How Much Energy Can Be Stored in Solar Active Region Magnetic Fields?

NASA Astrophysics Data System (ADS)

Linker, J.; Downs, C.; Torok, T.; Titov, V. S.; Lionello, R.; Mikic, Z.; Riley, P.

2015-12-01

Major solar eruptions such as X-class flares and very fast coronal mass ejections usually originate in active regions on the Sun. The energy that powers these events is believed to be stored as free magnetic energy (energy above the potential field state) prior to eruption. While coronal magnetic fields are not in general force-free, active regions have very strong magnetic fields and at low coronal heights the plasma beta is therefore very small, making the field (in equilibrium) essentially force-free. The Aly-Sturrock theorem shows that the energy of a fully force-free field cannot exceed the energy of the so-called open field. If the theorem holds, this places an upper limit on the amount of free energy that can be stored: the maximum free energy (MFE) is the difference between the open field energy and the potential field energy of the active region. In thermodynamic MHD simulations of a major eruption (the July 14, 2000 'Bastille' day event) and a modest event (February 13, 2009, we have found that the MFE indeed bounds the energy stored prior to eruption. We compute the MFE for major eruptive events in cycles 23 and 24 to investigate the maximum amount of energy that can be stored in solar active regions.Research supported by AFOSR, NASA, and NSF.

The aircraft energy efficiency active controls technology program

NASA Technical Reports Server (NTRS)

Hood, R. V., Jr.

1977-01-01

Broad outlines of the NASA Aircraft Energy Efficiency Program for expediting the application of active controls technology to civil transport aircraft are presented. Advances in propulsion and airframe technology to cut down on fuel consumption and fuel costs, a program for an energy-efficient transport, and integrated analysis and design technology in aerodynamics, structures, and active controls are envisaged. Fault-tolerant computer systems and fault-tolerant flight control system architectures are under study. Contracts with leading manufacturers for research and development work on wing-tip extensions and winglets for the B-747, a wing load alleviation system, elastic mode suppression, maneuver-load control, and gust alleviation are mentioned.

Effective moisture diffusivity and activation energy of rambutan seed under different drying methods to promote storage stability

NASA Astrophysics Data System (ADS)

Ahmad, So'bah; Shamsul Anuar, Mohd; Saleena Taip, Farah; Shamsudin, Rosnah; M, Siti Roha A.

2017-05-01

The effects of two drying methods, oven and microwave drying on the effective moisture diffusivity and activation energy of rambutan seed were studied. Effective moisture diffusivity and activation energy are the main indicators used for moisture movement within the material. Hence, it is beneficial to determine an appropriate drying method to attain a final moisture content of rambutan seed that potentially could be used as secondary sources in the industry. An appropriate final moisture content will provide better storage stability that can extend the lifespan of the rambutan seed. The rambutan seeds were dried with two drying methods (oven and microwave) at two level of the process variables (oven temperature; 40°C and 60°C and microwave power; 250W and 1000W) at constant initial moisture contents. The result showed that a higher value of effective moisture diffusivity and less activation energy were observed in microwave drying compared to oven drying. This finding portrays microwave drying expedites the moisture removal to achieve the required final moisture content and the most appropriate drying method for longer storage stability for rambutan seed. With respect to the process variables; higher oven temperatures and lower microwave powers also exhibit similar trends. Hopefully, this study would provide a baseline data to determine an appropriate drying method for longer storage period for turning waste to by-products.

Effects of Activation Energy to Transient Response of Semiconductor Gas Sensor

NASA Astrophysics Data System (ADS)

Fujimoto, Akira; Ohtani, Tatsuki

The smell classifiable gas sensor will be desired for many applications such as gas detection alarms, process controls for food production and so on. We have tried to realize the sensor using transient responses of semiconductor gas sensor consisting of tin dioxide and pointed out that the sensor gave us different transient responses for kinds of gas. Results of model calculation showed the activation energy of chemical reaction on the sensor surface strongly depended on the transient response. We tried to estimate the activation energies by molecular orbital calculation with SnO2 Cluster. The results show that there is a liner relationship between the gradient of the transient responses and activation energies for carboxylic and alcoholic gases. Transient response will be predicted from activation energy in the same kind of gas and the smell discrimination by single semiconductor gas sensor will be realized by this relationship.

Focusing of noncircular self-similar shock waves.

PubMed

Betelu, S I; Aronson, D G

2001-08-13

We study the focusing of noncircular shock waves in a perfect gas. We construct an explicit self-similar solution by combining three convergent plane waves with regular shock reflections between them. We then show, with a numerical Riemann solver, that there are initial conditions with smooth shocks whose intermediate asymptotic stage is described by the exact solution. Unlike the focusing of circular shocks, our self-similar shocks have bounded energy density.

The use of a running wheel to measure activity in rodents: relationship to energy balance, general activity, and reward.

PubMed

Novak, Colleen M; Burghardt, Paul R; Levine, James A

2012-03-01

Running wheels are commonly employed to measure rodent physical activity in a variety of contexts, including studies of energy balance and obesity. There is no consensus on the nature of wheel-running activity or its underlying causes, however. Here, we will begin by systematically reviewing how running wheel availability affects physical activity and other aspects of energy balance in laboratory rodents. While wheel running and physical activity in the absence of a wheel commonly correlate in a general sense, in many specific aspects the two do not correspond. In fact, the presence of running wheels alters several aspects of energy balance, including body weight and composition, food intake, and energy expenditure of activity. We contend that wheel-running activity should be considered a behavior in and of itself, reflecting several underlying behavioral processes in addition to a rodent's general, spontaneous activity. These behavioral processes include defensive behavior, predatory aggression, and depression- and anxiety-like behaviors. As it relates to energy balance, wheel running engages several brain systems-including those related to the stress response, mood, and reward, and those responsive to growth factors-that influence energy balance indirectly. We contend that wheel-running behavior represents factors in addition to rodents' tendency to be physically active, engaging additional neural and physiological mechanisms which can then independently alter energy balance and behavior. Given the impact of wheel-running behavior on numerous overlapping systems that influence behavior and physiology, this review outlines the need for careful design and interpretation of studies that utilize running wheels as a means for exercise or as a measurement of general physical activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

The use of a running wheel to measure activity in rodents: Relationship to energy balance, general activity, and reward

PubMed Central

Levine, James A.

2015-01-01

Running wheels are commonly employed to measure rodent physical activity in a variety of contexts, including studies of energy balance and obesity. There is no consensus on the nature of wheel-running activity or its underlying causes, however. Here, we will begin by systematically reviewing how running wheel availability affects physical activity and other aspects of energy balance in laboratory rodents. While wheel running and physical activity in the absence of a wheel commonly correlate in a general sense, in many specific aspects the two do not correspond. In fact, the presence of running wheels alters several aspects of energy balance, including body weight and composition, food intake, and energy expenditure of activity. We contend that wheel-running activity should be considered a behavior in and of itself, reflecting several underlying behavioral processes in addition to a rodent's general, spontaneous activity. These behavioral processes include defensive behavior, predatory aggression, and depression- and anxiety-like behaviors. As it relates to energy balance, wheel running engages several brain systems—including those related to the stress response, mood, and reward, and those responsive to growth factors—that influence energy balance indirectly. We contend that wheel-running behavior represents factors in addition to rodents' tendency to be physically active, engaging additional neural and physiological mechanisms which can then independently alter energy balance and behavior. Given the impact of wheel-running behavior on numerous overlapping systems that influence behavior and physiology, this review outlines the need for careful design and interpretation of studies that utilize running wheels as a means for exercise or as a measurement of general physical activity. PMID:22230703

Similarity of Turbulent Energy Scale Budget Equation of a Round Turbulent Jet

NASA Astrophysics Data System (ADS)

Sadeghi, Hamed; Lavoie, Philippe; Pollard, Andrew

2014-11-01

A novel extension to the similarity-based form of the transport equation for the second-order velocity structure function of <(δq) 2 > along the jet centreline (see Danaila et al., 2004) has been obtained. This new self-similar equation has the desirable benefit of requiring less extensive measurements to calculate the inhomogeneous (decay and production) terms of the transport equation. According to this equation, the normalized third-order structure function can be uniquely determined when the normalized second-order structure function, the power-law exponent of and the decay rate constants of and are available. In addition, on the basis of the current similarity analysis, the similarity assumptions in combination with power-law decay of mean velocity (U ~(x -x0) - 1) are strong enough to imply power-law decay of fluctuations ( ~(x -x0) m). The similarity solutions are then tested against new experimental data, which were taken along the centreline of a round jet at ReD = 50 , 000 . For the present set of initial conditions, exhibits a power-law behaviour with m = - 1 . 83 . This work was supported by grants from NSERC (Canada).

Temperature Dependence of Field-Effect Mobility in Organic Thin-Film Transistors: Similarity to Inorganic Transistors.

PubMed

Okada, Jun; Nagase, Takashi; Kobayashi, Takashi; Naito, Hiroyoshi

2016-04-01

Carrier transport in solution-processed organic thin-film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8-BTBT) has been investigated in a wide temperature range from 296 to 10 K. The field-effect mobility shows thermally activated behavior whose activation energy becomes smaller with decreasing temperature. The temperature dependence of field-effect mobility found in C8-BTBT is similar to that of others materials: organic semiconducting polymers, amorphous oxide semiconductors and hydrogenated amorphous silicon. These results indicate that hopping transport between isoenergetic localized states becomes dominated in a low temperature regime in these materials.

Strain-dependent activation energy of shear transformation in metallic glasses

NASA Astrophysics Data System (ADS)

Xu, Bin; Falk, Michael; Li, Jinfu; Kong, Lingti

2017-04-01

Shear transformation (ST) plays a decisive role in determining the mechanical behavior of metallic glasses, which is believed to be a stress-assisted thermally activated process. Understanding the dependence in its activation energy on the stress imposed on the material is of central importance to model the deformation process of metallic glasses and other amorphous solids. Here a theoretical model is proposed to predict the variation of the minimum energy path (MEP) associated with a particular ST event upon further deformation. Verification based on atomistic simulations and calculations are also conducted. The proposed model reproduces the MEP and activation energy of an ST event under different imposed macroscopic strains based on a known MEP at a reference strain. Moreover, an analytical approach is proposed based on the atomistic calculations, which works well when the stress varies linearity along the MEP. These findings provide necessary background for understanding the activation processes and, in turn, the mechanical behavior of metallic glasses.

Energy Conservation Activity Guide, Grades 9-12. Bulletin 1602.

ERIC Educational Resources Information Center

Fraser, Mollie; And Others

As an interdisciplinary, non-sequential teaching guide, this publication was developed to increase awareness and understanding of the energy situation and to encourage individuals to become energy conservationists. Sections provide background information for the teacher followed by a variety of student activities using different subject areas for…

A kinetic analysis of DNA ejection from tailed phages revealing the prerequisite activation energy.

PubMed

Raspaud, Eric; Forth, Thomas; São-José, Carlos; Tavares, Paulo; de Frutos, Marta

2007-12-01

All tailed bacteriophages follow the same general scheme of infection: they bind to their specific host receptor and then transfer their genome into the bacterium. DNA translocation is thought to be initiated by the strong pressure due to DNA packing inside the capsid. However, the exact mechanism by which each phage controls its DNA ejection remains unknown. Using light scattering, we analyzed the kinetics of in vitro DNA release from phages SPP1 and lambda (Siphoviridae family) and found a simple exponential decay. The ejection characteristic time was studied as a function of the temperature and found to follow an Arrhenius law, allowing us to determine the activation energy that governs DNA ejection. A value of 25-30 kcal/mol is obtained for SPP1 and lambda, comparable to the one measured in vitro for T5 (Siphoviridae) and in vivo for T7 (Podoviridae). This suggests similar mechanisms of DNA ejection control. In all tailed phages, the opening of the connector-tail channel is needed for DNA release and could constitute the limiting step. The common value of the activation energy likely reflects the existence for all phages of an optimum value, ensuring a compromise between efficient DNA delivery and high stability of the virus.

Beyond conventional dose-response curves: Sensorgram comparison in SPR allows single concentration activity and similarity assessment.

PubMed

Gassner, C; Karlsson, R; Lipsmeier, F; Moelleken, J

2018-05-30

Previously we have introduced two SPR-based assay principles (dual-binding assay and bridging assay), which allow the determination of two out of three possible interaction parameters for bispecific molecules within one assay setup: two individual interactions to both targets, and/or one simultaneous/overall interaction, which potentially reflects the inter-dependency of both individual binding events. However, activity and similarity are determined by comparing report points over a concentration range, which also mirrors the way data is generated by conventional ELISA-based methods So far, binding kinetics have not been specifically considered in generic approaches for activity assessment. Here, we introduce an improved slope-ratio model which, together with a sensorgram comparison based similarity assessment, allows the development of a detailed, USP-conformal ligand binding assay using only a single sample concentration. We compare this novel analysis method to the usual concentration-range approach for both SPR-based assay principles and discuss its impact on data quality and increased sample throughput. Copyright © 2018 Elsevier B.V. All rights reserved.

The Atomic Energy Commission's Annual Report to Congress for 1960. Major Activities in the Atomic Energy Programs, January - December 1960

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCone, John A.

1961-01-31

The document covers activities for the period January - December 1960. The report consists of two parts: Part One, The Atomic Energy Industry in 1960 and Related Activities; and Part Two, Major Activities in Atomic Energy Programs. Twenty-one appendices are also included.

Quantum Tunneling Contribution for the Activation Energy in Microwave-Induced Reactions.

PubMed

Kuhnen, Carlos A; Dall'Oglio, Evandro L; de Sousa, Paulo T

2017-08-03

In this study, a quantum approach is presented to explain microwave-enhanced reaction rates by considering the tunneling effects in chemical reactions. In the Arrhenius equation, the part of the Hamiltonian relative to the interaction energy during tunneling, between the particle that tunnels and the electrical field defined in the medium, whose spatial component is specified by its rms value, is taken into account. An approximate evaluation of the interaction energy leads to a linear dependence of the effective activation energy on the applied field. The evaluation of the rms value of the field for pure liquids and reaction mixtures, through their known dielectric properties, leads to an appreciable reduction in the activation energies for the proton transfer process in these liquids. The results indicate the need to move toward the use of more refined methods of modern quantum chemistry to calculate more accurately field-induced reaction rates and effective activation energies.

Reinstatement of Individual Past Events Revealed by the Similarity of Distributed Activation Patterns during Encoding and Retrieval

PubMed Central

Wing, Erik A.; Ritchey, Maureen; Cabeza, Roberto

2015-01-01

Neurobiological memory models assume memory traces are stored in neocortex, with pointers in the hippocampus, and are then reactivated during retrieval, yielding the experience of remembering. Whereas most prior neuroimaging studies on reactivation have focused on the reactivation of sets or categories of items, the current study sought to identify cortical patterns pertaining to memory for individual scenes. During encoding, participants viewed pictures of scenes paired with matching labels (e.g., “barn,” “tunnel”), and, during retrieval, they recalled the scenes in response to the labels and rated the quality of their visual memories. Using representational similarity analyses, we interrogated the similarity between activation patterns during encoding and retrieval both at the item level (individual scenes) and the set level (all scenes). The study yielded four main findings. First, in occipitotemporal cortex, memory success increased with encoding-retrieval similarity (ERS) at the item level but not at the set level, indicating the reactivation of individual scenes. Second, in ventrolateral pFC, memory increased with ERS for both item and set levels, indicating the recapitulation of memory processes that benefit encoding and retrieval of all scenes. Third, in retrosplenial/posterior cingulate cortex, ERS was sensitive to individual scene information irrespective of memory success, suggesting automatic activation of scene contexts. Finally, consistent with neurobiological models, hippocampal activity during encoding predicted the subsequent reactivation of individual items. These findings show the promise of studying memory with greater specificity by isolating individual mnemonic representations and determining their relationship to factors like the detail with which past events are remembered. PMID:25313659

The activation energy for nanocrystalline diamond films deposited from an Ar/H2/CH4 hot-filament reactor.

PubMed

Barbosa, D C; Melo, L L; Trava-Airoldi, V J; Corat, E J

2009-06-01

In this work we have investigated the effect of substrate temperature on the growth rate and properties of nanocrystalline diamond thin films deposited by hot filament chemical vapor deposition (HFCVD). Mixtures of 0.5 vol% CH4 and 25 vol% H2 balanced with Ar at a pressure of 50 Torr and typical deposition time of 12 h. We present the measurement of the activation energy by accurately controlling the substrate temperature independently of other CVD parameters. Growth rates have been measured in the temperature range from 550 to 800 degrees C. Characterization techniques have involved Raman spectroscopy, high resolution X-ray difractometry and scanning electron microscopy. We also present a comparison with most activation energy for micro and nanocrystalline diamond determinations in the literature and propose that there is a common trend in most observations. The result obtained can be an evidence that the growth mechanism of NCD in HFCVD reactors is very similar to MCD growth.

Thermodynamic Derivation of the Activation Energy for Ice Nucleation

NASA Technical Reports Server (NTRS)

Barahona, D.

2015-01-01

Cirrus clouds play a key role in the radiative and hydrological balance of the upper troposphere. Their correct representation in atmospheric models requires an understanding of the microscopic processes leading to ice nucleation. A key parameter in the theoretical description of ice nucleation is the activation energy, which controls the flux of water molecules from the bulk of the liquid to the solid during the early stages of ice formation. In most studies it is estimated by direct association with the bulk properties of water, typically viscosity and self-diffusivity. As the environment in the ice-liquid interface may differ from that of the bulk, this approach may introduce bias in calculated nucleation rates. In this work a theoretical model is proposed to describe the transfer of water molecules across the ice-liquid interface. Within this framework the activation energy naturally emerges from the combination of the energy required to break hydrogen bonds in the liquid, i.e., the bulk diffusion process, and the work dissipated from the molecular rearrangement of water molecules within the ice-liquid interface. The new expression is introduced into a generalized form of classical nucleation theory. Even though no nucleation rate measurements are used to fit any of the parameters of the theory the predicted nucleation rate is in good agreement with experimental results, even at temperature as low as 190 K, where it tends to be underestimated by most models. It is shown that the activation energy has a strong dependency on temperature and a weak dependency on water activity. Such dependencies are masked by thermodynamic effects at temperatures typical of homogeneous freezing of cloud droplets; however, they may affect the formation of ice in haze aerosol particles. The new model provides an independent estimation of the activation energy and the homogeneous ice nucleation rate, and it may help to improve the interpretation of experimental results and the

Consequences of lower food intake on the digestive enzymes activities, the energy reserves and the reproductive outcome in Gammarus fossarum.

PubMed

Charron, Laetitia; Geffard, Olivier; Chaumot, Arnaud; Coulaud, Romain; Jaffal, Ali; Gaillet, Véronique; Dedourge-Geffard, Odile; Geffard, Alain

2015-01-01

Digestive enzyme activity is often used as a sensitive response to environmental pollution. However, only little is known about the negative effects of stress on digestive capacities and their consequences on energy reserves and reproduction, although these parameters are important for the maintenance of populations. To highlight if changes in biochemical responses (digestive enzymes and reserves) led to impairments at an individual level (fertility), Gammarus fossarum were submitted to a lower food intake throughout a complete female reproductive cycle (i.e. from ovogenesis to offspring production). For both males and females, amylase activity was inhibited by the diet stress, whereas trypsin activity was not influenced. These results underline similar sensitivity of males and females concerning their digestive capacity. Energy reserves decreased with food starvation in females, and remained stable in males. The number of embryos per female decreased with food starvation. Lower digestive activity in males and females therefore appears as an early response. These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics.

Similarities and differences in signal transduction by interleukin 4 and interleukin 13: analysis of Janus kinase activation.

PubMed

Keegan, A D; Johnston, J A; Tortolani, P J; McReynolds, L J; Kinzer, C; O'Shea, J J; Paul, W E

1995-08-15

The cytokines interleukin (IL) 4 and IL-13 induce many of the same biological responses, including class switching to IgE and induction of major histocompatibility complex class II antigens and CD23 on human B cells. It has recently been shown that IL-4 induces the tyrosine phosphorylation of a 170-kDa protein, a substrate called 4PS, and of the Janus kinase (JAK) family members JAK1 and JAK3. Because IL-13 has many functional effects similar to those of IL-4, we compared the ability of IL-4 and IL-13 to activate these signaling molecules in the human multifactor-dependent cell line TF-1. In this report we demonstrate that both IL-4 and IL-13 induced the tyrosine phosphorylation of 4PS and JAK1. Interestingly, although IL-4 induced the tyrosine phosphorylation of JAK3, we did not detect JAK3 phosphorylation in response to IL-13. These data suggest that IL-4 and IL-13 signal in similar ways via the activation of JAK1 and 4PS. However, our data further indicate that there are significant differences because IL-13 does not activate JAK3.

Does similarity in educational level between health promotion volunteers and local residents affect activity involvement of the volunteers?

PubMed

Murayama, Hiroshi; Taguchi, Atsuko; Murashima, Sachiyo

2012-01-01

This study examined whether similarity in educational level, as a socioeconomic background factor, between health promotion volunteers (HPVs) and residents in the district where HPVs work encourages the volunteers' involvement in providing activities. Cross-sectional questionnaire survey. A total of 512 HPVs in a Japanese city with 5 districts. We focused on the number of activities related to working as an HPV as an aspect of involvement in the HPV role. HPV individual educational level was collected from a questionnaire. District educational level was obtained from the Japanese census database. Of 512 questionnaires, 363 were returned and used for the analysis. Multiple regression analysis stratified by district educational level indicated that a higher educational level in HPVs was significantly associated with a greater number of self-motivated activities in the districts with a higher educational level, although the association between a lower HPV educational level and more activity involvement was not found in districts with a lower educational level. It is important to consider similarity in educational level, as a socioeconomic status factor, between HPVs and the districts in which they will work when recruiting new members and when allocating HPVs to work areas. © 2011 Wiley Periodicals, Inc.

Analysis of coals and biomass pyrolysis using the distributed activation energy model.

PubMed

Li, Zhengqi; Liu, Chunlong; Chen, Zhichao; Qian, Juan; Zhao, Wei; Zhu, Qunyi

2009-01-01

The thermal decomposition of coals and biomass was studied using thermogravimetric analysis with the distributed activation energy model. The integral method resulted in Datong bituminous coal conversions of 3-73% at activation energies of 100-486 kJ/mol. The corresponding frequency factors were e(19.5)-e(59.0)s(-1). Jindongnan lean coal conversions were 8-52% at activation energies of 100-462 kJ/mol. Their corresponding frequency factors were e(13.0)-e(55.8)s(-1). The conversion of corn-stalk skins were 1-84% at activation energies of 62-169 kJ/mol with frequency factors of e(10.8)-e(26.5)s(-1). Datong bituminous coal, Jindongnan lean coal and corn-stalk skins had approximate Gaussian distribution functions with linear ln k(0) to E relationships.

Self-Similar Compressible Free Vortices

NASA Technical Reports Server (NTRS)

vonEllenrieder, Karl

1998-01-01

Lie group methods are used to find both exact and numerical similarity solutions for compressible perturbations to all incompressible, two-dimensional, axisymmetric vortex reference flow. The reference flow vorticity satisfies an eigenvalue problem for which the solutions are a set of two-dimensional, self-similar, incompressible vortices. These solutions are augmented by deriving a conserved quantity for each eigenvalue, and identifying a Lie group which leaves the reference flow equations invariant. The partial differential equations governing the compressible perturbations to these reference flows are also invariant under the action of the same group. The similarity variables found with this group are used to determine the decay rates of the velocities and thermodynamic variables in the self-similar flows, and to reduce the governing partial differential equations to a set of ordinary differential equations. The ODE's are solved analytically and numerically for a Taylor vortex reference flow, and numerically for an Oseen vortex reference flow. The solutions are used to examine the dependencies of the temperature, density, entropy, dissipation and radial velocity on the Prandtl number. Also, experimental data on compressible free vortex flow are compared to the analytical results, the evolution of vortices from initial states which are not self-similar is discussed, and the energy transfer in a slightly-compressible vortex is considered.

Unobtrusive measurement of indoor energy expenditure using an infrared sensor-based activity monitoring system.

PubMed

Hwang, Bosun; Han, Jonghee; Choi, Jong Min; Park, Kwang Suk

2008-11-01

The purpose of this study was to develop an unobtrusive energy expenditure (EE) measurement system using an infrared (IR) sensor-based activity monitoring system to measure indoor activities and to estimate individual quantitative EE. IR-sensor activation counts were measured with a Bluetooth-based monitoring system and the standard EE was calculated using an established regression equation. Ten male subjects participated in the experiment and three different EE measurement systems (gas analyzer, accelerometer, IR sensor) were used simultaneously in order to determine the regression equation and evaluate the performance. As a standard measurement, oxygen consumption was simultaneously measured by a portable metabolic system (Metamax 3X, Cortex, Germany). A single room experiment was performed to develop a regression model of the standard EE measurement from the proposed IR sensor-based measurement system. In addition, correlation and regression analyses were done to compare the performance of the IR system with that of the Actigraph system. We determined that our proposed IR-based EE measurement system shows a similar correlation to the Actigraph system with the standard measurement system.

Fractures of the Tibial Plateau Involve Similar Energies as the Tibial Pilon but Greater Articular Surface Involvement

PubMed Central

Dibbern, Kevin; Kempton, Laurence B.; Higgins, Thomas F.; Morshed, Saam; McKinley, Todd O.; Marsh, J. Lawrence; Anderson, Donald D.

2016-01-01

Patients with tibial pilon fractures have a higher incidence of post-traumatic osteoarthritis than those with fractures of the tibial plateau. This may indicate that pilon fractures present a greater mechanical insult to the joint than do plateau fractures. We tested the hypothesis that fracture energy and articular fracture edge length, two independent indicators of severity, are higher in pilon than plateau fractures. We also evaluated if clinical fracture classification systems accurately reflect severity. Seventy-five tibial plateau fractures and fifty-two tibial pilon fractures from a multi-institutional study were selected to span the spectrum of severity. Fracture severity measures were calculated using objective CT-based image analysis methods. The ranges of fracture energies measured for tibial plateau and pilon fractures were 3.2 to 33.2 Joules (J) and 3.6 to 32.2 J, respectively, and articular fracture edge lengths were 68.0 to 493.0 mm and 56.1 to 288.6 mm, respectively. There were no differences in the fracture energies between the two fracture types, but plateau fractures had greater articular fracture edge lengths (p<0.001). The clinical fracture classifications generally reflected severity, but there was substantial overlap of fracture severity measures between different classes. Clinical Significance Similar fracture energies with different degrees of articular surface involvement suggest a possible explanation for dissimilar rates of post-traumatic osteoarthritis for fractures of the tibial plateau compared to the tibial pilon. The substantial overlap of severity measures between different fracture classes may well have confounded prior clinical studies relying on fracture classification as a surrogate for severity. PMID:27381653

Self-similarity in high Atwood number Rayleigh-Taylor experiments

NASA Astrophysics Data System (ADS)

Mikhaeil, Mark; Suchandra, Prasoon; Pathikonda, Gokul; Ranjan, Devesh

2017-11-01

Self-similarity is a critical concept in turbulent and mixing flows. In the Rayleigh-Taylor instability, theory and simulations have shown that the flow exhibits properties of self-similarity as the mixing Reynolds number exceeds 20000 and the flow enters the turbulent regime. Here, we present results from the first large Atwood number (0.7) Rayleigh-Taylor experimental campaign for mixing Reynolds number beyond 20000 in an effort to characterize the self-similar nature of the instability. Experiments are performed in a statistically steady gas tunnel facility, allowing for the evaluation of turbulence statistics. A visualization diagnostic is used to study the evolution of the mixing width as the instability grows. This allows for computation of the instability growth rate. For the first time in such a facility, stereoscopic particle image velocimetry is used to resolve three-component velocity information in a plane. Velocity means, fluctuations, and correlations are considered as well as their appropriate scaling. Probability density functions of velocity fields, energy spectra, and higher-order statistics are also presented. The energy budget of the flow is described, including the ratio of the kinetic energy to the released potential energy. This work was supported by the DOE-NNSA SSAA Grant DE-NA0002922.

Antimalarial activity of synthetic 1,2,4-trioxanes and cyclic peroxy ketals, a quantum similarity study

NASA Astrophysics Data System (ADS)

Gironés, X.; Gallegos, A.; Carbó-Dorca, R.

2001-12-01

In this work, the antimalarial activity of two series of 20 and 7 synthetic 1,2,4-trioxanes and a set of 20 cyclic peroxy ketals are tested for correlation search by means of Molecular Quantum Similarity Measures (MQSM). QSAR models, dealing with different biological responses (IC90, IC50 and ED90) of the parasite Plasmodium Falciparum, are constructed using MQSM as molecular descriptors and are satisfactorily correlated. The statistical results of the 20 1,2,4-trioxanes are deeply analyzed to elucidate the relevant structural features in the biological activity, revealing the importance of phenyl substitutions.

Effects of easy-to-use protein-rich energy bar on energy balance, physical activity and performance during 8 days of sustained physical exertion.

PubMed

Tanskanen, Minna M; Westerterp, Klaas R; Uusitalo, Arja L; Atalay, Mustafa; Häkkinen, Keijo; Kinnunen, Hannu O; Kyröläinen, Heikki

2012-01-01

Previous military studies have shown an energy deficit during a strenuous field training course (TC). This study aimed to determine the effects of energy bar supplementation on energy balance, physical activity (PA), physical performance and well-being and to evaluate ad libitum fluid intake during wintertime 8-day strenuous TC. Twenty-six men (age 20±1 yr.) were randomly divided into two groups: The control group (n = 12) had traditional field rations and the experimental (Ebar) group (n = 14) field rations plus energy bars of 4.1 MJ•day(-1). Energy (EI) and water intake was recorded. Fat-free mass and water loss were measured with deuterium dilution and elimination, respectively. The energy expenditure was calculated using the intake/balance method and energy availability as (EI/estimated basal metabolic rate). PA was monitored using an accelerometer. Physical performance was measured and questionnaires of upper respiratory tract infections (URTI), hunger and mood state were recorded before, during and after TC. Ebar had a higher EI and energy availability than the controls. However, decreases in body mass and fat mass were similar in both groups representing an energy deficit. No differences were observed between the groups in PA, water balance, URTI symptoms and changes in physical performance and fat-free mass. Ebar felt less hunger after TC than the controls and they had improved positive mood state during the latter part of TC while controls did not. Water deficit associated to higher PA. Furthermore, URTI symptoms and negative mood state associated negatively with energy availability and PA. An easy-to-use protein-rich energy bars did not prevent energy deficit nor influence PA during an 8-day TC. The high content of protein in the bars might have induced satiation decreasing energy intake from field rations. PA and energy intake seems to be primarily affected by other factors than energy supplementation such as mood state.

Effects of Easy-to-Use Protein-Rich Energy Bar on Energy Balance, Physical Activity and Performance during 8 Days of Sustained Physical Exertion

PubMed Central

Tanskanen, Minna M.; Westerterp, Klaas R.; Uusitalo, Arja L.; Atalay, Mustafa; Häkkinen, Keijo; Kinnunen, Hannu O.; Kyröläinen, Heikki

2012-01-01

Background Previous military studies have shown an energy deficit during a strenuous field training course (TC). This study aimed to determine the effects of energy bar supplementation on energy balance, physical activity (PA), physical performance and well-being and to evaluate ad libitum fluid intake during wintertime 8-day strenuous TC. Methods Twenty-six men (age 20±1 yr.) were randomly divided into two groups: The control group (n = 12) had traditional field rations and the experimental (Ebar) group (n = 14) field rations plus energy bars of 4.1 MJ•day−1. Energy (EI) and water intake was recorded. Fat-free mass and water loss were measured with deuterium dilution and elimination, respectively. The energy expenditure was calculated using the intake/balance method and energy availability as (EI/estimated basal metabolic rate). PA was monitored using an accelerometer. Physical performance was measured and questionnaires of upper respiratory tract infections (URTI), hunger and mood state were recorded before, during and after TC. Results Ebar had a higher EI and energy availability than the controls. However, decreases in body mass and fat mass were similar in both groups representing an energy deficit. No differences were observed between the groups in PA, water balance, URTI symptoms and changes in physical performance and fat-free mass. Ebar felt less hunger after TC than the controls and they had improved positive mood state during the latter part of TC while controls did not. Water deficit associated to higher PA. Furthermore, URTI symptoms and negative mood state associated negatively with energy availability and PA. Conclusion An easy-to-use protein-rich energy bars did not prevent energy deficit nor influence PA during an 8-day TC. The high content of protein in the bars might have induced satiation decreasing energy intake from field rations. PA and energy intake seems to be primarily affected by other factors than energy supplementation such

Resonance energy transfer between the active sites of creatine kinase from rabbit brain.

PubMed

Grossman, S H

1990-09-03

Resonance energy transfer was measured between the active site domains of the brain isozyme of creatine kinase (CK-BB). The reactive thiol near the active sites, one on each subunit of the dimeric protein, was derivatized using 5-[2-[iodoacetyl)amino)ethyl]aminonaphthalene-1-sulfonic acid (AED), 2-[4'-iodoacetamidoanilino]naphthalene-6-sulfonic acid (AANS) and 5-iodoacetamidofluorescein (AF). Suitable donor/acceptor protein conjugated hybrids were prepared by controlled kinetics producing CK-BB-AED/AF and CK-BB-AANS/AF. Transfer efficiencies, measured from the quenching of the donor lifetime and steady-state sensitized acceptor emission, ranged from 0.10 to 0.17. From determination of the donor/acceptor overlap integrals, donor quantum yields and attempts to delimit the orientation factor using steady-state and phase-resolved anisotropy measurements, it was found that a suitable estimate of the range between the active sites was between 45 and 57 A. This range is similar to that reported previously for the muscle isozyme of creatine kinase (Grossman, S.H. (1989) Biochemistry 28, 4894-4902) but is a significantly greater distance than detected for the hybrid, myocardial specific isozyme (Grossman, S.H. (1983) Biochemistry 22, 5369-5375).

Density functional calculation of activation energies for lattice and grain boundary diffusion in alumina

NASA Astrophysics Data System (ADS)

Lei, Yinkai; Gong, Yu; Duan, Zhiyao; Wang, Guofeng

2013-06-01

To acquire knowledge on the lattice and grain boundary diffusion processes in alumina, we have determined the activation energies of elementary O and Al diffusive jumps in the bulk crystal, Σ3(0001) grain boundaries, and Σ3(101¯0) grain boundaries of α-Al2O3 using the first-principles density functional theory method. Specifically, we calculated the activation energies for four elementary jumps of both O and Al lattice diffusion in alumina. It was predicted that the activation energy of O lattice diffusion varied from 3.58 to 5.03 eV, while the activation energy of Al lattice diffusion ranged from 1.80 to 3.17 eV. As compared with experimental measurements, the theoretical predictions of the activation energy for lattice diffusion were lower and thus implied that there might be other high-energy diffusive jumps in the experimental alumina samples. Moreover, our results suggested that the Al lattice diffusion was faster than the O lattice diffusion in alumina, in agreement with experiment observations. Furthermore, it was found from our calculations for α-Al2O3 that the activation energies of O and Al grain boundary diffusion in the high-energy Σ3(0001) grain boundaries were significantly lower than those of the lattice diffusion. In contrast, the activation energies of O and Al grain boundary diffusion in the low-energy Σ3(101¯0) grain boundaries could be even higher than those of the lattice diffusion.

Iowa Developed Energy Activity Sampler (IDEAS), Grades 7-12: Industrial Arts.

ERIC Educational Resources Information Center

Simonis, Doris G.

Described is the Industrial Arts component of the Iowa Developed Energy Activity Sampler (IDEAS), a multidisciplinary energy education program designed for infusion into the curriculum of grades 7-12. Also included in the program are activity sets for Home Economics (SE 034 678), Language Arts (SE 034 680), Mathematics (SE 034 681), Science (SE…

Pharmacophore-Based Similarity Scoring for DOCK

PubMed Central

2015-01-01

Pharmacophore modeling incorporates geometric and chemical features of known inhibitors and/or targeted binding sites to rationally identify and design new drug leads. In this study, we have encoded a three-dimensional pharmacophore matching similarity (FMS) scoring function into the structure-based design program DOCK. Validation and characterization of the method are presented through pose reproduction, crossdocking, and enrichment studies. When used alone, FMS scoring dramatically improves pose reproduction success to 93.5% (∼20% increase) and reduces sampling failures to 3.7% (∼6% drop) compared to the standard energy score (SGE) across 1043 protein–ligand complexes. The combined FMS+SGE function further improves success to 98.3%. Crossdocking experiments using FMS and FMS+SGE scoring, for six diverse protein families, similarly showed improvements in success, provided proper pharmacophore references are employed. For enrichment, incorporating pharmacophores during sampling and scoring, in most cases, also yield improved outcomes when docking and rank-ordering libraries of known actives and decoys to 15 systems. Retrospective analyses of virtual screenings to three clinical drug targets (EGFR, IGF-1R, and HIVgp41) using X-ray structures of known inhibitors as pharmacophore references are also reported, including a customized FMS scoring protocol to bias on selected regions in the reference. Overall, the results and fundamental insights gained from this study should benefit the docking community in general, particularly researchers using the new FMS method to guide computational drug discovery with DOCK. PMID:25229837

Kinetic study of solid waste pyrolysis using distributed activation energy model.

PubMed

Bhavanam, Anjireddy; Sastry, R C

2015-02-01

The pyrolysis characteristics of municipal solid waste, agricultural residues such as ground nut shell, cotton husk and their blends are investigated using non-isothermal thermogravimetric analysis (TGA) with in a temperature range of 30-900 °C at different heating rates of 10 °C, 30 °C and 50 °C/min in inert atmosphere. From the thermograms obtained from TGA, it is observed that the maximum rate of degradation occurred in the second stage of the pyrolysis process for all the solid wastes. The distributed activation energy model (DAEM) is used to study the pyrolysis kinetics of the solid wastes. The kinetic parameters E (activation energy), k0 (frequency factor) are calculated from this model. It is found that the range of activation energies for agricultural residues are lower than the municipal solid waste. The activation energies for the municipal solid waste pyrolysis process drastically decreased with addition of agricultural residues. The proposed DAEM is successfully validated with TGA experimental data. Copyright © 2014 Elsevier Ltd. All rights reserved.

World Energy Projection System Plus (WEPS ): Global Activity Module

EIA Publications

2016-01-01

The World Energy Projection System Plus (WEPS ) is a comprehensive, mid?term energy forecasting and policy analysis tool used by EIA. WEPS projects energy supply, demand, and prices by country or region, given assumptions about the state of various economies, international energy markets, and energy policies. The Global Activity Module (GLAM) provides projections of economic driver variables for use by the supply, demand, and conversion modules of WEPS . GLAM’s baseline economic projection contains the economic assumptions used in WEPS to help determine energy demand and supply. GLAM can also provide WEPS with alternative economic assumptions representing a range of uncertainty about economic growth. The resulting economic impacts of such assumptions are inputs to the remaining supply and demand modules of WEPS .

Householders’ Mental Models of Domestic Energy Consumption: Using a Sort-And-Cluster Method to Identify Shared Concepts of Appliance Similarity

PubMed Central

Walker, Ian; Verplanken, Bas; Shaddick, Gavin

2016-01-01

If in-home displays and other interventions are to successfully influence people’s energy consumption, they need to communicate about energy in terms that make sense to users. Here we explore householders’ perceptions of energy consumption, using a novel combination of card-sorting and clustering to reveal shared patterns in the way people think about domestic energy consumption. The data suggest that, when participants were asked to group appliances which they felt naturally ‘went together’, there are relatively few shared ideas about which appliances are conceptually related. To the extent participants agreed on which appliances belonged together, these groupings were based on activities (e.g., entertainment) and location within the home (e.g., kitchen); energy consumption was not an important factor in people’s categorisations. This suggests messages about behaviour change aimed at reducing energy consumption might better be tied to social practices than to consumption itself. PMID:27467206

Householders' Mental Models of Domestic Energy Consumption: Using a Sort-And-Cluster Method to Identify Shared Concepts of Appliance Similarity.

PubMed

Gabe-Thomas, Elizabeth; Walker, Ian; Verplanken, Bas; Shaddick, Gavin

2016-01-01

If in-home displays and other interventions are to successfully influence people's energy consumption, they need to communicate about energy in terms that make sense to users. Here we explore householders' perceptions of energy consumption, using a novel combination of card-sorting and clustering to reveal shared patterns in the way people think about domestic energy consumption. The data suggest that, when participants were asked to group appliances which they felt naturally 'went together', there are relatively few shared ideas about which appliances are conceptually related. To the extent participants agreed on which appliances belonged together, these groupings were based on activities (e.g., entertainment) and location within the home (e.g., kitchen); energy consumption was not an important factor in people's categorisations. This suggests messages about behaviour change aimed at reducing energy consumption might better be tied to social practices than to consumption itself.

Assessment of Physical Activity and Energy Expenditure: An Overview of Objective Measures

PubMed Central

Hills, Andrew P.; Mokhtar, Najat; Byrne, Nuala M.

2014-01-01

The ability to assess energy expenditure (EE) and estimate physical activity (PA) in free-living individuals is extremely important in the global context of non-communicable diseases including malnutrition, overnutrition (obesity), and diabetes. It is also important to appreciate that PA and EE are different constructs with PA defined as any bodily movement that results in EE and accordingly, energy is expended as a result of PA. However, total energy expenditure, best assessed using the criterion doubly labeled water (DLW) technique, includes components in addition to physical activity energy expenditure, namely resting energy expenditure and the thermic effect of food. Given the large number of assessment techniques currently used to estimate PA in humans, it is imperative to understand the relative merits of each. The goal of this review is to provide information on the utility and limitations of a range of objective measures of PA and their relationship with EE. The measures discussed include those based on EE or oxygen uptake including DLW, activity energy expenditure, physical activity level, and metabolic equivalent; those based on heart rate monitoring and motion sensors; and because of their widespread use, selected subjective measures. PMID:25988109

The Geography of Wind Energy: Problem Solving Activities.

ERIC Educational Resources Information Center

Lahart, David E.; Allen, Rodney F.

1985-01-01

Today there are many attempts to use wind machines to confront the increasing costs of electricity. Described are activities to help secondary students understand wind energy, its distribution, applications, and limitations. (RM)

Primate energy expenditure and life history

PubMed Central

Pontzer, Herman; Raichlen, David A.; Gordon, Adam D.; Schroepfer-Walker, Kara K.; Hare, Brian; O’Neill, Matthew C.; Muldoon, Kathleen M.; Dunsworth, Holly M.; Wood, Brian M.; Isler, Karin; Burkart, Judith; Irwin, Mitchell; Shumaker, Robert W.; Lonsdorf, Elizabeth V.; Ross, Stephen R.

2014-01-01

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that primates use remarkably little energy each day, expending on average only 50% of the energy expected for a placental mammal of similar mass. Such large differences in TEE are not easily explained by differences in physical activity, and instead appear to reflect systemic metabolic adaptation for low energy expenditures in primates. Indeed, comparisons of wild and captive primate populations indicate similar levels of energy expenditure. Broad interspecific comparisons of growth, reproduction, and maximum life span indicate that primates’ slow metabolic rates contribute to their characteristically slow life histories. PMID:24474770

Energy Expenditure During Extravehicular Activity Through Apollo

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2011-01-01

Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and crewmembers (CMs) ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVA, and provides a historical look at energy expenditure during EVA through the Apollo program.

Touch-Initiated Reaction of Nitrogen Triiodide as a Template for Activation Energy Classroom Discussions

ERIC Educational Resources Information Center

Short, Duncan

2017-01-01

Activation energies form an energy barrier to a chemical reaction taking place. Simple collision theory, i.e. that particles need to collide to react, would suggest that activation energy is the energy needed to overcome a coulombic barrier provided by the negatively charged electrons contained within energy shells surrounding an atomic nucleus.…

Tracking Photospheric Energy Transport in Active Regions with SDO

NASA Astrophysics Data System (ADS)

Attié, R.; Thompson, B. J.

2017-12-01

The solar photosphere presents flow fields at all observable scales. Where energy-bearing magnetic active regions break through the photosphere these flows are particularly strong, as sheared and twisted magnetic fields come into equilibrium with their surroundings while transporting magnetic energy into the corona. A part of this magnetic energy - the so-called `free energy' stored in the magnetic field in the form of "twisted" and shear of the field - is released in flares and eruptions. We can quantify the energy arrival and build-up in the corona by tracking flow fields and magnetic features at the photosphere as magnetic flux emerges and evolves before and after a flare or eruption.To do this reliably requires two things: a long series of photospheric observations at high sensitivity, spatial and temporal resolution, and an efficient, reliable and robust framework that tracks the photospheric plasma flows and magnetic evolution in both the quiet sun and active regions. SDO/HMI provides the observations, and we present here an innovative high resolution tracking framework that involves the `Balltracking' and `Magnetic Balltracking' algorithms. We show the first results of a systematic, quantitative and comprehensive measurements of the flows and transport of magnetic energy into the solar atmosphere and investigate whether this dynamic view can improve predictions of flares and Coronal Mass Ejections (CMEs).

Energy Activities for Junior High Social Studies.

ERIC Educational Resources Information Center

Minnesota State Energy Agency, St. Paul.

The document contains seven learning activities for junior high students on the energy situation. Objectives are to help students gain understanding and knowledge about the relationships between humans and their social and physical environments; solve problems and clarify issues; examine personal beliefs and values; and recognize the relationships…

Low-Force Muscle Activity Regulates Energy Expenditure after Spinal Cord Injury.

PubMed

Woelfel, Jessica R; Kimball, Amy L; Yen, Chu-Ling; Shields, Richard K

2017-05-01

Reduced physical activity is a primary risk factor for increased morbidity and mortality. People with spinal cord injury (SCI) have reduced activity for a lifetime, as they cannot volitionally activate affected skeletal muscles. We explored whether low-force and low-frequency stimulation is a viable strategy to enhance systemic energy expenditure in people with SCI. This study aimed to determine the effects of low stimulation frequency (1 and 3 Hz) and stimulation intensity (50 and 100 mA) on energy expenditure in people with SCI. We also examined the relationship between body mass index and visceral adipose tissue on energy expenditure during low-frequency stimulation. Ten individuals with complete SCI underwent oxygen consumption monitoring during electrical activation of the quadriceps and hamstrings at 1 and 3 Hz and at 50 and 100 mA. We calculated the difference in energy expenditure between stimulation and rest and estimated the number of days that would be necessary to burn 1 lb of body fat (3500 kcal) for each stimulation protocol (1 vs 3 Hz). Both training frequencies induced a significant increase in oxygen consumption above a resting baseline level (P < 0.05). Energy expenditure positively correlated with stimulus intensity (muscle recruitment) and negatively correlated with adiposity (reflecting the insulating properties of adipose tissue). We estimated that 1 lb of body fat could be burned more quickly with 1 Hz training (58 d) as compared with 3 Hz training (87 d) if an identical number of pulses were delivered. Low-frequency stimulation increased energy expenditure per pulse and may be a feasible option to subsidize physical activity to improve metabolic status after SCI.

Deletion of Gpr55 Results in Subtle Effects on Energy Metabolism, Motor Activity and Thermal Pain Sensation.

PubMed

Bjursell, Mikael; Ryberg, Erik; Wu, Tingting; Greasley, Peter J; Bohlooly-Y, Mohammad; Hjorth, Stephan

2016-01-01

The G-protein coupled receptor 55 (GPR55) is activated by cannabinoids and non-cannabinoid molecules and has been speculated to play a modulatory role in a large variety of physiological and pathological processes, including in metabolically perturbed states. We therefore generated male mice deficient in the gene coding for the cannabinoid/lysophosphatidylinositol (LPI) receptor Gpr55 and characterized them under normal dietary conditions as well as during high energy dense diet feeding followed by challenge with the CB1 receptor antagonist/GPR55 agonist rimonabant. Gpr55 deficient male mice (Gpr55 KO) were phenotypically indistinguishable from their wild type (WT) siblings for the most part. However, Gpr55 KO animals displayed an intriguing nocturnal pattern of motor activity and energy expenditure (EE). During the initial 6 hours of the night, motor activity was significantly elevated without any significant effect observed in EE. Interestingly, during the last 6 hours of the night motor activity was similar but EE was significantly decreased in the Gpr55 KO mice. No significant difference in motor activity was detected during daytime, but EE was lower in the Gpr55 KO compared to WT mice. The aforementioned patterns were not associated with alterations in energy intake, daytime core body temperature, body weight (BW) or composition, although a non-significant tendency to increased adiposity was seen in Gpr55 KO compared to WT mice. Detailed analyses of daytime activity in the Open Field paradigm unveiled lower horizontal activity and rearing time for the Gpr55 KO mice. Moreover, the Gpr55 KO mice displayed significantly faster reaction time in the tail flick test, indicative of thermal hyperalgesia. The BW-decreasing effect of rimonabant in mice on long-term cafeteria diet did not differ between Gpr55 KO and WT mice. In conclusion, Gpr55 deficiency is associated with subtle effects on diurnal/nocturnal EE and motor activity behaviours but does not appear per se

Deletion of Gpr55 Results in Subtle Effects on Energy Metabolism, Motor Activity and Thermal Pain Sensation

PubMed Central

Ryberg, Erik; Wu, Tingting; Greasley, Peter J.; Bohlooly-Y, Mohammad; Hjorth, Stephan

2016-01-01

The G-protein coupled receptor 55 (GPR55) is activated by cannabinoids and non-cannabinoid molecules and has been speculated to play a modulatory role in a large variety of physiological and pathological processes, including in metabolically perturbed states. We therefore generated male mice deficient in the gene coding for the cannabinoid/lysophosphatidylinositol (LPI) receptor Gpr55 and characterized them under normal dietary conditions as well as during high energy dense diet feeding followed by challenge with the CB1 receptor antagonist/GPR55 agonist rimonabant. Gpr55 deficient male mice (Gpr55 KO) were phenotypically indistinguishable from their wild type (WT) siblings for the most part. However, Gpr55 KO animals displayed an intriguing nocturnal pattern of motor activity and energy expenditure (EE). During the initial 6 hours of the night, motor activity was significantly elevated without any significant effect observed in EE. Interestingly, during the last 6 hours of the night motor activity was similar but EE was significantly decreased in the Gpr55 KO mice. No significant difference in motor activity was detected during daytime, but EE was lower in the Gpr55 KO compared to WT mice. The aforementioned patterns were not associated with alterations in energy intake, daytime core body temperature, body weight (BW) or composition, although a non-significant tendency to increased adiposity was seen in Gpr55 KO compared to WT mice. Detailed analyses of daytime activity in the Open Field paradigm unveiled lower horizontal activity and rearing time for the Gpr55 KO mice. Moreover, the Gpr55 KO mice displayed significantly faster reaction time in the tail flick test, indicative of thermal hyperalgesia. The BW-decreasing effect of rimonabant in mice on long-term cafeteria diet did not differ between Gpr55 KO and WT mice. In conclusion, Gpr55 deficiency is associated with subtle effects on diurnal/nocturnal EE and motor activity behaviours but does not appear per se

Nonaqueous lithium-ion capacitors with high energy densities using trigol-reduced graphene oxide nanosheets as cathode-active material.

PubMed

Aravindan, Vanchiappan; Mhamane, Dattakumar; Ling, Wong Chui; Ogale, Satishchandra; Madhavi, Srinivasan

2013-12-01

One HEC of a material: The use of trigol-reduced graphene oxide nanosheets as cathode material in hybrid lithium-ion electrochemical capacitors (Li-HECs) results in an energy density of 45 Wh kg(-1) ; much enhanced when compared to similar devices. The mass loading of the active materials is optimized, and the devices show good cycling performance. Li-HECs employing these materials outperform other supercapacitors, making them attractive for use in power sources. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

NASA Astrophysics Data System (ADS)

Yan, Shuai; Sun, Weichao

2017-09-01

Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

Energy management and control of active distribution systems

NASA Astrophysics Data System (ADS)

Shariatzadeh, Farshid

Advancements in the communication, control, computation and information technologies have driven the transition to the next generation active power distribution systems. Novel control techniques and management strategies are required to achieve the efficient, economic and reliable grid. The focus of this work is energy management and control of active distribution systems (ADS) with integrated renewable energy sources (RESs) and demand response (DR). Here, ADS mean automated distribution system with remotely operated controllers and distributed energy resources (DERs). DER as active part of the next generation future distribution system includes: distributed generations (DGs), RESs, energy storage system (ESS), plug-in hybrid electric vehicles (PHEV) and DR. Integration of DR and RESs into ADS is critical to realize the vision of sustainability. The objective of this dissertation is the development of management architecture to control and operate ADS in the presence of DR and RES. One of the most challenging issues for operating ADS is the inherent uncertainty of DR and RES as well as conflicting objective of DER and electric utilities. ADS can consist of different layers such as system layer and building layer and coordination between these layers is essential. In order to address these challenges, multi-layer energy management and control architecture is proposed with robust algorithms in this work. First layer of proposed multi-layer architecture have been implemented at the system layer. Developed AC optimal power flow (AC-OPF) generates fair price for all DR and non-DR loads which is used as a control signal for second layer. Second layer controls DR load at buildings using a developed look-ahead robust controller. Load aggregator collects information from all buildings and send aggregated load to the system optimizer. Due to the different time scale at these two management layers, time coordination scheme is developed. Robust and deterministic controllers

Determination of the Arrhenius Activation Energy Using a Temperature-Programmed Flow Reactor.

ERIC Educational Resources Information Center

Chan, Kit-ha C.; Tse, R. S.

1984-01-01

Describes a novel method for the determination of the Arrhenius activation energy, without prejudging the validity of the Arrhenius equation or the concept of activation energy. The method involves use of a temperature-programed flow reactor connected to a concentration detector. (JN)

Energy and Safety: Science Activities for Elementary Students, Level III (Grades (5-6).

ERIC Educational Resources Information Center

Westcott, Dale; And Others

Thirteen activities are presented that focus on a common phenomenon of a child's world: energy. These activities relate energy, how it occurs, how it is used, and how to use it safely. Each activity includes the purpose, introduction, background, procedure, materials, estimated time for the activity, typical results, safety notes, and more ideas.…

Flowable Conducting Particle Networks in Redox-Active Electrolytes for Grid Energy Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatzell, K. B.; Boota, M.; Kumbur, E. C.

2015-01-01

This study reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO2+/VO2+ redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage. Charge storage contributionsmore » (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO2+/VO2+ redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s-1) than one based on a non-redox active electrolyte. Furthermore, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.« less

Flowable conducting particle networks in redox-active electrolytes for grid energy storage

DOE PAGES

Hatzell, K. B.; Boota, M.; Kumbur, E. C.; ...

2015-01-09

This paper reports a new hybrid approach toward achieving high volumetric energy and power densities in an electrochemical flow capacitor for grid energy storage. The electrochemical flow capacitor suffers from high self-discharge and low energy density because charge storage is limited to the available surface area (electric double layer charge storage). Here, we examine two carbon materials as conducting particles in a flow battery electrolyte containing the VO 2+/VO 2 + redox couple. Highly porous activated carbon spheres (CSs) and multi-walled carbon nanotubes (MWCNTs) are investigated as conducting particle networks that facilitate both faradaic and electric double layer charge storage.more » Charge storage contributions (electric double layer and faradaic) are distinguished for flow-electrodes composed of MWCNTs and activated CSs. A MWCNT flow-electrode based in a redox-active electrolyte containing the VO 2+/VO 2 + redox couple demonstrates 18% less self-discharge, 10 X more energy density, and 20 X greater power densities (at 20 mV s -1) than one based on a non-redox active electrolyte. Additionally, a MWCNT redox-active flow electrode demonstrates 80% capacitance retention, and >95% coulombic efficiency over 100 cycles, indicating the feasibility of utilizing conducting networks with redox chemistries for grid energy storage.« less

Surface similarity-based molecular query-retrieval

PubMed Central

Singh, Rahul

2007-01-01

Background Discerning the similarity between molecules is a challenging problem in drug discovery as well as in molecular biology. The importance of this problem is due to the fact that the biochemical characteristics of a molecule are closely related to its structure. Therefore molecular similarity is a key notion in investigations targeting exploration of molecular structural space, query-retrieval in molecular databases, and structure-activity modelling. Determining molecular similarity is related to the choice of molecular representation. Currently, representations with high descriptive power and physical relevance like 3D surface-based descriptors are available. Information from such representations is both surface-based and volumetric. However, most techniques for determining molecular similarity tend to focus on idealized 2D graph-based descriptors due to the complexity that accompanies reasoning with more elaborate representations. Results This paper addresses the problem of determining similarity when molecules are described using complex surface-based representations. It proposes an intrinsic, spherical representation that systematically maps points on a molecular surface to points on a standard coordinate system (a sphere). Molecular surface properties such as shape, field strengths, and effects due to field super-positioningcan then be captured as distributions on the surface of the sphere. Surface-based molecular similarity is subsequently determined by computing the similarity of the surface-property distributions using a novel formulation of histogram-intersection. The similarity formulation is not only sensitive to the 3D distribution of the surface properties, but is also highly efficient to compute. Conclusion The proposed method obviates the computationally expensive step of molecular pose-optimisation, can incorporate conformational variations, and facilitates highly efficient determination of similarity by directly comparing molecular surfaces

Intrinsic atopic dermatitis (AD) shows similar Th2 and higher Th17 immune activation compared to extrinsic AD

PubMed Central

Suárez-Fariñas, M; Dhingra, N; Gittler, J; Shemer, A; Cardinale, I; de Guzman Strong, C; Krueger, JG; Guttman-Yassky, E

2013-01-01

Background Atopic dermatitis (AD) is classified as extrinsic (ADe) and intrinsic (ADi), representing approximately 80% and 20% of patients, respectively. While sharing a similar clinical phenotype, only ADe is characterized by high serum IgE. Since most AD patients exhibit high IgE, an “allergic”/IgE-mediated disease pathogenesis was hypothesized. However, current models associate AD with T-cell activation, particularly Th2/Th22 polarization, and epidermal barrier defects. Objective To define if both variants share a common pathogenesis. Methods We stratified 51 severe AD patients as ADe (42) and ADi (9) (with similar mean disease activity/SCORAD), and analyzed the molecular and cellular skin pathology of lesional and non-lesional ADi and ADe using gene-expression (RT-PCR) and immunohistochemistry. Results A significant correlation between IgE levels and SCORAD (r=0.76, p<10−5) was found only in ADe. Marked infiltrates of T-cells and dendritic cells and corresponding epidermal alterations (K16, Mki67, S100A7/A8/A9) defined lesional skin of both variants. However, higher activation of all inflammatory axes (including Th2) was detected in ADi, particularly Th17 and Th22-cytokines. Positive correlations between Th17-related molecules and SCORAD were only found in ADi, while only ADe showed positive correlations between SCORAD and Th2-cytokines (IL-4, IL-5), and negative correlations with differentiation products (loricrin, periplakin). Conclusions Although differences in Th17 and Th22 activation exist between ADi and ADe, we identified common disease-defining features of T-cell activation, production of polarized cytokines, and keratinocyte responses to immune products. Our data indicate that a Th2 bias is not the sole cause of high IgE in ADe, with important implications for similar therapeutic interventions. Clinical Implications Both extrinsic and intrinsic AD variants might be treated with T-cell targeted therapeutics or agents that modify keratinocyte

Biotinidase knockout mice show cellular energy deficit and altered carbon metabolism gene expression similar to that of nutritional biotin deprivation: clues for the pathogenesis in the human inherited disorder.

PubMed

Hernández-Vázquez, A; Wolf, B; Pindolia, K; Ortega-Cuellar, D; Hernández-González, R; Heredia-Antúnez, A; Ibarra-González, I; Velázquez-Arellano, A

2013-11-01

Biotin is the prosthetic group of carboxylases that have important roles in the metabolism of glucose, fatty acids and amino acids. Biotinidase has a key role in the reutilization of the biotin, catalyzing the hydrolysis of biocytin (ε-N-biotinyl-l-lysine) and biocytin-containing peptides derived from carboxylase turnover, thus contributing substantially to the bioavailability of this vitamin. Deficient activity of biotinidase causes late-onset multiple carboxylase in humans, whose pathogenic mechanisms are poorly understood. Here we show that a knock-out biotinidase-deficient mouse from a C57BL/6 background that was fed a low biotin diet develops severe ATP deficit with activation of the energy sensor adenosine monophosphate (AMP)-activated protein kinase (AMPK), inhibition of the signaling protein mTOR, driver of protein synthesis and growth, and affecting the expression of central-carbon metabolism genes. In addition, sensitivity to insulin is augmented. These changes are similar to those observed in nutritionally biotin-starved rats. These findings further our understanding of the pathogenesis of human biotinidase deficiency. © 2013 Elsevier Inc. All rights reserved.

Complete description of all self-similar models driven by Lévy stable noise

NASA Astrophysics Data System (ADS)

Weron, Aleksander; Burnecki, Krzysztof; Mercik, Szymon; Weron, Karina

2005-01-01

A canonical decomposition of H -self-similar Lévy symmetric α -stable processes is presented. The resulting components completely described by both deterministic kernels and the corresponding stochastic integral with respect to the Lévy symmetric α -stable motion are shown to be related to the dissipative and conservative parts of the dynamics. This result provides stochastic analysis tools for study the anomalous diffusion phenomena in the Langevin equation framework. For example, a simple computer test for testing the origins of self-similarity is implemented for four real empirical time series recorded from different physical systems: an ionic current flow through a single channel in a biological membrane, an energy of solar flares, a seismic electric signal recorded during seismic Earth activity, and foreign exchange rate daily returns.

Energy Expenditure During Extravehicular Activity Through Apollo

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2012-01-01

Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and, as a result, crew members ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVAs, and provides a historical look at energy expenditure during EVAs through the Apollo Program.

Tax-1 and Tax-2 similarities and differences: focus on post-translational modifications and NF-κB activation

PubMed Central

Shirinian, Margret; Kfoury, Youmna; Dassouki, Zeina; El-Hajj, Hiba; Bazarbachi, Ali

2013-01-01

Although human T cell leukemia virus type 1 and 2 (HTLV-1 and HTLV-2) share similar genetic organization, they have major differences in their pathogenesis and disease manifestation. HTLV-1 is capable of transforming T lymphocytes in infected patients resulting in adult T cell leukemia/lymphoma whereas HTLV-2 is not clearly associated with lymphoproliferative diseases. Numerous studies have provided accumulating evidence on the involvement of the viral transactivators Tax-1 versus Tax-2 in T cell transformation. Tax-1 is a potent transcriptional activator of both viral and cellular genes. Tax-1 post-translational modifications and specifically ubiquitylation and SUMOylation have been implicated in nuclear factor-kappaB (NF-κB) activation and may contribute to its transformation capacity. Although Tax-2 has similar protein structure compared to Tax-1, the two proteins display differences both in their protein–protein interaction and activation of signal transduction pathways. Recent studies on Tax-2 have suggested ubiquitylation and SUMOylation independent mechanisms of NF-κB activation. In this present review, structural and functional differences between Tax-1 and Tax-2 will be summarized. Specifically, we will address their subcellular localization, nuclear trafficking and their effect on cellular regulatory proteins. A special attention will be given to Tax-1/Tax-2 post-translational modification such as ubiquitylation, SUMOylation, phosphorylation, acetylation, NF-κB activation, and protein–protein interactions involved in oncogenecity both in vivo and in vitro. PMID:23966989

The activation energy of stabilised/solidified contaminated soils.

PubMed

Chitambira, B; Al-Tabbaa, A; Perera, A S R; Yu, X D

2007-03-15

Developing an understanding of the time-related performance of cement-treated materials is essential in understanding their durability and long-term effectiveness. A number of models have been developed to predict this time-related performance. One such model is the maturity concept which involves use of the 'global' activation energy which derives from the Arrhenius equation. The accurate assessment of the activation energy is essential in the realistic modelling of the accelerated ageing of cement-treated soils. Experimentally, this model is applied to a series of tests performed at different elevated temperatures. Experimental work, related to the results of a time-related performance on a contaminated site in the UK treated with in situ stabilisation/solidification was carried out. Three different cement-based grouts were used on two model site soils which were both contaminated with a number of heavy metals and a hydrocarbon. Uncontaminated soils were also tested. Elevated temperatures up to 60 degrees C and curing periods up to 90 days were used. The resulting global activation energies for the uncontaminated and contaminated soils were compared. Lower values were obtained for the contaminated soils reflecting the effect of the contaminants. The resulting equivalent ages for the uncontaminated and contaminated mixes tested were 5.1-7.4 and 0.8-4.1 years, respectively. This work shows how a specific set of contaminants affect the E(a) values for particular cementitious systems and how the maturity concept can be applied to cement-treated contaminated soils.

Iowa Developed Energy Activity Sampler (IDEAS), Grades 7-12: Social Studies.

ERIC Educational Resources Information Center

Simonis, Doris G.

Described is the Social Studies component of the Iowa Developed Energy Activity Sampler (IDEAS), a multidisciplinary energy education program designed for infusion into the curriculum of grades seven through twelve. Aspects of the energy situation addressed in these lessons include resource finiteness, exponential growth, standard of living,…

Energy homeostasis and running wheel activity during pregnancy in the mouse.

PubMed

Ladyman, S R; Carter, K M; Grattan, D R

2018-05-05

Pregnancy and lactation are metabolically challenging states, where the mother must supply all the energy requirements for the developing fetus and growing pups respectively. The aim of the current study was to characterize many aspects of energy homeostasis before and during pregnancy in the mouse, and to examine the role of voluntary activity on changes in energy expenditure during pregnancy. In a secondary aim, we evaluate measures of energy homeostasis during pregnancy in mice that successfully reared their litter or in mice that went on to abandon their litter, to determine if an impairment in pregnancy-induced adaptation of energy homeostasis might underlie the abandonment of pups soon after birth. During pregnancy, food intake was increased, characterized by increased meal size and duration but not number of meals per day. The duration of time spent inactive, predicted to indicate sleep behaviour, was increased both early and late in pregnancy compared to pre-pregnancy levels. Increased x + y beam breaks, as a measure of activity increased during pregnancy and this reflected an increase in ambulatory behaviour in mid pregnancy and an increase in non-ambulatory movement in late pregnancy. Energy expenditure, as measured by indirect calorimetry, increased across pregnancy, likely due to the growth and development of fetal tissue. There was also a dramatic reduction in voluntary wheel running as soon as the mice became pregnant. Compared with successful pregnancies and lactations, pregnancies where pups were abandoned soon after birth were associated with reduced body weight gain and an increase in running wheel activity at the end of pregnancy, but no difference in food intake or energy expenditure. Overall, during pregnancy there are multiple adaptations to change energy homeostasis, resulting in partitioning of provisions of energy to the developing fetus and storing energy for future metabolic demands. Copyright © 2018 Elsevier Inc. All rights reserved.

Energy expenditure prediction via a footwear-based physical activity monitor: Accuracy and comparison to other devices

NASA Astrophysics Data System (ADS)

Dannecker, Kathryn

2011-12-01

Accurately estimating free-living energy expenditure (EE) is important for monitoring or altering energy balance and quantifying levels of physical activity. The use of accelerometers to monitor physical activity and estimate physical activity EE is common in both research and consumer settings. Recent advances in physical activity monitors include the ability to identify specific activities (e.g. stand vs. walk) which has resulted in improved EE estimation accuracy. Recently, a multi-sensor footwear-based physical activity monitor that is capable of achieving 98% activity identification accuracy has been developed. However, no study has compared the EE estimation accuracy for this monitor and compared this accuracy to other similar devices. Purpose . To determine the accuracy of physical activity EE estimation of a footwear-based physical activity monitor that uses an embedded accelerometer and insole pressure sensors and to compare this accuracy against a variety of research and consumer physical activity monitors. Methods. Nineteen adults (10 male, 9 female), mass: 75.14 (17.1) kg, BMI: 25.07(4.6) kg/m2 (mean (SD)), completed a four hour stay in a room calorimeter. Participants wore a footwear-based physical activity monitor, as well as three physical activity monitoring devices used in research: hip-mounted Actical and Actigraph accelerometers and a multi-accelerometer IDEEA device with sensors secured to the limb and chest. In addition, participants wore two consumer devices: Philips DirectLife and Fitbit. Each individual performed a series of randomly assigned and ordered postures/activities including lying, sitting (quietly and using a computer), standing, walking, stepping, cycling, sweeping, as well as a period of self-selected activities. We developed branched (i.e. activity specific) linear regression models to estimate EE from the footwear-based device, and we used the manufacturer's software to estimate EE for all other devices. Results. The shoe

Energy Requirements in Early Life Are Similar for Male and Female Goat Kids

PubMed Central

Bompadre, T. F. V.; Neto, O. Boaventura; Mendonca, A. N.; Souza, S. F.; Oliveira, D.; Fernandes, M. H. M. R.; Harter, C. J.; Almeida, A. K.; Resende, K. T.; Teixeira, I. A. M. A.

2014-01-01

Little is known about the gender differences in energetic requirements of goats in early life. In this study, we determined the energy requirements for maintenance and gain in intact male, castrated male and female Saanen goat kids using the comparative slaughter technique and provide new data on their body composition and energy efficiency. To determine the energy requirements for maintenance, we studied 21 intact males, 15 castrated males and 18 females (5.0±0.1 kg initial body weight (BW) and 23±5 d of age) using a split-plot design with the following main factors: three genders (intact males, castrated males, and females) and three dry matter intake levels (ad libitum, 75% and 50% of ad libitum intake). A slaughter group included three kids, one for each nutritional plane, of each gender, and all three animals within a group were slaughtered when the ad libitum kid reached 15 kg in BW. Net energy requirements for gain were obtained for 17 intact males, eight castrated males and 15 females (5.1±0.4 kg BW and 23±13 d of age). Animals were fed ad libitum and slaughtered when they reached 5, 10, and 15 kg in BW. A digestion trial was performed with nine kids of each gender to determine digestible energy, metabolizable energy and energy metabolizability of the diet. Our results show no effect of gender on the energy requirements for maintenance and gain, and overall net energy for maintenance was 205.6 kJ/kg0.75 empty body weight gain (EBW) (170.3 kJ/kg0.75 BW) from 5 to 15 kg BW. Metabolizable energy for maintenance was calculated by iteration, assuming heat production equal to metabolizable energy intake at maintenance, and the result was 294.34 kJ/kg0.75 EBW and km of 0.70. As BW increased from 5 to 15 kg for all genders, the net energy required for gain increased from 9.5 to 12.0 kJ/g EBW gain (EWG), and assuming kg = 0.47, metabolizable energy for gain ranged from 20.2 to 25.5 kJ/g EWG. Our results indicate that it is not necessary to formulate diets with

Energy Around Us. A Fall Activity Packet for Fourth Grade.

ERIC Educational Resources Information Center

Jackson Community Coll., MI. Dahlem Environmental Education Center.

This instructional packet is one of 14 school environmental education programs developed for use in the classroom and at the Dahlem Environmental Education Center (DEEC) of the Jackson Community College (Michigan). Provided in the packet are pre-trip activities, field trip activities, and post-trip activities which focus on energy uses, energy…

Antiaflatoxigenic and Antimicrobial Activities of Schiff Bases of 2-Hydroxy-4-methoxybenzaldehyde, Cinnamaldehyde, and Similar Aldehydes.

PubMed

Harohally, Nanishankar V; Cherita, Chris; Bhatt, Praveena; Anu Appaiah, K A

2017-10-11

2-Hydroxy-4-methoxybenzaldehyde (HMBA) is a nontoxic phenolic flavor from dietary source Decalipus hamiltonii and Hemidesmus indicus. HMBA is an excellent antimicrobial agent with additional antiaflatoxigenic potency. On the other hand, cinnamaldehyde from cinnamon is a widely employed flavor with significant antiaflatoxigenic activity. We have attempted the enhancement of antiaflatoxigenic and antimicrobial properties of HMBA, cinnamaldehyde, and similar molecules via Schiff base formation accomplished from condensation reaction with amino sugar (d-glucamine). HMBA derived Schiff bases exhibited commendable antiaflatoxigenic activity at the concentration 0.1 mg/mL resulting in 9.6 ± 1.9% growth of Aspergillus flavus and subsequent 91.4 ± 3.9% reduction of aflatoxin B 1 with respect to control.

Lipidemic profile of athletes and non-athletes with similar body fat.

PubMed

Petridou, Anatoli; Lazaridou, Despina; Mougios, Vassilis

2005-08-01

Although chronic exercise is generally believed to improve the lipidemic profile, it is not clear whether this is due to exercise training or to other determinants such as the usually low body fat of athletes. The aim of the present study was to compare the lipidemic profile of young lean athletes and non-athletes matched for percentage body fat. Fourteen endurance athletes and fourteen sedentary men participated in the study. Participants provided two blood samples at the beginning and end of a 7-d period, during which they recorded physical activity and food intake. Athletes had significantly higher energy expenditure and energy intake but not significantly different macronutrient composition of their diet from non-athletes. No significant differences were found in serum triacylglycerol, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol concentrations between groups. These data suggest that athletes and non-athletes with similar body fat do not differ in their lipidemic profiles.

Activation energy measurements in rheological analysis of cheese

USDA-ARS?s Scientific Manuscript database

Activation energy of flow (Ea) was calculated from temperature sweeps of cheeses with contrasting characteristics to determine its usefulness in predicting rheological behavior upon heating. Cheddar, Colby, whole milk Mozzarella, low moisture part skim Mozzarella, Parmesan, soft goat, and Queso Fre...

[Sedentary lifestyle: physical activity duration versus percentage of energy expenditure].

PubMed

Cabrera de León, Antonio; Rodríguez-Pérez, María del C; Rodríguez-Benjumeda, Luis M; Anía-Lafuente, Basilio; Brito-Díaz, Buenaventura; Muros de Fuentes, Mercedes; Almeida-González, Delia; Batista-Medina, Marta; Aguirre-Jaime, Armando

2007-03-01

To compare different definitions of a sedentary lifestyle and to determine which is the most appropriate for demonstrating its relationship with the metabolic syndrome and other cardiovascular risk factors. A cross-sectional study of 5814 individuals was carried out. Comparisons were made between two definitions of a sedentary lifestyle: one based on active energy expenditure being less than 10% of total energy expenditure, and the other, on performing less than 25-30 minutes of physical activity per day. Reported levels of physical activity, anthropometric measurements, and biochemical markers of cardiovascular risk were recorded. The associations between a sedentary lifestyle and metabolic syndrome and other risk factors were adjusted for gender, age and tobacco use. The prevalence of a sedentary lifestyle was higher in women (70%) than in men (45-60%, according to the definition used). The definitions based on physical activity duration and on energy expenditure were equally useful: there were direct associations between a sedentary lifestyle and metabolic syndrome, body mass index, abdominal and pelvic circumferences, systolic blood pressure, heart rate, apolipoprotein B, and triglycerides, and inverse associations with high-density lipoprotein cholesterol and paraoxonase activity, which demonstrated the greatest percentage difference between sedentary and active individuals. An incidental finding was that both definitions of a sedentary lifestyle were more strongly associated with the metabolic syndrome as defined by International Diabetes Federation criteria than by Adult Treatment Panel III criteria. Given that it is relatively easy to determine whether a patient performs less than 25 minutes of physical activity per day, use of this definition of a sedentary lifestyle is recommended for clinical practice. The serum paraoxonase activity level could provide a useful marker for studying sedentary lifestyles.

ACTIVITY ENERGY EXPENDITURE AND INCIDENT COGNITIVE IMPAIRMENT IN OLDER ADULTS

PubMed Central

Middleton, Laura E.; Manini, Todd M.; Simonsick, Eleanor M.; Harris, Tamara B.; Barnes, Deborah E.; Tylavsky, Frances; Brach, Jennifer S.; Everhart, James E.; Yaffe, Kristine

2013-01-01

Introduction Studies suggest that physically active people have reduced risk of incident cognitive impairment in late life. However, these studies are limited by reliance on subjective self-reports of physical activity, which only moderately correlate to objective measures and often exclude activity not readily quantifiable by frequency and duration. The objective of this study was to investigate the relationship between activity energy expenditure (AEE), an objective measure of total activity, and incidence of cognitive impairment. Methods We calculated AEE as 90% of total energy expenditure (assessed over two weeks using doubly-labeled water) minus resting metabolic rate (measured using indirect calorimetry) in 197 men and women (mean 74.8 years) who were free of mobility and cognitive impairments at study baseline (1998–2000). Cognitive function was assessed at baseline and 2 or 5 years later using the Modified Mini-Mental State Examination (3MS). Cognitive impairment was defined as a decline of >1.0 SD (9 points) between baseline and follow-up. Results After adjustment for baseline 3MS, demographics, fat free mass, sleep duration, self-reported health, and diabetes, older adults in the highest sex-specific tertile of AEE had lower odds of incident cognitive impairment than those in the lowest tertile (OR, 95% CI 0.09, 0.01–0.79). There was also a significant dose response between AEE and incidence of cognitive impairment (p-for-trend over tertiles=0.05). Conclusions These findings indicate that greater activity energy expenditure may be protective against cognitive impairment in a dose-response manner. The significance of overall activity in contrast to vigorous or light activity should be determined. PMID:21771893

Body Segment Kinematics and Energy Expenditure in Active Videogames.

PubMed

Böhm, Birgit; Hartmann, Michael; Böhm, Harald

2016-06-01

Energy expenditure (EE) in active videogames (AVGs) is a component for assessing its benefit for cardiovascular health. Existing evidence suggests that AVGs are able to increase EE above rest and when compared with playing passive videogames. However, the association between body movement and EE remains unclear. Furthermore, for goal-directed game design, it is important to know the contribution of body segments to EE. This knowledge will help to acquire a certain level of exercise intensity during active gaming. Therefore, the purpose of this study was to determine the best predictors of EE from body segment energies, acceleration, and heart rate during different game situations. EE and body segment movement of 17 subjects, aged 22.1 ± 2.5 years, were measured in two different AVGs. In randomized order, the subjects played a handheld-controlled Nintendo(®) Wii™ tennis (NWT) game and a whole body-controlled Sony EyeToy(®) waterfall (ETW) game. Body segment movement was analyzed using a three-dimensional motion capture system. From the video data, mean values of mechanical energy change and acceleration of 10 body segments were analyzed. Measured EE was significantly higher in ETW (7.8 ± 1.4 metabolic equivalents [METs]) than in NWT (3.4 ± 1.0 METs). The best prediction parameter for the more intense ETW game was the energy change of the right thigh and for the less intense hand-controlled NWT game was the energy change of the upper torso. Segment acceleration was less accurate in predicting EE. The best predictors of metabolic EE were the thighs and the upper torso in whole body and handheld-controlled games, respectively. Increasing movement of these body segments would lead to higher physical activity intensity during gaming, reducing sedentary behavior.

Physical activity assessment: biomarkers and self-report of activity-related energy expenditure in the WHI.

PubMed

Neuhouser, Marian L; Di, Chongzhi; Tinker, Lesley F; Thomson, Cynthia; Sternfeld, Barbara; Mossavar-Rahmani, Yasmin; Stefanick, Marcia L; Sims, Stacy; Curb, J David; Lamonte, Michael; Seguin, Rebecca; Johnson, Karen C; Prentice, Ross L

2013-03-15

We used a biomarker of activity-related energy expenditure (AREE) to assess measurement properties of self-reported physical activity and to determine the usefulness of AREE regression calibration equations in the Women's Health Initiative. Biomarker AREE, calculated as the total energy expenditure from doubly labeled water minus the resting energy expenditure from indirect calorimetry, was assessed in 450 Women's Health Initiative participants (2007-2009). Self-reported AREE was obtained from the Arizona Activity Frequency Questionnaire (AAFQ), the 7-Day Physical Activity Recall (PAR), and the Women's Health Initiative Personal Habits Questionnaire (PHQ). Eighty-eight participants repeated the protocol 6 months later. Reporting error, measured as log(self-report AREE) minus log(biomarker AREE), was regressed on participant characteristics for each instrument. Body mass index was associated with underreporting on the AAFQ and PHQ but overreporting on PAR. Blacks and Hispanics underreported physical activity levels on the AAFQ and PAR, respectively. Underreporting decreased with age for the PAR and PHQ. Regressing logbiomarker AREE on logself-reported AREE revealed that self-report alone explained minimal biomarker variance (R(2) = 7.6, 4.8, and 3.4 for AAFQ, PAR, and PHQ, respectively). R(2) increased to 25.2, 21.5, and 21.8, respectively, when participant characteristics were included. Six-month repeatability data adjusted for temporal biomarker variation, improving R(2) to 79.4, 67.8, and 68.7 for AAFQ, PAR, and PHQ, respectively. Calibration equations "recover" substantial variation in average AREE and valuably enhance AREE self-assessment.

A thermal extrapolation method for the effective temperatures and internal energies of activated ions

NASA Astrophysics Data System (ADS)

Meot-Ner (Mautner), Michael; Somogyi, Árpád

2007-11-01

The internal energies of dissociating ions, activated chemically or collisionally, can be estimated using the kinetics of thermal dissociation. The thermal Arrhenius parameters can be combined with the observed dissociation rate of the activated ions using kdiss = Athermalexp(-Ea,thermal/RTeff). This Arrhenius-type relation yields the effective temperature, Teff, at which the ions would dissociate thermally at the same rate, or yield the same product distributions, as the activated ions. In turn, Teff is used to calculate the internal energy of the ions and the energy deposited by the activation process. The method yields an energy deposition efficiency of 10% for a chemical ionization proton transfer reaction and 8-26% for the surface collisions of various peptide ions. Internal energies of ions activated by chemical ionization or by gas phase collisions, and of ions produced by desorption methods such as fast atom bombardment, can be also evaluated. Thermal extrapolation is especially useful for ion-molecule reaction products and for biological ions, where other methods to evaluate internal energies are laborious or unavailable.

Physical Activity Energy Expenditure in Dutch Adolescents: Contribution of Active Transport to School, Physical Education, and Leisure Time Activities

ERIC Educational Resources Information Center

Slingerland, Menno; Borghouts, Lars B.; Hesselink, Matthijs K. C.

2012-01-01

Background: Detailed knowledge about physical activity energy expenditure (PAEE) can guide the development of school interventions aimed at reducing overweight in adolescents. However, relevant components of PAEE have never been objectively quantified in this population. This study investigated the contribution of active transport to and from…

Magnetic Energy and Helicity in Two Emerging Active Regions in the Sun

NASA Technical Reports Server (NTRS)

Liu, Y.; Schuck, P. W.

2012-01-01

The magnetic energy and relative magnetic helicity in two emerging solar active regions, AR 11072 and AR 11158,are studied. They are computed by integrating over time the energy and relative helicity fluxes across the photosphere. The fluxes consist of two components: one from photospheric tangential flows that shear and braid field lines (shear term), the other from normal flows that advect magnetic flux into the corona (emergence term). For these active regions: (1) relative magnetic helicity in the active-region corona is mainly contributed by the shear term,(2) helicity fluxes from the emergence and the shear terms have the same sign, (3) magnetic energy in the corona (including both potential energy and free energy) is mainly contributed by the emergence term, and(4) energy fluxes from the emergence term and the shear term evolved consistently in phase during the entire flux emergence course.We also examine the apparent tangential velocity derived by tracking field-line footpoints using a simple tracking method. It is found that this velocity is more consistent with tangential plasma velocity than with the flux transport velocity, which agrees with the conclusion by Schuck.

Active interrogation using low-energy nuclear reactions

NASA Astrophysics Data System (ADS)

Antolak, Arlyn; Doyle, Barney; Leung, Ka-Ngo; Morse, Daniel; Provencio, Paula

2005-09-01

High-energy photons and neutrons can be used to interrogate for heavily shielded fissile materials inside sealed cargo containers by detecting their prompt and/or delayed fission signatures. The FIND (Fissmat Inspection for Nuclear Detection) active interrogation system is based on a dual neutron+gamma source that uses low-energy (< 500 keV) proton- or deuteron-induced nuclear reactions to produce high intensities of mono-energetic gamma rays and/or neutrons. The source can be operated in either pulsed (e.g., to detect delayed photofission neutrons and gammas) or continuous (e.g., detecting prompt fission signatures) modes. For the gamma-rays, the source target can be segmented to incorporate different (p,γ) isotopes for producing gamma-rays at selective energies, thereby improving the probability of detection. The design parameters for the FIND system are discussed and preliminary accelerator-based measurements of gamma and neutron yields, background levels, and fission signals for several target materials under consideration are presented.

Energy expenditure while playing active and inactive video games.

PubMed

Leatherdale, Scott T; Woodruff, Sarah J; Manske, Stephen R

2010-01-01

To examine energy expenditure (EE) when playing active and inactive videogames (VG). Predicted EE was measured among 51 undergraduate students while playing active and inactive VG (Ontario, Canada). Predicted EE was significantly higher playing the active VG compared to the inactive VG according to heart rate monitor (97.4 kcal vs 64.7 kcal) and SenseWear armband (192.4 kcal vs 42.3 kcal) estimates. Active VG may be a viable intervention tool for increasing EE among students who would otherwise be spending time in sedentary screen-based behaviors.

ERP Energy and Cognitive Activity Correlates

NASA Astrophysics Data System (ADS)

Schillaci, Michael Jay; Vendemia, Jennifer M. C.

2014-03-01

We propose a novel analysis approach for high-density event related scalp potential (ERP) data where the integrated channel-power is used to attain an energy density functional state for channel-clusters of neurophysiological significance. The method is applied to data recorded during a two-stimulus, directed lie paradigm and shows that deceptive responses emit between 8% and 10% less power. A time course analysis of these cognitive activity measures over posterior and anterior regions of the cortex suggests that neocortical interactions, reflecting the differing workload demands during executive and semantic processes, take about 50% longer for the case of deception. These results suggest that the proposed method may provide a useful tool for the analysis of ERP correlates of high-order cognitive functioning. We also report on a possible equivalence between the energy functional distribution and near-infrared signatures that have been measured with other modalities.

Daily energy expenditure, physical activity, and weight loss in Parkinson's disease patients

USDA-ARS?s Scientific Manuscript database

Patients with Parkinson's disease (PD) commonly exhibit weight loss (WL) which investigators attribute to various factors, including elevated energy expenditure. We tested the hypothesis that daily energy expenditure (DEE) and its components, resting energy expenditure (REE) and physical activity (P...

Intrinsic atopic dermatitis shows similar TH2 and higher TH17 immune activation compared with extrinsic atopic dermatitis.

PubMed

Suárez-Fariñas, Mayte; Dhingra, Nikhil; Gittler, Julia; Shemer, Avner; Cardinale, Irma; de Guzman Strong, Cristina; Krueger, James G; Guttman-Yassky, Emma

2013-08-01

Atopic dermatitis (AD) is classified as extrinsic and intrinsic, representing approximately 80% and 20% of patients with the disease, respectively. Although sharing a similar clinical phenotype, only extrinsic AD is characterized by high serum IgE levels. Because most patients with AD exhibit high IgE levels, an "allergic"/IgE-mediated disease pathogenesis was hypothesized. However, current models associate AD with T-cell activation, particularly TH2/TH22 polarization, and epidermal barrier defects. We sought to define whether both variants share a common pathogenesis. We stratified 51 patients with severe AD into extrinsic AD (n = 42) and intrinsic AD (n = 9) groups (with similar mean disease activity/SCORAD scores) and analyzed the molecular and cellular skin pathology of lesional and nonlesional intrinsic AD and extrinsic AD by using gene expression (real-time PCR) and immunohistochemistry. A significant correlation between IgE levels and SCORAD scores (r = 0.76, P < 10(-5)) was found only in patients with extrinsic AD. Marked infiltrates of T cells and dendritic cells and corresponding epidermal alterations (keratin 16, Mki67, and S100A7/A8/A9) defined lesional skin of patients with both variants. However, higher activation of all inflammatory axes (including TH2) was detected in patients with intrinsic AD, particularly TH17 and TH22 cytokines. Positive correlations between TH17-related molecules and SCORAD scores were only found in patients with intrinsic AD, whereas only patients with extrinsic AD showed positive correlations between SCORAD scores and TH2 cytokine (IL-4 and IL-5) levels and negative correlations with differentiation products (loricrin and periplakin). Although differences in TH17 and TH22 activation exist between patients with intrinsic AD and those with extrinsic AD, we identified common disease-defining features of T-cell activation, production of polarized cytokines, and keratinocyte responses to immune products. Our data indicate that a

An electrophysiological signature of summed similarity in visual working memory.

PubMed

van Vugt, Marieke K; Sekuler, Robert; Wilson, Hugh R; Kahana, Michael J

2013-05-01

Summed-similarity models of short-term item recognition posit that participants base their judgments of an item's prior occurrence on that item's summed similarity to the ensemble of items on the remembered list. We examined the neural predictions of these models in 3 short-term recognition memory experiments using electrocorticographic/depth electrode recordings and scalp electroencephalography. On each experimental trial, participants judged whether a test face had been among a small set of recently studied faces. Consistent with summed-similarity theory, participants' tendency to endorse a test item increased as a function of its summed similarity to the items on the just-studied list. To characterize this behavioral effect of summed similarity, we successfully fit a summed-similarity model to individual participant data from each experiment. Using the parameters determined from fitting the summed-similarity model to the behavioral data, we examined the relation between summed similarity and brain activity. We found that 4-9 Hz theta activity in the medial temporal lobe and 2-4 Hz delta activity recorded from frontal and parietal cortices increased with summed similarity. These findings demonstrate direct neural correlates of the similarity computations that form the foundation of several major cognitive theories of human recognition memory. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Clustering of 3D-Structure Similarity Based Network of Secondary Metabolites Reveals Their Relationships with Biological Activities.

PubMed

Ohtana, Yuki; Abdullah, Azian Azamimi; Altaf-Ul-Amin, Md; Huang, Ming; Ono, Naoaki; Sato, Tetsuo; Sugiura, Tadao; Horai, Hisayuki; Nakamura, Yukiko; Morita Hirai, Aki; Lange, Klaus W; Kibinge, Nelson K; Katsuragi, Tetsuo; Shirai, Tsuyoshi; Kanaya, Shigehiko

2014-12-01

Developing database systems connecting diverse species based on omics is the most important theme in big data biology. To attain this purpose, we have developed KNApSAcK Family Databases, which are utilized in a number of researches in metabolomics. In the present study, we have developed a network-based approach to analyze relationships between 3D structure and biological activity of metabolites consisting of four steps as follows: construction of a network of metabolites based on structural similarity (Step 1), classification of metabolites into structure groups (Step 2), assessment of statistically significant relations between structure groups and biological activities (Step 3), and 2-dimensional clustering of the constructed data matrix based on statistically significant relations between structure groups and biological activities (Step 4). Applying this method to a data set consisting of 2072 secondary metabolites and 140 biological activities reported in KNApSAcK Metabolite Activity DB, we obtained 983 statistically significant structure group-biological activity pairs. As a whole, we systematically analyzed the relationship between 3D-chemical structures of metabolites and biological activities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physical Activity Energy Expenditure and Sarcopenia in Black South African Urban Women.

PubMed

Kruger, Herculina S; Havemann-Nel, Lize; Ravyse, Chrisna; Moss, Sarah J; Tieland, Michael

2016-03-01

Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women. In a cross-sectional study, 247 women (mean age 57 y) were randomly selected. Anthropometric and sociodemographic variables, dietary intakes, and physical activity were measured. Activity was also measured by combined accelerometery/heart rate monitoring (ActiHeart), and HIV status was tested. Dual energy x-ray absorptiometry was used to measure appendicular skeletal mass (ASM). Sarcopenia was defined according to a recently derived SA cutpoint of ASM index (ASM/height squared) < 4.94 kg/m(2). In total, 8.9% of the women were sarcopenic, decreasing to 8.1% after exclusion of participants who were HIV positive. In multiple regressions with ASM index, grip strength, and gait speed, respectively, as dependent variables, only activity energy expenditure (β = .27) was significantly associated with ASM index. Age (β = -.50) and activity energy expenditure (β = .17) were significantly associated with gait speed. Age (β = -.11) and lean mass (β = .21) were significantly associated with handgrip strength. Sarcopenia was prevalent among these SA women and was associated with low physical activity energy expenditure.

Lean adolescents achieve higher intensities but not higher energy expenditure while playing active video games compared with obese ones.

PubMed

Chaput, J P; Genin, P M; Le Moel, B; Pereira, B; Boirie, Y; Duclos, M; Thivel, D

2016-04-01

While decreased physical activity and increased sedentary behaviours are incriminated for their role in the progression of obesity, active video games (AVG) may offer a new alternative to increase energy expenditure in youth. This study is the first to examine the effect of a 1-h AVG play on lean and obese adolescents' energy expenditure. Body composition and aerobic fitness were assessed in 19 obese and 12 lean adolescent boys (12-15 years old). Participants performed a 1-h AVG session (Kinect Sports technology) while wearing a portable indirect calorimeter (K4b2) to assess their energy expenditure and heart rate. Body weight (91.0 ± 9.5 vs. 58.5 ± 12.4 kg), body mass index (32.2 ± 3.1 vs. 20.3 ± 1.6 kg m(-2) ) and body fat (38.1 ± 2.7 vs. 13.4 ± 3.9%) were significantly higher in obese adolescents (P < 0.001). Absolute energy expenditure was significantly higher in obese (P < 0.05) but not when corrected for body composition. Maximal heart rate reached during AVG was significantly higher in lean adolescents (190 ± 25 vs. 183 ± 28 bpm, P < 0.05). Time spent between 3 and 6 METs (Metabolic Equivalent Task) was not different between groups but time spent above 6 METs was higher in lean adolescents (P < 0.05). Although lean and obese adolescent boys experienced similar energy expenditure relative to their body size during a 1-h Kinect AVG session, lean adolescents spent more time in moderate-to-vigorous physical activity. © 2015 World Obesity.

Kinetic energy budgets during the life cycle of intense convective activity

NASA Technical Reports Server (NTRS)

Fuelberg, H. E.; Scoggins, J. R.

1978-01-01

Synoptic-scale data at three- and six-hour intervals are employed to study the relationship between changing kinetic energy variables and the life cycles of two severe squall lines. The kinetic energy budgets indicate a high degree of kinetic energy generation, especially pronounced near the jet-stream level. Energy losses in the storm environment are due to the transfer of kinetic energy from grid to subgrid scales of motion; large-scale upward vertical motion carries aloft the kinetic energy generated by storm activity at lower levels. In general, the time of maximum storm intensity is also the time of maximum energy conversion and transport.

Free-energy landscape of the GB1 hairpin in all-atom explicit solvent simulations with different force fields: Similarities and differences.

PubMed

Best, Robert B; Mittal, Jeetain

2011-04-01

Although it is now possible to fold peptides and miniproteins in molecular dynamics simulations, it is well appreciated that force fields are not all transferable to different proteins. Here, we investigate the influence of the protein force field and the solvent model on the folding energy landscape of a prototypical two-state folder, the GB1 hairpin. We use extensive replica-exchange molecular dynamics simulations to characterize the free-energy surface as a function of temperature. Most of these force fields appear similar at a global level, giving a fraction folded at 300 K between 0.2 and 0.8 in all cases, which is a difference in stability of 2.8 kT, and are generally consistent with experimental data at this temperature. The most significant differences appear in the unfolded state, where there are different residual secondary structures which are populated, and the overall dimensions of the unfolded states, which in most of the force fields are too collapsed relative to experimental Förster Resonance Energy Transfer (FRET) data.

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing or other similar activities? (a) The towing of a person... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false May I use a vessel to tow a...

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing or other similar activities? (a) The towing of a person... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false May I use a vessel to tow a...

Estimating Physical Activity Energy Expenditure with the Kinect Sensor in an Exergaming Environment

PubMed Central

Nathan, David; Huynh, Du Q.; Rubenson, Jonas; Rosenberg, Michael

2015-01-01

Active video games that require physical exertion during game play have been shown to confer health benefits. Typically, energy expended during game play is measured using devices attached to players, such as accelerometers, or portable gas analyzers. Since 2010, active video gaming technology incorporates marker-less motion capture devices to simulate human movement into game play. Using the Kinect Sensor and Microsoft SDK this research aimed to estimate the mechanical work performed by the human body and estimate subsequent metabolic energy using predictive algorithmic models. Nineteen University students participated in a repeated measures experiment performing four fundamental movements (arm swings, standing jumps, body-weight squats, and jumping jacks). Metabolic energy was captured using a Cortex Metamax 3B automated gas analysis system with mechanical movement captured by the combined motion data from two Kinect cameras. Estimations of the body segment properties, such as segment mass, length, centre of mass position, and radius of gyration, were calculated from the Zatsiorsky-Seluyanov's equations of de Leva, with adjustment made for posture cost. GPML toolbox implementation of the Gaussian Process Regression, a locally weighted k-Nearest Neighbour Regression, and a linear regression technique were evaluated for their performance on predicting the metabolic cost from new feature vectors. The experimental results show that Gaussian Process Regression outperformed the other two techniques by a small margin. This study demonstrated that physical activity energy expenditure during exercise, using the Kinect camera as a motion capture system, can be estimated from segmental mechanical work. Estimates for high-energy activities, such as standing jumps and jumping jacks, can be made accurately, but for low-energy activities, such as squatting, the posture of static poses should be considered as a contributing factor. When translated into the active video gaming

High-Throughput Gene Expression Profiles to Define Drug Similarity and Predict Compound Activity.

PubMed

De Wolf, Hans; Cougnaud, Laure; Van Hoorde, Kirsten; De Bondt, An; Wegner, Joerg K; Ceulemans, Hugo; Göhlmann, Hinrich

2018-04-01

By adding biological information, beyond the chemical properties and desired effect of a compound, uncharted compound areas and connections can be explored. In this study, we add transcriptional information for 31K compounds of Janssen's primary screening deck, using the HT L1000 platform and assess (a) the transcriptional connection score for generating compound similarities, (b) machine learning algorithms for generating target activity predictions, and (c) the scaffold hopping potential of the resulting hits. We demonstrate that the transcriptional connection score is best computed from the significant genes only and should be interpreted within its confidence interval for which we provide the stats. These guidelines help to reduce noise, increase reproducibility, and enable the separation of specific and promiscuous compounds. The added value of machine learning is demonstrated for the NR3C1 and HSP90 targets. Support Vector Machine models yielded balanced accuracy values ≥80% when the expression values from DDIT4 & SERPINE1 and TMEM97 & SPR were used to predict the NR3C1 and HSP90 activity, respectively. Combining both models resulted in 22 new and confirmed HSP90-independent NR3C1 inhibitors, providing two scaffolds (i.e., pyrimidine and pyrazolo-pyrimidine), which could potentially be of interest in the treatment of depression (i.e., inhibiting the glucocorticoid receptor (i.e., NR3C1), while leaving its chaperone, HSP90, unaffected). As such, the initial hit rate increased by a factor 300, as less, but more specific chemistry could be screened, based on the upfront computed activity predictions.

25 CFR 224.80 - Under what authority will a tribe perform activities for energy resource development?

Code of Federal Regulations, 2011 CFR

2011-04-01

... energy resource development? 224.80 Section 224.80 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS TRIBAL ENERGY RESOURCE AGREEMENTS UNDER THE INDIAN TRIBAL ENERGY DEVELOPMENT... development? A tribe will perform activities for energy resource development activities undertaken under a...

Apparent Activation Energies Associated with Protein Dynamics on Hydrophobic and Hydrophilic Surfaces

PubMed Central

Langdon, Blake B.; Kastantin, Mark; Schwartz, Daniel K.

2012-01-01

With the use of single-molecule total internal reflection fluorescence microscopy (TIRFM), the dynamics of bovine serum albumin (BSA) and human fibrinogen (Fg) at low concentrations were observed at the solid-aqueous interface as a function of temperature on hydrophobic trimethylsilane (TMS) and hydrophilic fused silica (FS) surfaces. Multiple dynamic modes and populations were observed and characterized by their surface residence times and squared-displacement distributions (surface diffusion). Characteristic desorption and diffusion rates for each population/mode were generally found to increase with temperature, and apparent activation energies were determined from Arrhenius analyses. The apparent activation energies of desorption and diffusion were typically higher on FS than on TMS surfaces, suggesting that protein desorption and mobility were hindered on hydrophilic surfaces due to favorable protein-surface and solvent-surface interactions. The diffusion of BSA on TMS appeared to be activationless for several populations, whereas diffusion on FS always exhibited an apparent activation energy. All activation energies were small in absolute terms (generally only a few kBT), suggesting that most adsorbed protein molecules are weakly bound and move and desorb readily under ambient conditions. PMID:22713578

Statistical analysis of activation and reaction energies with quasi-variational coupled-cluster theory

NASA Astrophysics Data System (ADS)

Black, Joshua A.; Knowles, Peter J.

2018-06-01

The performance of quasi-variational coupled-cluster (QV) theory applied to the calculation of activation and reaction energies has been investigated. A statistical analysis of results obtained for six different sets of reactions has been carried out, and the results have been compared to those from standard single-reference methods. In general, the QV methods lead to increased activation energies and larger absolute reaction energies compared to those obtained with traditional coupled-cluster theory.

Energy Expenditure and Intensity of Physical Activity in Soccer Referees During Match-Play

PubMed Central

da Silva, Alberto Inácio; Fernandes, Luiz Cláudio; Fernandez, Ricardo

2008-01-01

The aim of this study was to determine the caloric expenditure and the intensity of physical activities performed by official soccer referees during a match expressed in Metabolic Equivalent (METs). The physical activity of referees accredited by CBF (Brazilian Confederation of Soccer) was video-recorded during twenty-nine official games of Paraná Championship (Brasil), Series A and B of the 2005/2006. Computerized video analysis was used to determine the time spent in 6 locomotor activities (standing still, walking, jogging, backwards running, running and sprint). The frequency and duration of each activity were recorded and these data were utilized to calculate the distance covered by the referee. Energy expenditure values were estimated, utilizing specific equations, from the time players spent in each motor activity. The referees observed in this study had a mean age of 38.9 ± 3.8 years, body mass of 86.1 ± 7.1 kg, stature of 1.80 ± 0.07 m and a body mass index of 26.5 ± 0.6 kg·m-2. During match-play, referees covered an average distance of 9155.4 ± 70.3 meters (8411 - 9765), with a mean energy expenditure of 734.7 ± 65 kcal. This energy expenditure was significantly reduced in the second half: 359.9 ± 6.3 vs 374.7 ± 6.6 kcal (p = 0.006), and averaged to be moderate energy intensity (5 METs) with predominant utilization of the aerobic energy system. In total, during 67% of match-play the intensity was equal or lower than 3.8 METs and in 33% it was higher than 9.8 METs. The pattern of movement observed in the present study confirms that soccer refereeing may be considered as a highly intermittent exercise mode. The high to low-intensity activity ratio may be defined as 1:7.1. In conclusion, referees officiating in professional soccer matches in Brazil should perform a physical conditioning regime that provides the stamina required at this level and consume appropriate and adequate nutrition to meet the energetic demands for match-play. Key points

Energy expenditure and intensity of physical activity in soccer referees during match-play.

PubMed

da Silva, Alberto Inácio; Fernandes, Luiz Cláudio; Fernandez, Ricardo

2008-01-01

The aim of this study was to determine the caloric expenditure and the intensity of physical activities performed by official soccer referees during a match expressed in Metabolic Equivalent (METs). The physical activity of referees accredited by CBF (Brazilian Confederation of Soccer) was video-recorded during twenty-nine official games of Paraná Championship (Brasil), Series A and B of the 2005/2006. Computerized video analysis was used to determine the time spent in 6 locomotor activities (standing still, walking, jogging, backwards running, running and sprint). The frequency and duration of each activity were recorded and these data were utilized to calculate the distance covered by the referee. Energy expenditure values were estimated, utilizing specific equations, from the time players spent in each motor activity. The referees observed in this study had a mean age of 38.9 ± 3.8 years, body mass of 86.1 ± 7.1 kg, stature of 1.80 ± 0.07 m and a body mass index of 26.5 ± 0.6 kg·m(-2). During match-play, referees covered an average distance of 9155.4 ± 70.3 meters (8411 - 9765), with a mean energy expenditure of 734.7 ± 65 kcal. This energy expenditure was significantly reduced in the second half: 359.9 ± 6.3 vs 374.7 ± 6.6 kcal (p = 0.006), and averaged to be moderate energy intensity (5 METs) with predominant utilization of the aerobic energy system. In total, during 67% of match-play the intensity was equal or lower than 3.8 METs and in 33% it was higher than 9.8 METs. The pattern of movement observed in the present study confirms that soccer refereeing may be considered as a highly intermittent exercise mode. The high to low-intensity activity ratio may be defined as 1:7.1. In conclusion, referees officiating in professional soccer matches in Brazil should perform a physical conditioning regime that provides the stamina required at this level and consume appropriate and adequate nutrition to meet the energetic demands for match-play. Key points

Leanness and heightened nonresting energy expenditure: role of skeletal muscle activity thermogenesis

PubMed Central

Mukherjee, Sromona; Shukla, Charu; Britton, Steven L.; Koch, Lauren G.; Shi, Haifei; Novak, Colleen M.

2014-01-01

A high-calorie diet accompanied by low levels of physical activity (PA) accounts for the widespread prevalence of obesity today, and yet some people remain lean even in this obesogenic environment. Here, we investigate the cause for this exception. A key trait that predicts high PA in both humans and laboratory rodents is intrinsic aerobic capacity. Rats artificially selected as high-capacity runners (HCR) are lean and consistently more physically active than their low-capacity runner (LCR) counterparts; this applies to both males and females. Here, we demonstrate that HCR show heightened total energy expenditure (TEE) and hypothesize that this is due to higher nonresting energy expenditure (NREE; includes activity EE). After matching for body weight and lean mass, female HCR consistently had heightened nonresting EE, but not resting EE, compared with female LCR. Because of the dominant role of skeletal muscle in nonresting EE, we examined muscle energy use. We found that lean female HCR had higher muscle heat dissipation during activity, explaining their low economy of activity and high activity EE. This may be due to the amplified skeletal muscle expression levels of proteins involved in EE and reduced expression levels of proteins involved in energy conservation in HCR relative to LCR. This is also associated with an increased sympathetic drive to skeletal muscle in HCR compared with LCR. We find little support for the hypothesis that resting metabolic rate is correlated with maximal aerobic capacity if body size and composition are fully considered; rather, the critical factor appears to be activity thermogenesis. PMID:24398400

Conservation II. Science Activities in Energy. [Student's and] Teacher's Guide.

ERIC Educational Resources Information Center

Oak Ridge Associated Universities, TN.

Designed for science students in fourth, fifth, and sixth grades, the activities in this unit illustrate principles and problems related to the conservation of energy. Eleven student activities using art, economics, arithmetic, and other skills and disciplines help teachers directly involve students in exploring scientific questions and making…

Effects of Experimental Sleep Restriction on Caloric Intake and Activity Energy Expenditure

PubMed Central

Calvin, Andrew D.; Carter, Rickey E.; Adachi, Taro; G. Macedo, Paula; Albuquerque, Felipe N.; van der Walt, Christelle; Bukartyk, Jan; Davison, Diane E.; Levine, James A.

2013-01-01

Background: Epidemiologic studies link short sleep duration to obesity and weight gain. Insufficient sleep appears to alter circulating levels of the hormones leptin and ghrelin, which may promote appetite, although the effects of sleep restriction on caloric intake and energy expenditure are unclear. We sought to determine the effect of 8 days/8 nights of sleep restriction on caloric intake, activity energy expenditure, and circulating levels of leptin and ghrelin. Methods: We conducted a randomized study of usual sleep vs a sleep restriction of two-thirds of normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcomes were caloric intake, activity energy expenditure, and circulating levels of leptin and ghrelin. Results: Caloric intake in the sleep-restricted group increased by +559 kcal/d (SD, 706 kcal/d, P = .006) and decreased in the control group by −118 kcal/d (SD, 386 kcal/d, P = .51) for a net change of +677 kcal/d (95% CI, 148-1,206 kcal/d; P = .014). Sleep restriction was not associated with changes in activity energy expenditure (P = .62). No change was seen in levels of leptin (P = .27) or ghrelin (P = .21). Conclusions: Sleep restriction was associated with an increase in caloric consumption with no change in activity energy expenditure or leptin and ghrelin concentrations. Increased caloric intake without any accompanying increase in energy expenditure may contribute to obesity in people who are exposed to long-term sleep restriction. Trial Registration: ClinicalTrials.gov; No.: NCT01334788; URL: www.clinicaltrials.gov PMID:23392199

Structural and functional properties of the N transcriptional activation domain of thyroid transcription factor-1: similarities with the acidic activation domains.

PubMed Central

Tell, G; Perrone, L; Fabbro, D; Pellizzari, L; Pucillo, C; De Felice, M; Acquaviva, R; Formisano, S; Damante, G

1998-01-01

The thyroid transcription factor 1 (TTF-1) is a tissue-specific transcription factor involved in the development of thyroid and lung. TTF-1 contains two transcriptional activation domains (N and C domain). The primary amino acid sequence of the N domain does not show any typical characteristic of known transcriptional activation domains. In aqueous solution the N domain exists in a random-coil conformation. The increase of the milieu hydrophobicity, by the addition of trifluoroethanol, induces a considerable gain of alpha-helical structure. Acidic transcriptional activation domains are largely unstructured in solution, but, under hydrophobic conditions, folding into alpha-helices or beta-strands can be induced. Therefore our data indicate that the inducibility of alpha-helix by hydrophobic conditions is a property not restricted to acidic domains. Co-transfections experiments indicate that the acidic domain of herpes simplex virus protein VP16 (VP16) and the TTF-1 N domain are interchangeable and that a chimaeric protein, which combines VP16 linked to the DNA-binding domain of TTF-1, undergoes the same regulatory constraints that operate for the wild-type TTF-1. In addition, we demonstrate that the TTF-1 N domain possesses two typical properties of acidic activation domains: TBP (TATA-binding protein) binding and ability to activate transcription in yeast. Accordingly, the TTF-1 N domain is able to squelch the activity of the p65 acidic domain. Altogether, these structural and functional data suggest that a non-acidic transcriptional activation domain (TTF-1 N domain) activates transcription by using molecular mechanisms similar to those used by acidic domains. TTF-1 N domain and acidic domains define a family of proteins whose common property is to activate transcription through the use of mechanisms largely conserved during evolutionary development. PMID:9425125

Activity-Based Approach for Teaching Aqueous Solubility, Energy, and Entropy

ERIC Educational Resources Information Center

Eisen, Laura; Marano, Nadia; Glazier, Samantha

2014-01-01

We describe an activity-based approach for teaching aqueous solubility to introductory chemistry students that provides a more balanced presentation of the roles of energy and entropy in dissolution than is found in most general chemistry textbooks. In the first few activities, students observe that polar substances dissolve in water, whereas…

Free-energy landscape of ion-channel voltage-sensor–domain activation

PubMed Central

Delemotte, Lucie; Kasimova, Marina A.; Klein, Michael L.; Tarek, Mounir; Carnevale, Vincenzo

2015-01-01

Voltage sensor domains (VSDs) are membrane-bound protein modules that confer voltage sensitivity to membrane proteins. VSDs sense changes in the transmembrane voltage and convert the electrical signal into a conformational change called activation. Activation involves a reorganization of the membrane protein charges that is detected experimentally as transient currents. These so-called gating currents have been investigated extensively within the theoretical framework of so-called discrete-state Markov models (DMMs), whereby activation is conceptualized as a series of transitions across a discrete set of states. Historically, the interpretation of DMM transition rates in terms of transition state theory has been instrumental in shaping our view of the activation process, whose free-energy profile is currently envisioned as composed of a few local minima separated by steep barriers. Here we use atomistic level modeling and well-tempered metadynamics to calculate the configurational free energy along a single transition from first principles. We show that this transition is intrinsically multidimensional and described by a rough free-energy landscape. Remarkably, a coarse-grained description of the system, based on the use of the gating charge as reaction coordinate, reveals a smooth profile with a single barrier, consistent with phenomenological models. Our results bridge the gap between microscopic and macroscopic descriptions of activation dynamics and show that choosing the gating charge as reaction coordinate masks the topological complexity of the network of microstates participating in the transition. Importantly, full characterization of the latter is a prerequisite to rationalize modulation of this process by lipids, toxins, drugs, and genetic mutations. PMID:25535341

Free-energy landscape of ion-channel voltage-sensor-domain activation.

PubMed

Delemotte, Lucie; Kasimova, Marina A; Klein, Michael L; Tarek, Mounir; Carnevale, Vincenzo

2015-01-06

Voltage sensor domains (VSDs) are membrane-bound protein modules that confer voltage sensitivity to membrane proteins. VSDs sense changes in the transmembrane voltage and convert the electrical signal into a conformational change called activation. Activation involves a reorganization of the membrane protein charges that is detected experimentally as transient currents. These so-called gating currents have been investigated extensively within the theoretical framework of so-called discrete-state Markov models (DMMs), whereby activation is conceptualized as a series of transitions across a discrete set of states. Historically, the interpretation of DMM transition rates in terms of transition state theory has been instrumental in shaping our view of the activation process, whose free-energy profile is currently envisioned as composed of a few local minima separated by steep barriers. Here we use atomistic level modeling and well-tempered metadynamics to calculate the configurational free energy along a single transition from first principles. We show that this transition is intrinsically multidimensional and described by a rough free-energy landscape. Remarkably, a coarse-grained description of the system, based on the use of the gating charge as reaction coordinate, reveals a smooth profile with a single barrier, consistent with phenomenological models. Our results bridge the gap between microscopic and macroscopic descriptions of activation dynamics and show that choosing the gating charge as reaction coordinate masks the topological complexity of the network of microstates participating in the transition. Importantly, full characterization of the latter is a prerequisite to rationalize modulation of this process by lipids, toxins, drugs, and genetic mutations.

The Differential Gibbs Free Energy of Activation and its Implications in the Transition-State of Enzymatic Reactions

NASA Astrophysics Data System (ADS)

Maggi, F.; Riley, W. J.

2016-12-01

We propose a mathematical framework to introduce the concept of differential free energy of activation in enzymatically catalyzed reactions, and apply it to N uptake by microalgae and bacteria. This framework extends the thermodynamic capabilities of the classical transition-state theory in and harmonizes the consolidated definitions of kinetic parameters with their thermodynamic and physical meaning. Here, the activation energy is assumed to be a necessary energetic level for equilibrium complexation between reactants and activated complex; however, an additional energy contribution is required for the equilibrium activated complex to release reaction products. We call this "differential free energy of activation"; it can be described by a Boltzmann distribution, and corresponds to a free energy level different from that of complexation. Whether this level is above or below the free energy of activation depends on the reaction, and defines energy domains that correspond to "superactivated", "activated", and "subactivated" complexes. The activated complex reaching one of those states will eventually release the products from an energy level different than that of activation. The concept of differential free energy of activation was tested on 57 independent experiments of NH­4+ and NO3- uptake by various microalgae and bacteria at temperatures ranging between 1 and 45oC. Results showed that the complexation equilibrium always favored the activated complex, but the differential energy of activation led to an apparent energy barrier consistent with observations. Temperature affected all energy levels within this framework but did not alter substantially these thermodynamic features. Overall the approach: (1) provides a thermodynamic and mathematical link between Michaelis-Menten and rate constants; (2) shows that both kinetic parameters can be described or approximated by Arrhenius' like equations; (3) describes the likelihood of formation of sub-, super-, and

Conflating Time and Energy: Views From Older Adults in Lower Socioeconomic Status Areas on Physical Activity.

PubMed

Devereux-Fitzgerald, Angela; Powell, Rachael; French, David P

2018-05-24

Perceptions of time and energy and their role in physical activity engagement were examined in older adults living in lower socioeconomic status areas. Semistructured interviews were conducted with 19 participants aged 67-94 years. A thematic framework analysis identified four themes: Time is Energy (older adults conflate time and energy in relation to physical activity), Reduced Day (engaging in activities outside a certain time frame is deemed unacceptable), Being Given Enough Time (need for time to socialize and go at own pace), and Seasonal Impact (seasonal differences affecting access). Enjoyment appears to mitigate the perceived energy drain and increase the capacity for physical activities for many. Conflation of time and energy may explain observed discrepancies between older adults' actual and perceived available time. Having locally based physical activities means less time/energy is required to attend, leaving more resources for physical activity itself. A limited availability of resources in lower socioeconomic status areas is therefore problematic.

Similar or Different? The Role of the Ventrolateral Prefrontal Cortex in Similarity Detection

PubMed Central

Garcin, Béatrice; Volle, Emmanuelle; Dubois, Bruno; Levy, Richard

2012-01-01

Patients with frontal lobe syndrome can exhibit two types of abnormal behaviour when asked to place a banana and an orange in a single category: some patients categorize them at a concrete level (e.g., “both have peel”), while others continue to look for differences between these objects (e.g., “one is yellow, the other is orange”). These observations raise the question of whether abstraction and similarity detection are distinct processes involved in abstract categorization, and that depend on separate areas of the prefrontal cortex (PFC). We designed an original experimental paradigm for a functional magnetic resonance imaging (fMRI) study involving healthy subjects, confirming the existence of two distinct processes relying on different prefrontal areas, and thus explaining the behavioural dissociation in frontal lesion patients. We showed that: 1) Similarity detection involves the anterior ventrolateral PFC bilaterally with a right-left asymmetry: the right anterior ventrolateral PFC is only engaged in detecting physical similarities; 2) Abstraction per se activates the left dorsolateral PFC. PMID:22479551

Coupling effect of nodes popularity and similarity on social network persistence

PubMed Central

Jin, Xiaogang; Jin, Cheng; Huang, Jiaxuan; Min, Yong

2017-01-01

Network robustness represents the ability of networks to withstand failures and perturbations. In social networks, maintenance of individual activities, also called persistence, is significant towards understanding robustness. Previous works usually consider persistence on pre-generated network structures; while in social networks, the network structure is growing with the cascading inactivity of existed individuals. Here, we address this challenge through analysis for nodes under a coevolution model, which characterizes individual activity changes under three network growth modes: following the descending order of nodes’ popularity, similarity or uniform random. We show that when nodes possess high spontaneous activities, a popularity-first growth mode obtains highly persistent networks; otherwise, with low spontaneous activities, a similarity-first mode does better. Moreover, a compound growth mode, with the consecutive joining of similar nodes in a short period and mixing a few high popularity nodes, obtains the highest persistence. Therefore, nodes similarity is essential for persistent social networks, while properly coupling popularity with similarity further optimizes the persistence. This demonstrates the evolution of nodes activity not only depends on network topology, but also their connective typology. PMID:28220840

Coupling effect of nodes popularity and similarity on social network persistence

NASA Astrophysics Data System (ADS)

Jin, Xiaogang; Jin, Cheng; Huang, Jiaxuan; Min, Yong

2017-02-01

Network robustness represents the ability of networks to withstand failures and perturbations. In social networks, maintenance of individual activities, also called persistence, is significant towards understanding robustness. Previous works usually consider persistence on pre-generated network structures; while in social networks, the network structure is growing with the cascading inactivity of existed individuals. Here, we address this challenge through analysis for nodes under a coevolution model, which characterizes individual activity changes under three network growth modes: following the descending order of nodes’ popularity, similarity or uniform random. We show that when nodes possess high spontaneous activities, a popularity-first growth mode obtains highly persistent networks; otherwise, with low spontaneous activities, a similarity-first mode does better. Moreover, a compound growth mode, with the consecutive joining of similar nodes in a short period and mixing a few high popularity nodes, obtains the highest persistence. Therefore, nodes similarity is essential for persistent social networks, while properly coupling popularity with similarity further optimizes the persistence. This demonstrates the evolution of nodes activity not only depends on network topology, but also their connective typology.

Coupling effect of nodes popularity and similarity on social network persistence.

PubMed

Jin, Xiaogang; Jin, Cheng; Huang, Jiaxuan; Min, Yong

2017-02-21

Network robustness represents the ability of networks to withstand failures and perturbations. In social networks, maintenance of individual activities, also called persistence, is significant towards understanding robustness. Previous works usually consider persistence on pre-generated network structures; while in social networks, the network structure is growing with the cascading inactivity of existed individuals. Here, we address this challenge through analysis for nodes under a coevolution model, which characterizes individual activity changes under three network growth modes: following the descending order of nodes' popularity, similarity or uniform random. We show that when nodes possess high spontaneous activities, a popularity-first growth mode obtains highly persistent networks; otherwise, with low spontaneous activities, a similarity-first mode does better. Moreover, a compound growth mode, with the consecutive joining of similar nodes in a short period and mixing a few high popularity nodes, obtains the highest persistence. Therefore, nodes similarity is essential for persistent social networks, while properly coupling popularity with similarity further optimizes the persistence. This demonstrates the evolution of nodes activity not only depends on network topology, but also their connective typology.

Communication: Understanding molecular representations in machine learning: The role of uniqueness and target similarity

NASA Astrophysics Data System (ADS)

Huang, Bing; von Lilienfeld, O. Anatole

2016-10-01

The predictive accuracy of Machine Learning (ML) models of molecular properties depends on the choice of the molecular representation. Inspired by the postulates of quantum mechanics, we introduce a hierarchy of representations which meet uniqueness and target similarity criteria. To systematically control target similarity, we simply rely on interatomic many body expansions, as implemented in universal force-fields, including Bonding, Angular (BA), and higher order terms. Addition of higher order contributions systematically increases similarity to the true potential energy and predictive accuracy of the resulting ML models. We report numerical evidence for the performance of BAML models trained on molecular properties pre-calculated at electron-correlated and density functional theory level of theory for thousands of small organic molecules. Properties studied include enthalpies and free energies of atomization, heat capacity, zero-point vibrational energies, dipole-moment, polarizability, HOMO/LUMO energies and gap, ionization potential, electron affinity, and electronic excitations. After training, BAML predicts energies or electronic properties of out-of-sample molecules with unprecedented accuracy and speed.

Carbon Nanotube Thin Films for Active Noise Cancellation, Solar Energy Harvesting, and Energy Storage in Building Windows

NASA Astrophysics Data System (ADS)

Hu, Shan

This research explores the application of carbon nanotube (CNT) films for active noise cancellation, solar energy harvesting and energy storage in building windows. The CNT-based components developed herein can be integrated into a solar-powered active noise control system for a building window. First, the use of a transparent acoustic transducer as both an invisible speaker for auxiliary audio playback and for active noise cancellation is accomplished in this work. Several challenges related to active noise cancellation in the window are addressed. These include secondary path estimation and directional cancellation of noise so as to preserve auxiliary audio and internal sounds while preventing transmission of external noise into the building. Solar energy can be harvested at a low rate of power over long durations while acoustic sound cancellation requires short durations of high power. A supercapacitor based energy storage system is therefore considered for the window. Using CNTs as electrode materials, two generations of flexible, thin, and fully solid-state supercapacitors are developed that can be integrated into the window frame. Both generations consist of carbon nanotube films coated on supporting substrates as electrodes and a solid-state polymer gel layer for the electrolyte. The first generation is a single-cell parallel-plate supercapacitor with a working voltage of 3 Volts. Its energy density is competitive with commercially available supercapacitors (which use liquid electrolyte). For many applications that will require higher working voltage, the second-generation multi-cell supercapacitor is developed. A six-cell device with a working voltage as high as 12 Volts is demonstrated here. Unlike the first generation's 3D structure, the second generation has a novel planar (2D) architecture, which makes it easy to integrate multiple cells into a thin and flexible supercapacitor. The multi-cell planar supercapacitor has energy density exceeding that of

Activation energy of extracellular enzymes in soils from different biomes.

PubMed

Steinweg, J Megan; Jagadamma, Sindhu; Frerichs, Joshua; Mayes, Melanie A

2013-01-01

Enzyme dynamics are being incorporated into soil carbon cycling models and accurate representation of enzyme kinetics is an important step in predicting belowground nutrient dynamics. A scarce number of studies have measured activation energy (Ea) in soils and fewer studies have measured Ea in arctic and tropical soils, or in subsurface soils. We determined the Ea for four typical lignocellulose degrading enzymes in the A and B horizons of seven soils covering six different soil orders. We also elucidated which soil properties predicted any measurable differences in Ea. β-glucosidase, cellobiohydrolase, phenol oxidase and peroxidase activities were measured at five temperatures, 4, 21, 30, 40, and 60°C. Ea was calculated using the Arrhenius equation. β-glucosidase and cellobiohydrolase Ea values for both A and B horizons in this study were similar to previously reported values, however we could not make a direct comparison for B horizon soils because of the lack of data. There was no consistent relationship between hydrolase enzyme Ea and the environmental variables we measured. Phenol oxidase was the only enzyme that had a consistent positive relationship between Ea and pH in both horizons. The Ea in the arctic and subarctic zones for peroxidase was lower than the hydrolases and phenol oxidase values, indicating peroxidase may be a rate limited enzyme in environments under warming conditions. By including these six soil types we have increased the number of soil oxidative enzyme Ea values reported in the literature by 50%. This study is a step towards better quantifying enzyme kinetics in different climate zones.

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false May I use a vessel to tow a person for water skiing or other similar activities? 3.12 Section 3.12 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing o...

36 CFR 3.12 - May I use a vessel to tow a person for water skiing or other similar activities?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false May I use a vessel to tow a person for water skiing or other similar activities? 3.12 Section 3.12 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR BOATING AND WATER USE ACTIVITIES § 3.12 May I use a vessel to tow a person for water skiing o...

Exploring metrics to express energy expenditure of physical activity in youth

USDA-ARS?s Scientific Manuscript database

Several approaches have been used to express energy expenditure in youth, but no consensus exists as to which best normalizes data for the wide range of ages and body sizes across a range of physical activities. This study examined several common metrics for expressing energy expenditure to determin...

Activation energy of light induced isomerization of resveratrol.

PubMed

Figueiras, Teresa Sofia; Neves-Petersen, Maria Teresa; Petersen, Steffen B

2011-09-01

Isomerization of trans-stilbenes is known to be induced by light. The two isomers have distinct absorption, fluorescence excitation and emission spectra. Resveratrol, 3,4',5-trihydroxystilbene, is a member of the stilbene family. The interest of the scientific community in resveratrol has increased over the last years due to its biomedical properties. Whereas there is a growing confidence that trans-resveratrol is non-toxic, very little is known about the pharmacology of cis-resveratrol. Of this very reason there is considerable interest in knowing the energetics of the trans-cis conversion. Cis-resveratrol is characterized by a large fluorescence quantum yield when compared to trans-resveratrol. In the present paper we report a detailed analysis of the spectral changes induced in trans-resveratrol upon 260 nm excitation for different time periods. Spectral changes have been monitored with UV-visible absorption and steady-state fluorescence spectroscopy at pH 4 at 20, 25, 30, 35, 40, 45 and 50 °C. Continuous 260 nm excitation induces a blue shift in the absorption and fluorescence excitation spectra of resveratrol and a 14 nm blue shift in its fluorescence emission. The photoisomerization yield is reported as a function of 260 nm excitation time. 330 min continuous excitation led to ~60% isomerization yield. The kinetics of trans-cis isomerization has been monitored following the increase in fluorescence quantum yield upon continuous 260 nm excitation of trans-resveratrol. The study was carried out at the above mentioned temperatures in order to obtain the Arrhenius activation energy of photoisomerization. Activation energy and pre-exponential factor were 3.7 ± 0.3 kcal.mol(-1) and 10.6 ± 1.6 s(-1), respectively. The activation energy is comparable with previously reported values for the photoisomerization of other stilbenes.

Activation energy of tantalum-tungsten oxide thermite reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cervantes, Octavio G.; Munir, Zuhair A.; Chemical Engineering and Materials Science, University of California, Davis, CA

2011-01-15

The activation energy of a sol-gel (SG) derived tantalum-tungsten oxide thermite composite was determined using the Kissinger isoconversion method. The SG derived powder was consolidated using the high-pressure spark plasma sintering (HPSPS) technique at 300 and 400 C. The ignition temperatures were investigated under high heating rates (500-2000 C min{sup -1}). Such heating rates were required in order to ignite the thermite composite. Samples consolidated at 300 C exhibit an abrupt change in temperature response prior to the main ignition temperature. This change in temperature response is attributed to the crystallization of the amorphous WO{sub 3} in the SG derivedmore » Ta-WO{sub 3} thermite composite and not to a pre-ignition reaction between the constituents. Ignition temperatures for the Ta-WO{sub 3} thermite ranged from approximately 465 to 670 C. The activation energies of the SG derived Ta-WO{sub 3} thermite composite consolidated at 300 and 400 C were determined to be 38{+-} 2 kJ mol{sup -1} and 57 {+-} 2 kJ mol{sup -1}, respectively. (author)« less

Redox Active Colloids as Discrete Energy Storage Carriers.

PubMed

Montoto, Elena C; Nagarjuna, Gavvalapalli; Hui, Jingshu; Burgess, Mark; Sekerak, Nina M; Hernández-Burgos, Kenneth; Wei, Teng-Sing; Kneer, Marissa; Grolman, Joshua; Cheng, Kevin J; Lewis, Jennifer A; Moore, Jeffrey S; Rodríguez-López, Joaquín

2016-10-12

Versatile and readily available battery materials compatible with a range of electrode configurations and cell designs are desirable for renewable energy storage. Here we report a promising class of materials based on redox active colloids (RACs) that are inherently modular in their design and overcome challenges faced by small-molecule organic materials for battery applications, such as crossover and chemical/morphological stability. RACs are cross-linked polymer spheres, synthesized with uniform diameters between 80 and 800 nm, and exhibit reversible redox activity as single particles, as monolayer films, and in the form of flowable dispersions. Viologen-based RACs display reversible cycling, accessing up to 99% of their capacity and 99 ± 1% Coulombic efficiency over 50 cycles by bulk electrolysis owing to efficient, long-distance intraparticle charge transfer. Ferrocene-based RACs paired with viologen-based RACs cycled efficiently in a nonaqueous redox flow battery employing a simple size-selective separator, thus demonstrating a possible application that benefits from their colloidal dimensions. The unprecedented versatility in RAC synthetic and electrochemical design opens new avenues for energy storage.

MAGNETIC ENERGY SPECTRA IN SOLAR ACTIVE REGIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramenko, Valentyna; Yurchyshyn, Vasyl

Line-of-sight magnetograms for 217 active regions (ARs) with different flare rates observed at the solar disk center from 1997 January until 2006 December are utilized to study the turbulence regime and its relationship to flare productivity. Data from the SOHO/MDI instrument recorded in the high-resolution mode and data from the BBSO magnetograph were used. The turbulence regime was probed via magnetic energy spectra and magnetic dissipation spectra. We found steeper energy spectra for ARs with higher flare productivity. We also report that both the power index, {alpha}, of the energy spectrum, E(k) {approx} k{sup -}{alpha}, and the total spectral energy,more » W = {integral}E(k)dk, are comparably correlated with the flare index, A, of an AR. The correlations are found to be stronger than those found between the flare index and the total unsigned flux. The flare index for an AR can be estimated based on measurements of {alpha} and W as A = 10{sup b}({alpha}W){sup c}, with b = -7.92 {+-} 0.58 and c = 1.85 {+-} 0.13. We found that the regime of the fully developed turbulence occurs in decaying ARs and in emerging ARs (at the very early stage of emergence). Well-developed ARs display underdeveloped turbulence with strong magnetic dissipation at all scales.« less

Young Scientists Explore an Encyclopedia of Energy Activities. Book 8--Intermediate Level. A Good Apple Activity Book.

ERIC Educational Resources Information Center

DeBruin, Jerry

Designed to develop creativity in young learners, this book contains interdisciplinary activities which focus on the theme of energy. Activity pages are provided that can serve as front and back covers of a student booklet and the suggested activities can be duplicated for insertion between the covers resulting in a booklet for each student. A…

Reduced Nonexercise Activity Attenuates Negative Energy Balance in Mice Engaged in Voluntary Exercise.

PubMed

Lark, Daniel S; Kwan, Jamie R; McClatchey, P Mason; James, Merrygay N; James, Freyja D; Lighton, John R B; Lantier, Louise; Wasserman, David H

2018-05-01

Exercise alone is often ineffective for treating obesity despite the associated increase in metabolic requirements. Decreased nonexercise physical activity has been implicated in this resistance to weight loss, but the mechanisms responsible are unclear. We quantified the metabolic cost of nonexercise activity, or "off-wheel" activity (OWA), and voluntary wheel running (VWR) and examined whether changes in OWA during VWR altered energy balance in chow-fed C57BL/6J mice ( n = 12). Energy expenditure (EE), energy intake, and behavior (VWR and OWA) were continuously monitored for 4 days with locked running wheels followed by 9 days with unlocked running wheels. Unlocking the running wheels increased EE as a function of VWR distance. The metabolic cost of exercise (kcal/m traveled) decreased with increasing VWR speed. Unlocking the wheel led to a negative energy balance but also decreased OWA, which was predicted to mitigate the expected change in energy balance by ∼45%. A novel behavioral circuit involved repeated bouts of VWR, and roaming was discovered and represented novel predictors of VWR behavior. The integrated analysis described here reveals that the weight loss effects of voluntary exercise can be countered by a reduction in nonexercise activity. © 2018 by the American Diabetes Association.

Self-similar seismogenic structure of the crust: A review of the problem and a mathematical model

NASA Astrophysics Data System (ADS)

Stakhovsky, I. R.

2007-12-01

The paper presents a brief review of studies of the structural organization of a seismogenic medium showing that the crust of seismically active regions possesses a fractal structure. A new mathematical model of the self-similar seismogenic structure (SSS) of the crust generalizing the reviewed publications is proposed on the basis of the scaling correspondence between the fault, seismic, and seismic energy multifractal fields of the crust. Multifractal fields of other physical origin can also be incorporated in the SSS model.

Arrhenius activation energy of damage to catalase during spray-drying.

PubMed

Schaefer, Joachim; Lee, Geoffrey

2015-07-15

The inactivation of catalase during spray-drying over a range of outlet gas temperatures could be closely represented by the Arrhenius equation. From this an activation energy for damage to the catalase could be calculated. The close fit to Arrhenius suggests that the thermally-induced part of inactivation of the catalase during the complex drying and particle-formation processes takes place at constant temperature. These processes are rapid compared with the residence time of the powder in the collecting vessel of the cyclone where dried catalase is exposed to a constant temperature equal to approximately the drying gas outlet temperature. A lower activation energy after spray drying with the ultrasonic nozzle was found than with the 2-fluid nozzle under otherwise identical spray drying conditions. It is feasible that the ultrasonic nozzle when mounted in the lid of the spray dryer heats up toward the drying gas inlet temperature much more that the air-cooled 2-fluid nozzle. Calculation of the Arrhenius activation energy also showed how the stabilizing efficacy of trehalose and mannitol on the catalase varies in strength across the range of drying gas inlet and outlet temperatures examined. Copyright © 2015 Elsevier B.V. All rights reserved.

Prediction of energy expenditure and physical activity in preschoolers

USDA-ARS?s Scientific Manuscript database

Accurate, nonintrusive, and feasible methods are needed to predict energy expenditure (EE) and physical activity (PA) levels in preschoolers. Herein, we validated cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on accelerometry and heart rate (HR) ...

Surveying predictors of late-life longitudinal change in daily activity energy expenditure.

PubMed

Valiani, Vincenzo; Sourdet, Sandrine; Schoeller, Dale A; Mackey, Dawn C; Bauer, Douglas C; Glynn, Nancy W; Yamada, Yosuke; Harris, Tamara B; Manini, Todd M

2017-01-01

Total daily energy expenditure (TEE) is composed of resting metabolic rate (RMR), post-prandial thermogenesis and activity energy expenditure (AEE). Higher AEE is strongly associated with lower mortality and physical limitations among older adults, but factors that predict changes in AEE in septu and octogenarians are not clearly understood. To identify factors associated with late-life longitudinal change in AEE. Energy expenditure was re-assessed in 83 participants (average age at baseline, 74.4±3.2 years)-an average of 7.5±0.54 years since the baseline measure. RMR was measured using indirect calorimetry and the thermic effect of meals was estimated at 10% of TEE. AEE was calculated as: TEE(0.9)-RMR. Participants were categorized into two groups according to the estimated day-to-day precision of the doubly-labeled water technique. Those who were within 10% or increased relative to their initial AEE measurement were categorized as having preserved AEE. Participants who declined greater than 10% of their initial measurement were categorized as having reduced AEE. A variety of socio-demographic, functional and mental factors, body composition, community and personal behaviors, blood measurements and health conditions were evaluated between groups at baseline and changes during follow-up. Daily AEE declined 106.61±293.25 kcal, which equated to a 14.63±40.57 kcal/d decrease per year. Fifty-nine percent (n = 49) preserved their AEE and 41% (n = 34) declined. Those who demonstrated a decline in AEE were older, had lower walking speed at baseline and showed a higher lean mass loss during follow up. Otherwise, groups were similar for socio-demographic characteristics, body composition, mental and physical function, health conditions and community and personal behaviors at baseline and change in these factors during follow-up. This study demonstrates that AEE declines through the 8th decade of life and is associated with age, lower walking speed at baseline and lean

Influence of several metal ions on the gelation activation energy of silicon tetraethoxide

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.

1988-01-01

The effects of nine metal cations (Li(+), Na(+), Mg(2+), Ca(2+), Sr(2+), Cu(2+), Al(3+), La(3+), and Y(3+) on silica gel formation has been investigated by studying the hydrolysis and polycondensation of silicon tetraethoxide (TEOS) in the presence of metal nitrates. The influence of water: TEOS mole ratio, metal ion concentration, and the reaction temperature has been investigated. The overall activation energy for gel formation has been determined from the temperature dependence of the time of gelation for each system. The activation energy for -Si-O-Si- network formation is found to be 54.5 kJ/mol. The gel formation time as well as the activation energy sharply increase in the presence of Cu(2+), Al(3+), La(3+) and Y(3+). In contrast, the presence of Li(+), Na(+), Mg(2+), Ca(2+), or, Sr(2+) lowers the gelation time, but has no appreciable effect on the activation energy. This difference may be attributed to the participation or nonparticipation of the metal ions in the formation of the three-dimensional polymeric network during the polycondensation step. The concentration of metal ion (Mg(2+), Ca(2+), Y(3+) or the water: TEOS mole ratio had no appreciable effect on the gelation activation energy. A simple test has been proposed to determine whether a metal ion would act as a network intermediate or modifier in silica and other glassy networks.

Active Flash: Performance-Energy Tradeoffs for Out-of-Core Processing on Non-Volatile Memory Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S

2012-01-01

In this abstract, we study the performance and energy tradeoffs involved in migrating data analysis into the flash device, a process we refer to as Active Flash. The Active Flash paradigm is similar to 'active disks', which has received considerable attention. Active Flash allows us to move processing closer to data, thereby minimizing data movement costs and reducing power consumption. It enables true out-of-core computation. The conventional definition of out-of-core solvers refers to an approach to process data that is too large to fit in the main memory and, consequently, requires access to disk. However, in Active Flash, processing outsidemore » the host CPU literally frees the core and achieves real 'out-of-core' analysis. Moving analysis to data has long been desirable, not just at this level, but at all levels of the system hierarchy. However, this requires a detailed study on the tradeoffs involved in achieving analysis turnaround under an acceptable energy envelope. To this end, we first need to evaluate if there is enough computing power on the flash device to warrant such an exploration. Flash processors require decent computing power to run the internal logic pertaining to the Flash Translation Layer (FTL), which is responsible for operations such as address translation, garbage collection (GC) and wear-leveling. Modern SSDs are composed of multiple packages and several flash chips within a package. The packages are connected using multiple I/O channels to offer high I/O bandwidth. SSD computing power is also expected to be high enough to exploit such inherent internal parallelism within the drive to increase the bandwidth and to handle fast I/O requests. More recently, SSD devices are being equipped with powerful processing units and are even embedded with multicore CPUs (e.g. ARM Cortex-A9 embedded processor is advertised to reach 2GHz frequency and deliver 5000 DMIPS; OCZ RevoDrive X2 SSD has 4 SandForce controllers, each with 780MHz max frequency

Accuracy of a novel multi-sensor board for measuring physical activity and energy expenditure

PubMed Central

Lester, Jonathan; Migotsky, Sean; Goh, Jorming; Higgins, Lisa; Borriello, Gaetano

2011-01-01

The ability to relate physical activity to health depends on accurate measurement. Yet, none of the available methods are fully satisfactory due to several factors. This study examined the accuracy of a multi-sensor board (MSB) that infers activity types (sitting, standing, walking, stair climbing, and running) and estimates energy expenditure in 57 adults (32 females) 39.2 ± 13.5 years. In the laboratory, subjects walked and ran on a treadmill over a select range of speeds and grades for 3 min each (six stages in random order) while connected to a stationary calorimeter, preceded and followed by brief sitting and standing. On a different day, subjects completed scripted activities in the field connected to a portable calorimeter. The MSB was attached to a strap at the right hip. Subjects repeated one condition (randomly selected) on the third day. Accuracy of inferred activities compared with recorded activities (correctly identified activities/total activities × 100) was 97 and 84% in the laboratory and field, respectively. Absolute accuracy of energy expenditure [100 – absolute value (kilocalories MSB – kilocalories calorimeter/kilocalories calorimeter) × 100] was 89 and 76% in the laboratory and field, the later being different (P < 0.05) from the calorimeter. Test–retest reliability for energy expenditure was significant in both settings (P < 0.0001; r = 0.97). In general, the MSB provides accurate measures of activity type in laboratory and field settings and energy expenditure during treadmill walking and running although the device underestimates energy expenditure in the field. PMID:21249383

Activation energy-activation volume master plots for ion transport behavior in polymer electrolytes and supercooled molten salts.

PubMed

Ingram, Malcolm D; Imrie, Corrie T; Stoeva, Zlatka; Pas, Steven J; Funke, Klaus; Chandler, Howard W

2005-09-08

We demonstrate the use of activation energy versus activation volume "master plots" to explore ion transport in typical fragile glass forming systems exhibiting non-Arrhenius behavior. These systems include solvent-free salt complexes in poly(ethylene oxide) (PEO) and low molecular weight poly(propylene oxide) (PPO) and molten 2Ca(NO3)2.3KNO3 (CKN). Plots showing variations in apparent activation energy EA versus apparent activation volume VA are straight lines with slopes given by M = DeltaEA/DeltaVA. A simple ion transport mechanism is described where the rate determining step involves a dilatation (expressed as VA) around microscopic cavities and a corresponding work of expansion (EA). The slopes of the master plots M are equated to internal elastic moduli, which vary from 1.1 GPa for liquid PPO to 5.0 GPa for molten CKN on account of differing intermolecular forces in these materials.

Module greenhouse with high efficiency of transformation of solar energy, utilizing active and passive glass optical rasters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korecko, J.; Jirka, V.; Sourek, B.

2010-10-15

Since the eighties of the 20th century, various types of linear glass rasters for architectural usage have been developed in the Czech Republic made by the continuous melting technology. The development was focused on two main groups of rasters - active rasters with linear Fresnel lenses in fixed installation and with movable photo-thermal and/or photo-thermal/photo-voltaic absorbers. The second group are passive rasters based on total reflection of rays on an optical prism. During the last years we have been working on their standardization, exact measuring of their optical and thermal-technical characteristics and on creation of a final product that couldmore » be applied in solar architecture. With the project supported by the Ministry of Environment of the Czech Republic we were able to build an experimental greenhouse using these active and passive optical glass rasters. The project followed the growing number of technical objectives. The concept of the greenhouse consisted of interdependence construction - structural design of the greenhouse with its technological equipment securing the required temperature and humidity conditions in the interior of the greenhouse. This article aims to show the merits of the proposed scheme and presents the results of the mathematical model in the TRNSYS environment through which we could predict the future energy balance carried out similar works, thus optimizing the investment and operating costs. In this article description of various technology applications for passive and active utilization of solar radiation is presented, as well as some results of short-term and long-term experiments, including evaluation of 1-year operation of the greenhouse from the energy and interior temperature viewpoints. A comparison of the calculated energy flows in the greenhouse to real measured values, for verification of the installed model is also involved. (author)« less

Hours spent and energy expended in physical activity domains: Results from The Tomorrow Project cohort in Alberta, Canada

PubMed Central

2011-01-01

Background Knowledge of adult activity patterns across domains of physical activity is essential for the planning of population-based strategies that will increase overall energy expenditure and reduce the risk of obesity and related chronic diseases. We describe domain-specific hours of activity and energy expended among participants in a prospective cohort in Alberta, Canada. Methods The Past Year Total Physical Activity Questionnaire was completed by 15,591 Tomorrow Project® participants, between 2001 and 2005 detailing physical activity type, duration, frequency and intensity. Domain-specific hours of activity and activity-related energy expenditure, expressed as a percent of total energy expenditure (TEE) (Mean (SD); Median (IQR)) are reported across inactive (<1.4), low active (1.4 to 1.59), active (1.6 to 1.89) and very active (≥ 1.9) Physical Activity Level (PAL = TEE:REE) categories. Results In very active women and amongst all men except those classified as inactive, activity-related energy expenditure comprised primarily occupational activity. Amongst inactive men and women in active, low active and inactive groups, activity-related energy expenditure from household activity was comparable to, or exceeded that for occupational activity. Leisure-time activity-related energy expenditure decreased with decreasing PAL categories; however, even amongst the most active men and women it accounted for less than 10 percent of TEE. When stratified by employment status, leisure-time activity-related energy expenditure was greatest for retired men [mean (SD): 10.8 (8.5) percent of TEE], compared with those who were fully employed, employed part-time or not employed. Transportation-related activity was negligible across all categories of PAL and employment status. Conclusion For the inactive portion of this population, active non-leisure activities, specifically in the transportation and occupational domains, need to be considered for inclusion in daily routines

Hours spent and energy expended in physical activity domains: results from the Tomorrow Project cohort in Alberta, Canada.

PubMed

Csizmadi, Ilona; Lo Siou, Geraldine; Friedenreich, Christine M; Owen, Neville; Robson, Paula J

2011-10-10

Knowledge of adult activity patterns across domains of physical activity is essential for the planning of population-based strategies that will increase overall energy expenditure and reduce the risk of obesity and related chronic diseases. We describe domain-specific hours of activity and energy expended among participants in a prospective cohort in Alberta, Canada. The Past Year Total Physical Activity Questionnaire was completed by 15,591 Tomorrow Project® participants, between 2001 and 2005 detailing physical activity type, duration, frequency and intensity. Domain-specific hours of activity and activity-related energy expenditure, expressed as a percent of total energy expenditure (TEE) (Mean (SD); Median (IQR)) are reported across inactive (<1.4), low active (1.4 to 1.59), active (1.6 to 1.89) and very active (≥ 1.9) Physical Activity Level (PAL = TEE:REE) categories. In very active women and amongst all men except those classified as inactive, activity-related energy expenditure comprised primarily occupational activity. Amongst inactive men and women in active, low active and inactive groups, activity-related energy expenditure from household activity was comparable to, or exceeded that for occupational activity. Leisure-time activity-related energy expenditure decreased with decreasing PAL categories; however, even amongst the most active men and women it accounted for less than 10 percent of TEE. When stratified by employment status, leisure-time activity-related energy expenditure was greatest for retired men [mean (SD): 10.8 (8.5) percent of TEE], compared with those who were fully employed, employed part-time or not employed. Transportation-related activity was negligible across all categories of PAL and employment status. For the inactive portion of this population, active non-leisure activities, specifically in the transportation and occupational domains, need to be considered for inclusion in daily routines as a means of increasing population

Apg-2 has a chaperone-like activity similar to Hsp110 and is overexpressed in hepatocellular carcinomas.

PubMed

Gotoh, Kazuhisa; Nonoguchi, Kohsuke; Higashitsuji, Hiroaki; Kaneko, Yoshiyuki; Sakurai, Toshiharu; Sumitomo, Yasuhiko; Itoh, Katsuhiko; Subjeck, John R; Fujita, Jun

2004-02-27

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. We constructed subtracted cDNA libraries enriched with genes overexpressed in HCCs. Among the 17 genes identified were molecular chaperones, Hsp110, Hsp90B, and Hsp70-1. Expression of the Hsp110 family members was further analyzed, and increased transcript levels of Hsp110 and Apg-2, but not Apg-1, were found in 12 and 14, respectively, of 18 HCCs. Immunohistochemical analysis demonstrated the overexpression of the proteins in tumor cells. Apg-2 had chaperone ability similar to Hsp110 in a thermal denaturation assay using luciferase, and showed anti-apoptotic activity. These results suggest that the Hsp110 family members play important roles in hepatocarcinogenesis through their chaperoning activities.

Peptide deformylases from Vibrio parahaemolyticus phage and bacteria display similar deformylase activity and inhibitor binding clefts.

PubMed

Grzela, Renata; Nusbaum, Julien; Fieulaine, Sonia; Lavecchia, Francesco; Desmadril, Michel; Nhiri, Naima; Van Dorsselaer, Alain; Cianferani, Sarah; Jacquet, Eric; Meinnel, Thierry; Giglione, Carmela

2018-02-01

Unexpected peptide deformylase (PDF) genes were recently retrieved in numerous marine phage genomes. While various hypotheses dealing with the occurrence of these intriguing sequences have been made, no further characterization and functional studies have been described thus far. In this study, we characterize the bacteriophage Vp16 PDF enzyme, as representative member of the newly identified C-terminally truncated viral PDFs. We show here that conditions classically used for bacterial PDFs lead to an enzyme exhibiting weak activity. Nonetheless, our integrated biophysical and biochemical approaches reveal specific effects of pH and metals on Vp16 PDF stability and activity. A novel purification protocol taking in account these data allowed strong improvement of Vp16 PDF specific activity to values similar to those of bacterial PDFs. We next show that Vp16 PDF is as sensitive to the natural inhibitor compound of PDFs, actinonin, as bacterial PDFs. Comparison of the 3D structures of Vp16 and E. coli PDFs bound to actinonin also reveals that both PDFs display identical substrate binding mode. We conclude that bacteriophage Vp16 PDF protein has functional peptide deformylase activity and we suggest that encoded phage PDFs might be important for viral fitness. Copyright © 2017 Elsevier B.V. All rights reserved.

Reasearch Activities for the Establishment of The Center for Sustainable Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Michael Seliger

2005-08-08

In 2003, Bronx Community College received a grant of $481,000 through the United States Department of Energy for the purpose of conducting research- related activities leading to the creation of the Center for Sustainable Energy at Bronx Community College. The award, which was administered on behalf of Bronx Community College by the Research Foundation of the City University of New York, was initially for one year, from October 2003 through September 30, 2004. It received a no-cost extension to June 30, 2005. This report presents a summary of the activities and accomplishments attributable to the award.

Protein-Nanoparticle Interactions: Improving Immobilized Lytic Enzyme Activity and Surface Energy Effects

NASA Astrophysics Data System (ADS)

Downs, Emily Elizabeth

Protein-nanostructure conjugates, particularly particles, are a subject of significant interest due to changes in their fundamental behavior compared to bulk surfaces. As the size scale of nano-structured materials and proteins are on the same order of magnitude, nanomaterial properties can heavily influence how proteins adsorb and conform to the surface. Previous work has demonstrated the ability of nanoscale surfaces to modulate protein activity, conformation, and retention by modifying the particle surface curvature, morphology, and surface charge. This work has improved our understanding of the protein material interactions, but a complete understanding is still lacking. The goal of this thesis is to investigate two missing areas of understanding using two distinct systems. The first system utilizes a particle with controlled surface energy to observe the impact of surface energy on protein-particle interactions, while the second system uses a modified Listeria-specific protein to determine how protein structure and flexibility affects protein adsorption and activity on particles. Spherical, amorphous, and uniformly doped Zn-silica particles with tailored surface energies were synthesized to understand the impact of surface energy on protein adsorption behavior. Particle surface energy increased with a decrease in particle size and greater dopant concentrations. Protein adsorption and structural loss increased with both particle size and particle surface energy. Higher surface energies promoted protein-particle association and increased protein unfolding. Particle curvature and protein steric hindrance effects limited adsorption and structural loss on smaller particles. Protein surface charge heterogeneity was also found to be linked to both protein adsorption and unfolding behavior on larger particles. Greater surface charge heterogeneity led to higher adsorption concentrations and multilayer formation. These multilayers transitioned from protein

Adaptive Highly Flexible Multifunctional Wings for Active and Passive Control and Energy Harvesting with Piezoelectric Materials

NASA Astrophysics Data System (ADS)

Tsushima, Natsuki

The purpose of this dissertation is to develop an analytical framework to analyze highly flexible multifunctional wings with integral active and passive control and energy harvesting using piezoelectric transduction. Such multifunctional wings can be designed to enhance aircraft flight performance, especially to support long-endurance flights and to be adaptive to various flight conditions. This work also demonstrates the feasibility of the concept of piezoelectric multifunctional wings for the concurrent active control and energy harvesting to improve the aeroelastic performance of high-altitude long-endurance unmanned air vehicles. Functions of flutter suppression, gust alleviation, energy generation, and energy storage are realized for the performance improvement. The multifunctional wings utilize active and passive piezoelectric effects for the efficient adaptive control and energy harvesting. An energy storage with thin-film lithium-ion battery cells is designed for harvested energy accumulation. Piezoelectric effects are included in a strain-based geometrically nonlinear beam formulation for the numerical studies. The resulting structural dynamic equations are coupled with a finite-state unsteady aerodynamic formulation, allowing for piezoelectric energy harvesting and active actuation with the nonlinear aeroelastic system. This development helps to provide an integral electro-aeroelastic solution of concurrent active piezoelectric control and energy harvesting for wing vibrations, with the consideration of the geometrical nonlinear effects of slender multifunctional wings. A multifunctional structure for active actuation is designed by introducing anisotropic piezoelectric laminates. Linear quadratic regulator and linear quadratic Gaussian controllers are implemented for the active control of wing vibrations including post-flutter limit-cycle oscillations and gust perturbation. An adaptive control algorithm for gust perturbation is then developed. In this

Energy expenditures & physical activity in rats with chronic suboptimal nutrition.

PubMed

Rising, Russell; Lifshitz, Fima

2006-01-31

Sub-optimally nourished rats show reduced growth, biochemical and physiological changes. However, no one has assessed metabolic rate adaptations in rats subjected to chronic suboptimal nutrition (CSN). In this study energy expenditure (EE; kcal/100 g body weight) and physical activity (PA; oscillations in weight/min/kg body weight) were assessed in rats subjected to three levels of CSN. Body weight gain was diminished (76.7 +/- 12.0 and 61.6 +/- 11.0 g) in rats fed 70 and 60% of the ad-libitum fed controls which gained more weight (148.5 +/- 32.3 g). The rats fed 80% gained weight similarly to controls (136.3 +/- 10.5 g). Percent Fat-free body mass was reduced (143.8 +/- 8.7 and 142.0 +/- 7.6 g) in rats fed 70 and 60% of ad-libitum, but not in those fed 80% (200.8 +/- 17.5 g) as compared with controls (201.6 +/- 33.4 g). Body fat (g) decreased in rats fed 80% (19.7 +/- 5.3), 70% (15.3 +/- 3.5) and 60% (9.6 +/- 2.7) of ad-libitum in comparison to controls (26.0 +/- 6.7). EE and PA were also altered by CSN. The control rats increased their EE and PA during the dark periods by 1.4 +/- 0.8 and 1.7 +/- 1.1 respectively, as compared with light the period; whereas CSN rats fed 80 and 70% of ad-libitum energy intake had reduced EE and PA during the dark periods as compared with the light period EE(7.5 +/- 1.4 and 7.8 +/- 0.6 vs. 9.0 +/- 1.2 and 9.7 +/- 0.8; p < 0.05, respectively), PA(3.1 +/- 0.8 and 1.6 +/- 0.4 vs. 4.1 +/- 0.9 and 2.4 +/- 0.4; p < 0.05) and RQ (0.87 +/- 0.04 and 0.85 +/- 0.5; vs. 0.95 +/- 0.03 and 0.91 +/- 0.05 p < 0.05). In contrast, both light (7.1 +/- 1.4) and dark period (6.2 +/- 1.0) EE and PA (3.4 +/- 0.9 and 2.5 +/- 0.5 respectively) were reduced in rats fed 60% of ad-libitum energy intake. CSN rats adapt to mild energy restriction by reducing body fat, EE and PA mainly during the dark period while growth proceeds and lean body mass is preserved. At higher levels of energy restrictions there is decreased growth, body fat and lean mass. Moreover EE

Homogeneous near surface activity distribution by double energy activation for TLA

NASA Astrophysics Data System (ADS)

Takács, S.; Ditrói, F.; Tárkányi, F.

2007-10-01

Thin layer activation (TLA) is a versatile tool for activating thin surface layers in order to study real-time the surface loss by wear, corrosion or erosion processes of the activated parts, without disassembling or stopping running mechanical structures or equipment. The research problem is the determination of the irradiation parameters to produce point-like or large area optimal activity-depth distribution in the sample. Different activity-depth profiles can be produced depending on the type of the investigated material and the nuclear reaction used. To produce activity that is independent of the depth up to a certain depth is desirable when the material removed from the surface by wear, corrosion or erosion can be collected completely. By applying dual energy irradiation the thickness of this quasi-constant activity layer can be increased or the deviation of the activity distribution from a constant value can be minimized. In the main, parts made of metals and alloys are suitable for direct activation, but by using secondary particle implantation the wear of other materials can also be studied in a surface range a few micrometers thick. In most practical cases activation of a point-like spot (several mm2) is enough to monitor the wear, corrosion or erosion, but for special problems relatively large surfaces areas of complicated spatial geometry need to be activated uniformly. Two ways are available for fulfilling this task, (1) production of large area beam spot or scanning the beam over the surface in question from the accelerator side, or (2) a programmed 3D movement of the sample from the target side. Taking into account the large variability of tasks occurring in practice, the latter method was chosen as the routine solution in our cyclotron laboratory.

Award Winning Energy Education Activities for Elementary and High School Teachers.

ERIC Educational Resources Information Center

Carey, Helen H., Ed.

This publication contains descriptions of the winning entries to the National Science Teachers Association (NSTA) Teacher Participation Contest conducted in 1976. This was a nationwide contest for the design of activities around energy themes at any grade level, K-12. The ten winning entries described here are: (1) Energy Units for Primary Grades;…

Developmental programming of energy balance regulation: is physical activity more 'programmable' than food intake?

PubMed

Zhu, Shaoyu; Eclarinal, Jesse; Baker, Maria S; Li, Ge; Waterland, Robert A

2016-02-01

Extensive human and animal model data show that environmental influences during critical periods of prenatal and early postnatal development can cause persistent alterations in energy balance regulation. Although a potentially important factor in the worldwide obesity epidemic, the fundamental mechanisms underlying such developmental programming of energy balance are poorly understood, limiting our ability to intervene. Most studies of developmental programming of energy balance have focused on persistent alterations in the regulation of energy intake; energy expenditure has been relatively underemphasised. In particular, very few studies have evaluated developmental programming of physical activity. The aim of this review is to summarise recent evidence that early environment may have a profound impact on establishment of individual propensity for physical activity. Recently, we characterised two different mouse models of developmental programming of obesity; one models fetal growth restriction followed by catch-up growth, and the other models early postnatal overnutrition. In both studies, we observed alterations in body-weight regulation that persisted to adulthood, but no group differences in food intake. Rather, in both cases, programming of energy balance appeared to be due to persistent alterations in energy expenditure and spontaneous physical activity (SPA). These effects were stronger in female offspring. We are currently exploring the hypothesis that developmental programming of SPA occurs via induced sex-specific alterations in epigenetic regulation in the hypothalamus and other regions of the central nervous system. We will summarise the current progress towards testing this hypothesis. Early environmental influences on establishment of physical activity are likely an important factor in developmental programming of energy balance. Understanding the fundamental underlying mechanisms in appropriate animal models will help determine whether early life

Similarities and Differences in Neurobiology.

PubMed

Chen, Manli; Sun, Yan; Lu, Lin; Shi, Jie

2017-01-01

Substance addiction is a chronic, relapsing brain disease characterized by compulsive drug seeking and use despite harmful consequences. Non-substance addiction is defined recently that people may compulsively engage in an activity despite any negative consequences to their lives. Despite differences with respect to their addictive object, substance addiction and non-substance addiction may share similarities with respect to biological, epidemiological, clinical, genetic and other features. Here we review the similarities and differences in neurobiology between these two addictions with a focus on dopamine, serotonin, opioid, glutamate and norepinephrine systems. Studies suggest the involvement of all these systems in both substance addiction and non-substance addiction while differences may exist with respect to their contributions.

Energy-converting [NiFe] hydrogenases: more than just H2 activation.

PubMed

Hedderich, Reiner; Forzi, Lucia

2005-01-01

The well-characterized [NiFe] hydrogenases have a key function in the H2 metabolism of various microorganisms. A subfamily of the [NiFe] hydrogenases with unique properties has recently been identified. The six conserved subunits that build the core of these membrane-bound hydrogenases share sequence similarity with subunits that form the catalytic core of energy-conserving NADH:quinone oxidoreductases (complex I). The physiological role of some of these hydrogenases is to catalyze the reduction of H+ with electrons derived from reduced ferredoxins or polyferredoxins. This exergonic reaction is coupled to energy conservation by means of electron-transport phosphorylation. Other members of this hydrogenase subfamily mainly function in providing the cell with reduced ferredoxin using H2 as electron donor in a reaction driven by reverse electron transport. These hydrogenases have therefore been designated as energy-converting [NiFe] hydrogenases. Copyright 2005 S. Karger AG, Basel.

Effects of atmospheric composition on apparent activation energy of silicate weathering: I. Model formulation

NASA Astrophysics Data System (ADS)

Kanzaki, Yoshiki; Murakami, Takashi

2018-07-01

We have developed a weathering model to comprehensively understand the determining factors of the apparent activation energy of silicate weathering in order to better estimate the silicate-weathering flux in the Precambrian. The model formulates the reaction rate of a mineral as a basis, then the elemental loss by summing the reaction rates of whole minerals, and finally the weathering flux from a given weathering profile by integrating the elemental losses along the depth of the profile. The rate expressions are formulated with physicochemical parameters relevant to weathering, including solution and atmospheric compositions. The apparent activation energies of silicate weathering are then represented by the temperature dependences of the physicochemical parameters based on the rate expressions. It was found that the interactions between individual mineral-reactions and the compositions of solution and atmosphere are necessarily accompanied by those of temperature-dependence counterparts. Indeed, the model calculates the apparent activation energy of silicate weathering as a function of the temperature dependence of atmospheric CO2 (Δ HCO2‧) . The dependence of the apparent activation energy of silicate weathering on Δ HCO2‧ may explain the empirical dependence of silicate weathering on the atmospheric composition. We further introduce a compensation law between the apparent activation energy and the pre-exponential factor to obtain the relationship between the silicate-weathering flux (FCO2), temperature and the apparent activation energy. The model calculation and the compensation law enable us to predict FCO2 as a function of temperature, once Δ HCO2‧ is given. The validity of the model is supported by agreements between the model prediction and observations of the apparent activation energy and FCO2 in the modern weathering systems. The present weathering model will be useful for the estimation of FCO2 in the Precambrian, for which Δ HCO2‧ can be

Context-dependent similarity effects in letter recognition.

PubMed

Kinoshita, Sachiko; Robidoux, Serje; Guilbert, Daniel; Norris, Dennis

2015-10-01

In visual word recognition tasks, digit primes that are visually similar to letter string targets (e.g., 4/A, 8/B) are known to facilitate letter identification relative to visually dissimilar digits (e.g., 6/A, 7/B); in contrast, with letter primes, visual similarity effects have been elusive. In the present study we show that the visual similarity effect with letter primes can be made to come and go, depending on whether it is necessary to discriminate between visually similar letters. The results support a Bayesian view which regards letter recognition not as a passive activation process driven by the fixed stimulus properties, but as a dynamic evidence accumulation process for a decision that is guided by the task context.

Is Dark Matter Similar to the Force?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernstein, Adam; Vranas, Pavlos

When Obi Wan Kenobi explained the Force to Luke Skywalker, he said, "It's an energy field created by all living things. It surrounds us and penetrates us; it binds the galaxy together." The same thing could be said of the invisible, elusive, yet ubiquitous dark matter. Explore the similarities and differences between dark matter and the Force and find out why LLNL studies dark matter.

Evaluation of dietary energy intake and physical activity in dogs undergoing a controlled weight-loss program.

PubMed

Wakshlag, Joseph J; Struble, Angela M; Warren, Barbour S; Maley, Mary; Panasevich, Matthew R; Cummings, Kevin J; Long, Grace M; Laflamme, Dorothy E

2012-02-15

To quantify physical activity and dietary energy intake in dogs enrolled in a controlled weight-loss program and assess relationships between energy intake and physical activity, sex, age, body weight, and body condition score (BCS). Prospective clinical study. 35 client-owned obese dogs (BCS > 7/9). Dogs were fed a therapeutic diet with energy intake restrictions to maintain weight loss of approximately 2%/wk. Collar-mounted pedometers were used to record the number of steps taken daily as a measure of activity. Body weight and BCS were assessed at the beginning of the weight-loss program and every 2 weeks thereafter throughout the study. Relationships between energy intake and sex, age, activity, BCS, and body weight at the end of the study were assessed via multivariable linear regression. Variables were compared among dogs stratified post hoc into inactive and active groups on the basis of mean number of steps taken (< or > 7,250 steps/d, respectively). Mean ± SD daily energy intake per unit of metabolic body weight (kg(0.75)) of active dogs was significantly greater than that of inactive dogs (53.6 ± 15.2 kcal/kg(0.75) vs 42.2 ± 9.7 kcal/kg(0.75), respectively) while maintaining weight-loss goals. In regression analysis, only the number of steps per day was significantly associated with energy intake. Increased physical activity was associated with higher energy intake while maintaining weight-loss goals. Each 1,000-step interval was associated with a 1 kcal/kg(0.75) increase in energy intake.

Improved model of activation energy absorption for different electrical breakdowns in semi-crystalline insulating polymers

NASA Astrophysics Data System (ADS)

Sima, Wenxia; Jiang, Xiongwei; Peng, Qingjun; Sun, Potao

2018-05-01

Electrical breakdown is an important physical phenomenon in electrical equipment and electronic devices. Many related models and theories of electrical breakdown have been proposed. However, a widely recognized understanding on the following phenomenon is still lacking: impulse breakdown strength which varies with waveform parameters, decrease in the breakdown strength of AC voltage with increasing frequency, and higher impulse breakdown strength than that of AC. In this work, an improved model of activation energy absorption for different electrical breakdowns in semi-crystalline insulating polymers is proposed based on the Harmonic oscillator model. Simulation and experimental results show that, the energy of trapped charges obtained from AC stress is higher than that of impulse voltage, and the absorbed activation energy increases with the increase in the electric field frequency. Meanwhile, the frequency-dependent relative dielectric constant ε r and dielectric loss tanδ also affect the absorption of activation energy. The absorbed activation energy and modified trap level synergistically determine the breakdown strength. The mechanism analysis of breakdown strength under various voltage waveforms is consistent with the experimental results. Therefore, the proposed model of activation energy absorption in the present work may provide a new possible method for analyzing and explaining the breakdown phenomenon in semi-crystalline insulating polymers.

The relationship between physical activity, appetite and energy intake in older adults: A systematic review.

PubMed

Clegg, M E; Godfrey, A

2018-06-07

Ageing often causes a reduction in appetite and energy intake in older adults which can result in malnutrition. Current guidelines for older adults suggest increasing physical activity to enhance appetite. However, it is unclear if there is evidence to support this advice. This aim of this review is to assess if appetite and energy intake is changed in older adults that undertake acute or regular physical activity (measured from cross sectional and intervention studies). Databases SPORTDiscus, CINAHL, MEDLINE were searched for studies between 1970 and 2017 using search terms related to ageing, physical activity (including exercise), energy and appetite. Studies included contained adults over 60 years, including acute, cross-sectional and intervention (longitudinal) studies. Of 34 full-text articles assessed, 8 were included. The Cochrane Collaboration's tool was used for assessing risk of bias. No acute studies were found. Of the cross-sectional studies, one study suggested that individuals who undertake habitual physical activity had an increased energy intake and none of the studies found differences in appetite ratings. Energy intakes increased in the intervention studies, though not always sufficiently to maintain energy balance. One study showed that ability to correctly compensate for previous energy intake was better in those that undertake habitual physical activity. The limited number of studies, wide range of data collection methodologies, time-scales and interventions mean that definitive outcomes are difficult to identify. At this stage advice to increase acute or habitual physical activity as a mean to increase appetite is not supported by sufficient evidence. Copyright © 2018. Published by Elsevier Ltd.

Self-similar cosmological solutions with dark energy. I. Formulation and asymptotic analysis

NASA Astrophysics Data System (ADS)

Harada, Tomohiro; Maeda, Hideki; Carr, B. J.

2008-01-01

Based on the asymptotic analysis of ordinary differential equations, we classify all spherically symmetric self-similar solutions to the Einstein equations which are asymptotically Friedmann at large distances and contain a perfect fluid with equation of state p=(γ-1)μ with 0<γ<2/3. This corresponds to a “dark energy” fluid and the Friedmann solution is accelerated in this case due to antigravity. This extends the previous analysis of spherically symmetric self-similar solutions for fluids with positive pressure (γ>1). However, in the latter case there is an additional parameter associated with the weak discontinuity at the sonic point and the solutions are only asymptotically “quasi-Friedmann,” in the sense that they exhibit an angle deficit at large distances. In the 0<γ<2/3 case, there is no sonic point and there exists a one-parameter family of solutions which are genuinely asymptotically Friedmann at large distances. We find eight classes of asymptotic behavior: Friedmann or quasi-Friedmann or quasistatic or constant-velocity at large distances, quasi-Friedmann or positive-mass singular or negative-mass singular at small distances, and quasi-Kantowski-Sachs at intermediate distances. The self-similar asymptotically quasistatic and quasi-Kantowski-Sachs solutions are analytically extendible and of great cosmological interest. We also investigate their conformal diagrams. The results of the present analysis are utilized in an accompanying paper to obtain and physically interpret numerical solutions.

Isometric immersions and self-similar buckling in elastic sheets.

NASA Astrophysics Data System (ADS)

Gemmer, John

The edges of torn elastic sheets and growing leaves often display hierarchical self-similar like buckling patterns. On the one hand, such complex, self similar patterns are usually associated with a competition between two distinct energy scales, e.g. elastic sheets with boundary conditions that preclude the possibility of relieving in plane strains, or at alloy-alloy interfaces between distinct crystal structures. On the other hand, within the non-Euclidean plate theory this complex morphology can be understood as low bending energy isometric immersions of hyperbolic Riemannian metrics. In particular, many growth patterns generate residual in-plane strains which can be entirely relieved by the sheet forming part of a surface of revolution or a helix. In this talk we will show that this complex morphology (i) arises from isometric immersions (ii) is driven by a competition between the two principal curvatures, rather than between bending and stretching. We identify the key role of branch-point (or monkey-saddle) singularities, in complex wrinkling patterns within the class of finite bending energy isometric immersions. Using these defects we will give an explicit construction of strain-free embeddings of hyperbolic surfaces that are fractal like and have lower elastic energy than their smooth counterparts US-Israel BSF Grant 2008432. NSF Grant DMS-0807501. NSF-RTG Grant DMS-1148284.

The Production and Perception of Emotionally Expressive Walking Sounds: Similarities between Musical Performance and Everyday Motor Activity

PubMed Central

Giordano, Bruno L.; Egermann, Hauke; Bresin, Roberto

2014-01-01

Several studies have investigated the encoding and perception of emotional expressivity in music performance. A relevant question concerns how the ability to communicate emotions in music performance is acquired. In accordance with recent theories on the embodiment of emotion, we suggest here that both the expression and recognition of emotion in music might at least in part rely on knowledge about the sounds of expressive body movements. We test this hypothesis by drawing parallels between musical expression of emotions and expression of emotions in sounds associated with a non-musical motor activity: walking. In a combined production-perception design, two experiments were conducted, and expressive acoustical features were compared across modalities. An initial performance experiment tested for similar feature use in walking sounds and music performance, and revealed that strong similarities exist. Features related to sound intensity, tempo and tempo regularity were identified as been used similarly in both domains. Participants in a subsequent perception experiment were able to recognize both non-emotional and emotional properties of the sound-generating walkers. An analysis of the acoustical correlates of behavioral data revealed that variations in sound intensity, tempo, and tempo regularity were likely used to recognize expressed emotions. Taken together, these results lend support the motor origin hypothesis for the musical expression of emotions. PMID:25551392

The production and perception of emotionally expressive walking sounds: similarities between musical performance and everyday motor activity.

PubMed

Giordano, Bruno L; Egermann, Hauke; Bresin, Roberto

2014-01-01

Several studies have investigated the encoding and perception of emotional expressivity in music performance. A relevant question concerns how the ability to communicate emotions in music performance is acquired. In accordance with recent theories on the embodiment of emotion, we suggest here that both the expression and recognition of emotion in music might at least in part rely on knowledge about the sounds of expressive body movements. We test this hypothesis by drawing parallels between musical expression of emotions and expression of emotions in sounds associated with a non-musical motor activity: walking. In a combined production-perception design, two experiments were conducted, and expressive acoustical features were compared across modalities. An initial performance experiment tested for similar feature use in walking sounds and music performance, and revealed that strong similarities exist. Features related to sound intensity, tempo and tempo regularity were identified as been used similarly in both domains. Participants in a subsequent perception experiment were able to recognize both non-emotional and emotional properties of the sound-generating walkers. An analysis of the acoustical correlates of behavioral data revealed that variations in sound intensity, tempo, and tempo regularity were likely used to recognize expressed emotions. Taken together, these results lend support the motor origin hypothesis for the musical expression of emotions.

Energy Cost of Free-Play Activities in 10- to 11-Year-Old Children.

PubMed

Mackintosh, Kelly Alexandra; Ridley, Kate; Stratton, Gareth; Ridgers, Nicola D

2016-06-01

This study sought to ascertain the energy expenditure (EE) associated with different sedentary and physically active free-play activities in primary school-aged children. Twenty-eight children (13 boys; 11.4 ± 0.3 years; 1.45 ± 0.09 m; 20.0 ± 4.7 kg∙m-2) from 1 primary school in Northwest England engaged in 6 activities representative of children's play for 10 minutes (drawing, watching a DVD, playground games and free-choice) and 5 minutes (self-paced walking and jogging), with 5 minutes rest between each activity. Gas exchange variables were measured throughout. Resting energy expenditure was measured during 15 minutes of supine rest. Child (Schofield-predicted) MET values for watching a DVD, self-paced jogging and playing reaction ball were significantly higher for girls (P < .05). Utilizing a field-based protocol to examine children's free-living behaviors, these data contribute to the scarcity of information concerning children's EE during play to update the Compendium of Energy Expenditures for Youth.

Neuroimaging and Neuroenergetics: Brain Activations as Information-Driven Reorganization of Energy Flows

ERIC Educational Resources Information Center

Strelnikov, Kuzma

2010-01-01

There is increasing focus on the neurophysiological underpinnings of brain activations, giving birth to an emerging branch of neuroscience--neuroenergetics. However, no common definition of "brain activation" exists thus far. In this article, we define brain activation as the information-driven reorganization of energy flows in a population of…

Active Noise Control Experiments using Sound Energy Flu

NASA Astrophysics Data System (ADS)

Krause, Uli

2015-03-01

This paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.

The eMouveRecherche application competes with research devices to evaluate energy expenditure, physical activity and still time in free-living conditions.

PubMed

Guidoux, Romain; Duclos, Martine; Fleury, Gérard; Lacomme, Philippe; Lamaudière, Nicolas; Saboul, Damien; Ren, Libo; Rousset, Sylvie

2017-05-01

The proliferation of smartphones is creating new opportunities to monitor and interact with human subjects in free-living conditions since smartphones are familiar to large segments of the population and facilitate data collection, transmission and analysis. From accelerometry data collected by smartphones, the present work aims to estimate time spent in different activity categories and the energy expenditure in free-living conditions. Our research encompasses the definition of an energy-saving function (Pred EE ) considering four physical categories of activities (still, light, moderate and vigorous), their duration and metabolic cost (MET). To create an efficient discrimination function, the method consists of classifying accelerometry-transformed signals into categories and of associating each category with corresponding Metabolic Equivalent Tasks. The performance of the Pred EE function was compared with two previously published functions (f(η,d)aedes,f(η,d)nrjsi), and with two dedicated sensors (Armband® and Actiheart®) in free-living conditions over a 12-h monitoring period using 30 volunteers. Compared to the two previous functions, Pred EE was the only one able to provide estimations of time spent in each activity category. In relative value, all the activity categories were evaluated similarly to those given by Armband®. Compared to Actiheart®, the function underestimated still activities by 10.1% and overestimated light- and moderate-intensity activities by 7.9% and 4.2%, respectively. The total energy expenditure error produced by Pred EE compared to Armband® was lower than those given by the two previous functions (5.7% vs. 14.1% and 17.0%). Pred EE provides the user with an accurate physical activity feedback which should help self-monitoring in free-living conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of active video games to increase physical activity in children: a (virtual) reality?

PubMed

Foley, Louise; Maddison, Ralph

2010-02-01

There has been increased research interest in the use of active video games (in which players physically interact with images onscreen) as a means to promote physical activity in children. The aim of this review was to assess active video games as a means of increasing energy expenditure and physical activity behavior in children. Studies were obtained from computerized searches of multiple electronic bibliographic databases. The last search was conducted in December 2008. Eleven studies focused on the quantification of the energy cost associated with playing active video games, and eight studies focused on the utility of active video games as an intervention to increase physical activity in children. Compared with traditional nonactive video games, active video games elicited greater energy expenditure, which was similar in intensity to mild to moderate intensity physical activity. The intervention studies indicate that active video games may have the potential to increase free-living physical activity and improve body composition in children; however, methodological limitations prevent definitive conclusions. Future research should focus on larger, methodologically sound intervention trials to provide definitive answers as to whether this technology is effective in promoting long-term physical activity in children.

Scalar Similarity for Relaxed Eddy Accumulation Methods

NASA Astrophysics Data System (ADS)

Ruppert, Johannes; Thomas, Christoph; Foken, Thomas

2006-07-01

The relaxed eddy accumulation (REA) method allows the measurement of trace gas fluxes when no fast sensors are available for eddy covariance measurements. The flux parameterisation used in REA is based on the assumption of scalar similarity, i.e., similarity of the turbulent exchange of two scalar quantities. In this study changes in scalar similarity between carbon dioxide, sonic temperature and water vapour were assessed using scalar correlation coefficients and spectral analysis. The influence on REA measurements was assessed by simulation. The evaluation is based on observations over grassland, irrigated cotton plantation and spruce forest. Scalar similarity between carbon dioxide, sonic temperature and water vapour showed a distinct diurnal pattern and change within the day. Poor scalar similarity was found to be linked to dissimilarities in the energy contained in the low frequency part of the turbulent spectra ( < 0.01 Hz). The simulations of REA showed significant change in b-factors throughout the diurnal course. The b-factor is part of the REA parameterisation scheme and describes a relation between the concentration difference and the vertical flux of a trace gas. The diurnal course of b-factors for carbon dioxide, sonic temperature and water vapour matched well. Relative flux errors induced in REA by varying scalar similarity were generally below ± 10%. Systematic underestimation of the flux of up to - 40% was found for the use of REA applying a hyperbolic deadband (HREA). This underestimation was related to poor scalar similarity between the scalar of interest and the scalar used as proxy for the deadband definition.

Energy expenditure, television viewing and obesity.

PubMed

Buchowski, M S; Sun, M

1996-03-01

To measure energy expenditure (EE) of television viewing, sitting, and resting and duration of self-selected television viewing in obese and non-obese men and women. Cross-over randomized study consisting of two separate 24-h stays in a whole-room indirect calorimeter. 123 obese and non-obese healthy men and women (age: 38 +/- 9, BMI: 29.4 +/- 7.9) Rates of energy expenditure during resting (RMR), sitting (EEsit) and television viewing (EEtv) using indirect calorimetry technique on two separate 24-h stays in a whole-room indirect calorimeter. Physical activities and work of body movements during these periods using a large force platform system located inside the calorimeter. Rates of EE for television viewing, adjusted for differences in body composition were 18% higher than resting metabolic rate (RMR), but similar to rates of other sedentary activities. There were no significant differences between obese and non-obese subjects in metabolic rates during resting, television viewing, and other sedentary activities. Average time of self-selected television viewing was significantly greater in obese than in non-obese subjects and also in women than in men. EE rate for television viewing in adults is higher than RMR and similar to other sedentary activities. Obese adults choose television viewing as a form of leisure activity more often than non-obese individuals and as a result they could significantly reduce other forms of physical activities and total daily EE.

Characterization of two geraniol synthases from Valeriana officinalis and Lippia dulcis: similar activity but difference in subcellular localization.

PubMed

Dong, Lemeng; Miettinen, Karel; Goedbloed, Miriam; Verstappen, Francel W A; Voster, Alessandra; Jongsma, Maarten A; Memelink, Johan; van der Krol, Sander; Bouwmeester, Harro J

2013-11-01

Two geraniol synthases (GES), from Valeriana officinalis (VoGES) and Lippia dulcis (LdGES), were isolated and were shown to have geraniol biosynthetic activity with Km values of 32 µM and 51 µM for GPP, respectively, upon expression in Escherichia coli. The in planta enzymatic activity and sub-cellular localization of VoGES and LdGES were characterized in stable transformed tobacco and using transient expression in Nicotiana benthamiana. Transgenic tobacco expressing VoGES or LdGES accumulate geraniol, oxidized geraniol compounds like geranial, geranic acid and hexose conjugates of these compounds to similar levels. Geraniol emission of leaves was lower than that of flowers, which could be related to higher levels of competing geraniol-conjugating activities in leaves. GFP-fusions of the two GES proteins show that VoGES resides (as expected) predominantly in the plastids, while LdGES import into to the plastid is clearly impaired compared to that of VoGES, resulting in both cytosolic and plastidic localization. Geraniol production by VoGES and LdGES in N. benthamiana was nonetheless very similar. Expression of a truncated version of VoGES or LdGES (cytosolic targeting) resulted in the accumulation of 30% less geraniol glycosides than with the plastid targeted VoGES and LdGES, suggesting that the substrate geranyl diphosphate is readily available, both in the plastids as well as in the cytosol. The potential role of GES in the engineering of the TIA pathway in heterologous hosts is discussed. © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

In Vitro Effects of Sports and Energy Drinks on Streptococcus mutans Biofilm Formation and Metabolic Activity.

PubMed

Vinson, LaQuia A; Goodlett, Amy K; Huang, Ruijie; Eckert, George J; Gregory, Richard L

2017-09-15

Sports and energy drinks are being increasingly consumed and contain large amounts of sugars, which are known to increase Streptococcus mutans biofilm formation and metabolic activity. The purpose of this in vitro study was to investigate the effects of sports and energy drinks on S. mutans biofilm formation and metabolic activity. S. mutans UA159 was cultured with and without a dilution (1:3 ratio) of a variety of sports and energy drinks in bacterial media for 24 hours. The biofilm was washed, fixed, and stained. Biofilm growth was evaluated by reading absorbance of the crystal violet. Biofilm metabolic activity was measured by the biofilm-reducing XTT to a water-soluble orange compound. Gatorade Protein Recovery Shake and Starbucks Doubleshot Espresso Energy were found to significantly increase biofilm (30-fold and 22-fold, respectively) and metabolic activity (2-fold and 3-fold, respectively). However, most of the remaining drinks significantly inhibited biofilm growth and metabolic activity. Several sports and energy drinks, with sugars or sugar substitutes as their main ingredients inhibited S. mutans biofilm formation. Among the drinks evaluated, Gatorade Protein Recovery Chocolate Shake and Starbucks Doubleshot Energy appear to have cariogenic potential since they increased the biofilm formation and metabolic activity of S. mutans.

Activation energy of the low-load NaCl transition from nanoindentation loading curves.

PubMed

Kaupp, Gerd

2014-01-01

Access to activation energies E(a) of phase transitions is opened by unprecedented analyses of temperature dependent nanoindentation loading curves. It is based on kinks in linearized loading curves, with additional support by coincidence of kink and electrical conductivity of silicon loading curves. Physical properties of B1, B2, NaCl and further phases are discussed. The normalized low-load transition energy of NaCl (Wtrans/µN) increases with temperature and slightly decreases with load. Its semi-logarithmic plot versus T obtains activation energy E(a)/µN for calculation of the transition work for all interesting temperatures and pressures. Arrhenius-type activation energy (kJ/mol) is unavailable for indentation phase transitions. The E(a) per load normalization proves insensitive to creep-on-load, which excludes normalization to depth or volume for large temperature ranges. Such phase transition E(a)/µN is unprecedented material's property and will be of practical importance for the compatibility of composite materials under impact and further shearing interactions at elevated temperatures. © 2014 Wiley Periodicals, Inc.

Effects of Charge State on Fragmentation Pathways, Dynamics, and Activation Energies of Ubiquitin Ions Measured by Blackbody Infrared Radiative Dissociation

PubMed Central

Jockusch, Rebecca A.; Schnier, Paul D.; Price, William D.; Strittmatter, Eric. F.; Demirev, Plamen A.; Williams*, Evan R.

2005-01-01

Blackbody infrared radiative dissociation spectra of the (M + 5H)5+ through (M + 11H)11+ ions of the protein ubiquitin (8.6 kDa) formed by electrospray ionization were measured in a Fourier-transform mass spectrometer. The 5+ ion dissociates exclusively by loss of water and/or ammonia, whereas the 11+ charge state dissociates only by formation of complementary y and b ions. These two processes are competitive for intermediate charge state ions, with the formation of y and b ions increasingly favored for the higher charge states. The y and b ions are formed by cleavage of the backbone amide bond on the C-terminal side of acidic residues exclusively, with cleavage adjacent to aspartic acid favored. Thermal unimolecular dissociation rate constants for the dissociation of each of these charge states were measured. From the temperature dependence of these rates, Arrhenius activation parameters in the rapid energy exchange limit are obtained. The activation energies (Ea) and preexponential factors (A) for the 5+, 8+, and 9+ ions are 1.2 eV and 1012 s−1, respectively. These values for the 6+ and 7+ ions are 0.9–1.0 eV and 109 s−1, and those for the 10+ and 11+ ions are 1.6 eV and 1016–1017 s−1. Thus, with the exception of the 5+ ion, the higher charge states of ubiquitin have larger dissociation activation energies than the lower charge states. The different A factors observed for production of y and b ions from different precursor charge states indicate that they are formed by different mechanisms, ranging from relatively complex rearrangements to direct bond cleavages. These results clearly demonstrate that the relative dissociation rates of large biomolecule ions by themselves are not necessarily a reliable indicator of their relative dissociation energies, even when similar fragment ions are formed. PMID:9075403

Effects of charge state on fragmentation pathways, dynamics, and activation energies of ubiquitin ions measured by blackbody infrared radiative dissociation.

PubMed

Jockusch, R A; Schnier, P D; Price, W D; Strittmatter, E F; Demirev, P A; Williams, E R

1997-03-15

Blackbody infrared radiative dissociation spectra of the (M + 5H)5+ through (M + 11H)11+ ions of the protein ubiquitin (8.6 kDa) formed by electrospray ionization were measured in a Fourier-transform mass spectrometer. The 5+ ion dissociates exclusively by loss of water and/or ammonia, whereas the 11+ charge state dissociates only by formation of complementary y and b ions. These two processes are competitive for intermediate charge state ions, with the formation of y and b ions increasingly favored for the higher charge states. The y and b ions are formed by cleavage of the backbone amide bond on the C-terminal side of acidic residues exclusively, with cleavage adjacent to aspartic acid favored. Thermal unimolecular dissociation rate constants for the dissociation of each of these charge states were measured. From the temperature dependence of these rates, Arrhenius activation parameters in the rapid energy exchange limit are obtained. The activation energies (Ea) and preexponential factors (A) for the 5+, 8+, and 9+ ions are 1.2 eV and 10(12) s-1, respectively. These values for the 6+ and 7+ ions are 0.9-1.0 eV and 10(9) s-1, and those for the 10+ and 11+ ions are 1.6 eV and 10(16)-10(17) s-1. Thus, with the exception of the 5+ ion, the higher charge states of ubiquitin have larger dissociation activation energies than the lower charge states. The different A factors observed for production of y and b ions from different precursor charge states indicate that they are formed by different mechanisms, ranging from relatively complex rearrangements to direct bond cleavages. These results clearly demonstrate that the relative dissociation rates of large biomolecule ions by themselves are not necessarily a reliable indicator of their relative dissociation energies, even when similar fragment ions are formed.

Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheng, WC; Zhuang, ZB; Gao, MR

2015-01-08

The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearlymore » increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.« less

Activity-related energy expenditure during lower limb cast immobilization in children.

PubMed

Maggio, Albane B; Martin, Xavier E; Ceroni, Dimitri

2017-05-01

Physical inactivity, which may result from immobilization, is recognized as a risk factor for the development of obesity. We aimed to quantify the decrease in activity-related energy expenditure (AEE) because of lower limb cast immobilization. We carried out a longitudinal matched case-control study: 34 adolescents with a first episode of lower limb fracture and 34 healthy cases. Physical activity was assessed during cast immobilization by an accelerometer from which we calculated the decrease in AEE. AEE in adolescents with lower limb fractures was estimated to be 16.0% lower than healthy controls. When converted into kcal per mean participants' weight, the difference in AEE amounted to 125 kcal/day, which corresponds to 5.2 h of slow walking. A significant reduction of AEE in adolescents with lower limb fractures may lead to a significantly positive energy balance as there is usually no compensatory reduction of energy intake. An increase of walking seems unrealistic in this situation and patients should be advised at the emergency unit to reduce their energy intake during the immobilization period. Level III, prospective case-control study.

Adults With Idiopathic Scoliosis Diagnosed at Youth Experience Similar Physical Activity and Fracture Rate as Controls.

PubMed

Diarbakerli, Elias; Grauers, Anna; Danielsson, Aina; Gerdhem, Paul

2017-04-01

Cross-sectional. To describe physical activity level and fracture rates in adults with idiopathic scoliosis, diagnosed before maturity, and to compare with a control group. A previous study found a lower level of sporting activities in adults treated for idiopathic scoliosis compared with controls. Other studies have shown a lower bone mass in adults with idiopathic scoliosis compared with controls. One thousand two hundred seventy-eight adults (aged 18-71 yr) with idiopathic scoliosis and 214 controls (aged 18-70 yr) were included and answered the International Physical Activity Questionnaire - Short Form (IPAQ-SF) and questions about previous fractures. The three scoliosis treatment groups (untreated n = 360, brace n = 460, and surgically treated n = 458) were compared. Furthermore, a comparison based on onset (juvenile n = 169 or adolescent n = 976) was performed. Achieved weekly moderate activity level and metabolic equivalent task (MET) minutes/week were assessed for patients and controls. Statistical comparisons were made with analysis of covariance with adjustments for age, body mass index, and sex. The proportion achieving weekly moderate activity level was 962 out of 1278 for individuals with idiopathic scoliosis (75%) and 157 out of 214 (73%) for controls (P = 0.40). The scoliosis patients reported 2016 MET-minutes/week (median value) and the controls 2456 (P = 0.06). Fracture rates did not differ (P = 0.72). Fewer surgically treated individuals achieved moderate activity level (P = 0.046) compared with the untreated and the previously braced individuals. No difference was seen regarding MET-minutes/week (P = 0.86). No differences were seen between individuals with a juvenile onset compared with individuals with an adolescent onset (all P ≥ 0.05). Adults with idiopathic scoliosis have similar physical activity level and do not sustain more fractures compared with controls. Adults with surgically treated

Illustrating the Effect of pH on Enzyme Activity Using Gibbs Energy Profiles

ERIC Educational Resources Information Center

Bearne, Stephen L.

2014-01-01

Gibbs energy profiles provide students with a visual representation of the energy changes that occur during enzyme catalysis, making such profiles useful as teaching and learning tools. Traditional kinetic topics, such as the effect of pH on enzyme activity, are often not discussed in terms of Gibbs energy profiles. Herein, the symbolism of Gibbs…

Energy Expenditure During Extravehicular Activity: Apollo Skylab Through STS-135

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2011-01-01

The importance of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to conduct an EVA over-tasked the crewmember and exceeded the capabilities of vehicle and space suit life support systems. Energy expenditure was closely evaluated through the Apollo lunar surface EVAs, resulting in modifications to space suit design and EVA operations. After the Apollo lunar surface missions were completed, the United States shifted its focus to long duration human space flight, to study the human response to living and working in a microgravity environment. This paper summarizes the energy expenditure during EVA from Apollo Skylab through STS-135.

Solar Energy Information and Education Project. Final Report.

ERIC Educational Resources Information Center

Hensley, Michael

The New Mexico Solar Energy Institute (NMSEI) conducted a concentrated information and education program during 1985. This report summarizes NMSEI's Information and Education project activities. It provides detailed descriptions of project costs and concise recommendations for similar programs. Individual sections contain explanations of the scope…

Similarity to the self influences cortical recruitment during impression formation

PubMed Central

Leshikar, Eric D.; Cassidy, Brittany S.; Gutchess, Angela H.

2015-01-01

Prior work has shown that whether or not someone is similar to the self influences person memory—a type of self-reference effect for others. In this study, we were interested in understanding the neural regions supporting the generation of impressions and subsequent memory for targets who vary in similarity to the self. Participants underwent fMRI scanning while forming positive or negative impressions of face-behavior pairs. We tested participants’ memory for their generated impressions, and then back-sorted the impression trials (encoding) into different levels of self-similarity (high, medium, low) using a self-similarity post-test that came after recognition. Extending prior behavioral work, our data confirmed our hypothesis that memory would be highest for self-similar others and lowest for self-dissimilar others. Dorsal anterior cingulate cortex (dACC) activity increased with self-similarity (high > medium > low) to targets, regardless of later memory for them. An analysis of regions supporting impression memory revealed a double dissociation within medial temporal lobe regions: for similar others, amygdala recruitment supported memory, whereas for dissimilar others, hippocampal activation supported memory. These results suggest that self-similarity influences evaluation and memory for targets, but also affects the underlying neural resources engaged when thinking about others who vary in self-similarity. PMID:26558615

Design and experiment study of a semi-active energy-regenerative suspension system

NASA Astrophysics Data System (ADS)

Shi, Dehua; Chen, Long; Wang, Ruochen; Jiang, Haobin; Shen, Yujie

2015-01-01

A new kind of semi-active energy-regenerative suspension system is proposed to recover suspension vibration energy, as well as to reduce the suspension cost and demands for the motor-rated capacity. The system consists of an energy-regenerative damper and a DC-DC converter-based energy-regenerative circuit. The energy-regenerative damper is composed of an electromagnetic linear motor and an adjustable shock absorber with three regulating levels. The linear motor just works as the generator to harvest the suspension vibration energy. The circuit can be used to improve the system’s energy-regenerative performance and to continuously regulate the motor’s electromagnetic damping force. Therefore, although the motor works as a generator and damps the isolation without an external power source, the motor damping force is controllable. The damping characteristics of the system are studied based on a two degrees of freedom vehicle vibration model. By further analyzing the circuit operation characteristics under different working modes, the double-loop controller is designed to track the desired damping force. The external-loop is a fuzzy controller that offers the desired equivalent damping. The inner-loop controller, on one hand, is used to generate the pulse number and the frequency to control the angle and the rotational speed of the step motor; on the other hand, the inner-loop is used to offer the duty cycle of the energy-regenerative circuit. Simulations and experiments are conducted to validate such a new suspension system. The results show that the semi-active energy-regenerative suspension can improve vehicle ride comfort with the controllable damping characteristics of the linear motor. Meanwhile, it also ensures energy regeneration.

Cytosolic Calcium Coordinates Mitochondrial Energy Metabolism with Presynaptic Activity

PubMed Central

Chouhan, Amit K.; Ivannikov, Maxim V.; Lu, Zhongmin; Sugimori, Mutsuyuki; Llinas, Rodolfo R.; Macleod, Gregory T.

2012-01-01

Most neurons fire in bursts, imposing episodic energy demands, but how these demands are coordinated with oxidative phosphorylation is still unknown. Here, using fluorescence imaging techniques on presynaptic termini of Drosophila motor neurons (MNs), we show that mitochondrial matrix pH (pHm), inner membrane potential (Δψm), and NAD(P)H levels ([NAD(P)H]m) increase within seconds of nerve stimulation. The elevations of pHm, Δψm, and [NAD(P)H]m indicate an increased capacity for ATP production. Elevations in pHm were blocked by manipulations which blocked mitochondrial Ca2+ uptake, including replacement of extracellular Ca2+ with Sr2+, and application of either tetraphenylphosphonium chloride or KB-R7943, indicating that it is Ca2+ that stimulates presynaptic mitochondrial energy metabolism. To place this phenomenon within the context of endogenous neuronal activity, the firing rates of a number of individually identified MNs were determined during fictive locomotion. Surprisingly, although endogenous firing rates are significantly different, there was little difference in presynaptic cytosolic Ca2+ levels ([Ca2+]c) between MNs when each fires at its endogenous rate. The average [Ca2+]c level (329±11nM) was slightly above the average Ca2+ affinity of the mitochondria (281±13nM). In summary, we show that when MNs fire at endogenous rates [Ca2+]c is driven into a range where mitochondria rapidly acquire Ca2+. As we also show that Ca2+ stimulates presynaptic mitochondrial energy metabolism, we conclude that [Ca2+]c levels play an integral role in coordinating mitochondrial energy metabolism with presynaptic activity in Drosophila MNs. PMID:22279208

Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

PubMed Central

Corona de la Peña, Norma; Gutiérrez-Aguilar, Manuel; Hernández-Reséndiz, Ileana; Marín-Hernández, Álvaro

2017-01-01

Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway i.e., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times vs. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation. PMID:28817667

Regulation of Na(+)/K(+)-ATPase by nuclear respiratory factor 1: implication in the tight coupling of neuronal activity, energy generation, and energy consumption.

PubMed

Johar, Kaid; Priya, Anusha; Wong-Riley, Margaret T T

2012-11-23

NRF-1 regulates mediators of neuronal activity and energy generation. NRF-1 transcriptionally regulates Na(+)/K(+)-ATPase subunits α1 and β1. NRF-1 functionally regulates mediators of energy consumption in neurons. NRF-1 mediates the tight coupling of neuronal activity, energy generation, and energy consumption at the molecular level. Energy generation and energy consumption are tightly coupled to neuronal activity at the cellular level. Na(+)/K(+)-ATPase, a major energy-consuming enzyme, is well expressed in neurons rich in cytochrome c oxidase, an important enzyme of the energy-generating machinery, and glutamatergic receptors that are mediators of neuronal activity. The present study sought to test our hypothesis that the coupling extends to the molecular level, whereby Na(+)/K(+)-ATPase subunits are regulated by the same transcription factor, nuclear respiratory factor 1 (NRF-1), found recently by our laboratory to regulate all cytochrome c oxidase subunit genes and some NMDA and AMPA receptor subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutational analysis, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Atp1a1 and Atp1b1 genes but not of the Atp1a3 gene in neurons. The transcripts of Atp1a1 and Atp1b1 subunit genes were up-regulated by KCl and down-regulated by tetrodotoxin. Atp1b1 is positively regulated by NRF-1, and silencing of NRF-1 with small interference RNA blocked the up-regulation of Atp1b1 induced by KCl, whereas overexpression of NRF-1 rescued these transcripts from being suppressed by tetrodotoxin. On the other hand, Atp1a1 is negatively regulated by NRF-1. The binding sites of NRF-1 on Atp1a1 and Atp1b1 are conserved among mice, rats, and humans. Thus, NRF-1 regulates key Na(+)/K(+)-ATPase subunits and plays an important role in mediating the tight coupling between

Ngram time series model to predict activity type and energy cost from wrist, hip and ankle accelerometers: implications of age

PubMed Central

Strath, Scott J; Kate, Rohit J; Keenan, Kevin G; Welch, Whitney A; Swartz, Ann M

2016-01-01

To develop and test time series single site and multi-site placement models, we used wrist, hip and ankle processed accelerometer data to estimate energy cost and type of physical activity in adults. Ninety-nine subjects in three age groups (18–39, 40–64, 65 + years) performed 11 activities while wearing three triaxial accelereometers: one each on the non-dominant wrist, hip, and ankle. During each activity net oxygen cost (METs) was assessed. The time series of accelerometer signals were represented in terms of uniformly discretized values called bins. Support Vector Machine was used for activity classification with bins and every pair of bins used as features. Bagged decision tree regression was used for net metabolic cost prediction. To evaluate model performance we employed the jackknife leave-one-out cross validation method. Single accelerometer and multi-accelerometer site model estimates across and within age group revealed similar accuracy, with a bias range of −0.03 to 0.01 METs, bias percent of −0.8 to 0.3%, and a rMSE range of 0.81–1.04 METs. Multi-site accelerometer location models improved activity type classification over single site location models from a low of 69.3% to a maximum of 92.8% accuracy. For each accelerometer site location model, or combined site location model, percent accuracy classification decreased as a function of age group, or when young age groups models were generalized to older age groups. Specific age group models on average performed better than when all age groups were combined. A time series computation show promising results for predicting energy cost and activity type. Differences in prediction across age group, a lack of generalizability across age groups, and that age group specific models perform better than when all ages are combined needs to be considered as analytic calibration procedures to detect energy cost and type are further developed. PMID:26449155

K.E.E.P. - Kentucky's Energy Education Program Activities for the Classroom, K-6.

ERIC Educational Resources Information Center

Theiss, Nancy Stearns, Ed.; And Others

Seventy-seven multidisciplinary activities for grades K-6 are contained in this revised edition of energy education lessons for Kentucky students. Section I introduces students to the topic of energy by emphasizing human interaction with the environment. It focuses on personal energy, food as the source of human energy, food chains, and the sun as…

Proteins with similar architecture exhibit similar large-scale dynamic behavior.

PubMed Central

Keskin, O; Jernigan, R L; Bahar, I

2000-01-01

We have investigated the similarities and differences in the computed dynamic fluctuations exhibited by six members of a protein fold family with a coarse-grained Gaussian network model. Specifically, we consider the cofactor binding fragment of CysB; the lysine/arginine/ornithine-binding protein (LAO); the enzyme porphobilinogen deaminase (PBGD); the ribose-binding protein (RBP); the N-terminal lobe of ovotransferrin in apo-form (apo-OVOT); and the leucine/isoleucine/valine-binding protein (LIVBP). All have domains that resemble a Rossmann fold, but there are also some significant differences. Results indicate that similar global dynamic behavior is preserved for the members of a fold family, and that differences usually occur in regions only where specific function is localized. The present work is a computational demonstration that the scaffold of a protein fold may be utilized for diverse purposes. LAO requires a bound ligand before it conforms to the large-scale fluctuation behavior of the three other members of the family, CysB, PBGD, and RBP, all of which contain a substrate (cofactor) at the active site cleft. The dynamics of the ligand-free enzymes LIVBP and apo-OVOT, on the other hand, concur with that of unliganded LAO. The present results suggest that it is possible to construct structure alignments based on dynamic fluctuation behavior. PMID:10733987

Wave energy budget analysis in the Earth's radiation belts uncovers a missing energy.

PubMed

Artemyev, A V; Agapitov, O V; Mourenas, D; Krasnoselskikh, V V; Mozer, F S

2015-05-15

Whistler-mode emissions are important electromagnetic waves pervasive in the Earth's magnetosphere, where they continuously remove or energize electrons trapped by the geomagnetic field, controlling radiation hazards to satellites and astronauts and the upper-atmosphere ionization or chemical composition. Here, we report an analysis of 10-year Cluster data, statistically evaluating the full wave energy budget in the Earth's magnetosphere, revealing that a significant fraction of the energy corresponds to hitherto generally neglected very oblique waves. Such waves, with 10 times smaller magnetic power than parallel waves, typically have similar total energy. Moreover, they carry up to 80% of the wave energy involved in wave-particle resonant interactions. It implies that electron heating and precipitation into the atmosphere may have been significantly under/over-valued in past studies considering only conventional quasi-parallel waves. Very oblique waves may turn out to be a crucial agent of energy redistribution in the Earth's radiation belts, controlled by solar activity.

Relative to Quinine and Quinidine, Their 9-Epimers Exhibit Decreased Cytostatic Activity and Altered Heme Binding but Similar Cytocidal Activity versus Plasmodium falciparum

PubMed Central

Gorka, Alexander P.; Sherlach, Katy S.; de Dios, Angel C.

2013-01-01

The 9-epimers of quinine (QN) and quinidine (QD) are known to exhibit poor cytostatic potency against P. falciparum (Karle JM, Karle IL, Gerena L, Milhous WK, Antimicrob. Agents Chemother. 36:1538–1544, 1992). We synthesized 9-epi-QN (eQN) and 9-epi-QD (eQD) via Mitsunobu esterification-saponification and evaluated both cytostatic and cytocidal antimalarial activities. Relative to the cytostatic activity of QN and QD, we observed a large decrease in cytostatic activity (higher 50% inhibitory concentration [IC50s]) against QN-sensitive strain HB3, QN-resistant strain Dd2, and QN-hypersensitive strain K76I, consistent with previous work. However, we observed relatively small changes in cytocidal activity (the 50% lethal dose), similar to observations with chloroquine (CQ) analogues with a wide range of IC50s (see the accompanying paper [A. P. Gorka, J. N. Alumasa, K. S. Sherlach, L. M. Jacobs, K. B. Nickley, J. P. Brower, A. C. de Dios, and P. D. Roepe, Antimicrob. Agents Chemother. 57:356–364, 2013]). Compared to QN and QD, the 9-epimers had significantly reduced hemozoin inhibition efficiency and did not affect pH-dependent aggregation of ferriprotoporphyrin IX (FPIX) heme. Magnetic susceptibility measurements showed that the 9-epimers perturb FPIX monomer-dimer equilibrium in favor of monomer, and UV-visible (VIS) titrations showed that eQN and eQD bind monomer with similar affinity relative to QN and QD. However, unique ring proton shifts in the presence of zinc(II) protoporphyrin IX (ZnPIX) indicate that binding of the 9-epimers to monomeric heme is via a distinct geometry. We isolated eQN- and eQD-FPIX complexes formed under aqueous conditions and analyzed them by mass, fluorescence, and UV-VIS spectroscopies. The 9-epimers produced low-fluorescent adducts with a 2:1 stoichiometry (drug to FPIX) which did not survive electrospray ionization, in contrast to QN and QD complexes. The data offer important insight into the relevance of heme interactions as a

Energy-Related Activities in Two-Year Postsecondary Vocational-Technical Institutions: A Representative Sampling by State.

ERIC Educational Resources Information Center

Crowell, Mayme R.

Described are results of a preliminary investigation of the status of energy education activities within two-year postsecondary educational institutions. The specific areas investigated were coal technology, petroleum technology, nuclear technology, solar energy, energy conservation, and energy generation and transmission. Information was gathered…

Energy expenditure and activity of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.

PubMed

Kaufman, Kenton R; Levine, James A; Brey, Robert H; McCrady, Shelly K; Padgett, Denny J; Joyner, Michael J

2008-07-01

To quantify the energy efficiency of locomotion and free-living physical activity energy expenditure of transfemoral amputees using a mechanical and microprocessor-controlled prosthetic knee. Repeated-measures design to evaluate comparative functional outcomes. Exercise physiology laboratory and community free-living environment. Subjects (N=15; 12 men, 3 women; age, 42+/-9 y; range, 26-57 y) with transfemoral amputation. Research participants were long-term users of a mechanical prosthesis (20+/-10 y as an amputee; range, 3-36 y). They were fitted with a microprocessor-controlled knee prosthesis and allowed to acclimate (mean time, 18+/-8 wk) before being retested. Objective measurements of energy efficiency and total daily energy expenditure were obtained. The Prosthetic Evaluation Questionnaire was used to gather subjective feedback from the participants. Subjects demonstrated significantly increased physical activity-related energy expenditure levels in the participant's free-living environment (P=.04) after wearing the microprocessor-controlled prosthetic knee joint. There was no significant difference in the energy efficiency of walking (P=.34). When using the microprocessor-controlled knee, the subjects expressed increased satisfaction in their daily lives (P=.02). People ambulating with a microprocessor-controlled knee significantly increased their physical activity during daily life, outside the laboratory setting, and expressed an increased quality of life.

Higher similarity in beta topography between tasks than subjects.

PubMed

Basile, Luis F H; Sato, João R; Pasquini, Henrique A; Velasques, Bruna; Ribeiro, Pedro; Anghinah, Renato

2018-05-01

We have recently provided evidence for highly idiosyncratic topographic distributions of beta oscillations (as well as slow potentials) across individuals. More recently, by emphasizing the analysis of similarity instead of differences across tasks, we concluded that differences between an attention task and quiet resting may be negligible or at least unsystematic across subjects. Due to the possibility that individual differences could be due to noise in a wide sense or some inherent instability of beta activity, we designed a replication study to explicitly test whether pairs of individuals matched for head size and shape would still present less similar beta topography than each individual between sessions or tasks. We used independent component analysis (ICA) for an exhaustive decomposition of beta activity in a visual attention task and in quiet resting, recorded by 256-channel EEG in 20 subjects, on two separate days. We evaluated whether each ICA component obtained in one task and in one given individual could be explained by a linear regression model based on the topographic patterns of the complementary task (correlation between one component with a linear combination of components from complementary conditions), of the same task in a second session and of a matched individual. Results again showed a high topographic similarity between conditions, as previously seen between reasoning and simple visual attention beta correlates. From an overall number of 16 components representing brain activity obtained for the tasks (out of 60 originally computed where the remaining were considered noise), over 92% could satisfactorily be explained by the complementary task. Although the similarity between sessions was significantly smaller than between tasks on each day, the similarity between sessions was statistically higher than that between subjects in a highly significant way. We discuss the possible biases of group spatial averaging and the emphasis on differences

Energy metabolism during activity-promoting video games practice in subjects with spinal cord injury: evidences for health promotion.

PubMed

Gaffurini, P; Bissolotti, L; Calza, S; Calabretto, C; Orizio, C; Gobbo, M

2013-02-01

Activity promoting video game (APVG) practice significantly affects energy metabolism through energy expenditure (EE) increase and has been recently included in strategies for health promotion. It is not known if the APVG practice provides similar outcomes in subjects with spinal cord injury (SCI). Aim of the study was to evaluate cardio-pulmonary and metabolic adaptations during APVG practice and to find whether EE increase above resting condition could suggest the inclusion of this exercise in a more general strategy for health promotion and body weight control in subjects with SCI. Repeated measures study. Rehabilitation Institute. Ten male subjects with SCI (lesion levels from C7 to L1) age 26 to 55 years. We recorded pulmonary ventilation (VE), oxygen consumption (VO2) for EE esteem and heart rate (HR) at rest and while playing virtual bowling, tennis and boxing games using a portable metabolimeter equipped with ECG electrodes. The standard metabolic equivalent of task (METs) was calculated offline. The metabolic and functional parameters were referred to the 10th minute of each activity. Metabolic and functional parameters increased significantly from rest to bowling, tennis and boxing. METs exceeded in average 3 during boxing. One hour of APVG can increase daily EE by about 6% (bowling), 10% (tennis) and 15% (boxing). These considerable results suggest that physical exertion during APVG practice in subjects with SCI could contribute to health promotion as well as caloric balance control, especially when boxing is considered. This can be safely achieved at home with regular activity. These findings substantiate the potential for novel exercise modalities to counteract deconditioning due to inactivity in subjects with SCI by promoting physical activity through implementation of APVG exercise programs.

Bioturbo similarity searching: combining chemical and biological similarity to discover structurally diverse bioactive molecules.

PubMed

Wassermann, Anne Mai; Lounkine, Eugen; Glick, Meir

2013-03-25

Virtual screening using bioactivity profiles has become an integral part of currently applied hit finding methods in pharmaceutical industry. However, a significant drawback of this approach is that it is only applicable to compounds that have been biologically tested in the past and have sufficient activity annotations for meaningful profile comparisons. Although bioactivity data generated in pharmaceutical institutions are growing on an unprecedented scale, the number of biologically annotated compounds still covers only a minuscule fraction of chemical space. For a newly synthesized compound or an isolated natural product to be biologically characterized across multiple assays, it may take a considerable amount of time. Consequently, this chemical matter will not be included in virtual screening campaigns based on bioactivity profiles. To overcome this problem, we herein introduce bioturbo similarity searching that uses chemical similarity to map molecules without biological annotations into bioactivity space and then searches for biologically similar compounds in this reference system. In benchmark calculations on primary screening data, we demonstrate that our approach generally achieves higher hit rates and identifies structurally more diverse compounds than approaches using chemical information only. Furthermore, our method is able to discover hits with novel modes of inhibition that traditional 2D and 3D similarity approaches are unlikely to discover. Test calculations on a set of natural products reveal the practical utility of the approach for identifying novel and synthetically more accessible chemical matter.

Universal energy spectrum from point sources

NASA Technical Reports Server (NTRS)

Tomozawa, Yukio

1992-01-01

The suggestion is made that the energy spectrum from point sources such as galactic black hole candidates (GBHC) and active galactic nuclei (AGN) is universal on the average, irrespective of the species of the emitted particles, photons, nucleons, or others. The similarity between the observed energy spectra of cosmic rays, gamma-rays, and X-rays is discussed. In other words, the existing data for gamma-rays and X-rays seem to support the prediction. The expected data from the Gamma Ray Observatory are to provide a further test.

Electromagnetic radiation due to naked singularity formation in self-similar gravitational collapse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitsuda, Eiji; Yoshino, Hirotaka; Tomimatsu, Akira

Dynamical evolution of test fields in background geometry with a naked singularity is an important problem relevant to the Cauchy horizon instability and the observational signatures different from black hole formation. In this paper we study electromagnetic perturbations generated by a given current distribution in collapsing matter under a spherically symmetric self-similar background. Using the Green's function method, we construct the formula to evaluate the outgoing energy flux observed at the future null infinity. The contributions from 'quasinormal' modes of the self-similar system as well as 'high-frequency' waves are clarified. We find a characteristic power-law time evolution of the outgoingmore » energy flux which appears just before naked singularity formation and give the criteria as to whether or not the outgoing energy flux diverges at the future Cauchy horizon.« less

The energy expenditure of an activity-promoting video game compared to sedentary video games and TV watching.

PubMed

Mitre, Naim; Foster, Randal C; Lanningham-Foster, Lorraine; Levine, James A

2011-01-01

In the present study we investigated the effect of television watching and the use of activity-promoting video games on energy expenditure in obese and lean children. Energy expenditure and physical activity were measured while participants were watching television, playing a video game on a traditional sedentary video game console, and while playing the same video game on an activity-promoting video game console. Energy expenditure was significantly greater than television watching and playing video games on a sedentary video game console when children played the video game on the activity-promoting console. When examining movement with accelerometry, children moved significantly more when playing the video game on the Nintendo Wii console. Activity-promoting video games have shown to increase movement, and be an important tool to raise energy expenditure by 50% when compared to sedentary activities of daily living.

Neuromuscular fatigue following isometric contractions with similar torque time integral.

PubMed

Rozand, V; Cattagni, T; Theurel, J; Martin, A; Lepers, R

2015-01-01

Torque time integral (TTI) is the combination of intensity and duration of a contraction. The aim of this study was to compare neuromuscular alterations following different isometric sub-maximal contractions of the knee extensor muscles but with similar TTI. Sixteen participants performed 3 sustained contractions at different intensities (25%, 50%, and 75% of Maximal Voluntary Contraction (MVC) torque) with different durations (68.5±33.4 s, 35.1±16.8 s and 24.8±12.9 s, respectively) but similar TTI value. MVC torque, maximal voluntary activation level (VAL), M-wave characteristics and potentiated doublet amplitude were assessed before and immediately after the sustained contractions. EMG activity of the vastus lateralis (VL) and -rectus femoris (RF) muscles was recorded during the sustained contractions. MVC torque reduction was similar in the 3 conditions after the exercise (-23.4±2.7%). VAL decreased significantly in a similar extent (-3.1±1.3%) after the 3 sustained contractions. Potentiated doublet amplitude was similarly reduced in the 3 conditions (-19.7±1.5%), but VL and RF M-wave amplitudes remained unchanged. EMG activity of VL and RF muscles increased in the same extent during the 3 contractions (VL: 54.5±40.4%; RF: 53.1±48.7%). These results suggest that central and peripheral alterations accounting for muscle fatigue are similar following isometric contractions with similar TTI. TTI should be considered in the exploration of muscle fatigue during sustained isometric contractions. © Georg Thieme Verlag KG Stuttgart · New York.

A similar shot to the previous image, this photograph, looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A similar shot to the previous image, this photograph, looking northwest, provides a closer image of the brick penthouse and other devices - Department of Energy, Mound Facility, Electronics Laboratory Building (E Building), One Mound Road, Miamisburg, Montgomery County, OH

Using a Simple Optical Rangefinder To Teach Similar Triangles.

ERIC Educational Resources Information Center

Cuicchi, Paul M.; Hutchison, Paul S.

2003-01-01

Describes how the concept of similar triangles was taught using an optical method of estimating large distances as a corresponding activity. Includes the derivation of a formula to calculate one source of measurement error and is a nice exercise in the use of the properties of similar triangles. (Author/NB)

Demonstration of Functional Similarity of Proposed Biosimilar ABP 501 to Adalimumab.

PubMed

Velayudhan, Jyoti; Chen, Yuh-Feng; Rohrbach, Amanda; Pastula, Christina; Maher, Gwen; Thomas, Heather; Brown, Ryan; Born, Teresa L

2016-08-01

Due to the complex molecular structure and proprietary manufacturing processes of monoclonal antibodies (mAbs), differences in structure and function may be expected during development of biosimilar mAbs. Important regulatory requirements for approval of biosimilar products involve comprehensive assessments of any potential differences between proposed biosimilars and reference mAbs, including differences in all known mechanisms of action, using sensitive and relevant methods. Any identified structural differences should not result in differences in biofunctional or clinical activity. A comprehensive assessment comparing the Amgen biosimilar candidate ABP 501 with FDA-licensed adalimumab (adalimumab [US]) and EU-authorized adalimumab (adalimumab [EU]) was conducted to demonstrate similarity in biofunctional activity. The functional similarity assessment included testing of binding kinetics to soluble tumor necrosis factor α (TNFα) and relative binding to transmembrane TNFα. The neutralization of TNFα-induced caspase activation, TNFα- and lymphotoxin-α (LTα)-induced chemokine production, and cytotoxicity was also tested. Binding to Fc-gamma receptors FcγRIa, FcγRIIa (131H), FcγRIIIa (158V and 158F), and neonatal Fc receptor (FcRn) was compared with the reference mAbs, as was antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The data demonstrate that ABP 501 is similar to both adalimumab (US) and adalimumab (EU) with respect to evaluated biofunctional activities. Similarity in biofunctional activity is a critical component of the totality of evidence required for demonstration of biosimilarity. The functional similarity demonstrated for ABP 501 comprehensively assesses the known mechanisms of action of adalimumab, supporting the conclusion that ABP 501, adalimumab (US), and adalimumab (EU) are likely to be clinically similar.

Energy Cost of Active and Sedentary Music Video Games: Drum and Handheld Gaming vs. Walking and Sitting

PubMed Central

MIRANDA, EDWIN; OVERSTREET, BRITTANY S.; FOUNTAIN, WILLIAM A.; GUTIERREZ, VINCENT; KOLANKOWSKI, MICHAEL; OVERSTREET, MATTHEW L.; SAPP, RYAN M.; WOLFF, CHRISTOPHER A.; MAZZETTI, SCOTT A.

2017-01-01

To compare energy expenditure during and after active and handheld video game drumming compared to walking and sitting. Ten experienced, college-aged men performed four protocols (one per week): no-exercise seated control (CTRL), virtual drumming on a handheld gaming device (HANDHELD), active drumming on drum pads (DRUM), and walking on a treadmill at ~30% of VO2max (WALK). Protocols were performed after an overnight fast, and expired air was collected continuously during (30min) and after (30min) exercise. DRUM and HANDHELD song lists, day of the week, and time of day were identical for each participant. Significant differences (p < 0.05) among the average rates of energy expenditure (kcal·min−1) during activity included WALK > DRUM > HANDHELD. No significant differences in the rates of energy expenditure among groups during recovery were observed. Total energy expenditure was significantly greater (p < 0.05) during WALK (149.5 ± 30.6 kcal) compared to DRUM (118.7 ± 18.8 kcal) and HANDHELD (44.9±11.6 kcal), and greater during DRUM compared to HANDHELD. Total energy expenditure was not significantly different between HANDHELD (44.9 ± 11.6 kcal) and CTRL (38.2 ± 6.0 kcal). Active video game drumming at expert-level significantly increased energy expenditure compared to handheld, but it hardly met moderate-intensity activity standards, and energy expenditure was greatest during walking. Energy expenditure with handheld video game drumming was not different from no-exercise control. Thus, traditional aerobic exercise remains at the forefront for achieving the minimum amount and intensity of physical activity for health, individuals desiring to use video games for achieving weekly physical activity recommendations should choose games that require significant involvement of lower-body musculature, and time spent playing sedentary games should be a limited part of an active lifestyle. PMID:29170705

Energy Cost of Active and Sedentary Music Video Games: Drum and Handheld Gaming vs. Walking and Sitting.

PubMed

Miranda, Edwin; Overstreet, Brittany S; Fountain, William A; Gutierrez, Vincent; Kolankowski, Michael; Overstreet, Matthew L; Sapp, Ryan M; Wolff, Christopher A; Mazzetti, Scott A

2017-01-01

To compare energy expenditure during and after active and handheld video game drumming compared to walking and sitting. Ten experienced, college-aged men performed four protocols (one per week): no-exercise seated control (CTRL), virtual drumming on a handheld gaming device (HANDHELD), active drumming on drum pads (DRUM), and walking on a treadmill at ~30% of VO 2max (WALK). Protocols were performed after an overnight fast, and expired air was collected continuously during (30min) and after (30min) exercise. DRUM and HANDHELD song lists, day of the week, and time of day were identical for each participant. Significant differences (p < 0.05) among the average rates of energy expenditure (kcal·min -1 ) during activity included WALK > DRUM > HANDHELD. No significant differences in the rates of energy expenditure among groups during recovery were observed. Total energy expenditure was significantly greater (p < 0.05) during WALK (149.5 ± 30.6 kcal) compared to DRUM (118.7 ± 18.8 kcal) and HANDHELD (44.9±11.6 kcal), and greater during DRUM compared to HANDHELD. Total energy expenditure was not significantly different between HANDHELD (44.9 ± 11.6 kcal) and CTRL (38.2 ± 6.0 kcal). Active video game drumming at expert-level significantly increased energy expenditure compared to handheld, but it hardly met moderate-intensity activity standards, and energy expenditure was greatest during walking. Energy expenditure with handheld video game drumming was not different from no-exercise control. Thus, traditional aerobic exercise remains at the forefront for achieving the minimum amount and intensity of physical activity for health, individuals desiring to use video games for achieving weekly physical activity recommendations should choose games that require significant involvement of lower-body musculature, and time spent playing sedentary games should be a limited part of an active lifestyle.

Aloe vera Derived Activated High-Surface-Area Carbon for Flexible and High-Energy Supercapacitors.

PubMed

Karnan, M; Subramani, K; Sudhan, N; Ilayaraja, N; Sathish, M

2016-12-28