considered, the treadmill running group showed more changes in their theta frequency (4-12 Hz), in their theta power between 9.5-12 Hz, and in their heart rate than the wheel running group. A positive correlation between the changes in high-frequency (9.5-12 Hz) theta power and heart rate was identified. Our results reveal various voluntary and involuntary changes in hippocampal theta rhythm as well as divergences in heart rate and high-frequency theta activity that may represent the effects of an additional emotional state or the sensory interaction during involuntary running by rats. PMID:24623507

  18. High-rate activated sludge system for carbon management--Evaluation of crucial process mechanisms and design parameters.

    PubMed

    Jimenez, Jose; Miller, Mark; Bott, Charles; Murthy, Sudhir; De Clippeleir, Haydee; Wett, Bernhard

    2015-12-15

    The high-rate activated sludge (HRAS) process is a technology suitable for the removal and redirection of organics from wastewater to energy generating processes in an efficient manner. A HRAS pilot plant was operated under controlled conditions resulting in concentrating the influent particulate, colloidal, and soluble COD to a waste solids stream with minimal energy input by maximizing sludge production, bacterial storage, and bioflocculation. The impact of important process parameters such as solids retention time (SRT), hydraulic residence time (HRT) and dissolved oxygen (DO) levels on the performance of a HRAS system was demonstrated in a pilot study. The results showed that maximum removal efficiencies of soluble COD were reached at a DO > 0.3 mg O2/L, SRT > 0.5 days and HRT > 15 min which indicates that minimizing the oxidation of the soluble COD in the high-rate activated sludge process is difficult. The study of DO, SRT and HRT exhibited high degree of impact on the colloidal and particulate COD removal. Thus, more attention should be focused on controlling the removal of these COD fractions. Colloidal COD removal plateaued at a DO > 0.7 mg O2/L, SRT > 1.5 days and HRT > 30 min, similar to particulate COD removal. Concurrent increase in extracellular polymers (EPS) production in the reactor and the association of particulate and colloidal material into sludge flocs (bioflocculation) indicated carbon capture by biomass. The SRT impacted the overall mass and energy balance of the high-rate process indicating that at low SRT conditions, lower COD mineralization or loss of COD content occurred. In addition, the lower SRT conditions resulted in higher sludge yields and higher COD content in the WAS.

  19. High-rate activated sludge system for carbon management--Evaluation of crucial process mechanisms and design parameters.

    PubMed

    Jimenez, Jose; Miller, Mark; Bott, Charles; Murthy, Sudhir; De Clippeleir, Haydee; Wett, Bernhard

    2015-12-15

    The high-rate activated sludge (HRAS) process is a technology suitable for the removal and redirection of organics from wastewater to energy generating processes in an efficient manner. A HRAS pilot plant was operated under controlled conditions resulting in concentrating the influent particulate, colloidal, and soluble COD to a waste solids stream with minimal energy input by maximizing sludge production, bacterial storage, and bioflocculation. The impact of important process parameters such as solids retention time (SRT), hydraulic residence time (HRT) and dissolved oxygen (DO) levels on the performance of a HRAS system was demonstrated in a pilot study. The results showed that maximum removal efficiencies of soluble COD were reached at a DO > 0.3 mg O2/L, SRT > 0.5 days and HRT > 15 min which indicates that minimizing the oxidation of the soluble COD in the high-rate activated sludge process is difficult. The study of DO, SRT and HRT exhibited high degree of impact on the colloidal and particulate COD removal. Thus, more attention should be focused on controlling the removal of these COD fractions. Colloidal COD removal plateaued at a DO > 0.7 mg O2/L, SRT > 1.5 days and HRT > 30 min, similar to particulate COD removal. Concurrent increase in extracellular polymers (EPS) production in the reactor and the association of particulate and colloidal material into sludge flocs (bioflocculation) indicated carbon capture by biomass. The SRT impacted the overall mass and energy balance of the high-rate process indicating that at low SRT conditions, lower COD mineralization or loss of COD content occurred. In addition, the lower SRT conditions resulted in higher sludge yields and higher COD content in the WAS. PMID:26260539

  20. On the relation between the activation energy for electron attachment reactions and the size of their thermal rate coefficients.

    PubMed

    Hotop, H; Ruf, M-W; Kopyra, J; Miller, T M; Fabrikant, I I

    2011-02-14

    Rate coefficients k(T) for dissociative electron attachment (DEA) to molecules in many cases exhibit a more or less strong rise with increasing temperature T (the electron temperature T(e) and the molecular temperature T(G) are assumed to be in thermal equilibrium, i.e., T = T(e) = T(G)). This rise is frequently modeled by the Arrhenius equation k(T) = k(A) exp[-E(a)∕(k(B)T)], and an activation energy E(a) is deduced from fits to the experimental data k(T). This behavior reflects the presence of an energy barrier for the anion on its path to the dissociated products. In a recent paper [J. Kopyra, J. Wnorowska, M. Foryś, and I. Szamrej, Int. J. Mass Spectrom. 268, 60 (2007)] it was suggested that the size of the rate coefficients for DEA reactions at room temperature exhibits an exponential dependence on the activation energy, i.e., k(E(a); T ≈ 300 K) = k(1) exp[-E(a)∕E(0)]. More recent experimental data for molecules with high barriers [T. M. Miller, J. F. Friedman, L. C. Schaffer, and A. A. Viggiano, J. Chem. Phys. 131, 084302 (2009)] are compatible with such a correlation. We investigate the validity and the possible origin of this dependence by analyzing the results of R-matrix calculations for temperature-dependent rate coefficients of exothermic DEA processes with intermediate barrier toward dissociation. These include results for model systems with systematically varied barrier height as well as results of molecule-specific calculations for CH(3)Cl, CH(3)Br, CF(3)Cl, and CH(2)Cl(2) (activation energies above 0.2 eV) involving appropriate molecular parameters. A comparison of the experimental and theoretical results for the considered class of molecules (halogenated alkanes) supports the idea that the exponential dependence of k(T = 300 K) on the activation energy reflects a general phenomenon associated with Franck-Condon factors for getting from the initial neutral vibrational levels to the dissociating final anion state in a direct DEA process

  1. An investigation of how radiation may cause accelerated rates of tropical cyclogenesis and diurnal cycles of convective activity

    NASA Astrophysics Data System (ADS)

    Nicholls, M. E.

    2015-08-01

    Recent cloud-resolving numerical modeling results suggest that radiative forcing causes accelerated rates of tropical cyclogenesis and early intensification. Furthermore, observational studies of tropical cyclones have found that oscillations of the cloud canopy areal extent often occur that are clearly related to the solar diurnal cycle. A theory is put forward to explain these findings. The primary mechanism that seems responsible can be considered a refinement of the mechanism proposed by Gray and Jacobson (1977) to explain diurnal variations of oceanic tropical deep cumulus convection. It is hypothesized that differential radiative cooling or heating between a relatively cloud-free environment and a developing tropical disturbance generates circulations that can have very significant influences on convective activity in the core of the system. It is further suggested that there are benefits to understanding this mechanism by viewing it in terms of the lateral propagation of thermally driven gravity wave circulations, also known as buoyancy bores. Numerical model experiments indicate that mean environmental radiative cooling outside the cloud system is playing an important role in causing a significant horizontal differential radiative forcing and accelerating the rate of tropical cyclogenesis. As an expansive stratiform cloud layer forms aloft within a developing system the mean low-level radiative cooling is reduced, while at mid levels small warming occurs. During the daytime there is not a very large differential radiative forcing between the environment and the cloud system, but at nighttime when there is strong radiative clear-sky cooling of the environment it becomes significant. Thermally driven circulations develop, characterized by relatively weak subsidence in the environment but much stronger upward motion in the cloud system. This upward motion leads to a cooling tendency and increased relative humidity. The increased relative humidity at night

  2. An investigation of how radiation may cause accelerated rates of tropical cyclogenesis and diurnal cycles of convective activity

    NASA Astrophysics Data System (ADS)

    Nicholls, M. E.

    2015-03-01

    Recent cloud-resolving numerical modeling results suggest that radiative forcing causes accelerated rates of tropical cyclogenesis and early intensification. Furthermore, observational studies of tropical cyclones have found that oscillations of the cloud canopy areal extent often occur that are clearly related to the solar diurnal cycle. A theory is put forward to explain these findings. The primary mechanism that seems responsible can be considered a refinement of the mechanism proposed by Gray and Jacobson (1977) to explain diurnal variations of oceanic tropical deep cumulus convection. It is hypothesized that differential radiative cooling or heating between a relatively cloud-free environment and a developing tropical disturbance generates circulations that can have very significant influences on convective activity in the core of the system. It is further suggested that there are benefits to understanding this mechanism by viewing it in terms of the lateral propagation of thermally driven gravity wave circulations, also known as buoyancy bores. Numerical model experiments indicate that mean environmental radiative cooling outside the cloud system is playing an important role in causing a significant horizontal differential radiative forcing and accelerating the rate of tropical cyclogenesis. As an expansive stratiform cloud layer forms aloft within a developing system the mean low level radiative cooling is reduced while at mid levels small warming occurs. During the daytime there is not a very large differential radiative forcing between the environment and the cloud system, but at nighttime when there is strong radiative clear sky cooling of the environment it becomes significant. Thermally driven circulations develop, characterized by relatively weak subsidence in the environment but much stronger upward motion in the cloud system. This upward motion leads to a cooling tendency and increased relative humidity. The increased relative humidity at night

  3. On the depth and scale of metabolic rate variation: scaling of oxygen consumption rates and enzymatic activity in the Class Cephalopoda (Mollusca).

    PubMed

    Seibel, Brad A

    2007-01-01

    Recent ecological theory depends, for predictive power, on the apparent similarity of metabolic rates within broad taxonomic or functional groups of organisms (e.g. invertebrates or ectotherms). Such metabolic commonality is challenged here, as I demonstrate more than 200-fold variation in metabolic rates independent of body mass and temperature in a single class of animals, the Cephalopoda, over seven orders of magnitude size range. I further demonstrate wide variation in the slopes of metabolic scaling curves. The observed variation in metabolism reflects differential selection among species for locomotory capacity rather than mass or temperature constraints. Such selection is highest among epipelagic squids (Lolignidae and Ommastrephidae) that, as adults, have temperature-corrected metabolic rates higher than mammals of similar size.

  4. Dependence of synchronized bursting activity on medium stirring and the perfusion rate in a cultured network of neurons

    NASA Astrophysics Data System (ADS)

    Heo, Ryoun; Kim, Hyun; Lee, Kyoung J.

    2016-05-01

    A cultured network of neurons coupled with a multi-electrode-array (MEA) recording system has been a useful platform for investigating various issues in neuroscience and engineering. The neural activity supported by the system can be sensitive to environmental fluctuations, for example, in the medium's nutrient composition, ph, and temperature, and to mechanical disturbances, yet this issue has not been the subject. Especially, a normal practice in maintaining neuronal cell cultures involves an intermittent sequence of medium exchanges, typically at a time interval of a few days, and one such sudden medium exchange is unavoidably accompanied by many unintended disturbances. Here, based on a quantitative time-series analysis of synchronized bursting events, we explicitly demonstrate that such a medium exchange can, indeed, bring a huge change in the existing neural activity. Subsequently, we develop a medium perfusion-stirring system and an ideal protocol that can be used in conjunction with a MEA recording system, providing long-term stability. Specifically, we systematically evaluate the effects of medium stirring and perfusion rates. Unexpectedly, even some vigorous mechanical agitations do not have any impacts on neural activity. On the other hand, too much replenishment ( e.g., 1.8 ml/day for a 1.8-ml dish) of neurobasal medium results in an excitotoxicity.

  5. Global Distribution of Cloud Droplet Number Concentration, Autoconversion Rate, and Aerosol Indirect Effect Under Diabatic Droplet Activation

    NASA Technical Reports Server (NTRS)

    Barahona, Donifan; Sotiropoulou, Rafaella; Nenes, Athanasios

    2011-01-01

    This study presents a global assessment of the sensitivity of droplet number to diabatic activation (i.e., including effects from entrainment of dry air) and its first-order tendency on indirect forcing and autoconversion. Simulations were carried out with the NASA Global Modeling Initiative (GMI) atmospheric and transport model using climatological metereorological fields derived from the former NASA Data Assimilation Office (DAO), the NASA Finite volume GCM (FVGCM) and the Goddard Institute for Space Studies version II (GISS) GCM. Cloud droplet number concentration (CDNC) is calculated using a physically based prognostic parameterization that explicitly includes entrainment effects on droplet formation. Diabatic activation results in lower CDNC, compared to adiabatic treatment of the process. The largest decrease in CDNC (by up to 75 percent) was found in the tropics and in zones of moderate CCN concentration. This leads to a global mean effective radius increase between 0.2-0.5 micrometers (up to 3.5 micrometers over the tropics), a global mean autoconversion rate increase by a factor of 1.1 to 1.7 (up to a factor of 4 in the tropics), and a 0.2-0.4 W m(exp -2) decrease in indirect forcing. The spatial patterns of entrainment effects on droplet activation tend to reduce biases in effective radius (particularly in the tropics) when compared to satellite retrievals. Considering the diabatic nature of ambient clouds, entrainment effects on CDNC need to be considered in GCM studies of the aerosol indirect effect.

  6. Estimation of (41)Ar activity concentration and release rate from the TRIGA Mark-II research reactor.

    PubMed

    Hoq, M Ajijul; Soner, M A Malek; Rahman, A; Salam, M A; Islam, S M A

    2016-03-01

    The BAEC TRIGA research reactor (BTRR) is the only nuclear reactor in Bangladesh. Bangladesh Atomic Energy Regulatory Authority (BAERA) regulations require that nuclear reactor licensees undertake all reasonable precautions to protect the environment and the health and safety of persons, including identifying, controlling and monitoring the release of nuclear substances to the environment. The primary activation product of interest in terms of airborne release from the reactor is (41)Ar. (41)Ar is a noble gas readily released from the reactor stacks and most has not decayed by the time it moves offsite with normal wind speed. Initially (41)Ar is produced from irradiation of dissolved air in the primary water which eventually transfers into the air in the reactor bay. In this study, the airborne radioisotope (41)Ar generation concentration, ground level concentration and release rate from the BTRR bay region are evaluated theoretically during the normal reactor operation condition by several governing equations. This theoretical calculation eventually minimizes the doubt about radiological safety to determine the radiation level for (41)Ar activity whether it is below the permissible limit or not. Results show that the estimated activity for (41)Ar is well below the maximum permissible concentration limit set by the regulatory body, which is an assurance for the reactor operating personnel and general public. Thus the analysis performed within this paper is so much effective in the sense of ensuring radiological safety for working personnel and the environment.

  7. Estimation of (41)Ar activity concentration and release rate from the TRIGA Mark-II research reactor.

    PubMed

    Hoq, M Ajijul; Soner, M A Malek; Rahman, A; Salam, M A; Islam, S M A

    2016-03-01

    The BAEC TRIGA research reactor (BTRR) is the only nuclear reactor in Bangladesh. Bangladesh Atomic Energy Regulatory Authority (BAERA) regulations require that nuclear reactor licensees undertake all reasonable precautions to protect the environment and the health and safety of persons, including identifying, controlling and monitoring the release of nuclear substances to the environment. The primary activation product of interest in terms of airborne release from the reactor is (41)Ar. (41)Ar is a noble gas readily released from the reactor stacks and most has not decayed by the time it moves offsite with normal wind speed. Initially (41)Ar is produced from irradiation of dissolved air in the primary water which eventually transfers into the air in the reactor bay. In this study, the airborne radioisotope (41)Ar generation concentration, ground level concentration and release rate from the BTRR bay region are evaluated theoretically during the normal reactor operation condition by several governing equations. This theoretical calculation eventually minimizes the doubt about radiological safety to determine the radiation level for (41)Ar activity whether it is below the permissible limit or not. Results show that the estimated activity for (41)Ar is well below the maximum permissible concentration limit set by the regulatory body, which is an assurance for the reactor operating personnel and general public. Thus the analysis performed within this paper is so much effective in the sense of ensuring radiological safety for working personnel and the environment. PMID:26736180

  8. Tectonic Windows Reveal Off-axis Volcanic and Hydrothermal Activity and Along-strike Variations in Eruption Effusion Rates

    NASA Astrophysics Data System (ADS)

    MacDonald, K. C.

    2005-12-01

    Alvin transects of faulted escarpments 50-500m high provide tectonic windows to investigate the top 500m of oceanic crustal structure and lava stratigraphy. The Alvin archives were used to review dives from the East Pacific Rise, the Mid-Atlantic Ridge, the Juan de Fuca Ridge, the Blanco Trough, Cayman Trough and the Galapagos Spreading Center. A spreading rate dependence in lava morphology based solely on areal coverage(Bonatti and Harrison, 1988) was confirmed in scarp transects: mostly pillow lavas at slow spreading rates and sheet flows/lobate flows at faster spreading rates. More interestingly; there is a systematic variation within first, second and third order segments on intermediate and fast-spreading centers such that sheet/lobate flows dominate at segment centers and pillow flows and lava domes are more common at segment ends. This confirms earlier studies which were based on areal coverage (White et al, 2000, 2002, Soule et al 2005). This suggests higher eruption effusion rates and perhaps higher magma pressure and lower magma viscosity at segment centers relative to segment ends. This has important implications for the relationship between segmentation, magma supply, volcanism and hydrothermal activity (Haymon and White 2005). A conundrum remains; based on areal photographic surveys, why are pillow lavas so much more common off-axis than on-axis for intermediate to fast-spreading ridges? If there is an eruption cycle in which sheeted and lobate flows dominate early on, and pillow lavas dominate the waning stages of eruption (e.g. Ballard et al 1979), then more pillow lavas should be seen on axis than are seen on-axis in either areal or transect data. Another explanation is that pillow lavas off-axis are primarily produced by off-axis eruptions (except near segment ends, they may also occur as the pillowed terminations of channeled sheet and lobate flows; the association with channels will make this obvious.) Off-axis volcanism is also indicated by a

  9. Development of a technique for the measurement of the radon exhalation rate using an activated charcoal collector.

    PubMed

    Iimoto, Takeshi; Akasaka, Yoshinori; Koike, Yuya; Kosako, Toshiso

    2008-04-01

    A simple system to evaluate the 222Rn (radon) exhalation rate from soil has been improved. A sampling cuvette of 2.1 L is placed so that it covers the targeted ground soil, and radon emanating from the soil accumulates within the cuvette for 24 h. Its internal radon concentration is measured by the combination of an activated charcoal (PICO-RAD) and a liquid scintillation counting system. This study shows variations of the conversion factor (CF: unit Bq m(-3)/cpm) of PICO-RAD. The range of CF due to temperature (10-30 degrees C) was between -21% and +69%, and this due to humidity (30-90%) was between 0% and -15%. Humidity and radon concentration in the cuvette covering soil tended to saturate in a few hours. The above information was used to correct the CF for the evaluation. The improved system shows high reliability and can be easily applied to natural environments.

  10. Brain activity modeling in general anesthesia: Enhancing local mean-field models using a slow adaptive firing rate

    NASA Astrophysics Data System (ADS)

    Molaee-Ardekani, B.; Senhadji, L.; Shamsollahi, M. B.; Vosoughi-Vahdat, B.; Wodey, E.

    2007-10-01

    In this paper, an enhanced local mean-field model that is suitable for simulating the electroencephalogram (EEG) in different depths of anesthesia is presented. The main building elements of the model (e.g., excitatory and inhibitory populations) are taken from Steyn-Ross [M. L. Steyn-Ross , Phys. Rev. E 64, 011917 (2001), D. A. Steyn-Ross , Phys. Rev. E 64, 011918 (2001)] and Bojak and Liley [I. Bojak and D. T. Liley, Phys. Rev. E 71, 041902 (2005)] mean-field models and a new slow ionic mechanism is included in the main model. Generally, in mean-field models, some sigmoid-shape functions determine firing rates of neural populations according to their mean membrane potentials. In the enhanced model, the sigmoid function corresponding to excitatory population is redefined to be also a function of the slow ionic mechanism. This modification adapts the firing rate of neural populations to slow ionic activities of the brain. When an anesthetic drug is administered, the slow mechanism may induce neural cells to alternate between two levels of activity referred to as up and down states. Basically, the frequency of up-down switching is in the delta band (0-4Hz) and this is the main reason behind high amplitude, low frequency fluctuations of EEG signals in anesthesia. Our analyses show that the enhanced model may have different working states driven by anesthetic drug concentration. The model is settled in the up state in the waking period, it may switch to up and down states in moderate anesthesia while in deep anesthesia it remains in the down state.

  11. Reductions in carotid chemoreceptor activity with low-dose dopamine improves baroreflex control of heart rate during hypoxia in humans.

    PubMed

    Mozer, Michael T; Holbein, Walter W; Joyner, Michael J; Curry, Timothy B; Limberg, Jacqueline K

    2016-07-01

    The purpose of the present investigation was to examine the contribution of the carotid body chemoreceptors to changes in baroreflex control of heart rate with exposure to hypoxia. We hypothesized spontaneous cardiac baroreflex sensitivity (scBRS) would be reduced with hypoxia and this effect would be blunted when carotid chemoreceptor activity was reduced with low-dose dopamine. Fifteen healthy adults (11 M/4 F) completed two visits randomized to intravenous dopamine or placebo (saline). On each visit, subjects were exposed to 5-min normoxia (~99% SpO2), followed by 5-min hypoxia (~84% SpO2). Blood pressure (intra-arterial catheter) and heart rate (ECG) were measured continuously and scBRS was assessed by spectrum and sequence methodologies. scBRS was reduced with hypoxia (P < 0.01). Using the spectrum analysis approach, the fall in scBRS with hypoxia was attenuated with infusion of low-dose dopamine (P < 0.01). The decrease in baroreflex sensitivity to rising pressures (scBRS "up-up") was also attenuated with low-dose dopamine (P < 0.05). However, dopamine did not attenuate the decrease in baroreflex sensitivity to falling pressures (scBRS "down-down"; P > 0.05). Present findings are consistent with a reduction in scBRS with systemic hypoxia. Furthermore, we show this effect is partially mediated by the carotid body chemoreceptors, given the fall in scBRS is attenuated when activity of the chemoreceptors is reduced with low-dose dopamine. However, the improvement in scBRS with dopamine appears to be specific to rising blood pressures. These results may have important implications for impairments in baroreflex function common in disease states of acute and/or chronic hypoxemia, as well as the experimental use of dopamine to assess such changes. PMID:27418545

  12. Reductions in carotid chemoreceptor activity with low-dose dopamine improves baroreflex control of heart rate during hypoxia in humans.

    PubMed

    Mozer, Michael T; Holbein, Walter W; Joyner, Michael J; Curry, Timothy B; Limberg, Jacqueline K

    2016-07-01

    The purpose of the present investigation was to examine the contribution of the carotid body chemoreceptors to changes in baroreflex control of heart rate with exposure to hypoxia. We hypothesized spontaneous cardiac baroreflex sensitivity (scBRS) would be reduced with hypoxia and this effect would be blunted when carotid chemoreceptor activity was reduced with low-dose dopamine. Fifteen healthy adults (11 M/4 F) completed two visits randomized to intravenous dopamine or placebo (saline). On each visit, subjects were exposed to 5-min normoxia (~99% SpO2), followed by 5-min hypoxia (~84% SpO2). Blood pressure (intra-arterial catheter) and heart rate (ECG) were measured continuously and scBRS was assessed by spectrum and sequence methodologies. scBRS was reduced with hypoxia (P < 0.01). Using the spectrum analysis approach, the fall in scBRS with hypoxia was attenuated with infusion of low-dose dopamine (P < 0.01). The decrease in baroreflex sensitivity to rising pressures (scBRS "up-up") was also attenuated with low-dose dopamine (P < 0.05). However, dopamine did not attenuate the decrease in baroreflex sensitivity to falling pressures (scBRS "down-down"; P > 0.05). Present findings are consistent with a reduction in scBRS with systemic hypoxia. Furthermore, we show this effect is partially mediated by the carotid body chemoreceptors, given the fall in scBRS is attenuated when activity of the chemoreceptors is reduced with low-dose dopamine. However, the improvement in scBRS with dopamine appears to be specific to rising blood pressures. These results may have important implications for impairments in baroreflex function common in disease states of acute and/or chronic hypoxemia, as well as the experimental use of dopamine to assess such changes.

  13. Plasma membrane aquaporin activity can affect the rate of apoptosis but is inhibited after apoptotic volume decrease.

    PubMed

    Jablonski, Elizabeth M; Webb, Ashley N; McConnell, Nisha A; Riley, Marcus C; Hughes, Francis M

    2004-04-01

    Apoptosis is characterized by a conserved series of morphological events beginning with the apoptotic volume decrease (AVD). This study investigated a role for aquaporins (AQPs) during the AVD. Inhibition of AQPs blocked the AVD in ovarian granulosa cells undergoing growth factor withdrawal and blocked downstream apoptotic events such as cell shrinkage, changes in the mitochondrial membrane potential, DNA degradation, and caspase-3 activation. The effects of AQP inhibition on the AVD and DNA degradation were consistent in thymocytes and with two additional apoptotic signals, thapsigargin and C(6)-ceramide. Overexpression of AQP-1 in Chinese hamster ovary (CHO-AQP-1) cells enhanced their rate of apoptosis. The AVD is driven by loss of K(+) from the cell, and we hypothesize that after the AVD, AQPs become inactive, which halts further water loss and allows K(+) concentrations to decrease to levels necessary for apoptotic enzyme activation. Swelling assays on granulosa cells, thymocytes, and CHO-AQP-1 cells revealed that indeed, the shrunken (apoptotic) subpopulation has very low water permeability compared with the normal-sized (nonapoptotic) subpopulation. In thymocytes, AQP-1 is present and was shown to colocalize with the plasma membrane receptor tumor necrosis factor receptor-1 (TNF-R1) both before and after the AVD, which suggests that this protein is not proteolytically cleaved and remains on the cell membrane. Overall, these data indicate that AQP-mediated water loss is important for the AVD and downstream apoptotic events, that the water permeability of the plasma membrane can control the rate of apoptosis, and that inactivation after the AVD may help create the low K(+) concentration that is essential in apoptotic cells. Furthermore, inactivation of AQPs after the AVD does not appear to be through degradation or removal from the cell membrane.

  14. Rates of ubiquitin conjugation increase when muscles atrophy, largely through activation of the N-end rule pathway

    NASA Technical Reports Server (NTRS)

    Solomon, V.; Baracos, V.; Sarraf, P.; Goldberg, A. L.

    1998-01-01

    The rapid loss of muscle mass that accompanies many disease states, such as cancer or sepsis, is primarily a result of increased protein breakdown in muscle, and several observations have suggested an activation of the ubiquitin-proteasome system. Accordingly, in extracts of atrophying muscles from tumor-bearing or septic rats, rates of 125I-ubiquitin conjugation to endogenous proteins were found to be higher than in control extracts. On the other hand, in extracts of muscles from hypothyroid rats, where overall proteolysis is reduced below normal, the conjugation of 125I-ubiquitin to soluble proteins decreased by 50%, and treatment with triiodothyronine (T3) restored ubiquitination to control levels. Surprisingly, the N-end rule pathway, which selectively degrades proteins with basic or large hydrophobic N-terminal residues, was found to be responsible for most of these changes in ubiquitin conjugation. Competitive inhibitors of this pathway that specifically block the ubiquitin ligase, E3alpha, suppressed most of the increased ubiquitin conjugation in the muscle extracts from tumor-bearing and septic rats. These inhibitors also suppressed ubiquitination in normal extracts toward levels in hypothyroid extracts, which showed little E3alpha-dependent ubiquitination. Thus, the inhibitors eliminated most of the differences in ubiquitination under these different pathological conditions. Moreover, 125I-lysozyme, a model N-end rule substrate, was ubiquitinated more rapidly in extracts from tumor-bearing and septic rats, and more slowly in those from hypothyroid rats, than in controls. Thus, the rate of ubiquitin conjugation increases in atrophying muscles, and these hormone- and cytokine-dependent responses are in large part due to activation of the N-end rule pathway.

  15. Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

    PubMed Central

    El-Amrawy, Fatema

    2015-01-01

    Objectives The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Methods Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. Results The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. Conclusions The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure. PMID:26618039

  16. Late Quaternary tectonic activity and crustal shortening rate of the Bogda mountain area, eastern Tian Shan, China

    NASA Astrophysics Data System (ADS)

    Wu, Chuanyong; Wu, Guodong; Shen, Jun; Dai, Xunye; Chen, Jianbo; Song, Heping

    2016-04-01

    The Bogda mountain range is the highest range among the northern Tian Shan mountains. Based on geologic and geomorphologic field surveys, trench excavation and optically stimulated luminescence (OSL) dating, we targeted the active Fukang fault along the Bogda mountain range and identified the late Quaternary deformation characteristics of this area. We found that the Fukang fault dislocated different geomorphic surfaces of the northern Bogda piedmont. The vertical fault displacement corresponds to the topographic relief of the Bogda over long time scales. Since the late Quaternary, the crustal shortening rate was estimated to be 0.90 ± 0.20 mm/yr, which is less than that of the western segment of the northern Tian Shan. We interpret the Bogda fold and thrust belt to be a thick-skinned structure, since a high angle thrust fault bounds the Bogda mountain range and the foreland basin. The deformation characteristics of this region have been dominated by vertical uplift, and the component of propagation toward the basin has been very limited. This tectonic deformation is evidenced as vertical growth. Although the deformation rate is small, the uplift amplitude is very significant in this region.

  17. Study of the Northern Qinghai-Tibetan Plateau Permafrost Active Layer Depth Rate Using Satellite Geodetic Observations

    NASA Astrophysics Data System (ADS)

    Jia, Y.; Su, X.; Shum, C. K.; Kim, J. W.; Kuo, C. Y.

    2015-12-01

    The Tibetan Plateau is the world's largest and the highest plateau with distinct and competing surface and subsurface processes. It is the Third Pole and the World Water Tower, owing to its vast ice reservoir with the largest number of glaciers in the world, and covered by a large (1.3 to 1.6 million km2) layer of discontinuous and sporadic alpine permafrost. The thawing over Tibetan Plateau permafrost regions is thought to be more severe compared with other high latitude permafrost regions by the fact that the permafrost is warm. During the past few decades, 82% of Tibetan Plateau glaciers have retreated and 10% permafrost has degraded. The overall mean active layer depth (ALD) rate increase over the Plateau is 1.4 cm yr-1, 1980-2001, based on model studies and comparison with in situ borehole data. Here we report on the work in progress to quantify ALD rate increase in the northern Tibetan Plateau near the Tibetan national highway, using multi-band SAR/InSAR for improved the thermokarst surface classification, Envisat radar altimetry and ALOS-1 InSAR observed land subsidence, ALD modeling for the various thermokarst surface to relate to subsidence measurements, and the associated validations using available in situ borehole subsidence measurements.

  18. Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1985: Annual Report.

    SciTech Connect

    Palmer, Douglas E.; United States. Bonneville Power Administration; U.S. Fish and Wildlife Service; National Fishery Research Center

    1986-10-01

    This report summarizes activities in 1985 to determine the extent of predation on juvenile salmonids in John Day Reservoir. To estimate consumption of juvenile salmonids we used the composition of the natural diet of predators and in the laboratory determined rate of gastric evacuation by predators. Salmonids were the single most important food item for northern squawfish (Ptychocheilus oregonensis) at McNary tailrace during all sampling periods and at John Day forebay during July. Salmonids accounted for 11.6% of the diet of walleye (Stizostedion vitreum vitreum) in 1985 which was about twice that found in previous years. Salmonids contributed little to smallmouth bass (Micropterus dolomieui) diet but comprised about 25% of the diet of channel catfish (Ictalurus punctatus). Composition of prey taxa in beach seine catches in 1985 was similar to 1983 and 1984 with chinook salmon (Oncorhynchus tschawytscha), northern squawfish, largescale sucker (Catostomus macrocheilus), and sand roller (Percopsis transmontana) dominating the catch at main channel stations and crappies (Pomoxis spp.) and largescale sucker dominating at backwater stations. Preliminary results of beach seine efficiency studies suggest that seine efficiency varied significantly among prey species and between substrate types in 1985. Results of digestion rate experiments indicate that gastric evacuation in northern squawfish can be predicted using water temperature, prey weight, predator weight and time. 19 refs., 19 figs., 13 tabs.

  19. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

    NASA Astrophysics Data System (ADS)

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-01

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d-1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

  20. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

    PubMed Central

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-01

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d−1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery. PMID:26791952

  1. rRNA Gene Expression of Abundant and Rare Activated-Sludge Microorganisms and Growth Rate Induced Micropollutant Removal.

    PubMed

    Vuono, David C; Regnery, Julia; Li, Dong; Jones, Zackary L; Holloway, Ryan W; Drewes, Jörg E

    2016-06-21

    The role of abundant and rare taxa in modulating the performance of wastewater-treatment systems is a critical component of making better predictions for enhanced functions such as micropollutant biotransformation. In this study, we compared 16S rRNA genes (rDNA) and rRNA gene expression of taxa in an activated-sludge-treatment plant (sequencing batch membrane bioreactor) at two solids retention times (SRTs): 20 and 5 days. These two SRTs were used to influence the rates of micropollutant biotransformation and nutrient removal. Our results show that rare taxa (<1%) have disproportionally high ratios of rRNA to rDNA, an indication of higher protein synthesis, compared to abundant taxa (≥1%) and suggests that rare taxa likely play an unrecognized role in bioreactor performance. There were also significant differences in community-wide rRNA expression signatures at 20-day SRT: anaerobic-oxic-anoxic periods were the primary driver of rRNA similarity. These results indicate differential expression of rRNA at high SRTs, which may further explain why high SRTs promote higher rates of micropollutant biotransformation. An analysis of micropollutant-associated degradation genes via metagenomics and direct measurements of a suite of micropollutants and nutrients further corroborates the loss of enhanced functions at 5-day SRT operation. This work advances our knowledge of the underlying ecosystem properties and dynamics of abundant and rare organisms associated with enhanced functions in engineered systems. PMID:27196630

  2. EFFECTS OF COVAPORS ON ADSORPTION RATE COEFFICIENTS OF ORGANIC VAPORS ADSORBED ONTO ACTIVATED CARBON FROM FLOWING AIR

    SciTech Connect

    G. WOOD

    2000-12-01

    Published breakthrough time, adsorption rate, and capacity data for components of organic vapor mixtures adsorbed from flows through fixed activated carbon beds have been analyzed. Capacities (as stoichiometric centers of constant pattern breakthrough curves) yielded stoichiometric times {tau}, which are useful for determining elution orders of mixture components. We also calculated adsorption rate coefficients k{sub v} of the Wheeler (or, more general Reaction Kinetic) breakthrough curve equation, when not reported, from breakthrough times and {tau}. Ninety-five k{sub v} (in mixture)/ k{sub v} (single vapor) ratios at similar vapor concentrations were calculated and averaged for elution order categories. For 43 first-eluting vapors the average ratio (1.07) was statistically no different (0.21 standard deviation) than unity, so that we recommend using the single-vapor k{sub v} for such. Forty-seven second-eluting vapor ratios averaged 0.85 (0.24 standard deviation), also not significantly different from unity; however, other evidence and considerations lead us recommend using k{sub v} (in mixture) = 0.85 k{sub v} (single vapor). Five third- and fourth-eluting vapors gave an average of 0.56 (0.16 standard deviation) for a recommended k{sub v} (in mixture) = 0.56 k{sub v} (single vapor) for such.

  3. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate.

    PubMed

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-01

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d(-1)) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery. PMID:26791952

  4. [Semiautomatic procedure for the investigation of synchronized activity of EEG and heart rate--examination of preterm births].

    PubMed

    Dax, Josef F; Müller-Putz, Gernot R; Pfurtscheller, Klaus; Urlesberger, Berndt; Müller, Wilhelm; Pfurtscheller, Gert

    2005-01-01

    Recordings of the electroencephalogram (EEG) and of the heart rate variability (HRV) of preterm neonates can give important information on the actual state of the nervous system. Both signals, EEG and HRV, are affected by parameters such as gestational age, stage of maturation and behavioral state. This work describes a method for automatic detection of slow wave EEG-bursts and a tool to average changes in the EEG and the corresponding heart rate. The detection is based on the hjorth activity (HA), calculated from the EEG. HA spikes (HAS) are identified by the determination of the beginning and end of existing spikes. HAS maxima and the time between two consecutive HAS are the basis for the triggering of the bursts. EEG power and time synchronized HR changes are averaged with a time window length of 20 s. Resultant, HR increase and duration are determined. These parameters, obtained by the automatic detection, proved to be comparable to the results of an expert. PMID:15792197

  5. Zero valent iron significantly enhances methane production from waste activated sludge by improving biochemical methane potential rather than hydrolysis rate.

    PubMed

    Liu, Yiwen; Wang, Qilin; Zhang, Yaobin; Ni, Bing-Jie

    2015-02-05

    Anaerobic digestion has been widely applied for waste activated sludge (WAS) treatment. However, methane production from anaerobic digestion of WAS is usually limited by the slow hydrolysis rate and/or poor biochemical methane potential of WAS. This work systematically studied the effects of three different types of zero valent iron (i.e., iron powder, clean scrap and rusty scrap) on methane production from WAS in anaerobic digestion, by using both experimental and mathematical approaches. The results demonstrated that both the clean and the rusty iron scrap were more effective than the iron powder for improving methane production from WAS. Model-based analysis showed that ZVI addition significantly enhanced methane production from WAS through improving the biochemical methane potential of WAS rather than its hydrolysis rate. Economic analysis indicated that the ZVI-based technology for enhancing methane production from WAS is economically attractive, particularly considering that iron scrap can be freely acquired from industrial waste. Based on these results, the ZVI-based anaerobic digestion process of this work could be easily integrated with the conventional chemical phosphorus removal process in wastewater treatment plant to form a cost-effective and environment-friendly approach, enabling maximum resource recovery/reuse while achieving enhanced methane production in wastewater treatment system.

  6. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate

    NASA Astrophysics Data System (ADS)

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-01

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d‑1) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

  7. Polyhydroxyalkanoates in waste activated sludge enhances anaerobic methane production through improving biochemical methane potential instead of hydrolysis rate.

    PubMed

    Wang, Qilin; Sun, Jing; Zhang, Chang; Xie, Guo-Jun; Zhou, Xu; Qian, Jin; Yang, Guojing; Zeng, Guangming; Liu, Yiqi; Wang, Dongbo

    2016-01-21

    Anaerobic sludge digestion is the main technology for sludge reduction and stabilization prior to sludge disposal. Nevertheless, methane production from anaerobic digestion of waste activated sludge (WAS) is often restricted by the poor biochemical methane potential and slow hydrolysis rate of WAS. This work systematically investigated the effect of PHA levels of WAS on anaerobic methane production, using both experimental and mathematical modeling approaches. Biochemical methane potential tests showed that methane production increased with increased PHA levels in WAS. Model-based analysis suggested that the PHA-based method enhanced methane production by improving biochemical methane potential of WAS, with the highest enhancement being around 40% (from 192 to 274 L CH4/kg VS added; VS: volatile solid) when the PHA levels increased from 21 to 143 mg/g VS. In contrast, the hydrolysis rate (approximately 0.10 d(-1)) was not significantly affected by the PHA levels. Economic analysis suggested that the PHA-based method could save $1.2/PE/y (PE: population equivalent) in a typical wastewater treatment plant (WWTP). The PHA-based method can be easily integrated into the current WWTP to enhance methane production, thereby providing a strong support to the on-going paradigm shift in wastewater management from pollutant removal to resource recovery.

  8. Zero Valent Iron Significantly Enhances Methane Production from Waste Activated Sludge by Improving Biochemical Methane Potential Rather Than Hydrolysis Rate

    NASA Astrophysics Data System (ADS)

    Liu, Yiwen; Wang, Qilin; Zhang, Yaobin; Ni, Bing-Jie

    2015-02-01

    Anaerobic digestion has been widely applied for waste activated sludge (WAS) treatment. However, methane production from anaerobic digestion of WAS is usually limited by the slow hydrolysis rate and/or poor biochemical methane potential of WAS. This work systematically studied the effects of three different types of zero valent iron (i.e., iron powder, clean scrap and rusty scrap) on methane production from WAS in anaerobic digestion, by using both experimental and mathematical approaches. The results demonstrated that both the clean and the rusty iron scrap were more effective than the iron powder for improving methane production from WAS. Model-based analysis showed that ZVI addition significantly enhanced methane production from WAS through improving the biochemical methane potential of WAS rather than its hydrolysis rate. Economic analysis indicated that the ZVI-based technology for enhancing methane production from WAS is economically attractive, particularly considering that iron scrap can be freely acquired from industrial waste. Based on these results, the ZVI-based anaerobic digestion process of this work could be easily integrated with the conventional chemical phosphorus removal process in wastewater treatment plant to form a cost-effective and environment-friendly approach, enabling maximum resource recovery/reuse while achieving enhanced methane production in wastewater treatment system.

  9. High rate mesophilic, thermophilic, and temperature phased anaerobic digestion of waste activated sludge: A pilot scale study

    SciTech Connect

    Bolzonella, David; Cavinato, Cristina; Fatone, Francesco; Pavan, Paolo; Cecchi, Franco

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer High temperatures were tested in single and two-stage anaerobic digestion of waste activated sludge. Black-Right-Pointing-Pointer The increased temperature demonstrated the possibility of improving typical yields of the conventional mesophilic process. Black-Right-Pointing-Pointer The temperature phased anaerobic digestion process (65 + 55 Degree-Sign C) showed the best performances with yields of 0.49 m{sup 3}/kgVS{sub fed}. Black-Right-Pointing-Pointer Ammonia and phosphate released from solids destruction determined the precipitation of struvite in the reactor. - Abstract: The paper reports the findings of a two-year pilot scale experimental trial for the mesophilic (35 Degree-Sign C), thermophilic (55 Degree-Sign C) and temperature phased (65 + 55 Degree-Sign C) anaerobic digestion of waste activated sludge. During the mesophilic and thermophilic runs, the reactor operated at an organic loading rate of 2.2 kgVS/m{sup 3}d and a hydraulic retention time of 20 days. In the temperature phased run, the first reactor operated at an organic loading rate of 15 kgVS/m{sup 3}d and a hydraulic retention time of 2 days while the second reactor operated at an organic loading rate of 2.2 kgVS/m{sup 3}d and a hydraulic retention time of 18 days (20 days for the whole temperature phased system). The performance of the reactor improved with increases in temperature. The COD removal increased from 35% in mesophilic conditions, to 45% in thermophilic conditions, and 55% in the two stage temperature phased system. As a consequence, the specific biogas production increased from 0.33 to 0.45 and to 0.49 m{sup 3}/kgVS{sub fed} at 35, 55, and 65 + 55 Degree-Sign C, respectively. The extreme thermophilic reactor working at 65 Degree-Sign C showed a high hydrolytic capability and a specific yield of 0.33 gCOD (soluble) per gVS{sub fed}. The effluent of the extreme thermophilic reactor showed an average concentration of soluble COD and volatile

  10. High-rate iron-rich activated sludge as stabilizing agent for the anaerobic digestion of kitchen waste.

    PubMed

    De Vrieze, Jo; De Lathouwer, Lars; Verstraete, Willy; Boon, Nico

    2013-07-01

    Anaerobic digestion is a key technology in the bio-based economy and can be applied to convert a wide range of organic substrates into CH4 and CO2. Kitchen waste is a valuable substrate for anaerobic digestion, since it is an abundant source of organic matter. Yet, digestion of single kitchen waste often results in process failure. High-rate activated sludge or A-sludge is produced during the highly loaded first stage of the two-phase 'Adsorptions-Belebungsverfahren' or A/B activated sludge system for municipal wastewater treatment. In this specific case, the A-sludge was amended with FeSO4 to enhance phosphorous removal and coagulation during the water treatment step. This study therefore evaluated whether this Fe-rich A-sludge could be used to obtain stable methanation and higher methane production values during co-digestion with kitchen waste. It was revealed that Fe-rich A-sludge can be a suitable co-substrate for kitchen waste; i.e. methane production rate values of 1.15 ± 0.22 and 1.12 ± 0.28 L L(-1) d(-1) were obtained during mesophilic and thermophilic co-digestion respectively of a feed-mixture consisting of 15% KW and 85% A-sludge. The thermophilic process led to higher residual VFA concentrations, up to 2070 mg COD L(-1), and can therefore be considered less stable. Addition of micro- and macronutrients provided a more stable digestion of single kitchen waste, i.e. a methane production of 0.45 L L(-1) d(-1) was obtained in the micronutrient treatment compared to 0.30 L L(-1) d(-1) in the control treatment on day 61. Yet, methane production during single kitchen waste digestion still decreased toward the end of the experiment, despite the addition of micronutrients. Methane production rates were clearly influenced by the total numbers of archaea in the different reactors. This study showed that Fe-rich A-sludge and kitchen waste are suitable for co-digestion. PMID:23726710

  11. Effects of chronic sleep deprivation on autonomic activity by examining heart rate variability, plasma catecholamine, and intracellular magnesium levels.

    PubMed

    Takase, Bonpei; Akima, Takashi; Satomura, Kimio; Ohsuzu, Fumitaka; Mastui, Takemi; Ishihara, Masayuki; Kurita, Akira

    2004-10-01

    Chronic sleep deprivation is associated with cardiovascular events. In addition, autonomic activity determined from the levels of the heart rate variability (HRV), plasma catecholamine, and intracellular magnesium (Mg) are important in the pathophysiology of cardiovascular events. This study therefore aimed to determine the effects of chronic sleep deprivation on autonomic activity by examining the HRV, plasma catecholamine, and intracellular magnesium levels. Thirty (30) healthy male college students ranging in age from 20 to 24 years of age (average 22 +/- 1 years; mean +/- SD) with no coronary risk factors such as hypertension, diabetes mellitus, hyperlipidemia or a family history of premature coronary artery disease (CAD) were included in the study. Over a 4-week period, the volunteers' plasma levels of epinephrine, norepinephrine, and erythrocyte-Mg were measured. The study was made during the 4 weeks before and immediately after college finals exams. HRV, obtained from 24-hour ambulatory ECG monitoring, included time and frequency domain indices. The HRV indices and erythrocyte-Mg decreased while norepinephrine increased during chronic sleep deprivation. It is concluded that chronic sleep deprivation causes an autonomic imbalance and decreases intracellular Mg, which could be associated with chronic sleep deprivation-induced cardiovascular events. PMID:15754837

  12. Supermassive black holes with high accretion rates in active galactic nuclei. II. The most luminous standard candles in the universe

    SciTech Connect

    Wang, Jian-Min; Du, Pu; Hu, Chen; Qiu, Jie; Li, Yan-Rong; Netzer, Hagai; Kaspi, Shai; Bai, Jin-Ming; Wang, Fang; Lu, Kai-Xing; Collaboration: SEAMBH collaboration

    2014-10-01

    This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting massive black holes (SEAMBHs) and to use their unique properties to construct a new method for measuring cosmological distances. Based on theoretical models, the saturated bolometric luminosity of such sources is proportional to the BH mass, which can be used to obtain their distance. Here we report on five new RM measurements and show that in four of the cases, we can measure the BH mass and three of these sources are SEAMBHs. Together with the three sources from our earlier work, we now have six new sources of this type. We use a novel method based on a minimal radiation efficiency to identify nine additional SEAMBHs from earlier RM-based mass measurements. We use a Bayesian analysis to determine the parameters of the new distance expression and the method uncertainties from the observed properties of the objects in the sample. The ratio of the newly measured distances to the standard cosmological ones has a mean scatter of 0.14 dex, indicating that SEAMBHs can be use as cosmological distance probes. With their high luminosity, long period of activity, and large numbers at high redshifts, SEAMBHs have a potential to extend the cosmic distance ladder beyond the range now explored by Type Ia supernovae.

  13. Exercise training associated with diet improves heart rate recovery and cardiac autonomic nervous system activity in obese children.

    PubMed

    Prado, D M; Silva, A G; Trombetta, I C; Ribeiro, M M; Guazzelli, I C; Matos, L N; Santos, M S; Nicolau, C M; Negrão, C E; Villares, S M

    2010-12-01

    The purpose of this study was to test the hypotheses that in obese children: 1) hypocaloric diet (D) improves both heart rate recovery at 1 min (Δ HRR1) cfter an exercise test, and cardiac autonomic nervous system activity (CANSA) in obese children; 2) Diet and exercise training (DET) combined leads to greater improvement in both Δ HRR1 after an exercise test and in CANSA, than D alone. Moreover, we examined the relationships among Δ HRR1, CANSA, cardiorespiratory fitness and anthropometric variables (AV) in obese children submitted to D and to DET. 33 obese children (10 ± 0.2 years; body mass index (BMI) >95 (th) percentile) were divided into 2 groups: D (n=15; BMI=31 ± 1 kg/m²)) and DET (n=18; 29 ± 1 kg/m²). All children performed a maximal cardiopulmonary exercise test on a treadmill. The Δ HRR1 or LF/HF ratio (P>0.05). In contrast, the DET group showed increased peak VO₂ ( P=0.01) and improved Δ HRR1 (Δ HRR1=37.3 ± 2.6; P=0.01) and LF/HF ratio ( P=0.001). The DET group demonstrated significant relationships among Δ HRR1, peak VO₂ and CANSA (P<0.05). In conclusion, DET, in contrast to D, promoted improved ÄΔ HRR1 and CANSA in obese children, suggesting a positive influence of increased levels of cardiorespiratory fitness by exercise training on cardiac autonomic activity.

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

    NASA Astrophysics Data System (ADS)

    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 ( P<0.001) in α1 (hyperthyroid 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 ( P<0.001) in the standard deviation of the R-R intervals (SDNN) and high frequency power (HF). In conclusion, hyperthyroidism 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.

  15. Mice expressing markedly reduced striatal dopamine transporters exhibit increased locomotor activity, dopamine uptake turnover rate, and cocaine responsiveness.

    PubMed

    Rao, Anjali; Sorkin, Alexander; Zahniser, Nancy R

    2013-10-01

    Variations in the expression levels of the dopamine transporter (DAT) can influence responsiveness to psychostimulant drugs like cocaine. To better understand this relationship, we studied a new DAT-low expresser (DAT-LE) mouse model and performed behavioral and biochemical studies with it. Immunoblotting and [(3) H]WIN 35,428 binding analyses revealed that these mice express ∼35% of wildtype (WT) mouse striatal DAT levels. Compared to WT mice, DAT-LE mice were hyperactive in a novel open-field environment. Despite their higher basal locomotor activity, cocaine (10 or 20 mg/kg, i.p.) induced greater locomotor activation in DAT-LE mice than in WT mice. The maximal velocity (Vmax ) of DAT-mediated [(3) H]DA uptake into striatal synaptosomes was reduced by 46% in DAT-LE mice, as compared to WT. Overall, considering the reduced number of DAT binding sites (Bmax ) along with the reduced Vmax in DAT-LE mice, a 2-fold increase in DA uptake turnover rate (Vmax /Bmax ) was found, relative to WT mice. This suggests that neuroadaptive changes have occurred in the DAT-LE mice that would help to compensate for their low DAT numbers. Interestingly, these changes do not include a reduction in tyrosine hydroxylase levels, as was previously reported in DAT knockout homozygous and heterozygous animals. Further, these changes are not sufficient to prevent elevated novelty- and cocaine-induced locomotor activity. Hence, these mice represent a unique model for studying changes of in vivo DAT function and regulation that result from markedly reduced levels of DAT expression. PMID:23564231

  16. Endothelin-1 activation of ETB receptors leads to a reduced cellular proliferative rate and an increased cellular footprint

    SciTech Connect

    Wilson, Jamie L.; Taylor, Linda; Polgar, Peter

    2012-06-10

    Endothelin-1 (ET-1) is a vasoactive peptide which signals through two G-protein coupled receptors, endothelin receptor A (ETA) and B (ETB). We determined that ET-1 activation of its ETB receptor in stably cDNA transfected CHO cells leads to a 55% reduction in cell number by end-point cell counting and a 35% decrease in cell growth by a real-time cell-substrate impedance-based assay after 24 h of cell growth. When CHO ETB cells were synchronized in the late G1 cell cycle phase, ET-1 delayed their S phase progression compared to control by 30% as determined by [{sup 3}H]-thymidine incorporation. On the other hand, no such delay was observed during late G2/M to G1 transit when cells were treated with ET-1 after release from mitotic arrest. Using the cell-substrate impedance-based assay, we observed that ET-1 induces opposing morphological changes in CHO ETA and CHO ETB cells with ETB causing an increase in the cell footprint and ETA a decrease. Likewise, in pulmonary artery smooth muscle cells, which express both ETA and ETB receptors, ET-1 induces an ETA-dependent contraction and an ETB dependent dilation. These results are shedding light on a possible beneficial role for ETB in diseases involving ET-1 dysfunction such as pulmonary hypertension. -- Highlights: Black-Right-Pointing-Pointer ET- hinders cell proliferation in CHO cells transfected with ETB. Black-Right-Pointing-Pointer ET-1 also decreases the rate of DNA synthesis in CHO ETB cells. Black-Right-Pointing-Pointer JNK and PI3K appear to be involved in this reduction of DNA synthesis. Black-Right-Pointing-Pointer ETB activation in CHO ETB cells and hSMCs leads to dilatory morphological changes. Black-Right-Pointing-Pointer In CHO ETA and hSMCs, ETA activation leads to constrictive morphological changes.

  17. Methanosarcinaceae and Acetate-Oxidizing Pathways Dominate in High-Rate Thermophilic Anaerobic Digestion of Waste-Activated Sludge

    PubMed Central

    Ho, Dang P.; Jensen, Paul D.

    2013-01-01

    This study investigated the process of high-rate, high-temperature methanogenesis to enable very-high-volume loading during anaerobic digestion of waste-activated sludge. Reducing the hydraulic retention time (HRT) from 15 to 20 days in mesophilic digestion down to 3 days was achievable at a thermophilic temperature (55°C) with stable digester performance and methanogenic activity. A volatile solids (VS) destruction efficiency of 33 to 35% was achieved on waste-activated sludge, comparable to that obtained via mesophilic processes with low organic acid levels (<200 mg/liter chemical oxygen demand [COD]). Methane yield (VS basis) was 150 to 180 liters of CH4/kg of VSadded. According to 16S rRNA pyrotag sequencing and fluorescence in situ hybridization (FISH), the methanogenic community was dominated by members of the Methanosarcinaceae, which have a high level of metabolic capability, including acetoclastic and hydrogenotrophic methanogenesis. Loss of function at an HRT of 2 days was accompanied by a loss of the methanogens, according to pyrotag sequencing. The two acetate conversion pathways, namely, acetoclastic methanogenesis and syntrophic acetate oxidation, were quantified by stable carbon isotope ratio mass spectrometry. The results showed that the majority of methane was generated by nonacetoclastic pathways, both in the reactors and in off-line batch tests, confirming that syntrophic acetate oxidation is a key pathway at elevated temperatures. The proportion of methane due to acetate cleavage increased later in the batch, and it is likely that stable oxidation in the continuous reactor was maintained by application of the consistently low retention time. PMID:23956388

  18. Mice expressing markedly reduced striatal dopamine transporters exhibit increased locomotor activity, dopamine uptake turnover rate, and cocaine responsiveness.

    PubMed

    Rao, Anjali; Sorkin, Alexander; Zahniser, Nancy R

    2013-10-01

    Variations in the expression levels of the dopamine transporter (DAT) can influence responsiveness to psychostimulant drugs like cocaine. To better understand this relationship, we studied a new DAT-low expresser (DAT-LE) mouse model and performed behavioral and biochemical studies with it. Immunoblotting and [(3) H]WIN 35,428 binding analyses revealed that these mice express ∼35% of wildtype (WT) mouse striatal DAT levels. Compared to WT mice, DAT-LE mice were hyperactive in a novel open-field environment. Despite their higher basal locomotor activity, cocaine (10 or 20 mg/kg, i.p.) induced greater locomotor activation in DAT-LE mice than in WT mice. The maximal velocity (Vmax ) of DAT-mediated [(3) H]DA uptake into striatal synaptosomes was reduced by 46% in DAT-LE mice, as compared to WT. Overall, considering the reduced number of DAT binding sites (Bmax ) along with the reduced Vmax in DAT-LE mice, a 2-fold increase in DA uptake turnover rate (Vmax /Bmax ) was found, relative to WT mice. This suggests that neuroadaptive changes have occurred in the DAT-LE mice that would help to compensate for their low DAT numbers. Interestingly, these changes do not include a reduction in tyrosine hydroxylase levels, as was previously reported in DAT knockout homozygous and heterozygous animals. Further, these changes are not sufficient to prevent elevated novelty- and cocaine-induced locomotor activity. Hence, these mice represent a unique model for studying changes of in vivo DAT function and regulation that result from markedly reduced levels of DAT expression.

  19. Validity of combining heart rate and uniaxial acceleration to measure free-living physical activity energy expenditure in young men.

    PubMed

    Villars, C; Bergouignan, A; Dugas, J; Antoun, E; Schoeller, D A; Roth, H; Maingon, A C; Lefai, E; Blanc, S; Simon, C

    2012-12-01

    Combining accelerometry (ACC) with heart rate (HR) monitoring is thought to improve activity energy expenditure (AEE) estimations compared with ACC alone to evaluate the validity of ACC and HR used alone or combined. The purpose of this study was to estimate AEE in free-living conditions compared with doubly labeled water (DLW). Ten-day free-living AEE was measured by a DLW protocol in 35 18- to 55-yr-old men (11 lean active; 12 lean sedentary; 12 overweight sedentary) wearing an Actiheart (combining ACC and HR) and a RT3 accelerometer. AEE was estimated using group or individual calibration of the HR/AEE relationship, based on an exercise-tolerance test. In a subset (n = 21), AEE changes (ΔAEE) were measured after 1 mo of detraining (active subjects) or an 8-wk training (sedentary subjects). Actiheart-combined ACC/HR estimates were more accurate than estimates from HR or ACC alone. Accuracy of the Actiheart group-calibrated ACC/HR estimates was modest [intraclass correlation coefficient (ICC) = 0.62], with no bias but high root mean square error (RMSE) and limits of agreement (LOA). The mean bias of the estimates was reduced by one-third, like RMSE and LOA, by individual calibration (ICC = 0.81). Contrasting with group-calibrated estimates, the Actiheart individual-calibrated ACC/HR estimates explained 40% of the variance of the DLW-ΔAEE (ICC = 0.63). This study supports a good level of agreement between the Actiheart ACC/HR estimates and DLW-measured AEE in lean and overweight men with varying fitness levels. Individual calibration of the HR/AEE relationship is necessary for AEE estimations at an individual level rather than at group scale and for ΔAEE evaluation.

  20. AVERAGE HEATING RATE OF HOT ATMOSPHERES IN DISTANT CLUSTERS BY RADIO ACTIVE GALACTIC NUCLEUS: EVIDENCE FOR CONTINUOUS ACTIVE GALACTIC NUCLEUS HEATING

    SciTech Connect

    Ma, C.-J.; McNamara, B. R.; Schaffer, R.; Nulsen, P. E. J.; Vikhlinin, A.

    2011-10-20

    We examine atmospheric heating by radio active galactic nuclei (AGNs) in distant X-ray clusters by cross correlating clusters selected from the 400 Square Degree (400SD) X-ray Cluster survey with radio sources in the NRAO VLA Sky Survey. Roughly 30% of the clusters show radio emission above a flux threshold of 3 mJy within a projected radius of 250 kpc. The radio emission is presumably associated with the brightest cluster galaxy. The mechanical jet power for each radio source was determined using scaling relations between radio power and cavity (mechanical) power determined for nearby clusters, groups, and galaxies with hot atmospheres containing X-ray cavities. The average jet power of central radio AGNs is approximately 2 x 10{sup 44} erg s{sup -1}. We find no significant correlation between radio power, and hence mechanical jet power, and the X-ray luminosities of clusters in the redshift range 0.1-0.6. This implies that the mechanical heating rate per particle is higher in lower mass, lower X-ray luminosity clusters. The jet power averaged over the sample corresponds to an atmospheric heating of approximately 0.2 keV per particle within R{sub 500}. Assuming the current AGN heating rate does not evolve but remains constant to redshifts of 2, the heating rate per particle would rise by a factor of two. We find that the energy injected from radio AGNs contribute substantially to the excess entropy in hot atmospheres needed to break self-similarity in cluster scaling relations. The detection frequency of radio AGNs is inconsistent with the presence of strong cooling flows in 400SD clusters, but does not exclude weak cooling flows. It is unclear whether central AGNs in 400SD clusters are maintained by feedback at the base of a cooling flow. Atmospheric heating by radio AGNs may retard the development of strong cooling flows at early epochs.

  1. Activation of NADP-Malate Dehydrogenase, Pyruvate,Pi Dikinase, and Fructose 1,6-Bisphosphatase in Relation to Photosynthetic Rate in Maize 1

    PubMed Central

    Usuda, Hideaki; Ku, Maurice S. B.; Edwards, Gerald E.

    1984-01-01

    The activity and extent of light activation of three photosynthetic enzymes, pyruvate,Pi dikinase, NADP-malate dehydrogenase (NADP-MDH), and fructose 1,6-bisphosphatase (FBPase), were examined in maize (Zea mays var Royal Crest) leaves relative to the rate of photosynthesis during induction and under varying light intensities. There was a strong light activation of NADP-MDH and pyruvate,Pi dikinase, and light also activated FBPase 2- to 4-fold. During the induction period for whole leaf photosynthesis at 30°C under high light, the time required to reach half-maximum activation for all three enzymes was only 1 minute or less. After 2.5 minutes of illumination the enzymes were fully activated, while the photosynthetic rate was only at half-maximum activity, indicating that factors other than enzyme activation limit photosynthesis during the induction period in C4 plants. Under steady state conditions, the light intensity required to reach half-maximum activation of the three enzymes was similar (300-400 microEinsteins per square meter per second), while the light intensity required for half-maximum rates of photosynthesis was about 550 microEinsteins per square meter per second. The light activated levels of NADP-MDH and FBPase were well in excess of the in vivo activities which would be required during photosynthesis, while maximum activities of pyruvate,Pi dikinase were generally just sufficient to accommodate photosynthesis, suggesting the latter may be a rate limiting enzyme. There was a large (5-fold) light activation of FBPase in isolated bundle sheath strands of maize, whereas there was little light activation of the enzyme in isolated mesophyll protoplasts. In mesophyll protoplasts the enzyme was largely located in the cytoplasm, although there was a low amount of light-activated enzyme in the mesophyll chloroplasts. The results suggest the chloroplastic FBPase in maize is primarily located in the bundle sheath cells. PMID:16663806

  2. Graded response of heart rate variability, associated with an alteration of geomagnetic activity in a subarctic area.

    PubMed

    Oinuma, S; Kubo, Y; Otsuka, K; Yamanaka, T; Murakami, S; Matsuoka, O; Ohkawa, S; Cornélissen, G; Weydahl, A; Holmeslet, B; Hall, C; Halberg, F

    2002-01-01

    It is becoming recognized that geomagnetic activity may influence biological processes, including the incidence of various human diseases. There is evidence that heart rate variability (HRV) may serve not only as an index of autonomic coordination of the circulation, but also as a powerful predictor of risk in apparently healthy subjects. This study focuses on the effects of geomagnetic disturbance on HRV, by comparing different indices of HRV of young, healthy men living in a subarctic area on days of low (Ap; 0-7), middle (Ap; 7-20), and high (Ap; 20-45) geomagnetic activity. The effect of geomagnetic disturbance on HRV is examined on the basis of 7-day records by Holter ECG, obtained longitudinally on 5 clinically healthy men, 21-31 years of age, in Alta, Norway (70 degree N). Frequency- and time-domain measures of HRV were analyzed for each subject on separate 24-hour spans. A graded alteration of HRV endpoints was found in association with increased geomagnetic activity. As time-domain measures of HRV, SDNNIDX and the 90% length of the Lorenz plot decreased statistically significantly on days with increased geomagnetic disturbance (p = 0.0144 and p = 0.0102, respectively). A graded decrease in frequency-domain HRV measures was also validated statistically for the total spectral power (decrease of 18.1% and 31.6% on days when 7 < Ap < 20 and 20 < Ap < 45 versus days when Ap < 7; p = 0.0013). The decrease in spectral power was mainly found at frequencies below 0.04 Hz, in the "ultra-low-frequency" (0.0001-0.003 Hz; 18.1% and 27.5% decrease, respectively; p = 0.0102) and "very-low-frequency" (0.003-0.04 Hz; 12.9% and 28.6% decrease, respectively; p = 0.0209) regions of the spectrum. The decrease in spectral power was much less pronounced around 10.5 sec ("low frequency"; N.S.) and around 3.6 sec ("high frequency"; N.S.). Evidence is provided here that HRV decreases on magnetically disturbed days, and that it does so in a dose-dependent fashion, HRV being

  3. A versatile telemetry system for continuous measurement of heart rate, body temperature and locomotor activity in free-ranging ruminants

    PubMed Central

    Signer, Claudio; Ruf, Thomas; Schober, Franz; Fluch, Gerhard; Paumann, Thomas; Arnold, Walter

    2012-01-01

    Summary 1. Measuring physiological and behavioural parameters in free-ranging animals – and therefore under fully natural conditions – is of general biological concern but difficult to perform. 2. We have developed a minimally invasive telemetry system for ruminants that is capable of measuring heart rate (HR), body temperature (Tb) and locomotor activity (LA). A ruminal transmitter unit was per os placed into the reticulum and therefore located in close proximity to the heart. The unit detected HR by the use of an acceleration sensor and also measured Tb. HR and Tb signals were transmitted via short-distance UHF link to a repeater system located in a collar unit. The collar unit decoded and processed signals received from the ruminal unit, measured LA with two different activity sensors and transmitted pulse interval-modulated VHF signals over distances of up to 10 km. 3. HR data measured with the new device contained noise caused by reticulum contractions and animal movements that triggered the acceleration sensor in the ruminal unit. We have developed a software filter to remove this noise. Hence, the system was only capable of measuring HR in animals that showed little or no activity and in the absence of rumen contractions. Reliability of this ‘stationary HR’ measurement was confirmed with a second independent measurement of HR detected by an electrocardiogram in a domestic sheep (Ovis aries). 4. In addition, we developed an algorithm to correctly classify an animal as ‘active’ or ‘at rest’ during each 3-min interval from the output of the activity sensors. Comparison with direct behavioural observations on free-ranging Alpine ibex (Capra ibex) showed that 87% of intervals were classified correctly. 5. First results from applications of this new technique in free-ranging Alpine ibex underlined its suitability for reliable and long-term monitoring of physiological and behavioural parameters in ruminants under harsh field conditions. With the

  4. Influence of cadmium concentration and length of exposure on metabolic rate and gill Na+/K+ ATPase activity of golden shiners (Notemigonus crysoleucas).

    PubMed

    Peles, John D; Pistole, David H; Moffe, Mickey

    2012-06-01

    Although metabolic rate is considered to be useful as a general indicator of the biological effects of exposure to metals, it is seldom measured in conjunction with specific physiological, biochemical or cellular parameters. The purpose of this investigation was to examine the influence of cadmium (Cd) exposure on metabolic rate and gill Na(+)/K(+) ATPase activity in golden shiners (Notemigonus crysoleucas). Shiners were exposed to six levels of Cd (ranging from control to the maximum sublethal concentration) for 24- and 96-h periods. After 24-h, metabolic rate and Na(+)/K(+) ATPase activity of individual fish were strongly correlated. Shiners exposed to the four highest Cd concentrations (500, 800, 1100, and 1400 μg L(-1)) for 24-h exhibited a shock response that was characterized by mean values for metabolic rate and Na(+)/K(+) ATPase activity that were significantly lower compared to the control. Although results for 96-h exposures reflect a repair/recovery phase, there was no significant correlation between metabolic rate and Na(+)/K(+) ATPase activity. Metabolic rate of shiners was significantly elevated (65-100%) at all concentrations compared to the control after 96-h, whereas Na(+)/K(+) ATPase activity did not differ from the control. Elevated metabolic rate after 96-h likely reflects the influence of a variety of energetically demanding processes associated with repair and recovery.

  5. Temporal repeatability of metabolic rate and the effect of organ mass and enzyme activity on metabolism in European eel (Anguilla anguilla).

    PubMed

    Boldsen, Martin Maagaard; Norin, Tommy; Malte, Hans

    2013-05-01

    Intraspecific variation in metabolic rate of fish can be pronounced and have been linked to various fitness-related behavioural and physiological traits, but the underlying causes for this variation have received far less attention than the consequences of it. In the present study we investigated whether European eels (Anguilla anguilla) displayed temporal repeatability of body-mass-corrected (residual) metabolic rate over a two-month period and if variations in organ mass and enzyme activity between individual fish could be the cause for the observed variation in metabolic rate. Both standard metabolic rate (SMR; Pearson's r=0.743) and routine metabolic rate (RMR; r=0.496) were repeatable over the two-month period. Repeatability of RMR is an interesting finding as it indicates that the level of spontaneous activity in respirometer-confined fish is not random. Cumulative organ mass (liver, heart, spleen and intestine; mean 1.6% total body mass) was found to explain 38% of the variation in SMR (r=0.613) with the liver (one of the metabolically most active organs) being the driver for the correlation between organ mass and metabolic rate. No relationships were found for either liver citrate synthase or cytochrome oxidase activity and metabolic rate in the European eels. Reasons for, and contributions to, the observed variation in metabolic rate are discussed.

  6. Recorded gonorrhoea rates in Denmark, 1900–2010: the impact of clinical testing activity and laboratory diagnostic procedures

    PubMed Central

    Lind, Inga; Hoffmann, Steen

    2015-01-01

    Objectives Assessment of the relations between recorded gonorrhoea rates and clinical testing activity and disposable diagnostic tests. Methods In Denmark, two sources of information on the epidemiology of gonorrhoea are available: (1) a mandatory clinical notification system (since 1867) comprising summary information about geographic distribution, season, age group and gender; in 1994, more detailed anonymous individualised epidemiological information was included; (2) a voluntary countrywide laboratory surveillance system for culture-confirmed cases (since 1957) comprising information about patient's age and gender, infected anatomical sites and medical setting attended. Results Both surveillance systems showed marked simultaneous changes in gonorrhoea rates, although periodically considerable under-reporting or under-diagnosing was demonstrated. The annual incidence of notified cases peaked in 1919 (474/100 000), in 1944 (583/100 000) and in 1972 (344/100 000). Since 1995, the incidence has been at a low endemic level (1.5–10/100 000) and the total male/female incidence ratios were from 3 to 7 times higher than previously recorded. Among approximately 2 million persons tested during 1974–1988 78 213 men and 63 143 women with culture-confirmed gonorrhoea were identified. During this period, pharyngeal sampling was performed in 36% of men and 25% of women with gonorrhoea; pharyngeal gonorrhoea was found in 10% and 16%, respectively; 40% and 30% of these patients had no concomitant urogenital gonorrhoea. Among men with gonorrhoea, 34% were sampled from the rectum; 9% had rectal gonorrhoea, among whom the rectum was the only infected site in 67%. Conclusions Crucial factors for case finding are clinical sampling tradition and appropriate laboratory diagnostic facilities. When case finding is insufficient, a reservoir of asymptomatic rectal or pharyngeal gonorrhoea remains unrecognised. PMID:26621510

  7. Effect of self-alkalization on nitrite accumulation in a high-rate denitrification system: Performance, microflora and enzymatic activities.

    PubMed

    Li, Wei; Shan, Xiao-Yu; Wang, Zhi-Yao; Lin, Xiao-Yu; Li, Chen-Xu; Cai, Chao-Yang; Abbas, Ghulam; Zhang, Meng; Shen, Li-Dong; Hu, Zhi-Qiang; Zhao, He-Ping; Zheng, Ping

    2016-01-01

    The self-alkalization of denitrifying automatic circulation (DAC) reactor resulted in a large increase of pH up to 9.20 and caused a tremendous accumulation of nitrite up to 451.1 ± 49.0 mgN L(-1) at nitrate loading rate (NLR) from 35 kgN m(-3) d(-1) to 55 kgN m(-3) d(-1). The nitrite accumulation was greatly relieved even at the same NLR once the pH was maintained at 7.6 ± 0.2 in the system. Enzymatic assays indicated that the long-term bacterial exposure to high pH significantly inhibited the activity of copper type nitrite reductase (NirK) rather than the cytochrome cd1 type nitrite reductase (NirS). The terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that the dominant denitrifying bacteria shifted from the NirS-containing Thauear sp. 27 to the NirK-containing Hyphomicrobium nitrativorans strain NL23 during the self-alkalization. The significant nitrite accumulation in the high-rate denitrification system could be therefore, due to the inhibition of Cu-containing NirK by high pH from the self-alkalization. The results suggest that the NirK-containing H. nitrativorans strain NL23 could be an ideal functional bacterium for the conversion of nitrate to nitrite, i.e. denitritation, which could be combined with anaerobic ammonium oxidation (Anammox) to develop a new process for nitrogen removal from wastewater. PMID:26595097

  8. Active faulting within a megacity: the geometry and slip rate of the Pardisan thrust in central Tehran, Iran

    NASA Astrophysics Data System (ADS)

    Talebian, M.; Copley, A. C.; Fattahi, M.; Ghoraishi, M.; Jackson, J. A.; Nazari, H.; Sloan, R. A.; Walker, R. T.

    2016-09-01

    Tehran, the capital city of Iran with a population of over 12 million, is one of the largest urban centres within the seismically active Alpine-Himalayan orogenic belt. Although several historic earthquakes have affected Tehran, their relation to individual faults is ambiguous for most. This ambiguity is partly due to a lack of knowledge about the locations, geometries, and seismic potential of structures that have been obscured by dramatic urban growth over the past three decades, and which have covered most of the young geomorphic markers and natural exposures. Here we use aerial photographs from 1956, combined with an ˜1 m DEM derived from stereo Pleiades satellite imagery, to investigate the geomorphology of a growing anticline above a thrust fault - the Pardisan thrust - within central Tehran. The topography across the ridge is consistent with a steep ramp extending from close to the surface to a depth of ˜2 km, where it presumably connects with a shallow-dipping detachment. No primary fault is visible at the surface, and it is possible that the faulting dissipates in the near surface as distributed shearing. We use optically-stimulated luminescence to date remnants of uplifted and warped alluvial deposits that are offset vertically across the Pardisan fault, providing minimum uplift and slip-rates of at least 1 mm/yr. Our study shows that the faults within the Tehran urban region have relatively rapid rates of slip, are important in the regional tectonics, and have a great impact on earthquake hazard assessment of the city and surrounding region.

  9. Effect of self-alkalization on nitrite accumulation in a high-rate denitrification system: Performance, microflora and enzymatic activities.

    PubMed

    Li, Wei; Shan, Xiao-Yu; Wang, Zhi-Yao; Lin, Xiao-Yu; Li, Chen-Xu; Cai, Chao-Yang; Abbas, Ghulam; Zhang, Meng; Shen, Li-Dong; Hu, Zhi-Qiang; Zhao, He-Ping; Zheng, Ping

    2016-01-01

    The self-alkalization of denitrifying automatic circulation (DAC) reactor resulted in a large increase of pH up to 9.20 and caused a tremendous accumulation of nitrite up to 451.1 ± 49.0 mgN L(-1) at nitrate loading rate (NLR) from 35 kgN m(-3) d(-1) to 55 kgN m(-3) d(-1). The nitrite accumulation was greatly relieved even at the same NLR once the pH was maintained at 7.6 ± 0.2 in the system. Enzymatic assays indicated that the long-term bacterial exposure to high pH significantly inhibited the activity of copper type nitrite reductase (NirK) rather than the cytochrome cd1 type nitrite reductase (NirS). The terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that the dominant denitrifying bacteria shifted from the NirS-containing Thauear sp. 27 to the NirK-containing Hyphomicrobium nitrativorans strain NL23 during the self-alkalization. The significant nitrite accumulation in the high-rate denitrification system could be therefore, due to the inhibition of Cu-containing NirK by high pH from the self-alkalization. The results suggest that the NirK-containing H. nitrativorans strain NL23 could be an ideal functional bacterium for the conversion of nitrate to nitrite, i.e. denitritation, which could be combined with anaerobic ammonium oxidation (Anammox) to develop a new process for nitrogen removal from wastewater.

  10. Effects of low power microwave radiation on biological activity of Collagenase enzyme and growth rate of S. Cerevisiae yeast

    NASA Astrophysics Data System (ADS)

    Alsuhaim, Hamad S.; Vojisavljevic, Vuk; Pirogova, E.

    2013-12-01

    Recently, microwave radiation, a type/subset of non-ionizing electromagnetic radiation (EMR) has been widely used in industry, medicine, as well as food technology and mobile communication. Use of mobile phones is rapidly growing. Four years from now, 5.1 billion people will be mobile phone users around the globe - almost 1 billion more mobile users than the 4.3 billion people worldwide using them now. Consequently, exposure to weak radiofrequency/microwave radiation generated by these devices is markedly increasing. Accordingly, public concern about potential hazards on human health is mounting [1]. Thermal effects of radiofrequency/microwave radiation are very well-known and extensively studied. Of particular interest are non-thermal effects of microwave exposures on biological systems. Nonthermal effects are described as changes in cellular metabolism caused by both resonance absorption and induced EMR and are often accompanied by a specific biological response. Non-thermal biological effects are measurable changes in biological systems that may or may not be associated with adverse health effects. In this study we studied non-thermal effects of low power microwave exposures on kinetics of L-lactate dehydrogenase enzyme and growth rate of yeast Saccharomyces Cerevisiae strains type II. The selected model systems were continuously exposed to microwave radiation at the frequency of 968MHz and power of 10dBm using the designed and constructed (custom made) Transverse Electro-Magnetic (TEM) cell [2]. The findings reveal that microwave radiation at 968MHz and power of 10dBm inhibits L-lactate dehydrogenase enzyme activity by 26% and increases significantly (15%) the proliferation rate of yeast cells.

  11. Active tectonics and Holocene versus modern catchment erosion rates at 300 MW Baspa II hydroelectric power plant (NW Himalaya, India)

    NASA Astrophysics Data System (ADS)

    Draganits, Erich; Grasemann, Bernhard; Gier, Susanne; Hofmann, Christa-Charlotte; Janda, Christoph; Bookhagen, Bodo; Preh, Alexander

    2015-04-01

    The Baspa River is one of the most important tributaries to the Sutlej River in the NW Himalaya (India). Its catchment is 1116 km2 in size, ranges from c. 6400 m asl to 1770 m asl and contains India's largest private hydroelectric facility, the 300 MW Baspa II. Geologically, the hydroelectric installation is located in the Higher Himalayan Crystalline, just above the active Karcham Normal Fault, which is reactivating the Early Miocene Main Central Thrust, one of the principal Himalayan faults. The area is seismically active and mass-movements are common. Around 8200 yrs BP the Baspa was dammed by a rock-avalanche dam, leading to the formation of the originally c. 260 m deep palaeo-lake Sangla palaeo-lake. Detailed sedimentological investigations and radiocarbon dating indicate that the palaeo-lake was completely filled with sediments until c. 5100 yrs BP. This makes the Sangla palaeo-lake to a very rare example of a mass-movement dam with very long duration and its lacustrine sediments represent a valuable archive for geological processes and environmental proxies within the Baspa catchment during the c. 3100 years of its existence - which are the aim of our study. At least 5 levels of soft-sediment deformation have been recorded in the exposed part of the lacustrine sediments of Sangla palaeo-lake, including brecciated laminae, overturned laminae, folds, faults and deformation bands, separated by undeformed deposits. They are interpreted as seismites, indicating at least 5 earthquakes within 2500 years strong enough to cause liquefaction. The 300 MW Baspa II hydro-electric power plant has been built exactly on top of this palaeo-lake. This special location represents a very rare possibility to evaluate the short-term, river load and hydrological parameters measured during the planning and operational stages of Baspa II with the long-term parameters gained from the palaeo-lake sediments from the catchment. This data show that the Mid-Holocene erosion rates of the

  12. Slip-rate Estimation of Active Fault by Luminescence Dating on Deformed River Terraces at Tsaotun, Central Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Chen, W.; Lee, C.

    2003-12-01

    This study carried out luminescence ages of the deformed terraces located at Tsaotun in central Taiwan. These terraces are considered as a result of crustal deformation caused by recent activity of the Chelungpu fault, 1999 surface rupture. Since this active fault runs through urban area, it is urgently needed to figure out its neotectonic behavior, including slip-rate and recurrence interval. Based on new ages, we also discuss the terrace correlation and its related structures. The study terraces are all strath terraces with only a few meters of veneered fluvial deposits on top. Due to the strong stream-power, nearly all the outcrops are dominated by fluvial cobbles, which is worst condition to preserve the syndepositional carbonaceous materials. Alternatively, optical stimulated luminescence (OSL) dating uses sandy quartz as the material and even has longer dating upper limit (up to several hundreds of years). Fortunately, sandy layer are found intercalated within the fluvial cobbles in studying terraces. We adopted the Single-Aliquot Regenerative (SAR) dose protocol on large aliquots of 90-150μ m quartz, which were cleaned using HCL, H2O2 and HF in the usual way. In case of incomplete bleaching during quick deposition, the OSL/TL ratio was adopted to approach the true De. Dosimetry is derived by ICP-MS and XRF analyses. For ascertainment of the initial bleaching of fluvial sediment, the modern samples collected in river bed of Wuhsi were also measured. Based on the results of modern samples, we believe that the residuals are inevitable in younger sediments, especially along the upper stream. On the contrary, the samples older than 10 kyr are little influenced due to the larger age error than the younger ones. The OSL age of the terrace samples in the hanging wall is dated ca. 13 kyr, which has been corrected for poorly-bleaching problem. Comparing to the ages collected down hole in the footwalls, we found out vertical displacements of ca. 67 and 37 m, has been

  13. Effect of game format on heart rate, activity profile, and player involvement in elite and recreational youth players.

    PubMed

    Randers, M B; Andersen, T B; Rasmussen, L S; Larsen, M N; Krustrup, P

    2014-08-01

    The purpose of this study was to evaluate activity profile, aerobic load, and player involvement in two game formats of recreational and elite youth football for two age groups. A total of 152 youth players participated, with 45 U10 players playing 5v5 and 8v8 games, and 41 U13 players playing 8v8 and 11v11 (20 min) games. Activity profile, heart rate (HR), and technical actions were measured during all games using 10 Hz GPS, video filming, and HR monitors. For U10, no difference was found in total distance covered (1754 ± 237 vs 1771 ± 314 m, P = 0.650, d = 0.06), whereas mean HR (174 ± 10 vs 168 ± 12 bpm, P = 0.001, d = 0.59) and number of technical actions (65.1 ± 24.0 vs 36.9 ± 20.4, P    0.001, d = 1.27) were higher in 5v5 than in 8v8. For U13, lower total distance covered (1821 ± 325 vs 2038 ± 328 m, P < 0.001, d = 0.66) and higher number of technical actions (36.2 ± 14.9 vs 26.9 ± 14.1, P < 0.001, d = 0.64) were observed in 8v8 than in 11v11, with no difference in mean HR (170 ± 10 vs 171 ± 10 bpm, P = 0.679, d = 0.10). In conclusion, HR is high in youth football matches irrespective of the level of play and the game format. Playing with fewer players on smaller pitches results in minor changes to the physical loading but elevates the technical involvement of youth players both at elite level and recreational level.

  14. A PANCHROMATIC STUDY OF BLAST COUNTERPARTS: TOTAL STAR FORMATION RATE, MORPHOLOGY, ACTIVE GALACTIC NUCLEUS FRACTION, AND STELLAR MASS

    SciTech Connect

    Moncelsi, Lorenzo; Ade, Peter A. R.; Cortese, Luca; Dye, Simon; Eales, Stephen; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Pascale, Enzo; Tucker, Carole; Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas; Wiebe, Donald V.; Devlin, Mark J.; Truch, Matthew D. P.; Netterfield, Calvin B.; Viero, Marco P.

    2011-02-01

    We carry out a multi-wavelength study of individual galaxies detected by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) and identified at other wavelengths, using data spanning the radio to the ultraviolet (UV). We develop a Monte Carlo method to account for flux boosting, source blending, and correlations among bands, which we use to derive deboosted far-infrared (FIR) luminosities for our sample. We estimate total star-formation rates (SFRs) for BLAST counterparts with z {<=} 0.9 by combining their FIR and UV luminosities. Star formation is heavily obscured at L{sub FIR} {approx}> 10{sup 11} L{sub sun}, z {approx}> 0.5, but the contribution from unobscured starlight cannot be neglected at L{sub FIR} {approx}< 10{sup 11} L{sub sun}, z {approx}< 0.25. We assess that about 20% of the galaxies in our sample show indication of a type 1 active galactic nucleus, but their submillimeter emission is mainly due to star formation in the host galaxy. We compute stellar masses for a subset of 92 BLAST counterparts; these are relatively massive objects, with a median mass of {approx}10{sup 11} M{sub sun}, which seem to link the 24 {mu}m and Submillimetre Common-User Bolometer Array (SCUBA) populations, in terms of both stellar mass and star formation activity. The bulk of the BLAST counterparts at z {approx}< 1 appears to be run-of-the-mill star-forming galaxies, typically spiral in shape, with intermediate stellar masses and practically constant specific SFRs. On the other hand, the high-z tail of the BLAST counterparts significantly overlaps with the SCUBA population, in terms of both SFRs and stellar masses, with observed trends of specific SFR that support strong evolution and downsizing.

  15. Effect of physical activity on heart rate variability in normal weight, overweight and obese subjects: results from the SAPALDIA study

    PubMed Central

    Dietrich, Denise Felber; Ackermann-Liebrich, Ursula; Schindler, Christian; Barthélémy, Jean-Claude; Brändli, Otto; Gold, Diane R; Knöpfli, Bruno; Probst-Hensch, Nicole M; Roche, Frédéric; Tschopp, Jean-Marie; von Eckardstein, Arnold; Gaspoz, Jean-Michel

    2011-01-01

    Many studies have demonstrated an association of both a sedentary lifestyle and a high body mass index (BMI) with greater risk for cardiovascular disease. Within the prospective SAPALDIA cohort (Swiss cohort study on Air Pollution and Lung Diseases in Adults), we investigated whether regular exercise was protective against reduced heart rate variability (HRV), a clinically relevant predictor of cardiovascular morbidity and mortality, and whether adverse effects of obesity and weight gain on HRV were modified by regular exercise. 24-hour electrocardiograms were recorded in 1712 randomly selected SAPALDIA participants aged ≥50, for whom BMI was assessed in the years 1991 and 2001–2003. Other examinations included an interview investigating health status (especially respiratory and cardiovascular health and health relevant behaviours including physical activity) and measurements of blood pressure, body height and weight. The association between regular physical activity and HRV and interactions with BMI and BMI change was assessed in multivariable linear regression analyses. Compared to sedentary obese subjects, SDNN (standard deviation of all RR intervals) was 14% (95% CI: 8–20%) higher in sedentary normal weight subjects; 19% (CI: 12–27%) higher in normal weight subjects exercising regularly ≥ 2h/week; and 19% (CI:11–28%) higher in obese subjects exercising regularly ≥ 2h/week. Compared with sedentary subjects who gained weight, those who gained weight but did exercise regularly had a 13% higher SDNN (CI: 7–20%). Regular physical exercise has strong beneficial effects on cardiac autonomic nervous function and thus appears to offset the negative effect of obesity on HRV. PMID:18597107

  16. Altered feeding response as a cause for the altered heartbeat rate and locomotor activity of Schistosoma mansoni-infected biomphalaria glabrata.

    PubMed

    Williams, C L; Gilbertson, D E

    1983-08-01

    Biomphalaria glabrata infected with Schistosoma mansoni for 33 days fed more often than uninfected snails. Whereas uninfected snails had nocturnal increases in feeding, snails with a 33-day-old infection of S. mansoni fed as often during the day as in the night. Using direct observation and film analysis, we found that feeding increased the heartbeat rate and locomotor activity of B. glabrata. When snails were allowed to feed ad lib., infected snails had higher heartbeat rates than uninfected snails both during the day (P less than 0.01) and the night (P less than 0.001). However, when the snails were deprived of food for 24 hr, infected snails had slightly higher heartbeat rates than uninfected snails only during the day (P less than 0.05). There was no difference between the heartbeat rates of feeding, infected snails and the heartbeat rates of uninfected snails that were starved for 8 hr, and then allowed to feed. Uninfected snails had nocturnal increases in heartbeat rate regardless of feeding schedule, but infected snails had greater nighttime heartbeat rate than daytime heartbeat rate only when they were not allowed to feed. Infected snails had less nocturnal locomotor activity than uninfected snails when feeding, but there was no difference between the locomotor activity of infected and uninfected snails when the snails were deprived of food for 24 hr. Absence of food also resulted in an increased nighttime to daytime ratio of locomotor activity of infected snails. These results suggest that the increased heartbeat rate and altered rhythms of heartbeat rate and locomotor activity in B. glabrata infected with S. mansoni for 33 days were caused by the altered feeding response of these snails.

  17. [Inhibition rate of gamma-aminolevulinic acid dehydratase activity in erythrocytes as a reliable index for individual workers of low lead exposure].

    PubMed

    Hirano, H; Omichi, M; Ohishi, H; Ishikawa, K; Hirashima, N

    1983-09-01

    As the delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocytes is decreased by lead exposure, we considered that a net reduction of ALAD activity by lead in blood should be the difference between the activity fully activated with zinc (Zn2+) and dithiothreitol (DTT) and that without activation. The optimal condition of activation of ALAD was found by addition of 0.25 mM of Zn2+ and 10 mM of DTT in the reaction mixture. Judging from our previous results that the amount of inhibition of ALAD activity can be represented as the rate of inhibition and is closely correlated with the dose of lead administered to rabbits, the inhibition rate of ALAD activity and lead content in blood (Pb-B) of lead workers were measured. The scatter diagram obtained from the inhibition rate and lead content in blood has two groups being divided at 50 micrograms/ml of Pb-B. In one group less than 50 micrograms/100 ml of Pb-B, the inhibition rate has been closely related to Pb-B., the regression equation being Y = 1.82 X + 11.7, and the correlation coefficient + 0.926. In another group more than 50 micrograms/100 ml of Pb-B the inhibition rate remained constant at the 90% level. Measurement of the inhibition rate suggests to have practical validity for monitoring lead exposure in workers, and by means of a nomograph lead content in blood can be estimated from the inhibition rate.

  18. Wnt5a Increases the Glycolytic Rate and the Activity of the Pentose Phosphate Pathway in Cortical Neurons

    PubMed Central

    Cisternas, Pedro; Salazar, Paulina; Silva-Álvarez, Carmen; Barros, L. Felipe

    2016-01-01

    In the last few years, several reports have proposed that Wnt signaling is a general metabolic regulator, suggesting a role for this pathway in the control of metabolic flux. Wnt signaling is critical for several neuronal functions, but little is known about the correlation between this pathway and energy metabolism. The brain has a high demand for glucose, which is mainly used for energy production. Neurons use energy for highly specific processes that require a high energy level, such as maintaining the electrical potential and synthesizing neurotransmitters. Moreover, an important metabolic impairment has been described in all neurodegenerative disorders. Despite the key role of glucose metabolism in the brain, little is known about the cellular pathways involved in regulating this process. We report here that Wnt5a induces an increase in glucose uptake and glycolytic rate and an increase in the activity of the pentose phosphate pathway; the effects of Wnt5a require the intracellular generation of nitric oxide. Our data suggest that Wnt signaling stimulates neuronal glucose metabolism, an effect that could be important for the reported neuroprotective role of Wnt signaling in neurodegenerative disorders. PMID:27688915

  19. Power, pulse width, and repetition rate agile low-cost multi-spectral semi-active laser simulator

    NASA Astrophysics Data System (ADS)

    O'Daniel, Jason K.; Young, Preston; Golden, Eric; Barton, Robert; Snyder, Donald

    2010-04-01

    The emergence of spectrally multimode smart missiles requires hardware-in-the-loop (HWIL) facilities to simulate multiple spectral signatures simultaneously. While traditional diode-pumped solid-state (DPSS) sources provide a great basic testing source for smart missiles, they typically are bulky and provide substantially more power peak power than what is required for laboratory simulation, have fixed pulse widths, and require some external means to attenuate the output power. HWIL facilities require systems capable of high speed variability of the angular divergence and optical intensity over several orders of magnitude, which is not typically provided by basic DPSS systems. In order to meet the needs of HWIL facilities, we present a low-cost semi-active laser (SAL) simulator source using laser diode sources that emits laser light at the critical wavelengths of 1064 nm and 1550 nm, along with light in the visible for alignment, from a single fiber aperture. Fiber delivery of the multi-spectral output can provide several advantages depending on the testing setup. The SAL simulator source presented is capable of providing attenuation of greater than 70 dB with a response time of a few milliseconds and provides a means to change the angular divergence over an entire dynamic range of 0.02- 6º in less than 400 ms. Further, the SAL simulator is pulse width and pulse repetition rate agile making it capable of producing both current and any future coding format necessary.

  20. The Effect of Exposure to High Noise Levels on the Performance and Rate of Error in Manual Activities

    PubMed Central

    Khajenasiri, Farahnaz; Zamanian, Alireza; Zamanian, Zahra

    2016-01-01

    Introduction Sound is among the significant environmental factors for people’s health, and it has an important role in both physical and psychological injuries, and it also affects individuals’ performance and productivity. The aim of this study was to determine the effect of exposure to high noise levels on the performance and rate of error in manual activities. Methods This was an interventional study conducted on 50 students at Shiraz University of Medical Sciences (25 males and 25 females) in which each person was considered as its own control to assess the effect of noise on her or his performance at the sound levels of 70, 90, and 110 dB by using two factors of physical features and the creation of different conditions of sound source as well as applying the Two-Arm coordination Test. The data were analyzed using SPSS version 16. Repeated measurements were used to compare the length of performance as well as the errors measured in the test. Results Based on the results, we found a direct and significant association between the levels of sound and the length of performance. Moreover, the participant’s performance was significantly different for different sound levels (at 110 dB as opposed to 70 and 90 dB, p < 0.05 and p < 0.001, respectively). Conclusion This study found that a sound level of 110 dB had an important effect on the individuals’ performances, i.e., the performances were decreased. PMID:27123216

  1. Life cycle assessment comparison of activated sludge, trickling filter, and high-rate anaerobic-aerobic digestion (HRAAD).

    PubMed

    Postacchini, Leonardo; Lamichhane, Krishna M; Furukawa, Dennis; Babcock, Roger W; Ciarapica, F E; Cooney, Michael J

    2016-01-01

    This paper conducts a comparative assessment of the environmental impacts of three methods of treating primary clarifier effluent in wastewater treatment plants (WWTPs) through life cycle assessment methodology. The three technologies, activated sludge (AS), high rate anaerobic-aerobic digestion (HRAAD), and trickling filter (TF), were assessed for treatment of wastewater possessing average values of biochemical oxygen demand and total suspended solids of 90 mg L(-1) and 70 mg L(-1), respectively. The operational requirements to process the municipal wastewater to effluent that meets USEPA regulations have been calculated. The data for the AS system were collected from the East Honolulu WWTP (Hawaii, USA) while data for the HRAAD system were collected from a demonstration-scale system at the same plant. The data for the TF system were estimated from published literature. Two different assessment methods have been used in this study: IMPACT 2002+ and TRACI 2. The results show that TF had the smallest environmental impacts and that AS had the largest, while HRAAD was in between the two but with much reduced impacts compared with AS. Additionally, the study shows that lower sludge production is the greatest advantage of HRAAD for reducing environmental impacts compared with AS. PMID:27191555

  2. Product and rate determinations with chemically activated nucleotides in the presence of various prebiotic materials, including other mono- and polynucleotides

    NASA Technical Reports Server (NTRS)

    Kanavarioti, A.; Alberas, D. J.; Rosenbach, M. T.; Bernasconi, C. F.; Chang, S.

    1991-01-01

    We are investigating the reactions of ImpN's in the presence of a number of prebiotically plausible materials, such as metal ions, phosphate, amines and other nucleotides and hope to learn more about the stability/reactivity of ImpN's in a prebiotic aqueous environment. We find that, in the presence of phosphate, ImpN's form substantial amounts of diphosphate nucleotides. These diphosphate nucleotides are not very good substrates for template directed reactions, but are chemically activated and are known to revert to the phosphoimidazolides in the presence of imidazole under solid state conditions. With respect to our studies of the oligomerization reaction, the determination of the dimerization rate constant of a specific ImpN (guanosine 5'-phospho 2 methylimidazolide) both in the absence and the presence of the template leads to the conclusion that at 37 C the dimerization is not template directed, although the subsequent polymerization steps are. In other words, this specific polynucleotide synthesizing system favors the elongation of oligonucleotides as compared with the formation of dimers and trimers. This favoring of the synthesis of long as opposed to short oligonucleotides may be regarded as a rudimentary example of natural selection at the molecular level.

  3. Wnt5a Increases the Glycolytic Rate and the Activity of the Pentose Phosphate Pathway in Cortical Neurons

    PubMed Central

    Cisternas, Pedro; Salazar, Paulina; Silva-Álvarez, Carmen; Barros, L. Felipe

    2016-01-01

    In the last few years, several reports have proposed that Wnt signaling is a general metabolic regulator, suggesting a role for this pathway in the control of metabolic flux. Wnt signaling is critical for several neuronal functions, but little is known about the correlation between this pathway and energy metabolism. The brain has a high demand for glucose, which is mainly used for energy production. Neurons use energy for highly specific processes that require a high energy level, such as maintaining the electrical potential and synthesizing neurotransmitters. Moreover, an important metabolic impairment has been described in all neurodegenerative disorders. Despite the key role of glucose metabolism in the brain, little is known about the cellular pathways involved in regulating this process. We report here that Wnt5a induces an increase in glucose uptake and glycolytic rate and an increase in the activity of the pentose phosphate pathway; the effects of Wnt5a require the intracellular generation of nitric oxide. Our data suggest that Wnt signaling stimulates neuronal glucose metabolism, an effect that could be important for the reported neuroprotective role of Wnt signaling in neurodegenerative disorders.

  4. Fluence Rate Differences in Photodynamic Therapy Efficacy and Activation of Epidermal Growth Factor Receptor after Treatment of the Tumor-Involved Murine Thoracic Cavity

    PubMed Central

    Grossman, Craig E.; Carter, Shirron L.; Czupryna, Julie; Wang, Le; Putt, Mary E.; Busch, Theresa M.

    2016-01-01

    Photodynamic therapy (PDT) of the thoracic cavity can be performed in conjunction with surgery to treat cancers of the lung and its pleura. However, illumination of the cavity results in tissue exposure to a broad range of fluence rates. In a murine model of intrathoracic PDT, we studied the efficacy of 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH; Photochlor®)-mediated PDT in reducing the burden of non-small cell lung cancer for treatments performed at different incident fluence rates (75 versus 150 mW/cm). To better understand a role for growth factor signaling in disease progression after intrathoracic PDT, the expression and activation of epidermal growth factor receptor (EGFR) was evaluated in areas of post-treatment proliferation. The low fluence rate of 75 mW/cm produced the largest reductions in tumor burden. Bioluminescent imaging and histological staining for cell proliferation (anti-Ki-67) identified areas of disease progression at both fluence rates after PDT. However, increased EGFR activation in proliferative areas was detected only after treatment at the higher fluence rate of 150 mW/cm. These data suggest that fluence rate may affect the activation of survival factors, such as EGFR, and weaker activation at lower fluence rate could contribute to a smaller tumor burden after PDT at 75 mW/cm. PMID:26784170

  5. Metabolic rates, enzyme activities and chemical compositions of some deep-sea pelagic worms, particularly Nectonemertes mirabilis (Nemertea; Hoplonemertinea) and Poeobius meseres (Annelida; Polychaeta)

    NASA Astrophysics Data System (ADS)

    Thuesen, Erik V.; Childress, James J.

    1993-05-01

    Investigations of metabolic rate, enzyme activity and chemical composition were undertaken on two abundant deep-sea pelagic worms: Nectonemertes mirabilis (Nemertea; Hoplonemertinea) and Poeobius meseres (Annelida; Polychaeta). Six other species of worms ( Pelagonemertes brinkmanni (Nemertea) and the following polychaetes: Pelagobia species A, Tomopteris nisseni, Tomopteris pacifica, Tomopteris species A, and Traviopsis lobifera) were captured in smaller numbers and used for comparison in the physiological and biochemical measurements. Polychaete worms had the highest oxygen consumption rates and, along with N. mirabilis, displayed significant size effects on metabolic rate. Poeobius meseres had the lowest rates of oxygen consumption and displayed no significant relationship of oxygen consumption rate to wet weight. No significant effect of size on the activities of citrate synthase, lactate dehydrogenase or pyruvate kinase was observed in P. meseres or N. mirabilis. Lipid content was higher than protein content for all the worms in this study. Carbohydrate was of little significance in these worms and was usually <0.01% of the total weight. Citrate synthase activities of pelagic worms showed excellent correlation with metabolic rates. It appears that polychaete worms as a group have higher metabolic rates than bathypelagic shrimps, copepods and fishes, and may be the animals with the highest metabolic rates in the bathypelagic regions of the world's oceans.

  6. ACDOS1: a computer code to calculate dose rates from neutron activation of neutral beamlines and other fusion-reactor components

    SciTech Connect

    Keney, G.S.

    1981-08-01

    A computer code has been written to calculate neutron induced activation of neutral-beam injector components and the corresponding dose rates as a function of geometry, component composition, and time after shutdown. The code, ACDOS1, was written in FORTRAN IV to calculate both activity and dose rates for up to 30 target nuclides and 50 neutron groups. Sufficient versatility has also been incorporated into the code to make it applicable to a variety of general activation problems due to neutrons of energy less than 20 MeV.

  7. Active Aging: Exploration into Self-Ratings of “Being Active,” Out-of-Home Physical Activity, and Participation among Older Australian Adults Living in Four Different Settings

    PubMed Central

    Aird, Rosemary L.; Buys, Laurie

    2015-01-01

    We examined whether self-ratings of “being active” among older people living in four different settings (major city high and lower density suburbs, a regional city, and a rural area) were associated with out-of-home participation and outdoor physical activity. A mixed-methods approach (survey, travel diary, and GPS tracking over a one-week period) was used to gather data from 48 individuals aged over 55 years. Self-ratings of “being active” were found to be positively correlated with the number of days older people spent time away from home but unrelated to time traveled by active means (walking and biking). No significant differences in active travel were found between the four study locations, despite differences in their respective built environments. The findings suggest that additional strategies to the creation of “age-friendly” environments are needed if older people are to increase their levels of outdoor physical activity. “Active aging” promotion campaigns may need to explicitly identify the benefits of walking outdoors to ambulatory older people as a means of maintaining their overall health, functional ability, and participation within society in the long-term and also encourage the development of community-based programs in order to facilitate regular walking for this group. PMID:26346381

  8. Agreement between participant-rated and compendium-coded intensity of daily activities in a triethnic sample of women ages 40 years and older.

    PubMed

    Wilcox, S; Irwin, M L; Addy, C; Stolarczyk, L; Ainsworth, B E; Whitt, M; Tudor-Locke, C

    2001-01-01

    Participant-rated and compendium-coded intensity of daily physical activities were compared in 148 African American, 144 Native American, 51 non-Hispanic White women ages 40 to 91 years who completed 4 days of activity records. For compendium-coded intensity, reported activities were classified as light (< 3 metabolic equivalents [METS]), moderate (3-6 METS), or vigorous (> 6 METS) using the Compendium of Physical Activities (1), whereas these categories were self-assigned for participant-rated intensity. Minutes per day (min/d) spent in activities at each intensity level were computed. Relative to compendium-coded min/d, participants reported significantly greater time spent in light (+10 min/d; p < .01) and vigorous (+17 min/d; p < .001) activities, and less time spent in moderate activities (-27 min/d; p <.001). Similarly, compendium-coded estimates yielded higher rates ofparticipants meeting Centersfor Disease Control and Prevention-American College of Sports Medicine and Surgeon General recommendations than participant-rated estimates (11-18% differences) but substantially lower rates meeting American College of Sports Medicine vigorous recommendations (22% difference). Further, 247 greater kilocalories per day were estimated based on compendium-coded intensity. Kilocalories per day estimates based on compendium codings were more highly associated with pedometer counts than those based on participant ratings (p < .05). Studypatterns were generally seen across all sample subgroups. Discrepancies between participant and compendium estimates are likely to be most meaningful in studies estimating energy expenditure as it relates to health outcomes and in studies estimating vigorous activities. PMID:11761342

  9. Embryonic Development and Rates of Metabolic Activity in Early and Late Hatching Eggs of the Major Malaria Vector Anopheles gambiae

    PubMed Central

    Kaiser, Maria L.; Duncan, Frances D.; Brooke, Basil D.

    2014-01-01

    Anopheles gambiae eggs generally hatch at the completion of embryo development; two-three days post oviposition. However, staggered or delayed hatching has been observed whereby a single batch of eggs shows marked variation in time-to-hatch, with some eggs hatching 18 days post oviposition or later. The mechanism enabling delayed hatch has not been clearly elucidated but is likely mediated by environmental and genetic factors that either induce diapause or slow embryo development. This study aimed to compare metabolic activity and embryonic development between eggs collected from sub-colonies of the baseline Anopheles gambiae GAH colony previously selected for early or late time-to-hatch. Egg batches from early and late hatch sub-colonies as well as from the baseline colony were monitored for hatching. For both time-to-hatch selected sub-colonies and the baseline colony the majority of eggs hatched on day two post oviposition. Nevertheless, eggs produced by the late hatch sub-colony showed a significantly longer mean time to hatch than those produced by the early hatch sub-colony. The overall proportions that hatched were similar for all egg batches. CO2 output between eggs from early and late hatch sub-colonies showed significant differences only at 3 and 7 days post oviposition where eggs from the early hatch and the late hatch sub-colony were more metabolically active, respectively. No qualitative differences were observed in embryo development between the sub-colonies. It is concluded that all viable embryos develop to maturity at the same rate and that a small proportion then enter a state of diapause enabling them to hatch later. As it has previously been shown that it is possible to at least partially select for late hatch, this characteristic is likely to involve genetic as well as environmental factors. Delayed hatching in An. gambiae is likely an adaptation to maximise reproductive output despite the increased risk of desiccation in an unstable aquatic

  10. Geometry, Timing, and Rates of Active Northeast Tilting Across the Southern Coachella Valley and Santa Rosa Mountains

    NASA Astrophysics Data System (ADS)

    Dorsey, R. J.; Langenheim, V. E.; McNabb, J. C.

    2012-12-01

    The Coachella Valley occupies an important transition along the San Andreas fault (SAF) from strong transpression in the north to transtension and lithospheric rupture in the south. The deformation processes and crustal architecture that accommodate this transition are not well understood. Geomorphic, stratigraphic, and gravity data support a hypothesis for northeast tilting of a large tilt block in the southern Coachella Valley and Santa Rosa Mountains, between the San Jacinto fault zone on the SW (dated in other studies at ~1.2 Ma) and the SAF on the NE. The Santa Rosa fault (SRF) is a strand of the San Jacinto fault zone that marks the steep SW flank of the Santa Rosa Mts and merges with the Clark fault beneath Clark Valley. The SRF is an active normal fault with well developed triangular facets, steeply SW-dipping fault zone with brittle gouge and microfaults, and narrow footwall canyons that feed steep alluvial fans in the hanging wall (east side of Clark Valley). Pliocene marine deposits have been raised by Quaternary uplift in the footwall of the SRF to ~625 m elevation in the Santa Rosa Mts (King et al., 2002). The subsurface Clark basin is ~4 km deep, and the pre-SRF West Salton detachment fault projects ~1.5 km above the valley floor in the Santa Rosa Mts. A steep linear gravity gradient reveals combined vertical separation of ~5.5 km across the SRF and Clark fault, for an average slip rate of ~4.5 mm/yr across the two faults. The NE side of the Santa Rosa Mts has a gentler surface gradient and no large-offset active faults. The ratio of alluvial fan area to catchment area is 0.5-0.6 for fan-catchment pairs along the SRF, compared to an average of ~1.1-1.2 on the NE slope of the Santa Rosa Mts. The different ratios suggest rapid subsidence in the hanging wall of the SRF and relatively slow subsidence in the NE-tilting footwall (cf. Allen and Hovius, 1998). The depth of the southern Coachella Valley increases from the SW side, where sediments onlap

  11. [C II] 158 μm Luminosities and Star Formation Rate in Dusty Starbursts and Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Sargsyan, L.; Lebouteiller, V.; Weedman, D.; Spoon, H.; Bernard-Salas, J.; Engels, D.; Stacey, G.; Houck, J.; Barry, D.; Miles, J.; Samsonyan, A.

    2012-08-01

    Results are presented for [C II] 158 μm line fluxes observed with the Herschel PACS instrument in 112 sources with both starburst and active galactic nucleus (AGN) classifications, of which 102 sources have confident detections. Results are compared with mid-infrared spectra from the Spitzer Infrared Spectrometer and with L ir from IRAS fluxes; AGN/starburst classifications are determined from equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon (PAH) feature. It is found that the [C II] line flux correlates closely with the flux of the 11.3 μm PAH feature independent of AGN/starburst classification, log [f([C II] 158 μm)/f(11.3 μm PAH)] = -0.22 ± 0.25. It is concluded that the [C II] line flux measures the photodissociation region associated with starbursts in the same fashion as the PAH feature. A calibration of star formation rate (SFR) for the starburst component in any source having [C II] is derived comparing [C II] luminosity L([C II]) to L ir with the result that log SFR = log L([C II)]) - 7.08 ± 0.3, for SFR in M ⊙ yr-1 and L([C II]) in L ⊙. The decreasing ratio of L([C II]) to L ir in more luminous sources (the "[C II] deficit") is shown to be a consequence of the dominant contribution to L ir arising from a luminous AGN component because the sources with the largest L ir and smallest L([C II])/L ir are AGNs. Based on observations with the Herschel Space Observatory, which is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  12. A Model of Blood Pressure, Heart Rate, and Vaso-Vagal Responses Produced by Vestibulo-Sympathetic Activation.

    PubMed

    Raphan, Theodore; Cohen, Bernard; Xiang, Yongqing; Yakushin, Sergei B

    2016-01-01

    Blood Pressure (BP), comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation of an input related to Desired BP, feedback from the states, and an input from the vestibular system into one of the feedback loops. This nonlinear function was structured to best simulate the shapes of systoles and diastoles, the relationship between BP and Heart Rate (HR) as well as the amplitude modulations of BP and Pulse Pressure. Increases in threshold in one of the feedback loops produced lower frequencies of HR, but generated large pulse pressures to maintain orthostasis, without generating a VasoVagal Response (VVR). Pulse pressures were considerably smaller in the anesthetized rats than during the simulations, but simulated pulse pressures were lowered by including saturation in the feedback loop. Stochastic changes in threshold maintained the compensatory Baroreflex Sensitivity. Sudden decreases in Desired BP elicited non-compensatory VVRs with smaller pulse pressures, consistent with experimental data. The model suggests that the Vestibular Sympathetic Reflex (VSR) modulates BP and HR of an oscillating system by manipulating parameters of the baroreflex feedback and the signals that maintain the oscillations. It also shows that a VVR is generated when the vestibular input triggers a marked reduction in Desired BP. PMID:27065779

  13. Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. I. First Results from a New Reverberation Mapping Campaign

    NASA Astrophysics Data System (ADS)

    Du, Pu; Hu, Chen; Lu, Kai-Xing; Wang, Fang; Qiu, Jie; Li, Yan-Rong; Bai, Jin-Ming; Kaspi, Shai; Netzer, Hagai; Wang, Jian-Min; SEAMBH Collaboration

    2014-02-01

    We report first results from a large project to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). Such objects may be different from other AGNs in being powered by slim accretion disks and showing saturated accretion luminosities, but both are not yet fully understood. The results are part of a large reverberation mapping (RM) campaign using the 2.4 m Shangri-La telescope at the Yunnan Observatory in China. The goals are to investigate the gas distribution near the BH and the properties of the central accretion disks, to measure BH mass and Eddington ratios, and to test the feasibility of using such objects as a new type of cosmological candles. The paper presents results for three objects, Mrk 335, Mrk 142, and IRAS F12397+3333, with Hβ time lags relative to the 5100 Å continuum of 10.6^{+1.7}_{-2.9}, 6.4^{+0.8}_{-2.2} and 11.4^{+2.9}_{-1.9} days, respectively. The corresponding BH masses are (8.3_{-3.2}^{+2.6})\\times 10^6\\,M_{\\odot }, (3.4_{-1.2}^{+0.5})\\times 10^6\\,M_{\\odot }, and (7.5_{-4.1}^{+4.3})\\times 10^6\\,M_{\\odot }, and the lower limits on the Eddington ratios are 0.6, 2.3, and 4.6 for the minimal radiative efficiency of 0.038. Mrk 142 and IRAS F12397+333 (extinction corrected) clearly deviate from the currently known relation between Hβ lag and continuum luminosity. The three Eddington ratios are beyond the values expected in thin accretion disks and two of them are the largest measured so far among objects with RM-based BH masses. We briefly discuss implications for slim disks, BH growth, and cosmology.

  14. Feed-Forward Propagation of Temporal and Rate Information between Cortical Populations during Coherent Activation in Engineered In Vitro Networks.

    PubMed

    DeMarse, Thomas B; Pan, Liangbin; Alagapan, Sankaraleengam; Brewer, Gregory J; Wheeler, Bruce C

    2016-01-01

    Transient propagation of information across neuronal assembles is thought to underlie many cognitive processes. However, the nature of the neural code that is embedded within these transmissions remains uncertain. Much of our understanding of how information is transmitted among these assemblies has been derived from computational models. While these models have been instrumental in understanding these processes they often make simplifying assumptions about the biophysical properties of neurons that may influence the nature and properties expressed. To address this issue we created an in vitro analog of a feed-forward network composed of two small populations (also referred to as assemblies or layers) of living dissociated rat cortical neurons. The populations were separated by, and communicated through, a microelectromechanical systems (MEMS) device containing a strip of microscale tunnels. Delayed culturing of one population in the first layer followed by the second a few days later induced the unidirectional growth of axons through the microtunnels resulting in a primarily feed-forward communication between these two small neural populations. In this study we systematically manipulated the number of tunnels that connected each layer and hence, the number of axons providing communication between those populations. We then assess the effect of reducing the number of tunnels has upon the properties of between-layer communication capacity and fidelity of neural transmission among spike trains transmitted across and within layers. We show evidence based on Victor-Purpura's and van Rossum's spike train similarity metrics supporting the presence of both rate and temporal information embedded within these transmissions whose fidelity increased during communication both between and within layers when the number of tunnels are increased. We also provide evidence reinforcing the role of synchronized activity upon transmission fidelity during the spontaneous synchronized

  15. Feed-Forward Propagation of Temporal and Rate Information between Cortical Populations during Coherent Activation in Engineered In Vitro Networks

    PubMed Central

    DeMarse, Thomas B.; Pan, Liangbin; Alagapan, Sankaraleengam; Brewer, Gregory J.; Wheeler, Bruce C.

    2016-01-01

    Transient propagation of information across neuronal assembles is thought to underlie many cognitive processes. However, the nature of the neural code that is embedded within these transmissions remains uncertain. Much of our understanding of how information is transmitted among these assemblies has been derived from computational models. While these models have been instrumental in understanding these processes they often make simplifying assumptions about the biophysical properties of neurons that may influence the nature and properties expressed. To address this issue we created an in vitro analog of a feed-forward network composed of two small populations (also referred to as assemblies or layers) of living dissociated rat cortical neurons. The populations were separated by, and communicated through, a microelectromechanical systems (MEMS) device containing a strip of microscale tunnels. Delayed culturing of one population in the first layer followed by the second a few days later induced the unidirectional growth of axons through the microtunnels resulting in a primarily feed-forward communication between these two small neural populations. In this study we systematically manipulated the number of tunnels that connected each layer and hence, the number of axons providing communication between those populations. We then assess the effect of reducing the number of tunnels has upon the properties of between-layer communication capacity and fidelity of neural transmission among spike trains transmitted across and within layers. We show evidence based on Victor-Purpura’s and van Rossum’s spike train similarity metrics supporting the presence of both rate and temporal information embedded within these transmissions whose fidelity increased during communication both between and within layers when the number of tunnels are increased. We also provide evidence reinforcing the role of synchronized activity upon transmission fidelity during the spontaneous

  16. High-voltage integrated active quenching circuit for single photon count rate up to 80 Mcounts/s.

    PubMed

    Acconcia, Giulia; Rech, Ivan; Gulinatti, Angelo; Ghioni, Massimo

    2016-08-01

    Single photon avalanche diodes (SPADs) have been subject to a fast improvement in recent years. In particular, custom technologies specifically developed to fabricate SPAD devices give the designer the freedom to pursue the best detector performance required by applications. A significant breakthrough in this field is represented by the recent introduction of a red enhanced SPAD (RE-SPAD) technology, capable of attaining a good photon detection efficiency in the near infrared range (e.g. 40% at a wavelength of 800 nm) while maintaining a remarkable timing resolution of about 100ps full width at half maximum. Being planar, the RE-SPAD custom technology opened the way to the development of SPAD arrays particularly suited for demanding applications in the field of life sciences. However, to achieve such excellent performance custom SPAD detectors must be operated with an external active quenching circuit (AQC) designed on purpose. Next steps toward the development of compact and practical multichannel systems will require a new generation of monolithically integrated AQC arrays. In this paper we present a new, fully integrated AQC fabricated in a high-voltage 0.18 µm CMOS technology able to provide quenching pulses up to 50 Volts with fast leading and trailing edges. Although specifically designed for optimal operation of RE-SPAD devices, the new AQC is quite versatile: it can be used with any SPAD detector, regardless its fabrication technology, reaching remarkable count rates up to 80 Mcounts/s and generating a photon detection pulse with a timing jitter as low as 119 ps full width at half maximum. The compact design of our circuit has been specifically laid out to make this IC a suitable building block for monolithically integrated AQC arrays.

  17. Chandra and MMT observations of low-mass black hole active galactic nuclei accreting at low rates in dwarf galaxies

    SciTech Connect

    Yuan, W.; Zhou, H.; Dou, L.; Dong, X.-B.; Wang, T.-G.; Fan, X.

    2014-02-10

    We report on Chandra X-ray observations of four candidate low-mass black hole (M {sub bh} ≲ 10{sup 6} M {sub ☉}) active galactic nuclei (AGNs) that have the estimated Eddington ratios among the lowest (∼10{sup –2}) found for this class. The aims are to validate the nature of their AGNs and to confirm the low Eddington ratios that are derived from the broad Hα line, and to explore this poorly studied regime in the AGN parameter space. Among them, two objects with the lowest significance of the broad lines are also observed with the Multi-Mirror Telescope, and the high-quality optical spectra taken confirm them as Seyfert 1 AGNs and as having small black hole masses. X-ray emission is detected from the nuclei of two of the galaxies, which is variable on timescales of ∼10{sup 3} s, whereas no significant (or only marginal at best) detection is found for the remaining two. The X-ray luminosities are on the order of 10{sup 41} erg s{sup –1} or even lower, on the order of 10{sup 40} erg s{sup –1} for non-detections, which are among the lowest regimes ever probed for Seyfert galaxies. The low X-ray luminosities, compared to their black hole masses derived from Hα, confirm their low accretion rates assuming typical bolometric corrections. Our results hint at the existence of a possibly large population of under-luminous low-mass black holes in the local universe. An off-nucleus ultra-luminous X-ray source in one of the dwarf galaxies is detected serendipitously, with a luminosity (6-9)× 10{sup 39} erg s{sup –1} in 2-10 keV.

  18. Active immunization against the proregions of GDF9 or BMP15 alters ovulation rate and litter size in mice.

    PubMed

    McIntosh, C Joy; Lawrence, Steve; Smith, Peter; Juengel, Jennifer L; McNatty, Kenneth P

    2012-02-01

    The transforming growth factor β (TGFB) superfamily proteins bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), are essential for mammalian fertility. Recent in vitro evidence suggests that the proregions of mouse BMP15 and GDF9 interact with their mature proteins after secretion. In this study, we have actively immunized mice against these proregions to test the potential in vivo roles on fertility. Mice were immunized with either N- or C-terminus proregion peptides of BMP15 or GDF9, or a full-length GDF9 proregion protein, each conjugated to keyhole limpet hemocyanin (KLH). For each immunization group, ovaries were collected from ten mice for histology after immunization, while a further 20 mice were allowed to breed and litter sizes were counted. To link the ovulation and fertility data of these two experimental end points, mice were joined during the time period identified by histology as being the ovulatory period resulting in to the corpora lutea (CL) counted. Antibody titers in sera increased throughout the study period, with no cross-reactivity observed between BMP15 and GDF9 sera and antigens. Compared with KLH controls, mice immunized with the N-terminus BMP15 proregion peptide had ovaries with fewer CL (P<0.05) and produced smaller litters (P<0.05). In contrast, mice immunized with the full-length GDF9 proregion not only had more CL (P<0.01) but also had significantly smaller litter sizes (P<0.01). None of the treatments affected the number of antral follicles per ovary. These findings are consistent with the hypothesis that the proregions of BMP15 and GDF9, after secretion by the oocyte, have physiologically important roles in regulating ovulation rate and litter size in mice.

  19. High-voltage integrated active quenching circuit for single photon count rate up to 80 Mcounts/s.

    PubMed

    Acconcia, Giulia; Rech, Ivan; Gulinatti, Angelo; Ghioni, Massimo

    2016-08-01

    Single photon avalanche diodes (SPADs) have been subject to a fast improvement in recent years. In particular, custom technologies specifically developed to fabricate SPAD devices give the designer the freedom to pursue the best detector performance required by applications. A significant breakthrough in this field is represented by the recent introduction of a red enhanced SPAD (RE-SPAD) technology, capable of attaining a good photon detection efficiency in the near infrared range (e.g. 40% at a wavelength of 800 nm) while maintaining a remarkable timing resolution of about 100ps full width at half maximum. Being planar, the RE-SPAD custom technology opened the way to the development of SPAD arrays particularly suited for demanding applications in the field of life sciences. However, to achieve such excellent performance custom SPAD detectors must be operated with an external active quenching circuit (AQC) designed on purpose. Next steps toward the development of compact and practical multichannel systems will require a new generation of monolithically integrated AQC arrays. In this paper we present a new, fully integrated AQC fabricated in a high-voltage 0.18 µm CMOS technology able to provide quenching pulses up to 50 Volts with fast leading and trailing edges. Although specifically designed for optimal operation of RE-SPAD devices, the new AQC is quite versatile: it can be used with any SPAD detector, regardless its fabrication technology, reaching remarkable count rates up to 80 Mcounts/s and generating a photon detection pulse with a timing jitter as low as 119 ps full width at half maximum. The compact design of our circuit has been specifically laid out to make this IC a suitable building block for monolithically integrated AQC arrays. PMID:27505749

  20. Effect of calorie restriction on spontaneous physical activity and body mass in mice divergently selected for basal metabolic rate (BMR).

    PubMed

    Brzęk, Paweł; Gębczyński, Andrzej K; Książek, Aneta; Konarzewski, Marek

    2016-07-01

    Spontaneous physical activity (SPA) represents an important component of daily energy expenditures in animals and humans. Intra-specific variation in SPA may be related to the susceptibility to metabolic disease or obesity. In particular, reduced SPA under conditions of limited food availability may conserve energy and prevent loss of body and fat mass ('thrifty genotype hypothesis'). However, both SPA and its changes during food restriction show wide inter-individual variations. We studied the effect of 30% caloric restriction (CR) on SPA in laboratory mice divergently selected for high (H-BMR) and low (L-BMR) basal metabolic rate. Selection increased SPA in the H-BMR line but did not change it in the L-BMR mice. This effect reflected changes in SPA intensity but not SPA duration. CR increased SPA intensity more strongly in the L-BMR line than in the H-BMR line and significantly modified the temporal variation of SPA. However, the initial between-line differences in SPA were not affected by CR. Loss of body mass during CR did not differ between both lines. Our results show that the H-BMR mice can maintain their genetically determined high SPA under conditions of reduced food intake without sacrificing their body mass. We hypothesize that this pattern may reflect the higher flexibility in the energy budget in the H-BMR line, as we showed previously that mice from this line reduced their BMR during CR. These energy savings may allow for the maintenance of elevated SPA in spite of reduced food intake. We conclude that the effect of CR on SPA is in large part determined by the initial level of BMR, whose variation may account for the lack of universal pattern of behavioural responses to CR. PMID:27090226

  1. A Model of Blood Pressure, Heart Rate, and Vaso-Vagal Responses Produced by Vestibulo-Sympathetic Activation

    PubMed Central

    Raphan, Theodore; Cohen, Bernard; Xiang, Yongqing; Yakushin, Sergei B.

    2016-01-01

    Blood Pressure (BP), comprised of recurrent systoles and diastoles, is controlled by central mechanisms to maintain blood flow. Periodic behavior of BP was modeled to study how peak amplitudes and frequencies of the systoles are modulated by vestibular activation. The model was implemented as a relaxation oscillator, driven by a central signal related to Desired BP. Relaxation oscillations were maintained by a second order system comprising two integrators and a threshold element in the feedback loop. The output signal related to BP was generated as a nonlinear function of the derivative of the first state variable, which is a summation of an input related to Desired BP, feedback from the states, and an input from the vestibular system into one of the feedback loops. This nonlinear function was structured to best simulate the shapes of systoles and diastoles, the relationship between BP and Heart Rate (HR) as well as the amplitude modulations of BP and Pulse Pressure. Increases in threshold in one of the feedback loops produced lower frequencies of HR, but generated large pulse pressures to maintain orthostasis, without generating a VasoVagal Response (VVR). Pulse pressures were considerably smaller in the anesthetized rats than during the simulations, but simulated pulse pressures were lowered by including saturation in the feedback loop. Stochastic changes in threshold maintained the compensatory Baroreflex Sensitivity. Sudden decreases in Desired BP elicited non-compensatory VVRs with smaller pulse pressures, consistent with experimental data. The model suggests that the Vestibular Sympathetic Reflex (VSR) modulates BP and HR of an oscillating system by manipulating parameters of the baroreflex feedback and the signals that maintain the oscillations. It also shows that a VVR is generated when the vestibular input triggers a marked reduction in Desired BP. PMID:27065779

  2. Variation in the emission rate of sounds in a captive group of false killer whales Pseudorca crassidens during feedings: possible food anticipatory vocal activity?

    NASA Astrophysics Data System (ADS)

    Platto, Sara; Wang, Ding; Wang, Kexiong

    2016-11-01

    This study examines whether a group of captive false killer whales ( Pseudorca crassidens ) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World (Qingdao, China) showed significant variations of the rates of both the total sounds and sound classes (whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate (3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival (13.08 s/m/d). The high rate was maintained or intensified throughout the food delivery (25.12 s/m/d), and then reduced immediately after the animals were fed (9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.

  3. Variation in the emission rate of sounds in a captive group of false killer whales Pseudorca crassidens during feedings: possible food anticipatory vocal activity?

    NASA Astrophysics Data System (ADS)

    Platto, Sara; Wang, Ding; Wang, Kexiong

    2015-11-01

    This study examines whether a group of captive false killer whales (Pseudorca crassidens ) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World (Qingdao, China) showed significant variations of the rates of both the total sounds and sound classes (whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate (3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival (13.08 s/m/d). The high rate was maintained or intensified throughout the food delivery (25.12 s/m/d), and then reduced immediately after the animals were fed (9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.

  4. Using feedback control to actively regulate the healing rate of a self-healing process subjected to low cycle dynamic stress

    NASA Astrophysics Data System (ADS)

    Kuponu, O. S.; Kadirkamanathan, V.; Bhattacharya, B.; Pope, S. A.

    2016-05-01

    Intrinsic and extrinsic self-healing approaches through which materials can be healed generally suffer from several problems. One key problem is that to ensure effective healing and to minimise the propagation of a fault, the healing rate needs to be matched to the damage rate. This requirement is usually not met with passive approaches. An alternative to passive healing is active self-healing, whereby the healing mechanism and in particular the healing rate, is controlled in the face of uncertainty and varying conditions. Active self-healing takes advantage of sensing and added external energy to achieve a desired healing rate. To demonstrate active self-healing, an electrochemical material based on the principles of piezoelectricity and electrolysis is modelled and adaptive feedback control is implemented. The adaptive feedback control compensates for the insufficient piezo-induced voltage and guarantees a response that meets the desired healing rate. Importantly, fault propagation can be eliminated or minimised by attaining a match between the healing and damage rate quicker than can be achieved with the equivalent passive system. The desired healing rate is a function of the fault propagation and is assumed known in this paper, but can be estimated in practice through established prognostic techniques.

  5. The effect of current density and thickness of the active mass upon the corrosion rate of the spines of lead-acid battery plates

    NASA Astrophysics Data System (ADS)

    Rogatchev, T.; Papazov, G.; Pavlov, D.

    The effect of current density and the thickness of the active mass upon the corrosion of the spines of tubular lead-acid batteries has been determined by measuring the corrosion rate by the weight loss method. The presence of antimony in the alloy decreases the overvoltage of the corrosion reaction. Study of electrodes of different active mass layer thickness shows that with increase in thickness the corrosion rate decreases. If the thickness is above 3 mm, the corrosion rate remains constant, and is affected only by the nature of the alloy. The density of the active mass does not affect the corrosion behaviour of the electrodes. The experimental results confirm the validity of the oxygen corrosion model.

  6. Supermassive black holes with high accretion rates in active galactic nuclei. I. First results from a new reverberation mapping campaign

    SciTech Connect

    Du, Pu; Hu, Chen; Qiu, Jie; Li, Yan-Rong; Wang, Jian-Min; Lu, Kai-Xing; Wang, Fang; Bai, Jin-Ming; Kaspi, Shai; Netzer, Hagai; Collaboration: SEAMBH collaboration

    2014-02-10

    We report first results from a large project to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). Such objects may be different from other AGNs in being powered by slim accretion disks and showing saturated accretion luminosities, but both are not yet fully understood. The results are part of a large reverberation mapping (RM) campaign using the 2.4 m Shangri-La telescope at the Yunnan Observatory in China. The goals are to investigate the gas distribution near the BH and the properties of the central accretion disks, to measure BH mass and Eddington ratios, and to test the feasibility of using such objects as a new type of cosmological candles. The paper presents results for three objects, Mrk 335, Mrk 142, and IRAS F12397+3333, with Hβ time lags relative to the 5100 Å continuum of 10.6{sub −2.9}{sup +1.7}, 6.4{sub −2.2}{sup +0.8} and 11.4{sub −1.9}{sup +2.9} days, respectively. The corresponding BH masses are (8.3{sub −3.2}{sup +2.6})×10{sup 6} M{sub ⊙}, (3.4{sub −1.2}{sup +0.5})×10{sup 6} M{sub ⊙}, and (7.5{sub −4.1}{sup +4.3})×10{sup 6} M{sub ⊙}, and the lower limits on the Eddington ratios are 0.6, 2.3, and 4.6 for the minimal radiative efficiency of 0.038. Mrk 142 and IRAS F12397+333 (extinction corrected) clearly deviate from the currently known relation between Hβ lag and continuum luminosity. The three Eddington ratios are beyond the values expected in thin accretion disks and two of them are the largest measured so far among objects with RM-based BH masses. We briefly discuss implications for slim disks, BH growth, and cosmology.

  7. The Association between Baseline Subjective Anxiety Rating and Changes in Cardiac Autonomic Nervous Activity in Response to Tryptophan Depletion in Healthy Volunteers.

    PubMed

    Hsiao, Chih Yin; Tsai, Hsin Chun; Chi, Mei Hung; Chen, Kao Chin; Chen, Po See; Lee, I Hui; Yeh, Tzung Lieh; Yang, Yen Kuang

    2016-05-01

    The aim of this study was to investigate the influence of serotonin on anxiety and autonomic nervous system (ANS) function; the correlation between subjective anxiety rating and changes of ANS function following tryptophan depletion (TD) in healthy volunteers was examined. Twenty-eight healthy participants, consisting of 15 females and 13 males, with an average age of 33.3 years, were recruited.Baseline Chinese Symptom Checklist-90-Revised and ANS function measurements were taken. TD was carried out on the testing day, and participants provided blood samples right before and 5 hours after TD. ANS function, somatic symptoms, and Visual Analogue Scales (VASs) were determined after TD. Wilcoxon signed rank test and Spearman ρ correlation were adapted for analyses of the results.The TD procedure reduced total and free plasma tryptophan effectively. After TD, the sympathetic nervous activity increased and parasympathetic nervous activity decreased. Baseline anxiety ratings positively correlated with post-TD changes in sympathetic nervous activity, VAS ratings, and physical symptoms. However, a negative correlation with post-TD changes in parasympathetic nervous activity was found.The change in ANS function after TD was associated with the severity of anxiety in healthy volunteers. This supports the fact that the effect of anxiety on heart rate variability is related to serotonin vulnerability. Furthermore, it also shows that the subjective anxiety rating has a biological basis related to serotonin.

  8. The Association between Baseline Subjective Anxiety Rating and Changes in Cardiac Autonomic Nervous Activity in Response to Tryptophan Depletion in Healthy Volunteers.

    PubMed

    Hsiao, Chih Yin; Tsai, Hsin Chun; Chi, Mei Hung; Chen, Kao Chin; Chen, Po See; Lee, I Hui; Yeh, Tzung Lieh; Yang, Yen Kuang

    2016-05-01

    The aim of this study was to investigate the influence of serotonin on anxiety and autonomic nervous system (ANS) function; the correlation between subjective anxiety rating and changes of ANS function following tryptophan depletion (TD) in healthy volunteers was examined. Twenty-eight healthy participants, consisting of 15 females and 13 males, with an average age of 33.3 years, were recruited.Baseline Chinese Symptom Checklist-90-Revised and ANS function measurements were taken. TD was carried out on the testing day, and participants provided blood samples right before and 5 hours after TD. ANS function, somatic symptoms, and Visual Analogue Scales (VASs) were determined after TD. Wilcoxon signed rank test and Spearman ρ correlation were adapted for analyses of the results.The TD procedure reduced total and free plasma tryptophan effectively. After TD, the sympathetic nervous activity increased and parasympathetic nervous activity decreased. Baseline anxiety ratings positively correlated with post-TD changes in sympathetic nervous activity, VAS ratings, and physical symptoms. However, a negative correlation with post-TD changes in parasympathetic nervous activity was found.The change in ANS function after TD was associated with the severity of anxiety in healthy volunteers. This supports the fact that the effect of anxiety on heart rate variability is related to serotonin vulnerability. Furthermore, it also shows that the subjective anxiety rating has a biological basis related to serotonin. PMID:27175645

  9. The Association between Baseline Subjective Anxiety Rating and Changes in Cardiac Autonomic Nervous Activity in Response to Tryptophan Depletion in Healthy Volunteers

    PubMed Central

    Hsiao, Chih Yin; Tsai, Hsin Chun; Chi, Mei Hung; Chen, Kao Chin; Chen, Po See; Lee, I Hui; Yeh, Tzung Lieh; Yang, Yen Kuang

    2016-01-01

    Abstract The aim of this study was to investigate the influence of serotonin on anxiety and autonomic nervous system (ANS) function; the correlation between subjective anxiety rating and changes of ANS function following tryptophan depletion (TD) in healthy volunteers was examined. Twenty-eight healthy participants, consisting of 15 females and 13 males, with an average age of 33.3 years, were recruited. Baseline Chinese Symptom Checklist-90-Revised and ANS function measurements were taken. TD was carried out on the testing day, and participants provided blood samples right before and 5 hours after TD. ANS function, somatic symptoms, and Visual Analogue Scales (VASs) were determined after TD. Wilcoxon signed rank test and Spearman ρ correlation were adapted for analyses of the results. The TD procedure reduced total and free plasma tryptophan effectively. After TD, the sympathetic nervous activity increased and parasympathetic nervous activity decreased. Baseline anxiety ratings positively correlated with post-TD changes in sympathetic nervous activity, VAS ratings, and physical symptoms. However, a negative correlation with post-TD changes in parasympathetic nervous activity was found. The change in ANS function after TD was associated with the severity of anxiety in healthy volunteers. This supports the fact that the effect of anxiety on heart rate variability is related to serotonin vulnerability. Furthermore, it also shows that the subjective anxiety rating has a biological basis related to serotonin. PMID:27175645

  10. An extended equation for rate coefficients for adsorption of organic vapors and gases on activated carbons in air-purifying respirator cartridges.

    PubMed

    Wood, G O; Lodewyckx, P

    2003-01-01

    Organic vapor adsorption rates in air-purifying respirator cartridges (and other packed beds of activated carbon granules) need to be known for estimating service lives. The correlation of Lodewyckx and Vansant [AIHAJ 61:501-505 (2000)] for mass transfer coefficients for organic vapor adsorption onto activated carbon was tested with additional data from three sources. It was then extended to better describe all the data, including that for gases. The additional parameter that accomplished this was the square root of molar equilibrium capacity of the vapor or gas on the carbon. This change, along with skew corrections when appropriate, resulted in better correlations with all experimental rate coefficients. PMID:14521430

  11. Psychological affect at different ratings of perceived exertion in high- and low-active women: a study using a production protocol.

    PubMed

    Parfitt, G; Eston, R; Connolly, D

    1996-06-01

    The purpose of this study was to examine psychological affect at different ratings of perceived exertion (RPE) in 15 high- and 15 low-active women. Both groups performed three steady-state exercise bouts on a cycle ergometer at RPEs 9, 13, and 17 and reported their affect in the last 20 sec. of and 5 min. after each work rate. There were no differences between groups in percentage of maximal oxygen uptake (% VO2max) at each RPE. Low-active women reported feeling significantly more negative at RPE 17 than RPE 9 and less positive than the high-active women at RPEs 9, 13, and 17. In addition, all subjects reported more positive feelings 5 min. postexercise than in the last 20 sec. of exercising, especially at RPE 17. These results have implications for exercise prescription in groups differing in habitual activity levels. PMID:8774048

  12. Correlation between erythropoietic activity and body growth rate in hypertransfused polycythemic growing rats as the result of an erythropoietin-dependent operating mechanism

    SciTech Connect

    Bozzini, C.E.; Alippi, R.M.; Barcelo, A.C.; Caro, J.

    1989-02-01

    The established relationship between erythropoietic activity and body growth rate in the polycythemic growing rat could be the result of either an erythropoietin (EPO)-dependent or an EPO-independent operating mechanism. The present study was thus undertaken to elucidate the nature of the aforementioned mechanism by assessing the ratio between plasma immunoreactive EPO (iEPO) concentration and erythropoietic activity in young hypertransfused rats for different body growth rates. Red blood cell (RBC)-59Fe uptake was about 75% in 21-day-old rats; it rapidly decreased with time when the animals were placed on a protein-free diet, approaching a level of about 1% by the 10th day of protein starvation. Over the same period plasma iEPO decreased from 55 mU/ml to 7 mU/ml. Body growth rate was 0. Following this ''protein depletion period'' the rats received diets containing different amounts of casein (''protein repletion period'') added isocalorically to the protein-free diet to elicit a rise in body growth rate. Statistically significant relationships (p less than 0.001) were found between dietary casein concentration and body growth rate (r = 0.991), dietary casein concentration and RBC-59Fe uptake (r = 0.991), dietary casein concentration and plasma iEPO level (r = 0.992), body growth rate and RBC-59Fe (r = 0.986), and body growth rate and plasma iEPO level (r = 0.994) in hypertransfused polycythemic rats during the protein repletion period. These findings suggest that the correlation between erythropoietic activity and growth rate in the growing rat is the result of an erythropoietin-dependent operating mechanism, which appears to be independent of the ratio tissue oxygen supply/tissue oxygen demand.

  13. Predictors of the rate of change in disease activity over time in LUMINA, a multiethnic US cohort of patients with systemic lupus erythematosus: LUMINA LXX.

    PubMed

    Zhang, J; González, L A; Roseman, J M; Vilá, L M; Reveille, J D; Alárcon, G S

    2010-05-01

    The objectives of the present study were (1) to clarify and quantify the relationship between age and disease duration with the rate of change in disease activity over time in patients with systemic lupus erythematosus (SLE) and (2) to explore other possible factors associated with this rate of change. To this end, SLE patients from LUMINA were studied if they had at least three visits in which disease activity (Systemic Lupus Activity Measure-Revised [SLAM-R]) had been ascertained. Variables associated with the rate (slope) of change in disease activity (obtained by regressing the SLAM-R score against the length of time from diagnosis to visit date) were examined by univariable and multivariable analyses. Five hundred and forty two of the 632 patients had at least three SLAM-R score. In multivariable analyses, Whites exhibited the fastest decline in disease activity, Texan Hispanics exhibited the slowest, trailed by the African Americans. Longer disease duration and HLA-DRB1*1503 positivity were associated with a slower decline whereas a greater number of American College of Rheumatology criteria and abnormal laboratory parameters (white blood cell counts, hematocrit and serum creatinine) were associated with a faster decline. These findings complement existing knowledge on SLE disease activity and are potentially useful to clinicians managing these patients.

  14. Leucine Aminopeptidase, β-Glucosidase and Alkaline Phosphatase Activity Rates and Their Significance in Nutrient Cycles in Some Coastal Mediterranean Sites

    PubMed Central

    Caruso, Gabriella

    2010-01-01

    In aquatic microbial ecology, knowledge of the processes involved in the turnover of organic matter is of utmost importance to understand ecosystem functioning. Microorganisms are major players in the cycling of nutrients (nitrogen, phosphorus) and carbon, thanks to their enzymatic activities (leucine aminopeptidase, LAP, alkaline phosphatase, AP, and β-glucosidase, β-GLU) on organic polymers (proteins, organic phosphates and polysaccharides, respectively). Estimates of the decomposition rates of organic polymers are performed using fluorogenic compounds, whose hydrolysis rate allow us to obtain information on the “potential” metabolic activity of the prokaryotic community. This paper refers the enzyme patterns measured during recent oceanographic cruises performed in some coastal Mediterranean sites, not yet fully investigated in terms of microbial biogeochemical processes. Mean enzyme activity rates ranged from 5.24 to 5558.1 nM/h, from 12.68 to 244.73 nM/h and from 0.006 to 9.51 nM/h for LAP, AP and β-GLU, respectively. The highest LAP and AP activity rates were measured in the Gulf of Milazzo (Tyrrhenian Sea) and in the Straits of Messina, in association with the lowest bacterioplankton abundance; in contrast, the lowest ones were found in the northern Adriatic Sea. β-GLU was more active in the Straits of Messina. Activity rates were analysed in relation to the main environmental variables. Along the northern Adriatic coastal side affected by the Po river, significant inverse relationships linked LAP and AP with salinity, pointing out that fluvial inputs provided organic substrates for microbial metabolism. Both in the Gulf of Manfredonia and in the Straits of Messina, LAP and AP levels were inversely related with the concentration of nitrate and inorganic phosphorus, respectively. In the Gulf of Milazzo, high cell-specific AP measured in spite of phosphorus availability suggested the role of this enzyme not only in phosphorus, but also in carbon

  15. Leucine aminopeptidase, beta-glucosidase and alkaline phosphatase activity rates and their significance in nutrient cycles in some coastal Mediterranean sites.

    PubMed

    Caruso, Gabriella

    2010-01-01

    In aquatic microbial ecology, knowledge of the processes involved in the turnover of organic matter is of utmost importance to understand ecosystem functioning. Microorganisms are major players in the cycling of nutrients (nitrogen, phosphorus) and carbon, thanks to their enzymatic activities (leucine aminopeptidase, LAP, alkaline phosphatase, AP, and beta-glucosidase, beta-GLU) on organic polymers (proteins, organic phosphates and polysaccharides, respectively). Estimates of the decomposition rates of organic polymers are performed using fluorogenic compounds, whose hydrolysis rate allow us to obtain information on the "potential" metabolic activity of the prokaryotic community. This paper refers the enzyme patterns measured during recent oceanographic cruises performed in some coastal Mediterranean sites, not yet fully investigated in terms of microbial biogeochemical processes. Mean enzyme activity rates ranged from 5.24 to 5558.1 nM/h, from 12.68 to 244.73 nM/h and from 0.006 to 9.51 nM/h for LAP, AP and beta-GLU, respectively. The highest LAP and AP activity rates were measured in the Gulf of Milazzo (Tyrrhenian Sea) and in the Straits of Messina, in association with the lowest bacterioplankton abundance; in contrast, the lowest ones were found in the northern Adriatic Sea. beta-GLU was more active in the Straits of Messina. Activity rates were analysed in relation to the main environmental variables. Along the northern Adriatic coastal side affected by the Po river, significant inverse relationships linked LAP and AP with salinity, pointing out that fluvial inputs provided organic substrates for microbial metabolism. Both in the Gulf of Manfredonia and in the Straits of Messina, LAP and AP levels were inversely related with the concentration of nitrate and inorganic phosphorus, respectively. In the Gulf of Milazzo, high cell-specific AP measured in spite of phosphorus availability suggested the role of this enzyme not only in phosphorus, but also in carbon

  16. Leucine aminopeptidase, beta-glucosidase and alkaline phosphatase activity rates and their significance in nutrient cycles in some coastal Mediterranean sites.

    PubMed

    Caruso, Gabriella

    2010-03-29

    In aquatic microbial ecology, knowledge of the processes involved in the turnover of organic matter is of utmost importance to understand ecosystem functioning. Microorganisms are major players in the cycling of nutrients (nitrogen, phosphorus) and carbon, thanks to their enzymatic activities (leucine aminopeptidase, LAP, alkaline phosphatase, AP, and beta-glucosidase, beta-GLU) on organic polymers (proteins, organic phosphates and polysaccharides, respectively). Estimates of the decomposition rates of organic polymers are performed using fluorogenic compounds, whose hydrolysis rate allow us to obtain information on the "potential" metabolic activity of the prokaryotic community. This paper refers the enzyme patterns measured during recent oceanographic cruises performed in some coastal Mediterranean sites, not yet fully investigated in terms of microbial biogeochemical processes. Mean enzyme activity rates ranged from 5.24 to 5558.1 nM/h, from 12.68 to 244.73 nM/h and from 0.006 to 9.51 nM/h for LAP, AP and beta-GLU, respectively. The highest LAP and AP activity rates were measured in the Gulf of Milazzo (Tyrrhenian Sea) and in the Straits of Messina, in association with the lowest bacterioplankton abundance; in contrast, the lowest ones were found in the northern Adriatic Sea. beta-GLU was more active in the Straits of Messina. Activity rates were analysed in relation to the main environmental variables. Along the northern Adriatic coastal side affected by the Po river, significant inverse relationships linked LAP and AP with salinity, pointing out that fluvial inputs provided organic substrates for microbial metabolism. Both in the Gulf of Manfredonia and in the Straits of Messina, LAP and AP levels were inversely related with the concentration of nitrate and inorganic phosphorus, respectively. In the Gulf of Milazzo, high cell-specific AP measured in spite of phosphorus availability suggested the role of this enzyme not only in phosphorus, but also in carbon

  17. Hydroxychloroquine reduces heart rate by modulating the hyperpolarization-activated current If: Novel electrophysiological insights and therapeutic potential

    PubMed Central

    Capel, Rebecca A.; Herring, Neil; Kalla, Manish; Yavari, Arash; Mirams, Gary R.; Douglas, Gillian; Bub, Gil; Channon, Keith; Paterson, David J.; Terrar, Derek A.; Burton, Rebecca-Ann B.

    2015-01-01

    Background Bradycardic agents are of interest for the treatment of ischemic heart disease and heart failure, as heart rate is an important determinant of myocardial oxygen consumption. Objectives The purpose of this study was to investigate the propensity of hydroxychloroquine (HCQ) to cause bradycardia. Methods We assessed the effects of HCQ on (1) cardiac beating rate in vitro (mice); (2) the “funny” current (If) in isolated guinea pig sinoatrial node (SAN) myocytes (1, 3, 10 µM); (3) heart rate and blood pressure in vivo by acute bolus injection (rat, dose range 1–30 mg/kg), (4) blood pressure and ventricular function during feeding (mouse, 100 mg/kg/d for 2 wk, tail cuff plethysmography, anesthetized echocardiography). Results In mouse atria, spontaneous beating rate was significantly (P < .05) reduced (by 9% ± 3% and 15% ± 2% at 3 and 10 µM HCQ, n = 7). In guinea pig isolated SAN cells, HCQ conferred a significant reduction in spontaneous action potential firing rate (17% ± 6%, 1 μM dose) and a dose-dependent reduction in If (13% ± 3% at 1 µM; 19% ± 2% at 3 µM). Effects were also observed on L-type calcium ion current (ICaL) (12% ± 4% reduction) and rapid delayed rectifier potassium current (IKr) (35% ± 4%) at 3 µM. Intravenous HCQ decreased heart rate in anesthetized rats (14.3% ± 1.1% at 15mg/kg; n = 6) without significantly reducing mean arterial blood pressure. In vivo feeding studies in mice showed no significant change in systolic blood pressure nor left ventricular function. Conclusions We have shown that HCQ acts as a bradycardic agent in SAN cells, in atrial preparations, and in vivo. HCQ slows the rate of spontaneous action potential firing in the SAN through multichannel inhibition, including that of If. PMID:26025323

  18. Surface activation of polyethylene with an argon atmospheric pressure plasma jet: Influence of applied power and flow rate

    NASA Astrophysics Data System (ADS)

    Van Deynse, A.; Cools, P.; Leys, C.; De Geyter, N.; Morent, R.

    2015-02-01

    Atmospheric pressure plasma technology offers attractive perspectives to alter the surface properties of polymers. Within this context, the surface modification of polyethylene (LDPE) by an argon atmospheric pressure plasma jet (APPJ) is profoundly investigated in this work. The influence of two different parameters (applied power and argon flow rate) on the plasma jet characteristics and the LDPE surface properties is examined in detail. In a first step, the APPJ is electrically and visually characterized and visual inspection of the afterglow clearly shows that mainly a variation in argon flow rate can result in a changing afterglow length. A maximum afterglow length is obtained at an argon flow rate of 1-1.25 slm, while higher gas flows result in turbulence leading to a shorter afterglow. Secondly, the surface modification of LDPE is examined using different analyzing techniques namely water contact angle (WCA) measurements for the wettability, X-ray photoelectron spectroscopy (XPS) for the chemical composition and atomic force microscopy (AFM) for the surface morphology determination. WCA measurements show that by increasing the applied power the wettability of the LDPE increases. Increasing the argon flow rate up to 1.25 slm gives a decrease in WCA value or in other words an increased wettability. From 1.25 slm on, an increase in argon flow rate during plasma treatment decreases the LDPE wettability as can be concluded from the increased WCA values. An increased wettability can be explained by the incorporation of oxygen moieties. By increasing the discharge power, the concentrations of all oxygen containing groups such as Csbnd O, Cdbnd O and Osbnd Cdbnd O increase. Increasing the flow rate up to 1.25 slm results mainly in an increase in Osbnd Cdbnd O groups. However, from a flow rate of 1.25 slm on, the concentration of all oxygen groups again decreases. Based on these results, the appropriate settings for an efficient plasma treatment can easily be selected.

  19. [Heart rate variability of subjects when the instruction reading and their interrelations with the effectiveness of the follow-visual-motor activities].

    PubMed

    Murtazina, E P

    2015-01-01

    Investigation of the processes of studying human instructions relevant follow-up in terms of systemic mechanisms of learning and memory processes, and moreover affects such a fundamental issue as psychophysiology focused attention, understanding the meaning of the information provided and the formation of social motivation in human activities. Analysis of heart rate variability in reading the instructions compared to the initial state of operational rest showed that this stage of the activity causes pronounced emotional stress, which is manifested in increased heart rate, decrease in variability and pronounced changes in the spectral characteristics of heart rate. Besides, it was revealed that heart rate variability in a state of operational rest before testing, and in the process of reading instructions positively correlated with the duration of the instruction reading and inversely correlated with effectiveness and the level of resistance of the subjects to the error after error when follow-up activities. Showing pronounced gender differences in the relationships between changes in the variability of heart rate when reading the instructions and the subsequent execution indicators of visual-motor test.

  20. Acute effects of advertisements on children's choices, preferences, and ratings of liking for physical activities and sedentary behaviours: a randomised controlled pilot study.

    PubMed

    Atlantis, Evan; Salmon, Jo; Bauman, Adrian

    2008-11-01

    The acute decision prompting effects of social marketing via television (TV) advertisements promoting physical activity to children are unknown. This pilot study aimed to determine the acute effects of an Australian government-sponsored TV advertisement (called 'Get Moving'), promoting more physical activity and less sedentary behaviour, on children's choices, preferences, and ratings of liking for physical activities and sedentary behaviours. Thirty-one children aged 10-12 years were recruited from a single public school, and randomised to one of two treatment groups or two control groups (Solomon four-group design). Treatment participants watched an episode of The Simpsons embedded every 10min with three 30s Get Moving advertisements plus standard advertisements. Control participants watched the same episode plus standard advertisements, but without the Get Moving advertisements. The following dependent variables were assessed immediately before and/or after exposure: activity preference (participants selected either verbally or by pointing to one of eight picture cards depicting four physical activities and four sedentary behaviours); ratings of liking (participants rated how much they liked or disliked each of these activities/behaviours either verbally or by pointing to one of nine values with an adjacent smile or frown on a Likert-type scale); and time spent in physical activities was assessed by direct observation during a 10min free-time session. No significant effects or trends were seen for any of the dependent variables. Further research is needed to determine whether different content and/or higher doses of exposure to physical activity promoting advertisements are needed to influence children's activity choices. PMID:17928265

  1. An Illustration of a Methodology to Maximize Mail Survey Response Rates in a Provincial School-Based Physical Activity Needs Assessment

    ERIC Educational Resources Information Center

    Dwyer, John J. M.; Allison, Kenneth R.; Lysy, Daria C.; LeMoine, Karen N.; Adlaf, Edward M.; Faulkner, Guy E. J.; Goodman, Jack

    2009-01-01

    Two mail surveys were conducted as a province-wide needs assessment to examine the opportunities for, barriers to, and participation in physical activity in Ontario elementary and secondary schools. Dillman's Tailored Design Method (TDM) was used to maximize the quality of responses and the response rate. Both surveys entailed five mailings to key…

  2. Heart rate, body temperature and physical activity are variously affected during insulin treatment in alloxan-induced type 1 diabetic rat.

    PubMed

    Howarth, F C; Jacobson, M; Shafiullah, M; Ljubisavljevic, M; Adeghate, E

    2011-01-01

    Diabetes mellitus is associated with a variety of cardiovascular complications including impaired cardiac muscle function. The effects of insulin treatment on heart rate, body temperature and physical activity in the alloxan (ALX)-induced diabetic rat were investigated using in vivo biotelemetry techniques. The electrocardiogram, physical activity and body temperature were recorded in vivo with a biotelemetry system for 10 days before ALX treatment, for 20 days following administration of ALX (120 mg/kg) and thereafter, for 15 days whilst rats received daily insulin. Heart rate declined rapidly after administration of ALX. Pre-ALX heart rate was 321+/-9 beats per minute, falling to 285+/-12 beats per minute 15-20 days after ALX and recovering to 331+/-10 beats per minute 5-10 days after commencement of insulin. Heart rate variability declined and PQ, QRS and QT intervals were prolonged after administration of ALX. Physical activity and body temperature declined after administration of ALX. Pre-ALX body temperature was 37.6+/-0.1 °C, falling to 37.3+/-0.1 °C 15-20 days after ALX and recovering to 37.8+/-0.1 °C 5-10 days after commencement insulin. ALX-induced diabetes is associated with disturbances in heart rhythm, physical activity and body temperature that are variously affected during insulin treatment.

  3. Comparison of Heart Rate Response to Tennis Activity between Persons with and without Spinal Cord Injuries: Implications for a Training Threshold

    ERIC Educational Resources Information Center

    Barfield, J. P.; Malone, Laurie A.; Coleman, Tristica A.

    2009-01-01

    The purpose of this study was to evaluate the ability of individuals with spinal cord injury (SCI) to reach a training threshold during on-court sport activity. Monitors collected heart rate (HR) data every 5 s for 11 wheelchair tennis players (WCT) with low paraplegia and 11 able-bodied controls matched on experience and skill level (ABT).…

  4. The Relationship between Situational and Contextual Self-Determined Motivation and Physical Activity Intensity as Measured by Heart Rates during Ninth Grade Students' Physical Education Classes

    ERIC Educational Resources Information Center

    Jaakkola, Timo; Liukkonen, Jarmo; Laakso, Timo; Ommundsen, Yngvar

    2008-01-01

    The aim of the study was to investigate the relationships between situational and contextual self-determined motivation and physical activity intensity as measured by heart rates during a ninth-grade students' physical education (PE) class. The participants of the study were 139 Finnish ninth-grade students (15-year-olds). The data were collected…

  5. Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22

    NASA Astrophysics Data System (ADS)

    Silva, H. G.; Lopes, I.

    2016-07-01

    Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

  6. Decreased rate of protein synthesis, caspase-3 activity, and ubiquitin-proteasome proteolysis in soleus muscles from growing rats fed a low-protein, high-carbohydrate diet.

    PubMed

    Batistela, Emanuele; Pereira, Mayara Peron; Siqueira, Juliany Torres; Paula-Gomes, Silvia; Zanon, Neusa Maria; Oliveira, Eduardo Brandt; Navegantes, Luiz Carlos Carvalho; Kettelhut, Isis C; Andrade, Claudia Marlise Balbinotti; Kawashita, Nair Honda; Baviera, Amanda Martins

    2014-06-01

    The aim of this study was to investigate the changes in the rates of both protein synthesis and breakdown, and the activation of intracellular effectors that control these processes in soleus muscles from growing rats fed a low-protein, high-carbohydrate (LPHC) diet for 15 days. The mass and the protein content, as well as the rate of protein synthesis, were decreased in the soleus from LPHC-fed rats. The availability of amino acids was diminished, since the levels of various essential amino acids were decreased in the plasma of LPHC-fed rats. Overall rate of proteolysis was also decreased, explained by reductions in the mRNA levels of atrogin-1 and MuRF-1, ubiquitin conjugates, proteasome activity, and in the activity of caspase-3. Soleus muscles from LPHC-fed rats showed increased insulin sensitivity, with increased levels of insulin receptor and phosphorylation levels of AKT, which probably explains the inhibition of both the caspase-3 activity and the ubiquitin-proteasome system. The fall of muscle proteolysis seems to represent an adaptive response that contributes to spare proteins in a condition of diminished availability of dietary amino acids. Furthermore, the decreased rate of protein synthesis may be the driving factor to the lower muscle mass gain in growing rats fed the LPHC diet.

  7. Quantification of pulmonary thallium-201 activity after upright exercise in normal persons: importance of peak heart rate and propranolol usage in defining normal values

    SciTech Connect

    Brown, K.A.; Boucher, C.A.; Okada, R.D.; Strauss, H.W.; Pohost, G.M.

    1984-06-01

    Fifty-nine normal patients (34 angiographically normal and 25 clinically normal by Bayesian analysis) underwent thallium-201 imaging after maximal upright exercise. Lung activity was quantitated relative to myocardial activity and a lung/myocardial activity ratio was determined for each patient. Stepwise regression analysis was then used to examine the influence of patient clinical characteristics and exercise variables on the lung/myocardium ratio. Peak heart rate during exercise and propranolol usage both showed significant negative regression coefficients (p less than 0.001). No other patient data showed a significant relation. Using the regression equation and the estimated variance, a 95% confidence level upper limit of normal could be determined for a give peak heart rate and propranolol status. Sixty-one other patients were studied to validate the predicted upper limits of normal based on this model. None of the 27 patients without coronary artery disease had an elevated lung/myocardial ratio, compared with 1 of 8 with 1-vessel disease (difference not significant), 6 of 14 with 2-vessel disease (p less than 0.005), and 6 of 12 with 3-vessel disease (p less than 0.0001). Thus, lung activity on upright exercise thallium-201 studies can be quantitated relative to myocardial activity, and is inversely related to peak heart rate and propranolol use. Use of a regression analysis allows determination of a 95% confidence upper limit of normal to be anticipated in an individual patient.

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

    ERIC Educational Resources Information Center

    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…

  9. Dutch Young Adults Ratings of Behavior Change Techniques Applied in Mobile Phone Apps to Promote Physical Activity: A Cross-Sectional Survey

    PubMed Central

    Belmon, Laura S; te Velde, Saskia J; Brug, Johannes

    2015-01-01

    Background Interventions delivered through new device technology, including mobile phone apps, appear to be an effective method to reach young adults. Previous research indicates that self-efficacy and social support for physical activity and self-regulation behavior change techniques (BCT), such as goal setting, feedback, and self-monitoring, are important for promoting physical activity; however, little is known about evaluations by the target population of BCTs applied to physical activity apps and whether these preferences are associated with individual personality characteristics. Objective This study aimed to explore young adults’ opinions regarding BCTs (including self-regulation techniques) applied in mobile phone physical activity apps, and to examine associations between personality characteristics and ratings of BCTs applied in physical activity apps. Methods We conducted a cross-sectional online survey among healthy 18 to 30-year-old adults (N=179). Data on participants’ gender, age, height, weight, current education level, living situation, mobile phone use, personality traits, exercise self-efficacy, exercise self-identity, total physical activity level, and whether participants met Dutch physical activity guidelines were collected. Items for rating BCTs applied in physical activity apps were selected from a hierarchical taxonomy for BCTs, and were clustered into three BCT categories according to factor analysis: “goal setting and goal reviewing,” “feedback and self-monitoring,” and “social support and social comparison.” Results Most participants were female (n=146), highly educated (n=169), physically active, and had high levels of self-efficacy. In general, we observed high ratings of BCTs aimed to increase “goal setting and goal reviewing” and “feedback and self-monitoring,” but not for BCTs addressing “social support and social comparison.” Only 3 (out of 16 tested) significant associations between personality

  10. Computer Simulation Model for the Biosynthesis of Galactosyldiacylglycerols and Fatty Acid Desaturation in Plants (Determination of Rates of Desaturase Activity in Monogalactosyldiacylglycerol).

    PubMed Central

    Williams, J. P.; Khan, M. U.; Wong, D.

    1993-01-01

    The level of unsaturation of the constituent fatty acids of many glycerolipids in plant membranes is modified by environmental factors. The measurement of the rate of the desaturation of these fatty acids is essential to an understanding of how plants adapt to changing environments. This is difficult because of the complexity of the system and the problems involved in measuring rates of these enzyme reactions in cell-free preparations. A computer program has been developed that simulates the synthesis of galactosyldiacylglycerols and desaturation of their fatty acids in chloroplasts. The program uses the rate of incorporation and distribution of 14C in fatty acids after 14CO2 feeding to estimate rates of desaturation in the fatty acids of glycerolipids. Data are presented to demonstrate the use of the program in comparing rates of desaturation in the five enzyme reactions associated with monogalactosyldiacylglycerol in the chloroplastic pathway of leaves from Brassica napus. The method represents a quick, reliable, and accurate measure of desaturase activity in vivo and is the only method available to estimate desaturase activity of all five enzymes at the same time. PMID:12231750

  11. An orally active adenosine A1 receptor antagonist, FK838, increases renal excretion and maintains glomerular filtration rate in furosemide-resistant rats

    PubMed Central

    Schnackenberg, Christine G; Merz, Emily; Brooks, David P

    2003-01-01

    Loop and thiazide diuretics are common therapeutic agents for the treatment of sodium retention and oedema. However, resistance to diuretics and decreases in renal function can develop during diuretic therapy. Adenosine causes renal vasoconstriction, sodium reabsorption, and participates in the tubuloglomerular feedback mechanism for the regulation of glomerular filtration rate.We tested the hypothesis that the selective adenosine A1 receptor antagonist FK838 is orally active and causes diuresis and natriuresis, but maintains glomerular filtration rate in normal rats or in rats with furosemide resistance.In normal male Sprague – Dawley rats, FK838 dose-dependently increased urine flow and sodium and chloride excretion while sparing potassium. In combination with furosemide, FK838 enhanced the diuretic and natriuretic actions of furosemide to the same extent as hydrochlorothiazide and did not increase the potassium loss in normal rats. In furosemide-resistant rats, FK838 increased urine flow and electrolyte excretion to a greater extent than hydrochlorothiazide. In addition, hydrochlorothiazide significantly decreased glomerular filtration rate, whereas FK838 maintained glomerular filtration rate in furosemide-resistant rats.This study shows that the adenosine A1 receptor antagonist FK838 is orally active and causes potent diuresis and natriuresis and maintains glomerular filtration rate in normal or furosemide-resistant rats. Adenosine A1 receptor antagonists may be novel therapeutics for the treatment of oedema in normal or otherwise diuretic-resistant patients. PMID:12922924

  12. Aerobic N2O emission for activated sludge acclimated under different aeration rates in the multiple anoxic and aerobic process.

    PubMed

    Wang, Huoqing; Guan, Yuntao; Pan, Min; Wu, Guangxue

    2016-05-01

    Nitrous oxide (N2O) is a potent greenhouse gas that can be emitted during biological nitrogen removal. N2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600mL/min sequencing batch reactor (SBRL) and 1200mL/min (SBRH). The nitrogen removal percentage was 89% in SBRL and 71% in SBRH, respectively. N2O emission mainly occurred during the aerobic phase, and the N2O emission factor was 10.1% in SBRL and 2.3% in SBRH, respectively. In all batch experiments, the N2O emission potential was high in SBRL compared with SBRH. In SBRL, with increasing aeration rates, the N2O emission factor decreased during nitrification, while it increased during denitrification and simultaneous nitrification and denitrification (SND). By contrast, in SBRH the N2O emission factor during nitrification, denitrification and SND was relatively low and changed little with increasing aeration rates. The microbial competition affected the N2O emission during biological nitrogen removal.

  13. Aerobic N2O emission for activated sludge acclimated under different aeration rates in the multiple anoxic and aerobic process.

    PubMed

    Wang, Huoqing; Guan, Yuntao; Pan, Min; Wu, Guangxue

    2016-05-01

    Nitrous oxide (N2O) is a potent greenhouse gas that can be emitted during biological nitrogen removal. N2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600mL/min sequencing batch reactor (SBRL) and 1200mL/min (SBRH). The nitrogen removal percentage was 89% in SBRL and 71% in SBRH, respectively. N2O emission mainly occurred during the aerobic phase, and the N2O emission factor was 10.1% in SBRL and 2.3% in SBRH, respectively. In all batch experiments, the N2O emission potential was high in SBRL compared with SBRH. In SBRL, with increasing aeration rates, the N2O emission factor decreased during nitrification, while it increased during denitrification and simultaneous nitrification and denitrification (SND). By contrast, in SBRH the N2O emission factor during nitrification, denitrification and SND was relatively low and changed little with increasing aeration rates. The microbial competition affected the N2O emission during biological nitrogen removal. PMID:27155411

  14. Decreased food intake rather than zinc deficiency is associated with changes in plasma leptin, metabolic rate, and activity levels in zinc deficient rats( small star, filled).

    PubMed

    Gaetke, Lisa M.; Frederich, Robert C.; Oz, Helieh S.; McClain, Craig J.

    2002-04-01

    This study investigated the hypothesis that the reduced food intake and poor weight gain in zinc deficient rats is due to: increased plasma leptin concentration, increased physical activity and/or increased metabolic rate. Weanling rats were assigned to three groups: controls fed ad libitum (C), zinc deficient (ZD), and pair-fed controls (PF), and tested in a metabolic chamber and activity monitor at baseline and weekly for four weeks. At the end of the study, all groups were compared for differences in plasma leptin concentrations. ZD and PF animals had markedly reduced food intake and weight gain. ZD had reduced stereotypic and locomotor activity compared to PF animals and both groups demonstrated an abolished peri-nocturnal activity spike and were much less active than controls. This was associated with a reduced total metabolic rate by day 30: ZD (0.73 +/- 0.07 kcal/hr, p = 0.0001) and PF (0.83 +/- 0.06 kcal/hr, p = 0.0001) groups vs. controls (1.82 +/- 0.09 kcal/hr). Plasma leptin concentrations in ZD (1.55 +/- 0.06 &mgr;g/L) were lower than controls (2.01 +/- 0.18 &mgr;g/L, p < 0.03), but neither ZD nor controls were statistically different from PF (1.68 +/- 0.05 &mgr;g/L). Both low leptin concentrations and low metabolic rates in the ZD and PF rats were associated with decreased food intake rather than zinc deficiency. The reduced food intake and poor weight gain observed in zinc deficient rats could not be explained by elevated leptin concentrations, hypermetabolism, or increased activity. Low serum leptin concentrations, hypometabolism, and decreased activity are more likely the result of the anorexia of zinc deficiency.

  15. [Effects of different application rates of calcium cyanamide on soil microbial biomass and enzyme activity in cucumber continuous cropping].

    PubMed

    Zhang, Xue-peng; Ning, Tang-yuan; Yang, Yan; Sun, Tao; Zhang, Shu-min; Wang, Bin

    2015-10-01

    A 2-year field experiment was conducted to study the effects of CaCN2 combined with cucumber straw retention on soil microbial biomass carbon (SMBC) , soil microbial biomass nitrogen (SMBN) and soil enzyme activities under cucumber continuous cropping system. Four treatments were used in this study as follows: CK (null CaCN2), CaCN2-90 (1350 kg CaCN2 . hm-2) CaCN2-60 (900 kg CaCN2 . hm-2), CaCN2-30 (450 kg CaCN2 . hm-2). The results indicated that, compared with the other treatments, CaCN2-90 treatment significantly decreased SMBC in 0-10 cm soil layer at seedling stage, but increased SMBC in 0-20 cm soil layer after early-fruit stage. Compared with CK, CaCN2 increased SMBC in 0-20 cm soil layer at late-fruit stage, and increased SMBN in 0-10 cm soil layer at mid- and late-fruit stages, however there was no significant trend among CaCN2 treatments in the first year (2012), while in the second year (2013) SMBN increased with the increasing CaCN2 amount after mid-fruit stage. CaCN2 increased straw decaying and nutrients releasing, and also increased soil organic matter. Furthermore, the CaCN2-90 could accelerate straw decomposition. Compared with CK, CaCN2 effectively increased soil urease, catalase and polyphenol oxidase activity. The soil urease activity increased while the polyphenol oxidase activity decreased with the increase of CaCN2, and CaCN2-60 could significantly improve catalase activity. Soil organic matter, urease activity and catalase activity had significant positive correlations with SMBC and SMBN. However, polyphenol oxidase activity was negatively correlated to SMBC and SMBN. Our findings indicated that CaCN2 application at 900 kg . hm-2 combined with cucumber straw retention could effectively improve soil environment, alleviating the soil obstacles under the cucumber continuous cropping system. PMID:26995916

  16. Role of Exchange Protein Activated by cAMP 1 in Regulating Rates of Microtubule Formation in Cystic Fibrosis Epithelial Cells.

    PubMed

    Rymut, Sharon M; Ivy, Tracy; Corey, Deborah A; Cotton, Calvin U; Burgess, James D; Kelley, Thomas J

    2015-12-01

    The regulation of microtubule dynamics in cystic fibrosis (CF) epithelial cells and the consequences of reduced rates of microtubule polymerization on downstream CF cellular events, such as cholesterol accumulation, a marker of impaired intracellular transport, are explored here. It is identified that microtubules in both CF cell models and in primary CF nasal epithelial cells repolymerize at a slower rate compared with respective controls. Previous studies suggest a role for cAMP in modulating organelle transport in CF cells, implicating a role for exchange protein activated by cAMP (EPAC) 1, a regulator of microtubule elongation, as a potential mechanism. EPAC1 activity is reduced in CF cell models and in Cftr(-/-) mouse lung compared with respective non-CF controls. Stimulation of EPAC1 activity with the selective EPAC1 agonist, 8-cpt-2-O-Me-cAMP, stimulates microtubule repolymerization to wild-type rates in CF cells. EPAC1 activation also alleviates cholesterol accumulation in CF cells, suggesting a direct link between microtubule regulation and intracellular transport. To verify the relationship between transport and microtubule regulation, expression of the protein, tubulin polymerization-promoting protein, was knocked down in non-CF human tracheal (9/HTEo(-)) cells to mimic the microtubule dysregulation in CF cells. Transduced cells with short hairpin RNA targeting tubulin polymerization-promoting protein exhibit CF-like perinuclear cholesterol accumulation and other cellular manifestations of CF cells, thus supporting a role for microtubule regulation as a mechanism linking CFTR function to downstream cellular manifestation.

  17. Aminopeptidase activity in seminal plasma and effect of dilution rate on rabbit reproductive performance after insemination with an extender supplemented with buserelin acetate.

    PubMed

    Viudes-de-Castro, M P; Mocé, E; Lavara, R; Marco-Jiménez, F; Vicente, J S

    2014-06-01

    Ovulation induction in artificially inseminated rabbits by adding GnRH synthetic analogues in the seminal doses is a welfare-orientated method to induce ovulation in rabbits and could have some advantages in field practice. This study was conducted to determine the effect of male genotype on the aminopeptidase activity in rabbit seminal plasma and the effects of dilution rate of semen on availability and reproductive performance when buserelin acetate is added to the seminal dose. To study the aminopeptidase activity, 12 mature bucks belonging to a paternal line and 12 from a maternal line were used. The bucks from the paternal line were used to study the effect of dilution rate on the availability of buserelin acetate after 2 hours of dilution and on the reproductive performance of the doses after artificial insemination of 389 commercial crossbreed does. Aminopeptidase activity in seminal plasma is dependent on the male genotype. The paternal line resulted 27% more aminopeptidase activity than the maternal line (P < 0.05). On the other hand, semen diluted 1:20 exhibited a marked increase in the availability of buserelin acetate and the fertility in this group was significantly higher than females from dilution rate 1:5 group, which showed similar results to that of the negative control group (does inseminated with semen diluted 1:20 in non-GnRH-supplemented extender). We conclude that the bioavailability of buserelin acetate when added to the seminal dose appears to be determined by the activity of the existing aminopeptidases and is consequently affected by the dilution rate used to prepare the artificial insemination doses.

  18. Effect of sire on mu- and m-calpain activity and rate of tenderization as indicated by myofibril fragmentation indices of steaks from Brahman cattle.

    PubMed

    Riley, D G; Chase, C C; Pringle, T D; West, R L; Johnson, D D; Olson, T A; Hammond, A C; Coleman, S W

    2003-10-01

    The objectives of this study were to assess the influence of sire on mu- and m-calpain activities, to evaluate the relationships of activities